| /* DWARF 2 Expression Evaluator. |
| |
| Copyright (C) 2001, 2002, 2003, 2005, 2007, 2008, 2009, 2010 |
| Free Software Foundation, Inc. |
| |
| Contributed by Daniel Berlin (dan@dberlin.org) |
| |
| 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 "symtab.h" |
| #include "gdbtypes.h" |
| #include "value.h" |
| #include "gdbcore.h" |
| #include "dwarf2.h" |
| #include "dwarf2expr.h" |
| #include "gdb_assert.h" |
| |
| /* Local prototypes. */ |
| |
| static void execute_stack_op (struct dwarf_expr_context *, |
| const gdb_byte *, const gdb_byte *); |
| |
| /* Create a new context for the expression evaluator. */ |
| |
| struct dwarf_expr_context * |
| new_dwarf_expr_context (void) |
| { |
| struct dwarf_expr_context *retval; |
| |
| retval = xcalloc (1, sizeof (struct dwarf_expr_context)); |
| retval->stack_len = 0; |
| retval->stack_allocated = 10; |
| retval->stack = xmalloc (retval->stack_allocated |
| * sizeof (struct dwarf_stack_value)); |
| retval->num_pieces = 0; |
| retval->pieces = 0; |
| retval->max_recursion_depth = 0x100; |
| return retval; |
| } |
| |
| /* Release the memory allocated to CTX. */ |
| |
| void |
| free_dwarf_expr_context (struct dwarf_expr_context *ctx) |
| { |
| xfree (ctx->stack); |
| xfree (ctx->pieces); |
| xfree (ctx); |
| } |
| |
| /* Helper for make_cleanup_free_dwarf_expr_context. */ |
| |
| static void |
| free_dwarf_expr_context_cleanup (void *arg) |
| { |
| free_dwarf_expr_context (arg); |
| } |
| |
| /* Return a cleanup that calls free_dwarf_expr_context. */ |
| |
| struct cleanup * |
| make_cleanup_free_dwarf_expr_context (struct dwarf_expr_context *ctx) |
| { |
| return make_cleanup (free_dwarf_expr_context_cleanup, ctx); |
| } |
| |
| /* Expand the memory allocated to CTX's stack to contain at least |
| NEED more elements than are currently used. */ |
| |
| static void |
| dwarf_expr_grow_stack (struct dwarf_expr_context *ctx, size_t need) |
| { |
| if (ctx->stack_len + need > ctx->stack_allocated) |
| { |
| size_t newlen = ctx->stack_len + need + 10; |
| |
| ctx->stack = xrealloc (ctx->stack, |
| newlen * sizeof (struct dwarf_stack_value)); |
| ctx->stack_allocated = newlen; |
| } |
| } |
| |
| /* Push VALUE onto CTX's stack. */ |
| |
| void |
| dwarf_expr_push (struct dwarf_expr_context *ctx, ULONGEST value, |
| int in_stack_memory) |
| { |
| struct dwarf_stack_value *v; |
| |
| /* We keep all stack elements within the range defined by the |
| DWARF address size. */ |
| if (ctx->addr_size < sizeof (ULONGEST)) |
| value &= ((ULONGEST) 1 << (ctx->addr_size * HOST_CHAR_BIT)) - 1; |
| |
| dwarf_expr_grow_stack (ctx, 1); |
| v = &ctx->stack[ctx->stack_len++]; |
| v->value = value; |
| v->in_stack_memory = in_stack_memory; |
| } |
| |
| /* Pop the top item off of CTX's stack. */ |
| |
| void |
| dwarf_expr_pop (struct dwarf_expr_context *ctx) |
| { |
| if (ctx->stack_len <= 0) |
| error (_("dwarf expression stack underflow")); |
| ctx->stack_len--; |
| } |
| |
| /* Retrieve the N'th item on CTX's stack. */ |
| |
| ULONGEST |
| dwarf_expr_fetch (struct dwarf_expr_context *ctx, int n) |
| { |
