[flang-commits] [flang] [flang][debug] Supply missing subprogram attributes (PR #181425)
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Fri Feb 13 13:44:03 PST 2026
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-flang-fir-hlfir
Author: Tim (timsmith78)
<details>
<summary>Changes</summary>
Add DW_AT_elemental, DW_AT_pure, and DW_AT_recursive attributes to subprograms and functions when they are specified in the source.
---
Full diff: https://github.com/llvm/llvm-project/pull/181425.diff
4 Files Affected:
- (modified) flang/include/flang/Optimizer/Dialect/FIRAttr.td (+8-6)
- (modified) flang/lib/Lower/CallInterface.cpp (+6)
- (modified) flang/lib/Optimizer/Transforms/AddDebugInfo.cpp (+17)
- (added) flang/test/Transforms/debug-fn-attr.fir (+67)
``````````diff
diff --git a/flang/include/flang/Optimizer/Dialect/FIRAttr.td b/flang/include/flang/Optimizer/Dialect/FIRAttr.td
index 2fbe195ee9f33..b23d28fdde55c 100644
--- a/flang/include/flang/Optimizer/Dialect/FIRAttr.td
+++ b/flang/include/flang/Optimizer/Dialect/FIRAttr.td
@@ -77,12 +77,14 @@ def FIRfuncPure : I32BitEnumAttrCaseBit<"pure", 1>;
def FIRfuncNonRecursive : I32BitEnumAttrCaseBit<"non_recursive", 2>;
def FIRfuncSimple : I32BitEnumAttrCaseBit<"simple", 3>;
def FIRfuncBind_c : I32BitEnumAttrCaseBit<"bind_c", 4>;
-
-def fir_FortranProcedureFlagsEnum : I32BitEnumAttr<
- "FortranProcedureFlagsEnum",
- "Fortran procedure attributes",
- [FIRfuncNoAttributes, FIRfuncElemental, FIRfuncPure, FIRfuncNonRecursive,
- FIRfuncSimple, FIRfuncBind_c]> {
+def FIRfuncRecursive : I32BitEnumAttrCaseBit<"recursive", 5>;
+
+def fir_FortranProcedureFlagsEnum
+ : I32BitEnumAttr<"FortranProcedureFlagsEnum",
+ "Fortran procedure attributes",
+ [FIRfuncNoAttributes, FIRfuncElemental, FIRfuncPure,
+ FIRfuncNonRecursive, FIRfuncSimple, FIRfuncBind_c,
+ FIRfuncRecursive]> {
let separator = ", ";
let cppNamespace = "::fir";
let genSpecializedAttr = 0;
diff --git a/flang/lib/Lower/CallInterface.cpp b/flang/lib/Lower/CallInterface.cpp
index f5ae2de5cad8b..a40741781d191 100644
--- a/flang/lib/Lower/CallInterface.cpp
+++ b/flang/lib/Lower/CallInterface.cpp
@@ -1582,6 +1582,12 @@ Fortran::lower::CallInterface<T>::getProcedureAttrs(
!sym->attrs().test(Fortran::semantics::Attr::RECURSIVE))) {
flags = flags | fir::FortranProcedureFlagsEnum::non_recursive;
}
+ // Set RECURSIVE if the attribute is explicitly present. This is only
+ // used for debug info generation to maintain consistency with pre-F2018
+ // compilers.
+ if (sym->attrs().test(Fortran::semantics::Attr::RECURSIVE)) {
+ flags = flags | fir::FortranProcedureFlagsEnum::recursive;
+ }
}
}
if (flags != fir::FortranProcedureFlagsEnum::none)
diff --git a/flang/lib/Optimizer/Transforms/AddDebugInfo.cpp b/flang/lib/Optimizer/Transforms/AddDebugInfo.cpp
index 35d8a2f6c3aa9..4fa13179d6f38 100644
--- a/flang/lib/Optimizer/Transforms/AddDebugInfo.cpp
+++ b/flang/lib/Optimizer/Transforms/AddDebugInfo.cpp
@@ -511,6 +511,23 @@ void AddDebugInfoPass::handleFuncOp(mlir::func::FuncOp funcOp,
subprogramFlags =
subprogramFlags | mlir::LLVM::DISubprogramFlags::Definition;
}
+
+ // Check if the function has the pure, elemental, or recursive procedure
+ // attribute
+ if (fir::hasProcedureAttr<fir::FortranProcedureFlagsEnum::pure>(funcOp)) {
+ subprogramFlags = subprogramFlags | mlir::LLVM::DISubprogramFlags::Pure;
+ }
+ if (fir::hasProcedureAttr<fir::FortranProcedureFlagsEnum::elemental>(
+ funcOp)) {
+ subprogramFlags =
+ subprogramFlags | mlir::LLVM::DISubprogramFlags::Elemental;
+ }
+ if (fir::hasProcedureAttr<fir::FortranProcedureFlagsEnum::recursive>(
+ funcOp)) {
+ subprogramFlags =
+ subprogramFlags | mlir::LLVM::DISubprogramFlags::Recursive;
+ }
+
unsigned line = getLineFromLoc(l);
if (fir::isInternalProcedure(funcOp)) {
// For contained functions, the scope is the parent subroutine.
