Merge "Support empty strings in bp2build" am: a9351ef6e6

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/1907331

Change-Id: I3b32f0e039a705bcc25233470a09498fefd03bdb

apex/apex.go

@@ -3201,7 +3201,7 @@ type bazelApexBundleAttributes struct {
 	File_contexts      bazel.LabelAttribute
 	Key                bazel.LabelAttribute
 	Certificate        bazel.LabelAttribute
-	Min_sdk_version    string
+	Min_sdk_version    *string
 	Updatable          bazel.BoolAttribute
 	Installable        bazel.BoolAttribute
 	Native_shared_libs bazel.LabelListAttribute
@@ -3241,9 +3241,9 @@ func apexBundleBp2BuildInternal(ctx android.TopDownMutatorContext, module *apexB
 		fileContextsLabelAttribute.SetValue(android.BazelLabelForModuleDepSingle(ctx, *module.properties.File_contexts))
 	}
 
-	var minSdkVersion string
+	var minSdkVersion *string
 	if module.properties.Min_sdk_version != nil {
-		minSdkVersion = *module.properties.Min_sdk_version
+		minSdkVersion = module.properties.Min_sdk_version
 	}
 
 	var keyLabelAttribute bazel.LabelAttribute

bp2build/build_conversion.go

@@ -698,9 +698,9 @@ func isZero(value reflect.Value) bool {
 		} else {
 			return true
 		}
-	// Always print bools, if you want a bool attribute to be able to take the default value, use a
-	// bool pointer instead
-	case reflect.Bool:
+	// Always print bool/strings, if you want a bool/string attribute to be able to take the default value, use a
+	// pointer instead
+	case reflect.Bool, reflect.String:
 		return false
 	default:
 		if !value.IsValid() {

bp2build/build_conversion_test.go

@@ -41,6 +41,7 @@ func TestGenerateSoongModuleTargets(t *testing.T) {
     soong_module_deps = [
     ],
     bool_prop = False,
+    string_prop = "",
 )`,
 		},
 		{
@@ -58,6 +59,7 @@ func TestGenerateSoongModuleTargets(t *testing.T) {
     soong_module_deps = [
     ],
     bool_prop = True,
+    string_prop = "",
 )`,
 		},
 		{
@@ -76,6 +78,7 @@ func TestGenerateSoongModuleTargets(t *testing.T) {
     ],
     bool_prop = False,
     owner = "a_string_with\"quotes\"_and_\\backslashes\\\\",
+    string_prop = "",
 )`,
 		},
 		{
@@ -94,6 +97,7 @@ func TestGenerateSoongModuleTargets(t *testing.T) {
     ],
     bool_prop = False,
     required = ["bar"],
+    string_prop = "",
 )`,
 		},
 		{
@@ -111,6 +115,7 @@ func TestGenerateSoongModuleTargets(t *testing.T) {
     soong_module_deps = [
     ],
     bool_prop = False,
+    string_prop = "",
     target_required = [
         "qux",
         "bazqux",
@@ -147,6 +152,7 @@ func TestGenerateSoongModuleTargets(t *testing.T) {
         "tag": ".bar",
         "targets": ["goal_bar"],
     }],
+    string_prop = "",
 )`,
 		},
 		{
@@ -179,6 +185,7 @@ func TestGenerateSoongModuleTargets(t *testing.T) {
     }],
     owner = "custom_owner",
     required = ["bar"],
+    string_prop = "",
     target_required = [
         "qux",
         "bazqux",
@@ -222,12 +229,25 @@ func TestGenerateSoongModuleTargets(t *testing.T) {
 
 func TestGenerateBazelTargetModules(t *testing.T) {
 	testCases := []bp2buildTestCase{
+		{
+			description: "string ptr props",
+			blueprint: `custom {
+	name: "foo",
+    string_ptr_prop: "",
+    bazel_module: { bp2build_available: true },
+}`,
+			expectedBazelTargets: []string{
+				makeBazelTarget("custom", "foo", attrNameToString{
+					"string_ptr_prop": `""`,
+				}),
+			},
+		},
 		{
 			description: "string props",
 			blueprint: `custom {
 	name: "foo",
     string_list_prop: ["a", "b"],
-    string_prop: "a",
+    string_ptr_prop: "a",
     bazel_module: { bp2build_available: true },
 }`,
 			expectedBazelTargets: []string{
@@ -236,7 +256,7 @@ func TestGenerateBazelTargetModules(t *testing.T) {
         "a",
         "b",
     ]`,
-					"string_prop": `"a"`,
+					"string_ptr_prop": `"a"`,
 				}),
 			},
 		},
@@ -245,7 +265,7 @@ func TestGenerateBazelTargetModules(t *testing.T) {
 			blueprint: `custom {
     name: "foo",
     string_list_prop: ["\t", "\n"],
-    string_prop: "a\t\n\r",
+    string_ptr_prop: "a\t\n\r",
     bazel_module: { bp2build_available: true },
 }`,
 			expectedBazelTargets: []string{
@@ -254,7 +274,7 @@ func TestGenerateBazelTargetModules(t *testing.T) {
         "\t",
         "\n",
     ]`,
-					"string_prop": `"a\t\n\r"`,
+					"string_ptr_prop": `"a\t\n\r"`,
 				}),
 			},
 		},

