Browse Source

Pass rsp files into sbox and rewrapper

The current implementation causes inputs listed in an rsp file used with
sbox to be duplicated 3 times in the build.ninja file; once as a
dependency of the rule, once in the rspfile_content field of the rule
with the paths rewritten to be relative to the sandbox, and once in the
rule to write the sbox manifest.  When RBE is enabled it also gets a
fourth copy in the list of files to be treated as inputs by rewrapper.

Reduce this to a single copy by using "$in" for the rspfile_content so
that the files only have to be listed in the input dependencies of the
rule, and then add support to sbox to rewrite the rsp file while copying
it into the sandbox, and pass it to rewrapper as well.

Test: m lint-check
Change-Id: I3f46f61119508d39a8bb231c99fc130153fb6f04
Colin Cross 3 years ago
parent
commit
e55bd423df

+ 1 - 0
android/Android.bp

@@ -14,6 +14,7 @@ bootstrap_go_package {
         "soong-bazel",
         "soong-cquery",
         "soong-remoteexec",
+        "soong-response",
         "soong-shared",
         "soong-ui-metrics_proto",
     ],

+ 45 - 42
android/rule_builder.go

@@ -28,6 +28,7 @@ import (
 
 	"android/soong/cmd/sbox/sbox_proto"
 	"android/soong/remoteexec"
+	"android/soong/response"
 	"android/soong/shared"
 )
 
@@ -459,26 +460,6 @@ func (r *RuleBuilder) depFileMergerCmd(depFiles WritablePaths) *RuleBuilderComma
 		Inputs(depFiles.Paths())
 }
 
-// composeRspFileContent returns a string that will serve as the contents of the rsp file to pass
-// the listed input files to the command running in the sandbox.
-func (r *RuleBuilder) composeRspFileContent(rspFileInputs Paths) string {
-	if r.sboxInputs {
-		if len(rspFileInputs) > 0 {
-			// When SandboxInputs is used the paths need to be rewritten to be relative to the sandbox
-			// directory so that they are valid after sbox chdirs into the sandbox directory.
-			return proptools.NinjaEscape(strings.Join(r.sboxPathsForInputsRel(rspFileInputs), " "))
-		} else {
-			// If the list of inputs is empty fall back to "$in" so that the rspfilecontent Ninja
-			// variable is set to something non-empty, otherwise ninja will complain.  The inputs
-			// will be empty (all the non-rspfile inputs are implicits), so $in will evaluate to
-			// an empty string.
-			return "$in"
-		}
-	} else {
-		return "$in"
-	}
-}
-
 // Build adds the built command line to the build graph, with dependencies on Inputs and Tools, and output files for
 // Outputs.
 func (r *RuleBuilder) Build(name string, desc string) {
@@ -577,9 +558,19 @@ func (r *RuleBuilder) Build(name string, desc string) {
 
 			// If using an rsp file copy it into the sbox directory.
 			if rspFilePath != nil {
-				command.CopyBefore = append(command.CopyBefore, &sbox_proto.Copy{
-					From: proto.String(rspFilePath.String()),
-					To:   proto.String(r.sboxPathForInputRel(rspFilePath)),
+				command.RspFiles = append(command.RspFiles, &sbox_proto.RspFile{
+					File: proto.String(rspFilePath.String()),
+					// These have to match the logic in sboxPathForInputRel
+					PathMappings: []*sbox_proto.PathMapping{
+						{
+							From: proto.String(r.outDir.String()),
+							To:   proto.String(sboxOutSubDir),
+						},
+						{
+							From: proto.String(PathForOutput(r.ctx).String()),
+							To:   proto.String(sboxOutSubDir),
+						},
+					},
 				})
 			}
 
@@ -641,20 +632,30 @@ func (r *RuleBuilder) Build(name string, desc string) {
 		inputs = append(inputs, sboxCmd.inputs...)
 
