X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=gdb%2Fdummy-frame.c;h=998ca934805308ebe9c4a5eef0730190101d7f62;hb=b86138fb0484f42db6cb83abed1e3d0ad2ec4eac;hp=2c5153ebe20d7e94e546eb4dccb3dd5e77022e95;hpb=8adf9e781b1b67596348ab95877cf6f012ec6a68;p=deliverable%2Fbinutils-gdb.git diff --git a/gdb/dummy-frame.c b/gdb/dummy-frame.c index 2c5153ebe2..998ca93480 100644 --- a/gdb/dummy-frame.c +++ b/gdb/dummy-frame.c @@ -1,14 +1,12 @@ /* Code dealing with dummy stack frames, for GDB, the GNU debugger. - Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, - 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002 Free Software - Foundation, Inc. + Copyright (C) 1986-2014 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 + the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, @@ -17,9 +15,7 @@ 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. */ + along with this program. If not, see . */ #include "defs.h" @@ -31,12 +27,9 @@ #include "frame-unwind.h" #include "command.h" #include "gdbcmd.h" - -static void dummy_frame_this_id (struct frame_info *next_frame, - void **this_prologue_cache, - struct frame_id *this_id); - -static int pc_in_dummy_frame (CORE_ADDR pc); +#include +#include "observer.h" +#include "gdbthread.h" /* Dummy frame. This saves the processor state just prior to setting up the inferior function call. Older targets save the registers @@ -45,382 +38,267 @@ static int pc_in_dummy_frame (CORE_ADDR pc); struct dummy_frame { struct dummy_frame *next; - - /* These values belong to the caller (the previous frame, the frame - that this unwinds back to). */ - CORE_ADDR pc; - CORE_ADDR fp; - CORE_ADDR sp; - CORE_ADDR top; + /* This frame's ID. Must match the value returned by + gdbarch_dummy_id. */ struct frame_id id; - struct regcache *regcache; - - /* Address range of the call dummy code. Look for PC in the range - [LO..HI) (after allowing for DECR_PC_AFTER_BREAK). */ - CORE_ADDR call_lo; - CORE_ADDR call_hi; + /* The caller's state prior to the call. */ + struct infcall_suspend_state *caller_state; }; static struct dummy_frame *dummy_frame_stack = NULL; -/* Function: find_dummy_frame(pc, fp, sp) - - Search the stack of dummy frames for one matching the given PC and - FP/SP. Unlike pc_in_dummy_frame(), this function doesn't need to - adjust for DECR_PC_AFTER_BREAK. This is because it is only legal - to call this function after the PC has been adjusted. */ +/* Push the caller's state, along with the dummy frame info, onto the + dummy-frame stack. */ -static struct dummy_frame * -find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp) +void +dummy_frame_push (struct infcall_suspend_state *caller_state, + const struct frame_id *dummy_id) { - struct dummy_frame *dummyframe; - - for (dummyframe = dummy_frame_stack; dummyframe != NULL; - dummyframe = dummyframe->next) - { - /* Does the PC fall within the dummy frame's breakpoint - instruction. If not, discard this one. */ - if (!(pc >= dummyframe->call_lo && pc < dummyframe->call_hi)) - continue; - /* Does the FP match? */ - if (dummyframe->top != 0) - { - /* If the target architecture explicitly saved the - top-of-stack before the inferior function call, assume - that that same architecture will always pass in an FP - (frame base) value that eactly matches that saved TOS. - Don't check the saved SP and SP as they can lead to false - hits. */ - if (fp != dummyframe->top) - continue; - } - else - { - /* An older target that hasn't explicitly or implicitly - saved the dummy frame's top-of-stack. Try matching the - FP against the saved SP and FP. NOTE: If you're trying - to fix a problem with GDB not correctly finding a dummy - frame, check the comments that go with FRAME_ALIGN() and - UNWIND_DUMMY_ID(). */ - if (fp != dummyframe->fp && fp != dummyframe->sp) - continue; - } - /* The FP matches this dummy frame. */ - return dummyframe; - } + struct dummy_frame *dummy_frame; - return