[flang-commits] [flang] [flang][debug] Add debug type support for procedure pointers (PR #166764)
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Thu Nov 6 04:42:34 PST 2025
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-flang-fir-hlfir
Author: Abid Qadeer (abidh)
<details>
<summary>Changes</summary>
Fixes #<!-- -->161223
Procedure pointers in Fortran were generating incorrect debug type information, showing as 'integer' in GDB instead of the actual procedure signature.
---
Full diff: https://github.com/llvm/llvm-project/pull/166764.diff
3 Files Affected:
- (modified) flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp (+24)
- (added) flang/test/Transforms/debug-proc-ptr-e2e.f90 (+26)
- (added) flang/test/Transforms/debug-proc-ptr.fir (+41)
``````````diff
diff --git a/flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp b/flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp
index e1e6125fc348b..ed31746bf8dea 100644
--- a/flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp
+++ b/flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp
@@ -718,6 +718,30 @@ DebugTypeGenerator::convertType(mlir::Type Ty, mlir::LLVM::DIFileAttr fileAttr,
return convertRecordType(recTy, fileAttr, scope, declOp);
} else if (auto tupleTy = mlir::dyn_cast_if_present<mlir::TupleType>(Ty)) {
return convertTupleType(tupleTy, fileAttr, scope, declOp);
+ } else if (mlir::isa<mlir::FunctionType>(Ty)) {
+ // Handle function types - these represent procedure pointers after the
+ // BoxedProcedure pass has run and unwrapped the fir.boxproc type
+ llvm::SmallVector<mlir::LLVM::DITypeAttr> types;
+
+ auto funcTy = mlir::cast<mlir::FunctionType>(Ty);
+ // Add return type (or void if no return type)
+ if (funcTy.getNumResults() == 0)
+ types.push_back(mlir::LLVM::DINullTypeAttr::get(context));
+ else
+ types.push_back(
+ convertType(funcTy.getResult(0), fileAttr, scope, declOp));
+
+ for (mlir::Type paramTy : funcTy.getInputs())
+ types.push_back(convertType(paramTy, fileAttr, scope, declOp));
+
+ auto subroutineTy = mlir::LLVM::DISubroutineTypeAttr::get(
+ context, /*callingConvention=*/0, types);
+
+ return mlir::LLVM::DIDerivedTypeAttr::get(
+ context, llvm::dwarf::DW_TAG_pointer_type,
+ mlir::StringAttr::get(context, ""), subroutineTy,
+ /*sizeInBits=*/ptrSize * 8, /*alignInBits=*/0, /*offset=*/0,
+ /*optional<address space>=*/std::nullopt, /*extra data=*/nullptr);
} else if (auto refTy = mlir::dyn_cast_if_present<fir::ReferenceType>(Ty)) {
auto elTy = refTy.getEleTy();
return convertPointerLikeType(elTy, fileAttr, scope, declOp,
diff --git a/flang/test/Transforms/debug-proc-ptr-e2e.f90 b/flang/test/Transforms/debug-proc-ptr-e2e.f90
new file mode 100644
index 0000000000000..aa89160b7c8f9
--- /dev/null
+++ b/flang/test/Transforms/debug-proc-ptr-e2e.f90
@@ -0,0 +1,26 @@
+! RUN: %flang_fc1 -emit-llvm -debug-info-kind=standalone %s -o - | FileCheck %s
+
+program test_proc_ptr
+ implicit none
+ procedure(fun1), pointer :: fun_ptr
+
+ fun_ptr => fun1
+ print *, fun_ptr(3)
+
+contains
+ integer function fun1(x)
+ integer :: x
+ fun1 = x + 1
+ end function fun1
+end program test_proc_ptr
+
+! Check that fun_ptr is declared with correct type
+! CHECK-DAG: ![[INT:.*]] = !DIBasicType(name: "integer", size: 32, encoding: DW_ATE_signed)
+! CHECK-DAG: ![[PTR_INT:.*]] = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: ![[INT]], size: 64)
+
+! Check that fun_ptr variable is a pointer to a subroutine type
+! The order is: DILocalVariable -> pointer type -> subroutine type -> {return, params}