 		if r.rbeParams != nil {
-			var remoteInputs []string
-			remoteInputs = append(remoteInputs, inputs.Strings()...)
-			remoteInputs = append(remoteInputs, tools.Strings()...)
-			remoteInputs = append(remoteInputs, rspFileInputs.Strings()...)
+			// RBE needs a list of input files to copy to the remote builder.  For inputs already
+			// listed in an rsp file, pass the rsp file directly to rewrapper.  For the rest,
+			// create a new rsp file to pass to rewrapper.
+			var remoteRspFiles Paths
+			var remoteInputs Paths
+
+			remoteInputs = append(remoteInputs, inputs...)
+			remoteInputs = append(remoteInputs, tools...)
+
 			if rspFilePath != nil {
-				remoteInputs = append(remoteInputs, rspFilePath.String())
+				remoteInputs = append(remoteInputs, rspFilePath)
+				remoteRspFiles = append(remoteRspFiles, rspFilePath)
+			}
+
+			if len(remoteInputs) > 0 {
+				inputsListFile := r.sboxManifestPath.ReplaceExtension(r.ctx, "rbe_inputs.list")
+				writeRspFileRule(r.ctx, inputsListFile, remoteInputs)
+				remoteRspFiles = append(remoteRspFiles, inputsListFile)
+				// Add the new rsp file as an extra input to the rule.
+				inputs = append(inputs, inputsListFile)
 			}
-			inputsListFile := r.sboxManifestPath.ReplaceExtension(r.ctx, "rbe_inputs.list")
-			inputsListContents := rspFileForInputs(remoteInputs)
-			WriteFileRule(r.ctx, inputsListFile, inputsListContents)
-			inputs = append(inputs, inputsListFile)
 
 			r.rbeParams.OutputFiles = outputs.Strings()
-			r.rbeParams.RSPFiles = []string{inputsListFile.String()}
+			r.rbeParams.RSPFiles = remoteRspFiles.Strings()
 			rewrapperCommand := r.rbeParams.NoVarTemplate(r.ctx.Config().RBEWrapper())
 			commandString = rewrapperCommand + " bash -c '" + strings.ReplaceAll(commandString, `'`, `'\''`) + "'"
 		}
@@ -674,7 +675,10 @@ func (r *RuleBuilder) Build(name string, desc string) {
 	var rspFile, rspFileContent string
 	if rspFilePath != nil {
 		rspFile = rspFilePath.String()
-		rspFileContent = r.composeRspFileContent(rspFileInputs)
+		// Use "$in" for rspFileContent to avoid duplicating the list of files in the dependency
+		// list and in the contents of the rsp file.  Inputs to the rule that are not in the
+		// rsp file will be listed in Implicits instead of Inputs so they don't show up in "$in".
+		rspFileContent = "$in"
 	}
 
 	var pool blueprint.Pool
@@ -1264,13 +1268,12 @@ func (builderContextForTests) Rule(PackageContext, string, blueprint.RuleParams,
 }
 func (builderContextForTests) Build(PackageContext, BuildParams) {}
 
-func rspFileForInputs(paths []string) string {
-	s := strings.Builder{}
-	for i, path := range paths {
-		if i != 0 {
-			s.WriteByte(' ')
-		}
-		s.WriteString(proptools.ShellEscape(path))
+func writeRspFileRule(ctx BuilderContext, rspFile WritablePath, paths Paths) {
+	buf := &strings.Builder{}
+	err := response.WriteRspFile(buf, paths.Strings())
+	if err != nil {
+		// There should never be I/O errors writing to a bytes.Buffer.
+		panic(err)
 	}
-	return s.String()
+	WriteFileRule(ctx, rspFile, buf.String())
 }

+ 0 - 12
android/rule_builder_test.go

@@ -376,8 +376,6 @@ func TestRuleBuilder(t *testing.T) {
 		wantDepMergerCommand := "out_local/host/" + ctx.Config().PrebuiltOS() + "/bin/dep_fixer " +
 			"out_local/module/DepFile out_local/module/depfile out_local/module/ImplicitDepFile out_local/module/depfile2"
 
-		wantRspFileContent := "$in"
-
 		AssertDeepEquals(t, "rule.Commands()", wantCommands, rule.Commands())
 
 		AssertDeepEquals(t, "rule.Inputs()", wantInputs, rule.Inputs())
@@ -389,8 +387,6 @@ func TestRuleBuilder(t *testing.T) {
 		AssertDeepEquals(t, "rule.OrderOnlys()", wantOrderOnlys, rule.OrderOnlys())
 
