From 53e81033ce18fd94fcdcde9010b7c9d41f30aa2c Mon Sep 17 00:00:00 2001
From: Rui Ueyama <ruiu@cs.stanford.edu>
Date: Wed, 2 Sep 2020 20:11:28 +0900
Subject: [PATCH] Add usual arithmetic conversion for function pointer

---
 test/usualconv.c | 4 ++++
 type.c           | 5 +++++
 2 files changed, 9 insertions(+)

diff --git a/test/usualconv.c b/test/usualconv.c
index b1f951a..b173fe1 100644
--- a/test/usualconv.c
+++ b/test/usualconv.c
@@ -1,5 +1,7 @@
 #include "test.h"
 
+static int ret10(void) { return 10; }
+
 int main() {
   ASSERT((long)-5, -10 + (long)5);
   ASSERT((long)-15, -10 - (long)5);
@@ -23,6 +25,8 @@ int main() {
   ASSERT(0, ({ char x[3]; x[0]=0; x[1]=1; x[2]=2; char *y=x+1; y[-1]; }));
   ASSERT(5, ({ struct t {char a;} x, y; x.a=5; y=x; y.a; }));
 
+  ASSERT(10, (1 ? ret10 : (void *)0)());
+
   printf("OK\n");
   return 0;
 }
diff --git a/type.c b/type.c
index 299307f..b50c3c3 100644
--- a/type.c
+++ b/type.c
@@ -77,6 +77,11 @@ static Type *get_common_type(Type *ty1, Type *ty2) {
   if (ty1->base)
     return pointer_to(ty1->base);
 
+  if (ty1->kind == TY_FUNC)
+    return pointer_to(ty1);
+  if (ty2->kind == TY_FUNC)
+    return pointer_to(ty2);
+
   if (ty1->kind == TY_DOUBLE || ty2->kind == TY_DOUBLE)
     return ty_double;
   if (ty1->kind == TY_FLOAT || ty2->kind == TY_FLOAT)