[flang][debug] Add support for fixed size arrays. (#92568)

abidh · tblah · web-flow · commit 5434b04234a8 · 2024-05-24T12:55:54.000+01:00
This PR adds the type conversion support for fixed size arrays. Mostly
mechanical changes converting dimension values to subrange fields. A
limitation is that lower bound is always one for the moment as that
information is missing in `SequenceType`.

With this change in place, I can evaluate fixed size arrays in debugger.
```

(gdb) p x
$1 = ((2, 3, 4, 5) (3, 4, 5, 6) (4, 5, 6, 7) (5, 6, 7, 8) (6, 7, 8, 9))
(gdb) ptype x
type = integer (4,5)
```

---------

Co-authored-by: Tom Eccles &lt;t@freedommail.info&gt;
diff --git a/flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp b/flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp
@@ -37,6 +37,45 @@ static mlir::LLVM::DITypeAttr genPlaceholderType(mlir::MLIRContext *context) {
                       llvm::dwarf::DW_ATE_signed);
 }
 
+mlir::LLVM::DITypeAttr DebugTypeGenerator::convertSequenceType(
+    fir::SequenceType seqTy, mlir::LLVM::DIFileAttr fileAttr,
+    mlir::LLVM::DIScopeAttr scope, mlir::Location loc) {
+
+  mlir::MLIRContext *context = module.getContext();
+  // FIXME: Only fixed sizes arrays handled at the moment.
+  if (seqTy.hasDynamicExtents())
+    return genPlaceholderType(context);
+
+  llvm::SmallVector<mlir::LLVM::DINodeAttr> elements;
+  mlir::LLVM::DITypeAttr elemTy =
+      convertType(seqTy.getEleTy(), fileAttr, scope, loc);
+
+  for (fir::SequenceType::Extent dim : seqTy.getShape()) {
+    auto intTy = mlir::IntegerType::get(context, 64);
+    // FIXME: Only supporting lower bound of 1 at the moment. The
+    // 'SequenceType' has information about the shape but not the shift. In
+    // cases where the conversion originated during the processing of
+    // 'DeclareOp', it may be possible to pass on this information. But the
+    // type conversion should ideally be based on what information present in
+    // the type class so that it works from everywhere (e.g. when it is part
+    // of a module or a derived type.)
+    auto countAttr = mlir::IntegerAttr::get(intTy, llvm::APInt(64, dim));
+    auto lowerAttr = mlir::IntegerAttr::get(intTy, llvm::APInt(64, 1));
+    auto subrangeTy = mlir::LLVM::DISubrangeAttr::get(
+        context, countAttr, lowerAttr, nullptr, nullptr);
+    elements.push_back(subrangeTy);
+  }
+  // Apart from arrays, the `DICompositeTypeAttr` is used for other things like
+  // structure types. Many of its fields which are not applicable to arrays
+  // have been set to some valid default values.
+
+  return mlir::LLVM::DICompositeTypeAttr::get(
+      context, llvm::dwarf::DW_TAG_array_type, /*recursive id*/ {},
+      /* name */ nullptr, /* file */ nullptr, /* line */ 0, /* scope */ nullptr,
+      elemTy, mlir::LLVM::DIFlags::Zero, /* sizeInBits */ 0,
+      /*alignInBits*/ 0, elements);
+}
+
 mlir::LLVM::DITypeAttr
 DebugTypeGenerator::convertType(mlir::Type Ty, mlir::LLVM::DIFileAttr fileAttr,
                                 mlir::LLVM::DIScopeAttr scope,
@@ -69,6 +108,8 @@ DebugTypeGenerator::convertType(mlir::Type Ty, mlir::LLVM::DIFileAttr fileAttr,
     }
     return genBasicType(context, mlir::StringAttr::get(context, "complex"),
                         bitWidth * 2, llvm::dwarf::DW_ATE_complex_float);
+  } else if (auto seqTy = mlir::dyn_cast_or_null<fir::SequenceType>(Ty)) {
+    return convertSequenceType(seqTy, fileAttr, scope, loc);
   } else {
     // FIXME: These types are currently unhandled. We are generating a
     // placeholder type to allow us to test supported bits.
diff --git a/flang/lib/Optimizer/Transforms/DebugTypeGenerator.h b/flang/lib/Optimizer/Transforms/DebugTypeGenerator.h
@@ -31,6 +31,10 @@ class DebugTypeGenerator {
                                      mlir::Location loc);
 
