cmd/go: handle spaces in pkg-config ldflags output

Change-Id: I2949befa42bf572836ecf112fe8af098178e3ee5

Author: zlasd

src/cmd/go/go_test.go

@@ -1616,6 +1616,22 @@ func main() {
 `)
 	tg.setenv("PKG_CONFIG_PATH", tg.path("."))
 	tg.run("run", tg.path("foo.go"))
+
+	// test for ldflags
+	tg.tempFile("bar.pc", `
+Name: bar
+Description: The bar library
+Version: 1.0.0
+Libs: -Wl,-rpath=/path\ with\ spaces/bin
+`)
+	tg.tempFile("bar.go", `package main
+/*
+#cgo pkg-config: bar
+*/
+import "C"
+func main() {}
+`)
+	tg.run("run", tg.path("bar.go"))
 }
 
 func TestListTemplateContextFunction(t *testing.T) {

src/cmd/go/internal/work/exec.go

@@ -1549,9 +1549,12 @@ func (b *Builder) getPkgConfigFlags(p *load.Package) (cflags, ldflags []string,
 			return nil, nil, err
 		}
 		if len(out) > 0 {
-			// NOTE: we don't attempt to parse quotes and unescapes here. pkg-config
-			// is typically used within shell backticks, which treats quotes literally.
-			ldflags = strings.Fields(string(out))
+			// We need to handle path with spaces so that C:/Program\ Files can pass
+			// checkLinkerFlags. Use splitPkgConfigOutput here just like we treat cflags.
+			ldflags, err = splitPkgConfigOutput(out)
+			if err != nil {
+				return nil, nil, err
+			}
 			if err := checkLinkerFlags("LDFLAGS", "pkg-config --libs", ldflags); err != nil {
 				return nil, nil, err
 			}