/* Get info from stack frames;
convert between frames, blocks, functions and pc values.
- Copyright (C) 1986, 1987, 1988, 1989 Free Software Foundation, Inc.
+ Copyright 1986, 1987, 1988, 1989, 1991 Free Software Foundation, Inc.
This file is part of GDB.
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 "bfd.h"
+#include "symfile.h"
+#include "objfiles.h"
#include "frame.h"
#include "gdbcore.h"
#include "value.h" /* for read_register */
#include "target.h" /* for target_has_stack */
+#include "inferior.h" /* for read_pc */
-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.
- This file is assumed to be a startup file
- and frames with pc's inside it
- are treated as nonexistent.
-
- Setting these variables is necessary so that backtraces do not fly off
- the bottom of the stack. */
-CORE_ADDR startup_file_start;
-CORE_ADDR startup_file_end;
-
-/* Is ADDR outside the startup file? Note that if your machine
+/* Is ADDR inside 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. */
+ of stack.
+
+ A PC of zero is always considered to be the bottom of the stack. */
+
int
-outside_startup_file (addr)
+inside_entry_file (addr)
CORE_ADDR addr;
{
- return !(addr >= startup_file_start && addr < startup_file_end);
+ if (addr == 0)
+ return 1;
+ if (symfile_objfile == 0)
+ return 0;
+#if CALL_DUMMY_LOCATION == AT_ENTRY_POINT
+ /* Do not stop backtracing if the pc is in the call dummy
+ at the entry point. */
+ if (PC_IN_CALL_DUMMY (addr, 0, 0))
+ return 0;
+#endif
+ return (addr >= symfile_objfile -> ei.entry_file_lowpc &&
+ addr < symfile_objfile -> ei.entry_file_highpc);
}
-/* 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. */
+ Typically called from FRAME_CHAIN_VALID.
+
+ A PC of zero is always considered to be the bottom of the stack. */
int
-inside_main_scope (pc)
+inside_main_func (pc)
CORE_ADDR pc;
{
- return (main_scope_lowpc <= pc && pc < main_scope_highpc);
+ if (pc == 0)
+ return 1;
+ if (symfile_objfile == 0)
+ return 0;
+ return (symfile_objfile -> ei.main_func_lowpc <= pc &&
+ symfile_objfile -> ei.main_func_highpc > pc);
}
/* 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.
+ that correspond to the process entry point function. See comments
+ in objfiles.h for why we might want to do this.
- Typically called from FRAME_CHAIN_VALID. */
+ Typically called from FRAME_CHAIN_VALID.
+
+ A PC of zero is always considered to be the bottom of the stack. */
int
-inside_entry_scope (pc)
+inside_entry_func (pc)
CORE_ADDR pc;
{
- return (entry_scope_lowpc <= pc && pc < entry_scope_highpc);
+ if (pc == 0)
+ return 1;
+ if (symfile_objfile == 0)
+ return 0;
+#if CALL_DUMMY_LOCATION == AT_ENTRY_POINT
+ /* Do not stop backtracing if the pc is in the call dummy
+ at the entry point. */
+ if (PC_IN_CALL_DUMMY (pc, 0, 0))
+ return 0;
+#endif
+ return (symfile_objfile -> ei.entry_func_lowpc <= pc &&
+ symfile_objfile -> ei.entry_func_highpc > pc);
}
/* Address of innermost stack frame (contents of FP register) */
CORE_ADDR pc;
{
struct frame_info *fci; /* Same type as FRAME */
+ char *name;
fci = (struct frame_info *)
obstack_alloc (&frame_cache_obstack,
fci->next = (struct frame_info *) 0;
fci->prev = (struct frame_info *) 0;
fci->frame = addr;
- fci->next_frame = 0; /* Since arbitrary */
fci->pc = pc;
+ find_pc_partial_function (pc, &name, (CORE_ADDR *)NULL,(CORE_ADDR *)NULL);
+ fci->signal_handler_caller = IN_SIGTRAMP (fci->pc, name);
#ifdef INIT_EXTRA_FRAME_INFO
INIT_EXTRA_FRAME_INFO (0, fci);
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 ()));
+ if (target_has_stack)
+ {
+ set_current_frame (create_new_frame (read_fp (), read_pc ()));
+ select_frame (get_current_frame (), 0);
+ }
+ else
+ {
+ set_current_frame (0);
+ select_frame ((FRAME) 0, -1);
+ }
}
/* Return a structure containing various interesting information
frame_info for the frame, and FRAMELESS should be set to nonzero
if it represents a frameless function invocation. */
-/* Return nonzero if the function for this frame has a prologue. Many
+/* Return nonzero if the function for this frame lacks a prologue. Many
machines can define FRAMELESS_FUNCTION_INVOCATION to just call this
function. */
get_prev_frame_info (next_frame)
FRAME next_frame;
{
- FRAME_ADDR address;
+ FRAME_ADDR address = 0;
struct frame_info *prev;
int fromleaf = 0;
+ char *name;
/* If the requested entry is in the cache, return it.