diff --git a/flang/test/Transforms/debug-fn-attr.fir b/flang/test/Transforms/debug-fn-attr.fir
new file mode 100644
index 0000000000000..c067adecdbf94
--- /dev/null
+++ b/flang/test/Transforms/debug-fn-attr.fir
@@ -0,0 +1,67 @@
+// RUN: fir-opt --add-debug-info --mlir-print-debuginfo %s | FileCheck %s
+
+module attributes {dlti.dl_spec = #dlti.dl_spec<!llvm.ptr<270> = dense<32> : vector<4xi64>, !llvm.ptr<271> = dense<32> : vector<4xi64>, !llvm.ptr<272> = dense<64> : vector<4xi64>, i64 = dense<64> : vector<2xi64>, i128 = dense<128> : vector<2xi64>, f80 = dense<128> : vector<2xi64>, !llvm.ptr = dense<64> : vector<4xi64>, i1 = dense<8> : vector<2xi64>, i8 = dense<8> : vector<2xi64>, i16 = dense<16> : vector<2xi64>, i32 = dense<32> : vector<2xi64>, f16 = dense<16> : vector<2xi64>, f64 = dense<64> : vector<2xi64>, f128 = dense<128> : vector<2xi64>, "dlti.endianness" = "little", "dlti.mangling_mode" = "e", "dlti.legal_int_widths" = array<i32: 8, 16, 32, 64>, "dlti.stack_alignment" = 128 : i64>, fir.defaultkind = "a1c4d8i4l4r4", fir.kindmap = "", llvm.data_layout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128", llvm.ident = "flang version 23.0.0 (https://github.com/llvm/llvm-project.git a092e95d2d07ac974268b5d555209027b275f4da)", llvm.target_triple = "x86_64-unknown-linux-gnu"} {
+ func.func @_QPvector_magnitude(%arg0: !fir.ref<f64> {fir.bindc_name = "x"}, %arg1: !fir.ref<f64> {fir.bindc_name = "y"}, %arg2: !fir.ref<f64> {fir.bindc_name = "z"}) -> f64 attributes {fir.proc_attrs = #fir.proc_attrs<pure>} {
+ %0 = fir.dummy_scope : !fir.dscope
+ %1 = fir.alloca f64 {bindc_name = "magnitude", uniq_name = "_QFvector_magnitudeEmagnitude"}
+ %2 = fir.declare %1 {uniq_name = "_QFvector_magnitudeEmagnitude"} : (!fir.ref<f64>) -> !fir.ref<f64>
+ %3 = fir.declare %arg0 dummy_scope %0 arg 1 {fortran_attrs = #fir.var_attrs<intent_in>, uniq_name = "_QFvector_magnitudeEx"} : (!fir.ref<f64>, !fir.dscope) -> !fir.ref<f64>
+ %4 = fir.declare %arg1 dummy_scope %0 arg 2 {fortran_attrs = #fir.var_attrs<intent_in>, uniq_name = "_QFvector_magnitudeEy"} : (!fir.ref<f64>, !fir.dscope) -> !fir.ref<f64>
+ %5 = fir.declare %arg2 dummy_scope %0 arg 3 {fortran_attrs = #fir.var_attrs<intent_in>, uniq_name = "_QFvector_magnitudeEz"} : (!fir.ref<f64>, !fir.dscope) -> !fir.ref<f64>
+ %6 = fir.load %3 : !fir.ref<f64>
+ %7 = fir.load %3 : !fir.ref<f64>
+ %8 = arith.mulf %6, %7 fastmath<contract> : f64
+ %9 = fir.load %4 : !fir.ref<f64>
+ %10 = fir.load %4 : !fir.ref<f64>
+ %11 = arith.mulf %9, %10 fastmath<contract> : f64
+ %12 = arith.addf %8, %11 fastmath<contract> : f64
+ %13 = fir.load %5 : !fir.ref<f64>
