build: Endian compatibility

- Detect endian instead of stopping configure on big-endian
- Add `byteswap.h` and `endian.h` header for compatibility with
  Windows and other operating systems that don't come with them
- Update `crypto/common.h` functions to use compat
  endian header

1 files changed, 11 insertions, 65 deletions

diff --git a/src/crypto/common.h b/src/crypto/common.h
index 8b04b1f728..580c72f5a6 100644
--- a/src/crypto/common.h
+++ b/src/crypto/common.h
@@ -11,110 +11,56 @@
 
 #include <stdint.h>
 
-#if defined(HAVE_ENDIAN_H)
-#include <endian.h>
-#endif
+#include "compat/endian.h"
+
+uint16_t static inline ReadLE16(const unsigned char* ptr)
+{
+    return le16toh(*((uint16_t*)ptr));
+}
 
 uint32_t static inline ReadLE32(const unsigned char* ptr)
 {
-#if HAVE_DECL_LE32TOH == 1
     return le32toh(*((uint32_t*)ptr));
-#elif !defined(WORDS_BIGENDIAN)
-    return *((uint32_t*)ptr);
-#else
-    return ((uint32_t)ptr[3] << 24 | (uint32_t)ptr[2] << 16 | (uint32_t)ptr[1] << 8 | (uint32_t)ptr[0]);
-#endif
 }
 
 uint64_t static inline ReadLE64(const unsigned char* ptr)
 {
-#if HAVE_DECL_LE64TOH == 1
     return le64toh(*((uint64_t*)ptr));
-#elif !defined(WORDS_BIGENDIAN)
-    return *((uint64_t*)ptr);
-#else
-    return ((uint64_t)ptr[7] << 56 | (uint64_t)ptr[6] << 48 | (uint64_t)ptr[5] << 40 | (uint64_t)ptr[4] << 32 |
-            (uint64_t)ptr[3] << 24 | (uint64_t)ptr[2] << 16 | (uint64_t)ptr[1] << 8 | (uint64_t)ptr[0]);
-#endif
+}
+
+void static inline WriteLE16(unsigned char* ptr, uint16_t x)
+{
+    *((uint16_t*)ptr) = htole16(x);
 }
 
 void static inline WriteLE32(unsigned char* ptr, uint32_t x)
 {
-#if HAVE_DECL_HTOLE32 == 1
     *((uint32_t*)ptr) = htole32(x);
-#elif !defined(WORDS_BIGENDIAN)
-    *((uint32_t*)ptr) = x;
-#else
-    ptr[3] = x >> 24;
-    ptr[2] = x >> 16;
-    ptr[1] = x >> 8;
-    ptr[0] = x;
-#endif
 }
 
 void static inline WriteLE64(unsigned char* ptr, uint64_t x)
 {
-#if HAVE_DECL_HTOLE64 == 1
     *((uint64_t*)ptr) = htole64(x);
-#elif !defined(WORDS_BIGENDIAN)
-    *((uint64_t*)ptr) = x;
-#else
-    ptr[7] = x >> 56;
-    ptr[6] = x >> 48;
-    ptr[5] = x >> 40;
-    ptr[4] = x >> 32;
-    ptr[3] = x >> 24;
-    ptr[2] = x >> 16;
-    ptr[1] = x >> 8;
-    ptr[0] = x;
-#endif
 }
 
 uint32_t static inline ReadBE32(const unsigned char* ptr)
 {
-#if HAVE_DECL_BE32TOH == 1
     return be32toh(*((uint32_t*)ptr));
-#else
-    return ((uint32_t)ptr[0] << 24 | (uint32_t)ptr[1] << 16 | (uint32_t)ptr[2] << 8 | (uint32_t)ptr[3]);
-#endif
 }
 
 uint64_t static inline ReadBE64(const unsigned char* ptr)
 {
-#if HAVE_DECL_BE64TOH == 1
     return be64toh(*((uint64_t*)ptr));
-#else
-    return ((uint64_t)ptr[0] << 56 | (uint64_t)ptr[1] << 48 | (uint64_t)ptr[2] << 40 | (uint64_t)ptr[3] << 32 |
-            (uint64_t)ptr[4] << 24 | (uint64_t)ptr[5] << 16 | (uint64_t)ptr[6] << 8 | (uint64_t)ptr[7]);
-#endif
 }
 
 void static inline WriteBE32(unsigned char* ptr, uint32_t x)
 {
-#if HAVE_DECL_HTOBE32 == 1
     *((uint32_t*)ptr) = htobe32(x);
-#else
-    ptr[0] = x >> 24;
-    ptr[1] = x >> 16;
-    ptr[2] = x >> 8;
-    ptr[3] = x;
-#endif
 }
 
 void static inline WriteBE64(unsigned char* ptr, uint64_t x)
 {
-#if HAVE_DECL_HTOBE64 == 1
     *((uint64_t*)ptr) = htobe64(x);
-#else
-    ptr[0] = x >> 56;
-    ptr[1] = x >> 48;
-    ptr[2] = x >> 40;
-    ptr[3] = x >> 32;
-    ptr[4] = x >> 24;
-    ptr[5] = x >> 16;
-    ptr[6] = x >> 8;
-    ptr[7] = x;
-#endif
 }
 
 #endif // BITCOIN_CRYPTO_COMMON_H