feat: adapt to msvc compiler

CMakeLists.txt

@@ -37,24 +37,38 @@ if (NOT CMAKE_BUILD_TYPE)
   set(CMAKE_BUILD_TYPE Release)  # using release build in default
 endif()
 
-add_compile_options(-Wall -Wextra -Werror)
-if (MD5_ENABLE_LTO)
+if (MSVC)
+  add_compile_options(/W4)  # TODO: add `/WX` after fix MSVC warnings
+  if (MD5_ENABLE_LTO)
+    add_compile_options(/GL)
+    add_link_options(/LTCG)
+  endif()
+else()
+  add_compile_options(-Wall -Wextra -Werror)
+  if (MD5_ENABLE_LTO)
     add_compile_options(-flto=auto)
+  endif()
 endif()
 
+# ------------------------------------------------------------------------------------ #
+
 file(GLOB MD5_SRC src/impl/*.cc)
 if (NOT MD5_SHARED_LIB)
   add_library(md5sum STATIC ${MD5_SRC})
 else()
   add_library(md5sum SHARED ${MD5_SRC})
+  if (NOT MSVC)
     target_compile_options(md5sum PRIVATE -fvisibility=hidden)
+  endif()
 endif()
 
-set(MD5_COMPILE_OPTIONS
-        -fno-rtti
-        -fno-exceptions
-        -fno-unwind-tables
-        -fno-asynchronous-unwind-tables)
+if (MSVC)
+  set(MD5_COMPILE_OPTIONS /GR-)
+else()
+  set(MD5_COMPILE_OPTIONS
+          -fno-rtti -fno-exceptions
+          -fno-unwind-tables -fno-asynchronous-unwind-tables)
+endif()
 
 target_compile_options(md5sum PRIVATE ${MD5_COMPILE_OPTIONS})
 target_include_directories(md5sum PUBLIC src/)

src/impl/constexpr.inl

@@ -36,10 +36,13 @@ constexpr Block GetBlock(const md5_data &data, const uint64_t index) {
     Block block {};
     for (int i = 0; i < 16; ++i) {
         const auto offset = index + i * 4;
-        (block[i] <<= 8) |= GetByte(data, offset + 3);
-        (block[i] <<= 8) |= GetByte(data, offset + 2);
-        (block[i] <<= 8) |= GetByte(data, offset + 1);
-        (block[i] <<= 8) |= GetByte(data, offset + 0);
+        block[i] |= GetByte(data, offset + 3);
+        block[i] <<= 8;
+        block[i] |= GetByte(data, offset + 2);
+        block[i] <<= 8;
+        block[i] |= GetByte(data, offset + 1);
+        block[i] <<= 8;
+        block[i] |= GetByte(data, offset + 0);
     }
     return block;
 }

src/impl/core.cc

@@ -16,17 +16,24 @@ using md5::value::T;
 #define H(x, y, z) (x ^ y ^ z)
 #define I(x, y, z) (y ^ (x | ~z))
 
-#define STEP(i, f, a, b, c, d)                \
+#define MD5_ROUND(i, f, a, b, c, d)           \
     do {                                      \
         a += f(b, c, d) + block[K(i)] + T(i); \
         a = a << S(i) | a >> (32 - S(i));     \
         a += b;                               \
     } while (0)
 
-#define FF(i, ...) STEP((0x00 | i), F, __VA_ARGS__)
-#define GG(i, ...) STEP((0x10 | i), G, __VA_ARGS__)
-#define HH(i, ...) STEP((0x20 | i), H, __VA_ARGS__)
-#define II(i, ...) STEP((0x30 | i), I, __VA_ARGS__)
+#ifdef _MSC_VER
+#define EXPAND(...) __VA_ARGS__
+#define ROUND(...) EXPAND(MD5_ROUND(__VA_ARGS__))
+#else
+#define ROUND MD5_ROUND
+#endif
+
+#define FF(i, ...) ROUND(i | 0x00, F, __VA_ARGS__)
+#define GG(i, ...) ROUND(i | 0x10, G, __VA_ARGS__)
+#define HH(i, ...) ROUND(i | 0x20, H, __VA_ARGS__)
+#define II(i, ...) ROUND(i | 0x30, I, __VA_ARGS__)
 
 #define MD5_UPDATE(OP)                                  \
     OP(0x0, R1); OP(0x1, R2); OP(0x2, R3); OP(0x3, R4); \

src/md5.h

@@ -7,10 +7,18 @@
 static_assert(sizeof(uintptr_t) == 8,
     "Project only works on 64-bits architecture.");
 
+#ifdef _MSC_VER
+static_assert('\x01\x02\x03\x04' == 0x04030201,
+#else
 static_assert(__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__,
+#endif
     "Project only works on little-endian architecture.");
 
+#if defined(__clang__) || defined(__GNUC__)
 #define MD5_EXPORT __attribute__ ((visibility ("default")))
+#else
+#define MD5_EXPORT
+#endif
 
 #include "impl/value.inl"
 #include "impl/constexpr.inl"

third_party/ThirdParty.cmake

@@ -1,9 +1,14 @@
 if (MD5_ENABLE_TESTING)
+  if (MSVC)
+    set(gtest_force_shared_crt ON)
+  endif()
   add_subdirectory(third_party/googletest/ EXCLUDE_FROM_ALL)
 endif()
 
 if (MD5_ENABLE_BENCHMARK)
-    set(BENCHMARK_ENABLE_TESTING OFF)
+  if (NOT MSVC)
     set(BENCHMARK_ENABLE_EXCEPTIONS OFF)
+  endif()
+  set(BENCHMARK_ENABLE_TESTING OFF)
   add_subdirectory(third_party/benchmark/ EXCLUDE_FROM_ALL)
 endif()