| /* DWARF 2 location expression support for GDB. |
| |
| Copyright (C) 2003-2017 Free Software Foundation, Inc. |
| |
| Contributed by Daniel Jacobowitz, MontaVista Software, Inc. |
| |
| This file is part of GDB. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| |
| #include "defs.h" |
| #include "ui-out.h" |
| #include "value.h" |
| #include "frame.h" |
| #include "gdbcore.h" |
| #include "target.h" |
| #include "inferior.h" |
| #include "ax.h" |
| #include "ax-gdb.h" |
| #include "regcache.h" |
| #include "objfiles.h" |
| #include "block.h" |
| #include "gdbcmd.h" |
| #include "complaints.h" |
| #include "dwarf2.h" |
| #include "dwarf2expr.h" |
| #include "dwarf2loc.h" |
| #include "dwarf2-frame.h" |
| #include "compile/compile.h" |
| #include "selftest.h" |
| #include <algorithm> |
| #include <vector> |
| #include <unordered_set> |
| |
| extern int dwarf_always_disassemble; |
| |
| static struct value *dwarf2_evaluate_loc_desc_full (struct type *type, |
| struct frame_info *frame, |
| const gdb_byte *data, |
| size_t size, |
| struct dwarf2_per_cu_data *per_cu, |
| LONGEST byte_offset); |
| |
| static struct call_site_parameter *dwarf_expr_reg_to_entry_parameter |
| (struct frame_info *frame, |
| enum call_site_parameter_kind kind, |
| union call_site_parameter_u kind_u, |
| struct dwarf2_per_cu_data **per_cu_return); |
| |
| /* Until these have formal names, we define these here. |
| ref: http://gcc.gnu.org/wiki/DebugFission |
| Each entry in .debug_loc.dwo begins with a byte that describes the entry, |
| and is then followed by data specific to that entry. */ |
| |
| enum debug_loc_kind |
| { |
| /* Indicates the end of the list of entries. */ |
| DEBUG_LOC_END_OF_LIST = 0, |
| |
| /* This is followed by an unsigned LEB128 number that is an index into |
| .debug_addr and specifies the base address for all following entries. */ |
| DEBUG_LOC_BASE_ADDRESS = 1, |
| |
| /* This is followed by two unsigned LEB128 numbers that are indices into |
| .debug_addr and specify the beginning and ending addresses, and then |
| a normal location expression as in .debug_loc. */ |
| DEBUG_LOC_START_END = 2, |
| |
| /* This is followed by an unsigned LEB128 number that is an index into |
| .debug_addr and specifies the beginning address, and a 4 byte unsigned |
| number that specifies the length, and then a normal location expression |
| as in .debug_loc. */ |
| DEBUG_LOC_START_LENGTH = 3, |
| |
| /* An internal value indicating there is insufficient data. */ |
| DEBUG_LOC_BUFFER_OVERFLOW = -1, |
| |
| /* An internal value indicating an invalid kind of entry was found. */ |
| DEBUG_LOC_INVALID_ENTRY = -2 |
| }; |
| |
| /* Helper function which throws an error if a synthetic pointer is |
| invalid. */ |
| |
| static void |
| invalid_synthetic_pointer (void) |
| { |
| error (_("access outside bounds of object " |
| "referenced via synthetic pointer")); |
| } |
| |
| /* Decode the addresses in a non-dwo .debug_loc entry. |
| A pointer to the next byte to examine is returned in *NEW_PTR. |
| The encoded low,high addresses are return in *LOW,*HIGH. |
| The result indicates the kind of entry found. */ |
| |
| static enum debug_loc_kind |
| decode_debug_loc_addresses (const gdb_byte *loc_ptr, const gdb_byte *buf_end, |
| const gdb_byte **new_ptr, |
| CORE_ADDR *low, CORE_ADDR *high, |
| enum bfd_endian byte_order, |
| unsigned int addr_size, |
| int signed_addr_p) |
| { |
| CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1)); |
| |
| if (buf_end - loc_ptr < 2 * addr_size) |
| return DEBUG_LOC_BUFFER_OVERFLOW; |
| |
| if (signed_addr_p) |
| *low = extract_signed_integer (loc_ptr, addr_size, byte_order); |
| else |
| *low = extract_unsigned_integer (loc_ptr, addr_size, byte_order); |
| loc_ptr += addr_size; |
| |
| if (signed_addr_p) |
| *high = extract_signed_integer (loc_ptr, addr_size, byte_order); |
| else |
| *high = extract_unsigned_integer (loc_ptr, addr_size, byte_order); |
| loc_ptr += addr_size; |
| |
| *new_ptr = loc_ptr; |
| |
| /* A base-address-selection entry. */ |
| if ((*low & base_mask) == base_mask) |
| return DEBUG_LOC_BASE_ADDRESS; |
| |
| /* An end-of-list entry. */ |
| if (*low == 0 && *high == 0) |
| return DEBUG_LOC_END_OF_LIST; |
| |
| return DEBUG_LOC_START_END; |
| } |
| |
| /* Decode the addresses in .debug_loclists entry. |
| A pointer to the next byte to examine is returned in *NEW_PTR. |
| The encoded low,high addresses are return in *LOW,*HIGH. |
| The result indicates the kind of entry found. */ |
| |
| static enum debug_loc_kind |
| decode_debug_loclists_addresses (struct dwarf2_per_cu_data *per_cu, |
| const gdb_byte *loc_ptr, |
| const gdb_byte *buf_end, |
| const gdb_byte **new_ptr, |
| CORE_ADDR *low, CORE_ADDR *high, |
| enum bfd_endian byte_order, |
| unsigned int addr_size, |
| int signed_addr_p) |
| { |
| uint64_t u64; |
| |
| if (loc_ptr == buf_end) |
| return DEBUG_LOC_BUFFER_OVERFLOW; |
| |
| switch (*loc_ptr++) |
| { |
| case DW_LLE_end_of_list: |
| *new_ptr = loc_ptr; |
| return DEBUG_LOC_END_OF_LIST; |
| case DW_LLE_base_address: |
| if (loc_ptr + addr_size > buf_end) |
| return DEBUG_LOC_BUFFER_OVERFLOW; |
| if (signed_addr_p) |
| *high = extract_signed_integer (loc_ptr, addr_size, byte_order); |
| else |
| *high = extract_unsigned_integer (loc_ptr, addr_size, byte_order); |
| loc_ptr += addr_size; |
| *new_ptr = loc_ptr; |
| return DEBUG_LOC_BASE_ADDRESS; |
| case DW_LLE_offset_pair: |
| loc_ptr = gdb_read_uleb128 (loc_ptr, buf_end, &u64); |
| if (loc_ptr == NULL) |
| return DEBUG_LOC_BUFFER_OVERFLOW; |
| *low = u64; |
| loc_ptr = gdb_read_uleb128 (loc_ptr, buf_end, &u64); |
| if (loc_ptr == NULL) |
| return DEBUG_LOC_BUFFER_OVERFLOW; |
| *high = u64; |
| *new_ptr = loc_ptr; |
| return DEBUG_LOC_START_END; |
| default: |
| return DEBUG_LOC_INVALID_ENTRY; |
| } |
| } |
| |
| /* Decode the addresses in .debug_loc.dwo entry. |
| A pointer to the next byte to examine is returned in *NEW_PTR. |
| The encoded low,high addresses are return in *LOW,*HIGH. |
| The result indicates the kind of entry found. */ |
| |
| static enum debug_loc_kind |
| decode_debug_loc_dwo_addresses (struct dwarf2_per_cu_data *per_cu, |
| const gdb_byte *loc_ptr, |
| const gdb_byte *buf_end, |
| const gdb_byte **new_ptr, |
| CORE_ADDR *low, CORE_ADDR *high, |
| enum bfd_endian byte_order) |
| { |
| uint64_t low_index, high_index; |
| |
| if (loc_ptr == buf_end) |
| return DEBUG_LOC_BUFFER_OVERFLOW; |
| |
| switch (*loc_ptr++) |
| { |
| case DW_LLE_GNU_end_of_list_entry: |
| *new_ptr = loc_ptr; |
| return DEBUG_LOC_END_OF_LIST; |
| case DW_LLE_GNU_base_address_selection_entry: |
| *low = 0; |
| loc_ptr = gdb_read_uleb128 (loc_ptr, buf_end, &high_index); |
| if (loc_ptr == NULL) |
| return DEBUG_LOC_BUFFER_OVERFLOW; |
| *high = dwarf2_read_addr_index (per_cu, high_index); |
| *new_ptr = loc_ptr; |
| return DEBUG_LOC_BASE_ADDRESS; |
| case DW_LLE_GNU_start_end_entry: |
| loc_ptr = gdb_read_uleb128 (loc_ptr, buf_end, &low_index); |
| if (loc_ptr == NULL) |
| return DEBUG_LOC_BUFFER_OVERFLOW; |
| *low = dwarf2_read_addr_index (per_cu, low_index); |
| loc_ptr = gdb_read_uleb128 (loc_ptr, buf_end, &high_index); |
| if (loc_ptr == NULL) |
| return DEBUG_LOC_BUFFER_OVERFLOW; |
| *high = dwarf2_read_addr_index (per_cu, high_index); |
| *new_ptr = loc_ptr; |
| return DEBUG_LOC_START_END; |
| case DW_LLE_GNU_start_length_entry: |
| loc_ptr = gdb_read_uleb128 (loc_ptr, buf_end, &low_index); |
| if (loc_ptr == NULL) |
| return DEBUG_LOC_BUFFER_OVERFLOW; |
| *low = dwarf2_read_addr_index (per_cu, low_index); |
| if (loc_ptr + 4 > buf_end) |
| return DEBUG_LOC_BUFFER_OVERFLOW; |
| *high = *low; |
| *high += extract_unsigned_integer (loc_ptr, 4, byte_order); |
| *new_ptr = loc_ptr + 4; |
| return DEBUG_LOC_START_LENGTH; |
| default: |
| return DEBUG_LOC_INVALID_ENTRY; |
| } |
| } |
| |
| /* A function for dealing with location lists. Given a |
| symbol baton (BATON) and a pc value (PC), find the appropriate |
| location expression, set *LOCEXPR_LENGTH, and return a pointer |
| to the beginning of the expression. Returns NULL on failure. |
| |
| For now, only return the first matching location expression; there |
| can be more than one in the list. */ |
| |
| const gdb_byte * |
| dwarf2_find_location_expression (struct dwarf2_loclist_baton *baton, |
| size_t *locexpr_length, CORE_ADDR pc) |
| { |
| struct objfile *objfile = dwarf2_per_cu_objfile (baton->per_cu); |
| struct gdbarch *gdbarch = get_objfile_arch (objfile); |
| enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| unsigned int addr_size = dwarf2_per_cu_addr_size (baton->per_cu); |
| int signed_addr_p = bfd_get_sign_extend_vma (objfile->obfd); |
| /* Adjust base_address for relocatable objects. */ |
| CORE_ADDR base_offset = dwarf2_per_cu_text_offset (baton->per_cu); |
| CORE_ADDR base_address = baton->base_address + base_offset; |
| const gdb_byte *loc_ptr, *buf_end; |
| |
| loc_ptr = baton->data; |
| buf_end = baton->data + baton->size; |
| |
| while (1) |
| { |
| CORE_ADDR low = 0, high = 0; /* init for gcc -Wall */ |
| int length; |
| enum debug_loc_kind kind; |
| const gdb_byte *new_ptr = NULL; /* init for gcc -Wall */ |
| |
| if (baton->from_dwo) |
| kind = decode_debug_loc_dwo_addresses (baton->per_cu, |
| loc_ptr, buf_end, &new_ptr, |
| &low, &high, byte_order); |
| else if (dwarf2_version (baton->per_cu) < 5) |
| kind = decode_debug_loc_addresses (loc_ptr, buf_end, &new_ptr, |
| &low, &high, |
| byte_order, addr_size, |
| signed_addr_p); |
| else |
| kind = decode_debug_loclists_addresses (baton->per_cu, |
| loc_ptr, buf_end, &new_ptr, |
| &low, &high, byte_order, |
| addr_size, signed_addr_p); |
| |
| loc_ptr = new_ptr; |
| switch (kind) |
| { |
| case DEBUG_LOC_END_OF_LIST: |
| *locexpr_length = 0; |
| return NULL; |
| case DEBUG_LOC_BASE_ADDRESS: |
| base_address = high + base_offset; |
| continue; |
| case DEBUG_LOC_START_END: |
| case DEBUG_LOC_START_LENGTH: |
| break; |
| case DEBUG_LOC_BUFFER_OVERFLOW: |
| case DEBUG_LOC_INVALID_ENTRY: |
| error (_("dwarf2_find_location_expression: " |
| "Corrupted DWARF expression.")); |
| default: |
| gdb_assert_not_reached ("bad debug_loc_kind"); |
| } |
| |
| /* Otherwise, a location expression entry. |
| If the entry is from a DWO, don't add base address: the entry is from |
| .debug_addr which already has the DWARF "base address". We still add |
| base_offset in case we're debugging a PIE executable. */ |
| if (baton->from_dwo) |
| { |
| low += base_offset; |
| high += base_offset; |
| } |
| else |
| { |
| low += base_address; |
| high += base_address; |
| } |
| |
| if (dwarf2_version (baton->per_cu) < 5) |
| { |
| length = extract_unsigned_integer (loc_ptr, 2, byte_order); |
| loc_ptr += 2; |
| } |
| else |
| { |
| unsigned int bytes_read; |
| |
| length = read_unsigned_leb128 (NULL, loc_ptr, &bytes_read); |
| loc_ptr += bytes_read; |
| } |
| |
| if (low == high && pc == low) |
| { |
| /* This is entry PC record present only at entry point |
| of a function. Verify it is really the function entry point. */ |
| |
| const struct block *pc_block = block_for_pc (pc); |
| struct symbol *pc_func = NULL; |
| |
| if (pc_block) |
| pc_func = block_linkage_function (pc_block); |
| |
| if (pc_func && pc == BLOCK_START (SYMBOL_BLOCK_VALUE (pc_func))) |
| { |
| *locexpr_length = length; |
| return loc_ptr; |
| } |
| } |
| |
| if (pc >= low && pc < high) |
| { |
| *locexpr_length = length; |
| return loc_ptr; |
| } |
| |
| loc_ptr += length; |
| } |
| } |
| |
| /* This is the baton used when performing dwarf2 expression |
| evaluation. */ |
| struct dwarf_expr_baton |
| { |
| struct frame_info *frame; |
| struct dwarf2_per_cu_data *per_cu; |
| CORE_ADDR obj_address; |
| }; |
| |
| /* Implement find_frame_base_location method for LOC_BLOCK functions using |
| DWARF expression for its DW_AT_frame_base. */ |
| |
| static void |
| locexpr_find_frame_base_location (struct symbol *framefunc, CORE_ADDR pc, |
| const gdb_byte **start, size_t *length) |
| { |
| struct dwarf2_locexpr_baton *symbaton |
| = (struct dwarf2_locexpr_baton *) SYMBOL_LOCATION_BATON (framefunc); |
| |
| *length = symbaton->size; |
| *start = symbaton->data; |
| } |
| |
| /* Implement the struct symbol_block_ops::get_frame_base method for |
| LOC_BLOCK functions using a DWARF expression as its DW_AT_frame_base. */ |
| |
| static CORE_ADDR |
| locexpr_get_frame_base (struct symbol *framefunc, struct frame_info *frame) |
| { |
| struct gdbarch *gdbarch; |
| struct type *type; |
| struct dwarf2_locexpr_baton *dlbaton; |
| const gdb_byte *start; |
| size_t length; |
| struct value *result; |
| |
| /* If this method is called, then FRAMEFUNC is supposed to be a DWARF block. |
| Thus, it's supposed to provide the find_frame_base_location method as |
| well. */ |
| gdb_assert (SYMBOL_BLOCK_OPS (framefunc)->find_frame_base_location != NULL); |
| |
| gdbarch = get_frame_arch (frame); |
| type = builtin_type (gdbarch)->builtin_data_ptr; |
| dlbaton = (struct dwarf2_locexpr_baton *) SYMBOL_LOCATION_BATON (framefunc); |
| |
| SYMBOL_BLOCK_OPS (framefunc)->find_frame_base_location |
| (framefunc, get_frame_pc (frame), &start, &length); |
| result = dwarf2_evaluate_loc_desc (type, frame, start, length, |
| dlbaton->per_cu); |
| |
| /* The DW_AT_frame_base attribute contains a location description which |
| computes the base address itself. However, the call to |
| dwarf2_evaluate_loc_desc returns a value representing a variable at |
| that address. The frame base address is thus this variable's |
| address. */ |
| return value_address (result); |
| } |
| |
| /* Vector for inferior functions as represented by LOC_BLOCK, if the inferior |
| function uses DWARF expression for its DW_AT_frame_base. */ |
| |
| const struct symbol_block_ops dwarf2_block_frame_base_locexpr_funcs = |
| { |
| locexpr_find_frame_base_location, |
| locexpr_get_frame_base |
| }; |
| |
| /* Implement find_frame_base_location method for LOC_BLOCK functions using |
| DWARF location list for its DW_AT_frame_base. */ |
| |
| static void |
| loclist_find_frame_base_location (struct symbol *framefunc, CORE_ADDR pc, |
| const gdb_byte **start, size_t *length) |
| { |
| struct dwarf2_loclist_baton *symbaton |
| = (struct dwarf2_loclist_baton *) SYMBOL_LOCATION_BATON (framefunc); |
| |
| *start = dwarf2_find_location_expression (symbaton, length, pc); |
| } |
| |
| /* Implement the struct symbol_block_ops::get_frame_base method for |
| LOC_BLOCK functions using a DWARF location list as its DW_AT_frame_base. */ |
| |
| static CORE_ADDR |
| loclist_get_frame_base (struct symbol *framefunc, struct frame_info *frame) |
| { |
| struct gdbarch *gdbarch; |
| struct type *type; |
| struct dwarf2_loclist_baton *dlbaton; |
| const gdb_byte *start; |
| size_t length; |
| struct value *result; |
| |
| /* If this method is called, then FRAMEFUNC is supposed to be a DWARF block. |
| Thus, it's supposed to provide the find_frame_base_location method as |
| well. */ |
| gdb_assert (SYMBOL_BLOCK_OPS (framefunc)->find_frame_base_location != NULL); |
| |
| gdbarch = get_frame_arch (frame); |
| type = builtin_type (gdbarch)->builtin_data_ptr; |
| dlbaton = (struct dwarf2_loclist_baton *) SYMBOL_LOCATION_BATON (framefunc); |
| |
| SYMBOL_BLOCK_OPS (framefunc)->find_frame_base_location |
| (framefunc, get_frame_pc (frame), &start, &length); |
| result = dwarf2_evaluate_loc_desc (type, frame, start, length, |
| dlbaton->per_cu); |
| |
| /* The DW_AT_frame_base attribute contains a location description which |
| computes the base address itself. However, the call to |
| dwarf2_evaluate_loc_desc returns a value representing a variable at |
| that address. The frame base address is thus this variable's |
| address. */ |
| return value_address (result); |
| } |
| |
| /* Vector for inferior functions as represented by LOC_BLOCK, if the inferior |
| function uses DWARF location list for its DW_AT_frame_base. */ |
| |
| const struct symbol_block_ops dwarf2_block_frame_base_loclist_funcs = |
| { |
| loclist_find_frame_base_location, |
| loclist_get_frame_base |
| }; |
| |
| /* See dwarf2loc.h. */ |
| |
| void |
| func_get_frame_base_dwarf_block (struct symbol *framefunc, CORE_ADDR pc, |
| const gdb_byte **start, size_t *length) |
| { |
| if (SYMBOL_BLOCK_OPS (framefunc) != NULL) |
| { |
| const struct symbol_block_ops *ops_block = SYMBOL_BLOCK_OPS (framefunc); |
| |
| ops_block->find_frame_base_location (framefunc, pc, start, length); |
| } |
| else |
| *length = 0; |
| |
| if (*length == 0) |
| error (_("Could not find the frame base for \"%s\"."), |
| SYMBOL_NATURAL_NAME (framefunc)); |
| } |
| |
| static CORE_ADDR |
| get_frame_pc_for_per_cu_dwarf_call (void *baton) |
| { |
| dwarf_expr_context *ctx = (dwarf_expr_context *) baton; |
| |
| return ctx->get_frame_pc (); |
| } |
| |
| static void |
| per_cu_dwarf_call (struct dwarf_expr_context *ctx, cu_offset die_offset, |
| struct dwarf2_per_cu_data *per_cu) |
| { |
| struct dwarf2_locexpr_baton block; |
| |
| block = dwarf2_fetch_die_loc_cu_off (die_offset, per_cu, |
| get_frame_pc_for_per_cu_dwarf_call, |
| ctx); |
| |
| /* DW_OP_call_ref is currently not supported. */ |
| gdb_assert (block.per_cu == per_cu); |
| |
| ctx->eval (block.data, block.size); |
| } |
| |
| class dwarf_evaluate_loc_desc : public dwarf_expr_context |
| { |
| public: |
| |
| struct frame_info *frame; |
| struct dwarf2_per_cu_data *per_cu; |
| CORE_ADDR obj_address; |
| |
