first primitive cut at resolving missing imports automatically:

if an import file is missing, the corresponding source
is compiled automatically, if found

R=r
OCL=13990
CL=13990

usr/gri/gosrc/compilation.go

@@ -17,18 +17,25 @@ import Printer "printer"
 import Verifier "verifier"
 
 
-export func Compile(comp *Globals.Compilation, file_name string) {
-	src, ok := sys.readfile(file_name);
+export func Compile(flags *Globals.Flags, filename string) {
+	// setup compilation
+	comp := new(Globals.Compilation);
+	comp.flags = flags;
+	comp.Compile = &Compile;
+	
+	src, ok := sys.readfile(filename);
 	if !ok {
-		print "cannot open ", file_name, "\n"
+		print "cannot open ", filename, "\n"
 		return;
 	}
 	
+	print filename, "\n";
+	
 	scanner := new(Scanner.Scanner);
-	scanner.Open(file_name, src);
+	scanner.Open(filename, src);
 	
 	var tstream *chan *Scanner.Token;
-	if comp.flags.pscan {
+	if comp.flags.token_chan {
 		tstream = new(chan *Scanner.Token, 100);
 		go scanner.Server(tstream);
 	}
@@ -41,15 +48,15 @@ export func Compile(comp *Globals.Compilation, file_name string) {
 		return;
 	}
 	
-	if !comp.flags.semantic_checks {
+	if !comp.flags.ast {
 		return;
 	}
 	
 	Verifier.Verify(comp);
 	
-	if comp.flags.print_export {
+	if comp.flags.print_interface {
 		Printer.PrintObject(comp, comp.pkg_list[0].obj, false);
 	}
 	
-	Export.Export(comp, file_name);
+	Export.Export(comp, filename);
 }

usr/gri/gosrc/export.go

@@ -247,6 +247,12 @@ func (E *Exporter) Export(comp* Globals.Compilation, file_name string) {
 		print "exporting to ", file_name, "\n";
 	}
 
+	// write magic bits
+	magic := Globals.MAGIC_obj_file;  // TODO remove once len(constant) works
+	for i := 0; i < len(magic); i++ {
+		E.WriteByte(magic[i]);
+	}
+	
 	// Predeclared types are "pre-exported".
 	// TODO run the loop below only in debug mode
 	{	i := 0;
@@ -279,5 +285,5 @@ func (E *Exporter) Export(comp* Globals.Compilation, file_name string) {
 
 export func Export(comp* Globals.Compilation, pkg_name string) {
 	var E Exporter;
-	(&E).Export(comp, Utils.FixExt(Utils.BaseName(pkg_name)));
+	(&E).Export(comp, Utils.TrimExt(Utils.BaseName(pkg_name), Globals.src_file_ext) + Globals.obj_file_ext);
 }

usr/gri/gosrc/globals.go

@@ -5,6 +5,18 @@
 package Globals
 
 
+// ----------------------------------------------------------------------------
+// Constants
+
+export const (
+	MAGIC_obj_file = "/*go.7*/";  // anything, really
+	src_file_ext = ".go";
+	obj_file_ext = ".7";
+)
+
+
+// ----------------------------------------------------------------------------
+
 // The following types should really be in their respective files
 // (object.go, type.go, scope.go, package.go, compilation.go, etc.) but
 // they refer to each other and we don't know how to handle forward
@@ -60,16 +72,28 @@ export type Scope struct {
 
 export type Flags struct {
 	debug bool;
-	print_export bool;
-	semantic_checks bool;
-	verbose int;
-	sixg bool;  // 6g compatibility
-	pscan bool;  // parallel scanning using a token channel
+	object_filename string;
+	update_packages bool;
+	print_interface bool;
+	verbosity uint;
+	sixg bool;
+
+	scan bool;
+	parse bool;
+	ast bool;
+	deps bool;
+	token_chan bool;
 }
 
 
 export type Compilation struct {
+	// envionment
 	flags *Flags;
+	Error *func(comp *Compilation);  // TODO complete this
+	Import *func(comp *Compilation, data string) *Package;
+	Export *func(comp *Compilation) string;
+    Compile *func(flags *Flags, filename string);  // TODO remove this eventually
+	
 	// TODO use open arrays eventually
 	pkg_list [256] *Package;  // pkg_list[0] is the current package
 	pkg_ref int;
@@ -150,13 +174,6 @@ export func NewScope(parent *Scope) *Scope {
 }
 
 
-export func NewCompilation(flags *Flags) *Compilation {
-	comp := new(Compilation);
-	comp.flags = flags;
-	return comp;
-}
-
-
 // ----------------------------------------------------------------------------
 // Object methods
 

usr/gri/gosrc/go.go

@@ -9,49 +9,80 @@ import Globals "globals"
 import Compilation "compilation"
 
