liblink: require use of TYPE_ADDR, not TYPE_CONST

Add Addr-checking for all Progs on input to liblink, in liblink/pass.c,
including requiring use of TYPE_ADDR, not TYPE_CONST.
Update compilers and assemblers to satisfy checks.

Change-Id: Idac36b9f6805f0451cb541d2338992ca5eaf3963
Reviewed-on: https://go-review.googlesource.com/3801
Reviewed-by: Austin Clements <austin@google.com>

6 files changed, 94 insertions, 10 deletions

diff --git a/src/liblink/asm5.c b/src/liblink/asm5.c
index 5be4a87d7d..8d597750b7 100644
--- a/src/liblink/asm5.c
+++ b/src/liblink/asm5.c
@@ -588,7 +588,7 @@ asmoutnacl(Link *ctxt, int32 origPC, Prog *p, Optab *o, uint32 *out)
 				// make p into MOVW $X(R), R11
 				p->as = AMOVW;
 				p->from = *a;
-				p->from.type = TYPE_CONST;
+				p->from.type = TYPE_ADDR;
 				p->to = zprog.to;
 				p->to.type = TYPE_REG;
 				p->to.reg = REG_R11;
@@ -1125,6 +1125,7 @@ aclass(Link *ctxt, Addr *a)
 		return C_TEXTSIZE;
 
 	case TYPE_CONST:
+	case TYPE_ADDR:
 		switch(a->name) {
 
 		case TYPE_NONE:
diff --git a/src/liblink/asm9.c b/src/liblink/asm9.c
index 84aa14e7f5..742d204b5b 100644
--- a/src/liblink/asm9.c
+++ b/src/liblink/asm9.c
@@ -673,6 +673,7 @@ aclass(Link *ctxt, Addr *a)
 		return C_TEXTSIZE;
 
 	case TYPE_CONST:
+	case TYPE_ADDR:
 		switch(a->name) {
 		case TYPE_NONE:
 			ctxt->instoffset = a->offset;
diff --git a/src/liblink/list5.c b/src/liblink/list5.c
index b8451041ae..3d3e8e7d12 100644
--- a/src/liblink/list5.c
+++ b/src/liblink/list5.c
@@ -157,6 +157,7 @@ Dconv(Fmt *fp)
 		break;
 
 	case TYPE_CONST:
+	case TYPE_ADDR:
 		if(a->reg != 0)
 			sprint(str, "$%M(%R)", a, a->reg);
 		else
@@ -227,7 +228,6 @@ RAconv(Fmt *fp)
 	sprint(str, "GOK-reglist");
 	switch(a->type) {
 	case TYPE_CONST:
-	case TYPE_TEXTSIZE:
 		if(a->reg != 0)
 			break;
 		if(a->sym != nil)
diff --git a/src/liblink/list9.c b/src/liblink/list9.c
index 1cd0cdb353..a45e73e61e 100644
--- a/src/liblink/list9.c
+++ b/src/liblink/list9.c
@@ -161,6 +161,7 @@ Dconv(Fmt *fp)
 		break;
 
 	case TYPE_CONST:
+	case TYPE_ADDR:
 		if(a->reg != 0)
 			sprint(str, "$%M(%R)", a, a->reg);
 		else
diff --git a/src/liblink/obj5.c b/src/liblink/obj5.c
index 805b2b921d..805d7a59c2 100644
--- a/src/liblink/obj5.c
+++ b/src/liblink/obj5.c
@@ -151,9 +151,9 @@ progedit(Link *ctxt, Prog *p)
 		if(ctxt->tlsg == nil)
 			ctxt->tlsg = linklookup(ctxt, "runtime.tlsg", 0);
 
-		if(p->from.type == TYPE_CONST && p->from.name == NAME_EXTERN && p->from.sym == ctxt->tlsg)
+		if(p->from.type == TYPE_ADDR && p->from.name == NAME_EXTERN && p->from.sym == ctxt->tlsg)
 			p->from.type = TYPE_MEM;
-		if(p->to.type == TYPE_CONST && p->to.name == NAME_EXTERN && p->to.sym == ctxt->tlsg)
+		if(p->to.type == TYPE_ADDR && p->to.name == NAME_EXTERN && p->to.sym == ctxt->tlsg)
 			p->to.type = TYPE_MEM;
 	}
 }
@@ -227,7 +227,7 @@ preprocess(Link *ctxt, LSym *cursym)
 			// MOVW $4(R13), R1
 			p = appendp(ctxt, p);
 			p->as = AMOVW;
-			p->from.type = TYPE_CONST;
+			p->from.type = TYPE_ADDR;
 			p->from.reg = REG_R13;
 			p->from.offset = 4;
 			p->to.type = TYPE_REG;
@@ -236,7 +236,7 @@ preprocess(Link *ctxt, LSym *cursym)
 			// MOVW $n(R13), R2
 			p = appendp(ctxt, p);
 			p->as = AMOVW;
-			p->from.type = TYPE_CONST;
+			p->from.type = TYPE_ADDR;
 			p->from.reg = REG_R13;
 			p->from.offset = 4 + autoffset;
 			p->to.type = TYPE_REG;
@@ -631,7 +631,7 @@ preprocess(Link *ctxt, LSym *cursym)
 				p->spadj = -p->to.offset;
 			if((p->scond & C_PBIT) && p->from.type == TYPE_MEM && p->from.reg == REGSP && p->to.reg != REGPC)
 				p->spadj = -p->from.offset;
-			if(p->from.type == TYPE_CONST && p->from.reg == REGSP && p->to.type == TYPE_REG && p->to.reg == REGSP)
+			if(p->from.type == TYPE_ADDR && p->from.reg == REGSP && p->to.type == TYPE_REG && p->to.reg == REGSP)
 				p->spadj = -p->from.offset;
 			break;
 		}
@@ -747,7 +747,7 @@ stacksplit(Link *ctxt, Prog *p, int32 framesize, int noctxt)
 		//	CMP stackguard, R2
 		p = appendp(ctxt, p);
 		p->as = AMOVW;
-		p->from.type = TYPE_CONST;
+		p->from.type = TYPE_ADDR;
 		p->from.reg = REGSP;
 		p->from.offset = -framesize;
 		p->to.type = TYPE_REG;
@@ -777,7 +777,7 @@ stacksplit(Link *ctxt, Prog *p, int32 framesize, int noctxt)
 
