[SCons] Move toolchains logic to tools folder.

tools/windows.py

@@ -0,0 +1,68 @@
+import sys
+
+import my_spawn
+from SCons.Tool.MSCommon import msvc_exists
+from SCons.Variables import *
+
+
+def options(opts):
+    opts.Add(BoolVariable("use_mingw", "Use the MinGW compiler instead of MSVC - only effective on Windows", False))
+
+
+def exists(env):
+    return True
+
+
+def generate(env):
+    base = None
+    if not env["use_mingw"] and msvc_exists(env):
+        base = env.Tool("msvc")
+        env["is_msvc"] = True
+        if env["arch"] == "x86_64":
+            env["TARGET_ARCH"] = "amd64"
+        elif env["arch"] == "x86_32":
+            env["TARGET_ARCH"] = "x86"
+        base.generate(env)
+        env.Append(CPPDEFINES=["TYPED_METHOD_BIND"])
+        env.Append(LINKFLAGS=["/WX"])
+        if env["target"] == "debug":
+            env.Append(CCFLAGS=["/Z7", "/Od", "/EHsc", "/D_DEBUG", "/MDd"])
+        elif env["target"] == "release":
+            env.Append(CCFLAGS=["/O2", "/EHsc", "/DNDEBUG", "/MD"])
+
+    elif sys.platform == "win32" or sys.platform == "msys":
+        env["use_mingw"] = True
+        base = env.Tool("mingw")
+        base.generate(env)
+        # Still need to use C++17.
+        env.Append(CCFLAGS=["-std=c++17"])
+        # Don't want lib prefixes
+        env["IMPLIBPREFIX"] = ""
+        env["SHLIBPREFIX"] = ""
+        # Want dll suffix
+        env["SHLIBSUFFIX"] = ".dll"
+        # Long line hack. Use custom spawn, quick AR append (to avoid files with the same names to override each other).
+        my_spawn.configure(env)
+
+    else:
+        env["use_mingw"] = True
+        # Cross-compilation using MinGW
+        prefix = "i686" if env["arch"] == "x86_32" else env["arch"]
+        env["CXX"] = prefix + "-w64-mingw32-g++"
+        env["CC"] = prefix + "-w64-mingw32-gcc"
+        env["AR"] = prefix + "-w64-mingw32-ar"
+        env["RANLIB"] = prefix + "-w64-mingw32-ranlib"
+        env["LINK"] = prefix + "-w64-mingw32-g++"
+        # Want dll suffix
+        env["SHLIBSUFFIX"] = ".dll"
+
+        # These options are for a release build even using target=debug
+        env.Append(CCFLAGS=["-O3", "-Wwrite-strings"])
+        env.Append(
+            LINKFLAGS=[
+                "--static",
+                "-Wl,--no-undefined",
+                "-static-libgcc",
+                "-static-libstdc++",
+            ]
+        )