From 16c718729adfaf40cf22aa4efeafb0d92ef5ee3c Mon Sep 17 00:00:00 2001
From: Michael Forney <mforney@mforney.org>
Date: Sat, 4 Sep 2021 13:43:16 -0700
Subject: Prepare for supporting architecture-specific va_list type

---
 cc.h   |  2 +-
 expr.c | 29 ++++++++++++++++++++++-------
 type.c | 14 +++++---------
 3 files changed, 28 insertions(+), 17 deletions(-)

diff --git a/cc.h b/cc.h
index 3b33e8c..9c4484b 100644
--- a/cc.h
+++ b/cc.h
@@ -428,7 +428,7 @@ extern struct type typeint, typeuint;
 extern struct type typelong, typeulong;
 extern struct type typellong, typeullong;
 extern struct type typefloat, typedouble, typeldouble;
-extern struct type typevalist, typevalistptr;
+extern struct type typevalist;
 
 /* targ */
 
diff --git a/expr.c b/expr.c
index 70aa3bd..6837adb 100644
--- a/expr.c
+++ b/expr.c
@@ -642,26 +642,41 @@ builtinfunc(struct scope *s, enum builtinkind kind)
 	case BUILTINVAARG:
 		e = mkexpr(EXPRBUILTIN, NULL);
 		e->builtin.kind = BUILTINVAARG;
-		e->base = exprconvert(assignexpr(s), &typevalistptr);
+		e->base = mkunaryexpr(TBAND, assignexpr(s));
+		if (e->base->base->type != &typevalist)
+			error(&tok.loc, "va_arg argument must have type va_list");
 		expect(TCOMMA, "after va_list");
 		e->type = typename(s, &e->qual);
 		break;
 	case BUILTINVACOPY:
-		e = mkexpr(EXPRASSIGN, typevalist.base);
-		e->assign.l = mkunaryexpr(TMUL, exprconvert(assignexpr(s), &typevalistptr));
+		e = mkexpr(EXPRASSIGN, &typevoid);
+		e->assign.l = assignexpr(s);
+		if (e->assign.l->decayed)
+			e->assign.l = e->assign.l->base;
+		if (e->assign.l->type != &typevalist)
+			error(&tok.loc, "va_copy destination must have type va_list");
 		expect(TCOMMA, "after target va_list");
-		e->assign.r = mkunaryexpr(TMUL, exprconvert(assignexpr(s), &typevalistptr));
-		e = exprconvert(e, &typevoid);
+		e->assign.r = assignexpr(s);
+		if (e->assign.r->decayed)
+			e->assign.r = e->assign.r->base;
+		if (e->assign.r->type != &typevalist)
+			error(&tok.loc, "va_copy source must have type va_list");
 		break;
 	case BUILTINVAEND:
+		e = assignexpr(s);
+		if (e->decayed)
+			e = e->base;
+		if (e->type != &typevalist)
+			error(&tok.loc, "va_end argument must have type va_list");
 		e = mkexpr(EXPRBUILTIN, &typevoid);
 		e->builtin.kind = BUILTINVAEND;
-		exprconvert(assignexpr(s), &typevalistptr);
 		break;
 	case BUILTINVASTART:
 		e = mkexpr(EXPRBUILTIN, &typevoid);
 		e->builtin.kind = BUILTINVASTART;
-		e->base = exprconvert(assignexpr(s), &typevalistptr);
+		e->base = mkunaryexpr(TBAND, assignexpr(s));
+		if (e->base->base->type != &typevalist)
+			error(&tok.loc, "va_start argument must have type va_list");
 		expect(TCOMMA, "after va_list");
 		param = assignexpr(s);
 		if (param->kind != EXPRIDENT)
diff --git a/type.c b/type.c
index f58247a..a97175a 100644
--- a/type.c
+++ b/type.c
@@ -39,17 +39,13 @@ struct type typefloat   = FLTTYPE(TYPEFLOAT, 4);
 struct type typedouble  = FLTTYPE(TYPEDOUBLE, 8);
 struct type typeldouble = FLTTYPE(TYPELDOUBLE, 16);
 
-static struct type typevaliststruct = {
-	.kind = TYPESTRUCT, .size = 32, .align = 8,
-	.prop = PROPOBJECT|PROPAGGR,
-};
 struct type typevalist = {
-	.kind = TYPEARRAY, .size = 32, .align = 8, .array = {1}, .base = &typevaliststruct,
+	.kind = TYPEARRAY, .size = 32, .align = 8, .array = {1},
 	.prop = PROPOBJECT|PROPDERIVED|PROPAGGR,
-};
-struct type typevalistptr = {
-	.kind = TYPEPOINTER, .size = 8, .align = 8, .base = &typevaliststruct,
-	.prop = PROPOBJECT|PROPDERIVED|PROPSCALAR,
+	.base = &(struct type){
+		.kind = TYPESTRUCT, .size = 32, .align = 8,
+		.prop = PROPOBJECT|PROPAGGR,
+	},
 };
 
 struct type *
-- 
cgit v1.2.3