Can use C++ and FORTRAN in a single target. Closes #2685.

mesonbuild/compilers/fortran.py

@@ -183,13 +183,15 @@ class GnuFortranCompiler(FortranCompiler):
     def openmp_flags(self):
         return ['-fopenmp']
 
+    def language_stdlib_only_link_flags(self):
+        return ['-lgfortran', '-lm', '-lquadmath']
+
 
 class ElbrusFortranCompiler(GnuFortranCompiler, ElbrusCompiler):
     def __init__(self, exelist, version, gcc_type, is_cross, exe_wrapper=None, defines=None, **kwargs):
         GnuFortranCompiler.__init__(self, exelist, version, gcc_type, is_cross, exe_wrapper, defines, **kwargs)
         ElbrusCompiler.__init__(self, gcc_type, defines)
 
-
 class G95FortranCompiler(FortranCompiler):
     def __init__(self, exelist, version, is_cross, exe_wrapper=None, **kwags):
         super().__init__(exelist, version, is_cross, exe_wrapper=None, **kwags)

test cases/fortran/9 cpp/fortran.f

@@ -0,0 +1,5 @@
+      function fortran() bind(C)
+      use, intrinsic :: iso_c_binding
+      real(kind=c_double) :: fortran
+      fortran = 2.0**rand(1)
+      end function fortran

test cases/fortran/9 cpp/main.cpp

@@ -0,0 +1,8 @@
+#include <iostream>
+
+extern "C" double fortran();
+
+int main(int, char**) {
+    std::cout << "FORTRAN gave us this number: " << fortran() << '\n';
+    return 0;
+}

test cases/fortran/9 cpp/meson.build

@@ -0,0 +1,10 @@
+project('C++ and FORTRAN', 'cpp', 'fortran')
+
+cpp = meson.get_compiler('cpp')
+
+if cpp.get_id() == 'clang'
+  error('MESON_SKIP_TEST Clang C++ does not find -lgfortran for some reason.')
+endif
+
+e = executable('cppfort', 'main.cpp', 'fortran.f')
+test('C++ FORTRAN', e)