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Re: PATCH: Add "-z muldefs" (Re: question of ld)
On Wed, May 22, 2002 at 02:08:40PM +0930, Alan Modra wrote:
> On Tue, May 21, 2002 at 08:09:03PM -0700, H . J . Lu wrote:
> > 2002-05-21 H.J. Lu (hjl@gnu.org)
> >
> > * linker.c (_bfd_generic_link_add_one_symbol): Allow multiple
> > definition.
> >
> > 2002-05-21 H.J. Lu (hjl@gnu.org)
> >
> > * bfdlink.h (bfd_link_info): Add allow_multiple_definition.
> >
> > 2002-05-21 H.J. Lu (hjl@gnu.org)
> >
> > * emultempl/elf32.em (gld${EMULATION_NAME}_parse_args): Handle
> > "-z muldefs".
> > (gld${EMULATION_NAME}_list_options): Add "-z muldefs".
> >
> > * ldmain.c (main): Initialize the allow_multiple_definition
> > field to false.
> >
> > * lexsup.c (OPTION_ALLOW_MULTIPLE_DEFINITION): New.
> > (ld_options): Add --allow-multiple-definition.
> > (parse_args): Support OPTION_ALLOW_MULTIPLE_DEFINITION.
>
> OK. Please fix the formatting when applying your linker.c patch.
>
I am going to check in this with updated documentation.
H.J.
---
2002-05-21 H.J. Lu (hjl@gnu.org)
* linker.c (_bfd_generic_link_add_one_symbol): Allow multiple
definition.
2002-05-21 H.J. Lu (hjl@gnu.org)
* bfdlink.h (bfd_link_info): Add allow_multiple_definition.
2002-05-21 H.J. Lu (hjl@gnu.org)
* emultempl/elf32.em (gld${EMULATION_NAME}_parse_args): Handle
"-z muldefs".
(gld${EMULATION_NAME}_list_options): Add "-z muldefs".
* ld.texinfo: Updated for --allow-multiple-definition and
"-z muldefs".
* ldmain.c (main): Initialize the allow_multiple_definition
field to false.
* lexsup.c (OPTION_ALLOW_MULTIPLE_DEFINITION): New.
(ld_options): Add --allow-multiple-definition.
(parse_args): Support OPTION_ALLOW_MULTIPLE_DEFINITION.
--- binutils/bfd/linker.c.muldefs Mon May 20 11:03:04 2002
+++ binutils/bfd/linker.c Tue May 21 21:45:40 2002
@@ -1813,37 +1813,38 @@ _bfd_generic_link_add_one_symbol (info,
/* Fall through. */
case MDEF:
/* Handle a multiple definition. */
- {
- asection *msec = NULL;
- bfd_vma mval = 0;
+ if (!info->allow_multiple_definition)
+ {
+ asection *msec = NULL;
+ bfd_vma mval = 0;
- switch (h->type)
- {
- case bfd_link_hash_defined:
- msec = h->u.def.section;
- mval = h->u.def.value;
- break;
- case bfd_link_hash_indirect:
- msec = bfd_ind_section_ptr;
- mval = 0;
- break;
- default:
- abort ();
- }
+ switch (h->type)
+ {
+ case bfd_link_hash_defined:
+ msec = h->u.def.section;
+ mval = h->u.def.value;
+ break;
+ case bfd_link_hash_indirect:
+ msec = bfd_ind_section_ptr;
+ mval = 0;
+ break;
+ default:
+ abort ();
+ }
- /* Ignore a redefinition of an absolute symbol to the same
- value; it's harmless. */
- if (h->type == bfd_link_hash_defined
- && bfd_is_abs_section (msec)
- && bfd_is_abs_section (section)
- && value == mval)
- break;
+ /* Ignore a redefinition of an absolute symbol to the
+ same value; it's harmless. */
+ if (h->type == bfd_link_hash_defined
+ && bfd_is_abs_section (msec)
+ && bfd_is_abs_section (section)
+ && value == mval)
+ break;
- if (! ((*info->callbacks->multiple_definition)
- (info, h->root.string, msec->owner, msec, mval, abfd,
- section, value)))
- return false;
- }
+ if (! ((*info->callbacks->multiple_definition)
+ (info, h->root.string, msec->owner, msec, mval,
+ abfd, section, value)))
+ return false;
+ }
break;
case CIND:
--- binutils/include/bfdlink.h.muldefs Fri Mar 8 09:48:28 2002
+++ binutils/include/bfdlink.h Tue May 21 19:39:48 2002
@@ -231,6 +231,8 @@ struct bfd_link_info
select an appropriate memset function. Apparently it is also
normal for HPPA shared libraries to have undefined symbols. */
boolean allow_shlib_undefined;
+ /* True if ok to have multiple definition. */
+ boolean allow_multiple_definition;
/* Which symbols to strip. */
enum bfd_link_strip strip;
/* Which local symbols to discard. */
--- binutils/ld/emultempl/elf32.em.muldefs Tue Apr 23 15:18:44 2002
+++ binutils/ld/emultempl/elf32.em Tue May 21 19:53:45 2002
@@ -1541,6 +1541,8 @@ cat >>e${EMULATION_NAME}.c <<EOF
}
else if (strcmp (optarg, "defs") == 0)
link_info.no_undefined = true;
+ else if (strcmp (optarg, "muldefs") == 0)
+ link_info.allow_multiple_definition = true;
else if (strcmp (optarg, "combreloc") == 0)
link_info.combreloc = true;
else if (strcmp (optarg, "nocombreloc") == 0)
@@ -1589,6 +1591,7 @@ cat >>e${EMULATION_NAME}.c <<EOF
fprintf (file, _(" -z initfirst\t\tMark DSO to be initialized first at runtime\n"));
fprintf (file, _(" -z interpose\t\tMark object to interpose all DSOs but executable\n"));
fprintf (file, _(" -z loadfltr\t\tMark object requiring immediate process\n"));
+ fprintf (file, _(" -z muldefs\t\tAllow multiple definitions\n"));
fprintf (file, _(" -z nocombreloc\tDon't merge dynamic relocs into one section\n"));
fprintf (file, _(" -z nocopyreloc\tDon't create copy relocs\n"));
fprintf (file, _(" -z nodefaultlib\tMark object not to use default search paths\n"));
--- binutils/ld/ld.texinfo.muldefs Tue Apr 23 15:18:43 2002
+++ binutils/ld/ld.texinfo Tue May 21 21:32:24 2002
@@ -859,6 +859,7 @@ of this object will ignore any default l
@code{now} marks the object with the non-lazy runtime binding.
