Merge pull request #1008 from banach-space/andrzej/generate_fir

schweitzpgi · web-flow · commit 2cfe75f49483 · 2021-09-29T11:57:50.000-07:00
[flang][driver] Add support for `-emit-fir`
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
@@ -4467,6 +4467,10 @@ def fintrinsic_modules_path : Separate<["-"], "fintrinsic-modules-path">,  Group
   HelpText<"Specify where to find the compiled intrinsic modules">,
   DocBrief<[{This option specifies the location of pre-compiled intrinsic modules, 
   if they are not in the default location expected by the compiler.}]>;
+
+def emit_mlir : Flag<["-"], "emit-mlir">, Group<Action_Group>,
+  HelpText<"Build the parse tree, then lower it to MLIR and dump">;
+def emit_fir : Flag<["-"], "emit-fir">, Alias<emit_mlir>;
 }
 
 def J : JoinedOrSeparate<["-"], "J">,
diff --git a/flang/include/flang/Frontend/CompilerInstance.h b/flang/include/flang/Frontend/CompilerInstance.h
@@ -250,6 +250,13 @@ class CompilerInstance {
   void WriteOutputStream(const std::string &message) {
     *outputStream_ << message;
   }
+
+  /// Get the user specified output stream.
+  llvm::raw_pwrite_stream &GetOutputStream() {
+    assert(outputStream_ &&
+        "Compiler instance has no user-specified output stream!");
+    return *outputStream_;
+  }
 };
 
 } // end namespace Fortran::frontend
diff --git a/flang/include/flang/Frontend/FrontendActions.h b/flang/include/flang/Frontend/FrontendActions.h
@@ -127,6 +127,19 @@ class ParseSyntaxOnlyAction : public PrescanAndSemaAction {
   void ExecuteAction() override;
 };
 
+//===----------------------------------------------------------------------===//
+// CodeGen Actions
+//===----------------------------------------------------------------------===//
+class CodeGenAction : public FrontendAction {
+
+  void ExecuteAction() override = 0;
+  bool BeginSourceFileAction() override;
+};
+
+class EmitMLIRAction : public CodeGenAction {
+  void ExecuteAction() override;
+};
+
 } // namespace Fortran::frontend
 
 #endif // LLVM_FLANG_FRONTEND_FRONTENDACTIONS_H
diff --git a/flang/include/flang/Frontend/FrontendOptions.h b/flang/include/flang/Frontend/FrontendOptions.h
@@ -31,6 +31,9 @@ enum ActionKind {
   /// -fsyntax-only
   ParseSyntaxOnly,
 
+  /// Emit a .mlir file
+  EmitMLIR,
+
   /// Emit a .o file.
   EmitObj,
 
diff --git a/flang/lib/Frontend/CMakeLists.txt b/flang/lib/Frontend/CMakeLists.txt
@@ -1,3 +1,5 @@
+get_property(dialect_libs GLOBAL PROPERTY MLIR_DIALECT_LIBS)
+
 add_flang_library(flangFrontend
   CompilerInstance.cpp
   CompilerInvocation.cpp
@@ -19,6 +21,11 @@ add_flang_library(flangFrontend
   FortranLower
   clangBasic
   clangDriver
+  FIRDialect
+  FIRAnalysis
+  FIRSupport
+  FIRBuilder
+  ${dialect_libs}
 
   LINK_COMPONENTS
   Option
diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -123,6 +123,9 @@ static bool ParseFrontendArgs(FrontendOptions &opts, llvm::opt::ArgList &args,
     case clang::driver::options::OPT_fsyntax_only:
       opts.programAction = ParseSyntaxOnly;
       break;
+    case clang::driver::options::OPT_emit_mlir:
+      opts.programAction = EmitMLIR;
+      break;
     case clang::driver::options::OPT_emit_obj:
       opts.programAction = EmitObj;
       break;
diff --git a/flang/lib/Frontend/FrontendActions.cpp b/flang/lib/Frontend/FrontendActions.cpp
@@ -7,11 +7,19 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Frontend/FrontendActions.h"
+#include "mlir/IR/Dialect.h"
+#include "mlir/Pass/PassManager.h"
+#include "mlir/Support/LogicalResult.h"
 #include "flang/Common/default-kinds.h"
 #include "flang/Frontend/CompilerInstance.h"
 #include "flang/Frontend/FrontendOptions.h"
 #include "flang/Frontend/PreprocessorOptions.h"
+#include "flang/Lower/Bridge.h"
 #include "flang/Lower/PFTBuilder.h"
+#include "flang/Lower/Support/Verifier.h"
+#include "flang/Optimizer/Dialect/FIRType.h"
+#include "flang/Optimizer/Support/InitFIR.h"
+#include "flang/Optimizer/Support/KindMapping.h"
 #include "flang/Parser/dump-parse-tree.h"
 #include "flang/Parser/parsing.h"
 #include "flang/Parser/provenance.h"
@@ -22,6 +30,7 @@
 #include "flang/Semantics/unparse-with-symbols.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
 #include <clang/Basic/Diagnostic.h>
 #include <memory>
 
