tests/hdf5: work around some problems

There are two cases that won't work (these are taken from fortran/9
cpp), using gfortran with a non-gcc compiler on windows, or using
gfortran with apple clang. The latter is due to default search paths,
which we can fix, but is out of scope for this MR.

test cases/frameworks/25 hdf5/meson.build

@@ -19,11 +19,26 @@ if add_languages('cpp', required: false)
   test('HDF5 C++', execpp, timeout: 30)
 endif
 
-# --- Fortran tests
-if add_languages('fortran', required: false)
+test_fortran = add_languages('fortran', required: false)
+
+if test_fortran
+  cpp = meson.get_compiler('cpp')
+  fc = meson.get_compiler('fortran')
+
+  if host_machine.system() == 'darwin' and cpp.get_id() == 'clang' and fc.get_id() == 'gcc'
+    # Search paths don't work correctly here and -lgfortran doesn't work
+    test_fortran = false
+  elif host_machine.system() == 'windows' and cpp.get_id() != 'gcc' and fc.get_id() == 'gcc'
+    # mixing gfotran with non-gcc doesn't work on windows
+    test_fortran = false
+  endif
+
+  # --- Fortran tests
+  if test_fortran
     h5f = dependency('hdf5', language : 'fortran', required : false, disabler: true, method : method)
     exef = executable('exef', 'main.f90', dependencies : h5f)
     test('HDF5 Fortran', exef, timeout: 30)
+  endif
 endif
 
 # Check we can apply a version constraint