diff --git a/cc/library.go b/cc/library.go
index f1681db..151b63d 100644
--- a/cc/library.go
+++ b/cc/library.go
@@ -82,7 +82,8 @@
 type FlagExporterProperties struct {
 	// list of directories relative to the Blueprints file that will
 	// be added to the include path (using -I) for this module and any module that links
-	// against this module
+	// against this module.  Directories listed in export_include_dirs do not need to be
+	// listed in local_include_dirs.
 	Export_include_dirs []string `android:"arch_variant"`
 
 	Target struct {
diff --git a/cmd/javac_wrapper/javac_wrapper.go b/cmd/javac_wrapper/javac_wrapper.go
index ab4d23f..a86f1e9 100644
--- a/cmd/javac_wrapper/javac_wrapper.go
+++ b/cmd/javac_wrapper/javac_wrapper.go
@@ -170,4 +170,5 @@
 	regexp.MustCompile(`Note: Recompile with -Xlint:deprecation for details.`),
 	regexp.MustCompile(`Note: (Some input files|.*\.java) uses? unchecked or unsafe operations.`),
 	regexp.MustCompile(`Note: Recompile with -Xlint:unchecked for details.`),
+	regexp.MustCompile(`bootstrap class path not set in conjunction with -source`),
 }
diff --git a/cmd/javac_wrapper/javac_wrapper_test.go b/cmd/javac_wrapper/javac_wrapper_test.go
index c345479..d76793f 100644
--- a/cmd/javac_wrapper/javac_wrapper_test.go
+++ b/cmd/javac_wrapper/javac_wrapper_test.go
@@ -41,8 +41,8 @@
 		out: "\x1b[1mFile.java:398: \x1b[35mwarning:\x1b[0m\x1b[1m [RectIntersectReturnValueIgnored] Return value of com.blah.function() must be checked\x1b[0m\n",
 	},
 	{
-		in:  "warning: [options] bootstrap class path not set in conjunction with -source 1.7\n",
-		out: "\x1b[1m\x1b[35mwarning:\x1b[0m\x1b[1m [options] bootstrap class path not set in conjunction with -source 1.7\x1b[0m\n",
+		in:  "warning: [options] blah\n",
+		out: "\x1b[1m\x1b[35mwarning:\x1b[0m\x1b[1m [options] blah\x1b[0m\n",
 	},
 	{
 		in:  "    (see http://go/errorprone/bugpattern/RectIntersectReturnValueIgnored.md)\n",
@@ -56,6 +56,7 @@
 Note: Recompile with -Xlint:unchecked for details.
 Note: dir/file.java uses or overrides a deprecated API.
 Note: dir/file.java uses unchecked or unsafe operations.
+warning: [options] bootstrap class path not set in conjunction with -source 1.7
 `,
 		out: "\n",
 	},
diff --git a/cmd/soong_ui/main.go b/cmd/soong_ui/main.go
index 8a26171..0619b5c 100644
--- a/cmd/soong_ui/main.go
+++ b/cmd/soong_ui/main.go
@@ -16,6 +16,8 @@
 
 import (
 	"context"
+	"flag"
+	"fmt"
 	"os"
 	"path/filepath"
 	"strconv"
@@ -45,7 +47,10 @@
 	log := logger.New(os.Stderr)
 	defer log.Cleanup()
 
-	if len(os.Args) < 2 || !inList("--make-mode", os.Args) {
+	if len(os.Args) < 2 || !(inList("--make-mode", os.Args) ||
+		os.Args[1] == "--dumpvars-mode" ||
+		os.Args[1] == "--dumpvar-mode") {
+
 		log.Fatalln("The `soong` native UI is not yet available.")
 	}
 
@@ -66,7 +71,12 @@
 		Tracer:         trace,
 		StdioInterface: build.StdioImpl{},
 	}}
-	config := build.NewConfig(buildCtx, os.Args[1:]...)
+	var config build.Config
+	if os.Args[1] == "--dumpvars-mode" || os.Args[1] == "--dumpvar-mode" {
+		config = build.NewConfig(buildCtx)
+	} else {
+		config = build.NewConfig(buildCtx, os.Args[1:]...)
+	}
 
 	log.SetVerbose(config.IsVerbose())
 	build.SetupOutDir(buildCtx, config)
@@ -99,5 +109,129 @@
 	defer f.Shutdown()
 	build.FindSources(buildCtx, config, f)
 
