Windows: Improve the check for endianness when using Visual Studio.

Visual studio does not define __BYTE_ORDER__ so all architectures
were detected as LITTLE_ENDIAN since both __BYTE_ORDER__ and
__ORDER_LITTLE_ENDIAN__ would evaluate to 0 and compare equal. This
updates the checks to use CMakes detection of endianness, with a hard
error, if this also fails.

1 files changed, 9 insertions, 0 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3b8c1aa..730b84d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -142,6 +142,15 @@ endif()
 if(MSVC)
         add_definitions(-Dinline=__inline)
         message(STATUS "Using [${CMAKE_C_COMPILER_ID}] compiler")
+
+        include(TestBigEndian)
+        TEST_BIG_ENDIAN(HAVE_BIG_ENDIAN)
+        if(HAVE_BIG_ENDIAN)
+                add_definitions(-DHAVE_BIG_ENDIAN)
+        else()
+                add_definitions(-DHAVE_LITTLE_ENDIAN)
+        endif()
+
         if(CMAKE_C_COMPILER_ID MATCHES "MSVC" OR CMAKE_C_COMPILER_ID MATCHES "Clang")
                 set(MSVC_DISABLED_WARNINGS_LIST
                         "C4018" # 'expression' : signed/unsigned mismatch