X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gdb%2Fframe.c;h=7df7c43e2967d4ba5815b95692a610127d1fe005;hb=2c0b251b29eeafa90c84a3a938c744bc7ba81aea;hp=a7da9196b0f222147c339fbb771a0d6109709f7d;hpb=5bf00f29a7836dcffc1368181b66ee8f3b703861;p=deliverable%2Fbinutils-gdb.git diff --git a/gdb/frame.c b/gdb/frame.c index a7da9196b0..dfd6b3d53c 100644 --- a/gdb/frame.c +++ b/gdb/frame.c @@ -1,13 +1,13 @@ /* Cache and manage frames for GDB, the GNU debugger. - Copyright 1986, 1987, 1989, 1991, 1994, 1995, 1996, 1998, 2000, - 2001, 2002, 2003, 2004 Free Software Foundation, Inc. + Copyright (C) 1986, 1987, 1989, 1991, 1994, 1995, 1996, 1998, 2000, 2001, + 2002, 2003, 2004, 2007, 2008, 2009 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, @@ -16,9 +16,7 @@ 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" #include "frame.h" @@ -39,6 +37,12 @@ #include "frame-base.h" #include "command.h" #include "gdbcmd.h" +#include "observer.h" +#include "objfiles.h" +#include "exceptions.h" +#include "gdbthread.h" + +static struct frame_info *get_prev_frame_1 (struct frame_info *this_frame); /* We keep a cache of stack frames, each of which is a "struct frame_info". The innermost one gets allocated (in @@ -57,39 +61,16 @@ struct frame_info increases. This is a cached value. It could just as easily be computed by counting back from the selected frame to the inner most frame. */ - /* NOTE: cagney/2002-04-05: Perhaphs a level of ``-1'' should be + /* NOTE: cagney/2002-04-05: Perhaps a level of ``-1'' should be reserved to indicate a bogus frame - one that has been created just to keep GDB happy (GDB always needs a frame). For the moment leave this as speculation. */ int level; - /* The frame's type. */ - /* FIXME: cagney/2003-04-02: Should instead be returning - ->unwind->type. Unfortunately, legacy code is still explicitly - setting the type using the method deprecated_set_frame_type. - Eliminate that method and this field can be eliminated. */ - enum frame_type type; - - /* For each register, address of where it was saved on entry to the - frame, or zero if it was not saved on entry to this frame. This - includes special registers such as pc and fp saved in special - ways in the stack frame. The SP_REGNUM is even more special, the - address here is the sp for the previous frame, not the address - where the sp was saved. */ - /* Allocated by frame_saved_regs_zalloc () which is called / - initialized by DEPRECATED_FRAME_INIT_SAVED_REGS(). */ - CORE_ADDR *saved_regs; /*NUM_REGS + NUM_PSEUDO_REGS*/ - - /* Anything extra for this structure that may have been defined in - the machine dependent files. */ - /* Allocated by frame_extra_info_zalloc () which is called / - initialized by DEPRECATED_INIT_EXTRA_FRAME_INFO */ - struct frame_extra_info *extra_info; - /* The frame's low-level unwinder and corresponding cache. The low-level unwinder is responsible for unwinding register values for the previous frame. The low-level unwind methods are - selected based on the presence, or otherwize, of register unwind + selected based on the presence, or otherwise, of register unwind information such as CFI. */ void *prologue_cache; const struct frame_unwind *unwind; @@ -125,25 +106,74 @@ struct frame_info struct frame_info *next; /* down, inner, younger */ int prev_p; struct frame_info *prev; /* up, outer, older */ + + /* The reason why we could not set PREV, or UNWIND_NO_REASON if we + could. Only valid when PREV_P is set. */ + enum unwind_stop_reason stop_reason; }; /* Flag to control debugging. */ -static int frame_debug; +int frame_debug; +static void +show_frame_debug (struct ui_file *file, int from_tty, + struct cmd_list_element *c, const char *value) +{ + fprintf_filtered (file, _("Frame debugging is %s.\n"), value); +} /* Flag to indicate whether backtraces should stop at main et.al. */ static int backtrace_past_main; -static unsigned int backtrace_limit = UINT_MAX; +static void +show_backtrace_past_main (struct ui_file *file, int from_tty, + struct cmd_list_element *c, const char *value) +{ + fprintf_filtered (file, _("\ +Whether backtraces should continue past \"main\" is %s.\n"), + value); +} + +static int backtrace_past_entry; +static void +show_backtrace_past_entry (struct ui_file *file, int from_tty, + struct cmd_list_element *c, const char *value) +{ + fprintf_filtered (file, _("\ +Whether backtraces should continue past the entry point of a program is %s.\n"), + value); +} + +static int backtrace_limit = INT_MAX; +static void +show_backtrace_limit (struct ui_file *file, int from_tty, + struct cmd_list_element *c, const char *value) +{ + fprintf_filtered (file, _("\ +An upper bound on the number of backtrace levels is %s.\n"), + value); +} + +static void +fprint_field (struct ui_file *file, const char *name, int p, CORE_ADDR addr) +{ + if (p) + fprintf_unfiltered (file, "%s=0x%s", name, paddr_nz (addr)); + else + fprintf_unfiltered (file, "!%s", name); +} void fprint_frame_id (struct ui_file *file, struct frame_id id) { - fprintf_unfiltered (file, "{stack=0x%s,code=0x%s,special=0x%s}", - paddr_nz (id.stack_addr), - paddr_nz (id.code_addr), - paddr_nz (id.special_addr)); + fprintf_unfiltered (file, "{"); + fprint_field (file, "stack", id.stack_addr_p, id.stack_addr); + fprintf_unfiltered (file, ","); + fprint_field (file, "code", id.code_addr_p, id.code_addr); + fprintf_unfiltered (file, ","); + fprint_field (file, "special", id.special_addr_p, id.special_addr); + fprintf_unfiltered (file, "}"); } static void @@ -151,9 +181,6 @@ fprint_frame_type (struct ui_file *file, enum frame_type type) { switch (type) { - case UNKNOWN_FRAME: - fprintf_unfiltered (file, "UNKNOWN_FRAME"); - return; case NORMAL_FRAME: fprintf_unfiltered (file, "NORMAL_FRAME"); return; @@ -181,7 +208,10 @@ fprint_frame (struct ui_file *file, struct frame_info *fi) fprintf_unfiltered (file, "level=%d", fi->level); fprintf_unfiltered (file, ","); fprintf_unfiltered (file, "type="); - fprint_frame_type (file, fi->type); + if (fi->unwind != NULL) + fprint_frame_type (file, fi->unwind->type); + else + fprintf_unfiltered (file, ""); fprintf_unfiltered (file, ","); fprintf_unfiltered (file, "unwind="); if (fi->unwind != NULL) @@ -221,24 +251,14 @@ get_frame_id (struct frame_info *fi) } if (!fi->this_id.p) { - gdb_assert (!legacy_frame_p (current_gdbarch)); if (frame_debug) fprintf_unfiltered (gdb_stdlog, "{ get_frame_id (fi=%d) ", fi->level); /* Find the unwinder. */ if (fi->unwind == NULL) - { - fi->unwind = frame_unwind_find_by_frame (fi->next); - /* FIXME: cagney/2003-04-02: Rather than storing the frame's - type in the frame, the unwinder's type should be returned - directly. Unfortunately, legacy code, called by - legacy_get_prev_frame, explicitly set the frames type - using the method deprecated_set_frame_type(). */ - gdb_assert (fi->unwind->type != UNKNOWN_FRAME); - fi->type = fi->unwind->type; - } + fi->unwind = frame_unwind_find_by_frame (fi, &fi->prologue_cache); /* Find THIS frame's ID. */ - fi->unwind->this_id (fi->next, &fi->prologue_cache, &fi->this_id.value); + fi->unwind->this_id (fi, &fi->prologue_cache, &fi->this_id.value); fi->this_id.p = 1; if (frame_debug) { @@ -250,31 +270,58 @@ get_frame_id (struct frame_info *fi) return fi->this_id.value; } +struct frame_id +frame_unwind_id (struct frame_info *next_frame) +{ + /* Use prev_frame, and not get_prev_frame. The latter will truncate + the frame chain, leading to this function unintentionally + returning a null_frame_id (e.g., when a caller requests the frame + ID of "main()"s caller. */ + return get_frame_id (get_prev_frame_1 (next_frame)); +} + const struct frame_id null_frame_id; /* All zeros. */ struct frame_id frame_id_build_special (CORE_ADDR stack_addr, CORE_ADDR code_addr, CORE_ADDR special_addr) { - struct frame_id id; + struct frame_id id = null_frame_id; id.stack_addr = stack_addr; + id.stack_addr_p = 1; id.code_addr = code_addr; + id.code_addr_p = 1; id.special_addr = special_addr; + id.special_addr_p = 1; return id; } struct frame_id frame_id_build (CORE_ADDR stack_addr, CORE_ADDR code_addr) { - return frame_id_build_special (stack_addr, code_addr, 0); + struct frame_id id = null_frame_id; + id.stack_addr = stack_addr; + id.stack_addr_p = 1; + id.code_addr = code_addr; + id.code_addr_p = 1; + return id; +} + +struct frame_id +frame_id_build_wild (CORE_ADDR stack_addr) +{ + struct frame_id id = null_frame_id; + id.stack_addr = stack_addr; + id.stack_addr_p = 1; + return id; } int frame_id_p (struct frame_id l) { int p; - /* The .code can be NULL but the .stack cannot. */ - p = (l.stack_addr != 0); + /* The frame is valid iff it has a valid stack address. */ + p = l.stack_addr_p; if (frame_debug) { fprintf_unfiltered (gdb_stdlog, "{ frame_id_p (l="); @@ -288,20 +335,21 @@ int frame_id_eq (struct frame_id l, struct frame_id r) { int eq; - if (l.stack_addr == 0 || r.stack_addr == 0) - /* Like a NaN, if either ID is invalid, the result is false. */ + if (!l.stack_addr_p || !r.stack_addr_p) + /* Like a NaN, if either ID is invalid, the result is false. + Note that a frame ID is invalid iff it is the null frame ID. */ eq = 0; else if (l.stack_addr != r.stack_addr) /* If .stack addresses are different, the frames are different. */ eq = 0; - else if (l.code_addr == 0 || r.code_addr == 0) - /* A zero code addr is a wild card, always succeed. */ + else if (!l.code_addr_p || !r.code_addr_p) + /* An invalid code addr is a wild card, always succeed. */ eq = 1; else if (l.code_addr != r.code_addr) /* If .code addresses are different, the frames are different. */ eq = 0; - else if (l.special_addr == 0 || r.special_addr == 0) - /* A zero special addr is a wild card (or unused), always succeed. */ + else if (!l.special_addr_p || !r.special_addr_p) + /* An invalid special addr is a wild card (or unused), always succeed. */ eq = 1; else if (l.special_addr == r.special_addr) /* Frames are equal. */ @@ -320,11 +368,37 @@ frame_id_eq (struct frame_id l, struct frame_id r) return eq; } -int -frame_id_inner (struct frame_id l, struct frame_id r) +/* Safety net to check whether frame ID L should be inner to + frame ID R, according to their stack addresses. + + This method cannot be used to compare arbitrary frames, as the + ranges of valid stack addresses may be discontiguous (e.g. due + to sigaltstack). + + However, it can be used as safety net to discover invalid frame + IDs in certain circumstances. + + * If frame NEXT is the immediate inner frame to THIS, and NEXT + is a NORMAL frame, then the stack address of NEXT must be + inner-than-or-equal to the stack address of THIS. + + Therefore, if frame_id_inner (THIS, NEXT) holds, some unwind + error has occurred. + + * If frame NEXT is the immediate inner frame to THIS, and NEXT + is a NORMAL frame, and NEXT and THIS have different stack + addresses, no other frame in the frame chain may have a stack + address in between. + + Therefore, if frame_id_inner (TEST, THIS) holds, but + frame_id_inner (TEST, NEXT) does not hold, TEST cannot refer + to a valid frame in the frame chain. */ + +static int +frame_id_inner (struct gdbarch *gdbarch, struct frame_id l, struct frame_id r) { int inner; - if (l.stack_addr == 0 || r.stack_addr == 0) + if (!l.stack_addr_p || !r.stack_addr_p) /* Like NaN, any operation involving an invalid ID always fails. */ inner = 0; else @@ -332,7 +406,7 @@ frame_id_inner (struct frame_id l, struct frame_id r) comment in "frame.h", there is some fuzz here. Frameless functions are not strictly inner than (same .stack but different .code and/or .special address). */ - inner = INNER_THAN (l.stack_addr, r.stack_addr); + inner = gdbarch_inner_than (gdbarch, l.stack_addr, r.stack_addr); if (frame_debug) { fprintf_unfiltered (gdb_stdlog, "{ frame_id_inner (l="); @@ -347,28 +421,34 @@ frame_id_inner (struct frame_id l, struct frame_id r) struct frame_info * frame_find_by_id (struct frame_id id) { - struct frame_info *frame; + struct frame_info *frame, *prev_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)) + for (frame = get_current_frame (); ; frame = prev_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. */ + + prev_frame = get_prev_frame (frame); + if (!prev_frame) + return NULL; + + /* As a safety net to avoid unnecessary backtracing while trying + to find an invalid ID, we check for a common situation where + we can detect from comparing stack addresses that no other + frame in the current frame chain can have this ID. See the + comment at frame_id_inner for details. */ + if (get_frame_type (frame) == NORMAL_FRAME + && !frame_id_inner (get_frame_arch (frame), id, this) + && frame_id_inner (get_frame_arch (prev_frame), id, + get_frame_id (prev_frame))) 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; } @@ -379,7 +459,7 @@ frame_pc_unwind (struct frame_info *this_frame) if (!this_frame->prev_pc.p) { CORE_ADDR pc; - if (gdbarch_unwind_pc_p (current_gdbarch)) + if (gdbarch_unwind_pc_p (get_frame_arch (this_frame))) { /* The right way. The `pure' way. The one true way. This method depends solely on the register-unwind code to @@ -397,27 +477,10 @@ frame_pc_unwind (struct frame_info *this_frame) 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); + pc = gdbarch_unwind_pc (get_frame_arch (this_frame), this_frame); } else - internal_error (__FILE__, __LINE__, "No gdbarch_unwind_pc method"); + internal_error (__FILE__, __LINE__, _("No unwind_pc method")); this_frame->prev_pc.value = pc; this_frame->prev_pc.p = 1; if (frame_debug) @@ -430,90 +493,94 @@ frame_pc_unwind (struct frame_info *this_frame) } CORE_ADDR -frame_func_unwind (struct frame_info *fi) +get_frame_func (struct frame_info *this_frame) { - if (!fi->prev_func.p) + struct frame_info *next_frame = this_frame->next; + + if (!next_frame->prev_func.p) { /* Make certain that this, and not the adjacent, function is found. */ - CORE_ADDR addr_in_block = frame_unwind_address_in_block (fi); - fi->prev_func.p = 1; - fi->prev_func.addr = get_pc_function_start (addr_in_block); + CORE_ADDR addr_in_block = get_frame_address_in_block (this_frame); + next_frame->prev_func.p = 1; + next_frame->prev_func.addr = get_pc_function_start (addr_in_block); if (frame_debug) fprintf_unfiltered (gdb_stdlog, - "{ frame_func_unwind (fi=%d) -> 0x%s }\n", - fi->level, paddr_nz (fi->prev_func.addr)); + "{ get_frame_func (this_frame=%d) -> 0x%s }\n", + this_frame->level, + paddr_nz (next_frame->prev_func.addr)); } - return fi->prev_func.addr; + return next_frame->prev_func.addr; } -CORE_ADDR -get_frame_func (struct frame_info *fi) +static int +do_frame_register_read (void *src, int regnum, gdb_byte *buf) { - return frame_func_unwind (fi->next); + return frame_register_read (src, regnum, buf); } -static int -do_frame_unwind_register (void *src, int regnum, void *buf) +struct regcache * +frame_save_as_regcache (struct frame_info *this_frame) { - frame_unwind_register (src, regnum, buf); - return 1; + struct regcache *regcache = regcache_xmalloc (get_frame_arch (this_frame)); + struct cleanup *cleanups = make_cleanup_regcache_xfree (regcache); + regcache_save (regcache, do_frame_register_read, this_frame); + discard_cleanups (cleanups); + return regcache; } void frame_pop (struct frame_info *this_frame) { - struct regcache *scratch_regcache; + struct frame_info *prev_frame; + struct regcache *scratch; struct cleanup *cleanups; - if (DEPRECATED_POP_FRAME_P ()) + if (get_frame_type (this_frame) == DUMMY_FRAME) { - /* 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. Unfortunately, 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); + /* Popping a dummy frame involves restoring more than just registers. + dummy_frame_pop does all the work. */ + dummy_frame_pop (get_frame_id (this_frame)); + return; } + + /* Ensure that we have a frame to pop to. */ + prev_frame = get_prev_frame_1 (this_frame); + + if (!prev_frame) + error (_("Cannot pop the initial frame.")); + + /* 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 between + trying to extract the old values from the current regcache while + at the same time writing new values into that same cache. */ + scratch = frame_save_as_regcache (prev_frame); + cleanups = make_cleanup_regcache_xfree (scratch); + + /* 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. + Unfortunately, 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 (get_current_regcache (), scratch); + do_cleanups (cleanups); + /* We've made right mess of GDB's local state, just discard everything. */ - flush_cached_frames (); + reinit_frame_cache (); } void frame_register_unwind (struct frame_info *frame, int regnum, int *optimizedp, enum lval_type *lvalp, - CORE_ADDR *addrp, int *realnump, void *bufferp) + CORE_ADDR *addrp, int *realnump, gdb_byte *bufferp) { - struct frame_unwind_cache *cache; - - if (frame_debug) - { - fprintf_unfiltered (gdb_stdlog, - "{ frame_register_unwind (frame=%d,regnum=\"%s\",...) ", - frame->level, frame_map_regnum_to_name (frame, regnum)); - } + struct value *value; /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates that the value proper does not need to be fetched. */ @@ -523,57 +590,29 @@ frame_register_unwind (struct frame_info *frame, int regnum, 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); + value = frame_unwind_register_value (frame, regnum); - /* Find the unwinder. */ - if (frame->unwind == NULL) - { - frame->unwind = frame_unwind_find_by_frame (frame->next); - /* FIXME: cagney/2003-04-02: Rather than storing the frame's - type in the frame, the unwinder's type should be returned - directly. Unfortunately, legacy code, called by - legacy_get_prev_frame, explicitly set the frames type using - the method deprecated_set_frame_type(). */ - gdb_assert (frame->unwind->type != UNKNOWN_FRAME); - frame->type = frame->unwind->type; - } + gdb_assert (value != 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); + *optimizedp = value_optimized_out (value); + *lvalp = VALUE_LVAL (value); + *addrp = VALUE_ADDRESS (value); + *realnump = VALUE_REGNUM (value); - if (frame_debug) - { - fprintf_unfiltered (gdb_stdlog, "->"); - fprintf_unfiltered (gdb_stdlog, " *optimizedp=%d", (*optimizedp)); - fprintf_unfiltered (gdb_stdlog, " *lvalp=%d", (int) (*lvalp)); - fprintf_unfiltered (gdb_stdlog, " *addrp=0x%s", paddr_nz ((*addrp))); - fprintf_unfiltered (gdb_stdlog, " *bufferp="); - if (bufferp == NULL) - fprintf_unfiltered (gdb_stdlog, ""); - else - { - int i; - const unsigned char *buf = bufferp; - fprintf_unfiltered (gdb_stdlog, "["); - for (i = 0; i < register_size (current_gdbarch, regnum); i++) - fprintf_unfiltered (gdb_stdlog, "%02x", buf[i]); - fprintf_unfiltered (gdb_stdlog, "]"); - } - fprintf_unfiltered (gdb_stdlog, " }\n"); - } + if (bufferp) + memcpy (bufferp, value_contents_all (value), + TYPE_LENGTH (value_type (value))); + + /* Dispose of the new value. This prevents watchpoints from + trying to watch the saved frame pointer. */ + release_value (value); + value_free (value); } void frame_register (struct frame_info *frame, int regnum, int *optimizedp, enum lval_type *lvalp, - CORE_ADDR *addrp, int *realnump, void *bufferp) + CORE_ADDR *addrp, int *realnump, gdb_byte *bufferp) { /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates that the value proper does not need to be fetched. */ @@ -583,33 +622,6 @@ frame_register (struct frame_info *frame, int regnum, 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); @@ -618,7 +630,7 @@ frame_register (struct frame_info *frame, int regnum, } void -frame_unwind_register (struct frame_info *frame, int regnum, void *buf) +frame_unwind_register (struct frame_info *frame, int regnum, gdb_byte *buf) { int optimized; CORE_ADDR addr; @@ -630,17 +642,84 @@ frame_unwind_register (struct frame_info *frame, int regnum, void *buf) void get_frame_register (struct frame_info *frame, - int regnum, void *buf) + int regnum, gdb_byte *buf) { frame_unwind_register (frame->next, regnum, buf); } +struct value * +frame_unwind_register_value (struct frame_info *frame, int regnum) +{ + struct value *value; + + gdb_assert (frame != NULL); + + if (frame_debug) + { + fprintf_unfiltered (gdb_stdlog, "\ +{ frame_unwind_register_value (frame=%d,regnum=%d(%s),...) ", + frame->level, regnum, + user_reg_map_regnum_to_name + (get_frame_arch (frame), regnum)); + } + + /* Find the unwinder. */ + if (frame->unwind == NULL) + frame->unwind = frame_unwind_find_by_frame (frame, &frame->prologue_cache); + + /* Ask this frame to unwind its register. */ + value = frame->unwind->prev_register (frame, &frame->prologue_cache, regnum); + + if (frame_debug) + { + fprintf_unfiltered (gdb_stdlog, "->"); + if (value_optimized_out (value)) + fprintf_unfiltered (gdb_stdlog, " optimized out"); + else + { + if (VALUE_LVAL (value) == lval_register) + fprintf_unfiltered (gdb_stdlog, " register=%d", + VALUE_REGNUM (value)); + else if (VALUE_LVAL (value) == lval_memory) + fprintf_unfiltered (gdb_stdlog, " address=0x%s", + paddr_nz (VALUE_ADDRESS (value))); + else + fprintf_unfiltered (gdb_stdlog, " computed"); + + if (value_lazy (value)) + fprintf_unfiltered (gdb_stdlog, " lazy"); + else + { + int i; + const gdb_byte *buf = value_contents (value); + + fprintf_unfiltered (gdb_stdlog, " bytes="); + fprintf_unfiltered (gdb_stdlog, "["); + for (i = 0; i < register_size (get_frame_arch (frame), regnum); i++) + fprintf_unfiltered (gdb_stdlog, "%02x", buf[i]); + fprintf_unfiltered (gdb_stdlog, "]"); + } + } + + fprintf_unfiltered (gdb_stdlog, " }\n"); + } + + return value; +} + +struct value * +get_frame_register_value (struct frame_info *frame, int regnum) +{ + return frame_unwind_register_value (frame->next, regnum); +} + LONGEST frame_unwind_register_signed (struct frame_info *frame, int regnum) { - char buf[MAX_REGISTER_SIZE]; + gdb_byte buf[MAX_REGISTER_SIZE]; frame_unwind_register (frame, regnum, buf); - return extract_signed_integer (buf, DEPRECATED_REGISTER_VIRTUAL_SIZE (regnum)); + return extract_signed_integer (buf, register_size (get_frame_arch (frame), + regnum)); } LONGEST @@ -652,9 +731,10 @@ get_frame_register_signed (struct frame_info *frame, int regnum) ULONGEST frame_unwind_register_unsigned (struct frame_info *frame, int regnum) { - char buf[MAX_REGISTER_SIZE]; + gdb_byte buf[MAX_REGISTER_SIZE]; frame_unwind_register (frame, regnum, buf); - return extract_unsigned_integer (buf, DEPRECATED_REGISTER_VIRTUAL_SIZE (regnum)); + return extract_unsigned_integer (buf, register_size (get_frame_arch (frame), + regnum)); } ULONGEST @@ -664,16 +744,8 @@ get_frame_register_unsigned (struct frame_info *frame, int regnum) } void -frame_unwind_unsigned_register (struct frame_info *frame, int regnum, - ULONGEST *val) -{ - char buf[MAX_REGISTER_SIZE]; - frame_unwind_register (frame, regnum, buf); - (*val) = extract_unsigned_integer (buf, DEPRECATED_REGISTER_VIRTUAL_SIZE (regnum)); -} - -void -put_frame_register (struct frame_info *frame, int regnum, const void *buf) +put_frame_register (struct frame_info *frame, int regnum, + const gdb_byte *buf) { struct gdbarch *gdbarch = get_frame_arch (frame); int realnum; @@ -682,36 +754,36 @@ put_frame_register (struct frame_info *frame, int regnum, const void *buf) CORE_ADDR addr; frame_register (frame, regnum, &optim, &lval, &addr, &realnum, NULL); if (optim) - error ("Attempt to assign to a value that was optimized out."); + error (_("Attempt to assign to a value that was optimized out.")); switch (lval) { case lval_memory: { /* FIXME: write_memory doesn't yet take constant buffers. Arrrg! */ - char tmp[MAX_REGISTER_SIZE]; + gdb_byte tmp[MAX_REGISTER_SIZE]; memcpy (tmp, buf, register_size (gdbarch, regnum)); write_memory (addr, tmp, register_size (gdbarch, regnum)); break; } case lval_register: - regcache_cooked_write (current_regcache, realnum, buf); + regcache_cooked_write (get_current_regcache (), realnum, buf); break; default: - error ("Attempt to assign to an unmodifiable value."); + error (_("Attempt to assign to an unmodifiable value.")); } } /* frame_register_read () Find and return the value of REGNUM for the specified stack frame. - The number of bytes copied is DEPRECATED_REGISTER_RAW_SIZE - (REGNUM). + The number of bytes copied is REGISTER_SIZE (REGNUM). Returns 0 if the register value could not be found. */ int -frame_register_read (struct frame_info *frame, int regnum, void *myaddr) +frame_register_read (struct frame_info *frame, int regnum, + gdb_byte *myaddr) { int optimized; enum lval_type lval; @@ -719,34 +791,109 @@ frame_register_read (struct frame_info *frame, int regnum, void *myaddr) int realnum; frame_register (frame, regnum, &optimized, &lval, &addr, &realnum, myaddr); - /* FIXME: cagney/2002-05-15: This test, is just bogus. + return !optimized; +} - 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. */ +int +get_frame_register_bytes (struct frame_info *frame, int regnum, + CORE_ADDR offset, int len, gdb_byte *myaddr) +{ + struct gdbarch *gdbarch = get_frame_arch (frame); + int i; + int maxsize; + int numregs; - if (register_cached (regnum) < 0) - return 0; /* register value not available */ + /* Skip registers wholly inside of OFFSET. */ + while (offset >= register_size (gdbarch, regnum)) + { + offset -= register_size (gdbarch, regnum); + regnum++; + } - return !optimized; -} + /* Ensure that we will not read beyond the end of the register file. + This can only ever happen if the debug information is bad. */ + maxsize = -offset; + numregs = gdbarch_num_regs (gdbarch) + gdbarch_num_pseudo_regs (gdbarch); + for (i = regnum; i < numregs; i++) + { + int thissize = register_size (gdbarch, i); + if (thissize == 0) + break; /* This register is not available on this architecture. */ + maxsize += thissize; + } + if (len > maxsize) + { + warning (_("Bad debug information detected: " + "Attempt to read %d bytes from registers."), len); + return 0; + } + + /* Copy the data. */ + while (len > 0) + { + int curr_len = register_size (gdbarch, regnum) - offset; + if (curr_len > len) + curr_len = len; + if (curr_len == register_size (gdbarch, regnum)) + { + if (!frame_register_read (frame, regnum, myaddr)) + return 0; + } + else + { + gdb_byte buf[MAX_REGISTER_SIZE]; + if (!frame_register_read (frame, regnum, buf)) + return 0; + memcpy (myaddr, buf + offset, curr_len); + } -/* 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. */ + myaddr += curr_len; + len -= curr_len; + offset = 0; + regnum++; + } -int -frame_map_name_to_regnum (struct frame_info *frame, const char *name, int len) -{ - return user_reg_map_name_to_regnum (get_frame_arch (frame), name, len); + return 1; } -const char * -frame_map_regnum_to_name (struct frame_info *frame, int regnum) +void +put_frame_register_bytes (struct frame_info *frame, int regnum, + CORE_ADDR offset, int len, const gdb_byte *myaddr) { - return user_reg_map_regnum_to_name (get_frame_arch (frame), regnum); + struct gdbarch *gdbarch = get_frame_arch (frame); + + /* Skip registers wholly inside of OFFSET. */ + while (offset >= register_size (gdbarch, regnum)) + { + offset -= register_size (gdbarch, regnum); + regnum++; + } + + /* Copy the data. */ + while (len > 0) + { + int curr_len = register_size (gdbarch, regnum) - offset; + if (curr_len > len) + curr_len = len; + + if (curr_len == register_size (gdbarch, regnum)) + { + put_frame_register (frame, regnum, myaddr); + } + else + { + gdb_byte buf[MAX_REGISTER_SIZE]; + frame_register_read (frame, regnum, buf); + memcpy (buf + offset, myaddr, curr_len); + put_frame_register (frame, regnum, buf); + } + + myaddr += curr_len; + len -= curr_len; + offset = 0; + regnum++; + } } /* Create a sentinel frame. */ @@ -755,7 +902,6 @@ static 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 @@ -797,20 +943,6 @@ frame_obstack_zalloc (unsigned long 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 * -deprecated_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 @@ -820,7 +952,7 @@ 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 + /* A sentinel frame can fail to unwind, e.g., because its PC value lands in somewhere like start. */ if (frame == NULL) return 1; @@ -837,17 +969,20 @@ get_current_frame (void) explicitly checks that ``print $pc'' with no registers prints "No registers". */ if (!target_has_registers) - error ("No registers."); + error (_("No registers.")); if (!target_has_stack) - error ("No stack."); + error (_("No stack.")); if (!target_has_memory) - error ("No memory."); + error (_("No memory.")); + if (is_executing (inferior_ptid)) + error (_("Target is executing.")); + if (current_frame == NULL) { struct frame_info *sentinel_frame = - create_sentinel_frame (current_regcache); + create_sentinel_frame (get_current_regcache ()); if (catch_exceptions (uiout, unwind_to_current_frame, sentinel_frame, - NULL, RETURN_MASK_ERROR) != 0) + RETURN_MASK_ERROR) != 0) { /* Oops! Fake a current frame? Is this useful? It has a PC of zero, for instance. */ @@ -860,35 +995,53 @@ get_current_frame (void) /* 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; +static struct frame_info *selected_frame; + +int +has_stack_frames (void) +{ + if (!target_has_registers || !target_has_stack || !target_has_memory) + return 0; + + /* If the current thread is executing, don't try to read from + it. */ + if (is_executing (inferior_ptid)) + return 0; + + return 1; +} -/* Return the selected frame. Always non-null (unless there isn't an +/* 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) +get_selected_frame (const char *message) { - 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 ()); + if (selected_frame == NULL) + { + if (message != NULL && !has_stack_frames ()) + error (("%s"), message); + /* 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; + gdb_assert (selected_frame != NULL); + return selected_frame; } -/* This is a variant of get_selected_frame which can be called when +/* This is a variant of get_selected_frame() which can be called when the inferior does not have a frame; in that case it will return - NULL instead of calling error (). */ + NULL instead of calling error(). */ struct frame_info * deprecated_safe_get_selected_frame (void) { - if (!target_has_registers || !target_has_stack || !target_has_memory) + if (!has_stack_frames ()) return NULL; - return get_selected_frame (); + return get_selected_frame (NULL); } /* Select frame FI (or NULL - to invalidate the current frame). */ @@ -898,27 +1051,27 @@ select_frame (struct frame_info *fi) { struct symtab *s; - deprecated_selected_frame = fi; - /* NOTE: cagney/2002-05-04: FI can be NULL. This occures when the + selected_frame = fi; + /* NOTE: cagney/2002-05-04: FI can be NULL. This occurs when the frame is being invalidated. */ - if (selected_frame_level_changed_hook) - selected_frame_level_changed_hook (frame_relative_level (fi)); + if (deprecated_selected_frame_level_changed_hook) + deprecated_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 + 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. + 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. */ + be called when the user's 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) { /* We retrieve the frame's symtab by using the frame PC. However - we cannot use the frame pc as is, because it usually points to + we cannot use the frame PC as-is, because it usually points to the instruction following the "call", which is sometimes the first instruction of another function. So we rely on get_frame_address_in_block() which provides us with a PC which @@ -933,814 +1086,146 @@ select_frame (struct frame_info *fi) } } } + +/* Create an arbitrary (i.e. address specified by user) or innermost frame. + Always returns a non-NULL value. */ -/* 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. - Unfortunately, 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); +struct frame_info * +create_new_frame (CORE_ADDR addr, CORE_ADDR pc) +{ + struct frame_info *fi; - if (deprecated_get_frame_saved_regs (frame) == NULL) + if (frame_debug) { - /* If nothing's initialized the saved regs, do it now. */ - gdb_assert (DEPRECATED_FRAME_INIT_SAVED_REGS_P ()); - DEPRECATED_FRAME_INIT_SAVED_REGS (frame); - gdb_assert (deprecated_get_frame_saved_regs (frame) != NULL); + fprintf_unfiltered (gdb_stdlog, + "{ create_new_frame (addr=0x%s, pc=0x%s) ", + paddr_nz (addr), paddr_nz (pc)); } - if (deprecated_get_frame_saved_regs (frame) != NULL - && deprecated_get_frame_saved_regs (frame)[regnum] != 0) + fi = FRAME_OBSTACK_ZALLOC (struct frame_info); + + fi->next = create_sentinel_frame (get_current_regcache ()); + + /* Set/update this frame's cached PC value, found in the next frame. + Do this before looking for this frame's unwinder. A sniffer is + very likely to read this, and the corresponding unwinder is + entitled to rely that the PC doesn't magically change. */ + fi->next->prev_pc.value = pc; + fi->next->prev_pc.p = 1; + + /* Select/initialize both the unwind function and the frame's type + based on the PC. */ + fi->unwind = frame_unwind_find_by_frame (fi, &fi->prologue_cache); + + fi->this_id.p = 1; + fi->this_id.value = frame_id_build (addr, pc); + + if (frame_debug) { - if (regnum == SP_REGNUM) - { - /* SP register treated specially. */ - *optimizedp = 0; - *lvalp = not_lval; - *addrp = 0; - *realnump = -1; - if (bufferp != NULL) - /* NOTE: cagney/2003-05-09: In-lined store_address with - it's body - store_unsigned_integer. */ - store_unsigned_integer (bufferp, DEPRECATED_REGISTER_RAW_SIZE (regnum), - deprecated_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 = deprecated_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 (DEPRECATED_REGISTER_RAW_SIZE (regnum)); - read_memory (deprecated_get_frame_saved_regs (frame)[regnum], regs[regnum], - DEPRECATED_REGISTER_RAW_SIZE (regnum)); - } - memcpy (bufferp, regs[regnum], DEPRECATED_REGISTER_RAW_SIZE (regnum)); -#else - /* Read the value in from memory. */ - read_memory (deprecated_get_frame_saved_regs (frame)[regnum], bufferp, - DEPRECATED_REGISTER_RAW_SIZE (regnum)); -#endif - } - } - return; + fprintf_unfiltered (gdb_stdlog, "-> "); + fprint_frame (gdb_stdlog, fi); + fprintf_unfiltered (gdb_stdlog, " }\n"); } - /* 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); + return fi; } -static void -legacy_saved_regs_this_id (struct frame_info *next_frame, - void **this_prologue_cache, - struct frame_id *id) +/* 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) { - /* legacy_get_prev_frame() always sets ->this_id.p, hence this is - never needed. */ - internal_error (__FILE__, __LINE__, "legacy_saved_regs_this_id() called"); + if (this_frame->level > 0) + return this_frame->next; + else + return NULL; } - -const struct frame_unwind legacy_saved_regs_unwinder = { - /* Not really. It gets overridden by legacy_get_prev_frame. */ - UNKNOWN_FRAME, - 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. +/* Observer for the target_changed event. */ - 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 - DEPRECATED_REGISTER_BYTE offset into the registers array. If the - value is stored in a dummy frame, set *ADDRP to zero. +static void +frame_observer_target_changed (struct target_ops *target) +{ + reinit_frame_cache (); +} - The argument RAW_BUFFER must point to aligned memory. */ +/* Flush the entire frame cache. */ void -deprecated_generic_get_saved_register (char *raw_buffer, int *optimized, - CORE_ADDR *addrp, - struct frame_info *frame, int regnum, - enum lval_type *lval) +reinit_frame_cache (void) { - if (!target_has_registers) - error ("No registers."); + struct frame_info *fi; - /* 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 - (deprecated_find_dummy_frame_regcache (get_frame_pc (frame), - get_frame_base (frame)), - regnum, raw_buffer); - return; - } - - DEPRECATED_FRAME_INIT_SAVED_REGS (frame); - if (deprecated_get_frame_saved_regs (frame) != NULL - && deprecated_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 */ - /* NOTE: cagney/2003-05-09: In-line store_address - with it's body - store_unsigned_integer. */ - store_unsigned_integer (raw_buffer, - DEPRECATED_REGISTER_RAW_SIZE (regnum), - deprecated_get_frame_saved_regs (frame)[regnum]); - } - else - { - if (addrp) /* any other register */ - *addrp = deprecated_get_frame_saved_regs (frame)[regnum]; - if (raw_buffer) - read_memory (deprecated_get_frame_saved_regs (frame)[regnum], raw_buffer, - DEPRECATED_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 = DEPRECATED_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; - - if (frame_debug) - { - fprintf_unfiltered (gdb_stdlog, - "{ create_new_frame (addr=0x%s, pc=0x%s) ", - paddr_nz (addr), paddr_nz (pc)); - } - - fi = frame_obstack_zalloc (sizeof (struct frame_info)); - - fi->next = create_sentinel_frame (current_regcache); - - /* Select/initialize both the unwind function and the frame's type - based on the PC. */ - fi->unwind = frame_unwind_find_by_frame (fi->next); - if (fi->unwind->type != UNKNOWN_FRAME) - fi->type = fi->unwind->type; - else - fi->type = frame_type_from_pc (pc); - - fi->this_id.p = 1; - deprecated_update_frame_base_hack (fi, addr); - deprecated_update_frame_pc_hack (fi, pc); - - if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ()) - DEPRECATED_INIT_EXTRA_FRAME_INFO (0, fi); - - if (frame_debug) + /* Tear down all frame caches. */ + for (fi = current_frame; fi != NULL; fi = fi->prev) { - fprintf_unfiltered (gdb_stdlog, "-> "); - fprint_frame (gdb_stdlog, fi); - fprintf_unfiltered (gdb_stdlog, " }\n"); + if (fi->prologue_cache && fi->unwind->dealloc_cache) + fi->unwind->dealloc_cache (fi, fi->prologue_cache); + if (fi->base_cache && fi->base->unwind->dealloc_cache) + fi->base->unwind->dealloc_cache (fi, fi->base_cache); } - 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; -} - -struct frame_info * -deprecated_get_next_frame_hack (struct frame_info *this_frame) -{ - return