| if (ctx->stack_len <= n) |
| error (_("Asked for position %d of stack, stack only has %d elements on it."), |
| n, ctx->stack_len); |
| return ctx->stack[ctx->stack_len - (1 + n)].value; |
| |
| } |
| |
| /* Retrieve the N'th item on CTX's stack, converted to an address. */ |
| |
| CORE_ADDR |
| dwarf_expr_fetch_address (struct dwarf_expr_context *ctx, int n) |
| { |
| ULONGEST result = dwarf_expr_fetch (ctx, n); |
| |
| /* For most architectures, calling extract_unsigned_integer() alone |
| is sufficient for extracting an address. However, some |
| architectures (e.g. MIPS) use signed addresses and using |
| extract_unsigned_integer() will not produce a correct |
| result. Make sure we invoke gdbarch_integer_to_address() |
| for those architectures which require it. */ |
| if (gdbarch_integer_to_address_p (ctx->gdbarch)) |
| { |
| enum bfd_endian byte_order = gdbarch_byte_order (ctx->gdbarch); |
| gdb_byte *buf = alloca (ctx->addr_size); |
| struct type *int_type; |
| |
| switch (ctx->addr_size) |
| { |
| case 2: |
| int_type = builtin_type (ctx->gdbarch)->builtin_uint16; |
| break; |
| case 4: |
| int_type = builtin_type (ctx->gdbarch)->builtin_uint32; |
| break; |
| case 8: |
| int_type = builtin_type (ctx->gdbarch)->builtin_uint64; |
| break; |
| default: |
| internal_error (__FILE__, __LINE__, |
| _("Unsupported address size.\n")); |
| } |
| |
| store_unsigned_integer (buf, ctx->addr_size, byte_order, result); |
| return gdbarch_integer_to_address (ctx->gdbarch, int_type, buf); |
| } |
| |
| return (CORE_ADDR) result; |
| } |
| |
| /* Retrieve the in_stack_memory flag of the N'th item on CTX's stack. */ |
| |
| int |
| dwarf_expr_fetch_in_stack_memory (struct dwarf_expr_context *ctx, int n) |
| { |
| if (ctx->stack_len <= n) |
| error (_("Asked for position %d of stack, stack only has %d elements on it."), |
| n, ctx->stack_len); |
| return ctx->stack[ctx->stack_len - (1 + n)].in_stack_memory; |
| |
| } |
| |
| /* Return true if the expression stack is empty. */ |
| |
| static int |
| dwarf_expr_stack_empty_p (struct dwarf_expr_context *ctx) |
| { |
| return ctx->stack_len == 0; |
| } |
| |
| /* Add a new piece to CTX's piece list. */ |
| static void |
| add_piece (struct dwarf_expr_context *ctx, ULONGEST size, ULONGEST offset) |
| { |
| struct dwarf_expr_piece *p; |
| |
| ctx->num_pieces++; |
| |
| ctx->pieces = xrealloc (ctx->pieces, |
| (ctx->num_pieces |
| * sizeof (struct dwarf_expr_piece))); |
| |
| p = &ctx->pieces[ctx->num_pieces - 1]; |
| p->location = ctx->location; |
| p->size = size; |
| p->offset = offset; |
| |
| if (p->location == DWARF_VALUE_LITERAL) |
| { |
| p->v.literal.data = ctx->data; |
| p->v.literal.length = ctx->len; |
| } |
| else if (dwarf_expr_stack_empty_p (ctx)) |
| { |
| p->location = DWARF_VALUE_OPTIMIZED_OUT; |
| /* Also reset the context's location, for our callers. This is |
| a somewhat strange approach, but this lets us avoid setting |
| the location to DWARF_VALUE_MEMORY in all the individual |
| cases in the evaluator. */ |
| ctx->location = DWARF_VALUE_OPTIMIZED_OUT; |
| } |
