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Re: PATCH: PR ld/14272: Mark the plugin symbol undefined
- From: "H.J. Lu" <hjl dot tools at gmail dot com>
- To: Binutils <binutils at sourceware dot org>
- Date: Thu, 5 Feb 2015 21:10:32 -0800
- Subject: Re: PATCH: PR ld/14272: Mark the plugin symbol undefined
- Authentication-results: sourceware.org; auth=none
- References: <20120628221026 dot GA5008 at intel dot com> <CAMe9rOqVkDWQ3gzojEQzRLmcj=DC+a9GS5HWX2Zy9S7HD9QkBA at mail dot gmail dot com> <20150204110841 dot GN14796 at bubble dot grove dot modra dot org> <CAMe9rOoh3dVaRUSWFb5=V=CEtsL24+s=7DeZiDQ+a7LtEU4q_w at mail dot gmail dot com> <20150206005938 dot GY14796 at bubble dot grove dot modra dot org> <CAMe9rOqd1RzU9hfqYkg+Tbyd0hSLgoWi3ECVBWaX8YAr5iNQ7Q at mail dot gmail dot com> <20150206015245 dot GZ14796 at bubble dot grove dot modra dot org> <CAMe9rOowvONfJkrP2cNA8TvPQWyGAWM72MegATaq6cNcP6MbYQ at mail dot gmail dot com>
On Thu, Feb 5, 2015 at 8:06 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Thu, Feb 5, 2015 at 5:52 PM, Alan Modra <amodra@gmail.com> wrote:
>> On Thu, Feb 05, 2015 at 05:06:38PM -0800, H.J. Lu wrote:
>>> On Thu, Feb 5, 2015 at 4:59 PM, Alan Modra <amodra@gmail.com> wrote:
>>> > On Wed, Feb 04, 2015 at 04:36:16AM -0800, H.J. Lu wrote:
>>> >> On Wed, Feb 4, 2015 at 3:08 AM, Alan Modra <amodra@gmail.com> wrote:
>>> >> > On Tue, Feb 03, 2015 at 09:06:47AM -0800, H.J. Lu wrote:
>>> >> >> PR ld/12365
>>> >> >> * ld-plugin/pr12365a.c: New file.
>>> >> >> * ld-plugin/pr12365b.c: Likewise.
>>> >> >> * ld-plugin/pr12365c.c: Likewise.
>>> >> >
>>> >> > The testcase fails when using gcc-5. Also, gcc-5 objects don't seem
>>> >> > exercise your _bfd_elf_fix_symbol_flags code. I presume you need an
>>> >> > older version of gcc, with lto bugs, to need those hacks. Is that
>>> >> > true? Can you write a testcase that does exercise your
>>> >> > _bfd_elf_fix_symbol_flags code?
>>> >>
>>> >> The -flto-partition default was changed. I checked in this patch
>>> >> to pass -flto-partition=none to the PR ld/12365 test.
>>> >
>>> > The test fails when using gcc-4.7.2 on powerpc64-linux. Please fix it.
>>>
>>> Does it fail with gcc 4.8? What is the error message?
>>
>> No error message. The link succeeds. Similarly with gcc-4.9 and
>
> The test is very sensitive to LTO partition. Also
The test is also sensitive to LTO IR order. I am testing this patch.
> #define ASMNAME(cname) ASMNAME2 (__USER_LABEL_PREFIX__, cname)
> #define ASMNAME2(prefix, cname) STRING (prefix) cname
> #define STRING(x) #x
>
> typedef __SIZE_TYPE__ size_t;
> extern void abort (void);
> extern void *memcpy (void *, const void *, size_t)
> __asm (ASMNAME ("my_memcpy"));
>
> doesn't work for all platforms. I will keep digging.
>
I will also limit this test to x86 for now until we find a way to make it
work for other platforms.
--
H.J.
diff --git a/bfd/elflink.c b/bfd/elflink.c
index 604cfb6..15b82a9 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -2423,20 +2423,6 @@ _bfd_elf_fix_symbol_flags (struct elf_link_hash_entry *h,
}
else
{
- /* If a plugin symbol is referenced from a non-IR file, mark
- the symbol as undefined, except for symbol for linker
- created section. */
- if (h->root.non_ir_ref
- && (h->root.type == bfd_link_hash_defined
- || h->root.type == bfd_link_hash_defweak)
- && (h->root.u.def.section->flags & SEC_LINKER_CREATED) == 0
- && h->root.u.def.section->owner != NULL
- && (h->root.u.def.section->owner->flags & BFD_PLUGIN) != 0)
- {
- h->root.type = bfd_link_hash_undefined;
- h->root.u.undef.abfd = h->root.u.def.section->owner;
- }
-
/* Unfortunately, NON_ELF is only correct if the symbol
was first seen in a non-ELF file. Fortunately, if the symbol
was first seen in an ELF file, we're probably OK unless the
@@ -9807,6 +9793,22 @@ elf_link_input_bfd (struct elf_final_link_info *flinfo, bfd *input_bfd)
s_type = h->type;
+ /* If a plugin symbol is referenced from a non-IR file, mark
+ the symbol as undefined, except for symbol for linker
+ created section. */
+ if (h->root.non_ir_ref
+ && (h->root.type == bfd_link_hash_defined
+ || h->root.type == bfd_link_hash_defweak)
+ && (h->root.u.def.section->flags
+ & SEC_LINKER_CREATED) == 0
+ && h->root.u.def.section->owner != NULL
+ && (h->root.u.def.section->owner->flags
+ & BFD_PLUGIN) != 0)
+ {
+ h->root.type = bfd_link_hash_undefined;
+ h->root.u.undef.abfd = h->root.u.def.section->owner;
+ }
+
ps = NULL;
if (h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)