diff --git a/flang/docs/OpenACC.md b/flang/docs/OpenACC.md
--- a/flang/docs/OpenACC.md
+++ b/flang/docs/OpenACC.md
@@ -17,3 +17,4 @@
* The end directive for combined construct can omit the `loop` keyword.
* An `!$acc routine` with no parallelism clause is treated as if the `seq`
clause was present.
+* `!$acc end loop` does not trigger a parsing error and is just ignored.
diff --git a/flang/include/flang/Parser/dump-parse-tree.h b/flang/include/flang/Parser/dump-parse-tree.h
--- a/flang/include/flang/Parser/dump-parse-tree.h
+++ b/flang/include/flang/Parser/dump-parse-tree.h
@@ -105,6 +105,7 @@
NODE(parser, AccTileExpr)
NODE(parser, AccTileExprList)
NODE(parser, AccLoopDirective)
+ NODE(parser, AccEndLoop)
NODE(parser, AccWaitArgument)
static std::string GetNodeName(const llvm::acc::Directive &x) {
return llvm::Twine(
diff --git a/flang/include/flang/Parser/parse-tree.h b/flang/include/flang/Parser/parse-tree.h
--- a/flang/include/flang/Parser/parse-tree.h
+++ b/flang/include/flang/Parser/parse-tree.h
@@ -4244,11 +4244,10 @@
};
// OpenACC directives enclosing do loop
+EMPTY_CLASS(AccEndLoop);
struct OpenACCLoopConstruct {
TUPLE_CLASS_BOILERPLATE(OpenACCLoopConstruct);
- OpenACCLoopConstruct(AccBeginLoopDirective &&a)
- : t({std::move(a), std::nullopt}) {}
- std::tuple<AccBeginLoopDirective, std::optional<DoConstruct>> t;
+ std::tuple<AccBeginLoopDirective, DoConstruct, std::optional<AccEndLoop>> t;
};
struct OpenACCStandaloneConstruct {
diff --git a/flang/lib/Parser/openacc-parsers.cpp b/flang/lib/Parser/openacc-parsers.cpp
--- a/flang/lib/Parser/openacc-parsers.cpp
+++ b/flang/lib/Parser/openacc-parsers.cpp
@@ -150,8 +150,13 @@
TYPE_PARSER(construct<AccBeginLoopDirective>(
sourced(Parser<AccLoopDirective>{}), Parser<AccClauseList>{}))
-TYPE_PARSER(
- construct<OpenACCLoopConstruct>(sourced(Parser<AccBeginLoopDirective>{})))
+TYPE_PARSER(construct<AccEndLoop>(startAccLine >> "END LOOP"_tok))
+
+TYPE_PARSER(construct<OpenACCLoopConstruct>(
+ sourced(Parser<AccBeginLoopDirective>{} / endAccLine),
+ withMessage("A DO loop must follow the loop construct"_err_en_US,
+ Parser<DoConstruct>{}),
+ maybe(Parser<AccEndLoop>{} / endAccLine)))
// 2.15.1 Routine directive
TYPE_PARSER(sourced(construct<OpenACCRoutineConstruct>(verbatim("ROUTINE"_tok),
diff --git a/flang/lib/Parser/unparse.cpp b/flang/lib/Parser/unparse.cpp
--- a/flang/lib/Parser/unparse.cpp
+++ b/flang/lib/Parser/unparse.cpp
@@ -1947,7 +1947,7 @@
Walk(std::get<AccBeginLoopDirective>(x.t));
Put("\n");
EndOpenACC();
- Walk(std::get<std::optional<DoConstruct>>(x.t));
+ Walk(std::get<DoConstruct>(x.t));
}
void Unparse(const AccBeginLoopDirective &x) {
Walk(std::get<AccLoopDirective>(x.t));
diff --git a/flang/lib/Semantics/canonicalize-acc.cpp b/flang/lib/Semantics/canonicalize-acc.cpp
--- a/flang/lib/Semantics/canonicalize-acc.cpp
+++ b/flang/lib/Semantics/canonicalize-acc.cpp
@@ -52,7 +52,8 @@
// If there are n tile sizes in the list, the loop construct must be
// immediately followed by n tightly-nested loops.