 private:
+  mlir::LLVM::DITypeAttr convertSequenceType(fir::SequenceType seqTy,
+                                             mlir::LLVM::DIFileAttr fileAttr,
+                                             mlir::LLVM::DIScopeAttr scope,
+                                             mlir::Location loc);
   mlir::ModuleOp module;
   KindMapping kindMapping;
 };
diff --git a/flang/test/Integration/debug-fixed-array-type-2.f90 b/flang/test/Integration/debug-fixed-array-type-2.f90
@@ -0,0 +1,43 @@
+! RUN: %flang_fc1 -emit-llvm -debug-info-kind=standalone %s -o - | FileCheck %s
+
+program mn
+
+  integer d1(3)
+  integer d2(2, 5)
+  real d3(6, 8, 7)
+
+  i8 = fn1(d1, d2, d3)
+contains
+  function fn1(a1, b1, c1) result (res)
+    integer a1(3)
+    integer b1(2, 5)
+    real c1(6, 8, 7)
+    integer res
+    res = a1(1) + b1(1,2) + c1(3, 3, 4)
+  end function
+
+end program
+
+! CHECK-DAG: ![[INT:.*]] = !DIBasicType(name: "integer", size: 32, encoding: DW_ATE_signed)
+! CHECK-DAG: ![[REAL:.*]] = !DIBasicType(name: "real", size: 32, encoding: DW_ATE_float)
+! CHECK-DAG: ![[R1:.*]] = !DISubrange(count: 3, lowerBound: 1)
+! CHECK-DAG: ![[SUB1:.*]] = !{![[R1]]}
+! CHECK-DAG: ![[D1TY:.*]] = !DICompositeType(tag: DW_TAG_array_type, baseType: ![[INT]], elements: ![[SUB1]])
+! CHECK-DAG: !DILocalVariable(name: "d1"{{.*}}type: ![[D1TY]])
+
+! CHECK-DAG: ![[R21:.*]] = !DISubrange(count: 2, lowerBound: 1)
+! CHECK-DAG: ![[R22:.*]] = !DISubrange(count: 5, lowerBound: 1)
+! CHECK-DAG: ![[SUB2:.*]] = !{![[R21]], ![[R22]]}
+! CHECK-DAG: ![[D2TY:.*]] = !DICompositeType(tag: DW_TAG_array_type, baseType: ![[INT]], elements: ![[SUB2]])
+! CHECK-DAG: !DILocalVariable(name: "d2"{{.*}}type: ![[D2TY]])
+
+! CHECK-DAG: ![[R31:.*]] = !DISubrange(count: 6, lowerBound: 1)
+! CHECK-DAG: ![[R32:.*]] = !DISubrange(count: 8, lowerBound: 1)
+! CHECK-DAG: ![[R33:.*]] = !DISubrange(count: 7, lowerBound: 1)
+! CHECK-DAG: ![[SUB3:.*]] = !{![[R31]], ![[R32]], ![[R33]]}
+! CHECK-DAG: ![[D3TY:.*]] = !DICompositeType(tag: DW_TAG_array_type, baseType: ![[REAL]], elements: ![[SUB3]])
+! CHECK-DAG: !DILocalVariable(name: "d3"{{.*}}type: ![[D3TY]])
+
+! CHECK-DAG: !DILocalVariable(name: "a1", arg: 1{{.*}}type: ![[D1TY]])
+! CHECK-DAG: !DILocalVariable(name: "b1", arg: 2{{.*}}type: ![[D2TY]])
+! CHECK-DAG: !DILocalVariable(name: "c1", arg: 3{{.*}}type: ![[D3TY]])
diff --git a/flang/test/Transforms/debug-fixed-array-type.fir b/flang/test/Transforms/debug-fixed-array-type.fir
