Expand handling of unconverted deps in bp2build

Support three options for converting modules with unconverted
dependencies
1. (default) Warn when converting a module if it has unconverted deps.
2. Error when encountering a module with unconverted deps. (not hooked
up yet)

Test: build/bazel/ci/bp2build.sh
Test: build/bazel/ci/mixed_libc.sh
Test: BP2BUILD_ERROR_UNCONVERTED=1 build/bazel/ci/bp2build.sh with
      unconverted deps -- get appropriate error
Bug: 181155349
Change-Id: Ifaabf0cd2e43e963366dc137159c705294165c3d
diff --git a/bp2build/bp2build.go b/bp2build/bp2build.go
index 06a7306..48b2945 100644
--- a/bp2build/bp2build.go
+++ b/bp2build/bp2build.go
@@ -19,6 +19,7 @@
 	"android/soong/bazel"
 	"fmt"
 	"os"
+	"strings"
 )
 
 // Codegen is the backend of bp2build. The code generator is responsible for
@@ -29,14 +30,22 @@
 	bp2buildDir := android.PathForOutput(ctx, "bp2build")
 	android.RemoveAllOutputDir(bp2buildDir)
 
-	buildToTargets, metrics, compatLayer := GenerateBazelTargets(ctx, true)
-	bp2buildFiles := CreateBazelFiles(nil, buildToTargets, ctx.mode)
+	res, errs := GenerateBazelTargets(ctx, true)
+	if len(errs) > 0 {
+		errMsgs := make([]string, len(errs))
+		for i, err := range errs {
+			errMsgs[i] = fmt.Sprintf("%q", err)
+		}
+		fmt.Printf("ERROR: Encountered %d error(s): \nERROR: %s", len(errs), strings.Join(errMsgs, "\n"))
+		os.Exit(1)
+	}
+	bp2buildFiles := CreateBazelFiles(nil, res.buildFileToTargets, ctx.mode)
 	writeFiles(ctx, bp2buildDir, bp2buildFiles)
 
 	soongInjectionDir := android.PathForOutput(ctx, bazel.SoongInjectionDirName)
-	writeFiles(ctx, soongInjectionDir, CreateSoongInjectionFiles(compatLayer))
+	writeFiles(ctx, soongInjectionDir, CreateSoongInjectionFiles(res.compatLayer))
 
-	return metrics
+	return res.metrics
 }
 
 // Get the output directory and create it if it doesn't exist.
diff --git a/bp2build/build_conversion.go b/bp2build/build_conversion.go
index f652a35..6cce819 100644
--- a/bp2build/build_conversion.go
+++ b/bp2build/build_conversion.go
@@ -153,10 +153,11 @@
 }
 
 type CodegenContext struct {
-	config         android.Config
-	context        android.Context
-	mode           CodegenMode
-	additionalDeps []string
+	config                  android.Config
+	context                 android.Context
+	mode                    CodegenMode
+	additionalDeps          []string
+	unconvertedDepMode unconvertedDepsMode
 }
 
 func (c *CodegenContext) Mode() CodegenMode {
@@ -181,6 +182,16 @@
 	QueryView
 )
 
+type unconvertedDepsMode int
+
+const (
+	// Include a warning in conversion metrics about converted modules with unconverted direct deps
+	warnUnconvertedDeps unconvertedDepsMode = iota
+	// Error and fail conversion if encountering a module with unconverted direct deps
+	// Enabled by setting environment variable `BP2BUILD_ERROR_UNCONVERTED`
+	errorModulesUnconvertedDeps
+)
+
 func (mode CodegenMode) String() string {
 	switch mode {
 	case Bp2Build:
@@ -211,10 +222,15 @@
 // NewCodegenContext creates a wrapper context that conforms to PathContext for
 // writing BUILD files in the output directory.
 func NewCodegenContext(config android.Config, context android.Context, mode CodegenMode) *CodegenContext {
+	var unconvertedDeps unconvertedDepsMode
+	if config.IsEnvTrue("BP2BUILD_ERROR_UNCONVERTED") {
+		unconvertedDeps = errorModulesUnconvertedDeps
+	}
 	return &CodegenContext{
-		context: context,
-		config:  config,
-		mode:    mode,
+		context:            context,
+		config:             config,
+		mode:               mode,
+		unconvertedDepMode: unconvertedDeps,
 	}
 }
 