-	build.Build(buildCtx, config, build.BuildAll)
+	if os.Args[1] == "--dumpvar-mode" {
+		dumpVar(buildCtx, config, os.Args[2:])
+	} else if os.Args[1] == "--dumpvars-mode" {
+		dumpVars(buildCtx, config, os.Args[2:])
+	} else {
+		build.Build(buildCtx, config, build.BuildAll)
+	}
+}
+
+func dumpVar(ctx build.Context, config build.Config, args []string) {
+	flags := flag.NewFlagSet("dumpvar", flag.ExitOnError)
+	flags.Usage = func() {
+		fmt.Fprintf(os.Stderr, "usage: %s --dumpvar-mode [--abs] <VAR>\n\n", os.Args[0])
+		fmt.Fprintln(os.Stderr, "In dumpvar mode, print the value of the legacy make variable VAR to stdout")
+		fmt.Fprintln(os.Stderr, "")
+
+		fmt.Fprintln(os.Stderr, "'report_config' is a special case that prints the human-readable config banner")
+		fmt.Fprintln(os.Stderr, "from the beginning of the build.")
+		fmt.Fprintln(os.Stderr, "")
+		flags.PrintDefaults()
+	}
+	abs := flags.Bool("abs", false, "Print the absolute path of the value")
+	flags.Parse(args)
+
+	if flags.NArg() != 1 {
+		flags.Usage()
+		os.Exit(1)
+	}
+
+	varName := flags.Arg(0)
+	if varName == "report_config" {
+		varData, err := build.DumpMakeVars(ctx, config, nil, build.BannerVars)
+		if err != nil {
+			ctx.Fatal(err)
+		}
+
+		fmt.Println(build.Banner(varData))
+	} else {
+		varData, err := build.DumpMakeVars(ctx, config, nil, []string{varName})
+		if err != nil {
+			ctx.Fatal(err)
+		}
+
+		if *abs {
+			var res []string
+			for _, path := range strings.Fields(varData[varName]) {
+				if abs, err := filepath.Abs(path); err == nil {
+					res = append(res, abs)
+				} else {
+					ctx.Fatalln("Failed to get absolute path of", path, err)
+				}
+			}
+			fmt.Println(strings.Join(res, " "))
+		} else {
+			fmt.Println(varData[varName])
+		}
+	}
+}
+
+func dumpVars(ctx build.Context, config build.Config, args []string) {
+	flags := flag.NewFlagSet("dumpvars", flag.ExitOnError)
+	flags.Usage = func() {
+		fmt.Fprintf(os.Stderr, "usage: %s --dumpvars-mode [--vars=\"VAR VAR ...\"]\n\n", os.Args[0])
+		fmt.Fprintln(os.Stderr, "In dumpvars mode, dump the values of one or more legacy make variables, in")
+		fmt.Fprintln(os.Stderr, "shell syntax. The resulting output may be sourced directly into a shell to")
+		fmt.Fprintln(os.Stderr, "set corresponding shell variables.")
+		fmt.Fprintln(os.Stderr, "")
+
+		fmt.Fprintln(os.Stderr, "'report_config' is a special case that dumps a variable containing the")
+		fmt.Fprintln(os.Stderr, "human-readable config banner from the beginning of the build.")
+		fmt.Fprintln(os.Stderr, "")
+		flags.PrintDefaults()
+	}
+
+	varsStr := flags.String("vars", "", "Space-separated list of variables to dump")
+	absVarsStr := flags.String("abs-vars", "", "Space-separated list of variables to dump (using absolute paths)")
+
+	varPrefix := flags.String("var-prefix", "", "String to prepend to all variable names when dumping")
