diff options
Diffstat (limited to 'contrib/gdb/gdb/frame.c')
| -rw-r--r-- | contrib/gdb/gdb/frame.c | 2420 |
1 files changed, 2279 insertions, 141 deletions
diff --git a/contrib/gdb/gdb/frame.c b/contrib/gdb/gdb/frame.c index ea59eba..a032c47 100644 --- a/contrib/gdb/gdb/frame.c +++ b/contrib/gdb/gdb/frame.c @@ -1,6 +1,7 @@ -/* Cache and manage the values of registers for GDB, the GNU debugger. - Copyright 1986, 1987, 1989, 1991, 1994, 1995, 1996, 1998, 2000, 2001 - Free Software Foundation, Inc. +/* 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. This file is part of GDB. @@ -25,201 +26,2338 @@ #include "value.h" #include "inferior.h" /* for inferior_ptid */ #include "regcache.h" +#include "gdb_assert.h" +#include "gdb_string.h" +#include "user-regs.h" +#include "gdb_obstack.h" +#include "dummy-frame.h" +#include "sentinel-frame.h" +#include "gdbcore.h" +#include "annotate.h" +#include "language.h" +#include "frame-unwind.h" +#include "frame-base.h" +#include "command.h" +#include "gdbcmd.h" + +/* We keep a cache of stack frames, each of which is a "struct + frame_info". The innermost one gets allocated (in + wait_for_inferior) each time the inferior stops; current_frame + points to it. Additional frames get allocated (in get_prev_frame) + as needed, and are chained through the next and prev fields. Any + time that the frame cache becomes invalid (most notably when we + execute something, but also if we change how we interpret the + frames (e.g. "set heuristic-fence-post" in mips-tdep.c, or anything + which reads new symbols)), we should call reinit_frame_cache. */ + +struct frame_info +{ + /* Level of this frame. The inner-most (youngest) frame is at level + 0. As you move towards the outer-most (oldest) frame, the level + 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 + 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 + information such as CFI. */ + void *prologue_cache; + const struct frame_unwind *unwind; + + /* Cached copy of the previous frame's resume address. */ + struct { + int p; + CORE_ADDR value; + } prev_pc; + + /* Cached copy of the previous frame's function address. */ + struct + { + CORE_ADDR addr; + int p; + } prev_func; + + /* This frame's ID. */ + struct + { + int p; + struct frame_id value; + } this_id; + + /* The frame's high-level base methods, and corresponding cache. + The high level base methods are selected based on the frame's + debug info. */ + const struct frame_base *base; + void *base_cache; + + /* Pointers to the next (down, inner, younger) and previous (up, + outer, older) frame_info's in the frame cache. */ + struct frame_info *next; /* down, inner, younger */ + int prev_p; + struct frame_info *prev; /* up, outer, older */ +}; + +/* Flag to control debugging. */ + +static int frame_debug; + +/* Flag to indicate whether backtraces should stop at main et.al. */ + +static int backtrace_past_main; +static unsigned int backtrace_limit = UINT_MAX; + + +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)); +} + +static void +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; + case DUMMY_FRAME: + fprintf_unfiltered (file, "DUMMY_FRAME"); + return; + case SIGTRAMP_FRAME: + fprintf_unfiltered (file, "SIGTRAMP_FRAME"); + return; + default: + fprintf_unfiltered (file, "<unknown type>"); + return; + }; +} + +static void +fprint_frame (struct ui_file *file, struct frame_info *fi) +{ + if (fi == NULL) + { + fprintf_unfiltered (file, "<NULL frame>"); + return; + } + fprintf_unfiltered (file, "{"); + fprintf_unfiltered (file, "level=%d", fi->level); + fprintf_unfiltered (file, ","); + fprintf_unfiltered (file, "type="); + fprint_frame_type (file, fi->type); + fprintf_unfiltered (file, ","); + fprintf_unfiltered (file, "unwind="); + if (fi->unwind != NULL) + gdb_print_host_address (fi->unwind, file); + else + fprintf_unfiltered (file, "<unknown>"); + fprintf_unfiltered (file, ","); + fprintf_unfiltered (file, "pc="); + if (fi->next != NULL && fi->next->prev_pc.p) + fprintf_unfiltered (file, "0x%s", paddr_nz (fi->next->prev_pc.value)); + else + fprintf_unfiltered (file, "<unknown>"); + fprintf_unfiltered (file, ","); + fprintf_unfiltered (file, "id="); + if (fi->this_id.p) + fprint_frame_id (file, fi->this_id.value); + else + fprintf_unfiltered (file, "<unknown>"); + fprintf_unfiltered (file, ","); + fprintf_unfiltered (file, "func="); + if (fi->next != NULL && fi->next->prev_func.p) + fprintf_unfiltered (file, "0x%s", paddr_nz (fi->next->prev_func.addr)); + else + fprintf_unfiltered (file, "<unknown>"); + fprintf_unfiltered (file, "}"); +} + +/* Return a frame uniq ID that can be used to, later, re-find the + frame. */ + +struct frame_id +get_frame_id (struct frame_info *fi) +{ + if (fi == NULL) + { + return null_frame_id; + } + 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(). */ + fi->type = fi->unwind->type; + } + /* Find THIS frame's ID. */ + fi->unwind->this_id (fi->next, &fi->prologue_cache, &fi->this_id.value); + fi->this_id.p = 1; + if (frame_debug) + { + fprintf_unfiltered (gdb_stdlog, "-> "); + fprint_frame_id (gdb_stdlog, fi->this_id.value); + fprintf_unfiltered (gdb_stdlog, " }\n"); + } + } + return fi->this_id.value; +} + +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; + id.stack_addr = stack_addr; + id.code_addr = code_addr; + id.special_addr = special_addr; + 