symbol table changes

* add gotype string to symbol table
	* fill in gotype in 6l for known funcs/vars
	* print gotype with nm -t

	* load symbol and pc/ln tables into memory at magic address 0x99<<32.
	* add sys.symdat() to retrieve raw bytes of symbol table
	  and pc/ln table.

most of this should be considered experimental
and subject to change.

R=r
DELTA=157  (128 added, 0 deleted, 29 changed)
OCL=19746
CL=19750

include/mach_amd64.h

@@ -84,6 +84,7 @@ struct	Sym
 	uint	sig;
 	char	type;
 	char	*name;
+	char *gotype;
 };
 /*
  * End of Plan 9 a.out.h

src/cmd/6l/asm.c

@@ -121,10 +121,11 @@ asmb(void)
 {
 	Prog *p;
 	int32 v, magic;
-	int a;
+	int a, np;
 	uchar *op1;
-	vlong vl, va, fo, w;
+	vlong vl, va, fo, w, symo;
 	int strtabsize;
+	vlong symdatva = 0x99LL<<32;
 
 	strtabsize = 0;
 
@@ -221,6 +222,7 @@ asmb(void)
 	symsize = 0;
 	spsize = 0;
 	lcsize = 0;
+	symo = 0;
 	if(!debug['s']) {
 		if(debug['v'])
 			Bprint(&bso, "%5.2f sym\n", cputime());
@@ -230,15 +232,17 @@ asmb(void)
 		case 2:
 		case 5:
 			debug['s'] = 1;
-			seek(cout, HEADR+textsize+datsize, 0);
+			symo = HEADR+textsize+datsize;
 			break;
 		case 6:
-			seek(cout, rnd(HEADR+textsize, INITRND)+rnd(datsize, INITRND), 0);
+			symo = rnd(HEADR+textsize, INITRND)+rnd(datsize, INITRND);
 			break;
 		case 7:
-			seek(cout, rnd(HEADR+textsize, INITRND)+datsize+strtabsize, 0);
+			symo = rnd(HEADR+textsize, INITRND)+datsize+strtabsize;
+			symo = rnd(symo, INITRND);
 			break;
 		}
+		seek(cout, symo+8, 0);
 		if(!debug['s'])
 			asmsym();
 		if(debug['v'])
@@ -252,6 +256,10 @@ asmb(void)
 		if(dlm)
 			asmdyn();
 		cflush();
+		seek(cout, symo, 0);
+		lputl(symsize);
+		lputl(lcsize);
+		cflush();
 	} else
 	if(dlm){
 		seek(cout, HEADR+textsize+datsize, 0);
@@ -352,7 +360,7 @@ asmb(void)
 		if (debug['s'])
 			lputl(4);			/* number of loads */
 		else
-			lputl(6);			/* number of loads */
+			lputl(7);			/* number of loads */
 		lputl(machheadr()-32);		/* size of loads */
 		lputl(1);			/* flags - no undefines */
 		lputl(0);			/* reserved */
@@ -394,6 +402,13 @@ asmb(void)
 		machstack(va+HEADR);
 
 		if (!debug['s']) {
+			machseg("__SYMDAT",
+				symdatva,		/* vaddr */
+				8+symsize+lcsize,		/* vsize */
+				symo, 8+symsize+lcsize,	/* fileoffset filesize */
+				7, 5,			/* protects */
+				0, 0);			/* sections flags */
+
 			v += rnd(datsize, INITRND);
 			machsymseg(v,symsize);	/* fileoffset,filesize */
 			v += symsize;
@@ -413,11 +428,14 @@ asmb(void)
 		lputl(1L);			/* version = CURRENT */
 		llputl(entryvalue());		/* entry vaddr */
 		llputl(64L);			/* offset to first phdr */
-		llputl(64L+56*3);		/* offset to first shdr */
+		np = 3;
+		if(!debug['s'])
+			np++;
+		llputl(64L+56*np);		/* offset to first shdr */
 		lputl(0L);			/* processor specific flags */
 		wputl(64);			/* Ehdr size */
 		wputl(56);			/* Phdr size */
-		wputl(3);			/* # of Phdrs */
+		wputl(np);			/* # of Phdrs */
 		wputl(64);			/* Shdr size */
 		if (!debug['s'])
 			wputl(7);			/* # of Shdrs */
@@ -451,6 +469,17 @@ asmb(void)
 			w+bsssize,		/* memory size */
 			INITRND);		/* alignment */
 
