From 4309257cda01fce18971fd5a5ea28ed6aaf552cc Mon Sep 17 00:00:00 2001 From: Pierre Muller Date: Wed, 11 Jun 2008 22:03:49 +0000 Subject: [PATCH] * 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. --- gdb/ChangeLog | 12 ++++++++++++ gdb/gdbarch.c | 33 +++++++++++++++++++++++++++++++++ gdb/gdbarch.h | 6 ++++++ gdb/gdbarch.sh | 1 + gdb/i386-cygwin-tdep.c | 2 ++ gdb/i386-tdep.c | 32 ++++++++++++++++++++++++++++++++ gdb/i386-tdep.h | 1 + gdb/symtab.c | 15 +++++++++++++++ 8 files changed, 102 insertions(+) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 80160aa..a207f34 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,15 @@ +2008-06-12 Pedro Alves + Pierre Muller + + * 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. + 2008-06-11 Daniel Jacobowitz * value.c (value_primitive_field): Fetch lazy register values. diff --git a/gdb/gdbarch.c b/gdb/gdbarch.c index 6594b35..3a967a9 100644 --- a/gdb/gdbarch.c +++ b/gdb/gdbarch.c @@ -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, struct ui_file *file) "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 gdbarch *gdbarch, } 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); diff --git a/gdb/gdbarch.h b/gdb/gdbarch.h index 44d1f2d..cede826 100644 --- a/gdb/gdbarch.h +++ b/gdb/gdbarch.h @@ -379,6 +379,12 @@ typedef CORE_ADDR (gdbarch_skip_prologue_ftype) (struct gdbarch *gdbarch, CORE_A 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); diff --git a/gdb/gdbarch.sh b/gdb/gdbarch.sh index a38ba03..d33fd7d 100755 --- a/gdb/gdbarch.sh +++ b/gdb/gdbarch.sh @@ -482,6 +482,7 @@ M:CORE_ADDR:integer_to_address:struct type *type, const gdb_byte *buf:type, buf 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 diff --git a/gdb/i386-cygwin-tdep.c b/gdb/i386-cygwin-tdep.c index 3a8d6ee..1e4205d 100644 --- a/gdb/i386-cygwin-tdep.c +++ b/gdb/i386-cygwin-tdep.c @@ -227,6 +227,8 @@ i386_cygwin_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) 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; diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c index be4f4f3..91bd7d0 100644 --- a/gdb/i386-tdep.c +++ b/gdb/i386-tdep.c @@ -1160,6 +1160,38 @@ i386_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR start_pc) 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 diff --git a/gdb/i386-tdep.h b/gdb/i386-tdep.h index 227ac66..d1366b6 100644 --- a/gdb/i386-tdep.h +++ b/gdb/i386-tdep.h @@ -170,6 +170,7 @@ extern struct type *i386_sse_type (struct gdbarch *gdbarch); /* 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); diff --git a/gdb/symtab.c b/gdb/symtab.c index 6adecbf..0466490 100644 --- a/gdb/symtab.c +++ b/gdb/symtab.c @@ -2617,6 +2617,21 @@ find_function_start_sal (struct symbol *sym, int funfirstline) /* 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; -- 2.7.4