Clang now attempts to create a TargetMachine whenever a triple is given.

Many of our tests specify triples that are not built into clang.
In this commit we allow clang to fail loading the triple if we are only
using clang to emit llvm ir.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@166543 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/BackendUtil.cpp

@@ -100,9 +100,15 @@ private:
 
   void CreatePasses(TargetMachine *TM);
 
-  /// CreateTargetMachine - Generates the TargetMachine. Returns Null
-  /// if it is unable to create the target machine.
-  TargetMachine *CreateTargetMachine();
+  /// CreateTargetMachine - Generates the TargetMachine.
+  /// Returns Null if it is unable to create the target machine.
+  /// Some of our clang tests specify triples which are not built
+  /// into clang. This is okay because these tests check the generated
+  /// IR, and they require DataLayout which depends on the triple.
+  /// In this case, we allow this method to fail and not report an error.
+  /// When MustCreateTM is used, we print an error if we are unable to load
+  /// the requested target.
+  TargetMachine *CreateTargetMachine(bool MustCreateTM);
 
   /// AddEmitPasses - Add passes necessary to emit assembly or LLVM IR.
   ///
@@ -261,16 +267,16 @@ void EmitAssemblyHelper::CreatePasses(TargetMachine *TM) {
       MPM->add(createStripSymbolsPass(true));
   }
 
-  
   PMBuilder.populateModulePassManager(*MPM);
 }
 
-TargetMachine *EmitAssemblyHelper::CreateTargetMachine() {
+TargetMachine *EmitAssemblyHelper::CreateTargetMachine(bool MustCreateTM) {
   // Create the TargetMachine for generating code.
   std::string Error;
   std::string Triple = TheModule->getTargetTriple();
   const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error);
   if (!TheTarget) {
+    if (MustCreateTM)
       Diags.Report(diag::err_fe_unable_to_create_target) << Error;
     return 0;
   }
@@ -466,7 +472,10 @@ void EmitAssemblyHelper::EmitAssembly(BackendAction Action, raw_ostream *OS) {
   TimeRegion Region(llvm::TimePassesIsEnabled ? &CodeGenerationTime : 0);
   llvm::formatted_raw_ostream FormattedOS;
 
-  TargetMachine *TM = CreateTargetMachine();
+  bool UsesCodeGen = (Action != Backend_EmitNothing &&
+                      Action != Backend_EmitBC &&
+                      Action != Backend_EmitLL);
+  TargetMachine *TM = CreateTargetMachine(UsesCodeGen);
   CreatePasses(TM);
 
   switch (Action) {