[flang] Initial debug info support for local variables.

flang/lib/Optimizer/CodeGen/CGOps.h → flang/include/flang/Optimizer/CodeGen/CGOps.h

@@ -13,6 +13,7 @@
 #ifndef OPTIMIZER_CODEGEN_CGOPS_H
 #define OPTIMIZER_CODEGEN_CGOPS_H
 
+#include "flang/Optimizer/Dialect/FIRAttr.h"
 #include "flang/Optimizer/Dialect/FIRType.h"
 #include "mlir/Dialect/Func/IR/FuncOps.h"
 

flang/include/flang/Optimizer/CodeGen/CGOps.td

@@ -16,6 +16,8 @@
 
 include "mlir/IR/SymbolInterfaces.td"
 include "flang/Optimizer/Dialect/FIRTypes.td"
+include "flang/Optimizer/Dialect/FIRAttr.td"
+include "mlir/IR/BuiltinAttributes.td"
 
 def fircg_Dialect : Dialect {
   let name = "fircg";
@@ -202,4 +204,36 @@ def fircg_XArrayCoorOp : fircg_Op<"ext_array_coor", [AttrSizedOperandSegments]>
   }];
 }
 
+// Extended Declare operation.
+def fircg_XDeclareOp : fircg_Op<"ext_declare", [AttrSizedOperandSegments]> {
+  let summary = "for internal conversion only";
+
+  let description = [{
+    Prior to lowering to LLVM IR dialect, a DeclareOp will
+    be converted to an extended DeclareOp.
+  }];
+
+  let arguments = (ins
+    AnyRefOrBox:$memref,
+    Variadic<AnyIntegerType>:$shape,
+    Variadic<AnyIntegerType>:$shift,
+    Variadic<AnyIntegerType>:$typeparams,
+    Optional<fir_DummyScopeType>:$dummy_scope,
+    Builtin_StringAttr:$uniq_name
+  );
+  let results = (outs AnyRefOrBox);
+
+  let assemblyFormat = [{
+    $memref (`(` $shape^ `)`)? (`origin` $shift^)? (`typeparams` $typeparams^)?
+    (`dummy_scope` $dummy_scope^)?
+    attr-dict `:` functional-type(operands, results)
+  }];
+
+  let extraClassDeclaration = [{
+    // Shape is optional, but if it exists, it will be at offset 1.
+    unsigned shapeOffset() { return 1; }
+    unsigned shiftOffset() { return shapeOffset() + getShape().size(); }
+  }];
+}
+
 #endif

flang/include/flang/Optimizer/CodeGen/CGPasses.td

@@ -47,6 +47,10 @@ def CodeGenRewrite : Pass<"cg-rewrite", "mlir::ModuleOp"> {
   let dependentDialects = [
     "fir::FIROpsDialect", "fir::FIRCodeGenDialect"
   ];
+  let options = [
+    Option<"preserveDeclare", "preserve-declare", "bool", /*default=*/"false",
+           "Preserve DeclareOp during pre codegen re-write.">
+  ];
   let statistics = [
     Statistic<"numDCE", "num-dce'd", "Number of operations eliminated">
   ];

flang/include/flang/Optimizer/CodeGen/CodeGen.h

@@ -30,7 +30,8 @@ struct NameUniquer;
 
 /// Prerequiste pass for code gen. Perform intermediate rewrites to perform
 /// the code gen (to LLVM-IR dialect) conversion.
-std::unique_ptr<mlir::Pass> createFirCodeGenRewritePass();
+std::unique_ptr<mlir::Pass> createFirCodeGenRewritePass(
+    CodeGenRewriteOptions Options = CodeGenRewriteOptions{});
 
 /// FirTargetRewritePass options.
 struct TargetRewriteOptions {
@@ -88,7 +89,8 @@ void populateFIRToLLVMConversionPatterns(fir::LLVMTypeConverter &converter,
                                          fir::FIRToLLVMPassOptions &options);
 
 /// Populate the pattern set with the PreCGRewrite patterns.
-void populatePreCGRewritePatterns(mlir::RewritePatternSet &patterns);
+void populatePreCGRewritePatterns(mlir::RewritePatternSet &patterns,
+                                  bool preserveDeclare);
 
 // declarative passes
 #define GEN_PASS_REGISTRATION

flang/include/flang/Tools/CLOptions.inc

@@ -169,9 +169,11 @@ inline void addMemoryAllocationOpt(mlir::PassManager &pm) {
 }
 
