| /* Cache and manage frames for GDB, the GNU debugger. |
| |
| Copyright 1986, 1987, 1989, 1991, 1994, 1995, 1996, 1998, 2000, |
| 2001, 2002 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 "gdbcore.h" |
| #include "annotate.h" |
| |
| /* Return a frame uniq ID that can be used to, later re-find the |
| frame. */ |
| |
| void |
| get_frame_id (struct frame_info *fi, struct frame_id *id) |
| { |
| if (fi == NULL) |
| { |
| id->base = 0; |
| id->pc = 0; |
| } |
| else |
| { |
| id->base = FRAME_FP (fi); |
| id->pc = fi->pc; |
| } |
| } |
| |
| 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 (id.base == 0 && id.pc == 0) |
| return NULL; |
| |
| for (frame = get_current_frame (); |
| frame != NULL; |
| frame = get_prev_frame (frame)) |
| { |
| if (INNER_THAN (FRAME_FP (frame), id.base)) |
| /* ``inner/current < frame < id.base''. Keep looking along |
| the frame chain. */ |
| continue; |
| if (INNER_THAN (id.base, FRAME_FP (frame))) |
| /* ``inner/current < id.base < frame''. Oops, gone past it. |
| Just give up. */ |
| return NULL; |
| /* FIXME: cagney/2002-04-21: This isn't sufficient. It should |
| use id.pc to check that the two frames belong to the same |
| function. Otherwise we'll do things like match dummy frames |
| or mis-match frameless functions. However, until someone |
| notices, stick with the existing behavour. */ |
| return frame; |
| } |
| return NULL; |
| } |
| |
| 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/2002-04-14: It would be nice if, instead of a |
| special case, there was always an inner frame dedicated to the |
| hardware registers. Unfortunatly, there is too much unwind code |
| around that looks up/down the frame chain while making the |
| assumption that each frame level is using the same unwind code. */ |
| |
| if (frame == NULL) |
| { |
| /* We're in the inner-most frame, get the value direct from the |
| register cache. */ |
| *optimizedp = 0; |
| *lvalp = lval_register; |
| /* ULGH! Code uses the offset into the raw register byte array |
| as a way of identifying a register. */ |
| *addrp = REGISTER_BYTE (regnum); |
| /* Should this code test ``register_cached (regnum) < 0'' and do |
| something like set realnum to -1 when the register isn't |
| available? */ |
| *realnump = regnum; |
| if (bufferp) |
| deprecated_read_register_gen (regnum, bufferp); |
| return; |
| } |
| |
| /* Ask this frame to unwind its register. */ |
| frame->register_unwind (frame, &frame->register_unwind_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 (GET_SAVED_REGISTER_P ()) |
| { |
| 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; |
| } |
| |
| /* Reached the the bottom (youngest, inner most) of the frame chain |
| (youngest, inner most) frame, go direct to the hardware register |
| cache (do not pass go, do not try to cache the value, ...). The |
| unwound value would have been cached in frame->next but that |
| doesn't exist. This doesn't matter as the hardware register |
| cache is stopping any unnecessary accesses to the target. */ |
| |
| /* NOTE: cagney/2002-04-14: It would be nice if, instead of a |
| special case, there was always an inner frame dedicated to the |
| hardware registers. Unfortunatly, there is too much unwind code |
| around that looks up/down the frame chain while making the |
| assumption that each frame level is using the same unwind code. */ |
| |
| if (frame == NULL) |
| frame_register_unwind (NULL, regnum, optimizedp, lvalp, addrp, realnump, |
| bufferp); |
| else |
| frame_register_unwind (frame->next, regnum, optimizedp, lvalp, addrp, |
| realnump, bufferp); |
| } |
| |
| void |
| frame_unwind_signed_register (struct frame_info *frame, int regnum, |
| LONGEST *val) |
| { |
| int optimized; |
| CORE_ADDR addr; |
| int realnum; |
| enum lval_type lval; |
| void *buf = alloca (MAX_REGISTER_RAW_SIZE); |
| frame_register_unwind (frame, regnum, &optimized, &lval, &addr, |
| &realnum, buf); |
| (*val) = extract_signed_integer (buf, REGISTER_VIRTUAL_SIZE (regnum)); |
| } |
| |
| void |
| frame_unwind_unsigned_register (struct frame_info *frame, int regnum, |
| ULONGEST *val) |
| { |
| int optimized; |
| CORE_ADDR addr; |
| int realnum; |
| enum lval_type lval; |