@@ -40,6 +49,10 @@ bool PrescanAndSemaAction::BeginSourceFileAction() {
   return RunPrescan() & RunParse() && RunSemanticChecks();
 }
 
+bool CodeGenAction::BeginSourceFileAction() {
+  return RunPrescan() & RunParse() && RunSemanticChecks();
+}
+
 //===----------------------------------------------------------------------===//
 // Custom ExecuteAction
 //===----------------------------------------------------------------------===//
@@ -351,6 +364,77 @@ void GetSymbolsSourcesAction::ExecuteAction() {
   ci.semantics().DumpSymbolsSources(llvm::outs());
 }
 
+// Translate front-end KINDs for use in the IR and code gen. Extracted from
+// bbc.cpp.
+static std::vector<fir::KindTy>
+fromDefaultKinds(const Fortran::common::IntrinsicTypeDefaultKinds &defKinds) {
+  return {static_cast<fir::KindTy>(defKinds.GetDefaultKind(
+              Fortran::common::TypeCategory::Character)),
+          static_cast<fir::KindTy>(
+              defKinds.GetDefaultKind(Fortran::common::TypeCategory::Complex)),
+          static_cast<fir::KindTy>(defKinds.doublePrecisionKind()),
+          static_cast<fir::KindTy>(
+              defKinds.GetDefaultKind(Fortran::common::TypeCategory::Integer)),
+          static_cast<fir::KindTy>(
+              defKinds.GetDefaultKind(Fortran::common::TypeCategory::Logical)),
+          static_cast<fir::KindTy>(
+              defKinds.GetDefaultKind(Fortran::common::TypeCategory::Real))};
+}
+
+void EmitMLIRAction::ExecuteAction() {
+  CompilerInstance &ci = this->instance();
+
+  // Load the MLIR dialects required by Flang
+  mlir::DialectRegistry registry;
+  mlir::MLIRContext ctx(registry);
+  fir::support::registerNonCodegenDialects(registry);
+  fir::support::loadNonCodegenDialects(ctx);
+
+  // Create a LoweringBridge
+  auto &defKinds = ci.invocation().semanticsContext().defaultKinds();
+  fir::KindMapping kindMap(
+      &ctx, llvm::ArrayRef<fir::KindTy>{fromDefaultKinds(defKinds)});
+  auto lb = Fortran::lower::LoweringBridge::create(ctx, defKinds,
+      ci.invocation().semanticsContext().intrinsics(), ci.parsing().allCooked(),
+      "", kindMap);
+
+  // Create a parse tree and lower it to FIR
+  auto &parseTree{*ci.parsing().parseTree()};
+  lb.lower(parseTree, ci.invocation().semanticsContext());
+
+  // Run the default passes.
+  mlir::PassManager pm(&ctx, mlir::OpPassManager::Nesting::Implicit);
+  pm.enableVerifier(/*verifyPasses=*/true);
+  pm.addPass(std::make_unique<Fortran::lower::VerifierPass>());
+  mlir::ModuleOp mlirModule = lb.getModule();
+  if (mlir::failed(pm.run(mlirModule))) {
+    unsigned diagID =
+        ci.diagnostics().getCustomDiagID(clang::DiagnosticsEngine::Error,
+            "verification of lowering to FIR failed");
+    ci.diagnostics().Report(diagID);
+    return;
+  }
+
+  // Print the output. If a pre-defined output stream exists, dump the MLIR
+  // content there.
+  if (!ci.IsOutputStreamNull()) {
+    mlirModule.print(ci.GetOutputStream());
+    return;
+  }
+
+  // ... otherwise, print to a file.
+  auto os{ci.CreateDefaultOutputFile(
+      /*Binary=*/true, /*InFile=*/GetCurrentFileOrBufferName(), "mlir")};
+  if (!os) {
+    unsigned diagID = ci.diagnostics().getCustomDiagID(
+        clang::DiagnosticsEngine::Error, "failed to create the output file");
+    ci.diagnostics().Report(diagID);
+    return;
+  }
+
+  mlirModule.print(*os);
+}
+
 void EmitObjAction::ExecuteAction() {
   CompilerInstance &ci = this->instance();
   unsigned DiagID = ci.diagnostics().getCustomDiagID(
diff --git a/flang/lib/FrontendTool/ExecuteCompilerInvocation.cpp b/flang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
@@ -32,6 +32,8 @@ static std::unique_ptr<FrontendAction> CreateFrontendBaseAction(