bp2build/testing.go

@@ -149,15 +149,15 @@ func runBp2BuildTestCase(t *testing.T, registerModuleTypes func(ctx android.Regi
 }
 
 type nestedProps struct {
-	Nested_prop string
+	Nested_prop *string
 }
 
 type EmbeddedProps struct {
-	Embedded_prop string
+	Embedded_prop *string
 }
 
 type OtherEmbeddedProps struct {
-	Other_embedded_prop string
+	Other_embedded_prop *string
 }
 
 type customProps struct {
@@ -262,17 +262,17 @@ func customDefaultsModuleFactory() android.Module {
 }
 
 type EmbeddedAttr struct {
-	Embedded_attr string
+	Embedded_attr *string
 }
 
 type OtherEmbeddedAttr struct {
-	Other_embedded_attr string
+	Other_embedded_attr *string
 }
 
 type customBazelModuleAttributes struct {
 	EmbeddedAttr
 	*OtherEmbeddedAttr
-	String_prop      string
+	String_ptr_prop  *string
 	String_list_prop []string
 	Arch_paths       bazel.LabelListAttribute
 }
@@ -296,7 +296,7 @@ func customBp2BuildMutator(ctx android.TopDownMutatorContext) {
 		paths.ResolveExcludes()
 
 		attrs := &customBazelModuleAttributes{
-			String_prop:      m.props.String_prop,
+			String_ptr_prop:  m.props.String_ptr_prop,
 			String_list_prop: m.props.String_list_prop,
 			Arch_paths:       paths,
 		}

cc/bp2build.go

@@ -388,7 +388,15 @@ func bp2buildResolveCppStdValue(c_std *string, cpp_std *string, gnu_extensions *
 	}
 
 	cStdVal, cppStdVal = maybeReplaceGnuToC(gnu_extensions, cStdVal, cppStdVal)
-	return &cStdVal, &cppStdVal
+	var c_std_prop, cpp_std_prop *string
+	if cStdVal != "" {
+		c_std_prop = &cStdVal
+	}
+	if cppStdVal != "" {
+		cpp_std_prop = &cppStdVal
+	}
+
+	return c_std_prop, cpp_std_prop
 }
 
 // bp2BuildParseCompilerProps returns copts, srcs and hdrs and other attributes.

python/binary.go

@@ -35,10 +35,10 @@ func registerPythonBinaryComponents(ctx android.RegistrationContext) {
 }
 
 type bazelPythonBinaryAttributes struct {
-	Main           string
+	Main           *string
 	Srcs           bazel.LabelListAttribute
 	Deps           bazel.LabelListAttribute
-	Python_version string
+	Python_version *string
 }
 
 func PythonBinaryBp2Build(ctx android.TopDownMutatorContext) {
@@ -52,12 +52,12 @@ func PythonBinaryBp2Build(ctx android.TopDownMutatorContext) {
 		return
 	}
 
-	var main string
+	var main *string
 	for _, propIntf := range m.GetProperties() {
 		if props, ok := propIntf.(*BinaryProperties); ok {
 			// main is optional.
 			if props.Main != nil {
-				main = *props.Main
+				main = props.Main
 				break
 			}
 		}
@@ -69,13 +69,13 @@ func PythonBinaryBp2Build(ctx android.TopDownMutatorContext) {
 	// under Bionic.
 	py3Enabled := proptools.BoolDefault(m.properties.Version.Py3.Enabled, false)
 	py2Enabled := proptools.BoolDefault(m.properties.Version.Py2.Enabled, false)
-	var python_version string
+	var python_version *string
 	if py3Enabled && py2Enabled {
 		panic(fmt.Errorf(
 			"error for '%s' module: bp2build's python_binary_host converter does not support "+
 				"converting a module that is enabled for both Python 2 and 3 at the same time.", m.Name()))
 	} else if py2Enabled {
-		python_version = "PY2"
+		python_version = &pyVersion2
 	} else {
 		// do nothing, since python_version defaults to PY3.
 	}

python/library.go

@@ -21,6 +21,7 @@ import (
 
 	"android/soong/android"
 	"android/soong/bazel"
+
 	"github.com/google/blueprint/proptools"
 )
 
@@ -46,7 +47,7 @@ func PythonLibraryHostFactory() android.Module {
 type bazelPythonLibraryAttributes struct {
 	Srcs         bazel.LabelListAttribute
 	Deps         bazel.LabelListAttribute
-	Srcs_version string
+	Srcs_version *string
 }
 
 func PythonLibraryHostBp2Build(ctx android.TopDownMutatorContext) {
@@ -74,11 +75,11 @@ func pythonLibBp2Build(ctx android.TopDownMutatorContext, modType string) {
 	// Bionic.
 	py3Enabled := proptools.BoolDefault(m.properties.Version.Py3.Enabled, true)
 	py2Enabled := proptools.BoolDefault(m.properties.Version.Py2.Enabled, false)
-	var python_version string
+	var python_version *string
 	if py2Enabled && !py3Enabled {
-		python_version = "PY2"
+		python_version = &pyVersion2
 	} else if !py2Enabled && py3Enabled {
-		python_version = "PY3"
+		python_version = &pyVersion3
 	} else if !py2Enabled && !py3Enabled {
 		panic(fmt.Errorf(
 			"error for '%s' module: bp2build's %s converter doesn't understand having "+