[flang][debug] Support allocatables. #95557

abidh · 2024-06-14T15:28:29Z

This PR adds debug support for allocatable. The allocatable arrays use the existing functionality to read the array information from descriptor. The allocatable for the scalar shows up as pointer to the scalar.

While testing this, I notices that values of allocated and associated flags were swapped. This is also fixed in this PR.

Here is how the debugging of the allocatable looks like with this patch in place.

integer, allocatable :: ar1(:, :)
real, allocatable :: sc

allocate(sc)
allocate(ar1(3, 4))

(gdb) ptype ar1
type = integer, allocatable (3,4)
(gdb) p ar1
$1 = ((5, 6, 7) (9, 10, 11) (13, 14, 15) (17, 18, 19)) (gdb) p sc
$2 = (PTR TO -> ( real )) 0x205300
(gdb) p *sc
$3 = 3.1400001

llvmbot · 2024-06-14T15:29:10Z

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

Author: Abid Qadeer (abidh)

Changes

This PR adds debug support for allocatable. The allocatable arrays use the existing functionality to read the array information from descriptor. The allocatable for the scalar shows up as pointer to the scalar.

While testing this, I notices that values of allocated and associated flags were swapped. This is also fixed in this PR.

Here is how the debugging of the allocatable looks like with this patch in place.

integer, allocatable :: ar1(:, :)
real, allocatable :: sc

allocate(sc)
allocate(ar1(3, 4))

(gdb) ptype ar1
type = integer, allocatable (3,4)
(gdb) p ar1
$1 = ((5, 6, 7) (9, 10, 11) (13, 14, 15) (17, 18, 19)) (gdb) p sc
$2 = (PTR TO -> ( real )) 0x205300
(gdb) p *sc
$3 = 3.1400001

Full diff: https://github.com/llvm/llvm-project/pull/95557.diff

4 Files Affected:

(modified) flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp (+29-2)
(modified) flang/lib/Optimizer/Transforms/DebugTypeGenerator.h (+7)
(added) flang/test/Integration/debug-allocatable-1.f90 (+24)
(added) flang/test/Transforms/debug-allocatable-1.fir (+26)

diff --git a/flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp b/flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp
index 53745d10fe9e4..e0cea83f5c4c6 100644
--- a/flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp
+++ b/flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp
@@ -60,8 +60,10 @@ DebugTypeGenerator::DebugTypeGenerator(mlir::ModuleOp m)
   // The debug information requires the offset of certain fields in the
   // descriptors like lower_bound and extent for each dimension.
   mlir::Type llvmDimsType = getDescFieldTypeModel<kDimsPosInBox>()(context);
+  mlir::Type llvmPtrType = getDescFieldTypeModel<kAddrPosInBox>()(context);
   dimsOffset = getComponentOffset<kDimsPosInBox>(*dl, context, llvmDimsType);
   dimsSize = dl->getTypeSize(llvmDimsType);
+  ptrSize = dl->getTypeSize(llvmPtrType);
 }
 
 static mlir::LLVM::DITypeAttr genBasicType(mlir::MLIRContext *context,
@@ -104,8 +106,8 @@ mlir::LLVM::DITypeAttr DebugTypeGenerator::convertBoxedSequenceType(
   // allocated = associated = (*base_addr != 0)
   mlir::LLVM::DIExpressionAttr valid =
       mlir::LLVM::DIExpressionAttr::get(context, ops);
-  mlir::LLVM::DIExpressionAttr associated = genAllocated ? valid : nullptr;
-  mlir::LLVM::DIExpressionAttr allocated = genAssociated ? valid : nullptr;
+  mlir::LLVM::DIExpressionAttr allocated = genAllocated ? valid : nullptr;
+  mlir::LLVM::DIExpressionAttr associated = genAssociated ? valid : nullptr;
   ops.clear();
 
   llvm::SmallVector<mlir::LLVM::DINodeAttr> elements;
@@ -190,6 +192,28 @@ mlir::LLVM::DITypeAttr DebugTypeGenerator::convertSequenceType(
       /* associated */ nullptr);
 }
 
