Add build def ZT_NO_TYPE_PUNNING, which when defined disables type punning code that might cause unaligned access errors on architectures that care (e.g. Android/ARM)

1 files changed, 6 insertions, 4 deletions

diff --git a/node/Salsa20.cpp b/node/Salsa20.cpp
index ae8e1802..de8f1569 100644
--- a/node/Salsa20.cpp
+++ b/node/Salsa20.cpp
@@ -19,13 +19,15 @@
 
 #if __BYTE_ORDER == __LITTLE_ENDIAN
 
-// Slow version that does not use type punning
-//#define U8TO32_LITTLE(p) ( ((uint32_t)(p)[0]) | ((uint32_t)(p)[1] << 8) | ((uint32_t)(p)[2] << 16) | ((uint32_t)(p)[3] << 24) )
-//static inline void U32TO8_LITTLE(uint8_t *const c,const uint32_t v) { c[0] = (uint8_t)v; c[1] = (uint8_t)(v >> 8); c[2] = (uint8_t)(v >> 16); c[3] = (uint8_t)(v >> 24); }
-
+#ifdef ZT_NO_TYPE_PUNNING
+// Slower version that does not use type punning
+#define U8TO32_LITTLE(p) ( ((uint32_t)(p)[0]) | ((uint32_t)(p)[1] << 8) | ((uint32_t)(p)[2] << 16) | ((uint32_t)(p)[3] << 24) )
+static inline void U32TO8_LITTLE(uint8_t *const c,const uint32_t v) { c[0] = (uint8_t)v; c[1] = (uint8_t)(v >> 8); c[2] = (uint8_t)(v >> 16); c[3] = (uint8_t)(v >> 24); }
+#else
 // Fast version that just does 32-bit load/store
 #define U8TO32_LITTLE(p) (*((const uint32_t *)((const void *)(p))))
 #define U32TO8_LITTLE(c,v) *((uint32_t *)((void *)(c))) = (v)
+#endif // ZT_NO_TYPE_PUNNING
 
 #else // __BYTE_ORDER == __BIG_ENDIAN (we don't support anything else... does MIDDLE_ENDIAN even still exist?)