1 files changed, 81 insertions, 0 deletions
diff --git a/misc/cgo/fortran/fortran_test.go b/misc/cgo/fortran/fortran_test.go
new file mode 100644
index 0000000..4604a4d
--- /dev/null
+++ b/misc/cgo/fortran/fortran_test.go
@@ -0,0 +1,81 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fortran
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+)
+
+func TestFortran(t *testing.T) {
+	// Find the FORTRAN compiler.
+	fc := os.Getenv("FC")
+	if fc == "" {
+		fc, _ = exec.LookPath("gfortran")
+	}
+	if fc == "" {
+		t.Skip("fortran compiler not found (try setting $FC)")
+	}
+
+	var fcExtra []string
+	if strings.Contains(fc, "gfortran") {
+		// TODO: This duplicates but also diverges from logic from cmd/go
+		// itself. For example, cmd/go merely adds -lgfortran without the extra
+		// library path work. If this is what's necessary to run gfortran, we
+		// should reconcile the logic here and in cmd/go.. Maybe this should
+		// become a cmd/go script test to share that logic.
+
+		// Add -m32 if we're targeting 386, in case this is a cross-compile.
+		if runtime.GOARCH == "386" {
+			fcExtra = append(fcExtra, "-m32")
+		}
+
+		// Find libgfortran. If the FORTRAN compiler isn't bundled
+		// with the C linker, this may be in a path the C linker can't
+		// find on its own. (See #14544)
+		libExt := "so"
+		switch runtime.GOOS {
+		case "darwin":
+			libExt = "dylib"
+		case "aix":
+			libExt = "a"
+		}
+		libPath, err := exec.Command(fc, append([]string{"-print-file-name=libgfortran." + libExt}, fcExtra...)...).CombinedOutput()
+		if err != nil {
+			t.Errorf("error invoking %s: %s", fc, err)
+		}
+		libDir := filepath.Dir(string(libPath))
+		cgoLDFlags := os.Getenv("CGO_LDFLAGS")
+		cgoLDFlags += " -L " + libDir
+		if runtime.GOOS != "aix" {
+			cgoLDFlags += " -Wl,-rpath," + libDir
+		}
+		t.Logf("CGO_LDFLAGS=%s", cgoLDFlags)
+		os.Setenv("CGO_LDFLAGS", cgoLDFlags)
+
+	}
+
+	// Do a test build that doesn't involve Go FORTRAN support.
+	fcArgs := append([]string{"helloworld/helloworld.f90", "-o", "/dev/null"}, fcExtra...)
+	t.Logf("%s %s", fc, fcArgs)
+	if err := exec.Command(fc, fcArgs...).Run(); err != nil {
+		t.Skipf("skipping Fortran test: could not build helloworld.f90 with %s: %s", fc, err)
+	}
+
+	// Finally, run the actual test.
+	t.Log("go", "run", "./testdata/testprog")
+	out, err := exec.Command("go", "run", "./testdata/testprog").CombinedOutput()
+	if err == nil && string(out) != "ok\n" {
+		err = fmt.Errorf("expected ok")
+	}
+	if err != nil {
+		t.Errorf("%s\nOutput:\n%s", err, string(out))
+	}
+}