[RFA] New skip __main version
Pierre Muller
muller@ics.u-strasbg.fr
Sat Jun 7 07:48:00 GMT 2008
Here is a new version of this patch:
it should fix the concern I raised about
potential wrapping problems if
CORE_ADDR is 64 bit wide.
I am still unable to test the 64-bit as
the --enable-target=all --enable-64bit-bfd
is still broken.
A patch has been submitted by Ulrich Weigand
http://sourceware.org/ml/gdb-patches/2008-05/msg00537.html
but has not yet been committed, prevent
successful compilation of gdb configured with the two options
above :(
For cygwin native gdb, the testsuite results show no change to the previous
version.
=== gdb Summary ===
! # of expected passes 10791
! # of unexpected failures 581
# of expected failures 59
# of unknown successes 2
! # of known failures 22
# of unresolved testcases 40
# of untested testcases 14
# of unsupported tests 23
! /usr/local/src/gdbcvs/build-bare/gdb/testsuite/../../gdb/gdb version
6.8.50.2
0080606-cvs -nx
--- 12103,12115 ----
=== gdb Summary ===
! # of expected passes 10954
! # of unexpected failures 386
# of expected failures 59
# of unknown successes 2
! # of known failures 23
# of unresolved testcases 40
# of untested testcases 14
# of unsupported tests 23
! /usr/local/src/gdbcvs/build-bare/gdb/testsuite/../../gdb/gdb version
6.8.50.2
0080604-cvs -nx
ChangeLog entry:
2008-06-07 Pedro Alves <pedro_alves@portugalmail.pt>
Pierre Muller <muller@ics.u-strasbg.fr>
* gdbarch.sh (gdbarch_skip_main_prologue): New.
* gdbarch.h, gdbarch.c: Regenerate.
* i386-tdep.h (i386_skip_main_prologue): Declare.
* i386-tdep.c (i386_skip_main_prologue): New.
* i386-cygwin-tdep.c (i386_cygwin_init_abi): Register
i386_skip_main_prologue as gdbarch_skip_main_prologue gdbarch
callback.
* symtab.c (find_function_start_sal): When pc points at the "main"
function, call gdbarch_skip_main_prologue.
Index: gdb/gdbarch.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbarch.c,v
retrieving revision 1.428
diff -u -p -r1.428 gdbarch.c
--- gdb/gdbarch.c 24 May 2008 16:32:01 -0000 1.428
+++ gdb/gdbarch.c 6 Jun 2008 10:54:57 -0000
@@ -183,6 +183,7 @@ struct gdbarch
gdbarch_integer_to_address_ftype *integer_to_address;
gdbarch_return_value_ftype *return_value;
gdbarch_skip_prologue_ftype *skip_prologue;
+ gdbarch_skip_main_prologue_ftype *skip_main_prologue;
gdbarch_inner_than_ftype *inner_than;
gdbarch_breakpoint_from_pc_ftype *breakpoint_from_pc;
gdbarch_adjust_breakpoint_address_ftype *adjust_breakpoint_address;
@@ -313,6 +314,7 @@ struct gdbarch startup_gdbarch =
0, /* integer_to_address */
0, /* return_value */
0, /* skip_prologue */
+ 0, /* skip_main_prologue */
0, /* inner_than */
0, /* breakpoint_from_pc */
0, /* adjust_breakpoint_address */
@@ -561,6 +563,7 @@ verify_gdbarch (struct gdbarch *gdbarch)
/* Skip verify of return_value, has predicate */
if (gdbarch->skip_prologue == 0)
fprintf_unfiltered (log, "\n\tskip_prologue");
+ /* Skip verify of skip_main_prologue, has predicate */
if (gdbarch->inner_than == 0)
fprintf_unfiltered (log, "\n\tinner_than");
if (gdbarch->breakpoint_from_pc == 0)
@@ -999,6 +1002,12 @@ gdbarch_dump (struct gdbarch *gdbarch, s
"gdbarch_dump: single_step_through_delay =
<0x%lx>\n",
(long) gdbarch->single_step_through_delay);
fprintf_unfiltered (file,
+ "gdbarch_dump: gdbarch_skip_main_prologue_p() =
%d\n",