 		AssertSame(t, "rule.depFileMergerCmd()", wantDepMergerCommand, rule.depFileMergerCmd(rule.DepFiles()).String())
-
-		AssertSame(t, "rule.composeRspFileContent()", wantRspFileContent, rule.composeRspFileContent(rule.RspFileInputs()))
 	})
 
 	t.Run("sbox", func(t *testing.T) {
@@ -409,8 +405,6 @@ func TestRuleBuilder(t *testing.T) {
 
 		wantDepMergerCommand := "out_local/host/" + ctx.Config().PrebuiltOS() + "/bin/dep_fixer __SBOX_SANDBOX_DIR__/out/DepFile __SBOX_SANDBOX_DIR__/out/depfile __SBOX_SANDBOX_DIR__/out/ImplicitDepFile __SBOX_SANDBOX_DIR__/out/depfile2"
 
-		wantRspFileContent := "$in"
-
 		AssertDeepEquals(t, "rule.Commands()", wantCommands, rule.Commands())
 
 		AssertDeepEquals(t, "rule.Inputs()", wantInputs, rule.Inputs())
@@ -422,8 +416,6 @@ func TestRuleBuilder(t *testing.T) {
 		AssertDeepEquals(t, "rule.OrderOnlys()", wantOrderOnlys, rule.OrderOnlys())
 
 		AssertSame(t, "rule.depFileMergerCmd()", wantDepMergerCommand, rule.depFileMergerCmd(rule.DepFiles()).String())
-
-		AssertSame(t, "rule.composeRspFileContent()", wantRspFileContent, rule.composeRspFileContent(rule.RspFileInputs()))
 	})
 
 	t.Run("sbox tools", func(t *testing.T) {
@@ -442,8 +434,6 @@ func TestRuleBuilder(t *testing.T) {
 
 		wantDepMergerCommand := "__SBOX_SANDBOX_DIR__/tools/out/bin/dep_fixer __SBOX_SANDBOX_DIR__/out/DepFile __SBOX_SANDBOX_DIR__/out/depfile __SBOX_SANDBOX_DIR__/out/ImplicitDepFile __SBOX_SANDBOX_DIR__/out/depfile2"
 
-		wantRspFileContent := "$in"
-
 		AssertDeepEquals(t, "rule.Commands()", wantCommands, rule.Commands())
 
 		AssertDeepEquals(t, "rule.Inputs()", wantInputs, rule.Inputs())
@@ -455,8 +445,6 @@ func TestRuleBuilder(t *testing.T) {
 		AssertDeepEquals(t, "rule.OrderOnlys()", wantOrderOnlys, rule.OrderOnlys())
 
 		AssertSame(t, "rule.depFileMergerCmd()", wantDepMergerCommand, rule.depFileMergerCmd(rule.DepFiles()).String())
-
-		AssertSame(t, "rule.composeRspFileContent()", wantRspFileContent, rule.composeRspFileContent(rule.RspFileInputs()))
 	})
 
 	t.Run("sbox inputs", func(t *testing.T) {

+ 1 - 0
cmd/sbox/Android.bp

@@ -21,6 +21,7 @@ blueprint_go_binary {
     deps: [
         "sbox_proto",
         "soong-makedeps",
+        "soong-response",
     ],
     srcs: [
         "sbox.go",

+ 86 - 4
cmd/sbox/sbox.go

@@ -32,6 +32,7 @@ import (
 
 	"android/soong/cmd/sbox/sbox_proto"
 	"android/soong/makedeps"
+	"android/soong/response"
 
 	"github.com/golang/protobuf/proto"
 )
@@ -218,6 +219,11 @@ func runCommand(command *sbox_proto.Command, tempDir string) (depFile string, er
 		return "", fmt.Errorf("command is required")
 	}
 
+	pathToTempDirInSbox := tempDir
+	if command.GetChdir() {
+		pathToTempDirInSbox = "."
+	}
+
 	err = os.MkdirAll(tempDir, 0777)
 	if err != nil {
 		return "", fmt.Errorf("failed to create %q: %w", tempDir, err)
@@ -228,10 +234,9 @@ func runCommand(command *sbox_proto.Command, tempDir string) (depFile string, er
 	if err != nil {
 		return "", err
 	}
-
-	pathToTempDirInSbox := tempDir
-	if command.GetChdir() {
-		pathToTempDirInSbox = "."
+	err = copyRspFiles(command.RspFiles, tempDir, pathToTempDirInSbox)
+	if err != nil {
+		return "", err
 	}
 
 	if strings.Contains(rawCommand, depFilePlaceholder) {
@@ -409,6 +414,83 @@ func copyOneFile(from string, to string, executable bool) error {
 	return nil
 }
 
