llvm-project/flang/lib/Parser/parse-tree.cpp
Krzysztof Parzyszek 6533ad04ed
[flang][OpenMP] Make all block constructs share the same structure (#150956)
The structure is
- OmpBeginDirective (aka OmpDirectiveSpecification)
- Block
- optional<OmpEndDirective> (aka optional<OmpDirectiveSpecification>)

The OmpBeginDirective and OmpEndDirective are effectively different
names for OmpDirectiveSpecification. They exist to allow the semantic
analyses to distinguish between the beginning and the ending of a block
construct without maintaining additional context.

The actual changes are in the parser: parse-tree.h and openmp-parser.cpp
in particular. The rest is simply changing the way the directive/clause
information is accessed (typically for the simpler).

All standalone and block constructs now use OmpDirectiveSpecification to
store the directive/clause information.
2025-08-01 07:52:59 -05:00

434 lines
14 KiB
C++

//===-- lib/Parser/parse-tree.cpp -----------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "flang/Parser/parse-tree.h"
#include "flang/Common/idioms.h"
#include "flang/Common/indirection.h"
#include "flang/Parser/tools.h"
#include "flang/Parser/user-state.h"
#include "llvm/Frontend/OpenMP/OMP.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
namespace Fortran::parser {
// R867
ImportStmt::ImportStmt(common::ImportKind &&k, std::list<Name> &&n)
: kind{k}, names(std::move(n)) {
CHECK(kind == common::ImportKind::Default ||
kind == common::ImportKind::Only || names.empty());
}
// R873
CommonStmt::CommonStmt(std::optional<Name> &&name,
std::list<CommonBlockObject> &&objects, std::list<Block> &&others) {
blocks.emplace_front(std::move(name), std::move(objects));
blocks.splice(blocks.end(), std::move(others));
}
// R901 designator
bool Designator::EndsInBareName() const {
return common::visit(
common::visitors{
[](const DataRef &dr) {
return std::holds_alternative<Name>(dr.u) ||
std::holds_alternative<common::Indirection<StructureComponent>>(
dr.u);
},
[](const Substring &) { return false; },
},
u);
}
// R911 data-ref -> part-ref [% part-ref]...
DataRef::DataRef(std::list<PartRef> &&prl) : u{std::move(prl.front().name)} {
for (bool first{true}; !prl.empty(); first = false, prl.pop_front()) {
PartRef &pr{prl.front()};
if (!first) {
u = common::Indirection<StructureComponent>::Make(
std::move(*this), std::move(pr.name));
}
if (!pr.subscripts.empty()) {
u = common::Indirection<ArrayElement>::Make(
std::move(*this), std::move(pr.subscripts));
}
if (pr.imageSelector) {
u = common::Indirection<CoindexedNamedObject>::Make(
std::move(*this), std::move(*pr.imageSelector));
}
}
}
// R1001 - R1022 expression
Expr::Expr(Designator &&x)
: u{common::Indirection<Designator>::Make(std::move(x))} {}
Expr::Expr(FunctionReference &&x)
: u{common::Indirection<FunctionReference>::Make(std::move(x))} {}
const std::optional<LoopControl> &DoConstruct::GetLoopControl() const {
const NonLabelDoStmt &doStmt{
std::get<Statement<NonLabelDoStmt>>(t).statement};
const std::optional<LoopControl> &control{
std::get<std::optional<LoopControl>>(doStmt.t)};
return control;
}
bool DoConstruct::IsDoNormal() const {
const std::optional<LoopControl> &control{GetLoopControl()};
return control && std::holds_alternative<LoopControl::Bounds>(control->u);
}
bool DoConstruct::IsDoWhile() const {
const std::optional<LoopControl> &control{GetLoopControl()};
return control && std::holds_alternative<ScalarLogicalExpr>(control->u);
}
bool DoConstruct::IsDoConcurrent() const {
const std::optional<LoopControl> &control{GetLoopControl()};
return control && std::holds_alternative<LoopControl::Concurrent>(control->u);
}
static Designator MakeArrayElementRef(
const Name &name, std::list<Expr> &&subscripts) {
ArrayElement arrayElement{DataRef{Name{name}}, std::list<SectionSubscript>{}};
for (Expr &expr : subscripts) {
arrayElement.subscripts.push_back(
SectionSubscript{Integer{common::Indirection{std::move(expr)}}});
}
return Designator{DataRef{common::Indirection{std::move(arrayElement)}}};
}
static Designator MakeArrayElementRef(
StructureComponent &&sc, std::list<Expr> &&subscripts) {
ArrayElement arrayElement{DataRef{common::Indirection{std::move(sc)}},
std::list<SectionSubscript>{}};
for (Expr &expr : subscripts) {
arrayElement.subscripts.push_back(
SectionSubscript{Integer{common::Indirection{std::move(expr)}}});
}
return Designator{DataRef{common::Indirection{std::move(arrayElement)}}};
}
// Set source in any type of node that has it.
