cmd/nm: reimplement in Go

The immediate goal is to support the new object file format,
which libmach (nm's support library) does not understand.
Rather than add code to libmach or reengineer liblink to
support this new use, just write it in Go.

The C version of nm reads the Plan 9 symbol table stored in
Go binaries, now otherwise unused.

This reimplementation uses the standard symbol table for
the corresponding file format instead, bringing us one step
closer to removing the Plan 9 symbol table from Go binaries.

Tell cmd/dist not to build cmd/nm anymore.
Tell cmd/go to install cmd/nm in the tool directory.

R=golang-dev, r, iant, alex.brainman
CC=golang-dev
https://golang.org/cl/40600043

1 files changed, 0 insertions, 401 deletions

diff --git a/src/cmd/nm/nm.c b/src/cmd/nm/nm.c
deleted file mode 100644
index 8209424269..0000000000
--- a/src/cmd/nm/nm.c
+++ /dev/null
@@ -1,401 +0,0 @@
-// Inferno utils/nm/nm.c
-// http://code.google.com/p/inferno-os/source/browse/utils/nm/nm.c
-//
-//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
-//	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
-//	Portions Copyright © 1997-1999 Vita Nuova Limited
-//	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
-//	Portions Copyright © 2004,2006 Bruce Ellis
-//	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
-//	Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
-//	Portions Copyright © 2009 The Go Authors. All rights reserved.
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-
-/*
- * nm.c -- drive nm
- */
-#include <u.h>
-#include <libc.h>
-#include <ar.h>
-#include <bio.h>
-#include <mach.h>
-
-enum{
-	CHUNK	=	256	/* must be power of 2 */
-};
-
-char	*errs;			/* exit status */
-char	*filename;		/* current file */
-char	symname[]="__.GOSYMDEF";	/* table of contents file name */
-int	multifile;		/* processing multiple files */
-int	aflag;
-int	gflag;
-int	hflag;
-int	nflag;
-int	sflag;
-int	Sflag;
-int	uflag;
-int	Tflag;
-int	tflag;
-
-Sym	**fnames;		/* file path translation table */
-Sym	**symptr;
-int	nsym;
-Biobuf	bout;
-
-int	cmp(void*, void*);
-void	error(char*, ...);
-void	execsyms(int);
-void	psym(Sym*, void*);
-void	printsyms(Sym**, long);
-void	doar(Biobuf*);
-void	dofile(Biobuf*);
-void	zenter(Sym*);
-
-void
-usage(void)
-{
-	fprint(2, "usage: nm [-aghnsSTu] file ...\n");
-	exits("usage");
-}
-
-void
-main(int argc, char *argv[])
-{
-	int i;
-	Biobuf	*bin;
-
-	Binit(&bout, 1, OWRITE);
-	argv0 = argv[0];
-	ARGBEGIN {
-	default:	usage();
-	case 'a':	aflag = 1; break;
-	case 'g':	gflag = 1; break;
-	case 'h':	hflag = 1; break;
-	case 'n':	nflag = 1; break;
-	case 's':	sflag = 1; break;
-	case 'S':	nflag = Sflag = 1; break;
-	case 'u':	uflag = 1; break;
-	case 't':	tflag = 1; break;
-	case 'T':	Tflag = 1; break;
-	} ARGEND
-	if (argc == 0)
-		usage();
-	if (argc > 1)
-		multifile++;
-	for(i=0; i<argc; i++){
-		filename = argv[i];
-		bin = Bopen(filename, OREAD);
-		if(bin == 0){
-			error("cannot open %s", filename);
-			continue;
-		}
-		if (isar(bin))
-			doar(bin);
-		else{
-			Bseek(bin, 0, 0);
-			dofile(bin);
-		}
-		Bterm(bin);
-	}
-	exits(errs);
-}
-
-/*
- * read an archive file,
- * processing the symbols for each intermediate file in it.
- */
-void
-doar(Biobuf *bp)
-{
-	int offset, size, obj;
-	char name[SARNAME];
-
-	multifile = 1;
-	for (offset = Boffset(bp);;offset += size) {
-		size = nextar(bp, offset, name);
-		if (size < 0) {
-			error("phase error on ar header %d", offset);
-			return;
-		}
-		if (size == 0)
-			return;
-		if (strcmp(name, symname) == 0)
-			continue;
-		obj = objtype(bp, 0);
-		if (obj < 0) {
-			// perhaps foreign object
-			if(strlen(name) > 2 && strcmp(name+strlen(name)-2, ".o") == 0)
-				return;
-			error("inconsistent file %s in %s",
-					name, filename);
-			return;
-		}
-		if (!readar(bp, obj, offset+size, 1)) {
-			error("invalid symbol reference in file %s",
-					name);
-			return;
-		}
-		filename = name;
-		nsym=0;
-		objtraverse(psym, 0);
-		printsyms(symptr, nsym);
-	}
-}
-
-/*
- * process symbols in a file
- */
-void
-dofile(Biobuf *bp)
-{
-	int obj;
-
-	obj = objtype(bp, 0);
