From 20f9802e4f25922884448d9581c66d76cc905c0c Mon Sep 17 00:00:00 2001
From: Qi Wang <interwq@gwu.edu>
Date: Wed, 26 Jan 2022 18:40:49 -0800
Subject: [PATCH] Avoid overflow warnings in test/unit/safety_check.

---
 test/unit/safety_check.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/test/unit/safety_check.c b/test/unit/safety_check.c
index 516a0969..84726675 100644
--- a/test/unit/safety_check.c
+++ b/test/unit/safety_check.c
@@ -13,6 +13,13 @@ void fake_abort(const char *message) {
 	fake_abort_called = true;
 }
 
+static void
+buffer_overflow_write(char *ptr, size_t size) {
+	/* Avoid overflow warnings. */
+	volatile size_t idx = size;
+	ptr[idx] = 0;
+}
+
 TEST_BEGIN(test_malloc_free_overflow) {
 	test_skip_if(!config_prof);
 	test_skip_if(!config_opt_safety_checks);
@@ -20,7 +27,7 @@ TEST_BEGIN(test_malloc_free_overflow) {
 	safety_check_set_abort(&fake_abort);
 	/* Buffer overflow! */
 	char* ptr = malloc(128);
-	ptr[128] = 0;
+	buffer_overflow_write(ptr, 128);
 	free(ptr);
 	safety_check_set_abort(NULL);
 
@@ -36,7 +43,7 @@ TEST_BEGIN(test_mallocx_dallocx_overflow) {
 	safety_check_set_abort(&fake_abort);
 	/* Buffer overflow! */
 	char* ptr = mallocx(128, 0);
-	ptr[128] = 0;
+	buffer_overflow_write(ptr, 128);
 	dallocx(ptr, 0);
 	safety_check_set_abort(NULL);
 
@@ -52,7 +59,7 @@ TEST_BEGIN(test_malloc_sdallocx_overflow) {
 	safety_check_set_abort(&fake_abort);
 	/* Buffer overflow! */
 	char* ptr = malloc(128);
-	ptr[128] = 0;
+	buffer_overflow_write(ptr, 128);
 	sdallocx(ptr, 128, 0);
 	safety_check_set_abort(NULL);
 
@@ -68,7 +75,7 @@ TEST_BEGIN(test_realloc_overflow) {
 	safety_check_set_abort(&fake_abort);
 	/* Buffer overflow! */
 	char* ptr = malloc(128);
-	ptr[128] = 0;
+	buffer_overflow_write(ptr, 128);
 	ptr = realloc(ptr, 129);
 	safety_check_set_abort(NULL);
 	free(ptr);
@@ -85,7 +92,7 @@ TEST_BEGIN(test_rallocx_overflow) {
 	safety_check_set_abort(&fake_abort);
 	/* Buffer overflow! */
 	char* ptr = malloc(128);
-	ptr[128] = 0;
+	buffer_overflow_write(ptr, 128);
 	ptr = rallocx(ptr, 129, 0);
 	safety_check_set_abort(NULL);
 	free(ptr);
@@ -102,7 +109,7 @@ TEST_BEGIN(test_xallocx_overflow) {
 	safety_check_set_abort(&fake_abort);
 	/* Buffer overflow! */
 	char* ptr = malloc(128);
-	ptr[128] = 0;
+	buffer_overflow_write(ptr, 128);
 	size_t result = xallocx(ptr, 129, 0, 0);
 	expect_zu_eq(result, 128, "");
 	free(ptr);