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AK: Eliminate avoidable strlen call in String::matches

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We already know the length of these substrings, so there's no need to
check their lengths using strlen in the StringView(char*) constructor.

This patch also removes an accidental 1-byte OOB read that was left over
from when this method received null-terminated char pointers instead of
string views, as well removes the unnecessary lambda call (two of the
checks were impossible, and this was only called in one place, so we can
just inline it)
This commit is contained in:
Idan Horowitz 2021-09-27 20:17:56 +03:00 committed by Andreas Kling
parent f7ac3545cc
commit b56b0ba689
1 changed files with 6 additions and 13 deletions
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19
AK/StringUtils.cpp
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@ -29,7 +29,7 @@ bool matches(const StringView& str, const StringView& mask, CaseSensitivity case
if (str.is_null() || mask.is_null())
return str.is_null() && mask.is_null();
if (mask == "*") {
if (mask == "*"sv) {
record_span(0, str.length());
return true;
}
@ -40,24 +40,15 @@ bool matches(const StringView& str, const StringView& mask, CaseSensitivity case
const char* mask_ptr = mask.characters_without_null_termination();
const char* mask_end = mask_ptr + mask.length();
auto matches_one = [](char ch, char p, CaseSensitivity case_sensitivity) {
if (p == '?')
return true;
if (ch == 0)
return false;
if (case_sensitivity == CaseSensitivity::CaseSensitive)
return p == ch;
return to_ascii_lowercase(p) == to_ascii_lowercase(ch);
};
while (string_ptr < string_end && mask_ptr < mask_end) {
auto string_start_ptr = string_ptr;
switch (*mask_ptr) {
case '*':
if (mask_ptr[1] == 0) {
if (mask_ptr == mask_end - 1) {
record_span(string_ptr - string_start, string_end - string_ptr);
return true;
}
while (string_ptr < string_end && !matches(string_ptr, mask_ptr + 1, case_sensitivity))
while (string_ptr < string_end && !matches({ string_ptr, static_cast<size_t>(string_end - string_ptr) }, { mask_ptr + 1, static_cast<size_t>(mask_end - mask_ptr - 1) }, case_sensitivity))
++string_ptr;
record_span(string_start_ptr - string_start, string_ptr - string_start_ptr);
--string_ptr;
@ -66,7 +57,9 @@ bool matches(const StringView& str, const StringView& mask, CaseSensitivity case
record_span(string_ptr - string_start, 1);
break;
default:
if (!matches_one(*string_ptr, *mask_ptr, case_sensitivity))
auto p = *mask_ptr;
auto ch = *string_ptr;
if (case_sensitivity == CaseSensitivity::CaseSensitive ? p != ch : to_ascii_lowercase(p) != to_ascii_lowercase(ch))
return false;
break;
}