| /* Helper function for dwarf2_evaluate_loc_desc. Computes the CFA for |
| the frame in BATON. */ |
| |
| CORE_ADDR get_frame_cfa () OVERRIDE |
| { |
| return dwarf2_frame_cfa (frame); |
| } |
| |
| /* Helper function for dwarf2_evaluate_loc_desc. Computes the PC for |
| the frame in BATON. */ |
| |
| CORE_ADDR get_frame_pc () OVERRIDE |
| { |
| return get_frame_address_in_block (frame); |
| } |
| |
| /* Using the objfile specified in BATON, find the address for the |
| current thread's thread-local storage with offset OFFSET. */ |
| CORE_ADDR get_tls_address (CORE_ADDR offset) OVERRIDE |
| { |
| struct objfile *objfile = dwarf2_per_cu_objfile (per_cu); |
| |
| return target_translate_tls_address (objfile, offset); |
| } |
| |
| /* Helper interface of per_cu_dwarf_call for |
| dwarf2_evaluate_loc_desc. */ |
| |
| void dwarf_call (cu_offset die_offset) OVERRIDE |
| { |
| per_cu_dwarf_call (this, die_offset, per_cu); |
| } |
| |
| struct type *get_base_type (cu_offset die_offset, int size) OVERRIDE |
| { |
| struct type *result = dwarf2_get_die_type (die_offset, per_cu); |
| if (result == NULL) |
| error (_("Could not find type for DW_OP_const_type")); |
| if (size != 0 && TYPE_LENGTH (result) != size) |
| error (_("DW_OP_const_type has different sizes for type and data")); |
| return result; |
| } |
| |
| /* Callback function for dwarf2_evaluate_loc_desc. |
| Fetch the address indexed by DW_OP_GNU_addr_index. */ |
| |
| CORE_ADDR get_addr_index (unsigned int index) OVERRIDE |
| { |
| return dwarf2_read_addr_index (per_cu, index); |
| } |
| |
| /* Callback function for get_object_address. Return the address of the VLA |
| object. */ |
| |
| CORE_ADDR get_object_address () OVERRIDE |
| { |
| if (obj_address == 0) |
| error (_("Location address is not set.")); |
| return obj_address; |
| } |
| |
| /* Execute DWARF block of call_site_parameter which matches KIND and |
| KIND_U. Choose DEREF_SIZE value of that parameter. Search |
| caller of this objects's frame. |
| |
| The caller can be from a different CU - per_cu_dwarf_call |
| implementation can be more simple as it does not support cross-CU |
| DWARF executions. */ |
| |
| void push_dwarf_reg_entry_value (enum call_site_parameter_kind kind, |
| union call_site_parameter_u kind_u, |
| int deref_size) OVERRIDE |
| { |
| struct frame_info *caller_frame; |
| struct dwarf2_per_cu_data *caller_per_cu; |
| struct call_site_parameter *parameter; |
| const gdb_byte *data_src; |
| size_t size; |
| |
| caller_frame = get_prev_frame (frame); |
| |
| parameter = dwarf_expr_reg_to_entry_parameter (frame, kind, kind_u, |
| &caller_per_cu); |
| data_src = deref_size == -1 ? parameter->value : parameter->data_value; |
| size = deref_size == -1 ? parameter->value_size : parameter->data_value_size; |
| |
| /* DEREF_SIZE size is not verified here. */ |
| if (data_src == NULL) |
| throw_error (NO_ENTRY_VALUE_ERROR, |
| _("Cannot resolve DW_AT_call_data_value")); |
| |
| scoped_restore save_frame = make_scoped_restore (&this->frame, |
| caller_frame); |
| scoped_restore save_per_cu = make_scoped_restore (&this->per_cu, |
| caller_per_cu); |
| scoped_restore save_obj_addr = make_scoped_restore (&this->obj_address, |
| (CORE_ADDR) 0); |
| |
| scoped_restore save_arch = make_scoped_restore (&this->gdbarch); |
| this->gdbarch |
| = get_objfile_arch (dwarf2_per_cu_objfile (per_cu)); |
| scoped_restore save_addr_size = make_scoped_restore (&this->addr_size); |
| this->addr_size = dwarf2_per_cu_addr_size (per_cu); |
| scoped_restore save_offset = make_scoped_restore (&this->offset); |
| this->offset = dwarf2_per_cu_text_offset (per_cu); |
| |
| this->eval (data_src, size); |
| } |
| |
| /* Using the frame specified in BATON, find the location expression |
| describing the frame base. Return a pointer to it in START and |
| its length in LENGTH. */ |
| void get_frame_base (const gdb_byte **start, size_t * length) OVERRIDE |
| { |
| /* FIXME: cagney/2003-03-26: This code should be using |
| get_frame_base_address(), and then implement a dwarf2 specific |
| this_base method. */ |
| struct symbol *framefunc; |
| const struct block *bl = get_frame_block (frame, NULL); |
| |
| if (bl == NULL) |
| error (_("frame address is not available.")); |
| |
| /* Use block_linkage_function, which returns a real (not inlined) |
| function, instead of get_frame_function, which may return an |
| inlined function. */ |
| framefunc = block_linkage_function (bl); |
| |
| /* If we found a frame-relative symbol then it was certainly within |
| some function associated with a frame. If we can't find the frame, |
| something has gone wrong. */ |
| gdb_assert (framefunc != NULL); |
| |
| func_get_frame_base_dwarf_block (framefunc, |
| get_frame_address_in_block (frame), |
| start, length); |
| } |
| |
| /* Read memory at ADDR (length LEN) into BUF. */ |
| |
| void read_mem (gdb_byte *buf, CORE_ADDR addr, size_t len) OVERRIDE |
| { |
| read_memory (addr, buf, len); |
| } |
| |
| /* Using the frame specified in BATON, return the value of register |
| REGNUM, treated as a pointer. */ |
| CORE_ADDR read_addr_from_reg (int dwarf_regnum) OVERRIDE |
| { |
| struct gdbarch *gdbarch = get_frame_arch (frame); |
| int regnum = dwarf_reg_to_regnum_or_error (gdbarch, dwarf_regnum); |
| |
| return address_from_register (regnum, frame); |
| } |
| |
| /* Implement "get_reg_value" callback. */ |
| |
| struct value *get_reg_value (struct type *type, int dwarf_regnum) OVERRIDE |
| { |
| struct gdbarch *gdbarch = get_frame_arch (frame); |
| int regnum = dwarf_reg_to_regnum_or_error (gdbarch, dwarf_regnum); |
| |
| return value_from_register (type, regnum, frame); |
| } |
| }; |
| |
| /* See dwarf2loc.h. */ |
| |
| unsigned int entry_values_debug = 0; |
| |
| /* Helper to set entry_values_debug. */ |
| |
| static void |
| show_entry_values_debug (struct ui_file *file, int from_tty, |
| struct cmd_list_element *c, const char *value) |
| { |
| fprintf_filtered (file, |
| _("Entry values and tail call frames debugging is %s.\n"), |
| value); |
| } |
| |
| /* Find DW_TAG_call_site's DW_AT_call_target address. |
| CALLER_FRAME (for registers) can be NULL if it is not known. This function |
| always returns valid address or it throws NO_ENTRY_VALUE_ERROR. */ |
| |
| static CORE_ADDR |
| call_site_to_target_addr (struct gdbarch *call_site_gdbarch, |
| struct call_site *call_site, |
| struct frame_info *caller_frame) |
| { |
| switch (FIELD_LOC_KIND (call_site->target)) |
| { |
| case FIELD_LOC_KIND_DWARF_BLOCK: |
| { |
| struct dwarf2_locexpr_baton *dwarf_block; |
| struct value *val; |
| struct type *caller_core_addr_type; |
| struct gdbarch *caller_arch; |
| |
| dwarf_block = FIELD_DWARF_BLOCK (call_site->target); |
| if (dwarf_block == NULL) |
| { |
| struct bound_minimal_symbol msym; |
| |
| msym = lookup_minimal_symbol_by_pc (call_site->pc - 1); |
| throw_error (NO_ENTRY_VALUE_ERROR, |
| _("DW_AT_call_target is not specified at %s in %s"), |
| paddress (call_site_gdbarch, call_site->pc), |
| (msym.minsym == NULL ? "???" |
| : MSYMBOL_PRINT_NAME (msym.minsym))); |
| |
| } |
| if (caller_frame == NULL) |
| { |
| struct bound_minimal_symbol msym; |
| |
| msym = lookup_minimal_symbol_by_pc (call_site->pc - 1); |
| throw_error (NO_ENTRY_VALUE_ERROR, |
| _("DW_AT_call_target DWARF block resolving " |
| "requires known frame which is currently not " |
| "available at %s in %s"), |
| paddress (call_site_gdbarch, call_site->pc), |
| (msym.minsym == NULL ? "???" |
| : MSYMBOL_PRINT_NAME (msym.minsym))); |
| |
| } |
| caller_arch = get_frame_arch (caller_frame); |
| caller_core_addr_type = builtin_type (caller_arch)->builtin_func_ptr; |
| val = dwarf2_evaluate_loc_desc (caller_core_addr_type, caller_frame, |
| dwarf_block->data, dwarf_block->size, |
| dwarf_block->per_cu); |
| /* DW_AT_call_target is a DWARF expression, not a DWARF location. */ |
| if (VALUE_LVAL (val) == lval_memory) |
| return value_address (val); |
| else |
| return value_as_address (val); |
| } |
| |
| case FIELD_LOC_KIND_PHYSNAME: |
| { |
| const char *physname; |
| struct bound_minimal_symbol msym; |
| |
| physname = FIELD_STATIC_PHYSNAME (call_site->target); |
| |
| /* Handle both the mangled and demangled PHYSNAME. */ |
| msym = lookup_minimal_symbol (physname, NULL, NULL); |
| if (msym.minsym == NULL) |
| { |
| msym = lookup_minimal_symbol_by_pc (call_site->pc - 1); |
| throw_error (NO_ENTRY_VALUE_ERROR, |
| _("Cannot find function \"%s\" for a call site target " |
| "at %s in %s"), |
| physname, paddress (call_site_gdbarch, call_site->pc), |
| (msym.minsym == NULL ? "???" |
| : MSYMBOL_PRINT_NAME (msym.minsym))); |
| |
| } |
| return BMSYMBOL_VALUE_ADDRESS (msym); |
| } |
| |
| case FIELD_LOC_KIND_PHYSADDR: |
| return FIELD_STATIC_PHYSADDR (call_site->target); |
| |
| default: |
| internal_error (__FILE__, __LINE__, _("invalid call site target kind")); |
| } |
| } |
| |
| /* Convert function entry point exact address ADDR to the function which is |
| compliant with TAIL_CALL_LIST_COMPLETE condition. Throw |
| NO_ENTRY_VALUE_ERROR otherwise. */ |
| |
| static struct symbol * |
| func_addr_to_tail_call_list (struct gdbarch *gdbarch, CORE_ADDR addr) |
| { |
| struct symbol *sym = find_pc_function (addr); |
| struct type *type; |
| |
| if (sym == NULL || BLOCK_START (SYMBOL_BLOCK_VALUE (sym)) != addr) |
| throw_error (NO_ENTRY_VALUE_ERROR, |
| _("DW_TAG_call_site resolving failed to find function " |
| "name for address %s"), |
| paddress (gdbarch, addr)); |
| |
| type = SYMBOL_TYPE (sym); |
| gdb_assert (TYPE_CODE (type) == TYPE_CODE_FUNC); |
| gdb_assert (TYPE_SPECIFIC_FIELD (type) == TYPE_SPECIFIC_FUNC); |
| |
| return sym; |
| } |
| |
| /* Verify function with entry point exact address ADDR can never call itself |
| via its tail calls (incl. transitively). Throw NO_ENTRY_VALUE_ERROR if it |
| can call itself via tail calls. |
| |
| If a funtion can tail call itself its entry value based parameters are |
| unreliable. There is no verification whether the value of some/all |
| parameters is unchanged through the self tail call, we expect if there is |
| a self tail call all the parameters can be modified. */ |
| |
| static void |
| func_verify_no_selftailcall (struct gdbarch *gdbarch, CORE_ADDR verify_addr) |
| { |
| CORE_ADDR addr; |
| |
| /* The verification is completely unordered. Track here function addresses |
| which still need to be iterated. */ |
| std::vector<CORE_ADDR> todo; |
| |
| /* Track here CORE_ADDRs which were already visited. */ |
| std::unordered_set<CORE_ADDR> addr_hash; |
| |
| todo.push_back (verify_addr); |
| while (!todo.empty ()) |
| { |
| struct symbol *func_sym; |
| struct call_site *call_site; |
| |
| addr = todo.back (); |
| todo.pop_back (); |
| |
| func_sym = func_addr_to_tail_call_list (gdbarch, addr); |
| |
| for (call_site = TYPE_TAIL_CALL_LIST (SYMBOL_TYPE (func_sym)); |
| call_site; call_site = call_site->tail_call_next) |
| { |
| CORE_ADDR target_addr; |
| |
| /* CALLER_FRAME with registers is not available for tail-call jumped |
| frames. */ |
| target_addr = call_site_to_target_addr (gdbarch, call_site, NULL); |
| |
| if (target_addr == verify_addr) |
| { |
| struct bound_minimal_symbol msym; |
| |
| msym = lookup_minimal_symbol_by_pc (verify_addr); |
| throw_error (NO_ENTRY_VALUE_ERROR, |
| _("DW_OP_entry_value resolving has found " |
| "function \"%s\" at %s can call itself via tail " |
| "calls"), |
| (msym.minsym == NULL ? "???" |
| : MSYMBOL_PRINT_NAME (msym.minsym)), |
| paddress (gdbarch, verify_addr)); |
| } |
| |
| if (addr_hash.insert (target_addr).second) |
| todo.push_back (target_addr); |
| } |
| } |
| } |
| |
| /* Print user readable form of CALL_SITE->PC to gdb_stdlog. Used only for |
| ENTRY_VALUES_DEBUG. */ |
| |
| static void |
| tailcall_dump (struct gdbarch *gdbarch, const struct call_site *call_site) |
| { |
| CORE_ADDR addr = call_site->pc; |
| struct bound_minimal_symbol msym = lookup_minimal_symbol_by_pc (addr - 1); |
| |
| fprintf_unfiltered (gdb_stdlog, " %s(%s)", paddress (gdbarch, addr), |
| (msym.minsym == NULL ? "???" |
| : MSYMBOL_PRINT_NAME (msym.minsym))); |
| |
| } |
| |
| /* Intersect RESULTP with CHAIN to keep RESULTP unambiguous, keep in RESULTP |
| only top callers and bottom callees which are present in both. GDBARCH is |
| used only for ENTRY_VALUES_DEBUG. RESULTP is NULL after return if there are |
| no remaining possibilities to provide unambiguous non-trivial result. |
| RESULTP should point to NULL on the first (initialization) call. Caller is |
| responsible for xfree of any RESULTP data. */ |
| |
| static void |
| chain_candidate (struct gdbarch *gdbarch, |
| gdb::unique_xmalloc_ptr<struct call_site_chain> *resultp, |
| std::vector<struct call_site *> *chain) |
| { |
| long length = chain->size (); |
| int callers, callees, idx; |
| |
| if (*resultp == NULL) |
| { |
| /* Create the initial chain containing all the passed PCs. */ |
| |
| struct call_site_chain *result |
| = ((struct call_site_chain *) |
| xmalloc (sizeof (*result) |
| + sizeof (*result->call_site) * (length - 1))); |
| result->length = length; |
| result->callers = result->callees = length; |
| if (!chain->empty ()) |
| memcpy (result->call_site, chain->data (), |
| sizeof (*result->call_site) * length); |
| resultp->reset (result); |
| |
| if (entry_values_debug) |
| { |
| fprintf_unfiltered (gdb_stdlog, "tailcall: initial:"); |
| for (idx = 0; idx < length; idx++) |
| tailcall_dump (gdbarch, result->call_site[idx]); |
| fputc_unfiltered ('\n', gdb_stdlog); |
| } |
| |
| return; |
| } |
| |
| if (entry_values_debug) |
| { |
| fprintf_unfiltered (gdb_stdlog, "tailcall: compare:"); |
| for (idx = 0; idx < length; idx++) |
| tailcall_dump (gdbarch, chain->at (idx)); |
| fputc_unfiltered ('\n', gdb_stdlog); |
| } |
| |
| /* Intersect callers. */ |
| |
| callers = std::min ((long) (*resultp)->callers, length); |
| for (idx = 0; idx < callers; idx++) |
| if ((*resultp)->call_site[idx] != chain->at (idx)) |
| { |
| (*resultp)->callers = idx; |
| break; |
| } |
| |
| /* Intersect callees. */ |
| |
| callees = std::min ((long) (*resultp)->callees, length); |
| for (idx = 0; idx < callees; idx++) |
| if ((*resultp)->call_site[(*resultp)->length - 1 - idx] |
| != chain->at (length - 1 - idx)) |
| { |
| (*resultp)->callees = idx; |
| break; |
| } |
| |
| if (entry_values_debug) |
| { |
| fprintf_unfiltered (gdb_stdlog, "tailcall: reduced:"); |
| for (idx = 0; idx < (*resultp)->callers; idx++) |
| tailcall_dump (gdbarch, (*resultp)->call_site[idx]); |
| fputs_unfiltered (" |", gdb_stdlog); |
| for (idx = 0; idx < (*resultp)->callees; idx++) |
| tailcall_dump (gdbarch, |
| (*resultp)->call_site[(*resultp)->length |
| - (*resultp)->callees + idx]); |
| fputc_unfiltered ('\n', gdb_stdlog); |
| } |
| |
| if ((*resultp)->callers == 0 && (*resultp)->callees == 0) |
| { |
| /* There are no common callers or callees. It could be also a direct |
| call (which has length 0) with ambiguous possibility of an indirect |
| call - CALLERS == CALLEES == 0 is valid during the first allocation |
| but any subsequence processing of such entry means ambiguity. */ |
| resultp->reset (NULL); |
| return; |
| } |
| |
| /* See call_site_find_chain_1 why there is no way to reach the bottom callee |
| PC again. In such case there must be two different code paths to reach |
| it. CALLERS + CALLEES equal to LENGTH in the case of self tail-call. */ |
| gdb_assert ((*resultp)->callers + (*resultp)->callees <= (*resultp)->length); |
| } |
| |
| /* Create and return call_site_chain for CALLER_PC and CALLEE_PC. All the |
| assumed frames between them use GDBARCH. Use depth first search so we can |
| keep single CHAIN of call_site's back to CALLER_PC. Function recursion |
| would have needless GDB stack overhead. Caller is responsible for xfree of |
| the returned result. Any unreliability results in thrown |
| NO_ENTRY_VALUE_ERROR. */ |
| |
| static struct call_site_chain * |
| call_site_find_chain_1 (struct gdbarch *gdbarch, CORE_ADDR caller_pc, |
| CORE_ADDR callee_pc) |
| { |
| CORE_ADDR save_callee_pc = callee_pc; |
| gdb::unique_xmalloc_ptr<struct call_site_chain> retval; |
| struct call_site *call_site; |
| |
| /* CHAIN contains only the intermediate CALL_SITEs. Neither CALLER_PC's |
| call_site nor any possible call_site at CALLEE_PC's function is there. |
| Any CALL_SITE in CHAIN will be iterated to its siblings - via |
| TAIL_CALL_NEXT. This is inappropriate for CALLER_PC's call_site. */ |
| std::vector<struct call_site *> chain; |
| |
| /* We are not interested in the specific PC inside the callee function. */ |
| callee_pc = get_pc_function_start (callee_pc); |
| if (callee_pc == 0) |
| throw_error (NO_ENTRY_VALUE_ERROR, _("Unable to find function for PC %s"), |
| paddress (gdbarch, save_callee_pc)); |
| |
| /* Mark CALL_SITEs so we do not visit the same ones twice. */ |
| std::unordered_set<CORE_ADDR> addr_hash; |
| |
| /* Do not push CALL_SITE to CHAIN. Push there only the first tail call site |
| at the target's function. All the possible tail call sites in the |
| target's function will get iterated as already pushed into CHAIN via their |
| TAIL_CALL_NEXT. */ |
| call_site = call_site_for_pc (gdbarch, caller_pc); |
| |
| while (call_site) |
| { |
| CORE_ADDR target_func_addr; |
| struct call_site *target_call_site; |
| |
| /* CALLER_FRAME with registers is not available for tail-call jumped |
| frames. */ |
| target_func_addr = call_site_to_target_addr (gdbarch, call_site, NULL); |