NULL; + dummy_frame = XCNEW (struct dummy_frame); + dummy_frame->caller_state = caller_state; + dummy_frame->id = (*dummy_id); + dummy_frame->next = dummy_frame_stack; + dummy_frame_stack = dummy_frame; } -struct regcache * -deprecated_find_dummy_frame_regcache (CORE_ADDR pc, CORE_ADDR fp) +/* Remove *DUMMY_PTR from the dummy frame stack. */ + +static void +remove_dummy_frame (struct dummy_frame **dummy_ptr) { - struct dummy_frame *dummy = find_dummy_frame (pc, fp); - if (dummy != NULL) - return dummy->regcache; - else - return NULL; + struct dummy_frame *dummy = *dummy_ptr; + + *dummy_ptr = dummy->next; + discard_infcall_suspend_state (dummy->caller_state); + xfree (dummy); } -char * -deprecated_generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp) +/* Delete any breakpoint B which is a momentary breakpoint for return from + inferior call matching DUMMY_VOIDP. */ + +static int +pop_dummy_frame_bpt (struct breakpoint *b, void *dummy_voidp) { - struct regcache *regcache = deprecated_find_dummy_frame_regcache (pc, fp); - if (regcache == NULL) - return NULL; - return deprecated_grub_regcache_for_registers (regcache); -} + struct dummy_frame *dummy = dummy_voidp; + + if (b->thread == pid_to_thread_id (inferior_ptid) + && b->disposition == disp_del && frame_id_eq (b->frame_id, dummy->id)) + { + while (b->related_breakpoint != b) + delete_breakpoint (b->related_breakpoint); -/* Function: pc_in_call_dummy (pc, sp, fp) + delete_breakpoint (b); - Return true if the PC falls in a dummy frame created by gdb for an - inferior call. The code below which allows DECR_PC_AFTER_BREAK is - for infrun.c, which may give the function a PC without that - subtracted out. */ + /* Stop the traversal. */ + return 1; + } -int -deprecated_pc_in_call_dummy (CORE_ADDR pc, CORE_ADDR sp, CORE_ADDR fp) -{ - return pc_in_dummy_frame (pc); + /* Continue the traversal. */ + return 0; } -/* Return non-zero if the PC falls in a dummy frame. +/* Pop *DUMMY_PTR, restoring program state to that before the + frame was created. */ - The code below which allows DECR_PC_AFTER_BREAK is for infrun.c, - which may give the function a PC without that subtracted out. +static void +pop_dummy_frame (struct dummy_frame **dummy_ptr) +{ + struct dummy_frame *dummy = *dummy_ptr; - FIXME: cagney/2002-11-23: This is silly. Surely "infrun.c" can - figure out what the real PC (as in the resume address) is BEFORE - calling this function (Oh, and I'm not even sure that this function - is called with an decremented PC, the call to pc_in_call_dummy() in - that file is conditional on - !DEPRECATED_CALL_DUMMY_BREAKPOINT_OFFSET_P yet generic dummy - targets set DEPRECATED_CALL_DUMMY_BREAKPOINT_OFFSET. True?). */ + restore_infcall_suspend_state (dummy->caller_state); -static int -pc_in_dummy_frame (CORE_ADDR pc) -{ - struct dummy_frame *dummyframe; - for (dummyframe = dummy_frame_stack; - dummyframe != NULL; - dummyframe = dummyframe->next) - { - if ((pc >= dummyframe->call_lo) - && (pc < dummyframe->call_hi + DECR_PC_AFTER_BREAK)) - return 1; - } - return 0; + iterate_over_breakpoints (pop_dummy_frame_bpt, dummy); + + /* restore_infcall_control_state frees inf_state, + all that remains is to pop *dummy_ptr. */ + *dummy_ptr = dummy->next; + xfree (dummy); + + /* We've made right mess of GDB's local state, just discard + everything. */ + reinit_frame_cache (); } -/* Function: read_register_dummy - Find a saved register from before GDB calls a function in the inferior */ +/* Look up DUMMY_ID. + Return NULL if not found. */ -CORE_ADDR -deprecated_read_register_dummy (CORE_ADDR pc, CORE_ADDR fp, int regno) +static struct dummy_frame ** +lookup_dummy_frame (struct frame_id dummy_id) { - struct regcache *dummy_regs = deprecated_find_dummy_frame_regcache (pc, fp); + struct dummy_frame **dp; - if (dummy_regs) + for (dp = &dummy_frame_stack; *dp != NULL; dp = &(*dp)->next) { - /* NOTE: cagney/2002-08-12: Replaced a call to - regcache_raw_read_as_address() with a call to - regcache_cooked_read_unsigned(). The old, ...as_address - function was eventually calling extract_unsigned_integer (nee - extract_address) to unpack the registers value. The below is - doing an unsigned extract so that it is functionally - equivalent. The read needs to be cooked as, otherwise, it - will never correctly return the value of a register in the - [NUM_REGS .. NUM_REGS+NUM_PSEUDO_REGS) range. */ - ULONGEST val; - regcache_cooked_read_unsigned (dummy_regs, regno, &val); - return val; + if (frame_id_eq ((*dp)->id, dummy_id)) + return dp; } - else - return 0; + + return NULL; } -/* Save all the registers on the dummy frame stack. Most ports save the - registers on the target stack. This results in lots of unnecessary memory - references, which are slow when debugging via a serial line. Instead, we - save all the registers internally, and never write them to the stack. The - registers get restored when the called function returns to the entry point, - where a breakpoint is laying in wait. */ +/* Pop the dummy frame DUMMY_ID, restoring program state to that before the + frame was created. + On return reinit_frame_cache has been called. + If the frame isn't found, flag an internal error. -void -generic_push_dummy_frame (void) -{ - struct dummy_frame *dummy_frame; - CORE_ADDR fp = get_frame_base (get_current_frame ()); - - /* check to see if there are stale dummy frames, - perhaps left over from when a longjump took us out of a - function that was called by the debugger */ - - dummy_frame = dummy_frame_stack; - while (dummy_frame) - if (INNER_THAN (dummy_frame->fp, fp)) /* stale -- destroy! */ - { - dummy_frame_stack = dummy_frame->next; - regcache_xfree (dummy_frame->regcache); - xfree (dummy_frame); - dummy_frame = dummy_frame_stack; - } - else - dummy_frame = dummy_frame->next; - - dummy_frame = xmalloc (sizeof (struct dummy_frame)); - dummy_frame->regcache = regcache_xmalloc (current_gdbarch); - - dummy_frame->pc = read_pc (); - dummy_frame->sp = read_sp (); - dummy_frame->top = 0; - dummy_frame->fp = fp; - dummy_frame->id = get_frame_id (get_current_frame ()); - regcache_cpy (dummy_frame->regcache, current_regcache); - dummy_frame->next = dummy_frame_stack; - dummy_frame_stack = dummy_frame; -} + NOTE: This can only pop the one frame, even if it is in the middle of the + stack, because the other frames may be for different threads, and there's + currently no way to tell which stack frame is for which thread. */ void -generic_save_dummy_frame_tos (CORE_ADDR sp) +dummy_frame_pop (struct frame_id dummy_id) { - dummy_frame_stack->top = sp; + struct dummy_frame **dp; + + dp = lookup_dummy_frame (dummy_id); + gdb_assert (dp != NULL); + + pop_dummy_frame (dp); } -/* Record the upper/lower bounds on the address of the call dummy. */ +/* Drop dummy frame DUMMY_ID. Do nothing if it is not found. Do not restore + its state into inferior, just free its memory. */ void -generic_save_call_dummy_addr (CORE_ADDR lo, CORE_ADDR hi) +dummy_frame_discard (struct frame_id dummy_id) { - dummy_frame_stack->call_lo = lo; - dummy_frame_stack->call_hi = hi; + struct dummy_frame **dp; + + dp = lookup_dummy_frame (dummy_id); + if (dp) + remove_dummy_frame (dp); } -/* Discard the innermost dummy frame from the dummy frame stack - (passed in as a parameter). */ +/* There may be stale dummy frames, perhaps left over from when an uncaught + longjmp took us out of a function that was called by the debugger. Clean + them up at least once whenever we start a new inferior. */ static void -discard_innermost_dummy (struct dummy_frame **stack) +cleanup_dummy_frames (struct target_ops *target, int from_tty) { - struct dummy_frame *tbd = (*stack); - (*stack) = (*stack)->next; - regcache_xfree (tbd->regcache); - xfree (tbd); + while (dummy_frame_stack != NULL) + remove_dummy_frame (&dummy_frame_stack); } -void -deprecated_pop_dummy_frame (void) +/* Return the dummy frame cache, it contains both the ID, and a + pointer to the regcache. */ +struct dummy_frame_cache { - struct dummy_frame *dummy_frame = dummy_frame_stack; - - /* FIXME: what if the first frame isn't the right one, eg.. - because one call-by-hand function has done a longjmp into another one? */ + struct frame_id this_id; + struct regcache *prev_regcache; +}; - if (!dummy_frame) - error ("Can't pop dummy frame!"); - regcache_cpy (current_regcache, dummy_frame->regcache); - flush_cached_frames (); +static int +dummy_frame_sniffer (const struct frame_unwind *self, + struct frame_info *this_frame, + void **this_prologue_cache) +{ + struct dummy_frame *dummyframe; + struct frame_id this_id; - discard_innermost_dummy (&dummy_frame_stack); + /* 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 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. */ + + /* Don't bother unless there is at least one dummy frame. */ + if (dummy_frame_stack != NULL) + { + /* Use an architecture specific method to extract this frame's + dummy ID, assuming it is a dummy frame. */ + this_id = gdbarch_dummy_id (get_frame_arch (this_frame), this_frame); + + /* Use that ID to find the corresponding cache entry. */ + for (dummyframe = dummy_frame_stack; + dummyframe != NULL; + dummyframe = dummyframe->next) + { + if (frame_id_eq (dummyframe->id, this_id)) + { + struct dummy_frame_cache *cache; + + cache = FRAME_OBSTACK_ZALLOC (struct dummy_frame_cache); + cache->prev_regcache = get_infcall_suspend_state_regcache + (dummyframe->caller_state); + cache->this_id = this_id; + (*this_prologue_cache) = cache; + return 1; + } + } + } + return 0; } /* Given a call-dummy dummy-frame, return the registers. Here the register value is taken from the local copy of the register buffer. */ -static void -dummy_frame_prev_register (struct frame_info *next_frame, +static struct value * +dummy_frame_prev_register (struct frame_info *this_frame, void **this_prologue_cache, - int regnum, int *optimized, - enum lval_type *lvalp, CORE_ADDR *addrp, - int *realnum, void *bufferp) + int regnum) { - struct dummy_frame *dummy; - struct frame_id id; + struct dummy_frame_cache *cache = (*this_prologue_cache); + struct gdbarch *gdbarch = get_frame_arch (this_frame); + struct value *reg_val; - /* Call the ID method which, if at all possible, will set the - prologue cache. */ - dummy_frame_this_id (next_frame, this_prologue_cache, &id); - dummy = (*this_prologue_cache); - gdb_assert (dummy != NULL); + /* The dummy-frame sniffer always fills in the cache. */ + gdb_assert (cache != NULL); /* Describe the register's location. Generic dummy frames always have the register value in an ``expression''. */ - *optimized = 0; - *lvalp = not_lval; - *addrp = 0; - *realnum = -1; - - /* If needed, find and return the value of the register. */ - if (bufferp != NULL) - { - /* Return the actual value. */ - /* Use the regcache_cooked_read() method so that it, on the fly, - constructs either a raw or pseudo register from the raw - register cache. */ - regcache_cooked_read (dummy->regcache, regnum, bufferp); - } + reg_val = value_zero (register_type (gdbarch, regnum), not_lval); + + /* Use the regcache_cooked_read() method so that it, on the fly, + constructs either a raw or pseudo register from the raw + register cache. */ + regcache_cooked_read (cache->prev_regcache, regnum, + value_contents_writeable (reg_val)); + return reg_val; } -/* Assuming that THIS frame is a dummy (remember, the NEXT and not - THIS frame is passed in), return the ID of THIS frame. That ID is +/* Assuming that THIS_FRAME is a dummy, return its ID. That ID is determined by examining the NEXT frame's unwound registers using - the method unwind_dummy_id(). As a side effect, THIS dummy frame's - dummy cache is located and and saved in THIS_PROLOGUE_CACHE. */ + the method dummy_id(). As a