[flang][debug] Handle array types with variable size/bounds.

flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp

@@ -78,6 +78,35 @@ static mlir::LLVM::DITypeAttr genPlaceholderType(mlir::MLIRContext *context) {
                       /*bitSize=*/32, llvm::dwarf::DW_ATE_signed);
 }
 
+// Helper function to create DILocalVariableAttr and DbgValueOp when information
+// about the size or dimension of a variable etc lives in an mlir::Value.
+mlir::LLVM::DILocalVariableAttr DebugTypeGenerator::generateArtificialVariable(
+    mlir::MLIRContext *context, mlir::Value val,
+    mlir::LLVM::DIFileAttr fileAttr, mlir::LLVM::DIScopeAttr scope,
+    fir::cg::XDeclareOp declOp) {
+  // There can be multiple artificial variable for a single declOp. To help
+  // distinguish them, we pad the name with a counter. The counter is the
+  // position of 'val' in the operands of declOp.
+  auto varID = std::distance(
+      declOp.getOperands().begin(),
+      std::find(declOp.getOperands().begin(), declOp.getOperands().end(), val));
+  mlir::OpBuilder builder(context);
+  auto name = mlir::StringAttr::get(context, "." + declOp.getUniqName().str() +
+                                                 std::to_string(varID));
+  builder.setInsertionPoint(declOp);
+  mlir::Type type = val.getType();
+  if (!mlir::isa<mlir::IntegerType>(type) || !type.isSignlessInteger()) {
+    type = builder.getIntegerType(64);
+    val = builder.create<fir::ConvertOp>(declOp.getLoc(), type, val);
+  }
+  mlir::LLVM::DITypeAttr Ty = convertType(type, fileAttr, scope, declOp);
+  auto lvAttr = mlir::LLVM::DILocalVariableAttr::get(
+      context, scope, name, fileAttr, /*line=*/0, /*argNo=*/0,
+      /*alignInBits=*/0, Ty, mlir::LLVM::DIFlags::Artificial);
+  builder.create<mlir::LLVM::DbgValueOp>(declOp.getLoc(), val, lvAttr, nullptr);
+  return lvAttr;
+}
+
 mlir::LLVM::DITypeAttr DebugTypeGenerator::convertBoxedSequenceType(
     fir::SequenceType seqTy, mlir::LLVM::DIFileAttr fileAttr,
     mlir::LLVM::DIScopeAttr scope, fir::cg::XDeclareOp declOp,
@@ -122,11 +151,12 @@ mlir::LLVM::DITypeAttr DebugTypeGenerator::convertBoxedSequenceType(
     mlir::Attribute lowerAttr = nullptr;
     // If declaration has a lower bound, use it.
     if (declOp && declOp.getShift().size() > index) {
-      // TODO: Handle case where lower bound is a variable (instead of a
-      // constant as handled here)
       if (std::optional<std::int64_t> optint =
               getIntIfConstant(declOp.getShift()[index]))
         lowerAttr = mlir::IntegerAttr::get(intTy, llvm::APInt(64, *optint));
+      else
+        lowerAttr = generateArtificialVariable(
+            context, declOp.getShift()[index], fileAttr, scope, declOp);
     }
     // FIXME: If `indexSize` happens to be bigger than address size on the
     // system then we may have to change 'DW_OP_deref' here.
@@ -320,31 +350,43 @@ mlir::LLVM::DITypeAttr DebugTypeGenerator::convertSequenceType(
   unsigned index = 0;
   auto intTy = mlir::IntegerType::get(context, 64);
   for (fir::SequenceType::Extent dim : seqTy.getShape()) {
-    int64_t shift = 1;
+    mlir::Attribute lowerAttr = nullptr;
+    mlir::Attribute countAttr = nullptr;
+    // If declOp is present, we use the shift in it to get the lower bound of
+    // the array. If it is constant, that is used. If it is not constant, we
+    // create a variable that represents its location and use that as lower
+    // bound. As an optimization, we don't create a lower bound when shift is a
+    // constant 1 as that is the default.
     if (declOp && declOp.getShift().size() > index) {
       if (std::optional<std::int64_t> optint =
-              getIntIfConstant(declOp.getShift()[index]))
-        shift = *optint;