| |
| if (target_func_addr == callee_pc) |
| { |
| chain_candidate (gdbarch, &retval, &chain); |
| if (retval == NULL) |
| break; |
| |
| /* There is no way to reach CALLEE_PC again as we would prevent |
| entering it twice as being already marked in ADDR_HASH. */ |
| target_call_site = NULL; |
| } |
| else |
| { |
| struct symbol *target_func; |
| |
| target_func = func_addr_to_tail_call_list (gdbarch, target_func_addr); |
| target_call_site = TYPE_TAIL_CALL_LIST (SYMBOL_TYPE (target_func)); |
| } |
| |
| do |
| { |
| /* Attempt to visit TARGET_CALL_SITE. */ |
| |
| if (target_call_site) |
| { |
| if (addr_hash.insert (target_call_site->pc).second) |
| { |
| /* Successfully entered TARGET_CALL_SITE. */ |
| |
| chain.push_back (target_call_site); |
| break; |
| } |
| } |
| |
| /* Backtrack (without revisiting the originating call_site). Try the |
| callers's sibling; if there isn't any try the callers's callers's |
| sibling etc. */ |
| |
| target_call_site = NULL; |
| while (!chain.empty ()) |
| { |
| call_site = chain.back (); |
| chain.pop_back (); |
| |
| size_t removed = addr_hash.erase (call_site->pc); |
| gdb_assert (removed == 1); |
| |
| target_call_site = call_site->tail_call_next; |
| if (target_call_site) |
| break; |
| } |
| } |
| while (target_call_site); |
| |
| if (chain.empty ()) |
| call_site = NULL; |
| else |
| call_site = chain.back (); |
| } |
| |
| if (retval == NULL) |
| { |
| struct bound_minimal_symbol msym_caller, msym_callee; |
| |
| msym_caller = lookup_minimal_symbol_by_pc (caller_pc); |
| msym_callee = lookup_minimal_symbol_by_pc (callee_pc); |
| throw_error (NO_ENTRY_VALUE_ERROR, |
| _("There are no unambiguously determinable intermediate " |
| "callers or callees between caller function \"%s\" at %s " |
| "and callee function \"%s\" at %s"), |
| (msym_caller.minsym == NULL |
| ? "???" : MSYMBOL_PRINT_NAME (msym_caller.minsym)), |
| paddress (gdbarch, caller_pc), |
| (msym_callee.minsym == NULL |
| ? "???" : MSYMBOL_PRINT_NAME (msym_callee.minsym)), |
| paddress (gdbarch, callee_pc)); |
| } |
| |
| return retval.release (); |
| } |
| |
| /* Create and return call_site_chain for CALLER_PC and CALLEE_PC. All the |
| assumed frames between them use GDBARCH. If valid call_site_chain cannot be |
| constructed return NULL. Caller is responsible for xfree of the returned |
| result. */ |
| |
| struct call_site_chain * |
| call_site_find_chain (struct gdbarch *gdbarch, CORE_ADDR caller_pc, |
| CORE_ADDR callee_pc) |
| { |
| struct call_site_chain *retval = NULL; |
| |
| TRY |
| { |
| retval = call_site_find_chain_1 (gdbarch, caller_pc, callee_pc); |
| } |
| CATCH (e, RETURN_MASK_ERROR) |
| { |
| if (e.error == NO_ENTRY_VALUE_ERROR) |
| { |
| if (entry_values_debug) |
| exception_print (gdb_stdout, e); |
| |
| return NULL; |
| } |
| else |
| throw_exception (e); |
| } |
| END_CATCH |
| |
| return retval; |
| } |
| |
| /* Return 1 if KIND and KIND_U match PARAMETER. Return 0 otherwise. */ |
| |
| static int |
| call_site_parameter_matches (struct call_site_parameter *parameter, |
| enum call_site_parameter_kind kind, |
| union call_site_parameter_u kind_u) |
| { |
| if (kind == parameter->kind) |
| switch (kind) |
| { |
| case CALL_SITE_PARAMETER_DWARF_REG: |
| return kind_u.dwarf_reg == parameter->u.dwarf_reg; |
| case CALL_SITE_PARAMETER_FB_OFFSET: |
| return kind_u.fb_offset == parameter->u.fb_offset; |
| case CALL_SITE_PARAMETER_PARAM_OFFSET: |
| return kind_u.param_offset.cu_off == parameter->u.param_offset.cu_off; |
| } |
| return 0; |
| } |
| |
| /* Fetch call_site_parameter from caller matching KIND and KIND_U. |
| FRAME is for callee. |
| |
| Function always returns non-NULL, it throws NO_ENTRY_VALUE_ERROR |
| otherwise. */ |
| |
| static struct call_site_parameter * |
| dwarf_expr_reg_to_entry_parameter (struct frame_info *frame, |
| enum call_site_parameter_kind kind, |
| union call_site_parameter_u kind_u, |
| struct dwarf2_per_cu_data **per_cu_return) |
| { |
| CORE_ADDR func_addr, caller_pc; |
| struct gdbarch *gdbarch; |
| struct frame_info *caller_frame; |
| struct call_site *call_site; |
| int iparams; |
| /* Initialize it just to avoid a GCC false warning. */ |
| struct call_site_parameter *parameter = NULL; |
| CORE_ADDR target_addr; |
| |
| while (get_frame_type (frame) == INLINE_FRAME) |
| { |
| frame = get_prev_frame (frame); |
| gdb_assert (frame != NULL); |
| } |
| |
| func_addr = get_frame_func (frame); |
| gdbarch = get_frame_arch (frame); |
| caller_frame = get_prev_frame (frame); |
| if (gdbarch != frame_unwind_arch (frame)) |
| { |
| struct bound_minimal_symbol msym |
| = lookup_minimal_symbol_by_pc (func_addr); |
| struct gdbarch *caller_gdbarch = frame_unwind_arch (frame); |
| |
| throw_error (NO_ENTRY_VALUE_ERROR, |
| _("DW_OP_entry_value resolving callee gdbarch %s " |
| "(of %s (%s)) does not match caller gdbarch %s"), |
| gdbarch_bfd_arch_info (gdbarch)->printable_name, |
| paddress (gdbarch, func_addr), |
| (msym.minsym == NULL ? "???" |
| : MSYMBOL_PRINT_NAME (msym.minsym)), |
| gdbarch_bfd_arch_info (caller_gdbarch)->printable_name); |
| } |
| |
| if (caller_frame == NULL) |
| { |
| struct bound_minimal_symbol msym |
| = lookup_minimal_symbol_by_pc (func_addr); |
| |
| throw_error (NO_ENTRY_VALUE_ERROR, _("DW_OP_entry_value resolving " |
| "requires caller of %s (%s)"), |
| paddress (gdbarch, func_addr), |
| (msym.minsym == NULL ? "???" |
| : MSYMBOL_PRINT_NAME (msym.minsym))); |
| } |
| caller_pc = get_frame_pc (caller_frame); |
| call_site = call_site_for_pc (gdbarch, caller_pc); |
| |
| target_addr = call_site_to_target_addr (gdbarch, call_site, caller_frame); |
| if (target_addr != func_addr) |
| { |
| struct minimal_symbol *target_msym, *func_msym; |
| |
| target_msym = lookup_minimal_symbol_by_pc (target_addr).minsym; |
| func_msym = lookup_minimal_symbol_by_pc (func_addr).minsym; |
| throw_error (NO_ENTRY_VALUE_ERROR, |
| _("DW_OP_entry_value resolving expects callee %s at %s " |
| "but the called frame is for %s at %s"), |
| (target_msym == NULL ? "???" |
| : MSYMBOL_PRINT_NAME (target_msym)), |
| paddress (gdbarch, target_addr), |
| func_msym == NULL ? "???" : MSYMBOL_PRINT_NAME (func_msym), |
| paddress (gdbarch, func_addr)); |
| } |
| |
| /* No entry value based parameters would be reliable if this function can |
| call itself via tail calls. */ |
| func_verify_no_selftailcall (gdbarch, func_addr); |
| |
| for (iparams = 0; iparams < call_site->parameter_count; iparams++) |
| { |
| parameter = &call_site->parameter[iparams]; |
| if (call_site_parameter_matches (parameter, kind, kind_u)) |
| break; |
| } |
| if (iparams == call_site->parameter_count) |
| { |
| struct minimal_symbol *msym |
| = lookup_minimal_symbol_by_pc (caller_pc).minsym; |
| |
| /* DW_TAG_call_site_parameter will be missing just if GCC could not |
| determine its value. */ |
| throw_error (NO_ENTRY_VALUE_ERROR, _("Cannot find matching parameter " |
| "at DW_TAG_call_site %s at %s"), |
| paddress (gdbarch, caller_pc), |
| msym == NULL ? "???" : MSYMBOL_PRINT_NAME (msym)); |
| } |
| |
| *per_cu_return = call_site->per_cu; |
| return parameter; |
| } |
| |
| /* Return value for PARAMETER matching DEREF_SIZE. If DEREF_SIZE is -1, return |
| the normal DW_AT_call_value block. Otherwise return the |
| DW_AT_call_data_value (dereferenced) block. |
| |
| TYPE and CALLER_FRAME specify how to evaluate the DWARF block into returned |
| struct value. |
| |
| Function always returns non-NULL, non-optimized out value. It throws |
| NO_ENTRY_VALUE_ERROR if it cannot resolve the value for any reason. */ |
| |
| static struct value * |
| dwarf_entry_parameter_to_value (struct call_site_parameter *parameter, |
| CORE_ADDR deref_size, struct type *type, |
| struct frame_info *caller_frame, |
| struct dwarf2_per_cu_data *per_cu) |
| { |
| const gdb_byte *data_src; |
| gdb_byte *data; |
| size_t size; |
| |
| data_src = deref_size == -1 ? parameter->value : parameter->data_value; |
| size = deref_size == -1 ? parameter->value_size : parameter->data_value_size; |
| |
| /* DEREF_SIZE size is not verified here. */ |
| if (data_src == NULL) |
| throw_error (NO_ENTRY_VALUE_ERROR, |
| _("Cannot resolve DW_AT_call_data_value")); |
| |
| /* DW_AT_call_value is a DWARF expression, not a DWARF |
| location. Postprocessing of DWARF_VALUE_MEMORY would lose the type from |
| DWARF block. */ |
| data = (gdb_byte *) alloca (size + 1); |
| memcpy (data, data_src, size); |
| data[size] = DW_OP_stack_value; |
| |
| return dwarf2_evaluate_loc_desc (type, caller_frame, data, size + 1, per_cu); |
| } |
| |
| /* VALUE must be of type lval_computed with entry_data_value_funcs. Perform |
| the indirect method on it, that is use its stored target value, the sole |
| purpose of entry_data_value_funcs.. */ |
| |
| static struct value * |
| entry_data_value_coerce_ref (const struct value *value) |
| { |
| struct type *checked_type = check_typedef (value_type (value)); |
| struct value *target_val; |
| |
| if (TYPE_CODE (checked_type) != TYPE_CODE_REF) |
| return NULL; |
| |
| target_val = (struct value *) value_computed_closure (value); |
| value_incref (target_val); |
| return target_val; |
| } |
| |
| /* Implement copy_closure. */ |
| |
| static void * |
| entry_data_value_copy_closure (const struct value *v) |
| { |
| struct value *target_val = (struct value *) value_computed_closure (v); |
| |
| value_incref (target_val); |
| return target_val; |
| } |
| |
| /* Implement free_closure. */ |
| |
| static void |
| entry_data_value_free_closure (struct value *v) |
| { |
| struct value *target_val = (struct value *) value_computed_closure (v); |
| |
| value_free (target_val); |
| } |
| |
| /* Vector for methods for an entry value reference where the referenced value |
| is stored in the caller. On the first dereference use |
| DW_AT_call_data_value in the caller. */ |
| |
| static const struct lval_funcs entry_data_value_funcs = |
| { |
| NULL, /* read */ |
| NULL, /* write */ |
| NULL, /* indirect */ |
| entry_data_value_coerce_ref, |
| NULL, /* check_synthetic_pointer */ |
| entry_data_value_copy_closure, |
| entry_data_value_free_closure |
| }; |
| |
| /* Read parameter of TYPE at (callee) FRAME's function entry. KIND and KIND_U |
| are used to match DW_AT_location at the caller's |
| DW_TAG_call_site_parameter. |
| |
| Function always returns non-NULL value. It throws NO_ENTRY_VALUE_ERROR if it |
| cannot resolve the parameter for any reason. */ |
| |
| static struct value * |
| value_of_dwarf_reg_entry (struct type *type, struct frame_info *frame, |
| enum call_site_parameter_kind kind, |
| union call_site_parameter_u kind_u) |
| { |
| struct type *checked_type = check_typedef (type); |
| struct type *target_type = TYPE_TARGET_TYPE (checked_type); |
| struct frame_info *caller_frame = get_prev_frame (frame); |
| struct value *outer_val, *target_val, *val; |
| struct call_site_parameter *parameter; |
| struct dwarf2_per_cu_data *caller_per_cu; |
| |
| parameter = dwarf_expr_reg_to_entry_parameter (frame, kind, kind_u, |
| &caller_per_cu); |
| |
| outer_val = dwarf_entry_parameter_to_value (parameter, -1 /* deref_size */, |
| type, caller_frame, |
| caller_per_cu); |
| |
| /* Check if DW_AT_call_data_value cannot be used. If it should be |
| used and it is not available do not fall back to OUTER_VAL - dereferencing |
| TYPE_CODE_REF with non-entry data value would give current value - not the |
| entry value. */ |
| |
| if (TYPE_CODE (checked_type) != TYPE_CODE_REF |
| || TYPE_TARGET_TYPE (checked_type) == NULL) |
| return outer_val; |
| |
| target_val = dwarf_entry_parameter_to_value (parameter, |
| TYPE_LENGTH (target_type), |
| target_type, caller_frame, |
| caller_per_cu); |
| |
| release_value (target_val); |
| val = allocate_computed_value (type, &entry_data_value_funcs, |
| target_val /* closure */); |
| |
| /* Copy the referencing pointer to the new computed value. */ |
| memcpy (value_contents_raw (val), value_contents_raw (outer_val), |
| TYPE_LENGTH (checked_type)); |
| set_value_lazy (val, 0); |
| |
| return val; |
| } |
| |
| /* Read parameter of TYPE at (callee) FRAME's function entry. DATA and |
| SIZE are DWARF block used to match DW_AT_location at the caller's |
| DW_TAG_call_site_parameter. |
| |
| Function always returns non-NULL value. It throws NO_ENTRY_VALUE_ERROR if it |
| cannot resolve the parameter for any reason. */ |
| |
| static struct value * |
| value_of_dwarf_block_entry (struct type *type, struct frame_info *frame, |
| const gdb_byte *block, size_t block_len) |
| { |
| union call_site_parameter_u kind_u; |
| |
| kind_u.dwarf_reg = dwarf_block_to_dwarf_reg (block, block + block_len); |
| if (kind_u.dwarf_reg != -1) |
| return value_of_dwarf_reg_entry (type, frame, CALL_SITE_PARAMETER_DWARF_REG, |
| kind_u); |
| |
| if (dwarf_block_to_fb_offset (block, block + block_len, &kind_u.fb_offset)) |
| return value_of_dwarf_reg_entry (type, frame, CALL_SITE_PARAMETER_FB_OFFSET, |
| kind_u); |
| |
| /* This can normally happen - throw NO_ENTRY_VALUE_ERROR to get the message |
| suppressed during normal operation. The expression can be arbitrary if |
| there is no caller-callee entry value binding expected. */ |
| throw_error (NO_ENTRY_VALUE_ERROR, |
| _("DWARF-2 expression error: DW_OP_entry_value is supported " |
| "only for single DW_OP_reg* or for DW_OP_fbreg(*)")); |
| } |
| |
| struct piece_closure |
| { |
| /* Reference count. */ |
| int refc; |
| |
| /* The CU from which this closure's expression came. */ |
| struct dwarf2_per_cu_data *per_cu; |
| |
| /* The number of pieces used to describe this variable. */ |
| int n_pieces; |
| |
| /* The target address size, used only for DWARF_VALUE_STACK. */ |
| int addr_size; |
| |
| /* The pieces themselves. */ |
| struct dwarf_expr_piece *pieces; |
| |
| /* Frame ID of frame to which a register value is relative, used |
| only by DWARF_VALUE_REGISTER. */ |
| struct frame_id frame_id; |
| }; |
| |
| /* Allocate a closure for a value formed from separately-described |
| PIECES. */ |
| |
| static struct piece_closure * |
| allocate_piece_closure (struct dwarf2_per_cu_data *per_cu, |
| int n_pieces, struct dwarf_expr_piece *pieces, |
| int addr_size, struct frame_info *frame) |
| { |
| struct piece_closure *c = XCNEW (struct piece_closure); |
| int i; |
| |
| c->refc = 1; |
| c->per_cu = per_cu; |
| c->n_pieces = n_pieces; |
| c->addr_size = addr_size; |
| c->pieces = XCNEWVEC (struct dwarf_expr_piece, n_pieces); |
| if (frame == NULL) |
| c->frame_id = null_frame_id; |
| else |
| c->frame_id = get_frame_id (frame); |
| |
| memcpy (c->pieces, pieces, n_pieces * sizeof (struct dwarf_expr_piece)); |
| for (i = 0; i < n_pieces; ++i) |
| if (c->pieces[i].location == DWARF_VALUE_STACK) |
| value_incref (c->pieces[i].v.value); |
| |
| return c; |
| } |
| |
| /* Copy NBITS bits from SOURCE to DEST starting at the given bit |
| offsets. Use the bit order as specified by BITS_BIG_ENDIAN. |
| Source and destination buffers must not overlap. */ |
| |
| static void |
| copy_bitwise (gdb_byte *dest, ULONGEST dest_offset, |
| const gdb_byte *source, ULONGEST source_offset, |
| ULONGEST nbits, int bits_big_endian) |
| { |
| unsigned int buf, avail; |
| |
| if (nbits == 0) |
| return; |
| |
| if (bits_big_endian) |
| { |
| /* Start from the end, then work backwards. */ |
| dest_offset += nbits - 1; |
| dest += dest_offset / 8; |
| dest_offset = 7 - dest_offset % 8; |
| source_offset += nbits - 1; |
| source += source_offset / 8; |
| source_offset = 7 - source_offset % 8; |
| } |
| else |
| { |
| dest += dest_offset / 8; |
| dest_offset %= 8; |
| source += source_offset / 8; |
| source_offset %= 8; |
| } |
| |
| /* Fill BUF with DEST_OFFSET bits from the destination and 8 - |
| SOURCE_OFFSET bits from the source. */ |
| buf = *(bits_big_endian ? source-- : source++) >> source_offset; |
| buf <<= dest_offset; |
| buf |= *dest & ((1 << dest_offset) - 1); |
| |
| /* NBITS: bits yet to be written; AVAIL: BUF's fill level. */ |
| nbits += dest_offset; |
| avail = dest_offset + 8 - source_offset; |
| |
| /* Flush 8 bits from BUF, if appropriate. */ |
| if (nbits >= 8 && avail >= 8) |
| { |
| *(bits_big_endian ? dest-- : dest++) = buf; |
| buf >>= 8; |
| avail -= 8; |
| nbits -= 8; |
| } |
| |
| /* Copy the middle part. */ |
| if (nbits >= 8) |
| { |
| size_t len = nbits / 8; |
| |
| /* Use a faster method for byte-aligned copies. */ |
| if (avail == 0) |
| { |
| if (bits_big_endian) |
| { |
| dest -= len; |
| source -= len; |
| memcpy (dest + 1, source + 1, len); |
| } |
| else |
| { |
| memcpy (dest, source, len); |
| dest += len; |
| source += len; |
| } |
| } |
| else |
| { |
| while (len--) |
| { |
| buf |= *(bits_big_endian ? source-- : source++) << avail; |
| *(bits_big_endian ? dest-- : dest++) = buf; |
| buf >>= 8; |
| } |
| } |
| nbits %= 8; |
| } |
| |
| /* Write the last byte. */ |
| if (nbits) |
| { |
| if (avail < nbits) |
| buf |= *source << avail; |
| |
| buf &= (1 << nbits) - 1; |
| *dest = (*dest & (~0 << nbits)) | buf; |
| } |
| } |
| |
| #if GDB_SELF_TEST |
| |
| namespace selftests { |
| |
| /* Helper function for the unit test of copy_bitwise. Convert NBITS bits |
| out of BITS, starting at OFFS, to the respective '0'/'1'-string. MSB0 |
| specifies whether to assume big endian bit numbering. Store the |
| resulting (not null-terminated) string at STR. */ |
| |
| static void |
| bits_to_str (char *str, const gdb_byte *bits, ULONGEST offs, |
