| /* Cache and manage frames for GDB, the GNU debugger. |
| |
| Copyright 1986, 1987, 1989, 1991, 1994, 1995, 1996, 1998, 2000, |
| 2001, 2002, 2003 Free Software Foundation, 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 2 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, write to the Free Software |
| Foundation, Inc., 59 Temple Place - Suite 330, |
| Boston, MA 02111-1307, USA. */ |
| |
| #include "defs.h" |
| #include "frame.h" |
| #include "target.h" |
| #include "value.h" |
| #include "inferior.h" /* for inferior_ptid */ |
| #include "regcache.h" |
| #include "gdb_assert.h" |
| #include "gdb_string.h" |
| #include "builtin-regs.h" |
| #include "gdb_obstack.h" |
| #include "dummy-frame.h" |
| #include "sentinel-frame.h" |
| #include "gdbcore.h" |
| #include "annotate.h" |
| #include "language.h" |
| #include "frame-unwind.h" |
| #include "command.h" |
| #include "gdbcmd.h" |
| |
| /* Flag to control debugging. */ |
| |
| static int frame_debug; |
| |
| /* Flag to indicate whether backtraces should stop at main. */ |
| |
| static int backtrace_below_main; |
| |
| /* Return a frame uniq ID that can be used to, later, re-find the |
| frame. */ |
| |
| struct frame_id |
| get_frame_id (struct frame_info *fi) |
| { |
| if (fi == NULL) |
| { |
| return null_frame_id; |
| } |
| else |
| { |
| struct frame_id id; |
| id.base = fi->frame; |
| id.pc = fi->pc; |
| return id; |
| } |
| } |
| |
| const struct frame_id null_frame_id; /* All zeros. */ |
| |
| struct frame_id |
| frame_id_build (CORE_ADDR base, CORE_ADDR func_or_pc) |
| { |
| struct frame_id id; |
| id.base = base; |
| id.pc = func_or_pc; |
| return id; |
| } |
| |
| int |
| frame_id_p (struct frame_id l) |
| { |
| /* The .func can be NULL but the .base cannot. */ |
| return (l.base != 0); |
| } |
| |
| int |
| frame_id_eq (struct frame_id l, struct frame_id r) |
| { |
| /* If .base is different, the frames are different. */ |
| if (l.base != r.base) |
| return 0; |
| /* Add a test to check that the frame ID's are for the same function |
| here. */ |
| return 1; |
| } |
| |
| int |
| frame_id_inner (struct frame_id l, struct frame_id r) |
| { |
| /* Only return non-zero when strictly inner than. Note that, per |
| comment in "frame.h", there is some fuzz here. Frameless |
| functions are not strictly inner than (same .base but different |
| .func). */ |
| return INNER_THAN (l.base, r.base); |
| } |
| |
| struct frame_info * |
| frame_find_by_id (struct frame_id id) |
| { |
| struct frame_info *frame; |
| |
| /* ZERO denotes the null frame, let the caller decide what to do |
| about it. Should it instead return get_current_frame()? */ |
| if (!frame_id_p (id)) |
| return NULL; |
| |
| for (frame = get_current_frame (); |
| frame != NULL; |
| frame = get_prev_frame (frame)) |
| { |
| struct frame_id this = get_frame_id (frame); |
| if (frame_id_eq (id, this)) |
| /* An exact match. */ |
| return frame; |
| if (frame_id_inner (id, this)) |
| /* Gone to far. */ |
| return NULL; |
| /* Either, we're not yet gone far enough out along the frame |
| chain (inner(this,id), or we're comparing frameless functions |
| (same .base, different .func, no test available). Struggle |
| on until we've definitly gone to far. */ |
| } |
| return NULL; |
| } |
| |
| CORE_ADDR |
| frame_pc_unwind (struct frame_info *this_frame) |
| { |
| if (!this_frame->pc_unwind_cache_p) |
| { |
| CORE_ADDR pc; |
| if (gdbarch_unwind_pc_p (current_gdbarch)) |
| { |
| /* The right way. The `pure' way. The one true way. This |
| method depends solely on the register-unwind code to |
| determine the value of registers in THIS frame, and hence |
| the value of this frame's PC (resume address). A typical |
| implementation is no more than: |
| |
| frame_unwind_register (this_frame, ISA_PC_REGNUM, buf); |
| return extract_address (buf, size of ISA_PC_REGNUM); |
| |
| Note: this method is very heavily dependent on a correct |
| register-unwind implementation, it pays to fix that |
| method first; this method is frame type agnostic, since |
| it only deals with register values, it works with any |
| frame. This is all in stark contrast to the old |
| FRAME_SAVED_PC which would try to directly handle all the |
| different ways that a PC could be unwound. */ |
| pc = gdbarch_unwind_pc (current_gdbarch, this_frame); |
| } |
| else if (this_frame->level < 0) |
| { |
| /* FIXME: cagney/2003-03-06: Old code and and a sentinel |
| frame. Do like was always done. Fetch the PC's value |
| direct from the global registers array (via read_pc). |
| This assumes that this frame belongs to the current |
| global register cache. The assumption is dangerous. */ |
| pc = read_pc (); |
| } |
| else if (DEPRECATED_FRAME_SAVED_PC_P ()) |
| { |
| /* FIXME: cagney/2003-03-06: Old code, but not a sentinel |
| frame. Do like was always done. Note that this method, |
| unlike unwind_pc(), tries to handle all the different |
| frame cases directly. It fails. */ |
| pc = DEPRECATED_FRAME_SAVED_PC (this_frame); |
| } |
| else |
| internal_error (__FILE__, __LINE__, "No gdbarch_unwind_pc method"); |
| this_frame->pc_unwind_cache = pc; |
| this_frame->pc_unwind_cache_p = 1; |
| } |
| return this_frame->pc_unwind_cache; |
| } |
| |
| static int |
| do_frame_unwind_register (void *src, int regnum, void *buf) |
| { |
| frame_unwind_register (src, regnum, buf); |
| return 1; |
| } |
| |
| void |
| frame_pop (struct frame_info *this_frame) |
| { |
| struct regcache *scratch_regcache; |
| struct cleanup *cleanups; |
| |
| if (DEPRECATED_POP_FRAME_P ()) |
| { |
| /* A legacy architecture that has implemented a custom pop |
| function. All new architectures should instead be using the |
| generic code below. */ |
| DEPRECATED_POP_FRAME; |
| } |
| else |
| { |
| /* Make a copy of all the register values unwound from this |
| frame. Save them in a scratch buffer so that there isn't a |
| race betweening trying to extract the old values from the |
| current_regcache while, at the same time writing new values |
| into that same cache. */ |
| struct regcache *scratch = regcache_xmalloc (current_gdbarch); |
| struct cleanup *cleanups = make_cleanup_regcache_xfree (scratch); |
| regcache_save (scratch, do_frame_unwind_register, this_frame); |
| /* FIXME: cagney/2003-03-16: It should be possible to tell the |
| target's register cache that it is about to be hit with a |
| burst register transfer and that the sequence of register |
| writes should be batched. The pair target_prepare_to_store() |
| and target_store_registers() kind of suggest this |
| functionality. Unfortunatly, they don't implement it. Their |
| lack of a formal definition can lead to targets writing back |
| bogus values (arguably a bug in the target code mind). */ |
| /* Now copy those saved registers into the current regcache. |
| Here, regcache_cpy() calls regcache_restore(). */ |
| regcache_cpy (current_regcache, scratch); |
| do_cleanups (cleanups); |
| } |
| /* We've made right mess of GDB's local state, just discard |
| everything. */ |
| flush_cached_frames (); |
| } |
| |
| void |
| frame_register_unwind (struct frame_info *frame, int regnum, |
| int *optimizedp, enum lval_type *lvalp, |
| CORE_ADDR *addrp, int *realnump, void *bufferp) |
| { |
| struct frame_unwind_cache *cache; |
| |
| /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates |
| that the value proper does not need to be fetched. */ |
| gdb_assert (optimizedp != NULL); |
| gdb_assert (lvalp != NULL); |
| gdb_assert (addrp != NULL); |
| gdb_assert (realnump != NULL); |
| /* gdb_assert (bufferp != NULL); */ |
| |
| /* NOTE: cagney/2002-11-27: A program trying to unwind a NULL frame |
| is broken. There is always a frame. If there, for some reason, |
| isn't, there is some pretty busted code as it should have |
| detected the problem before calling here. */ |
| gdb_assert (frame != NULL); |
| |
| /* Ask this frame to unwind its register. See comment in |
| "frame-unwind.h" for why NEXT frame and this unwind cace are |
| passed in. */ |