| else if (p->location == DWARF_VALUE_MEMORY) |
| { |
| p->v.mem.addr = dwarf_expr_fetch_address (ctx, 0); |
| p->v.mem.in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 0); |
| } |
| else |
| { |
| p->v.value = dwarf_expr_fetch (ctx, 0); |
| } |
| } |
| |
| /* Evaluate the expression at ADDR (LEN bytes long) using the context |
| CTX. */ |
| |
| void |
| dwarf_expr_eval (struct dwarf_expr_context *ctx, const gdb_byte *addr, |
| size_t len) |
| { |
| int old_recursion_depth = ctx->recursion_depth; |
| |
| execute_stack_op (ctx, addr, addr + len); |
| |
| /* CTX RECURSION_DEPTH becomes invalid if an exception was thrown here. */ |
| |
| gdb_assert (ctx->recursion_depth == old_recursion_depth); |
| } |
| |
| /* Decode the unsigned LEB128 constant at BUF into the variable pointed to |
| by R, and return the new value of BUF. Verify that it doesn't extend |
| past BUF_END. */ |
| |
| const gdb_byte * |
| read_uleb128 (const gdb_byte *buf, const gdb_byte *buf_end, ULONGEST * r) |
| { |
| unsigned shift = 0; |
| ULONGEST result = 0; |
| gdb_byte byte; |
| |
| while (1) |
| { |
| if (buf >= buf_end) |
| error (_("read_uleb128: Corrupted DWARF expression.")); |
| |
| byte = *buf++; |
| result |= (byte & 0x7f) << shift; |
| if ((byte & 0x80) == 0) |
| break; |
| shift += 7; |
| } |
| *r = result; |
| return buf; |
| } |
| |
| /* Decode the signed LEB128 constant at BUF into the variable pointed to |
| by R, and return the new value of BUF. Verify that it doesn't extend |
| past BUF_END. */ |
| |
| const gdb_byte * |
| read_sleb128 (const gdb_byte *buf, const gdb_byte *buf_end, LONGEST * r) |
| { |
| unsigned shift = 0; |
| LONGEST result = 0; |
| gdb_byte byte; |
| |
| while (1) |
| { |
| if (buf >= buf_end) |
| error (_("read_sleb128: Corrupted DWARF expression.")); |
| |
| byte = *buf++; |
| result |= (byte & 0x7f) << shift; |
| shift += 7; |
| if ((byte & 0x80) == 0) |
| break; |
| } |
| if (shift < (sizeof (*r) * 8) && (byte & 0x40) != 0) |
| result |= -(1 << shift); |
| |
| *r = result; |
| return buf; |
| } |
| |
| |
| /* Check that the current operator is either at the end of an |
| expression, or that it is followed by a composition operator. */ |
| |
| void |
| dwarf_expr_require_composition (const gdb_byte *op_ptr, const gdb_byte *op_end, |
| const char *op_name) |
| { |
| /* It seems like DW_OP_GNU_uninit should be handled here. However, |
| it doesn't seem to make sense for DW_OP_*_value, and it was not |
| checked at the other place that this function is called. */ |
| if (op_ptr != op_end && *op_ptr != DW_OP_piece && *op_ptr != DW_OP_bit_piece) |
| error (_("DWARF-2 expression error: `%s' operations must be " |
| "used either alone or in conjuction with DW_OP_piece " |
| "or DW_OP_bit_piece."), |
| op_name); |
| } |
| |
| /* The engine for the expression evaluator. Using the context in CTX, |
| evaluate the expression between OP_PTR and OP_END. */ |
| |
| static void |
| execute_stack_op (struct dwarf_expr_context *ctx, |
| const gdb_byte *op_ptr, const gdb_byte *op_end) |
| { |
| #define sign_ext(x) ((LONGEST) (((x) ^ sign_bit) - sign_bit)) |
