This file is part of GDB.
-GDB is free software; you can redistribute it and/or modify
+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 1, or (at your option)
-any later version.
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
-GDB is distributed in the hope that it will be useful,
+This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
-along with GDB; see the file COPYING. If not, write to
-the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
+along with this program; if not, write to the Free Software
+Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+#include <stdio.h>
#include "defs.h"
#include "param.h"
#include "symtab.h"
#include "frame.h"
+#include "gdbcore.h"
+#include "value.h" /* for read_register */
+#include "target.h" /* for target_has_stack */
-#include <obstack.h>
+CORE_ADDR read_pc (); /* In infcmd.c */
/* Start and end of object file containing the entry point.
STARTUP_FILE_END is the first address of the next file.
CORE_ADDR startup_file_start;
CORE_ADDR startup_file_end;
-/* Is ADDR outside the startup file? */
+/* Is ADDR outside the startup file? Note that if your machine
+ has a way to detect the bottom of the stack, there is no need
+ to call this function from FRAME_CHAIN_VALID; the reason for
+ doing so is that some machines have no way of detecting bottom
+ of stack. */
int
outside_startup_file (addr)
CORE_ADDR addr;
return !(addr >= startup_file_start && addr < startup_file_end);
}
+/* Support an alternate method to avoid running off the bottom of
+ the stack (or top, depending upon your stack orientation).
+
+ There are two frames that are "special", the frame for the function
+ containing the process entry point, since it has no predecessor frame,
+ and the frame for the function containing the user code entry point
+ (the main() function), since all the predecessor frames are for the
+ process startup code. Since we have no guarantee that the linked
+ in startup modules have any debugging information that gdb can use,
+ we need to avoid following frame pointers back into frames that might
+ have been built in the startup code, as we might get hopelessly
+ confused. However, we almost always have debugging information
+ available for main().
+
+ These variables are used to save the range of PC values which are valid
+ within the main() function and within the function containing the process
+ entry point. If we always consider the frame for main() as the outermost
+ frame when debugging user code, and the frame for the process entry
+ point function as the outermost frame when debugging startup code, then
+ all we have to do is have FRAME_CHAIN_VALID return false whenever a
+ frame's current PC is within the range specified by these variables.
+ In essence, we set "blocks" in the frame chain beyond which we will
+ not proceed when following the frame chain.
+
+ A nice side effect is that we can still debug startup code without
+ running off the end of the frame chain, assuming that we have usable
+ debugging information in the startup modules, and if we choose to not
+ use the block at main, or can't find it for some reason, everything
+ still works as before. And if we have no startup code debugging
+ information but we do have usable information for main(), backtraces
+ from user code don't go wandering off into the startup code.
+
+ To use this method, define your FRAME_CHAIN_VALID macro like:
+
+ #define FRAME_CHAIN_VALID(chain, thisframe) \
+ (chain != 0 \
+ && !(inside_main_scope ((thisframe)->pc)) \
+ && !(inside_entry_scope ((thisframe)->pc)))
+
+ and add initializations of the four scope controlling variables inside
+ the object file / debugging information processing modules. */
+
+CORE_ADDR entry_scope_lowpc;
+CORE_ADDR entry_scope_highpc;
+CORE_ADDR main_scope_lowpc;
+CORE_ADDR main_scope_highpc;
+
+/* Test a specified PC value to see if it is in the range of addresses
+ that correspond to the main() function. See comments above for why
+ we might want to do this.
+
+ Typically called from FRAME_CHAIN_VALID. */
+
+int
+inside_main_scope (pc)
+CORE_ADDR pc;
+{
+ return (main_scope_lowpc <= pc && pc < main_scope_highpc);
+}
+
+/* Test a specified PC value to see if it is in the range of addresses
+ that correspond to the process entry point function. See comments above
+ for why we might want to do this.