Otherwise, figure out what the address should be for the entry
prev->next = next_frame;
prev->prev = (struct frame_info *) 0;
prev->frame = address;
- prev->next_frame = prev->next ? prev->next->frame : 0;
+ prev->signal_handler_caller = 0;
+
+/* This change should not be needed, FIXME! We should
+ determine whether any targets *need* INIT_FRAME_PC to happen
+ after INIT_EXTRA_FRAME_INFO and come up with a simple way to
+ express what goes on here.
+
+ INIT_EXTRA_FRAME_INFO is called from two places: create_new_frame
+ (where the PC is already set up) and here (where it isn't).
+ INIT_FRAME_PC is only called from here, always after
+ INIT_EXTRA_FRAME_INFO.
+
+ The catch is the MIPS, where INIT_EXTRA_FRAME_INFO requires the PC
+ value (which hasn't been set yet). Some other machines appear to
+ require INIT_EXTRA_FRAME_INFO before they can do INIT_FRAME_PC. Phoo.
+
+ We shouldn't need INIT_FRAME_PC_FIRST to add more complication to
+ an already overcomplicated part of GDB. gnu@cygnus.com, 15Sep92.
+
+ To answer the question, yes the sparc needs INIT_FRAME_PC after
+ INIT_EXTRA_FRAME_INFO. Suggested scheme:
+
+ SETUP_INNERMOST_FRAME()
+ Default version is just create_new_frame (read_fp ()),
+ read_pc ()). Machines with extra frame info would do that (or the
+ local equivalent) and then set the extra fields.
+ SETUP_ARBITRARY_FRAME(argc, argv)
+ Only change here is that create_new_frame would no longer init extra
+ frame info; SETUP_ARBITRARY_FRAME would have to do that.
+ INIT_PREV_FRAME(fromleaf, prev)
+ Replace INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC.
+ std_frame_pc(fromleaf, prev)
+ This is the default setting for INIT_PREV_FRAME. It just does what
+ the default INIT_FRAME_PC does. Some machines will call it from
+ INIT_PREV_FRAME (either at the beginning, the end, or in the middle).
+ Some machines won't use it.
+ kingdon@cygnus.com, 13Apr93. */
+
+#ifdef INIT_FRAME_PC_FIRST
+ INIT_FRAME_PC_FIRST (fromleaf, prev);
+#endif
#ifdef INIT_EXTRA_FRAME_INFO
INIT_EXTRA_FRAME_INFO(fromleaf, prev);
(see tm-sparc.h). We want the pc saved in the inferior frame. */
INIT_FRAME_PC(fromleaf, prev);
+ find_pc_partial_function (prev->pc, &name,
+ (CORE_ADDR *)NULL,(CORE_ADDR *)NULL);
+ if (IN_SIGTRAMP (prev->pc, name))
+ prev->signal_handler_caller = 1;
+
return prev;
}
fi = get_frame_info (frame);
pc = fi->pc;
- if (fi->next_frame != 0)
+ if (fi->next != 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
get_pc_function_start (pc)
CORE_ADDR pc;
{
- register struct block *bl = block_for_pc (pc);
+ register struct block *bl;
register struct symbol *symbol;
- if (bl == 0 || (symbol = block_function (bl)) == 0)
+ register struct minimal_symbol *msymbol;
+ CORE_ADDR fstart;
+
+ if ((bl = block_for_pc (pc)) != NULL &&
+ (symbol = block_function (bl)) != NULL)
{
- register int misc_index = find_pc_misc_function (pc);
- if (misc_index >= 0)
- return misc_function_vector[misc_index].address;
- return 0;
+ bl = SYMBOL_BLOCK_VALUE (symbol);
+ fstart = BLOCK_START (bl);
+ }
+ else if ((msymbol = lookup_minimal_symbol_by_pc (pc)) != NULL)
+ {
+ fstart = SYMBOL_VALUE_ADDRESS (msymbol);
}
- bl = SYMBOL_BLOCK_VALUE (symbol);
- return BLOCK_START (bl);
+ else
+ {
+ fstart = 0;
+ }
+ return (fstart);
}
/* Return the symbol for the function executing in frame FRAME. */
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. On a zero
- return, *NAME and *ADDRESS are always set to zero. On a 1 return,
- *NAME and *ADDRESS contain real information. */
+/* 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-null. If ENDADDR is
+ non-null, then set *ENDADDR to be the end of the function
+ (exclusive), but passing ENDADDR as non-null means that the
+ function might cause symbols to be read. This function either
+ succeeds or fails (not halfway succeeds). If it succeeds, it sets
+ *NAME, *ADDRESS, and *ENDADDR to real information and returns 1.
