[SCons] Move toolchains logic to tools folder.

tools/ios.py

@@ -0,0 +1,74 @@
+import os
+import sys
+import subprocess
+from SCons.Variables import *
+
+if sys.version_info < (3,):
+
+    def decode_utf8(x):
+        return x
+
+else:
+    import codecs
+
+    def decode_utf8(x):
+        return codecs.utf_8_decode(x)[0]
+
+
+def options(opts):
+    opts.Add(BoolVariable("ios_simulator", "Target iOS Simulator", False))
+    opts.Add(
+        "IPHONEPATH",
+        "Path to iPhone toolchain",
+        "/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain",
+    )
+
+
+def exists(env):
+    return sys.platform == "darwin"
+
+
+def generate(env):
+    if env["arch"] not in ("universal", "arm64", "x86_64"):
+        print("Only universal, arm64, and x86_64 are supported on iOS. Exiting.")
+        Exit()
+
+    if env["ios_simulator"]:
+        sdk_name = "iphonesimulator"
+        env.Append(CCFLAGS=["-mios-simulator-version-min=10.0"])
+    else:
+        sdk_name = "iphoneos"
+        env.Append(CCFLAGS=["-miphoneos-version-min=10.0"])
+
+    try:
+        sdk_path = decode_utf8(subprocess.check_output(["xcrun", "--sdk", sdk_name, "--show-sdk-path"]).strip())
+    except (subprocess.CalledProcessError, OSError):
+        raise ValueError("Failed to find SDK path while running xcrun --sdk {} --show-sdk-path.".format(sdk_name))
+
+    compiler_path = env["IPHONEPATH"] + "/usr/bin/"
+    env["ENV"]["PATH"] = env["IPHONEPATH"] + "/Developer/usr/bin/:" + env["ENV"]["PATH"]
+
+    env["CC"] = compiler_path + "clang"
+    env["CXX"] = compiler_path + "clang++"
+    env["AR"] = compiler_path + "ar"
+    env["RANLIB"] = compiler_path + "ranlib"
+    env["SHLIBSUFFIX"] = ".dylib"
+
+    if env["arch"] == "universal":
+        if env["ios_simulator"]:
+            env.Append(LINKFLAGS=["-arch", "x86_64", "-arch", "arm64"])
+            env.Append(CCFLAGS=["-arch", "x86_64", "-arch", "arm64"])
+        else:
+            env.Append(LINKFLAGS=["-arch", "arm64"])
+            env.Append(CCFLAGS=["-arch", "arm64"])
+    else:
+        env.Append(LINKFLAGS=["-arch", env["arch"]])
+        env.Append(CCFLAGS=["-arch", env["arch"]])
+
+    env.Append(CCFLAGS=["-isysroot", sdk_path])
+    env.Append(LINKFLAGS=["-isysroot", sdk_path, "-F" + sdk_path])
+
+    if env["target"] == "debug":
+        env.Append(CCFLAGS=["-Og", "-g"])
+    elif env["target"] == "release":
+        env.Append(CCFLAGS=["-O3"])