This patch fixes a problem with -fdebug-types-section and with -gsplit-dwarf where the hash computation for the type signature and for the DW_AT_dwo_id attribute may produce results that differ from run to run. For dw_val_class_vec values (e.g., the const value of a small struct), both hash computations use the value of a pointer instead of the actual data.
Bootstrapped, tested, and committed to trunk. -cary 2013-08-13 Cary Coutant <ccout...@google.com> gcc/ * dwarf2out.c (CHECKSUM_BLOCK): New macro. (attr_checksum): Hash vector contents instead of pointer. (attr_checksum_ordered): Likewise. Index: dwarf2out.c =================================================================== --- dwarf2out.c (revision 201711) +++ dwarf2out.c (working copy) @@ -5432,6 +5432,7 @@ pop_compile_unit (dw_die_ref old_unit) } #define CHECKSUM(FOO) md5_process_bytes (&(FOO), sizeof (FOO), ctx) +#define CHECKSUM_BLOCK(FOO, SIZE) md5_process_bytes ((FOO), (SIZE), ctx) #define CHECKSUM_STRING(FOO) md5_process_bytes ((FOO), strlen (FOO), ctx) /* Calculate the checksum of a location expression. */ @@ -5475,7 +5476,9 @@ attr_checksum (dw_attr_ref at, struct md CHECKSUM (at->dw_attr_val.v.val_double); break; case dw_val_class_vec: - CHECKSUM (at->dw_attr_val.v.val_vec); + CHECKSUM_BLOCK (at->dw_attr_val.v.val_vec.array, + (at->dw_attr_val.v.val_vec.length + * at->dw_attr_val.v.val_vec.elt_size)); break; case dw_val_class_flag: CHECKSUM (at->dw_attr_val.v.val_flag); @@ -5550,10 +5553,12 @@ die_checksum (dw_die_ref die, struct md5 } #undef CHECKSUM +#undef CHECKSUM_BLOCK #undef CHECKSUM_STRING /* For DWARF-4 types, include the trailing NULL when checksumming strings. */ #define CHECKSUM(FOO) md5_process_bytes (&(FOO), sizeof (FOO), ctx) +#define CHECKSUM_BLOCK(FOO, SIZE) md5_process_bytes ((FOO), (SIZE), ctx) #define CHECKSUM_STRING(FOO) md5_process_bytes ((FOO), strlen (FOO) + 1, ctx) #define CHECKSUM_SLEB128(FOO) checksum_sleb128 ((FOO), ctx) #define CHECKSUM_ULEB128(FOO) checksum_uleb128 ((FOO), ctx) @@ -5749,8 +5754,11 @@ attr_checksum_ordered (enum dwarf_tag ta case dw_val_class_vec: CHECKSUM_ULEB128 (DW_FORM_block); - CHECKSUM_ULEB128 (sizeof (at->dw_attr_val.v.val_vec)); - CHECKSUM (at->dw_attr_val.v.val_vec); + CHECKSUM_ULEB128 (at->dw_attr_val.v.val_vec.length + * at->dw_attr_val.v.val_vec.elt_size); + CHECKSUM_BLOCK (at->dw_attr_val.v.val_vec.array, + (at->dw_attr_val.v.val_vec.length + * at->dw_attr_val.v.val_vec.elt_size)); break; case dw_val_class_flag: