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[NFC][LLVM][ADT] Simplify StringRef case insensitive compare #147994

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Merged
jurahul merged 1 commit into from
Jul 10, 2025
Merged

[NFC][LLVM][ADT] Simplify StringRef case insensitive compare #147994

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17 changes: 8 additions & 9 deletions llvm/lib/Support/StringRef.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -24,19 +24,19 @@ constexpr size_t StringRef::npos;

// strncasecmp() is not available on non-POSIX systems, so define an
// alternative function here.
static int ascii_strncasecmp(const char *LHS, const char *RHS, size_t Length) {
for (size_t I = 0; I < Length; ++I) {
unsigned char LHC = toLower(LHS[I]);
unsigned char RHC = toLower(RHS[I]);
static int ascii_strncasecmp(StringRef LHS, StringRef RHS) {
for (auto [LC, RC] : zip_equal(LHS, RHS)) {
unsigned char LHC = toLower(LC);
unsigned char RHC = toLower(RC);
if (LHC != RHC)
return LHC < RHC ? -1 : 1;
}
return 0;
}

int StringRef::compare_insensitive(StringRef RHS) const {
if (int Res =
ascii_strncasecmp(data(), RHS.data(), std::min(size(), RHS.size())))
size_t Min = std::min(size(), RHS.size());
if (int Res = ascii_strncasecmp(take_front(Min), RHS.take_front(Min)))
return Res;
if (size() == RHS.size())
return 0;
Expand All @@ -45,13 +45,12 @@ int StringRef::compare_insensitive(StringRef RHS) const {

bool StringRef::starts_with_insensitive(StringRef Prefix) const {
return size() >= Prefix.size() &&
ascii_strncasecmp(data(), Prefix.data(), Prefix.size()) == 0;
ascii_strncasecmp(take_front(Prefix.size()), Prefix) == 0;
}

bool StringRef::ends_with_insensitive(StringRef Suffix) const {
return size() >= Suffix.size() &&
ascii_strncasecmp(end() - Suffix.size(), Suffix.data(),
Suffix.size()) == 0;
ascii_strncasecmp(take_back(Suffix.size()), Suffix) == 0;
}

size_t StringRef::find_insensitive(char C, size_t From) const {
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