llvm-17.0.0-rc1: libcxxabi does not build on macOS 10.12.6

[debohman]

FAILED: libcxxabi/src/CMakeFiles/cxxabi_shared_objects.dir/cxa_handlers.cpp.o 
/tera/tera/debo/Projects/llvm/llvmorg-17.0.0-rc1-build/./bin/clang++ --target=x86_64-apple-darwin16.7.0 -DLIBCXX_BUILDING_LIBCXXABI -D_LIBCPP_BUILDING_LIBRARY -D_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER -D_LIBCXXABI_BUILDING_LIBRARY -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/tera/tera/debo/Projects/llvm/llvmorg-17.0.0-rc1/libcxxabi/../libcxx/src -I/tera/tera/debo/Projects/llvm/llvmorg-17.0.0-rc1-build/include/c++/v1 -I/tera/tera/debo/Projects/llvm/llvmorg-17.0.0-rc1/libcxxabi/include -I/usr/local/include -fPIC -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color  -O3 -DNDEBUG -std=c++20 -fPIC -nostdinc++ -fstrict-aliasing -funwind-tables -D_DEBUG -UNDEBUG -Wall -Wextra -Wnewline-eof -Wshadow -Wwrite-strings -Wno-unused-parameter -Wno-long-long -Werror=return-type -Wextra-semi -Wundef -Wunused-template -Wformat-nonliteral -Wno-user-defined-literals -Wno-covered-switch-default -Wno-suggest-override -Wno-error -MD -MT libcxxabi/src/CMakeFiles/cxxabi_shared_objects.dir/cxa_handlers.cpp.o -MF libcxxabi/src/CMakeFiles/cxxabi_shared_objects.dir/cxa_handlers.cpp.o.d -o libcxxabi/src/CMakeFiles/cxxabi_shared_objects.dir/cxa_handlers.cpp.o -c /tera/tera/debo/Projects/llvm/llvmorg-17.0.0-rc1/libcxxabi/src/cxa_handlers.cpp
In file included from /tera/tera/debo/Projects/llvm/llvmorg-17.0.0-rc1/libcxxabi/src/cxa_handlers.cpp:12:
In file included from /tera/tera/debo/Projects/llvm/llvmorg-17.0.0-rc1-build/include/c++/v1/stdexcept:48:
In file included from /tera/tera/debo/Projects/llvm/llvmorg-17.0.0-rc1-build/include/c++/v1/iosfwd:106:
In file included from /tera/tera/debo/Projects/llvm/llvmorg-17.0.0-rc1-build/include/c++/v1/__std_mbstate_t.h:14:
In file included from /tera/tera/debo/Projects/llvm/llvmorg-17.0.0-rc1-build/include/c++/v1/__mbstate_t.h:48:
/usr/include/sys/_types/_mbstate_t.h:31:9: error: unknown type name '__darwin_mbstate_t'
   31 | typedef __darwin_mbstate_t mbstate_t;
      |         ^
1 error generated.

The following change allows it to build:

diff --git a/libcxx/include/__mbstate_t.h b/libcxx/include/__mbstate_t.h
index 2b9e719b1f2e..044c10a58c04 100644
--- a/libcxx/include/__mbstate_t.h
+++ b/libcxx/include/__mbstate_t.h
@@ -42,7 +42,10 @@
 #elif __has_include(<bits/types/mbstate_t.h>)
 #   include <bits/types/mbstate_t.h> // works on most Unixes
 #elif __has_include(<sys/_types/_mbstate_t.h>)
-#   include <sys/_types/_mbstate_t.h> // works on Darwin
+#  if __has_include(<machine/_types.h>)
+#    include <machine/_types.h>
+#  endif
+#  include <sys/_types/_mbstate_t.h> // works on Darwin
 #elif !defined(_LIBCPP_HAS_NO_WIDE_CHARACTERS) && __has_include_next(<wchar.h>)
 #   include_next <wchar.h> // fall back to the C standard provider of mbstate_t
 #elif __has_include_next(<uchar.h>)

[h-vetinari]

If you're building libcxx as a shared library (can't tell from the logs), you'll need at least 10.13, see https://libcxx.llvm.org/index.html#platform-and-compiler-support

[debohman]

This looks like a header file problem. I am doing a default build here and it did build both a static and dynamic library.

[debohman]

Here is what the install generated in lib, of course with the header file modification:

  -rwxr-xr-x    1 debo  wheel    1031836 Jul 29 17:24 libc++.1.0.dylib
  lrwxr-xr-x    1 debo  wheel         16 Jul 29 17:24 libc++.1.dylib -> libc++.1.0.dylib
  -rw-r--r--    1 debo  wheel    1513792 Jul 29 17:24 libc++.a
  lrwxr-xr-x    1 debo  wheel         14 Jul 29 17:24 libc++.dylib -> libc++.1.dylib
  -rwxr-xr-x    1 debo  wheel     284680 Jul 29 17:23 libc++abi.1.0.dylib
  lrwxr-xr-x    1 debo  wheel         19 Jul 29 17:24 libc++abi.1.dylib -> libc++abi.1.0.dylib
  -rw-r--r--    1 debo  wheel     395592 Jul 29 17:23 libc++abi.a
  lrwxr-xr-x    1 debo  wheel         17 Jul 29 17:24 libc++abi.dylib -> libc++abi.1.dylib
  -rw-r--r--    1 debo  wheel       7520 Jul 29 17:24 libc++experimental.a

[tru]

Is this a issue we should try to fix for 17.X? cc @mordante @ldionne

[mordante]

I've asked @ldionne privately, he's more familiar with MacOS.

[ldionne]

@debohman What version of Xcode do you have installed? I suspect you are using a Xcode that is older than Xcode 14, which means it wouldn't be supported anymore. If that's the case, then unfortunately this is NTBF, you need a more recent Xcode.

I strongly suspect that is the case, because Xcode 14 requires at least macOS 12.5, so I don't think it would be possible for you to be using a sufficiently-recent Xcode on your current OS.

If I misunderstood something please re-open and we'll figure out what the issue is.

[debohman]

I will patch it myself.