Merge pull request #17194 from garyo/scons_find_msvc

Enable SCons to autodetect Windows MSVC compiler

3 files changed, 245 insertions, 192 deletions

diff --git a/SConstruct b/SConstruct
index 9d8dd7f5cb..7a8db10931 100644
--- a/SConstruct
+++ b/SConstruct
@@ -65,7 +65,7 @@ platform_arg = ARGUMENTS.get("platform", ARGUMENTS.get("p", False))
 if (os.name == "posix"):
     pass
 elif (os.name == "nt"):
-    if (os.getenv("VCINSTALLDIR") == None or platform_arg == "android" or platform_arg == "javascript"):
+    if platform_arg == "android" or platform_arg == "javascript" or ARGUMENTS.get("use_mingw", False):
         custom_tools = ['mingw']
 
 env_base = Environment(tools=custom_tools)
@@ -92,6 +92,7 @@ env_base.use_ptrcall = False
 env_base.split_drivers = False
 env_base.split_modules = False
 env_base.module_version_string = ""
+env_base.msvc = False
 
 # To decide whether to rebuild a file, use the MD5 sum only if the timestamp has changed.
 # http://scons.org/doc/production/HTML/scons-user/ch06.html#idm139837621851792
@@ -240,14 +241,13 @@ sys.modules.pop('detect')
 """
 
 if (env_base['target'] == 'debug'):
-    env_base.Append(CPPFLAGS=['-DDEBUG_MEMORY_ALLOC'])
-    env_base.Append(CPPFLAGS=['-DSCI_NAMESPACE'])
+    env_base.Append(CPPDEFINES=['DEBUG_MEMORY_ALLOC', 'SCI_NAMESPACE'])
 
 if (env_base['no_editor_splash']):
-    env_base.Append(CPPFLAGS=['-DNO_EDITOR_SPLASH'])
+    env_base.Append(CPPDEFINES=['NO_EDITOR_SPLASH'])
 
 if not env_base['deprecated']:
-    env_base.Append(CPPFLAGS=['-DDISABLE_DEPRECATED'])
+    env_base.Append(CPPDEFINES=['DISABLE_DEPRECATED'])
 
 env_base.platforms = {}
 
@@ -329,9 +329,7 @@ if selected_platform in platform_list:
     if (env["warnings"] == 'yes'):
         print("WARNING: warnings=yes is deprecated; assuming warnings=all")
 
-    env.msvc = 0
-    if (os.name == "nt" and os.getenv("VCINSTALLDIR") and (platform_arg == "windows" or platform_arg == "uwp")): # MSVC, needs to stand out of course
-        env.msvc = 1
+    if env.msvc:
         disable_nonessential_warnings = ['/wd4267', '/wd4244', '/wd4305', '/wd4800'] # Truncations, narrowing conversions...
         if (env["warnings"] == 'extra'):
             env.Append(CCFLAGS=['/Wall']) # Implies /W4
@@ -363,7 +361,7 @@ if selected_platform in platform_list:
             print("Tools can only be built with targets 'debug' and 'release_debug'.")
             sys.exit(255)
         suffix += ".opt"
-        env.Append(CCFLAGS=['-DNDEBUG'])
+        env.Append(CPPDEFINES=['NDEBUG'])
 
     elif (env["target"] == "release_debug"):
         if env["tools"]:
@@ -420,25 +418,25 @@ if selected_platform in platform_list:
     env["SHLIBSUFFIX"] = suffix + env["SHLIBSUFFIX"]
 
     if (env.use_ptrcall):
-        env.Append(CPPFLAGS=['-DPTRCALL_ENABLED'])
+        env.Append(CPPDEFINES=['PTRCALL_ENABLED'])
 
