Address review comments

voltur01 · voltur01 · commit dad9c9aa0a2e · 2025-07-16T14:47:44.000+01:00
- Use _LIBCXX_... reserved namespace macro names.
- Move library definition code closer to the rest of __config_site definitions in CMake.
- Remove unused LIBCXX_LIBC_NEWLIB definition.
- Use #cmakedefine01 and thus avoid defined() in conditional statements.
- Remove deprecation check.
diff --git a/libcxx/CMakeLists.txt b/libcxx/CMakeLists.txt
@@ -481,21 +481,6 @@ include(config-ix)
 include(HandleLibC) # Setup the C library flags
 include(HandleLibCXXABI) # Setup the ABI library flags
 
-# Set C library in use to define respective macro in __config_site
-# RUNTIMES_USE_LIBC was checked in HandleLibC to be one of accepted values
-if (RUNTIMES_USE_LIBC STREQUAL "llvm-libc")
-  set(LIBCXX_LIBC_LLVMLIBC 1)
-elseif (RUNTIMES_USE_LIBC STREQUAL "picolibc")
-  set(LIBCXX_LIBC_PICOLIBC 1)
-  # picolibc is derived from newlib and behaves the same in regards to libc++
-  # so setting both here:
-  # * LIBCXX_LIBC_NEWLIB is used now
-  # * LIBCXX_LIBC_PICOLIBC can be used for further customizations later
-  set(LIBCXX_LIBC_NEWLIB 1) 
-elseif (RUNTIMES_USE_LIBC STREQUAL "newlib")
-  set(LIBCXX_LIBC_NEWLIB 1)
-endif()
-
 # FIXME(EricWF): See the FIXME on LIBCXX_ENABLE_PEDANTIC.
 # Remove the -pedantic flag and -Wno-pedantic and -pedantic-errors
 # so they don't get transformed into -Wno and -errors respectively.
@@ -766,6 +751,18 @@ config_define(${LIBCXX_ENABLE_WIDE_CHARACTERS} _LIBCPP_HAS_WIDE_CHARACTERS)
 config_define(${LIBCXX_ENABLE_TIME_ZONE_DATABASE} _LIBCPP_HAS_TIME_ZONE_DATABASE)
 config_define(${LIBCXX_ENABLE_VENDOR_AVAILABILITY_ANNOTATIONS} _LIBCPP_HAS_VENDOR_AVAILABILITY_ANNOTATIONS)
 
+# Set C library in use
+if (RUNTIMES_USE_LIBC STREQUAL "picolibc")
+  config_define(1 _LIBCXX_LIBC_PICOLIBC)
+  # picolibc is derived from newlib and behaves the same in regards to libc++
+  # so setting both here:
+  # * _LIBCXX_LIBC_NEWLIB is used now
+  # * _LIBCXX_LIBC_PICOLIBC can be used for further customizations later
+  config_define(1 _LIBCXX_LIBC_NEWLIB)
+elseif (RUNTIMES_USE_LIBC STREQUAL "newlib")
+  config_define(1 _LIBCXX_LIBC_NEWLIB)
+endif()
+
 # TODO: Remove in LLVM 21. We're leaving an error to make this fail explicitly.
 if (LIBCXX_ENABLE_ASSERTIONS)
   message(FATAL_ERROR "LIBCXX_ENABLE_ASSERTIONS has been removed. Please use LIBCXX_HARDENING_MODE instead.")
diff --git a/libcxx/include/__config_site.in b/libcxx/include/__config_site.in
@@ -43,9 +43,8 @@
 #cmakedefine _LIBCPP_HARDENING_MODE_DEFAULT @_LIBCPP_HARDENING_MODE_DEFAULT@
 
 // C libraries
-#cmakedefine LIBCXX_LIBC_LLVMLIBC
-#cmakedefine LIBCXX_LIBC_PICOLIBC
-#cmakedefine LIBCXX_LIBC_NEWLIB
+#cmakedefine01 _LIBCXX_LIBC_PICOLIBC
+#cmakedefine01 _LIBCXX_LIBC_NEWLIB
 
 // __USE_MINGW_ANSI_STDIO gets redefined on MinGW
 #ifdef __clang__
diff --git a/libcxx/include/__configuration/platform.h b/libcxx/include/__configuration/platform.h
@@ -42,17 +42,6 @@
 #  endif
 #endif
 