-	if (obj < 0)
-		execsyms(Bfildes(bp));
-	else
-	if (readobj(bp, obj)) {
-		nsym = 0;
-		objtraverse(psym, 0);
-		printsyms(symptr, nsym);
-	}
-}
-
-/*
- * comparison routine for sorting the symbol table
- *	this screws up on 'z' records when aflag == 1
- */
-int
-cmp(void *vs, void *vt)
-{
-	Sym **s, **t;
-
-	s = vs;
-	t = vt;
-	if(nflag)	// sort on address (numeric) order
-		if((*s)->value < (*t)->value)
-			return -1;
-		else
-			return (*s)->value > (*t)->value;
-	if(sflag)	// sort on file order (sequence)
-		return (*s)->sequence - (*t)->sequence;
-	return strcmp((*s)->name, (*t)->name);
-}
-/*
- * enter a symbol in the table of filename elements
- */
-void
-zenter(Sym *s)
-{
-	static int maxf = 0;
-
-	if (s->value > maxf) {
-		maxf = (s->value+CHUNK-1) &~ (CHUNK-1);
-		fnames = realloc(fnames, (maxf+1)*sizeof(*fnames));
-		if(fnames == 0) {
-			error("out of memory", argv0);
-			exits("memory");
-		}
-	}
-	fnames[s->value] = s;
-}
-
-/*
- * get the symbol table from an executable file, if it has one
- */
-void
-execsyms(int fd)
-{
-	Fhdr f;
-	Sym *s;
-	int32 n;
-
-	seek(fd, 0, 0);
-	if (crackhdr(fd, &f) == 0) {
-		error("Can't read header for %s", filename);
-		return;
-	}
-	if (syminit(fd, &f) < 0)
-		return;
-	s = symbase(&n);
-	nsym = 0;
-	while(n--)
-		psym(s++, 0);
-
-	printsyms(symptr, nsym);
-}
-
-void
-psym(Sym *s, void* p)
-{
-	USED(p);
-	switch(s->type) {
-	case 'T':
-	case 'L':
-	case 'D':
-	case 'B':
-		if (uflag)
-			return;
-		if (!aflag && ((s->name[0] == '.' || s->name[0] == '$')))
-			return;
-		break;
-	case 'b':
-	case 'd':
-	case 'l':
-	case 't':
-		if (uflag || gflag)
-			return;
-		if (!aflag && ((s->name[0] == '.' || s->name[0] == '$')))
-			return;
-		break;
-	case 'U':
-		if (gflag)
-			return;
-		break;
-	case 'Z':
-		if (!aflag)
-			return;
-		break;
-	case 'm':
-		if(!aflag || uflag || gflag)
-			return;
-		break;
-	case 'f':	/* we only see a 'z' when the following is true*/
-		if(!aflag || uflag || gflag)
-			return;
-		zenter(s);
-		break;
-	case 'a':
-	case 'p':
-	case 'z':
-	default:
-		if(!aflag || uflag || gflag)
-			return;
-		break;
-	}
-	symptr = realloc(symptr, (nsym+1)*sizeof(Sym*));
-	if (symptr == 0) {
-		error("out of memory");
-		exits("memory");
-	}
-	symptr[nsym++] = s;
-}
-
-const char *skipnames[] = {
-	"bss",
-	"data",
-	"ebss",
-	"edata",
-	"egcbss",
-	"egcdata",
-	"enoptrbss",
-	"enoptrdata",
-	"epclntab",
-	"erodata",
-	"esymtab",
-	"etext",
-	"etypelink",
-	"noptrbss",
-	"noptrdata",
-	"rodata",
-	"text",
-};
-
-int
-skipsize(char *name)
-{
-	int i;
-	
-	for(i=0; i<nelem(skipnames); i++)
-		if(strcmp(skipnames[i], name) == 0)
-			return 1;
-	return 0;
-}
-
-void
-printsyms(Sym **symptr, long nsym)
-{
-	int i, j, wid;
-	Sym *s;
-	char *cp;
-	char path[512];
-
-	qsort(symptr, nsym, sizeof(*symptr), (void*)cmp);
-
-	wid = 0;
-	for (i=0; i<nsym; i++) {
-		s = symptr[i];
-		if (s->value && wid == 0)
-			wid = 8;
-		else if (s->value >= 0x100000000LL && wid == 8)
-			wid = 16;
-	}
-	for (i=0; i<nsym; i++) {
-		s = symptr[i];
-		if (multifile && !hflag)
-			Bprint(&bout, "%s:", filename);
-		if (s->type == 'z') {
-			fileelem(fnames, (uchar *) s->name, path, 512);
-			cp = path;
-		} else
-			cp = s->name;
-		if (Tflag)
-			Bprint(&bout, "%8ux ", s->sig);
-		if (s->value || s->type == 'a' || s->type == 'p')
-			Bprint(&bout, "%*llux ", wid, s->value);
-		else
-			Bprint(&bout, "%*s ", wid, "");
-		if(Sflag && !skipsize(cp)) {
-			vlong siz;
-
-			siz = 0;
-			for(j=i+1; j<nsym; j++) {
-				if(!skipsize(symptr[j]->name) && symptr[j]->type != 'a' && symptr[j]->type != 'p') {
-					siz = symptr[j]->value - s->value;
-					break;
-				}
-			}
-			if(siz > 0)
-				Bprint(&bout, "%*llud ", wid, siz);
-		}
-		Bprint(&bout, "%c %s", s->type, cp);
-		if(tflag && s->gotype)
-			Bprint(&bout, " %*llux", wid, s->gotype);
-		Bprint(&bout, "\n");
-	}
-}
-
-void
-error(char *fmt, ...)
-{
-	Fmt f;
-	char buf[128];
-	va_list arg;
-
-	fmtfdinit(&f, 2, buf, sizeof buf);
-	fmtprint(&f, "%s: ", argv0);
-	va_start(arg, fmt);
-	fmtvprint(&f, fmt, arg);
-	va_end(arg);
-	fmtprint(&f, "\n");
-	fmtfdflush(&f);
-	errs = "errors";
-}