Cabal support

inventory/cabal.go

@@ -0,0 +1,75 @@
+package inventory
+
+import "os/exec"
+import "bytes"
+import "strings"
+
+func readCabalDeps(packagePath string) ([]Project, error) {
+	var returned []Project
+	// Read the names of all Cabal dependencies.
+	deps, err := cabalListDeps(packagePath)
+	if err != nil {
+		return nil, err
+	}
+	// Iterate the package names.
+	for _, dep := range deps {
+		// Get package information.
+		info, err := cabalListPackageInfo(dep)
+		if err != nil {
+			continue
+		}
+		// Try to read licensezero.json in the package's path.
+		projects, err := ReadLicenseZeroJSON(info.Dir)
+		if err != nil {
+			continue
+		}
+		for _, project := range projects {
+			projectID := project.Envelope.Manifest.ProjectID
+			if alreadyHaveProject(returned, projectID) {
+				continue
+			}
+			project.Type = "cabal"
+			project.Name = info.Name
+		}
+	}
+	return returned, nil
+}
+
+func cabalListDeps(packagePath string) ([]string, error) {
+	list := exec.Command("ghc-pkg", "field", "-f", "{{ join .Deps \"\\n\" }}")
+	list.Dir = packagePath
+	var stdout bytes.Buffer
+	list.Stdout = &stdout
+	err := list.Run()
+	if err != nil {
+		return nil, err
+	}
+	deps := strings.Split(string(stdout.Bytes()), "\n")
+	// Remove empty string after final newline.
+	if len(deps) != 0 {
+		deps = deps[0 : len(deps)-1]
+	}
+	return deps, nil
+}
+
+type cabalPackageInfo struct {
+	Name       string
+	Dir        string
+	ImportPath string
+}
+
+func cabalListPackageInfo(name string) (*cabalPackageInfo, error) {
+	list := exec.Command("ghc-pkg", "field", name)
+	var stdout bytes.Buffer
+	list.Stdout = &stdout
+	err := list.Run()
+	if err != nil {
+		return nil, err
+	}
+	lines := strings.Split(string(stdout.Bytes()), "\n")
+	return &cabalPackageInfo{
+		Name:       lines[0],
+		Dir:        lines[1],
+		ImportPath: lines[2],
+	}, nil
+}

inventory/inventory.go

@@ -140,6 +140,7 @@ func readProjects(cwd string) ([]Project, error) {
 		readNPMProjects,
 		readRubyGemsProjects,
 		readGoDeps,
+		readCabalDeps,
 		recurseLicenseZeroFiles,
 	}
 	returned := []Project{}