[Bug libfortran/108618] New: ISO C-Fortran Interface fails to pass CFI descriptor version check when using code coverage flags for fortran

[Bug libfortran/108618] New: ISO C-Fortran Interface fails to pass CFI descriptor version check when using code coverage flags for fortran

[kyle.shores44 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108618

            Bug ID: 108618
           Summary: ISO C-Fortran Interface fails to pass CFI descriptor
                    version check when using code coverage flags for
                    fortran
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libfortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: kyle.shores44 at gmail dot com
  Target Milestone: ---

Created attachment 54378
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54378&action=edit
A zipped archive with 5 files, a dockerfile, CMakeLists.txt, a cmake file for
code coverage, a fortran source file, a c++ source file

The C-Fortran interface fails to pass a runtime Fortran check for the CFI
descriptor when checking code coverage. Specifically, the `-fcheck=bounds` flag
causes the runtime failure.

Included is a zip file that has a minimal working example. It's a cmake project
with two source files (one c++, one fortran), a Dockerfile, a CMakeLists.txt
file as well as the necessary code coverage cmake file. Fortran creates some
strings and passes them to C(++) through the `CFI_cdesc_t` struct defined in
ISO_Fortran_binding.h.

Inside of the CMakeLists.txt file there are two calls to
`set(CMAKE_Fortran_FLAGS ...`. Above each is a comment indicating which of the
flags passes and which fails. You can comment and uncomment the pair to watch
the created executable fail intermittently. 

When I compile the sources on my machine with the below versions of tools, I
see the failure.

os: macOS 12.5
architecture: Apple M1 Pro
gfortran: GNU Fortran (Homebrew GCC 12.2.0) 12.2.0
g++: (Homebrew GCC 12.2.0) 12.2.0
cmake: 3.25.1

I also see the failure in the Dockerfile included in the zipped archive
(hopefully this aids in the reproducibility of the issue). The tool versions in
the Dockerfile are

os: Fedora Linux 38
architecture: Apple M1 Pro
gfortran: GNU Fortran (GCC) 13.0.1 20230127 (Red Hat 13.0.1-0)
g++: (GCC) 13.0.1 20230127 (Red Hat 13.0.1-0)
cmake: 3.25.2

The specific flag that causes the issue is `-fcheck=bounds`.

The full list of compiler flags passed to gfortran on my machine:

/opt/homebrew/bin/gfortran 
-I/Users/kshores/Downloads/mwe/build/_deps/googletest-src/googletest/include
-I/Users/kshores/Downloads/mwe/build/_deps/googletest-src/googletest -g -O0
-fprofile-arcs -ftest-coverage -fcheck=bounds,do,pointer
-ffpe-trap=zero,overflow,invalid -fprofile-abs-path -isysroot
/Library/Developer/CommandLineTools/SDKs/MacOSX12.3.sdk -c
/Users/kshores/Downloads/mwe/fortran_strings.F90 -o
CMakeFiles/bad_version.dir/fortran_strings.F90.o

The full list of compiler flags passed to gfortran in the Dockerfile:

/usr/bin/gfortran  -I/build/_deps/googletest-src/googletest/include
-I/build/_deps/googletest-src/googletest -g -O0 -fprofile-arcs -ftest-coverage
-fcheck=bounds,do,pointer -ffpe-trap=zero,overflow,invalid -fprofile-abs-path
-c /mwe/fortran_strings.F90 -o CMakeFiles/bad_version.dir/fortran_strings.F90.o


I hope that this is enough information. Please let me know if there is more
that is needed from me.

[Bug libfortran/108618] ISO C-Fortran Interface fails to pass CFI descriptor version check when using code coverage flags for fortran

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108618

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Is there a way to remove the depedency on gtest/gtest.h ?

[Bug libfortran/108618] ISO C-Fortran Interface fails to pass CFI descriptor version check when using code coverage flags for fortran

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108618

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
and use make rather than cmake here?