| frame->unwind->prev_register (frame->next, &frame->prologue_cache, regnum, |
| optimizedp, lvalp, addrp, realnump, bufferp); |
| |
| } |
| |
| void |
| frame_register (struct frame_info *frame, int regnum, |
| int *optimizedp, enum lval_type *lvalp, |
| CORE_ADDR *addrp, int *realnump, void *bufferp) |
| { |
| /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates |
| that the value proper does not need to be fetched. */ |
| gdb_assert (optimizedp != NULL); |
| gdb_assert (lvalp != NULL); |
| gdb_assert (addrp != NULL); |
| gdb_assert (realnump != NULL); |
| /* gdb_assert (bufferp != NULL); */ |
| |
| /* Ulgh! Old code that, for lval_register, sets ADDRP to the offset |
| of the register in the register cache. It should instead return |
| the REGNUM corresponding to that register. Translate the . */ |
| if (DEPRECATED_GET_SAVED_REGISTER_P ()) |
| { |
| DEPRECATED_GET_SAVED_REGISTER (bufferp, optimizedp, addrp, frame, |
| regnum, lvalp); |
| /* Compute the REALNUM if the caller wants it. */ |
| if (*lvalp == lval_register) |
| { |
| int regnum; |
| for (regnum = 0; regnum < NUM_REGS + NUM_PSEUDO_REGS; regnum++) |
| { |
| if (*addrp == register_offset_hack (current_gdbarch, regnum)) |
| { |
| *realnump = regnum; |
| return; |
| } |
| } |
| internal_error (__FILE__, __LINE__, |
| "Failed to compute the register number corresponding" |
| " to 0x%s", paddr_d (*addrp)); |
| } |
| *realnump = -1; |
| return; |
| } |
| |
| /* Obtain the register value by unwinding the register from the next |
| (more inner frame). */ |
| gdb_assert (frame != NULL && frame->next != NULL); |
| frame_register_unwind (frame->next, regnum, optimizedp, lvalp, addrp, |
| realnump, bufferp); |
| } |
| |
| void |
| frame_unwind_register (struct frame_info *frame, int regnum, void *buf) |
| { |
| int optimized; |
| CORE_ADDR addr; |
| int realnum; |
| enum lval_type lval; |
| frame_register_unwind (frame, regnum, &optimized, &lval, &addr, |
| &realnum, buf); |
| } |
| |
| void |
| frame_unwind_signed_register (struct frame_info *frame, int regnum, |
| LONGEST *val) |
| { |
| void *buf = alloca (MAX_REGISTER_RAW_SIZE); |
| frame_unwind_register (frame, regnum, buf); |
| (*val) = extract_signed_integer (buf, REGISTER_VIRTUAL_SIZE (regnum)); |
| } |
| |
| void |
| frame_unwind_unsigned_register (struct frame_info *frame, int regnum, |
| ULONGEST *val) |
| { |
| void *buf = alloca (MAX_REGISTER_RAW_SIZE); |
| frame_unwind_register (frame, regnum, buf); |
| (*val) = extract_unsigned_integer (buf, REGISTER_VIRTUAL_SIZE (regnum)); |
| } |
| |
| void |
| frame_read_register (struct frame_info *frame, int regnum, void *buf) |
| { |
| gdb_assert (frame != NULL && frame->next != NULL); |
| frame_unwind_register (frame->next, regnum, buf); |
| } |
| |
| void |
| frame_read_unsigned_register (struct frame_info *frame, int regnum, |
| ULONGEST *val) |
| { |
| /* NOTE: cagney/2002-10-31: There is a bit of dogma here - there is |
| always a frame. Both this, and the equivalent |
| frame_read_signed_register() function, can only be called with a |
| valid frame. If, for some reason, this function is called |
| without a frame then the problem isn't here, but rather in the |
| caller. It should of first created a frame and then passed that |
| in. */ |
| /* NOTE: cagney/2002-10-31: As a side bar, keep in mind that the |
| ``current_frame'' should not be treated as a special case. While |
| ``get_next_frame (current_frame) == NULL'' currently holds, it |
| should, as far as possible, not be relied upon. In the future, |
| ``get_next_frame (current_frame)'' may instead simply return a |
| normal frame object that simply always gets register values from |
| the register cache. Consequently, frame code should try to avoid |
| tests like ``if get_next_frame() == NULL'' and instead just rely |
| on recursive frame calls (like the below code) when manipulating |
| a frame chain. */ |
| gdb_assert (frame != NULL && frame->next != NULL); |
| frame_unwind_unsigned_register (frame->next, regnum, val); |
| } |
| |
| void |
| frame_read_signed_register (struct frame_info *frame, int regnum, |
| LONGEST *val) |
| { |
| /* See note above in frame_read_unsigned_register(). */ |
| gdb_assert (frame != NULL && frame->next != NULL); |
| frame_unwind_signed_register (frame->next, regnum, val); |
| } |
| |
| void |
| generic_unwind_get_saved_register (char *raw_buffer, |
| int *optimizedp, |
| CORE_ADDR *addrp, |
| struct frame_info *frame, |
| int regnum, |
| enum lval_type *lvalp) |
| { |
| int optimizedx; |
| CORE_ADDR addrx; |
| int realnumx; |
| enum lval_type lvalx; |
| |
| if (!target_has_registers) |
| error ("No registers."); |
| |
| /* Keep things simple, ensure that all the pointers (except valuep) |
| are non NULL. */ |
| if (optimizedp == NULL) |
| optimizedp = &optimizedx; |
| if (lvalp == NULL) |
| lvalp = &lvalx; |
| if (addrp == NULL) |
| addrp = &addrx; |
| |
| gdb_assert (frame != NULL && frame->next != NULL); |
| frame_register_unwind (frame->next, regnum, optimizedp, lvalp, addrp, |
| &realnumx, raw_buffer); |
| } |
| |
| /* frame_register_read () |
| |
| Find and return the value of REGNUM for the specified stack frame. |
| The number of bytes copied is REGISTER_RAW_SIZE (REGNUM). |
| |
| Returns 0 if the register value could not be found. */ |
| |
| int |
| frame_register_read (struct frame_info *frame, int regnum, void *myaddr) |
| { |
| int optimized; |
| enum lval_type lval; |
| CORE_ADDR addr; |
| int realnum; |
| frame_register (frame, regnum, &optimized, &lval, &addr, &realnum, myaddr); |
| |
| /* FIXME: cagney/2002-05-15: This test, is just bogus. |
| |
| It indicates that the target failed to supply a value for a |
| register because it was "not available" at this time. Problem |
| is, the target still has the register and so get saved_register() |
| may be returning a value saved on the stack. */ |
| |
| if (register_cached (regnum) < 0) |
| return 0; /* register value not available */ |
| |
| return !optimized; |
| } |
| |
| |
| /* Map between a frame register number and its name. A frame register |
| space is a superset of the cooked register space --- it also |
| includes builtin registers. */ |
| |
| int |
| frame_map_name_to_regnum (const char *name, int len) |
| { |
| int i; |
| |
| if (len < 0) |
| len = strlen (name); |
| |
| /* Search register name space. */ |
| for (i = 0; i < NUM_REGS + NUM_PSEUDO_REGS; i++) |
| if (REGISTER_NAME (i) && len == strlen (REGISTER_NAME (i)) |
| && strncmp (name, REGISTER_NAME (i), len) == 0) |
| { |
| return i; |
| } |
| |
| /* Try builtin registers. */ |
| i = builtin_reg_map_name_to_regnum (name, len); |
| if (i >= 0) |
| { |
| /* A builtin register doesn't fall into the architecture's |
| register range. */ |
| gdb_assert (i >= NUM_REGS + NUM_PSEUDO_REGS); |
| return i; |
| } |
| |
| return -1; |
| } |
| |
| const char * |
| frame_map_regnum_to_name (int regnum) |
| { |
| if (regnum < 0) |
| return NULL; |
| if (regnum < NUM_REGS + NUM_PSEUDO_REGS) |
| return REGISTER_NAME (regnum); |
| return builtin_reg_map_regnum_to_name (regnum); |
| } |
| |
| /* Create a sentinel frame. */ |
| |
| struct frame_info * |
| create_sentinel_frame (struct regcache *regcache) |
| { |
| struct frame_info *frame = FRAME_OBSTACK_ZALLOC (struct frame_info); |
| frame->type = NORMAL_FRAME; |
| frame->level = -1; |
| /* Explicitly initialize the sentinel frame's cache. Provide it |
| with the underlying regcache. In the future additional |
| information, such as the frame's thread will be added. */ |
| frame->prologue_cache = sentinel_frame_cache (regcache); |
| /* For the moment there is only one sentinel frame implementation. */ |
| frame->unwind = sentinel_frame_unwind; |
| /* Link this frame back to itself. The frame is self referential |
| (the unwound PC is the same as the pc), so make it so. */ |
| frame->next = frame; |
| /* Always unwind the PC as part of creating this frame. This |
| ensures that the frame's PC points at something valid. */ |
| /* FIXME: cagney/2003-01-10: Problem here. Unwinding a sentinel |
