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| author | Paolo Bonzini <bonzini@gnu.org> | 2009-06-17 16:26:06 +0200 |
|---|---|---|
| committer | Junio C Hamano <gitster@pobox.com> | 2009-06-18 09:52:10 -0700 |
| commit | 959e2e64a594e2fb8de2585078e31b07a8da6fc9 (patch) | |
| tree | bd57636123d4d79e88965e88f4eafebaa5434bee | |
| parent | 9b7dc7183528d42c46786a0be1acc58d4cd1f47a (diff) | |
| download | git-959e2e64a594e2fb8de2585078e31b07a8da6fc9.tar.gz git-959e2e64a594e2fb8de2585078e31b07a8da6fc9.tar.xz | |
avoid exponential regex match for java and objc function names
In the old regex
^[ \t]*(([ \t]*[A-Za-z_][A-Za-z_0-9]*){2,}[ \t]*\([^;]*)$
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
you can backtrack arbitrarily from [A-Za-z_0-9]* into [A-Za-z_], thus
causing an exponential number of backtracks. Ironically it also causes
the regex not to work as intended; for example "catch" can match the
underlined part of the regex, the first repetition matching "c" and
the second matching "atch".
The replacement regex avoids this problem, because it makes sure that
at least a space/tab is eaten on each repetition. In other words,
a suffix of a repetition can never be a prefix of the next repetition.
Signed-off-by: Paolo Bonzini <bonzini@gnu.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
| -rw-r--r-- | userdiff.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/userdiff.c b/userdiff.c index d556da975..57529ae63 100644 --- a/userdiff.c +++ b/userdiff.c @@ -13,7 +13,8 @@ PATTERNS("html", "^[ \t]*(<[Hh][1-6][ \t].*>.*)$", "[^<>= \t]+|[^[:space:]]|[\x80-\xff]+"), PATTERNS("java", "!^[ \t]*(catch|do|for|if|instanceof|new|return|switch|throw|while)\n" - "^[ \t]*(([ \t]*[A-Za-z_][A-Za-z_0-9]*){2,}[ \t]*\\([^;]*)$", + "^[ \t]*(([A-Za-z_][A-Za-z_0-9]*[ \t]+)+[A-Za-z_][A-Za-z_0-9]*[ \t]*\\([^;]*)$", + /* -- */ "[a-zA-Z_][a-zA-Z0-9_]*" "|[-+0-9.e]+[fFlL]?|0[xXbB]?[0-9a-fA-F]+[lL]?" "|[-+*/<>%&^|=!]=" @@ -25,7 +26,7 @@ PATTERNS("objc", /* Objective-C methods */ "^[ \t]*([-+][ \t]*\\([ \t]*[A-Za-z_][A-Za-z_0-9* \t]*\\)[ \t]*[A-Za-z_].*)$\n" /* C functions */ - "^[ \t]*(([ \t]*[A-Za-z_][A-Za-z_0-9]*){2,}[ \t]*\\([^;]*)$\n" + "^[ \t]*(([A-Za-z_][A-Za-z_0-9]*[ \t]+)+[A-Za-z_][A-Za-z_0-9]*[ \t]*\\([^;]*)$\n" /* Objective-C class/protocol definitions */ "^(@(implementation|interface|protocol)[ \t].*)$", /* -- */ |