+              getIntIfConstant(declOp.getShift()[index])) {
+        if (*optint != 1)
+          lowerAttr = mlir::IntegerAttr::get(intTy, llvm::APInt(64, *optint));
+      } else
+        lowerAttr = generateArtificialVariable(
+            context, declOp.getShift()[index], fileAttr, scope, declOp);
     }
+
     if (dim == seqTy.getUnknownExtent()) {
-      mlir::IntegerAttr lowerAttr = nullptr;
-      if (declOp && declOp.getShift().size() > index)
-        lowerAttr = mlir::IntegerAttr::get(intTy, llvm::APInt(64, shift));
-      // FIXME: This path is taken for assumed size arrays but also for arrays
-      // with non constant extent. For the latter case, the DISubrangeAttr
-      // should point to a variable which will have the extent at runtime.
-      auto subrangeTy = mlir::LLVM::DISubrangeAttr::get(
-          context, /*count=*/nullptr, lowerAttr, /*upperBound*/ nullptr,
-          /*stride*/ nullptr);
-      elements.push_back(subrangeTy);
-    } else {
-      auto countAttr = mlir::IntegerAttr::get(intTy, llvm::APInt(64, dim));
-      auto lowerAttr = mlir::IntegerAttr::get(intTy, llvm::APInt(64, shift));
-      auto subrangeTy = mlir::LLVM::DISubrangeAttr::get(
-          context, countAttr, lowerAttr, /*upperBound=*/nullptr,
-          /*stride=*/nullptr);
-      elements.push_back(subrangeTy);
-    }
+      // This path is taken for both assumed size array or when the size of the
+      // array is variable. In the case of variable size, we create a variable
+      // to use as countAttr. Note that fir has a constant size of -1 for
+      // assumed size array. So !optint check makes sure we don't generate
+      // variable in that case.
+      if (declOp && declOp.getShape().size() > index) {
+        std::optional<std::int64_t> optint =
+            getIntIfConstant(declOp.getShape()[index]);
+        if (!optint)
+          countAttr = generateArtificialVariable(
+              context, declOp.getShape()[index], fileAttr, scope, declOp);
+      }
+    } else
+      countAttr = mlir::IntegerAttr::get(intTy, llvm::APInt(64, dim));
+
+    auto subrangeTy = mlir::LLVM::DISubrangeAttr::get(
+        context, countAttr, lowerAttr, /*upperBound=*/nullptr,
+        /*stride=*/nullptr);
+    elements.push_back(subrangeTy);
     ++index;
   }
   // Apart from arrays, the `DICompositeTypeAttr` is used for other things like
@@ -400,23 +442,8 @@ mlir::LLVM::DITypeAttr DebugTypeGenerator::convertCharacterType(
     // variable that will contain that length. This variable is used as
     // 'stringLength' in DIStringTypeAttr.
     if (declOp && !declOp.getTypeparams().empty()) {
-      auto name =
-          mlir::StringAttr::get(context, "." + declOp.getUniqName().str());
-      mlir::OpBuilder builder(context);
-      builder.setInsertionPoint(declOp);
-      mlir::Value sizeVal = declOp.getTypeparams()[0];
-      mlir::Type type = sizeVal.getType();
-      if (!mlir::isa<mlir::IntegerType>(type) || !type.isSignlessInteger()) {
-        type = builder.getIntegerType(64);
-        sizeVal =
-            builder.create<fir::ConvertOp>(declOp.getLoc(), type, sizeVal);
-      }
-      mlir::LLVM::DITypeAttr Ty = convertType(type, fileAttr, scope, declOp);
-      auto lvAttr = mlir::LLVM::DILocalVariableAttr::get(
-          context, scope, name, fileAttr, /*line=*/0, /*argNo=*/0,
-          /*alignInBits=*/0, Ty, mlir::LLVM::DIFlags::Artificial);
-      builder.create<mlir::LLVM::DbgValueOp>(declOp.getLoc(), sizeVal, lvAttr,
-                                             nullptr);
+      mlir::LLVM::DILocalVariableAttr lvAttr = generateArtificialVariable(
+          context, declOp.getTypeparams()[0], fileAttr, scope, declOp);
       varAttr = mlir::cast<mlir::LLVM::DIVariableAttr>(lvAttr);
     }
   }

