Module Name: src
Committed By: rillig
Date: Sat Nov 21 23:09:07 UTC 2020
Modified Files:
src/usr.bin/make: suff.c
Log Message:
make(1): clean up Suffix_GetSuffix
This eliminates the unspecific variable names p1 and p2 and furthermore
ensures that there is never a pointer that points out of bounds.
The code could have used memcmp or strncmp as well, but since the
suffixes are usuall very short, there is no benefit over a direct loop
comparing individual characters.
To generate a diff of this commit:
cvs rdiff -u -r1.278 -r1.279 src/usr.bin/make/suff.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/usr.bin/make/suff.c
diff -u src/usr.bin/make/suff.c:1.278 src/usr.bin/make/suff.c:1.279
--- src/usr.bin/make/suff.c:1.278 Sat Nov 21 22:00:34 2020
+++ src/usr.bin/make/suff.c Sat Nov 21 23:09:07 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: suff.c,v 1.278 2020/11/21 22:00:34 rillig Exp $ */
+/* $NetBSD: suff.c,v 1.279 2020/11/21 23:09:07 rillig Exp $ */
/*
* Copyright (c) 1988, 1989, 1990, 1993
@@ -114,7 +114,7 @@
#include "dir.h"
/* "@(#)suff.c 8.4 (Berkeley) 3/21/94" */
-MAKE_RCSID("$NetBSD: suff.c,v 1.278 2020/11/21 22:00:34 rillig Exp $");
+MAKE_RCSID("$NetBSD: suff.c,v 1.279 2020/11/21 23:09:07 rillig Exp $");
#define SUFF_DEBUG0(text) DEBUG0(SUFF, text)
#define SUFF_DEBUG1(fmt, arg1) DEBUG1(SUFF, fmt, arg1)
@@ -255,22 +255,18 @@ SuffStrIsPrefix(const char *pref, const
static const char *
Suffix_GetSuffix(const Suffix *suff, size_t nameLen, const char *nameEnd)
{
- const char *p1; /* Pointer into suffix name */
- const char *p2; /* Pointer into string being examined */
+ size_t suffLen = suff->nameLen;
+ const char *suffInName;
- if (nameLen < suff->nameLen)
- return NULL; /* this string is shorter than the suffix */
-
- p1 = suff->name + suff->nameLen;
- p2 = nameEnd;
+ if (nameLen < suffLen)
+ return NULL;
- while (p1 >= suff->name && *p1 == *p2) {
- p1--;
- p2--;
+ suffInName = nameEnd - suffLen;
+ for (size_t i = 0; i < suffLen; i++) {
+ if (suff->name[i] != suffInName[i])
+ return NULL;
}
-
- /* XXX: s->name - 1 invokes undefined behavior */
- return p1 == suff->name - 1 ? p2 + 1 : NULL;
+ return suffInName;
}
static Boolean
