new tool godefs.

uses gcc to determine system header layouts and
emits simple C or Go.  see comment in main.c.

R=r
DELTA=1069  (1067 added, 0 deleted, 2 changed)
OCL=26682
CL=26880

src/cmd/clean.bash

@@ -3,7 +3,7 @@
 # Use of this source code is governed by a BSD-style
 # license that can be found in the LICENSE file.
 
-for i in cc 6l 6a 6c 8l 8a 8c 5l 5a 5c gc 6g ar db nm acid cov gobuild prof gotest
+for i in cc 6l 6a 6c 8l 8a 8c 5l 5a 5c gc 6g ar db nm acid cov gobuild godefs prof gotest
 do
 	cd $i
 	make clean

src/cmd/godefs/Makefile

@@ -0,0 +1,24 @@
+# Copyright 2009 The Go Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+include ../../Make.conf
+
+TARG=godefs
+OFILES=\
+	main.$O\
+	stabs.$O\
+	util.$O\
+
+HFILES=a.h
+
+$(TARG): $(OFILES)
+	$(LD) -o $(TARG) -L$(GOROOT)/lib $(OFILES) -lbio -l9
+
+clean:
+	rm -f $(OFILES) $(TARG)
+
+install: $(TARG)
+	cp $(TARG) $(BIN)/$(TARG)
+
+$(OFILES): $(HFILES)

src/cmd/godefs/a.h

@@ -0,0 +1,101 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+
+enum
+{
+	Void = 1,
+	Int8,
+	Uint8,
+	Int16,
+	Uint16,
+	Int32,
+	Uint32,
+	Int64,
+	Uint64,
+	Float32,
+	Float64,
+	Ptr,
+	Struct,
+	Array,
+	Union,
+	Typedef,
+};
+
+typedef struct Field Field;
+typedef struct Type Type;
+
+struct Type
+{
+	Type *next;	// next in hash table
+
+	// stabs name and two-integer id
+	char *name;
+	int n1;
+	int n2;
+
+	// int kind
+	int kind;
+
+	// sub-type for ptr, array
+	Type *type;
+
+	// struct fields
+	Field *f;
+	int nf;
+	int size;
+
+	int saved;	// recorded in typ array
+	int warned;	// warned about needing type
+};
+
+struct Field
+{
+	char *name;
+	Type *type;
+	int offset;
+	int size;
+};
+
+// Constants
+typedef struct Const Const;
+struct Const
+{
+	char *name;
+	vlong value;
+};
+
+// Recorded constants and types, to be printed.
+extern Const *con;
+extern int ncon;
+extern Type **typ;
+extern int ntyp;
+
+// Language output
+typedef struct Lang Lang;
+struct Lang
+{
+	char *constbegin;
+	char *constfmt;
+	char *constend;
+
+	char *typdef;
+
+	char *structbegin;
+	char *unionbegin;
+	char *structpadfmt;
+	char *structend;
+
+	int (*typefmt)(Fmt*);
+};
+
+extern Lang go, c;
+
+void*	emalloc(int);
+char*	estrdup(char*);
+void*	erealloc(void*, int);
+void		parsestabtype(char*);

