[libcxx] r290801 - build: dont detect libraries for Windows

[Saleem Abdulrasool via cfe-commits]

Author: compnerd
Date: Sun Jan  1 14:20:38 2017
New Revision: 290801

URL: http://llvm.org/viewvc/llvm-project?rev=290801&view=rev
Log:
build: dont detect libraries for Windows

Hard code the defaults for Windows for the time being.  The checks
really are always going to return the same value.  Technically, the
pthread linkage is possible, however, it seems better to use the Win32
threading along with the external threading support that we have added.

Modified:
    libcxx/trunk/cmake/config-ix.cmake

Modified: libcxx/trunk/cmake/config-ix.cmake
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/cmake/config-ix.cmake?rev=290801&r1=290800&r2=290801&view=diff
==============================================================================
--- libcxx/trunk/cmake/config-ix.cmake (original)
+++ libcxx/trunk/cmake/config-ix.cmake Sun Jan  1 14:20:38 2017
@@ -1,9 +1,20 @@
 include(CheckLibraryExists)
 include(CheckCXXCompilerFlag)
 
-check_library_exists(c fopen "" LIBCXX_HAS_C_LIB)
+if(WIN32 AND NOT MINGW)
+  # NOTE(compnerd) this is technically a lie, there is msvcrt, but for now, lets
+  # let the default linking take care of that.
+  set(LIBCXX_HAS_C_LIB NO)
+else()
+  check_library_exists(c fopen "" LIBCXX_HAS_C_LIB)
+endif()
+
 if (NOT LIBCXX_USE_COMPILER_RT)
-  check_library_exists(gcc_s __gcc_personality_v0 "" LIBCXX_HAS_GCC_S_LIB)
+  if(WIN32 AND NOT MINGW)
+    set(LIBCXX_HAS_GCC_S_LIB NO)
+  else()
+    check_library_exists(gcc_s __gcc_personality_v0 "" LIBCXX_HAS_GCC_S_LIB)
+  endif()
 endif()
 
 # libc++ is built with -nodefaultlibs, so we want all our checks to also
@@ -32,7 +43,9 @@ if (LIBCXX_SUPPORTS_NODEFAULTLIBS_FLAG)
   endif ()
 endif ()
 
-include(CheckLibcxxAtomic)
+if(NOT WIN32 OR MINGW)
+  include(CheckLibcxxAtomic)
+endif()
 
 # Check compiler flags
 
@@ -45,6 +58,14 @@ check_cxx_compiler_flag(/GR-
 
 
 # Check libraries
-check_library_exists(pthread pthread_create "" LIBCXX_HAS_PTHREAD_LIB)
-check_library_exists(m ccos "" LIBCXX_HAS_M_LIB)
-check_library_exists(rt clock_gettime "" LIBCXX_HAS_RT_LIB)
+if(WIN32 AND NOT MINGW)
+  # TODO(compnerd) do we want to support an emulation layer that allows for the
+  # use of pthread-win32 or similar libraries to emulate pthreads on Windows?
+  set(LIBCXX_HAS_PTHREAD_LIB NO)
+  set(LIBCXX_HAS_M_LIB NO)
+  set(LIBCXX_HAS_RT_LIB NO)
+else()
+  check_library_exists(pthread pthread_create "" LIBCXX_HAS_PTHREAD_LIB)
+  check_library_exists(m ccos "" LIBCXX_HAS_M_LIB)
+  check_library_exists(rt clock_gettime "" LIBCXX_HAS_RT_LIB)
+endif()