template <typename C, typename D>
- void CheckTileClauseRestriction(const C &x) {
+ void CheckTileClauseRestriction(
+ const C &x, const parser::DoConstruct &outer) {
const auto &beginLoopDirective = std::get<D>(x.t);
const auto &accClauseList =
std::get<parser::AccClauseList>(beginLoopDirective.t);
@@ -63,11 +64,10 @@
const std::list<parser::AccTileExpr> &listTileExpr = tileExprList.v;
std::size_t tileArgNb = listTileExpr.size();
- const auto &outer{std::get<std::optional<parser::DoConstruct>>(x.t)};
- if (outer->IsDoConcurrent()) {
+ if (outer.IsDoConcurrent()) {
return; // Tile is not allowed on DO CONCURRENT
}
- for (const parser::DoConstruct *loop{&*outer}; loop && tileArgNb > 0;
+ for (const parser::DoConstruct *loop{&outer}; loop && tileArgNb > 0;
--tileArgNb) {
const auto &block{std::get<parser::Block>(loop->t)};
const auto it{block.begin()};
@@ -89,9 +89,9 @@
// A tile and collapse clause may not appear on loop that is associated with
// do concurrent.
template <typename C, typename D>
- void CheckDoConcurrentClauseRestriction(const C &x) {
- const auto &doCons{std::get<std::optional<parser::DoConstruct>>(x.t)};
- if (!doCons->IsDoConcurrent()) {
+ void CheckDoConcurrentClauseRestriction(
+ const C &x, const parser::DoConstruct &doCons) {
+ if (!doCons.IsDoConcurrent()) {
return;
}
const auto &beginLoopDirective = std::get<D>(x.t);
@@ -109,73 +109,36 @@
void RewriteOpenACCLoopConstruct(parser::OpenACCLoopConstruct &x,
parser::Block &block, parser::Block::iterator it) {
- // Check the sequence of DoConstruct in the same iteration
- //
- // Original:
- // ExecutableConstruct -> OpenACCConstruct -> OpenACCLoopConstruct
- // ACCBeginLoopDirective
- // ExecutableConstruct -> DoConstruct
- //
- // After rewriting:
- // ExecutableConstruct -> OpenACCConstruct -> OpenACCLoopConstruct
- // AccBeginLoopDirective
- // DoConstruct
- parser::Block::iterator nextIt;
auto &beginDir{std::get<parser::AccBeginLoopDirective>(x.t)};
auto &dir{std::get<parser::AccLoopDirective>(beginDir.t)};
+ const auto &doCons{std::get<parser::DoConstruct>(x.t)};
- nextIt = it;
- if (++nextIt != block.end()) {
- if (auto *doCons{parser::Unwrap<parser::DoConstruct>(*nextIt)}) {
- if (!doCons->GetLoopControl()) {
- messages_.Say(dir.source,
- "DO loop after the %s directive must have loop control"_err_en_US,
- parser::ToUpperCaseLetters(dir.source.ToString()));
- return;
- }
-
- // move DoConstruct
- std::get<std::optional<parser::DoConstruct>>(x.t) = std::move(*doCons);
- nextIt = block.erase(nextIt);
-
- CheckDoConcurrentClauseRestriction<parser::OpenACCLoopConstruct,
- parser::AccBeginLoopDirective>(x);
- CheckTileClauseRestriction<parser::OpenACCLoopConstruct,
- parser::AccBeginLoopDirective>(x);
-
- return; // found do-loop
- }
+ if (!doCons.GetLoopControl()) {
+ messages_.Say(dir.source,
+ "DO loop after the %s directive must have loop control"_err_en_US,
+ parser::ToUpperCaseLetters(dir.source.ToString()));
+ return;
}
- messages_.Say(dir.source,
- "A DO loop must follow the %s directive"_err_en_US,
- parser::ToUpperCaseLetters(dir.source.ToString()));
+
+ CheckDoConcurrentClauseRestriction<parser::OpenACCLoopConstruct,
+ parser::AccBeginLoopDirective>(x, doCons);
+ CheckTileClauseRestriction<parser::OpenACCLoopConstruct,
+ parser::AccBeginLoopDirective>(x, doCons);
}
void RewriteOpenACCCombinedConstruct(parser::OpenACCCombinedConstruct &x,
parser::Block &block, parser::Block::iterator it) {
- // Check the sequence of DoConstruct in the same iteration
- //
- // Original:
- // ExecutableConstruct -> OpenACCConstruct -> OpenACCCombinedConstruct
- // ACCBeginCombinedDirective
- // ExecutableConstruct -> DoConstruct
- // ExecutableConstruct -> AccEndCombinedDirective (if available)
- //
- // After rewriting:
- // ExecutableConstruct -> OpenACCConstruct -> OpenACCCombinedConstruct
- // ACCBeginCombinedDirective
- // DoConstruct
- // AccEndCombinedDirective (if available)
+ // Check the sequence of DoConstruct in the same iteration.
