diff options
| author | Todd C. Miller <millert@cvs.openbsd.org> | 2024-06-04 14:40:47 +0000 |
|---|---|---|
| committer | Todd C. Miller <millert@cvs.openbsd.org> | 2024-06-04 14:40:47 +0000 |
| commit | 2e14e0c68c351352dd224815a531683d75507bd9 (patch) | |
| tree | c494d1e8662297d75787234db2031884d1bfb43d | |
| parent | f8994633398d4c8e81c3d9eea7a16bf4bfa4f3c6 (diff) | |
Avoid unnecessary string traversals in u8_isutf() and substr().
For u8_isutf() the conditionals already ensure that a NUL byte won't
match. For substr() we can use the byte offset of 'm' to avoid
re-scanning the initial part of the string. From Jonas Bechtel.
| -rw-r--r-- | usr.bin/awk/run.c | 18 |
1 files changed, 8 insertions, 10 deletions
diff --git a/usr.bin/awk/run.c b/usr.bin/awk/run.c index 23bf3a9fabc..778477df1e7 100644 --- a/usr.bin/awk/run.c +++ b/usr.bin/awk/run.c @@ -1,4 +1,4 @@ -/* $OpenBSD: run.c,v 1.87 2024/06/03 00:55:05 millert Exp $ */ +/* $OpenBSD: run.c,v 1.88 2024/06/04 14:40:46 millert Exp $ */ /**************************************************************** Copyright (C) Lucent Technologies 1997 All Rights Reserved @@ -602,20 +602,18 @@ Cell *intest(Node **a, int n) /* a[0] is index (list), a[1] is symtab */ /* return length 1..4 if yes, 0 if no */ static int u8_isutf(const char *s) { - int n, ret; + int ret; unsigned char c; c = s[0]; - if (c < 128 || awk_mb_cur_max == 1) - return 1; /* what if it's 0? */ - - n = strlen(s); - if (n >= 2 && ((c>>5) & 0x7) == 0x6 && (s[1] & 0xC0) == 0x80) { + if (c < 128 || awk_mb_cur_max == 1) { + ret = 1; /* what if it's 0? */ + } else if (((c>>5) & 0x7) == 0x6 && (s[1] & 0xC0) == 0x80) { ret = 2; /* 110xxxxx 10xxxxxx */ - } else if (n >= 3 && ((c>>4) & 0xF) == 0xE && (s[1] & 0xC0) == 0x80 + } else if (((c>>4) & 0xF) == 0xE && (s[1] & 0xC0) == 0x80 && (s[2] & 0xC0) == 0x80) { ret = 3; /* 1110xxxx 10xxxxxx 10xxxxxx */ - } else if (n >= 4 && ((c>>3) & 0x1F) == 0x1E && (s[1] & 0xC0) == 0x80 + } else if (((c>>3) & 0x1F) == 0x1E && (s[1] & 0xC0) == 0x80 && (s[2] & 0xC0) == 0x80 && (s[3] & 0xC0) == 0x80) { ret = 4; /* 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx */ } else { @@ -1018,7 +1016,7 @@ Cell *substr(Node **a, int nnn) /* substr(a[0], a[1], a[2]) */ DPRINTF("substr: m=%d, n=%d, s=%s\n", m, n, s); y = gettemp(); mb = u8_char2byte(s, m-1); /* byte offset of start char in s */ - nb = u8_char2byte(s, m-1+n); /* byte offset of end+1 char in s */ + nb = mb + u8_char2byte(&s[mb], n); /* byte offset of end+1 char in s */ temp = s[nb]; /* with thanks to John Linderman */ s[nb] = '\0'; |