@@ -230,7 +246,17 @@
 	return attributes
 }
 
-func GenerateBazelTargets(ctx *CodegenContext, generateFilegroups bool) (map[string]BazelTargets, CodegenMetrics, CodegenCompatLayer) {
+type conversionResults struct {
+	buildFileToTargets map[string]BazelTargets
+	metrics            CodegenMetrics
+	compatLayer        CodegenCompatLayer
+}
+
+func (r conversionResults) BuildDirToTargets() map[string]BazelTargets {
+	return r.buildFileToTargets
+}
+
+func GenerateBazelTargets(ctx *CodegenContext, generateFilegroups bool) (conversionResults, []error) {
 	buildFileToTargets := make(map[string]BazelTargets)
 	buildFileToAppend := make(map[string]bool)
 
@@ -245,6 +271,8 @@
 
 	dirs := make(map[string]bool)
 
+	var errs []error
+
 	bpCtx := ctx.Context()
 	bpCtx.VisitAllModules(func(m blueprint.Module) {
 		dir := bpCtx.ModuleDir(m)
@@ -266,13 +294,24 @@
 				}
 				t, err := getHandcraftedBuildContent(ctx, b, pathToBuildFile)
 				if err != nil {
-					panic(fmt.Errorf("Error converting %s: %s", bpCtx.ModuleName(m), err))
+					errs = append(errs, fmt.Errorf("Error converting %s: %s", bpCtx.ModuleName(m), err))
+					return
 				}
 				targets = append(targets, t)
 				// TODO(b/181575318): currently we append the whole BUILD file, let's change that to do
 				// something more targeted based on the rule type and target
 				buildFileToAppend[pathToBuildFile] = true
 			} else if aModule, ok := m.(android.Module); ok && aModule.IsConvertedByBp2build() {
+				if unconvertedDeps := aModule.GetUnconvertedBp2buildDeps(); len(unconvertedDeps) > 0 {
+					msg := fmt.Sprintf("%q depends on unconverted modules: %s", m.Name(), strings.Join(unconvertedDeps, ", "))
+					if ctx.unconvertedDepMode == warnUnconvertedDeps {
+						metrics.moduleWithUnconvertedDepsMsgs = append(metrics.moduleWithUnconvertedDepsMsgs, msg)
+					} else if ctx.unconvertedDepMode == errorModulesUnconvertedDeps {
+						metrics.TotalModuleCount += 1
+						errs = append(errs, fmt.Errorf(msg))
+						return
+					}
+				}
 				targets = generateBazelTargets(bpCtx, aModule)
 				for _, t := range targets {
 					if t.name == m.Name() {
@@ -295,11 +334,17 @@
 			t := generateSoongModuleTarget(bpCtx, m)
 			targets = append(targets, t)
 		default:
-			panic(fmt.Errorf("Unknown code-generation mode: %s", ctx.Mode()))
+			errs = append(errs, fmt.Errorf("Unknown code-generation mode: %s", ctx.Mode()))
+			return
 		}
 
 		buildFileToTargets[dir] = append(buildFileToTargets[dir], targets...)
 	})
+
+	if len(errs) > 0 {
+		return conversionResults{}, errs
+	}
+
 	if generateFilegroups {
 		// Add a filegroup target that exposes all sources in the subtree of this package
 		// NOTE: This also means we generate a BUILD file for every Android.bp file (as long as it has at least one module)
@@ -312,7 +357,11 @@
 		}
 	}
 
-	return buildFileToTargets, metrics, compatLayer
+	return conversionResults{
+		buildFileToTargets: buildFileToTargets,
+		metrics:            metrics,
+		compatLayer:        compatLayer,
+	}, errs
 }
 
 func getBazelPackagePath(b android.Bazelable) string {
diff --git a/bp2build/build_conversion_test.go b/bp2build/build_conversion_test.go
index ecea6b2..09d536f 100644
--- a/bp2build/build_conversion_test.go
+++ b/bp2build/build_conversion_test.go
@@ -16,6 +16,7 @@
 
 import (
 	"android/soong/android"
+	"fmt"
 	"strings"
 	"testing"
 )
@@ -199,7 +200,8 @@
 			android.FailIfErrored(t, errs)
 
