[Bug gcov-profile/103666] New: compiling single-file programs with -fprofile-generate no longer leads to intended results

[Bug gcov-profile/103666] New: compiling single-file programs with -fprofile-generate no longer leads to intended results

[hubicka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103666

            Bug ID: 103666
           Summary: compiling single-file programs with -fprofile-generate
                    no longer leads to intended results
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: gcov-profile
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hubicka at gcc dot gnu.org
                CC: marxin at gcc dot gnu.org
  Target Milestone: ---

The following should work but we fail to name the gcda file same way in both
builds:

jh@ryzen3:~> ~/trunk-install/bin/g++ -Ofast -march=native -fprofile-generate
tramp3d-v44.ii  -fpermissive -std=c++03
jh@ryzen3:~> ./a.out -n 5
jh@ryzen3:~> ~/trunk-install/bin/g++ -Ofast -march=native -fprofile-use
tramp3d-v44.ii  -fpermissive -std=c++03 -o a.out-use
/aux/hubicka/tramp3d-v4b.cpp: In function ‘(static initializers for
/aux/hubicka/tramp3d-v4b.cpp)’:
/aux/hubicka/tramp3d-v4b.cpp:56088:1: warning:
‘/home/jh/a.out-use-tramp3d-v44.gcda’ profile count data file not found
[-Wmissing-profile]

[Bug gcov-profile/103666] [11/12 Regression] compiling single-file preprocessed programs with -fprofile-generate no longer leads to intended results since r11-627-g1dedc12d186a1108

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103666

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1
                 CC|                            |aoliva at gcc dot gnu.org
   Last reconfirmed|                            |2021-12-13
            Summary|compiling single-file       |[11/12 Regression]
                   |preprocessed programs with  |compiling single-file
                   |-fprofile-generate no       |preprocessed programs with
                   |longer leads to intended    |-fprofile-generate no
                   |results                     |longer leads to intended
                   |                            |results since
                   |                            |r11-627-g1dedc12d186a1108

--- Comment #1 from Martin Liška <marxin at gcc dot gnu.org> ---
Started with r11-627-g1dedc12d186a1108.

[Bug gcov-profile/103666] [11/12 Regression] compiling single-file preprocessed programs with -fprofile-generate no longer leads to intended results since r11-627-g1dedc12d186a1108

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103666

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |rejects-valid
   Target Milestone|---                         |11.3

[Bug gcov-profile/103666] [11/12 Regression] compiling single-file programs with -fprofile-generate no longer leads to intended results since r11-627-g1dedc12d186a1108

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103666

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |WONTFIX
            Summary|[11/12 Regression]          |[11/12 Regression]
                   |compiling single-file       |compiling single-file
                   |preprocessed programs with  |programs with
                   |-fprofile-generate no       |-fprofile-generate no
                   |longer leads to intended    |longer leads to intended
                   |results since               |results since
                   |r11-627-g1dedc12d186a1108   |r11-627-g1dedc12d186a1108

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
that's because the explicitely named linker output in the -fprofile-use case. 
A fix might be to separate compile and link step.  I don't think there's
anything special about using preprocessed source:

> cat t.c
int main(){}
> ./xgcc -B. t.c -fprofile-generate
> ./a.out 
> ./xgcc -B. t.c -fprofile-use -o a.out-use
t.c: In function 'main':
t.c:1:1: warning: '/tmp/obj/gcc/a.out-use-t.gcda' profile count data file not
found [-Wmissing-profile]
    1 | int main(){}
      | ^~~
> ls *.gcda
a-t.gcda

I'd declare this as WONTFIX.  I've adjusted the C++ tester for tramp3d to use
an
explicit -dumpbase