+ %14 = fir.load %5 : !fir.ref<f64>
+ %15 = arith.mulf %13, %14 fastmath<contract> : f64
+ %16 = arith.addf %12, %15 fastmath<contract> : f64
+ %17 = math.sqrt %16 fastmath<contract> : f64
+ fir.store %17 to %2 : !fir.ref<f64>
+ %18 = fir.load %2 : !fir.ref<f64>
+ return %18 : f64
+ }
+ func.func @_QPsquare(%arg0: !fir.ref<f64> {fir.bindc_name = "x"}) -> f64 attributes {fir.proc_attrs = #fir.proc_attrs<elemental, pure>} {
+ %0 = fir.dummy_scope : !fir.dscope
+ %1 = fir.declare %arg0 dummy_scope %0 arg 1 {fortran_attrs = #fir.var_attrs<intent_in>, uniq_name = "_QFsquareEx"} : (!fir.ref<f64>, !fir.dscope) -> !fir.ref<f64>
+ %2 = fir.alloca f64 {bindc_name = "x_squared", uniq_name = "_QFsquareEx_squared"}
+ %3 = fir.declare %2 {uniq_name = "_QFsquareEx_squared"} : (!fir.ref<f64>) -> !fir.ref<f64>
+ %4 = fir.load %1 : !fir.ref<f64>
+ %5 = fir.load %1 : !fir.ref<f64>
+ %6 = arith.mulf %4, %5 fastmath<contract> : f64
+ fir.store %6 to %3 : !fir.ref<f64>
+ %7 = fir.load %3 : !fir.ref<f64>
+ return %7 : f64
+ }
+ func.func @_QPfactorial(%arg0: !fir.ref<i32> {fir.bindc_name = "n"}) -> i32 attributes {fir.proc_attrs = #fir.proc_attrs<recursive>} {
+ %0 = fir.alloca i32 {adapt.valuebyref}
+ %c1_i32 = arith.constant 1 : i32
+ %1 = fir.dummy_scope : !fir.dscope
+ %2 = fir.alloca i32 {bindc_name = "fact", uniq_name = "_QFfactorialEfact"}
+ %3 = fir.declare %2 {uniq_name = "_QFfactorialEfact"} : (!fir.ref<i32>) -> !fir.ref<i32>
+ %4 = fir.declare %arg0 dummy_scope %1 arg 1 {fortran_attrs = #fir.var_attrs<intent_in>, uniq_name = "_QFfactorialEn"} : (!fir.ref<i32>, !fir.dscope) -> !fir.ref<i32>
+ %5 = fir.load %4 : !fir.ref<i32>
+ %6 = arith.cmpi sle, %5, %c1_i32 : i32
+ fir.if %6 {
+ fir.store %c1_i32 to %3 : !fir.ref<i32>
+ } else {
+ %8 = fir.load %4 : !fir.ref<i32>
+ %9 = fir.load %4 : !fir.ref<i32>
+ %10 = arith.subi %9, %c1_i32 : i32
+ fir.store %10 to %0 : !fir.ref<i32>
+ %false = arith.constant false
+ %11 = fir.call @_QPfactorial(%0) fastmath<contract> : (!fir.ref<i32>) -> i32
+ %12 = arith.muli %8, %11 : i32
+ fir.store %12 to %3 : !fir.ref<i32>
+ }
+ %7 = fir.load %3 : !fir.ref<i32>
+ return %7 : i32
+ }
+}
+
+// CHECK: #di_subprogram = #llvm.di_subprogram<{{.*}}, name = "vector_magnitude",{{.*}}subprogramFlags = "Definition|Pure"
+// CHECK: #di_subprogram1 = #llvm.di_subprogram<{{.*}}, name = "square",{{.*}}subprogramFlags = "Definition|Pure|Elemental"
+// CHECK: #di_subprogram2 = #llvm.di_subprogram<{{.*}}, name = "factorial",{{.*}}subprogramFlags = "Definition|Recursive"
``````````
</details>
https://github.com/llvm/llvm-project/pull/181425
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