| ULONGEST sign_bit = (ctx->addr_size >= sizeof (ULONGEST) ? 0 |
| : ((ULONGEST) 1) << (ctx->addr_size * 8 - 1)); |
| enum bfd_endian byte_order = gdbarch_byte_order (ctx->gdbarch); |
| |
| ctx->location = DWARF_VALUE_MEMORY; |
| ctx->initialized = 1; /* Default is initialized. */ |
| |
| if (ctx->recursion_depth > ctx->max_recursion_depth) |
| error (_("DWARF-2 expression error: Loop detected (%d)."), |
| ctx->recursion_depth); |
| ctx->recursion_depth++; |
| |
| while (op_ptr < op_end) |
| { |
| enum dwarf_location_atom op = *op_ptr++; |
| ULONGEST result; |
| /* Assume the value is not in stack memory. |
| Code that knows otherwise sets this to 1. |
| Some arithmetic on stack addresses can probably be assumed to still |
| be a stack address, but we skip this complication for now. |
| This is just an optimization, so it's always ok to punt |
| and leave this as 0. */ |
| int in_stack_memory = 0; |
| ULONGEST uoffset, reg; |
| LONGEST offset; |
| |
| 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: |
| result = op - DW_OP_lit0; |
| break; |
| |
| case DW_OP_addr: |
| result = extract_unsigned_integer (op_ptr, |
| ctx->addr_size, byte_order); |
| op_ptr += ctx->addr_size; |
| break; |
| |
| case DW_OP_const1u: |
| result = extract_unsigned_integer (op_ptr, 1, byte_order); |
| op_ptr += 1; |
| break; |
| case DW_OP_const1s: |
| result = extract_signed_integer (op_ptr, 1, byte_order); |
| op_ptr += 1; |
| break; |
| case DW_OP_const2u: |
| result = extract_unsigned_integer (op_ptr, 2, byte_order); |
| op_ptr += 2; |
| break; |
| case DW_OP_const2s: |
| result = extract_signed_integer (op_ptr, 2, byte_order); |
| op_ptr += 2; |
| break; |
| case DW_OP_const4u: |
| result = extract_unsigned_integer (op_ptr, 4, byte_order); |
| op_ptr += 4; |
| break; |
| case DW_OP_const4s: |
| result = extract_signed_integer (op_ptr, 4, byte_order); |
| op_ptr += 4; |
| break; |
| case DW_OP_const8u: |
| result = extract_unsigned_integer (op_ptr, 8, byte_order); |
| op_ptr += 8; |
| break; |
| case DW_OP_const8s: |
| result = extract_signed_integer (op_ptr, 8, byte_order); |
| op_ptr += 8; |
| break; |
| case DW_OP_constu: |
| op_ptr = read_uleb128 (op_ptr, op_end, &uoffset); |
| result = uoffset; |
| break; |
| case DW_OP_consts: |
| op_ptr = read_sleb128 (op_ptr, op_end, &offset); |
| result = offset; |
| break; |
| |
| /* The DW_OP_reg operations are required to occur alone in |
| location expressions. */ |
| 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: |
| if (op_ptr != op_end |
| && *op_ptr != DW_OP_piece |
| && *op_ptr != DW_OP_bit_piece |
| && *op_ptr != DW_OP_GNU_uninit) |
| error (_("DWARF-2 expression error: DW_OP_reg operations must be " |
| "used either alone or in conjuction with DW_OP_piece " |
| "or DW_OP_bit_piece.")); |
| |
| result = op - DW_OP_reg0; |
| ctx->location = DWARF_VALUE_REGISTER; |
| break; |
| |
| case DW_OP_regx: |
| op_ptr = read_uleb128 (op_ptr, op_end, ®); |
| dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_regx"); |
| |
| result = reg; |
| ctx->location = DWARF_VALUE_REGISTER; |
| break; |
