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Bug 1882386: Correctly handle empty search string case when inlining String.p.lastIndexOf. r=jandem

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Differential Revision: https://phabricator.services.mozilla.com/D203248
This commit is contained in:
André Bargull 2024-03-01 12:23:08 +00:00
parent f658742e04
commit 4551ff49c0
2 changed files with 107 additions and 4 deletions
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9
js/src/builtin/String.cpp
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@ -2652,10 +2652,14 @@ bool js::StringLastIndexOf(JSContext* cx, HandleString string,
return true;
}
MOZ_ASSERT(len >= searchLen);
size_t start = len - searchLen;
if (searchLen == 0) {
*result = 0;
*result = start;
return true;
}
MOZ_ASSERT(start < len);
JSLinearString* text = string->ensureLinear(cx);
if (!text) {
@ -2667,9 +2671,6 @@ bool js::StringLastIndexOf(JSContext* cx, HandleString string,
return false;
}
MOZ_ASSERT(len >= searchLen);
size_t start = len - searchLen;
*result = LastIndexOf(text, searchStr, start);
return true;
}

102
js/src/jit-test/tests/cacheir/string-lastIndexOf.js Normal file
View File

@ -0,0 +1,102 @@
function testEmpty() {
var strings = [
"",
"a",
"ab",
];
for (var i = 0; i < 200; ++i) {
var str = strings[i % strings.length];
assertEq(str.lastIndexOf(""), str.length);
}
}
testEmpty();
function testSingle() {
var strings = [
"",
"a",
"b",
"aa",
"ab",
"ba",
"bb",
];
var searchStrings = [
"a",
"b",
];
for (var i = 0; i < 200; ++i) {
var str = strings[i % strings.length];
var searchString = searchStrings[i % searchStrings.length];
var j = str.length;
while (--j >= 0 && str[j] !== searchString);
assertEq(str.lastIndexOf(searchString), j);
}
}
testSingle();
function testDouble() {
var strings = [
"",
"a",
"b",
"aa",
"ab",
"ba",
"bb",
"aaa",
"aab",
"aba",
"abb",
"baa",
"bab",
"bba",
"bbb",
"aaaa",
"aaab",
"aaba",
"aabb",
"abaa",
"abab",
"abba",
"abbb",
"baaa",
"baab",
"baba",
"babb",
"bbaa",
"bbab",
"bbba",
"bbbb",
];
var searchStrings = [
"aa",
"ab",
"ba",
"bb",
];
for (var i = 0; i < 200; ++i) {
var str = strings[i % strings.length];
var searchString = searchStrings[i % searchStrings.length];
var j = str.length;
while (--j >= 0 && (str[j] !== searchString[0] || str[j + 1] !== searchString[1]));
assertEq(str.lastIndexOf(searchString), j);
}
}
testDouble();