[flang] Improve debug info for functions. #90083

abidh · 2024-04-25T16:52:45Z

This PR improves the debug information for functions in the following ways:

Get line number information from FuncOp and remove hard-coded line numbers.
Use proper type for function signature. I have a added a type converter. Currently, it is very limited but will be enhanced with time.
Use de-constructed function name.

This PR improves the debug information for functions in the following way: 1. Remove hardcoded line numbers. 2. Use proper type for function signature. I have a added a type convertor. It currently is very limited but will be enhanced with time. 3. Use de-constructed function name so that user see the same name as was in the source.

llvmbot · 2024-04-25T16:53:18Z

@llvm/pr-subscribers-flang-fir-hlfir

Author: Abid Qadeer (abidh)

Changes

This PR improves the debug information for functions in the following ways:

Get line number information from FuncOp and remove hard-coded line numbers.
Use proper type for function signature. I have a added a type converter. Currently, it is very limited but will be enhanced with time.
Use de-constructed function name.

Full diff: https://github.com/llvm/llvm-project/pull/90083.diff

6 Files Affected:

(modified) flang/lib/Optimizer/Transforms/AddDebugInfo.cpp (+26-10)
(modified) flang/lib/Optimizer/Transforms/CMakeLists.txt (+1)
(added) flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp (+63)
(added) flang/lib/Optimizer/Transforms/DebugTypeGenerator.h (+40)
(added) flang/test/Transforms/debug-fn-info.f90 (+43)
(modified) flang/test/Transforms/debug-line-table-inc-file.fir (+1-1)

diff --git a/flang/lib/Optimizer/Transforms/AddDebugInfo.cpp b/flang/lib/Optimizer/Transforms/AddDebugInfo.cpp
index 68584bef055b61..5a023db7dd59af 100644
--- a/flang/lib/Optimizer/Transforms/AddDebugInfo.cpp
+++ b/flang/lib/Optimizer/Transforms/AddDebugInfo.cpp
@@ -11,6 +11,7 @@
 /// This pass populates some debug information for the module and functions.
 //===----------------------------------------------------------------------===//
 
+#include "DebugTypeGenerator.h"
 #include "flang/Common/Version.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
 #include "flang/Optimizer/Builder/Todo.h"
@@ -106,14 +107,27 @@ void AddDebugInfoPass::runOnOperation() {
       filePath = llvm::sys::path::parent_path(funcLoc.getFilename().getValue());
     }
 
-    mlir::StringAttr funcName =
+    mlir::StringAttr fullName =
         mlir::StringAttr::get(context, funcOp.getName());
-    mlir::LLVM::DIBasicTypeAttr bT = mlir::LLVM::DIBasicTypeAttr::get(
-        context, llvm::dwarf::DW_TAG_base_type, "void", /*sizeInBits=*/0,
-        /*encoding=*/1);
-    // FIXME: Provide proper type for subroutine
+    auto result = fir::NameUniquer::deconstruct(funcOp.getName());
+    mlir::StringAttr funcName =
+        mlir::StringAttr::get(context, result.second.name);
+
+    llvm::SmallVector<mlir::LLVM::DITypeAttr> types;
+    fir::DebugTypeGenerator typeGen(module);
+    for (auto resTy : funcOp.getResultTypes()) {
+      auto tyAttr = typeGen.convertType(fir::unwrapRefType(resTy), fileAttr,
+                                        cuAttr, funcOp.getLoc());
+      types.push_back(tyAttr);
+    }
+    for (auto inTy : funcOp.getArgumentTypes()) {
+      auto tyAttr = typeGen.convertType(fir::unwrapRefType(inTy), fileAttr,
+                                        cuAttr, funcOp.getLoc());
+      types.push_back(tyAttr);
+    }
+
     mlir::LLVM::DISubroutineTypeAttr subTypeAttr =
-        mlir::LLVM::DISubroutineTypeAttr::get(context, CC, {bT, bT});
+        mlir::LLVM::DISubroutineTypeAttr::get(context, CC, types);
     mlir::LLVM::DIFileAttr funcFileAttr =
         mlir::LLVM::DIFileAttr::get(context, fileName, filePath);
 
