Travis: Add Mingw third-party builds

- Build third-party/ in Travis using mingw
- Import mingw-w64 cmake toolchain

.ci/mingw.sh

@@ -0,0 +1,18 @@
+. "$CI_SCRIPTS/common.sh"
+
+# FIXME: When Travis gets a recent version of Mingw-w64 use this
+#sudo apt-get install binutils-mingw-w64-i686 gcc-mingw-w64-i686 g++-mingw-w64-i686 mingw-w64-dev mingw-w64-tools
+#sudo apt-get install wine
+sudo apt-get install libc6-dev-i386
+
+# mingw-w64 build from http://sourceforge.net/projects/mingw-w64/files/Toolchains%20targetting%20Win32/Personal%20Builds/rubenvb/gcc-4.8-release/
+wget "http://downloads.sourceforge.net/project/mingw-w64/Toolchains%20targetting%20Win32/Personal%20Builds/rubenvb/gcc-4.8-release/i686-w64-mingw32-gcc-4.8.0-linux64_rubenvb.tar.xz" -O mingw.tar.xz
+sudo tar -axf mingw.tar.xz -C /opt
+export PATH=$PATH:/opt/mingw32/bin
+
+# Build third-party
+mkdir .deps
+cd .deps
+cmake -DCMAKE_TOOLCHAIN_FILE=../cmake/mingw32-w64-cross-travis.toolchain.cmake ../third-party/
+cmake --build .
+cd ..

.travis.yml

@@ -24,6 +24,7 @@ env:
     - CI_TARGET=gcc
     - CI_TARGET=gcc-32
     - CI_TARGET=clint
+    - CI_TARGET=mingw
 matrix:
   include:
     - os: osx

cmake/mingw32-w64-cross-travis.toolchain.cmake

@@ -0,0 +1,53 @@
+#
+# Mingw-w64 cross compiler toolchain
+#
+# - The usual CMAKE variables will point to the cross compiler
+# - HOST_EXE_LINKER, HOST_C_COMPILER, HOST_EXE_LINKER_FLAGS,
+#   HOST_C_FLAGS point to a host compiler
+#
+
+set(MINGW_TRIPLET i686-w64-mingw32)
+# For x86_64 use
+#set(MINGW_TRIPLET x86_64-w64-mingw32)
+
+# The location of your toolchain sys-root
+set(MINGW_PREFIX_PATH /opt/mingw32/${MINGW_TRIPLET}/)
+# or sometimes like this
+#set(MINGW_PREFIX_PATH /usr/${MINGW_TRIPLET}/sys-root)
+
+# the name of the target operating system
+set(CMAKE_SYSTEM_NAME Windows)
+
+# which compilers to use for C and C++
+set(CMAKE_C_COMPILER ${MINGW_TRIPLET}-gcc)
+set(CMAKE_CXX_COMPILER ${MINGW_TRIPLET}-g++)
+set(CMAKE_RC_COMPILER ${MINGW_TRIPLET}-windres)
+set(CMAKE_C_COMPILER ${MINGW_TRIPLET}-gcc)
+set(CMAKE_CXX_COMPILER ${MINGW_TRIPLET}-g++)
+set(CMAKE_RC_COMPILER ${MINGW_TRIPLET}-windres)
+
+# Where is the target environment located
+set(CMAKE_FIND_ROOT_PATH "${MINGW_PREFIX_PATH}/mingw")
+
+# adjust the default behaviour of the FIND_XXX() commands:
+# search headers and libraries in the target environment, search
+# programs in the host environment
+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
+
+set(CROSS_TARGET ${MINGW_TRIPLET})
+
+# We need a host compiler too - assuming mildly sane Unix
+# defaults here
+set(HOST_C_COMPILER cc)
+set(HOST_EXE_LINKER ld)
+
+if (MINGW_TRIPLET MATCHES "^x86_64")
+  set(HOST_C_FLAGS)
+  set(HOST_EXE_LINKER_FLAGS)
+else()
+  # In 32 bits systems have the HOST compiler generate 32 bits binaries
+  set(HOST_C_FLAGS -m32)
+  set(HOST_EXE_LINKER_FLAGS -m32)
+endif()