| frame's PC may require information such as the frame's thread's |
| stop reason. Is it possible to get to that? */ |
| frame->pc = frame_pc_unwind (frame); |
| return frame; |
| } |
| |
| /* Info about the innermost stack frame (contents of FP register) */ |
| |
| static struct frame_info *current_frame; |
| |
| /* Cache for frame addresses already read by gdb. Valid only while |
| inferior is stopped. Control variables for the frame cache should |
| be local to this module. */ |
| |
| static struct obstack frame_cache_obstack; |
| |
| void * |
| frame_obstack_zalloc (unsigned long size) |
| { |
| void *data = obstack_alloc (&frame_cache_obstack, size); |
| memset (data, 0, size); |
| return data; |
| } |
| |
| CORE_ADDR * |
| frame_saved_regs_zalloc (struct frame_info *fi) |
| { |
| fi->saved_regs = (CORE_ADDR *) |
| frame_obstack_zalloc (SIZEOF_FRAME_SAVED_REGS); |
| return fi->saved_regs; |
| } |
| |
| CORE_ADDR * |
| get_frame_saved_regs (struct frame_info *fi) |
| { |
| return fi->saved_regs; |
| } |
| |
| /* Return the innermost (currently executing) stack frame. This is |
| split into two functions. The function unwind_to_current_frame() |
| is wrapped in catch exceptions so that, even when the unwind of the |
| sentinel frame fails, the function still returns a stack frame. */ |
| |
| static int |
| unwind_to_current_frame (struct ui_out *ui_out, void *args) |
| { |
| struct frame_info *frame = get_prev_frame (args); |
| /* A sentinel frame can fail to unwind, eg, because it's PC value |
| lands in somewhere like start. */ |
| if (frame == NULL) |
| return 1; |
| current_frame = frame; |
| return 0; |
| } |
| |
| struct frame_info * |
| get_current_frame (void) |
| { |
| /* First check, and report, the lack of registers. Having GDB |
| report "No stack!" or "No memory" when the target doesn't even |
| have registers is very confusing. Besides, "printcmd.exp" |
| explicitly checks that ``print $pc'' with no registers prints "No |
| registers". */ |
| if (!target_has_registers) |
| error ("No registers."); |
| if (!target_has_stack) |
| error ("No stack."); |
| if (!target_has_memory) |
| error ("No memory."); |
| if (current_frame == NULL) |
| { |
| struct frame_info *sentinel_frame = |
| create_sentinel_frame (current_regcache); |
| if (catch_exceptions (uiout, unwind_to_current_frame, sentinel_frame, |
| NULL, RETURN_MASK_ERROR) != 0) |
| { |
| /* Oops! Fake a current frame? Is this useful? It has a PC |
| of zero, for instance. */ |
| current_frame = sentinel_frame; |
| } |
| } |
| return current_frame; |
| } |
| |
| /* The "selected" stack frame is used by default for local and arg |
| access. May be zero, for no selected frame. */ |
| |
| struct frame_info *deprecated_selected_frame; |
| |
| /* Return the selected frame. Always non-null (unless there isn't an |
| inferior sufficient for creating a frame) in which case an error is |
| thrown. */ |
| |
| struct frame_info * |
| get_selected_frame (void) |
| { |
| if (deprecated_selected_frame == NULL) |
| /* Hey! Don't trust this. It should really be re-finding the |
| last selected frame of the currently selected thread. This, |
| though, is better than nothing. */ |
| select_frame (get_current_frame ()); |
| /* There is always a frame. */ |
| gdb_assert (deprecated_selected_frame != NULL); |
| return deprecated_selected_frame; |
| } |
| |
| /* Select frame FI (or NULL - to invalidate the current frame). */ |
| |
| void |
| select_frame (struct frame_info *fi) |
| { |
| register struct symtab *s; |
| |
| deprecated_selected_frame = fi; |
| /* NOTE: cagney/2002-05-04: FI can be NULL. This occures when the |
| frame is being invalidated. */ |
| if (selected_frame_level_changed_hook) |
| selected_frame_level_changed_hook (frame_relative_level (fi)); |
| |
| /* FIXME: kseitz/2002-08-28: It would be nice to call |
| selected_frame_level_changed_event right here, but due to limitations |
| in the current interfaces, we would end up flooding UIs with events |
| because select_frame is used extensively internally. |
| |
| Once we have frame-parameterized frame (and frame-related) commands, |
| the event notification can be moved here, since this function will only |
| be called when the users selected frame is being changed. */ |
| |
| /* Ensure that symbols for this frame are read in. Also, determine the |
| source language of this frame, and switch to it if desired. */ |
| if (fi) |
| { |
| s = find_pc_symtab (fi->pc); |
| if (s |
| && s->language != current_language->la_language |
| && s->language != language_unknown |
| && language_mode == language_mode_auto) |
| { |
| set_language (s->language); |
| } |
| } |
| } |
| |
| /* Return the register saved in the simplistic ``saved_regs'' cache. |
| If the value isn't here AND a value is needed, try the next inner |
| most frame. */ |
| |
| static void |
| legacy_saved_regs_prev_register (struct frame_info *next_frame, |
| void **this_prologue_cache, |
| int regnum, int *optimizedp, |
| enum lval_type *lvalp, CORE_ADDR *addrp, |
| int *realnump, void *bufferp) |
| { |
| /* HACK: New code is passed the next frame and this cache. |
| Unfortunatly, old code expects this frame. Since this is a |
| backward compatibility hack, cheat by walking one level along the |
| prologue chain to the frame the old code expects. |
| |
| Do not try this at home. Professional driver, closed course. */ |
| struct frame_info *frame = next_frame->prev; |
| gdb_assert (frame != NULL); |
| |
| /* Only (older) architectures that implement the |
| DEPRECATED_FRAME_INIT_SAVED_REGS method should be using this |
| function. */ |
| gdb_assert (DEPRECATED_FRAME_INIT_SAVED_REGS_P ()); |
| |
| /* Load the saved_regs register cache. */ |
| if (get_frame_saved_regs (frame) == NULL) |
| DEPRECATED_FRAME_INIT_SAVED_REGS (frame); |
| |
| if (get_frame_saved_regs (frame) != NULL |
| && get_frame_saved_regs (frame)[regnum] != 0) |
| { |
| if (regnum == SP_REGNUM) |
| { |
| /* SP register treated specially. */ |
| *optimizedp = 0; |
| *lvalp = not_lval; |
| *addrp = 0; |
| *realnump = -1; |
| if (bufferp != NULL) |
| store_address (bufferp, REGISTER_RAW_SIZE (regnum), |
| get_frame_saved_regs (frame)[regnum]); |
| } |
| else |
| { |
| /* Any other register is saved in memory, fetch it but cache |
| a local copy of its value. */ |
| *optimizedp = 0; |
| *lvalp = lval_memory; |
| *addrp = get_frame_saved_regs (frame)[regnum]; |
| *realnump = -1; |
| if (bufferp != NULL) |
| { |
| #if 1 |
| /* Save each register value, as it is read in, in a |
| frame based cache. */ |
| void **regs = (*this_prologue_cache); |
| if (regs == NULL) |
| { |
| int sizeof_cache = ((NUM_REGS + NUM_PSEUDO_REGS) |
| * sizeof (void *)); |
| regs = frame_obstack_zalloc (sizeof_cache); |
| (*this_prologue_cache) = regs; |
| } |
| if (regs[regnum] == NULL) |
| { |
| regs[regnum] |
| = frame_obstack_zalloc (REGISTER_RAW_SIZE (regnum)); |
| read_memory (get_frame_saved_regs (frame)[regnum], regs[regnum], |
| REGISTER_RAW_SIZE (regnum)); |
| } |
| memcpy (bufferp, regs[regnum], REGISTER_RAW_SIZE (regnum)); |
| #else |
| /* Read the value in from memory. */ |
| read_memory (get_frame_saved_regs (frame)[regnum], bufferp, |
| REGISTER_RAW_SIZE (regnum)); |
| #endif |
| } |
| } |
| return; |
| } |
| |
| /* No luck. Assume this and the next frame have the same register |
| value. Pass the unwind request down the frame chain to the next |
| frame. Hopefully that frame will find the register's location. */ |
| frame_register_unwind (next_frame, regnum, optimizedp, lvalp, addrp, |
| realnump, bufferp); |
| } |
| |
| static void |
| legacy_saved_regs_this_id (struct frame_info *next_frame, |
| void **this_prologue_cache, |
| struct frame_id *id) |
| { |
| int fromleaf; |
| CORE_ADDR base; |
| CORE_ADDR pc; |
| |
| if (frame_relative_level (next_frame) < 0) |
| { |
| /* FIXME: cagney/2003-03-14: We've got the extra special case of |
| unwinding a sentinel frame, the PC of which is pointing at a |
| stack dummy. Fake up the dummy frame's ID using the same |