@@ -130,11 +144,13 @@ void AddDebugInfoPass::runOnOperation() {
       subprogramFlags =
           subprogramFlags | mlir::LLVM::DISubprogramFlags::Definition;
     }
-    // FIXME: Provide proper line and scopeline.
+    unsigned line = 1;
+    if (auto funcLoc = l.dyn_cast<mlir::FileLineColLoc>())
+      line = funcLoc.getLine();
+
     auto spAttr = mlir::LLVM::DISubprogramAttr::get(
-        context, id, compilationUnit, fileAttr, funcName, funcName,
-        funcFileAttr, /*line=*/1, /*scopeline=*/1, subprogramFlags,
-        subTypeAttr);
+        context, id, compilationUnit, fileAttr, funcName, fullName,
+        funcFileAttr, line, line, subprogramFlags, subTypeAttr);
     funcOp->setLoc(builder.getFusedLoc({funcOp->getLoc()}, spAttr));
   });
 }
diff --git a/flang/lib/Optimizer/Transforms/CMakeLists.txt b/flang/lib/Optimizer/Transforms/CMakeLists.txt
index fc08d67540ceb0..5a542f237f8f98 100644
--- a/flang/lib/Optimizer/Transforms/CMakeLists.txt
+++ b/flang/lib/Optimizer/Transforms/CMakeLists.txt
@@ -22,6 +22,7 @@ add_flang_library(FIRTransforms
   OMPMarkDeclareTarget.cpp
   VScaleAttr.cpp
   FunctionAttr.cpp
+  DebugTypeGenerator.cpp
 
