[libc] Fixed mbtowc functions #150118
Merged
[libc] Fixed mbtowc functions #150118
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
mbrtowc was not handling null destination correctly
|
@llvm/pr-subscribers-libc Author: None (sribee8) Changesmbrtowc was not handling null destination correctly Full diff: https://github.com/llvm/llvm-project/pull/150118.diff 2 Files Affected:
diff --git a/libc/src/__support/wchar/mbrtowc.cpp b/libc/src/__support/wchar/mbrtowc.cpp
index 90ba934c42b69..0f730d6e6dbec 100644
--- a/libc/src/__support/wchar/mbrtowc.cpp
+++ b/libc/src/__support/wchar/mbrtowc.cpp
@@ -37,7 +37,8 @@ ErrorOr<size_t> mbrtowc(wchar_t *__restrict pwc, const char *__restrict s,
}
auto wc = char_conv.pop_utf32();
if (wc.has_value()) {
- *pwc = wc.value();
+ if (pwc != nullptr)
+ *pwc = wc.value();
// null terminator -> return 0
if (wc.value() == L'\0')
return 0;
diff --git a/libc/src/wchar/mbtowc.cpp b/libc/src/wchar/mbtowc.cpp
index eae39ba6081f3..6d099d43da5fa 100644
--- a/libc/src/wchar/mbtowc.cpp
+++ b/libc/src/wchar/mbtowc.cpp
@@ -25,10 +25,7 @@ LLVM_LIBC_FUNCTION(int, mbtowc,
if (s == nullptr)
return 0;
internal::mbstate internal_mbstate;
- // temp ptr to use if pwc is nullptr
- wchar_t buf[1];
- auto ret =
- internal::mbrtowc(pwc == nullptr ? buf : pwc, s, n, &internal_mbstate);
+ auto ret = internal::mbrtowc(pwc, s, n, &internal_mbstate);
if (!ret.has_value() || static_cast<int>(ret.value()) == -2) {
// Encoding failure
libc_errno = EILSEQ;
|
uzairnawaz
approved these changes
Jul 22, 2025
mahesh-attarde
pushed a commit
to mahesh-attarde/llvm-project
that referenced
this pull request
Jul 28, 2025
mbrtowc was not handling null destination correctly --------- Co-authored-by: Sriya Pratipati <sriyap@google.com>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
mbrtowc was not handling null destination correctly