| sequence as is found a traditional unwinder. */ |
| (*id).base = read_fp (); |
| (*id).pc = read_pc (); |
| return; |
| } |
| |
| /* Start out by assuming it's NULL. */ |
| (*id) = null_frame_id; |
| |
| if (frame_relative_level (next_frame) <= 0) |
| /* FIXME: 2002-11-09: Frameless functions can occure anywhere in |
| the frame chain, not just the inner most frame! The generic, |
| per-architecture, frame code should handle this and the below |
| should simply be removed. */ |
| fromleaf = FRAMELESS_FUNCTION_INVOCATION (next_frame); |
| else |
| fromleaf = 0; |
| |
| if (fromleaf) |
| /* A frameless inner-most frame. The `FP' (which isn't an |
| architecture frame-pointer register!) of the caller is the same |
| as the callee. */ |
| /* FIXME: 2002-11-09: There isn't any reason to special case this |
| edge condition. Instead the per-architecture code should hande |
| it locally. */ |
| base = get_frame_base (next_frame); |
| else |
| { |
| /* Two macros defined in tm.h specify the machine-dependent |
| actions to be performed here. |
| |
| First, get the frame's chain-pointer. |
| |
| If that is zero, the frame is the outermost frame or a leaf |
| called by the outermost frame. This means that if start |
| calls main without a frame, we'll return 0 (which is fine |
| anyway). |
| |
| Nope; there's a problem. This also returns when the current |
| routine is a leaf of main. This is unacceptable. We move |
| this to after the ffi test; I'd rather have backtraces from |
| start go curfluy than have an abort called from main not show |
| main. */ |
| gdb_assert (DEPRECATED_FRAME_CHAIN_P ()); |
| base = DEPRECATED_FRAME_CHAIN (next_frame); |
| |
| if (!frame_chain_valid (base, next_frame)) |
| return; |
| } |
| if (base == 0) |
| return; |
| |
| /* FIXME: cagney/2002-06-08: This should probably return the frame's |
| function and not the PC (a.k.a. resume address). */ |
| pc = frame_pc_unwind (next_frame); |
| id->pc = pc; |
| id->base = base; |
| } |
| |
| const struct frame_unwind legacy_saved_regs_unwinder = { |
| legacy_saved_regs_this_id, |
| legacy_saved_regs_prev_register |
| }; |
| const struct frame_unwind *legacy_saved_regs_unwind = &legacy_saved_regs_unwinder; |
| |
| |
| /* Function: deprecated_generic_get_saved_register |
| Find register number REGNUM relative to FRAME and put its (raw, |
| target format) contents in *RAW_BUFFER. |
| |
| Set *OPTIMIZED if the variable was optimized out (and thus can't be |
| fetched). Note that this is never set to anything other than zero |
| in this implementation. |
| |
| Set *LVAL to lval_memory, lval_register, or not_lval, depending on |
| whether the value was fetched from memory, from a register, or in a |
| strange and non-modifiable way (e.g. a frame pointer which was |
| calculated rather than fetched). We will use not_lval for values |
| fetched from generic dummy frames. |
| |
| Set *ADDRP to the address, either in memory or as a REGISTER_BYTE |
| offset into the registers array. If the value is stored in a dummy |
| frame, set *ADDRP to zero. |
| |
| The argument RAW_BUFFER must point to aligned memory. */ |
| |
| void |
| deprecated_generic_get_saved_register (char *raw_buffer, int *optimized, |
| CORE_ADDR *addrp, |
| struct frame_info *frame, int regnum, |
| enum lval_type *lval) |
| { |
| if (!target_has_registers) |
| error ("No registers."); |
| |
| gdb_assert (DEPRECATED_FRAME_INIT_SAVED_REGS_P ()); |
| |
| /* Normal systems don't optimize out things with register numbers. */ |
| if (optimized != NULL) |
| *optimized = 0; |
| |
| if (addrp) /* default assumption: not found in memory */ |
| *addrp = 0; |
| |
| /* Note: since the current frame's registers could only have been |
| saved by frames INTERIOR TO the current frame, we skip examining |
| the current frame itself: otherwise, we would be getting the |
| previous frame's registers which were saved by the current frame. */ |
| |
| if (frame != NULL) |
| { |
| for (frame = get_next_frame (frame); |
| frame_relative_level (frame) >= 0; |
| frame = get_next_frame (frame)) |
| { |
| if (get_frame_type (frame) == DUMMY_FRAME) |
| { |
| if (lval) /* found it in a CALL_DUMMY frame */ |
| *lval = not_lval; |
| if (raw_buffer) |
| /* FIXME: cagney/2002-06-26: This should be via the |
| gdbarch_register_read() method so that it, on the |
| fly, constructs either a raw or pseudo register |
| from the raw register cache. */ |
| regcache_raw_read |
| (generic_find_dummy_frame (get_frame_pc (frame), |
| get_frame_base (frame)), |
| regnum, raw_buffer); |
| return; |
| } |
| |
| DEPRECATED_FRAME_INIT_SAVED_REGS (frame); |
| if (get_frame_saved_regs (frame) != NULL |
| && get_frame_saved_regs (frame)[regnum] != 0) |
| { |
| if (lval) /* found it saved on the stack */ |
| *lval = lval_memory; |
| if (regnum == SP_REGNUM) |
| { |
| if (raw_buffer) /* SP register treated specially */ |
| store_address (raw_buffer, REGISTER_RAW_SIZE (regnum), |
| get_frame_saved_regs (frame)[regnum]); |
| } |
| else |
| { |
| if (addrp) /* any other register */ |
| *addrp = get_frame_saved_regs (frame)[regnum]; |
| if (raw_buffer) |
| read_memory (get_frame_saved_regs (frame)[regnum], raw_buffer, |
| REGISTER_RAW_SIZE (regnum)); |
| } |
| return; |
| } |
| } |
| } |
| |
| /* If we get thru the loop to this point, it means the register was |
| not saved in any frame. Return the actual live-register value. */ |
| |
| if (lval) /* found it in a live register */ |
| *lval = lval_register; |
| if (addrp) |
| *addrp = REGISTER_BYTE (regnum); |
| if (raw_buffer) |
| deprecated_read_register_gen (regnum, raw_buffer); |
| } |
| |
| /* Determine the frame's type based on its PC. */ |
| |
| static enum frame_type |
| frame_type_from_pc (CORE_ADDR pc) |
| { |
| /* FIXME: cagney/2002-11-24: Can't yet directly call |
| pc_in_dummy_frame() as some architectures don't set |
| PC_IN_CALL_DUMMY() to generic_pc_in_call_dummy() (remember the |
| latter is implemented by simply calling pc_in_dummy_frame). */ |
| if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES |
| && DEPRECATED_PC_IN_CALL_DUMMY (pc, 0, 0)) |
| return DUMMY_FRAME; |
| else |
| { |
| char *name; |
| find_pc_partial_function (pc, &name, NULL, NULL); |
| if (PC_IN_SIGTRAMP (pc, name)) |
| return SIGTRAMP_FRAME; |
| else |
| return NORMAL_FRAME; |
| } |
| } |
| |
| /* Create an arbitrary (i.e. address specified by user) or innermost frame. |
| Always returns a non-NULL value. */ |
| |
| struct frame_info * |
| create_new_frame (CORE_ADDR addr, CORE_ADDR pc) |
| { |
| struct frame_info *fi; |
| |
| fi = frame_obstack_zalloc (sizeof (struct frame_info)); |
| |
| fi->frame = addr; |
| fi->pc = pc; |
| fi->next = create_sentinel_frame (current_regcache); |
| fi->type = frame_type_from_pc (pc); |
| |
| if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ()) |
| DEPRECATED_INIT_EXTRA_FRAME_INFO (0, fi); |
| |
| /* Select/initialize an unwind function. */ |
| fi->unwind = frame_unwind_find_by_pc (current_gdbarch, fi->pc); |
| |
| return fi; |
| } |
| |
| /* Return the frame that THIS_FRAME calls (NULL if THIS_FRAME is the |
| innermost frame). Be careful to not fall off the bottom of the |
| frame chain and onto the sentinel frame. */ |
| |
| struct frame_info * |
| get_next_frame (struct frame_info *this_frame) |
| { |
| if (this_frame->level > 0) |
| return this_frame->next; |
| else |
| return NULL; |
| } |
| |
| /* Flush the entire frame cache. */ |
| |
| void |
| flush_cached_frames (void) |
| { |
| /* Since we can't really be sure what the first object allocated was */ |
| obstack_free (&frame_cache_obstack, 0); |
| obstack_init (&frame_cache_obstack); |
| |
| current_frame = NULL; /* Invalidate cache */ |
| select_frame (NULL); |
| annotate_frames_invalid (); |
| } |
| |
| /* Flush the frame cache, and start a new one if necessary. */ |
| |
| void |
| reinit_frame_cache (void) |
| { |
| flush_cached_frames (); |
| |
| /* FIXME: The inferior_ptid test is wrong if there is a corefile. */ |
| if (PIDGET (inferior_ptid) != 0) |
| { |
| select_frame (get_current_frame ()); |
