(rs6000_in_solib_return_trampoline): Declare.
* rs6000-tdep.c (rs6000_in_solib_return_trampoline): New
function.
(rs6000_skip_trampoline_code): Skip bigtoc fixup code.
* xcoffread.c (read_xcoff_symtab): Perform the ISFCN function
check after the CSECT check rather than before it. Allocate
separate symtabs for CSECTs whose names begin with '@'.
(scan_xcoff_symtab): Don't ignore symbols beginning with '@'.
Activate the misc_func_recorded mechanism for whose names begin
with '@'.
+2001-05-01 Nicholas Duffek <nsd@redhat.com>
+
+ * config/rs6000/tm-rs6000.h (IN_SOLIB_RETURN_TRAMPOLINE): Define.
+ (rs6000_in_solib_return_trampoline): Declare.
+ * rs6000-tdep.c (rs6000_in_solib_return_trampoline): New
+ function.
+ (rs6000_skip_trampoline_code): Skip bigtoc fixup code.
+ * xcoffread.c (read_xcoff_symtab): Perform the ISFCN function
+ check after the CSECT check rather than before it. Allocate
+ separate symtabs for CSECTs whose names begin with '@'.
+ (scan_xcoff_symtab): Don't ignore symbols beginning with '@'.
+ Activate the misc_func_recorded mechanism for whose names begin
+ with '@'.
+
2001-04-30 J.T. Conklin <jtc@redback.com>
* ppcnbsd-nat.c (fetch_inferior_registers)
#undef CPLUS_MARKER
#define CPLUS_MARKER '.'
+/* Return whether PC in function NAME is in code that should be skipped when
+ single-stepping. */
+
+#define IN_SOLIB_RETURN_TRAMPOLINE(pc, name) \
+ rs6000_in_solib_return_trampoline (pc, name)
+extern int rs6000_in_solib_return_trampoline (CORE_ADDR, char *);
+
/* If PC is in some function-call trampoline code, return the PC
where the function itself actually starts. If not, return NULL. */
static CORE_ADDR rs6000_struct_return_address;
-/* Indirect function calls use a piece of trampoline code to do context
- switching, i.e. to set the new TOC table. Skip such code if we are on
- its first instruction (as when we have single-stepped to here).
- Also skip shared library trampoline code (which is different from
+/* Return whether handle_inferior_event() should proceed through code
+ starting at PC in function NAME when stepping.
+
+ The AIX -bbigtoc linker option generates functions @FIX0, @FIX1, etc. to
+ handle memory references that are too distant to fit in instructions
+ generated by the compiler. For example, if 'foo' in the following
+ instruction:
+
+ lwz r9,foo(r2)
+
+ is greater than 32767, the linker might replace the lwz with a branch to
+ somewhere in @FIX1 that does the load in 2 instructions and then branches
+ back to where execution should continue.
+
+ GDB should silently step over @FIX code, just like AIX dbx does.
+ Unfortunately, the linker uses the "b" instruction for the branches,
+ meaning that the link register doesn't get set. Therefore, GDB's usual
+ step_over_function() mechanism won't work.
+
+ Instead, use the IN_SOLIB_RETURN_TRAMPOLINE and SKIP_TRAMPOLINE_CODE hooks
+ in handle_inferior_event() to skip past @FIX code. */
+
+int
+rs6000_in_solib_return_trampoline (CORE_ADDR pc, char *name)
+{
+ return name && !strncmp (name, "@FIX", 4);
+}
+
+/* Skip code that the user doesn't want to see when stepping:
+
+ 1. Indirect function calls use a piece of trampoline code to do context
+ switching, i.e. to set the new TOC table. Skip such code if we are on
+ its first instruction (as when we have single-stepped to here).
+
+ 2. Skip shared library trampoline code (which is different from
indirect function call trampolines).
+
+ 3. Skip bigtoc fixup code.
+
Result is desired PC to step until, or NULL if we are not in
- trampoline code. */
+ code that should be skipped. */
CORE_ADDR
rs6000_skip_trampoline_code (CORE_ADDR pc)
{
register unsigned int ii, op;
+ int rel;
CORE_ADDR solib_target_pc;
+ struct minimal_symbol *msymbol;
static unsigned trampoline_code[] =
{
0
};
+ /* Check for bigtoc fixup code. */
+ msymbol = lookup_minimal_symbol_by_pc (pc);
+ if (msymbol && rs6000_in_solib_return_trampoline (pc, SYMBOL_NAME (msymbol)))
+ {
+ /* Double-check that the third instruction from PC is relative "b". */
+ op = read_memory_integer (pc + 8, 4);
+ if ((op & 0xfc000003) == 0x48000000)
+ {
+ /* Extract bits 6-29 as a signed 24-bit relative word address and
+ add it to the containing PC. */
+ rel = ((int)(op << 6) >> 6);
+ return pc + 8 + rel;
+ }
+ }
+
/* If pc is in a shared library trampoline, return its target. */
solib_target_pc = find_solib_trampoline_target (pc);
if (solib_target_pc)
/* done with all files, everything from here on is globals */
}
- /* if explicitly specified as a function, treat is as one. */
- if (ISFCN (cs->c_type) && cs->c_sclass != C_TPDEF)
- {
- bfd_coff_swap_aux_in (abfd, raw_auxptr, cs->c_type, cs->c_sclass,
- 0, cs->c_naux, &main_aux);
- goto function_entry_point;
- }
-
if ((cs->c_sclass == C_EXT || cs->c_sclass == C_HIDEXT)
&& cs->c_naux == 1)
{
SECT_OFF_TEXT (objfile));
file_end_addr = file_start_addr + CSECT_LEN (&main_aux);
- if (cs->c_name && cs->c_name[0] == '.')
+ if (cs->c_name && (cs->c_name[0] == '.'
+ || cs->c_name[0] == '@'))
{
last_csect_name = cs->c_name;
last_csect_val = cs->c_value;
}
}
+ /* If explicitly specified as a function, treat is as one. This check
+ evaluates to true for @FIX* bigtoc CSECT symbols, so it must occur
+ after the above CSECT check. */
+ if (ISFCN (cs->c_type) && cs->c_sclass != C_TPDEF)
+ {
+ bfd_coff_swap_aux_in (abfd, raw_auxptr, cs->c_type, cs->c_sclass,
+ 0, cs->c_naux, &main_aux);
+ goto function_entry_point;
+ }
+
switch (cs->c_sclass)
{
else
csect_aux = main_aux[0];
- /* If symbol name starts with ".$" or "$", ignore it.
-
- A symbol like "@FIX1" introduces a section for -bbigtoc jump
- tables, which contain anonymous linker-generated code.
- Ignore those sections to avoid "pc 0x... in read in psymtab,
- but not in symtab" warnings from find_pc_sect_symtab. */
-
- if (namestring[0] == '$' || namestring[0] == '@'
+ /* If symbol name starts with ".$" or "$", ignore it. */
+ if (namestring[0] == '$'
|| (namestring[0] == '.' && namestring[1] == '$'))
break;
objfile->static_psymbols.next);
}
}
- if (namestring && namestring[0] == '.')
+ /* Activate the misc_func_recorded mechanism for
+ compiler- and linker-generated CSECTs like ".strcmp"
+ and "@FIX1". */
+ if (namestring && (namestring[0] == '.'
+ || namestring[0] == '@'))
{
last_csect_name = namestring;
last_csect_val = symbol.n_value;
projects / binutils-gdb.git / commitdiff