| |
| case DW_OP_implicit_value: |
| { |
| ULONGEST len; |
| |
| op_ptr = read_uleb128 (op_ptr, op_end, &len); |
| if (op_ptr + len > op_end) |
| error (_("DW_OP_implicit_value: too few bytes available.")); |
| ctx->len = len; |
| ctx->data = op_ptr; |
| ctx->location = DWARF_VALUE_LITERAL; |
| op_ptr += len; |
| dwarf_expr_require_composition (op_ptr, op_end, |
| "DW_OP_implicit_value"); |
| } |
| goto no_push; |
| |
| case DW_OP_stack_value: |
| ctx->location = DWARF_VALUE_STACK; |
| dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_stack_value"); |
| goto no_push; |
| |
| 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 = read_sleb128 (op_ptr, op_end, &offset); |
| result = (ctx->read_reg) (ctx->baton, op - DW_OP_breg0); |
| result += offset; |
| } |
| break; |
| case DW_OP_bregx: |
| { |
| op_ptr = read_uleb128 (op_ptr, op_end, ®); |
| op_ptr = read_sleb128 (op_ptr, op_end, &offset); |
| result = (ctx->read_reg) (ctx->baton, reg); |
| result += offset; |
| } |
| break; |
| case DW_OP_fbreg: |
| { |
| const gdb_byte *datastart; |
| size_t datalen; |
| unsigned int before_stack_len; |
| |
| op_ptr = read_sleb128 (op_ptr, op_end, &offset); |
| /* Rather than create a whole new context, we simply |
| record the stack length before execution, then reset it |
| afterwards, effectively erasing whatever the recursive |
| call put there. */ |
| before_stack_len = ctx->stack_len; |
| /* FIXME: cagney/2003-03-26: This code should be using |
| get_frame_base_address(), and then implement a dwarf2 |
| specific this_base method. */ |
| (ctx->get_frame_base) (ctx->baton, &datastart, &datalen); |
| dwarf_expr_eval (ctx, datastart, datalen); |
| if (ctx->location == DWARF_VALUE_MEMORY) |
| result = dwarf_expr_fetch_address (ctx, 0); |
| else if (ctx->location == DWARF_VALUE_REGISTER) |
| result = (ctx->read_reg) (ctx->baton, dwarf_expr_fetch (ctx, 0)); |
| else |
| error (_("Not implemented: computing frame base using explicit value operator")); |
| result = result + offset; |
| in_stack_memory = 1; |
| ctx->stack_len = before_stack_len; |
| ctx->location = DWARF_VALUE_MEMORY; |
| } |
| break; |
| |
| case DW_OP_dup: |
| result = dwarf_expr_fetch (ctx, 0); |
| in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 0); |
| break; |
| |
| case DW_OP_drop: |
| dwarf_expr_pop (ctx); |
| goto no_push; |
| |
| case DW_OP_pick: |
| offset = *op_ptr++; |
| result = dwarf_expr_fetch (ctx, offset); |
| in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, offset); |
| break; |
| |
| case DW_OP_swap: |
| { |
| struct dwarf_stack_value t1, t2; |
| |
| if (ctx->stack_len < 2) |
| error (_("Not enough elements for DW_OP_swap. Need 2, have %d."), |
| ctx->stack_len); |
| t1 = ctx->stack[ctx->stack_len - 1]; |
| t2 = ctx->stack[ctx->stack_len - 2]; |
| ctx->stack[ctx->stack_len - 1] = t2; |
| ctx->stack[ctx->stack_len - 2] = t1; |
| goto no_push; |
| } |
| |
| case DW_OP_over: |
| result = dwarf_expr_fetch (ctx, 1); |
| in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 1); |
| break; |
| |
| case DW_OP_rot: |
| { |
| struct dwarf_stack_value t1, t2, t3; |