-// TODO: Remove this deprecated behavior after LLVM 22 release
-#if __has_include(<picolibc.h>) && !defined(LIBCXX_LIBC_NEWLIB)
-#  define LIBCXX_LIBC_NEWLIB
-
-#  if defined(__clang__) || defined(__GNUC__)
-#    warning "To build libc++ with picolibc provide RUNTIMES_USE_LIBC=picolibc"
-#  else
-#    pragma message("To build libc++ with picolibc provide RUNTIMES_USE_LIBC=picolibc")
-#  endif
-#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/__cxx03/__fwd/ios.h b/libcxx/include/__cxx03/__fwd/ios.h
@@ -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(LIBCXX_LIBC_NEWLIB)
+#if _LIBCXX_LIBC_NEWLIB
 // On newlib, off_t is 'long int'
 using streamoff = long int; // for char_traits in <string>
 #else
diff --git a/libcxx/include/__cxx03/__locale b/libcxx/include/__cxx03/__locale
@@ -384,7 +384,7 @@ public:
   static const mask xdigit       = _ISXDIGIT;
   static const mask blank        = _ISBLANK;
   static const mask __regex_word = 0x8000;
-#elif defined(LIBCXX_LIBC_NEWLIB)
+#elif _LIBCXX_LIBC_NEWLIB
   // 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/__cxx03/__locale_dir/locale_base_api.h b/libcxx/include/__cxx03/__locale_dir/locale_base_api.h
@@ -17,7 +17,7 @@
 #  include <__cxx03/__locale_dir/locale_base_api/android.h>
 #elif defined(__sun__)
 #  include <__cxx03/__locale_dir/locale_base_api/solaris.h>
-#elif defined(LIBCXX_LIBC_NEWLIB)
+#elif _LIBCXX_LIBC_NEWLIB
 #  include <__cxx03/__locale_dir/locale_base_api/newlib.h>
 #elif defined(__OpenBSD__)
 #  include <__cxx03/__locale_dir/locale_base_api/openbsd.h>
diff --git a/libcxx/include/__cxx03/fstream b/libcxx/include/__cxx03/fstream
@@ -209,7 +209,7 @@ typedef basic_fstream<wchar_t> wfstream;
 _LIBCPP_PUSH_MACROS
 #include <__cxx03/__undef_macros>
 
-#if defined(_LIBCPP_MSVCRT) || defined(LIBCXX_LIBC_NEWLIB)
+#if defined(_LIBCPP_MSVCRT) || _LIBCXX_LIBC_NEWLIB
 #  define _LIBCPP_HAS_NO_OFF_T_FUNCTIONS
 #endif
 
diff --git a/libcxx/include/__cxx03/locale b/libcxx/include/__cxx03/locale
@@ -220,7 +220,7 @@ template <class charT> class messages_byname;
 