+
+ Typically called from FRAME_CHAIN_VALID. */
+
+int
+inside_entry_scope (pc)
+CORE_ADDR pc;
+{
+ return (entry_scope_lowpc <= pc && pc < entry_scope_highpc);
+}
+
/* Address of innermost stack frame (contents of FP register) */
static FRAME current_frame;
-struct block *block_for_pc ();
-CORE_ADDR get_pc_function_start ();
-
/*
* Cache for frame addresses already read by gdb. Valid only while
* inferior is stopped. Control variables for the frame cache should
fci->pc = pc;
#ifdef INIT_EXTRA_FRAME_INFO
- INIT_EXTRA_FRAME_INFO (fci);
+ INIT_EXTRA_FRAME_INFO (0, fci);
#endif
return fci;
current_frame = (struct frame_info *) 0; /* Invalidate cache */
}
+/* Flush the frame cache, and start a new one if necessary. */
+void
+reinit_frame_cache ()
+{
+ FRAME fr = current_frame;
+ flush_cached_frames ();
+ if (fr)
+ set_current_frame ( create_new_frame (read_register (FP_REGNUM),
+ read_pc ()));
+}
+
/* Return a structure containing various interesting information
about a specified stack frame. */
/* How do I justify including this function? Well, the FRAME
frame_info for the frame, and FRAMELESS should be set to nonzero
if it represents a frameless function invocation. */
-/* Many machines which allow frameless functions can detect them using
- this macro. Such machines should define FRAMELESS_FUNCTION_INVOCATION
- to just call this macro. */
-#define FRAMELESS_LOOK_FOR_PROLOGUE(FI, FRAMELESS) \
-{ \
- CORE_ADDR func_start, after_prologue; \
- func_start = (get_pc_function_start ((FI)->pc) + \
- FUNCTION_START_OFFSET); \
- if (func_start) \
- { \
- after_prologue = func_start; \
- SKIP_PROLOGUE (after_prologue); \
- (FRAMELESS) = (after_prologue == func_start); \
- } \
- else \
- /* If we can't find the start of the function, we don't really */ \
- /* know whether the function is frameless, but we should be */ \
- /* able to get a reasonable (i.e. best we can do under the */ \
- /* circumstances) backtrace by saying that it isn't. */ \
- (FRAMELESS) = 0; \
+/* Return nonzero if the function for this frame has a prologue. Many
+ machines can define FRAMELESS_FUNCTION_INVOCATION to just call this
+ function. */
+
+int
+frameless_look_for_prologue (frame)
+ FRAME frame;
+{
+ CORE_ADDR func_start, after_prologue;
+ func_start = (get_pc_function_start (frame->pc) +
+ FUNCTION_START_OFFSET);
+ if (func_start)
+ {
+ after_prologue = func_start;
+#ifdef SKIP_PROLOGUE_FRAMELESS_P
+ /* This is faster, since only care whether there *is* a prologue,
+ not how long it is. */
+ SKIP_PROLOGUE_FRAMELESS_P (after_prologue);
+#else
+ SKIP_PROLOGUE (after_prologue);
+#endif
+ return after_prologue == func_start;
+ }
+ else
+ /* If we can't find the start of the function, we don't really
+ know whether the function is frameless, but we should be able
+ to get a reasonable (i.e. best we can do under the
+ circumstances) backtrace by saying that it isn't. */
+ return 0;
}
+/* Default a few macros that people seldom redefine. */
+
+#if !defined (INIT_FRAME_PC)
+#define INIT_FRAME_PC(fromleaf, prev) \
+ prev->pc = (fromleaf ? SAVED_PC_AFTER_CALL (prev->next) : \
+ prev->next ? FRAME_SAVED_PC (prev->next) : read_pc ());
+#endif
+
+#ifndef FRAME_CHAIN_COMBINE
+#define FRAME_CHAIN_COMBINE(chain, thisframe) (chain)
+#endif
+
/* Return a structure containing various interesting information
- about the frame that called NEXT_FRAME. */
+ about the frame that called NEXT_FRAME. Returns NULL
+ if there is no such frame. */
struct frame_info *
get_prev_frame_info (next_frame)
{
if (!current_frame)
{
- if (!have_inferior_p () && !have_core_file_p ())
- fatal ("get_prev_frame_info: Called before cache primed. \"Shouldn't happen.\"");
- else
- error ("No inferior or core file.");
+ error ("You haven't set up a process's stack to examine.");
}
return current_frame;
if (!fromleaf)
{
- /* Two macros defined in param.h specify the machine-dependent
+ /* 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
address = FRAME_CHAIN (next_frame);
if (!FRAME_CHAIN_VALID (address, next_frame))
return 0;
- /* If this frame is a leaf, this will be superceeded by the
- code below. */
address = FRAME_CHAIN_COMBINE (address, next_frame);
}
+ if (address == 0)
+ return 0;