+	absVarPrefix := flags.String("abs-var-prefix", "", "String to prepent to all absolute path variable names when dumping")
+
+	flags.Parse(args)
+
+	if flags.NArg() != 0 {
+		flags.Usage()
+		os.Exit(1)
+	}
+
+	vars := strings.Fields(*varsStr)
+	absVars := strings.Fields(*absVarsStr)
+
+	allVars := append([]string{}, vars...)
+	allVars = append(allVars, absVars...)
+
+	if i := indexList("report_config", allVars); i != -1 {
+		allVars = append(allVars[:i], allVars[i+1:]...)
+		allVars = append(allVars, build.BannerVars...)
+	}
+
+	if len(allVars) == 0 {
+		return
+	}
+
+	varData, err := build.DumpMakeVars(ctx, config, nil, allVars)
+	if err != nil {
+		ctx.Fatal(err)
+	}
+
+	for _, name := range vars {
+		if name == "report_config" {
+			fmt.Printf("%sreport_config='%s'\n", *varPrefix, build.Banner(varData))
+		} else {
+			fmt.Printf("%s%s='%s'\n", *varPrefix, name, varData[name])
+		}
+	}
+	for _, name := range absVars {
+		var res []string
+		for _, path := range strings.Fields(varData[name]) {
+			abs, err := filepath.Abs(path)
+			if err != nil {
+				ctx.Fatalln("Failed to get absolute path of", path, err)
+			}
+			res = append(res, abs)
+		}
+		fmt.Printf("%s%s='%s'\n", *absVarPrefix, name, strings.Join(res, " "))
+	}
 }
diff --git a/genrule/genrule.go b/genrule/genrule.go
index 7c1350e..4a734da 100644
--- a/genrule/genrule.go
+++ b/genrule/genrule.go
@@ -61,13 +61,13 @@
 	//
 	// Available variables for substitution:
 	//
-	// $(location): the path to the first entry in tools or tool_files
-	// $(location <label>): the path to the tool or tool_file with name <label>
-	// $(in): one or more input files
-	// $(out): a single output file
-	// $(depfile): a file to which dependencies will be written, if the depfile property is set to true
-	// $(genDir): the sandbox directory for this tool; contains $(out)
-	// $$: a literal $
+	//  $(location): the path to the first entry in tools or tool_files
+	//  $(location <label>): the path to the tool or tool_file with name <label>
+	//  $(in): one or more input files
+	//  $(out): a single output file
+	//  $(depfile): a file to which dependencies will be written, if the depfile property is set to true
+	//  $(genDir): the sandbox directory for this tool; contains $(out)
+	//  $$: a literal $
 	//
 	// All files used must be declared as inputs (to ensure proper up-to-date checks).
 	// Use "$(in)" directly in Cmd to ensure that all inputs used are declared.
diff --git a/ui/build/config.go b/ui/build/config.go
index c8d7292..191a102 100644
--- a/ui/build/config.go
+++ b/ui/build/config.go
@@ -154,7 +154,7 @@
 			c.verbose = true
 		} else if arg == "--skip-make" {
 			c.skipMake = true
-		} else if arg[0] == '-' {
+		} else if len(arg) > 0 && arg[0] == '-' {
 			parseArgNum := func(def int) int {
 				if len(arg) > 2 {
 					p, err := strconv.ParseUint(arg[2:], 10, 31)
@@ -172,9 +172,9 @@
 				return def
 			}
 
