http://sourceware.org/ml/gdb-patches/2013-01/msg00469.html

Subject: [patch] Fix gdb.fortran/common-block.exp crash in PIE mode

Hi Tom,

runtest F90_FOR_TARGET="gfortran -fPIE -pie" gdb.fortran/common-block.exp

crashes GDB as function relocate_one_symbol

	if ((SYMBOL_CLASS (sym) == LOC_LABEL

	     || SYMBOL_CLASS (sym) == LOC_STATIC)

	    && SYMBOL_SECTION (sym) >= 0)

	  SYMBOL_VALUE_ADDRESS (sym) += ANOFFSET (delta, SYMBOL_SECTION (sym));

corrupts SYMBOL_VALUE_COMMON_BLOCK

	struct common_block *common_block;

as it thinks it can update it like SYMBOL_VALUE_ADDRESS

	CORE_ADDR address;

due to its LOC_STATIC.

No regressions on {x86_64,x86_64-m32,i686}-fedora18-linux-gnu and in PIE mode.

Thanks,

Jan

gdb/

2013-01-19  Jan Kratochvil  <jan.kratochvil@redhat.com>

	Fix gdb.fortran/common-block.exp crash in PIE mode.

	* dwarf2read.c (new_symbol_full) <DW_TAG_common_block>: Use

	LOC_COMMON_BLOCK.

	* f-valprint.c (info_common_command_for_block): Expect

	LOC_COMMON_BLOCK in gdb_assert.

	* symtab.h (struct general_symbol_info): Update comment for the

	common_block member.

	(domain_enum): Extend comment for the COMMON_BLOCK_DOMAIN member.

	(enum address_class): New member LOC_COMMON_BLOCK.

diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c

index 7a58c45..364e6af 100644

--- a/gdb/dwarf2read.c

+++ b/gdb/dwarf2read.c

@@ -16071,7 +16071,7 @@ new_symbol_full (struct die_info *die, struct type *type, struct dwarf2_cu *cu,

 	  list_to_add = &global_symbols;

 	  break;

 	case DW_TAG_common_block:

-	  SYMBOL_CLASS (sym) = LOC_STATIC;

+	  SYMBOL_CLASS (sym) = LOC_COMMON_BLOCK;

 	  SYMBOL_DOMAIN (sym) = COMMON_BLOCK_DOMAIN;

 	  add_symbol_to_list (sym, cu->list_in_scope);

 	  break;

diff --git a/gdb/f-valprint.c b/gdb/f-valprint.c

index 22cca83..d01d6ec 100644

--- a/gdb/f-valprint.c

+++ b/gdb/f-valprint.c

@@ -427,7 +427,7 @@ info_common_command_for_block (struct block *block, const char *comname,

 	struct common_block *common = SYMBOL_VALUE_COMMON_BLOCK (sym);

 	size_t index;

-	gdb_assert (SYMBOL_CLASS (sym) == LOC_STATIC);

+	gdb_assert (SYMBOL_CLASS (sym) == LOC_COMMON_BLOCK);

 	if (comname && (!SYMBOL_LINKAGE_NAME (sym)

 	                || strcmp (comname, SYMBOL_LINKAGE_NAME (sym)) != 0))

diff --git a/gdb/symtab.h b/gdb/symtab.h

index c334a3a..b992266 100644

--- a/gdb/symtab.h

+++ b/gdb/symtab.h

@@ -120,7 +120,7 @@ struct general_symbol_info

     CORE_ADDR address;

-    /* A common block.  Used with COMMON_BLOCK_DOMAIN.  */

+    /* A common block.  Used with LOC_COMMON_BLOCK.  */

     struct common_block *common_block;

@@ -414,7 +414,8 @@ typedef enum domain_enum_tag

   LABEL_DOMAIN,

-  /* Fortran common blocks.  Their naming must be separate from VAR_DOMAIN.  */

+  /* Fortran common blocks.  Their naming must be separate from VAR_DOMAIN.

+     They also always use LOC_COMMON_BLOCK.  */

   COMMON_BLOCK_DOMAIN

 } domain_enum;

@@ -533,6 +534,10 @@ enum address_class

   /* The variable's address is computed by a set of location

      functions (see "struct symbol_computed_ops" below).  */

   LOC_COMPUTED,

+

+  /* The variable uses general_symbol_info->value->common_block field.

+     It also always uses COMMON_BLOCK_DOMAIN.  */

+  LOC_COMMON_BLOCK,

 };

 /* The methods needed to implement LOC_COMPUTED.  These methods can