+// copyRspFiles copies rsp files into the sandbox with path mappings, and also copies the files
+// listed into the sandbox.
+func copyRspFiles(rspFiles []*sbox_proto.RspFile, toDir, toDirInSandbox string) error {
+	for _, rspFile := range rspFiles {
+		err := copyOneRspFile(rspFile, toDir, toDirInSandbox)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// copyOneRspFiles copies an rsp file into the sandbox with path mappings, and also copies the files
+// listed into the sandbox.
+func copyOneRspFile(rspFile *sbox_proto.RspFile, toDir, toDirInSandbox string) error {
+	in, err := os.Open(rspFile.GetFile())
+	if err != nil {
+		return err
+	}
+	defer in.Close()
+
+	files, err := response.ReadRspFile(in)
+	if err != nil {
+		return err
+	}
+
+	for i, from := range files {
+		// Convert the real path of the input file into the path inside the sandbox using the
+		// path mappings.
+		to := applyPathMappings(rspFile.PathMappings, from)
+
+		// Copy the file into the sandbox.
+		err := copyOneFile(from, joinPath(toDir, to), false)
+		if err != nil {
+			return err
+		}
+
+		// Rewrite the name in the list of files to be relative to the sandbox directory.
+		files[i] = joinPath(toDirInSandbox, to)
+	}
+
+	// Convert the real path of the rsp file into the path inside the sandbox using the path
+	// mappings.
+	outRspFile := joinPath(toDir, applyPathMappings(rspFile.PathMappings, rspFile.GetFile()))
+
+	err = os.MkdirAll(filepath.Dir(outRspFile), 0777)
+	if err != nil {
+		return err
+	}
+
+	out, err := os.Create(outRspFile)
+	if err != nil {
+		return err
+	}
+	defer out.Close()
+
+	// Write the rsp file with converted paths into the sandbox.
+	err = response.WriteRspFile(out, files)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// applyPathMappings takes a list of path mappings and a path, and returns the path with the first
+// matching path mapping applied.  If the path does not match any of the path mappings then it is
+// returned unmodified.
+func applyPathMappings(pathMappings []*sbox_proto.PathMapping, path string) string {
+	for _, mapping := range pathMappings {
+		if strings.HasPrefix(path, mapping.GetFrom()+"/") {
+			return joinPath(mapping.GetTo()+"/", strings.TrimPrefix(path, mapping.GetFrom()+"/"))
+		}
+	}
+	return path
+}
+
 // moveFiles moves files specified by a set of copy rules.  It uses os.Rename, so it is restricted
 // to moving files where the source and destination are in the same filesystem.  This is OK for
 // sbox because the temporary directory is inside the out directory.  It updates the timestamp

+ 137 - 22
cmd/sbox/sbox_proto/sbox.pb.go

@@ -86,10 +86,13 @@ type Command struct {
 	CopyAfter []*Copy `protobuf:"bytes,4,rep,name=copy_after,json=copyAfter" json:"copy_after,omitempty"`
 	// An optional hash of the input files to ensure the textproto files and the sbox rule reruns
 	// when the lists of inputs changes, even if the inputs are not on the command line.
-	InputHash            *string  `protobuf:"bytes,5,opt,name=input_hash,json=inputHash" json:"input_hash,omitempty"`
-	XXX_NoUnkeyedLiteral struct{} `json:"-"`
-	XXX_unrecognized     []byte   `json:"-"`
-	XXX_sizecache        int32    `json:"-"`
+	InputHash *string `protobuf:"bytes,5,opt,name=input_hash,json=inputHash" json:"input_hash,omitempty"`
+	// A list of files that will be copied before the sandboxed command, and whose contents should be
+	// copied as if they were listed in copy_before.
+	RspFiles             []*RspFile `protobuf:"bytes,6,rep,name=rsp_files,json=rspFiles" json:"rsp_files,omitempty"`
+	XXX_NoUnkeyedLiteral struct{}   `json:"-"`
+	XXX_unrecognized     []byte     `json:"-"`
+	XXX_sizecache        int32      `json:"-"`
 }
 
 func (m *Command) Reset()         { *m = Command{} }
@@ -152,6 +155,13 @@ func (m *Command) GetInputHash() string {
 	return ""
 }
 