 #if !defined(FLANG_EXCLUDE_CODEGEN)
-inline void addCodeGenRewritePass(mlir::PassManager &pm) {
-  addPassConditionally(
-      pm, disableCodeGenRewrite, fir::createFirCodeGenRewritePass);
+inline void addCodeGenRewritePass(mlir::PassManager &pm, bool preserveDeclare) {
+  fir::CodeGenRewriteOptions options;
+  options.preserveDeclare = preserveDeclare;
+  addPassConditionally(pm, disableCodeGenRewrite,
+      [&]() { return fir::createFirCodeGenRewritePass(options); });
 }
 
 inline void addTargetRewritePass(mlir::PassManager &pm) {
@@ -337,7 +339,8 @@ inline void createDefaultFIRCodeGenPassPipeline(mlir::PassManager &pm,
     MLIRToLLVMPassPipelineConfig config, llvm::StringRef inputFilename = {}) {
   fir::addBoxedProcedurePass(pm);
   addNestedPassToAllTopLevelOperations(pm, fir::createAbstractResultOpt);
-  fir::addCodeGenRewritePass(pm);
+  fir::addCodeGenRewritePass(
+      pm, (config.DebugInfo != llvm::codegenoptions::NoDebugInfo));
   fir::addTargetRewritePass(pm);
   fir::addExternalNameConversionPass(pm, config.Underscoring);
   fir::createDebugPasses(pm, config.DebugInfo, config.OptLevel, inputFilename);

flang/lib/Optimizer/CodeGen/CGOps.cpp

@@ -10,7 +10,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "CGOps.h"
+#include "flang/Optimizer/CodeGen/CGOps.h"
 #include "flang/Optimizer/Dialect/FIRDialect.h"
 #include "flang/Optimizer/Dialect/FIROps.h"
 #include "flang/Optimizer/Dialect/FIRType.h"

flang/lib/Optimizer/CodeGen/CodeGen.cpp

@@ -12,7 +12,7 @@
 
 #include "flang/Optimizer/CodeGen/CodeGen.h"
 
-#include "CGOps.h"
+#include "flang/Optimizer/CodeGen/CGOps.h"
 #include "flang/Optimizer/CodeGen/CodeGenOpenMP.h"
 #include "flang/Optimizer/CodeGen/FIROpPatterns.h"
 #include "flang/Optimizer/CodeGen/TypeConverter.h"
@@ -170,6 +170,28 @@ genAllocationScaleSize(OP op, mlir::Type ity,
   return nullptr;
 }
 
