[flang-commits] [flang] [Flang][OpenMP] Improve Semantics for Derived Type Array Elements (PR #167296)
Jack Styles via flang-commits
flang-commits at lists.llvm.org
Mon Nov 10 02:50:49 PST 2025
https://github.com/Stylie777 created https://github.com/llvm/llvm-project/pull/167296
Flang does not allow the use of Structure Component types inside of certain OpenMP clauses. While this has been introduced, it seemed that Structure Component Array Elements were not being captured as they got embedded in the parse tree. To ensure all structure component types are identified, a new `HasStructureComponent` evaluate function has been introduced to walk a Semantics expression, identified where Components are used within.
This replaces the previous implementation of `CheckStructureComponent` which just looked for the StructureComponent inside of a DataRef.
Fixes #150830
>From d25a6d51478aa5037eabac8f02d3c49df91f6415 Mon Sep 17 00:00:00 2001
From: Jack Styles <jack.styles at arm.com>
Date: Mon, 10 Nov 2025 08:41:48 +0000
Subject: [PATCH] [Flang][OpenMP] Improve Semantics for Derived Type Array
Elements
Flang does not allow the use of Structure Component types inside of
certain OpenMP clauses. While this has been introduced, it seemed
that Structure Component Array Elements were not being captured as
they got embedded in the parse tree. To ensure all structure component
types are identified, a new `HasStructureComponent` evaluate function
has been introduced to walk a Semantics expression, identified where
Components are used within.
This replaces the previous implementation of `CheckStructureComponent`
which just looked for the StructureComponent inside of a DataRef.
Fixes #150830
---
flang/include/flang/Evaluate/tools.h | 3 +++
flang/lib/Evaluate/tools.cpp | 21 +++++++++++++++++++
flang/lib/Semantics/check-omp-structure.cpp | 11 +++++-----
flang/test/Semantics/OpenMP/in-reduction.f90 | 2 ++
flang/test/Semantics/OpenMP/reduction15.f90 | 2 ++
flang/test/Semantics/OpenMP/reduction17.f90 | 18 ++++++++++++++++
.../test/Semantics/OpenMP/task-reduction.f90 | 2 ++
7 files changed, 54 insertions(+), 5 deletions(-)
create mode 100644 flang/test/Semantics/OpenMP/reduction17.f90
diff --git a/flang/include/flang/Evaluate/tools.h b/flang/include/flang/Evaluate/tools.h
index 7f64d230f7348..4248e3a5461f5 100644
--- a/flang/include/flang/Evaluate/tools.h
+++ b/flang/include/flang/Evaluate/tools.h
@@ -1110,6 +1110,9 @@ bool IsArraySection(const Expr<SomeType> &expr);
// Predicate: does an expression contain constant?
bool HasConstant(const Expr<SomeType> &);
+// Predicate: Does an expression contain a component
+bool HasStructureComponent(const Expr<SomeType> &expr);
+
// Utilities for attaching the location of the declaration of a symbol
// of interest to a message. Handles the case of USE association gracefully.
parser::Message *AttachDeclaration(parser::Message &, const Symbol &);
diff --git a/flang/lib/Evaluate/tools.cpp b/flang/lib/Evaluate/tools.cpp
index bd06acc21e47f..a26c862d00dba 100644
--- a/flang/lib/Evaluate/tools.cpp
+++ b/flang/lib/Evaluate/tools.cpp
@@ -1210,6 +1210,27 @@ bool HasConstant(const Expr<SomeType> &expr) {
return HasConstantHelper{}(expr);
}
+// HasStructureComponent()
+struct HasStructureComponentHelper : public AnyTraverse<HasStructureComponentHelper, bool, false> {
+ using Base = AnyTraverse<HasStructureComponentHelper, bool, false>;
+ HasStructureComponentHelper() : Base(*this) {}
+ using Base::operator();
+
+ bool operator()(const DataRef &dataRef) const {
+ return std::holds_alternative<Component>(dataRef.u);
+ }
+ bool operator()(const NamedEntity &NamedEntity) const {
+ return NamedEntity.UnwrapComponent() != nullptr;
+ }
+ bool operator()(const Component &) const {
+ return true;
+ }
+};
+
+bool HasStructureComponent(const Expr<SomeType> &expr) {
+ return HasStructureComponentHelper{}(expr);
+}
+
parser::Message *AttachDeclaration(
parser::Message &message, const Symbol &symbol) {
const Symbol *unhosted{&symbol};
diff --git a/flang/lib/Semantics/check-omp-structure.cpp b/flang/lib/Semantics/check-omp-structure.cpp
index d7db15dd37949..5bc644bd4e0f6 100644
--- a/flang/lib/Semantics/check-omp-structure.cpp
+++ b/flang/lib/Semantics/check-omp-structure.cpp
@@ -4673,12 +4673,13 @@ void OmpStructureChecker::Enter(const parser::OmpClause::Copyin &x) {
void OmpStructureChecker::CheckStructureComponent(