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); +} + +int +frame_id_p (struct frame_id l) +{ + int p; + /* The .code can be NULL but the .stack cannot. */ + p = (l.stack_addr != 0); + if (frame_debug) + { + fprintf_unfiltered (gdb_stdlog, "{ frame_id_p (l="); + fprint_frame_id (gdb_stdlog, l); + fprintf_unfiltered (gdb_stdlog, ") -> %d }\n", p); + } + return p; +} + +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. */ + 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. */ + 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. */ + eq = 1; + else if (l.special_addr == r.special_addr) + /* Frames are equal. */ + eq = 1; + else + /* No luck. */ + eq = 0; + if (frame_debug) + { + fprintf_unfiltered (gdb_stdlog, "{ frame_id_eq (l="); + fprint_frame_id (gdb_stdlog, l); + fprintf_unfiltered (gdb_stdlog, ",r="); + fprint_frame_id (gdb_stdlog, r); + fprintf_unfiltered (gdb_stdlog, ") -> %d }\n", eq); + } + return eq; +} + +int +frame_id_inner (struct frame_id l, struct frame_id r) +{ + int inner; + if (l.stack_addr == 0 || r.stack_addr == 0) + /* Like NaN, any operation involving an invalid ID always fails. */ + inner = 0; + else + /* Only return non-zero when strictly inner than. Note that, per + comment in "frame.h", there is some fuzz here. Frameless + functions are not strictly inner than (same .stack but + different .code and/or .special address). */ + inner = INNER_THAN (l.stack_addr, r.stack_addr); + if (frame_debug) + { + fprintf_unfiltered (gdb_stdlog, "{ frame_id_inner (l="); + fprint_frame_id (gdb_stdlog, l); + fprintf_unfiltered (gdb_stdlog, ",r="); + fprint_frame_id (gdb_stdlog, r); + fprintf_unfiltered (gdb_stdlog, ") -> %d }\n", inner); + } + return inner; +} + +struct frame_info * +frame_find_by_id (struct frame_id id) +{ + struct frame_info *frame; -/* FIND_SAVED_REGISTER () + /* 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; - Return the address in which frame FRAME's value of register REGNUM - has been saved in memory. Or return zero if it has not been saved. - If REGNUM specifies the SP, the value we return is actually - the SP value, not an address where it was saved. */ + for (frame = get_current_frame (); + frame != NULL; + frame = get_prev_frame (frame)) + { + struct frame_id this = get_frame_id (frame); + if (frame_id_eq (id, this)) + /* An exact match. */ + return frame; + if (frame_id_inner (id, this)) + /* Gone to far. */ + return NULL; + /* Either, we're not yet gone far enough out along the frame + chain (inner(this,id), or we're comparing frameless functions + (same .base, different .func, no test available). Struggle + on until we've definitly gone to far. */ + } + return NULL; +} CORE_ADDR -find_saved_register (struct frame_info *frame, int regnum) +frame_pc_unwind (struct frame_info *this_frame) { - register struct frame_info *frame1 = NULL; - register CORE_ADDR addr = 0; + if (!this_frame->prev_pc.p) + { + CORE_ADDR pc; + if (gdbarch_unwind_pc_p (current_gdbarch)) + { + /* The right way. The `pure' way. The one true way. This + method depends solely on the register-unwind code to + determine the value of registers in THIS frame, and hence + the value of this frame's PC (resume address). A typical + implementation is no more than: + + frame_unwind_register (this_frame, ISA_PC_REGNUM, buf); + return extract_unsigned_integer (buf, size of ISA_PC_REGNUM); - if (frame == NULL) /* No regs saved if want current frame */ - return 0; + Note: this method is very heavily dependent on a correct + register-unwind implementation, it pays to fix that + method first; this method is frame type agnostic, since + it only deals with register values, it works with any + frame. This is all in stark contrast to the old + FRAME_SAVED_PC which would try to directly handle all the + different ways that a PC could be unwound. */ + pc = gdbarch_unwind_pc (current_gdbarch, this_frame); + } + else if (this_frame->level < 0) + { + /* FIXME: cagney/2003-03-06: Old code and and a sentinel + frame. Do like was always done. Fetch the PC's value + direct from the global registers array (via read_pc). + This assumes that this frame belongs to the current + global register cache. The assumption is dangerous. */ + pc = read_pc (); + } + else if (DEPRECATED_FRAME_SAVED_PC_P ()) + { + /* FIXME: cagney/2003-03-06: Old code, but not a sentinel + frame. Do like was always done. Note that this method, + unlike unwind_pc(), tries to handle all the different + frame cases directly. It fails. */ + pc = DEPRECATED_FRAME_SAVED_PC (this_frame); + } + else + internal_error (__FILE__, __LINE__, "No gdbarch_unwind_pc method"); + this_frame->prev_pc.value = pc; + this_frame->prev_pc.p = 1; + if (frame_debug) + fprintf_unfiltered (gdb_stdlog, + "{ frame_pc_unwind (this_frame=%d) -> 0x%s }\n", + this_frame->level, + paddr_nz (this_frame->prev_pc.value)); + } + return this_frame->prev_pc.value; +} + +CORE_ADDR +frame_func_unwind (struct frame_info *fi) +{ + if (!fi->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); + if (frame_debug) + fprintf_unfiltered (gdb_stdlog, + "{ frame_func_unwind (fi=%d) -> 0x%s }\n", + fi->level, paddr_nz (fi->prev_func.addr)); + } + return fi->prev_func.addr; +} + +CORE_ADDR +get_frame_func (struct frame_info *fi) +{ + return frame_func_unwind (fi->next); +} + +static int +do_frame_unwind_register (void *src, int regnum, void *buf) +{ + frame_unwind_register (src, regnum, buf); + return 1; +} + +void +frame_pop (struct frame_info *this_frame) +{ + struct regcache *scratch_regcache; + struct cleanup *cleanups; + + if (DEPRECATED_POP_FRAME_P ()) + { + /* A legacy architecture that has implemented a custom pop + function. All new architectures should instead be using the + generic code below. */ + DEPRECATED_POP_FRAME; + } + else + { + /* Make a copy of all the register values unwound from this + frame. Save them in a scratch buffer so that there isn't a + race betweening trying to extract the old values from the + current_regcache while, at the same time writing new values + into that same cache. */ + struct regcache *scratch = regcache_xmalloc (current_gdbarch); + struct cleanup *cleanups = make_cleanup_regcache_xfree (scratch); + regcache_save (scratch, do_frame_unwind_register, this_frame); + /* FIXME: cagney/2003-03-16: It should be possible to tell the + target's register cache that it is about to be hit with a + burst register transfer and that the sequence of register + writes should be batched. The pair target_prepare_to_store() + and target_store_registers() kind of suggest this + functionality. 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); + } + /* We've made right mess of GDB's local state, just discard + everything. */ + flush_cached_frames (); +} + +void +frame_register_unwind (struct frame_info *frame, int regnum, + int *optimizedp, enum lval_type *lvalp, + CORE_ADDR *addrp, int *realnump, void *bufferp) +{ + struct frame_unwind_cache *cache; + + if (frame_debug) + { + fprintf_unfiltered (gdb_stdlog, "\ +{ frame_register_unwind (frame=%d,regnum=%d(%s),...) ", + frame->level, regnum, + frame_map_regnum_to_name (frame, regnum)); + } + + /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates + that the value proper does not need to be fetched. */ + gdb_assert (optimizedp != NULL); + gdb_assert (lvalp != NULL); + gdb_assert (addrp != NULL); + gdb_assert (realnump != NULL); + /* gdb_assert (bufferp != NULL); */ + + /* NOTE: cagney/2002-11-27: A program trying to unwind a NULL frame + is broken. There is always a frame. If there, for some reason, + isn't, there is some pretty busted code as it should have + detected the problem before calling here. */ + gdb_assert (frame != NULL); + + /* 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(). */ + frame->type = frame->unwind->type; + } + + /* 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); + + 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, "<NULL>"); + 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"); + } +} + +void +frame_register (struct frame_info *frame, int regnum, + int *optimizedp, enum lval_type *lvalp, + CORE_ADDR *addrp, int *realnump, void *bufferp) +{ + /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates + that the value proper does not need to be fetched. */ + gdb_assert (optimizedp != NULL); + gdb_assert (lvalp != NULL); + gdb_assert (addrp != NULL); + gdb_assert (realnump != NULL); + /* gdb_assert (bufferp != NULL); */ + + /* Ulgh! Old code that, for lval_register, sets ADDRP to the offset + of the register in the register cache. It should instead return + the REGNUM corresponding to that register. Translate the . */ + if (DEPRECATED_GET_SAVED_REGISTER_P ()) + { + DEPRECATED_GET_SAVED_REGISTER (bufferp, optimizedp, addrp, frame, + regnum, lvalp); + /* Compute the REALNUM if the caller wants it. */ + if (*lvalp == lval_register) + { + int regnum; + for (regnum = 0; regnum < NUM_REGS + NUM_PSEUDO_REGS; regnum++) + { + if (*addrp == register_offset_hack (current_gdbarch, regnum)) + { + *realnump = regnum; + return; + } + } + internal_error (__FILE__, __LINE__, + "Failed to compute the register number corresponding" + " to 0x%s", paddr_d (*addrp)); + } + *realnump = -1; + return; + } + + /* Obtain the register value by unwinding the register from the next + (more inner frame). */ + gdb_assert (frame != NULL && frame->next != NULL); + frame_register_unwind (frame->next, regnum, optimizedp, lvalp, addrp, + realnump, bufferp); +} + +void +frame_unwind_register (struct frame_info *frame, int regnum, void *buf) +{ + int optimized; + CORE_ADDR addr; + int realnum; + enum lval_type lval; + frame_register_unwind (frame, regnum, &optimized, &lval, &addr, + &realnum, buf); +} + +void +get_frame_register (struct frame_info *frame, + int regnum, void *buf) +{ + frame_unwind_register (frame->next, regnum, buf); +} + +LONGEST +frame_unwind_register_signed (struct frame_info *frame, int regnum) +{ + char buf[MAX_REGISTER_SIZE]; + frame_unwind_register (frame, regnum, buf); + return extract_signed_integer (buf, DEPRECATED_REGISTER_VIRTUAL_SIZE (regnum)); +} + +LONGEST +get_frame_register_signed (struct frame_info *frame, int regnum) +{ + return frame_unwind_register_signed (frame->next, regnum); +} + +ULONGEST +frame_unwind_register_unsigned (struct frame_info *frame, int regnum) +{ + char buf[MAX_REGISTER_SIZE]; + frame_unwind_register (frame, regnum, buf); + return extract_unsigned_integer (buf, DEPRECATED_REGISTER_VIRTUAL_SIZE (regnum)); +} -#ifdef HAVE_REGISTER_WINDOWS - /* We assume that a register in a register window will only be saved - in one place (since the name changes and/or disappears as you