Add support for finding libraries in Fortran projects

 * mesonbuild/compilers/c.py: Make the `find_library` method more generic by allowing the user to supply the `code` for compiling and linking.
 * mesonbuild/compilers/fortran.py: Use the methods inherited from `Compiler` base class where appropriate. Also reuse `CComiler` methods where applicable. This should be sufficient to get various compiler/linker arguments as well as to compile and link Fortran programs. This was tested with `gfortran` compiler, and while the other compilers ought to work for simple cases, their methods are primarily inherited from the base `FortranCompiler` class.
 * test cases/fortran/10 find library/gzip.f90: Fortran module with some basic Fortran wrapper interfaces to `gzopen`, `gzwrite`, and `gzclose` C `zlib` functions.
 * test cases/fortran/10 find library/main.f90: Fortran program using the `gzip` Fortran interface module to write some data to a gzip file.
 * test cases/fortran/10 find library/meson.build: Meson build file for this test case. This demonstrates the ability to link the Fortran program against an external library.

1 files changed, 5 insertions, 2 deletions

diff --git a/mesonbuild/compilers/c.py b/mesonbuild/compilers/c.py
index 81c0229..13b3dcc 100644
--- a/mesonbuild/compilers/c.py
+++ b/mesonbuild/compilers/c.py
@@ -808,12 +808,11 @@ class CCompiler(Compiler):
             raise AssertionError('BUG: unknown libtype {!r}'.format(libtype))
         return prefixes, suffixes
 
-    def find_library(self, libname, env, extra_dirs, libtype='default'):
+    def find_library_impl(self, libname, env, extra_dirs, code, libtype='default'):
         # These libraries are either built-in or invalid
         if libname in self.ignore_libs:
             return []
         # First try if we can just add the library as -l.
-        code = 'int main(int argc, char **argv) { return 0; }'
         if extra_dirs and isinstance(extra_dirs, str):
             extra_dirs = [extra_dirs]
         # Gcc + co seem to prefer builtin lib dirs to -L dirs.
@@ -838,6 +837,10 @@ class CCompiler(Compiler):
                         return [trial]
         return None
 
+    def find_library(self, libname, env, extra_dirs, libtype='default'):
+        code = 'int main(int argc, char **argv) { return 0; }'
+        return self.find_library_impl(libname, env, extra_dirs, code, libtype)
+
     def thread_flags(self, env):
         if for_haiku(self.is_cross, env):
             return []