+		if(!debug['s']) {
+			linuxphdr(1,			/* data - type = PT_LOAD */
+				2L+4L,			/* data - flags = PF_W+PF_R */
+				symo,		/* file offset */
+				symdatva,			/* vaddr */
+				symdatva,			/* paddr */
+				8+symsize+lcsize,			/* file size */
+				8+symsize+lcsize,		/* memory size */
+				INITRND);		/* alignment */
+		}
+
 		linuxphdr(0x6474e551,		/* gok - type = gok */
 			1L+2L+4L,		/* gok - flags = PF_X+PF_W+PF_R */
 			0,			/* file offset */
@@ -533,7 +562,7 @@ asmb(void)
 		if (debug['s'])
 			break;
 
-		fo += w;
+		fo = symo+8;
 		w = symsize;
 
 		linuxshdr(".gosymtab",		/* name */
@@ -829,6 +858,7 @@ machheadr(void)
 	a += 20;	/* bss sect */
 	a += 46;	/* stack sect */
 	if (!debug['s']) {
+		a += 18;	/* symdat seg */
 		a += 4;	/* symtab seg */
 		a += 4;	/* lctab seg */
 	}
@@ -853,6 +883,7 @@ linuxheadr(void)
 	a += 64;	/* .bss sect */
 	a += 64;	/* .shstrtab sect - strings for headers */
 	if (!debug['s']) {
+		a += 56;	/* symdat seg */
 		a += 64;	/* .gosymtab sect */
 		a += 64;	/* .gopclntab sect */
 	}

src/cmd/6l/go.c

@@ -70,6 +70,27 @@ ilookup(char *name)
 	return x;
 }
 
+char*
+gotypefor(char *name)
+{
+	Import *x;
+	char *s, *p;
+
+	s = strdup(name);
+	p = utfrune(s, 0xB7);	// center dot
+	if(p == nil)
+		return nil;
+	*p++ = '.';
+	memmove(p, p+1, strlen(p));
+	x = ilookup(s);
+	free(s);
+	if(x == nil || x->prefix == nil)
+		return nil;
+	if(strcmp(x->prefix, "var") != 0 && strcmp(x->prefix, "func") != 0)
+		return nil;
+	return x->def;
+}
+
 static void loadpkgdata(char*, char*, int);
 static int parsemethod(char**, char*, char**);
 static int parsepkgdata(char*, char**, char*, int*, char**, char**, char**);

src/cmd/6l/l.h

@@ -397,6 +397,8 @@ int	find2(int32, int);
 void	follow(void);
 void	addstachmark(void);
 void	gethunk(void);
+void	gotypestrings(void);
+char*	gotypefor(char*);
 void	histtoauto(void);
 double	ieeedtod(Ieee*);
 int32	ieeedtof(Ieee*);

src/cmd/6l/span.c

@@ -150,9 +150,9 @@ xdefine(char *p, int t, vlong v)
 }
 
 void
-putsymb(char *s, int t, vlong v, int ver)
+putsymb(char *s, int t, vlong v, int ver, char *go)
 {
-	int i, f, l;
+	int i, j, f, l;
 
 	if(t == 'f')
 		s++;
@@ -181,7 +181,13 @@ putsymb(char *s, int t, vlong v, int ver)
 			cput(s[i]);
 		cput(0);
 	}
-	symsize += l + 1 + i + 1;
+	j = 0;
+	if(go) {
+		for(j=0; go[j]; j++)
+			cput(go[j]);
+	}
+	cput(0);
+	symsize += l + 1 + i + 1 + j + 1;
 
 	if(debug['n']) {
 		if(t == 'z' || t == 'Z') {
@@ -194,9 +200,9 @@ putsymb(char *s, int t, vlong v, int ver)
 			return;
 		}
 		if(ver)
-			Bprint(&bso, "%c %.8llux %s<%d>\n", t, v, s, ver);
+			Bprint(&bso, "%c %.8llux %s<%d> %s\n", t, v, s, ver, go);
 		else
-			Bprint(&bso, "%c %.8llux %s\n", t, v, s);
+			Bprint(&bso, "%c %.8llux %s %s\n", t, v, s, go);
 	}
 }
 
