> Ping?
Sorry for late reply
> >Hi,
> >
> >This patch fixes an assert failure when linking one LTOed object file
> >having a weak alias with a regular object file containing a strong
> >definition for that same symbol. The patch is twofold:
> >
> >+ do not add an alias to a partition if it is external
> >+ do not declare (.globl) an alias if it is external
Adding external alises to partitions is important to keep the information
that two symbols are the same.
The second part makes sense to me. What breaks when you drop the first
change?
Honza
> >
> >ChangeLog entries are as follow:
> >
> >*** gcc/lto/ChangeLog ***
> >
> >2017-03-01 Thomas Preud'homme <thomas.preudho...@arm.com>
> >
> > PR lto/69866
> > * lto/lto-partition.c (add_symbol_to_partition_1): Do not add external
> > aliases to partition.
> >
> >*** gcc/ChangeLog ***
> >
> >2017-03-01 Thomas Preud'homme <thomas.preudho...@arm.com>
> >
> > PR lto/69866
> > * cgraphunit.c (cgraph_node::assemble_thunks_and_aliases): Do not
> > declare external aliases.
> >
> >*** gcc/testsuite/ChangeLog ***
> >
> >2017-02-28 Thomas Preud'homme <thomas.preudho...@arm.com>
> >
> > PR lto/69866
> > * gcc.dg/lto/pr69866_0.c: New test.
> > * gcc.dg/lto/pr69866_1.c: Likewise.
> >
> >
> >Testing: Testsuite shows no regression when targeting Cortex-M3 with an
> >arm-none-eabi GCC cross-compiler, neither does it show any regression with
> >native LTO-bootstrapped x86-64_linux-gnu and aarch64-linux-gnu compilers.
> >
> >Is this ok for stage4?
> >
> >Best regards,
> >
> >Thomas
> >
> >On 31/03/17 18:07, Richard Biener wrote:
> >>On March 31, 2017 5:23:03 PM GMT+02:00, Jeff Law <l...@redhat.com> wrote:
> >>>On 03/16/2017 08:05 AM, Thomas Preudhomme wrote:
> >>>>Ping?
> >>>>
> >>>>Is this ok for stage4?
> >>>Given the lack of response from Richi, I'd suggest deferring to stage1.
> >>
> >>Honza needs to review this, i habe too little knowledge here.
> >>
> >>Richard.
> >>
> >>>jeff
> >>
> diff --git a/gcc/cgraphunit.c b/gcc/cgraphunit.c
> index
> c82a88a599ca61b068dd9783d2a6158163809b37..580500ff922b8546d33119261a2455235edbf16d
> 100644
> --- a/gcc/cgraphunit.c
> +++ b/gcc/cgraphunit.c
> @@ -1972,7 +1972,7 @@ cgraph_node::assemble_thunks_and_aliases (void)
> FOR_EACH_ALIAS (this, ref)
> {
> cgraph_node *alias = dyn_cast <cgraph_node *> (ref->referring);
> - if (!alias->transparent_alias)
> + if (!alias->transparent_alias && !DECL_EXTERNAL (alias->decl))
> {
> bool saved_written = TREE_ASM_WRITTEN (decl);
>
> diff --git a/gcc/lto/lto-partition.c b/gcc/lto/lto-partition.c
> index
> e27d0d1690c1fcfb39e2fac03ce0f4154031fc7c..f44fd435ed075a27e373bdfdf0464eb06e1731ef
> 100644
> --- a/gcc/lto/lto-partition.c
> +++ b/gcc/lto/lto-partition.c
> @@ -178,7 +178,8 @@ add_symbol_to_partition_1 (ltrans_partition part,
> symtab_node *node)
> /* Add all aliases associated with the symbol. */
>
> FOR_EACH_ALIAS (node, ref)
> - if (!ref->referring->transparent_alias)
> + if (!ref->referring->transparent_alias
> + && ref->referring->get_partitioning_class () != SYMBOL_EXTERNAL)
> add_symbol_to_partition_1 (part, ref->referring);
> else
> {
> @@ -189,7 +190,8 @@ add_symbol_to_partition_1 (ltrans_partition part,
> symtab_node *node)
> {
> /* Nested transparent aliases are not permitted. */
> gcc_checking_assert (!ref2->referring->transparent_alias);
> - add_symbol_to_partition_1 (part, ref2->referring);
> + if (ref2->referring->get_partitioning_class () != SYMBOL_EXTERNAL)
> + add_symbol_to_partition_1 (part, ref2->referring);
> }
> }
>
> diff --git a/gcc/testsuite/gcc.dg/lto/pr69866_0.c
> b/gcc/testsuite/gcc.dg/lto/pr69866_0.c
> new file mode 100644
> index
> 0000000000000000000000000000000000000000..f49ef8d4c1da7a21d1bfb5409d647bd18141595b
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/lto/pr69866_0.c
> @@ -0,0 +1,13 @@
> +/* { dg-lto-do link } */
> +
> +int _umh(int i)
> +{
> + return i+1;
> +}
> +
> +int weaks(int i) __attribute__((weak, alias("_umh")));
> +
> +int main()
> +{
> + return weaks(10);
> +}
> diff --git a/gcc/testsuite/gcc.dg/lto/pr69866_1.c
> b/gcc/testsuite/gcc.dg/lto/pr69866_1.c
> new file mode 100644
> index
> 0000000000000000000000000000000000000000..3a14f850eefaffbf659ce4642adef7900330f4ed
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/lto/pr69866_1.c
> @@ -0,0 +1,6 @@
> +/* { dg-options { -fno-lto } } */
> +
> +int weaks(int i)
> +{
> + return i+1;
> +}