 			codegenCtx := NewCodegenContext(config, *ctx.Context, QueryView)
-			bazelTargets := generateBazelTargetsForDir(codegenCtx, dir)
+			bazelTargets, err := generateBazelTargetsForDir(codegenCtx, dir)
+			android.FailIfErrored(t, err)
 			if actualCount, expectedCount := len(bazelTargets), 1; actualCount != expectedCount {
 				t.Fatalf("Expected %d bazel target, got %d", expectedCount, actualCount)
 			}
@@ -341,7 +343,8 @@
 		}
 
 		codegenCtx := NewCodegenContext(config, *ctx.Context, Bp2Build)
-		bazelTargets := generateBazelTargetsForDir(codegenCtx, dir)
+		bazelTargets, err := generateBazelTargetsForDir(codegenCtx, dir)
+		android.FailIfErrored(t, err)
 
 		if actualCount, expectedCount := len(bazelTargets), len(testCase.expectedBazelTargets); actualCount != expectedCount {
 			t.Errorf("Expected %d bazel target, got %d", expectedCount, actualCount)
@@ -502,7 +505,8 @@
 		android.FailIfErrored(t, errs)
 
 		codegenCtx := NewCodegenContext(config, *ctx.Context, Bp2Build)
-		bazelTargets := generateBazelTargetsForDir(codegenCtx, dir)
+		bazelTargets, err := generateBazelTargetsForDir(codegenCtx, dir)
+		android.FailIfErrored(t, err)
 		if actualCount := len(bazelTargets); actualCount != testCase.expectedBazelTargetCount {
 			t.Fatalf("Expected %d bazel target, got %d", testCase.expectedBazelTargetCount, actualCount)
 		}
@@ -679,59 +683,38 @@
 				"other/Android.bp": `filegroup {
     name: "foo",
     srcs: ["a", "b"],
+    bazel_module: { bp2build_available: true },
+}`,
+			},
+		},
+		{
+			description:                        "depends_on_other_unconverted_module_error",
+			moduleTypeUnderTest:                "filegroup",
+			moduleTypeUnderTestFactory:         android.FileGroupFactory,
+			moduleTypeUnderTestBp2BuildMutator: android.FilegroupBp2Build,
+			unconvertedDepsMode:                errorModulesUnconvertedDeps,
+			blueprint: `filegroup {
+    name: "foobar",
+    srcs: [
+        ":foo",
+        "c",
+    ],
+    bazel_module: { bp2build_available: true },
+}`,
+			expectedErr: fmt.Errorf(`"foobar" depends on unconverted modules: foo`),
+			filesystem: map[string]string{
+				"other/Android.bp": `filegroup {
+    name: "foo",
+    srcs: ["a", "b"],
 }`,
 			},
 		},
 	}
 
-	dir := "."
 	for _, testCase := range testCases {
-		fs := make(map[string][]byte)
-		toParse := []string{
-			"Android.bp",
-		}
-		for f, content := range testCase.filesystem {
-			if strings.HasSuffix(f, "Android.bp") {
-				toParse = append(toParse, f)
-			}
-			fs[f] = []byte(content)
-		}
-		config := android.TestConfig(buildDir, nil, testCase.blueprint, fs)
-		ctx := android.NewTestContext(config)
-		ctx.RegisterModuleType(testCase.moduleTypeUnderTest, testCase.moduleTypeUnderTestFactory)
-		ctx.RegisterBp2BuildMutator(testCase.moduleTypeUnderTest, testCase.moduleTypeUnderTestBp2BuildMutator)
-		ctx.RegisterForBazelConversion()
-
-		_, errs := ctx.ParseFileList(dir, toParse)
-		if errored(t, testCase, errs) {
-			continue
-		}
-		_, errs = ctx.ResolveDependencies(config)
-		if errored(t, testCase, errs) {
-			continue
-		}
-
-		checkDir := dir
-		if testCase.dir != "" {
-			checkDir = testCase.dir
-		}
-
-		codegenCtx := NewCodegenContext(config, *ctx.Context, Bp2Build)
-		bazelTargets := generateBazelTargetsForDir(codegenCtx, checkDir)
-		if actualCount, expectedCount := len(bazelTargets), len(testCase.expectedBazelTargets); actualCount != expectedCount {
-			t.Errorf("%s: Expected %d bazel target, got %d", testCase.description, expectedCount, actualCount)
-		} else {
-			for i, target := range bazelTargets {
-				if w, g := testCase.expectedBazelTargets[i], target.content; w != g {
-					t.Errorf(
-						"%s: Expected generated Bazel target to be '%s', got '%s'",
-						testCase.description,
-						w,
-						g,
-					)
-				}
-			}
-		}
+		t.Run(testCase.description, func(t *testing.T) {
+			runBp2BuildTestCase(t, func(ctx android.RegistrationContext) {}, testCase)
+		})
 	}
 }
 