| |
| if (ctx->stack_len < 3) |
| error (_("Not enough elements for DW_OP_rot. Need 3, have %d."), |
| ctx->stack_len); |
| t1 = ctx->stack[ctx->stack_len - 1]; |
| t2 = ctx->stack[ctx->stack_len - 2]; |
| t3 = ctx->stack[ctx->stack_len - 3]; |
| ctx->stack[ctx->stack_len - 1] = t2; |
| ctx->stack[ctx->stack_len - 2] = t3; |
| ctx->stack[ctx->stack_len - 3] = t1; |
| goto no_push; |
| } |
| |
| case DW_OP_deref: |
| case DW_OP_deref_size: |
| { |
| int addr_size = (op == DW_OP_deref ? ctx->addr_size : *op_ptr++); |
| gdb_byte *buf = alloca (addr_size); |
| CORE_ADDR addr = dwarf_expr_fetch_address (ctx, 0); |
| dwarf_expr_pop (ctx); |
| |
| (ctx->read_mem) (ctx->baton, buf, addr, addr_size); |
| result = extract_unsigned_integer (buf, addr_size, byte_order); |
| break; |
| } |
| |
| case DW_OP_abs: |
| case DW_OP_neg: |
| case DW_OP_not: |
| case DW_OP_plus_uconst: |
| /* Unary operations. */ |
| result = dwarf_expr_fetch (ctx, 0); |
| dwarf_expr_pop (ctx); |
| |
| switch (op) |
| { |
| case DW_OP_abs: |
| if (sign_ext (result) < 0) |
| result = -result; |
| break; |
| case DW_OP_neg: |
| result = -result; |
| break; |
| case DW_OP_not: |
| result = ~result; |
| break; |
| case DW_OP_plus_uconst: |
| op_ptr = read_uleb128 (op_ptr, op_end, ®); |
| result += reg; |
| break; |
| } |
| break; |
| |
| case DW_OP_and: |
| case DW_OP_div: |
| case DW_OP_minus: |
| case DW_OP_mod: |
| case DW_OP_mul: |
| case DW_OP_or: |
| case DW_OP_plus: |
| case DW_OP_shl: |
| case DW_OP_shr: |
| case DW_OP_shra: |
| case DW_OP_xor: |
| case DW_OP_le: |
| case DW_OP_ge: |
| case DW_OP_eq: |
| case DW_OP_lt: |
| case DW_OP_gt: |
| case DW_OP_ne: |
| { |
| /* Binary operations. */ |
| ULONGEST first, second; |
| |
| second = dwarf_expr_fetch (ctx, 0); |
| dwarf_expr_pop (ctx); |
| |
| first = dwarf_expr_fetch (ctx, 0); |
| dwarf_expr_pop (ctx); |
| |
| switch (op) |
| { |
| case DW_OP_and: |
| result = first & second; |
| break; |
| case DW_OP_div: |
| if (!second) |
| error (_("Division by zero")); |
| result = sign_ext (first) / sign_ext (second); |
| break; |
| case DW_OP_minus: |
| result = first - second; |
| break; |
| case DW_OP_mod: |
| if (!second) |
| error (_("Division by zero")); |
| result = first % second; |
| break; |
| case DW_OP_mul: |
| result = first * second; |
| break; |
| case DW_OP_or: |
| result = first | second; |
| break; |
| case DW_OP_plus: |
| result = first + second; |
| break; |
| case DW_OP_shl: |
| result = first << second; |
| break; |
| case DW_OP_shr: |
| result = first >> second; |
| break; |
| case DW_OP_shra: |
| result = sign_ext (first) >> second; |
| break; |
| case DW_OP_xor: |
| result = first ^ second; |
| break; |
| case DW_OP_le: |
| result = sign_ext (first) <= sign_ext (second); |
| break; |
| case DW_OP_ge: |
| result = sign_ext (first) >= sign_ext (second); |
| break; |
| case DW_OP_eq: |
| result = sign_ext (first) == sign_ext (second); |
| break; |
| case DW_OP_lt: |
| result = sign_ext (first) < sign_ext (second); |
| break; |
| case DW_OP_gt: |
| result = sign_ext (first) > sign_ext (second); |