 
-// For now we are not using the flags package to minimize
-// external dependencies, and because the requirements are
-// very minimal at this point.
-
 func PrintHelp() {
-  print "go in go (", Build.time, ")\n";
-  print "usage:\n";
-  print "  go { flag | file }\n";
-  print "  -d  print debug information\n";
-  print "  -p  print export\n";
-  print "  -s  enable semantic checks\n";
-  print "  -v  verbose mode\n";
-  print "  -vv  very verbose mode\n";
-  print "  -6g  6g compatibility mode\n";
-  print "  -pscan  scan and parse in parallel (use token channel)\n";
+	print
+		"go (" + Build.time + ")\n" +
+		"usage:\n" +
+		"  go { flag } { file }\n" +
+		"  -d             debug mode, additional self tests and prints\n" +
+		"  -o filename    explicit object filename\n" +
+		"  -r             recursively update imported packages in current directory\n" +
+		"  -p             print package interface\n" +
+		"  -v [0 .. 3]    verbosity level\n" +
+		"  -6g            6g compatibility mode\n" +
+		"  -scan          scan only, print tokens\n" +
+		"  -parse         parse only, print productions\n" +
+		"  -ast           analyse only, print ast\n" +
+		"  -deps          print package dependencies\n" +
+		"  -token_chan    use token channel to scan and parse in parallel\n";
+}
+
+
+var argno int = 1;
+func Next() string {
+	arg := "";
+	if argno < sys.argc() {
+		arg = sys.argv(argno);
+		argno++;
+	}
+	return arg;
 }
 
 
 func main() {
-	if sys.argc() <= 1 {
+	arg := Next();
+	
+	if arg == "" {
 		PrintHelp();
-		sys.exit(1);
+		return;
 	}
-	
+
 	// collect flags and files
 	flags := new(Globals.Flags);
 	files := Globals.NewList();
-	for i := 1; i < sys.argc(); i++ {
-		switch arg := sys.argv(i); arg {
+	for arg != "" {
+	    switch arg {
 		case "-d": flags.debug = true;
-		case "-p": flags.print_export = true;
-		case "-s": flags.semantic_checks = true;
-		case "-v": flags.verbose = 1;
-		case "-vv": flags.verbose = 2;
+		case "-o": flags.object_filename = Next();
+			print "note: -o flag ignored at the moment\n";
+		case "-r": flags.update_packages = true;
+		case "-p": flags.print_interface = true;
+		case "-v":
+			arg = Next();
+			switch arg {
+			case "0", "1", "2", "3":
+				flags.verbosity = uint(arg[0] - '0');
+			default:
+				// anything else is considered the next argument
+				flags.verbosity = 1;
+				continue;
+			}
 		case "-6g": flags.sixg = true;
-		case "-pscan": flags.pscan = true;
+		case "-scan": flags.scan = true;
+			print "note: -scan flag ignored at the moment\n";
+		case "-parse": flags.parse = true;
+			print "note: -parse flag ignored at the moment\n";
+		case "-ast": flags.ast = true;
+		case "-deps": flags.deps = true;
+			print "note: -deps flag ignored at the moment\n";
+		case "-token_chan": flags.token_chan = true;
 		default: files.AddStr(arg);
 		}
+		arg = Next();
 	}
 	
 	// compile files
 	for p := files.first; p != nil; p = p.next {
-		comp := Globals.NewCompilation(flags);
-		Compilation.Compile(comp, p.str);
+		Compilation.Compile(flags, p.str);
 	}
 }