parser::Block::iterator nextIt;
auto &beginDir{std::get<parser::AccBeginCombinedDirective>(x.t)};
auto &dir{std::get<parser::AccCombinedDirective>(beginDir.t)};
- auto &doConstruct{std::get<std::optional<parser::DoConstruct>>(x.t)};
+ const auto &doConstruct{std::get<std::optional<parser::DoConstruct>>(x.t)};
if (doConstruct) {
CheckDoConcurrentClauseRestriction<parser::OpenACCCombinedConstruct,
- parser::AccBeginCombinedDirective>(x);
+ parser::AccBeginCombinedDirective>(x, *doConstruct);
CheckTileClauseRestriction<parser::OpenACCCombinedConstruct,
- parser::AccBeginCombinedDirective>(x);
+ parser::AccBeginCombinedDirective>(x, *doConstruct);
if (!doConstruct->GetLoopControl()) {
messages_.Say(dir.source,
"DO loop after the %s directive must have loop control"_err_en_US,
diff --git a/flang/lib/Semantics/resolve-directives.cpp b/flang/lib/Semantics/resolve-directives.cpp
--- a/flang/lib/Semantics/resolve-directives.cpp
+++ b/flang/lib/Semantics/resolve-directives.cpp
@@ -1088,8 +1088,8 @@
return nullptr;
};
- const auto &outer{std::get<std::optional<parser::DoConstruct>>(x.t)};
- for (const parser::DoConstruct *loop{&*outer}; loop && level > 0; --level) {
+ const auto &outer{std::get<parser::DoConstruct>(x.t)};
+ for (const parser::DoConstruct *loop{&outer}; loop && level > 0; --level) {
// go through all the nested do-loops and resolve index variables
const parser::Name *iv{GetLoopIndex(*loop)};
if (iv) {
diff --git a/flang/test/Semantics/OpenACC/acc-canonicalization-validity.f90 b/flang/test/Semantics/OpenACC/acc-canonicalization-validity.f90
--- a/flang/test/Semantics/OpenACC/acc-canonicalization-validity.f90
+++ b/flang/test/Semantics/OpenACC/acc-canonicalization-validity.f90
@@ -15,9 +15,7 @@
real(8) :: a(256)
real(8) :: aa(256, 256)
- !ERROR: A DO loop must follow the LOOP directive
- !$acc loop
- i = 1
+ i = 0
!ERROR: DO loop after the LOOP directive must have loop control
!$acc loop
diff --git a/flang/test/Semantics/OpenACC/acc-loop.f90 b/flang/test/Semantics/OpenACC/acc-loop.f90
--- a/flang/test/Semantics/OpenACC/acc-loop.f90
+++ b/flang/test/Semantics/OpenACC/acc-loop.f90
@@ -263,4 +263,9 @@
do i = 1, N
end do
+ !$acc loop
+ do i = 1, N
+ end do
+ !$acc end loop
+
end program openacc_loop_validity