+mlir::LLVM::DITypeAttr DebugTypeGenerator::convertPointerLikeType(
+    mlir::Type elTy, mlir::LLVM::DIFileAttr fileAttr,
+    mlir::LLVM::DIScopeAttr scope, mlir::Location loc, bool genAllocated,
+    bool genAssociated) {
+  mlir::MLIRContext *context = module.getContext();
+
+  // Arrays and character need different treatment because DWARF have special
+  // constructs for them to get the location from the descriptor. Rest of
+  // types are handled like pointer to underlying type.
+  if (auto seqTy = mlir::dyn_cast_or_null<fir::SequenceType>(elTy))
+    return convertBoxedSequenceType(seqTy, fileAttr, scope, loc, genAllocated,
+                                    genAssociated);
+
+  mlir::LLVM::DITypeAttr elTyAttr = convertType(elTy, fileAttr, scope, loc);
+
+  return mlir::LLVM::DIDerivedTypeAttr::get(
+      context, llvm::dwarf::DW_TAG_pointer_type,
+      mlir::StringAttr::get(context, ""), elTyAttr, ptrSize,
+      /*alignInBits*/ 0, /* offset */ 0,
+      /* optional<address space> */ std::nullopt, /* extra data */ nullptr);
+}
+
 mlir::LLVM::DITypeAttr
 DebugTypeGenerator::convertType(mlir::Type Ty, mlir::LLVM::DIFileAttr fileAttr,
                                 mlir::LLVM::DIScopeAttr scope,
@@ -229,6 +253,9 @@ DebugTypeGenerator::convertType(mlir::Type Ty, mlir::LLVM::DIFileAttr fileAttr,
     if (auto seqTy = mlir::dyn_cast_or_null<fir::SequenceType>(elTy))
       return convertBoxedSequenceType(seqTy, fileAttr, scope, loc, false,
                                       false);
+    if (auto heapTy = mlir::dyn_cast_or_null<fir::HeapType>(elTy))
+      return convertPointerLikeType(heapTy.getElementType(), fileAttr, scope,
+                                    loc, true, false);
     return genPlaceholderType(context);
   } else {
     // FIXME: These types are currently unhandled. We are generating a
diff --git a/flang/lib/Optimizer/Transforms/DebugTypeGenerator.h b/flang/lib/Optimizer/Transforms/DebugTypeGenerator.h
index 11515d11dfed6..0ced989414d86 100644
--- a/flang/lib/Optimizer/Transforms/DebugTypeGenerator.h
+++ b/flang/lib/Optimizer/Transforms/DebugTypeGenerator.h
@@ -45,10 +45,17 @@ class DebugTypeGenerator {
                            mlir::LLVM::DIFileAttr fileAttr,
                            mlir::LLVM::DIScopeAttr scope, mlir::Location loc,
                            bool genAllocated, bool genAssociated);
+
+  mlir::LLVM::DITypeAttr
+  convertPointerLikeType(mlir::Type elTy, mlir::LLVM::DIFileAttr fileAttr,
+                         mlir::LLVM::DIScopeAttr scope, mlir::Location loc,
+                         bool genAllocated, bool genAssociated);
+
   mlir::ModuleOp module;
   KindMapping kindMapping;
   std::uint64_t dimsSize;
   std::uint64_t dimsOffset;
+  std::uint64_t ptrSize;
 };
 
 } // namespace fir
diff --git a/flang/test/Integration/debug-allocatable-1.f90 b/flang/test/Integration/debug-allocatable-1.f90
new file mode 100644
index 0000000000000..471c8cdb7d54e
--- /dev/null
+++ b/flang/test/Integration/debug-allocatable-1.f90
@@ -0,0 +1,24 @@
+! RUN: %flang_fc1 -emit-llvm -debug-info-kind=standalone %s -o - | FileCheck  %s
+
+subroutine ff(n, m)
+  integer n, m, i, j
+  integer, allocatable :: ar1(:, :)
+  real, allocatable :: sc
+
+  allocate(ar1(n, m))
+  allocate(sc)
+  sc = 3.14
+
+  print *, sc
+  print *, ar1
+end subroutine ff
+
+
+! CHECK-DAG: !DILocalVariable(name: "ar1"{{.*}}type: ![[TY1:[0-9]+]])
+! CHECK-DAG: ![[TY1]] = !DICompositeType(tag: DW_TAG_array_type{{.*}}elements: ![[ELEMS2:[0-9]+]]{{.*}}dataLocation{{.*}}allocated: !DIExpression(DW_OP_push_object_address, DW_OP_deref, DW_OP_lit0, DW_OP_ne))
+! CHECK-DAG: ![[ELEMS2]] = !{![[ELEM1:[0-9]+]], ![[ELEM2:[0-9]+]]}
+! CHECK-DAG: ![[ELEM1]] = !DISubrange
+! CHECK-DAG: ![[ELEM2]] = !DISubrange
+! CHECK-DAG: !DILocalVariable(name: "sc"{{.*}}type: ![[TY2:[0-9]+]])
+! CHECK-DAG: ![[TY2]] = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: ![[TY3:[0-9]+]]{{.*}})
+! CHECK-DAG: ![[TY3]] = !DIBasicType(name: "real"{{.*}})
diff --git a/flang/test/Transforms/debug-allocatable-1.fir b/flang/test/Transforms/debug-allocatable-1.fir
new file mode 100644
index 0000000000000..fd0beaddcdb70
--- /dev/null
+++ b/flang/test/Transforms/debug-allocatable-1.fir
@@ -0,0 +1,26 @@
+// RUN: fir-opt --add-debug-info --mlir-print-debuginfo %s | FileCheck %s
+
+
+module attributes {dlti.dl_spec = #dlti.dl_spec<>} {
+  func.func private @_QFPff()  {
+    %c1 = arith.constant 1 : index
+    %c0 = arith.constant 0 : index
+    %0 = fir.undefined !fir.dscope
+    %1 = fir.alloca !fir.box<!fir.heap<!fir.array<?x?xi32>>> {bindc_name = "ar2", uniq_name = "_QFFffEar2"}
+    %4 = fircg.ext_declare %1 {uniq_name = "_QFFffEar2"} : (!fir.ref<!fir.box<!fir.heap<!fir.array<?x?xi32>>>>) -> !fir.ref<!fir.box<!fir.heap<!fir.array<?x?xi32>>>>  loc(#loc1)
+    %15 = fir.alloca !fir.box<!fir.heap<f32>> {bindc_name = "sc", uniq_name = "_QFFffEsc"}
+    %18 = fircg.ext_declare %15 {uniq_name = "_QFFffEsc"} : (!fir.ref<!fir.box<!fir.heap<f32>>>) -> !fir.ref<!fir.box<!fir.heap<f32>>> loc(#loc2)
+    return
+  } loc(#loc3)
+}
+
+#loc1 = loc("test.f90":3:3)
+#loc2 = loc("test.f90":4:3)
+#loc3 = loc("test.f90":1:3)
+
+// CHECK-DAG: #[[TY1:.*]] = #llvm.di_basic_type<tag = DW_TAG_base_type, name = "real"{{.*}}>
+// CHECK-DAG: #[[TY2:.*]] = #llvm.di_composite_type<tag = DW_TAG_array_type{{.*}}#llvm.di_subrange{{.*}}#llvm.di_subrange{{.*}}allocated = <[DW_OP_push_object_address, DW_OP_deref, DW_OP_lit0, DW_OP_ne]>>
+// CHECK-DAG: #[[TY3:.*]] = #llvm.di_derived_type<tag = DW_TAG_pointer_type{{.*}}baseType = #[[TY1]]{{.*}}>
+
+// CHECK-DAG: #llvm.di_local_variable<{{.*}}name = "ar2"{{.*}}type = #[[TY2]]>
+// CHECK-DAG: #llvm.di_local_variable<{{.*}}name = "sc"{{.*}}type = #[[TY3]]>

