/* 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)
- /* 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. */
+ if (fi->next != 0 && fi->next->signal_handler_caller == 0)
+ /* We are not in the innermost frame and we were not interrupted
+ by a signal. 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);
}
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;
+ struct obj_section *sec;
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)
+ {
+ /* Need to get the terminal in case symbol-reading produces
+ output. */
+ target_terminal_ours_for_output ();
+ 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. */
+
+ /* Not in the normal symbol tables, see if the pc is in a known section.
+ If it's not, then give up. This ensures that anything beyond the end
+ of the text seg doesn't appear to be part of the last function in the
+ text segment. */
+
+ sec = find_pc_section (pc);
+
+ if (!sec)
+ msymbol = NULL;
+
+ /* 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;
+ /* See if we're in a transfer table for Sun shared libs. */
+
+ if (msymbol -> type == mst_text)
+ cache_pc_function_low = SYMBOL_VALUE_ADDRESS (msymbol);
else
- cache_pc_function_high = cache_pc_function_low + 1;
+ /* It is a transfer table for Sun shared libraries. */
+ cache_pc_function_low = pc - FUNCTION_START_OFFSET;
+
+ cache_pc_function_name = SYMBOL_NAME (msymbol);
+
+ /* Use the lesser of the next minimal symbol, or the end of the section, as
+ the end of the function. */
+
+ if (SYMBOL_NAME (msymbol + 1) != NULL
+ && SYMBOL_VALUE_ADDRESS (msymbol + 1) < sec->endaddr)
+ cache_pc_function_high = SYMBOL_VALUE_ADDRESS (msymbol + 1);
+ else
+ /* We got the start address from the last msymbol in the objfile.
+ So the end address is the end of the section. */
+ 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 ()
{
projects / deliverable / binutils-gdb.git / blobdiff