+namespace {
+struct DeclareOpConversion : public fir::FIROpConversion<fir::cg::XDeclareOp> {
+public:
+  using FIROpConversion::FIROpConversion;
+  mlir::LogicalResult
+  matchAndRewrite(fir::cg::XDeclareOp declareOp, OpAdaptor adaptor,
+                  mlir::ConversionPatternRewriter &rewriter) const override {
+    auto memRef = adaptor.getOperands()[0];
+    if (auto fusedLoc = mlir::dyn_cast<mlir::FusedLoc>(declareOp.getLoc())) {
+      if (auto varAttr =
+              mlir::dyn_cast_or_null<mlir::LLVM::DILocalVariableAttr>(
+                  fusedLoc.getMetadata())) {
+        rewriter.create<mlir::LLVM::DbgDeclareOp>(memRef.getLoc(), memRef,
+                                                  varAttr, nullptr);
+      }
+    }
+    rewriter.replaceOp(declareOp, memRef);
+    return mlir::success();
+  }
+};
+} // namespace
+
 namespace {
 /// convert to LLVM IR dialect `alloca`
 struct AllocaOpConversion : public fir::FIROpConversion<fir::AllocaOp> {
@@ -3714,19 +3736,19 @@ void fir::populateFIRToLLVMConversionPatterns(
       BoxOffsetOpConversion, BoxProcHostOpConversion, BoxRankOpConversion,
       BoxTypeCodeOpConversion, BoxTypeDescOpConversion, CallOpConversion,
       CmpcOpConversion, ConstcOpConversion, ConvertOpConversion,
-      CoordinateOpConversion, DTEntryOpConversion, DivcOpConversion,
-      EmboxOpConversion, EmboxCharOpConversion, EmboxProcOpConversion,
-      ExtractValueOpConversion, FieldIndexOpConversion, FirEndOpConversion,
-      FreeMemOpConversion, GlobalLenOpConversion, GlobalOpConversion,
-      HasValueOpConversion, InsertOnRangeOpConversion, InsertValueOpConversion,
-      IsPresentOpConversion, LenParamIndexOpConversion, LoadOpConversion,
-      MulcOpConversion, NegcOpConversion, NoReassocOpConversion,
-      SelectCaseOpConversion, SelectOpConversion, SelectRankOpConversion,
-      SelectTypeOpConversion, ShapeOpConversion, ShapeShiftOpConversion,
-      ShiftOpConversion, SliceOpConversion, StoreOpConversion,
-      StringLitOpConversion, SubcOpConversion, TypeDescOpConversion,
-      TypeInfoOpConversion, UnboxCharOpConversion, UnboxProcOpConversion,
-      UndefOpConversion, UnreachableOpConversion,
+      CoordinateOpConversion, DTEntryOpConversion, DeclareOpConversion,
+      DivcOpConversion, EmboxOpConversion, EmboxCharOpConversion,
+      EmboxProcOpConversion, ExtractValueOpConversion, FieldIndexOpConversion,
+      FirEndOpConversion, FreeMemOpConversion, GlobalLenOpConversion,
+      GlobalOpConversion, HasValueOpConversion, InsertOnRangeOpConversion,
+      InsertValueOpConversion, IsPresentOpConversion, LenParamIndexOpConversion,
+      LoadOpConversion, MulcOpConversion, NegcOpConversion,
+      NoReassocOpConversion, SelectCaseOpConversion, SelectOpConversion,
+      SelectRankOpConversion, SelectTypeOpConversion, ShapeOpConversion,
+      ShapeShiftOpConversion, ShiftOpConversion, SliceOpConversion,
+      StoreOpConversion, StringLitOpConversion, SubcOpConversion,
+      TypeDescOpConversion, TypeInfoOpConversion, UnboxCharOpConversion,
+      UnboxProcOpConversion, UndefOpConversion, UnreachableOpConversion,
       UnrealizedConversionCastOpConversion, XArrayCoorOpConversion,
       XEmboxOpConversion, XReboxOpConversion, ZeroOpConversion>(converter,
                                                                 options);

flang/lib/Optimizer/CodeGen/PreCGRewrite.cpp

@@ -12,8 +12,8 @@
 
 #include "flang/Optimizer/CodeGen/CodeGen.h"
 
-#include "CGOps.h"
 #include "flang/Optimizer/Builder/Todo.h" // remove when TODO's are done
+#include "flang/Optimizer/CodeGen/CGOps.h"
 #include "flang/Optimizer/Dialect/FIRDialect.h"
 #include "flang/Optimizer/Dialect/FIROps.h"
 #include "flang/Optimizer/Dialect/FIRType.h"
@@ -270,13 +270,43 @@ class ArrayCoorConversion : public mlir::OpRewritePattern<fir::ArrayCoorOp> {
 };
 
 class DeclareOpConversion : public mlir::OpRewritePattern<fir::DeclareOp> {
+  bool preserveDeclare;
+
 public:
   using OpRewritePattern::OpRewritePattern;
+  DeclareOpConversion(mlir::MLIRContext *ctx, bool preserveDecl)
+      : OpRewritePattern(ctx), preserveDeclare(preserveDecl) {}
 
