Compile Godot with Clang 5.0 with the mingw32-64 and posix threading.

[fire]

Operating system or device, Godot version, GPU Model and driver (if graphics related):
Ubuntu Linux (Bash for Windows); Godot master;

Issue description:
Allow the use of Clang 5.0 with the mingw32-64 ONLY WITH posix threading.

Steps to reproduce:

Now allows:

wget -O - http://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
Add the PPA:
sudo apt-add-repository "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-5.0 main"
sudo apt-get update
sudo apt-get install -y mingw-w64 build-essential cmake scons clang-5.0 # ccache distcc
# https://github.com/godotengine/godot/issues/9258
$ sudo update-alternatives --config x86_64-w64-mingw32-gcc
<choose x86_64-w64-mingw32-gcc-posix from the list>
$ sudo update-alternatives --config x86_64-w64-mingw32-g++
<choose x86_64-w64-mingw32-gcc-posix from the list>
# HACK HACK HACK to force posix
sudo mv /usr/lib/gcc/x86_64-w64-mingw32/5.3-win32 /usr/lib/gcc/x86_64-w64-mingw32/5.3-win32-backup
# END HACK HACK HACK
sudo update-alternatives --install /usr/bin/cc cc /usr/bin/clang-5.0 100
sudo update-alternatives --install /usr/bin/c++ c++ /usr/bin/clang-5.0 100
sudo update-alternatives --install /usr/bin/clang++ clang++ /usr/bin/clang-5.0 100
sudo update-alternatives --install /usr/bin/clang clang /usr/bin/clang-5.0 100
git clone https://github.com/tpoechtrager/wclang.git
cmake .
make
make install
git clone https://github.com/godotengine/godot.git
cd godot
scons p=windows bits=64 target=release_debug use_llvm=yes

diff --git a/platform/windows/detect.py b/platform/windows/detect.py
index 5bd9a78f4..ea154ee5b 100644
--- a/platform/windows/detect.py
+++ b/platform/windows/detect.py
@@ -249,6 +249,21 @@ def configure(env):
         env['AR'] = mingw_prefix + "ar"
         env['RANLIB'] = mingw_prefix + "ranlib"
         env['LD'] = mingw_prefix + "g++"
+
+        if (env["use_llvm"] == "yes"):
+            env["CC"] = mingw_prefix + "clang"
+            env['AS'] = mingw_prefix + "as"
+            env['CXX'] = mingw_prefix + "clang++"
+            env['AR'] = mingw_prefix + "ar"
+            env['RANLIB'] = mingw_prefix + "ranlib"
+            env['LD'] = mingw_prefix + "clang++"
+            # Allow linking to dlls in mingw32
+            env.Append(CPPFLAGS=['-Xclang', '-flto-visibility-public-std'])
+            env.Append(CPPFLAGS=['-pthread'])
+            # Hack to allow multiple definitions
+            env.Append(LINKFLAGS=['-Wl,--allow-multiple-definition'])
+            env.Append(LINKFLAGS=['-pthread'])
+
         env["x86_libtheora_opt_gcc"] = True

         ## Compile flags

Also depends on #11333.

Issue tracking wclang + posix threading tpoechtrager/wclang#37

Issue tracking clang 4.0 support tpoechtrager/wclang#31

Issue tracking static causes multiple symbols to be defined https://github.com/Alexpux/MINGW-packages/issues/1819

Issue tracking Cannot compile with "-static" when using exceptions tpoechtrager/wclang#32

[fire]

wget -O - http://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
Add the PPA:
sudo apt-add-repository "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-5.0 main"
sudo apt-get update
sudo apt-get install -y mingw-w64 build-essential cmake scons clang-5.0 # ccache distcc
sudo apt-get install pkg-config libx11-dev libxcursor-dev libxinerama-dev libxrandr-dev -y
git clone https://github.com/tpoechtrager/wclang.git
cmake .
make
sudo make install
git clone https://github.com/godotengine/godot.git
cd godot
scons p=windows bits=64 target=release_debug use_llvm=yes use_lto=no module_etc_enabled=no

I couldn't get lto working.

9678231 Broke ubuntu xenial's mingw.

diff --git a/platform/windows/detect.py b/platform/windows/detect.py
index fbb02c9..8787ac3 100644
--- a/platform/windows/detect.py
+++ b/platform/windows/detect.py
@@ -265,6 +265,18 @@ def configure(env):
             env.Append(CCFLAGS=['-flto'])
             env.Append(LINKFLAGS=['-flto=' + str(env.GetOption("num_jobs"))])

+        if env['use_llvm']:
+            env["CC"] = "x86_64-w64-mingw32-clang"
+            env['AS'] = "as"
+            env['CXX'] = "x86_64-w64-mingw32-clang++"
+            env['AR'] = mingw_prefix + "gcc-ar"
+            env['RANLIB'] = mingw_prefix + "gcc-ranlib"
+            env['LD'] = "x86_64-w64-mingw32-clang++"
+            # Allow linking to dlls in mingw32
+            env.Append(CPPFLAGS=['-Xclang', '-flto-visibility-public-std'])
+            # Hack to allow multiple definitions
+            env.Append(LINKFLAGS=['-Wl,--allow-multiple-definition'])
+
         ## Compile flags

         env.Append(CCFLAGS=['-DWINDOWS_ENABLED', '-mwindows'])
diff --git a/platform/windows/os_windows.cpp b/platform/windows/os_windows.cpp
index 9bcbb6d..01e0ef5 100644
--- a/platform/windows/os_windows.cpp
+++ b/platform/windows/os_windows.cpp
@@ -1611,15 +1611,15 @@ Error OS_Windows::open_dynamic_library(const String p_path, void *&p_library_han

        DLL_DIRECTORY_COOKIE cookie;

-       if (p_also_set_library_path) {
-               cookie = AddDllDirectory(p_path.get_base_dir().c_str());
-       }
+//     if (p_also_set_library_path) {
+//             cookie = AddDllDirectory(p_path.get_base_dir().c_str());
+//     }

        p_library_handle = (void *)LoadLibraryExW(p_path.c_str(), NULL, p_also_set_library_path ? LOAD_LIBRARY_SEARCH_DE
FAULT_DIRS : 0);

-       if (p_also_set_library_path) {
-               RemoveDllDirectory(cookie);
-       }
+//     if (p_also_set_library_path) {
+//             RemoveDllDirectory(cookie);
+//     }

        if (!p_library_handle) {
                ERR_EXPLAIN("Can't open dynamic library: " + p_path + ". Error: " + format_error_message(GetLastError()));
diff --git a/platform/windows/os_windows.h b/platform/windows/os_windows.h
index e98f827..18222d2 100644
--- a/platform/windows/os_windows.h
+++ b/platform/windows/os_windows.h
@@ -1,3 +1,5 @@
+
+
 /*************************************************************************/
 /*  os_windows.h                                                         */
 /*************************************************************************/

[fire]

I was able to compile with mingw clang today.

https://github.com/mstorsjo/llvm-mingw/releases/tag/20191230

Install bin into path

scons p=windows tools=yes use_mingw=yes use_llvm=yes bits=64 use_thinlto=yes target=release_debug -j8```