| void *buf = alloca (MAX_REGISTER_RAW_SIZE); |
| frame_register_unwind (frame, regnum, &optimized, &lval, &addr, |
| &realnum, buf); |
| (*val) = extract_unsigned_integer (buf, REGISTER_VIRTUAL_SIZE (regnum)); |
| } |
| |
| 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_unwind_unsigned_register (get_next_frame (frame), regnum, val); |
| } |
| |
| void |
| frame_read_signed_register (struct frame_info *frame, int regnum, |
| LONGEST *val) |
| { |
| /* See note in frame_read_unsigned_register(). */ |
| gdb_assert (frame != NULL); |
| frame_unwind_signed_register (get_next_frame (frame), 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; |
| |
| /* Reached the the bottom (youngest, inner most) of the frame chain |
| (youngest, inner most) frame, go direct to the hardware register |
| cache (do not pass go, do not try to cache the value, ...). The |
| unwound value would have been cached in frame->next but that |
| doesn't exist. This doesn't matter as the hardware register |
| cache is stopping any unnecessary accesses to the target. */ |
| |
| /* NOTE: cagney/2002-04-14: It would be nice if, instead of a |
| special case, there was always an inner frame dedicated to the |
| hardware registers. Unfortunatly, there is too much unwind code |
| around that looks up/down the frame chain while making the |
| assumption that each frame level is using the same unwind code. */ |
| |
| if (frame == NULL) |
| frame_register_unwind (NULL, regnum, optimizedp, lvalp, addrp, &realnumx, |
| raw_buffer); |
| else |
| frame_register_unwind (frame->next, regnum, optimizedp, lvalp, addrp, |
| &realnumx, raw_buffer); |
| } |
| |
| void |
| get_saved_register (char *raw_buffer, |
| int *optimized, |
| CORE_ADDR *addrp, |
| struct frame_info *frame, |
| int regnum, |
| enum lval_type *lval) |
| { |
| if (GET_SAVED_REGISTER_P ()) |
| { |
| GET_SAVED_REGISTER (raw_buffer, optimized, addrp, frame, regnum, lval); |
| return; |
| } |
| generic_unwind_get_saved_register (raw_buffer, optimized, addrp, frame, |
| regnum, lval); |
| } |
| |
| /* 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; |
| |
| /* 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); |
| } |
| |
| /* 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_alloc (unsigned long size) |
| { |
| return obstack_alloc (&frame_cache_obstack, size); |
| } |
| |
| void |
| frame_saved_regs_zalloc (struct frame_info *fi) |
| { |
| fi->saved_regs = (CORE_ADDR *) |
| frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS); |
| memset (fi->saved_regs, 0, SIZEOF_FRAME_SAVED_REGS); |
| } |
| |
| |
| /* Return the innermost (currently executing) stack frame. */ |
| |
| struct frame_info * |
| get_current_frame (void) |
| { |
| if (current_frame == NULL) |
| { |
| if (target_has_stack) |
| current_frame = create_new_frame (read_fp (), read_pc ()); |
| else |
| error ("No stack."); |
| } |
| return current_frame; |
| } |
| |
| void |
| set_current_frame (struct frame_info *frame) |
| { |
| current_frame = frame; |
| } |
| |
| /* 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 |
| frame_saved_regs_register_unwind (struct frame_info *frame, void **cache, |
| int regnum, int *optimizedp, |
| enum lval_type *lvalp, CORE_ADDR *addrp, |
| int *realnump, void *bufferp) |
| { |
| /* There is always a frame at this point. And THIS is the frame |
| we're interested in. */ |
| gdb_assert (frame != NULL); |
| /* If we're using generic dummy frames, we'd better not be in a call |
| dummy. (generic_call_dummy_register_unwind ought to have been called |
| instead.) */ |
| gdb_assert (!(USE_GENERIC_DUMMY_FRAMES |
| && PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame))); |
| |
| /* Load the saved_regs register cache. */ |
| if (frame->saved_regs == NULL) |
| FRAME_INIT_SAVED_REGS (frame); |
| |
| if (frame->saved_regs != NULL |
| && frame->saved_regs[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), |
| frame->saved_regs[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 = frame->saved_regs[regnum]; |
| *realnump = -1; |
| if (bufferp != NULL) |
| { |
| #if 1 |
| /* Save each register value, as it is read in, in a |
| frame based cache. */ |
| void **regs = (*cache); |
| if (regs == NULL) |
| { |