+ gdbarch_skip_main_prologue_p (gdbarch));
+ fprintf_unfiltered (file,
+ "gdbarch_dump: skip_main_prologue = <0x%lx>\n",
+ (long) gdbarch->skip_main_prologue);
+ fprintf_unfiltered (file,
"gdbarch_dump: gdbarch_skip_permanent_breakpoint_p()
= %d\n",
gdbarch_skip_permanent_breakpoint_p (gdbarch));
fprintf_unfiltered (file,
@@ -2123,6 +2132,30 @@ set_gdbarch_skip_prologue (struct gdbarc
}
int
+gdbarch_skip_main_prologue_p (struct gdbarch *gdbarch)
+{
+ gdb_assert (gdbarch != NULL);
+ return gdbarch->skip_main_prologue != NULL;
+}
+
+CORE_ADDR
+gdbarch_skip_main_prologue (struct gdbarch *gdbarch, CORE_ADDR ip)
+{
+ gdb_assert (gdbarch != NULL);
+ gdb_assert (gdbarch->skip_main_prologue != NULL);
+ if (gdbarch_debug >= 2)
+ fprintf_unfiltered (gdb_stdlog, "gdbarch_skip_main_prologue called\n");
+ return gdbarch->skip_main_prologue (gdbarch, ip);
+}
+
+void
+set_gdbarch_skip_main_prologue (struct gdbarch *gdbarch,
+ gdbarch_skip_main_prologue_ftype
skip_main_prologue)
+{
+ gdbarch->skip_main_prologue = skip_main_prologue;
+}
+
+int
gdbarch_inner_than (struct gdbarch *gdbarch, CORE_ADDR lhs, CORE_ADDR rhs)
{
gdb_assert (gdbarch != NULL);
Index: gdb/gdbarch.h
===================================================================
RCS file: /cvs/src/src/gdb/gdbarch.h,v
retrieving revision 1.383
diff -u -p -r1.383 gdbarch.h
--- gdb/gdbarch.h 24 May 2008 16:32:01 -0000 1.383
+++ gdb/gdbarch.h 6 Jun 2008 10:54:57 -0000
@@ -379,6 +379,12 @@ typedef CORE_ADDR (gdbarch_skip_prologue
extern CORE_ADDR gdbarch_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR
ip);
extern void set_gdbarch_skip_prologue (struct gdbarch *gdbarch,
gdbarch_skip_prologue_ftype *skip_prologue);
+extern int gdbarch_skip_main_prologue_p (struct gdbarch *gdbarch);
+
+typedef CORE_ADDR (gdbarch_skip_main_prologue_ftype) (struct gdbarch
*gdbarch, CORE_ADDR ip);
+extern CORE_ADDR gdbarch_skip_main_prologue (struct gdbarch *gdbarch,
CORE_ADDR ip);
+extern void set_gdbarch_skip_main_prologue (struct gdbarch *gdbarch,
gdbarch_skip_main_prologue_ftype *skip_main_prologue);
+
typedef int (gdbarch_inner_than_ftype) (CORE_ADDR lhs, CORE_ADDR rhs);
extern int gdbarch_inner_than (struct gdbarch *gdbarch, CORE_ADDR lhs,
CORE_ADDR rhs);
extern void set_gdbarch_inner_than (struct gdbarch *gdbarch,
gdbarch_inner_than_ftype *inner_than);
Index: gdb/gdbarch.sh
===================================================================
RCS file: /cvs/src/src/gdb/gdbarch.sh,v
retrieving revision 1.469
diff -u -p -r1.469 gdbarch.sh
--- gdb/gdbarch.sh 24 May 2008 16:32:01 -0000 1.469
+++ gdb/gdbarch.sh 6 Jun 2008 10:54:58 -0000
@@ -482,6 +482,7 @@ M:CORE_ADDR:integer_to_address:struct ty
M:enum return_value_convention:return_value:struct type *functype, struct
type *valtype, struct regcache *regcache, gdb_byte *readbuf, const gdb_byte
*writebuf:functype, valtype, regcache, readbuf, writebuf
m:CORE_ADDR:skip_prologue:CORE_ADDR ip:ip:0:0
+M:CORE_ADDR:skip_main_prologue:CORE_ADDR ip:ip
f:int:inner_than:CORE_ADDR lhs, CORE_ADDR rhs:lhs, rhs:0:0
m:const gdb_byte *:breakpoint_from_pc:CORE_ADDR *pcptr, int *lenptr:pcptr,
lenptr::0:
M:CORE_ADDR:adjust_breakpoint_address:CORE_ADDR bpaddr:bpaddr
Index: gdb/i386-cygwin-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/i386-cygwin-tdep.c,v
retrieving revision 1.16
diff -u -p -r1.16 i386-cygwin-tdep.c
