From: Ken Thompson <ken@golang.org>
Date: Thu, 19 Jun 2008 05:07:09 +0000 (-0700)
Subject: stack offset
X-Git-Tag: weekly.2009-11-06~3651
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=ddba96aed81ab702b9be4cf0efd4d98ca6f2fe4d;p=gostls13.git

stack offset

SVN=123521
---

diff --git a/src/cmd/6l/6.out.h b/src/cmd/6l/6.out.h
index 6473bc0bb2..ae67854a18 100644
--- a/src/cmd/6l/6.out.h
+++ b/src/cmd/6l/6.out.h
@@ -32,7 +32,7 @@
 #define	NSNAME	8
 #define NOPROF	(1<<0)
 #define DUPOK	(1<<1)
-#define SOFmark	(11)
+#define SOFmark	"\xa7\xf1\xd9\x2a\x82\xc8\xd8\xfe"
 
 /*
  *	amd64
diff --git a/src/cmd/6l/asm.c b/src/cmd/6l/asm.c
index fca576fa6e..3ae914afe4 100644
--- a/src/cmd/6l/asm.c
+++ b/src/cmd/6l/asm.c
@@ -138,8 +138,7 @@ asmb(void)
 	for(p = firstp; p != P; p = p->link) {
 		if(p->as == ATEXT)
 			curtext = p;
-		if(p->pc != pc)
-		if(p->as != ATEXT || p->pc != pc+SOFmark) {
+		if(p->pc != pc) {
 			if(!debug['a'])
 				print("%P\n", curp);
 			diag("phase error %llux sb %llux in %s", p->pc, pc, TNAME);
diff --git a/src/cmd/6l/l.h b/src/cmd/6l/l.h
index 5e437cd380..ae1bec5c02 100644
--- a/src/cmd/6l/l.h
+++ b/src/cmd/6l/l.h
@@ -217,7 +217,6 @@ enum
 	Zaut_r,
 	Zo_m,
 	Zo_m64,
-	Ztext,
 	Zpseudo,
 	Zr_m,
 	Zr_m_xm,
@@ -388,6 +387,7 @@ void	export(void);
 int	find1(long, int);
 int	find2(long, int);
 void	follow(void);
+void	addstachmark(void);
 void	gethunk(void);
 void	histtoauto(void);
 double	ieeedtod(Ieee*);
diff --git a/src/cmd/6l/obj.c b/src/cmd/6l/obj.c
index 47339fe7e0..83fae2e5a0 100644
--- a/src/cmd/6l/obj.c
+++ b/src/cmd/6l/obj.c
@@ -400,6 +400,7 @@ main(int argc, char *argv[])
 			doprof1();
 		else
 			doprof2();
+	addstackmark();
 	span();
 	doinit();
 	asmb();
@@ -925,9 +926,9 @@ loop:
 			sig = 1729;
 		if(sig != 0){
 			if(s->sig != 0 && s->sig != sig)
-				diag("incompatible type signatures %lux(%s)"
-					"and %lux(%s) for %s", s->sig,
-					filen[s->file], sig, pn, s->name);
+				diag("incompatible type signatures"
+					"%lux(%s) and %lux(%s) for %s",
+					s->sig, filen[s->file], sig, pn, s->name);
 			s->sig = sig;
 			s->file = files-1;
 		}
diff --git a/src/cmd/6l/optab.c b/src/cmd/6l/optab.c
index f07eb18df2..d997971662 100644
--- a/src/cmd/6l/optab.c
+++ b/src/cmd/6l/optab.c
@@ -37,7 +37,7 @@ uchar	ynone[] =
 };
 uchar	ytext[] =
 {
-	Ymb,	Yi32,	Ztext,	1,
+	Ymb,	Yi32,	Zpseudo,1,
 	0
 };
 uchar	ynop[] =
diff --git a/src/cmd/6l/pass.c b/src/cmd/6l/pass.c
index 5884022383..db81bf163e 100644
--- a/src/cmd/6l/pass.c
+++ b/src/cmd/6l/pass.c
@@ -281,6 +281,112 @@ loop:
 	goto loop;
 }
 
