8l, ld: Initial adjustments for Plan 9 native compilation of 8l

These changes are not particularly invasive and have been tested
as broadly as possible.

8l/l.h:
  -	#pragma varargck: added some, removed duplicates.

ld/dwarf.c:
  -	As Plan 9 has no NULL, changed all occurrences to nil.
  -	Added USED(size); where necessary.
  -	Added (void) argument in definition of finddebugruntimepath().
  -	Plan 9 compiler was complaining about multiple
        assignments, repeaired by breaking up the commands.
  -	Correction: havedynamic = 1; restored.

ld/go.c:
  -	Needed USED(file); in two functions.
  -	Removed unused assignments flagged by the Plan 9 compiler.

ld/lib.c:
  -	Replaced unlink() with remove() which seems available everywhere.
  -	Removed USED(c4); and USED(magic) no longer required.
  -	Removed code flagged as unused by the Plan 9 compiler.
  -	Added attributes to a number of format strings.

R=rsc
CC=golang-dev
https://golang.org/cl/4435047

src/cmd/8l/l.h

@@ -260,11 +260,15 @@ EXTERN union
 #define	cbuf	u.obuf
 #define	xbuf	u.ibuf
 
-#pragma	varargck	type	"A"	uint
+#pragma	varargck	type	"A"	int
 #pragma	varargck	type	"D"	Adr*
+#pragma	varargck	type	"I"	int
+#pragma	varargck	type	"I"	uchar*
 #pragma	varargck	type	"P"	Prog*
 #pragma	varargck	type	"R"	int
 #pragma	varargck	type	"S"	char*
+#pragma	varargck	type	"Y"	Sym*
+#pragma	varargck	type	"i"	char*
 
 EXTERN	int32	HEADR;
 EXTERN	int32	HEADTYPE;
@@ -383,11 +387,6 @@ void	deadcode(void);
 #define	WPUT(a)	wputl(a)
 #define	VPUT(a)	vputl(a)
 
-#pragma	varargck	type	"D"	Adr*
-#pragma	varargck	type	"P"	Prog*
-#pragma	varargck	type	"R"	int
-#pragma	varargck	type	"A"	int
-
 /* Used by ../ld/dwarf.c */
 enum
 {

src/cmd/ld/dwarf.c

@@ -1348,7 +1348,7 @@ synthesizemaptypes(DWDie *die)
 			valtype = defptrto(valtype);
 		newrefattr(fld, DW_AT_type, valtype);
 		newmemberoffsetattr(fld, hashsize + datavo);
-		newattr(dwhe, DW_AT_byte_size, DW_CLS_CONSTANT, hashsize + datsize, NULL);
+		newattr(dwhe, DW_AT_byte_size, DW_CLS_CONSTANT, hashsize + datsize, nil);
 
 		// Construct hash_subtable<hash_entry<K,V>>
 		dwhs = newdie(&dwtypes, DW_ABRV_STRUCTTYPE,
@@ -1359,7 +1359,7 @@ synthesizemaptypes(DWDie *die)
 		substitutetype(dwhs, "end", defptrto(dwhe));
 		substitutetype(dwhs, "entry", dwhe);  // todo: []hash_entry with dynamic size
 		newattr(dwhs, DW_AT_byte_size, DW_CLS_CONSTANT,
-			getattr(hash_subtable, DW_AT_byte_size)->value, NULL);
+			getattr(hash_subtable, DW_AT_byte_size)->value, nil);
 
 		// Construct hash<K,V>
 		dwh = newdie(&dwtypes, DW_ABRV_STRUCTTYPE,
@@ -1369,7 +1369,7 @@ synthesizemaptypes(DWDie *die)
 		copychildren(dwh, hash);
 		substitutetype(dwh, "st", defptrto(dwhs));
 		newattr(dwh, DW_AT_byte_size, DW_CLS_CONSTANT,
-			getattr(hash, DW_AT_byte_size)->value, NULL);
+			getattr(hash, DW_AT_byte_size)->value, nil);
 
 		newrefattr(die, DW_AT_type, defptrto(dwh));
 	}
@@ -1401,30 +1401,30 @@ synthesizechantypes(DWDie *die)
 		// sudog<T>
 		dws = newdie(&dwtypes, DW_ABRV_STRUCTTYPE,
 			mkinternaltypename("sudog",
-				getattr(elemtype, DW_AT_name)->data, NULL));
+				getattr(elemtype, DW_AT_name)->data, nil));
 		copychildren(dws, sudog);
 		substitutetype(dws, "elem", elemtype);
 		newattr(dws, DW_AT_byte_size, DW_CLS_CONSTANT,
-			sudogsize + (elemsize > 8 ? elemsize - 8 : 0), NULL);
+			sudogsize + (elemsize > 8 ? elemsize - 8 : 0), nil);
 
 		// waitq<T>
 		dww = newdie(&dwtypes, DW_ABRV_STRUCTTYPE,
-			mkinternaltypename("waitq", getattr(elemtype, DW_AT_name)->data, NULL));
+			mkinternaltypename("waitq", getattr(elemtype, DW_AT_name)->data, nil));
 		copychildren(dww, waitq);
 		substitutetype(dww, "first", defptrto(dws));
 		substitutetype(dww, "last",  defptrto(dws));
 		newattr(dww, DW_AT_byte_size, DW_CLS_CONSTANT,
-			getattr(waitq, DW_AT_byte_size)->value, NULL);
+			getattr(waitq, DW_AT_byte_size)->value, nil);
 