@@ -210,25 +216,25 @@ asmsym(void)
 
 	s = lookup("etext", 0);
 	if(s->type == STEXT)
-		putsymb(s->name, 'T', s->value, s->version);
+		putsymb(s->name, 'T', s->value, s->version, nil);
 
 	for(h=0; h<NHASH; h++)
 		for(s=hash[h]; s!=S; s=s->link)
 			switch(s->type) {
 			case SCONST:
-				putsymb(s->name, 'D', s->value, s->version);
+				putsymb(s->name, 'D', s->value, s->version, gotypefor(s->name));
 				continue;
 
 			case SDATA:
-				putsymb(s->name, 'D', s->value+INITDAT, s->version);
+				putsymb(s->name, 'D', s->value+INITDAT, s->version, gotypefor(s->name));
 				continue;
 
 			case SBSS:
-				putsymb(s->name, 'B', s->value+INITDAT, s->version);
+				putsymb(s->name, 'B', s->value+INITDAT, s->version, gotypefor(s->name));
 				continue;
 
 			case SFILE:
-				putsymb(s->name, 'f', s->value, s->version);
+				putsymb(s->name, 'f', s->value, s->version, nil);
 				continue;
 			}
 
@@ -240,22 +246,23 @@ asmsym(void)
 		/* filenames first */
 		for(a=p->to.autom; a; a=a->link)
 			if(a->type == D_FILE)
-				putsymb(a->asym->name, 'z', a->aoffset, 0);
+				putsymb(a->asym->name, 'z', a->aoffset, 0, nil);
 			else
 			if(a->type == D_FILE1)
-				putsymb(a->asym->name, 'Z', a->aoffset, 0);
+				putsymb(a->asym->name, 'Z', a->aoffset, 0, nil);
 
-		putsymb(s->name, 'T', s->value, s->version);
+		putsymb(s->name, 'T', s->value, s->version, gotypefor(s->name));
 
 		/* frame, auto and param after */
-		putsymb(".frame", 'm', p->to.offset+8, 0);
+		putsymb(".frame", 'm', p->to.offset+8, 0, nil);
 
+		/* TODO(rsc): Add types for D_AUTO and D_PARAM */
 		for(a=p->to.autom; a; a=a->link)
 			if(a->type == D_AUTO)
-				putsymb(a->asym->name, 'a', -a->aoffset, 0);
+				putsymb(a->asym->name, 'a', -a->aoffset, 0, nil);
 			else
 			if(a->type == D_PARAM)
-				putsymb(a->asym->name, 'p', a->aoffset, 0);
+				putsymb(a->asym->name, 'p', a->aoffset, 0, nil);
 	}
 	if(debug['v'] || debug['n'])
 		Bprint(&bso, "symsize = %lud\n", symsize);

src/cmd/gc/sys.go

@@ -89,3 +89,6 @@ export func	bytestorune(*byte, int, int) (int, int);	// convert bytes to runes
 export func	stringtorune(string, int) (int, int);	// convert bytes to runes
 
 export func	exit(int);
+
+export func	symdat() (symtab *[]byte, pclntab *[]byte);
+

src/cmd/gc/sysimport.c

@@ -70,5 +70,6 @@ char *sysimport =
 	"export func sys.bytestorune (? *uint8, ? int, ? int) (? int, ? int)\n"
 	"export func sys.stringtorune (? string, ? int) (? int, ? int)\n"
 	"export func sys.exit (? int)\n"
+	"export func sys.symdat () (symtab *[]uint8, pclntab *[]uint8)\n"
 	"\n"
 	"$$\n";

src/cmd/nm/nm.c

@@ -52,6 +52,7 @@ int	nflag;
 int	sflag;
 int	uflag;
 int	Tflag;
+int	tflag;
 