vzakhari

LGTM, though, the literal arguments' comments may need to be cleaned up across the file.

vzakhari · 2024-06-14T17:14:00Z

flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp

@@ -229,6 +253,9 @@ DebugTypeGenerator::convertType(mlir::Type Ty, mlir::LLVM::DIFileAttr fileAttr,
    if (auto seqTy = mlir::dyn_cast_or_null<fir::SequenceType>(elTy))
      return convertBoxedSequenceType(seqTy, fileAttr, scope, loc, false,
                                      false);
+    if (auto heapTy = mlir::dyn_cast_or_null<fir::HeapType>(elTy))
+      return convertPointerLikeType(heapTy.getElementType(), fileAttr, scope,
+                                    loc, true, false);


nit: please add comments with argument names for the literal arguments.

I will fix this and will also open a separate PR to cleanup the comments throughout the file.

tblah

LGTM (with Slava's comment), thanks!

jeanPerier · 2024-06-17T07:46:59Z

flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp

+    bool genAssociated) {
+  mlir::MLIRContext *context = module.getContext();
+
+  // Arrays and character need different treatment because DWARF have special


You mention character as a special case here, but the condition just below is only checking for arrays. How are characters handled?

The special handling of allocatable characters will come in the next PR. I only added arrays in this one as their handling was already present.

This PR adds debug support for allocatable. The allocatable arrays use the existing functionality to read the array information from descriptor. The allocatable for the scalar shows up as pointer to the scalar. While testing this, I notices that values of allocated and associated flags were swapped. This is also fixed in this PR. Here is how the debugging of the allocatable looks like with this patch in place. integer, allocatable :: ar1(:, :) real, allocatable :: sc allocate(sc) allocate(ar1(3, 4)) (gdb) ptype ar1 type = integer, allocatable (3,4) (gdb) p ar1 $1 = ((5, 6, 7) (9, 10, 11) (13, 14, 15) (17, 18, 19)) (gdb) p sc $2 = (PTR TO -> ( real )) 0x205300 (gdb) p *sc $3 = 3.1400001

abidh requested review from tblah, kiranchandramohan, jeanPerier, dpalermo, jinisusan, kiranktp and vzakhari June 14, 2024 15:28

llvmbot added flang Flang issues not falling into any other category flang:fir-hlfir labels Jun 14, 2024

vzakhari approved these changes Jun 14, 2024

View reviewed changes

tblah approved these changes Jun 14, 2024

View reviewed changes

jeanPerier reviewed Jun 17, 2024

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abidh added 2 commits June 17, 2024 11:59

Fix comments.

44c5bd5

abidh force-pushed the allocatable branch from fcf9a90 to 44c5bd5 Compare June 17, 2024 12:11

abidh merged commit 0432221 into llvm:main Jun 17, 2024
7 checks passed

jpienaar mentioned this pull request Jun 17, 2024

[mlirc] Add missing extern C #95829

Merged

abidh deleted the allocatable branch October 9, 2024 16:42

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[flang][debug] Support allocatables. #95557

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[flang][debug] Support allocatables. #95557

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