-			if arg[1] == 'j' {
+			if len(arg) > 1 && arg[1] == 'j' {
 				c.parallel = parseArgNum(c.parallel)
-			} else if arg[1] == 'k' {
+			} else if len(arg) > 1 && arg[1] == 'k' {
 				c.keepGoing = parseArgNum(0)
 			} else {
 				ctx.Fatalln("Unknown option:", arg)
diff --git a/ui/build/dumpvars.go b/ui/build/dumpvars.go
index e6c3f56..fb20d63 100644
--- a/ui/build/dumpvars.go
+++ b/ui/build/dumpvars.go
@@ -15,6 +15,7 @@
 package build
 
 import (
+	"bytes"
 	"fmt"
 	"strings"
 )
@@ -78,6 +79,49 @@
 	return ret, nil
 }
 
+// Variables to print out in the top banner
+var BannerVars = []string{
+	"PLATFORM_VERSION_CODENAME",
+	"PLATFORM_VERSION",
+	"TARGET_PRODUCT",
+	"TARGET_BUILD_VARIANT",
+	"TARGET_BUILD_TYPE",
+	"TARGET_BUILD_APPS",
+	"TARGET_ARCH",
+	"TARGET_ARCH_VARIANT",
+	"TARGET_CPU_VARIANT",
+	"TARGET_2ND_ARCH",
+	"TARGET_2ND_ARCH_VARIANT",
+	"TARGET_2ND_CPU_VARIANT",
+	"HOST_ARCH",
+	"HOST_2ND_ARCH",
+	"HOST_OS",
+	"HOST_OS_EXTRA",
+	"HOST_CROSS_OS",
+	"HOST_CROSS_ARCH",
+	"HOST_CROSS_2ND_ARCH",
+	"HOST_BUILD_TYPE",
+	"BUILD_ID",
+	"OUT_DIR",
+	"AUX_OS_VARIANT_LIST",
+	"TARGET_BUILD_PDK",
+	"PDK_FUSION_PLATFORM_ZIP",
+}
+
+func Banner(make_vars map[string]string) string {
+	b := &bytes.Buffer{}
+
+	fmt.Fprintln(b, "============================================")
+	for _, name := range BannerVars {
+		if make_vars[name] != "" {
+			fmt.Fprintf(b, "%s=%s\n", name, make_vars[name])
+		}
+	}
+	fmt.Fprint(b, "============================================")
+
+	return b.String()
+}
+
 func runMakeProductConfig(ctx Context, config Config) {
 	// Variables to export into the environment of Kati/Ninja
 	exportEnvVars := []string{
@@ -99,35 +143,6 @@
 		"CCACHE_CPP2",
 	}
 
-	// Variables to print out in the top banner
-	bannerVars := []string{
-		"PLATFORM_VERSION_CODENAME",
-		"PLATFORM_VERSION",
-		"TARGET_PRODUCT",
-		"TARGET_BUILD_VARIANT",
-		"TARGET_BUILD_TYPE",
-		"TARGET_BUILD_APPS",
-		"TARGET_ARCH",
-		"TARGET_ARCH_VARIANT",
-		"TARGET_CPU_VARIANT",
-		"TARGET_2ND_ARCH",
-		"TARGET_2ND_ARCH_VARIANT",
-		"TARGET_2ND_CPU_VARIANT",
-		"HOST_ARCH",
-		"HOST_2ND_ARCH",
-		"HOST_OS",
-		"HOST_OS_EXTRA",
-		"HOST_CROSS_OS",
-		"HOST_CROSS_ARCH",
-		"HOST_CROSS_2ND_ARCH",
-		"HOST_BUILD_TYPE",
-		"BUILD_ID",
-		"OUT_DIR",
-		"AUX_OS_VARIANT_LIST",
-		"TARGET_BUILD_PDK",
-		"PDK_FUSION_PLATFORM_ZIP",
-	}
-
 	allVars := append(append([]string{
 		// Used to execute Kati and Ninja
 		"NINJA_GOALS",
@@ -135,7 +150,7 @@
 
 		// To find target/product/<DEVICE>
 		"TARGET_DEVICE",
-	}, exportEnvVars...), bannerVars...)
+	}, exportEnvVars...), BannerVars...)
 
 	make_vars, err := dumpMakeVars(ctx, config, config.Arguments(), allVars, true)
 	if err != nil {
@@ -143,13 +158,7 @@
 	}
 
 	// Print the banner like make does
-	fmt.Fprintln(ctx.Stdout(), "============================================")
-	for _, name := range bannerVars {
-		if make_vars[name] != "" {
-			fmt.Fprintf(ctx.Stdout(), "%s=%s\n", name, make_vars[name])
-		}
-	}
-	fmt.Fprintln(ctx.Stdout(), "============================================")
+	fmt.Fprintln(ctx.Stdout(), Banner(make_vars))
 
 	// Populate the environment
 	env := config.Environment()