   DEPENDS
   FIRDialect
diff --git a/flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp b/flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp
new file mode 100644
index 00000000000000..0057e08f8a763b
--- /dev/null
+++ b/flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp
@@ -0,0 +1,63 @@
+//===-- DebugTypeGenerator.cpp -- type conversion ---------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Coding style: https://mlir.llvm.org/getting_started/DeveloperGuide/
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "flang-debug-type-generator"
+
+#include "DebugTypeGenerator.h"
+#include "llvm/ADT/ScopeExit.h"
+#include "llvm/BinaryFormat/Dwarf.h"
+#include "llvm/Support/Debug.h"
+
+namespace fir {
+
+DebugTypeGenerator::DebugTypeGenerator(mlir::ModuleOp m)
+    : module(m), kindMapping(getKindMapping(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,
+                                           unsigned decoding) {
+  return mlir::LLVM::DIBasicTypeAttr::get(
+      context, llvm::dwarf::DW_TAG_base_type, name, bitSize, decoding);
+}
+
+mlir::LLVM::DITypeAttr
+DebugTypeGenerator::convertType(mlir::Type Ty, mlir::LLVM::DIFileAttr fileAttr,
+                                mlir::LLVM::DIScopeAttr scope,
+                                mlir::Location loc) {
+  mlir::MLIRContext *context = module.getContext();
+  if (Ty.isIntOrIndex()) {
+    return genBasicType(context, mlir::StringAttr::get(context, "integer"),
+                        Ty.getIntOrFloatBitWidth(), llvm::dwarf::DW_ATE_signed);
+  } else if (Ty.isa<mlir::FloatType>() || Ty.isa<fir::RealType>()) {
+    return genBasicType(context, mlir::StringAttr::get(context, "real"),
+                        Ty.getIntOrFloatBitWidth(), llvm::dwarf::DW_ATE_float);
+  } else if (auto logTy = Ty.dyn_cast_or_null<fir::LogicalType>()) {
+    return genBasicType(context,
+                        mlir::StringAttr::get(context, logTy.getMnemonic()),
+                        kindMapping.getLogicalBitsize(logTy.getFKind()),
+                        llvm::dwarf::DW_ATE_boolean);
+  } else {
+    // FIXME: These types are currently unhandled. We are generating a
+    // placeholder type to allow us to test supported bits.
+    return genPlaceholderType(context);
+  }
+}
+
+} // namespace fir
diff --git a/flang/lib/Optimizer/Transforms/DebugTypeGenerator.h b/flang/lib/Optimizer/Transforms/DebugTypeGenerator.h
new file mode 100644
index 00000000000000..5a2bb201db47a3
--- /dev/null
+++ b/flang/lib/Optimizer/Transforms/DebugTypeGenerator.h
@@ -0,0 +1,40 @@
+//===-- DebugTypeGenerator.h -- type conversion ------------------- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Coding style: https://mlir.llvm.org/getting_started/DeveloperGuide/
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef FORTRAN_OPTIMIZER_TRANSFORMS_DEBUGTYPEGENERATOR_H
+#define FORTRAN_OPTIMIZER_TRANSFORMS_DEBUGTYPEGENERATOR_H
+
+#include "flang/Optimizer/Dialect/FIRType.h"
+#include "flang/Optimizer/Dialect/Support/FIRContext.h"
+#include "flang/Optimizer/Dialect/Support/KindMapping.h"
+#include "llvm/Support/Debug.h"
+
+namespace fir {
+
+/// This converts FIR/mlir type to DITypeAttr.
+class DebugTypeGenerator {
+public:
+  DebugTypeGenerator(mlir::ModuleOp module);
+
+  mlir::LLVM::DITypeAttr convertType(mlir::Type Ty,
+                                     mlir::LLVM::DIFileAttr fileAttr,
+                                     mlir::LLVM::DIScopeAttr scope,
+                                     mlir::Location loc);
+
+private:
+  mlir::ModuleOp module;
+  KindMapping kindMapping;
+};
+
+} // namespace fir
+
+#endif // FORTRAN_OPTIMIZER_TRANSFORMS_DEBUGTYPEGENERATOR_H
diff --git a/flang/test/Transforms/debug-fn-info.f90 b/flang/test/Transforms/debug-fn-info.f90
new file mode 100644
index 00000000000000..c1a817312c959c
--- /dev/null