@@ -809,7 +792,8 @@
 			android.FailIfErrored(t, errs)
 
 			codegenCtx := NewCodegenContext(config, *ctx.Context, Bp2Build)
-			bazelTargets := generateBazelTargetsForDir(codegenCtx, dir)
+			bazelTargets, err := generateBazelTargetsForDir(codegenCtx, dir)
+			android.FailIfErrored(t, err)
 			if actualCount := len(bazelTargets); actualCount != testCase.expectedCount {
 				t.Fatalf("%s: Expected %d bazel target, got %d", testCase.description, testCase.expectedCount, actualCount)
 			}
@@ -921,7 +905,8 @@
 
 		// For each directory, test that the expected number of generated targets is correct.
 		for dir, expectedCount := range testCase.expectedCount {
-			bazelTargets := generateBazelTargetsForDir(codegenCtx, dir)
+			bazelTargets, err := generateBazelTargetsForDir(codegenCtx, dir)
+			android.FailIfErrored(t, err)
 			if actualCount := len(bazelTargets); actualCount != expectedCount {
 				t.Fatalf(
 					"%s: Expected %d bazel target for %s package, got %d",
@@ -1064,7 +1049,9 @@
 			if testCase.dir != "" {
 				checkDir = testCase.dir
 			}
-			bazelTargets := generateBazelTargetsForDir(NewCodegenContext(config, *ctx.Context, Bp2Build), checkDir)
+			codegenCtx := NewCodegenContext(config, *ctx.Context, Bp2Build)
+			bazelTargets, err := generateBazelTargetsForDir(codegenCtx, checkDir)
+			android.FailIfErrored(t, err)
 			bazelTargets.sort()
 			actualCount := len(bazelTargets)
 			expectedCount := len(testCase.expectedBazelTargets)
@@ -1185,7 +1172,9 @@
 		if testCase.dir != "" {
 			checkDir = testCase.dir
 		}
-		bazelTargets := generateBazelTargetsForDir(NewCodegenContext(config, *ctx.Context, Bp2Build), checkDir)
+		codegenCtx := NewCodegenContext(config, *ctx.Context, Bp2Build)
+		bazelTargets, err := generateBazelTargetsForDir(codegenCtx, checkDir)
+		android.FailIfErrored(t, err)
 		if actualCount, expectedCount := len(bazelTargets), len(testCase.expectedBazelTargets); actualCount != expectedCount {
 			t.Errorf("%s: Expected %d bazel target, got %d\n%s", testCase.description, expectedCount, actualCount, bazelTargets)
 		} else {
diff --git a/bp2build/genrule_conversion_test.go b/bp2build/genrule_conversion_test.go
index a991180..f3bc1ba 100644
--- a/bp2build/genrule_conversion_test.go
+++ b/bp2build/genrule_conversion_test.go
@@ -267,7 +267,8 @@
 		}
 
 		codegenCtx := NewCodegenContext(config, *ctx.Context, Bp2Build)
-		bazelTargets := generateBazelTargetsForDir(codegenCtx, checkDir)
+		bazelTargets, err := generateBazelTargetsForDir(codegenCtx, checkDir)
+		android.FailIfErrored(t, err)
 		if actualCount, expectedCount := len(bazelTargets), len(testCase.expectedBazelTargets); actualCount != expectedCount {
 			t.Errorf("%s: Expected %d bazel target, got %d", testCase.description, expectedCount, actualCount)
 		} else {
@@ -461,7 +462,8 @@
 		android.FailIfErrored(t, errs)
 