 #  if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
 // Most unix variants have catopen.  These are the specific ones that don't.
-#    if !defined(__BIONIC__) && !defined(LIBCXX_LIBC_NEWLIB) && !defined(__EMSCRIPTEN__)
+#    if !defined(__BIONIC__) && !_LIBCXX_LIBC_NEWLIB && !defined(__EMSCRIPTEN__)
 #      define _LIBCPP_HAS_CATOPEN 1
 #      include <nl_types.h>
 #    endif
diff --git a/libcxx/include/__cxx03/regex b/libcxx/include/__cxx03/regex
@@ -984,7 +984,7 @@ public:
   typedef _CharT char_type;
   typedef basic_string<char_type> string_type;
   typedef locale locale_type;
-#if defined(__BIONIC__) || defined(LIBCXX_LIBC_NEWLIB)
+#if defined(__BIONIC__) || _LIBCXX_LIBC_NEWLIB
   // 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
diff --git a/libcxx/include/__fwd/ios.h b/libcxx/include/__fwd/ios.h
@@ -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(LIBCXX_LIBC_NEWLIB)
+#if _LIBCXX_LIBC_NEWLIB
 // On newlib, off_t is 'long int'
 using streamoff = long int; // for char_traits in <string>
 #else
diff --git a/libcxx/include/__locale b/libcxx/include/__locale
@@ -389,7 +389,7 @@ public:
   static const mask xdigit       = _ISXDIGIT;
   static const mask blank        = _ISBLANK;
   static const mask __regex_word = 0x8000;
-#  elif defined(LIBCXX_LIBC_NEWLIB)
+#  elif _LIBCXX_LIBC_NEWLIB
   // 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
@@ -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(LIBCXX_LIBC_NEWLIB) && !defined(__EMSCRIPTEN__)
+#    if !defined(__BIONIC__) && !_LIBCXX_LIBC_NEWLIB && !defined(__EMSCRIPTEN__)
 #      define _LIBCPP_HAS_CATOPEN 1
 #      include <nl_types.h>
 #    else
diff --git a/libcxx/include/fstream b/libcxx/include/fstream
@@ -964,7 +964,7 @@ 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(LIBCXX_LIBC_NEWLIB)
+#    elif _LIBCXX_LIBC_NEWLIB
   return fseek(__file, __offset, __whence);
 #    else
   return ::fseeko(__file, __offset, __whence);
@@ -975,7 +975,7 @@ 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(LIBCXX_LIBC_NEWLIB)
+#    elif _LIBCXX_LIBC_NEWLIB
   return ftell(__file);
 #    else
   return ftello(__file);
diff --git 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(LIBCXX_LIBC_NEWLIB)
+#    if defined(__BIONIC__) || _LIBCXX_LIBC_NEWLIB
   // 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
diff --git 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(LIBCXX_LIBC_NEWLIB)
+#elif _LIBCXX_LIBC_NEWLIB
 #  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
@@ -933,7 +933,7 @@ const ctype<char>::mask* ctype<char>::classic_table() noexcept {
   return __pctype_func();
 #  elif defined(__EMSCRIPTEN__)
   return *__ctype_b_loc();
-#  elif defined(LIBCXX_LIBC_NEWLIB)
+#  elif _LIBCXX_LIBC_NEWLIB
   // 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/test/libcxx/system_reserved_names.gen.py b/libcxx/test/libcxx/system_reserved_names.gen.py
@@ -78,7 +78,7 @@
 
 // Test that libc++ doesn't use names that collide with FreeBSD system macros.
 // newlib and picolibc also define these macros
-#if !defined(__FreeBSD__) && !defined(LIBCXX_LIBC_NEWLIB)
+#if !defined(__FreeBSD__) && !_LIBCXX_LIBC_NEWLIB
 #  define __null_sentinel SYSTEM_RESERVED_NAME
 #  define __generic SYSTEM_RESERVED_NAME
 #endif
@@ -117,7 +117,7 @@
 #endif
 
 // Newlib & picolibc use __input as a parameter name of a64l & l64a
-#ifndef LIBCXX_LIBC_NEWLIB
+#if !_LIBCXX_LIBC_NEWLIB
 # define __input SYSTEM_RESERVED_NAME
 #endif
 #define __output SYSTEM_RESERVED_NAME
diff --git a/libcxx/test/std/diagnostics/syserr/syserr.errcat/syserr.errcat.objects/generic_category.pass.cpp b/libcxx/test/std/diagnostics/syserr/syserr.errcat/syserr.errcat.objects/generic_category.pass.cpp
@@ -48,7 +48,7 @@ int main(int, char**)
         // responds with an empty message, which we probably want to
         // treat as a failure code otherwise, but we can detect that
         // with the preprocessor.
-#if defined(LIBCXX_LIBC_NEWLIB)
+#if _LIBCXX_LIBC_NEWLIB
         const bool is_newlib = true;
 #else
         const bool is_newlib = false;
diff --git a/libcxx/test/std/diagnostics/syserr/syserr.errcat/syserr.errcat.objects/system_category.pass.cpp b/libcxx/test/std/diagnostics/syserr/syserr.errcat/syserr.errcat.objects/system_category.pass.cpp
@@ -59,7 +59,7 @@ int main(int, char**) {
     // responds with an empty message, which we probably want to
     // treat as a failure code otherwise, but we can detect that
     // with the preprocessor.
-#if defined(LIBCXX_LIBC_NEWLIB)
+#if _LIBCXX_LIBC_NEWLIB
     const bool is_newlib = true;
 #else
     const bool is_newlib = false;
diff --git a/libcxx/test/support/platform_support.h b/libcxx/test/support/platform_support.h
@@ -48,7 +48,7 @@
 # include <string.h> // strverscmp
 #endif
 
-#if defined(LIBCXX_LIBC_NEWLIB) && defined(__STRICT_ANSI__)
+#if _LIBCXX_LIBC_NEWLIB && defined(__STRICT_ANSI__)
 // Newlib provides this, but in the header it's under __STRICT_ANSI__
 extern "C" {
   int mkstemp(char*);