src/cmd/godefs/main.c

@@ -0,0 +1,497 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Godefs takes as input a host-compilable C file that includes
+// standard system headers.  From that input file, it generates
+// a standalone (no #includes) C or Go file containing equivalent
+// definitions.
+//
+// The input C file is expected to define new types and enumerated
+// constants whose names begin with $ (a legal identifier character
+// in gcc).  The output is the standalone definitions of those names,
+// with the $ removed.
+//
+// For example, if this is x.c:
+//
+//	#include <sys/stat.h>
+//
+//	typedef struct timespec $Timespec;
+//	typedef struct stat $Stat;
+//	enum {
+//		$S_IFMT = S_IFMT,
+//		$S_IFIFO = S_IFIFO,
+//		$S_IFCHR = S_IFCHR,
+//	};
+//
+// then "godefs x.c" generates:
+//
+//	// godefs x.c
+//
+//	// MACHINE GENERATED - DO NOT EDIT.
+//
+//	// Constants
+//	enum {
+//		S_IFMT = 0xf000,
+//		S_IFIFO = 0x1000,
+//		S_IFCHR = 0x2000,
+//	};
+//
+//	// Types
+//	#pragma pack on
+//
+//	typedef struct Timespec Timespec;
+//	struct Timespec {
+//		int32 tv_sec;
+//		int32 tv_nsec;
+//	};
+//
+//	typedef struct Stat Stat;
+//	struct Stat {
+//		int32 st_dev;
+//		uint32 st_ino;
+//		uint16 st_mode;
+//		uint16 st_nlink;
+//		uint32 st_uid;
+//		uint32 st_gid;
+//		int32 st_rdev;
+//		Timespec st_atimespec;
+//		Timespec st_mtimespec;
+//		Timespec st_ctimespec;
+//		int64 st_size;
+//		int64 st_blocks;
+//		int32 st_blksize;
+//		uint32 st_flags;
+//		uint32 st_gen;
+//		int32 st_lspare;
+//		int64 st_qspare[2];
+//	};
+//	#pragma pack off
+//
+// The -g flag to godefs causes it to generate Go output, not C.
+// In the Go output, struct fields have leading xx_ prefixes removed
+// and the first character capitalized (exported).
+//
+// Godefs works by invoking gcc to compile the given input file
+// and then parses the debug info embedded in the assembly output.
+// This is far easier than reading system headers on most machines.
+//
+// The -c flag sets the compiler (default "gcc").
+//
+// The -f flag adds a flag to pass to the compiler (e.g., -f -m64).
+
+#include "a.h"
+
+void
+usage(void)
+{
+	fprint(2, "usage: godefs [-g] [-c cc] [-f cc-flag] defs.c\n");
+	exit(1);
+}
+
+int gotypefmt(Fmt*);
+int ctypefmt(Fmt*);
+int prefixlen(Type*);
+
+Lang go =
+{
+	"const (\n",
+	"\t%s = %#llx;\n",
+	")\n",
+
+	"type",
+
+	"type %s struct {\n",
+	"type %s union {\n",	// not really, but readable
+	"\tpad%d [%d]byte;\n",
+	"}\n",
+
+	gotypefmt,
+};
+
+Lang c =
+{
+	"enum {\n",
+	"\t%s = %#llx,\n",
+	"};\n",
+
+	"typedef",
+
+	"typedef struct %s %s;\nstruct %s {\n",
+	"typedef union %s %s;\nunion %s {\n",
+	"\tbyte pad%d[%d];\n",
+	"};\n",
+
+	ctypefmt,
+};
+
+int oargc;
+char **oargv;
+Lang *lang = &c;
+
+Const *con;
+int ncon;
+
+Type **typ;
+int ntyp;
+
+void
+main(int argc, char **argv)
+{
+	int p[2], pid, i, j, n, off, npad, prefix;
+	char *av[30], *q, *r, *tofree, *name;
+	Biobuf *bin, *bout;
+	Type *t;
+	Field *f;
+
+	quotefmtinstall();
+
+	oargc = argc;
+	oargv = argv;
+
+	n = 0;
+	av[n++] = "gcc";
+	av[n++] = "-S";	// write assembly
+	av[n++] = "-gstabs";	// include stabs info
+	av[n++] = "-o-";	// to stdout
+
+	ARGBEGIN{
+	case 'g':
+		lang = &go;
+		break;
+	case 'c':
+		av[0] = EARGF(usage());