| ULONGEST nbits, int msb0) |
| { |
| unsigned int j; |
| size_t i; |
| |
| for (i = offs / 8, j = offs % 8; nbits; i++, j = 0) |
| { |
| unsigned int ch = bits[i]; |
| for (; j < 8 && nbits; j++, nbits--) |
| *str++ = (ch & (msb0 ? (1 << (7 - j)) : (1 << j))) ? '1' : '0'; |
| } |
| } |
| |
| /* Check one invocation of copy_bitwise with the given parameters. */ |
| |
| static void |
| check_copy_bitwise (const gdb_byte *dest, unsigned int dest_offset, |
| const gdb_byte *source, unsigned int source_offset, |
| unsigned int nbits, int msb0) |
| { |
| size_t len = align_up (dest_offset + nbits, 8); |
| char *expected = (char *) alloca (len + 1); |
| char *actual = (char *) alloca (len + 1); |
| gdb_byte *buf = (gdb_byte *) alloca (len / 8); |
| |
| /* Compose a '0'/'1'-string that represents the expected result of |
| copy_bitwise below: |
| Bits from [0, DEST_OFFSET) are filled from DEST. |
| Bits from [DEST_OFFSET, DEST_OFFSET + NBITS) are filled from SOURCE. |
| Bits from [DEST_OFFSET + NBITS, LEN) are filled from DEST. |
| |
| E.g., with: |
| dest_offset: 4 |
| nbits: 2 |
| len: 8 |
| dest: 00000000 |
| source: 11111111 |
| |
| We should end up with: |
| buf: 00001100 |
| DDDDSSDD (D=dest, S=source) |
| */ |
| bits_to_str (expected, dest, 0, len, msb0); |
| bits_to_str (expected + dest_offset, source, source_offset, nbits, msb0); |
| |
| /* Fill BUF with data from DEST, apply copy_bitwise, and convert the |
| result to a '0'/'1'-string. */ |
| memcpy (buf, dest, len / 8); |
| copy_bitwise (buf, dest_offset, source, source_offset, nbits, msb0); |
| bits_to_str (actual, buf, 0, len, msb0); |
| |
| /* Compare the resulting strings. */ |
| expected[len] = actual[len] = '\0'; |
| if (strcmp (expected, actual) != 0) |
| error (_("copy_bitwise %s != %s (%u+%u -> %u)"), |
| expected, actual, source_offset, nbits, dest_offset); |
| } |
| |
| /* Unit test for copy_bitwise. */ |
| |
| static void |
| copy_bitwise_tests (void) |
| { |
| /* Data to be used as both source and destination buffers. The two |
| arrays below represent the lsb0- and msb0- encoded versions of the |
| following bit string, respectively: |
| 00000000 00011111 11111111 01001000 10100101 11110010 |
| This pattern is chosen such that it contains: |
| - constant 0- and 1- chunks of more than a full byte; |
| - 0/1- and 1/0 transitions on all bit positions within a byte; |
| - several sufficiently asymmetric bytes. |
| */ |
| static const gdb_byte data_lsb0[] = { |
| 0x00, 0xf8, 0xff, 0x12, 0xa5, 0x4f |
| }; |
| static const gdb_byte data_msb0[] = { |
| 0x00, 0x1f, 0xff, 0x48, 0xa5, 0xf2 |
| }; |
| |
| constexpr size_t data_nbits = 8 * sizeof (data_lsb0); |
| constexpr unsigned max_nbits = 24; |
| |
| /* Try all combinations of: |
| lsb0/msb0 bit order (using the respective data array) |
| X [0, MAX_NBITS] copy bit width |
| X feasible source offsets for the given copy bit width |
| X feasible destination offsets |
| */ |
| for (int msb0 = 0; msb0 < 2; msb0++) |
| { |
| const gdb_byte *data = msb0 ? data_msb0 : data_lsb0; |
| |
| for (unsigned int nbits = 1; nbits <= max_nbits; nbits++) |
| { |
| const unsigned int max_offset = data_nbits - nbits; |
| |
| for (unsigned source_offset = 0; |
| source_offset <= max_offset; |
| source_offset++) |
| { |
| for (unsigned dest_offset = 0; |
| dest_offset <= max_offset; |
| dest_offset++) |
| { |
| check_copy_bitwise (data + dest_offset / 8, |
| dest_offset % 8, |
| data + source_offset / 8, |
| source_offset % 8, |
| nbits, msb0); |
| } |
| } |
| } |
| |
| /* Special cases: copy all, copy nothing. */ |
| check_copy_bitwise (data_lsb0, 0, data_msb0, 0, data_nbits, msb0); |
| check_copy_bitwise (data_msb0, 0, data_lsb0, 0, data_nbits, msb0); |
| check_copy_bitwise (data, data_nbits - 7, data, 9, 0, msb0); |
| } |
| } |
| |
| } /* namespace selftests */ |
| |
| #endif /* GDB_SELF_TEST */ |
| |
| static void |
| read_pieced_value (struct value *v) |
| { |
| int i; |
| long offset = 0; |
| ULONGEST bits_to_skip; |
| gdb_byte *contents; |
| struct piece_closure *c |
| = (struct piece_closure *) value_computed_closure (v); |
| size_t type_len; |
| size_t buffer_size = 0; |
| std::vector<gdb_byte> buffer; |
| int bits_big_endian |
| = gdbarch_bits_big_endian (get_type_arch (value_type (v))); |
| |
| if (value_type (v) != value_enclosing_type (v)) |
| internal_error (__FILE__, __LINE__, |
| _("Should not be able to create a lazy value with " |
| "an enclosing type")); |
| |
| contents = value_contents_raw (v); |
| bits_to_skip = 8 * value_offset (v); |
| if (value_bitsize (v)) |
| { |
| bits_to_skip += value_bitpos (v); |
| type_len = value_bitsize (v); |
| } |
| else |
| type_len = 8 * TYPE_LENGTH (value_type (v)); |
| |
| for (i = 0; i < c->n_pieces && offset < type_len; i++) |
| { |
| struct dwarf_expr_piece *p = &c->pieces[i]; |
| size_t this_size, this_size_bits; |
| long dest_offset_bits, source_offset_bits, source_offset; |
| const gdb_byte *intermediate_buffer; |
| |
| /* Compute size, source, and destination offsets for copying, in |
| bits. */ |
| this_size_bits = p->size; |
| if (bits_to_skip > 0 && bits_to_skip >= this_size_bits) |
| { |
| bits_to_skip -= this_size_bits; |
| continue; |
| } |
| if (bits_to_skip > 0) |
| { |
| dest_offset_bits = 0; |
| source_offset_bits = bits_to_skip; |
| this_size_bits -= bits_to_skip; |
| bits_to_skip = 0; |
| } |
| else |
| { |
| dest_offset_bits = offset; |
| source_offset_bits = 0; |
| } |
| if (this_size_bits > type_len - offset) |
| this_size_bits = type_len - offset; |
| |
| this_size = (this_size_bits + source_offset_bits % 8 + 7) / 8; |
| source_offset = source_offset_bits / 8; |
| if (buffer_size < this_size) |
| { |
| buffer_size = this_size; |
| buffer.reserve (buffer_size); |
| } |
| intermediate_buffer = buffer.data (); |
| |
| /* Copy from the source to DEST_BUFFER. */ |
| switch (p->location) |
| { |
| case DWARF_VALUE_REGISTER: |
| { |
| struct frame_info *frame = frame_find_by_id (c->frame_id); |
| struct gdbarch *arch = get_frame_arch (frame); |
| int gdb_regnum = dwarf_reg_to_regnum_or_error (arch, p->v.regno); |
| int optim, unavail; |
| LONGEST reg_offset = source_offset; |
| |
| if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG |
| && this_size < register_size (arch, gdb_regnum)) |
| { |
| /* Big-endian, and we want less than full size. */ |
| reg_offset = register_size (arch, gdb_regnum) - this_size; |
| /* We want the lower-order THIS_SIZE_BITS of the bytes |
| we extract from the register. */ |
| source_offset_bits += 8 * this_size - this_size_bits; |
| } |
| |
| if (!get_frame_register_bytes (frame, gdb_regnum, reg_offset, |
| this_size, buffer.data (), |
| &optim, &unavail)) |
| { |
| /* Just so garbage doesn't ever shine through. */ |
| memset (buffer.data (), 0, this_size); |
| |
| if (optim) |
| mark_value_bits_optimized_out (v, offset, this_size_bits); |
| if (unavail) |
| mark_value_bits_unavailable (v, offset, this_size_bits); |
| } |
| } |
| break; |
| |
| case DWARF_VALUE_MEMORY: |
| read_value_memory (v, offset, |
| p->v.mem.in_stack_memory, |
| p->v.mem.addr + source_offset, |
| buffer.data (), this_size); |
| break; |
| |
| case DWARF_VALUE_STACK: |
| { |
| size_t n = this_size; |
| |
| if (n > c->addr_size - source_offset) |
| n = (c->addr_size >= source_offset |
| ? c->addr_size - source_offset |
| : 0); |
| if (n == 0) |
| { |
| /* Nothing. */ |
| } |
| else |
| { |
| const gdb_byte *val_bytes = value_contents_all (p->v.value); |
| |
| intermediate_buffer = val_bytes + source_offset; |
| } |
| } |
| break; |
| |
| case DWARF_VALUE_LITERAL: |
| { |
| size_t n = this_size; |
| |
| if (n > p->v.literal.length - source_offset) |
| n = (p->v.literal.length >= source_offset |
| ? p->v.literal.length - source_offset |
| : 0); |
| if (n != 0) |
| intermediate_buffer = p->v.literal.data + source_offset; |
| } |
| break; |
| |
| /* These bits show up as zeros -- but do not cause the value |
| to be considered optimized-out. */ |
| case DWARF_VALUE_IMPLICIT_POINTER: |
| break; |
| |
| case DWARF_VALUE_OPTIMIZED_OUT: |
| mark_value_bits_optimized_out (v, offset, this_size_bits); |
| break; |
| |
| default: |
| internal_error (__FILE__, __LINE__, _("invalid location type")); |
| } |
| |
| if (p->location != DWARF_VALUE_OPTIMIZED_OUT |
| && p->location != DWARF_VALUE_IMPLICIT_POINTER) |
| copy_bitwise (contents, dest_offset_bits, |
| intermediate_buffer, source_offset_bits % 8, |
| this_size_bits, bits_big_endian); |
| |
| offset += this_size_bits; |
| } |
| } |
| |
| static void |
| write_pieced_value (struct value *to, struct value *from) |
| { |
| int i; |
| long offset = 0; |
| ULONGEST bits_to_skip; |
| const gdb_byte *contents; |
| struct piece_closure *c |
| = (struct piece_closure *) value_computed_closure (to); |
| size_t type_len; |
| size_t buffer_size = 0; |
| std::vector<gdb_byte> buffer; |
| int bits_big_endian |
| = gdbarch_bits_big_endian (get_type_arch (value_type (to))); |
| |
| contents = value_contents (from); |
| bits_to_skip = 8 * value_offset (to); |
| if (value_bitsize (to)) |
| { |
| bits_to_skip += value_bitpos (to); |
| type_len = value_bitsize (to); |
| } |
| else |
| type_len = 8 * TYPE_LENGTH (value_type (to)); |
| |
| for (i = 0; i < c->n_pieces && offset < type_len; i++) |
| { |
| struct dwarf_expr_piece *p = &c->pieces[i]; |
| size_t this_size_bits, this_size; |
| long dest_offset_bits, source_offset_bits, dest_offset, source_offset; |
| int need_bitwise; |
| const gdb_byte *source_buffer; |
| |
| this_size_bits = p->size; |
| if (bits_to_skip > 0 && bits_to_skip >= this_size_bits) |
| { |
| bits_to_skip -= this_size_bits; |
| continue; |
| } |
| if (this_size_bits > type_len - offset) |
| this_size_bits = type_len - offset; |
| if (bits_to_skip > 0) |
| { |
| dest_offset_bits = bits_to_skip; |
| source_offset_bits = 0; |
| this_size_bits -= bits_to_skip; |
| bits_to_skip = 0; |
| } |
| else |
| { |
| dest_offset_bits = 0; |
| source_offset_bits = offset; |
| } |
| |
| this_size = (this_size_bits + source_offset_bits % 8 + 7) / 8; |
| source_offset = source_offset_bits / 8; |
| dest_offset = dest_offset_bits / 8; |
| if (dest_offset_bits % 8 == 0 && source_offset_bits % 8 == 0) |
| { |
| source_buffer = contents + source_offset; |
| need_bitwise = 0; |
| } |
| else |
| { |
| if (buffer_size < this_size) |
| { |
| buffer_size = this_size; |
| buffer.reserve (buffer_size); |
| } |
| source_buffer = buffer.data (); |
| need_bitwise = 1; |
| } |
| |
| switch (p->location) |
| { |
| case DWARF_VALUE_REGISTER: |
| { |
| struct frame_info *frame = frame_find_by_id (c->frame_id); |
| struct gdbarch *arch = get_frame_arch (frame); |
| int gdb_regnum = dwarf_reg_to_regnum_or_error (arch, p->v.regno); |
| int reg_offset = dest_offset; |
| |
| if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG |
| && this_size <= register_size (arch, gdb_regnum)) |
| { |
| /* Big-endian, and we want less than full size. */ |
| reg_offset = register_size (arch, gdb_regnum) - this_size; |
| } |
| |
| if (need_bitwise) |
| { |
| int optim, unavail; |
| |
| if (!get_frame_register_bytes (frame, gdb_regnum, reg_offset, |
| this_size, buffer.data (), |
| &optim, &unavail)) |
| { |
| if (optim) |
| throw_error (OPTIMIZED_OUT_ERROR, |
| _("Can't do read-modify-write to " |
| "update bitfield; containing word " |
| "has been optimized out")); |
| if (unavail) |
| throw_error (NOT_AVAILABLE_ERROR, |
| _("Can't do read-modify-write to update " |
| "bitfield; containing word " |
| "is unavailable")); |
| } |
| copy_bitwise (buffer.data (), dest_offset_bits, |
| contents, source_offset_bits, |
| this_size_bits, |
| bits_big_endian); |
| } |
| |
| put_frame_register_bytes (frame, gdb_regnum, reg_offset, |
| this_size, source_buffer); |
| } |
| break; |
| case DWARF_VALUE_MEMORY: |
| if (need_bitwise) |
| { |
| /* Only the first and last bytes can possibly have any |
| bits reused. */ |
| read_memory (p->v.mem.addr + dest_offset, buffer.data (), 1); |
| read_memory (p->v.mem.addr + dest_offset + this_size - 1, |
| &buffer[this_size - 1], 1); |
| copy_bitwise (buffer.data (), dest_offset_bits, |
| contents, source_offset_bits, |
| this_size_bits, |
| bits_big_endian); |
| } |
| |
| write_memory (p->v.mem.addr + dest_offset, |
| source_buffer, this_size); |
| break; |
| default: |
| mark_value_bytes_optimized_out (to, 0, TYPE_LENGTH (value_type (to))); |
| break; |
| } |
| offset += this_size_bits; |
| } |
| } |
| |
| /* An implementation of an lval_funcs method to see whether a value is |
| a synthetic pointer. */ |
| |
| static int |
| check_pieced_synthetic_pointer (const struct value *value, LONGEST bit_offset, |
| int bit_length) |
| { |
| struct piece_closure *c |
| = (struct piece_closure *) value_computed_closure (value); |
| int i; |
| |
| bit_offset += 8 * value_offset (value); |
| if (value_bitsize (value)) |
| bit_offset += value_bitpos (value); |
| |
| for (i = 0; i < c->n_pieces && bit_length > 0; i++) |
| { |
| struct dwarf_expr_piece *p = &c->pieces[i]; |
| size_t this_size_bits = p->size; |
| |
| if (bit_offset > 0) |
| { |
| if (bit_offset >= this_size_bits) |
| { |
| bit_offset -= this_size_bits; |
| continue; |
| } |
| |
| bit_length -= this_size_bits - bit_offset; |
| bit_offset = 0; |
| } |
| else |
| bit_length -= this_size_bits; |
| |
| if (p->location != DWARF_VALUE_IMPLICIT_POINTER) |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| /* A wrapper function for get_frame_address_in_block. */ |
| |
| static CORE_ADDR |
| get_frame_address_in_block_wrapper (void *baton) |
| { |
| return get_frame_address_in_block ((struct frame_info *) baton); |
| } |
| |
| /* Fetch a DW_AT_const_value through a synthetic pointer. */ |
| |
| static struct value * |
| fetch_const_value_from_synthetic_pointer (sect_offset die, LONGEST byte_offset, |
| struct dwarf2_per_cu_data *per_cu, |
| struct type *type) |
| { |
| struct value *result = NULL; |
| struct obstack temp_obstack; |
| struct cleanup *cleanup; |
| const gdb_byte *bytes; |
| LONGEST len; |
| |
| obstack_init (&temp_obstack); |
| cleanup = make_cleanup_obstack_free (&temp_obstack); |
| bytes = dwarf2_fetch_constant_bytes (die, per_cu, &temp_obstack, &len); |
| |
| if (bytes != NULL) |
| { |
| if (byte_offset >= 0 |
| && byte_offset + TYPE_LENGTH (TYPE_TARGET_TYPE (type)) <= len) |
| { |
| bytes += byte_offset; |
| result = value_from_contents (TYPE_TARGET_TYPE (type), bytes); |
| } |
| else |
| invalid_synthetic_pointer (); |
| } |
| else |
| result = allocate_optimized_out_value (TYPE_TARGET_TYPE (type)); |
| |
| do_cleanups (cleanup); |
| |
| return result; |
| } |
| |
| /* Fetch the value pointed to by a synthetic pointer. */ |
| |
| static struct value * |
| indirect_synthetic_pointer (sect_offset die, LONGEST byte_offset, |
| struct dwarf2_per_cu_data *per_cu, |
| struct frame_info *frame, struct type *type) |
| { |
| /* Fetch the location expression of the DIE we're pointing to. */ |
| struct dwarf2_locexpr_baton baton |
| = dwarf2_fetch_die_loc_sect_off (die, per_cu, |
| get_frame_address_in_block_wrapper, frame); |
| |
| /* If pointed-to DIE has a DW_AT_location, evaluate it and return the |
| resulting value. Otherwise, it may have a DW_AT_const_value instead, |
| or it may've been optimized out. */ |
| if (baton.data != NULL) |
| return dwarf2_evaluate_loc_desc_full (TYPE_TARGET_TYPE (type), frame, |
| baton.data, baton.size, baton.per_cu, |
| byte_offset); |
| else |
| return fetch_const_value_from_synthetic_pointer (die, byte_offset, per_cu, |
| type); |
| } |
| |
| /* An implementation of an lval_funcs method to indirect through a |
| pointer. This handles the synthetic pointer case when needed. */ |
| |
| static struct value * |
| indirect_pieced_value (struct value *value) |
| { |
| struct piece_closure *c |
| = (struct piece_closure *) value_computed_closure (value); |
| struct type *type; |
| struct frame_info *frame; |
| struct dwarf2_locexpr_baton baton; |
| int i, bit_length; |
| LONGEST bit_offset; |
| struct dwarf_expr_piece *piece = NULL; |
| LONGEST byte_offset; |
| enum bfd_endian byte_order; |
| |
| type = check_typedef (value_type (value)); |
| if (TYPE_CODE (type) != TYPE_CODE_PTR) |
| return NULL; |
| |
| bit_length = 8 * TYPE_LENGTH (type); |
| bit_offset = 8 * value_offset (value); |
| if (value_bitsize (value)) |
| bit_offset += value_bitpos (value); |
| |
| for (i = 0; i < c->n_pieces && bit_length > 0; i++) |
| { |
| struct dwarf_expr_piece *p = &c->pieces[i]; |
| size_t this_size_bits = p->size; |
| |
| if (bit_offset > 0) |
| { |
| if (bit_offset >= this_size_bits) |
| { |
| bit_offset -= this_size_bits; |
| continue; |
| } |
| |
| bit_length -= this_size_bits - bit_offset; |
| bit_offset = 0; |
| } |
| else |
| bit_length -= this_size_bits; |
| |
| if (p->location != DWARF_VALUE_IMPLICIT_POINTER) |
| return NULL; |
| |
| if (bit_length != 0) |
| error (_("Invalid use of DW_OP_implicit_pointer")); |
| |
| piece = p; |
| break; |
| } |
| |
| gdb_assert (piece != NULL); |
| frame = get_selected_frame (_("No frame selected.")); |
| |
| /* This is an offset requested by GDB, such as value subscripts. |
| However, due to how synthetic pointers are implemented, this is |
| always presented to us as a pointer type. This means we have to |
| sign-extend it manually as appropriate. Use raw |
| extract_signed_integer directly rather than value_as_address and |
| sign extend afterwards on architectures that would need it |