     # to test 64 bits compiltion
     # env.Append(CPPFLAGS=['-m64'])
 
     if env['tools']:
-        env.Append(CPPFLAGS=['-DTOOLS_ENABLED'])
+        env.Append(CPPDEFINES=['TOOLS_ENABLED'])
     if env['disable_3d']:
-        env.Append(CPPFLAGS=['-D_3D_DISABLED'])
+        env.Append(CPPDEFINES=['_3D_DISABLED'])
     if env['gdscript']:
-        env.Append(CPPFLAGS=['-DGDSCRIPT_ENABLED'])
+        env.Append(CPPDEFINES=['GDSCRIPT_ENABLED'])
     if env['disable_advanced_gui']:
-        env.Append(CPPFLAGS=['-DADVANCED_GUI_DISABLED'])
+        env.Append(CPPDEFINES=['ADVANCED_GUI_DISABLED'])
 
     if env['minizip']:
-        env.Append(CPPFLAGS=['-DMINIZIP_ENABLED'])
+        env.Append(CPPDEFINES=['MINIZIP_ENABLED'])
 
     if env['xml']:
-        env.Append(CPPFLAGS=['-DXML_ENABLED'])
+        env.Append(CPPDEFINES=['XML_ENABLED'])
 
     if not env['verbose']:
         methods.no_verbose(sys, env)
@@ -479,10 +477,7 @@ if selected_platform in platform_list:
     if ("check_c_headers" in env):
         for header in env["check_c_headers"]:
             if (conf.CheckCHeader(header[0])):
-                if (env.msvc):
-                    env.Append(CCFLAGS=['/D' + header[1]])
-                else:
-                    env.Append(CCFLAGS=['-D' + header[1]])
+                env.AppendUnique(CPPDEFINES=[header[1]])
 
 else:
 
diff --git a/platform/uwp/detect.py b/platform/uwp/detect.py
index f2c5c5d42e..d850ab9436 100644
--- a/platform/uwp/detect.py
+++ b/platform/uwp/detect.py
@@ -27,6 +27,8 @@ def can_build():
 def get_opts():
 
     return [
+        ('msvc_version', 'MSVC version to use. Ignored if VCINSTALLDIR is set in shell env.', None),
+        (BoolVariable('use_mingw', 'Use the Mingw compiler, even if MSVC is installed. Only used on Windows.', False)),
     ]
 
 
diff --git a/platform/windows/detect.py b/platform/windows/detect.py
index b8ee2cd19f..1cb8cb0fc8 100644
--- a/platform/windows/detect.py
+++ b/platform/windows/detect.py
@@ -12,23 +12,17 @@ def get_name():
 
 
 def can_build():
-
     if (os.name == "nt"):
         # Building natively on Windows
-        if (os.getenv("VCINSTALLDIR")): # MSVC
+        # If VCINSTALLDIR is set in the OS environ, use traditional Godot logic to set up MSVC
+        if (os.getenv("VCINSTALLDIR")): # MSVC, manual setup
             return True
 
-        print("MSVC not detected (no VCINSTALLDIR environment variable), attempting MinGW.")
-        mingw32 = ""
-        mingw64 = ""
-        if (os.getenv("MINGW32_PREFIX")):
-            mingw32 = os.getenv("MINGW32_PREFIX")
-        if (os.getenv("MINGW64_PREFIX")):
-            mingw64 = os.getenv("MINGW64_PREFIX")
-
-        test = "gcc --version > NUL 2>&1"
-        if (os.system(test) == 0 or os.system(mingw32 + test) == 0 or os.system(mingw64 + test) == 0):
-            return True
+        # Otherwise, let SCons find MSVC if installed, or else Mingw.
+        # Since we're just returning True here, if there's no compiler
+        # installed, we'll get errors when it tries to build with the
+        # null compiler.
+        return True
 
     if (os.name == "posix"):
         # Cross-compiling with MinGW-w64 (old MinGW32 is not supported)
@@ -70,6 +64,8 @@ def get_opts():
         ('target_win_version', 'Targeted Windows version, >= 0x0601 (Windows 7)', '0x0601'),
         EnumVariable('debug_symbols', 'Add debug symbols to release version', 'yes', ('yes', 'no', 'full')),
         BoolVariable('separate_debug_symbols', 'Create a separate file with the debug symbols', False),
+        ('msvc_version', 'MSVC version to use. Ignored if VCINSTALLDIR is set in shell env.', None),
+        (BoolVariable('use_mingw', 'Use the Mingw compiler, even if MSVC is installed. Only used on Windows.', False)),
     ]
 