this_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); + if (current_frame != NULL) + annotate_frames_invalid (); + current_frame = NULL; /* Invalidate cache */ select_frame (NULL); - annotate_frames_invalid (); if (frame_debug) - fprintf_unfiltered (gdb_stdlog, "{ flush_cached_frames () }\n"); -} - -/* 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 ()); - } + fprintf_unfiltered (gdb_stdlog, "{ reinit_frame_cache () }\n"); } -/* Create the previous frame using the deprecated methods - INIT_EXTRA_INFO, INIT_FRAME_PC and INIT_FRAME_PC_FIRST. */ +/* Find where a register is saved (in memory or another register). + The result of frame_register_unwind is just where it is saved + relative to this particular frame. */ -static struct frame_info * -legacy_get_prev_frame (struct frame_info *this_frame) +static void +frame_register_unwind_location (struct frame_info *this_frame, int regnum, + int *optimizedp, enum lval_type *lvalp, + CORE_ADDR *addrp, int *realnump) { - CORE_ADDR address = 0; - struct frame_info *prev; - int fromleaf; - - /* Don't frame_debug print legacy_get_prev_frame() here, just - confuses the output. */ - - /* Allocate the new frame. - - 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; - - /* Do not completly wire it in to the frame chain. Some (bad) code - in INIT_FRAME_EXTRA_INFO tries to look along frame->prev to pull - some fancy tricks (of course such code is, by definition, - recursive). - - On the other hand, methods, such as get_frame_pc() and - get_frame_base() rely on being able to walk along the frame - chain. Make certain that at least they work by providing that - link. Of course things manipulating prev can't go back. */ - prev->next = this_frame; - - /* 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. - Unfortunately those same work-arounds rely on the type defaulting - to NORMAL_FRAME. Ulgh! The new frame code does not have this - problem. */ - prev->type = UNKNOWN_FRAME; - - /* A legacy frame's ID is always computed here. Mark it as valid. */ - prev->this_id.p = 1; - - /* 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. */ - - deprecated_update_frame_pc_hack (prev, frame_pc_unwind (this_frame)); - if (get_frame_pc (prev) == 0) - { - /* The allocated PREV_FRAME will be reclaimed when the frame - obstack is next purged. */ - if (frame_debug) - { - fprintf_unfiltered (gdb_stdlog, "-> "); - fprint_frame (gdb_stdlog, NULL); - fprintf_unfiltered (gdb_stdlog, - " // unwound legacy PC zero }\n"); - } - return NULL; - } - - /* Set the unwind functions based on that identified PC. Ditto - for the "type" but strongly prefer the unwinder's frame type. */ - prev->unwind = frame_unwind_find_by_frame (prev->next); - if (prev->unwind->type == UNKNOWN_FRAME) - prev->type = frame_type_from_pc (get_frame_pc (prev)); - else - prev->type = prev->unwind->type; - - /* 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. */ - /* 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->this_id.value = 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->this_id.value = frame_id_build (deprecated_read_fp (), - read_pc ()); - } - - /* Check that the unwound ID is valid. */ - if (!frame_id_p (prev->this_id.value)) - { - if (frame_debug) - { - fprintf_unfiltered (gdb_stdlog, "-> "); - fprint_frame (gdb_stdlog, NULL); - fprintf_unfiltered (gdb_stdlog, - " // unwound legacy 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. */ - - /* Link it in. */ - this_frame->prev = prev; - - /* 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. Unfortunately 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); - } - - if (prev->type == NORMAL_FRAME) - prev->this_id.value.code_addr - = get_pc_function_start (prev->this_id.value.code_addr); - - if (frame_debug) - { - fprintf_unfiltered (gdb_stdlog, "-> "); - fprint_frame (gdb_stdlog, prev); - fprintf_unfiltered (gdb_stdlog, " } // legacy innermost frame\n"); - } - 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. */ - /* FIXME: cagney/2003-06-16: This returns the inner most stack - address for the previous frame, that, however, is wrong. It - should be the inner most stack address for the previous to - previous frame. This is because it is the previous to previous - frame's innermost stack address that is constant through out - the lifetime of the previous frame (trust me :-). */ - 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. */ - if (DEPRECATED_FRAME_CHAIN_P ()) - address = DEPRECATED_FRAME_CHAIN (this_frame); - else - { - /* Someone is part way through coverting an old architecture - to the new frame code. Implement FRAME_CHAIN the way the - new frame will. */ - /* Find PREV frame's unwinder. */ - prev->unwind = frame_unwind_find_by_frame (this_frame->next); - /* FIXME: cagney/2003-04-02: Rather than storing the frame's - type in the frame, the unwinder's type should be returned - directly. Unfortunately, legacy code, called by - legacy_get_prev_frame, explicitly set the frames type - using the method deprecated_set_frame_type(). */ - prev->type = prev->unwind->type; - /* Find PREV frame's ID. */ - prev->unwind->this_id (this_frame, - &prev->prologue_cache, - &prev->this_id.value); - prev->this_id.p = 1; - address = prev->this_id.value.stack_addr; - } - - if (!legacy_frame_chain_valid (address, this_frame)) - { - if (frame_debug) - { - fprintf_unfiltered (gdb_stdlog, "-> "); - fprint_frame (gdb_stdlog, NULL); - fprintf_unfiltered (gdb_stdlog, - " // legacy frame chain invalid }\n"); - } - return NULL; - } - } - if (address == 0) - { - if (frame_debug) - { - fprintf_unfiltered (gdb_stdlog, "-> "); - fprint_frame (gdb_stdlog, NULL); - fprintf_unfiltered (gdb_stdlog, - " // legacy frame chain NULL }\n"); - } - return NULL; - } + gdb_assert (this_frame == NULL || this_frame->level >= 0); - /* Link in the already allocated prev frame. */ - this_frame->prev = prev; - deprecated_update_frame_base_hack (prev, 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 - (deprecated_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 ()) - deprecated_update_frame_pc_hack (prev, - 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 ()) - deprecated_update_frame_pc_hack (prev, - 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 (get_frame_base (prev) == get_frame_base (this_frame) - && get_frame_pc (prev) == get_frame_pc (this_frame)) + while (this_frame != NULL) { - this_frame->prev = NULL; - obstack_free (&frame_cache_obstack, prev); - if (frame_debug) - { - fprintf_unfiltered (gdb_stdlog, "-> "); - fprint_frame (gdb_stdlog, NULL); - fprintf_unfiltered (gdb_stdlog, - " // legacy this.id == prev.id }\n"); - } - 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. - - If there isn't a FRAME_CHAIN, the code above will have already - done this. */ - if (prev->unwind == NULL) - prev->unwind = frame_unwind_find_by_frame (prev->next); - - /* If the unwinder provides a frame type, use it. Otherwize - continue on to that heuristic mess. */ - if (prev->unwind->type != UNKNOWN_FRAME) - { - prev->type = prev->unwind->type; - if (prev->type == NORMAL_FRAME) - /* FIXME: cagney/2003-06-16: would get_frame_pc() be better? */ - prev->this_id.value.code_addr - = get_pc_function_start (prev->this_id.value.code_addr); - if (frame_debug) - { - fprintf_unfiltered (gdb_stdlog, "-> "); - fprint_frame (gdb_stdlog, prev); - fprintf_unfiltered (gdb_stdlog, " } // legacy with unwound type\n"); - } - return prev; - } + frame_register_unwind (this_frame, regnum, optimizedp, lvalp, + addrp, realnump, NULL); - /* 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 (get_frame_pc (prev), 0, 0) - : pc_in_dummy_frame (get_frame_pc (prev)))) - 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 (get_frame_pc (prev), &name, NULL, NULL); - if (PC_IN_SIGTRAMP (get_frame_pc (prev), 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. */ - } + if (*optimizedp) + break; - if (prev->type == NORMAL_FRAME) - prev->this_id.value.code_addr - = get_pc_function_start (prev->this_id.value.code_addr); + if (*lvalp != lval_register) + break; - if (frame_debug) - { - fprintf_unfiltered (gdb_stdlog, "-> "); - fprint_frame (gdb_stdlog, prev); - fprintf_unfiltered (gdb_stdlog, " } // legacy with confused type\n"); + regnum = *realnump; + this_frame = get_next_frame (this_frame); } - - return prev; } -/* Return a structure containing various interesting information - about the frame that called THIS_FRAME. Returns NULL - if there is no such frame. +/* Return a "struct frame_info" corresponding to the frame that called + THIS_FRAME. Returns NULL if there is no such frame. - This function tests some target-independent conditions that should - terminate the frame chain, such as unwinding past main(). It - should not contain any target-dependent tests, such as checking - whether the program-counter is zero. */ + Unlike get_prev_frame, this function always tries to unwind the + frame. */ -struct frame_info * -get_prev_frame (struct frame_info *this_frame) +static struct frame_info * +get_prev_frame_1 (struct frame_info *this_frame) { struct frame_info *prev_frame; + struct frame_id this_id; + struct gdbarch *gdbarch; + + gdb_assert (this_frame != NULL); + gdbarch = get_frame_arch (this_frame); if (frame_debug) { - fprintf_unfiltered (gdb_stdlog, "{ get_prev_frame (this_frame="); + fprintf_unfiltered (gdb_stdlog, "{ get_prev_frame_1 (this_frame="); if (this_frame != NULL) fprintf_unfiltered (gdb_stdlog, "%d", this_frame->level); else @@ -1748,107 +1233,6 @@ get_prev_frame (struct frame_info *this_frame) fprintf_unfiltered (gdb_stdlog, ") "); } - /* 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); - - /* Make sure we pass an address within THIS_FRAME's code block to - inside_main_func. Otherwise, we might stop unwinding at a - function which has a call instruction as its last instruction if - that function immediately precedes main(). */ - if (this_frame->level >= 0 - && !backtrace_past_main - && inside_main_func (get_frame_address_in_block (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, "-> NULL // inside main func }\n"); - return NULL; - } - - if (this_frame->level > backtrace_limit) - { - error ("Backtrace limit of %d exceeded", backtrace_limit); - } - - /* 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. */ - /* NOTE: cagney/2003-07-07: Fixed a bug in inside_main_func - wasn't - checking for "main" in the minimal symbols. With that fixed - asm-source tests now stop in "main" instead of halting the - backtrace in wierd and wonderful ways somewhere inside the entry - file. Suspect that deprecated_inside_entry_file and - inside_entry_func tests were added to work around that (now - fixed) case. */ - /* NOTE: cagney/2003-07-15: danielj (if I'm reading it right) - suggested having the inside_entry_func test use the - inside_main_func msymbol trick (along with entry_point_address I - guess) to determine the address range of the start function. - That should provide a far better stopper than the current - heuristics. */ - /* NOTE: cagney/2003-07-15: Need to add a "set backtrace - beyond-entry-func" command so that this can be selectively - disabled. */ - if (0 -#if 0 - && backtrace_beyond_entry_func -#endif - && this_frame->type != DUMMY_FRAME && this_frame->level >= 0 - && inside_entry_func (get_frame_pc (this_frame))) - { - if (frame_debug) - { - fprintf_unfiltered (gdb_stdlog, "-> "); - fprint_frame (gdb_stdlog, NULL); - fprintf_unfiltered (gdb_stdlog, "// inside entry func }\n"); - } - return NULL; - } - /* Only try to do the unwind once. */ if (this_frame->prev_p) { @@ -1860,80 +1244,113 @@ get_prev_frame (struct frame_info *this_frame) } return this_frame->prev; } + + /* If the frame unwinder hasn't been selected yet, we must do so + before setting prev_p; otherwise the check for misbehaved + sniffers will think that this frame's sniffer tried to unwind + further (see frame_cleanup_after_sniffer). */ + if (this_frame->unwind == NULL) + this_frame->unwind + = frame_unwind_find_by_frame (this_frame, &this_frame->prologue_cache); + this_frame->prev_p = 1; + this_frame->stop_reason = UNWIND_NO_REASON; - /* 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. */ - /* NOTE: vinschen/2003-04-01: Disabled. It turns out that the call - to deprecated_inside_entry_file destroys a meaningful backtrace - under some conditions. E. g. the backtrace tests in the - asm-source testcase are broken for some targets. In this test - the functions are all implemented as part of one file and the - testcase is not necessarily linked with a start file (depending - on the target). What happens is, that the first frame is printed - normaly and following frames are treated as being inside the - enttry file then. This way, only the #0 frame is printed in the - backtrace output. */ - if (0 - && this_frame->type != DUMMY_FRAME && this_frame->level >= 0 - && deprecated_inside_entry_file (get_frame_pc (this_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. */ + this_id = get_frame_id (this_frame); + if (this_frame->level >= 0 && !frame_id_p (this_id)) { if (frame_debug) { fprintf_unfiltered (gdb_stdlog, "-> "); fprint_frame (gdb_stdlog, NULL); - fprintf_unfiltered (gdb_stdlog, " // inside entry file }\n"); + fprintf_unfiltered (gdb_stdlog, " // this ID is NULL }\n"); } + this_frame->stop_reason = UNWIND_NULL_ID; 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)) + /* Check that this frame's ID isn't inner to (younger, below, next) + the next frame. This happens when a frame unwind goes backwards. + This check is valid only if the next frame is NORMAL. See the + comment at frame_id_inner for details. */ + if (this_frame->next->unwind->type == NORMAL_FRAME + && frame_id_inner (get_frame_arch (this_frame->next), this_id, + get_frame_id (this_frame->next))) { - prev_frame = legacy_get_prev_frame (this_frame); - return prev_frame; + if (frame_debug) + { + fprintf_unfiltered (gdb_stdlog, "-> "); + fprint_frame (gdb_stdlog, NULL); + fprintf_unfiltered (gdb_stdlog, " // this frame ID is inner }\n"); + } + this_frame->stop_reason = UNWIND_INNER_ID; + return NULL; } - /* 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))) + /* Check that this and the next frame are not identical. If they + are, there is most likely a stack cycle. As with the inner-than + test above, avoid comparing the inner-most and sentinel frames. */ + if (this_frame->level > 0 + && frame_id_eq (this_id, get_frame_id (this_frame->next))) { if (frame_debug) { fprintf_unfiltered (gdb_stdlog, "-> "); fprint_frame (gdb_stdlog, NULL); - fprintf_unfiltered (gdb_stdlog, " // this ID is NULL }\n"); + fprintf_unfiltered (gdb_stdlog, " // this frame has same ID }\n"); } + this_frame->stop_reason = UNWIND_SAME_ID; return NULL; } - /* Check that this frame's ID isn't inner to (younger, below, next) - the next frame. This happens when a frame unwind goes backwards. - Since the sentinel frame doesn't really exist, don't compare the - inner-most against that sentinel. */ + /* Check that this and the next frame do not unwind the PC register + to the same memory location. If they do, then even though they + have different frame IDs, the new frame will be bogus; two + functions can't share a register save slot for the PC. This can + happen when the prologue analyzer finds a stack adjustment, but + no PC save. + + This check does assume that the "PC register" is roughly a + traditional PC, even if the gdbarch_unwind_pc method adjusts + it (we do not rely on the value, only on the unwound PC being + dependent on this value). A potential improvement would be + to have the frame prev_pc method and the gdbarch unwind_pc + method set the same lval and location information as + frame_register_unwind. */ if (this_frame->level > 0 - && frame_id_inner (get_frame_id (this_frame), - get_frame_id (this_frame->next))) - error ("Previous frame inner to this frame (corrupt stack?)"); + && gdbarch_pc_regnum (gdbarch) >= 0 + && get_frame_type (this_frame) == NORMAL_FRAME + && get_frame_type (this_frame->next) == NORMAL_FRAME) + { + int optimized, realnum, nrealnum; + enum lval_type lval, nlval; + CORE_ADDR addr, naddr; + + frame_register_unwind_location (this_frame, + gdbarch_pc_regnum (gdbarch), + &optimized, &lval, &addr, &realnum); + frame_register_unwind_location (get_next_frame (this_frame), + gdbarch_pc_regnum (gdbarch), + &optimized, &nlval, &naddr, &nrealnum); + + if ((lval == lval_memory && lval == nlval && addr == naddr) + || (lval == lval_register && lval == nlval && realnum == nrealnum)) + { + if (frame_debug) + { + fprintf_unfiltered (gdb_stdlog, "-> "); + fprint_frame (gdb_stdlog, NULL); + fprintf_unfiltered (gdb_stdlog, " // no saved PC }\n"); + } - /* Check that this and the next frame are not identical. If they - are, there is most likely a stack cycle. As with the inner-than - test above, avoid comparing the inner-most and sentinel frames. */ - if (this_frame->level > 0 - && frame_id_eq (get_frame_id (this_frame), - get_frame_id (this_frame->next))) - error ("Previous frame identical to this frame (corrupt stack?)"); + this_frame->stop_reason = UNWIND_NO_SAVED_PC; + this_frame->prev = NULL; + return NULL; + } + } /* 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 @@ -1981,6 +1398,150 @@ get_prev_frame (struct frame_info *this_frame) return prev_frame; } +/* Debug routine to print a NULL frame being returned. */ + +static void +frame_debug_got_null_frame (struct frame_info *this_frame, + const char *reason) +{ + if (frame_debug) + { + fprintf_unfiltered (gdb_stdlog, "{ get_prev_frame (this_frame="); + if (this_frame != NULL) + fprintf_unfiltered (gdb_stdlog, "%d", this_frame->level); + else + fprintf_unfiltered (gdb_stdlog, ""); + fprintf_unfiltered (gdb_stdlog, ") -> // %s}\n", reason); + } +} + +/* Is this (non-sentinel) frame in the "main"() function? */ + +static int +inside_main_func (struct frame_info *this_frame) +{ + struct minimal_symbol *msymbol; + CORE_ADDR maddr; + + if (symfile_objfile == 0) + return 0; + msymbol = lookup_minimal_symbol (main_name (), NULL, symfile_objfile); + if (msymbol == NULL) + return 0; + /* Make certain that the code, and not descriptor, address is + returned. */ + maddr = gdbarch_convert_from_func_ptr_addr (get_frame_arch (this_frame), + SYMBOL_VALUE_ADDRESS (msymbol), + ¤t_target); + return maddr == get_frame_func (this_frame); +} + +/* Test whether THIS_FRAME is inside the process entry point function. */ + +static int +inside_entry_func (struct frame_info *this_frame) +{ + return (get_frame_func (this_frame) == entry_point_address ()); +} + +/* Return a structure containing various interesting information about + the frame that called THIS_FRAME. Returns NULL if there is entier + no such frame or the frame fails any of a set of target-independent + condition that should terminate the frame chain (e.g., as unwinding + past main()). + + This function should not contain target-dependent tests, such as + checking