introduce typecheck pass before walkexpr.

not complete but compiler still works.

R=ken
OCL=32424
CL=32426

src/cmd/gc/align.c

@@ -257,8 +257,10 @@ typeinit(void)
 	 * initialize okfor
 	 */
 	for(i=0; i<NTYPE; i++) {
-		if(isint[i]) {
+		if(isint[i] || i == TIDEAL) {
 			okforeq[i] = 1;
+			okforcmp[i] = 1;
+			okforarith[i] = 1;
 			okforadd[i] = 1;
 			okforand[i] = 1;
 			issimple[i] = 1;
@@ -267,26 +269,76 @@ typeinit(void)
 		}
 		if(isfloat[i]) {
 			okforeq[i] = 1;
+			okforcmp[i] = 1;
 			okforadd[i] = 1;
+			okforarith[i] = 1;
 			issimple[i] = 1;
 			minfltval[i] = mal(sizeof(*minfltval[i]));
 			maxfltval[i] = mal(sizeof(*maxfltval[i]));
 		}
-		switch(i) {
-		case TBOOL:
-			issimple[i] = 1;
-
-		case TPTR32:
-		case TPTR64:
-		case TINTER:
-		case TMAP:
-		case TCHAN:
-		case TFUNC:
-			okforeq[i] = 1;
-			break;
-		}
 	}
 
+	issimple[TBOOL] = 1;
+
+	okforadd[TSTRING] = 1;
+
+	okforbool[TBOOL] = 1;
+
+	okforcap[TARRAY] = 1;
+	//okforcap[TCHAN] = 1;
+	//okforcap[TMAP] = 1;
+
+	okforlen[TARRAY] = 1;
+	//okforlen[TCHAN] = 1;
+	okforlen[TMAP] = 1;
+	okforlen[TSTRING] = 1;
+
+	okforeq[TPTR32] = 1;
+	okforeq[TPTR64] = 1;
+	okforeq[TINTER] = 1;
+	okforeq[TMAP] = 1;
+	okforeq[TCHAN] = 1;
+	okforeq[TFUNC] = 1;
+	okforeq[TSTRING] = 1;
+	okforeq[TBOOL] = 1;
+	okforeq[TARRAY] = 1;	// refined in typecheck
+
+	okforcmp[TSTRING] = 1;
+
+	for(i=0; i<nelem(okfor); i++)
+		okfor[i] = okfornone;
+
+	// binary
+	okfor[OADD] = okforadd;
+	okfor[OAND] = okforand;
+	okfor[OANDAND] = okforbool;
+	okfor[OANDNOT] = okforand;
+	okfor[ODIV] = okforarith;
+	okfor[OEQ] = okforeq;
+	okfor[OGE] = okforcmp;
+	okfor[OGT] = okforcmp;
+	okfor[OLE] = okforcmp;
+	okfor[OLT] = okforcmp;
+	okfor[OMOD] = okforarith;
+	okfor[OMUL] = okforarith;
+	okfor[ONE] = okforeq;
+	okfor[OOR] = okforand;
+	okfor[OOROR] = okforbool;
+	okfor[OSUB] = okforarith;
+	okfor[OXOR] = okforand;
+	okfor[OLSH] = okforand;
+	okfor[ORSH] = okforand;
+
+	// unary
+	okfor[OCOM] = okforand;
+	okfor[OMINUS] = okforarith;
+	okfor[ONOT] = okforbool;
+	okfor[OPLUS] = okforadd;
+
+	// special
+	okfor[OCAP] = okforcap;
+	okfor[OLEN] = okforlen;
+
 	mpatofix(maxintval[TINT8], "0x7f");
 	mpatofix(minintval[TINT8], "-0x80");
 	mpatofix(maxintval[TINT16], "0x7fff");

src/cmd/gc/const.c

@@ -587,6 +587,12 @@ unary:
 		}
 		return;
 