 
@@ -98,192 +94,252 @@ def build_res_file(target, source, env):
     return 0
 
 
-def configure(env):
-
-    env.Append(CPPPATH=['#platform/windows'])
-
-    if (os.name == "nt" and os.getenv("VCINSTALLDIR")): # MSVC
-
-        env['ENV']['TMP'] = os.environ['TMP']
-
-        ## Build type
-
-        if (env["target"] == "release"):
-            env.Append(CCFLAGS=['/O2'])
-            env.Append(LINKFLAGS=['/SUBSYSTEM:WINDOWS'])
-            env.Append(LINKFLAGS=['/ENTRY:mainCRTStartup'])
-
-        elif (env["target"] == "release_debug"):
-            env.Append(CCFLAGS=['/O2', '/DDEBUG_ENABLED'])
-            env.Append(LINKFLAGS=['/SUBSYSTEM:CONSOLE'])
-
-        elif (env["target"] == "debug_release"):
-            env.Append(CCFLAGS=['/Z7', '/Od'])
-            env.Append(LINKFLAGS=['/DEBUG'])
-            env.Append(LINKFLAGS=['/SUBSYSTEM:WINDOWS'])
-            env.Append(LINKFLAGS=['/ENTRY:mainCRTStartup'])
-
-        elif (env["target"] == "debug"):
-            env.Append(CCFLAGS=['/Z7', '/DDEBUG_ENABLED', '/DDEBUG_MEMORY_ENABLED', '/DD3D_DEBUG_INFO', '/Od', '/EHsc'])
-            env.Append(LINKFLAGS=['/SUBSYSTEM:CONSOLE'])
-            env.Append(LINKFLAGS=['/DEBUG'])
-
-        ## Architecture
-
-        # Note: this detection/override code from here onward should be here instead of in SConstruct because it's platform and compiler specific (MSVC/Windows)
-        if (env["bits"] != "default"):
-            print("Error: bits argument is disabled for MSVC")
-            print("""
-                Bits argument is not supported for MSVC compilation. Architecture depends on the Native/Cross Compile Tools Prompt/Developer Console
-                (or Visual Studio settings) that is being used to run SCons. As a consequence, bits argument is disabled. Run scons again without bits
-                argument (example: scons p=windows) and SCons will attempt to detect what MSVC compiler will be executed and inform you.
-                """)
-            sys.exit()
-
-        # Forcing bits argument because MSVC does not have a flag to set this through SCons... it's different compilers (cl.exe's) called from the proper command prompt
-        # that decide the architecture that is build for. Scons can only detect the os.getenviron (because vsvarsall.bat sets a lot of stuff for cl.exe to work with)
-        env["bits"] = "32"
-        env["x86_libtheora_opt_vc"] = True
-
-        ## Compiler configuration
+def setup_msvc_manual(env):
+    """Set up env to use MSVC manually, using VCINSTALLDIR"""
+    if (env["bits"] != "default"):
+        print("""
+            Bits argument is not supported for MSVC compilation. Architecture depends on the Native/Cross Compile Tools Prompt/Developer Console
+            (or Visual Studio settings) that is being used to run SCons. As a consequence, bits argument is disabled. Run scons again without bits
+            argument (example: scons p=windows) and SCons will attempt to detect what MSVC compiler will be executed and inform you.
+            """)
+        raise SCons.Errors.UserError("Bits argument should not be used when using VCINSTALLDIR")
+
+    # Force bits arg
+    # (Actually msys2 mingw can support 64-bit, we could detect that)
+    env["bits"] = "32"
+    env["x86_libtheora_opt_vc"] = True
+
+    # find compiler manually
+    compiler_version_str = methods.detect_visual_c_compiler_version(env['ENV'])
+    print("Found MSVC compiler: " + compiler_version_str)
+
+    # If building for 64bit architecture, disable assembly optimisations for 32 bit builds (theora as of writing)... vc compiler for 64bit can not compile _asm
+    if(compiler_version_str == "amd64" or compiler_version_str == "x86_amd64"):
+        env["bits"] = "64"
+        env["x86_libtheora_opt_vc"] = False
+        print("Compiled program architecture will be a 64 bit executable (forcing bits=64).")
+    elif (compiler_version_str == "x86" or compiler_version_str == "amd64_x86"):
+        print("Compiled program architecture will be a 32 bit executable. (forcing bits=32).")
+    else:
+        print("Failed to manually detect MSVC compiler architecture version... Defaulting to 32bit executable settings (forcing bits=32). Compilation attempt will continue, but SCons can not detect for what architecture this build is compiled for. You should check your settings/compilation setup, or avoid setting VCINSTALLDIR.")
+
+def setup_msvc_auto(env):
+    """Set up MSVC using SCons's auto-detection logic"""
+
+    # If MSVC_VERSION is set by SCons, we know MSVC is installed.
+    # But we may want a different version or target arch.
+
+    # The env may have already been set up with default MSVC tools, so
+    # reset a few things so we can set it up with the tools we want.
+    # (Ideally we'd decide on the tool config before configuring any
+    # environment, and just set the env up once, but this function runs
+    # on an existing env so this is the simplest way.)
+    env['MSVC_SETUP_RUN'] = False # Need to set this to re-run the tool
+    env['MSVS_VERSION'] = None
+    env['MSVC_VERSION'] = None
+    env['TARGET_ARCH'] = None
+    if env['bits'] != 'default':
+        env['TARGET_ARCH'] = {'32': 'x86', '64': 'x86_64'}[env['bits']]
+    if env.has_key('msvc_version'):
+           env['MSVC_VERSION'] = env['msvc_version']
+    env.Tool('msvc')
+    env.Tool('mssdk')                      # we want the MS SDK
+    # Note: actual compiler version can be found in env['MSVC_VERSION'], e.g. "14.1" for VS2015
+    # Get actual target arch into bits (it may be "default" at this point):
+    if env['TARGET_ARCH'] in ('amd64', 'x86_64'):
+        env['bits'] = 64
+    else:
+        env['bits'] = 32
+    print(" Found MSVC version %s, arch %s, bits=%s" % (env['MSVC_VERSION'], env['TARGET_ARCH'], env['bits']))
+    if env['TARGET_ARCH'] in ('amd64', 'x86_64'):
+        env["x86_libtheora_opt_vc"] = False
+
+def setup_mingw(env):
+    """Set up env for use with mingw"""
+    # Nothing to do here
+    print("Using Mingw")
+    pass
+
+def configure_msvc(env, manual_msvc_config):
+    """Configure env to work with MSVC"""
+
+    # Build type
+
+    if (env["target"] == "release"):
+        env.Append(CCFLAGS=['/O2'])
+        env.Append(LINKFLAGS=['/SUBSYSTEM:WINDOWS'])
+        env.Append(LINKFLAGS=['/ENTRY:mainCRTStartup'])
+
+    elif (env["target"] == "release_debug"):
+        env.Append(CCFLAGS=['/O2'])
+        env.AppendUnique(CPPDEFINES = ['DEBUG_ENABLED'])
+        env.Append(LINKFLAGS=['/SUBSYSTEM:CONSOLE'])
+
+    elif (env["target"] == "debug_release"):
+        env.Append(CCFLAGS=['/Z7', '/Od'])
+        env.Append(LINKFLAGS=['/DEBUG'])
+        env.Append(LINKFLAGS=['/SUBSYSTEM:WINDOWS'])
+        env.Append(LINKFLAGS=['/ENTRY:mainCRTStartup'])
+
+    elif (env["target"] == "debug"):
+        env.AppendUnique(CCFLAGS=['/Z7', '/Od', '/EHsc'])
+        env.AppendUnique(CPPDEFINES = ['DEBUG_ENABLED', 'DEBUG_MEMORY_ENABLED',
+                                       'D3D_DEBUG_INFO'])
+        env.Append(LINKFLAGS=['/SUBSYSTEM:CONSOLE'])
+        env.Append(LINKFLAGS=['/DEBUG'])
+
+    ## Compile/link flags
+
+    env.AppendUnique(CCFLAGS=['/MT', '/Gd', '/GR', '/nologo'])
+    env.AppendUnique(CXXFLAGS=['/TP']) # assume all sources are C++
+    if manual_msvc_config: # should be automatic if SCons found it
+        env.Append(CPPPATH=[os.getenv("WindowsSdkDir") + "/Include"])
+
+    env.AppendUnique(CPPDEFINES = ['WINDOWS_ENABLED', 'OPENGL_ENABLED',
+                                   'RTAUDIO_ENABLED', 'WASAPI_ENABLED',
+                                   'TYPED_METHOD_BIND', 'WIN32', 'MSVC',
+                                   {'WINVER' : '$target_win_version',
+                                    '_WIN32_WINNT': '$target_win_version'}])
+    if env["bits"] == "64":
+        env.AppendUnique(CPPDEFINES=['_WIN64'])
+
+    ## Libs
+
+    LIBS = ['winmm', 'opengl32', 'dsound', 'kernel32', 'ole32', 'oleaut32',
+            'user32', 'gdi32', 'IPHLPAPI', 'Shlwapi', 'wsock32', 'Ws2_32',
+            'shell32', 'advapi32', 'dinput8', 'dxguid', 'imm32', 'bcrypt']
+    env.Append(LINKFLAGS=[p + env["LIBSUFFIX"] for p in LIBS])
+
+    if manual_msvc_config:
+        env.Append(LIBPATH=[os.getenv("WindowsSdkDir") + "/Lib"])
 
