Add new goroot extraction fallback

This commit adds a fallback to extract the GOROOT from the standard
library package path.

Author: joakim-intezer

goroot.go

@@ -19,7 +19,9 @@ package gore
 
 import (
 	"bytes"
+	"fmt"
 	"reflect"
+	"strings"
 	"unicode/utf8"
 
 	"golang.org/x/arch/x86/x86asm"
@@ -327,11 +329,36 @@ func findGoRootPath(f *GoFile) (string, error) {
 	// There is no GOROOT function may be inlined (after go1.16)
 	// at this time GOROOT is obtained through time_init function
 	goroot, err := tryFromGOROOT(f)
+	if goroot != "" {
+		return goroot, nil
+	}
+	if err != nil && err != ErrNoGoRootFound {
+		return "", err
+	}
+
+	goroot, err = tryFromTimeInit(f)
+	if goroot != "" {
+		return goroot, nil
+	}
+	if err != nil && err != ErrNoGoRootFound {
+		return "", err
+	}
+
+	// Try determine from std lib package paths.
+	pkg, err := f.GetSTDLib()
 	if err != nil {
-		if err == ErrNoGoRootFound {
-			return tryFromTimeInit(f)
+		return "", fmt.Errorf("error when getting standard library packages: %w", err)
+	}
+	if len(pkg) == 0 {
+		return "", fmt.Errorf("no standard library packages found")
+	}
+
+	for _, v := range pkg {
+		subpath := fmt.Sprintf("/src/%s", v.Name)
+		if strings.HasSuffix(v.Filepath, subpath) {
+			return strings.TrimSuffix(v.Filepath, subpath), nil
 		}
-		return "", err
 	}
-	return goroot, nil
+
+	return "", ErrNoGoRootFound
 }

goroot_test.go

@@ -48,36 +48,8 @@ func TestExtractGoRoot(t *testing.T) {
 			r.NoError(err)
 			defer f.Close()
 			goroot, err := findGoRootPath(f)
-			// Windows version 1.5 to 1.9 did not find a goroot string that can be searched, so we ruled it out
-			switch test {
-			case "gold-windows-386-1.5.0":
-				r.Equal(ErrNoGoRootFound, err)
-			case "gold-windows-386-1.6.0":
-				r.Equal(ErrNoGoRootFound, err)
-			case "gold-windows-386-1.7.0":
-				r.Equal(ErrNoGoRootFound, err)
-			case "gold-windows-386-1.7beta1":
-				r.Equal(ErrNoGoRootFound, err)
-			case "gold-windows-386-1.8.0":
-				r.Equal(ErrNoGoRootFound, err)
-			case "gold-windows-386-1.9.0":
-				r.Equal(ErrNoGoRootFound, err)
-			case "gold-windows-amd64-1.5.0":
-				r.Equal(ErrNoGoRootFound, err)
-			case "gold-windows-amd64-1.6.0":
-				r.Equal(ErrNoGoRootFound, err)
-			case "gold-windows-amd64-1.7.0":
-				r.Equal(ErrNoGoRootFound, err)
-			case "gold-windows-amd64-1.7beta1":
-				r.Equal(ErrNoGoRootFound, err)
-			case "gold-windows-amd64-1.8.0":
-				r.Equal(ErrNoGoRootFound, err)
-			case "gold-windows-amd64-1.9.0":
-				r.Equal(ErrNoGoRootFound, err)
-			default:
-				r.NoError(err)
-				r.Equal(expectGoRoot, goroot)
-			}
+			r.NoError(err)
+			r.Equal(expectGoRoot, goroot)
 		})
 	}
 }