Conditionally apply rustdoc flags to third party crates

This CL changes the logic in rust/builder.go so that some rustdoc flags
are only applied to external crates.  This will allow us to since
warnings and deal with soft-failures in external crates while allowing
us to be more strict with our internal Rust code.

Bug: 195136952
Test: m rustdoc
Change-Id: Icdde304bbbb323cae9657e8f842f58ae79e811ce

android/paths.go

@@ -20,6 +20,7 @@ import (
 	"os"
 	"path/filepath"
 	"reflect"
+	"regexp"
 	"sort"
 	"strings"
 
@@ -2094,3 +2095,25 @@ func PathsIfNonNil(paths ...Path) Paths {
 	}
 	return ret
 }
+
+var thirdPartyDirPrefixExceptions = []*regexp.Regexp{
+	regexp.MustCompile("^vendor/[^/]*google[^/]*/"),
+	regexp.MustCompile("^hardware/google/"),
+	regexp.MustCompile("^hardware/interfaces/"),
+	regexp.MustCompile("^hardware/libhardware[^/]*/"),
+	regexp.MustCompile("^hardware/ril/"),
+}
+
+func IsThirdPartyPath(path string) bool {
+	thirdPartyDirPrefixes := []string{"external/", "vendor/", "hardware/"}
+
+	if HasAnyPrefix(path, thirdPartyDirPrefixes) {
+		for _, prefix := range thirdPartyDirPrefixExceptions {
+			if prefix.MatchString(path) {
+				return false
+			}
+		}
+		return true
+	}
+	return false
+}

cc/compiler.go

@@ -450,7 +450,7 @@ func (compiler *baseCompiler) compilerFlags(ctx ModuleContext, flags Flags, deps
 		"${config.CommonGlobalCflags}",
 		fmt.Sprintf("${config.%sGlobalCflags}", hod))
 
-	if isThirdParty(modulePath) {
+	if android.IsThirdPartyPath(modulePath) {
 		flags.Global.CommonFlags = append(flags.Global.CommonFlags, "${config.ExternalCflags}")
 	}
 
@@ -675,28 +675,6 @@ func compileObjs(ctx android.ModuleContext, flags builderFlags,
 	return transformSourceToObj(ctx, subdir, srcFiles, flags, pathDeps, cFlagsDeps)
 }
 
-var thirdPartyDirPrefixExceptions = []*regexp.Regexp{
-	regexp.MustCompile("^vendor/[^/]*google[^/]*/"),
-	regexp.MustCompile("^hardware/google/"),
-	regexp.MustCompile("^hardware/interfaces/"),
-	regexp.MustCompile("^hardware/libhardware[^/]*/"),
-	regexp.MustCompile("^hardware/ril/"),
-}
-
-func isThirdParty(path string) bool {
-	thirdPartyDirPrefixes := []string{"external/", "vendor/", "hardware/"}
-
-	if android.HasAnyPrefix(path, thirdPartyDirPrefixes) {
-		for _, prefix := range thirdPartyDirPrefixExceptions {
-			if prefix.MatchString(path) {
-				return false
-			}
-		}
-		return true
-	}
-	return false
-}
-
 // Properties for rust_bindgen related to generating rust bindings.
 // This exists here so these properties can be included in a cc_default
 // which can be used in both cc and rust modules.

cc/compiler_test.go

@@ -16,6 +16,8 @@ package cc
 
 import (
 	"testing"
+
+	"android/soong/android"
 )
 
 func TestIsThirdParty(t *testing.T) {
@@ -32,12 +34,12 @@ func TestIsThirdParty(t *testing.T) {
 		"bionic/libc",
 	}
 	for _, path := range thirdPartyPaths {
-		if !isThirdParty(path) {
+		if !android.IsThirdPartyPath(path) {
 			t.Errorf("Expected %s to be considered third party", path)
 		}
 	}
 	for _, path := range nonThirdPartyPaths {
-		if isThirdParty(path) {
+		if android.IsThirdPartyPath(path) {
 			t.Errorf("Expected %s to *not* be considered third party", path)
 		}
 	}

rust/builder.go

@@ -332,8 +332,11 @@ func Rustdoc(ctx ModuleContext, main android.Path, deps PathDeps,
 	rustdocFlags = append(rustdocFlags, makeLibFlags(deps)...)
 	docTimestampFile := android.PathForModuleOut(ctx, "rustdoc.timestamp")
 
-	// Silence warnings about renamed lints
-	rustdocFlags = append(rustdocFlags, " -A renamed_and_removed_lints")
+	// Silence warnings about renamed lints for third-party crates
+	modulePath := android.PathForModuleSrc(ctx).String()
+	if android.IsThirdPartyPath(modulePath) {
+		rustdocFlags = append(rustdocFlags, " -A renamed_and_removed_lints")
+	}
 
 	// Yes, the same out directory is used simultaneously by all rustdoc builds.
 	// This is what cargo does. The docs for individual crates get generated to