+! CHECK-DAG: ![[FUN_PTR_VAR:.*]] = !DILocalVariable(name: "fun_ptr", {{.*}}type: ![[PROC_PTR:[0-9]+]]
+! CHECK-DAG: ![[PROC_PTR]] = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: ![[SUBR_TYPE:[0-9]+]], size: 64)
+! CHECK-DAG: ![[SUBR_TYPE]] = !DISubroutineType(types: ![[SUBR_TYPES:[0-9]+]])
+! CHECK-DAG: ![[SUBR_TYPES]] = !{![[INT]], ![[PTR_INT]]}
diff --git a/flang/test/Transforms/debug-proc-ptr.fir b/flang/test/Transforms/debug-proc-ptr.fir
new file mode 100644
index 0000000000000..2963557786907
--- /dev/null
+++ b/flang/test/Transforms/debug-proc-ptr.fir
@@ -0,0 +1,41 @@
+// RUN: fir-opt --add-debug-info --mlir-print-debuginfo %s | FileCheck %s
+
+module {
+ func.func @_QQmain() attributes {fir.bindc_name = "test"} {
+ %0 = fir.alloca (!fir.ref<i32>) -> i32 {bindc_name = "fun_ptr", uniq_name = "_QFEfun_ptr"}
+ %1 = fircg.ext_declare %0 {uniq_name = "_QFEfun_ptr"} : (!fir.ref<(!fir.ref<i32>) -> i32>) -> !fir.ref<(!fir.ref<i32>) -> i32> loc(#loc1)
+
+ // Procedure pointer with no return: procedure(sub1), pointer :: sub_ptr
+ %2 = fir.alloca () -> () {bindc_name = "sub_ptr", uniq_name = "_QFEsub_ptr"}
+ %3 = fircg.ext_declare %2 {uniq_name = "_QFEsub_ptr"} : (!fir.ref<() -> ()>) -> !fir.ref<() -> ()> loc(#loc2)
+
+ // Procedure pointer with multiple args: procedure(func2), pointer :: func_ptr
+ %4 = fir.alloca (!fir.ref<i32>, !fir.ref<f64>) -> f32 {bindc_name = "func_ptr", uniq_name = "_QFEfunc_ptr"}
+ %5 = fircg.ext_declare %4 {uniq_name = "_QFEfunc_ptr"} : (!fir.ref<(!fir.ref<i32>, !fir.ref<f64>) -> f32>) -> !fir.ref<(!fir.ref<i32>, !fir.ref<f64>) -> f32> loc(#loc3)
+
+ return
+ } loc(#loc)
+}
+#loc = loc("test.f90":1:1)
+#loc1 = loc("test.f90":2:30)
+#loc2 = loc("test.f90":3:30)
+#loc3 = loc("test.f90":4:30)
+
+// CHECK-DAG: #[[INT:.*]] = #llvm.di_basic_type<tag = DW_TAG_base_type, name = "integer", sizeInBits = 32, encoding = DW_ATE_signed>
+// CHECK-DAG: #[[REAL32:.*]] = #llvm.di_basic_type<tag = DW_TAG_base_type, name = "real", sizeInBits = 32, encoding = DW_ATE_float>
+// CHECK-DAG: #[[REAL:.*]] = #llvm.di_basic_type<tag = DW_TAG_base_type, name = "real(kind=8)", sizeInBits = 64, encoding = DW_ATE_float>
+
+// CHECK-DAG: #[[PTR_INT:.*]] = #llvm.di_derived_type<tag = DW_TAG_pointer_type{{.*}}baseType = #[[INT]]{{.*}}>
+// CHECK-DAG: #[[PTR_REAL:.*]] = #llvm.di_derived_type<tag = DW_TAG_pointer_type{{.*}}baseType = #[[REAL]]{{.*}}>
+
+// CHECK-DAG: #[[SUB1:.*]] = #llvm.di_subroutine_type<types = #[[INT]], #[[PTR_INT]]>
+// CHECK-DAG: #[[PTR_SUB1:.*]] = #llvm.di_derived_type<tag = DW_TAG_pointer_type{{.*}}baseType = #[[SUB1]]{{.*}}>
+// CHECK-DAG: #llvm.di_local_variable<{{.*}}name = "fun_ptr"{{.*}}type = #[[PTR_SUB1]]{{.*}}>
+
+// CHECK-DAG: #di_subroutine_type{{.*}} = #llvm.di_subroutine_type<types = #di_null_type>
+// CHECK-DAG: #di_local_variable{{.*}} = #llvm.di_local_variable<{{.*}}name = "sub_ptr"{{.*}}type = #di_derived_type{{.*}}>
+// CHECK-DAG: #di_derived_type{{.*}} = #llvm.di_derived_type<tag = DW_TAG_pointer_type{{.*}}baseType = #di_subroutine_type{{.*}}{{.*}}>
+
+// CHECK-DAG: #[[SUB3:.*]] = #llvm.di_subroutine_type<types = #[[REAL32]], #[[PTR_INT]], #[[PTR_REAL]]>
+// CHECK-DAG: #[[PTR_SUB3:.*]] = #llvm.di_derived_type<tag = DW_TAG_pointer_type{{.*}}baseType = #[[SUB3]]{{.*}}>
+// CHECK-DAG: #llvm.di_local_variable<{{.*}}name = "func_ptr"{{.*}}type = #[[PTR_SUB3]]{{.*}}>
``````````
</details>
https://github.com/llvm/llvm-project/pull/166764
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