prev = (struct frame_info *)
obstack_alloc (&frame_cache_obstack,
prev->next_frame = prev->next ? prev->next->frame : 0;
#ifdef INIT_EXTRA_FRAME_INFO
- INIT_EXTRA_FRAME_INFO(prev);
+ INIT_EXTRA_FRAME_INFO(fromleaf, prev);
#endif
/* This entry is in the frame queue now, which is good since
FRAME_SAVED_PC may use that queue to figure out it's value
- (see m-sparc.h). We want the pc saved in the inferior frame. */
- prev->pc = (fromleaf ? SAVED_PC_AFTER_CALL (next_frame) :
- next_frame ? FRAME_SAVED_PC (next_frame) : read_pc ());
+ (see tm-sparc.h). We want the pc saved in the inferior frame. */
+ INIT_FRAME_PC(fromleaf, prev);
return prev;
}
return fi->pc;
}
+#if defined (FRAME_FIND_SAVED_REGS)
/* Find the addresses in which registers are saved in FRAME. */
void
{
FRAME_FIND_SAVED_REGS (frame_info_addr, *saved_regs_addr);
}
+#endif
/* Return the innermost lexical block in execution
in a specified stack frame. The frame address is assumed valid. */
FRAME frame;
{
struct frame_info *fi;
+ CORE_ADDR pc;
fi = get_frame_info (frame);
- return block_for_pc (fi->pc);
+
+ pc = fi->pc;
+ if (fi->next_frame != 0)
+ /* We are not in the innermost frame. We need to subtract one to
+ get the correct block, in case the call instruction was the
+ last instruction of the block. If there are any machines on
+ which the saved pc does not point to after the call insn, we
+ probably want to make fi->pc point after the call insn anyway. */
+ --pc;
+ return block_for_pc (pc);
}
struct block *
return block_function (bl);
}
\f
-/* Return the innermost lexical block containing the specified pc value,
- or 0 if there is none. */
+/* Return the blockvector immediately containing the innermost lexical block
+ containing the specified pc value, or 0 if there is none.
+ PINDEX is a pointer to the index value of the block. If PINDEX
+ is NULL, we don't pass this information back to the caller. */
-extern struct symtab *psymtab_to_symtab ();
-
-struct block *
-block_for_pc (pc)
+struct blockvector *
+blockvector_for_pc (pc, pindex)
register CORE_ADDR pc;
+ int *pindex;
{
register struct block *b;
register int bot, top, half;
register struct symtab *s;
- register struct partial_symtab *ps;
struct blockvector *bl;
/* First search all symtabs for one whose file contains our pc */
-
- for (s = symtab_list; s; s = s->next)
- {
- bl = BLOCKVECTOR (s);
- b = BLOCKVECTOR_BLOCK (bl, 0);
- if (BLOCK_START (b) <= pc
- && BLOCK_END (b) > pc)
- break;
- }
-
- if (s == 0)
- for (ps = partial_symtab_list; ps; ps = ps->next)
- {
- if (ps->textlow <= pc
- && ps->texthigh > pc)
- {
- if (ps->readin)
- fatal ("Internal error: pc found in readin psymtab and not in any symtab.");
- s = psymtab_to_symtab (ps);
- bl = BLOCKVECTOR (s);
- b = BLOCKVECTOR_BLOCK (bl, 0);
- break;
- }
- }
-
+ s = find_pc_symtab (pc);
if (s == 0)
return 0;
+ bl = BLOCKVECTOR (s);
+ b = BLOCKVECTOR_BLOCK (bl, 0);
+
/* Then search that symtab for the smallest block that wins. */
/* Use binary search to find the last block that starts before PC. */
{
b = BLOCKVECTOR_BLOCK (bl, bot);
if (BLOCK_END (b) > pc)
- return b;
+ {
+ if (pindex)
+ *pindex = bot;
+ return bl;
+ }
bot--;
}
return 0;
}
+/* Return the innermost lexical block containing the specified pc value,
+ or 0 if there is none. */
+
+struct block *
+block_for_pc (pc)
+ register CORE_ADDR pc;
+{
+ register struct blockvector *bl;
+ int index;
+
+ bl = blockvector_for_pc (pc, &index);
+ if (bl)
+ return BLOCKVECTOR_BLOCK (bl, index);
+ return 0;
+}
+
/* Return the function containing pc value PC.
Returns 0 if function is not known. */
return block_function (b);
}
+/* These variables are used to cache the most recent result
+ * of find_pc_partial_function. */
+
+static CORE_ADDR cache_pc_function_low = 0;
+static CORE_ADDR cache_pc_function_high = 0;
+static char *cache_pc_function_name = 0;
+
+/* Clear cache, e.g. when symbol table is discarded. */
+
+void
+clear_pc_function_cache()
+{
+ cache_pc_function_low = 0;
+ cache_pc_function_high = 0;
+ cache_pc_function_name = (char *)0;
+}
+
/* Finds the "function" (text symbol) that is smaller than PC
but greatest of all of the potential text symbols. Sets
*NAME and/or *ADDRESS conditionally if that pointer is non-zero.
