[libcxx-commits] [libcxx] [libc++] Fix Newlib check in __fwd/ios.h (PR #168952)
Chenguang Wang via libcxx-commits
libcxx-commits at lists.llvm.org
Fri Nov 21 14:17:31 PST 2025
================
@@ -31,7 +31,7 @@ using wios = basic_ios<wchar_t>;
template <class _CharT, class _Traits>
class _LIBCPP_PREFERRED_NAME(ios) _LIBCPP_IF_WIDE_CHARACTERS(_LIBCPP_PREFERRED_NAME(wios)) basic_ios;
-#if defined(_NEWLIB_VERSION)
+#if _LIBCPP_HAS_NEWLIB_LIBC
----------------
wecing wrote:
Sure. I fixed all usages in `include/` and `src/` except `include/__cxx03`, and I can confirm at least for the setup I used, the final libc++.a did not change.
Here is my diff. Since this is not that straightforward, I will leave this PR unchanged, and send the fix as another PR.
```diff
diff --git a/libcxx/include/__configuration/platform.h b/libcxx/include/__configuration/platform.h
index f3c199dee172..8d0f8f63f521 100644
--- a/libcxx/include/__configuration/platform.h
+++ b/libcxx/include/__configuration/platform.h
@@ -42,13 +42,6 @@
# endif
#endif
-// This is required in order for _NEWLIB_VERSION to be defined in places where we use it.
-// TODO: We shouldn't be including arbitrarily-named headers from libc++ since this can break valid
-// user code. Move code paths that need _NEWLIB_VERSION to another customization mechanism.
-#if __has_include(<picolibc.h>)
-# include <picolibc.h>
-#endif
-
#ifndef __BYTE_ORDER__
# error \
"Your compiler doesn't seem to define __BYTE_ORDER__, which is required by libc++ to know the endianness of your target platform"
diff --git a/libcxx/include/__locale b/libcxx/include/__locale
index 0948bd29b6f1..59a7c460b046 100644
--- a/libcxx/include/__locale
+++ b/libcxx/include/__locale
@@ -388,7 +388,7 @@ public:
static const mask xdigit = _ISXDIGIT;
static const mask blank = _ISBLANK;
static const mask __regex_word = 0x8000;
-# elif defined(_NEWLIB_VERSION)
+# elif _LIBCPP_HAS_NEWLIB_LIBC
// Same type as Newlib's _ctype_ array in newlib/libc/include/ctype.h.
typedef char mask;
// In case char is signed, static_cast is needed to avoid warning on
diff --git a/libcxx/include/__locale_dir/messages.h b/libcxx/include/__locale_dir/messages.h
index c04bf04025ff..f6b08c1a8d4f 100644
--- a/libcxx/include/__locale_dir/messages.h
+++ b/libcxx/include/__locale_dir/messages.h
@@ -22,7 +22,7 @@
# if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
// Most unix variants have catopen. These are the specific ones that don't.