+ If it fails, it sets *NAME, *ADDRESS, and *ENDADDR to zero
+ and returns 0. */
int
-find_pc_partial_function (pc, name, address)
+find_pc_partial_function (pc, name, address, endaddr)
CORE_ADDR pc;
char **name;
CORE_ADDR *address;
+ CORE_ADDR *endaddr;
{
struct partial_symtab *pst;
struct symbol *f;
- int miscfunc;
+ struct minimal_symbol *msymbol;
struct partial_symbol *psb;
if (pc >= cache_pc_function_low && pc < cache_pc_function_high)
+ goto return_cached_value;
+
+ /* If sigtramp is in the u area, it counts as a function (especially
+ important for step_1). */
+#if defined SIGTRAMP_START
+ if (IN_SIGTRAMP (pc, (char *)NULL))
{
- if (address)
- *address = cache_pc_function_low;
- if (name)
- *name = cache_pc_function_name;
- return 1;
+ cache_pc_function_low = SIGTRAMP_START;
+ cache_pc_function_high = SIGTRAMP_END;
+ cache_pc_function_name = "<sigtramp>";
+
+ goto return_cached_value;
}
+#endif
+ msymbol = lookup_minimal_symbol_by_pc (pc);
pst = find_pc_psymtab (pc);
if (pst)
{
+ /* Need to read the symbols to get a good value for the end address. */
+ if (endaddr != NULL && !pst->readin)
+ PSYMTAB_TO_SYMTAB (pst);
+
if (pst->readin)
{
- /* The information we want has already been read in.
- We can go to the already readin symbols and we'll get
- the best possible answer. */
+ /* Checking whether the msymbol has a larger value is for the
+ "pathological" case mentioned in print_frame_info. */
f = find_pc_function (pc);
- if (!f)
+ if (f != NULL
+ && (msymbol == NULL
+ || (BLOCK_START (SYMBOL_BLOCK_VALUE (f))
+ >= SYMBOL_VALUE_ADDRESS (msymbol))))
{
- return_error:
- /* No available symbol. */
- if (name != 0)
- *name = 0;
- if (address != 0)
- *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);
+ goto return_cached_value;
}
-
- 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 = cache_pc_function_name;
- if (address)
- *address = cache_pc_function_low;
- return 1;
}
-
- /* Get the information from a combination of the pst
- (static symbols), and the misc function vector (extern
- symbols). */
- miscfunc = find_pc_misc_function (pc);
- psb = find_pc_psymbol (pst, pc);
-
- if (!psb && miscfunc == -1)
- {
- goto return_error;
- }
- if (psb
- && (miscfunc == -1
- || (SYMBOL_VALUE_ADDRESS (psb)
- >= misc_function_vector[miscfunc].address)))
+ else
{
- /* This case isn't being cached currently. */
- if (address)
- *address = SYMBOL_VALUE_ADDRESS (psb);
- if (name)
- *name = SYMBOL_NAME (psb);
- return 1;
+ /* Now that static symbols go in the minimal symbol table, perhaps
+ we could just ignore the partial symbols. But at least for now
+ we use the partial or minimal symbol, whichever is larger. */
+ psb = find_pc_psymbol (pst, pc);
+
+ if (psb
+ && (msymbol == NULL ||
+ (SYMBOL_VALUE_ADDRESS (psb)
+ >= SYMBOL_VALUE_ADDRESS (msymbol))))
+ {
+ /* This case isn't being cached currently. */
+ if (address)
+ *address = SYMBOL_VALUE_ADDRESS (psb);
+ if (name)
+ *name = SYMBOL_NAME (psb);
+ /* endaddr non-NULL can't happen here. */
+ return 1;
+ }
}
}
- else
- /* Must be in the misc function stuff. */
+
+ /* Must be in the minimal symbol table. */
+ if (msymbol == NULL)
{
- miscfunc = find_pc_misc_function (pc);
- if (miscfunc == -1)
- goto return_error;
+ /* No available symbol. */
+ if (name != NULL)
+ *name = 0;
+ if (address != NULL)
+ *address = 0;
+ if (endaddr != NULL)
+ *endaddr = 0;
+ return 0;
}
- {
- 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;
+ /* I believe the purpose of this check is to make sure that anything
+ beyond the end of the text segment does not appear as part of the
+ last function of the text segment. It assumes that there is something
+ other than a mst_text symbol after the text segment. It is broken in
+ various cases, so anything relying on this behavior (there might be
+ some places) should be using find_pc_section or some such instead. */
+ if (msymbol -> type == mst_text)
+ cache_pc_function_low = SYMBOL_VALUE_ADDRESS (msymbol);
+ else
+ /* It is a transfer table for Sun shared libraries. */
+ cache_pc_function_low = pc - FUNCTION_START_OFFSET;
+ cache_pc_function_name = SYMBOL_NAME (msymbol);
+
+ if (SYMBOL_NAME (msymbol + 1) != NULL)
+ /* This might be part of a different segment, which might be a bad
+ idea. Perhaps we should be using the smaller of this address or the
+ endaddr from find_pc_section. */
+ cache_pc_function_high = SYMBOL_VALUE_ADDRESS (msymbol + 1);
else
- cache_pc_function_high = cache_pc_function_low + 1;
+ {
+ /* We got the start address from the last msymbol in the objfile.