     return std::make_unique<PrintPreprocessedAction>();
   case ParseSyntaxOnly:
     return std::make_unique<ParseSyntaxOnlyAction>();
+  case EmitMLIR:
+    return std::make_unique<EmitMLIRAction>();
   case EmitObj:
     return std::make_unique<EmitObjAction>();
   case DebugUnparse:
diff --git a/flang/test/Driver/driver-help-hidden.f90 b/flang/test/Driver/driver-help-hidden.f90
@@ -22,6 +22,7 @@
 ! CHECK-NEXT: -cpp      Enable predefined and command line preprocessor macros
 ! CHECK-NEXT: -c        Only run preprocess, compile, and assemble steps
 ! CHECK-NEXT: -D <macro>=<value>     Define <macro> to <value> (or 1 if <value> omitted)
+! CHECK-NEXT: -emit-mlir             Build the parse tree, then lower it to MLIR and dump
 ! CHECK-NEXT: -E        Only run the preprocessor
 ! CHECK-NEXT: -falternative-parameter-statement
 ! CHECK-NEXT: Enable the old style PARAMETER statement
diff --git a/flang/test/Driver/driver-help.f90 b/flang/test/Driver/driver-help.f90
@@ -22,6 +22,7 @@
 ! HELP-NEXT: -cpp                   Enable predefined and command line preprocessor macros
 ! HELP-NEXT: -c                     Only run preprocess, compile, and assemble steps
 ! HELP-NEXT: -D <macro>=<value>     Define <macro> to <value> (or 1 if <value> omitted)
+! HELP-NEXT: -emit-mlir             Build the parse tree, then lower it to MLIR and dump
 ! HELP-NEXT: -E                     Only run the preprocessor
 ! HELP-NEXT: -falternative-parameter-statement
 ! HELP-NEXT: Enable the old style PARAMETER statement
@@ -65,6 +66,7 @@
 ! HELP-FC1-NEXT:OPTIONS:
 ! HELP-FC1-NEXT: -cpp                   Enable predefined and command line preprocessor macros
 ! HELP-FC1-NEXT: -D <macro>=<value>     Define <macro> to <value> (or 1 if <value> omitted)
+! HELP-FC1-NEXT: -emit-mlir             Build the parse tree, then lower it to MLIR and dump
 ! HELP-FC1-NEXT: -emit-obj Emit native object files
 ! HELP-FC1-NEXT: -E                     Only run the preprocessor
 ! HELP-FC1-NEXT: -falternative-parameter-statement
diff --git a/flang/test/Driver/emit-mlir.f90 b/flang/test/Driver/emit-mlir.f90
@@ -0,0 +1,10 @@
+! RUN: %flang_fc1 -emit-mlir %s -o - | FileCheck %s
+! RUN: %flang_fc1 -emit-fir %s -o - | FileCheck %s
+
+! CHECK: module attributes {
+! CHECK-LABEL: func @_QQmain() {
+! CHECK-NEXT:  return
+! CHECK-NEXT: }
+! CHECK-NEXT: }
+
+end program
diff --git a/flang/unittests/Frontend/FrontendActionTest.cpp b/flang/unittests/Frontend/FrontendActionTest.cpp
@@ -161,4 +161,30 @@ TEST_F(FrontendActionTest, ParseSyntaxOnly) {
           .contains(
               ":1:14: error: IF statement is not allowed in IF statement\n"));
 }
+
+TEST_F(FrontendActionTest, EmitMLIR) {
+  // Populate the input file with the pre-defined input and flush it.
+  *(inputFileOs_) << "end program";
+  inputFileOs_.reset();
+
+  // Set-up the action kind.
+  compInst_.invocation().frontendOpts().programAction = EmitMLIR;
+  compInst_.invocation().preprocessorOpts().noReformat = true;
+
+  // Set-up the output stream. We are using output buffer wrapped as an output
+  // stream, as opposed to an actual file (or a file descriptor).
+  llvm::SmallVector<char, 256> outputFileBuffer;
+  std::unique_ptr<llvm::raw_pwrite_stream> outputFileStream(
+      new llvm::raw_svector_ostream(outputFileBuffer));
+  compInst_.set_outputStream(std::move(outputFileStream));
+
+  // Execute the action.
+  bool success = ExecuteCompilerInvocation(&compInst_);
+
+  // Validate the expected output.
+  EXPECT_TRUE(success);
+  EXPECT_TRUE(!outputFileBuffer.empty());
+  EXPECT_TRUE(
+      llvm::StringRef(outputFileBuffer.data()).contains("func @_QQmain"));
+}
 } // namespace
