qbe: Use ... to separate named and variadic arguments

This requires a not-yet-upstream QBE patch, and is needed for riscv64
support, since the calling convention may be different depending
on whether the argument is named or variadic.

5 files changed, 19 insertions, 11 deletions

diff --git a/cc.h b/cc.h
index f98f6aa..14b71b0 100644
--- a/cc.h
+++ b/cc.h
@@ -219,6 +219,7 @@ struct type {
 		struct {
 			_Bool isprototype, isvararg, isnoreturn, paraminfo;
 			struct param *params;
+			size_t nparam;
 		} func;
 		struct {
 			char *tag;
diff --git a/decl.c b/decl.c
index c570efa..c673463 100644
--- a/decl.c
+++ b/decl.c
@@ -516,6 +516,7 @@ declaratortypes(struct scope *s, struct list *result, char **name, bool allowabs
 			t->func.isvararg = false;
 			t->func.isnoreturn = false;
 			t->func.params = NULL;
+			t->func.nparam = 0;
 			p = &t->func.params;
 			switch (tok.kind) {
 			case TIDENT:
@@ -534,6 +535,7 @@ declaratortypes(struct scope *s, struct list *result, char **name, bool allowabs
 				for (;;) {
 					*p = parameter(s);
 					p = &(*p)->next;
+					++t->func.nparam;
 					if (!consume(TCOMMA))
 						break;
 					if (consume(TELLIPSIS)) {
diff --git a/ops.h b/ops.h
index be588a1..b8b461a 100644
--- a/ops.h
+++ b/ops.h
@@ -93,7 +93,6 @@ OP(ICOPY,    "copy")
 
 /* call */
 OP(ICALL,    "call")
-OP(IVACALL,  "call")
 
 /* variadic */
 OP(IVASTART, "vastart")
diff --git a/qbe.c b/qbe.c
index f9a6f08..78a2feb 100644
--- a/qbe.c
+++ b/qbe.c
@@ -40,6 +40,7 @@ enum instkind {
 #undef OP
 
 	IARG,
+	IVARARG,
 };
 
 struct qbetype {
@@ -722,7 +723,7 @@ funcexpr(struct func *f, struct expr *e)
 	struct lvalue lval;
 	struct expr *arg;
 	struct block *b[3];
-	struct type *t;
+	struct type *t, *functype;
 	size_t i;
 
 	switch (e->kind) {
@@ -761,7 +762,6 @@ funcexpr(struct func *f, struct expr *e)
 		v = funcstore(f, e->type, e->qual, lval, v);
 		return e->incdec.post ? l : v;
 	case EXPRCALL:
-		op = e->base->type->base->func.isvararg ? IVACALL : ICALL;
 		argvals = xreallocarray(NULL, e->call.nargs, sizeof(argvals[0]));
 		for (arg = e->call.args, i = 0; arg; arg = arg->next, ++i) {
 			emittype(arg->type);
@@ -769,12 +769,15 @@ funcexpr(struct func *f, struct expr *e)
 		}
 		t = e->type;
 		emittype(t);
-		v = funcinst(f, op, qbetype(t).base, funcexpr(f, e->base), t->value);
+		v = funcinst(f, ICALL, qbetype(t).base, funcexpr(f, e->base), t->value);
+		functype = e->base->type->base;
 		for (arg = e->call.args, i = 0; arg; arg = arg->next, ++i) {
+			if (functype->func.isvararg && i == functype->func.nparam)
+				funcinst(f, IVARARG, 0, NULL, NULL);
 			t = arg->type;
 			funcinst(f, IARG, qbetype(t).base, argvals[i], t->value);
 		}
-		//if (e->base->type->base->func.isnoreturn)
+		//if (functype->func.isnoreturn)
 		//	funcret(f, NULL);
 		return v;
 	case EXPRUNARY:
@@ -1181,20 +1184,23 @@ emitinst(struct inst **instp, struct inst **instend)
 	op = inst->kind;
 	switch (op) {
 	case ICALL:
-	case IVACALL:
 		putchar('(');
-		for (first = 1; instp != instend && (*instp)->kind == IARG; ++instp) {
+		for (first = 1; instp != instend; ++instp) {
+			inst = *instp;
+			if (inst->kind == IVARARG) {
+				fputs(", ...", stdout);
+				continue;
+			}
+			if (inst->kind != IARG)
+				break;
 			if (first)
 				first = 0;
 			else
 				fputs(", ", stdout);
-			inst = *instp;
 			emitclass(inst->class, inst->arg[1]);
 			putchar(' ');
 			emitvalue(inst->arg[0]);
 		}
-		if (op == IVACALL)
-			fputs(", ...", stdout);
 		putchar(')');
 		break;
 	default:
diff --git a/test/float-promote.qbe b/test/float-promote.qbe
index 5dad07c..97638e7 100644
--- a/test/float-promote.qbe
+++ b/test/float-promote.qbe
@@ -5,7 +5,7 @@ function $f() {
 	%.1 =d exts s_1
 	call $g1(d %.1)
 	%.2 =d exts s_1
-	call $g2(w 0, d %.2, ...)
+	call $g2(w 0, ..., d %.2)
 	call $g3(s s_1)
 	ret
 }