 		p = appendp(ctxt, p);
 		p->as = AMOVW;
-		p->from.type = TYPE_CONST;
+		p->from.type = TYPE_ADDR;
 		p->from.reg = REGSP;
 		p->from.offset = StackGuard;
 		p->to.type = TYPE_REG;
@@ -794,7 +794,7 @@ stacksplit(Link *ctxt, Prog *p, int32 framesize, int noctxt)
 		
 		p = appendp(ctxt, p);
 		p->as = AMOVW;
-		p->from.type = TYPE_CONST;
+		p->from.type = TYPE_ADDR;
 		p->from.offset = framesize + (StackGuard - StackSmall);
 		p->to.type = TYPE_REG;
 		p->to.reg = REG_R3;
diff --git a/src/liblink/pass.c b/src/liblink/pass.c
index a8bf76f4d6..db5c4ebd13 100644
--- a/src/liblink/pass.c
+++ b/src/liblink/pass.c
@@ -67,6 +67,83 @@ brloop(Link *ctxt, Prog *p)
 	return q;
 }
 
+static void
+checkaddr(Link *ctxt, Prog *p, Addr *a)
+{
+	// Check expected encoding, especially TYPE_CONST vs TYPE_ADDR.
+	switch(a->type) {
+	case TYPE_NONE:
+		return;
+
+	case TYPE_BRANCH:
+		if(a->reg != 0 || a->index != 0 || a->scale != 0 || a->name != 0)
+			break;
+		return;
+
+	case TYPE_TEXTSIZE:
+		if(a->reg != 0 || a->index != 0 || a->scale != 0 || a->name != 0)
+			break;
+		return;
+
+	case TYPE_MEM:
+		//if(a->u.bits != 0)
+		//	break;
+		return;
+
+	case TYPE_CONST:
+		// TODO(rsc): After fixing SHRQ, check a->index != 0 too.
+		if(a->name != 0 || a->sym != 0 || a->reg != 0) {
+			ctxt->diag("argument %D is TYPE_CONST, should be TYPE_ADDR, in %P", a, p);
+			return;
+		}
+		if(a->reg != 0 || a->scale != 0 || a->name != 0 || a->sym != nil || a->u.bits != 0)
+			break;
+		return;
+
+	case TYPE_FCONST:
+	case TYPE_SCONST:
+		if(a->reg != 0 || a->index != 0 || a->scale != 0 || a->name != 0 || a->offset != 0 || a->sym != nil)
+			break;
+		return;
+
+	case TYPE_REG:
+		// TODO(rsc): After fixing PINSRQ, check a->offset != 0 too.
+		// TODO(rsc): After fixing SHRQ, check a->index != 0 too.
+		if(a->scale != 0 || a->name != 0 || a->sym != nil)
+			break;
+		return;
+
+	case TYPE_ADDR:
+		if(a->u.bits != 0)
+			break;
+		if(a->reg == 0 && a->index == 0 && a->scale == 0 && a->name == 0 && a->sym == nil)
+			ctxt->diag("argument %D is TYPE_ADDR, should be TYPE_CONST, in %P", a, p);
+		return;
+
+	case TYPE_SHIFT:
+		if(a->index != 0 || a->scale != 0 || a->name != 0 || a->sym != nil || a->u.bits != 0)
+			break;
+		return;
+
+	case TYPE_REGREG:
+		if(a->index != 0 || a->scale != 0 || a->name != 0 || a->sym != nil || a->u.bits != 0)
+			break;
+		return;
+
+	case TYPE_REGREG2:
+		return;
+
+	case TYPE_INDIR:
+		// Expect sym and name to be set, nothing else.
+		// Technically more is allowed, but this is only used for *name(SB).
+		if(a->reg != 0 || a->index != 0 || a->scale != 0 || a->name == 0 || a->offset != 0 || a->sym == nil || a->u.bits != 0)
+			break;
+		return;
+	}
+
+	ctxt->diag("invalid encoding for argument %D in %P", a, p);
+}
+
 void
 linkpatch(Link *ctxt, LSym *sym)
 {
@@ -77,6 +154,10 @@ linkpatch(Link *ctxt, LSym *sym)
 	ctxt->cursym = sym;
 	
 	for(p = sym->text; p != nil; p = p->link) {
+		checkaddr(ctxt, p, &p->from);
+		checkaddr(ctxt, p, &p->from3);
+		checkaddr(ctxt, p, &p->to);
+
 		if(ctxt->arch->progedit)
 			ctxt->arch->progedit(ctxt, p);
 		if(p->to.type != TYPE_BRANCH)