 Sym	**fnames;		/* file path translation table */
 Sym	**symptr;
@@ -90,6 +91,7 @@ main(int argc, char *argv[])
 	case 'n':	nflag = 1; break;
 	case 's':	sflag = 1; break;
 	case 'u':	uflag = 1; break;
+	case 't':	tflag = 1; break;
 	case 'T':	Tflag = 1; break;
 	} ARGEND
 	if (argc == 0)
@@ -322,7 +324,10 @@ printsyms(Sym **symptr, long nsym)
 			Bprint(&bout, "%*llux ", wid, s->value);
 		else
 			Bprint(&bout, "%*s ", wid, "");
-		Bprint(&bout, "%c %s\n", s->type, cp);
+		Bprint(&bout, "%c %s", s->type, cp);
+		if(tflag && s->gotype && s->gotype[0])
+			Bprint(&bout, " %s", s->gotype);
+		Bprint(&bout, "\n");
 	}
 }
 

src/libmach_amd64/sym.c

@@ -87,6 +87,7 @@ static	uvlong	firstinstr;		/* as found from symtab; needed for amd64 */
 
 static void	cleansyms(void);
 static int32	decodename(Biobuf*, Sym*);
+static int32	decodegotype(Biobuf*, Sym*);
 static short	*encfname(char*);
 static int 	fline(char*, int, int32, Hist*, Hist**);
 static void	fillsym(Sym*, Symbol*);
@@ -151,6 +152,10 @@ syminit(int fd, Fhdr *fp)
 		if(i < 0)
 			return -1;
 		size += i+svalsz+sizeof(p->type);
+		i = decodegotype(&b, p);
+		if(i < 0)
+			return -1;
+		size += i;
 
 		/* count global & auto vars, text symbols, and file names */
 		switch (p->type) {
@@ -293,6 +298,27 @@ decodename(Biobuf *bp, Sym *p)
 	return n;
 }
 
+static int32
+decodegotype(Biobuf *bp, Sym *p)
+{
+	char *cp;
+	int32 n;
+
+	cp = Brdline(bp, '\0');
+	if(cp == 0) {
+		werrstr("can't read go type");
+		return -1;
+	}
+	n = Blinelen(bp);
+	p->gotype = malloc(n);
+	if(p->gotype == 0) {
+		werrstr("can't malloc %ld bytes", n);
+		return -1;
+	}
+	strcpy(p->gotype, cp);
+	return n;
+}
+
 /*
  *	free any previously loaded symbol tables
  */

src/runtime/runtime.c

@@ -743,3 +743,34 @@ algarray[3] =
 //	{	pointerhash,	pointerequal,	pointerprint,	pointercopy	},  // 2
 	{	memhash,	memequal,	memprint,	memcopy	},  // 2 - treat pointers as ints
 };
+
+
+// Return a pointer to a byte array containing the symbol table segment.
+//
+// NOTE(rsc): I expect that we will clean up both the method of getting
+// at the symbol table and the exact format of the symbol table at some
+// point in the future.  It probably needs to be better integrated with
+// the type strings table too.  This is just a quick way to get started
+// and figure out what we want from/can do with it.
+void
+sys·symdat(Array *symtab, Array *pclntab)
+{
+	Array *a;
+	int32 *v;
+
+	v = (int32*)(0x99LL<<32);	/* known to 6l */
+
+	a = mal(sizeof *a);
+	a->nel = v[0];
+	a->cap = a->nel;
+	a->array = (byte*)&v[2];
+	symtab = a;
+	FLUSH(&symtab);
+
+	a = mal(sizeof *a);
+	a->nel = v[1];
+	a->cap = a->nel;
+	a->array = (byte*)&v[2] + v[0];
+	pclntab = a;
+	FLUSH(&pclntab);
+}