Add depfile handling for bazel_handler.

Test: go test soong tests
Test: TODO mixed build change header, mixed build
Change-Id: I7c51faf2d5b1a8717cbab6bb0b3eb75c307fcd85

android/bazel_handler.go

@@ -746,6 +746,10 @@ func (c *bazelSingleton) GenerateBuildActions(ctx SingletonContext) {
 			cmd.Implicit(PathForBazelOut(ctx, inputPath))
 		}
 
+		if depfile := buildStatement.Depfile; depfile != nil {
+			cmd.ImplicitDepFile(PathForBazelOut(ctx, *depfile))
+		}
+
 		// This is required to silence warnings pertaining to unexpected timestamps. Particularly,
 		// some Bazel builtins (such as files in the bazel_tools directory) have far-future
 		// timestamps. Without restat, Ninja would emit warnings that the input files of a

bazel/aquery.go

@@ -74,6 +74,7 @@ type actionGraphContainer struct {
 // with a Bazel action from Bazel's action graph.
 type BuildStatement struct {
 	Command     string
+	Depfile     *string
 	OutputPaths []string
 	InputPaths  []string
 	Env         []KeyValuePair
@@ -133,12 +134,22 @@ func AqueryBuildStatements(aqueryJsonProto []byte) ([]BuildStatement, error) {
 			continue
 		}
 		outputPaths := []string{}
+		var depfile *string
 		for _, outputId := range actionEntry.OutputIds {
 			outputPath, exists := artifactIdToPath[outputId]
 			if !exists {
 				return nil, fmt.Errorf("undefined outputId %d", outputId)
 			}
-			outputPaths = append(outputPaths, outputPath)
+			ext := filepath.Ext(outputPath)
+			if ext == ".d" {
+				if depfile != nil {
+					return nil, fmt.Errorf("found multiple potential depfiles %q, %q", *depfile, outputPath)
+				} else {
+					depfile = &outputPath
+				}
+			} else {
+				outputPaths = append(outputPaths, outputPath)
+			}
 		}
 		inputPaths := []string{}
 		for _, inputDepSetId := range actionEntry.InputDepSetIds {
@@ -161,12 +172,13 @@ func AqueryBuildStatements(aqueryJsonProto []byte) ([]BuildStatement, error) {
 		}
 		buildStatement := BuildStatement{
 			Command:     strings.Join(proptools.ShellEscapeList(actionEntry.Arguments), " "),
+			Depfile:     depfile,
 			OutputPaths: outputPaths,
 			InputPaths:  inputPaths,
 			Env:         actionEntry.EnvironmentVariables,
 			Mnemonic:    actionEntry.Mnemonic}
 		if len(actionEntry.Arguments) < 1 {
-			return nil, fmt.Errorf("received action with no command: [%s]", buildStatement)
+			return nil, fmt.Errorf("received action with no command: [%v]", buildStatement)
 			continue
 		}
 		buildStatements = append(buildStatements, buildStatement)

bazel/aquery_test.go

@@ -393,6 +393,109 @@ func TestInvalidPathFragmentId(t *testing.T) {
 	assertError(t, err, "undefined path fragment id 3")
 }
 
+func TestDepfiles(t *testing.T) {
+	const inputString = `
+{
+  "artifacts": [{
+    "id": 1,
+    "pathFragmentId": 1
+  }, {
+    "id": 2,
+    "pathFragmentId": 2
+  }, {
+    "id": 3,
+    "pathFragmentId": 3
+  }],
+  "actions": [{
+    "targetId": 1,
+    "actionKey": "x",
+    "mnemonic": "x",
+    "arguments": ["touch", "foo"],
+    "inputDepSetIds": [1],
+    "outputIds": [2, 3],
+    "primaryOutputId": 2
+  }],
+  "depSetOfFiles": [{
+    "id": 1,
+    "directArtifactIds": [1, 2, 3]
+  }],
+  "pathFragments": [{
+    "id": 1,
+    "label": "one"
+  }, {
+    "id": 2,
+    "label": "two"
+  }, {
+    "id": 3,
+    "label": "two.d"
+  }]
+}`
+
+	actual, err := AqueryBuildStatements([]byte(inputString))
+	if err != nil {
+		t.Errorf("Unexpected error %q", err)
+	}
+	if expected := 1; len(actual) != expected {
+		t.Fatalf("Expected %d build statements, got %d", expected, len(actual))
+	}
+
+	bs := actual[0]
+	expectedDepfile := "two.d"
+	if bs.Depfile == nil {
+		t.Errorf("Expected depfile %q, but there was none found", expectedDepfile)
+	} else if *bs.Depfile != expectedDepfile {
+		t.Errorf("Expected depfile %q, but got %q", expectedDepfile, *bs.Depfile)
+	}
+}
+
+func TestMultipleDepfiles(t *testing.T) {
+	const inputString = `
+{
+  "artifacts": [{
+    "id": 1,
+    "pathFragmentId": 1
+  }, {
+    "id": 2,
+    "pathFragmentId": 2
+  }, {
+    "id": 3,
+    "pathFragmentId": 3
+  }, {
+    "id": 4,
+    "pathFragmentId": 4
+  }],
+  "actions": [{
+    "targetId": 1,
+    "actionKey": "x",
+    "mnemonic": "x",
+    "arguments": ["touch", "foo"],
+    "inputDepSetIds": [1],
+    "outputIds": [2,3,4],
+    "primaryOutputId": 2
+  }],
+  "depSetOfFiles": [{
+    "id": 1,
+    "directArtifactIds": [1, 2, 3, 4]
+  }],
+  "pathFragments": [{
+    "id": 1,
+    "label": "one"
+  }, {
+    "id": 2,
+    "label": "two"
+  }, {
+    "id": 3,
+    "label": "two.d"
+  }, {
+    "id": 4,
+    "label": "other.d"
+  }]
+}`
+
+	_, err := AqueryBuildStatements([]byte(inputString))
+	assertError(t, err, `found multiple potential depfiles "two.d", "other.d"`)
+}
+
 func TestTransitiveInputDepsets(t *testing.T) {
 	// The input aquery for this test comes from a proof-of-concept starlark rule which registers
 	// a single action with many inputs given via a deep depset.
@@ -627,7 +730,7 @@ func assertError(t *testing.T, err error, expected string) {
 // Build statement equivalence is determined using buildStatementEquals.
 func assertBuildStatements(t *testing.T, expected []BuildStatement, actual []BuildStatement) {
 	if len(expected) != len(actual) {
-		t.Errorf("expected %d build statements, but got %d,\n expected: %s,\n actual: %s",
+		t.Errorf("expected %d build statements, but got %d,\n expected: %v,\n actual: %v",
 			len(expected), len(actual), expected, actual)
 		return
 	}
@@ -638,7 +741,7 @@ ACTUAL_LOOP:
 				continue ACTUAL_LOOP
 			}
 		}
-		t.Errorf("unexpected build statement %s.\n expected: %s",
+		t.Errorf("unexpected build statement %v.\n expected: %v",
 			actualStatement, expected)
 		return
 	}