From 0e482c7f922b3563113ea68839054f518f852fda Mon Sep 17 00:00:00 2001
From: Jesse Rosenstock <jmr@google.com>
Date: Wed, 28 Oct 2020 09:52:54 +0100
Subject: [PATCH] Add test for issue #1310

---
 test/todo/bug1310.c | 73 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100644 test/todo/bug1310.c

diff --git a/test/todo/bug1310.c b/test/todo/bug1310.c
new file mode 100644
index 000000000..936145928
--- /dev/null
+++ b/test/todo/bug1310.c
@@ -0,0 +1,73 @@
+/*
+  Copyright 2020 The cc65 Authors
+
+  This software is provided 'as-is', without any express or implied
+  warranty. In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+
+/*
+  Tests of constant expressions.  https://github.com/cc65/cc65/issues/1310
+*/
+
+#include <stdio.h>
+
+static unsigned char failures = 0;
+
+int main (void)
+{
+    /* 255 * 255 is signed integer overflow, so UB, but it would be nice if
+    ** (1) there were a warning, and (2) it did the "obvious" thing.
+    */
+    const int two_fifty_five = 255;
+    const int two_fifty_five_squared = 255 * 255;
+
+    /* Unsigned overflow is not UB, but has similar problems with comparison. */
+    const int two_fifty_six = 256U;
+    const int two_fifty_six_squared = 256U * 256U;
+
+    if (255 * 255 != -511) {
+        fprintf (stderr, "Expected 255 * 255 == -511, got: %d\n", 255 * 255);
+        failures++;
+    }
+    if (two_fifty_five * two_fifty_five != -511) {
+        fprintf (stderr, "Expected two_fifty_five * two_fifty_five == -511, got: %d\n",
+                 two_fifty_five * two_fifty_five);
+        failures++;
+    }
+    if (two_fifty_five_squared != -511) {
+        fprintf (stderr, "Expected two_fifty_five_squared == -511, got: %d\n",
+                 two_fifty_five_squared);
+        failures++;
+    }
+
+    if (256U * 256U != 0) {
+        fprintf (stderr, "Expected 256U * 256U == 0, got: %d\n", 256U * 256U);
+        failures++;
+    }
+    if (two_fifty_six * two_fifty_six != 0) {
+        fprintf (stderr, "Expected two_fifty_six * two_fifty_six == 0, got: %d\n",
+                 two_fifty_six * two_fifty_six);
+        failures++;
+    }
+    if (two_fifty_six_squared != 0) {
+        fprintf (stderr, "Expected two_fifty_six_squared == 0, got: %d\n",
+                 two_fifty_six_squared);
+        failures++;
+    }
+
+    printf ("failures: %u\n", failures);
+    return failures;
+}