+Prog*
+byteq(int v)
+{
+	Prog *p;
+
+	p = prg();
+	p->as = ABYTE;
+	p->from.type = D_CONST;
+	p->from.offset = v&0xff;
+	return p;
+}
+
+void
+markstk(Prog *l)
+{
+	Prog *p0, *p, *q, *r;
+	long i, n, line;
+	Sym *s;
+
+	version++;
+	s = lookup(l->from.sym->name, version);
+	s->type = STEXT;
+	line = l->line;
+
+	// start with fake copy of ATEXT
+	p0 = prg();
+	p = p0;
+	*p = *l;	// note this gets p->pcond and p->line
+
+	p->from.type = D_STATIC;
+	p->from.sym = s;
+	p->to.offset = 0;
+
+	// put out magic sequence
+	n = strlen(SOFmark);
+	for(i=0; i<n; i++) {
+		q = byteq(SOFmark[i]);
+		q->line = line;
+		p->link = q;
+		p = q;
+	}
+
+	// put out stack offset
+	n = l->to.offset;
+	if(n < 0)
+		n = 0;
+	for(i=0; i<3; i++) {
+		q = byteq(n);
+		q->line = line;
+		p->link = q;
+		p = q;
+		n = n>>8;
+	}
+
+	// put out null terminated name
+	for(i=0;; i++) {
+		n = s->name[i];
+		q = byteq(n);
+		q->line = line;
+		p->link = q;
+		p = q;
+		if(n == 0)
+			break;
+	}
+
+	// put out return instruction
+	q = prg();
+	q->as = ARET;
+	q->line = line;
+	p->link = q;
+	p = q;
+
+	r = l->pcond;
+	l->pcond = p0;
+	p->link = r;
+	p0->pcond = r;
+
+	// hard part is linking end of
+	// the text body to my fake ATEXT
+	for(p=l;; p=q) {
+		q = p->link;
+		if(q == r) {
+			p->link = p0;
+			return;
+		}
+	}
+}
+
+void
+addstackmark(void)
+{
+	Prog *p;
+
+	if(debug['v'])
+		Bprint(&bso, "%5.2f stkmark\n", cputime());
+	Bflush(&bso);
+
+	for(p=textp; p!=P; p=p->pcond) {
+		markstk(p);		// splice in new body
+		p = p->pcond;		// skip the one we just put in
+	}
+
+//	for(p=textp; p!=P; p=p->pcond)
+//		print("%P\n", p);
+}
+
 int
 relinv(int a)
 {
@@ -344,6 +450,7 @@ patch(void)
 	if(debug['v'])
 		Bprint(&bso, "%5.2f patch\n", cputime());
 	Bflush(&bso);
+
 	s = lookup("exit", 0);
 	vexit = s->value;
 	for(p = firstp; p != P; p = p->link) {
diff --git a/src/cmd/6l/span.c b/src/cmd/6l/span.c
index 4ade9e3d1f..4b225da8ca 100644
--- a/src/cmd/6l/span.c
+++ b/src/cmd/6l/span.c
@@ -83,8 +83,6 @@ start:
 				p->pc = c;
 		asmins(p);
 		p->pc = c;
-		if(p->as == ATEXT)
-			p->pc += SOFmark;	// skip the stack marker
 		m = andptr-and;
 		p->mark = m;
 		c += m;
@@ -115,8 +113,6 @@ loop:
 			}
 		}
 		p->pc = c;
-		if(p->as == ATEXT)
-			p->pc += SOFmark;	// skip the stack marker
 		c += p->mark;
 	}
 	if(again) {
@@ -273,7 +269,7 @@ asmlc(void)
 	Prog *p;
 	long oldlc, v, s;
 
-	oldpc = INITTEXT+SOFmark;
+	oldpc = INITTEXT;
 	oldlc = 0;
 	for(p = firstp; p != P; p = p->link) {
 		if(p->line == oldlc || p->as == ATEXT || p->as == ANOP) {
@@ -1124,19 +1120,6 @@ found:
 		diag("asmins: unknown z %d %P", t[2], p);
 		return;
 
-	case Ztext:
-		v = p->to.offset;
-		if(v < 0)
-			v = 0;
-
-		// eleven bytes of buried stack offset
-		*andptr++ = v>>3;
-		*andptr++ = v>>11;
-		*andptr++ = v>>19;
-		for(v=0; v<SOFmark-3; v++)
-			*andptr++ = "\xa7\xf1\xd9\x2a\x82\xc8\xd8\xfe"[v];
-		break;
-
 	case Zpseudo:
 		break;