+++ b/flang/test/Transforms/debug-fn-info.f90
@@ -0,0 +1,43 @@
+! RUN: %flang_fc1 -emit-fir -debug-info-kind=standalone -mmlir --mlir-print-debuginfo %s -o - | fir-opt --add-debug-info --mlir-print-debuginfo  | FileCheck %s
+
+
+! CHECK-DAG: #[[INT8:.*]] = #llvm.di_basic_type<tag = DW_TAG_base_type, name = "integer", sizeInBits = 64, encoding = DW_ATE_signed>
+! CHECK-DAG: #[[INT4:.*]] = #llvm.di_basic_type<tag = DW_TAG_base_type, name = "integer", sizeInBits = 32, encoding = DW_ATE_signed>
+! CHECK-DAG: #[[REAL8:.*]] = #llvm.di_basic_type<tag = DW_TAG_base_type, name = "real", sizeInBits = 64, encoding = DW_ATE_float>
+! CHECK-DAG: #[[LOG1:.*]] = #llvm.di_basic_type<tag = DW_TAG_base_type, name = "logical", sizeInBits = 8, encoding = DW_ATE_boolean>
+! CHECK-DAG: #[[REAL4:.*]] = #llvm.di_basic_type<tag = DW_TAG_base_type, name = "real", sizeInBits = 32, encoding = DW_ATE_float>
+! CHECK-DAG: #[[LOG4:.*]] = #llvm.di_basic_type<tag = DW_TAG_base_type, name = "logical", sizeInBits = 32, encoding = DW_ATE_boolean>
+! CHECK: #[[TY1:.*]] = #llvm.di_subroutine_type<callingConvention = DW_CC_normal, types = #[[INT8]], #[[INT4]], #[[REAL8]], #[[LOG1]]>
+! CHECK: #[[TY2:.*]] = #llvm.di_subroutine_type<callingConvention = DW_CC_normal, types = #[[INT4]], #[[INT8]], #[[REAL4]], #[[LOG4]]>
+
+program mn
+  integer(kind=4) :: i4
+  integer(kind=8) :: i8
+  real(kind=4) :: r4
+  real(kind=8) :: r8
+  logical(kind=1) :: l1
+  logical(kind=4) :: l4
+  i8 = fn1(i4, r8, l1)
+  i4 = fn2(i8, r4, l4)
+contains
+  ! CHECK: #di_subprogram1 = #llvm.di_subprogram<id = {{.*}}, compileUnit = {{.*}}, scope = {{.*}}, name = "fn1", linkageName = "_QFPfn1", file = {{.*}}, line = [[@LINE+1]], scopeLine = [[@LINE+1]], subprogramFlags = Definition, type = #[[TY1]]>
+  function fn1(a, b, c) result (res)
+    implicit none
+    integer(kind=4), intent(in) :: a
+    real(kind=8), intent(in) :: b
+    logical(kind=1), intent(in) :: c
+    integer(kind=8) :: res
+    res = a + b
+  end function
+
+! CHECK: #di_subprogram2 = #llvm.di_subprogram<id = {{.*}}, compileUnit = {{.*}}, scope = {{.*}}, name = "fn2", linkageName = "_QFPfn2", file = {{.*}}, line = [[@LINE+1]], scopeLine = [[@LINE+1]], subprogramFlags = Definition, type = #[[TY2]]>
+  function fn2(a, b, c) result (res)
+    implicit none
+    integer(kind=8), intent(in) :: a
+    real(kind=4), intent(in) :: b
+    logical(kind=4), intent(in) :: c
+    integer(kind=4) :: res
+    res = a + b
+  end function
+end program
+
diff --git a/flang/test/Transforms/debug-line-table-inc-file.fir b/flang/test/Transforms/debug-line-table-inc-file.fir
index dc75482d4f8a7f..d7f60a1a86dbf0 100644
--- a/flang/test/Transforms/debug-line-table-inc-file.fir
+++ b/flang/test/Transforms/debug-line-table-inc-file.fir
@@ -31,7 +31,7 @@ module attributes {} {
 // CHECK: #[[LOC_INC_FILE:.*]] = loc("{{.*}}inc.f90":1:1)
 // CHECK: #[[LOC_FILE:.*]] = loc("{{.*}}simple.f90":3:1)
 // CHECK: #[[DI_CU:.*]] = #llvm.di_compile_unit<id = distinct[{{.*}}]<>, sourceLanguage = DW_LANG_Fortran95, file = #[[DI_FILE]], producer = "flang{{.*}}", isOptimized = false, emissionKind = LineTablesOnly>
-// CHECK: #[[DI_SP_INC:.*]] = #llvm.di_subprogram<id = distinct[{{.*}}]<>, compileUnit = #[[DI_CU]], scope = #[[DI_FILE]], name = "_QPsinc", linkageName = "_QPsinc", file = #[[DI_INC_FILE]], {{.*}}>
+// CHECK: #[[DI_SP_INC:.*]] = #llvm.di_subprogram<id = distinct[{{.*}}]<>, compileUnit = #[[DI_CU]], scope = #[[DI_FILE]], name = "sinc", linkageName = "_QPsinc", file = #[[DI_INC_FILE]], {{.*}}>
 // CHECK: #[[DI_SP:.*]] = #llvm.di_subprogram<id = distinct[{{.*}}]<>, compileUnit = #[[DI_CU]], scope = #[[DI_FILE]], name = "_QQmain", linkageName = "_QQmain", file = #[[DI_FILE]], {{.*}}>
 // CHECK: #[[FUSED_LOC_INC_FILE]] = loc(fused<#[[DI_SP_INC]]>[#[[LOC_INC_FILE]]])
 // CHECK: #[[FUSED_LOC_FILE]] = loc(fused<#[[DI_SP]]>[#[[LOC_FILE]]])

