/* GDB routines for manipulating the minimal symbol tables.
- Copyright 1992 Free Software Foundation, Inc.
+ Copyright 1992, 1993, 1994 Free Software Foundation, Inc.
Contributed by Cygnus Support, using pieces from other GDB modules.
This file is part of GDB.
#include "defs.h"
+#include <string.h>
#include "symtab.h"
#include "bfd.h"
#include "symfile.h"
#include "objfiles.h"
#include "demangle.h"
+#include "gdb-stabs.h"
/* Accumulate the minimal symbols for each objfile in bunches of BUNCH_SIZE.
At the end, copy them all into one newly allocated location on an objfile's
struct minimal_symbol *msymbol;
struct minimal_symbol *found_symbol = NULL;
struct minimal_symbol *found_file_symbol = NULL;
-#ifdef IBM6000_TARGET
struct minimal_symbol *trampoline_symbol = NULL;
-#endif
for (objfile = object_files;
objfile != NULL && found_symbol == NULL;
found_file_symbol = msymbol;
break;
- case mst_unknown:
-#ifdef IBM6000_TARGET
- /* I *think* all platforms using shared
- libraries (and trampoline code) will suffer
- this problem. Consider a case where there are
- 5 shared libraries, each referencing `foo'
- with a trampoline entry. When someone wants
- to put a breakpoint on `foo' and the only
- info we have is minimal symbol vector, we
- want to use the real `foo', rather than one
- of those trampoline entries. MGO */
+ case mst_solib_trampoline:
/* If a trampoline symbol is found, we prefer to
keep looking for the *real* symbol. If the
- actual symbol not found, then we'll use the
- trampoline entry. Sorry for the machine
- dependent code here, but I hope this will
- benefit other platforms as well. For
- trampoline entries, we used mst_unknown
- earlier. Perhaps we should define a
- `mst_trampoline' type?? */
-
+ actual symbol is not found, then we'll use the
+ trampoline entry. */
if (trampoline_symbol == NULL)
trampoline_symbol = msymbol;
break;
-#else
- /* FALLTHROUGH */
-#endif
+
+ case mst_unknown:
default:
found_symbol = msymbol;
break;
if (found_file_symbol)
return found_file_symbol;
- /* Symbols for IBM shared library trampolines are next best. */
-#ifdef IBM6000_TARGET
+ /* Symbols for shared library trampolines are next best. */
if (trampoline_symbol)
return trampoline_symbol;
-#endif
return NULL;
}
objfile's minimal symbol table. See if it is the best one
overall. */
- if ((best_symbol == NULL) ||
- (SYMBOL_VALUE_ADDRESS (best_symbol) <
- SYMBOL_VALUE_ADDRESS (&msymbol[hi])))
+ /* Skip any absolute symbols. This is apparently what adb
+ and dbx do, and is needed for the CM-5. There are two
+ known possible problems: (1) on ELF, apparently end, edata,
+ etc. are absolute. Not sure ignoring them here is a big
+ deal, but if we want to use them, the fix would go in
+ elfread.c. (2) I think shared library entry points on the
+ NeXT are absolute. If we want special handling for this
+ it probably should be triggered by a special
+ mst_abs_or_lib or some such. */
+ while (hi >= 0
+ && msymbol[hi].type == mst_abs)
+ --hi;
+
+ if (hi >= 0
+ && ((best_symbol == NULL) ||
+ (SYMBOL_VALUE_ADDRESS (best_symbol) <
+ SYMBOL_VALUE_ADDRESS (&msymbol[hi]))))
{
best_symbol = &msymbol[hi];
}
return (best_symbol);
}
-/* Just like lookup_minimal_symbol_by_pc, but look up the closest minimal
- symbol > PC, not the one <= PC. */
-
-struct minimal_symbol *
-lookup_next_minimal_symbol (pc)
- CORE_ADDR pc;
-{
- register int lo;
- register int hi;
- register int new;
- register struct objfile *objfile;
- register struct minimal_symbol *msymbol;
- register struct minimal_symbol *best_symbol = NULL;
-
- for (objfile = object_files;
- objfile != NULL;
- objfile = objfile -> next)
- {
- /* If this objfile has a minimal symbol table, go search it using
- a binary search. Note that a minimal symbol table always consists
- of at least two symbols, a "real" symbol and the terminating
- "null symbol". If there are no real symbols, then there is no
- minimal symbol table at all. */
-
- if ((msymbol = objfile -> msymbols) != NULL)
- {
- lo = 0;
- hi = objfile -> minimal_symbol_count - 1;
-
- /* This code assumes that the minimal symbols are sorted by
- ascending address values. If the pc value is greater than or
- equal to the first symbol's address, then some symbol in this
- minimal symbol table is a suitable candidate for being the
- "best" symbol. This includes the last real symbol, for cases
- where the pc value is larger than any address in this vector.
