[flang-commits] [flang] [flang][debug] Support allocatables. (PR #95557)

Abid Qadeer via flang-commits flang-commits at lists.llvm.org
Fri Jun 14 08:28:36 PDT 2024


https://github.com/abidh created https://github.com/llvm/llvm-project/pull/95557

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

>From fcf9a90001383dad4e13192bf1efc1f1f546d3b5 Mon Sep 17 00:00:00 2001
From: Abid Qadeer <haqadeer at amd.com>
Date: Fri, 14 Jun 2024 14:55:10 +0100
Subject: [PATCH] [flang][debug] Support allocatables.

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
---
 .../Transforms/DebugTypeGenerator.cpp         | 31 +++++++++++++++++--
 .../Optimizer/Transforms/DebugTypeGenerator.h |  7 +++++
 .../test/Integration/debug-allocatable-1.f90  | 24 ++++++++++++++
 flang/test/Transforms/debug-allocatable-1.fir | 26 ++++++++++++++++
 4 files changed, 86 insertions(+), 2 deletions(-)
 create mode 100644 flang/test/Integration/debug-allocatable-1.f90
 create mode 100644 flang/test/Transforms/debug-allocatable-1.fir

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]]>



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