+func (m *Command) GetRspFiles() []*RspFile {
+	if m != nil {
+		return m.RspFiles
+	}
+	return nil
+}
+
 // Copy describes a from-to pair of files to copy.  The paths may be relative, the root that they
 // are relative to is specific to the context the Copy is used in and will be different for
 // from and to.
@@ -211,10 +221,110 @@ func (m *Copy) GetExecutable() bool {
 	return false
 }
 
+// RspFile describes an rspfile that should be copied into the sandbox directory.
+type RspFile struct {
+	// The path to the rsp file.
+	File *string `protobuf:"bytes,1,req,name=file" json:"file,omitempty"`
+	// A list of path mappings that should be applied to each file listed in the rsp file.
+	PathMappings         []*PathMapping `protobuf:"bytes,2,rep,name=path_mappings,json=pathMappings" json:"path_mappings,omitempty"`
+	XXX_NoUnkeyedLiteral struct{}       `json:"-"`
+	XXX_unrecognized     []byte         `json:"-"`
+	XXX_sizecache        int32          `json:"-"`
+}
+
+func (m *RspFile) Reset()         { *m = RspFile{} }
+func (m *RspFile) String() string { return proto.CompactTextString(m) }
+func (*RspFile) ProtoMessage()    {}
+func (*RspFile) Descriptor() ([]byte, []int) {
+	return fileDescriptor_9d0425bf0de86ed1, []int{3}
+}
+
+func (m *RspFile) XXX_Unmarshal(b []byte) error {
+	return xxx_messageInfo_RspFile.Unmarshal(m, b)
+}
+func (m *RspFile) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	return xxx_messageInfo_RspFile.Marshal(b, m, deterministic)
+}
+func (m *RspFile) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_RspFile.Merge(m, src)
+}
+func (m *RspFile) XXX_Size() int {
+	return xxx_messageInfo_RspFile.Size(m)
+}
+func (m *RspFile) XXX_DiscardUnknown() {
+	xxx_messageInfo_RspFile.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_RspFile proto.InternalMessageInfo
+
+func (m *RspFile) GetFile() string {
+	if m != nil && m.File != nil {
+		return *m.File
+	}
+	return ""
+}
+
+func (m *RspFile) GetPathMappings() []*PathMapping {
+	if m != nil {
+		return m.PathMappings
+	}
+	return nil
+}
+
+// PathMapping describes a mapping from a path outside the sandbox to the path inside the sandbox.
+type PathMapping struct {
+	From                 *string  `protobuf:"bytes,1,req,name=from" json:"from,omitempty"`
+	To                   *string  `protobuf:"bytes,2,req,name=to" json:"to,omitempty"`
+	XXX_NoUnkeyedLiteral struct{} `json:"-"`
+	XXX_unrecognized     []byte   `json:"-"`
+	XXX_sizecache        int32    `json:"-"`
+}
+
+func (m *PathMapping) Reset()         { *m = PathMapping{} }
+func (m *PathMapping) String() string { return proto.CompactTextString(m) }
+func (*PathMapping) ProtoMessage()    {}
+func (*PathMapping) Descriptor() ([]byte, []int) {
+	return fileDescriptor_9d0425bf0de86ed1, []int{4}
+}
+
+func (m *PathMapping) XXX_Unmarshal(b []byte) error {
+	return xxx_messageInfo_PathMapping.Unmarshal(m, b)
+}
+func (m *PathMapping) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	return xxx_messageInfo_PathMapping.Marshal(b, m, deterministic)
+}
+func (m *PathMapping) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_PathMapping.Merge(m, src)
+}
+func (m *PathMapping) XXX_Size() int {
+	return xxx_messageInfo_PathMapping.Size(m)
+}
+func (m *PathMapping) XXX_DiscardUnknown() {
+	xxx_messageInfo_PathMapping.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_PathMapping proto.InternalMessageInfo
+
+func (m *PathMapping) GetFrom() string {
+	if m != nil && m.From != nil {
+		return *m.From
+	}
+	return ""
+}
+
+func (m *PathMapping) GetTo() string {
+	if m != nil && m.To != nil {
+		return *m.To
+	}
+	return ""
+}
+
 func init() {
 	proto.RegisterType((*Manifest)(nil), "sbox.Manifest")
 	proto.RegisterType((*Command)(nil), "sbox.Command")
 	proto.RegisterType((*Copy)(nil), "sbox.Copy")
+	proto.RegisterType((*RspFile)(nil), "sbox.RspFile")
+	proto.RegisterType((*PathMapping)(nil), "sbox.PathMapping")
 }
 