| int sizeof_cache = ((NUM_REGS + NUM_PSEUDO_REGS) |
| * sizeof (void *)); |
| regs = frame_obstack_alloc (sizeof_cache); |
| memset (regs, 0, sizeof_cache); |
| (*cache) = regs; |
| } |
| if (regs[regnum] == NULL) |
| { |
| regs[regnum] |
| = frame_obstack_alloc (REGISTER_RAW_SIZE (regnum)); |
| read_memory (frame->saved_regs[regnum], regs[regnum], |
| REGISTER_RAW_SIZE (regnum)); |
| } |
| memcpy (bufferp, regs[regnum], REGISTER_RAW_SIZE (regnum)); |
| #else |
| /* Read the value in from memory. */ |
| read_memory (frame->saved_regs[regnum], bufferp, |
| REGISTER_RAW_SIZE (regnum)); |
| #endif |
| } |
| } |
| return; |
| } |
| |
| /* No luck, assume this and the next frame have the same register |
| value. If a value is needed, pass the request on down the chain; |
| otherwise just return an indication that the value is in the same |
| register as the next frame. */ |
| if (bufferp == NULL) |
| { |
| *optimizedp = 0; |
| *lvalp = lval_register; |
| *addrp = 0; |
| *realnump = regnum; |
| } |
| else |
| { |
| frame_register_unwind (frame->next, regnum, optimizedp, lvalp, addrp, |
| realnump, bufferp); |
| } |
| } |
| |
| /* Function: 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. |
| |
| To use this implementation, define a function called |
| "get_saved_register" in your target code, which simply passes all |
| of its arguments to this function. |
| |
| 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."); |
| |
| /* 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. */ |
| |
| while (frame && ((frame = frame->next) != NULL)) |
| { |
| if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->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 (frame->pc, |
| frame->frame), |
| regnum, raw_buffer); |
| return; |
| } |
| |
| FRAME_INIT_SAVED_REGS (frame); |
| if (frame->saved_regs != NULL |
| && frame->saved_regs[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), |
| frame->saved_regs[regnum]); |
| } |
| else |
| { |
| if (addrp) /* any other register */ |
| *addrp = frame->saved_regs[regnum]; |
| if (raw_buffer) |
| read_memory (frame->saved_regs[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); |
| } |
| |
| /* Using the PC, select a mechanism for unwinding a frame returning |
| the previous frame. The register unwind function should, on |
| demand, initialize the ->context object. */ |
| |
| static void |
| set_unwind_by_pc (CORE_ADDR pc, CORE_ADDR fp, |
| frame_register_unwind_ftype **unwind) |
| { |
| if (!USE_GENERIC_DUMMY_FRAMES) |
| /* Still need to set this to something. The ``info frame'' code |
| calls this function to find out where the saved registers are. |
| Hopefully this is robust enough to stop any core dumps and |
| return vaguely correct values.. */ |
| *unwind = frame_saved_regs_register_unwind; |
| else if (PC_IN_CALL_DUMMY (pc, fp, fp)) |
| *unwind = dummy_frame_register_unwind; |
| else |
| *unwind = frame_saved_regs_register_unwind; |
| } |
| |
| /* 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; |
| char *name; |
| |
| fi = (struct frame_info *) |
| obstack_alloc (&frame_cache_obstack, |
| sizeof (struct frame_info)); |
| |
| /* Zero all fields by default. */ |
| memset (fi, 0, sizeof (struct frame_info)); |
| |
| fi->frame = addr; |
| fi->pc = pc; |
| find_pc_partial_function (pc, &name, (CORE_ADDR *) NULL, (CORE_ADDR *) NULL); |
| fi->signal_handler_caller = PC_IN_SIGTRAMP (fi->pc, name); |
| |
| if (INIT_EXTRA_FRAME_INFO_P ()) |
| INIT_EXTRA_FRAME_INFO (0, fi); |
| |
| /* Select/initialize an unwind function. */ |
| set_unwind_by_pc (fi->pc, fi->frame, &fi->register_unwind); |
| |
| return fi; |
| } |
| |
| /* Return the frame that FRAME calls (NULL if FRAME is the innermost |
| frame). */ |
| |
| struct frame_info * |
| get_next_frame (struct frame_info *frame) |
| { |
| return frame->next; |
| } |
| |
| /* 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 ()); |
| } |
| } |
| |
| /* Return a structure containing various interesting information |
| about the frame that called NEXT_FRAME. Returns NULL |
| if there is no such frame. */ |
| |
| struct frame_info * |
| get_prev_frame (struct frame_info *next_frame) |
| { |
| CORE_ADDR address = 0; |
| struct frame_info *prev; |
| int fromleaf; |
| char *name; |
| |
| /* 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. */ |
| if (next_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 |
| NEXT_FRAME. */ |
| return current_frame; |
| } |
| |
| /* Only try to do the unwind once. */ |
| if (next_frame->prev_p) |
| return next_frame->prev; |
| next_frame->prev_p = 1; |
| |
| /* 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 NEXT_FRAME is a frameless |
| function invocation. */ |
| if (next_frame->next == NULL) |
| /* 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. */ |
| address = FRAME_FP (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. */ |
| address = FRAME_CHAIN (next_frame); |
| |
| /* FIXME: cagney/2002-06-08: There should be two tests here. |
| The first would check for a valid frame chain based on a user |
| selectable policy. The default being ``stop at main'' (as |
| implemented by generic_func_frame_chain_valid()). Other |
| policies would be available - stop at NULL, .... The second |
| test, if provided by the target architecture, would check for |
| more exotic cases - most target architectures wouldn't bother |
| with this second case. */ |
| if (!FRAME_CHAIN_VALID (address, next_frame)) |
| return 0; |
| } |
| if (address == 0) |
| return 0; |
| |
| /* Create an initially zero previous frame. */ |
| prev = (struct frame_info *) |
| obstack_alloc (&frame_cache_obstack, |
| sizeof (struct frame_info)); |
| memset (prev, 0, sizeof (struct frame_info)); |
| |
| /* Link it in. */ |
| next_frame->prev = prev; |
| prev->next = next_frame; |
| prev->frame = address; |
| prev->level = next_frame->level + 1; |
| |
| /* This change should not be needed, FIXME! We should determine |
| whether any targets *need* INIT_FRAME_PC to happen after |
| INIT_EXTRA_FRAME_INFO and come up with a simple way to express |
| what goes on here. |
| |
| 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). |
| INIT_FRAME_PC is only called from here, always after |
| INIT_EXTRA_FRAME_INFO. |
| |
| The catch is the MIPS, where INIT_EXTRA_FRAME_INFO requires the |
| PC value (which hasn't been set yet). Some other machines appear |
| to require INIT_EXTRA_FRAME_INFO before they can do |
| INIT_FRAME_PC. Phoo. |
| |
| We shouldn't need INIT_FRAME_PC_FIRST to add more complication to |
| an already overcomplicated part of GDB. gnu@cygnus.com, 15Sep92. |
| |
| Assuming that some machines need INIT_FRAME_PC after |
| 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 INIT_EXTRA_FRAME_INFO and |
| 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 |
| FRAME_CHAIN_VALID called *before* INIT_EXTRA_FRAME_INFO (there is |
| no good way to get information deduced in 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 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 (NEXT_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 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. */ |
| |
| INIT_FRAME_PC_FIRST (fromleaf, prev); |
| |
| if (INIT_EXTRA_FRAME_INFO_P ()) |
| 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. */ |
| 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 FRAME_CHAIN or thereabouts, but it seems like there |
| is no reason this can't be an architecture-independent check. */ |
| if (prev->frame == next_frame->frame |
| && prev->pc == next_frame->pc) |
| { |
| next_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. */ |
| set_unwind_by_pc (prev->pc, prev->frame, &prev->register_unwind); |
| |
| find_pc_partial_function (prev->pc, &name, |
| (CORE_ADDR *) NULL, (CORE_ADDR *) NULL); |
| if (PC_IN_SIGTRAMP (prev->pc, name)) |
| prev->signal_handler_caller = 1; |
| |
| return prev; |
| } |
| |
| CORE_ADDR |
| get_frame_pc (struct frame_info *frame) |
| { |
| return frame->pc; |
| } |
| |
| #ifdef FRAME_FIND_SAVED_REGS |
| /* XXX - deprecated. This is a compatibility function for targets |
| that do not yet implement FRAME_INIT_SAVED_REGS. */ |
| /* Find the addresses in which registers are saved in FRAME. */ |
| |
| void |
| 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_alloc (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 |
| |
| void |
| _initialize_frame (void) |
| { |
| obstack_init (&frame_cache_obstack); |
| } |