-
- By iterating until the address associated with the current
- hi index (the endpoint of the test interval) is less than
- or equal to the desired pc value, we accomplish two things:
- (1) the case where the pc value is larger than any minimal
- symbol address is trivially solved, (2) the address associated
- with the hi index is always the one we want when the interation
- terminates. In essence, we are iterating the test interval
- down until the pc value is pushed out of it from the high end.
-
- Warning: this code is trickier than it would appear at first. */
-
- /* Intentionally does not check that pc <= start of objfile.
- dbxread.c:process_one_symbol wants to call this with zero and
- get the first minimal symbol. */
- if (pc < SYMBOL_VALUE_ADDRESS (&msymbol[hi]))
- {
- while (SYMBOL_VALUE_ADDRESS (&msymbol[lo]) <= pc)
- {
- /* pc is still strictly less than highest address */
- /* Note "new" will always be >= lo */
- new = (lo + hi) / 2;
- if ((SYMBOL_VALUE_ADDRESS (&msymbol[new]) < pc) ||
- (lo == new))
- {
- hi = new;
- }
- else
- {
- lo = new;
- }
- }
- /* The minimal symbol indexed by hi now is the best one in this
- objfile's minimal symbol table. See if it is the best one
- overall. */
-
- if ((best_symbol == NULL) ||
- (SYMBOL_VALUE_ADDRESS (best_symbol) >
- SYMBOL_VALUE_ADDRESS (&msymbol[lo])))
- {
- best_symbol = &msymbol[lo];
- }
- }
- }
- }
- return (best_symbol);
-}
-
/* Prepare to start collecting minimal symbols. Note that presetting
msym_bunch_index to BUNCH_SIZE causes the first call to save a minimal
symbol to allocate the memory for the first bunch. */
}
void
-prim_record_minimal_symbol (name, address, ms_type)
+prim_record_minimal_symbol (name, address, ms_type, objfile)
const char *name;
CORE_ADDR address;
enum minimal_symbol_type ms_type;
+ struct objfile *objfile;
{
- register struct msym_bunch *new;
- register struct minimal_symbol *msymbol;
+ int section;
- if (msym_bunch_index == BUNCH_SIZE)
+ switch (ms_type)
{
- new = (struct msym_bunch *) xmalloc (sizeof (struct msym_bunch));
- msym_bunch_index = 0;
- new -> next = msym_bunch;
- msym_bunch = new;
+ case mst_text:
+ case mst_file_text:
+ case mst_solib_trampoline:
+ section = SECT_OFF_TEXT;
+ break;
+ case mst_data:
+ case mst_file_data:
+ section = SECT_OFF_DATA;
+ break;
+ case mst_bss:
+ case mst_file_bss:
+ section = SECT_OFF_BSS;
+ break;
+ default:
+ section = -1;
}
- msymbol = &msym_bunch -> contents[msym_bunch_index];
- SYMBOL_NAME (msymbol) = (char *) name;
- SYMBOL_INIT_LANGUAGE_SPECIFIC (msymbol, language_unknown);
- SYMBOL_VALUE_ADDRESS (msymbol) = address;
- SYMBOL_SECTION (msymbol) = -1;
- MSYMBOL_TYPE (msymbol) = ms_type;
- /* FIXME: This info, if it remains, needs its own field. */
- MSYMBOL_INFO (msymbol) = NULL; /* FIXME! */
- msym_bunch_index++;
- msym_count++;
-}
-/* FIXME: Why don't we just combine this function with the one above
- and pass it a NULL info pointer value if info is not needed? */
+ prim_record_minimal_symbol_and_info (name, address, ms_type,