+		break;
+	case 'f':
+		if(n+2 >= nelem(av))
+			sysfatal("too many -f options");
+		av[n++] = EARGF(usage());
+		break;
+	default:
+		usage();
+	}ARGEND
+
+	if(argc != 1)
+		usage();
+	av[n++] = argv[0];
+	av[n] = nil;
+
+	// Run gcc writing assembly and stabs debugging to p[1].
+	if(pipe(p) < 0)
+		sysfatal("pipe: %r");
+
+	pid = fork();
+	if(pid < 0)
+		sysfatal("fork: %r");
+	if(pid == 0) {
+		close(p[0]);
+		dup(p[1], 1);
+		close(0);
+		open("/dev/null", OREAD);
+		exec(av[0], av);
+		fprint(2, "exec gcc: %r\n");
+		exit(1);
+	}
+	close(p[1]);
+
+	// Read assembly, pulling out .stabs lines.
+	bin = Bfdopen(p[0], OREAD);
+	while((q = Brdstr(bin, '\n', 1)) != nil) {
+		//	.stabs	"float:t(0,12)=r(0,1);4;0;",128,0,0,0
+		tofree = q;
+		while(*q == ' ' || *q == '\t')
+			q++;
+		if(strncmp(q, ".stabs", 6) != 0)
+			goto Continue;
+		q += 6;
+		while(*q == ' ' || *q == '\t')
+			q++;
+		if(*q++ != '\"') {
+		Bad:
+			sysfatal("cannot parse .stabs line:\n%s", tofree);
+		}
+
+		r = strchr(q, '\"');
+		if(r == nil)
+			goto Bad;
+		*r++ = '\0';
+		if(*r++ != ',')
+			goto Bad;
+		if(*r < '0' || *r > '9')
+			goto Bad;
+		if(atoi(r) != 128)	// stabs kind = local symbol
+			goto Continue;
+
+		parsestabtype(q);
+
+	Continue:
+		free(tofree);
+	}
+	Bterm(bin);
+	waitpid();
+
+	// Write defs to standard output.
+	bout = Bfdopen(1, OWRITE);
+	fmtinstall('T', lang->typefmt);
+
+	// Echo original command line in header.
+	Bprint(bout, "//");
+	for(i=0; i<oargc; i++)
+		Bprint(bout, " %q", oargv[i]);
+	Bprint(bout, "\n");
+	Bprint(bout, "\n");
+	Bprint(bout, "// MACHINE GENERATED - DO NOT EDIT.\n");
+	Bprint(bout, "\n");
+
+	// Constants.
+	Bprint(bout, "// Constants\n");
+	if(ncon > 0) {
+		Bprint(bout, lang->constbegin);
+		for(i=0; i<ncon; i++)
+			Bprint(bout, lang->constfmt, con[i].name, con[i].value);
+		Bprint(bout, lang->constend);
+	}
+	Bprint(bout, "\n");
+
+	// Types
+
+	// push our names down
+	for(i=0; i<ntyp; i++) {
+		t = typ[i];
+		name = t->name;
+		while(t && t->kind == Typedef)
+			t = t->type;
+		if(t)
+			t->name = name;
+	}
+
+	Bprint(bout, "// Types\n");
+
+	// Have to turn off structure padding in Plan 9 compiler,
+	// mainly because it is more aggressive than gcc tends to be.
+	if(lang == &c)
+		Bprint(bout, "#pragma pack on\n");
+
+	for(i=0; i<ntyp; i++) {
+		Bprint(bout, "\n");
+		t = typ[i];
+		while(t && t->kind == Typedef)
+			t = t->type;
+		name = t->name;
+		if(name[0] == '$')
+			name++;
+		npad = 0;
+		off = 0;
+		switch(t->kind) {
+		case 0:
+			fprint(2, "unknown type definition for %s\n", name);
+			break;
+		default:	// numeric, array, or pointer
+		case Array:
+		case Ptr:
+			Bprint(bout, "%s %lT\n", lang->typdef, name, t);
+			break;
+		case Union:
+			if(lang == &go) {
+				fprint(2, "%s: cannot emit unions in go\n", name);
+				continue;
+			}
+			Bprint(bout, lang->unionbegin, name, name, name);
+			goto StructBody;
+		case Struct:
+			Bprint(bout, lang->structbegin, name, name, name);
+		StructBody:
+			prefix = 0;
+			if(lang == &go)
+				prefix = prefixlen(t);
+			for(j=0; j<t->nf; j++) {
+				f = &t->f[j];
+				// padding
+				if(t->kind == Struct) {
+					if(f->offset%8 != 0 || f->size%8 != 0) {
+						fprint(2, "ignoring bitfield %s.%s\n", t->name, f->name);