flang/lib/Optimizer/Transforms/DebugTypeGenerator.h

@@ -64,6 +64,11 @@ class DebugTypeGenerator {
                                                 fir::cg::XDeclareOp declOp,
                                                 bool genAllocated,
                                                 bool genAssociated);
+  mlir::LLVM::DILocalVariableAttr
+  generateArtificialVariable(mlir::MLIRContext *context, mlir::Value Val,
+                             mlir::LLVM::DIFileAttr fileAttr,
+                             mlir::LLVM::DIScopeAttr scope,
+                             fir::cg::XDeclareOp declOp);
 
   mlir::ModuleOp module;
   mlir::SymbolTable *symbolTable;

flang/test/Integration/debug-assumed-size-array.f90

@@ -12,7 +12,7 @@ end module helper
 
 ! CHECK-DAG: ![[TY1:[0-9]+]] = !DICompositeType(tag: DW_TAG_array_type{{.*}}elements: ![[ELEMS1:[0-9]+]]{{.*}})
 ! CHECK-DAG: ![[ELEMS1]] = !{![[ELM1:[0-9]+]], ![[EMPTY:[0-9]+]]}
-! CHECK-DAG: ![[ELM1]] = !DISubrange(count: 5, lowerBound: 1)
+! CHECK-DAG: ![[ELM1]] = !DISubrange(count: 5)
 ! CHECK-DAG: ![[EMPTY]] = !DISubrange()
 ! CHECK-DAG: ![[TY2:[0-9]+]] = !DICompositeType(tag: DW_TAG_array_type{{.*}}elements: ![[ELEMS2:[0-9]+]]{{.*}})
 ! CHECK-DAG: ![[ELEMS2]] = !{![[EMPTY:[0-9]+]]}

flang/test/Integration/debug-fixed-array-type-2.f90

@@ -23,11 +23,11 @@ function fn1(a1, b1, c1) result (res)
 
 ! 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: ![[R1:.*]] = !DISubrange(count: 3)
 ! CHECK-DAG: ![[SUB1:.*]] = !{![[R1]]}
 ! CHECK-DAG: ![[D1TY:.*]] = !DICompositeType(tag: DW_TAG_array_type, baseType: ![[INT]], elements: ![[SUB1]])
 
-! CHECK-DAG: ![[R21:.*]] = !DISubrange(count: 4, lowerBound: 1)
+! CHECK-DAG: ![[R21:.*]] = !DISubrange(count: 4)
 ! 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]])

flang/test/Integration/debug-variable-array-dim.f90

@@ -0,0 +1,19 @@
+! RUN: %flang_fc1 -emit-llvm -debug-info-kind=standalone %s -o - | FileCheck %s
+
+subroutine foo(a, n, m, p)
+  integer n, m, p
+  integer :: a(n:m, p)
+  a(1, 2) = 10
+  print *, a
+end subroutine foo
+
+
+! CHECK-DAG: ![[VAR0:.*]] = !DILocalVariable(name: "._QFfooEa3"{{.*}}scope: ![[SCOPE:[0-9]+]]{{.*}}flags: DIFlagArtificial)
+! CHECK-DAG: ![[VAR1:.*]] = !DILocalVariable(name: "._QFfooEa1"{{.*}}scope: ![[SCOPE]]{{.*}}flags: DIFlagArtificial)
+! CHECK-DAG: ![[VAR2:.*]] = !DILocalVariable(name: "._QFfooEa2"{{.*}}scope: ![[SCOPE]]{{.*}}flags: DIFlagArtificial)
+! CHECK-DAG: ![[SR1:.*]] = !DISubrange(count: ![[VAR1]], lowerBound: ![[VAR0]])
+! CHECK-DAG: ![[SR2:.*]] = !DISubrange(count: ![[VAR2]])
+! CHECK-DAG: ![[SR:.*]] = !{![[SR1]], ![[SR2]]}
+! CHECK-DAG: ![[TY:.*]] = !DICompositeType(tag: DW_TAG_array_type{{.*}}elements: ![[SR]])
+! CHECK-DAG: !DILocalVariable(name: "a"{{.*}}scope: ![[SCOPE]]{{.*}}type: ![[TY]])
+

flang/test/Transforms/debug-107988.fir

@@ -13,7 +13,7 @@ module attributes {dlti.dl_spec = #dlti.dl_spec<>} {
 #loc1 = loc("test.f90":5:1)
 #loc2 = loc("test.f90":15:1)
 
-// CHECK: #[[VAR:.*]] = #llvm.di_local_variable<{{.*}}name = "._QFtestEstr"{{.*}}flags = Artificial>
+// CHECK: #[[VAR:.*]] = #llvm.di_local_variable<{{.*}}name = "._QFtestEstr{{.*}}flags = Artificial>
 // CHECK: func.func @test
 // CHECK: %[[V1:.*]]:2 = fir.unboxchar{{.*}}
 // CHECK: %[[V2:.*]] = fir.convert %[[V1]]#1 : (index) -> i64