+ NULL, section, objfile);
+}
void
-prim_record_minimal_symbol_and_info (name, address, ms_type, info, section)
+prim_record_minimal_symbol_and_info (name, address, ms_type, info, section,
+ objfile)
const char *name;
CORE_ADDR address;
enum minimal_symbol_type ms_type;
char *info;
int section;
+ struct objfile *objfile;
{
register struct msym_bunch *new;
register struct minimal_symbol *msymbol;
+ if (ms_type == mst_file_text)
+ {
+ /* Don't put gcc_compiled, __gnu_compiled_cplus, and friends into
+ the minimal symbols, because if there is also another symbol
+ at the same address (e.g. the first function of the file),
+ lookup_minimal_symbol_by_pc would have no way of getting the
+ right one. */
+ if (name[0] == 'g'
+ && (strcmp (name, GCC_COMPILED_FLAG_SYMBOL) == 0
+ || strcmp (name, GCC2_COMPILED_FLAG_SYMBOL) == 0))
+ return;
+
+ {
+ const char *tempstring = name;
+ if (tempstring[0] == bfd_get_symbol_leading_char (objfile->obfd))
+ ++tempstring;
+ if (STREQN (tempstring, "__gnu_compiled", 14))
+ return;
+ }
+ }
+
if (msym_bunch_index == BUNCH_SIZE)
{
new = (struct msym_bunch *) xmalloc (sizeof (struct msym_bunch));
SYMBOL_INIT_LANGUAGE_SPECIFIC (msymbol, language_unknown);
SYMBOL_VALUE_ADDRESS (msymbol) = address;
SYMBOL_SECTION (msymbol) = section;
+
MSYMBOL_TYPE (msymbol) = ms_type;
/* FIXME: This info, if it remains, needs its own field. */
MSYMBOL_INFO (msymbol) = info; /* FIXME! */
}
}
+/* Sort all the minimal symbols in OBJFILE. */
+
+void
+msymbols_sort (objfile)
+ struct objfile *objfile;
+{
+ qsort (objfile->msymbols, objfile->minimal_symbol_count,
+ sizeof (struct minimal_symbol), compare_minimal_symbols);
+}
+
+/* Check if PC is in a shared library trampoline code stub.
+ Return minimal symbol for the trampoline entry or NULL if PC is not
+ in a trampoline code stub. */
+
+struct minimal_symbol *
+lookup_solib_trampoline_symbol_by_pc (pc)
+ CORE_ADDR pc;
+{
+ struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (pc);
+
+ if (msymbol != NULL && MSYMBOL_TYPE (msymbol) == mst_solib_trampoline)
+ return msymbol;
+ return NULL;
+}
+
+/* If PC is in a shared library trampoline code stub, return the
+ address of the `real' function belonging to the stub.
+ Return 0 if PC is not in a trampoline code stub or if the real
+ function is not found in the minimal symbol table.
+
+ We may fail to find the right function if a function with the
+ same name is defined in more than one shared library, but this
+ is considered bad programming style. We could return 0 if we find
+ a duplicate function in case this matters someday. */
+
+CORE_ADDR
+find_solib_trampoline_target (pc)
+ CORE_ADDR pc;
+{
+ struct objfile *objfile;
+ struct minimal_symbol *msymbol;
+ struct minimal_symbol *tsymbol = lookup_solib_trampoline_symbol_by_pc (pc);
+
+ if (tsymbol != NULL)
+ {
+ ALL_MSYMBOLS (objfile, msymbol)
+ {
+ if (MSYMBOL_TYPE (msymbol) == mst_text
+ && STREQ (SYMBOL_NAME (msymbol), SYMBOL_NAME (tsymbol)))
+ return SYMBOL_VALUE_ADDRESS (msymbol);
+ }
+ }
+ return 0;
+}
+