diff mbox

debug compile: Replace confusing debug message

Message ID 20150701122048.GA7170@host1.jankratochvil.net
State New, archived
Headers

Commit Message

Jan Kratochvil July 1, 2015, 12:20 p.m. UTC 
  Hi,

It was found that

(gdb) set debug compile 1
(gdb) compile code 1
[...]
allocated 0x7f bytes at 0x7ffff7ff9000 prot 5
allocated 0x38 bytes at 0x7ffff7ff8000 prot 1
lookup undefined ELF symbol "_GLOBAL_OFFSET_TABLE_"
allocated 0x10 bytes at 0x7ffff7ff7000 for registers
(gdb) _

the message 'lookup undefined ELF symbol' looks as an error to people,
including to myself once.

->
allocated 0x7f bytes at 0x7ffff7ff9000 prot 5
allocated 0x38 bytes at 0x7ffff7ff8000 prot 1
ELF symbol "_GLOBAL_OFFSET_TABLE_" relocated to zero
allocated 0x10 bytes at 0x7ffff7ff7000 for registers
(gdb) _


Jan
2015-07-01  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* compile/compile-object-load.c (compile_object_load): Replace debug
	message "lookup undefined ELF symbol" by 3 more specific messages.

Comments

Phil Muldoon July 1, 2015, 12:33 p.m. UTC | #1 
On 01/07/15 13:20, Jan Kratochvil wrote:
> Hi,
>
> It was found that
>
> (gdb) set debug compile 1
> (gdb) compile code 1
> [...]
> allocated 0x7f bytes at 0x7ffff7ff9000 prot 5
> allocated 0x38 bytes at 0x7ffff7ff8000 prot 1
> lookup undefined ELF symbol "_GLOBAL_OFFSET_TABLE_"
> allocated 0x10 bytes at 0x7ffff7ff7000 for registers
> (gdb) _
>
> the message 'lookup undefined ELF symbol' looks as an error to people,
> including to myself once.
>
> ->
> allocated 0x7f bytes at 0x7ffff7ff9000 prot 5
> allocated 0x38 bytes at 0x7ffff7ff8000 prot 1
> ELF symbol "_GLOBAL_OFFSET_TABLE_" relocated to zero
> allocated 0x10 bytes at 0x7ffff7ff7000 for registers
> (gdb) _
>
Fine by me

Cheers

Phil
Pedro Alves July 1, 2015, 2:10 p.m. UTC | #2 
OK.

On 07/01/2015 01:20 PM, Jan Kratochvil wrote:

>        if (strcmp (sym->name, "_GLOBAL_OFFSET_TABLE_") == 0)
>  	{

It'd be nice to have a comment here mentioning why we need to do this.

Thanks,
Pedro Alves
Jan Kratochvil July 1, 2015, 2:17 p.m. UTC | #3 
On Wed, 01 Jul 2015 16:10:22 +0200, Pedro Alves wrote:
> OK.
> 
> On 07/01/2015 01:20 PM, Jan Kratochvil wrote:
> 
> >        if (strcmp (sym->name, "_GLOBAL_OFFSET_TABLE_") == 0)
> >  	{
> 
> It'd be nice to have a comment here mentioning why we need to do this.

I do not know, I think it is a GCC bug, with -mcmodel=large I have no idea why
GCC needs _GLOBAL_OFFSET_TABLE_.  I can write there this info.


Jan
diff mbox

Patch

--- a/gdb/compile/compile-object-load.c
+++ b/gdb/compile/compile-object-load.c
@@ -731,14 +731,14 @@  compile_object_load (const char *object_file, const char *source_file,
 
       if (sym->flags != 0)
 	continue;
-      if (compile_debug)
-	fprintf_unfiltered (gdb_stdlog,
-			    "lookup undefined ELF symbol \"%s\"\n",
-			    sym->name);
       sym->flags = BSF_GLOBAL;
       sym->section = bfd_abs_section_ptr;
       if (strcmp (sym->name, "_GLOBAL_OFFSET_TABLE_") == 0)
 	{
+	  if (compile_debug)
+	    fprintf_unfiltered (gdb_stdlog,
+				"ELF symbol \"%s\" relocated to zero\n",
+				sym->name);
 	  sym->value = 0;
 	  continue;
 	}
@@ -748,10 +748,21 @@  compile_object_load (const char *object_file, const char *source_file,
 	{
 	case mst_text:
 	  sym->value = BMSYMBOL_VALUE_ADDRESS (bmsym);
+	  if (compile_debug)
+	    fprintf_unfiltered (gdb_stdlog,
+				"ELF mst_text symbol \"%s\" relocated to %s\n",
+				sym->name,
+				paddress (target_gdbarch (), sym->value));
 	  break;
 	case mst_text_gnu_ifunc:
 	  sym->value = gnu_ifunc_resolve_addr (target_gdbarch (),
 					       BMSYMBOL_VALUE_ADDRESS (bmsym));
+	  if (compile_debug)
+	    fprintf_unfiltered (gdb_stdlog,
+				"ELF mst_text_gnu_ifunc symbol \"%s\" "
+				"relocated to %s\n",
+				sym->name,
+				paddress (target_gdbarch (), sym->value));
 	  break;
 	default:
 	  warning (_("Could not find symbol \"%s\" "