   mlir::LogicalResult
   matchAndRewrite(fir::DeclareOp declareOp,
                   mlir::PatternRewriter &rewriter) const override {
-    rewriter.replaceOp(declareOp, declareOp.getMemref());
+    if (!preserveDeclare) {
+      rewriter.replaceOp(declareOp, declareOp.getMemref());
+      return mlir::success();
+    }
+    auto loc = declareOp.getLoc();
+    llvm::SmallVector<mlir::Value> shapeOpers;
+    llvm::SmallVector<mlir::Value> shiftOpers;
+    if (auto shapeVal = declareOp.getShape()) {
+      if (auto shapeOp = mlir::dyn_cast<fir::ShapeOp>(shapeVal.getDefiningOp()))
+        populateShape(shapeOpers, shapeOp);
+      else if (auto shiftOp =
+                   mlir::dyn_cast<fir::ShapeShiftOp>(shapeVal.getDefiningOp()))
+        populateShapeAndShift(shapeOpers, shiftOpers, shiftOp);
+      else if (auto shiftOp =
+                   mlir::dyn_cast<fir::ShiftOp>(shapeVal.getDefiningOp()))
+        populateShift(shiftOpers, shiftOp);
+      else
+        return mlir::failure();
+    }
+    // FIXME: Add FortranAttrs and CudaAttrs
+    auto xDeclOp = rewriter.create<fir::cg::XDeclareOp>(
+        loc, declareOp.getType(), declareOp.getMemref(), shapeOpers, shiftOpers,
+        declareOp.getTypeparams(), declareOp.getDummyScope(),
+        declareOp.getUniqName());
+    LLVM_DEBUG(llvm::dbgs()
+               << "rewriting " << declareOp << " to " << xDeclOp << '\n');
+    rewriter.replaceOp(declareOp, xDeclOp.getOperation()->getResults());
     return mlir::success();
   }
 };
@@ -297,6 +327,7 @@ class DummyScopeOpConversion
 
 class CodeGenRewrite : public fir::impl::CodeGenRewriteBase<CodeGenRewrite> {
 public:
+  CodeGenRewrite(fir::CodeGenRewriteOptions opts) : Base(opts) {}
   void runOnOperation() override final {
     mlir::ModuleOp mod = getOperation();
 
@@ -314,7 +345,7 @@ class CodeGenRewrite : public fir::impl::CodeGenRewriteBase<CodeGenRewrite> {
                    mlir::cast<fir::BaseBoxType>(embox.getType()).getEleTy()));
     });
     mlir::RewritePatternSet patterns(&context);
-    fir::populatePreCGRewritePatterns(patterns);
+    fir::populatePreCGRewritePatterns(patterns, preserveDeclare);
     if (mlir::failed(
             mlir::applyPartialConversion(mod, target, std::move(patterns)))) {
       mlir::emitError(mlir::UnknownLoc::get(&context),
@@ -330,12 +361,14 @@ class CodeGenRewrite : public fir::impl::CodeGenRewriteBase<CodeGenRewrite> {
 
 } // namespace
 
-std::unique_ptr<mlir::Pass> fir::createFirCodeGenRewritePass() {
-  return std::make_unique<CodeGenRewrite>();
+std::unique_ptr<mlir::Pass>
+fir::createFirCodeGenRewritePass(fir::CodeGenRewriteOptions Options) {
+  return std::make_unique<CodeGenRewrite>(Options);
 }
 
-void fir::populatePreCGRewritePatterns(mlir::RewritePatternSet &patterns) {
+void fir::populatePreCGRewritePatterns(mlir::RewritePatternSet &patterns,
+                                       bool preserveDeclare) {
   patterns.insert<EmboxConversion, ArrayCoorConversion, ReboxConversion,
-                  DeclareOpConversion, DummyScopeOpConversion>(
-      patterns.getContext());
+                  DummyScopeOpConversion>(patterns.getContext());
+  patterns.add<DeclareOpConversion>(patterns.getContext(), preserveDeclare);
 }

flang/lib/Optimizer/Transforms/AddDebugInfo.cpp

@@ -15,6 +15,7 @@
 #include "flang/Common/Version.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
 #include "flang/Optimizer/Builder/Todo.h"
+#include "flang/Optimizer/CodeGen/CGOps.h"
 #include "flang/Optimizer/Dialect/FIRDialect.h"
 #include "flang/Optimizer/Dialect/FIROps.h"
 #include "flang/Optimizer/Dialect/FIRType.h"
@@ -45,13 +46,59 @@ namespace fir {
 namespace {
 
 class AddDebugInfoPass : public fir::impl::AddDebugInfoBase<AddDebugInfoPass> {
+  void handleDeclareOp(fir::cg::XDeclareOp declOp,
+                       mlir::LLVM::DIFileAttr fileAttr,
+                       mlir::LLVM::DIScopeAttr scopeAttr,
+                       fir::DebugTypeGenerator &typeGen);
+
 public:
   AddDebugInfoPass(fir::AddDebugInfoOptions options) : Base(options) {}
   void runOnOperation() override;
 };
 
+static uint32_t getLineFromLoc(mlir::Location loc) {
+  uint32_t line = 1;
+  if (auto fileLoc = mlir::dyn_cast<mlir::FileLineColLoc>(loc))
+    line = fileLoc.getLine();
+  return line;
+}
+
 } // namespace
 
