crypt_sha256/crypt_sha512, fix build with more recent versions of clang (> 12).

clang picks up the address subtraction to null as UB, but the implementations
are based on glibc.

`error: performing pointer subtraction with a null pointer has undefined behavior [-Werror,-Wnull-pointer-subtraction]
        if ((key - (char *) 0) % __alignof__ (uint64_t) != 0) {`

Author: devnexen

ext/standard/crypt_sha256.c

@@ -322,6 +322,11 @@ static const char sha256_rounds_prefix[] = "rounds=";
 static const char b64t[64] =
 "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
 
+#if defined(__clang__) && __clang_major__ > 12
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wnull-pointer-subtraction"
+#endif
+
 char * php_sha256_crypt_r(const char *key, const char *salt, char *buffer, int buflen)
 {
 #ifdef PHP_WIN32
@@ -575,6 +580,9 @@ char * php_sha256_crypt_r(const char *key, const char *salt, char *buffer, int b
 	return buffer;
 }
 
+#if defined(__clang__) && __clang_major__ > 12
+#pragma clang diagnostic pop
+#endif
 
 /* This entry point is equivalent to the `crypt' function in Unix
    libcs.  */

ext/standard/crypt_sha512.c

@@ -355,6 +355,10 @@ static const char sha512_rounds_prefix[] = "rounds=";
 static const char b64t[64] =
 "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
 
+#if defined(__clang__) && __clang_major__ > 12
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wnull-pointer-subtraction"
+#endif
 
 char *
 php_sha512_crypt_r(const char *key, const char *salt, char *buffer, int buflen) {
@@ -622,6 +626,10 @@ php_sha512_crypt_r(const char *key, const char *salt, char *buffer, int buflen)
 	return buffer;
 }
 
+#if defined(__clang__) && __clang_major__ > 12
+#pragma clang diagnostic pop
+#endif
+
 
 /* This entry point is equivalent to the `crypt' function in Unix
    libcs.  */