Add support for lint baseline files

Test: m droid
Test: go test ^TestJavaLint # (from soong/build/java)

Change-Id: I249a0a0597b0bf8495460ed283b476ad2eb36edc

android/config.go

@@ -127,7 +127,7 @@ type config struct {
 
 	// If testAllowNonExistentPaths is true then PathForSource and PathForModuleSrc won't error
 	// in tests when a path doesn't exist.
-	testAllowNonExistentPaths bool
+	TestAllowNonExistentPaths bool
 
 	// The list of files that when changed, must invalidate soong_build to
 	// regenerate build.ninja.
@@ -254,7 +254,7 @@ func TestConfig(buildDir string, env map[string]string, bp string, fs map[string
 
 		// Set testAllowNonExistentPaths so that test contexts don't need to specify every path
 		// passed to PathForSource or PathForModuleSrc.
-		testAllowNonExistentPaths: true,
+		TestAllowNonExistentPaths: true,
 
 		BazelContext: noopBazelContext{},
 	}

android/paths.go

@@ -582,7 +582,7 @@ func expandOneSrcPath(ctx ModuleWithDepsPathContext, sPath string, expandedExclu
 		p := pathForModuleSrc(ctx, sPath)
 		if exists, _, err := ctx.Config().fs.Exists(p.String()); err != nil {
 			ReportPathErrorf(ctx, "%s: %s", p, err.Error())
-		} else if !exists && !ctx.Config().testAllowNonExistentPaths {
+		} else if !exists && !ctx.Config().TestAllowNonExistentPaths {
 			ReportPathErrorf(ctx, "module source path %q does not exist", p)
 		}
 
@@ -1018,7 +1018,7 @@ func PathForSource(ctx PathContext, pathComponents ...string) SourcePath {
 		}
 	} else if exists, _, err := ctx.Config().fs.Exists(path.String()); err != nil {
 		ReportPathErrorf(ctx, "%s: %s", path, err.Error())
-	} else if !exists && !ctx.Config().testAllowNonExistentPaths {
+	} else if !exists && !ctx.Config().TestAllowNonExistentPaths {
 		ReportPathErrorf(ctx, "source path %q does not exist", path)
 	}
 	return path

java/java_test.go

@@ -127,7 +127,6 @@ func testJavaErrorWithConfig(t *testing.T, pattern string, config android.Config
 	}
 
 	t.Fatalf("missing expected error %q (0 errors are returned)", pattern)
-
 	return ctx, config
 }
 
@@ -1179,6 +1178,110 @@ func TestIncludeSrcs(t *testing.T) {
 	}
 }
 
+func TestJavaLint(t *testing.T) {
+	ctx, _ := testJavaWithFS(t, `
+		java_library {
+			name: "foo",
+			srcs: [
+				"a.java",
+				"b.java",
+				"c.java",
+			],
+			min_sdk_version: "29",
+			sdk_version: "system_current",
+		}
+       `, map[string][]byte{
+		"lint-baseline.xml": nil,
+	})
+
+	foo := ctx.ModuleForTests("foo", "android_common")
+	rule := foo.Rule("lint")
+
+	if !strings.Contains(rule.RuleParams.Command, "--baseline lint-baseline.xml") {
+		t.Error("did not pass --baseline flag")
+	}
+}
+
+func TestJavaLintWithoutBaseline(t *testing.T) {
+	ctx, _ := testJavaWithFS(t, `
+		java_library {
+			name: "foo",
+			srcs: [
+				"a.java",
+				"b.java",
+				"c.java",
+			],
+			min_sdk_version: "29",
+			sdk_version: "system_current",
+		}
+       `, map[string][]byte{})
+
+	foo := ctx.ModuleForTests("foo", "android_common")
+	rule := foo.Rule("lint")
+
+	if strings.Contains(rule.RuleParams.Command, "--baseline") {
+		t.Error("passed --baseline flag for non existent file")
+	}
+}
+
+func TestJavaLintRequiresCustomLintFileToExist(t *testing.T) {
+	config := testConfig(
+		nil,
+		`
+		java_library {
+			name: "foo",
+			srcs: [
+			],
+			min_sdk_version: "29",
+			sdk_version: "system_current",
+			lint: {
+				baseline_filename: "mybaseline.xml",
+			},
+		}
+     `, map[string][]byte{
+			"build/soong/java/lint_defaults.txt":                   nil,
+			"prebuilts/cmdline-tools/tools/bin/lint":               nil,
+			"prebuilts/cmdline-tools/tools/lib/lint-classpath.jar": nil,
+			"framework/aidl":                     nil,
+			"a.java":                             nil,
+			"AndroidManifest.xml":                nil,
+			"build/make/target/product/security": nil,
+		})
+	config.TestAllowNonExistentPaths = false
+	testJavaErrorWithConfig(t,
+		"source path \"mybaseline.xml\" does not exist",
+		config,
+	)
+}
+
+func TestJavaLintUsesCorrectBpConfig(t *testing.T) {
+	ctx, _ := testJavaWithFS(t, `
+		java_library {
+			name: "foo",
+			srcs: [
+				"a.java",
+				"b.java",
+				"c.java",
+			],
+			min_sdk_version: "29",
+			sdk_version: "system_current",
+			lint: {
+				error_checks: ["SomeCheck"],
+				baseline_filename: "mybaseline.xml",
+			},
+		}
+       `, map[string][]byte{
+		"mybaseline.xml": nil,
+	})
+
+	foo := ctx.ModuleForTests("foo", "android_common")
+	rule := foo.Rule("lint")
+
+	if !strings.Contains(rule.RuleParams.Command, "--baseline mybaseline.xml") {
+		t.Error("did not use the correct file for baseline")
+	}
+}
+
 func TestGeneratedSources(t *testing.T) {
 	ctx, _ := testJavaWithFS(t, `
 		java_library {

java/lint.go

@@ -19,6 +19,8 @@ import (
 	"sort"
 	"strings"
 
+	"github.com/google/blueprint/proptools"
+
 	"android/soong/android"
 )
 
@@ -46,6 +48,9 @@ type LintProperties struct {
 
 		// Modules that provide extra lint checks
 		Extra_check_modules []string
+
+		// Name of the file that lint uses as the baseline. Defaults to "lint-baseline.xml".
+		Baseline_filename *string
 	}
 }
 
@@ -343,6 +348,19 @@ func (l *linter) lint(ctx android.ModuleContext) {
 		cmd.FlagWithArg("--check ", checkOnly)
 	}
 
+	if lintFilename := proptools.StringDefault(l.properties.Lint.Baseline_filename, "lint-baseline.xml"); lintFilename != "" {
+		var lintBaseline android.OptionalPath
+		if String(l.properties.Lint.Baseline_filename) != "" {
+			// if manually specified, we require the file to exist
+			lintBaseline = android.OptionalPathForPath(android.PathForModuleSrc(ctx, lintFilename))
+		} else {
+			lintBaseline = android.ExistentPathForSource(ctx, ctx.ModuleDir(), lintFilename)
+		}
+		if lintBaseline.Valid() {
+			cmd.FlagWithInput("--baseline ", lintBaseline.Path())
+		}
+	}
+
 	cmd.Text("|| (").Text("cat").Input(text).Text("; exit 7)").Text(")")
 
 	rule.Command().Text("rm -rf").Flag(cacheDir.String()).Flag(homeDir.String())