| } |
| } |
| |
| /* Create the previous frame using the deprecated methods |
| INIT_EXTRA_INFO, INIT_FRAME_PC and INIT_FRAME_PC_FIRST. */ |
| |
| static struct frame_info * |
| legacy_get_prev_frame (struct frame_info *this_frame) |
| { |
| CORE_ADDR address = 0; |
| struct frame_info *prev; |
| int fromleaf; |
| |
| /* Allocate the new frame but do not wire it in to the frame chain. |
| Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along |
| frame->next to pull some fancy tricks (of course such code is, by |
| definition, recursive). Try to prevent it. |
| |
| There is no reason to worry about memory leaks, should the |
| remainder of the function fail. The allocated memory will be |
| quickly reclaimed when the frame cache is flushed, and the `we've |
| been here before' check, in get_prev_frame will stop repeated |
| memory allocation calls. */ |
| prev = FRAME_OBSTACK_ZALLOC (struct frame_info); |
| prev->level = this_frame->level + 1; |
| |
| /* NOTE: cagney/2002-11-18: Should have been correctly setting the |
| frame's type here, before anything else, and not last, at the |
| bottom of this function. The various |
| DEPRECATED_INIT_EXTRA_FRAME_INFO, DEPRECATED_INIT_FRAME_PC, |
| DEPRECATED_INIT_FRAME_PC_FIRST and |
| DEPRECATED_FRAME_INIT_SAVED_REGS methods are full of work-arounds |
| that handle the frame not being correctly set from the start. |
| Unfortunatly those same work-arounds rely on the type defaulting |
| to NORMAL_FRAME. Ulgh! The new frame code does not have this |
| problem. */ |
| prev->type = NORMAL_FRAME; |
| |
| /* Handle sentinel frame unwind as a special case. */ |
| if (this_frame->level < 0) |
| { |
| /* Try to unwind the PC. If that doesn't work, assume we've reached |
| the oldest frame and simply return. Is there a better sentinal |
| value? The unwound PC value is then used to initialize the new |
| previous frame's type. |
| |
| Note that the pc-unwind is intentionally performed before the |
| frame chain. This is ok since, for old targets, both |
| frame_pc_unwind (nee, DEPRECATED_FRAME_SAVED_PC) and |
| DEPRECATED_FRAME_CHAIN()) assume THIS_FRAME's data structures |
| have already been initialized (using |
| DEPRECATED_INIT_EXTRA_FRAME_INFO) and hence the call order |
| doesn't matter. |
| |
| By unwinding the PC first, it becomes possible to, in the case of |
| a dummy frame, avoid also unwinding the frame ID. This is |
| because (well ignoring the PPC) a dummy frame can be located |
| using THIS_FRAME's frame ID. */ |
| |
| prev->pc = frame_pc_unwind (this_frame); |
| if (prev->pc == 0) |
| { |
| /* The allocated PREV_FRAME will be reclaimed when the frame |
| obstack is next purged. */ |
| if (frame_debug) |
| fprintf_unfiltered (gdb_stdlog, |
| "Outermost frame - unwound PC zero\n"); |
| return NULL; |
| } |
| prev->type = frame_type_from_pc (prev->pc); |
| |
| /* Set the unwind functions based on that identified PC. */ |
| prev->unwind = frame_unwind_find_by_pc (current_gdbarch, prev->pc); |
| |
| /* Find the prev's frame's ID. */ |
| if (prev->type == DUMMY_FRAME |
| && gdbarch_unwind_dummy_id_p (current_gdbarch)) |
| { |
| /* When unwinding a normal frame, the stack structure is |
| determined by analyzing the frame's function's code (be |
| it using brute force prologue analysis, or the dwarf2 |
| CFI). In the case of a dummy frame, that simply isn't |
| possible. The The PC is either the program entry point, |
| or some random address on the stack. Trying to use that |
| PC to apply standard frame ID unwind techniques is just |
| asking for trouble. */ |
| /* Assume hand_function_call(), via SAVE_DUMMY_FRAME_TOS, |
| previously saved the dummy frame's ID. Things only work |
| if the two return the same value. */ |
| gdb_assert (SAVE_DUMMY_FRAME_TOS_P ()); |
| /* Use an architecture specific method to extract the prev's |
| dummy ID from the next frame. Note that this method uses |
| frame_register_unwind to obtain the register values |
| needed to determine the dummy frame's ID. */ |
| prev->id = gdbarch_unwind_dummy_id (current_gdbarch, this_frame); |
| } |
| else |
| { |
| /* We're unwinding a sentinel frame, the PC of which is |
| pointing at a stack dummy. Fake up the dummy frame's ID |
| using the same sequence as is found a traditional |
| unwinder. Once all architectures supply the |
| unwind_dummy_id method, this code can go away. */ |
| prev->id.base = read_fp (); |
| prev->id.pc = read_pc (); |
| } |
| |
| /* Check that the unwound ID is valid. */ |
| if (!frame_id_p (prev->id)) |
| { |
| if (frame_debug) |
| fprintf_unfiltered (gdb_stdlog, |
| "Outermost legacy sentinel frame - unwound frame ID invalid\n"); |
| return NULL; |
| } |
| |
| /* Check that the new frame isn't inner to (younger, below, |
| next) the old frame. If that happens the frame unwind is |
| going backwards. */ |
| /* FIXME: cagney/2003-02-25: Ignore the sentinel frame since |
| that doesn't have a valid frame ID. Should instead set the |
| sentinel frame's frame ID to a `sentinel'. Leave it until |
| after the switch to storing the frame ID, instead of the |
| frame base, in the frame object. */ |
| |
| /* FIXME: cagney/2002-12-18: Instead of this hack, should only |
| store the frame ID in PREV_FRAME. Unfortunatly, some |
| architectures (HP/UX) still reply on EXTRA_FRAME_INFO and, |
| hence, still poke at the "struct frame_info" object directly. */ |
| prev->frame = prev->id.base; |
| |
| /* Link it in. */ |
| this_frame->prev = prev; |
| prev->next = this_frame; |
| |
| /* FIXME: cagney/2002-01-19: This call will go away. Instead of |
| initializing extra info, all frames will use the frame_cache |
| (passed to the unwind functions) to store additional frame |
| info. Unfortunatly legacy targets can't use |
| legacy_get_prev_frame() to unwind the sentinel frame and, |
| consequently, are forced to take this code path and rely on |
| the below call to DEPRECATED_INIT_EXTRA_FRAME_INFO to |
| initialize the inner-most frame. */ |
| if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ()) |
| { |
| DEPRECATED_INIT_EXTRA_FRAME_INFO (0, prev); |
| } |
| return prev; |
| } |
| |
| /* This code only works on normal frames. A sentinel frame, where |
| the level is -1, should never reach this code. */ |
| gdb_assert (this_frame->level >= 0); |
| |
| /* On some machines it is possible to call a function without |
| setting up a stack frame for it. On these machines, we |
| define this macro to take two args; a frameinfo pointer |
| identifying a frame and a variable to set or clear if it is |
| or isn't leafless. */ |
| |
| /* Still don't want to worry about this except on the innermost |
| frame. This macro will set FROMLEAF if THIS_FRAME is a frameless |
| function invocation. */ |
| if (this_frame->level == 0) |
| /* FIXME: 2002-11-09: Frameless functions can occure anywhere in |
| the frame chain, not just the inner most frame! The generic, |
| per-architecture, frame code should handle this and the below |
| should simply be removed. */ |
| fromleaf = FRAMELESS_FUNCTION_INVOCATION (this_frame); |
| else |
| fromleaf = 0; |
| |
| if (fromleaf) |
| /* A frameless inner-most frame. The `FP' (which isn't an |
| architecture frame-pointer register!) of the caller is the same |
| as the callee. */ |
| /* FIXME: 2002-11-09: There isn't any reason to special case this |
| edge condition. Instead the per-architecture code should hande |
| it locally. */ |
| address = get_frame_base (this_frame); |
| else |
| { |
| /* Two macros defined in tm.h specify the machine-dependent |
| actions to be performed here. |
| |
| First, get the frame's chain-pointer. |
| |
| If that is zero, the frame is the outermost frame or a leaf |
| called by the outermost frame. This means that if start |
| calls main without a frame, we'll return 0 (which is fine |
| anyway). |
| |
| Nope; there's a problem. This also returns when the current |
| routine is a leaf of main. This is unacceptable. We move |
| this to after the ffi test; I'd rather have backtraces from |