[Bug libfortran/108618] ISO C-Fortran Interface fails to pass CFI descriptor version check when using code coverage flags for fortran

[kyle.shores44 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108618

--- Comment #3 from Kyle Shores <kyle.shores44 at gmail dot com> ---
Ah, the specific error message printed at runtime:

Fortran runtime error: Unexpected version 16 (expected 1) in CFI descriptor
passed to dummy argument the_names

[Bug libfortran/108618] ISO C-Fortran Interface fails to pass CFI descriptor version check when using code coverage flags for fortran

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108618

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |WAITING
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2023-01-31

[Bug libfortran/108618] ISO C-Fortran Interface fails to pass CFI descriptor version check when using code coverage flags for fortran

[kyle.shores44 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108618

--- Comment #4 from Kyle Shores <kyle.shores44 at gmail dot com> ---
Sure, I'll attempt to remove gtest and cmake. I was merely slimming the example
down from my use case in case it mattered.

[Bug libfortran/108618] ISO C-Fortran Interface fails to pass CFI descriptor version check when using code coverage flags for fortran

[kyle.shores44 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108618

--- Comment #5 from Kyle Shores <kyle.shores44 at gmail dot com> ---
New C++ source file:

```
#include <string_view>
#include <vector>
#include <algorithm>
#include <iostream>
#include <cstring>

#include <ISO_Fortran_binding.h>

extern "C" {
  void Finit(void);
  void get_names( CFI_cdesc_t * );
}

std::vector<std::string_view> extract_names(CFI_cdesc_t* names){
  std::vector<std::string_view> vs;

  for (int i = 0; i < names->dim[0].extent; i++) {
    // determine the length of the string up to the first whitespace character
    char* addr = (char *)(names->base_addr) + i * names->elem_len;
    char* first_space = strchr(addr, ' ');
    size_t strlen = first_space - addr;
    vs.push_back(std::string_view(addr).substr(0, strlen));
  }

  return vs;
}

int main(){
  CFI_CDESC_T(1) names;

  std::cout << names.version << std::endl;

  get_names((CFI_cdesc_t *)&names);

  std::cout << names.version << std::endl;

  std::vector<std::string_view> vs = extract_names((CFI_cdesc_t *)&names);

  for(const auto& elem : vs)
  {
    std::cout << elem << std::endl;
  }
}
```

Makefile:

```
CXX=g++-12
FC=gfortran

CXX_FLAGS=-c -g -O0 -fprofile-arcs -ftest-coverage -fprofile-abs-path
FORT_FLAGS=-c -g -O0 -fprofile-arcs -ftest-coverage -fcheck=bounds,do,pointer
-ffpe-trap=zero,overflow,invalid -fprofile-abs-path

all: cpp fort
        ${CXX} -o bad_version test.o fortran_strings.o -lgcov -lgfortran

cpp:
        ${CXX} ${CXX_FLAGS} test.cpp

fort:
        ${FC} ${FORT_FLAGS} fortran_strings.F90
```

Hope that helps

[Bug libfortran/108618] ISO C-Fortran Interface fails to pass CFI descriptor version check when using code coverage flags for fortran

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108618

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Created attachment 54379
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54379&action=edit
FortranCode

[Bug libfortran/108618] ISO C-Fortran Interface fails to pass CFI descriptor version check when using code coverage flags for fortran

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108618

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |INVALID
             Status|WAITING                     |RESOLVED

--- Comment #7 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
  CFI_establish((CFI_cdesc_t *)&names, NULL,
                      CFI_attribute_pointer,
                      CFI_type_char, 0, (CFI_rank_t)1, NULL);


Is needed to setup the CFI_cdesc_t originally.

[Bug libfortran/108618] ISO C-Fortran Interface fails to pass CFI descriptor version check when using code coverage flags for fortran

[kyle.shores44 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108618

--- Comment #8 from Kyle Shores <kyle.shores44 at gmail dot com> ---
Thanks for looking into this. I believe that this worked for you, but for me,
on both my machine and in the docker container, that addition did not fix the
problem.

[Bug libfortran/108618] ISO C-Fortran Interface fails to pass CFI descriptor version check when using code coverage flags for fortran

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108618

--- Comment #9 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Kyle Shores from comment #8)
> Thanks for looking into this. I believe that this worked for you, but for
> me, on both my machine and in the docker container, that addition did not
> fix the problem.

Where did you put it, before the call to get_names?

[Bug libfortran/108618] ISO C-Fortran Interface fails to pass CFI descriptor version check when using code coverage flags for fortran

[kyle.shores44 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108618

--- Comment #10 from Kyle Shores <kyle.shores44 at gmail dot com> ---
Ah, wait I lied. I must not have recompiled or something because everything
works now. Thank you again for addressing this and sorry for submitting a false
positive.