From 5ec54ab00e4c14e1fd9df6b2e140e45bde0acdd5 Mon Sep 17 00:00:00 2001
From: Ankit Aggarwal <ankit.spd@gmail.com>
Date: Sat, 21 May 2016 02:55:00 +0530
Subject: [PATCH] Add C++ support in ClangModule

---
 .../Build/Command.compile(ClangModule).swift  |  6 +++-
 Sources/Build/misc.swift                      | 36 +++++++++++++++++++
 Sources/PackageModel/Sources.swift            |  2 +-
 3 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/Sources/Build/Command.compile(ClangModule).swift b/Sources/Build/Command.compile(ClangModule).swift
index 5713f105efb..83efc7c9574 100644
--- a/Sources/Build/Command.compile(ClangModule).swift
+++ b/Sources/Build/Command.compile(ClangModule).swift
@@ -86,7 +86,10 @@ extension Command {
             var args = basicArgs
             args += ["-MD", "-MT", "dependencies", "-MF", path.deps]
             args += ["-c", path.source, "-o", path.object]
-
+            // Append -std flag if file is cpp.
+            if path.source.isCpp {
+               args += ["-std=c++14"]
+            }
             let clang = ClangTool(desc: "Compile \(module.name) \(path.filename)",
                                   inputs: dependencies + [path.source],
                                   outputs: [path.object],
@@ -105,6 +108,7 @@ extension Command {
         var args = module.basicArgs
         args += module.optimizationFlags(conf)
         args += ["-L\(prefix)"]
+        args += module.languageArgs
         args += module.linkFlags
         args += module.sources.compilePathsForBuildDir(wd).map{$0.object}
         args += Xld
diff --git a/Sources/Build/misc.swift b/Sources/Build/misc.swift
index 35d95ec0cd0..4c47738869b 100644
--- a/Sources/Build/misc.swift
+++ b/Sources/Build/misc.swift
@@ -43,6 +43,42 @@ extension CModule {
     }
 }
 
+extension String {
+    var isCpp: Bool {
+        guard let ext = self.fileExt else {
+            return false
+        }
+        return ext == "cpp"
+    }
+}
+
+extension ClangModule {
+    // Returns language specific arguments for a ClangModule.
+    var languageArgs: [String] {
+        var args = [String]() 
+        // Check if this module contains any cpp file.
+        var linkCpp = self.containsCppFiles
+        // Otherwise check if any of its dependencies contains a cpp file.
+        if !linkCpp {
+            for case let dep as ClangModule in recursiveDependencies {
+                if dep.containsCppFiles {
+                    linkCpp = true
+                    break
+                }
+            }
+        }
+        // Link C++ if found any cpp source. 
+        if linkCpp {
+            args += ["-lc++"]
+        }
+        return args
+    }
+
+    var containsCppFiles: Bool {
+        return sources.paths.contains { $0.isCpp } 
+    }
+}
+
 extension ClangModule {
     
     public enum ModuleMapError: ErrorProtocol {
diff --git a/Sources/PackageModel/Sources.swift b/Sources/PackageModel/Sources.swift
index 2b8e0d2a349..6d093031343 100644
--- a/Sources/PackageModel/Sources.swift
+++ b/Sources/PackageModel/Sources.swift
@@ -29,7 +29,7 @@ public struct Sources {
     
     static public var validSwiftExtensions = Set<String>(["swift"])
     
-    static public var validCExtensions = Set<String>(["c", "m"])
+    static public var validCExtensions = Set<String>(["c", "m", "cc", "cpp", "cxx"])
     
     static public var validExtensions = { validSwiftExtensions.union(validCExtensions) }()
 }