whether the program-counter is zero. */ + +struct frame_info * +get_prev_frame (struct frame_info *this_frame) +{ + struct frame_info *prev_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); + + /* tausq/2004-12-07: Dummy frames are skipped because it doesn't make much + sense to stop unwinding at a dummy frame. One place where a dummy + frame may have an address "inside_main_func" is on HPUX. On HPUX, the + pcsqh register (space register for the instruction at the head of the + instruction queue) cannot be written directly; the only way to set it + is to branch to code that is in the target space. In order to implement + frame dummies on HPUX, the called function is made to jump back to where + the inferior was when the user function was called. If gdb was inside + the main function when we created the dummy frame, the dummy frame will + point inside the main function. */ + if (this_frame->level >= 0 + && get_frame_type (this_frame) != DUMMY_FRAME + && !backtrace_past_main + && inside_main_func (this_frame)) + /* Don't unwind past main(). Note, this is done _before_ the + frame has been marked as previously unwound. That way if the + user later decides to enable unwinds past main(), that will + automatically happen. */ + { + frame_debug_got_null_frame (this_frame, "inside main func"); + return NULL; + } + + /* If the user's backtrace limit has been exceeded, stop. We must + add two to the current level; one of those accounts for backtrace_limit + being 1-based and the level being 0-based, and the other accounts for + the level of the new frame instead of the level of the current + frame. */ + if (this_frame->level + 2 > backtrace_limit) + { + frame_debug_got_null_frame (this_frame, "backtrace limit exceeded"); + 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 PCs 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/2003-07-07: Fixed a bug in inside_main_func() - + wasn't checking for "main" in the minimal symbols. With that + fixed asm-source tests now stop in "main" instead of halting the + backtrace in weird and wonderful ways somewhere inside the entry + file. Suspect that tests for inside the entry file/func were + added to work around that (now fixed) case. */ + /* NOTE: cagney/2003-07-15: danielj (if I'm reading it right) + suggested having the inside_entry_func test use the + inside_main_func() msymbol trick (along with entry_point_address() + I guess) to determine the address range of the start function. + That should provide a far better stopper than the current + heuristics. */ + /* NOTE: tausq/2004-10-09: this is needed if, for example, the compiler + applied tail-call optimizations to main so that a function called + from main returns directly to the caller of main. Since we don't + stop at main, we should at least stop at the entry point of the + application. */ + if (!backtrace_past_entry + && get_frame_type (this_frame) != DUMMY_FRAME && this_frame->level >= 0 + && inside_entry_func (this_frame)) + { + frame_debug_got_null_frame (this_frame, "inside entry func"); + return NULL; + } + + /* Assume that the only way to get a zero PC is through something + like a SIGSEGV or a dummy frame, and hence that NORMAL frames + will never unwind a zero PC. */ + if (this_frame->level > 0 + && get_frame_type (this_frame) == NORMAL_FRAME + && get_frame_type (get_next_frame (this_frame)) == NORMAL_FRAME + && get_frame_pc (this_frame) == 0) + { + frame_debug_got_null_frame (this_frame, "zero PC"); + return NULL; + } + + return get_prev_frame_1 (this_frame); +} + CORE_ADDR get_frame_pc (struct frame_info *frame) { @@ -1988,31 +1549,54 @@ get_frame_pc (struct frame_info *frame) return frame_pc_unwind (frame->next); } -/* Return an address of that falls within the frame's code block. */ +/* Return an address that falls within THIS_FRAME's code block. */ CORE_ADDR -frame_unwind_address_in_block (struct frame_info *next_frame) +get_frame_address_in_block (struct frame_info *this_frame) { /* A draft address. */ - CORE_ADDR pc = frame_pc_unwind (next_frame); - - /* If THIS frame is not inner most (i.e., NEXT isn't the sentinel), - and NEXT is `normal' (i.e., not a sigtramp, dummy, ....) THIS - frame's PC ends up pointing at the instruction fallowing the - "call". Adjust that PC value so that it falls on the call - instruction (which, hopefully, falls within THIS frame's code - block. So far it's proved to be a very good approximation. See - get_frame_type for why ->type can't be used. */ - if (next_frame->level >= 0 - && get_frame_type (next_frame) == NORMAL_FRAME) - --pc; - return pc; -} + CORE_ADDR pc = get_frame_pc (this_frame); + + struct frame_info *next_frame = this_frame->next; + + /* Calling get_frame_pc returns the resume address for THIS_FRAME. + Normally the resume address is inside the body of the function + associated with THIS_FRAME, but there is a special case: when + calling a function which the compiler knows will never return + (for instance abort), the call may be the very last instruction + in the calling function. The resume address will point after the + call and may be at the beginning of a different function + entirely. + + If THIS_FRAME is a signal frame or dummy frame, then we should + not adjust the unwound PC. For a dummy frame, GDB pushed the + resume address manually onto the stack. For a signal frame, the + OS may have pushed the resume address manually and invoked the + handler (e.g. GNU/Linux), or invoked the trampoline which called + the signal handler - but in either case the signal handler is + expected to return to the trampoline. So in both of these + cases we know that the resume address is executable and + related. So we only need to adjust the PC if THIS_FRAME + is a normal function. + + If the program has been interrupted while THIS_FRAME is current, + then clearly the resume address is inside the associated + function. There are three kinds of interruption: debugger stop + (next frame will be SENTINEL_FRAME), operating system + signal or exception (next frame will be SIGTRAMP_FRAME), + or debugger-induced function call (next frame will be + DUMMY_FRAME). So we only need to adjust the PC if + NEXT_FRAME is a normal function. + + We check the type of NEXT_FRAME first, since it is already + known; frame type is determined by the unwinder, and since + we have THIS_FRAME we've already selected an unwinder for + NEXT_FRAME. */ + if (get_frame_type (next_frame) == NORMAL_FRAME + && get_frame_type (this_frame) == NORMAL_FRAME) + return pc - 1; -CORE_ADDR -get_frame_address_in_block (struct frame_info *this_frame) -{ - return frame_unwind_address_in_block (this_frame->next); + return pc; } static int @@ -2054,12 +1638,12 @@ get_frame_base_address (struct frame_info *fi) if (get_frame_type (fi) != NORMAL_FRAME) return 0; if (fi->base == NULL) - fi->base = frame_base_find_by_frame (fi->next); + fi->base = frame_base_find_by_frame (fi); /* Sneaky: If the low-level unwind and high-level base code share a common unwinder, let them share the prologue cache. */ if (fi->base->unwind == fi->unwind) - return fi->base->this_base (fi->next, &fi->prologue_cache); - return fi->base->this_base (fi->next, &fi->base_cache); + return fi->base->this_base (fi, &fi->prologue_cache); + return fi->base->this_base (fi, &fi->base_cache); } CORE_ADDR @@ -2070,14 +1654,12 @@ get_frame_locals_address (struct frame_info *fi) return 0; /* If there isn't a frame address method, find it. */ if (fi->base == NULL) - fi->base = frame_base_find_by_frame (fi->next); + fi->base = frame_base_find_by_frame (fi); /* Sneaky: If the low-level unwind and high-level base code share a common unwinder, let them share the prologue cache. */ if (fi->base->unwind == fi->unwind) - cache = &fi->prologue_cache; - else - cache = &fi->base_cache; - return fi->base->this_locals (fi->next, cache); + return fi->base->this_locals (fi, &fi->prologue_cache); + return fi->base->this_locals (fi, &fi->base_cache); } CORE_ADDR @@ -2088,14 +1670,12 @@ get_frame_args_address (struct frame_info *fi) return 0; /* If there isn't a frame address method, find it. */ if (fi->base == NULL) - fi->base = frame_base_find_by_frame (fi->next); + fi->base = frame_base_find_by_frame (fi); /* Sneaky: If the low-level unwind and high-level base code share a common unwinder, let them share the prologue cache. */ if (fi->base->unwind == fi->unwind) - cache = &fi->prologue_cache; - else - cache = &fi->base_cache; - return fi->base->this_args (fi->next, cache); + return fi->base->this_args (fi, &fi->prologue_cache); + return fi->base->this_args (fi, &fi->base_cache); } /* Level of the selected frame: 0 for innermost, 1 for its caller, ... @@ -2113,113 +1693,18 @@ frame_relative_level (struct frame_info *fi) 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; - - /* Some legacy code, e.g, mips_init_extra_frame_info() wants - to determine the frame's type prior to it being completely - initialized. Don't attempt to lazily initialize ->unwind for - legacy code. It will be initialized in legacy_get_prev_frame(). */ - if (frame->unwind == NULL && !legacy_frame_p (current_gdbarch)) - { - /* Initialize the frame's unwinder because it is that which - provides the frame's type. */ - frame->unwind = frame_unwind_find_by_frame (frame->next); - /* FIXME: cagney/2003-04-02: Rather than storing the frame's - type in the frame, the unwinder's type should be returned - directly. Unfortunately, legacy code, called by - legacy_get_prev_frame, explicitly set the frames type using - the method deprecated_set_frame_type(). */ - gdb_assert (frame->unwind->type != UNKNOWN_FRAME); - frame->type = frame->unwind->type; - } - if (frame->type == UNKNOWN_FRAME) - return NORMAL_FRAME; - else - 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; -} - -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) -{ - if (frame_debug) - fprintf_unfiltered (gdb_stdlog, - "{ deprecated_update_frame_pc_hack (frame=%d,pc=0x%s) }\n", - frame->level, paddr_nz (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->prev_pc.value = pc; - frame->next->prev_pc.p = 1; - } -} - -void -deprecated_update_frame_base_hack (struct frame_info *frame, CORE_ADDR base) -{ - if (frame_debug) - fprintf_unfiltered (gdb_stdlog, - "{ deprecated_update_frame_base_hack (frame=%d,base=0x%s) }\n", - frame->level, paddr_nz (base)); - /* See comment in "frame.h". */ - frame->this_id.value.stack_addr = base; -} - -struct frame_info * -deprecated_frame_xmalloc_with_cleanup (long sizeof_saved_regs, - long sizeof_extra_info) -{ - struct frame_info *frame = XMALLOC (struct frame_info); - memset (frame, 0, sizeof (*frame)); - frame->this_id.p = 1; - 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; + if (frame->unwind == NULL) + /* Initialize the frame's unwinder because that's what + provides the frame's type. */ + frame->unwind = frame_unwind_find_by_frame (frame, &frame->prologue_cache); + return frame->unwind->type; } /* Memory access methods. */ void -get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr, void *buf, - int len) +get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr, + gdb_byte *buf, int len) { read_memory (addr, buf, len); } @@ -2238,11 +1723,24 @@ get_frame_memory_unsigned (struct frame_info *this_frame, CORE_ADDR addr, return read_memory_unsigned_integer (addr, len); } +int +safe_frame_unwind_memory (struct frame_info *this_frame, + CORE_ADDR addr, gdb_byte *buf, int len) +{ + /* NOTE: target_read_memory returns zero on success! */ + return !target_read_memory (addr, buf, len); +} + /* Architecture method. */ struct gdbarch * get_frame_arch (struct frame_info *this_frame) { + /* In the future, this function will return a per-frame + architecture instead of current_gdbarch. Calling the + routine with a NULL value of this_frame is a bug! */ + gdb_assert (this_frame); + return current_gdbarch; } @@ -2251,40 +1749,105 @@ get_frame_arch (struct frame_info *this_frame) CORE_ADDR get_frame_sp (struct frame_info *this_frame) { - return frame_sp_unwind (this_frame->next); + struct gdbarch *gdbarch = get_frame_arch (this_frame); + /* Normality - an architecture that provides a way of obtaining any + frame inner-most address. */ + if (gdbarch_unwind_sp_p (gdbarch)) + /* NOTE drow/2008-06-28: gdbarch_unwind_sp could be converted to + operate on THIS_FRAME now. */ + return gdbarch_unwind_sp (gdbarch, this_frame->next); + /* Now things are really are grim. Hope that the value returned by + the gdbarch_sp_regnum register is meaningful. */ + if (gdbarch_sp_regnum (gdbarch) >= 0) + return get_frame_register_unsigned (this_frame, + gdbarch_sp_regnum (gdbarch)); + internal_error (__FILE__, __LINE__, _("Missing unwind SP method")); } -CORE_ADDR -frame_sp_unwind (struct frame_info *next_frame) +/* Return the reason why we can't unwind past FRAME. */ + +enum unwind_stop_reason +get_frame_unwind_stop_reason (struct frame_info *frame) { - /* Normality, an architecture that provides a way of obtaining any - frame inner-most address. */ - if (gdbarch_unwind_sp_p (current_gdbarch)) - return gdbarch_unwind_sp (current_gdbarch, next_frame); - /* Things are looking grim. If it's the inner-most frame and there - is a TARGET_READ_SP then that can be used. */ - if (next_frame->level < 0 && TARGET_READ_SP_P ()) - return TARGET_READ_SP (); - /* Now things are really are grim. Hope that the value returned by - the SP_REGNUM register is meaningful. */ - if (SP_REGNUM >= 0) + /* If we haven't tried to unwind past this point yet, then assume + that unwinding would succeed. */ + if (frame->prev_p == 0) + return UNWIND_NO_REASON; + + /* Otherwise, we set a reason when we succeeded (or failed) to + unwind. */ + return frame->stop_reason; +} + +/* Return a string explaining REASON. */ + +const char * +frame_stop_reason_string (enum unwind_stop_reason reason) +{ + switch (reason) { - ULONGEST sp; - frame_unwind_unsigned_register (next_frame, SP_REGNUM, &sp); - return sp; + case UNWIND_NULL_ID: + return _("unwinder did not report frame ID"); + + case UNWIND_INNER_ID: + return _("previous frame inner to this frame (corrupt stack?)"); + + case UNWIND_SAME_ID: + return _("previous frame identical to this frame (corrupt stack?)"); + + case UNWIND_NO_SAVED_PC: + return _("frame did not save the PC"); + + case UNWIND_NO_REASON: + case UNWIND_FIRST_ERROR: + default: + internal_error (__FILE__, __LINE__, + "Invalid frame stop reason"); } - internal_error (__FILE__, __LINE__, "Missing unwind SP method"); } +/* Clean up after a failed (wrong unwinder) attempt to unwind past + FRAME. */ -int -legacy_frame_p (struct gdbarch *current_gdbarch) +static void +frame_cleanup_after_sniffer (void *arg) +{ + struct frame_info *frame = arg; + + /* The sniffer should not allocate a prologue cache if it did not + match this frame. */ + gdb_assert (frame->prologue_cache == NULL); + + /* No sniffer should extend the frame chain; sniff based on what is + already certain. */ + gdb_assert (!frame->prev_p); + + /* The sniffer should not check the frame's ID; that's circular. */ + gdb_assert (!frame->this_id.p); + + /* Clear cached fields dependent on the unwinder. + + The previous PC is independent of the unwinder, but the previous + function is not (see get_frame_address_in_block). */ + frame->prev_func.p = 0; + frame->prev_func.addr = 0; + + /* Discard the unwinder last, so that we can easily find it if an assertion + in this function triggers. */ + frame->unwind = NULL; +} + +/* Set FRAME's unwinder temporarily, so that we can call a sniffer. + Return a cleanup which should be called if unwinding fails, and + discarded if it succeeds. */ + +struct cleanup * +frame_prepare_for_sniffer (struct frame_info *frame, + const struct frame_unwind *unwind) { - 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)); + gdb_assert (frame->unwind == NULL); + frame->unwind = unwind; + return make_cleanup (frame_cleanup_after_sniffer, frame); } extern initialize_file_ftype _initialize_frame; /* -Wmissing-prototypes */ @@ -2309,42 +1872,62 @@ _initialize_frame (void) { obstack_init (&frame_cache_obstack); - add_prefix_cmd ("backtrace", class_maintenance, set_backtrace_cmd, "\ + observer_attach_target_changed (frame_observer_target_changed); + + add_prefix_cmd ("backtrace", class_maintenance, set_backtrace_cmd, _("\ Set backtrace specific variables.\n\ -Configure backtrace variables such as the backtrace limit", +Configure backtrace variables such as the backtrace limit"), &set_backtrace_cmdlist, "set backtrace ", 0/*allow-unknown*/, &setlist); - add_prefix_cmd ("backtrace", class_maintenance, show_backtrace_cmd, "\ + add_prefix_cmd ("backtrace", class_maintenance, show_backtrace_cmd, _("\ Show backtrace specific variables\n\ -Show backtrace variables such as the backtrace limit", +Show backtrace variables such as the backtrace limit"), &show_backtrace_cmdlist, "show backtrace ", 0/*allow-unknown*/, &showlist); add_setshow_boolean_cmd ("past-main", class_obscure, - &backtrace_past_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\ + &backtrace_past_main, _("\ +Set whether backtraces should continue past \"main\"."), _("\ +Show whether backtraces should continue past \"main\"."), _("\ 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, &set_backtrace_cmdlist, +of the stack trace."), + NULL, + show_backtrace_past_main, + &set_backtrace_cmdlist, &show_backtrace_cmdlist); - add_setshow_uinteger_cmd ("limit", class_obscure, - &backtrace_limit, "\ -Set an upper bound on the number of backtrace levels.\n\ + add_setshow_boolean_cmd ("past-entry", class_obscure, + &backtrace_past_entry, _("\ +Set whether backtraces should continue past the entry point of a program."), + _("\ +Show whether backtraces should continue past the entry point of a program."), + _("\ +Normally there are no callers beyond the entry point of a program, so GDB\n\ +will terminate the backtrace there. Set this variable if you need to see \n\ +the rest of the stack trace."), + NULL, + show_backtrace_past_entry, + &set_backtrace_cmdlist, + &show_backtrace_cmdlist); + + add_setshow_integer_cmd ("limit", class_obscure, + &backtrace_limit, _("\ +Set an upper bound on the number of backtrace levels."), _("\ +Show the upper bound on the number of backtrace levels."), _("\ No more than the specified number of frames can be displayed or examined.\n\ -Zero is unlimited.", "\ -Show the upper bound on the number of backtrace levels.", - NULL, NULL, &set_backtrace_cmdlist, - &show_backtrace_cmdlist); +Zero is unlimited."), + NULL, + show_backtrace_limit, + &set_backtrace_cmdlist, + &show_backtrace_cmdlist); /* 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); + add_setshow_zinteger_cmd ("frame", class_maintenance, &frame_debug, _("\ +Set frame debugging."), _("\ +Show frame debugging."), _("\ +When non-zero, frame specific internal debugging is enabled."), + NULL, + show_frame_debug, + &setdebuglist, &showdebuglist); }