-        env['ENV'] = os.environ
-        # This detection function needs the tools env (that is env['ENV'], not SCons's env), and that is why it's this far below in the code
-        compiler_version_str = methods.detect_visual_c_compiler_version(env['ENV'])
+    ## LTO
 
-        print("Detected MSVC compiler: " + compiler_version_str)
-        # If building for 64bit architecture, disable assembly optimisations for 32 bit builds (theora as of writing)... vc compiler for 64bit can not compile _asm
-        if(compiler_version_str == "amd64" or compiler_version_str == "x86_amd64"):
-            env["bits"] = "64"
-            env["x86_libtheora_opt_vc"] = False
-            print("Compiled program architecture will be a 64 bit executable (forcing bits=64).")
-        elif (compiler_version_str == "x86" or compiler_version_str == "amd64_x86"):
-            print("Compiled program architecture will be a 32 bit executable. (forcing bits=32).")
+    if (env["use_lto"]):
+        env.AppendUnique(CCFLAGS=['/GL'])
+        env.AppendUnique(ARFLAGS=['/LTCG'])
+        if env["progress"]:
+            env.AppendUnique(LINKFLAGS=['/LTCG:STATUS'])
         else:
-            print("Failed to detect MSVC compiler architecture version... Defaulting to 32bit executable settings (forcing bits=32). Compilation attempt will continue, but SCons can not detect for what architecture this build is compiled for. You should check your settings/compilation setup.")
+            env.AppendUnique(LINKFLAGS=['/LTCG'])
 
-        ## Compile flags
+    if manual_msvc_config:
+        env.Append(CPPPATH=[p for p in os.getenv("INCLUDE").split(";")])
+        env.Append(LIBPATH=[p for p in os.getenv("LIB").split(";")])
 