+						continue;
+					}
+					if(f->offset < off)
+						sysfatal("%s: struct fields went backward", t->name);
+					if(off < f->offset) {
+						Bprint(bout, lang->structpadfmt, npad++, (f->offset - off) / 8);
+						off = f->offset;
+					}
+					off += f->size;
+				}
+				Bprint(bout, "\t%lT;\n", f->name+prefix, f->type);
+			}
+			// final padding
+			if(t->kind == Struct) {
+				if(off/8 < t->size)
+					Bprint(bout, lang->structpadfmt, npad++, t->size - off/8);
+			}
+			Bprint(bout, lang->structend);
+		}
+	}
+	if(lang == &c)
+		Bprint(bout, "#pragma pack off\n");
+	Bterm(bout);
+	exit(0);
+}
+
+char *kindnames[] = {
+	"void",	// actually unknown, but byte is good for pointers
+	"void",
+	"int8",
+	"uint8",
+	"int16",
+	"uint16",
+	"int32",
+	"uint32",
+	"int64",
+	"uint64",
+	"float32",
+	"float64",
+	"ptr",
+	"struct",
+	"array",
+	"union",
+	"typedef",
+};
+
+int
+ctypefmt(Fmt *f)
+{
+	char *name, *s;
+	Type *t;
+
+	name = nil;
+	if(f->flags & FmtLong) {
+		name = va_arg(f->args, char*);
+		if(name == nil || name[0] == '\0')
+			name = "_anon_";
+	}
+	t = va_arg(f->args, Type*);
+	while(t && t->kind == Typedef)
+		t = t->type;
+	switch(t->kind) {
+	case Struct:
+	case Union:
+		// must be named
+		s = t->name;
+		if(s == nil) {
+			fprint(2, "need name for anonymous struct\n");
+			goto bad;
+		}
+		else if(s[0] != '$')
+			fprint(2, "need name for struct %s\n", s);
+		else
+			s++;
+		fmtprint(f, "%s", s);
+		if(name)
+			fmtprint(f, " %s", name);
+		break;
+
+	case Array:
+		if(name)
+			fmtprint(f, "%T %s[%d]", t->type, name, t->size);
+		else
+			fmtprint(f, "%T[%d]", t->type, t->size);
+		break;
+
+	case Ptr:
+		if(name)
+			fmtprint(f, "%T *%s", t->type, name);
+		else
+			fmtprint(f, "%T*", t->type);
+		break;
+
+	default:
+		fmtprint(f, "%s", kindnames[t->kind]);
+		if(name)
+			fmtprint(f, " %s", name);
+		break;
+
+	bad:
+		if(name)
+			fmtprint(f, "byte %s[%d]", name, t->size);
+		else
+			fmtprint(f, "byte[%d]", t->size);
+		break;
+	}
+
+	return 0;
+}
+
+int
+gotypefmt(Fmt *f)
+{
+	char *name, *s;
+	Type *t;
+
+	if(f->flags & FmtLong) {
+		name = va_arg(f->args, char*);
+		if('a' <= name[0] && name[0] <= 'z')
+			name[0] += 'A' - 'a';
+		fmtprint(f, "%s ", name);
+	}
+	t = va_arg(f->args, Type*);
+	while(t && t->kind == Typedef)
+		t = t->type;
+
+	switch(t->kind) {
+	case Struct:
+	case Union:
+		// must be named
+		s = t->name;
+		if(s == nil) {
+			fprint(2, "need name for anonymous struct\n");
+			s = "STRUCT";
+		}
+		else if(s[0] != '$')
+			fprint(2, "need name for struct %s\n", s);
+		else
+			s++;
+		fmtprint(f, "%s", s);
+		break;
+
+	case Array:
+		fmtprint(f, "[%d]%T", t->size, t->type);
+		break;
+
+	case Ptr:
+		fmtprint(f, "*%T", t->type);
+		break;
+
+	default:
+		s = kindnames[t->kind];
+		if(strcmp(s, "void") == 0)
+			s = "byte";
+		fmtprint(f, "%s", s);
+	}
+
+	return 0;
+}
+
+// Figure out common struct prefix len
+int
+prefixlen(Type *t)
+{
+	int i;
+	int len;
+	char *p, *name;
+	Field *f;
+
+	len = 0;
+	name = nil;
+	for(i=0; i<t->nf; i++) {
+		f = &t->f[i];
+		p = strchr(f->name, '_');
+		if(p == nil)
+			return 0;
+		if(name == nil) {
+			name = f->name;
+			len = p+1 - name;
+		}
+		else if(strncmp(f->name, name, len) != 0)
+			return 0;
+	}
+	return len;
+}

