Make the endian test more C++-like

CMakeLists.txt

@@ -613,6 +613,7 @@ check_symbol_exists(getopt unistd.h HAVE_GETOPT)
 # Common sources used by both the OpenAL implementation library, the OpenAL
 # router, and certain tools and examples.
 set(COMMON_OBJS
+    common/albit.h
     common/albyte.h
     common/alcomplex.cpp
     common/alcomplex.h
@@ -628,7 +629,6 @@ set(COMMON_OBJS
     common/atomic.h
     common/dynload.cpp
     common/dynload.h
-    common/endiantest.h
     common/intrusive_ptr.h
     common/math_defs.h
     common/opthelpers.h

alc/backends/opensl.cpp

@@ -32,11 +32,11 @@
 #include <thread>
 #include <functional>
 
+#include "albit.h"
 #include "alcmain.h"
 #include "alu.h"
 #include "compat.h"
 #include "core/logging.h"
-#include "endiantest.h"
 #include "ringbuffer.h"
 #include "threads.h"
 
@@ -56,7 +56,7 @@ namespace {
 constexpr char opensl_device[] = "OpenSL";
 
 
-SLuint32 GetChannelMask(DevFmtChannels chans)
+constexpr SLuint32 GetChannelMask(DevFmtChannels chans) noexcept
 {
     switch(chans)
     {
@@ -83,7 +83,7 @@ SLuint32 GetChannelMask(DevFmtChannels chans)
 }
 
 #ifdef SL_ANDROID_DATAFORMAT_PCM_EX
-SLuint32 GetTypeRepresentation(DevFmtType type)
+constexpr SLuint32 GetTypeRepresentation(DevFmtType type) noexcept
 {
     switch(type)
     {
@@ -102,7 +102,14 @@ SLuint32 GetTypeRepresentation(DevFmtType type)
 }
 #endif
 
-const char *res_str(SLresult result)
+constexpr SLuint32 GetByteOrderEndianness() noexcept
+{
+    if /*constexpr*/(al::endian::native == al::endian::little)
+        return SL_BYTEORDER_LITTLEENDIAN;
+    return SL_BYTEORDER_BIGENDIAN;
+}
+
+const char *res_str(SLresult result) noexcept
 {
     switch(result)
     {
@@ -459,7 +466,7 @@ bool OpenSLPlayback::reset()
     format_pcm_ex.bitsPerSample = mDevice->bytesFromFmt() * 8;
     format_pcm_ex.containerSize = format_pcm_ex.bitsPerSample;
     format_pcm_ex.channelMask = GetChannelMask(mDevice->FmtChans);
-    format_pcm_ex.endianness = IS_LITTLE_ENDIAN ? SL_BYTEORDER_LITTLEENDIAN : SL_BYTEORDER_BIGENDIAN;
+    format_pcm_ex.endianness = GetByteOrderEndianness();
     format_pcm_ex.representation = GetTypeRepresentation(mDevice->FmtType);
 
     audioSrc.pLocator = &loc_bufq;
@@ -490,8 +497,7 @@ bool OpenSLPlayback::reset()
         format_pcm.bitsPerSample = mDevice->bytesFromFmt() * 8;
         format_pcm.containerSize = format_pcm.bitsPerSample;
         format_pcm.channelMask = GetChannelMask(mDevice->FmtChans);
-        format_pcm.endianness = IS_LITTLE_ENDIAN ? SL_BYTEORDER_LITTLEENDIAN :
+        format_pcm.endianness = GetByteOrderEndianness();
-            SL_BYTEORDER_BIGENDIAN;
 
         audioSrc.pLocator = &loc_bufq;
         audioSrc.pFormat = &format_pcm;
@@ -733,8 +739,7 @@ void OpenSLCapture::open(const char* name)
         format_pcm_ex.bitsPerSample = mDevice->bytesFromFmt() * 8;
         format_pcm_ex.containerSize = format_pcm_ex.bitsPerSample;
         format_pcm_ex.channelMask = GetChannelMask(mDevice->FmtChans);
-        format_pcm_ex.endianness = IS_LITTLE_ENDIAN ? SL_BYTEORDER_LITTLEENDIAN :
+        format_pcm_ex.endianness = GetByteOrderEndianness();
-            SL_BYTEORDER_BIGENDIAN;
         format_pcm_ex.representation = GetTypeRepresentation(mDevice->FmtType);
 