--- gdb/i386-cygwin-tdep.c 1 Jan 2008 22:53:10 -0000 1.16
+++ gdb/i386-cygwin-tdep.c 6 Jun 2008 10:54:58 -0000
@@ -227,6 +227,8 @@ i386_cygwin_init_abi (struct gdbarch_inf
set_gdbarch_skip_trampoline_code (gdbarch,
i386_cygwin_skip_trampoline_code);
+ set_gdbarch_skip_main_prologue (gdbarch, i386_skip_main_prologue);
+
tdep->struct_return = reg_struct_return;
tdep->gregset_reg_offset = i386_win32_gregset_reg_offset;
Index: gdb/i386-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/i386-tdep.c,v
retrieving revision 1.258
diff -u -p -r1.258 i386-tdep.c
--- gdb/i386-tdep.c 16 May 2008 00:27:23 -0000 1.258
+++ gdb/i386-tdep.c 6 Jun 2008 10:54:59 -0000
@@ -1160,6 +1160,38 @@ i386_skip_prologue (struct gdbarch *gdba
return pc;
}
+/* Check that the code pointed to by PC corresponds to a call to
+ __main, skip it if so. Return PC otherwise. */
+
+CORE_ADDR
+i386_skip_main_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
+{
+ gdb_byte op;
+
+ target_read_memory (pc, &op, 1);
+ if (op == 0xe8)
+ {
+ gdb_byte buf[4];
+
+ if (target_read_memory (pc + 1, buf, sizeof buf) == 0)
+ {
+ /* Make sure address is computed correctly as a 32bit
+ integer even if CORE_ADDR is 64 bit wide. */
+ struct minimal_symbol *s;
+ CORE_ADDR call_dest = pc + 5 + extract_signed_integer (buf, 4);
+
+ call_dest = call_dest & 0xffffffffU;
+ s = lookup_minimal_symbol_by_pc (call_dest);
+ if (s != NULL
+ && SYMBOL_LINKAGE_NAME (s) != NULL
+ && strcmp (SYMBOL_LINKAGE_NAME (s), "__main") == 0)
+ pc += 5;
+ }
+ }
+
+ return pc;
+}
+
/* This function is 64-bit safe. */
static CORE_ADDR
Index: gdb/i386-tdep.h
===================================================================
RCS file: /cvs/src/src/gdb/i386-tdep.h,v
retrieving revision 1.54
diff -u -p -r1.54 i386-tdep.h
--- gdb/i386-tdep.h 2 May 2008 16:49:54 -0000 1.54
+++ gdb/i386-tdep.h 6 Jun 2008 10:54:59 -0000
@@ -170,6 +170,7 @@ extern struct type *i386_sse_type (struc
/* Functions exported from i386-tdep.c. */
extern CORE_ADDR i386_pe_skip_trampoline_code (CORE_ADDR pc, char *name);
+extern CORE_ADDR i386_skip_main_prologue (struct gdbarch *gdbarch,
CORE_ADDR pc);
/* Return the name of register REGNUM. */
extern char const *i386_register_name (struct gdbarch * gdbarch, int
regnum);
Index: gdb/symtab.c
===================================================================
RCS file: /cvs/src/src/gdb/symtab.c,v
retrieving revision 1.189
diff -u -p -r1.189 symtab.c
--- gdb/symtab.c 27 May 2008 19:29:51 -0000 1.189
+++ gdb/symtab.c 6 Jun 2008 10:55:00 -0000
@@ -2617,6 +2617,21 @@ find_function_start_sal (struct symbol *
/* Recalculate the line number (might not be N+1). */
sal = find_pc_sect_line (pc, SYMBOL_BFD_SECTION (sym), 0);
}
+
+ /* On targets with executable formats that don't have a concept of
+ constructors (ELF with .init has, PE doesn't), gcc emits a call
+ to `__main' in `main' between the prologue and before user
+ code. */
+ if (funfirstline
+ && gdbarch_skip_main_prologue_p (current_gdbarch)
+ && SYMBOL_LINKAGE_NAME (sym)
+ && strcmp (SYMBOL_LINKAGE_NAME (sym), "main") == 0)
+ {
+ pc = gdbarch_skip_main_prologue (current_gdbarch, pc);
+ /* Recalculate the line number (might not be N+1). */
+ sal = find_pc_sect_line (pc, SYMBOL_BFD_SECTION (sym), 0);
+ }
+
sal.pc = pc;
return sal;
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