template <typename T> T WithSource(CharBlock source, T &&x) {
x.source = source;
return std::move(x);
}
static Expr ActualArgToExpr(ActualArgSpec &arg) {
return common::visit(
common::visitors{
[&](common::Indirection<Expr> &y) { return std::move(y.value()); },
[&](common::Indirection<Variable> &y) {
return common::visit(
common::visitors{
[&](common::Indirection<Designator> &z) {
return WithSource(
z.value().source, Expr{std::move(z.value())});
},
[&](common::Indirection<FunctionReference> &z) {
return WithSource(
z.value().source, Expr{std::move(z.value())});
},
},
y.value().u);
},
[&](auto &) -> Expr { common::die("unexpected type"); },
},
std::get<ActualArg>(arg.t).u);
}
Designator FunctionReference::ConvertToArrayElementRef() {
std::list<Expr> args;
for (auto &arg : std::get<std::list<ActualArgSpec>>(v.t)) {
args.emplace_back(ActualArgToExpr(arg));
}
return common::visit(
common::visitors{
[&](const Name &name) {
return WithSource(
source, MakeArrayElementRef(name, std::move(args)));
},
[&](ProcComponentRef &pcr) {
return WithSource(source,
MakeArrayElementRef(std::move(pcr.v.thing), std::move(args)));
},
},
std::get<ProcedureDesignator>(v.t).u);
}
StructureConstructor FunctionReference::ConvertToStructureConstructor(
const semantics::DerivedTypeSpec &derived) {
Name name{std::get<parser::Name>(std::get<ProcedureDesignator>(v.t).u)};
std::list<ComponentSpec> components;
for (auto &arg : std::get<std::list<ActualArgSpec>>(v.t)) {
std::optional<Keyword> keyword;
if (auto &kw{std::get<std::optional<Keyword>>(arg.t)}) {
keyword.emplace(Keyword{Name{kw->v}});
}
components.emplace_back(
std::move(keyword), ComponentDataSource{ActualArgToExpr(arg)});
}
DerivedTypeSpec spec{std::move(name), std::list<TypeParamSpec>{}};
spec.derivedTypeSpec = &derived;
return StructureConstructor{std::move(spec), std::move(components)};
}
StructureConstructor ArrayElement::ConvertToStructureConstructor(
const semantics::DerivedTypeSpec &derived) {
Name name{std::get<parser::Name>(base.u)};
std::list<ComponentSpec> components;
for (auto &subscript : subscripts) {
components.emplace_back(std::optional<Keyword>{},
ComponentDataSource{std::move(*Unwrap<Expr>(subscript))});
}
DerivedTypeSpec spec{std::move(name), std::list<TypeParamSpec>{}};
spec.derivedTypeSpec = &derived;
return StructureConstructor{std::move(spec), std::move(components)};
}
Substring ArrayElement::ConvertToSubstring() {
auto iter{subscripts.begin()};
CHECK(iter != subscripts.end());
auto &triplet{std::get<SubscriptTriplet>(iter->u)};
CHECK(!std::get<2>(triplet.t));
CHECK(++iter == subscripts.end());
return Substring{std::move(base),
SubstringRange{std::get<0>(std::move(triplet.t)),
std::get<1>(std::move(triplet.t))}};
}
// R1544 stmt-function-stmt
// Convert this stmt-function-stmt to an assignment to the result of a
// pointer-valued function call -- which itself will be converted to a
// much more likely array element assignment statement if it needs
// to be.
