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

[Xinliang David Li]

When absolute path is specified for the object file, no prefix will be
prepended to the gcda path. If you record the cwd as in the
_gcov_profile_prefix variable, at profile dump time, the prefix will
be wrong -- as it is never used.

David

On Thu, Sep 12, 2013 at 2:07 PM, Teresa Johnson <tejohnson@google.com> wrote:
> 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