+void AddDebugInfoPass::handleDeclareOp(fir::cg::XDeclareOp declOp,
+                                       mlir::LLVM::DIFileAttr fileAttr,
+                                       mlir::LLVM::DIScopeAttr scopeAttr,
+                                       fir::DebugTypeGenerator &typeGen) {
+  mlir::MLIRContext *context = &getContext();
+  mlir::OpBuilder builder(context);
+  auto result = fir::NameUniquer::deconstruct(declOp.getUniqName());
+
+  if (result.first != fir::NameUniquer::NameKind::VARIABLE)
+    return;
+
+  // Only accept local variables.
+  if (result.second.procs.empty())
+    return;
+
+  // FIXME: There may be cases where an argument is processed a bit before
+  // DeclareOp is generated. In that case, DeclareOp may point to an
+  // intermediate op and not to BlockArgument. We need to find those cases and
+  // walk the chain to get to the actual argument.
+
+  unsigned argNo = 0;
+  if (auto Arg = llvm::dyn_cast<mlir::BlockArgument>(declOp.getMemref()))
+    argNo = Arg.getArgNumber() + 1;
+
+  auto tyAttr = typeGen.convertType(fir::unwrapRefType(declOp.getType()),
+                                    fileAttr, scopeAttr, declOp.getLoc());
+
+  auto localVarAttr = mlir::LLVM::DILocalVariableAttr::get(
+      context, scopeAttr, mlir::StringAttr::get(context, result.second.name),
+      fileAttr, getLineFromLoc(declOp.getLoc()), argNo, /* alignInBits*/ 0,
+      tyAttr);
+  declOp->setLoc(builder.getFusedLoc({declOp->getLoc()}, localVarAttr));
+}
+
 void AddDebugInfoPass::runOnOperation() {
   mlir::ModuleOp module = getOperation();
   mlir::MLIRContext *context = &getContext();
@@ -144,14 +191,15 @@ void AddDebugInfoPass::runOnOperation() {
       subprogramFlags =
           subprogramFlags | mlir::LLVM::DISubprogramFlags::Definition;
     }
-    unsigned line = 1;
-    if (auto funcLoc = mlir::dyn_cast<mlir::FileLineColLoc>(l))
-      line = funcLoc.getLine();
-
+    unsigned line = getLineFromLoc(l);
     auto spAttr = mlir::LLVM::DISubprogramAttr::get(
         context, id, compilationUnit, fileAttr, funcName, fullName,
         funcFileAttr, line, line, subprogramFlags, subTypeAttr);
     funcOp->setLoc(builder.getFusedLoc({funcOp->getLoc()}, spAttr));
+
+    funcOp.walk([&](fir::cg::XDeclareOp declOp) {
+      handleDeclareOp(declOp, fileAttr, spAttr, typeGen);
+    });
   });
 }
 

flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp

@@ -24,11 +24,6 @@ DebugTypeGenerator::DebugTypeGenerator(mlir::ModuleOp m)
   LLVM_DEBUG(llvm::dbgs() << "DITypeAttr generator\n");
 }
 
-static mlir::LLVM::DITypeAttr genPlaceholderType(mlir::MLIRContext *context) {
-  return mlir::LLVM::DIBasicTypeAttr::get(
-      context, llvm::dwarf::DW_TAG_base_type, "void", 32, 1);
-}
-
 static mlir::LLVM::DITypeAttr genBasicType(mlir::MLIRContext *context,
                                            mlir::StringAttr name,
                                            unsigned bitSize,
@@ -37,6 +32,11 @@ static mlir::LLVM::DITypeAttr genBasicType(mlir::MLIRContext *context,
       context, llvm::dwarf::DW_TAG_base_type, name, bitSize, decoding);
 }
 
+static mlir::LLVM::DITypeAttr genPlaceholderType(mlir::MLIRContext *context) {
+  return genBasicType(context, mlir::StringAttr::get(context, "integer"), 32,
+                      llvm::dwarf::DW_ATE_signed);
+}
+
 mlir::LLVM::DITypeAttr
 DebugTypeGenerator::convertType(mlir::Type Ty, mlir::LLVM::DIFileAttr fileAttr,
                                 mlir::LLVM::DIScopeAttr scope,