[wasm][build] HACK: Add SwiftWasm compiler vendor support

This patch should not be upstreamed. Maybe we can use
`--compiler-vendor=none` to avoid hardcoding specific downstream names.

Author: kateinoigakukun

utils/build_swift/build_swift/driver_arguments.py

@@ -459,7 +459,7 @@ def create_argument_parser():
            help='if set, provide a fixed path for the Swift backtracer')
 
     option('--compiler-vendor', store,
-           choices=['none', 'apple'],
+           choices=['none', 'apple', 'swiftwasm'],
            default=defaults.COMPILER_VENDOR,
            help='Compiler vendor name')
     option('--clang-compiler-version', store,

utils/swift_build_support/swift_build_support/products/llvm.py

@@ -64,6 +64,13 @@ def _compiler_vendor_flags(self):
         if self.args.compiler_vendor == "none":
             return []
 
+        if self.args.compiler_vendor == "swiftwasm":
+            return [
+                ('CLANG_VENDOR', 'SwiftWasm'),
+                ('CLANG_VENDOR_UTI', 'org.swiftwasm.compilers.llvm.clang'),
+                ('PACKAGE_VERSION', str(self.args.clang_user_visible_version))
+            ]
+
         if self.args.compiler_vendor != "apple":
             raise RuntimeError("Unknown compiler vendor?!")
 

utils/swift_build_support/swift_build_support/products/swift.py

@@ -104,14 +104,22 @@ def _compiler_vendor_flags(self):
         if self.args.compiler_vendor == "none":
             return []
 
-        if self.args.compiler_vendor != "apple":
-            raise RuntimeError("Unknown compiler vendor?! Was build-script \
-updated without updating swift.py?")
-
         swift_compiler_version = ""
         if self.args.swift_compiler_version is not None:
             swift_compiler_version = self.args.swift_compiler_version
 
+        if self.args.compiler_vendor == "swiftwasm":
+            return [
+                ('SWIFT_VENDOR', 'SwiftWasm'),
+                ('SWIFT_VENDOR_UTI', 'org.swiftwasm.compilers.llvm.swift'),
+                ('SWIFT_VERSION', str(self.args.swift_user_visible_version)),
+                ('SWIFT_COMPILER_VERSION', str(swift_compiler_version)),
+            ]
+
+        if self.args.compiler_vendor != "apple":
+            raise RuntimeError("Unknown compiler vendor?! Was build-script \
+updated without updating swift.py?")
+
         return [
             ('SWIFT_VENDOR', 'Apple'),
             ('SWIFT_VENDOR_UTI', 'com.apple.compilers.llvm.swift'),