[PATCH] Do not declare artificial variables in tree-profile.c to have a definition (PR lto/69188).

[Kyrill Tkachov]

On 23/01/17 09:58, Christophe Lyon wrote:
> On 13 January 2017 at 18:21, Jeff Law <law@redhat.com> wrote:
>> On 01/13/2017 08:08 AM, Martin Liška wrote:
>>> Hello.
>>>
>>> Nice example provided in the PR causes ICE as we have an artificial symbol
>>> created in tree-profile.c once being removed by remove unreachable nodes
>>> (-O0)
>>> and once not (-O1). Well, difference is in process_references where
>>> following hunk
>>> prevent removal:
>>>
>>>                || (((before_inlining_p
>>>                      && ((TREE_CODE (node->decl) != FUNCTION_DECL
>>>                           && optimize)
>>>
>>> Anyway, these artificial symbols really should be just declarations as
>>> they are defined
>>> in libgcov library.
>>>
>>> Patch can bootstrap on ppc64le-redhat-linux and survives regression tests.
>>>
>>> Ready to be installed?
>>> Martin
>>>
>>>
>>> 0001-Do-not-declare-artificial-variables-in-tree-profile..patch
>>>
>>>
>>>  From 87262b1b60009381fd943fb433bc38f5d5685ac9 Mon Sep 17 00:00:00 2001
>>> From: marxin <mliska@suse.cz>
>>> Date: Fri, 13 Jan 2017 13:12:57 +0100
>>> Subject: [PATCH] Do not declare artificial variables in tree-profile.c to
>>> have
>>>   a definition (PR lto/69188).
>>>
>>> gcc/testsuite/ChangeLog:
>>>
>>> 2017-01-13  Martin Liska  <mliska@suse.cz>
>>>
>>>          PR lto/69188
>>>          * gcc.dg/lto/pr69188_0.c: New test.
>>>          * gcc.dg/lto/pr69188_1.c: New test.
>>>
>>> gcc/ChangeLog:
>>>
>>> 2017-01-13  Martin Liska  <mliska@suse.cz>
>>>
>>>          PR lto/69188
>>>          * tree-profile.c (init_ic_make_global_vars): Do not call
>>>          finalize_decl.
>>>          (gimple_init_gcov_profiler): Likewise.
>> OK.
>> jeff
>>
> Hi,
>
> The new test fails on arm-none-eabi:
> /cc6RcpEu.ltrans0.ltrans.o: In function `fn1':
> <artificial>:(.text+0x18): undefined reference to
> `__gcov_indirect_call_profiler_v2'
> <artificial>:(.text+0x1c): undefined reference to `__gcov_indirect_call_callee'
> <artificial>:(.text+0x20): undefined reference to `__gcov_indirect_call_callee'
> <artificial>:(.text+0x60): undefined reference to `__gcov_time_profiler_counter'
> <artificial>:(.text+0x64): undefined reference to `__gcov_time_profiler_counter'
> <artificial>:(.text+0x80): undefined reference to `__gcov_time_profiler_counter'
> <artificial>:(.text+0x84): undefined reference to `__gcov_time_profiler_counter'
> /cc6RcpEu.ltrans0.ltrans.o: In function `_GLOBAL__sub_D_00100_1_fn1':
> <artificial>:(.text+0xb8): undefined reference to `__gcov_exit'
> /cc6RcpEu.ltrans0.ltrans.o: In function `main':
> <artificial>:(.text+0xd4): undefined reference to
> `__gcov_indirect_call_profiler_v2'
> <artificial>:(.text+0xd8): undefined reference to `__gcov_indirect_call_callee'
> <artificial>:(.text+0xdc): undefined reference to `__gcov_indirect_call_callee'
> <artificial>:(.text+0x10c): undefined reference to
> `__gcov_time_profiler_counter'
> <artificial>:(.text+0x110): undefined reference to
> `__gcov_time_profiler_counter'
> /cc6RcpEu.ltrans0.ltrans.o: In function `_GLOBAL__sub_D_00100_1_main':
> <artificial>:(.text+0x180): undefined reference to `__gcov_exit'
> /cc6RcpEu.ltrans0.ltrans.o:(.data+0x4c): undefined reference to
> `__gcov_merge_time_profile'
> /cc6RcpEu.ltrans0.ltrans.o:(.data+0xac): undefined reference to
> `__gcov_merge_time_profile'
> collect2: error: ld returned 1 exit status
>
> FAIL: gcc.dg/lto/pr69188 c_lto_pr69188_0.o-c_lto_pr69188_1.o link,
> -flto -O0 -fprofile-generate
>
> It works on arm-linux*.

Hi,

The testcase fails on bare-metal targets that don't support profiling.
I believe it needs to be guarded with dg-require-profiling (I grepped around the testsuite for similar directives).
With this patch the testcase appears unsupported on aarch64-none-elf where I observed the failure.

Ok to commit?

Thanks,
Kyrill

2016-01-23  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>

     * gcc.dg/lto/pr69188_0.c: Require profiling support for testcase.


> Christophe

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