go - towards inner frames), so we only call get_frame_saved_regs on - the current frame. This is directly in contradiction to the - usage below, which assumes that registers used in a frame must be - saved in a lower (more interior) frame. This change is a result - of working on a register window machine; get_frame_saved_regs - always returns the registers saved within a frame, within the - context (register namespace) of that frame. */ - - /* However, note that we don't want this to return anything if - nothing is saved (if there's a frame inside of this one). Also, - callers to this routine asking for the stack pointer want the - stack pointer saved for *this* frame; this is returned from the - next frame. */ - - if (REGISTER_IN_WINDOW_P (regnum)) - { - frame1 = get_next_frame (frame); - if (!frame1) - return 0; /* Registers of this frame are active. */ - - /* Get the SP from the next frame in; it will be this - current frame. */ - if (regnum != SP_REGNUM) - frame1 = frame; - - FRAME_INIT_SAVED_REGS (frame1); - return frame1->saved_regs[regnum]; /* ... which might be zero */ - } -#endif /* HAVE_REGISTER_WINDOWS */ - - /* Note that this next routine assumes that registers used in - frame x will be saved only in the frame that x calls and - frames interior to it. This is not true on the sparc, but the - above macro takes care of it, so we should be all right. */ - while (1) - { - QUIT; - frame1 = get_prev_frame (frame1); - if (frame1 == 0 || frame1 == frame) +ULONGEST +get_frame_register_unsigned (struct frame_info *frame, int regnum) +{ + return frame_unwind_register_unsigned (frame->next, 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) +{ + struct gdbarch *gdbarch = get_frame_arch (frame); + int realnum; + int optim; + enum lval_type lval; + 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."); + switch (lval) + { + case lval_memory: + { + /* FIXME: write_memory doesn't yet take constant buffers. + Arrrg! */ + char tmp[MAX_REGISTER_SIZE]; + memcpy (tmp, buf, register_size (gdbarch, regnum)); + write_memory (addr, tmp, register_size (gdbarch, regnum)); break; - FRAME_INIT_SAVED_REGS (frame1); - if (frame1->saved_regs[regnum]) - addr = frame1->saved_regs[regnum]; + } + case lval_register: + regcache_cooked_write (current_regcache, realnum, buf); + break; + default: + error ("Attempt to assign to an unmodifiable value."); } +} + +/* frame_register_read () - return addr; + Find and return the value of REGNUM for the specified stack frame. + The number of bytes copied is DEPRECATED_REGISTER_RAW_SIZE + (REGNUM). + + Returns 0 if the register value could not be found. */ + +int +frame_register_read (struct frame_info *frame, int regnum, void *myaddr) +{ + int optimized; + enum lval_type lval; + CORE_ADDR addr; + int realnum; + frame_register (frame, regnum, &optimized, &lval, &addr, &realnum, myaddr); + + /* FIXME: cagney/2002-05-15: This test, is just bogus. + + It indicates that the target failed to supply a value for a + register because it was "not available" at this time. Problem + is, the target still has the register and so get saved_register() + may be returning a value saved on the stack. */ + + if (register_cached (regnum) < 0) + return 0; /* register value not available */ + + return !optimized; } -/* DEFAULT_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). 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). Set *ADDRP to the address, either in memory - on as a REGISTER_BYTE offset into the registers array. - - Note that this implementation never sets *LVAL to not_lval. But - it can be replaced by defining GET_SAVED_REGISTER and supplying - your own. +/* 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. */ - The argument RAW_BUFFER must point to aligned memory. */ +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); +} + +const char * +frame_map_regnum_to_name (struct frame_info *frame, int regnum) +{ + return user_reg_map_regnum_to_name (get_frame_arch (frame), regnum); +} + +/* Create a sentinel frame. */ + +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 + information, such as the frame's thread will be added. */ + frame->prologue_cache = sentinel_frame_cache (regcache); + /* For the moment there is only one sentinel frame implementation. */ + frame->unwind = sentinel_frame_unwind; + /* Link this frame back to itself. The frame is self referential + (the unwound PC is the same as the pc), so make it so. */ + frame->next = frame; + /* Make the sentinel frame's ID valid, but invalid. That way all + comparisons with it should fail. */ + frame->this_id.p = 1; + frame->this_id.value = null_frame_id; + if (frame_debug) + { + fprintf_unfiltered (gdb_stdlog, "{ create_sentinel_frame (...) -> "); + fprint_frame (gdb_stdlog, frame); + fprintf_unfiltered (gdb_stdlog, " }\n"); + } + return frame; +} + +/* Info about the innermost stack frame (contents of FP register) */ + +static struct frame_info *current_frame; + +/* Cache for frame addresses already read by gdb. Valid only while + inferior is stopped. Control variables for the frame cache should + be local to this module. */ + +static struct obstack frame_cache_obstack; + +void * +frame_obstack_zalloc (unsigned long size) +{ + void *data = obstack_alloc (&frame_cache_obstack, size); + memset (data, 0, size); + return data; +} + +CORE_ADDR * +frame_saved_regs_zalloc (struct frame_info *fi) +{ + fi->saved_regs = (CORE_ADDR *) + frame_obstack_zalloc (SIZEOF_FRAME_SAVED_REGS); + return fi->saved_regs; +} + +CORE_ADDR * +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 + sentinel frame fails, the function still returns a stack frame. */ + +static int +unwind_to_current_frame (struct ui_out *ui_out, void *args) +{ + struct frame_info *frame = get_prev_frame (args); + /* A sentinel frame can fail to unwind, eg, because it's PC value + lands in somewhere like start. */ + if (frame == NULL) + return 1; + current_frame = frame; + return 0; +} + +struct frame_info * +get_current_frame (void) +{ + /* First check, and report, the lack of registers. Having GDB + report "No stack!" or "No memory" when the target doesn't even + have registers is very confusing. Besides, "printcmd.exp" + explicitly checks that ``print $pc'' with no registers prints "No + registers". */ + if (!target_has_registers) + error ("No registers."); + if (!target_has_stack) + error ("No stack."); + if (!target_has_memory) + error ("No memory."); + if (current_frame == NULL) + { + struct frame_info *sentinel_frame = + create_sentinel_frame (current_regcache); + if (catch_exceptions (uiout, unwind_to_current_frame, sentinel_frame, + NULL, RETURN_MASK_ERROR) != 0) + { + /* Oops! Fake a current frame? Is this useful? It has a PC + of zero, for instance. */ + current_frame = sentinel_frame; + } + } + return current_frame; +} + +/* The "selected" stack frame is used by default for local and arg + access. May be zero, for no selected frame. */ + +struct frame_info *deprecated_selected_frame; + +/* Return the selected frame. Always non-null (unless there isn't an + inferior sufficient for creating a frame) in which case an error is + thrown. */ + +struct frame_info * +get_selected_frame (void) +{ + if (deprecated_selected_frame == NULL) + /* Hey! Don't trust this. It should really be re-finding the + last selected frame of the currently selected thread. This, + though, is better than nothing. */ + select_frame (get_current_frame ()); + /* There is always a frame. */ + gdb_assert (deprecated_selected_frame != NULL); + return deprecated_selected_frame; +} + +/* 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 (). */ + +struct frame_info * +deprecated_safe_get_selected_frame (void) +{ + if (!target_has_registers || !target_has_stack || !target_has_memory) + return NULL; + return get_selected_frame (); +} + +/* Select frame FI (or NULL - to invalidate the current frame). */ + +void +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 + frame is being invalidated. */ + if (selected_frame_level_changed_hook) + selected_frame_level_changed_hook (frame_relative_level (fi)); + + /* FIXME: kseitz/2002-08-28: It would be nice to call + selected_frame_level_changed_event right here, but due to limitations + in the current interfaces, we would end up flooding UIs with events + because select_frame is used extensively internally. + + Once we have frame-parameterized frame (and frame-related) commands, + the event notification can be moved here, since this function will only + be called when the users selected frame is being changed. */ + + /* Ensure that symbols for this frame are read in. Also, determine the + source language of this frame, and switch to it if desired. */ + if (fi) + { + /* 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 + 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 + is guaranteed to be inside the frame's code block. */ + s = find_pc_symtab (get_frame_address_in_block (fi)); + if (s + && s->language != current_language->la_language + && s->language != language_unknown + && language_mode == language_mode_auto) + { + set_language (s->language); + } + } +} + +/* Return the register saved in the simplistic ``saved_regs'' cache. + If the value isn't here AND a value is needed, try the next inner + most frame. */ static void -default_get_saved_register (char *raw_buffer, - int *optimized, - CORE_ADDR *addrp, - struct frame_info *frame, - int regnum, - enum lval_type *lval) +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) { - CORE_ADDR addr; + /* 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); + + if (deprecated_get_frame_saved_regs (frame) == NULL) + { + /* 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); + } + if (deprecated_get_frame_saved_regs (frame) != NULL + && deprecated_get_frame_saved_regs (frame)[regnum] != 0) + { + if (regnum == SP_REGNUM) + { + /* SP register treated specially. */ + *optimizedp = 0; + *lvalp = not_lval; + *addrp = 0; + *realnump = -1; + if (bufferp != NULL) + /* 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; + } + + /* No luck. Assume this and the next frame have the same register + value. Pass the unwind request down the frame chain to the next + frame. Hopefully that frame will find the register's location. */ + frame_register_unwind (next_frame, regnum, optimizedp, lvalp, addrp, + realnump, bufferp); +} + +static void +legacy_saved_regs_this_id (struct frame_info *next_frame, + void **this_prologue_cache, + struct frame_id *id) +{ + /* A developer is trying to bring up a new architecture, help them + by providing a default unwinder that refuses to unwind anything + (the ID is always NULL). In the case of legacy