src/cmd/godefs/stabs.c

@@ -0,0 +1,418 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Parse stabs debug info.
+
+#include "a.h"
+
+int stabsdebug = 1;
+
+// Hash table for type lookup by number.
+Type *hash[1024];
+
+// Look up type by number pair.
+// TODO(rsc): Iant points out that n1 and n2 are always small and dense,
+// so an array of arrays would be a better representation.
+Type*
+typebynum(uint n1, uint n2)
+{
+	uint h;
+	Type *t;
+
+	h = (n1*53+n2) % nelem(hash);
+	for(t=hash[h]; t; t=t->next)
+		if(t->n1 == n1 && t->n2 == n2)
+			return t;
+	t = emalloc(sizeof *t);
+	t->next = hash[h];
+	hash[h] = t;
+	t->n1 = n1;
+	t->n2 = n2;
+	return t;
+}
+
+// Parse name and colon from *pp, leaving copy in *sp.
+static int
+parsename(char **pp, char **sp)
+{
+	char *p;
+	char *s;
+
+	p = *pp;
+	while(*p != '\0' && *p != ':')
+		p++;
+	if(*p == '\0') {
+		fprint(2, "parsename expected colon\n");
+		return -1;
+	}
+	s = emalloc(p - *pp + 1);
+	memmove(s, *pp, p - *pp);
+	*sp = s;
+	*pp = p+1;
+	return 0;
+}
+
+// Parse single number from *pp.
+static int
+parsenum1(char **pp, vlong *np)
+{
+	char *p;
+
+	p = *pp;
+	if(*p != '-' && (*p < '0' || *p > '9')) {
+		fprint(2, "parsenum expected minus or digit\n");
+		return -1;
+	}
+	*np = strtoll(p, pp, 10);
+	return 0;
+}
+
+// Parse type number - either single number or (n1, n2).
+static int
+parsetypenum(char **pp, vlong *n1p, vlong *n2p)
+{
+	char *p;
+
+	p = *pp;
+	if(*p == '(') {
+		p++;
+		if(parsenum1(&p, n1p) < 0)
+			return -1;
+		if(*p++ != ',') {
+			if(stabsdebug)
+				fprint(2, "parsetypenum expected comma\n");
+			return -1;
+		}
+		if(parsenum1(&p, n2p) < 0)
+			return -1;
+		if(*p++ != ')') {
+			if(stabsdebug)
+				fprint(2, "parsetypenum expected right paren\n");
+			return -1;
+		}
+		*pp = p;
+		return 0;
+	}
+
+	if(parsenum1(&p, n1p) < 0)
+		return -1;
+	*n2p = 0;
+	*pp = p;
+	return 0;
+}
+
+// Integer types are represented in stabs as a "range"
+// type with a lo and a hi value.  The lo and hi used to
+// be lo and hi for the type, but there are now odd
+// extensions for floating point and 64-bit numbers.
+//
+// Have to keep signs separate from values because
+// Int64's lo is -0.
+typedef struct Intrange Intrange;
+struct Intrange
+{
+	int signlo;	// sign of lo
+	vlong lo;
+	int signhi;	// sign of hi
+	vlong hi;
+	int kind;
+};
+
+// NOTE(rsc): Iant says that these might be different depending
+// on the gcc mode, though I haven't observed this yet.
+Intrange intranges[] = {
+	'+', 0, '+', 127, Int8,	// char
+	'-', 128, '+', 127, Int8,	// signed char
+	'+', 0, '+', 255, Uint8,
+	'-', 32768, '+', 32767, Int16,
+	'+', 0, '+', 65535, Uint16,
+	'-', 2147483648LL, '+', 2147483647LL, Int32,
+	'+', 0, '+', 4294967295LL, Uint32,
+
+	// abnormal cases
+	'-', 0, '+', 4294967295LL, Int64,
+	'+', 0, '-', 1, Uint64,
+
+	'+', 4, '+', 0, Float32,
+	'+', 8, '+', 0, Float64,
+	'+', 16, '+', 0, Void,
+};
+
+static int kindsize[] = {
+	0,
+	8,
+	8,
+	16,
+	16,
+	32,
+	32,
+	64,
+	64,
+};
+