| (mostly everywhere except MIPS, which has signed addresses) as |
| the later would go through gdbarch_pointer_to_address and thus |
| return a CORE_ADDR with high bits set on architectures that |
| encode address spaces and other things in CORE_ADDR. */ |
| byte_order = gdbarch_byte_order (get_frame_arch (frame)); |
| byte_offset = extract_signed_integer (value_contents (value), |
| TYPE_LENGTH (type), byte_order); |
| byte_offset += piece->v.ptr.offset; |
| |
| return indirect_synthetic_pointer (piece->v.ptr.die, byte_offset, c->per_cu, |
| frame, type); |
| } |
| |
| /* Implementation of the coerce_ref method of lval_funcs for synthetic C++ |
| references. */ |
| |
| static struct value * |
| coerce_pieced_ref (const struct value *value) |
| { |
| struct type *type = check_typedef (value_type (value)); |
| |
| if (value_bits_synthetic_pointer (value, value_embedded_offset (value), |
| TARGET_CHAR_BIT * TYPE_LENGTH (type))) |
| { |
| const struct piece_closure *closure |
| = (struct piece_closure *) value_computed_closure (value); |
| struct frame_info *frame |
| = get_selected_frame (_("No frame selected.")); |
| |
| /* gdb represents synthetic pointers as pieced values with a single |
| piece. */ |
| gdb_assert (closure != NULL); |
| gdb_assert (closure->n_pieces == 1); |
| |
| return indirect_synthetic_pointer (closure->pieces->v.ptr.die, |
| closure->pieces->v.ptr.offset, |
| closure->per_cu, frame, type); |
| } |
| else |
| { |
| /* Else: not a synthetic reference; do nothing. */ |
| return NULL; |
| } |
| } |
| |
| static void * |
| copy_pieced_value_closure (const struct value *v) |
| { |
| struct piece_closure *c |
| = (struct piece_closure *) value_computed_closure (v); |
| |
| ++c->refc; |
| return c; |
| } |
| |
| static void |
| free_pieced_value_closure (struct value *v) |
| { |
| struct piece_closure *c |
| = (struct piece_closure *) value_computed_closure (v); |
| |
| --c->refc; |
| if (c->refc == 0) |
| { |
| int i; |
| |
| for (i = 0; i < c->n_pieces; ++i) |
| if (c->pieces[i].location == DWARF_VALUE_STACK) |
| value_free (c->pieces[i].v.value); |
| |
| xfree (c->pieces); |
| xfree (c); |
| } |
| } |
| |
| /* Functions for accessing a variable described by DW_OP_piece. */ |
| static const struct lval_funcs pieced_value_funcs = { |
| read_pieced_value, |
| write_pieced_value, |
| indirect_pieced_value, |
| coerce_pieced_ref, |
| check_pieced_synthetic_pointer, |
| copy_pieced_value_closure, |
| free_pieced_value_closure |
| }; |
| |
| /* Evaluate a location description, starting at DATA and with length |
| SIZE, to find the current location of variable of TYPE in the |
| context of FRAME. BYTE_OFFSET is applied after the contents are |
| computed. */ |
| |
| static struct value * |
| dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame, |
| const gdb_byte *data, size_t size, |
| struct dwarf2_per_cu_data *per_cu, |
| LONGEST byte_offset) |
| { |
| struct value *retval; |
| struct objfile *objfile = dwarf2_per_cu_objfile (per_cu); |
| |
| if (byte_offset < 0) |
| invalid_synthetic_pointer (); |
| |
| if (size == 0) |
| return allocate_optimized_out_value (type); |
| |
| dwarf_evaluate_loc_desc ctx; |
| ctx.frame = frame; |
| ctx.per_cu = per_cu; |
| ctx.obj_address = 0; |
| |
| scoped_value_mark free_values; |
| |
| ctx.gdbarch = get_objfile_arch (objfile); |
| ctx.addr_size = dwarf2_per_cu_addr_size (per_cu); |
| ctx.ref_addr_size = dwarf2_per_cu_ref_addr_size (per_cu); |
| ctx.offset = dwarf2_per_cu_text_offset (per_cu); |
| |
| TRY |
| { |
| ctx.eval (data, size); |
| } |
| CATCH (ex, RETURN_MASK_ERROR) |
| { |
| if (ex.error == NOT_AVAILABLE_ERROR) |
| { |
| free_values.free_to_mark (); |
| retval = allocate_value (type); |
| mark_value_bytes_unavailable (retval, 0, TYPE_LENGTH (type)); |
| return retval; |
| } |
| else if (ex.error == NO_ENTRY_VALUE_ERROR) |
| { |
| if (entry_values_debug) |
| exception_print (gdb_stdout, ex); |
| free_values.free_to_mark (); |
| return allocate_optimized_out_value (type); |
| } |
| else |
| throw_exception (ex); |
| } |
| END_CATCH |
| |
| if (ctx.num_pieces > 0) |
| { |
| struct piece_closure *c; |
| ULONGEST bit_size = 0; |
| int i; |
| |
| for (i = 0; i < ctx.num_pieces; ++i) |
| bit_size += ctx.pieces[i].size; |
| if (8 * (byte_offset + TYPE_LENGTH (type)) > bit_size) |
| invalid_synthetic_pointer (); |
| |
| c = allocate_piece_closure (per_cu, ctx.num_pieces, ctx.pieces, |
| ctx.addr_size, frame); |
| /* We must clean up the value chain after creating the piece |
| closure but before allocating the result. */ |
| free_values.free_to_mark (); |
| retval = allocate_computed_value (type, &pieced_value_funcs, c); |
| set_value_offset (retval, byte_offset); |
| } |
| else |
| { |
| switch (ctx.location) |
| { |
| case DWARF_VALUE_REGISTER: |
| { |
| struct gdbarch *arch = get_frame_arch (frame); |
| int dwarf_regnum |
| = longest_to_int (value_as_long (ctx.fetch (0))); |
| int gdb_regnum = dwarf_reg_to_regnum_or_error (arch, dwarf_regnum); |
| |
| if (byte_offset != 0) |
| error (_("cannot use offset on synthetic pointer to register")); |
| free_values.free_to_mark (); |
| retval = value_from_register (type, gdb_regnum, frame); |
| if (value_optimized_out (retval)) |
| { |
| struct value *tmp; |
| |
| /* This means the register has undefined value / was |
| not saved. As we're computing the location of some |
| variable etc. in the program, not a value for |
| inspecting a register ($pc, $sp, etc.), return a |
| generic optimized out value instead, so that we show |
| <optimized out> instead of <not saved>. */ |
| tmp = allocate_value (type); |
| value_contents_copy (tmp, 0, retval, 0, TYPE_LENGTH (type)); |
| retval = tmp; |
| } |
| } |
| break; |
| |
| case DWARF_VALUE_MEMORY: |
| { |
| struct type *ptr_type; |
| CORE_ADDR address = ctx.fetch_address (0); |
| int in_stack_memory = ctx.fetch_in_stack_memory (0); |
| |
| /* DW_OP_deref_size (and possibly other operations too) may |
| create a pointer instead of an address. Ideally, the |
| pointer to address conversion would be performed as part |
| of those operations, but the type of the object to |
| which the address refers is not known at the time of |
| the operation. Therefore, we do the conversion here |
| since the type is readily available. */ |
| |
| switch (TYPE_CODE (type)) |
| { |
| case TYPE_CODE_FUNC: |
| case TYPE_CODE_METHOD: |
| ptr_type = builtin_type (ctx.gdbarch)->builtin_func_ptr; |
| break; |
| default: |
| ptr_type = builtin_type (ctx.gdbarch)->builtin_data_ptr; |
| break; |
| } |
| address = value_as_address (value_from_pointer (ptr_type, address)); |
| |
| free_values.free_to_mark (); |
| retval = value_at_lazy (type, address + byte_offset); |
| if (in_stack_memory) |
| set_value_stack (retval, 1); |
| } |
| break; |
| |
| case DWARF_VALUE_STACK: |
| { |
| struct value *value = ctx.fetch (0); |
| gdb_byte *contents; |
| const gdb_byte *val_bytes; |
| size_t n = TYPE_LENGTH (value_type (value)); |
| struct cleanup *cleanup; |
| |
| if (byte_offset + TYPE_LENGTH (type) > n) |
| invalid_synthetic_pointer (); |
| |
| val_bytes = value_contents_all (value); |
| val_bytes += byte_offset; |
| n -= byte_offset; |
| |
| /* Preserve VALUE because we are going to free values back |
| to the mark, but we still need the value contents |
| below. */ |
| value_incref (value); |
| free_values.free_to_mark (); |
| cleanup = make_cleanup_value_free (value); |
| |
| retval = allocate_value (type); |
| contents = value_contents_raw (retval); |
| if (n > TYPE_LENGTH (type)) |
| { |
| struct gdbarch *objfile_gdbarch = get_objfile_arch (objfile); |
| |
| if (gdbarch_byte_order (objfile_gdbarch) == BFD_ENDIAN_BIG) |
| val_bytes += n - TYPE_LENGTH (type); |
| n = TYPE_LENGTH (type); |
| } |
| memcpy (contents, val_bytes, n); |
| |
| do_cleanups (cleanup); |
| } |
| break; |
| |
| case DWARF_VALUE_LITERAL: |
| { |
| bfd_byte *contents; |
| size_t n = TYPE_LENGTH (type); |
| |
| if (byte_offset + n > ctx.len) |
| invalid_synthetic_pointer (); |
| |
| free_values.free_to_mark (); |
| retval = allocate_value (type); |
| contents = value_contents_raw (retval); |
| memcpy (contents, ctx.data + byte_offset, n); |
| } |
| break; |
| |
| case DWARF_VALUE_OPTIMIZED_OUT: |
| free_values.free_to_mark (); |
| retval = allocate_optimized_out_value (type); |
| break; |
| |
| /* DWARF_VALUE_IMPLICIT_POINTER was converted to a pieced |
| operation by execute_stack_op. */ |
| case DWARF_VALUE_IMPLICIT_POINTER: |
| /* DWARF_VALUE_OPTIMIZED_OUT can't occur in this context -- |
| it can only be encountered when making a piece. */ |
| default: |
| internal_error (__FILE__, __LINE__, _("invalid location type")); |
| } |
| } |
| |
| set_value_initialized (retval, ctx.initialized); |
| |
| return retval; |
| } |
| |
| /* The exported interface to dwarf2_evaluate_loc_desc_full; it always |
| passes 0 as the byte_offset. */ |
| |
| struct value * |
| dwarf2_evaluate_loc_desc (struct type *type, struct frame_info *frame, |
| const gdb_byte *data, size_t size, |
| struct dwarf2_per_cu_data *per_cu) |
| { |
| return dwarf2_evaluate_loc_desc_full (type, frame, data, size, per_cu, 0); |
| } |
| |
| /* Evaluates a dwarf expression and stores the result in VAL, expecting |
| that the dwarf expression only produces a single CORE_ADDR. FRAME is the |
| frame in which the expression is evaluated. ADDR is a context (location of |
| a variable) and might be needed to evaluate the location expression. |
| Returns 1 on success, 0 otherwise. */ |
| |
| static int |
| dwarf2_locexpr_baton_eval (const struct dwarf2_locexpr_baton *dlbaton, |
| struct frame_info *frame, |
| CORE_ADDR addr, |
| CORE_ADDR *valp) |
| { |
| struct objfile *objfile; |
| |
| if (dlbaton == NULL || dlbaton->size == 0) |
| return 0; |
| |
| dwarf_evaluate_loc_desc ctx; |
| |
| ctx.frame = frame; |
| ctx.per_cu = dlbaton->per_cu; |
| ctx.obj_address = addr; |
| |
| objfile = dwarf2_per_cu_objfile (dlbaton->per_cu); |
| |
| ctx.gdbarch = get_objfile_arch (objfile); |
| ctx.addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu); |
| ctx.ref_addr_size = dwarf2_per_cu_ref_addr_size (dlbaton->per_cu); |
| ctx.offset = dwarf2_per_cu_text_offset (dlbaton->per_cu); |
| |
| ctx.eval (dlbaton->data, dlbaton->size); |
| |
| switch (ctx.location) |
| { |
| case DWARF_VALUE_REGISTER: |
| case DWARF_VALUE_MEMORY: |
| case DWARF_VALUE_STACK: |
| *valp = ctx.fetch_address (0); |
| if (ctx.location == DWARF_VALUE_REGISTER) |
| *valp = ctx.read_addr_from_reg (*valp); |
| return 1; |
| case DWARF_VALUE_LITERAL: |
| *valp = extract_signed_integer (ctx.data, ctx.len, |
| gdbarch_byte_order (ctx.gdbarch)); |
| return 1; |
| /* Unsupported dwarf values. */ |
| case DWARF_VALUE_OPTIMIZED_OUT: |
| case DWARF_VALUE_IMPLICIT_POINTER: |
| break; |
| } |
| |
| return 0; |
| } |
| |
| /* See dwarf2loc.h. */ |
| |
| int |
| dwarf2_evaluate_property (const struct dynamic_prop *prop, |
| struct frame_info *frame, |
| struct property_addr_info *addr_stack, |
| CORE_ADDR *value) |
| { |
| if (prop == NULL) |
| return 0; |
| |
| if (frame == NULL && has_stack_frames ()) |
| frame = get_selected_frame (NULL); |
| |
| switch (prop->kind) |
| { |
| case PROP_LOCEXPR: |
| { |
| const struct dwarf2_property_baton *baton |
| = (const struct dwarf2_property_baton *) prop->data.baton; |
| |
| if (dwarf2_locexpr_baton_eval (&baton->locexpr, frame, |
| addr_stack ? addr_stack->addr : 0, |
| value)) |
| { |
| if (baton->referenced_type) |
| { |
| struct value *val = value_at (baton->referenced_type, *value); |
| |
| *value = value_as_address (val); |
| } |
| return 1; |
| } |
| } |
| break; |
| |
| case PROP_LOCLIST: |
| { |
| struct dwarf2_property_baton *baton |
| = (struct dwarf2_property_baton *) prop->data.baton; |
| CORE_ADDR pc = get_frame_address_in_block (frame); |
| const gdb_byte *data; |
| struct value *val; |
| size_t size; |
| |
| data = dwarf2_find_location_expression (&baton->loclist, &size, pc); |
| if (data != NULL) |
| { |
| val = dwarf2_evaluate_loc_desc (baton->referenced_type, frame, data, |
| size, baton->loclist.per_cu); |
| if (!value_optimized_out (val)) |
| { |
| *value = value_as_address (val); |
| return 1; |
| } |
| } |
| } |
| break; |
| |
| case PROP_CONST: |
| *value = prop->data.const_val; |
| return 1; |
| |
| case PROP_ADDR_OFFSET: |
| { |
| struct dwarf2_property_baton *baton |
| = (struct dwarf2_property_baton *) prop->data.baton; |
| struct property_addr_info *pinfo; |
| struct value *val; |
| |
| for (pinfo = addr_stack; pinfo != NULL; pinfo = pinfo->next) |
| if (pinfo->type == baton->referenced_type) |
| break; |
| if (pinfo == NULL) |
| error (_("cannot find reference address for offset property")); |
| if (pinfo->valaddr != NULL) |
| val = value_from_contents |
| (baton->offset_info.type, |
| pinfo->valaddr + baton->offset_info.offset); |
| else |
| val = value_at (baton->offset_info.type, |
| pinfo->addr + baton->offset_info.offset); |
| *value = value_as_address (val); |
| return 1; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /* See dwarf2loc.h. */ |
| |
| void |
| dwarf2_compile_property_to_c (string_file &stream, |
| const char *result_name, |
| struct gdbarch *gdbarch, |
| unsigned char *registers_used, |
| const struct dynamic_prop *prop, |
| CORE_ADDR pc, |
| struct symbol *sym) |
| { |
| struct dwarf2_property_baton *baton |
| = (struct dwarf2_property_baton *) prop->data.baton; |
| const gdb_byte *data; |
| size_t size; |
| struct dwarf2_per_cu_data *per_cu; |
| |
| if (prop->kind == PROP_LOCEXPR) |
| { |
| data = baton->locexpr.data; |
| size = baton->locexpr.size; |
| per_cu = baton->locexpr.per_cu; |
| } |
| else |
| { |
| gdb_assert (prop->kind == PROP_LOCLIST); |
| |
| data = dwarf2_find_location_expression (&baton->loclist, &size, pc); |
| per_cu = baton->loclist.per_cu; |
| } |
| |
| compile_dwarf_bounds_to_c (stream, result_name, prop, sym, pc, |
| gdbarch, registers_used, |
| dwarf2_per_cu_addr_size (per_cu), |
| data, data + size, per_cu); |
| } |
| |
| |
| /* Helper functions and baton for dwarf2_loc_desc_get_symbol_read_needs. */ |
| |
| class symbol_needs_eval_context : public dwarf_expr_context |
| { |
| public: |
| |
| enum symbol_needs_kind needs; |
| struct dwarf2_per_cu_data *per_cu; |
| |
| /* Reads from registers do require a frame. */ |
| CORE_ADDR read_addr_from_reg (int regnum) OVERRIDE |
| { |
| needs = SYMBOL_NEEDS_FRAME; |
| return 1; |
| } |
| |
| /* "get_reg_value" callback: Reads from registers do require a |
| frame. */ |
| |
| struct value *get_reg_value (struct type *type, int regnum) OVERRIDE |
| { |
| needs = SYMBOL_NEEDS_FRAME; |
| return value_zero (type, not_lval); |
| } |
| |
| /* Reads from memory do not require a frame. */ |
| void read_mem (gdb_byte *buf, CORE_ADDR addr, size_t len) OVERRIDE |
| { |
| memset (buf, 0, len); |
| } |
| |
| /* Frame-relative accesses do require a frame. */ |
| void get_frame_base (const gdb_byte **start, size_t *length) OVERRIDE |
| { |
| static gdb_byte lit0 = DW_OP_lit0; |
| |
| *start = &lit0; |
| *length = 1; |
| |
| needs = SYMBOL_NEEDS_FRAME; |
| } |
| |
| /* CFA accesses require a frame. */ |
| CORE_ADDR get_frame_cfa () OVERRIDE |
| { |
| needs = SYMBOL_NEEDS_FRAME; |
| return 1; |
| } |
| |
| CORE_ADDR get_frame_pc () OVERRIDE |
| { |
| needs = SYMBOL_NEEDS_FRAME; |
| return 1; |
| } |
| |
| /* Thread-local accesses require registers, but not a frame. */ |
| CORE_ADDR get_tls_address (CORE_ADDR offset) OVERRIDE |
| { |
| if (needs <= SYMBOL_NEEDS_REGISTERS) |
| needs = SYMBOL_NEEDS_REGISTERS; |
| return 1; |
| } |
| |
| /* Helper interface of per_cu_dwarf_call for |
| dwarf2_loc_desc_get_symbol_read_needs. */ |
| |
| void dwarf_call (cu_offset die_offset) OVERRIDE |
| { |
| per_cu_dwarf_call (this, die_offset, per_cu); |
| } |
| |
| /* DW_OP_entry_value accesses require a caller, therefore a |
| frame. */ |
| |
| void push_dwarf_reg_entry_value (enum call_site_parameter_kind kind, |
| union call_site_parameter_u kind_u, |
| int deref_size) OVERRIDE |
| { |
| needs = SYMBOL_NEEDS_FRAME; |
| |
| /* The expression may require some stub values on DWARF stack. */ |
| push_address (0, 0); |
| } |
| |
| /* DW_OP_GNU_addr_index doesn't require a frame. */ |
| |
| CORE_ADDR get_addr_index (unsigned int index) OVERRIDE |
| { |
| /* Nothing to do. */ |
| return 1; |
| } |
| |
| /* DW_OP_push_object_address has a frame already passed through. */ |
| |
| CORE_ADDR get_object_address () OVERRIDE |
| { |
| /* Nothing to do. */ |
| return 1; |
| } |
| }; |
| |
| /* Compute the correct symbol_needs_kind value for the location |
| expression at DATA (length SIZE). */ |
| |
| static enum symbol_needs_kind |
| dwarf2_loc_desc_get_symbol_read_needs (const gdb_byte *data, size_t size, |
| struct dwarf2_per_cu_data *per_cu) |
| { |
| int in_reg; |
| struct objfile *objfile = dwarf2_per_cu_objfile (per_cu); |
| |
| scoped_value_mark free_values; |
| |
| symbol_needs_eval_context ctx; |
| |
| ctx.needs = SYMBOL_NEEDS_NONE; |
| ctx.per_cu = per_cu; |
| ctx.gdbarch = get_objfile_arch (objfile); |
| ctx.addr_size = dwarf2_per_cu_addr_size (per_cu); |
| ctx.ref_addr_size = dwarf2_per_cu_ref_addr_size (per_cu); |
| ctx.offset = dwarf2_per_cu_text_offset (per_cu); |
| |
| ctx.eval (data, size); |
| |
| in_reg = ctx.location == DWARF_VALUE_REGISTER; |
| |
| if (ctx.num_pieces > 0) |
| { |
| int i; |
| |
| /* If the location has several pieces, and any of them are in |
