From 7441e039d0a6c0b4faa8ba1ab586219f232ba75a Mon Sep 17 00:00:00 2001
From: Yuta Saito <kateinoigakukun@gmail.com>
Date: Thu, 29 Feb 2024 13:37:08 +0000
Subject: [PATCH] wasm: Add "_multithreaded" as valid `_runtime` argument

This patch adds "_multithreaded" as a valid `_runtime` argument and
sets it when the target is `wasm32-unknown-wasi-threads` or other
non-none OS targets.
---
 lib/Basic/LangOptions.cpp                        | 16 ++++++++++++++++
 .../ConditionalCompilation/noneOSTarget.swift    |  8 ++++++++
 .../ConditionalCompilation/wasm32Target.swift    |  4 ++++
 .../wasm32ThreadsTarget.swift                    |  8 ++++++++
 4 files changed, 36 insertions(+)
 create mode 100644 test/Parse/ConditionalCompilation/noneOSTarget.swift
 create mode 100644 test/Parse/ConditionalCompilation/wasm32ThreadsTarget.swift

diff --git a/lib/Basic/LangOptions.cpp b/lib/Basic/LangOptions.cpp
index 13441dc76ae50..53a0e327dcd5b 100644
--- a/lib/Basic/LangOptions.cpp
+++ b/lib/Basic/LangOptions.cpp
@@ -111,6 +111,7 @@ static const SupportedConditionalValue SupportedConditionalCompilationPointerBit
 static const SupportedConditionalValue SupportedConditionalCompilationRuntimes[] = {
   "_ObjC",
   "_Native",
+  "_multithreaded",
 };
 
 static const SupportedConditionalValue SupportedConditionalCompilationTargetEnvironments[] = {
@@ -400,6 +401,16 @@ void LangOptions::setHasAtomicBitWidth(llvm::Triple triple) {
   }
 }
 
+static bool isMultiThreadedRuntime(llvm::Triple triple) {
+  if (triple.getOS() == llvm::Triple::WASI) {
+    return triple.getEnvironmentName() == "threads";
+  }
+  if (triple.getOSName() == "none") {
+    return false;
+  }
+  return true;
+}
+
 std::pair<bool, bool> LangOptions::setTarget(llvm::Triple triple) {
   clearAllPlatformConditionValues();
   clearAtomicBitWidths();
@@ -572,6 +583,11 @@ std::pair<bool, bool> LangOptions::setTarget(llvm::Triple triple) {
     addPlatformConditionValue(PlatformConditionKind::TargetEnvironment,
                               "macabi");
 
+  if (isMultiThreadedRuntime(Target)) {
+    addPlatformConditionValue(PlatformConditionKind::Runtime,
+                              "_multithreaded");
+  }
+
   // Set the "_hasHasAtomicBitWidth" platform condition.
   setHasAtomicBitWidth(triple);
 
diff --git a/test/Parse/ConditionalCompilation/noneOSTarget.swift b/test/Parse/ConditionalCompilation/noneOSTarget.swift
new file mode 100644
index 0000000000000..c17cfe8b3feb6
--- /dev/null
+++ b/test/Parse/ConditionalCompilation/noneOSTarget.swift
@@ -0,0 +1,8 @@
+// RUN: %swift -typecheck %s -verify -target arm64-apple-none-macho -parse-stdlib
+// RUN: %swift-ide-test -test-input-complete -source-filename=%s -target arm64-apple-none-macho
+
+#if !_runtime(_multithreaded)
+  func underNoThreads() {
+    foo() // expected-error {{cannot find 'foo' in scope}}
+  }
+#endif
diff --git a/test/Parse/ConditionalCompilation/wasm32Target.swift b/test/Parse/ConditionalCompilation/wasm32Target.swift
index 8ca38d67f14ae..4ff8f5d9a2884 100644
--- a/test/Parse/ConditionalCompilation/wasm32Target.swift
+++ b/test/Parse/ConditionalCompilation/wasm32Target.swift
@@ -8,3 +8,7 @@ var x = C()
 #endif
 #endif
 var y = x
+
+#if !_runtime(_multithreaded)
+  let z = xx // expected-error {{cannot find 'xx' in scope}}
+#endif
diff --git a/test/Parse/ConditionalCompilation/wasm32ThreadsTarget.swift b/test/Parse/ConditionalCompilation/wasm32ThreadsTarget.swift
new file mode 100644
index 0000000000000..a61b548facb2a
--- /dev/null
+++ b/test/Parse/ConditionalCompilation/wasm32ThreadsTarget.swift
@@ -0,0 +1,8 @@
+// RUN: %swift -typecheck %s -verify -target wasm32-unknown-wasip1-threads -parse-stdlib
+// RUN: %swift-ide-test -test-input-complete -source-filename=%s -target wasm32-unknown-wasip1-threads
+
+#if _runtime(_multithreaded)
+  func underThreads() {
+    foo() // expected-error {{cannot find 'foo' in scope}}
+  }
+#endif