-# if !defined(__BIONIC__) && !defined(_NEWLIB_VERSION) && !defined(__EMSCRIPTEN__)
+# if !defined(__BIONIC__) && !_LIBCPP_HAS_NEWLIB_LIBC && !defined(__EMSCRIPTEN__)
# define _LIBCPP_HAS_CATOPEN 1
# include <nl_types.h>
# else
diff --git a/libcxx/include/fstream b/libcxx/include/fstream
index b07ca636094a..d91c582b1c10 100644
--- a/libcxx/include/fstream
+++ b/libcxx/include/fstream
@@ -999,7 +999,7 @@ template <class _CharT, class _Traits>
int basic_filebuf<_CharT, _Traits>::__fseek(FILE* __file, pos_type __offset, int __whence) {
# if defined(_LIBCPP_MSVCRT_LIKE)
return _fseeki64(__file, __offset, __whence);
-# elif defined(_NEWLIB_VERSION)
+# elif _LIBCPP_HAS_NEWLIB_LIBC
return fseek(__file, __offset, __whence);
# else
return ::fseeko(__file, __offset, __whence);
@@ -1010,7 +1010,7 @@ template <class _CharT, class _Traits>
typename basic_filebuf<_CharT, _Traits>::pos_type basic_filebuf<_CharT, _Traits>::__ftell(FILE* __file) {
# if defined(_LIBCPP_MSVCRT_LIKE)
return _ftelli64(__file);
-# elif defined(_NEWLIB_VERSION)
+# elif _LIBCPP_HAS_NEWLIB_LIBC
return ftell(__file);
# else
return ftello(__file);
diff --git a/libcxx/include/regex b/libcxx/include/regex
index 9bbc3a69021b..42e55e677064 100644
--- a/libcxx/include/regex
+++ b/libcxx/include/regex
@@ -1004,7 +1004,7 @@ public:
typedef _CharT char_type;
typedef basic_string<char_type> string_type;
typedef locale locale_type;
-# if defined(__BIONIC__) || defined(_NEWLIB_VERSION)
+# if defined(__BIONIC__) || _LIBCPP_HAS_NEWLIB_LIBC
// Originally bionic's ctype_base used its own ctype masks because the
// builtin ctype implementation wasn't in libc++ yet. Bionic's ctype mask
// was only 8 bits wide and already saturated, so it used a wider type here
@@ -1013,11 +1013,8 @@ public:
// implementation, but this was not updated to match. Since then Android has
// needed to maintain a stable libc++ ABI, and this can't be changed without
// an ABI break.
- // We also need this workaround for newlib since _NEWLIB_VERSION is not
- // defined yet inside __config, so we can't set the
- // _LIBCPP_PROVIDES_DEFAULT_RUNE_TABLE macro. Additionally, newlib is
- // often used for space constrained environments, so it makes sense not to
- // duplicate the ctype table.
+ // Newlib is often used for space constrained environments, so it makes sense
+ // not to duplicate the ctype table.
typedef uint16_t char_class_type;
# else
typedef ctype_base::mask char_class_type;
diff --git a/libcxx/src/include/config_elast.h b/libcxx/src/include/config_elast.h
index 7edff2d9375d..54b6a0c24eaa 100644
--- a/libcxx/src/include/config_elast.h
+++ b/libcxx/src/include/config_elast.h
@@ -23,7 +23,7 @@
# define _LIBCPP_ELAST ELAST
#elif defined(__LLVM_LIBC__)
// No _LIBCPP_ELAST needed for LLVM libc
-#elif defined(_NEWLIB_VERSION)
+#elif _LIBCPP_HAS_NEWLIB_LIBC
# define _LIBCPP_ELAST __ELASTERROR
#elif defined(__NuttX__)
// No _LIBCPP_ELAST needed on NuttX
diff --git a/libcxx/src/locale.cpp b/libcxx/src/locale.cpp
index 0f695d4f1a22..4446411a1506 100644
--- a/libcxx/src/locale.cpp
+++ b/libcxx/src/locale.cpp
@@ -919,7 +919,7 @@ const ctype<char>::mask* ctype<char>::classic_table() noexcept {
return __pctype_func();
# elif defined(__EMSCRIPTEN__)
return *__ctype_b_loc();
-# elif defined(_NEWLIB_VERSION)
+# elif _LIBCPP_HAS_NEWLIB_LIBC
// Newlib has a 257-entry table in ctype_.c, where (char)0 starts at [1].
return _ctype_ + 1;
# elif defined(_AIX)
diff --git a/libcxx/src/print.cpp b/libcxx/src/print.cpp
index 82cf2afd052e..e76376c6c389 100644
--- a/libcxx/src/print.cpp
+++ b/libcxx/src/print.cpp
@@ -22,7 +22,7 @@
# include <windows.h>
#elif __has_include(<unistd.h>)
# include <unistd.h>
-# if defined(_NEWLIB_VERSION)
+# if _LIBCPP_HAS_NEWLIB_LIBC
# if defined(_POSIX_C_SOURCE) && __has_include(<stdio.h>)
# include <stdio.h>
# define HAS_FILENO_AND_ISATTY
```
https://github.com/llvm/llvm-project/pull/168952
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