kiranchandramohan

LGTM.

Would it be possible to reconstruct the type for Complex, Derived and various array types without passing additional info from the frontend?

tblah · 2024-04-26T11:09:03Z

flang/lib/Optimizer/Transforms/AddDebugInfo.cpp

+    llvm::SmallVector<mlir::LLVM::DITypeAttr> types;
+    fir::DebugTypeGenerator typeGen(module);
+    for (auto resTy : funcOp.getResultTypes()) {
+      auto tyAttr = typeGen.convertType(fir::unwrapRefType(resTy), fileAttr,


Why do we need to remove the reference type of returned values?

You are right that it is not required. I will remove it. On this topic, can you kindly explain why the arguments are wrapped in the reference?

Without the VALUE keyword, fortran defaults to passing all arguments by reference

abidh · 2024-04-26T15:16:59Z

LGTM.

Would it be possible to reconstruct the type for Complex, Derived and various array types without passing additional info from the frontend?

I think complex and array type should be ok. Some work may need to be done for calculation of offsets for derived types but @jeanPerier commented on the design document that it should be do-able using FIR RecordType type directly + mlir datalayout.

tblah

thanks

DavidSpickett · 2024-04-29T09:58:40Z

This has caused a test suite failure. This particular bot is red already but this specific failure is new:
https://lab.llvm.org/buildbot/#/builders/184/builds/11961

> flang-new: ../llvm/mlir/lib/IR/Types.cpp:126: unsigned int mlir::Type::getIntOrFloatBitWidth() const: Assertion `isIntOrFloat() && "only integers and floats have a bitwidth"' failed.

The test file is https://github.com/llvm/llvm-test-suite/blob/main/Fortran/gfortran/regression/lto/20091016-1_0.f90.

This reverts commit f029da5.

Reverts #90083 due to a test suite failure: https://lab.llvm.org/buildbot/#/builders/184/builds/11961 ``` flang-new: ../llvm/mlir/lib/IR/Types.cpp:126: unsigned int mlir::Type::getIntOrFloatBitWidth() const: Assertion `isIntOrFloat() && "only integers and floats have a bitwidth"' failed. ```

abidh · 2024-04-29T12:36:56Z

Thanks @DavidSpickett for reverting it. I will investigate the regression.

The initial PR llvm#90083 was reverted as it caused the regression in one of the gfortran tests. This commit fixes this issue by replacing isIntOrIndex with isInteger which is the right function to check for integer type.

…ixed. (#90484) The original PR #90083 had to be reverted in PR #90444 as it caused one of the gfortran tests to fail. The issue was using `isIntOrIndex` for checking for integer type. It allowed index type which later caused assertion when calling `getIntOrFloatBitWidth`. I have now replaced it with `isInteger` which should fix this regression.

The initial PR llvm#90083 was reverted as it caused the regression in one of the gfortran tests. This commit fixes this issue by replacing isIntOrIndex with isInteger which is the right function to check for integer type.

abidh requested review from tblah, kiranchandramohan, Leporacanthicus, jeanPerier, dpalermo, kiranktp and vzakhari April 25, 2024 16:52

llvmbot added flang Flang issues not falling into any other category flang:fir-hlfir labels Apr 25, 2024

kiranchandramohan approved these changes Apr 26, 2024

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tblah reviewed Apr 26, 2024

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Address review comments.

0450758

tblah approved these changes Apr 26, 2024

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abidh merged commit f029da5 into llvm:main Apr 29, 2024
4 checks passed

abidh deleted the type_conv branch April 29, 2024 08:44

DavidSpickett added a commit that referenced this pull request Apr 29, 2024

Revert "[flang] Improve debug info for functions. (#90083)"

acc59b6

This reverts commit f029da5.

DavidSpickett mentioned this pull request Apr 29, 2024

Revert "[flang] Improve debug info for functions." #90444

Merged

abidh mentioned this pull request Apr 29, 2024

Reapply "[flang] Improve debug info for functions." with regression fixed. #90484

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[flang] Improve debug info for functions. #90083

[flang] Improve debug info for functions. #90083

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[flang] Improve debug info for functions. #90083

[flang] Improve debug info for functions. #90083

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