Statement<ActionStmt> StmtFunctionStmt::ConvertToAssignment() {
auto &funcName{std::get<Name>(t)};
auto &funcArgs{std::get<std::list<Name>>(t)};
auto &funcExpr{std::get<Scalar<Expr>>(t).thing};
CharBlock source{funcName.source};
// Extend source to include closing parenthesis
if (funcArgs.empty()) {
CHECK(*source.end() == '(');
source = CharBlock{source.begin(), source.end() + 1};
}
std::list<ActualArgSpec> actuals;
for (const Name &arg : funcArgs) {
actuals.emplace_back(std::optional<Keyword>{},
ActualArg{Expr{WithSource(
arg.source, Designator{DataRef{Name{arg.source, arg.symbol}}})}});
source.ExtendToCover(arg.source);
}
CHECK(*source.end() == ')');
source = CharBlock{source.begin(), source.end() + 1};
FunctionReference funcRef{
Call{ProcedureDesignator{Name{funcName.source, funcName.symbol}},
std::move(actuals)}};
funcRef.source = source;
auto variable{Variable{common::Indirection{std::move(funcRef)}}};
return Statement{std::nullopt,
ActionStmt{common::Indirection{
AssignmentStmt{std::move(variable), std::move(funcExpr)}}}};
}
CharBlock Variable::GetSource() const {
return common::visit(
common::visitors{
[&](const common::Indirection<Designator> &des) {
return des.value().source;
},
[&](const common::Indirection<parser::FunctionReference> &call) {
return call.value().source;
},
},
u);
}
llvm::raw_ostream &operator<<(llvm::raw_ostream &os, const Name &x) {
return os << x.ToString();
}
OmpDirectiveName::OmpDirectiveName(const Verbatim &name) {
std::string_view nameView{name.source.begin(), name.source.size()};
std::string nameLower{ToLowerCaseLetters(nameView)};
// The function getOpenMPDirectiveKind will return OMPD_unknown in two cases:
// (1) if the given string doesn't match any actual directive, or
// (2) if the given string was "unknown".
// The Verbatim(<token>) parser will succeed as long as the given token
// matches the source.
// Since using "construct<OmpDirectiveName>(verbatim(...))" will succeed
// if the verbatim parser succeeds, in order to get OMPD_unknown the
// token given to Verbatim must be invalid. Because it's an internal issue
// asserting is ok.
v = llvm::omp::getOpenMPDirectiveKind(nameLower);
assert(v != llvm::omp::Directive::OMPD_unknown && "Invalid directive name");
source = name.source;
}
OmpDependenceType::Value OmpDoacross::GetDepType() const {
return common::visit( //
common::visitors{
[](const OmpDoacross::Sink &) {
return OmpDependenceType::Value::Sink;
},
[](const OmpDoacross::Source &) {
return OmpDependenceType::Value::Source;
},
},
u);
}
OmpTaskDependenceType::Value OmpDependClause::TaskDep::GetTaskDepType() const {
using Modifier = OmpDependClause::TaskDep::Modifier;
auto &modifiers{std::get<std::optional<std::list<Modifier>>>(t)};
if (modifiers) {
for (auto &m : *modifiers) {
if (auto *dep{std::get_if<OmpTaskDependenceType>(&m.u)}) {
return dep->v;
}
}
llvm_unreachable("expecting OmpTaskDependenceType in TaskDep");
} else {
llvm_unreachable("expecting modifiers on OmpDependClause::TaskDep");
}
}
std::string OmpTraitSelectorName::ToString() const {
return common::visit( //
common::visitors{
[&](Value v) { //
return std::string(EnumToString(v));
},
[&](llvm::omp::Directive d) {
return llvm::omp::getOpenMPDirectiveName(
