[cmake] Disable building enable_execute_stack.c for baremetal targets.

Disable building enable_execute_stack.c for targets that do not have
support for mprotect().

Differential Revision: https://reviews.llvm.org/D33018

llvm-svn: 302680

compiler-rt/CMakeLists.txt

@@ -31,6 +31,9 @@ mark_as_advanced(COMPILER_RT_BUILD_SANITIZERS)
 option(COMPILER_RT_BUILD_XRAY "Build xray" ON)
 mark_as_advanced(COMPILER_RT_BUILD_XRAY)
 
+set(COMPILER_RT_BAREMETAL_BUILD OFF CACHE BOOLEAN
+  "Build for a bare-metal target.")
+
 if (COMPILER_RT_STANDALONE_BUILD)
   load_llvm_config()
 

compiler-rt/lib/builtins/CMakeLists.txt

@@ -66,7 +66,6 @@ set(GENERIC_SOURCES
   divti3.c
   divtf3.c
   divxc3.c
-  enable_execute_stack.c
   eprintf.c
   extendsfdf2.c
   extendhfsf2.c
@@ -191,6 +190,12 @@ option(COMPILER_RT_EXCLUDE_ATOMIC_BUILTIN
   "Skip the atomic builtin (this may be needed if system headers are unavailable)"
   Off)
 
+if(NOT COMPILER_RT_BAREMETAL_BUILD)
+  set(GENERIC_SOURCES
+    ${GENERIC_SOURCES}
+    enable_execute_stack.c)
+endif()
+
 if(COMPILER_RT_HAS_ATOMIC_KEYWORD AND NOT COMPILER_RT_EXCLUDE_ATOMIC_BUILTIN)
   set(GENERIC_SOURCES
     ${GENERIC_SOURCES}