| registers, then we will need a frame to fetch them from. */ |
| for (i = 0; i < ctx.num_pieces; i++) |
| if (ctx.pieces[i].location == DWARF_VALUE_REGISTER) |
| in_reg = 1; |
| } |
| |
| if (in_reg) |
| ctx.needs = SYMBOL_NEEDS_FRAME; |
| return ctx.needs; |
| } |
| |
| /* A helper function that throws an unimplemented error mentioning a |
| given DWARF operator. */ |
| |
| static void |
| unimplemented (unsigned int op) |
| { |
| const char *name = get_DW_OP_name (op); |
| |
| if (name) |
| error (_("DWARF operator %s cannot be translated to an agent expression"), |
| name); |
| else |
| error (_("Unknown DWARF operator 0x%02x cannot be translated " |
| "to an agent expression"), |
| op); |
| } |
| |
| /* See dwarf2loc.h. |
| |
| This is basically a wrapper on gdbarch_dwarf2_reg_to_regnum so that we |
| can issue a complaint, which is better than having every target's |
| implementation of dwarf2_reg_to_regnum do it. */ |
| |
| int |
| dwarf_reg_to_regnum (struct gdbarch *arch, int dwarf_reg) |
| { |
| int reg = gdbarch_dwarf2_reg_to_regnum (arch, dwarf_reg); |
| |
| if (reg == -1) |
| { |
| complaint (&symfile_complaints, |
| _("bad DWARF register number %d"), dwarf_reg); |
| } |
| return reg; |
| } |
| |
| /* Subroutine of dwarf_reg_to_regnum_or_error to simplify it. |
| Throw an error because DWARF_REG is bad. */ |
| |
| static void |
| throw_bad_regnum_error (ULONGEST dwarf_reg) |
| { |
| /* Still want to print -1 as "-1". |
| We *could* have int and ULONGEST versions of dwarf2_reg_to_regnum_or_error |
| but that's overkill for now. */ |
| if ((int) dwarf_reg == dwarf_reg) |
| error (_("Unable to access DWARF register number %d"), (int) dwarf_reg); |
| error (_("Unable to access DWARF register number %s"), |
| pulongest (dwarf_reg)); |
| } |
| |
| /* See dwarf2loc.h. */ |
| |
| int |
| dwarf_reg_to_regnum_or_error (struct gdbarch *arch, ULONGEST dwarf_reg) |
| { |
| int reg; |
| |
| if (dwarf_reg > INT_MAX) |
| throw_bad_regnum_error (dwarf_reg); |
| /* Yes, we will end up issuing a complaint and an error if DWARF_REG is |
| bad, but that's ok. */ |
| reg = dwarf_reg_to_regnum (arch, (int) dwarf_reg); |
| if (reg == -1) |
| throw_bad_regnum_error (dwarf_reg); |
| return reg; |
| } |
| |
| /* A helper function that emits an access to memory. ARCH is the |
| target architecture. EXPR is the expression which we are building. |
| NBITS is the number of bits we want to read. This emits the |
| opcodes needed to read the memory and then extract the desired |
| bits. */ |
| |
| static void |
| access_memory (struct gdbarch *arch, struct agent_expr *expr, ULONGEST nbits) |
| { |
| ULONGEST nbytes = (nbits + 7) / 8; |
| |
| gdb_assert (nbytes > 0 && nbytes <= sizeof (LONGEST)); |
| |
| if (expr->tracing) |
| ax_trace_quick (expr, nbytes); |
| |
| if (nbits <= 8) |
| ax_simple (expr, aop_ref8); |
| else if (nbits <= 16) |
| ax_simple (expr, aop_ref16); |
| else if (nbits <= 32) |
| ax_simple (expr, aop_ref32); |
| else |
| ax_simple (expr, aop_ref64); |
| |
| /* If we read exactly the number of bytes we wanted, we're done. */ |
| if (8 * nbytes == nbits) |
| return; |
| |
| if (gdbarch_bits_big_endian (arch)) |
| { |
| /* On a bits-big-endian machine, we want the high-order |
| NBITS. */ |
| ax_const_l (expr, 8 * nbytes - nbits); |
| ax_simple (expr, aop_rsh_unsigned); |
| } |
| else |
| { |
| /* On a bits-little-endian box, we want the low-order NBITS. */ |
| ax_zero_ext (expr, nbits); |
| } |
| } |
| |
| /* A helper function to return the frame's PC. */ |
| |
| static CORE_ADDR |
| get_ax_pc (void *baton) |
| { |
| struct agent_expr *expr = (struct agent_expr *) baton; |
| |
| return expr->scope; |
| } |
| |
| /* Compile a DWARF location expression to an agent expression. |
| |
| EXPR is the agent expression we are building. |
| LOC is the agent value we modify. |
| ARCH is the architecture. |
| ADDR_SIZE is the size of addresses, in bytes. |
| OP_PTR is the start of the location expression. |
| OP_END is one past the last byte of the location expression. |
| |
| This will throw an exception for various kinds of errors -- for |
| example, if the expression cannot be compiled, or if the expression |
| is invalid. */ |
| |
| void |
| dwarf2_compile_expr_to_ax (struct agent_expr *expr, struct axs_value *loc, |
| struct gdbarch *arch, unsigned int addr_size, |
| const gdb_byte *op_ptr, const gdb_byte *op_end, |
| struct dwarf2_per_cu_data *per_cu) |
| { |
| int i; |
| std::vector<int> dw_labels, patches; |
| const gdb_byte * const base = op_ptr; |
| const gdb_byte *previous_piece = op_ptr; |
| enum bfd_endian byte_order = gdbarch_byte_order (arch); |
| ULONGEST bits_collected = 0; |
| unsigned int addr_size_bits = 8 * addr_size; |
| int bits_big_endian = gdbarch_bits_big_endian (arch); |
| |
| std::vector<int> offsets (op_end - op_ptr, -1); |
| |
| /* By default we are making an address. */ |
| loc->kind = axs_lvalue_memory; |
| |
| while (op_ptr < op_end) |
| { |
| enum dwarf_location_atom op = (enum dwarf_location_atom) *op_ptr; |
| uint64_t uoffset, reg; |
| int64_t offset; |
| int i; |
| |
| offsets[op_ptr - base] = expr->len; |
| ++op_ptr; |
| |
| /* Our basic approach to code generation is to map DWARF |
| operations directly to AX operations. However, there are |
| some differences. |
| |
| First, DWARF works on address-sized units, but AX always uses |
| LONGEST. For most operations we simply ignore this |
| difference; instead we generate sign extensions as needed |
| before division and comparison operations. It would be nice |
| to omit the sign extensions, but there is no way to determine |
| the size of the target's LONGEST. (This code uses the size |
| of the host LONGEST in some cases -- that is a bug but it is |
| difficult to fix.) |
| |
| Second, some DWARF operations cannot be translated to AX. |
| For these we simply fail. See |
| http://sourceware.org/bugzilla/show_bug.cgi?id=11662. */ |
| switch (op) |
| { |
| case DW_OP_lit0: |
| case DW_OP_lit1: |
| case DW_OP_lit2: |
| case DW_OP_lit3: |
| case DW_OP_lit4: |
| case DW_OP_lit5: |
| case DW_OP_lit6: |
| case DW_OP_lit7: |
| case DW_OP_lit8: |
| case DW_OP_lit9: |
| case DW_OP_lit10: |
| case DW_OP_lit11: |
| case DW_OP_lit12: |
| case DW_OP_lit13: |
| case DW_OP_lit14: |
| case DW_OP_lit15: |
| case DW_OP_lit16: |
| case DW_OP_lit17: |
| case DW_OP_lit18: |
| case DW_OP_lit19: |
| case DW_OP_lit20: |
| case DW_OP_lit21: |
| case DW_OP_lit22: |
| case DW_OP_lit23: |
| case DW_OP_lit24: |
| case DW_OP_lit25: |
| case DW_OP_lit26: |
| case DW_OP_lit27: |
| case DW_OP_lit28: |
| case DW_OP_lit29: |
| case DW_OP_lit30: |
| case DW_OP_lit31: |
| ax_const_l (expr, op - DW_OP_lit0); |
| break; |
| |
| case DW_OP_addr: |
| uoffset = extract_unsigned_integer (op_ptr, addr_size, byte_order); |
| op_ptr += addr_size; |
| /* Some versions of GCC emit DW_OP_addr before |
| DW_OP_GNU_push_tls_address. In this case the value is an |
| index, not an address. We don't support things like |
| branching between the address and the TLS op. */ |
| if (op_ptr >= op_end || *op_ptr != DW_OP_GNU_push_tls_address) |
| uoffset += dwarf2_per_cu_text_offset (per_cu); |
| ax_const_l (expr, uoffset); |
| break; |
| |
| case DW_OP_const1u: |
| ax_const_l (expr, extract_unsigned_integer (op_ptr, 1, byte_order)); |
| op_ptr += 1; |
| break; |
| case DW_OP_const1s: |
| ax_const_l (expr, extract_signed_integer (op_ptr, 1, byte_order)); |
| op_ptr += 1; |
| break; |
| case DW_OP_const2u: |
| ax_const_l (expr, extract_unsigned_integer (op_ptr, 2, byte_order)); |
| op_ptr += 2; |
| break; |
| case DW_OP_const2s: |
| ax_const_l (expr, extract_signed_integer (op_ptr, 2, byte_order)); |
| op_ptr += 2; |
| break; |
| case DW_OP_const4u: |
| ax_const_l (expr, extract_unsigned_integer (op_ptr, 4, byte_order)); |
| op_ptr += 4; |
| break; |
| case DW_OP_const4s: |
| ax_const_l (expr, extract_signed_integer (op_ptr, 4, byte_order)); |
| op_ptr += 4; |
| break; |
| case DW_OP_const8u: |
| ax_const_l (expr, extract_unsigned_integer (op_ptr, 8, byte_order)); |
| op_ptr += 8; |
| break; |
| case DW_OP_const8s: |
| ax_const_l (expr, extract_signed_integer (op_ptr, 8, byte_order)); |
| op_ptr += 8; |
| break; |
| case DW_OP_constu: |
| op_ptr = safe_read_uleb128 (op_ptr, op_end, &uoffset); |
| ax_const_l (expr, uoffset); |
| break; |
| case DW_OP_consts: |
| op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset); |
| ax_const_l (expr, offset); |
| break; |
| |
| case DW_OP_reg0: |
| case DW_OP_reg1: |
| case DW_OP_reg2: |
| case DW_OP_reg3: |
| case DW_OP_reg4: |
| case DW_OP_reg5: |
| case DW_OP_reg6: |
| case DW_OP_reg7: |
| case DW_OP_reg8: |
| case DW_OP_reg9: |
| case DW_OP_reg10: |
| case DW_OP_reg11: |
| case DW_OP_reg12: |
| case DW_OP_reg13: |
| case DW_OP_reg14: |
| case DW_OP_reg15: |
| case DW_OP_reg16: |
| case DW_OP_reg17: |
| case DW_OP_reg18: |
| case DW_OP_reg19: |
| case DW_OP_reg20: |
| case DW_OP_reg21: |
| case DW_OP_reg22: |
| case DW_OP_reg23: |
| case DW_OP_reg24: |
| case DW_OP_reg25: |
| case DW_OP_reg26: |
| case DW_OP_reg27: |
| case DW_OP_reg28: |
| case DW_OP_reg29: |
| case DW_OP_reg30: |
| case DW_OP_reg31: |
| dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_regx"); |
| loc->u.reg = dwarf_reg_to_regnum_or_error (arch, op - DW_OP_reg0); |
| loc->kind = axs_lvalue_register; |
| break; |
| |
| case DW_OP_regx: |
| op_ptr = safe_read_uleb128 (op_ptr, op_end, ®); |
| dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_regx"); |
| loc->u.reg = dwarf_reg_to_regnum_or_error (arch, reg); |
| loc->kind = axs_lvalue_register; |
| break; |
| |
| case DW_OP_implicit_value: |
| { |
| uint64_t len; |
| |
| op_ptr = safe_read_uleb128 (op_ptr, op_end, &len); |
| if (op_ptr + len > op_end) |
| error (_("DW_OP_implicit_value: too few bytes available.")); |
| if (len > sizeof (ULONGEST)) |
| error (_("Cannot translate DW_OP_implicit_value of %d bytes"), |
| (int) len); |
| |
| ax_const_l (expr, extract_unsigned_integer (op_ptr, len, |
| byte_order)); |
| op_ptr += len; |
| dwarf_expr_require_composition (op_ptr, op_end, |
| "DW_OP_implicit_value"); |
| |
| loc->kind = axs_rvalue; |
| } |
| break; |
| |
| case DW_OP_stack_value: |
| dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_stack_value"); |
| loc->kind = axs_rvalue; |
| break; |
| |
| case DW_OP_breg0: |
| case DW_OP_breg1: |
| case DW_OP_breg2: |
| case DW_OP_breg3: |
| case DW_OP_breg4: |
| case DW_OP_breg5: |
| case DW_OP_breg6: |
| case DW_OP_breg7: |
| case DW_OP_breg8: |
| case DW_OP_breg9: |
| case DW_OP_breg10: |
| case DW_OP_breg11: |
| case DW_OP_breg12: |
| case DW_OP_breg13: |
| case DW_OP_breg14: |
| case DW_OP_breg15: |
| case DW_OP_breg16: |
| case DW_OP_breg17: |
| case DW_OP_breg18: |
| case DW_OP_breg19: |
| case DW_OP_breg20: |
| case DW_OP_breg21: |
| case DW_OP_breg22: |
| case DW_OP_breg23: |
| case DW_OP_breg24: |
| case DW_OP_breg25: |
| case DW_OP_breg26: |
| case DW_OP_breg27: |
| case DW_OP_breg28: |
| case DW_OP_breg29: |
| case DW_OP_breg30: |
| case DW_OP_breg31: |
| op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset); |
| i = dwarf_reg_to_regnum_or_error (arch, op - DW_OP_breg0); |
| ax_reg (expr, i); |
| if (offset != 0) |
| { |
| ax_const_l (expr, offset); |
| ax_simple (expr, aop_add); |
| } |
| break; |
| case DW_OP_bregx: |
| { |
| op_ptr = safe_read_uleb128 (op_ptr, op_end, ®); |
| op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset); |
| i = dwarf_reg_to_regnum_or_error (arch, reg); |
| ax_reg (expr, i); |
| if (offset != 0) |
| { |
| ax_const_l (expr, offset); |
| ax_simple (expr, aop_add); |
| } |
| } |
| break; |
| case DW_OP_fbreg: |
| { |
| const gdb_byte *datastart; |
| size_t datalen; |
| const struct block *b; |
| struct symbol *framefunc; |
| |
| b = block_for_pc (expr->scope); |
| |
| if (!b) |
| error (_("No block found for address")); |
| |
| framefunc = block_linkage_function (b); |
| |
| if (!framefunc) |
| error (_("No function found for block")); |
| |
| func_get_frame_base_dwarf_block (framefunc, expr->scope, |
| &datastart, &datalen); |
| |
| op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset); |
| dwarf2_compile_expr_to_ax (expr, loc, arch, addr_size, datastart, |
| datastart + datalen, per_cu); |
| if (loc->kind == axs_lvalue_register) |
| require_rvalue (expr, loc); |
| |
| if (offset != 0) |
| { |
| ax_const_l (expr, offset); |
| ax_simple (expr, aop_add); |
| } |
| |
| loc->kind = axs_lvalue_memory; |
| } |
| break; |
| |
| case DW_OP_dup: |
| ax_simple (expr, aop_dup); |
| break; |
| |
| case DW_OP_drop: |
| ax_simple (expr, aop_pop); |
| break; |
| |
| case DW_OP_pick: |
| offset = *op_ptr++; |
| ax_pick (expr, offset); |
| break; |
| |
| case DW_OP_swap: |
| ax_simple (expr, aop_swap); |
| break; |
| |
| case DW_OP_over: |
| ax_pick (expr, 1); |
| break; |
| |
| case DW_OP_rot: |
| ax_simple (expr, aop_rot); |
| break; |
| |
| case DW_OP_deref: |
| case DW_OP_deref_size: |
| { |
| int size; |
| |
| if (op == DW_OP_deref_size) |
| size = *op_ptr++; |
| else |
| size = addr_size; |
| |
| if (size != 1 && size != 2 && size != 4 && size != 8) |
| error (_("Unsupported size %d in %s"), |
| size, get_DW_OP_name (op)); |
| access_memory (arch, expr, size * TARGET_CHAR_BIT); |
| } |
| break; |
| |
| case DW_OP_abs: |
| /* Sign extend the operand. */ |
| ax_ext (expr, addr_size_bits); |
| ax_simple (expr, aop_dup); |
| ax_const_l (expr, 0); |
| ax_simple (expr, aop_less_signed); |
| ax_simple (expr, aop_log_not); |
| i = ax_goto (expr, aop_if_goto); |
| /* We have to emit 0 - X. */ |
| ax_const_l (expr, 0); |
| ax_simple (expr, aop_swap); |
| ax_simple (expr, aop_sub); |
| ax_label (expr, i, expr->len); |
| break; |
| |
| case DW_OP_neg: |
| /* No need to sign extend here. */ |
| ax_const_l (expr, 0); |
| ax_simple (expr, aop_swap); |
| ax_simple (expr, aop_sub); |
| break; |
| |
| case DW_OP_not: |
| /* Sign extend the operand. */ |
| ax_ext (expr, addr_size_bits); |
| ax_simple (expr, aop_bit_not); |
| break; |
| |
| case DW_OP_plus_uconst: |
| op_ptr = safe_read_uleb128 (op_ptr, op_end, ®); |
| /* It would be really weird to emit `DW_OP_plus_uconst 0', |
| but we micro-optimize anyhow. */ |
| if (reg != 0) |
| { |
| ax_const_l (expr, reg); |
| ax_simple (expr, aop_add); |
| } |
| break; |
| |
| case DW_OP_and: |
| ax_simple (expr, aop_bit_and); |
| break; |
| |
| case DW_OP_div: |
| /* Sign extend the operands. */ |
| ax_ext (expr, addr_size_bits); |
| ax_simple (expr, aop_swap); |
| ax_ext (expr, addr_size_bits); |
| ax_simple (expr, aop_swap); |
| ax_simple (expr, aop_div_signed); |
| break; |
| |
| case DW_OP_minus: |
| ax_simple (expr, aop_sub); |
| break; |
| |
| case DW_OP_mod: |
| ax_simple (expr, aop_rem_unsigned); |
| break; |
| |
| case DW_OP_mul: |
| ax_simple (expr, aop_mul); |
| break; |
| |
| case DW_OP_or: |
| ax_simple (expr, aop_bit_or); |
| break; |
| |
| case DW_OP_plus: |
| ax_simple (expr, aop_add); |
| break; |
| |
| case DW_OP_shl: |
| ax_simple (expr, aop_lsh); |
| break; |
| |
| case DW_OP_shr: |
| ax_simple (expr, aop_rsh_unsigned); |
| break; |
| |
| case DW_OP_shra: |
| ax_simple (expr, aop_rsh_signed); |
| break; |
| |
| case DW_OP_xor: |
| ax_simple (expr, aop_bit_xor); |
| break; |
| |
| case DW_OP_le: |
| /* Sign extend the operands. */ |
| ax_ext (expr, addr_size_bits); |
| ax_simple (expr, aop_swap); |
| ax_ext (expr, addr_size_bits); |
| /* Note no swap here: A <= B is !(B < A). */ |
| ax_simple (expr, aop_less_signed); |
| ax_simple (expr, aop_log_not); |
| break; |
| |
| case DW_OP_ge: |
| /* Sign extend the operands. */ |
| ax_ext (expr, addr_size_bits); |
| ax_simple (expr, aop_swap); |
| ax_ext (expr, addr_size_bits); |
| ax_simple (expr, aop_swap); |
| /* A >= B is !(A < B). */ |
| ax_simple (expr, aop_less_signed); |
| ax_simple (expr, aop_log_not); |
| break; |
| |
| case DW_OP_eq: |
| /* Sign extend the operands. */ |
| ax_ext (expr, addr_size_bits); |
| ax_simple (expr, aop_swap); |
| ax_ext (expr, addr_size_bits); |
| /* No need for a second swap here. */ |
| ax_simple (expr, aop_equal); |
| break; |
| |
| case DW_OP_lt: |
| /* Sign extend the operands. */ |
| ax_ext (expr, addr_size_bits); |
| ax_simple (expr, aop_swap); |
| ax_ext (expr, addr_size_bits); |
| ax_simple (expr, aop_swap); |
| ax_simple (expr, aop_less_signed); |
| break; |
| |
| case DW_OP_gt: |
| /* Sign extend the operands. */ |
| ax_ext (expr, addr_size_bits); |
| ax_simple (expr, aop_swap); |
| ax_ext (expr, addr_size_bits); |
| /* Note no swap here: A > B is B < A. */ |
| ax_simple (expr, aop_less_signed); |
| break; |
| |
| case DW_OP_ne: |
| /* Sign extend the operands. */ |
| ax_ext (expr, addr_size_bits); |
| ax_simple (expr, aop_swap); |
| ax_ext (expr, addr_size_bits); |
| /* No need for a swap here. */ |
| ax_simple (expr, aop_equal); |
| ax_simple (expr, aop_log_not); |
| break; |
| |
| case DW_OP_call_frame_cfa: |
| { |
| int regnum; |
| CORE_ADDR text_offset; |
| LONGEST off; |
| const gdb_byte *cfa_start, *cfa_end; |
| |
| if (dwarf2_fetch_cfa_info (arch, expr->scope, per_cu, |
| ®num, &off, |
| &text_offset, &cfa_start, &cfa_end)) |
| { |
| /* Register. */ |
| ax_reg (expr, regnum); |
| if (off != 0) |
| { |
| ax_const_l (expr, off); |
| ax_simple (expr, aop_add); |
| } |
| } |
| else |
| { |
| /* Another expression. */ |
| ax_const_l (expr, text_offset); |
| dwarf2_compile_expr_to_ax (expr, loc, arch, addr_size, |
| cfa_start, cfa_end, per_cu); |
| } |
| |
| loc->kind = axs_lvalue_memory; |
| } |
