[CMake] Support building on OS X without Xcode installation

This should resolve PR23162. This patch has two parts.

First we need to check the error code from xcodebuild when querying for SDKs, second if the OS X SDK is not discovered, we ensure that /usr/include exists and use / as the OS X sysroot.

llvm-svn: 279336

diff --git a/compiler-rt/cmake/Modules/CompilerRTDarwinUtils.cmake b/compiler-rt/cmake/Modules/CompilerRTDarwinUtils.cmake
index 95a06ce..28d3986 100644 (file)
--- a/compiler-rt/cmake/Modules/CompilerRTDarwinUtils.cmake
+++ b/compiler-rt/cmake/Modules/CompilerRTDarwinUtils.cmake
@@ -7,13 +7,15 @@ function(find_darwin_sdk_dir var sdk_name)
   # Let's first try the internal SDK, otherwise use the public SDK.
   execute_process(
     COMMAND xcodebuild -version -sdk ${sdk_name}.internal Path
+    RESULT_VARIABLE result_process
     OUTPUT_VARIABLE var_internal
     OUTPUT_STRIP_TRAILING_WHITESPACE
     ERROR_FILE /dev/null
   )
-  if("" STREQUAL "${var_internal}")
+  if((NOT result_process EQUAL 0) OR "" STREQUAL "${var_internal}")
     execute_process(
       COMMAND xcodebuild -version -sdk ${sdk_name} Path
+      RESULT_VARIABLE result_process
       OUTPUT_VARIABLE var_internal
       OUTPUT_STRIP_TRAILING_WHITESPACE
       ERROR_FILE /dev/null
@@ -21,7 +23,9 @@ function(find_darwin_sdk_dir var sdk_name)
   else()
     set(${var}_INTERNAL ${var_internal} PARENT_SCOPE)
   endif()
-  set(${var} ${var_internal} PARENT_SCOPE)
+  if(result_process EQUAL 0)
+    set(${var} ${var_internal} PARENT_SCOPE)
+  endif()
 endfunction()
 
 # There isn't a clear mapping of what architectures are supported with a given

diff --git a/compiler-rt/cmake/config-ix.cmake b/compiler-rt/cmake/config-ix.cmake
index 67d0c7c..9eb1353 100644 (file)
--- a/compiler-rt/cmake/config-ix.cmake
+++ b/compiler-rt/cmake/config-ix.cmake
@@ -174,6 +174,14 @@ if(APPLE)
   find_darwin_sdk_dir(DARWIN_tvossim_SYSROOT appletvsimulator)
   find_darwin_sdk_dir(DARWIN_tvos_SYSROOT appletvos)
 
+  if(NOT DARWIN_osx_SYSROOT)
+    if(EXISTS /usr/include)
+      set(DARWIN_osx_SYSROOT /)
+    else()
+      message(ERROR "Could not detect OS X Sysroot. Either install Xcode or the Apple Command Line Tools")
+    endif()
+  endif()
+
   if(COMPILER_RT_ENABLE_IOS)
     list(APPEND DARWIN_EMBEDDED_PLATFORMS ios)
     set(DARWIN_ios_MIN_VER_FLAG -miphoneos-version-min)