Refactored Package LLVM config

Author: mrLSD

.github/workflows/swift.yaml

@@ -18,7 +18,7 @@ jobs:
     - name: Pre-install
       run: |
         brew update
-        brew install llvm@18
+        brew install llvm@18.1.8
         # Important: add empty string
         echo "" >> /Users/runner/.bash_profile
         echo 'export PATH="/opt/homebrew/opt/llvm/bin:$PATH"' >> /Users/runner/.bash_profile
@@ -27,7 +27,7 @@ jobs:
         source /Users/runner/.bash_profile
         clang --version
         swift --version
-        swift utils/make-pkg-config.swift
+#        swift utils/make-pkg-config.swift
 
     - name: Build
       run: swift build -v

Package.swift

@@ -2,6 +2,9 @@
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription
+import Foundation
+
+let (cFlags, linkFlags) = try! getLLVMConfig()
 
 let package = Package(
     name: "llvm-api",
@@ -11,17 +14,76 @@ let package = Package(
     targets: [
         .systemLibrary(
             name: "CLLVM",
-            path: "llvm-api/CLLVM",
-            pkgConfig: "CLLVM",
-            providers: [
-                .brew(["llvm"]),
-            ]
+            path: "llvm-api/CLLVM"
         ),
         .target(
             name: "LLVM",
             dependencies: ["CLLVM"],
-            path: "llvm-api/LLVM"
+            path: "llvm-api/LLVM",
+            cSettings: [
+                .unsafeFlags(cFlags)
+            ],
+            linkerSettings: [
+                .unsafeFlags(linkFlags)
+            ]
         ),
-    ],
-    cxxLanguageStandard: .cxx20
+    ]
 )
+
+/// Get LLVM config flags
+func getLLVMConfig() throws -> ([String], [String]) {
+    let brewPrefix = {
+        guard let brew = which("brew") else { return nil }
+        return run(brew, args: ["--prefix"])
+    }() ?? "/usr/local"
+    /// Ensure we have llvm-config in the PATH
+    guard let llvmConfig = which("llvm-config") ?? which("\(brewPrefix)/opt/llvm/bin/llvm-config") else {
+        throw "Failed to find llvm-config. Ensure llvm-config is installed and in your PATH"
+    }
+    // Get linkage (LD) flags
+    let ldFlags = run(llvmConfig, args: ["--ldflags", "--libs", "all", "--system-libs"])!
+        .replacing(charactersIn: .newlines, with: " ")
+        .components(separatedBy: " ")
+        .filter { !$0.hasPrefix("-W") }
+    // Get C flags
+    let cFlags = run(llvmConfig, args: ["--cflags"])!
+        .replacing(charactersIn: .newlines, with: "")
+        .components(separatedBy: " ")
+        .filter { $0.hasPrefix("-I") }
+    return (cFlags, ldFlags)
+}
+
+/// Runs the specified program at the provided path.
+/// - parameter path: The full path of the executable you wish to run.
+/// - parameter args: The arguments you wish to pass to the process.
+/// - returns: The standard output of the process, or nil if it was empty.
+func run(_ path: String, args: [String] = []) -> String? {
+    let pipe = Pipe()
+    let process = Process()
+    process.executableURL = URL(fileURLWithPath: path)
+    process.arguments = args
+    process.standardOutput = pipe
+    try? process.run()
+    process.waitUntilExit()
+
+    let data = pipe.fileHandleForReading.readDataToEndOfFile()
+    guard let result = String(data: data, encoding: .utf8)?
+        .trimmingCharacters(in: .whitespacesAndNewlines),
+        !result.isEmpty else { return nil }
+    return result
+}
+
+/// Finds the location of the provided binary on your system.
+func which(_ name: String) -> String? {
+    run("/usr/bin/which", args: [name])
+}
+
+extension String: Error {
+    /// Replaces all occurrences of characters in the provided set with the provided string.
+    func replacing(charactersIn characterSet: CharacterSet,
+                   with separator: String) -> String
+    {
+        let components = components(separatedBy: characterSet)
+        return components.joined(separator: separator)
+    }
+}

utils/make-pkg-config.swift

@@ -10,7 +10,7 @@ let libCPP = "-lc++"
 ///                   process.
 /// - returns: The standard output of the process, or nil if it was empty.
 func run(_ path: String, args: [String] = []) -> String? {
-    print("Running \(path) \(args.joined(separator: " "))...")
+    print("Run: \(path) \(args.joined(separator: " "))")
     let pipe = Pipe()
     let process = Process()
     process.executableURL = URL(fileURLWithPath: path)
@@ -60,7 +60,7 @@ func makeFile() throws {
     let brewLLVMConfig = { which("\(brewPrefix)/opt/llvm/bin/llvm-config") }
 
     /// Ensure we have llvm-config in the PATH
-    guard let llvmConfig = which("llvm-config-15") ?? which("llvm-config") ?? brewLLVMConfig() else {
+    guard let llvmConfig = which("llvm-config") ?? brewLLVMConfig() else {
         throw "Failed to find llvm-config. Ensure llvm-config is installed and " +
             "in your PATH"
     }
@@ -79,12 +79,6 @@ func makeFile() throws {
         throw "Invalid version number \(versionStr)"
     }
 
-    let version = (components[0], components[1], components[2])
-
-    guard version >= (11, 0, 0) else {
-        throw "LLVMSwift requires LLVM version >=15.0.0, but you have \(versionStr)"
-    }
-
     print("LLVM version is \(versionStr)")
 
     let ldFlags = run(llvmConfig, args: ["--ldflags", "--libs", "all",