+ So the end address is the end of the section. */
+ struct obj_section *sec;
+
+ sec = find_pc_section (pc);
+ if (sec == NULL)
+ {
+ /* Don't know if this can happen but if it does, then just say
+ that the function is 1 byte long. */
+ cache_pc_function_high = cache_pc_function_low + 1;
+ }
+ else
+ cache_pc_function_high = sec->endaddr;
+ }
+
+ return_cached_value:
if (address)
*address = cache_pc_function_low;
if (name)
*name = cache_pc_function_name;
+ if (endaddr)
+ *endaddr = cache_pc_function_high;
return 1;
}
-/* Find the misc function whose address is the largest
- while being less than PC. Return its index in misc_function_vector.
- Returns -1 if PC is not in suitable range. */
-
-int
-find_pc_misc_function (pc)
- register CORE_ADDR pc;
-{
- register int lo = 0;
- register int hi = misc_function_count-1;
- register int new;
-
- /* Note that the last thing in the vector is always _etext. */
- /* Actually, "end", now that non-functions
- go on the misc_function_vector. */
-
- /* Above statement is not *always* true - fix for case where there are */
- /* no misc functions at all (ie no symbol table has been read). */
- if (hi < 0) return -1; /* no misc functions recorded */
-
- /* trivial reject range test */
- if (pc < misc_function_vector[0].address ||
- pc > misc_function_vector[hi].address)
- return -1;
-
- /* Note that the following search will not return hi if
- pc == misc_function_vector[hi].address. If "end" points to the
- first unused location, this is correct and the above test
- simply needs to be changed to
- "pc >= misc_function_vector[hi].address". */
- do {
- new = (lo + hi) >> 1;
- if (misc_function_vector[new].address == pc)
- return new; /* an exact match */
- else if (misc_function_vector[new].address > pc)
- hi = new;
- else
- lo = new;
- } while (hi-lo != 1);
-
- /* if here, we had no exact match, so return the lower choice */
- return lo;
-}
-
-/* Return the innermost stack frame executing inside of the specified block,
- or zero if there is no such frame. */
+/* Return the innermost stack frame executing inside of BLOCK,
+ or NULL if there is no such frame. If BLOCK is NULL, just return NULL. */
FRAME
block_innermost_frame (block)
{
struct frame_info *fi;
register FRAME frame;
- register CORE_ADDR start = BLOCK_START (block);
- register CORE_ADDR end = BLOCK_END (block);
+ register CORE_ADDR start;
+ register CORE_ADDR end;
+
+ if (block == NULL)
+ return NULL;
+
+ start = BLOCK_START (block);
+ end = BLOCK_END (block);
frame = 0;
while (1)
}
}
+#ifdef SIGCONTEXT_PC_OFFSET
+/* Get saved user PC for sigtramp from sigcontext for BSD style sigtramp. */
+
+CORE_ADDR
+sigtramp_saved_pc (frame)
+ FRAME frame;
+{
+ CORE_ADDR sigcontext_addr;
+ char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT];
+ int ptrbytes = TARGET_PTR_BIT / TARGET_CHAR_BIT;
+ int sigcontext_offs = (2 * TARGET_INT_BIT) / TARGET_CHAR_BIT;
+
+ /* Get sigcontext address, it is the third parameter on the stack. */
+ if (frame->next)
+ sigcontext_addr = read_memory_integer (FRAME_ARGS_ADDRESS (frame->next)
+ + FRAME_ARGS_SKIP + sigcontext_offs,
+ ptrbytes);
+ else
+ sigcontext_addr = read_memory_integer (read_register (SP_REGNUM)
+ + sigcontext_offs,
+ ptrbytes);
+
+ /* Don't cause a memory_error when accessing sigcontext in case the stack
+ layout has changed or the stack is corrupt. */
+ target_read_memory (sigcontext_addr + SIGCONTEXT_PC_OFFSET, buf, ptrbytes);
+ return extract_unsigned_integer (buf, ptrbytes);
+}
+#endif /* SIGCONTEXT_PC_OFFSET */
+
void
_initialize_blockframe ()
{