[Google] Fix test failure after porting __gcov_get_profile_prefix from google/4_7

[Teresa Johnson]

On Thu, Sep 12, 2013 at 1:20 PM, Xinliang David Li <davidxl@google.com> wrote:
> On Thu, Sep 12, 2013 at 1:06 PM, Teresa Johnson <tejohnson@google.com> wrote:
>> After porting r198033 from google/4_7 to google/4_8 a test case failed
>> with an assert when trying to take the strlen of profile_data_prefix.
>>
>> In most cases this is either set from the directory specified to
>> -fprofile-generate=, or to getpwd when a directory is not specified.
>> However, the exception is when no directory is specified for
>> -fprofile-generate and -auxbase-strip option is used with the absolute
>> pathname. In that case the code does not set profile_data_prefix since
>> the filenames already have the full path.
>>
>> In the code that sets __gcov_get_profile_prefix, the fix is to simply
>> check if profile_data_prefix is still NULL, and if so just set via
>> getpwd.
>
> Why setting it to getpwd() val? Should it be set to null instead?

The specified behavior when no path is given to -fprofile-generate (or
-fprofile-dir) is to use the current directory.

The case where this was happening was an lto test case, where lto1 was
first run in WPA (-fwpa) mode and was emitting the ltrans output to a
/tmp/ path (-fltrans-output-list=/tmp/cciR1m1o.ltrans.out). Then lto1
was run again in LTRANS mode (-fltrans) with -auxbase-strip
/tmp/cciR1m1o.ltrans0.ltrans.o, triggering the problem.

Teresa

>
> David
>
>>
>> Passes regression tests and failure I reproduced. Ok for google branches?
>>
>> Thanks,
>> Teresa
>>
>> 2013-09-12  Teresa Johnson  <tejohnson@google.com>
>>
>> * tree-profile.c (tree_init_instrumentation): Handle the case
>>         where profile_data_prefix is NULL.
>>
>> Index: tree-profile.c
>> ===================================================================
>> --- tree-profile.c (revision 202500)
>> +++ tree-profile.c (working copy)
>> @@ -470,8 +470,11 @@ tree_init_instrumentation (void)
>>                            DECL_ASSEMBLER_NAME (gcov_profile_prefix_decl));
>>        TREE_STATIC (gcov_profile_prefix_decl) = 1;
>>
>> -      prefix_len = strlen (profile_data_prefix);
>> -      prefix_string = build_string (prefix_len + 1, profile_data_prefix);
>> +      const char *prefix = profile_data_prefix;
>> +      if (!prefix)
>> +        prefix = getpwd ();
>> +      prefix_len = strlen (prefix);
>> +      prefix_string = build_string (prefix_len + 1, prefix);
>>        TREE_TYPE (prefix_string) = build_array_type
>>            (char_type_node, build_index_type
>>             (build_int_cst (NULL_TREE, prefix_len)));
>>
>>
>> --
>> Teresa Johnson | Software Engineer | tejohnson@google.com | 408-460-2413



-- 
Teresa Johnson | Software Engineer | tejohnson@google.com | 408-460-2413