flang/test/Transforms/debug-assumed-shape-array-2.fir

@@ -0,0 +1,23 @@
+// RUN: fir-opt --add-debug-info --mlir-print-debuginfo %s | FileCheck %s
+
+// Test assumed shape array with variable lower bound.
+
+module attributes {dlti.dl_spec = #dlti.dl_spec<>} {
+  func.func private @_QFPfn(%arg0: !fir.box<!fir.array<?xi32>> {fir.bindc_name = "b"}, %arg1: !fir.ref<i32> {fir.bindc_name = "n"}) attributes {} {
+    %c23_i32 = arith.constant 23 : i32
+    %c6_i32 = arith.constant 6 : i32
+    %c20_i32 = arith.constant 20 : i32
+    %0 = fir.undefined !fir.dscope
+    %1 = fircg.ext_declare %arg1 dummy_scope %0 {uniq_name = "_QFFfnEn"} : (!fir.ref<i32>, !fir.dscope) -> !fir.ref<i32> loc(#loc1)
+    %2 = fir.load %1 : !fir.ref<i32>
+    %3 = fir.convert %2 : (i32) -> index
+    %4 = fircg.ext_declare %arg0 origin %3 dummy_scope %0 {uniq_name = "_QFFfnEb"} : (!fir.box<!fir.array<?xi32>>, index, !fir.dscope) -> !fir.box<!fir.array<?xi32>> loc(#loc2)
+    return
+  } loc(#loc3)
+}
+#loc1 = loc("test1.f90":1:1)
+#loc2 = loc("test1.f90":3:16)
+#loc3 = loc("test1.f90":4:16)
+
+// CHECK: #[[VAR:.*]] = #llvm.di_local_variable<{{.*}}name = "._QFFfnEb1"{{.*}}flags = Artificial>
+// CHECK: #llvm.di_composite_type<tag = DW_TAG_array_type{{.*}}elements = #llvm.di_subrange<count = #llvm.di_expression<[{{.*}}]>, lowerBound = #[[VAR]], stride = #llvm.di_expression<[{{.*}}]>>, dataLocation = <[DW_OP_push_object_address, DW_OP_deref]>>

flang/test/Transforms/debug-assumed-size-array.fir

@@ -16,7 +16,7 @@ module attributes {dlti.dl_spec = #dlti.dl_spec<>} {
 #loc1 = loc("test.f90":3:1)
 #loc2 = loc("test.f90":4:1)
 
-// CHECK-DAG: #[[TY1:.*]] = #llvm.di_composite_type<tag = DW_TAG_array_type{{.*}}elements = #llvm.di_subrange<count = 5 : i64, lowerBound = 1 : i64>, #llvm.di_subrange<>>
+// CHECK-DAG: #[[TY1:.*]] = #llvm.di_composite_type<tag = DW_TAG_array_type{{.*}}elements = #llvm.di_subrange<count = 5 : i64>, #llvm.di_subrange<>>
 // CHECK-DAG: #[[TY2:.*]] = #llvm.di_composite_type<tag = DW_TAG_array_type{{.*}}elements = #llvm.di_subrange<lowerBound = 2 : i64>>
 // CHECK-DAG: #llvm.di_local_variable<{{.*}}name = "a1"{{.*}}type = #[[TY1]]>
 // CHECK-DAG: #llvm.di_local_variable<{{.*}}name = "a2"{{.*}}type = #[[TY2]]>

flang/test/Transforms/debug-fixed-array-type.fir

@@ -31,9 +31,9 @@ module attributes {dlti.dl_spec = #dlti.dl_spec<>} {
 
 // 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: #[[D1TY:.*]] = #llvm.di_composite_type<tag = DW_TAG_array_type{{.*}}baseType = #[[INT]], elements = #llvm.di_subrange<count = 3 : i64>>
+// CHECK-DAG: #[[D2TY:.*]] = #llvm.di_composite_type<tag = DW_TAG_array_type{{.*}}baseType = #[[INT]], elements = #llvm.di_subrange<count = 2 : i64>, #llvm.di_subrange<count = 5 : i64>>
+// CHECK-DAG: #[[D3TY:.*]] = #llvm.di_composite_type<tag = DW_TAG_array_type{{.*}}baseType = #[[REAL]], elements = #llvm.di_subrange<count = 6 : i64>, #llvm.di_subrange<count = 8 : i64>, #llvm.di_subrange<count = 7 : i64>>
 // CHECK-DAG: #[[D4TY:.*]] = #llvm.di_composite_type<tag = DW_TAG_array_type, baseType = #di_basic_type, elements = #llvm.di_subrange<count = 6 : i64, lowerBound = -2 : i64>, #llvm.di_subrange<count = 7 : i64, lowerBound = 4 : i64>>
 // CHECK-DAG: #llvm.di_local_variable<{{.*}}name = "d1"{{.*}}type = #[[D1TY]]>
 // CHECK-DAG: #llvm.di_local_variable<{{.*}}name = "d2"{{.*}}type = #[[D2TY]]>