| break; |
| case DW_OP_ne: |
| result = sign_ext (first) != sign_ext (second); |
| break; |
| default: |
| internal_error (__FILE__, __LINE__, |
| _("Can't be reached.")); |
| } |
| } |
| break; |
| |
| case DW_OP_call_frame_cfa: |
| result = (ctx->get_frame_cfa) (ctx->baton); |
| in_stack_memory = 1; |
| break; |
| |
| case DW_OP_GNU_push_tls_address: |
| /* Variable is at a constant offset in the thread-local |
| storage block into the objfile for the current thread and |
| the dynamic linker module containing this expression. Here |
| we return returns the offset from that base. The top of the |
| stack has the offset from the beginning of the thread |
| control block at which the variable is located. Nothing |
| should follow this operator, so the top of stack would be |
| returned. */ |
| result = dwarf_expr_fetch (ctx, 0); |
| dwarf_expr_pop (ctx); |
| result = (ctx->get_tls_address) (ctx->baton, result); |
| break; |
| |
| case DW_OP_skip: |
| offset = extract_signed_integer (op_ptr, 2, byte_order); |
| op_ptr += 2; |
| op_ptr += offset; |
| goto no_push; |
| |
| case DW_OP_bra: |
| offset = extract_signed_integer (op_ptr, 2, byte_order); |
| op_ptr += 2; |
| if (dwarf_expr_fetch (ctx, 0) != 0) |
| op_ptr += offset; |
| dwarf_expr_pop (ctx); |
| goto no_push; |
| |
| case DW_OP_nop: |
| goto no_push; |
| |
| case DW_OP_piece: |
| { |
| ULONGEST size; |
| |
| /* Record the piece. */ |
| op_ptr = read_uleb128 (op_ptr, op_end, &size); |
| add_piece (ctx, 8 * size, 0); |
| |
| /* Pop off the address/regnum, and reset the location |
| type. */ |
| if (ctx->location != DWARF_VALUE_LITERAL |
| && ctx->location != DWARF_VALUE_OPTIMIZED_OUT) |
| dwarf_expr_pop (ctx); |
| ctx->location = DWARF_VALUE_MEMORY; |
| } |
| goto no_push; |
| |
| case DW_OP_bit_piece: |
| { |
| ULONGEST size, offset; |
| |
| /* Record the piece. */ |
| op_ptr = read_uleb128 (op_ptr, op_end, &size); |
| op_ptr = read_uleb128 (op_ptr, op_end, &offset); |
| add_piece (ctx, size, offset); |
| |
| /* Pop off the address/regnum, and reset the location |
| type. */ |
| if (ctx->location != DWARF_VALUE_LITERAL |
| && ctx->location != DWARF_VALUE_OPTIMIZED_OUT) |
| dwarf_expr_pop (ctx); |
| ctx->location = DWARF_VALUE_MEMORY; |
| } |
| goto no_push; |
| |
| case DW_OP_GNU_uninit: |
| if (op_ptr != op_end) |
| error (_("DWARF-2 expression error: DW_OP_GNU_uninit must always " |
| "be the very last op.")); |
| |
| ctx->initialized = 0; |
| goto no_push; |
| |
| case DW_OP_call2: |
| result = extract_unsigned_integer (op_ptr, 2, byte_order); |
| op_ptr += 2; |
| ctx->dwarf_call (ctx, result); |
| goto no_push; |
| |
| case DW_OP_call4: |
| result = extract_unsigned_integer (op_ptr, 4, byte_order); |
| op_ptr += 4; |
| ctx->dwarf_call (ctx, result); |
| goto no_push; |
| |
| default: |
| error (_("Unhandled dwarf expression opcode 0x%x"), op); |
| } |
| |
| /* Most things push a result value. */ |
| dwarf_expr_push (ctx, result, in_stack_memory); |
| no_push:; |
| } |
| |
| ctx->recursion_depth--; |
| gdb_assert (ctx->recursion_depth >= 0); |
| #undef sign_ext |
| } |