| start go curfluy than have an abort called from main not show |
| main. */ |
| gdb_assert (DEPRECATED_FRAME_CHAIN_P ()); |
| address = DEPRECATED_FRAME_CHAIN (this_frame); |
| |
| if (!frame_chain_valid (address, this_frame)) |
| return 0; |
| } |
| if (address == 0) |
| return 0; |
| |
| /* Link in the already allocated prev frame. */ |
| this_frame->prev = prev; |
| prev->next = this_frame; |
| prev->frame = address; |
| |
| /* This change should not be needed, FIXME! We should determine |
| whether any targets *need* DEPRECATED_INIT_FRAME_PC to happen |
| after DEPRECATED_INIT_EXTRA_FRAME_INFO and come up with a simple |
| way to express what goes on here. |
| |
| DEPRECATED_INIT_EXTRA_FRAME_INFO is called from two places: |
| create_new_frame (where the PC is already set up) and here (where |
| it isn't). DEPRECATED_INIT_FRAME_PC is only called from here, |
| always after DEPRECATED_INIT_EXTRA_FRAME_INFO. |
| |
| The catch is the MIPS, where DEPRECATED_INIT_EXTRA_FRAME_INFO |
| requires the PC value (which hasn't been set yet). Some other |
| machines appear to require DEPRECATED_INIT_EXTRA_FRAME_INFO |
| before they can do DEPRECATED_INIT_FRAME_PC. Phoo. |
| |
| We shouldn't need DEPRECATED_INIT_FRAME_PC_FIRST to add more |
| complication to an already overcomplicated part of GDB. |
| gnu@cygnus.com, 15Sep92. |
| |
| Assuming that some machines need DEPRECATED_INIT_FRAME_PC after |
| DEPRECATED_INIT_EXTRA_FRAME_INFO, one possible scheme: |
| |
| SETUP_INNERMOST_FRAME(): Default version is just create_new_frame |
| (read_fp ()), read_pc ()). Machines with extra frame info would |
| do that (or the local equivalent) and then set the extra fields. |
| |
| SETUP_ARBITRARY_FRAME(argc, argv): Only change here is that |
| create_new_frame would no longer init extra frame info; |
| SETUP_ARBITRARY_FRAME would have to do that. |
| |
| INIT_PREV_FRAME(fromleaf, prev) Replace |
| DEPRECATED_INIT_EXTRA_FRAME_INFO and DEPRECATED_INIT_FRAME_PC. |
| This should also return a flag saying whether to keep the new |
| frame, or whether to discard it, because on some machines (e.g. |
| mips) it is really awkward to have DEPRECATED_FRAME_CHAIN_VALID |
| called BEFORE DEPRECATED_INIT_EXTRA_FRAME_INFO (there is no good |
| way to get information deduced in DEPRECATED_FRAME_CHAIN_VALID |
| into the extra fields of the new frame). std_frame_pc(fromleaf, |
| prev) |
| |
| This is the default setting for INIT_PREV_FRAME. It just does |
| what the default DEPRECATED_INIT_FRAME_PC does. Some machines |
| will call it from INIT_PREV_FRAME (either at the beginning, the |
| end, or in the middle). Some machines won't use it. |
| |
| kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */ |
| |
| /* NOTE: cagney/2002-11-09: Just ignore the above! There is no |
| reason for things to be this complicated. |
| |
| The trick is to assume that there is always a frame. Instead of |
| special casing the inner-most frame, create fake frame |
| (containing the hardware registers) that is inner to the |
| user-visible inner-most frame (...) and then unwind from that. |
| That way architecture code can use use the standard |
| frame_XX_unwind() functions and not differentiate between the |
| inner most and any other case. |
| |
| Since there is always a frame to unwind from, there is always |
| somewhere (THIS_FRAME) to store all the info needed to construct |
| a new (previous) frame without having to first create it. This |
| means that the convolution below - needing to carefully order a |
| frame's initialization - isn't needed. |
| |
| The irony here though, is that DEPRECATED_FRAME_CHAIN(), at least |
| for a more up-to-date architecture, always calls |
| FRAME_SAVED_PC(), and FRAME_SAVED_PC() computes the PC but |
| without first needing the frame! Instead of the convolution |
| below, we could have simply called FRAME_SAVED_PC() and been done |
| with it! Note that FRAME_SAVED_PC() is being superseed by |
| frame_pc_unwind() and that function does have somewhere to cache |
| that PC value. */ |
| |
| if (DEPRECATED_INIT_FRAME_PC_FIRST_P ()) |
| prev->pc = (DEPRECATED_INIT_FRAME_PC_FIRST (fromleaf, prev)); |
| |
| if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ()) |
| DEPRECATED_INIT_EXTRA_FRAME_INFO (fromleaf, prev); |
| |
| /* This entry is in the frame queue now, which is good since |
| FRAME_SAVED_PC may use that queue to figure out its value (see |
| tm-sparc.h). We want the pc saved in the inferior frame. */ |
| if (DEPRECATED_INIT_FRAME_PC_P ()) |
| prev->pc = DEPRECATED_INIT_FRAME_PC (fromleaf, prev); |
| |
| /* If ->frame and ->pc are unchanged, we are in the process of |
| getting ourselves into an infinite backtrace. Some architectures |
| check this in DEPRECATED_FRAME_CHAIN or thereabouts, but it seems |
| like there is no reason this can't be an architecture-independent |
| check. */ |
| if (prev->frame == this_frame->frame |
| && prev->pc == this_frame->pc) |
| { |
| this_frame->prev = NULL; |
| obstack_free (&frame_cache_obstack, prev); |
| return NULL; |
| } |
| |
| /* Initialize the code used to unwind the frame PREV based on the PC |
| (and probably other architectural information). The PC lets you |
| check things like the debug info at that point (dwarf2cfi?) and |
| use that to decide how the frame should be unwound. */ |
| prev->unwind = frame_unwind_find_by_pc (current_gdbarch, prev->pc); |
| |
| /* NOTE: cagney/2002-11-18: The code segments, found in |
| create_new_frame and get_prev_frame(), that initializes the |
| frames type is subtly different. The latter only updates ->type |
| when it encounters a SIGTRAMP_FRAME or DUMMY_FRAME. This stops |
| get_prev_frame() overriding the frame's type when the INIT code |
| has previously set it. This is really somewhat bogus. The |
| initialization, as seen in create_new_frame(), should occur |
| before the INIT function has been called. */ |
| if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES |
| && (DEPRECATED_PC_IN_CALL_DUMMY_P () |
| ? DEPRECATED_PC_IN_CALL_DUMMY (prev->pc, 0, 0) |
| : pc_in_dummy_frame (prev->pc))) |
| prev->type = DUMMY_FRAME; |
| else |
| { |
| /* FIXME: cagney/2002-11-10: This should be moved to before the |
| INIT code above so that the INIT code knows what the frame's |
| type is (in fact, for a [generic] dummy-frame, the type can |
| be set and then the entire initialization can be skipped. |
| Unforunatly, its the INIT code that sets the PC (Hmm, catch |
| 22). */ |
| char *name; |
| find_pc_partial_function (prev->pc, &name, NULL, NULL); |
| if (PC_IN_SIGTRAMP (prev->pc, name)) |
| prev->type = SIGTRAMP_FRAME; |
| /* FIXME: cagney/2002-11-11: Leave prev->type alone. Some |
| architectures are forcing the frame's type in INIT so we |
| don't want to override it here. Remember, NORMAL_FRAME == 0, |
| so it all works (just :-/). Once this initialization is |
| moved to the start of this function, all this nastness will |
| go away. */ |
| } |
| |
| return prev; |
| } |
| |
| /* Return a structure containing various interesting information |
| about the frame that called THIS_FRAME. Returns NULL |
| if there is no such frame. */ |
| |
| struct frame_info * |
| get_prev_frame (struct frame_info *this_frame) |
| { |
| struct frame_info *prev_frame; |
| |
| /* Return the inner-most frame, when the caller passes in NULL. */ |
| /* NOTE: cagney/2002-11-09: Not sure how this would happen. The |
| caller should have previously obtained a valid frame using |
| get_selected_frame() and then called this code - only possibility |
| I can think of is code behaving badly. |
| |
| NOTE: cagney/2003-01-10: Talk about code behaving badly. Check |
| block_innermost_frame(). It does the sequence: frame = NULL; |
| while (1) { frame = get_prev_frame (frame); .... }. Ulgh! Why |
| it couldn't be written better, I don't know. |
| |
| NOTE: cagney/2003-01-11: I suspect what is happening is |
| block_innermost_frame() is, when the target has no state |
| (registers, memory, ...), still calling this function. The |
