Module Name: src
Committed By: rillig
Date: Fri May 13 21:42:30 UTC 2022
Modified Files:
src/usr.bin/make: str.c
Log Message:
make: document platform dependency in string pattern matching
No unit test for this edge case since all other unit tests are platform-
independent.
To reproduce:
$ make clean
$ make -s PROG=s-make NOMAN=yes USER_CFLAGS=-fsigned-char
$ make clean
$ make -s PROG=u-make NOMAN=yes USER_CFLAGS=-funsigned-char
$ make clean
$ range=$(lua -e 'print(("[%c-%c]"):format(0xe4, 0x61))')
$ ./s-make -V "\${:UM:M$range}\${:UN:N$range}"
M
$ ./u-make -V "\${:UM:M$range}\${:UN:N$range}"
N
To generate a diff of this commit:
cvs rdiff -u -r1.90 -r1.91 src/usr.bin/make/str.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/str.c
diff -u src/usr.bin/make/str.c:1.90 src/usr.bin/make/str.c:1.91
--- src/usr.bin/make/str.c:1.90 Fri May 13 20:37:01 2022
+++ src/usr.bin/make/str.c Fri May 13 21:42:30 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: str.c,v 1.90 2022/05/13 20:37:01 rillig Exp $ */
+/* $NetBSD: str.c,v 1.91 2022/05/13 21:42:30 rillig Exp $ */
/*
* Copyright (c) 1988, 1989, 1990, 1993
@@ -71,7 +71,7 @@
#include "make.h"
/* "@(#)str.c 5.8 (Berkeley) 6/1/90" */
-MAKE_RCSID("$NetBSD: str.c,v 1.90 2022/05/13 20:37:01 rillig Exp $");
+MAKE_RCSID("$NetBSD: str.c,v 1.91 2022/05/13 21:42:30 rillig Exp $");
static HashTable interned_strings;
@@ -293,6 +293,26 @@ Str_Words(const char *str, bool expand)
}
/*
+ * XXX: In the extreme edge case that one of the characters is from the basic
+ * execution character set and the other isn't, the result of the comparison
+ * differs depending on whether plain char is signed or unsigned.
+ *
+ * An example is the character range from \xE4 to 'a', where \xE4 may come
+ * from U+00E4 'Latin small letter A with diaeresis'.
+ *
+ * If char is signed, \xE4 evaluates to -28, the first half of the condition
+ * becomes -28 <= '0' && '0' <= 'a', which evaluates to true.
+ *
+ * If char is unsigned, \xE4 evaluates to 228, the second half of the
+ * condition becomes 'a' <= '0' && '0' <= 228, which evaluates to false.
+ */
+static bool
+in_range(char e1, char c, char e2)
+{
+ return (e1 <= c && c <= e2) || (e2 <= c && c <= e1);
+}
+
+/*
* Str_Match -- Test if a string matches a pattern like "*.[ch]".
* The following special characters are known *?\[] (as in fnmatch(3)).
*
@@ -355,9 +375,7 @@ Str_Match(const char *str, const char *p
if (pat[1] == '-') {
if (pat[2] == '\0')
return neg;
- if (pat[0] <= *str && *str <= pat[2])
- break;
- if (pat[2] <= *str && *str <= pat[0])
+ if (in_range(pat[0], *str, pat[2]))
break;
pat += 2;
}
