Driver/Frontend: Add -emit-codegen-only, for running irgen + codegen but not the

.s printer or .o writer.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@104623 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Driver/CC1Options.td

@@ -314,6 +314,8 @@ def emit_llvm_bc : Flag<"-emit-llvm-bc">,
   HelpText<"Build ASTs then convert to LLVM, emit .bc file">;
 def emit_llvm_only : Flag<"-emit-llvm-only">,
   HelpText<"Build ASTs and convert to LLVM, discarding output">;
+def emit_codegen_only : Flag<"-emit-codegen-only">,
+  HelpText<"Generate machine code, but discard output">;
 def emit_obj : Flag<"-emit-obj">,
   HelpText<"Emit native object files">;
 def rewrite_test : Flag<"-rewrite-test">,

include/clang/Frontend/CodeGenAction.h

@@ -57,6 +57,11 @@ public:
   EmitLLVMOnlyAction();
 };
 
+class EmitCodeGenOnlyAction : public CodeGenAction {
+public:
+  EmitCodeGenOnlyAction();
+};
+
 class EmitObjAction : public CodeGenAction {
 public:
   EmitObjAction();

include/clang/Frontend/FrontendOptions.h

@@ -30,7 +30,8 @@ namespace frontend {
     EmitBC,                 ///< Emit a .bc file.
     EmitHTML,               ///< Translate input source into HTML.
     EmitLLVM,               ///< Emit a .ll file.
-    EmitLLVMOnly,           ///< Generate LLVM IR, but do not
+    EmitLLVMOnly,           ///< Generate LLVM IR, but do not emit anything.
+    EmitCodeGenOnly,        ///< Generate machine code, but don't emit anything.
     EmitObj,                ///< Emit a .o file.
     FixIt,                  ///< Parse and apply any fixits to the source.
     GeneratePCH,            ///< Generate pre-compiled header.

lib/Frontend/CodeGenAction.cpp

@@ -48,6 +48,7 @@ namespace {
     Backend_EmitBC,        ///< Emit LLVM bitcode files
     Backend_EmitLL,        ///< Emit human-readable LLVM assembly
     Backend_EmitNothing,   ///< Don't emit anything (benchmarking mode)
+    Backend_EmitMCNull,    ///< Run CodeGen, but don't emit anything
     Backend_EmitObj        ///< Emit native object files
   };
 
@@ -340,6 +341,10 @@ bool BackendConsumer::AddEmitPasses() {
   TargetMachine::CodeGenFileType CGFT = TargetMachine::CGFT_AssemblyFile;
   if (Action == Backend_EmitObj)
     CGFT = TargetMachine::CGFT_ObjectFile;
+  else if (Action == Backend_EmitMCNull)
+    CGFT = TargetMachine::CGFT_Null;
+  else
+    assert(Action == Backend_EmitAssembly && "Invalid action!");
   if (TM->addPassesToEmitFile(*PM, FormattedOutStream, CGFT, OptLevel,
                               /*DisableVerify=*/!CodeGenOpts.VerifyModule)) {
     Diags.Report(diag::err_fe_unable_to_interface_with_target);
@@ -557,6 +562,7 @@ ASTConsumer *CodeGenAction::CreateASTConsumer(CompilerInstance &CI,
     break;
   case Backend_EmitNothing:
     break;
+  case Backend_EmitMCNull:
   case Backend_EmitObj:
     OS.reset(CI.createDefaultOutputFile(true, InFile, "o"));
     break;
@@ -579,4 +585,6 @@ EmitLLVMAction::EmitLLVMAction() : CodeGenAction(Backend_EmitLL) {}
 
 EmitLLVMOnlyAction::EmitLLVMOnlyAction() : CodeGenAction(Backend_EmitNothing) {}
 
+EmitCodeGenOnlyAction::EmitCodeGenOnlyAction() : CodeGenAction(Backend_EmitMCNull) {}
+
 EmitObjAction::EmitObjAction() : CodeGenAction(Backend_EmitObj) {}

lib/Frontend/CompilerInvocation.cpp

@@ -316,6 +316,7 @@ static const char *getActionName(frontend::ActionKind Kind) {
   case frontend::EmitHTML:               return "-emit-html";
   case frontend::EmitLLVM:               return "-emit-llvm";
   case frontend::EmitLLVMOnly:           return "-emit-llvm-only";
+  case frontend::EmitCodeGenOnly:        return "-emit-codegen-only";
   case frontend::EmitObj:                return "-emit-obj";
   case frontend::FixIt:                  return "-fixit";
   case frontend::GeneratePCH:            return "-emit-pch";
@@ -927,6 +928,8 @@ ParseFrontendArgs(FrontendOptions &Opts, ArgList &Args, Diagnostic &Diags) {
       Opts.ProgramAction = frontend::EmitLLVM; break;
     case OPT_emit_llvm_only:
       Opts.ProgramAction = frontend::EmitLLVMOnly; break;
+    case OPT_emit_codegen_only:
+      Opts.ProgramAction = frontend::EmitCodeGenOnly; break;
     case OPT_emit_obj:
       Opts.ProgramAction = frontend::EmitObj; break;
     case OPT_fixit_EQ:

tools/driver/cc1_main.cpp

@@ -71,6 +71,7 @@ static FrontendAction *CreateFrontendBaseAction(CompilerInstance &CI) {
   case EmitHTML:               return new HTMLPrintAction();
   case EmitLLVM:               return new EmitLLVMAction();
   case EmitLLVMOnly:           return new EmitLLVMOnlyAction();
+  case EmitCodeGenOnly:        return new EmitCodeGenOnlyAction();
   case EmitObj:                return new EmitObjAction();
   case FixIt:                  return new FixItAction();
   case GeneratePCH:            return new GeneratePCHAction();