Skip to content

[clang][bytecode] Implement __builtin_wmemchr #132254

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Mar 20, 2025
Merged

[clang][bytecode] Implement __builtin_wmemchr #132254

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
25 changes: 20 additions & 5 deletions clang/lib/AST/ByteCode/InterpBuiltin.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2039,11 +2039,23 @@ static bool interp__builtin_memchr(InterpState &S, CodePtr OpPC,
}
}

uint64_t DesiredVal =
Desired.trunc(S.getASTContext().getCharWidth()).getZExtValue();
uint64_t DesiredVal;
if (ID == Builtin::BIwmemchr || ID == Builtin::BI__builtin_wmemchr ||
ID == Builtin::BIwcschr || ID == Builtin::BI__builtin_wcschr) {
// wcschr and wmemchr are given a wchar_t to look for. Just use it.
DesiredVal = Desired.getZExtValue();
} else {
DesiredVal = Desired.trunc(S.getASTContext().getCharWidth()).getZExtValue();
}

bool StopAtZero =
(ID == Builtin::BIstrchr || ID == Builtin::BI__builtin_strchr);

PrimType ElemT =
IsRawByte
? PT_Sint8
: *S.getContext().classify(Ptr.getFieldDesc()->getElemQualType());

size_t Index = Ptr.getIndex();
size_t Step = 0;
for (;;) {
Expand All @@ -2053,7 +2065,10 @@ static bool interp__builtin_memchr(InterpState &S, CodePtr OpPC,
if (!CheckLoad(S, OpPC, ElemPtr))
return false;

unsigned char V = static_cast<unsigned char>(ElemPtr.deref<char>());
uint64_t V;
INT_TYPE_SWITCH_NO_BOOL(
ElemT, { V = static_cast<uint64_t>(ElemPtr.deref<T>().toUnsigned()); });

if (V == DesiredVal) {
S.Stk.push<Pointer>(ElemPtr);
return true;
Expand Down Expand Up @@ -2556,11 +2571,11 @@ bool InterpretBuiltin(InterpState &S, CodePtr OpPC, const Function *F,
case Builtin::BI__builtin_memchr:
case Builtin::BIstrchr:
case Builtin::BI__builtin_strchr:
case Builtin::BIwmemchr:
case Builtin::BI__builtin_wmemchr:
#if 0
case Builtin::BIwcschr:
case Builtin::BI__builtin_wcschr:
case Builtin::BImemchr:
case Builtin::BI__builtin_wmemchr:
#endif
case Builtin::BI__builtin_char_memchr:
if (!interp__builtin_memchr(S, OpPC, Frame, F, Call))
Expand Down
24 changes: 24 additions & 0 deletions clang/test/AST/ByteCode/builtin-functions.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -20,6 +20,7 @@ extern "C" {
extern size_t wcslen(const wchar_t *p);
extern void *memchr(const void *s, int c, size_t n);
extern char *strchr(const char *s, int c);
extern wchar_t *wmemchr(const wchar_t *s, wchar_t c, size_t n);
}

namespace strcmp {
Expand Down Expand Up @@ -1489,3 +1490,26 @@ namespace Strchr {
constexpr bool a = !strchr("hello", 'h'); // both-error {{constant expression}} \
// both-note {{non-constexpr function 'strchr' cannot be used in a constant expression}}
}

namespace WMemChr {
constexpr const wchar_t *kStr = L"abca\xffff\0dL";
constexpr wchar_t kFoo[] = {L'f', L'o', L'o'};

static_assert(__builtin_wmemchr(kStr, L'a', 0) == nullptr);
static_assert(__builtin_wmemchr(kStr, L'a', 1) == kStr);
static_assert(__builtin_wmemchr(kStr, L'\0', 5) == nullptr);
static_assert(__builtin_wmemchr(kStr, L'\0', 6) == kStr + 5);
static_assert(__builtin_wmemchr(kStr, L'\xffff', 8) == kStr + 4);
static_assert(__builtin_wmemchr(kFoo, L'x', 3) == nullptr);
static_assert(__builtin_wmemchr(kFoo, L'x', 4) == nullptr); // both-error {{not an integral constant}} \
// both-note {{dereferenced one-past-the-end}}
static_assert(__builtin_wmemchr(nullptr, L'x', 3) == nullptr); // both-error {{not an integral constant}} \
// both-note {{dereferenced null}}
static_assert(__builtin_wmemchr(nullptr, L'x', 0) == nullptr);

constexpr bool b = !wmemchr(L"hello", L'h', 3); // both-error {{constant expression}} \
// both-note {{non-constexpr function 'wmemchr' cannot be used in a constant expression}}

constexpr wchar_t kStr2[] = {L'f', L'o', L'\xffff', L'o'};
static_assert(__builtin_wmemchr(kStr2, L'\xffff', 4) == kStr2 + 2);
}