support ldflags rewrites for initialized globals

internal/build/build_test.go

@@ -8,6 +8,9 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
 	"testing"
 
 	"github.com/goplus/llgo/internal/mockable"
@@ -94,4 +97,65 @@ func TestCmpTest(t *testing.T) {
 	mockRun([]string{"../../cl/_testgo/runtest"}, &Config{Mode: ModeCmpTest})
 }
 
-// TestGenerateOutputFilenames removed - functionality moved to filename_test.go
+const (
+	rewriteMainPkg = "github.com/goplus/llgo/cl/_testgo/rewrite"
+	rewriteDepPkg  = rewriteMainPkg + "/dep"
+	rewriteDirPath = "../../cl/_testgo/rewrite"
+)
+
+func TestLdFlagsRewriteVars(t *testing.T) {
+	buildRewriteBinary(t, false, "build-main", "build-pkg")
+	buildRewriteBinary(t, false, "rerun-main", "rerun-pkg")
+}
+
+func TestLdFlagsRewriteVarsMainAlias(t *testing.T) {
+	buildRewriteBinary(t, true, "alias-main", "alias-pkg")
+}
+
+func buildRewriteBinary(t *testing.T, useMainAlias bool, mainVal, depVal string) {
+	t.Helper()
+	binPath := filepath.Join(t.TempDir(), "rewrite")
+	if runtime.GOOS == "windows" {
+		binPath += ".exe"
+	}
+
+	cfg := &Config{Mode: ModeBuild, OutFile: binPath}
+	mainKey := rewriteMainPkg
+	var mainPkgs []string
+	if useMainAlias {
+		mainKey = "main"
+		mainPkgs = []string{rewriteMainPkg}
+	}
+	mainPlain := mainVal + "-plain"
+	depPlain := depVal + "-plain"
+	gorootVal := "goroot-" + mainVal
+	versionVal := "version-" + mainVal
+	addGlobalString(cfg, mainKey+".VarName="+mainVal, mainPkgs)
+	addGlobalString(cfg, mainKey+".VarPlain="+mainPlain, mainPkgs)
+	addGlobalString(cfg, rewriteDepPkg+".VarName="+depVal, nil)
+	addGlobalString(cfg, rewriteDepPkg+".VarPlain="+depPlain, nil)
+	addGlobalString(cfg, "runtime.defaultGOROOT="+gorootVal, nil)
+	addGlobalString(cfg, "runtime.buildVersion="+versionVal, nil)
+
+	if _, err := Do([]string{rewriteDirPath}, cfg); err != nil {
+		t.Fatalf("ModeBuild failed: %v", err)
+	}
+	got := runBinary(t, binPath)
+	want := fmt.Sprintf(
+		"main.VarName: %s\nmain.VarPlain: %s\ndep.VarName: %s\ndep.VarPlain: %s\nruntime.GOROOT(): %s\nruntime.Version(): %s\n",
+		mainVal, mainPlain, depVal, depPlain, gorootVal, versionVal,
+	)
+	if got != want {
+		t.Fatalf("unexpected binary output:\nwant %q\ngot  %q", want, got)
+	}
+}
+
+func runBinary(t *testing.T, path string, args ...string) string {
+	t.Helper()
+	cmd := exec.Command(path, args...)
+	output, err := cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("failed to run %s: %v\n%s", path, err, output)
+	}
+	return string(output)
+}