builder: fix ccache, mingw-cross

Update mingw cmake toolchain files to work-around a bug in cmake where
find_program() would return the current working directory instead of the
executable path if CMAKE_C_COMPILER and related are passed on the
command line.

Fix $CC/$CC_ORIG and $CXX/$CXX_ORIG handling for the core and
mingw-cross (_ORIG is without ccache.)

cmake/Toolchain-cross-MinGW-w64-i686.cmake

@@ -2,6 +2,11 @@ SET(CMAKE_SYSTEM_NAME Windows)
 
 set(COMPILER_PREFIX "i686-w64-mingw32")
 
+unset(CMAKE_RC_COMPILER     CACHE)
+unset(CMAKE_C_COMPILER      CACHE)
+unset(CMAKE_CXX_COMPILER    CACHE)
+unset(PKG_CONFIG_EXECUTABLE CACHE)
+
 # which compilers to use for C and C++
 find_program(CMAKE_RC_COMPILER NAMES ${COMPILER_PREFIX}-windres)
 find_program(CMAKE_C_COMPILER NAMES ${COMPILER_PREFIX}-gcc)

cmake/Toolchain-cross-MinGW-w64-x86_64.cmake

@@ -2,6 +2,11 @@ SET(CMAKE_SYSTEM_NAME Windows)
 
 set(COMPILER_PREFIX "x86_64-w64-mingw32")
 
+unset(CMAKE_RC_COMPILER     CACHE)
+unset(CMAKE_C_COMPILER      CACHE)
+unset(CMAKE_CXX_COMPILER    CACHE)
+unset(PKG_CONFIG_EXECUTABLE CACHE)
+
 # which compilers to use for C and C++
 find_program(CMAKE_RC_COMPILER NAMES ${COMPILER_PREFIX}-windres)
 find_program(CMAKE_C_COMPILER NAMES ${COMPILER_PREFIX}-gcc)

tools/builder/core.sh

@@ -40,6 +40,9 @@ case "\$CC" in
         ;;
 esac
 
+export CC_ORIG="\${CC_ORIG:-\$CC}"
+export CXX_ORIG="\${CXX_ORIG:-\$CXX}"
+
 export CPPFLAGS="$CPPFLAGS -I$BUILD_ROOT/root/include"
 export CFLAGS="$CFLAGS -fPIC -I$BUILD_ROOT/root/include -L$BUILD_ROOT/root/lib -Wno-error=all"
 export CXXFLAGS="$CXXFLAGS -fPIC -I$BUILD_ROOT/root/include -L$BUILD_ROOT/root/lib -std=gnu++11 -Wno-error=all -fpermissive"
@@ -112,7 +115,7 @@ DISTS=$DISTS'
     unzip           https://downloads.sourceforge.net/project/infozip/UnZip%206.x%20%28latest%29/UnZip%206.0/unzip60.tar.gz     bin/unzip
     zip             https://downloads.sourceforge.net/project/infozip/Zip%203.x%20%28latest%29/3.0/zip30.tar.gz                 bin/zip
     openssl         https://www.openssl.org/source/openssl-1.0.2o.tar.gz                                        lib/libssl.a
-    cmake           https://cmake.org/files/v3.10/cmake-3.10.0-rc3.tar.gz                                       bin/cmake
+    cmake           https://cmake.org/files/v3.10/cmake-3.10.3.tar.gz                                           bin/cmake
     zlib            https://zlib.net/zlib-1.2.11.tar.gz                                                         lib/libz.a
     m4              http://ftp.gnu.org/gnu/m4/m4-1.4.18.tar.xz                                                  bin/m4
     autoconf        https://ftp.gnu.org/gnu/autoconf/autoconf-2.69.tar.xz                                       bin/autoconf

tools/builder/mingw-cross.sh

@@ -40,8 +40,8 @@ both_dists='
 
 BUILD_ENV=$BUILD_ENV$(cat <<EOF
 
-export CC='ccache ${target_arch}-gcc'
-export CXX='ccache ${target_arch}-g++'
+export CC='${target_arch}-gcc'
+export CXX='${target_arch}-g++'
 
 EOF
 )

tools/builder/mingw.sh

@@ -50,9 +50,13 @@ set_host_env() {
     if [ -z "$OCC" ]; then
         OCC=$CC
         OCXX=$CXX
+        OCC_ORIG=$CC_ORIG
+        OCXX_ORIG=$CXX_ORIG
 
         export CC='ccache gcc'
         export CXX='ccache g++'
+        export CC_ORIG="gcc"
+        export CXX_ORIG="g++"
 
         OCFLAGS=$CFLAGS OCXXFLAGS=$CXXFLAGS OLDFLAGS=$LDFLAGS
 
@@ -75,7 +79,9 @@ unset_host_env() {
     if [ -n "$OCC" ]; then
         export CC="$OCC"
         export CXX="$OCXX"
-        OCC= OCXX=
+        export CC_ORIG="$OCC_ORIG"
+        export CXX_ORIG="$OCXX_ORIG"
+        OCC= OCXX= OCC_ORIG= OCXX_ORIG=
 
         export CFLAGS="$OCFLAGS"
         export CXXFLAGS="$OCXXFLAGS"