@@ -0,0 +1,34 @@
+// RUN: fir-opt --add-debug-info --mlir-print-debuginfo %s | FileCheck %s
+
+module attributes {} {
+  func.func @_QQmain() attributes {fir.bindc_name = "mn"} {
+    %c7 = arith.constant 7 : index
+    %c8 = arith.constant 8 : index
+    %c6 = arith.constant 6 : index
+    %c5 = arith.constant 5 : index
+    %c2 = arith.constant 2 : index
+    %c3 = arith.constant 3 : index
+    %0 = fir.alloca !fir.array<3xi32> {bindc_name = "d1", uniq_name = "_QFEd1"}
+    %1 = fircg.ext_declare %0(%c3) {uniq_name = "_QFEd1"} : (!fir.ref<!fir.array<3xi32>>, index) -> !fir.ref<!fir.array<3xi32>> loc(#loc1)
+    %2 = fir.address_of(@_QFEd2) : !fir.ref<!fir.array<2x5xi32>>
+    %3 = fircg.ext_declare %2(%c2, %c5) {uniq_name = "_QFEd2"} : (!fir.ref<!fir.array<2x5xi32>>, index, index) -> !fir.ref<!fir.array<2x5xi32>> loc(#loc2)
+    %4 = fir.address_of(@_QFEd3) : !fir.ref<!fir.array<6x8x7xf32>>
+    %5 = fircg.ext_declare %4(%c6, %c8, %c7) {uniq_name = "_QFEd3"} : (!fir.ref<!fir.array<6x8x7xf32>>, index, index, index) -> !fir.ref<!fir.array<6x8x7xf32>> loc(#loc3)
+    return
+  } loc(#loc4)
+}
+
+#loc1 = loc("test.f90":5:1)
+#loc2 = loc("test.f90":6:11)
+#loc3 = loc("test.f90":7:11)
+#loc4 = loc("test.f90":2:8)
+
+
+// CHECK-DAG: #[[INT:.*]] = #llvm.di_basic_type<tag = DW_TAG_base_type, name = "integer", sizeInBits = 32, encoding = DW_ATE_signed>
+// CHECK-DAG: #[[REAL:.*]] = #llvm.di_basic_type<tag = DW_TAG_base_type, name = "real", sizeInBits = 32, encoding = DW_ATE_float>
+// CHECK-DAG: #[[D1TY:.*]] = #llvm.di_composite_type<tag = DW_TAG_array_type{{.*}}baseType = #[[INT]], elements = #llvm.di_subrange<count = 3 : i64, lowerBound = 1 : i64>>
+// CHECK-DAG: #[[D2TY:.*]] = #llvm.di_composite_type<tag = DW_TAG_array_type{{.*}}baseType = #[[INT]], elements = #llvm.di_subrange<count = 2 : i64, lowerBound = 1 : i64>, #llvm.di_subrange<count = 5 : i64, lowerBound = 1 : i64>>
+// CHECK-DAG: #[[D3TY:.*]] = #llvm.di_composite_type<tag = DW_TAG_array_type{{.*}}baseType = #[[REAL]], elements = #llvm.di_subrange<count = 6 : i64, lowerBound = 1 : i64>, #llvm.di_subrange<count = 8 : i64, lowerBound = 1 : i64>, #llvm.di_subrange<count = 7 : i64, lowerBound = 1 : i64>>
+// CHECK-DAG: #llvm.di_local_variable<{{.*}}name = "d1"{{.*}}type = #[[D1TY]]>
+// CHECK-DAG: #llvm.di_local_variable<{{.*}}name = "d2"{{.*}}type = #[[D2TY]]>
+// CHECK-DAG: #llvm.di_local_variable<{{.*}}name = "d3"{{.*}}type = #[[D3TY]]>