| break; |
| |
| case DW_OP_GNU_push_tls_address: |
| case DW_OP_form_tls_address: |
| unimplemented (op); |
| break; |
| |
| case DW_OP_push_object_address: |
| unimplemented (op); |
| break; |
| |
| case DW_OP_skip: |
| offset = extract_signed_integer (op_ptr, 2, byte_order); |
| op_ptr += 2; |
| i = ax_goto (expr, aop_goto); |
| dw_labels.push_back (op_ptr + offset - base); |
| patches.push_back (i); |
| break; |
| |
| case DW_OP_bra: |
| offset = extract_signed_integer (op_ptr, 2, byte_order); |
| op_ptr += 2; |
| /* Zero extend the operand. */ |
| ax_zero_ext (expr, addr_size_bits); |
| i = ax_goto (expr, aop_if_goto); |
| dw_labels.push_back (op_ptr + offset - base); |
| patches.push_back (i); |
| break; |
| |
| case DW_OP_nop: |
| break; |
| |
| case DW_OP_piece: |
| case DW_OP_bit_piece: |
| { |
| uint64_t size, offset; |
| |
| if (op_ptr - 1 == previous_piece) |
| error (_("Cannot translate empty pieces to agent expressions")); |
| previous_piece = op_ptr - 1; |
| |
| op_ptr = safe_read_uleb128 (op_ptr, op_end, &size); |
| if (op == DW_OP_piece) |
| { |
| size *= 8; |
| offset = 0; |
| } |
| else |
| op_ptr = safe_read_uleb128 (op_ptr, op_end, &offset); |
| |
| if (bits_collected + size > 8 * sizeof (LONGEST)) |
| error (_("Expression pieces exceed word size")); |
| |
| /* Access the bits. */ |
| switch (loc->kind) |
| { |
| case axs_lvalue_register: |
| ax_reg (expr, loc->u.reg); |
| break; |
| |
| case axs_lvalue_memory: |
| /* Offset the pointer, if needed. */ |
| if (offset > 8) |
| { |
| ax_const_l (expr, offset / 8); |
| ax_simple (expr, aop_add); |
| offset %= 8; |
| } |
| access_memory (arch, expr, size); |
| break; |
| } |
| |
| /* For a bits-big-endian target, shift up what we already |
| have. For a bits-little-endian target, shift up the |
| new data. Note that there is a potential bug here if |
| the DWARF expression leaves multiple values on the |
| stack. */ |
| if (bits_collected > 0) |
| { |
| if (bits_big_endian) |
| { |
| ax_simple (expr, aop_swap); |
| ax_const_l (expr, size); |
| ax_simple (expr, aop_lsh); |
| /* We don't need a second swap here, because |
| aop_bit_or is symmetric. */ |
| } |
| else |
| { |
| ax_const_l (expr, size); |
| ax_simple (expr, aop_lsh); |
| } |
| ax_simple (expr, aop_bit_or); |
| } |
| |
| bits_collected += size; |
| loc->kind = axs_rvalue; |
| } |
| break; |
| |
| case DW_OP_GNU_uninit: |
| unimplemented (op); |
| |
| case DW_OP_call2: |
| case DW_OP_call4: |
| { |
| struct dwarf2_locexpr_baton block; |
| int size = (op == DW_OP_call2 ? 2 : 4); |
| cu_offset offset; |
| |
| uoffset = extract_unsigned_integer (op_ptr, size, byte_order); |
| op_ptr += size; |
| |
| offset.cu_off = uoffset; |
| block = dwarf2_fetch_die_loc_cu_off (offset, per_cu, |
| get_ax_pc, expr); |
| |
| /* DW_OP_call_ref is currently not supported. */ |
| gdb_assert (block.per_cu == per_cu); |
| |
| dwarf2_compile_expr_to_ax (expr, loc, arch, addr_size, |
| block.data, block.data + block.size, |
| per_cu); |
| } |
| break; |
| |
| case DW_OP_call_ref: |
| unimplemented (op); |
| |
| default: |
| unimplemented (op); |
| } |
| } |
| |
| /* Patch all the branches we emitted. */ |
| for (i = 0; i < patches.size (); ++i) |
| { |
| int targ = offsets[dw_labels[i]]; |
| if (targ == -1) |
| internal_error (__FILE__, __LINE__, _("invalid label")); |
| ax_label (expr, patches[i], targ); |
| } |
| } |
| |
| |
| /* Return the value of SYMBOL in FRAME using the DWARF-2 expression |
| evaluator to calculate the location. */ |
| static struct value * |
| locexpr_read_variable (struct symbol *symbol, struct frame_info *frame) |
| { |
| struct dwarf2_locexpr_baton *dlbaton |
| = (struct dwarf2_locexpr_baton *) SYMBOL_LOCATION_BATON (symbol); |
| struct value *val; |
| |
| val = dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol), frame, dlbaton->data, |
| dlbaton->size, dlbaton->per_cu); |
| |
| return val; |
| } |
| |
| /* Return the value of SYMBOL in FRAME at (callee) FRAME's function |
| entry. SYMBOL should be a function parameter, otherwise NO_ENTRY_VALUE_ERROR |
| will be thrown. */ |
| |
| static struct value * |
| locexpr_read_variable_at_entry (struct symbol *symbol, struct frame_info *frame) |
| { |
| struct dwarf2_locexpr_baton *dlbaton |
| = (struct dwarf2_locexpr_baton *) SYMBOL_LOCATION_BATON (symbol); |
| |
| return value_of_dwarf_block_entry (SYMBOL_TYPE (symbol), frame, dlbaton->data, |
| dlbaton->size); |
| } |
| |
| /* Implementation of get_symbol_read_needs from |
| symbol_computed_ops. */ |
| |
| static enum symbol_needs_kind |
| locexpr_get_symbol_read_needs (struct symbol *symbol) |
| { |
| struct dwarf2_locexpr_baton *dlbaton |
| = (struct dwarf2_locexpr_baton *) SYMBOL_LOCATION_BATON (symbol); |
| |
| return dwarf2_loc_desc_get_symbol_read_needs (dlbaton->data, dlbaton->size, |
| dlbaton->per_cu); |
| } |
| |
| /* Return true if DATA points to the end of a piece. END is one past |
| the last byte in the expression. */ |
| |
| static int |
| piece_end_p (const gdb_byte *data, const gdb_byte *end) |
| { |
| return data == end || data[0] == DW_OP_piece || data[0] == DW_OP_bit_piece; |
| } |
| |
| /* Helper for locexpr_describe_location_piece that finds the name of a |
| DWARF register. */ |
| |
| static const char * |
| locexpr_regname (struct gdbarch *gdbarch, int dwarf_regnum) |
| { |
| int regnum; |
| |
| /* This doesn't use dwarf_reg_to_regnum_or_error on purpose. |
| We'd rather print *something* here than throw an error. */ |
| regnum = dwarf_reg_to_regnum (gdbarch, dwarf_regnum); |
| /* gdbarch_register_name may just return "", return something more |
| descriptive for bad register numbers. */ |
| if (regnum == -1) |
| { |
| /* The text is output as "$bad_register_number". |
| That is why we use the underscores. */ |
| return _("bad_register_number"); |
| } |
| return gdbarch_register_name (gdbarch, regnum); |
| } |
| |
| /* Nicely describe a single piece of a location, returning an updated |
| position in the bytecode sequence. This function cannot recognize |
| all locations; if a location is not recognized, it simply returns |
| DATA. If there is an error during reading, e.g. we run off the end |
| of the buffer, an error is thrown. */ |
| |
| static const gdb_byte * |
| locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream, |
| CORE_ADDR addr, struct objfile *objfile, |
| struct dwarf2_per_cu_data *per_cu, |
| const gdb_byte *data, const gdb_byte *end, |
| unsigned int addr_size) |
| { |
| struct gdbarch *gdbarch = get_objfile_arch (objfile); |
| size_t leb128_size; |
| |
| if (data[0] >= DW_OP_reg0 && data[0] <= DW_OP_reg31) |
| { |
| fprintf_filtered (stream, _("a variable in $%s"), |
| locexpr_regname (gdbarch, data[0] - DW_OP_reg0)); |
| data += 1; |
| } |
| else if (data[0] == DW_OP_regx) |
| { |
| uint64_t reg; |
| |
| data = safe_read_uleb128 (data + 1, end, ®); |
| fprintf_filtered (stream, _("a variable in $%s"), |
| locexpr_regname (gdbarch, reg)); |
| } |
| else if (data[0] == DW_OP_fbreg) |
| { |
| const struct block *b; |
| struct symbol *framefunc; |
| int frame_reg = 0; |
| int64_t frame_offset; |
| const gdb_byte *base_data, *new_data, *save_data = data; |
| size_t base_size; |
| int64_t base_offset = 0; |
| |
| new_data = safe_read_sleb128 (data + 1, end, &frame_offset); |
| if (!piece_end_p (new_data, end)) |
| return data; |
| data = new_data; |
| |
| b = block_for_pc (addr); |
| |
| if (!b) |
| error (_("No block found for address for symbol \"%s\"."), |
| SYMBOL_PRINT_NAME (symbol)); |
| |
| framefunc = block_linkage_function (b); |
| |
| if (!framefunc) |
| error (_("No function found for block for symbol \"%s\"."), |
| SYMBOL_PRINT_NAME (symbol)); |
| |
| func_get_frame_base_dwarf_block (framefunc, addr, &base_data, &base_size); |
| |
| if (base_data[0] >= DW_OP_breg0 && base_data[0] <= DW_OP_breg31) |
| { |
| const gdb_byte *buf_end; |
| |
| frame_reg = base_data[0] - DW_OP_breg0; |
| buf_end = safe_read_sleb128 (base_data + 1, base_data + base_size, |
| &base_offset); |
| if (buf_end != base_data + base_size) |
| error (_("Unexpected opcode after " |
| "DW_OP_breg%u for symbol \"%s\"."), |
| frame_reg, SYMBOL_PRINT_NAME (symbol)); |
| } |
| else if (base_data[0] >= DW_OP_reg0 && base_data[0] <= DW_OP_reg31) |
| { |
| /* The frame base is just the register, with no offset. */ |
| frame_reg = base_data[0] - DW_OP_reg0; |
| base_offset = 0; |
| } |
| else |
| { |
| /* We don't know what to do with the frame base expression, |
| so we can't trace this variable; give up. */ |
| return save_data; |
| } |
| |
| fprintf_filtered (stream, |
| _("a variable at frame base reg $%s offset %s+%s"), |
| locexpr_regname (gdbarch, frame_reg), |
| plongest (base_offset), plongest (frame_offset)); |
| } |
| else if (data[0] >= DW_OP_breg0 && data[0] <= DW_OP_breg31 |
| && piece_end_p (data, end)) |
| { |
| int64_t offset; |
| |
| data = safe_read_sleb128 (data + 1, end, &offset); |
| |
| fprintf_filtered (stream, |
| _("a variable at offset %s from base reg $%s"), |
| plongest (offset), |
| locexpr_regname (gdbarch, data[0] - DW_OP_breg0)); |
| } |
| |
| /* The location expression for a TLS variable looks like this (on a |
| 64-bit LE machine): |
| |
| DW_AT_location : 10 byte block: 3 4 0 0 0 0 0 0 0 e0 |
| (DW_OP_addr: 4; DW_OP_GNU_push_tls_address) |
| |
| 0x3 is the encoding for DW_OP_addr, which has an operand as long |
| as the size of an address on the target machine (here is 8 |
| bytes). Note that more recent version of GCC emit DW_OP_const4u |
| or DW_OP_const8u, depending on address size, rather than |
| DW_OP_addr. 0xe0 is the encoding for DW_OP_GNU_push_tls_address. |
| The operand represents the offset at which the variable is within |
| the thread local storage. */ |
| |
| else if (data + 1 + addr_size < end |
| && (data[0] == DW_OP_addr |
| || (addr_size == 4 && data[0] == DW_OP_const4u) |
| || (addr_size == 8 && data[0] == DW_OP_const8u)) |
| && (data[1 + addr_size] == DW_OP_GNU_push_tls_address |
| || data[1 + addr_size] == DW_OP_form_tls_address) |
| && piece_end_p (data + 2 + addr_size, end)) |
| { |
| ULONGEST offset; |
| offset = extract_unsigned_integer (data + 1, addr_size, |
| gdbarch_byte_order (gdbarch)); |
| |
| fprintf_filtered (stream, |
| _("a thread-local variable at offset 0x%s " |
| "in the thread-local storage for `%s'"), |
| phex_nz (offset, addr_size), objfile_name (objfile)); |
| |
| data += 1 + addr_size + 1; |
| } |
| |
| /* With -gsplit-dwarf a TLS variable can also look like this: |
| DW_AT_location : 3 byte block: fc 4 e0 |
| (DW_OP_GNU_const_index: 4; |
| DW_OP_GNU_push_tls_address) */ |
| else if (data + 3 <= end |
| && data + 1 + (leb128_size = skip_leb128 (data + 1, end)) < end |
| && data[0] == DW_OP_GNU_const_index |
| && leb128_size > 0 |
| && (data[1 + leb128_size] == DW_OP_GNU_push_tls_address |
| || data[1 + leb128_size] == DW_OP_form_tls_address) |
| && piece_end_p (data + 2 + leb128_size, end)) |
| { |
| uint64_t offset; |
| |
| data = safe_read_uleb128 (data + 1, end, &offset); |
| offset = dwarf2_read_addr_index (per_cu, offset); |
| fprintf_filtered (stream, |
| _("a thread-local variable at offset 0x%s " |
| "in the thread-local storage for `%s'"), |
| phex_nz (offset, addr_size), objfile_name (objfile)); |
| ++data; |
| } |
| |
| else if (data[0] >= DW_OP_lit0 |
| && data[0] <= DW_OP_lit31 |
| && data + 1 < end |
| && data[1] == DW_OP_stack_value) |
| { |
| fprintf_filtered (stream, _("the constant %d"), data[0] - DW_OP_lit0); |
| data += 2; |
| } |
| |
| return data; |
| } |
| |
| /* Disassemble an expression, stopping at the end of a piece or at the |
| end of the expression. Returns a pointer to the next unread byte |
| in the input expression. If ALL is nonzero, then this function |
| will keep going until it reaches the end of the expression. |
| If there is an error during reading, e.g. we run off the end |
| of the buffer, an error is thrown. */ |
| |
| static const gdb_byte * |
| disassemble_dwarf_expression (struct ui_file *stream, |
| struct gdbarch *arch, unsigned int addr_size, |
| int offset_size, const gdb_byte *start, |
| const gdb_byte *data, const gdb_byte *end, |
| int indent, int all, |
| struct dwarf2_per_cu_data *per_cu) |
| { |
| while (data < end |
| && (all |
| || (data[0] != DW_OP_piece && data[0] != DW_OP_bit_piece))) |
| { |
| enum dwarf_location_atom op = (enum dwarf_location_atom) *data++; |
| uint64_t ul; |
| int64_t l; |
| const char *name; |
| |
| name = get_DW_OP_name (op); |
| |
| if (!name) |
| error (_("Unrecognized DWARF opcode 0x%02x at %ld"), |
| op, (long) (data - 1 - start)); |
| fprintf_filtered (stream, " %*ld: %s", indent + 4, |
| (long) (data - 1 - start), name); |
| |
| switch (op) |
| { |
| case DW_OP_addr: |
| ul = extract_unsigned_integer (data, addr_size, |
| gdbarch_byte_order (arch)); |
| data += addr_size; |
| fprintf_filtered (stream, " 0x%s", phex_nz (ul, addr_size)); |
| break; |
| |
| case DW_OP_const1u: |
| ul = extract_unsigned_integer (data, 1, gdbarch_byte_order (arch)); |
| data += 1; |
| fprintf_filtered (stream, " %s", pulongest (ul)); |
| break; |
| case DW_OP_const1s: |
| l = extract_signed_integer (data, 1, gdbarch_byte_order (arch)); |
| data += 1; |
| fprintf_filtered (stream, " %s", plongest (l)); |
| break; |
| case DW_OP_const2u: |
| ul = extract_unsigned_integer (data, 2, gdbarch_byte_order (arch)); |
| data += 2; |
| fprintf_filtered (stream, " %s", pulongest (ul)); |
| break; |
| case DW_OP_const2s: |
| l = extract_signed_integer (data, 2, gdbarch_byte_order (arch)); |
| data += 2; |
| fprintf_filtered (stream, " %s", plongest (l)); |
| break; |
| case DW_OP_const4u: |
| ul = extract_unsigned_integer (data, 4, gdbarch_byte_order (arch)); |
| data += 4; |
| fprintf_filtered (stream, " %s", pulongest (ul)); |
| break; |
| case DW_OP_const4s: |
| l = extract_signed_integer (data, 4, gdbarch_byte_order (arch)); |
| data += 4; |
| fprintf_filtered (stream, " %s", plongest (l)); |
| break; |
| case DW_OP_const8u: |
| ul = extract_unsigned_integer (data, 8, gdbarch_byte_order (arch)); |
| data += 8; |
| fprintf_filtered (stream, " %s", pulongest (ul)); |
| break; |
| case DW_OP_const8s: |
| l = extract_signed_integer (data, 8, gdbarch_byte_order (arch)); |
| data += 8; |
| fprintf_filtered (stream, " %s", plongest (l)); |
| break; |
| case DW_OP_constu: |
| data = safe_read_uleb128 (data, end, &ul); |
| fprintf_filtered (stream, " %s", pulongest (ul)); |
| break; |
| case DW_OP_consts: |
| data = safe_read_sleb128 (data, end, &l); |
| fprintf_filtered (stream, " %s", plongest (l)); |
| break; |
| |
| case DW_OP_reg0: |
| case DW_OP_reg1: |
| case DW_OP_reg2: |
| case DW_OP_reg3: |
| case DW_OP_reg4: |
| case DW_OP_reg5: |
| case DW_OP_reg6: |
| case DW_OP_reg7: |
| case DW_OP_reg8: |
| case DW_OP_reg9: |
| case DW_OP_reg10: |
| case DW_OP_reg11: |
| case DW_OP_reg12: |
| case DW_OP_reg13: |
| case DW_OP_reg14: |
| case DW_OP_reg15: |
| case DW_OP_reg16: |
| case DW_OP_reg17: |
| case DW_OP_reg18: |
| case DW_OP_reg19: |
| case DW_OP_reg20: |
| case DW_OP_reg21: |
| case DW_OP_reg22: |
| case DW_OP_reg23: |
| case DW_OP_reg24: |
| case DW_OP_reg25: |
| case DW_OP_reg26: |
| case DW_OP_reg27: |
| case DW_OP_reg28: |
| case DW_OP_reg29: |
| case DW_OP_reg30: |
| case DW_OP_reg31: |
| fprintf_filtered (stream, " [$%s]", |
| locexpr_regname (arch, op - DW_OP_reg0)); |
| break; |
| |
| case DW_OP_regx: |
| data = safe_read_uleb128 (data, end, &ul); |
| fprintf_filtered (stream, " %s [$%s]", pulongest (ul), |
| locexpr_regname (arch, (int) ul)); |
| break; |
| |
| case DW_OP_implicit_value: |
| data = safe_read_uleb128 (data, end, &ul); |
| data += ul; |
| fprintf_filtered (stream, " %s", pulongest (ul)); |
| break; |
| |
| case DW_OP_breg0: |
| case DW_OP_breg1: |
| case DW_OP_breg2: |
| case DW_OP_breg3: |
| case DW_OP_breg4: |
| case DW_OP_breg5: |
| case DW_OP_breg6: |
| case DW_OP_breg7: |
| case DW_OP_breg8: |
| case DW_OP_breg9: |
| case DW_OP_breg10: |
| case DW_OP_breg11: |
| case DW_OP_breg12: |
| case DW_OP_breg13: |
| case DW_OP_breg14: |
| case DW_OP_breg15: |
| case DW_OP_breg16: |
| case DW_OP_breg17: |
| case DW_OP_breg18: |
| case DW_OP_breg19: |
| case DW_OP_breg20: |
| case DW_OP_breg21: |
| case DW_OP_breg22: |
| case DW_OP_breg23: |
| case DW_OP_breg24: |
| case DW_OP_breg25: |
| case DW_OP_breg26: |
| case DW_OP_breg27: |
| case DW_OP_breg28: |
| case DW_OP_breg29: |
| case DW_OP_breg30: |
| case DW_OP_breg31: |
| data = safe_read_sleb128 (data, end, &l); |
| fprintf_filtered (stream, " %s [$%s]", plongest (l), |
| locexpr_regname (arch, op - DW_OP_breg0)); |
| break; |
| |
| case DW_OP_bregx: |
| data = safe_read_uleb128 (data, end, &ul); |
| data = safe_read_sleb128 (data, end, &l); |
| fprintf_filtered (stream, " register %s [$%s] offset %s", |
| pulongest (ul), |
| locexpr_regname (arch, (int) ul), |
| plongest (l)); |
| break; |
| |
| case DW_OP_fbreg: |
| data = safe_read_sleb128 (data, end, &l); |
| fprintf_filtered (stream, " %s", plongest (l)); |
| break; |
| |
| case DW_OP_xderef_size: |
| case DW_OP_deref_size: |
| case DW_OP_pick: |
| fprintf_filtered (stream, " %d", *data); |
| ++data; |
| break; |
| |
| case DW_OP_plus_uconst: |
| data = safe_read_uleb128 (data, end, &ul); |
| fprintf_filtered (stream, " %s", pulongest (ul)); |
| break; |
| |
| case DW_OP_skip: |
| l = extract_signed_integer (data, 2, gdbarch_byte_order (arch)); |
| data += 2; |
| fprintf_filtered (stream, " to %ld", |