code, + legacy_get_prev_frame() will have previously set ->this_id.p, so + this code won't be called. */ + (*id) = null_frame_id; +} + +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. + + 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. + + The argument RAW_BUFFER must point to aligned memory. */ + +void +deprecated_generic_get_saved_register (char *raw_buffer, int *optimized, + CORE_ADDR *addrp, + struct frame_info *frame, int regnum, + enum lval_type *lval) +{ if (!target_has_registers) error ("No registers."); /* Normal systems don't optimize out things with register numbers. */ if (optimized != NULL) *optimized = 0; - addr = find_saved_register (frame, regnum); - if (addr != 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) { - if (lval != NULL) - *lval = lval_memory; - if (regnum == SP_REGNUM) + for (frame = get_next_frame (frame); + frame_relative_level (frame) >= 0; + frame = get_next_frame (frame)) { - if (raw_buffer != NULL) + if (get_frame_type (frame) == DUMMY_FRAME) { - /* Put it back in target format. */ - store_address (raw_buffer, REGISTER_RAW_SIZE (regnum), - (LONGEST) addr); + 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 (addrp != NULL) - *addrp = 0; - return; } - if (raw_buffer != NULL) - target_read_memory (addr, raw_buffer, REGISTER_RAW_SIZE (regnum)); } + + /* 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 { - if (lval != NULL) - *lval = lval_register; - addr = REGISTER_BYTE (regnum); - if (raw_buffer != NULL) - read_register_gen (regnum, raw_buffer); + char *name; + find_pc_partial_function (pc, &name, NULL, NULL); + if (PC_IN_SIGTRAMP (pc, name)) + return SIGTRAMP_FRAME; + else + return NORMAL_FRAME; } - if (addrp != NULL) - *addrp = addr; } -#if !defined (GET_SAVED_REGISTER) -#define GET_SAVED_REGISTER(raw_buffer, optimized, addrp, frame, regnum, lval) \ - default_get_saved_register(raw_buffer, optimized, addrp, frame, regnum, lval) -#endif +/* 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) + { + fprintf_unfiltered (gdb_stdlog, "-> "); + fprint_frame (gdb_stdlog, fi); + fprintf_unfiltered (gdb_stdlog, " }\n"); + } + + return fi; +} + +/* Return the frame that THIS_FRAME calls (NULL if THIS_FRAME is the + innermost frame). Be careful to not fall off the bottom of the + frame chain and onto the sentinel frame. */ + +struct frame_info * +get_next_frame (struct frame_info *this_frame) +{ + if (this_frame->level > 0) + return this_frame->next; + else + return NULL; +} + +/* Flush the entire frame cache. */ + +void +flush_cached_frames (void) +{ + /* Since we can't really be sure what the first object allocated was */ + obstack_free (&frame_cache_obstack, 0); + obstack_init (&frame_cache_obstack); + + current_frame = NULL; /* Invalidate cache */ + select_frame (NULL); + annotate_frames_invalid (); + if (frame_debug) + fprintf_unfiltered (gdb_stdlog, "{ flush_cached_frames () }\n"); +} + +/* Flush the frame cache, and start a new one if necessary. */ void -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) { - GET_SAVED_REGISTER (raw_buffer, optimized, addrp, frame, regnum, lval); + flush_cached_frames (); + + /* FIXME: The inferior_ptid test is wrong if there is a corefile. */ + if (PIDGET (inferior_ptid) != 0) + { + select_frame (get_current_frame ()); + } +} + +/* Create the previous frame using the deprecated methods + INIT_EXTRA_INFO, INIT_FRAME_PC and INIT_FRAME_PC_FIRST. */ + +static struct frame_info * +legacy_get_prev_frame (struct frame_info *this_frame) +{ + CORE_ADDR address = 0; + struct frame_info *prev; + int fromleaf; + + /* 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 completely 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 = (DEPRECATED_FRAMELESS_FUNCTION_INVOCATION_P () + && DEPRECATED_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; + } + + /* 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)) + { + 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; + } + + /* 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 (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 with confused type\n"); + } + + return prev; } -/* READ_RELATIVE_REGISTER_RAW_BYTES_FOR_FRAME +/* Return a structure containing various interesting information + about the frame that called THIS_FRAME. Returns NULL + if there is no such frame. - Copy the bytes of register REGNUM, relative to the input stack frame, - into our memory at MYADDR, in target byte order. - The number of bytes copied is REGISTER_RAW_SIZE (REGNUM). + 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. */ - Returns 1 if could not be read, 0 if could. */ +struct frame_info * +get_prev_frame (struct frame_info *this_frame) +{ + struct frame_info *prev_frame; -/* FIXME: This function increases the confusion between FP_REGNUM - and the virtual/pseudo-frame pointer. */ + 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, "<NULL>"); + 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 (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) + { + if (frame_debug) + { + fprintf_unfiltered (gdb_stdlog, "-> "); + fprint_frame (gdb_stdlog, this_frame->prev); + fprintf_unfiltered (gdb_stdlog, " // cached \n"); + } + return this_frame->prev; + } + this_frame->prev_p = 1; + + /* If we're inside the entry file, it isn't valid. Don't apply this + test to a dummy frame - dummy frame PC's