From b2c20e6c16278fe556ce4c4ff7d3b146b3a8f009 Mon Sep 17 00:00:00 2001
From: jvoisin
Date: Mon, 11 Sep 2023 20:23:12 +0200
Subject: Factorize overlap checks into a macro

---
 include/string.h | 25 +++++--------------------
 1 file changed, 5 insertions(+), 20 deletions(-)

(limited to 'include/string.h')

diff --git a/include/string.h b/include/string.h
index 342bde0..0a9cd07 100644
--- a/include/string.h
+++ b/include/string.h
@@ -49,10 +49,7 @@ _FORTIFY_FN(memcpy) void *memcpy(void * _FORTIFY_POS0 __od,
 	char *__d = (char *)__od;
 	const char *__s = (const char *)__os;
 
-	/* trap if pointers are overlapping but not if dst == src.
-	 * gcc seems to like to generate code that relies on dst == src */
-	if ((__d < __s && __d + __n > __s) ||
-	    (__s < __d && __s + __n > __d))
+	if __fh_overlap(__d, __s, __n)
 		__builtin_trap();
 	if (__n > __bd || __n > __bs)
 		__builtin_trap();
@@ -131,10 +128,7 @@ _FORTIFY_FN(stpcpy) char *stpcpy(char * _FORTIFY_POS0 __d, const char *__s)
 {
 	size_t __n = strlen(__s) + 1;
 
-	/* trap if pointers are overlapping but not if dst == src.
-	 * gcc seems to like to generate code that relies on dst == src */
-	if ((__d < __s && __d + __n > __s) ||
-	    (__s < __d && __s + __n > __d))
+	if (__fh_overlap(__d, __s, __n))
 		__builtin_trap();
 
 	size_t __b = __bos(__d, 0);
@@ -150,10 +144,7 @@ __diagnose_as_builtin(__builtin_stpncpy, 1, 2, 3)
 _FORTIFY_FN(stpncpy) char *stpncpy(char * _FORTIFY_POS0 __d, const char *__s,
                                    size_t __n)
 {
-	/* trap if pointers are overlapping but not if dst == src.
-	 * gcc seems to like to generate code that relies on dst == src */
-	if ((__d < __s && __d + __n > __s) ||
-	    (__s < __d && __s + __n > __d))
+	if (__fh_overlap(__d, __s, __n))
 		__builtin_trap();
 
 	size_t __b = __bos(__d, 0);
@@ -182,10 +173,7 @@ _FORTIFY_FN(strcpy) char *strcpy(char * _FORTIFY_POS0 __d, const char *__s)
 {
 	size_t __n = strlen(__s) + 1;
 
-	/* trap if pointers are overlapping but not if dst == src.
-	 * gcc seems to like to generate code that relies on dst == src */
-	if ((__d < __s && __d + __n > __s) ||
-	    (__s < __d && __s + __n > __d))
+	if (__fh_overlap(__d, __s, __n))
 		__builtin_trap();
 
 	size_t __b = __bos(__d, 0);
@@ -219,10 +207,7 @@ __diagnose_as_builtin(__builtin_strncpy, 1, 2, 3)
 _FORTIFY_FN(strncpy) char *strncpy(char * _FORTIFY_POS0 __d,
                                    const char *__s, size_t __n)
 {
-	/* trap if pointers are overlapping but not if dst == src.
-	 * gcc seems to like to generate code that relies on dst == src */
-	if ((__d < __s && __d + __n > __s) ||
-	    (__s < __d && __s + __n > __d))
+	if (__fh_overlap(__d, __s, __n))
 		__builtin_trap();
 
 	size_t __b = __bos(__d, 0);
-- 
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