| (long) (data + l - start)); |
| break; |
| |
| case DW_OP_bra: |
| l = extract_signed_integer (data, 2, gdbarch_byte_order (arch)); |
| data += 2; |
| fprintf_filtered (stream, " %ld", |
| (long) (data + l - start)); |
| break; |
| |
| case DW_OP_call2: |
| ul = extract_unsigned_integer (data, 2, gdbarch_byte_order (arch)); |
| data += 2; |
| fprintf_filtered (stream, " offset %s", phex_nz (ul, 2)); |
| break; |
| |
| case DW_OP_call4: |
| ul = extract_unsigned_integer (data, 4, gdbarch_byte_order (arch)); |
| data += 4; |
| fprintf_filtered (stream, " offset %s", phex_nz (ul, 4)); |
| break; |
| |
| case DW_OP_call_ref: |
| ul = extract_unsigned_integer (data, offset_size, |
| gdbarch_byte_order (arch)); |
| data += offset_size; |
| fprintf_filtered (stream, " offset %s", phex_nz (ul, offset_size)); |
| break; |
| |
| case DW_OP_piece: |
| data = safe_read_uleb128 (data, end, &ul); |
| fprintf_filtered (stream, " %s (bytes)", pulongest (ul)); |
| break; |
| |
| case DW_OP_bit_piece: |
| { |
| uint64_t offset; |
| |
| data = safe_read_uleb128 (data, end, &ul); |
| data = safe_read_uleb128 (data, end, &offset); |
| fprintf_filtered (stream, " size %s offset %s (bits)", |
| pulongest (ul), pulongest (offset)); |
| } |
| break; |
| |
| case DW_OP_implicit_pointer: |
| case DW_OP_GNU_implicit_pointer: |
| { |
| ul = extract_unsigned_integer (data, offset_size, |
| gdbarch_byte_order (arch)); |
| data += offset_size; |
| |
| data = safe_read_sleb128 (data, end, &l); |
| |
| fprintf_filtered (stream, " DIE %s offset %s", |
| phex_nz (ul, offset_size), |
| plongest (l)); |
| } |
| break; |
| |
| case DW_OP_deref_type: |
| case DW_OP_GNU_deref_type: |
| { |
| int addr_size = *data++; |
| cu_offset offset; |
| struct type *type; |
| |
| data = safe_read_uleb128 (data, end, &ul); |
| offset.cu_off = ul; |
| type = dwarf2_get_die_type (offset, per_cu); |
| fprintf_filtered (stream, "<"); |
| type_print (type, "", stream, -1); |
| fprintf_filtered (stream, " [0x%s]> %d", phex_nz (offset.cu_off, 0), |
| addr_size); |
| } |
| break; |
| |
| case DW_OP_const_type: |
| case DW_OP_GNU_const_type: |
| { |
| cu_offset type_die; |
| struct type *type; |
| |
| data = safe_read_uleb128 (data, end, &ul); |
| type_die.cu_off = ul; |
| type = dwarf2_get_die_type (type_die, per_cu); |
| fprintf_filtered (stream, "<"); |
| type_print (type, "", stream, -1); |
| fprintf_filtered (stream, " [0x%s]>", phex_nz (type_die.cu_off, 0)); |
| } |
| break; |
| |
| case DW_OP_regval_type: |
| case DW_OP_GNU_regval_type: |
| { |
| uint64_t reg; |
| cu_offset type_die; |
| struct type *type; |
| |
| data = safe_read_uleb128 (data, end, ®); |
| data = safe_read_uleb128 (data, end, &ul); |
| type_die.cu_off = ul; |
| |
| type = dwarf2_get_die_type (type_die, per_cu); |
| fprintf_filtered (stream, "<"); |
| type_print (type, "", stream, -1); |
| fprintf_filtered (stream, " [0x%s]> [$%s]", |
| phex_nz (type_die.cu_off, 0), |
| locexpr_regname (arch, reg)); |
| } |
| break; |
| |
| case DW_OP_convert: |
| case DW_OP_GNU_convert: |
| case DW_OP_reinterpret: |
| case DW_OP_GNU_reinterpret: |
| { |
| cu_offset type_die; |
| |
| data = safe_read_uleb128 (data, end, &ul); |
| type_die.cu_off = ul; |
| |
| if (type_die.cu_off == 0) |
| fprintf_filtered (stream, "<0>"); |
| else |
| { |
| struct type *type; |
| |
| type = dwarf2_get_die_type (type_die, per_cu); |
| fprintf_filtered (stream, "<"); |
| type_print (type, "", stream, -1); |
| fprintf_filtered (stream, " [0x%s]>", phex_nz (type_die.cu_off, 0)); |
| } |
| } |
| break; |
| |
| case DW_OP_entry_value: |
| case DW_OP_GNU_entry_value: |
| data = safe_read_uleb128 (data, end, &ul); |
| fputc_filtered ('\n', stream); |
| disassemble_dwarf_expression (stream, arch, addr_size, offset_size, |
| start, data, data + ul, indent + 2, |
| all, per_cu); |
| data += ul; |
| continue; |
| |
| case DW_OP_GNU_parameter_ref: |
| ul = extract_unsigned_integer (data, 4, gdbarch_byte_order (arch)); |
| data += 4; |
| fprintf_filtered (stream, " offset %s", phex_nz (ul, 4)); |
| break; |
| |
| case DW_OP_GNU_addr_index: |
| data = safe_read_uleb128 (data, end, &ul); |
| ul = dwarf2_read_addr_index (per_cu, ul); |
| fprintf_filtered (stream, " 0x%s", phex_nz (ul, addr_size)); |
| break; |
| case DW_OP_GNU_const_index: |
| data = safe_read_uleb128 (data, end, &ul); |
| ul = dwarf2_read_addr_index (per_cu, ul); |
| fprintf_filtered (stream, " %s", pulongest (ul)); |
| break; |
| } |
| |
| fprintf_filtered (stream, "\n"); |
| } |
| |
| return data; |
| } |
| |
| /* Describe a single location, which may in turn consist of multiple |
| pieces. */ |
| |
| static void |
| locexpr_describe_location_1 (struct symbol *symbol, CORE_ADDR addr, |
| struct ui_file *stream, |
| const gdb_byte *data, size_t size, |
| struct objfile *objfile, unsigned int addr_size, |
| int offset_size, struct dwarf2_per_cu_data *per_cu) |
| { |
| const gdb_byte *end = data + size; |
| int first_piece = 1, bad = 0; |
| |
| while (data < end) |
| { |
| const gdb_byte *here = data; |
| int disassemble = 1; |
| |
| if (first_piece) |
| first_piece = 0; |
| else |
| fprintf_filtered (stream, _(", and ")); |
| |
| if (!dwarf_always_disassemble) |
| { |
| data = locexpr_describe_location_piece (symbol, stream, |
| addr, objfile, per_cu, |
| data, end, addr_size); |
| /* If we printed anything, or if we have an empty piece, |
| then don't disassemble. */ |
| if (data != here |
| || data[0] == DW_OP_piece |
| || data[0] == DW_OP_bit_piece) |
| disassemble = 0; |
| } |
| if (disassemble) |
| { |
| fprintf_filtered (stream, _("a complex DWARF expression:\n")); |
| data = disassemble_dwarf_expression (stream, |
| get_objfile_arch (objfile), |
| addr_size, offset_size, data, |
| data, end, 0, |
| dwarf_always_disassemble, |
| per_cu); |
| } |
| |
| if (data < end) |
| { |
| int empty = data == here; |
| |
| if (disassemble) |
| fprintf_filtered (stream, " "); |
| if (data[0] == DW_OP_piece) |
| { |
| uint64_t bytes; |
| |
| data = safe_read_uleb128 (data + 1, end, &bytes); |
| |
| if (empty) |
| fprintf_filtered (stream, _("an empty %s-byte piece"), |
| pulongest (bytes)); |
| else |
| fprintf_filtered (stream, _(" [%s-byte piece]"), |
| pulongest (bytes)); |
| } |
| else if (data[0] == DW_OP_bit_piece) |
| { |
| uint64_t bits, offset; |
| |
| data = safe_read_uleb128 (data + 1, end, &bits); |
| data = safe_read_uleb128 (data, end, &offset); |
| |
| if (empty) |
| fprintf_filtered (stream, |
| _("an empty %s-bit piece"), |
| pulongest (bits)); |
| else |
| fprintf_filtered (stream, |
| _(" [%s-bit piece, offset %s bits]"), |
| pulongest (bits), pulongest (offset)); |
| } |
| else |
| { |
| bad = 1; |
| break; |
| } |
| } |
| } |
| |
| if (bad || data > end) |
| error (_("Corrupted DWARF2 expression for \"%s\"."), |
| SYMBOL_PRINT_NAME (symbol)); |
| } |
| |
| /* Print a natural-language description of SYMBOL to STREAM. This |
| version is for a symbol with a single location. */ |
| |
| static void |
| locexpr_describe_location (struct symbol *symbol, CORE_ADDR addr, |
| struct ui_file *stream) |
| { |
| struct dwarf2_locexpr_baton *dlbaton |
| = (struct dwarf2_locexpr_baton *) SYMBOL_LOCATION_BATON (symbol); |
| struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu); |
| unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu); |
| int offset_size = dwarf2_per_cu_offset_size (dlbaton->per_cu); |
| |
| locexpr_describe_location_1 (symbol, addr, stream, |
| dlbaton->data, dlbaton->size, |
| objfile, addr_size, offset_size, |
| dlbaton->per_cu); |
| } |
| |
| /* Describe the location of SYMBOL as an agent value in VALUE, generating |
| any necessary bytecode in AX. */ |
| |
| static void |
| locexpr_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch, |
| struct agent_expr *ax, struct axs_value *value) |
| { |
| struct dwarf2_locexpr_baton *dlbaton |
| = (struct dwarf2_locexpr_baton *) SYMBOL_LOCATION_BATON (symbol); |
| unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu); |
| |
| if (dlbaton->size == 0) |
| value->optimized_out = 1; |
| else |
| dwarf2_compile_expr_to_ax (ax, value, gdbarch, addr_size, |
| dlbaton->data, dlbaton->data + dlbaton->size, |
| dlbaton->per_cu); |
| } |
| |
| /* symbol_computed_ops 'generate_c_location' method. */ |
| |
| static void |
| locexpr_generate_c_location (struct symbol *sym, string_file &stream, |
| struct gdbarch *gdbarch, |
| unsigned char *registers_used, |
| CORE_ADDR pc, const char *result_name) |
| { |
| struct dwarf2_locexpr_baton *dlbaton |
| = (struct dwarf2_locexpr_baton *) SYMBOL_LOCATION_BATON (sym); |
| unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu); |
| |
| if (dlbaton->size == 0) |
| error (_("symbol \"%s\" is optimized out"), SYMBOL_NATURAL_NAME (sym)); |
| |
| compile_dwarf_expr_to_c (stream, result_name, |
| sym, pc, gdbarch, registers_used, addr_size, |
| dlbaton->data, dlbaton->data + dlbaton->size, |
| dlbaton->per_cu); |
| } |
| |
| /* The set of location functions used with the DWARF-2 expression |
| evaluator. */ |
| const struct symbol_computed_ops dwarf2_locexpr_funcs = { |
| locexpr_read_variable, |
| locexpr_read_variable_at_entry, |
| locexpr_get_symbol_read_needs, |
| locexpr_describe_location, |
| 0, /* location_has_loclist */ |
| locexpr_tracepoint_var_ref, |
| locexpr_generate_c_location |
| }; |
| |
| |
| /* Wrapper functions for location lists. These generally find |
| the appropriate location expression and call something above. */ |
| |
| /* Return the value of SYMBOL in FRAME using the DWARF-2 expression |
| evaluator to calculate the location. */ |
| static struct value * |
| loclist_read_variable (struct symbol *symbol, struct frame_info *frame) |
| { |
| struct dwarf2_loclist_baton *dlbaton |
| = (struct dwarf2_loclist_baton *) SYMBOL_LOCATION_BATON (symbol); |
| struct value *val; |
| const gdb_byte *data; |
| size_t size; |
| CORE_ADDR pc = frame ? get_frame_address_in_block (frame) : 0; |
| |
| data = dwarf2_find_location_expression (dlbaton, &size, pc); |
| val = dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol), frame, data, size, |
| dlbaton->per_cu); |
| |
| return val; |
| } |
| |
| /* Read variable SYMBOL like loclist_read_variable at (callee) FRAME's function |
| entry. SYMBOL should be a function parameter, otherwise NO_ENTRY_VALUE_ERROR |
| will be thrown. |
| |
| Function always returns non-NULL value, it may be marked optimized out if |
| inferior frame information is not available. It throws NO_ENTRY_VALUE_ERROR |
| if it cannot resolve the parameter for any reason. */ |
| |
| static struct value * |
| loclist_read_variable_at_entry (struct symbol *symbol, struct frame_info *frame) |
| { |
| struct dwarf2_loclist_baton *dlbaton |
| = (struct dwarf2_loclist_baton *) SYMBOL_LOCATION_BATON (symbol); |
| const gdb_byte *data; |
| size_t size; |
| CORE_ADDR pc; |
| |
| if (frame == NULL || !get_frame_func_if_available (frame, &pc)) |
| return allocate_optimized_out_value (SYMBOL_TYPE (symbol)); |
| |
| data = dwarf2_find_location_expression (dlbaton, &size, pc); |
| if (data == NULL) |
| return allocate_optimized_out_value (SYMBOL_TYPE (symbol)); |
| |
| return value_of_dwarf_block_entry (SYMBOL_TYPE (symbol), frame, data, size); |
| } |
| |
| /* Implementation of get_symbol_read_needs from |
| symbol_computed_ops. */ |
| |
| static enum symbol_needs_kind |
| loclist_symbol_needs (struct symbol *symbol) |
| { |
| /* If there's a location list, then assume we need to have a frame |
| to choose the appropriate location expression. With tracking of |
| global variables this is not necessarily true, but such tracking |
| is disabled in GCC at the moment until we figure out how to |
| represent it. */ |
| |
| return SYMBOL_NEEDS_FRAME; |
| } |
| |
| /* Print a natural-language description of SYMBOL to STREAM. This |
| version applies when there is a list of different locations, each |
| with a specified address range. */ |
| |
| static void |
| loclist_describe_location (struct symbol *symbol, CORE_ADDR addr, |
| struct ui_file *stream) |
| { |
| struct dwarf2_loclist_baton *dlbaton |
| = (struct dwarf2_loclist_baton *) SYMBOL_LOCATION_BATON (symbol); |
| const gdb_byte *loc_ptr, *buf_end; |
| struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu); |
| struct gdbarch *gdbarch = get_objfile_arch (objfile); |
| enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu); |
| int offset_size = dwarf2_per_cu_offset_size (dlbaton->per_cu); |
| int signed_addr_p = bfd_get_sign_extend_vma (objfile->obfd); |
| /* Adjust base_address for relocatable objects. */ |
| CORE_ADDR base_offset = dwarf2_per_cu_text_offset (dlbaton->per_cu); |
| CORE_ADDR base_address = dlbaton->base_address + base_offset; |
| int done = 0; |
| |
| loc_ptr = dlbaton->data; |
| buf_end = dlbaton->data + dlbaton->size; |
| |
| fprintf_filtered (stream, _("multi-location:\n")); |
| |
| /* Iterate through locations until we run out. */ |
| while (!done) |
| { |
| CORE_ADDR low = 0, high = 0; /* init for gcc -Wall */ |
| int length; |
| enum debug_loc_kind kind; |
| const gdb_byte *new_ptr = NULL; /* init for gcc -Wall */ |
| |
| if (dlbaton->from_dwo) |
| kind = decode_debug_loc_dwo_addresses (dlbaton->per_cu, |
| loc_ptr, buf_end, &new_ptr, |
| &low, &high, byte_order); |
| else |
| kind = decode_debug_loc_addresses (loc_ptr, buf_end, &new_ptr, |
| &low, &high, |
| byte_order, addr_size, |
| signed_addr_p); |
| loc_ptr = new_ptr; |
| switch (kind) |
| { |
| case DEBUG_LOC_END_OF_LIST: |
| done = 1; |
| continue; |
| case DEBUG_LOC_BASE_ADDRESS: |
| base_address = high + base_offset; |
| fprintf_filtered (stream, _(" Base address %s"), |
| paddress (gdbarch, base_address)); |
| continue; |
| case DEBUG_LOC_START_END: |
| case DEBUG_LOC_START_LENGTH: |
| break; |
| case DEBUG_LOC_BUFFER_OVERFLOW: |
| case DEBUG_LOC_INVALID_ENTRY: |
| error (_("Corrupted DWARF expression for symbol \"%s\"."), |
| SYMBOL_PRINT_NAME (symbol)); |
| default: |
| gdb_assert_not_reached ("bad debug_loc_kind"); |
| } |
| |
| /* Otherwise, a location expression entry. */ |
| low += base_address; |
| high += base_address; |
| |
| low = gdbarch_adjust_dwarf2_addr (gdbarch, low); |
| high = gdbarch_adjust_dwarf2_addr (gdbarch, high); |
| |
| length = extract_unsigned_integer (loc_ptr, 2, byte_order); |
| loc_ptr += 2; |
| |
| /* (It would improve readability to print only the minimum |
| necessary digits of the second number of the range.) */ |
| fprintf_filtered (stream, _(" Range %s-%s: "), |
| paddress (gdbarch, low), paddress (gdbarch, high)); |
| |
| /* Now describe this particular location. */ |
| locexpr_describe_location_1 (symbol, low, stream, loc_ptr, length, |
| objfile, addr_size, offset_size, |
| dlbaton->per_cu); |
| |
| fprintf_filtered (stream, "\n"); |
| |
| loc_ptr += length; |
| } |
| } |
| |
| /* Describe the location of SYMBOL as an agent value in VALUE, generating |
| any necessary bytecode in AX. */ |
| static void |
| loclist_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch, |
| struct agent_expr *ax, struct axs_value *value) |
| { |
| struct dwarf2_loclist_baton *dlbaton |
| = (struct dwarf2_loclist_baton *) SYMBOL_LOCATION_BATON (symbol); |
| const gdb_byte *data; |
| size_t size; |
| unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu); |
| |
| data = dwarf2_find_location_expression (dlbaton, &size, ax->scope); |
| if (size == 0) |
| value->optimized_out = 1; |
| else |
| dwarf2_compile_expr_to_ax (ax, value, gdbarch, addr_size, data, data + size, |
| dlbaton->per_cu); |
| } |
| |
| /* symbol_computed_ops 'generate_c_location' method. */ |
| |
| static void |
| loclist_generate_c_location (struct symbol *sym, string_file &stream, |
| struct gdbarch *gdbarch, |
| unsigned char *registers_used, |
| CORE_ADDR pc, const char *result_name) |
| { |
| struct dwarf2_loclist_baton *dlbaton |
| = (struct dwarf2_loclist_baton *) SYMBOL_LOCATION_BATON (sym); |
| unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu); |
| const gdb_byte *data; |
| size_t size; |
| |
| data = dwarf2_find_location_expression (dlbaton, &size, pc); |
| if (size == 0) |
| error (_("symbol \"%s\" is optimized out"), SYMBOL_NATURAL_NAME (sym)); |
| |
| compile_dwarf_expr_to_c (stream, result_name, |
| sym, pc, gdbarch, registers_used, addr_size, |
| data, data + size, |
| dlbaton->per_cu); |
| } |
| |
| /* The set of location functions used with the DWARF-2 expression |
| evaluator and location lists. */ |
| const struct symbol_computed_ops dwarf2_loclist_funcs = { |
| loclist_read_variable, |
| loclist_read_variable_at_entry, |
| loclist_symbol_needs, |
| loclist_describe_location, |
| 1, /* location_has_loclist */ |
| loclist_tracepoint_var_ref, |
| loclist_generate_c_location |
| }; |
| |
| /* Provide a prototype to silence -Wmissing-prototypes. */ |
| extern initialize_file_ftype _initialize_dwarf2loc; |
| |
| void |
| _initialize_dwarf2loc (void) |
| { |
| add_setshow_zuinteger_cmd ("entry-values", class_maintenance, |
| &entry_values_debug, |
| _("Set entry values and tail call frames " |
| "debugging."), |
| _("Show entry values and tail call frames " |
| "debugging."), |
| _("When non-zero, the process of determining " |
| "parameter values from function entry point " |
| "and tail call frames will be printed."), |
| NULL, |
| show_entry_values_debug, |
| &setdebuglist, &showdebuglist); |
| |
| #if GDB_SELF_TEST |
| register_self_test (selftests::copy_bitwise_tests); |
| #endif |
| } |