typically land in the + entry file. Don't apply this test to the sentinel frame. + Sentinel frames should always be allowed to unwind. */ + /* NOTE: drow/2002-12-25: should there be a way to disable this + check? It assumes a single small entry file, and the way some + debug readers (e.g. dbxread) figure out which object is the + entry file is somewhat hokey. */ + /* NOTE: cagney/2003-01-10: If there is a way of disabling this test + then it should probably be moved to before the ->prev_p test, + above. */ + /* 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))) + { + if (frame_debug) + { + fprintf_unfiltered (gdb_stdlog, "-> "); + fprint_frame (gdb_stdlog, NULL); + fprintf_unfiltered (gdb_stdlog, " // inside entry file }\n"); + } + return NULL; + } + + /* If any of the old frame initialization methods are around, use + the legacy get_prev_frame method. */ + if (legacy_frame_p (current_gdbarch)) + { + prev_frame = legacy_get_prev_frame (this_frame); + return prev_frame; + } + + /* Check that this frame's ID was valid. If it wasn't, don't try to + unwind to the prev frame. Be careful to not apply this test to + the sentinel frame. */ + if (this_frame->level >= 0 && !frame_id_p (get_frame_id (this_frame))) + { + if (frame_debug) + { + fprintf_unfiltered (gdb_stdlog, "-> "); + fprint_frame (gdb_stdlog, NULL); + fprintf_unfiltered (gdb_stdlog, " // this ID is NULL }\n"); + } + return NULL; + } + + /* Check that this frame's ID isn't inner to (younger, below, next) + the next frame. This happens when a frame unwind goes backwards. + Since the sentinel frame doesn't really exist, don't compare the + inner-most against that sentinel. */ + 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?)"); + + /* 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?)"); + + /* Allocate the new frame but do not wire it in to the frame chain. + Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along + frame->next to pull some fancy tricks (of course such code is, by + definition, recursive). Try to prevent it. + + There is no reason to worry about memory leaks, should the + remainder of the function fail. The allocated memory will be + quickly reclaimed when the frame cache is flushed, and the `we've + been here before' check above will stop repeated memory + allocation calls. */ + prev_frame = FRAME_OBSTACK_ZALLOC (struct frame_info); + prev_frame->level = this_frame->level + 1; + + /* Don't yet compute ->unwind (and hence ->type). It is computed + on-demand in get_frame_type, frame_register_unwind, and + get_frame_id. */ + + /* Don't yet compute the frame's ID. It is computed on-demand by + get_frame_id(). */ + + /* The unwound frame ID is validate at the start of this function, + as part of the logic to decide if that frame should be further + unwound, and not here while the prev frame is being created. + Doing this makes it possible for the user to examine a frame that + has an invalid frame ID. + + Some very old VAX code noted: [...] For the sake of argument, + suppose that the stack is somewhat trashed (which is one reason + that "info frame" exists). So, return 0 (indicating we don't + know the address of the arglist) if we don't know what frame this + frame calls. */ + + /* Link it in. */ + this_frame->prev = prev_frame; + prev_frame->next = this_frame; + + if (frame_debug) + { + fprintf_unfiltered (gdb_stdlog, "-> "); + fprint_frame (gdb_stdlog, prev_frame); + fprintf_unfiltered (gdb_stdlog, " }\n"); + } + + return prev_frame; +} + +CORE_ADDR +get_frame_pc (struct frame_info *frame) +{ + gdb_assert (frame->next != NULL); + return frame_pc_unwind (frame->next); +} + +/* Return an address of that falls within the frame's code block. */ + +CORE_ADDR +frame_unwind_address_in_block (struct frame_info *next_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 +get_frame_address_in_block (struct frame_info *this_frame) +{ + return frame_unwind_address_in_block (this_frame->next); +} static int -read_relative_register_raw_bytes_for_frame (int regnum, - char *myaddr, - struct frame_info *frame) +pc_notcurrent (struct frame_info *frame) { - int optim; - if (regnum == FP_REGNUM && frame) + /* If FRAME is not the innermost frame, that normally means that + FRAME->pc points at the return instruction (which is *after* the + call instruction), and we want to get the line containing the + call (because the call is where the user thinks the program is). + However, if the next frame is either a SIGTRAMP_FRAME or a + DUMMY_FRAME, then the next frame will contain a saved interrupt + PC and such a PC indicates the current (rather than next) + instruction/line, consequently, for such cases, want to get the + line containing fi->pc. */ + struct frame_info *next = get_next_frame (frame); + int notcurrent = (next != NULL && get_frame_type (next) == NORMAL_FRAME); + return notcurrent; +} + +void +find_frame_sal (struct frame_info *frame, struct symtab_and_line *sal) +{ + (*sal) = find_pc_line (get_frame_pc (frame), pc_notcurrent (frame)); +} + +/* Per "frame.h", return the ``address'' of the frame. Code should + really be using get_frame_id(). */ +CORE_ADDR +get_frame_base (struct frame_info *fi) +{ + return get_frame_id (fi).stack_addr; +} + +/* High-level offsets into the frame. Used by the debug info. */ + +CORE_ADDR +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); + /* 