- Returns 0 if it couldn't find anything, 1 if it did.
-
- Note that there are several possible responses:
- * Set *NAME and *ADDRESS to nonzero values and return 0
- * Set *NAME and *ADDRESS to zero and return 0
- * Don't set *NAME and *ADDRESS and return 1
- (I don't know whether it *should* work this way, but I'd rather
- document it than risk breaking code
- which depends on this behavior). */
+ Returns 0 if it couldn't find anything, 1 if it did. On a zero
+ return, *NAME and *ADDRESS are always set to zero. On a 1 return,
+ *NAME and *ADDRESS contain real information. */
int
find_pc_partial_function (pc, name, address)
char **name;
CORE_ADDR *address;
{
- struct partial_symtab *pst = find_pc_psymtab (pc);
+ struct partial_symtab *pst;
struct symbol *f;
int miscfunc;
struct partial_symbol *psb;
+ if (pc >= cache_pc_function_low && pc < cache_pc_function_high)
+ {
+ if (address)
+ *address = cache_pc_function_low;
+ if (name)
+ *name = cache_pc_function_name;
+ return 1;
+ }
+
+ pst = find_pc_psymtab (pc);
if (pst)
{
if (pst->readin)
f = find_pc_function (pc);
if (!f)
{
- /* No availible symbol. */
+ return_error:
+ /* No available symbol. */
if (name != 0)
*name = 0;
if (address != 0)
return 0;
}
+ cache_pc_function_low = BLOCK_START (SYMBOL_BLOCK_VALUE (f));
+ cache_pc_function_high = BLOCK_END (SYMBOL_BLOCK_VALUE (f));
+ cache_pc_function_name = SYMBOL_NAME (f);
if (name)
- *name = SYMBOL_NAME (f);
+ *name = cache_pc_function_name;
if (address)
- *address = SYMBOL_VALUE (f);
+ *address = cache_pc_function_low;
+ return 1;
}
/* Get the information from a combination of the pst
if (!psb && miscfunc == -1)
{
- if (address != 0)
- *address = 0;
- if (name != 0)
- *name = 0;
- return 0;
+ goto return_error;
}
- if (!psb
- || (miscfunc != -1
- && SYMBOL_VALUE(psb) < misc_function_vector[miscfunc].address))
+ if (psb
+ && (miscfunc == -1
+ || (SYMBOL_VALUE_ADDRESS (psb)
+ >= misc_function_vector[miscfunc].address)))
{
+ /* This case isn't being cached currently. */
if (address)
- *address = misc_function_vector[miscfunc].address;
- if (name)
- *name = misc_function_vector[miscfunc].name;
- }
- else
- {
- if (address)
- *address = SYMBOL_VALUE (psb);
+ *address = SYMBOL_VALUE_ADDRESS (psb);
if (name)
*name = SYMBOL_NAME (psb);
+ return 1;
}
}
else
{
miscfunc = find_pc_misc_function (pc);
if (miscfunc == -1)
- return 0;
- if (address)
- *address = misc_function_vector[miscfunc].address;
- if (name)
- *name = misc_function_vector[miscfunc].name;
+ goto return_error;
}
+
+ {
+ if (misc_function_vector[miscfunc].type == mf_text)
+ cache_pc_function_low = misc_function_vector[miscfunc].address;
+ else
+ /* It is a transfer table for Sun shared libraries. */
+ cache_pc_function_low = pc - FUNCTION_START_OFFSET;
+ }
+ cache_pc_function_name = misc_function_vector[miscfunc].name;
+ if (miscfunc < misc_function_count /* && FIXME mf_text again? */ )
+ cache_pc_function_high = misc_function_vector[miscfunc+1].address;
+ else
+ cache_pc_function_high = cache_pc_function_low + 1;
+ if (address)
+ *address = cache_pc_function_low;
+ if (name)
+ *name = cache_pc_function_name;
return 1;
}
register int lo = 0;
register int hi = misc_function_count-1;
register int new;
- register int distance;
/* Note that the last thing in the vector is always _etext. */
/* Actually, "end", now that non-functions
"pc >= misc_function_vector[hi].address". */
do {
new = (lo + hi) >> 1;
- distance = misc_function_vector[new].address - pc;
- if (distance == 0)
+ if (misc_function_vector[new].address == pc)
return new; /* an exact match */
- else if (distance > 0)
+ else if (misc_function_vector[new].address > pc)
hi = new;
else
lo = new;
projects / deliverable / binutils-gdb.git / blobdiff