 		// hchan<T>
 		dwh = newdie(&dwtypes, DW_ABRV_STRUCTTYPE,
-			mkinternaltypename("hchan", getattr(elemtype, DW_AT_name)->data, NULL));
+			mkinternaltypename("hchan", getattr(elemtype, DW_AT_name)->data, nil));
 		copychildren(dwh, hchan);
 		substitutetype(dwh, "recvq", dww);
 		substitutetype(dwh, "sendq", dww);
 		substitutetype(dwh, "free", defptrto(dws));
 		newattr(dwh, DW_AT_byte_size, DW_CLS_CONSTANT,
-			getattr(hchan, DW_AT_byte_size)->value, NULL);
+			getattr(hchan, DW_AT_byte_size)->value, nil);
 
 		newrefattr(die, DW_AT_type, defptrto(dwh));
 	}
@@ -1436,6 +1436,7 @@ defdwsymb(Sym* sym, char *s, int t, vlong v, vlong size, int ver, Sym *gotype)
 {
 	DWDie *dv, *dt;
 
+	USED(size);
 	if (strncmp(s, "go.string.", 10) == 0)
 		return;
 
@@ -1592,7 +1593,7 @@ addhistfile(char *zentry)
 // if the histfile stack contains ..../runtime/runtime_defs.go
 // use that to set gdbscript
 static void
-finddebugruntimepath()
+finddebugruntimepath(void)
 {
 	int i, l;
 	char *c;
@@ -1841,7 +1842,8 @@ writelines(void)
 	char *n, *nn;
 
 	unitstart = -1;
-	epc = pc = 0;
+	pc = 0;
+	epc = 0;
 	lc = 1;
 	llc = 1;
 	currfile = -1;
@@ -1903,7 +1905,8 @@ writelines(void)
 				// 4 zeros: the string termination + 3 fields.
 			}
 
-			epc = pc = s->text->pc;
+			pc = s->text->pc;
+			epc = pc;
 			currfile = 1;
 			lc = 1;
 			llc = 1;
@@ -1992,7 +1995,7 @@ writelines(void)
 			newrefattr(dwvar, DW_AT_type, defgotype(a->gotype));
 
 			// push dwvar down dwfunc->child to preserve order
-			newattr(dwvar, DW_AT_internal_location, DW_CLS_CONSTANT, offs, NULL);
+			newattr(dwvar, DW_AT_internal_location, DW_CLS_CONSTANT, offs, nil);
 			dwfunc->child = dwvar->link;  // take dwvar out from the top of the list
 			for (dws = &dwfunc->child; *dws != nil; dws = &(*dws)->link)
 				if (offs > getattr(*dws, DW_AT_internal_location)->value)
@@ -2345,7 +2348,11 @@ dwarfemitdebugsections(void)
 
 	infoo = cpos();
 	writeinfo();
-	gdbscripto = arangeso = pubtypeso = pubnameso = infoe = cpos();
+	infoe = cpos();
+	pubnameso = infoe;
+	pubtypeso = infoe;
+	arangeso = infoe;
+	gdbscripto = infoe;
 
 	if (fwdcount > 0) {
 		if (debug['v'])

src/cmd/ld/go.c

@@ -415,8 +415,8 @@ loaddynimport(char *file, char *pkg, char *p, int n)
 	char *pend, *next, *name, *def, *p0, *lib, *q;
 	Sym *s;
 
+	USED(file);
 	pend = p + n;
-	p0 = p;
 	for(; p<pend; p=next) {
 		next = strchr(p, '\n');
 		if(next == nil)
@@ -485,8 +485,8 @@ loaddynexport(char *file, char *pkg, char *p, int n)
 	char *pend, *next, *local, *elocal, *remote, *p0;
 	Sym *s;
 
+	USED(file);
 	pend = p + n;
-	p0 = p;
 	for(; p<pend; p=next) {
 		next = strchr(p, '\n');
 		if(next == nil)

src/cmd/ld/lib.c

@@ -69,7 +69,7 @@ libinit(void)
 	// add goroot to the end of the libdir list.
 	libdir[nlibdir++] = smprint("%s/pkg/%s_%s", goroot, goos, goarch);
 
-	unlink(outfile);
+	remove(outfile);
 	cout = create(outfile, 1, 0775);
 	if(cout < 0) {
 		diag("cannot create %s", outfile);
@@ -399,9 +399,6 @@ ldobj(Biobuf *f, char *pkg, int64 len, char *pn, int whence)
 
 	pn = strdup(pn);
 
-	USED(c4);
-	USED(magic);
-
 	c1 = Bgetc(f);
 	c2 = Bgetc(f);
 	c3 = Bgetc(f);
@@ -498,7 +495,6 @@ _lookup(char *symb, int v, int creat)
 	// not if(h < 0) h = ~h, because gcc 4.3 -O2 miscompiles it.
 	h &= 0xffffff;
 	h %= NHASH;
-	c = symb[0];
 	for(s = hash[h]; s != S; s = s->hash)
 		if(memcmp(s->name, symb, l) == 0)
 			return s;
@@ -550,7 +546,6 @@ copyhistfrog(char *buf, int nbuf)
 
 	p = buf;
 	ep = buf + nbuf;
-	i = 0;
 	for(i=0; i<histfrogp; i++) {
 		p = seprint(p, ep, "%s", histfrog[i]->name+1);
 		if(i+1<histfrogp && (p == buf || p[-1] != '/'))