@code{origin} marks the object may contain $ORIGIN.
@code{defs} disallows undefined symbols.
+@code{muldefs} allows multiple definitions.
@code{combreloc} combines multiple reloc sections and sorts them
to make dynamic symbol lookup caching possible.
@code{nocombreloc} disables multiple reloc sections combining.
@@ -1080,6 +1081,14 @@ Normally when creating a non-symbolic sh
are allowed and left to be resolved by the runtime loader. These options
disallows such undefined symbols.
+@kindex --allow-multiple-definition
+@kindex -z muldefs
+@item --allow-multiple-definition
+@itemx -z muldefs
+Normally when a symbol is defined multiple times, the linker will
+report a fatal error. These options allow multiple definitions and the
+first definition will be used.
+
@kindex --allow-shlib-undefined
@item --allow-shlib-undefined
Allow undefined symbols in shared objects even when --no-undefined is
--- binutils/ld/ldmain.c.muldefs Mon May 20 11:03:50 2002
+++ binutils/ld/ldmain.c Tue May 21 19:39:14 2002
@@ -239,6 +239,7 @@ main (argc, argv)
link_info.optimize = false;
link_info.no_undefined = false;
link_info.allow_shlib_undefined = false;
+ link_info.allow_multiple_definition = false;
link_info.strip = strip_none;
link_info.discard = discard_sec_merge;
link_info.keep_memory = true;
--- binutils/ld/lexsup.c.muldefs Mon May 20 11:03:50 2002
+++ binutils/ld/lexsup.c Tue May 21 19:54:17 2002
@@ -126,7 +126,8 @@ int parsing_defsym = 0;
#define OPTION_UNIQUE (OPTION_SECTION_START + 1)
#define OPTION_TARGET_HELP (OPTION_UNIQUE + 1)
#define OPTION_ALLOW_SHLIB_UNDEFINED (OPTION_TARGET_HELP + 1)
-#define OPTION_DISCARD_NONE (OPTION_ALLOW_SHLIB_UNDEFINED + 1)
+#define OPTION_ALLOW_MULTIPLE_DEFINITION (OPTION_ALLOW_SHLIB_UNDEFINED + 1)
+#define OPTION_DISCARD_NONE (OPTION_ALLOW_MULTIPLE_DEFINITION + 1)
#define OPTION_SPARE_DYNAMIC_TAGS (OPTION_DISCARD_NONE + 1)
#define OPTION_NO_DEFINE_COMMON (OPTION_SPARE_DYNAMIC_TAGS + 1)
#define OPTION_NOSTDLIB (OPTION_NO_DEFINE_COMMON + 1)
@@ -319,6 +320,8 @@ static const struct ld_option ld_options
'\0', NULL, N_("Allow no undefined symbols"), TWO_DASHES },
{ {"allow-shlib-undefined", no_argument, NULL, OPTION_ALLOW_SHLIB_UNDEFINED},
'\0', NULL, N_("Allow undefined symbols in shared objects"), TWO_DASHES },
+ { {"allow-multiple-definition", no_argument, NULL, OPTION_ALLOW_MULTIPLE_DEFINITION},
+ '\0', NULL, N_("Allow multiple definitions"), TWO_DASHES },
{ {"no-warn-mismatch", no_argument, NULL, OPTION_NO_WARN_MISMATCH},
'\0', NULL, N_("Don't warn about mismatched input files"), TWO_DASHES},
{ {"no-whole-archive", no_argument, NULL, OPTION_NO_WHOLE_ARCHIVE},
@@ -761,6 +764,9 @@ parse_args (argc, argv)
case OPTION_ALLOW_SHLIB_UNDEFINED:
link_info.allow_shlib_undefined = true;
break;
+ case OPTION_ALLOW_MULTIPLE_DEFINITION:
+ link_info.allow_multiple_definition = true;
+ break;
case OPTION_NO_WARN_MISMATCH:
command_line.warn_mismatch = false;
break;