diff options
Diffstat (limited to 'gdb/frame.c')
| -rw-r--r-- | gdb/frame.c | 545 |
1 files changed, 545 insertions, 0 deletions
diff --git a/gdb/frame.c b/gdb/frame.c index 0966191..c5b355f 100644 --- a/gdb/frame.c +++ b/gdb/frame.c @@ -29,6 +29,10 @@ #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. */ @@ -378,3 +382,544 @@ frame_map_regnum_to_name (int regnum) 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 = generic_call_dummy_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 = 0; + char *name; + + /* If the requested entry is in the cache, return it. + Otherwise, figure out what the address should be for the entry + we're about to add to the cache. */ + + if (!next_frame) + { +#if 0 + /* 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. */ + if (!current_frame) + { + error ("You haven't set up a process's stack to examine."); + } +#endif + + return current_frame; + } + + /* If we have the prev one, return it */ + if (next_frame->prev) + return next_frame->prev; + + /* 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)) + { + fromleaf = FRAMELESS_FUNCTION_INVOCATION (next_frame); + if (fromleaf) + address = FRAME_FP (next_frame); + } + + if (!fromleaf) + { + /* 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; + + prev = (struct frame_info *) + obstack_alloc (&frame_cache_obstack, + sizeof (struct frame_info)); + + /* Zero all fields by default. */ + memset (prev, 0, sizeof (struct frame_info)); + + if (next_frame) + 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. */ + + 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 (next_frame != NULL) + { + 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); +} |