d, llvm::omp::FallbackVersion)
.str();
},
[&](const std::string &s) { //
return s;
},
},
u);
}
std::string OmpTraitSetSelectorName::ToString() const {
return std::string(EnumToString(v));
}
llvm::omp::Clause OpenMPAtomicConstruct::GetKind() const {
const OmpDirectiveSpecification &dirSpec{std::get<OmpBeginDirective>(t)};
for (auto &clause : dirSpec.Clauses().v) {
switch (clause.Id()) {
case llvm::omp::Clause::OMPC_read:
case llvm::omp::Clause::OMPC_write:
case llvm::omp::Clause::OMPC_update:
return clause.Id();
default:
break;
}
}
return llvm::omp::Clause::OMPC_update;
}
bool OpenMPAtomicConstruct::IsCapture() const {
const OmpDirectiveSpecification &dirSpec{std::get<OmpBeginDirective>(t)};
return llvm::any_of(dirSpec.Clauses().v, [](auto &clause) {
return clause.Id() == llvm::omp::Clause::OMPC_capture;
});
}
bool OpenMPAtomicConstruct::IsCompare() const {
const OmpDirectiveSpecification &dirSpec{std::get<OmpBeginDirective>(t)};
return llvm::any_of(dirSpec.Clauses().v, [](auto &clause) {
return clause.Id() == llvm::omp::Clause::OMPC_compare;
});
}
} // namespace Fortran::parser
template <typename C> static llvm::omp::Clause getClauseIdForClass(C &&) {
using namespace Fortran;
using A = llvm::remove_cvref_t<C>; // A is referenced in OMP.inc
// The code included below contains a sequence of checks like the following
// for each OpenMP clause
// if constexpr (std::is_same_v<A, parser::OmpClause::AcqRel>)
// return llvm::omp::Clause::OMPC_acq_rel;
// [...]
#define GEN_FLANG_CLAUSE_PARSER_KIND_MAP
#include "llvm/Frontend/OpenMP/OMP.inc"
}
namespace Fortran::parser {
llvm::omp::Clause OmpClause::Id() const {
return std::visit([](auto &&s) { return getClauseIdForClass(s); }, u);
}
bool OmpDirectiveName::IsExecutionPart() const {
// Can the directive appear in the execution part of the program.
llvm::omp::Directive id{v};
switch (llvm::omp::getDirectiveCategory(id)) {
case llvm::omp::Category::Executable:
return true;
case llvm::omp::Category::Declarative:
switch (id) {
case llvm::omp::Directive::OMPD_allocate:
return true;
default:
return false;
}
break;
case llvm::omp::Category::Informational:
switch (id) {
case llvm::omp::Directive::OMPD_assume:
return true;
default:
return false;
}
break;
case llvm::omp::Category::Meta:
return true;
case llvm::omp::Category::Subsidiary:
switch (id) {
// TODO: case llvm::omp::Directive::OMPD_task_iteration:
case llvm::omp::Directive::OMPD_section:
case llvm::omp::Directive::OMPD_scan:
return true;
default:
return false;
}
break;
case llvm::omp::Category::Utility:
switch (id) {
case llvm::omp::Directive::OMPD_error:
case llvm::omp::Directive::OMPD_nothing:
return true;
default:
return false;
}
break;
}
return false;
}
const OmpArgumentList &OmpDirectiveSpecification::Arguments() const {
static OmpArgumentList empty{decltype(OmpArgumentList::v){}};
if (auto &arguments = std::get<std::optional<OmpArgumentList>>(t)) {
return *arguments;
}
return empty;
}
const OmpClauseList &OmpDirectiveSpecification::Clauses() const {
static OmpClauseList empty{decltype(OmpClauseList::v){}};
if (auto &clauses = std::get<std::optional<OmpClauseList>>(t)) {
return *clauses;
}
return empty;
}
} // namespace Fortran::parser