+// Parse a single type definition from *pp.
+static Type*
+parsedef(char **pp, char *name)
+{
+	char *p;
+	Type *t, *tt;
+	int i, signlo, signhi;
+	vlong n1, n2, lo, hi;
+	Field *f;
+	Intrange *r;
+
+	p = *pp;
+
+	// reference to another type?
+	if(isdigit(*p) || *p == '(') {
+		if(parsetypenum(&p, &n1, &n2) < 0)
+			return nil;
+		t = typebynum(n1, n2);
+		if(name && t->name == nil) {
+			t->name = name;
+			// save definitions of names beginning with $
+			if(name[0] == '$' && !t->saved) {
+				typ = erealloc(typ, (ntyp+1)*sizeof typ[0]);
+				typ[ntyp] = t;
+				ntyp++;
+			}
+		}
+
+		// is there an =def suffix?
+		if(*p == '=') {
+			p++;
+			tt = parsedef(&p, name);
+			if(tt == nil)
+				return nil;
+
+			if(tt == t) {
+				tt->kind = Void;
+			} else {
+				t->type = tt;
+				t->kind = Typedef;
+			}
+
+			// assign given name, but do not record in typ.
+			// assume the name came from a typedef
+			// which will be recorded.
+			if(name)
+				tt->name = name;
+		}
+
+		*pp = p;
+		return t;
+	}
+
+	// otherwise a type literal.  first letter identifies kind
+	t = emalloc(sizeof *t);
+	switch(*p) {
+	default:
+		*pp = "";
+		return t;
+
+	case '*':	// pointer
+		p++;
+		t->kind = Ptr;
+		tt = parsedef(&p, nil);
+		if(tt == nil)
+			return nil;
+		t->type = tt;
+		break;
+
+	case 'a':	// array
+		p++;
+		t->kind = Array;
+		// index type
+		tt = parsedef(&p, nil);
+		if(tt == nil)
+			return nil;
+		t->size = tt->size;
+		// element type
+		tt = parsedef(&p, nil);
+		if(tt == nil)
+			return nil;
+		t->type = tt;
+		break;
+
+	case 'e':	// enum type - record $names in con array.
+		p++;
+		for(;;) {
+			if(*p == '\0')
+				return nil;
+			if(*p == ';') {
+				p++;
+				break;
+			}
+			if(parsename(&p, &name) < 0)
+				return nil;
+			if(parsenum1(&p, &n1) < 0)
+				return nil;
+			if(name[0] == '$') {
+				con = erealloc(con, (ncon+1)*sizeof con[0]);
+				name++;
+				con[ncon].name = name;
+				con[ncon].value = n1;
+				ncon++;
+			}
+			if(*p != ',')
+				return nil;
+			p++;
+		}
+		break;
+
+	case 'f':	// function
+		p++;
+		if(parsedef(&p, nil) == nil)
+			return nil;
+		break;
+
+	case 'r':	// sub-range (used for integers)
+		p++;
+		if(parsedef(&p, nil) == nil)
+			return nil;
+		// usually, the return from parsedef == t, but not always.
+
+		if(*p != ';' || *++p == ';') {
+			if(stabsdebug)
+				fprint(2, "range expected number: %s\n", p);
+			return nil;
+		}
+		if(*p == '-') {
+			signlo = '-';
+			p++;
+		} else
+			signlo = '+';
+		lo = strtoll(p, &p, 10);
+		if(*p != ';' || *++p == ';') {
+			if(stabsdebug)
+				fprint(2, "range expected number: %s\n", p);
+			return nil;
+		}
+		if(*p == '-') {
+			signhi = '-';
+			p++;
+		} else
+			signhi = '+';
+		hi = strtoll(p, &p, 10);
+		if(*p != ';') {
+			if(stabsdebug)
+				fprint(2, "range expected trailing semi: %s\n", p);
+			return nil;
+		}
+		p++;
+		t->size = hi+1;	// might be array size
+		for(i=0; i<nelem(intranges); i++) {
+			r = &intranges[i];
+			if(r->signlo == signlo && r->signhi == signhi && r->lo == lo && r->hi == hi) {