-        env.Append(CCFLAGS=['/MT', '/Gd', '/GR', '/nologo'])
-        env.Append(CXXFLAGS=['/TP'])
-        env.Append(CPPFLAGS=['/DMSVC', '/GR', ])
-        env.Append(CCFLAGS=['/I' + os.getenv("WindowsSdkDir") + "/Include"])
+    # Incremental linking fix
+    env['BUILDERS']['ProgramOriginal'] = env['BUILDERS']['Program']
+    env['BUILDERS']['Program'] = methods.precious_program
 
-        env.Append(CCFLAGS=['/DWINDOWS_ENABLED'])
-        env.Append(CCFLAGS=['/DOPENGL_ENABLED'])
-        env.Append(CCFLAGS=['/DRTAUDIO_ENABLED'])
-        env.Append(CCFLAGS=['/DWASAPI_ENABLED'])
-        env.Append(CCFLAGS=['/DTYPED_METHOD_BIND'])
-        env.Append(CCFLAGS=['/DWIN32'])
-        env.Append(CCFLAGS=['/DWINVER=%s' % env['target_win_version'], '/D_WIN32_WINNT=%s' % env['target_win_version']])
-        if env["bits"] == "64":
-            env.Append(CCFLAGS=['/D_WIN64'])
+def configure_mingw(env):
+    # Workaround for MinGW. See:
+    # http://www.scons.org/wiki/LongCmdLinesOnWin32
+    env.use_windows_spawn_fix()
 
-        LIBS = ['winmm', 'opengl32', 'dsound', 'kernel32', 'ole32', 'oleaut32', 'user32', 'gdi32', 'IPHLPAPI', 'Shlwapi', 'wsock32', 'Ws2_32', 'shell32', 'advapi32', 'dinput8', 'dxguid', 'imm32', 'bcrypt']
-        env.Append(LINKFLAGS=[p + env["LIBSUFFIX"] for p in LIBS])
+    ## Build type
 
-        env.Append(LIBPATH=[os.getenv("WindowsSdkDir") + "/Lib"])
+    if (env["target"] == "release"):
+        env.Append(CCFLAGS=['-msse2'])
 
-        if (os.getenv("VCINSTALLDIR")):
-            VC_PATH = os.getenv("VCINSTALLDIR")
+        if (env["bits"] == "64"):
+            env.Append(CCFLAGS=['-O3'])
         else:
-            VC_PATH = ""
-
-        if (env["use_lto"]):
-            env.Append(CCFLAGS=['/GL'])
-            env.Append(ARFLAGS=['/LTCG'])
-            if env["progress"]:
-                env.Append(LINKFLAGS=['/LTCG:STATUS'])
-            else:
-                env.Append(LINKFLAGS=['/LTCG'])
-
-        env.Append(CCFLAGS=["/I" + p for p in os.getenv("INCLUDE").split(";")])
-        env.Append(LIBPATH=[p for p in os.getenv("LIB").split(";")])
-
-        # Incremental linking fix
-        env['BUILDERS']['ProgramOriginal'] = env['BUILDERS']['Program']
-        env['BUILDERS']['Program'] = methods.precious_program
-
-    else: # MinGW
+            env.Append(CCFLAGS=['-O2'])
 
-        # Workaround for MinGW. See:
-        # http://www.scons.org/wiki/LongCmdLinesOnWin32
-        env.use_windows_spawn_fix()
+        env.Append(LINKFLAGS=['-Wl,--subsystem,windows'])
 
-        ## Build type
+        if (env["debug_symbols"] == "yes"):
+           env.Prepend(CCFLAGS=['-g1'])
+        if (env["debug_symbols"] == "full"):
+           env.Prepend(CCFLAGS=['-g2'])
 
-        if (env["target"] == "release"):
-            env.Append(CCFLAGS=['-msse2'])
+    elif (env["target"] == "release_debug"):
+        env.Append(CCFLAGS=['-O2', '-DDEBUG_ENABLED'])
+        if (env["debug_symbols"] == "yes"):
+           env.Prepend(CCFLAGS=['-g1'])
+        if (env["debug_symbols"] == "full"):
+           env.Prepend(CCFLAGS=['-g2'])
 