| assumption being that this function will return NULL indicating |
| that a frame isn't possible, rather than checking that the target |
| has state and then calling get_current_frame() and |
| get_prev_frame(). This is a guess mind. */ |
| if (this_frame == NULL) |
| { |
| /* NOTE: cagney/2002-11-09: There was a code segment here that |
| would error out when CURRENT_FRAME was NULL. The comment |
| that went with it made the claim ... |
| |
| ``This screws value_of_variable, which just wants a nice |
| clean NULL return from block_innermost_frame if there are no |
| frames. I don't think I've ever seen this message happen |
| otherwise. And returning NULL here is a perfectly legitimate |
| thing to do.'' |
| |
| Per the above, this code shouldn't even be called with a NULL |
| THIS_FRAME. */ |
| return current_frame; |
| } |
| |
| /* There is always a frame. If this assertion fails, suspect that |
| something should be calling get_selected_frame() or |
| get_current_frame(). */ |
| gdb_assert (this_frame != NULL); |
| |
| if (this_frame->level >= 0 |
| && !backtrace_below_main |
| && inside_main_func (get_frame_pc (this_frame))) |
| /* Don't unwind past main(), bug always unwind the sentinel frame. |
| Note, this is done _before_ the frame has been marked as |
| previously unwound. That way if the user later decides to |
| allow unwinds past main(), that just happens. */ |
| { |
| if (frame_debug) |
| fprintf_unfiltered (gdb_stdlog, |
| "Outermost frame - inside main func.\n"); |
| return NULL; |
| } |
| |
| /* Only try to do the unwind once. */ |
| if (this_frame->prev_p) |
| return this_frame->prev; |
| this_frame->prev_p = 1; |
| |
| /* If we're inside the entry file, it isn't valid. Don't apply this |
| test to a dummy frame - dummy frame PC's typically land in the |
| entry file. Don't apply this test to the sentinel frame. |
| Sentinel frames should always be allowed to unwind. */ |
| /* NOTE: drow/2002-12-25: should there be a way to disable this |
| check? It assumes a single small entry file, and the way some |
| debug readers (e.g. dbxread) figure out which object is the |
| entry file is somewhat hokey. */ |
| /* NOTE: cagney/2003-01-10: If there is a way of disabling this test |
| then it should probably be moved to before the ->prev_p test, |
| above. */ |
| if (this_frame->type != DUMMY_FRAME && this_frame->level >= 0 |
| && inside_entry_file (get_frame_pc (this_frame))) |
| { |
| if (frame_debug) |
| fprintf_unfiltered (gdb_stdlog, |
| "Outermost frame - inside entry file\n"); |
| return NULL; |
| } |
| |
| /* If we're already inside the entry function for the main objfile, |
| then it isn't valid. Don't apply this test to a dummy frame - |
| dummy frame PC's typically land in the entry func. Don't apply |
| this test to the sentinel frame. Sentinel frames should always |
| be allowed to unwind. */ |
| /* NOTE: cagney/2003-02-25: Don't enable until someone has found |
| hard evidence that this is needed. */ |
| if (0 |
| && this_frame->type != DUMMY_FRAME && this_frame->level >= 0 |
| && inside_entry_func (get_frame_pc (this_frame))) |
| { |
| if (frame_debug) |
| fprintf_unfiltered (gdb_stdlog, |
| "Outermost frame - inside entry func\n"); |
| return NULL; |
| } |
| |
| /* If any of the old frame initialization methods are around, use |
| the legacy get_prev_frame method. */ |
| if (legacy_frame_p (current_gdbarch)) |
| { |
| prev_frame = legacy_get_prev_frame (this_frame); |
| if (frame_debug && prev_frame == NULL) |
| fprintf_unfiltered (gdb_stdlog, |
| "Outermost frame - legacy_get_prev_frame NULL.\n"); |
| return prev_frame; |
| } |
| |
| /* Check that this frame's ID was valid. If it wasn't, don't try to |
| unwind to the prev frame. Be careful to not apply this test to |
| the sentinel frame. */ |
| if (this_frame->level >= 0 && !frame_id_p (get_frame_id (this_frame))) |
| { |
| if (frame_debug) |
| fprintf_filtered (gdb_stdlog, |
| "Outermost frame - this ID is NULL\n"); |
| return NULL; |
| } |
| |
| /* Check that this frame's ID isn't inner to (younger, below, next) |
| the next frame. This happens when frame unwind goes backwards. |
| Since the sentinel frame isn't valid, don't apply this if this |
| frame is entier the inner-most or sentinel frame. */ |
| if (this_frame->level > 0 |
| && frame_id_inner (get_frame_id (this_frame), |
| get_frame_id (this_frame->next))) |
| error ("This frame inner-to next frame (corrupt stack?)"); |
| |
| /* Check that this and the next frame are different. If they are |
| not, there is most likely a stack cycle. As with the inner-than |
| test, avoid the inner-most and sentinel frames. */ |
| /* FIXME: cagney/2003-03-17: Can't yet enable this this check. The |
| frame_id_eq() method doesn't yet use function addresses when |
| comparing frame IDs. */ |
| if (0 |
| && this_frame->level > 0 |
| && frame_id_eq (get_frame_id (this_frame), |
| get_frame_id (this_frame->next))) |
| error ("This frame identical to next frame (corrupt stack?)"); |
| |
| /* Allocate the new frame but do not wire it in to the frame chain. |
| Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along |
| frame->next to pull some fancy tricks (of course such code is, by |
| definition, recursive). Try to prevent it. |
| |
| There is no reason to worry about memory leaks, should the |
| remainder of the function fail. The allocated memory will be |
| quickly reclaimed when the frame cache is flushed, and the `we've |
| been here before' check above will stop repeated memory |
| allocation calls. */ |
| prev_frame = FRAME_OBSTACK_ZALLOC (struct frame_info); |
| prev_frame->level = this_frame->level + 1; |
| |
| /* Try to unwind the PC. If that doesn't work, assume we've reached |
| the oldest frame and simply return. Is there a better sentinal |
| value? The unwound PC value is then used to initialize the new |
| previous frame's type. |
| |
| Note that the pc-unwind is intentionally performed before the |
| frame chain. This is ok since, for old targets, both |
| frame_pc_unwind (nee, FRAME_SAVED_PC) and |
| DEPRECATED_FRAME_CHAIN()) assume THIS_FRAME's data structures |
| have already been initialized (using |
| DEPRECATED_INIT_EXTRA_FRAME_INFO) and hence the call order |
| doesn't matter. |
| |
| By unwinding the PC first, it becomes possible to, in the case of |
| a dummy frame, avoid also unwinding the frame ID. This is |
| because (well ignoring the PPC) a dummy frame can be located |
| using THIS_FRAME's frame ID. */ |
| |
| prev_frame->pc = frame_pc_unwind (this_frame); |
| if (prev_frame->pc == 0) |
| { |
| /* The allocated PREV_FRAME will be reclaimed when the frame |
| obstack is next purged. */ |
| if (frame_debug) |
| fprintf_unfiltered (gdb_stdlog, |
| "Outermost frame - unwound PC zero\n"); |
| return NULL; |
| } |
| prev_frame->type = frame_type_from_pc (prev_frame->pc); |
| |
| /* Set the unwind functions based on that identified PC. */ |
| prev_frame->unwind = frame_unwind_find_by_pc (current_gdbarch, |
| prev_frame->pc); |
| |
| /* Find the prev's frame's ID. */ |
| |
| /* The callee expects to be invoked with: |
| |
| this->unwind->this_id (this->next, &this->cache, &this->id); |
| |
| The below is carefully shifted one frame `to the left' so that |
| both the unwind->this_id and unwind->prev_register methods are |
| consistently invoked with NEXT_FRAME and THIS_PROLOGUE_CACHE. |
| |
| Also note that, while the PC for this new previous frame was |
| unwound first (see above), the below is the first call that |
| [potentially] requires analysis of the new previous frame's |
| prologue. Consequently, it is this call, that typically ends up |
| initializing the previous frame's prologue cache. */ |
| prev_frame->unwind->this_id (this_frame, |
| &prev_frame->prologue_cache, |
| &prev_frame->id); |
| |
| /* The unwound frame ID is validate at the start of this function, |
| as part of the logic to decide if that frame should be further |
| unwound, and not here while the prev frame is being created. |
| Doing this makes it possible for the user to examine a frame that |
