From 182f91ffe02c924082f917e9db816818f0abbbf9 Mon Sep 17 00:00:00 2001
From: Ken Thompson <ken@golang.org>
Date: Wed, 3 Sep 2008 14:40:22 -0700
Subject: [PATCH] map literals

R=r
OCL=14759
CL=14759
---
 src/cmd/gc/go.h   |  4 ++--
 src/cmd/gc/go.y   |  2 +-
 src/cmd/gc/subr.c |  1 +
 src/cmd/gc/walk.c | 55 ++++++++++++++++++++++++++++++++++++++++++++---
 4 files changed, 56 insertions(+), 6 deletions(-)

diff --git a/src/cmd/gc/go.h b/src/cmd/gc/go.h
index 748ea4cbd06..9a6b0422405 100644
--- a/src/cmd/gc/go.h
+++ b/src/cmd/gc/go.h
@@ -277,7 +277,7 @@ enum
 	OINDEX, OINDEXPTR, OSLICE,
 	ONOT, OCOM, OPLUS, OMINUS, OSEND, ORECV,
 	OLITERAL, OREGISTER, OINDREG,
-	OCONV,
+	OCONV, OKEY,
 	OBAD,
 
 	OEND,
@@ -691,7 +691,7 @@ Node*	reorder3(Node*);
 Node*	reorder4(Node*);
 Node*	structlit(Node*);
 Node*	arraylit(Node*);
-Node*	chantlit(Node*);
+Node*	maplit(Node*);
 
 /*
  *	const.c
diff --git a/src/cmd/gc/go.y b/src/cmd/gc/go.y
index 20d4ffac6de..a02425c3c20 100644
--- a/src/cmd/gc/go.y
+++ b/src/cmd/gc/go.y
@@ -990,7 +990,7 @@ chandir:
 keyval:
 	expr ':' expr
 	{
-		$$ = nod(OLIST, $1, $3);
+		$$ = nod(OKEY, $1, $3);
 	}
 
 /*
diff --git a/src/cmd/gc/subr.c b/src/cmd/gc/subr.c
index 0bc871a4b3c..33628d07a1b 100644
--- a/src/cmd/gc/subr.c
+++ b/src/cmd/gc/subr.c
@@ -619,6 +619,7 @@ opnames[] =
 	[OINDEX]	= "INDEX",
 	[OINDEXPTR]	= "INDEXPTR",
 	[OIND]		= "IND",
+	[OKEY]		= "KEY",
 	[OLABEL]	= "LABEL",
 	[OLE]		= "LE",
 	[OLEN]		= "LEN",
diff --git a/src/cmd/gc/walk.c b/src/cmd/gc/walk.c
index 7c7b2b4eec9..f1889864c1f 100644
--- a/src/cmd/gc/walk.c
+++ b/src/cmd/gc/walk.c
@@ -56,6 +56,7 @@ loop:
 		goto ret;
 
 	case OLIST:
+	case OKEY:
 		walktype(n->left, top);
 		n = n->right;
 		goto loop;
@@ -367,7 +368,7 @@ loop:
 		goto ret;
 
 	case OCONV:
-		if(top != Erv)
+		if(top == Etop)
 			goto nottop;
 		walktype(n->left, Erv);
 
@@ -434,6 +435,13 @@ loop:
 			goto ret;
 		}
 
+		// map literal
+		if(t->etype == TMAP) {
+			r = maplit(n);
+			*n = *r;
+			goto ret;
+		}
+
 		badtype(n->op, l->type, t);
 		goto ret;
 
@@ -2871,9 +2879,8 @@ arraylit(Node *n)
 	r = listfirst(&saver, &n->left);
 
 loop:
-	if(r == N) {
+	if(r == N)
 		return var;
-	}
 
 	// build list of var[c] = expr
 
@@ -2886,3 +2893,45 @@ loop:
 	r = listnext(&saver);
 	goto loop;
 }
+
+Node*
+maplit(Node *n)
+{
+	Iter saver;
+	Type *t;
+	Node *var, *r, *a;
+
+	t = n->type;
+	if(t->etype != TMAP)
+		fatal("maplit: not array");
+	t = ptrto(t);
+
+	var = nod(OXXX, N, N);
+	tempname(var, t);
+
+	a = nod(ONEW, N, N);
+	a->type = t;
+	a = nod(OAS, var, a);
+	addtop = list(addtop, a);
+
+	r = listfirst(&saver, &n->left);
+
+loop:
+	if(r == N) {
+		return var;
+	}
+
+	if(r->op != OKEY) {
+		yyerror("map literal must have key:value pairs");
+		return var;
+	}
+
+	// build list of var[c] = expr
+
+	a = nod(OINDEX, var, r->left);
+	a = nod(OAS, a, r->right);
+	addtop = list(addtop, a);
+
+	r = listnext(&saver);
+	goto loop;
+}