Prefer ucontext.h over sys/ucontext.h (#46790)

* Prefer ucontext.h over sys/ucontext.h

* Cleanup redundant _XOPEN_SOURCE definitions

* Remove unused makefile from PAL tests

Author: am11

eng/native/configurecompiler.cmake

@@ -195,6 +195,8 @@ elseif(CLR_CMAKE_HOST_SUNOS)
   set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fstack-protector")
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fstack-protector")
   add_definitions(-D__EXTENSIONS__)
+elseif(CLR_CMAKE_HOST_OSX)
+  add_definitions(-D_XOPEN_SOURCE)
 endif()
 
 #------------------------------------

src/coreclr/clrdefinitions.cmake

@@ -22,10 +22,6 @@ endif (CLR_CMAKE_TARGET_ARCH_ARM64)
 
 if (CLR_CMAKE_TARGET_UNIX)
 
-  if(CLR_CMAKE_TARGET_OSX)
-    add_definitions(-D_XOPEN_SOURCE)
-  endif(CLR_CMAKE_TARGET_OSX)
-
   if (CLR_CMAKE_TARGET_ARCH_AMD64)
     add_compile_definitions($<$<NOT:$<BOOL:$<TARGET_PROPERTY:IGNORE_DEFAULT_TARGET_ARCH>>>:UNIX_AMD64_ABI>)
     add_compile_definitions($<$<NOT:$<BOOL:$<TARGET_PROPERTY:IGNORE_DEFAULT_TARGET_ARCH>>>:FEATURE_MULTIREG_RETURN>)

src/coreclr/pal/src/CMakeLists.txt

@@ -240,10 +240,7 @@ if(CLR_CMAKE_TARGET_OSX)
     ${LIBUNWIND_DAC_OBJECTS}
   )
 
-  target_compile_definitions(coreclrpal_dac PUBLIC
-    "-D_XOPEN_SOURCE"
-    "-DUNW_REMOTE_ONLY"
-  )
+  target_compile_definitions(coreclrpal_dac PUBLIC -DUNW_REMOTE_ONLY)
 else()
   if(NOT FEATURE_CROSSBITNESS)
     add_library(coreclrpal_dac STATIC

src/coreclr/pal/src/configure.cmake

@@ -13,7 +13,10 @@ if(CLR_CMAKE_TARGET_FREEBSD)
 elseif(CLR_CMAKE_TARGET_SUNOS)
   set(CMAKE_REQUIRED_INCLUDES /opt/local/include)
 endif()
-if(NOT CLR_CMAKE_TARGET_OSX AND NOT CLR_CMAKE_TARGET_FREEBSD AND NOT CLR_CMAKE_TARGET_NETBSD)
+
+if(CLR_CMAKE_TARGET_OSX)
+  set(CMAKE_REQUIRED_DEFINITIONS -D_XOPEN_SOURCE)
+elseif(NOT CLR_CMAKE_TARGET_FREEBSD AND NOT CLR_CMAKE_TARGET_NETBSD)
   set(CMAKE_REQUIRED_DEFINITIONS "-D_BSD_SOURCE -D_SVID_SOURCE -D_DEFAULT_SOURCE -D_POSIX_C_SOURCE=200809L")
 endif()
 
@@ -156,7 +159,7 @@ check_type_size("struct pt_regs" PT_REGS)
 set(CMAKE_EXTRA_INCLUDE_FILES)
 set(CMAKE_EXTRA_INCLUDE_FILES signal.h)
 set(CMAKE_EXTRA_INCLUDE_FILES)
-set(CMAKE_EXTRA_INCLUDE_FILES sys/ucontext.h)
+set(CMAKE_EXTRA_INCLUDE_FILES ucontext.h)
 check_type_size(ucontext_t UCONTEXT_T)
 set(CMAKE_EXTRA_INCLUDE_FILES)
 set(CMAKE_EXTRA_INCLUDE_FILES pthread.h)

src/coreclr/pal/src/include/pal/context.h

@@ -31,7 +31,7 @@ extern "C"
 /* A type to wrap the native context type, which is ucontext_t on some
  * platforms and another type elsewhere. */
 #if HAVE_UCONTEXT_T
-#include <sys/ucontext.h>
+#include <ucontext.h>
 
 typedef ucontext_t native_context_t;
 #else   // HAVE_UCONTEXT_T

src/coreclr/pal/src/libunwind/CMakeLists.txt

@@ -71,9 +71,7 @@ if(CLR_CMAKE_HOST_UNIX)
     endif()
 
     if (CLR_CMAKE_HOST_OSX)
-        add_definitions(-D_XOPEN_SOURCE)
         add_definitions(-DUNW_REMOTE_ONLY)
-        add_definitions(-D__APPLE__)
         add_compile_options(-Wno-sometimes-uninitialized)
         add_compile_options(-Wno-implicit-function-declaration)