-            if (env["bits"] == "64"):
-                env.Append(CCFLAGS=['-O3'])
-            else:
-                env.Append(CCFLAGS=['-O2'])
+    elif (env["target"] == "debug"):
+        env.Append(CCFLAGS=['-g3', '-DDEBUG_ENABLED', '-DDEBUG_MEMORY_ENABLED'])
 
-            env.Append(LINKFLAGS=['-Wl,--subsystem,windows'])
+    ## Compiler configuration
 
-            if (env["debug_symbols"] == "yes"):
-               env.Prepend(CCFLAGS=['-g1'])
-            if (env["debug_symbols"] == "full"):
-               env.Prepend(CCFLAGS=['-g2'])
+    if (os.name == "nt"):
+        env['ENV']['TMP'] = os.environ['TMP']  # way to go scons, you can be so stupid sometimes
+    else:
+        env["PROGSUFFIX"] = env["PROGSUFFIX"] + ".exe"  # for linux cross-compilation
 
-        elif (env["target"] == "release_debug"):
-            env.Append(CCFLAGS=['-O2', '-DDEBUG_ENABLED'])
-            if (env["debug_symbols"] == "yes"):
-               env.Prepend(CCFLAGS=['-g1'])
-            if (env["debug_symbols"] == "full"):
-               env.Prepend(CCFLAGS=['-g2'])
+    if (env["bits"] == "default"):
+        if (os.name == "nt"):
+            env["bits"] = "64" if "PROGRAMFILES(X86)" in os.environ else "32"
+        else: # default to 64-bit on Linux
+            env["bits"] = "64"
 
-        elif (env["target"] == "debug"):
-            env.Append(CCFLAGS=['-g3', '-DDEBUG_ENABLED', '-DDEBUG_MEMORY_ENABLED'])
+    mingw_prefix = ""
 
-        ## Compiler configuration
+    if (env["bits"] == "32"):
+        env.Append(LINKFLAGS=['-static'])
+        env.Append(LINKFLAGS=['-static-libgcc'])
+        env.Append(LINKFLAGS=['-static-libstdc++'])
+        mingw_prefix = env["mingw_prefix_32"]
+    else:
+        env.Append(LINKFLAGS=['-static'])
+        mingw_prefix = env["mingw_prefix_64"]
 
-        if (os.name == "nt"):
-            env['ENV']['TMP'] = os.environ['TMP']  # way to go scons, you can be so stupid sometimes
-        else:
-            env["PROGSUFFIX"] = env["PROGSUFFIX"] + ".exe"  # for linux cross-compilation
+    env["CC"] = mingw_prefix + "gcc"
+    env['AS'] = mingw_prefix + "as"
+    env['CXX'] = mingw_prefix + "g++"
+    env['AR'] = mingw_prefix + "gcc-ar"
+    env['RANLIB'] = mingw_prefix + "gcc-ranlib"
+    env['LINK'] = mingw_prefix + "g++"
+    env["x86_libtheora_opt_gcc"] = True
 
-        if (env["bits"] == "default"):
-            if (os.name == "nt"):
-                env["bits"] = "64" if "PROGRAMFILES(X86)" in os.environ else "32"
-            else: # default to 64-bit on Linux
-                env["bits"] = "64"
+    if env['use_lto']:
+        env.Append(CCFLAGS=['-flto'])
+        env.Append(LINKFLAGS=['-flto=' + str(env.GetOption("num_jobs"))])
 
-        mingw_prefix = ""
 
-        if (env["bits"] == "32"):
-            env.Append(LINKFLAGS=['-static'])
-            env.Append(LINKFLAGS=['-static-libgcc'])
-            env.Append(LINKFLAGS=['-static-libstdc++'])
-            mingw_prefix = env["mingw_prefix_32"]
-        else:
-            env.Append(LINKFLAGS=['-static'])
-            mingw_prefix = env["mingw_prefix_64"]
+    ## Compile flags
 
