Use aquery results to determine if a file should be executable

Now that aquery includes this information.

Also added rm -f $out to some rules, because since they write files
by shell redirection, if the file existed before and was executable,
they wouldn't make the file non-executable and visa versa.

Fixes: 297366783
Test: m bazel_sandwich
Change-Id: Ie5b6c4275b162601f51deaec9912eea4be16988d

android/bazel_handler.go

@@ -1382,10 +1382,7 @@ func (c *bazelSingleton) GenerateBuildActions(ctx SingletonContext) {
 			WriteFileRuleVerbatim(ctx, out, "")
 		case "FileWrite", "SourceSymlinkManifest":
 			out := PathForBazelOut(ctx, buildStatement.OutputPaths[0])
-			// TODO(b/297366783) This is a hack to make files from skylib's diff_test executable.
-			// We need to update bazel to have aquery tell us whether a file is supposed to be
-			// executable or not.
-			if strings.HasSuffix(buildStatement.OutputPaths[0], "-test.sh") {
+			if buildStatement.IsExecutable {
 				WriteExecutableFileRuleVerbatim(ctx, out, buildStatement.FileContents)
 			} else {
 				WriteFileRuleVerbatim(ctx, out, buildStatement.FileContents)

android/defs.go

@@ -107,8 +107,8 @@ var (
 
 	Cat = pctx.AndroidStaticRule("Cat",
 		blueprint.RuleParams{
-			Command:     "cat $in > $out",
-			Description: "concatenate licenses $out",
+			Command:     "rm -f $out && cat $in > $out",
+			Description: "concatenate files to $out",
 		})
 
 	// ubuntu 14.04 offcially use dash for /bin/sh, and its builtin echo command
@@ -116,7 +116,7 @@ var (
 	// content to file.
 	writeFile = pctx.AndroidStaticRule("writeFile",
 		blueprint.RuleParams{
-			Command:     `/bin/bash -c 'echo -e -n "$$0" > $out' $content`,
+			Command:     `rm -f $out && /bin/bash -c 'echo -e -n "$$0" > $out' $content`,
 			Description: "writing file $out",
 		},
 		"content")

bazel/aquery.go

@@ -123,6 +123,7 @@ type BuildStatement struct {
 	// Unlike most properties in BuildStatement, these paths must be relative to the root of
 	// the whole out/ folder, instead of relative to ctx.Config().BazelContext.OutputBase()
 	ImplicitDeps []string
+	IsExecutable bool
 }
 
 // A helper type for aquery processing which facilitates retrieval of path IDs from their
@@ -560,6 +561,7 @@ func (a *aqueryArtifactHandler) fileWriteActionBuildStatement(actionEntry *analy
 		Mnemonic:          actionEntry.Mnemonic,
 		InputDepsetHashes: depsetHashes,
 		FileContents:      actionEntry.FileContents,
+		IsExecutable:      actionEntry.IsExecutable,
 	}, nil
 }