+	case TUP(OCONV, CTINT):
+	case TUP(OCONV, CTFLT):
+	case TUP(OCONV, CTSTR):
+		convlit1(&nl, n->type, 1);
+		break;
+
 	case TUP(OPLUS, CTINT):
 		break;
 	case TUP(OMINUS, CTINT):
@@ -711,7 +717,7 @@ defaultlit(Node **np, Type *t)
 	lineno = n->lineno;
 	switch(n->val.ctype) {
 	default:
-		yyerror("defaultlit: unknown literal: %N", n);
+		yyerror("defaultlit: unknown literal: %#N", n);
 		break;
 	case CTINT:
 		n->type = types[TINT];

src/cmd/gc/go.h

@@ -195,6 +195,7 @@ struct	Node
 	uchar	funcdepth;
 	uchar	builtin;	// built-in name, like len or close
 	uchar	walkdef;
+	uchar	typecheck;
 
 	// most nodes
 	Node*	left;
@@ -435,12 +436,11 @@ enum
 
 enum
 {
-	Exxx,
-	Eyyy,
-	Etop,		// evaluated at statement level
-	Elv,		// evaluated in lvalue context
-	Erv,		// evaluated in rvalue context
-	Etype = 1<<8,
+	Etop = 1<<1,	// evaluated at statement level
+	Elv = 1<<2,	// evaluated in lvalue context
+	Erv = 1<<3,	// evaluated in rvalue context
+	Etype = 1<<4,
+	Eideal = 1<<5,
 };
 
 #define	BITS	5
@@ -574,6 +574,7 @@ EXTERN	char*	filename;	// name to uniqify names
 EXTERN	Idir*	idirs;
 
 EXTERN	Type*	types[NTYPE];
+EXTERN	Type*	idealstring;
 EXTERN	uchar	simtype[NTYPE];
 EXTERN	uchar	isptr[NTYPE];
 EXTERN	uchar	isforw[NTYPE];
@@ -581,10 +582,17 @@ EXTERN	uchar	isint[NTYPE];
 EXTERN	uchar	isfloat[NTYPE];
 EXTERN	uchar	issigned[NTYPE];
 EXTERN	uchar	issimple[NTYPE];
+
 EXTERN	uchar	okforeq[NTYPE];
 EXTERN	uchar	okforadd[NTYPE];
 EXTERN	uchar	okforand[NTYPE];
-EXTERN	Type*	idealstring;
+EXTERN	uchar	okfornone[NTYPE];
+EXTERN	uchar	okforcmp[NTYPE];
+EXTERN	uchar	okforbool[NTYPE];
+EXTERN	uchar	okforcap[NTYPE];
+EXTERN	uchar	okforlen[NTYPE];
+EXTERN	uchar	okforarith[NTYPE];
+EXTERN	uchar*	okfor[OEND];
 
 EXTERN	Mpint*	minintval[NTYPE];
 EXTERN	Mpint*	maxintval[NTYPE];
@@ -977,6 +985,8 @@ void	addrescapes(Node*);
 void	heapmoves(void);
 void	walkdeflist(NodeList*);
 void	walkdef(Node*);
+void	typechecklist(NodeList*, int);
+Node*	typecheck(Node**, int);
 
 /*
  *	const.c

src/cmd/gc/subr.c

@@ -1324,7 +1324,7 @@ Nconv(Fmt *fp)
 		fmtprint(fp, "<N>");
 		goto out;
 	}
-	
+
 	if(fp->flags & FmtSharp) {
 		exprfmt(fp, n, 0);
 		goto out;
@@ -2123,7 +2123,6 @@ out:
 void
 badtype(int o, Type *tl, Type *tr)
 {
-
 	yyerror("illegal types for operand: %O", o);
 	if(tl != T)
 		print("	%T\n", tl);
@@ -2346,7 +2345,6 @@ tempname(Node *n, Type *t)
 	n->op = ONAME;
 	n->sym = s;
 	n->type = t;
-	n->etype = t->etype;
 	n->class = PAUTO;
 	n->addable = 1;
 	n->ullman = 1;

test/golden.out

@@ -133,6 +133,7 @@ fixedbugs/bug039.go:6: variable x redeclared in this block
 	previous declaration at fixedbugs/bug039.go:5
 
 =========== fixedbugs/bug049.go
+fixedbugs/bug049.go:6: invalid operation: s == nil
 fixedbugs/bug049.go:6: illegal types for operand: EQ
 	string
 	nil