 func init() {
@@ -222,22 +332,27 @@ func init() {
 }
 
 var fileDescriptor_9d0425bf0de86ed1 = []byte{
-	// 268 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x64, 0x90, 0x4f, 0x4b, 0xc3, 0x40,
-	0x10, 0xc5, 0xc9, 0x9f, 0xd2, 0x64, 0x6a, 0x7b, 0x18, 0x3c, 0xec, 0x45, 0x09, 0x01, 0x21, 0x45,
-	0xe8, 0xc1, 0x6f, 0x60, 0xf5, 0x20, 0x82, 0x97, 0x1c, 0x45, 0x08, 0x9b, 0x64, 0x43, 0x02, 0x4d,
-	0x26, 0xec, 0x6e, 0xa0, 0xfd, 0x56, 0x7e, 0x44, 0xd9, 0x49, 0x2a, 0x82, 0xb7, 0x99, 0xdf, 0xe3,
-	0xcd, 0x7b, 0x0c, 0x80, 0x29, 0xe9, 0x7c, 0x18, 0x35, 0x59, 0xc2, 0xd0, 0xcd, 0xe9, 0x17, 0x44,
-	0x1f, 0x72, 0xe8, 0x1a, 0x65, 0x2c, 0xee, 0x21, 0xaa, 0xa8, 0xef, 0xe5, 0x50, 0x1b, 0xe1, 0x25,
-	0x41, 0xb6, 0x79, 0xda, 0x1e, 0xd8, 0xf0, 0x32, 0xd3, 0xfc, 0x57, 0xc6, 0x07, 0xd8, 0xd1, 0x64,
-	0xc7, 0xc9, 0x16, 0xb5, 0x1a, 0x9b, 0xee, 0xa4, 0x84, 0x9f, 0x78, 0x59, 0x9c, 0x6f, 0x67, 0xfa,
-	0x3a, 0xc3, 0xf4, 0xdb, 0x83, 0xf5, 0x62, 0xc6, 0x47, 0xd8, 0x54, 0x34, 0x5e, 0x8a, 0x52, 0x35,
-	0xa4, 0xd5, 0x12, 0x00, 0xd7, 0x80, 0xf1, 0x92, 0x83, 0x93, 0x8f, 0xac, 0xe2, 0x2d, 0xac, 0xaa,
-	0xb6, 0xee, 0x34, 0x9f, 0x8d, 0xf2, 0x79, 0x41, 0x01, 0xeb, 0xa5, 0x81, 0x08, 0x12, 0x3f, 0x8b,
-	0xf3, 0xeb, 0x8a, 0x7b, 0x60, 0x77, 0x21, 0x1b, 0xab, 0xb4, 0x08, 0xff, 0xdd, 0x8e, 0x9d, 0xfa,
-	0xec, 0x44, 0xbc, 0x03, 0xe8, 0x06, 0xd7, 0xbc, 0x95, 0xa6, 0x15, 0x2b, 0xae, 0x1d, 0x33, 0x79,
-	0x93, 0xa6, 0x4d, 0xdf, 0x21, 0x74, 0x0e, 0x44, 0x08, 0x1b, 0x4d, 0xbd, 0xf0, 0x38, 0x88, 0x67,
-	0xdc, 0x81, 0x6f, 0x49, 0xf8, 0x4c, 0x7c, 0x4b, 0x78, 0x0f, 0xa0, 0xce, 0xaa, 0x9a, 0xac, 0x2c,
-	0x4f, 0x4a, 0x04, 0x5c, 0xf5, 0x0f, 0x39, 0xde, 0x7c, 0xf2, 0xc3, 0x0b, 0x7e, 0xf8, 0x4f, 0x00,
-	0x00, 0x00, 0xff, 0xff, 0x78, 0x37, 0x3e, 0x6a, 0x7d, 0x01, 0x00, 0x00,
+	// 342 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x8c, 0x92, 0x5f, 0x4b, 0xc3, 0x30,
+	0x14, 0xc5, 0x69, 0xd7, 0xb9, 0xf6, 0xee, 0x0f, 0x18, 0x7c, 0xc8, 0x8b, 0x32, 0x0a, 0xc2, 0xa6,