 		codegenCtx := NewCodegenContext(config, *ctx.Context, Bp2Build)
-		bazelTargets := generateBazelTargetsForDir(codegenCtx, dir)
+		bazelTargets, err := generateBazelTargetsForDir(codegenCtx, dir)
+		android.FailIfErrored(t, err)
 		if actualCount := len(bazelTargets); actualCount != 1 {
 			t.Fatalf("%s: Expected 1 bazel target, got %d", testCase.description, actualCount)
 		}
diff --git a/bp2build/metrics.go b/bp2build/metrics.go
index 65b06c6..645ef2d 100644
--- a/bp2build/metrics.go
+++ b/bp2build/metrics.go
@@ -3,6 +3,7 @@
 import (
 	"android/soong/android"
 	"fmt"
+	"strings"
 )
 
 // Simple metrics struct to collect information about a Blueprint to BUILD
@@ -16,6 +17,8 @@
 
 	// Total number of handcrafted targets
 	handCraftedTargetCount int
+
+	moduleWithUnconvertedDepsMsgs []string
 }
 
 // Print the codegen metrics to stdout.
@@ -27,8 +30,10 @@
 		generatedTargetCount += count
 	}
 	fmt.Printf(
-		"[bp2build] Generated %d total BUILD targets and included %d handcrafted BUILD targets from %d Android.bp modules.\n",
+		"[bp2build] Generated %d total BUILD targets and included %d handcrafted BUILD targets from %d Android.bp modules.\n With %d modules with unconverted deps \n\t%s",
 		generatedTargetCount,
 		metrics.handCraftedTargetCount,
-		metrics.TotalModuleCount)
+		metrics.TotalModuleCount,
+		len(metrics.moduleWithUnconvertedDepsMsgs),
+		strings.Join(metrics.moduleWithUnconvertedDepsMsgs, "\n\t"))
 }
diff --git a/bp2build/testing.go b/bp2build/testing.go
index 3ebe63d..04b8056 100644
--- a/bp2build/testing.go
+++ b/bp2build/testing.go
@@ -39,9 +39,8 @@
 func checkError(t *testing.T, errs []error, expectedErr error) bool {
 	t.Helper()
 
-	// expectedErr is not nil, find it in the list of errors
 	if len(errs) != 1 {
-		t.Errorf("Expected only 1 error, got %d: %q", len(errs), errs)
+		return false
 	}
 	if errs[0].Error() == expectedErr.Error() {
 		return true
@@ -83,6 +82,7 @@
 	filesystem                         map[string]string
 	dir                                string
 	expectedErr                        error
+	unconvertedDepsMode                unconvertedDepsMode
 }
 
 func runBp2BuildTestCase(t *testing.T, registerModuleTypes func(ctx android.RegistrationContext), tc bp2buildTestCase) {
@@ -126,7 +126,13 @@
 		checkDir = tc.dir
 	}
 	codegenCtx := NewCodegenContext(config, *ctx.Context, Bp2Build)
-	bazelTargets := generateBazelTargetsForDir(codegenCtx, checkDir)
+	codegenCtx.unconvertedDepMode = tc.unconvertedDepsMode
+	bazelTargets, errs := generateBazelTargetsForDir(codegenCtx, checkDir)
+	if tc.expectedErr != nil && checkError(t, errs, tc.expectedErr) {
+		return
+	} else {
+		android.FailIfErrored(t, errs)
+	}
 	if actualCount, expectedCount := len(bazelTargets), len(tc.expectedBazelTargets); actualCount != expectedCount {
 		t.Errorf("%s: Expected %d bazel target, got %d; %v",
 			tc.description, expectedCount, actualCount, bazelTargets)
@@ -316,10 +322,10 @@
 }
 
 // Helper method for tests to easily access the targets in a dir.
-func generateBazelTargetsForDir(codegenCtx *CodegenContext, dir string) BazelTargets {
+func generateBazelTargetsForDir(codegenCtx *CodegenContext, dir string) (BazelTargets, []error) {
 	// TODO: Set generateFilegroups to true and/or remove the generateFilegroups argument completely
-	buildFileToTargets, _, _ := GenerateBazelTargets(codegenCtx, false)
-	return buildFileToTargets[dir]
+	res, err := GenerateBazelTargets(codegenCtx, false)
+	return res.buildFileToTargets[dir], err
 }
 
 func registerCustomModuleForBp2buildConversion(ctx *android.TestContext) {