From bcc0751a4027f77e5c4db1f1ce4a558727a1c981 Mon Sep 17 00:00:00 2001
From: Weston Steimel <weston.steimel@anchore.com>
Date: Wed, 1 Mar 2023 14:26:44 +0000
Subject: [PATCH] feat: retain go package info when no module declared (#1632)

Signed-off-by: Weston Steimel <weston.steimel@anchore.com>
---
 syft/pkg/cataloger/golang/parse_go_binary.go  | 14 +++++--
 .../cataloger/golang/parse_go_binary_test.go  | 42 +++++++++++++++++++
 2 files changed, 53 insertions(+), 3 deletions(-)

diff --git a/syft/pkg/cataloger/golang/parse_go_binary.go b/syft/pkg/cataloger/golang/parse_go_binary.go
index 80008bd3a10..bc2f033ae27 100644
--- a/syft/pkg/cataloger/golang/parse_go_binary.go
+++ b/syft/pkg/cataloger/golang/parse_go_binary.go
@@ -179,12 +179,23 @@ func getBuildSettings(settings []debug.BuildSetting) map[string]string {
 	return m
 }
 
+func createMainModuleFromPath(path string) (mod debug.Module) {
+	mod.Path = path
+	mod.Version = devel
+	return
+}
+
 func buildGoPkgInfo(location source.Location, mod *debug.BuildInfo, arch string) []pkg.Package {
 	var pkgs []pkg.Package
 	if mod == nil {
 		return pkgs
 	}
 
+	var empty debug.Module
+	if mod.Main == empty && mod.Path != "" {
+		mod.Main = createMainModuleFromPath(mod.Path)
+	}
+
 	for _, dep := range mod.Deps {
 		if dep == nil {
 			continue
@@ -195,9 +206,6 @@ func buildGoPkgInfo(location source.Location, mod *debug.BuildInfo, arch string)
 		}
 	}
 
-	// NOTE(jonasagx): this use happened originally while creating unit tests. It might never
-	// happen in the wild, but I kept it as a safeguard against empty modules.
-	var empty debug.Module
 	if mod.Main == empty {
 		return pkgs
 	}
diff --git a/syft/pkg/cataloger/golang/parse_go_binary_test.go b/syft/pkg/cataloger/golang/parse_go_binary_test.go
index acfd435c59a..4cf7fb0fc5d 100644
--- a/syft/pkg/cataloger/golang/parse_go_binary_test.go
+++ b/syft/pkg/cataloger/golang/parse_go_binary_test.go
@@ -242,6 +242,48 @@ func TestBuildGoPkgInfo(t *testing.T) {
 				},
 			},
 		},
+		{
+			name: "parse a mod with path but no main module",
+			arch: archDetails,
+			mod: &debug.BuildInfo{
+				GoVersion: goCompiledVersion,
+				Settings: []debug.BuildSetting{
+					{Key: "GOARCH", Value: archDetails},
+					{Key: "GOOS", Value: "darwin"},
+					{Key: "GOAMD64", Value: "v1"},
+				},
+				Path: "github.com/a/b/c",
+			},
+			expected: []pkg.Package{
+				{
+					Name:     "github.com/a/b/c",
+					Version:  "(devel)",
+					PURL:     "pkg:golang/github.com/a/b/c@(devel)",
+					Language: pkg.Go,
+					Type:     pkg.GoModulePkg,
+					Locations: source.NewLocationSet(
+						source.Location{
+							Coordinates: source.Coordinates{
+								RealPath:     "/a-path",
+								FileSystemID: "layer-id",
+							},
+						},
+					),
+					MetadataType: pkg.GolangBinMetadataType,
+					Metadata: pkg.GolangBinMetadata{
+						GoCompiledVersion: goCompiledVersion,
+						Architecture:      archDetails,
+						H1Digest:          "",
+						BuildSettings: map[string]string{
+							"GOAMD64": "v1",
+							"GOARCH":  "amd64",
+							"GOOS":    "darwin",
+						},
+						MainModule: "github.com/a/b/c",
+					},
+				},
+			},
+		},
 		{
 			name: "parse a mod without packages",
 			arch: archDetails,