usr/gri/gosrc/import.go

@@ -264,6 +264,66 @@ func (I *Importer) ReadObject() *Globals.Object {
 }
 
 
+func ReadObjectFile(filename string) (data string, ok bool) {
+	data, ok = sys.readfile(filename + Globals.obj_file_ext);
+	magic := Globals.MAGIC_obj_file;  // TODO remove once len(constant) works
+	if ok && len(data) >= len(magic) && data[0 : len(magic)] == magic {
+		return data, ok;
+	}
+	return "", false;
+}
+
+
+func ReadSourceFile(filename string) (data string, ok bool) {
+	data, ok = sys.readfile(filename + Globals.src_file_ext);
+	return data, ok;
+}
+
+
+func ReadImport(comp* Globals.Compilation, filename string, update bool) (data string, ok bool) {
+	if filename == "" {
+		panic "illegal package file name";
+	}
+
+	// see if it just works
+	data, ok = ReadObjectFile(filename);
+	if ok {
+		return data, ok;
+	}
+	
+	if filename[0] == '/' {
+		// absolute path
+		panic `don't know how to handle absolute import file path "` + filename + `"`;
+	}
+	
+	// relative path
+	// try relative to the $GOROOT/pkg directory
+	std_filename := Utils.GOROOT + "/pkg/" + filename;
+	data, ok = ReadObjectFile(std_filename);
+	if ok {
+		return data, ok;
+	}
+	
+	if !update {
+		return "", false;
+	}
+	
+	// TODO BIG HACK - fix this!
+	// look for a src file
+	// see if it just works
+	data, ok = ReadSourceFile(filename);
+	if ok {
+		comp.Compile(comp.flags, filename + Globals.src_file_ext);
+		data, ok = ReadImport(comp, filename, false);
+		if ok {
+			return data, ok;
+		}
+	}
+	
+	return "", false;
+}
+
+
 func (I *Importer) Import(comp* Globals.Compilation, file_name string) *Globals.Package {
 	I.comp = comp;
 	I.debug = comp.flags.debug;
@@ -276,7 +336,8 @@ func (I *Importer) Import(comp* Globals.Compilation, file_name string) *Globals.
 		print "importing from ", file_name, "\n";
 	}
 	
-	buf, ok := sys.readfile(file_name);
+	//  read file and check magic bits
+	buf, ok := ReadImport(comp, file_name, comp.flags.update_packages);
 	if !ok {
 		return nil;
 	}
@@ -305,5 +366,5 @@ func (I *Importer) Import(comp* Globals.Compilation, file_name string) *Globals.
 
 export func Import(comp* Globals.Compilation, pkg_name string) *Globals.Package {
 	var I Importer;
-	return (&I).Import(comp, Utils.FixExt(pkg_name));
+	return (&I).Import(comp, pkg_name);
 }

usr/gri/gosrc/parser.go

@@ -17,7 +17,7 @@ import AST "ast"
 export type Parser struct {
 	comp *Globals.Compilation;
 	semantic_checks bool;
-	verbose, indent int;
+	verbose, indent uint;
 	S *Scanner.Scanner;
 	C *chan *Scanner.Token;
 	
@@ -78,8 +78,8 @@ func (P *Parser) Next() {
 
 func (P *Parser) Open(comp *Globals.Compilation, S *Scanner.Scanner, C *chan *Scanner.Token) {
 	P.comp = comp;
-	P.semantic_checks = comp.flags.semantic_checks;
-	P.verbose = comp.flags.verbose;
+	P.semantic_checks = comp.flags.ast;
+	P.verbose = comp.flags.verbosity;
 	P.indent = 0;
 	P.S = S;
 	P.C = C;

usr/gri/gosrc/scanner.go

@@ -223,7 +223,7 @@ func init() {
 	}
 	
 	// Provide column information in error messages for gri only...
-	VerboseMsgs = Utils.GetEnv("USER") == "gri";
+	VerboseMsgs = Utils.USER == "gri";
 }
 
 

usr/gri/gosrc/utils.go

@@ -5,6 +5,34 @@
 package Utils
 
 
+// Environment
+export var
+	GOARCH,
+	GOOS,
+	GOROOT,
+	USER string;
+
+
+func GetEnv(key string) string {
+	n := len(key);
+	for i := 0; i < sys.envc(); i++ {
+		v := sys.envv(i);
+		if v[0 : n] == key {
+			return v[n + 1 : len(v)];  // +1: trim "="
+		}
+	}
+	return "";
+}
+
+
+func init() {
+	GOARCH = GetEnv("GOARCH");
+	GOOS = GetEnv("GOOS");
+	GOROOT = GetEnv("GOROOT");
+	USER = GetEnv("USER");
+}
+
+
 export func BaseName(s string) string {
 	// TODO this is not correct for non-ASCII strings!
 	i := len(s) - 1;
@@ -18,22 +46,10 @@ export func BaseName(s string) string {
 }
 
 
-export func FixExt(s string) string {
-	i := len(s) - 3;  // 3 == len(".go");
-	if i >= 0 && s[i : len(s)] == ".go" {
+export func TrimExt(s, ext string) string {
+	i := len(s) - len(ext);
+	if i >= 0 && s[i : len(s)] == ext {
 		s = s[0 : i];
 	}
-	return s + ".7";
-}
-
-
-export func GetEnv(key string) string {
-	n := len(key);
-	for i := 0; i < sys.envc(); i++ {
-		v := sys.envv(i);
-		if v[0 : n] == key {
-			return v[n + 1 : len(v)];  // +1: skip "="
-		}
-	}
-	return "";
+	return s;
 }