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); +} + +CORE_ADDR +get_frame_locals_address (struct frame_info *fi) +{ + void **cache; + if (get_frame_type (fi) != NORMAL_FRAME) + 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); + /* 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); +} + +CORE_ADDR +get_frame_args_address (struct frame_info *fi) +{ + void **cache; + if (get_frame_type (fi) != NORMAL_FRAME) + 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); + /* 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); +} + +/* Level of the selected frame: 0 for innermost, 1 for its caller, ... + or -1 for a NULL frame. */ + +int +frame_relative_level (struct frame_info *fi) +{ + if (fi == NULL) + return -1; + else + return fi->level; +} + +enum frame_type +get_frame_type (struct frame_info *frame) +{ + /* Some targets still don't use [generic] dummy frames. Catch them + here. */ + if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES + && deprecated_frame_in_dummy (frame)) + return DUMMY_FRAME; + + /* 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)) { - /* Put it back in target format. */ - store_address (myaddr, REGISTER_RAW_SIZE (FP_REGNUM), - (LONGEST) FRAME_FP (frame)); + /* 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(). */ + 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; +} - return 0; +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; } +} - get_saved_register (myaddr, &optim, (CORE_ADDR *) NULL, frame, - regnum, (enum lval_type *) NULL); +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; +} - if (register_cached (regnum) < 0) - return 1; /* register value not available */ +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; +} + +/* Memory access methods. */ + +void +get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr, void *buf, + int len) +{ + read_memory (addr, buf, len); +} - return optim; +LONGEST +get_frame_memory_signed (struct frame_info *this_frame, CORE_ADDR addr, + int len) +{ + return read_memory_integer (addr, len); +} + +ULONGEST +get_frame_memory_unsigned (struct frame_info *this_frame, CORE_ADDR addr, + int len) +{ + return read_memory_unsigned_integer (addr, len); } -/* READ_RELATIVE_REGISTER_RAW_BYTES +/* Architecture method. */ - Copy the bytes of register REGNUM, relative to the current stack - frame, into our memory at MYADDR, in target byte order. - The number of bytes copied is REGISTER_RAW_SIZE (REGNUM). +struct gdbarch * +get_frame_arch (struct frame_info *this_frame) +{ + return current_gdbarch; +} + +/* Stack pointer methods. */ + +CORE_ADDR +get_frame_sp (struct frame_info *this_frame) +{ + return frame_sp_unwind (this_frame->next); +} + +CORE_ADDR +frame_sp_unwind (struct frame_info *next_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) + { + ULONGEST sp; + frame_unwind_unsigned_register (next_frame, SP_REGNUM, &sp); + return sp; + } + internal_error (__FILE__, __LINE__, "Missing unwind SP method"); +} - Returns 1 if could not be read, 0 if could. */ int -read_relative_register_raw_bytes (int regnum, char *myaddr) +legacy_frame_p (struct gdbarch *current_gdbarch) { - return read_relative_register_raw_bytes_for_frame (regnum, myaddr, - selected_frame); + if (DEPRECATED_INIT_FRAME_PC_P () + || DEPRECATED_INIT_FRAME_PC_FIRST_P () + || DEPRECATED_INIT_EXTRA_FRAME_INFO_P () + || DEPRECATED_FRAME_CHAIN_P ()) + /* No question, it's a legacy frame. */ + return 1; + if (gdbarch_unwind_dummy_id_p (current_gdbarch)) + /* No question, it's not a legacy frame (provided none of the + deprecated methods checked above are present that is). */ + return 0; + if (DEPRECATED_TARGET_READ_FP_P () + || DEPRECATED_FP_REGNUM >= 0) + /* Assume it's legacy. If you're trying to convert a legacy frame + target to the new mechanism, get rid of these. legacy + get_prev_frame requires these when unwind_frame_id isn't + available. */ + return 1; + /* Default to assuming that it's brand new code, and hence not + legacy. Force it down the non-legacy path so that the new code + uses the new frame mechanism from day one. Dummy frame's won't + work very well but we can live with that. */ + return 0; +} + +extern initialize_file_ftype _initialize_frame; /* -Wmissing-prototypes */ + +static struct cmd_list_element *set_backtrace_cmdlist; +static struct cmd_list_element *show_backtrace_cmdlist; + +static void +set_backtrace_cmd (char *args, int from_tty) +{ + help_list (set_backtrace_cmdlist, "set backtrace ", -1, gdb_stdout); +} + +static void +show_backtrace_cmd (char *args, int from_tty) +{ + cmd_show_list (show_backtrace_cmdlist, from_tty, ""); +} + +void +_initialize_frame (void) +{ + obstack_init (&frame_cache_obstack); + + add_prefix_cmd ("backtrace", class_maintenance, set_backtrace_cmd, "\ +Set backtrace specific variables.\n\ +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, "\ +Show backtrace specific variables\n\ +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\ +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, + &show_backtrace_cmdlist); + + add_setshow_uinteger_cmd ("limit", class_obscure, + &backtrace_limit, "\ +Set an upper bound on the number of backtrace levels.\n\ +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); + + /* 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); } |