+	0x30, 0xd0, 0x07, 0xdf, 0x9d, 0x22, 0x22, 0x0c, 0x24, 0xe0, 0x8b, 0x08, 0x25, 0xeb, 0x52, 0x5b,
+	0x58, 0x9b, 0x90, 0x64, 0xb0, 0x7d, 0x57, 0x3f, 0x8c, 0xe4, 0xa6, 0xd3, 0x82, 0x2f, 0xbe, 0xdd,
+	0x7b, 0x0e, 0xf7, 0xdc, 0x5f, 0xc2, 0x05, 0x30, 0x6b, 0xb9, 0x5f, 0x28, 0x2d, 0xad, 0x24, 0x91,
+	0xab, 0xd3, 0x0f, 0x88, 0x57, 0xbc, 0xa9, 0x0a, 0x61, 0x2c, 0x99, 0x43, 0x9c, 0xcb, 0xba, 0xe6,
+	0xcd, 0xc6, 0xd0, 0x60, 0xda, 0x9b, 0x0d, 0x6f, 0xc7, 0x0b, 0x1c, 0x78, 0xf0, 0x2a, 0xfb, 0xb1,
+	0xc9, 0x25, 0x4c, 0xe4, 0xce, 0xaa, 0x9d, 0xcd, 0x36, 0x42, 0x15, 0xd5, 0x56, 0xd0, 0x70, 0x1a,
+	0xcc, 0x12, 0x36, 0xf6, 0xea, 0xa3, 0x17, 0xd3, 0xaf, 0x00, 0x06, 0xed, 0x30, 0xb9, 0x86, 0x61,
+	0x2e, 0xd5, 0x21, 0x5b, 0x8b, 0x42, 0x6a, 0xd1, 0x2e, 0x80, 0xe3, 0x02, 0x75, 0x60, 0xe0, 0xec,
+	0x25, 0xba, 0xe4, 0x0c, 0xfa, 0x79, 0xb9, 0xa9, 0x34, 0xc6, 0xc6, 0xcc, 0x37, 0x84, 0xc2, 0xa0,
+	0x25, 0xa0, 0xbd, 0x69, 0x38, 0x4b, 0xd8, 0xb1, 0x25, 0x73, 0xc0, 0xe9, 0x8c, 0x17, 0x56, 0x68,
+	0x1a, 0xfd, 0xc9, 0x4e, 0x9c, 0x7b, 0xef, 0x4c, 0x72, 0x0e, 0x50, 0x35, 0x8e, 0xbc, 0xe4, 0xa6,
+	0xa4, 0x7d, 0xc4, 0x4e, 0x50, 0x79, 0xe6, 0xa6, 0x24, 0x57, 0x90, 0x68, 0xa3, 0x32, 0x87, 0x6f,
+	0xe8, 0x49, 0xf7, 0x17, 0x98, 0x51, 0x4f, 0xd5, 0x56, 0xb0, 0x58, 0xfb, 0xc2, 0xa4, 0x2f, 0x10,
+	0xb9, 0x74, 0x42, 0x20, 0x2a, 0xb4, 0xac, 0x69, 0x80, 0x50, 0x58, 0x93, 0x09, 0x84, 0x56, 0xd2,
+	0x10, 0x95, 0xd0, 0x4a, 0x72, 0x01, 0x20, 0xf6, 0x22, 0xdf, 0x59, 0xbe, 0xde, 0x0a, 0xda, 0xc3,
+	0x67, 0x75, 0x94, 0xf4, 0x0d, 0x06, 0xed, 0x02, 0x8c, 0x73, 0x5f, 0x7a, 0x8c, 0x73, 0xda, 0x1d,
+	0x8c, 0x15, 0xb7, 0x65, 0x56, 0x73, 0xa5, 0xaa, 0xe6, 0xd3, 0xd0, 0x10, 0xd1, 0x4e, 0x3d, 0xda,
+	0x2b, 0xb7, 0xe5, 0xca, 0x3b, 0x6c, 0xa4, 0x7e, 0x1b, 0x93, 0xde, 0xc0, 0xb0, 0x63, 0xfe, 0x87,
+	0x74, 0x39, 0x7a, 0xc7, 0x33, 0xc9, 0xf0, 0x4c, 0xbe, 0x03, 0x00, 0x00, 0xff, 0xff, 0x83, 0x82,
+	0xb0, 0xc3, 0x33, 0x02, 0x00, 0x00,
 }