side effect, THIS dummy frame's + dummy cache is located and saved in THIS_PROLOGUE_CACHE. */ static void -dummy_frame_this_id (struct frame_info *next_frame, +dummy_frame_this_id (struct frame_info *this_frame, void **this_prologue_cache, struct frame_id *this_id) { - struct dummy_frame *dummy = (*this_prologue_cache); - if (dummy != NULL) - { - (*this_id) = dummy->id; - return; - } - /* 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. */ - if (gdbarch_unwind_dummy_id_p (current_gdbarch)) - { - /* 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. */ - (*this_id) = gdbarch_unwind_dummy_id (current_gdbarch, next_frame); - } - else if (frame_relative_level (next_frame) < 0) - { - /* 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. */ - (*this_id) = frame_id_build (deprecated_read_fp (), read_pc ()); - } - else if (legacy_frame_p (current_gdbarch) - && get_prev_frame (next_frame)) - { - /* Things are looking seriously grim! Assume that the legacy - get_prev_frame code has already created THIS frame and linked - it in to the frame chain (a pretty bold assumption), extract - the ID from THIS base / pc. */ - (*this_id) = frame_id_build (get_frame_base (get_prev_frame (next_frame)), - get_frame_pc (get_prev_frame (next_frame))); - } - else - { - /* Ouch! We're not trying to find the innermost frame's ID yet - we're trying to unwind to a dummy. The architecture must - provide the unwind_dummy_id() method. Abandon the unwind - process but only after first warning the user. */ - internal_warning (__FILE__, __LINE__, - "Missing unwind_dummy_id architecture method"); - (*this_id) = null_frame_id; - return; - } - (*this_prologue_cache) = find_dummy_frame ((*this_id).code_addr, - (*this_id).stack_addr); + /* The dummy-frame sniffer always fills in the cache. */ + struct dummy_frame_cache *cache = (*this_prologue_cache); + + gdb_assert (cache != NULL); + (*this_id) = cache->this_id; } -static struct frame_unwind dummy_frame_unwind = +const struct frame_unwind dummy_frame_unwind = { DUMMY_FRAME, + default_frame_unwind_stop_reason, dummy_frame_this_id, - dummy_frame_prev_register + dummy_frame_prev_register, + NULL, + dummy_frame_sniffer, }; -const struct frame_unwind * -dummy_frame_sniffer (struct frame_info *next_frame) -{ - CORE_ADDR pc = frame_pc_unwind (next_frame); - gdb_assert (DEPRECATED_USE_GENERIC_DUMMY_FRAMES); - if (pc_in_dummy_frame (pc)) - return &dummy_frame_unwind; - else - return NULL; -} - static void fprint_dummy_frames (struct ui_file *file) { struct dummy_frame *s; + for (s = dummy_frame_stack; s != NULL; s = s->next) { gdb_print_host_address (s, file); fprintf_unfiltered (file, ":"); - fprintf_unfiltered (file, " pc=0x%s", paddr (s->pc)); - fprintf_unfiltered (file, " fp=0x%s", paddr (s->fp)); - fprintf_unfiltered (file, " sp=0x%s", paddr (s->sp)); - fprintf_unfiltered (file, " top=0x%s", paddr (s->top)); fprintf_unfiltered (file, " id="); fprint_frame_id (file, s->id); - fprintf_unfiltered (file, " call_lo=0x%s", paddr (s->call_lo)); - fprintf_unfiltered (file, " call_hi=0x%s", paddr (s->call_hi)); fprintf_unfiltered (file, "\n"); } } @@ -432,11 +310,14 @@ maintenance_print_dummy_frames (char *args, int from_tty) fprint_dummy_frames (gdb_stdout); else { + struct cleanup *cleanups; struct ui_file *file = gdb_fopen (args, "w"); + if (file == NULL) - perror_with_name ("maintenance print dummy-frames"); + perror_with_name (_("maintenance print dummy-frames")); + cleanups = make_cleanup_ui_file_delete (file); fprint_dummy_frames (file); - ui_file_delete (file); + do_cleanups (cleanups); } } @@ -446,7 +327,8 @@ void _initialize_dummy_frame (void) { add_cmd ("dummy-frames", class_maintenance, maintenance_print_dummy_frames, - "Print the contents of the internal dummy-frame stack.", + _("Print the contents of the internal dummy-frame stack."), &maintenanceprintlist); + observer_attach_inferior_created (cleanup_dummy_frames); }