const parser::OmpObjectList &objects, llvm::omp::Clause clauseId) {
auto CheckComponent{[&](const parser::Designator &designator) {
- if (auto *dataRef{std::get_if<parser::DataRef>(&designator.u)}) {
+ if (const parser::DataRef *dataRef{std::get_if<parser::DataRef>(&designator.u)}) {
if (!IsDataRefTypeParamInquiry(dataRef)) {
- if (auto *comp{parser::Unwrap<parser::StructureComponent>(*dataRef)}) {
- context_.Say(comp->component.source,
- "A variable that is part of another variable cannot appear on the %s clause"_err_en_US,
- parser::ToUpperCaseLetters(getClauseName(clauseId).str()));
+ const auto expr = AnalyzeExpr(context_, designator);
+ if (expr.has_value() && evaluate::HasStructureComponent(expr.value())) {
+ context_.Say(designator.source,
+ "A variable that is part of another variable cannot appear on the %s clause"_err_en_US,
+ parser::ToUpperCaseLetters(getClauseName(clauseId).str()));
}
}
}
diff --git a/flang/test/Semantics/OpenMP/in-reduction.f90 b/flang/test/Semantics/OpenMP/in-reduction.f90
index 1b82134b7104b..3f1e735214061 100644
--- a/flang/test/Semantics/OpenMP/in-reduction.f90
+++ b/flang/test/Semantics/OpenMP/in-reduction.f90
@@ -47,6 +47,7 @@ subroutine f06
integer :: a(10)
end type
type(t) :: x
+!ERROR: A variable that is part of another variable cannot appear on the IN_REDUCTION clause
!ERROR: The base expression of an array element or section in IN_REDUCTION clause must be an identifier
!$omp target in_reduction(+: x%a(2))
!$omp end target
@@ -57,6 +58,7 @@ subroutine f07
integer :: a(10)
end type
type(t) :: x
+!ERROR: A variable that is part of another variable cannot appear on the IN_REDUCTION clause
!ERROR: The base expression of an array element or section in IN_REDUCTION clause must be an identifier
!$omp target in_reduction(+: x%a(1:10))
!$omp end target
diff --git a/flang/test/Semantics/OpenMP/reduction15.f90 b/flang/test/Semantics/OpenMP/reduction15.f90
index 1d4de6ff702bb..61fa417f1111c 100644
--- a/flang/test/Semantics/OpenMP/reduction15.f90
+++ b/flang/test/Semantics/OpenMP/reduction15.f90
@@ -13,6 +13,7 @@ module m
subroutine f00
type(t) :: x
+ !ERROR: A variable that is part of another variable cannot appear on the REDUCTION clause
!ERROR: The base expression of an array element or section in REDUCTION clause must be an identifier
!$omp do reduction (+ : x%a(2))
do i = 1, 10
@@ -22,6 +23,7 @@ subroutine f00
subroutine f01
type(t) :: x
+ !ERROR: A variable that is part of another variable cannot appear on the REDUCTION clause
!ERROR: The base expression of an array element or section in REDUCTION clause must be an identifier
!$omp do reduction (+ : x%a(1:10))
do i = 1, 10
diff --git a/flang/test/Semantics/OpenMP/reduction17.f90 b/flang/test/Semantics/OpenMP/reduction17.f90
new file mode 100644
index 0000000000000..5b6e8e977f46c
--- /dev/null
+++ b/flang/test/Semantics/OpenMP/reduction17.f90
@@ -0,0 +1,18 @@
+! Test that Structure Component Array Elements are caught by Semantics and return an error
+! RUN: %python %S/../test_errors.py %s %flang_fc1 -fopenmp -fopenmp-version=45
+
+type test_type
+ integer :: array(2)
+end type
+
+contains
+ subroutine test
+ type(test_type) :: x
+
+ !ERROR: A variable that is part of another variable cannot appear on the REDUCTION clause
+ !$omp do reduction(+: x%array(2))
+ do i=1, 2
+ end do
+ !$omp end do
+ end subroutine
+end
diff --git a/flang/test/Semantics/OpenMP/task-reduction.f90 b/flang/test/Semantics/OpenMP/task-reduction.f90
index 5a18ee48e7728..f76b07ae568f4 100644
--- a/flang/test/Semantics/OpenMP/task-reduction.f90
+++ b/flang/test/Semantics/OpenMP/task-reduction.f90
@@ -47,6 +47,7 @@ subroutine f06
integer :: a(10)
end type
type(t) :: x
+!ERROR: A variable that is part of another variable cannot appear on the TASK_REDUCTION clause
!ERROR: The base expression of an array element or section in TASK_REDUCTION clause must be an identifier
!$omp taskgroup task_reduction(+: x%a(2))
!$omp end taskgroup
@@ -57,6 +58,7 @@ subroutine f07
integer :: a(10)
end type
type(t) :: x
+!ERROR: A variable that is part of another variable cannot appear on the TASK_REDUCTION clause
!ERROR: The base expression of an array element or section in TASK_REDUCTION clause must be an identifier
!$omp taskgroup task_reduction(+: x%a(1:10))
!$omp end taskgroup
More information about the flang-commits
mailing list