+ 20 - 1
cmd/sbox/sbox_proto/sbox.proto

@@ -47,6 +47,10 @@ message Command {
   // An optional hash of the input files to ensure the textproto files and the sbox rule reruns
   // when the lists of inputs changes, even if the inputs are not on the command line.
   optional string input_hash = 5;
+
+  // A list of files that will be copied before the sandboxed command, and whose contents should be
+  // copied as if they were listed in copy_before.
+  repeated RspFile rsp_files = 6;
 }
 
 // Copy describes a from-to pair of files to copy.  The paths may be relative, the root that they
@@ -58,4 +62,19 @@ message Copy {
 
   // If true, make the file executable after copying it.
   optional bool executable = 3;
-}
+}
+
+// RspFile describes an rspfile that should be copied into the sandbox directory.
+message RspFile {
+  // The path to the rsp file.
+  required string file = 1;
+
+  // A list of path mappings that should be applied to each file listed in the rsp file.
+  repeated PathMapping path_mappings = 2;
+}
+
+// PathMapping describes a mapping from a path outside the sandbox to the path inside the sandbox.
+message PathMapping {
+  required string from = 1;
+  required string to = 2;
+}

+ 42 - 0
response/response.go

@@ -17,6 +17,7 @@ package response
 import (
 	"io"
 	"io/ioutil"
+	"strings"
 	"unicode"
 )
 
@@ -68,3 +69,44 @@ func ReadRspFile(r io.Reader) ([]string, error) {
 
 	return files, nil
 }
+
+func rspUnsafeChar(r rune) bool {
+	switch {
+	case 'A' <= r && r <= 'Z',
+		'a' <= r && r <= 'z',
+		'0' <= r && r <= '9',
+		r == '_',
+		r == '+',
+		r == '-',
+		r == '.',
+		r == '/':
+		return false
+	default:
+		return true
+	}
+}
+
+var rspEscaper = strings.NewReplacer(`'`, `'\''`)
+
+// WriteRspFile writes a list of files to a file in Ninja's response file format.
+func WriteRspFile(w io.Writer, files []string) error {
+	for i, f := range files {
+		if i != 0 {
+			_, err := io.WriteString(w, " ")
+			if err != nil {
+				return err
+			}
+		}
+
+		if strings.IndexFunc(f, rspUnsafeChar) != -1 {
+			f = `'` + rspEscaper.Replace(f) + `'`
+		}
+
+		_, err := io.WriteString(w, f)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}

+ 27 - 0
response/response_test.go

@@ -94,3 +94,30 @@ func TestReadRspFile(t *testing.T) {
 		})
 	}
 }
+
+func TestWriteRspFile(t *testing.T) {
+	testCases := []struct {
+		name string
+		in   []string
+		out  string
+	}{
+		{
+			name: "ninja rsp file",
+			in:   []string{"a", "b", "@", "foo'bar", `foo"bar`},
+			out:  "a b '@' 'foo'\\''bar' 'foo\"bar'",
+		},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.name, func(t *testing.T) {
+			buf := &bytes.Buffer{}
+			err := WriteRspFile(buf, testCase.in)
+			if err != nil {
+				t.Errorf("unexpected error: %q", err)
+			}
+			if buf.String() != testCase.out {
+				t.Errorf("expected %q got %q", testCase.out, buf.String())
+			}
+		})
+	}
+}