flang/test/Transforms/debug-variable-array-dim.fir

@@ -0,0 +1,41 @@
+// RUN: fir-opt --add-debug-info --mlir-print-debuginfo %s | FileCheck %s
+
+module attributes {dlti.dl_spec = #dlti.dl_spec<>} {
+  func.func @foo_(%arg0: !fir.ref<!fir.array<?x?xi32>> {fir.bindc_name = "a"}, %arg1: !fir.ref<i32> {fir.bindc_name = "n"}, %arg2: !fir.ref<i32> {fir.bindc_name = "m"}, %arg3: !fir.ref<i32> {fir.bindc_name = "p"}) attributes {fir.internal_name = "_QPfoo"} {
+    %c5_i32 = arith.constant 5 : i32
+    %c6_i32 = arith.constant 6 : i32
+    %c2 = arith.constant 2 : index
+    %c10_i32 = arith.constant 10 : i32
+    %c0 = arith.constant 0 : index
+    %c1 = arith.constant 1 : index
+    %0 = fir.undefined !fir.dscope
+    %1 = fircg.ext_declare %arg1 dummy_scope %0 {uniq_name = "_QFfooEn"} : (!fir.ref<i32>, !fir.dscope) -> !fir.ref<i32> loc(#loc2)
+    %2 = fircg.ext_declare %arg2 dummy_scope %0 {uniq_name = "_QFfooEm"} : (!fir.ref<i32>, !fir.dscope) -> !fir.ref<i32> loc(#loc3)
+    %3 = fircg.ext_declare %arg3 dummy_scope %0 {uniq_name = "_QFfooEp"} : (!fir.ref<i32>, !fir.dscope) -> !fir.ref<i32> loc(#loc4)
+    %4 = fir.load %1 : !fir.ref<i32>
+    %5 = fir.convert %4 : (i32) -> index
+    %6 = fir.load %2 : !fir.ref<i32>
+    %7 = fir.convert %6 : (i32) -> index
+    %8 = arith.subi %7, %5 : index
+    %9 = arith.addi %8, %c1 : index
+    %10 = arith.cmpi sgt, %9, %c0 : index
+    %11 = arith.select %10, %9, %c0 : index
+    %12 = fir.load %3 : !fir.ref<i32>
+    %13 = fir.convert %12 : (i32) -> index
+    %14 = arith.cmpi sgt, %13, %c0 : index
+    %15 = arith.select %14, %13, %c0 : index
+    %16 = fircg.ext_declare %arg0(%11, %15) origin %5, %c1 dummy_scope %0 {uniq_name = "_QFfooEa"} : (!fir.ref<!fir.array<?x?xi32>>, index, index, index, index, !fir.dscope) -> !fir.ref<!fir.array<?x?xi32>> loc(#loc5)
+    return
+  } loc(#loc1)
+}
+
+#loc1 = loc("test.f90":5:1)
+#loc2 = loc("test.f90":6:11)
+#loc3 = loc("test.f90":7:11)
+#loc4 = loc("test.f90":2:8)
+#loc5 = loc("test.f90":8:11)
+
+// CHECK-DAG: #[[VAR0:.*]] = #llvm.di_local_variable<{{.*}}name = "._QFfooEa3"{{.*}}flags = Artificial>
+// CHECK-DAG: #[[VAR1:.*]] = #llvm.di_local_variable<{{.*}}name = "._QFfooEa1"{{.*}}flags = Artificial>
+// CHECK-DAG: #[[VAR2:.*]] = #llvm.di_local_variable<{{.*}}name = "._QFfooEa2"{{.*}}flags = Artificial>
+// CHECK-DAG: #llvm.di_composite_type<tag = DW_TAG_array_type{{.*}}elements = #llvm.di_subrange<count = #[[VAR1]], lowerBound = #[[VAR0]]>, #llvm.di_subrange<count = #[[VAR2]]>>

flang/test/Transforms/debug-variable-char-len.fir

@@ -22,7 +22,7 @@ module attributes {dlti.dl_spec = #dlti.dl_spec<>} {
 #loc2 = loc("test.f90":17:1)
 #loc3 = loc("test.f90":15:1)
 
-// CHECK: #[[VAR:.*]] = #llvm.di_local_variable<{{.*}}name = "._QFfooEstr1"{{.*}}flags = Artificial>
+// CHECK: #[[VAR:.*]] = #llvm.di_local_variable<{{.*}}name = "._QFfooEstr1{{.*}}flags = Artificial>
 // CHECK: func.func @foo
 // CHECK: llvm.intr.dbg.value #[[VAR]]
 // CHECK: return