+				t->kind = r->kind;
+				break;
+			}
+		}
+		break;
+
+	case 's':	// struct
+	case 'u':	// union
+		t->kind = Struct;
+		if(*p == 'u')
+			t->kind = Union;
+
+		// assign given name, but do not record in typ.
+		// assume the name came from a typedef
+		// which will be recorded.
+		if(name)
+			t->name = name;
+		p++;
+		if(parsenum1(&p, &n1) < 0)
+			return nil;
+		t->size = n1;
+		for(;;) {
+			if(*p == '\0')
+				return nil;
+			if(*p == ';') {
+				p++;
+				break;
+			}
+			t->f = erealloc(t->f, (t->nf+1)*sizeof t->f[0]);
+			f = &t->f[t->nf];
+			if(parsename(&p, &f->name) < 0)
+				return nil;
+			f->type = parsedef(&p, nil);
+			if(f->type == nil)
+				return nil;
+			if(*p != ',') {
+				fprint(2, "expected comma after def of %s:\n%s\n", f->name, p);
+				return nil;
+			}
+			p++;
+			if(parsenum1(&p, &n1) < 0)
+				return nil;
+			f->offset = n1;
+			if(*p != ',') {
+				fprint(2, "expected comma after offset of %s:\n%s\n", f->name, p);
+				return nil;
+			}
+			p++;
+			if(parsenum1(&p, &n1) < 0)
+				return nil;
+			f->size = n1;
+			if(*p != ';') {
+				fprint(2, "expected semi after size of %s:\n%s\n", f->name, p);
+				return nil;
+			}
+
+			// rewrite
+			//	uint32 x : 8;
+			// into
+			//	uint8 x;
+			// hooray for bitfields.
+			while(Int16 <= f->type->kind && f->type->kind <= Uint64 && kindsize[f->type->kind] > f->size) {
+				t = emalloc(sizeof *t);
+				*t = *f->type;
+				f->type = t;
+				f->type->kind -= 2;
+			}
+			p++;
+			t->nf++;
+		}
+		break;
+
+
+	}
+	*pp = p;
+	return t;
+}
+
+
+// Parse a stab type in p, saving info in the type hash table
+// and also in the list of recorded types if appropriate.
+void
+parsestabtype(char *p)
+{
+	char *p0, *name;
+
+	p0 = p;
+
+	// p is the quoted string output from gcc -gstabs on a .stabs line.
+	//	name:t(1,2)
+	//	name:t(1,2)=def
+	if(parsename(&p, &name) < 0) {
+	Bad:
+		// Use fprint instead of sysfatal to avoid
+		// sysfatal's internal buffer size limit.
+		fprint(2, "cannot parse stabs type:\n%s\n(at %s)\n", p0, p);
+		sysfatal("stabs parse");
+	}
+	if(*p != 't' && *p != 'T')
+		goto Bad;
+	p++;
+
+	// parse the definition.
+	if(name[0] == '\0')
+		name = nil;
+	if(parsedef(&p, name) == nil)
+		goto Bad;
+	if(*p != '\0')
+		goto Bad;
+}
+

src/cmd/godefs/util.c

@@ -0,0 +1,36 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "a.h"
+
+void*
+emalloc(int n)
+{
+	void *p;
+
+	p = malloc(n);
+	if(p == nil)
+		sysfatal("out of memory");
+	memset(p, 0, n);
+	return p;
+}
+
+char*
+estrdup(char *s)
+{
+	s = strdup(s);
+	if(s == nil)
+		sysfatal("out of memory");
+	return s;
+}
+
+void*
+erealloc(void *v, int n)
+{
+	v = realloc(v, n);
+	if(v == nil)
+		sysfatal("out of memory");
+	return v;
+}
+

src/cmd/make.bash

@@ -12,7 +12,7 @@ bash mkenam
 make enam.o
 cd ..
 
-for i in cc 6l 6a 6c gc 6g ar db nm acid cov gobuild prof gotest
+for i in cc 6l 6a 6c gc 6g ar db nm acid cov gobuild godefs prof gotest
 do
 	echo; echo; echo %%%% making $i %%%%; echo
 	cd $i