[GOOGLE] Define libgcov interface for distinguishing -ftest-coverage from -fprofile-generate

New patch below. Retested. Ok for google branches?

Thanks,
Teresa

2014-07-02  Teresa Johnson  <tejohnson@google.com>

        Google ref b/15378201.
        * gcc/tree-profile.c (gcov_test_coverage_decl): Declare.
        (tree_init_instrumentation): Initialize gcov_test_coverage_decl.
        * libgcc/libgcov-driver.c (__gcov_dummy_ref7): Define.
        * libgcc/libgcov-interface.c (__gcov_profiling_for_test_coverage): New
        function.

On Wed, Jul 2, 2014 at 1:25 PM, Xinliang David Li <davidxl@google.com> wrote:
> The reason is that test coverage is using the same underlying
> profiling. Returning false when calling '__gcov_profiling_enabled())
> in coverage mode is a little misleading.
>
> David
>
> On Wed, Jul 2, 2014 at 1:22 PM, Teresa Johnson <tejohnson@google.com> wrote:
>> On Wed, Jul 2, 2014 at 1:15 PM, Xinliang David Li <davidxl@google.com> wrote:
>>> Should the interface be something like:
>>>
>>> int __gcov_profiling_for_test_coverage(void)?
>>
>> I was equating the term "profiling" with -fprofile-generate, as
>> opposed to -ftest-coverage instrumentation. But I can change it to
>> this if you think that is clearer.
>>
>> Teresa
>>
>>>
>>> David
>>>
>>>
>>> On Wed, Jul 2, 2014 at 12:55 PM, Teresa Johnson <tejohnson@google.com> wrote:
>>>> The following patch adds support for a new libgcov interface,
>>>> __gcov_profiling_enabled, that can be used by applications to
>>>> determine whether a binary has been instrumented for test coverage or
>>>> profile optimization.
>>>>
>>>> Passes regression tests and manual testing with different options. Ok
>>>> for google branches?
>>>>
>>>> Thanks,
>>>> Teresa
>>>>
>>>> 2014-07-02  Teresa Johnson  <tejohnson@google.com>
>>>>
>>>>         Google ref b/15378201.
>>>>         * gcc/tree-profile.c (gcov_test_coverage_decl): Declare.
>>>>         (tree_init_instrumentation): Initialize gcov_test_coverage_decl.
>>>>         * libgcc/libgcov-driver.c (__gcov_dummy_ref7): Define.
>>>>         * libgcc/libgcov-interface.c (__gcov_profiling_enabled): New function.
>>>>
>>>> Index: gcc/tree-profile.c
>>>> ===================================================================
>>>> --- gcc/tree-profile.c  (revision 212044)
>>>> +++ gcc/tree-profile.c  (working copy)
>>>> @@ -164,6 +164,9 @@ static GTY(()) tree gcov_sample_counter_decl = NUL
>>>>  /* extern gcov_unsigned_t __gcov_profile_prefix  */
>>>>  static tree GTY(()) gcov_profile_prefix_decl = NULL_TREE;
>>>>
>>>> +/* extern gcov_unsigned_t __gcov_test_coverage  */
>>>> +static tree GTY(()) gcov_test_coverage_decl = NULL_TREE;
>>>> +
>>>>  /* extern gcov_unsigned_t __gcov_sampling_period  */
>>>>  static GTY(()) tree gcov_sampling_period_decl = NULL_TREE;
>>>>
>>>> @@ -498,6 +501,27 @@ tree_init_instrumentation (void)
>>>>        DECL_INITIAL (gcov_profile_prefix_decl) = prefix_ptr;
>>>>        varpool_finalize_decl (gcov_profile_prefix_decl);
>>>>      }
>>>> +
>>>> +  if (!gcov_test_coverage_decl)
>>>> +    {
>>>> +      /* Initialize __gcov_test_coverage to 1 if -ftest-coverage
>>>> +         specified, 0 otherwise. Used by libgcov to determine whether
>>>> +         a binary was instrumented for coverage or profile optimization.  */
>>>> +      gcov_test_coverage_decl = build_decl (
>>>> +          UNKNOWN_LOCATION,
>>>> +          VAR_DECL,
>>>> +          get_identifier ("__gcov_test_coverage"),
>>>> +          get_gcov_unsigned_t ());
>>>> +      TREE_PUBLIC (gcov_test_coverage_decl) = 1;
>>>> +      DECL_ARTIFICIAL (gcov_test_coverage_decl) = 1;
>>>> +      DECL_COMDAT_GROUP (gcov_test_coverage_decl)
>>>> +          = DECL_ASSEMBLER_NAME (gcov_test_coverage_decl);
>>>> +      TREE_STATIC (gcov_test_coverage_decl) = 1;
>>>> +      DECL_INITIAL (gcov_test_coverage_decl) = build_int_cst (
>>>> +          get_gcov_unsigned_t (),
>>>> +          flag_test_coverage ? 1 : 0);
>>>> +      varpool_finalize_decl (gcov_test_coverage_decl);
>>>> +    }
>>>>  }
>>>>
>>>>  /* Initialization function for FDO sampling.  */
>>>> Index: libgcc/libgcov-driver.c
>>>> ===================================================================
>>>> --- libgcc/libgcov-driver.c     (revision 212044)
>>>> +++ libgcc/libgcov-driver.c     (working copy)
>>>> @@ -79,6 +79,8 @@ extern unsigned int __gcov_sampling_enabled (void)
>>>>  char *(*__gcov_dummy_ref5)(void) = &__gcov_sampling_enabled;
>>>>  extern void __gcov_flush (void);
>>>>  char *(*__gcov_dummy_ref6)(void) = &__gcov_flush;
>>>> +extern unsigned int __gcov_profiling_enabled (void);
>>>> +char *(*__gcov_dummy_ref7)(void) = &__gcov_profiling_enabled;
>>>>
>>>>  /* Default callback function for profile instrumentation callback.  */
>>>>  extern void __coverage_callback (gcov_type, int);
>>>> Index: libgcc/libgcov-interface.c
>>>> ===================================================================
>>>> --- libgcc/libgcov-interface.c  (revision 212044)
>>>> +++ libgcc/libgcov-interface.c  (working copy)
>>>> @@ -116,6 +116,20 @@ __gcov_dump (void)
>>>>    set_gcov_dump_complete ();
>>>>  }
>>>>
>>>> +/* Emitted in coverage.c.  */
>>>> +extern gcov_unsigned_t __gcov_test_coverage;
>>>> +
>>>> +unsigned int __gcov_profiling_enabled (void);
>>>> +
>>>> +/* Function that can be called from application to distinguish binaries
>>>> +   instrumented from coverage fro those instrumented for profiling
>>>> +   (e.g. -fprofile-generate).  */
>>>> +
>>>> +unsigned int __gcov_profiling_enabled (void)
>>>> +{
>>>> +  return !__gcov_test_coverage;
>>>> +}
>>>> +
>>>>  #endif /* L_gcov_dump */
>>>>
>>>>  #ifdef L_gcov_sampling
>>>>
>>>>
>>>> --
>>>> Teresa Johnson | Software Engineer | tejohnson@google.com | 408-460-2413
>>
>>
>>
>> --
>> Teresa Johnson | Software Engineer | tejohnson@google.com | 408-460-2413

[GOOGLE] Define libgcov interface for distinguishing -ftest-coverage from -fprofile-generate

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