         audioSnk.pLocator = &loc_bq;
@@ -757,8 +762,7 @@ void OpenSLCapture::open(const char* name)
                 format_pcm.bitsPerSample = mDevice->bytesFromFmt() * 8;
                 format_pcm.containerSize = format_pcm.bitsPerSample;
                 format_pcm.channelMask = GetChannelMask(mDevice->FmtChans);
-                format_pcm.endianness = IS_LITTLE_ENDIAN ? SL_BYTEORDER_LITTLEENDIAN :
+                format_pcm.endianness = GetByteOrderEndianness();
-                    SL_BYTEORDER_BIGENDIAN;
 
                 audioSnk.pLocator = &loc_bq;
                 audioSnk.pFormat = &format_pcm;

alc/backends/wave.cpp

@@ -33,6 +33,7 @@
 #include <functional>
 #include <thread>
 
+#include "albit.h"
 #include "albyte.h"
 #include "alcmain.h"
 #include "alconfig.h"
@@ -41,7 +42,6 @@
 #include "alu.h"
 #include "compat.h"
 #include "core/logging.h"
-#include "endiantest.h"
 #include "strutils.h"
 #include "threads.h"
 #include "vector.h"
@@ -149,7 +149,7 @@ int WaveBackend::mixerProc()
             mDevice->renderSamples(mBuffer.data(), mDevice->UpdateSize, frameStep);
             done += mDevice->UpdateSize;
 
-            if /*constexpr*/(!IS_LITTLE_ENDIAN)
+            if /*constexpr*/(al::endian::native != al::endian::little)
             {
                 const uint bytesize{mDevice->bytesFromFmt()};
 

alc/hrtf.cpp

@@ -40,6 +40,7 @@
 #include <type_traits>
 #include <utility>
 
+#include "albit.h"
 #include "alcmain.h"
 #include "alconfig.h"
 #include "alfstream.h"
@@ -49,7 +50,6 @@
 #include "alspan.h"
 #include "core/filters/splitter.h"
 #include "core/logging.h"
-#include "endiantest.h"
 #include "math_defs.h"
 #include "opthelpers.h"
 #include "polyphase_resampler.h"
@@ -471,7 +471,7 @@ inline T readle(std::istream &data)
     static_assert(num_bits <= sizeof(T)*8, "num_bits is too large for the type");
 
     T ret{};
-    if(IS_LITTLE_ENDIAN)
+    if /*constexpr*/(al::endian::native == al::endian::little)
     {
         if(!data.read(reinterpret_cast<char*>(&ret), num_bits/8))
             return static_cast<T>(EOF);

common/albit.h

@@ -0,0 +1,35 @@
+#ifndef AL_BIT_H
+#define AL_BIT_H
+
+namespace al {
+
+#ifdef __BYTE_ORDER__
+enum class endian {
+    little = __ORDER_LITTLE_ENDIAN__,
+    big = __ORDER_BIG_ENDIAN__,
+    native = __BYTE_ORDER__
+};
+
+#else
+
+/* This doesn't support mixed-endian. */
+namespace detail_ {
+constexpr inline bool EndianTest() noexcept
+{
+    static_assert(sizeof(char) < sizeof(int), "char is too big");
+
+    constexpr int test_val{1};
+    return static_cast<const char&>(test_val);
+}
+} // namespace detail_
+
+enum class endian {
+    little = 0,
+    big = 1,
+    native = detail_::EndianTest() ? little : big
+};
+#endif
+
+} // namespace al
+
+#endif /* AL_BIT_H */

common/endiantest.h

@@ -1,15 +0,0 @@
-#ifndef AL_ENDIANTEST_H
-#define AL_ENDIANTEST_H
-
-#if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__)
-#define IS_LITTLE_ENDIAN (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
-#else
-constexpr inline bool EndianTest() noexcept
-{
-    constexpr int test_val{1};
-    return static_cast<const char&>(test_val);
-}
-#define IS_LITTLE_ENDIAN (EndianTest())
-#endif
-
-#endif /* AL_ENDIANTEST_H */