Use -emit-mlir=[core|cir] command-line options

Author: andykaylor

clang/include/clang/Driver/Options.td

@@ -2987,8 +2987,13 @@ defm clangir : BoolFOption<"clangir",
   BothFlags<[], [ClangOption, CC1Option], "">>;
 def emit_cir : Flag<["-"], "emit-cir">, Visibility<[ClangOption, CC1Option]>,
   Group<Action_Group>, HelpText<"Build ASTs and then lower to ClangIR">;
-def emit_core_mlir : Flag<["-"], "emit-core-mlir">, Visibility<[CC1Option]>, Group<Action_Group>,
-  HelpText<"Build ASTs and then lower through ClangIR to core MLIR dialects, emit the .milr file">;
+def emit_mlir_EQ : Joined<["-"], "emit-mlir=">, Visibility<[CC1Option]>, Group<Action_Group>,
+  HelpText<"Build ASTs and then generate/lower to the selected MLIR dialect, emit the .mlir or .cir file. "
+  "Allowed values are `core` for MLIR core dialects and `cir` for ClangIR">,
+  Values<"core,cir">,
+  NormalizedValuesScope<"clang::frontend">,
+  NormalizedValues<["MLIR_Core", "MLIR_CIR"]>,
+  MarshallingInfoEnum<FrontendOpts<"MLIRTargetDialect">, "MLIR_CIR">;
 /// ClangIR-specific options - END
 
 def flto_EQ : Joined<["-"], "flto=">,

clang/include/clang/Frontend/FrontendOptions.h

@@ -69,7 +69,7 @@ enum ActionKind {
   EmitCIR,
 
   /// Emit a .mlir file
-  EmitCoreMLIR,
+  EmitMLIR,
 
   /// Emit a .ll file.
   EmitLLVM,
@@ -151,6 +151,8 @@ enum ActionKind {
   PrintDependencyDirectivesSourceMinimizerOutput
 };
 
+enum MLIRDialectKind { MLIR_CIR, MLIR_Core };
+
 } // namespace frontend
 
 /// The kind of a file that we've been handed as an input.
@@ -420,6 +422,8 @@ class FrontendOptions {
   /// Specifies the output format of the AST.
   ASTDumpOutputFormat ASTDumpFormat = ADOF_Default;
 
+  frontend::MLIRDialectKind MLIRTargetDialect = frontend::MLIR_CIR;
+
   /// The input kind, either specified via -x argument or deduced from the input
   /// file name.
   InputKind DashX;

clang/lib/CIR/FrontendAction/CIRGenAction.cpp

@@ -13,6 +13,7 @@
 #include "clang/CIR/LowerToLLVM.h"
 #include "clang/CodeGen/BackendUtil.h"
 #include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/FrontendOptions.h"
 #include "llvm/IR/Module.h"
 
 using namespace cir;
@@ -86,21 +87,26 @@ class CIRGenConsumer : public clang::ASTConsumer {
     mlir::MLIRContext &MlirCtx = Gen->getMLIRContext();
     switch (Action) {
     case CIRGenAction::OutputType::EmitCIR:
-      if (OutputStream && MlirModule) {
+      assert(CI.getFrontendOpts().MLIRTargetDialect == frontend::MLIR_CIR);
+    case CIRGenAction::OutputType::EmitMLIR: {
+      switch (CI.getFrontendOpts().MLIRTargetDialect) {
+      case frontend::MLIR_CIR:
+        if (OutputStream && MlirModule) {
+          mlir::OpPrintingFlags Flags;
+          Flags.enableDebugInfo(/*enable=*/true, /*prettyForm=*/false);
+          MlirModule->print(*OutputStream, Flags);
+        }
+        break;
+      case frontend::MLIR_Core:
+        mlir::ModuleOp LoweredMlirModule =
+            lowerFromCIRToMLIR(MlirModule, MlirCtx);
+        assert(OutputStream && "No output stream when lowering to MLIR!");
+        // FIXME: we cannot roundtrip prettyForm=true right now.
         mlir::OpPrintingFlags Flags;
         Flags.enableDebugInfo(/*enable=*/true, /*prettyForm=*/false);
-        MlirModule->print(*OutputStream, Flags);
+        LoweredMlirModule->print(*OutputStream, Flags);
+        break;
       }
-      break;
-    case CIRGenAction::OutputType::EmitMLIR: {
-      mlir::ModuleOp LoweredMlirModule =
-          lowerFromCIRToMLIR(MlirModule, MlirCtx);
-      assert(OutputStream && "No output stream when lowering to MLIR!");
-      // FIXME: we cannot roundtrip prettyForm=true right now.
-      mlir::OpPrintingFlags Flags;
-      Flags.enableDebugInfo(/*enable=*/true, /*prettyForm=*/false);
-      LoweredMlirModule->print(*OutputStream, Flags);
-      break;
     }
     case CIRGenAction::OutputType::EmitLLVM:
     case CIRGenAction::OutputType::EmitBC:

clang/lib/Frontend/CompilerInvocation.cpp

@@ -2740,7 +2740,7 @@ static const auto &getFrontendActionTable() {
       {frontend::EmitAssembly, OPT_S},
       {frontend::EmitBC, OPT_emit_llvm_bc},
       {frontend::EmitCIR, OPT_emit_cir},
-      {frontend::EmitCoreMLIR, OPT_emit_core_mlir},
+      {frontend::EmitMLIR, OPT_emit_mlir_EQ},
       {frontend::EmitHTML, OPT_emit_html},
       {frontend::EmitLLVM, OPT_emit_llvm},
       {frontend::EmitLLVMOnly, OPT_emit_llvm_only},
@@ -2857,6 +2857,13 @@ static void GenerateFrontendArgs(const FrontendOptions &Opts,
     };
   }
 
+  if (Opts.ProgramAction == frontend::EmitMLIR) {
+    GenerateProgramAction = [&]() {
+      if (Opts.MLIRTargetDialect == frontend::MLIR_CIR)
+        GenerateArg(Consumer, OPT_emit_cir);
+    };
+  }
+
   GenerateProgramAction();
 
   for (const auto &PluginArgs : Opts.PluginArgs) {
@@ -4632,7 +4639,7 @@ static bool isStrictlyPreprocessorAction(frontend::ActionKind Action) {
   case frontend::EmitAssembly:
   case frontend::EmitBC:
   case frontend::EmitCIR:
-  case frontend::EmitCoreMLIR:
+  case frontend::EmitMLIR:
   case frontend::EmitHTML:
   case frontend::EmitLLVM:
   case frontend::EmitLLVMOnly:

clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp

@@ -80,7 +80,7 @@ CreateFrontendBaseAction(CompilerInstance &CI) {
 #else
     llvm_unreachable("CIR suppport not built into clang");
 #endif
-  case EmitCoreMLIR:
+  case EmitMLIR:
 #if CLANG_ENABLE_CIR
     return std::make_unique<cir::EmitMLIRAction>();
 #else

clang/test/CIR/Lowering/ThroughMLIR/global-ptrs.cpp

@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -std=c++20 -triple x86_64-unknown-linux-gnu -fclangir -emit-core-mlir %s -o %t.mlir
+// RUN: %clang_cc1 -std=c++20 -triple x86_64-unknown-linux-gnu -fclangir -emit-mlir=core %s -o %t.mlir
 // RUN: FileCheck --input-file=%t.mlir %s
 
 // XFAIL: *

clang/test/CIR/Lowering/ThroughMLIR/global.cpp

@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -std=c++20 -triple x86_64-unknown-linux-gnu -fclangir -emit-core-mlir %s -o %t.mlir
+// RUN: %clang_cc1 -std=c++20 -triple x86_64-unknown-linux-gnu -fclangir -emit-mlir=core %s -o %t.mlir
 // RUN: FileCheck --input-file=%t.mlir %s
 
 char c;

clang/test/CIR/global-var-simple.cpp

@@ -1,5 +1,5 @@
-// Global variables of scalar typees with initial values
-// RUN: %clang_cc1 -std=c++20 -triple x86_64-unknown-linux-gnu -fclangir -emit-cir %s -o -  | FileCheck %s
+// Global variables of scalar types with initial values
+// RUN: %clang_cc1 -std=c++20 -triple x86_64-unknown-linux-gnu -fclangir -emit-mlir=cir %s -o -  | FileCheck %s
 
 char c;
 // CHECK: cir.global external @c : !cir.int<s, 8>

clang/test/CIR/hello.c

@@ -0,0 +1,6 @@
+// Smoke test for ClangIR code generation
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -emit-mlir=cir %s -o -  | FileCheck %s
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -emit-cir %s -o -  | FileCheck %s
+
+void foo() {}
+// CHECK: cir.func @foo