| has an invalid frame ID. |
| |
| The very old VAX frame_args_address_correct() method noted: [...] |
| For the sake of argument, suppose that the stack is somewhat |
| trashed (which is one reason that "info frame" exists). So, |
| return 0 (indicating we don't know the address of the arglist) if |
| we don't know what frame this frame calls. */ |
| |
| /* FIXME: cagney/2002-12-18: Instead of this hack, should only store |
| the frame ID in PREV_FRAME. Unfortunatly, some architectures |
| (HP/UX) still reply on EXTRA_FRAME_INFO and, hence, still poke at |
| the "struct frame_info" object directly. */ |
| prev_frame->frame = prev_frame->id.base; |
| |
| /* Link it in. */ |
| this_frame->prev = prev_frame; |
| prev_frame->next = this_frame; |
| |
| return prev_frame; |
| } |
| |
| CORE_ADDR |
| get_frame_pc (struct frame_info *frame) |
| { |
| return frame->pc; |
| } |
| |
| static int |
| pc_notcurrent (struct frame_info *frame) |
| { |
| /* If FRAME is not the innermost frame, that normally means that |
| FRAME->pc points at the return instruction (which is *after* the |
| call instruction), and we want to get the line containing the |
| call (because the call is where the user thinks the program is). |
| However, if the next frame is either a SIGTRAMP_FRAME or a |
| DUMMY_FRAME, then the next frame will contain a saved interrupt |
| PC and such a PC indicates the current (rather than next) |
| instruction/line, consequently, for such cases, want to get the |
| line containing fi->pc. */ |
| struct frame_info *next = get_next_frame (frame); |
| int notcurrent = (next != NULL && get_frame_type (next) == NORMAL_FRAME); |
| return notcurrent; |
| } |
| |
| void |
| find_frame_sal (struct frame_info *frame, struct symtab_and_line *sal) |
| { |
| (*sal) = find_pc_line (frame->pc, pc_notcurrent (frame)); |
| } |
| |
| /* Per "frame.h", return the ``address'' of the frame. Code should |
| really be using get_frame_id(). */ |
| CORE_ADDR |
| get_frame_base (struct frame_info *fi) |
| { |
| return fi->frame; |
| } |
| |
| /* Level of the selected frame: 0 for innermost, 1 for its caller, ... |
| or -1 for a NULL frame. */ |
| |
| int |
| frame_relative_level (struct frame_info *fi) |
| { |
| if (fi == NULL) |
| return -1; |
| else |
| return fi->level; |
| } |
| |
| enum frame_type |
| get_frame_type (struct frame_info *frame) |
| { |
| /* Some targets still don't use [generic] dummy frames. Catch them |
| here. */ |
| if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES |
| && deprecated_frame_in_dummy (frame)) |
| return DUMMY_FRAME; |
| return frame->type; |
| } |
| |
| void |
| deprecated_set_frame_type (struct frame_info *frame, enum frame_type type) |
| { |
| /* Arrrg! See comment in "frame.h". */ |
| frame->type = type; |
| } |
| |
| #ifdef FRAME_FIND_SAVED_REGS |
| /* XXX - deprecated. This is a compatibility function for targets |
| that do not yet implement DEPRECATED_FRAME_INIT_SAVED_REGS. */ |
| /* Find the addresses in which registers are saved in FRAME. */ |
| |
| void |
| deprecated_get_frame_saved_regs (struct frame_info *frame, |
| struct frame_saved_regs *saved_regs_addr) |
| { |
| if (frame->saved_regs == NULL) |
| { |
| frame->saved_regs = (CORE_ADDR *) |
| frame_obstack_zalloc (SIZEOF_FRAME_SAVED_REGS); |
| } |
| if (saved_regs_addr == NULL) |
| { |
| struct frame_saved_regs saved_regs; |
| FRAME_FIND_SAVED_REGS (frame, saved_regs); |
| memcpy (frame->saved_regs, &saved_regs, SIZEOF_FRAME_SAVED_REGS); |
| } |
| else |
| { |
| FRAME_FIND_SAVED_REGS (frame, *saved_regs_addr); |
| memcpy (frame->saved_regs, saved_regs_addr, SIZEOF_FRAME_SAVED_REGS); |
| } |
| } |
| #endif |
| |
| struct frame_extra_info * |
| get_frame_extra_info (struct frame_info *fi) |
| { |
| return fi->extra_info; |
| } |
| |
| struct frame_extra_info * |
| frame_extra_info_zalloc (struct frame_info *fi, long size) |
| { |
| fi->extra_info = frame_obstack_zalloc (size); |
| return fi->extra_info; |
| } |
| |
| void |
| deprecated_update_frame_pc_hack (struct frame_info *frame, CORE_ADDR pc) |
| { |
| /* See comment in "frame.h". */ |
| frame->pc = pc; |
| /* NOTE: cagney/2003-03-11: Some architectures (e.g., Arm) are |
| maintaining a locally allocated frame object. Since such frame's |
| are not in the frame chain, it isn't possible to assume that the |
| frame has a next. Sigh. */ |
| if (frame->next != NULL) |
| { |
| /* While we're at it, update this frame's cached PC value, found |
| in the next frame. Oh for the day when "struct frame_info" |
| is opaque and this hack on hack can just go away. */ |
| frame->next->pc_unwind_cache = pc; |
| frame->next->pc_unwind_cache_p = 1; |
| } |
| } |
| |
| void |
| deprecated_update_frame_base_hack (struct frame_info *frame, CORE_ADDR base) |
| { |
| /* See comment in "frame.h". */ |
| frame->frame = base; |
| } |
| |
| void |
| deprecated_set_frame_saved_regs_hack (struct frame_info *frame, |
| CORE_ADDR *saved_regs) |
| { |
| frame->saved_regs = saved_regs; |
| } |
| |
| void |
| deprecated_set_frame_extra_info_hack (struct frame_info *frame, |
| struct frame_extra_info *extra_info) |
| { |
| frame->extra_info = extra_info; |
| } |
| |
| void |
| deprecated_set_frame_next_hack (struct frame_info *fi, |
| struct frame_info *next) |
| { |
| fi->next = next; |
| } |
| |
| void |
| deprecated_set_frame_prev_hack (struct frame_info *fi, |
| struct frame_info *prev) |
| { |
| fi->prev = prev; |
| } |
| |
| struct context * |
| deprecated_get_frame_context (struct frame_info *fi) |
| { |
| return fi->context; |
| } |
| |
| void |
| deprecated_set_frame_context (struct frame_info *fi, |
| struct context *context) |
| { |
| fi->context = context; |
| } |
| |
| struct frame_info * |
| deprecated_frame_xmalloc (void) |
| { |
| struct frame_info *frame = XMALLOC (struct frame_info); |
| memset (frame, 0, sizeof (struct frame_info)); |
| return frame; |
| } |
| |
| struct frame_info * |
| deprecated_frame_xmalloc_with_cleanup (long sizeof_saved_regs, |
| long sizeof_extra_info) |
| { |
| struct frame_info *frame = deprecated_frame_xmalloc (); |
| make_cleanup (xfree, frame); |
| if (sizeof_saved_regs > 0) |
| { |
| frame->saved_regs = xcalloc (1, sizeof_saved_regs); |
| make_cleanup (xfree, frame->saved_regs); |
| } |
| if (sizeof_extra_info > 0) |
| { |
| frame->extra_info = xcalloc (1, sizeof_extra_info); |
| make_cleanup (xfree, frame->extra_info); |
| } |
| return frame; |
| } |
| |
| int |
| legacy_frame_p (struct gdbarch *current_gdbarch) |
| { |
| return (DEPRECATED_INIT_FRAME_PC_P () |
| || DEPRECATED_INIT_FRAME_PC_FIRST_P () |
| || DEPRECATED_INIT_EXTRA_FRAME_INFO_P () |
| || DEPRECATED_FRAME_CHAIN_P () |
| || !gdbarch_unwind_dummy_id_p (current_gdbarch) |
| || !SAVE_DUMMY_FRAME_TOS_P ()); |
| } |
| |
| void |
| _initialize_frame (void) |
| { |
| obstack_init (&frame_cache_obstack); |
| |
| /* FIXME: cagney/2003-01-19: This command needs a rename. Suggest |
| `set backtrace {past,beyond,...}-main'. Also suggest adding `set |
| backtrace ...-start' to control backtraces past start. The |
| problem with `below' is that it stops the `up' command. */ |
| |
| add_setshow_boolean_cmd ("backtrace-below-main", class_obscure, |
| &backtrace_below_main, "\ |
| Set whether backtraces should continue past \"main\".\n\ |
| Normally the caller of \"main\" is not of interest, so GDB will terminate\n\ |
| the backtrace at \"main\". Set this variable if you need to see the rest\n\ |
| of the stack trace.", "\ |
| Show whether backtraces should continue past \"main\".\n\ |
| Normally the caller of \"main\" is not of interest, so GDB will terminate\n\ |
| the backtrace at \"main\". Set this variable if you need to see the rest\n\ |
| of the stack trace.", |
| NULL, NULL, &setlist, &showlist); |
| |
| |
| /* Debug this files internals. */ |
| add_show_from_set (add_set_cmd ("frame", class_maintenance, var_zinteger, |
| &frame_debug, "Set frame debugging.\n\ |
| When non-zero, frame specific internal debugging is enabled.", &setdebuglist), |
| &showdebuglist); |
| } |