Add compiler and linker options for wasm32-wasip1-threads

Author: kateinoigakukun

Sources/SwiftSDKGenerator/Generator/SwiftSDKGenerator+Metadata.swift

@@ -37,7 +37,7 @@ extension SwiftSDKGenerator {
     }
 
     var toolset = Toolset(rootPath: relativeToolchainBinDir.string)
-    recipe.applyPlatformOptions(toolset: &toolset)
+    recipe.applyPlatformOptions(toolset: &toolset, targetTriple: self.targetTriple)
     try writeFile(at: toolsetJSONPath, encoder.encode(toolset))
 
     return toolsetJSONPath

Sources/SwiftSDKGenerator/SwiftSDKRecipes/LinuxRecipe.swift

@@ -104,7 +104,7 @@ public struct LinuxRecipe: SwiftSDKRecipe {
     self.versionsConfiguration = versionsConfiguration
   }
 
-  public func applyPlatformOptions(toolset: inout Toolset) {
+  public func applyPlatformOptions(toolset: inout Toolset, targetTriple: Triple) {
     toolset.swiftCompiler = Toolset.ToolProperties(extraCLIOptions: ["-use-ld=lld", "-Xlinker", "-R/usr/lib/swift/linux/"])
     toolset.cxxCompiler = Toolset.ToolProperties(extraCLIOptions: ["-lstdc++"])
     toolset.linker = Toolset.ToolProperties(path: "ld.lld")

Sources/SwiftSDKGenerator/SwiftSDKRecipes/SwiftSDKRecipe.swift

@@ -22,7 +22,9 @@ public struct SwiftSDKProduct {
 /// A protocol describing a set of platform specific instructions to make a Swift SDK
 public protocol SwiftSDKRecipe: Sendable {
   /// Update the given toolset with platform specific options
-  func applyPlatformOptions(toolset: inout Toolset)
+  func applyPlatformOptions(
+    toolset: inout Toolset, targetTriple: Triple
+  )
   func applyPlatformOptions(
     metadata: inout SwiftSDKMetadataV4.TripleProperties,
     paths: PathsConfiguration,
@@ -37,7 +39,7 @@ public protocol SwiftSDKRecipe: Sendable {
 }
 
 extension SwiftSDKRecipe {
-  public func applyPlatformOptions(toolset: inout Toolset) {}
+  public func applyPlatformOptions(toolset: inout Toolset, targetTriple: Triple) {}
   public func applyPlatformOptions(
     metadata: inout SwiftSDKMetadataV4.TripleProperties,
     paths: PathsConfiguration,

Sources/SwiftSDKGenerator/SwiftSDKRecipes/WebAssemblyRecipe.swift

@@ -45,9 +45,34 @@ public struct WebAssemblyRecipe: SwiftSDKRecipe {
     "\(self.swiftVersion)_wasm"
   }
 
-  public func applyPlatformOptions(toolset: inout Toolset) {
+  public func applyPlatformOptions(toolset: inout Toolset, targetTriple: Triple) {
     // We only support static linking for WebAssembly for now, so make it the default.
     toolset.swiftCompiler = Toolset.ToolProperties(extraCLIOptions: ["-static-stdlib"])
+    if targetTriple.environmentName == "threads" {
+      // Enable features required for threading support
+      let ccOptions = [
+        "-matomics", "-mbulk-memory", "-mthread-model", "posix",
+        "-pthread", "-ftls-model=local-exec"
+      ]
+      // Tell LLVM codegen in swiftc to enable those features via clang options
+      toolset.swiftCompiler?.extraCLIOptions?.append(contentsOf: ccOptions.flatMap {
+        ["-Xcc", $0]
+      })
+      // Tell the C and C++ compilers to enable those features
+      toolset.cCompiler = Toolset.ToolProperties(extraCLIOptions: ccOptions)
+      toolset.cxxCompiler = Toolset.ToolProperties(extraCLIOptions: ccOptions)
+
+      let linkerOptions = [
+        // Shared memory is required for WASI threads ABI
+        // See https://github.com/WebAssembly/wasi-threads for more information.
+        "--import-memory", "--export-memory", "--shared-memory",
+        // Set the maximum memory size to 1GB because shared memory must specify
+        // a maximum size. 1GB is chosen as a conservative default, but it can be
+        // overridden by the user-provided --max-memory linker option.
+        "--max-memory=1073741824",
+      ]
+      toolset.linker = Toolset.ToolProperties(extraCLIOptions: linkerOptions)
+    }
   }
 
   public func applyPlatformOptions(