Improved support for Mingw-w64 (#648)

* Build fixed through Mingw-w64

* Initial try to build using appveyor and MSYS2

CMakeLists.txt

@@ -57,6 +57,9 @@ if(CMAKE_C_COMPILER_ID STREQUAL "Clang" OR
    CMAKE_C_COMPILER_ID STREQUAL "AppleClang")
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fcolor-diagnostics -Wno-missing-braces -Wno-missing-field-initializers")
 endif()
+if(MINGW OR MSYS OR CYGWIN)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-maybe-uninitialized")
+endif()
 if(BUILD_SHARED_LIBS)
   set(CMAKE_POSITION_INDEPENDENT_CODE TRUE)
 endif()

appveyor-build.bat

@@ -0,0 +1,14 @@
+@echo off
+IF %COMPILER%==msys2 (
+    @echo on
+    SET "PATH=C:\msys64\mingw64\bin;%PATH%"
+    bash -lc "cd ${APPVEYOR_BUILD_FOLDER} && mkdir build && cd build && cmake .. -GNinja -DBUILD_SHARED_LIBS=%BUILD_SHARED% && ninja"
+)
+IF %COMPILER%==msvc2019 (
+    @echo on
+    CALL "C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvars64.bat"
+    mkdir build
+    cd build
+    cmake .. -GNinja -DBUILD_SHARED_LIBS=%BUILD_SHARED%
+    ninja
+)

appveyor.yml

@@ -9,34 +9,31 @@ branches:
   except:
     - /master-new-.*/
     
-init:
-  - call "C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvars64.bat"
-  - set PATH="C:\\Python37";"C:\\Python37\Scripts";%PATH%
-
 environment:
   matrix:
     - BUILD_SHARED: OFF
+      COMPILER: msvc2019
     - BUILD_SHARED: ON
+      COMPILER: msvc2019
+    - BUILD_SHARED: OFF
+      COMPILER: msys2
+    - BUILD_SHARED: ON
+      COMPILER: msys2
 
-before_build:
-  - cmd: |-
-      mkdir build
-      cd build
-      cmake .. -G"Ninja" -DBUILD_SHARED_LIBS=%BUILD_SHARED%
 build_script:
-  - ninja
+  - cmd: '%APPVEYOR_BUILD_FOLDER%\appveyor-build.bat'
   
 before_test:
-  - python -m pip install pytest pytest-xdist
+  - cmd: |-
+         SET "PATH=C:\Python37;C:\Python37\Scripts;%PATH%"
+         pip.exe install pytest pytest-xdist
     
 test_script:
-  - cmd: >-
+  - cmd: |-
          cd %APPVEYOR_BUILD_FOLDER%\build
-
          set PATH=%cd%\bin;%PATH% && ninja run_tests
 
 after_test:
-  - ps: >-
+  - ps: |-
         $wc = New-Object 'System.Net.WebClient'
-
         $wc.UploadFile("https://ci.appveyor.com/api/testresults/xunit/$($env:APPVEYOR_JOB_ID)", (Resolve-Path .\test-results\pytest\test-results.xml))

src/common/common.h

@@ -92,11 +92,11 @@ OQS_API void OQS_MEM_insecure_free(void *ptr);
  * an API specification but when an implementation doesn't actually use the argument
  * and we'd get a compiler warning otherwise.
  */
-#if defined(_WIN32)
+#ifdef __GNUC__
-#define UNUSED
-// __attribute__ not supported in VS
-#else
 #define UNUSED __attribute__((unused))
+#else
+// __attribute__ not supported in VS
+#define UNUSED
 #endif
 
 #if defined(__cplusplus)

src/kem/sike/config.h

@@ -144,6 +144,11 @@ static __inline unsigned int is_digit_lessthan_ct(digit_t x, digit_t y) { // Is
 
 #elif (TARGET == TARGET_AMD64 && OS_TARGET == OS_WIN)
 
+#if defined(__MINGW64__)
+#include <x86intrin.h>
+#include <psdk_inc/intrin-impl.h>
+#endif
+
 // Digit multiplication
 #define MUL(multiplier, multiplicand, hi, lo) \
     (lo) = _umul128((multiplier), (multiplicand), (hi));

tests/CMakeLists.txt

@@ -2,7 +2,7 @@ if (MINGW OR MSYS OR CYGWIN)
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -D__USE_MINGW_ANSI_STDIO=1 -Wno-unknown-pragmas -Wno-unused-parameter")
 endif()
 
-if(NOT WIN32 OR MINGW OR MSYS OR CYGWIN)
+if(NOT WIN32)
     set(LIBM m)
 
     if(OQS_USE_OPENSSL)

tests/test_sha3.c

@@ -8,10 +8,10 @@
 
 #include "system_info.c"
 
-#if defined(_WIN32)
+#ifdef __GNUC__
-#define UNUSED
-#else
 #define UNUSED __attribute__((unused))
+#else
+#define UNUSED
 #endif
 
 /**