-        env["CC"] = mingw_prefix + "gcc"
-        env['AS'] = mingw_prefix + "as"
-        env['CXX'] = mingw_prefix + "g++"
-        env['AR'] = mingw_prefix + "gcc-ar"
-        env['RANLIB'] = mingw_prefix + "gcc-ranlib"
-        env['LINK'] = mingw_prefix + "g++"
-        env["x86_libtheora_opt_gcc"] = True
+    env.Append(CCFLAGS=['-DWINDOWS_ENABLED', '-mwindows'])
+    env.Append(CCFLAGS=['-DOPENGL_ENABLED'])
+    env.Append(CCFLAGS=['-DRTAUDIO_ENABLED'])
+    env.Append(CCFLAGS=['-DWASAPI_ENABLED'])
+    env.Append(CCFLAGS=['-DWINVER=%s' % env['target_win_version'], '-D_WIN32_WINNT=%s' % env['target_win_version']])
+    env.Append(LIBS=['mingw32', 'opengl32', 'dsound', 'ole32', 'd3d9', 'winmm', 'gdi32', 'iphlpapi', 'shlwapi', 'wsock32', 'ws2_32', 'kernel32', 'oleaut32', 'dinput8', 'dxguid', 'ksuser', 'imm32', 'bcrypt'])
 
-        if env['use_lto']:
-            env.Append(CCFLAGS=['-flto'])
-            env.Append(LINKFLAGS=['-flto=' + str(env.GetOption("num_jobs"))])
+    env.Append(CPPFLAGS=['-DMINGW_ENABLED'])
 
+    # resrc
+    env.Append(BUILDERS={'RES': env.Builder(action=build_res_file, suffix='.o', src_suffix='.rc')})
 
-        ## Compile flags
+def configure(env):
+    # At this point the env has been set up with basic tools/compilers.
+    env.Append(CPPPATH=['#platform/windows'])
 
-        env.Append(CCFLAGS=['-DWINDOWS_ENABLED', '-mwindows'])
-        env.Append(CCFLAGS=['-DOPENGL_ENABLED'])
-        env.Append(CCFLAGS=['-DRTAUDIO_ENABLED'])
-        env.Append(CCFLAGS=['-DWASAPI_ENABLED'])
-        env.Append(CCFLAGS=['-DWINVER=%s' % env['target_win_version'], '-D_WIN32_WINNT=%s' % env['target_win_version']])
-        env.Append(LIBS=['mingw32', 'opengl32', 'dsound', 'ole32', 'd3d9', 'winmm', 'gdi32', 'iphlpapi', 'shlwapi', 'wsock32', 'ws2_32', 'kernel32', 'oleaut32', 'dinput8', 'dxguid', 'ksuser', 'imm32', 'bcrypt'])
+    print("Configuring for Windows: target=%s, bits=%s" % (env['target'], env['bits']))
+
+    env['ENV'] = os.environ # this makes build less repeatable, but simplifies some things
+    env['ENV']['TMP'] = os.environ['TMP']
+
+    # First figure out which compiler, version, and target arch we're using
+    if os.getenv("VCINSTALLDIR"):
+        # Manual setup of MSVC
+        setup_msvc_manual(env)
+        env.msvc = True
+        manual_msvc_config = True
+    elif env.get('MSVC_VERSION', ''):
+        setup_msvc_auto(env)
+        env.msvc = True
+        manual_msvc_config = False
+    else:
+        setup_mingw(env)
+        env.msvc = False
 
-        env.Append(CPPFLAGS=['-DMINGW_ENABLED'])
+    # Now set compiler/linker flags
+    if env.msvc:
+        configure_msvc(env, manual_msvc_config)
 
-        # resrc
-        env.Append(BUILDERS={'RES': env.Builder(action=build_res_file, suffix='.o', src_suffix='.rc')})
+    else: # MinGW
+        configure_mingw(env)