Support building with MinGW-w64 toolchain

Signed-off-by: Patrick Masselink <[email protected]>

cmake/Modules/Generate.cmake

@@ -25,6 +25,12 @@ function(IDLC_GENERATE)
     endif()
     set(_idlc_depends CycloneDDS::libidlc)
   else()
+    if (CMAKE_HOST_SYSTEM_NAME STREQUAL "Linux" AND NOT ".so" IN_LIST CMAKE_FIND_LIBRARY_SUFFIXES)
+      # When cross-compiling, find_library looks for libraries using naming onventions of the target,
+      # But here we're trying to find the idlc backend library to run on the host.
+      # For now, building for a Windows target on a Linux host with w64-mingw is supported by this workaround.
+      list(APPEND CMAKE_FIND_LIBRARY_SUFFIXES ".so")
+    endif()
     find_library(_idlc_backend "cycloneddsidlc" NO_CMAKE_FIND_ROOT_PATH)
     if (_idlc_backend)
       if (NOT DEFINED _idlc_generate_skipreport)

examples/roundtrip/ping.c

@@ -108,7 +108,7 @@ static dds_time_t exampleGet99PercentileFromTimeStats (ExampleTimeStats *stats)
 static dds_entity_t waitSet;
 
 #ifdef _WIN32
-#include <Windows.h>
+#include <windows.h>
 static bool CtrlHandler (DWORD fdwCtrlType)
 {
   (void)fdwCtrlType;

examples/roundtrip/pong.c

@@ -15,7 +15,7 @@ static dds_entity_t prepare_dds(dds_entity_t *writer, dds_entity_t *reader, dds_
 static void finalize_dds(dds_entity_t participant, RoundTripModule_DataType data[MAX_SAMPLES]);
 
 #ifdef _WIN32
-#include <Windows.h>
+#include <windows.h>
 static bool CtrlHandler (DWORD fdwCtrlType)
 {
   (void)fdwCtrlType;

ports/mingw-w64/Dockerfile

@@ -0,0 +1,42 @@
+ARG ARCH=x86_64
+
+FROM ubuntu:24.04 AS build
+# supports x86_64 or i686
+ARG ARCH
+
+RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y -q\
+  build-essential \
+  cmake \
+  mingw-w64
+
+WORKDIR /project
+COPY --link . src
+
+# Host build, only for idlc (+ libidlc) but building individual targets doesn't really work...
+RUN cmake -S src -B host-build
+RUN cmake --build host-build --parallel
+RUN cmake --install host-build --prefix /project/install
+
+# Cross build with mingw-w64 toolchain
+RUN cmake -S src -B build \
+  -DBUILD_EXAMPLES=1 \
+  -DCMAKE_TOOLCHAIN_FILE=/project/src/ports/mingw-w64/mingw-w64-${ARCH}.cmake \
+  -DCMAKE_PREFIX_PATH=/project/install
+RUN cmake --build build --parallel
+RUN cmake --install build 
+
+FROM ubuntu:24.04
+ARG ARCH
+
+RUN if [ "${ARCH}" = "i686" ]; then \
+  dpkg --add-architecture i386; \
+  apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y -q mingw-w64 wine wine32:i386; \
+  echo "export WINEARCH=win32" >> /etc/bash.bashrc; \
+ else \
+  apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y -q mingw-w64 wine; \
+ fi
+
+COPY --from=build /usr/local/bin /usr/local/bin
+COPY --from=build /usr/local/lib /usr/local/lib
+COPY --from=build /usr/local/include /usr/local/include
+COPY --from=build /project/build/bin /usr/local/bin

ports/mingw-w64/mingw-w64-i686.cmake

@@ -0,0 +1,13 @@
+set(CMAKE_SYSTEM_NAME Windows)
+set(CMAKE_SYSTEM_PROCESSOR i686)
+
+set(TOOLCHAIN_PREFIX i686-w64-mingw32)
+
+set(CMAKE_C_COMPILER ${TOOLCHAIN_PREFIX}-gcc)
+set(CMAKE_CXX_COMPILER ${TOOLCHAIN_PREFIX}-g++)
+
+set(CMAKE_FIND_ROOT_PATH /usr/${TOOLCHAIN_PREFIX})
+
+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)

ports/mingw-w64/mingw-w64-x86_64.cmake

@@ -0,0 +1,13 @@
+set(CMAKE_SYSTEM_NAME Windows)
+set(CMAKE_SYSTEM_PROCESSOR x86_64)
+
+set(TOOLCHAIN_PREFIX x86_64-w64-mingw32)
+
+set(CMAKE_C_COMPILER ${TOOLCHAIN_PREFIX}-gcc)
+set(CMAKE_CXX_COMPILER ${TOOLCHAIN_PREFIX}-g++)
+
+set(CMAKE_FIND_ROOT_PATH /usr/${TOOLCHAIN_PREFIX})
+
+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)

src/ddsrt/include/dds/ddsrt/types/windows.h

@@ -20,11 +20,13 @@
 #endif
 
 #include <windows.h>
-#include <VersionHelpers.h>
+#include <versionhelpers.h>
 #include <stdint.h>
 #include <inttypes.h>
 #include <wchar.h>
 
+#ifdef _MSC_VER
 typedef SSIZE_T ssize_t;
+#endif
 
 #endif /* DDSRT_TYPES_WINDOWS_H */

src/ddsrt/src/netstat/windows/netstat.c

@@ -6,7 +6,7 @@
 #ifndef WIN32_LEAN_AND_MEAN
 #define WIN32_LEAN_AND_MEAN
 #endif
-#include <Windows.h>
+#include <windows.h>
 
 #include <ws2def.h>
 #include <ws2tcpip.h>

src/ddsrt/src/sockets/windows/socket.c

@@ -20,7 +20,7 @@
 #include "dds/ddsrt/time.h"
 
 // Has to be included after most of windows has been included, it seems
-#include <Mswsock.h>
+#include <mswsock.h>
 
 #ifdef ddsrt_select
 #undef ddsrt_select /* See sockets.h for details. */

src/tools/idlc/src/idlc/generator.c

@@ -16,7 +16,7 @@
 #include <string.h>
 
 #if WIN32
-#include <Windows.h>
+#include <windows.h>
 static const char sep[] = "/\\";
 static const char lib[] = "cyclonedds";
 static const char ext[] = "dll";