libgo, compiler: Upgrade libgo to Go 1.4, except for runtime.

This upgrades all of libgo other than the runtime package to
the Go 1.4 release.  In Go 1.4 much of the runtime was
rewritten into Go.  Merging that code will take more time and
will not change the API, so I'm putting it off for now.

There are a few runtime changes anyhow, to accomodate other
packages that rely on minor modifications to the runtime
support.

The compiler changes slightly to add a one-bit flag to each
type descriptor kind that is stored directly in an interface,
which for gccgo is currently only pointer types.  Another
one-bit flag (gcprog) is reserved because it is used by the gc
compiler, but gccgo does not currently use it.

There is another error check in the compiler since I ran
across it during testing.

gotools/:
	* Makefile.am (go_cmd_go_files): Sort entries.  Add generate.go.
	* Makefile.in: Rebuild.

From-SVN: r219627

2 files changed, 28 insertions, 9 deletions

diff --git a/libgo/go/flag/flag.go b/libgo/go/flag/flag.go
index cd2a165..60aef5d 100644
--- a/libgo/go/flag/flag.go
+++ b/libgo/go/flag/flag.go
@@ -73,7 +73,8 @@ import (
 	"time"
 )
 
-// ErrHelp is the error returned if the flag -help is invoked but no such flag is defined.
+// ErrHelp is the error returned if the -help or -h flag is invoked
+// but no such flag is defined.
 var ErrHelp = errors.New("flag: help requested")
 
 // -- bool Value
@@ -405,6 +406,7 @@ func defaultUsage(f *FlagSet) {
 // for how to write your own usage function.
 
 // Usage prints to standard error a usage message documenting all defined command-line flags.
+// It is called when an error occurs while parsing flags.
 // The function is a variable that may be changed to point to a custom function.
 var Usage = func() {
 	fmt.Fprintf(os.Stderr, "Usage of %s:\n", os.Args[0])
@@ -628,18 +630,21 @@ func Float64(name string, value float64, usage string) *float64 {
 
 // DurationVar defines a time.Duration flag with specified name, default value, and usage string.
 // The argument p points to a time.Duration variable in which to store the value of the flag.
+// The flag accepts a value acceptable to time.ParseDuration.
 func (f *FlagSet) DurationVar(p *time.Duration, name string, value time.Duration, usage string) {
 	f.Var(newDurationValue(value, p), name, usage)
 }
 
 // DurationVar defines a time.Duration flag with specified name, default value, and usage string.
 // The argument p points to a time.Duration variable in which to store the value of the flag.
+// The flag accepts a value acceptable to time.ParseDuration.
 func DurationVar(p *time.Duration, name string, value time.Duration, usage string) {
 	CommandLine.Var(newDurationValue(value, p), name, usage)
 }
 
 // Duration defines a time.Duration flag with specified name, default value, and usage string.
 // The return value is the address of a time.Duration variable that stores the value of the flag.
+// The flag accepts a value acceptable to time.ParseDuration.
 func (f *FlagSet) Duration(name string, value time.Duration, usage string) *time.Duration {
 	p := new(time.Duration)
 	f.DurationVar(p, name, value, usage)
@@ -648,6 +653,7 @@ func (f *FlagSet) Duration(name string, value time.Duration, usage string) *time
 
 // Duration defines a time.Duration flag with specified name, default value, and usage string.
 // The return value is the address of a time.Duration variable that stores the value of the flag.
+// The flag accepts a value acceptable to time.ParseDuration.
 func Duration(name string, value time.Duration, usage string) *time.Duration {
 	return CommandLine.Duration(name, value, usage)
 }
@@ -697,13 +703,15 @@ func (f *FlagSet) failf(format string, a ...interface{}) error {
 	return err
 }
 
-// usage calls the Usage method for the flag set, or the usage function if
-// the flag set is CommandLine.
+// usage calls the Usage method for the flag set if one is specified,
+// or the appropriate default usage function otherwise.
 func (f *FlagSet) usage() {
-	if f == CommandLine {
-		Usage()
-	} else if f.Usage == nil {
-		defaultUsage(f)
+	if f.Usage == nil {
+		if f == CommandLine {
+			Usage()
+		} else {
+			defaultUsage(f)
+		}
 	} else {
 		f.Usage()
 	}
@@ -752,6 +760,7 @@ func (f *FlagSet) parseOne() (bool, error) {
 		}
 		return false, f.failf("flag provided but not defined: -%s", name)
 	}
+
 	if fv, ok := flag.Value.(boolFlag); ok && fv.IsBoolFlag() { // special case: doesn't need an arg
 		if has_value {
 			if err := fv.Set(value); err != nil {
@@ -784,7 +793,7 @@ func (f *FlagSet) parseOne() (bool, error) {
 // Parse parses flag definitions from the argument list, which should not
 // include the command name.  Must be called after all flags in the FlagSet
 // are defined and before flags are accessed by the program.
-// The return value will be ErrHelp if -help was set but not defined.
+// The return value will be ErrHelp if -help or -h were set but not defined.
 func (f *FlagSet) Parse(arguments []string) error {
 	f.parsed = true
 	f.args = arguments
@@ -826,7 +835,7 @@ func Parsed() bool {
 }
 
 // CommandLine is the default set of command-line flags, parsed from os.Args.
-// The top-level functions such as BoolVar, Arg, and on are wrappers for the
+// The top-level functions such as BoolVar, Arg, and so on are wrappers for the
 // methods of CommandLine.
 var CommandLine = NewFlagSet(os.Args[0], ExitOnError)
 
diff --git a/libgo/go/flag/flag_test.go b/libgo/go/flag/flag_test.go
index 2c03872..8c88c8c 100644
--- a/libgo/go/flag/flag_test.go
+++ b/libgo/go/flag/flag_test.go
@@ -251,6 +251,16 @@ func TestUserDefined(t *testing.T) {
 	}
 }
 
+func TestUserDefinedForCommandLine(t *testing.T) {
+	const help = "HELP"
+	var result string
+	ResetForTesting(func() { result = help })
+	Usage()
+	if result != help {
+		t.Fatalf("got %q; expected %q", result, help)
+	}
+}
+
 // Declare a user-defined boolean flag type.
 type boolFlagVar struct {
 	count int