Merge pull request #12 from linux-on-ibm-z/byte_order_fix

Fix the endianness detection

The current BYTE_ORDER check is not detecting big endian correctly and test failures were observed because of this.
With this fix, all tests pass on s390x(big endian). Also this does not affect amd64 results.

.github/workflows/ci.yml

@@ -82,3 +82,26 @@ jobs:
         run: |
           pip install --user codecov
           /home/runner/.local/bin/codecov
+
+  test-on-s390x:
+    runs-on: ubuntu-22.04
+    steps:
+    - uses: actions/checkout@v3
+    - name: Setup emulator
+      run: |
+        sudo docker run --rm --privileged tonistiigi/binfmt:qemu-v6.2.0
+    - name: Run build
+      uses: uraimo/run-on-arch-action@v2.6.0
+      with:
+        arch: s390x
+        distro: ubuntu22.04
+        install: |
+          apt-get update -y
+          DEBIAN_FRONTEND=noninteractive apt-get install -y rebar3 gcc libssl-dev
+        run: |
+          echo "---rebar3 as test get-deps---"
+          rebar3 as test get-deps
+          echo "---rebar3 as test compile---"
+          rebar3 as test compile
+          echo "---rebar3 as test ct---"
+          rebar3 as test ct

c_src/fast_pbkdf2.c

@@ -38,7 +38,7 @@
 
 static inline void write32_be(uint32_t n, uint8_t out[4])
 {
-#if defined(__GNUC__) && __GNUC__ >= 4 && __BYTE_ORDER == __LITTLE_ENDIAN
+#if defined(__GNUC__) && __GNUC__ >= 4 && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
   *(uint32_t *)(out) = __builtin_bswap32(n);
 #else
   out[0] = (n >> 24) & 0xff;
@@ -50,7 +50,7 @@ static inline void write32_be(uint32_t n, uint8_t out[4])
 
 static inline void write64_be(uint64_t n, uint8_t out[8])
 {
-#if defined(__GNUC__) &&  __GNUC__ >= 4 && __BYTE_ORDER == __LITTLE_ENDIAN
+#if defined(__GNUC__) &&  __GNUC__ >= 4 && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
   *(uint64_t *)(out) = __builtin_bswap64(n);
 #else
   write32_be((n >> 32) & 0xffffffff, out);