Consolidate code that computes resource dir relative to swift executable.

Author: allevato

include/swift/Frontend/Frontend.h

@@ -202,6 +202,12 @@ class CompilerInvocation {
 
   void setRuntimeResourcePath(StringRef Path);
 
+  /// Computes the runtime resource path relative to the given Swift
+  /// executable.
+  static void computeRuntimeResourcePathFromExecutablePath(
+      StringRef mainExecutablePath,
+      llvm::SmallString<128> &runtimeResourcePath);
+
   void setSDKPath(const std::string &Path);
 
   StringRef getSDKPath() const {

lib/Frontend/CompilerInvocation.cpp

@@ -38,11 +38,17 @@ swift::CompilerInvocation::CompilerInvocation() {
   setTargetTriple(llvm::sys::getDefaultTargetTriple());
 }
 
+void CompilerInvocation::computeRuntimeResourcePathFromExecutablePath(
+    StringRef mainExecutablePath, llvm::SmallString<128> &runtimeResourcePath) {
+  runtimeResourcePath.assign(mainExecutablePath);
+  llvm::sys::path::remove_filename(runtimeResourcePath); // Remove /swift
+  llvm::sys::path::remove_filename(runtimeResourcePath); // Remove /bin
+  llvm::sys::path::append(runtimeResourcePath, "lib", "swift");
+}
+
 void CompilerInvocation::setMainExecutablePath(StringRef Path) {
-  llvm::SmallString<128> LibPath(Path);
-  llvm::sys::path::remove_filename(LibPath); // Remove /swift
-  llvm::sys::path::remove_filename(LibPath); // Remove /bin
-  llvm::sys::path::append(LibPath, "lib", "swift");
+  llvm::SmallString<128> LibPath;
+  computeRuntimeResourcePathFromExecutablePath(Path, LibPath);
   setRuntimeResourcePath(LibPath.str());
 
   llvm::SmallString<128> DiagnosticDocsPath(Path);

tools/driver/modulewrap_main.cpp

@@ -156,13 +156,9 @@ int modulewrap_main(ArrayRef<const char *> Args, const char *Argv0,
   // Wrap the bitstream in a module object file. To use the ClangImporter to
   // create the module loader, we need to properly set the runtime library path.
   SearchPathOptions SearchPathOpts;
-  // FIXME: This logic has been duplicated from
-  //        CompilerInvocation::setMainExecutablePath. ModuleWrapInvocation
-  //        should share its implementation.
-  SmallString<128> RuntimeResourcePath(MainExecutablePath);
-  llvm::sys::path::remove_filename(RuntimeResourcePath); // Remove /swift
-  llvm::sys::path::remove_filename(RuntimeResourcePath); // Remove /bin
-  llvm::sys::path::append(RuntimeResourcePath, "lib", "swift");
+  SmallString<128> RuntimeResourcePath;
+  CompilerInvocation::computeRuntimeResourcePathFromExecutablePath(
+    MainExecutablePath, RuntimeResourcePath);
   SearchPathOpts.RuntimeResourcePath = RuntimeResourcePath.str();
 
   SourceManager SrcMgr;