//===-- lib/Semantics/check-do-forall.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 "check-do-forall.h"
#include "definable.h"
#include "flang/Common/template.h"
#include "flang/Evaluate/call.h"
#include "flang/Evaluate/expression.h"
#include "flang/Evaluate/tools.h"
#include "flang/Evaluate/traverse.h"
#include "flang/Parser/message.h"
#include "flang/Parser/parse-tree-visitor.h"
#include "flang/Parser/tools.h"
#include "flang/Semantics/attr.h"
#include "flang/Semantics/scope.h"
#include "flang/Semantics/semantics.h"
#include "flang/Semantics/symbol.h"
#include "flang/Semantics/tools.h"
#include "flang/Semantics/type.h"
namespace Fortran::evaluate {
using ActualArgumentRef = common::Reference<const ActualArgument>;
inline bool operator<(ActualArgumentRef x, ActualArgumentRef y) {
return &*x < &*y;
}
} // namespace Fortran::evaluate
namespace Fortran::semantics {
using namespace parser::literals;
using Bounds = parser::LoopControl::Bounds;
using IndexVarKind = SemanticsContext::IndexVarKind;
static const parser::ConcurrentHeader &GetConcurrentHeader(
const parser::LoopControl &loopControl) {
const auto &concurrent{
std::get<parser::LoopControl::Concurrent>(loopControl.u)};
return std::get<parser::ConcurrentHeader>(concurrent.t);
}
static const parser::ConcurrentHeader &GetConcurrentHeader(
const parser::ForallConstruct &construct) {
const auto &stmt{
std::get<parser::Statement<parser::ForallConstructStmt>>(construct.t)};
return std::get<common::Indirection<parser::ConcurrentHeader>>(
stmt.statement.t)
.value();
}
static const parser::ConcurrentHeader &GetConcurrentHeader(
const parser::ForallStmt &stmt) {
return std::get<common::Indirection<parser::ConcurrentHeader>>(stmt.t)
.value();
}
template <typename T>
static const std::list<parser::ConcurrentControl> &GetControls(const T &x) {
return std::get<std::list<parser::ConcurrentControl>>(
GetConcurrentHeader(x).t);
}
static const Bounds &GetBounds(const parser::DoConstruct &doConstruct) {
auto &loopControl{doConstruct.GetLoopControl().value()};
return std::get<Bounds>(loopControl.u);
}
static const parser::Name &GetDoVariable(
const parser::DoConstruct &doConstruct) {
const Bounds &bounds{GetBounds(doConstruct)};
return bounds.name.thing;
}
static parser::MessageFixedText GetEnclosingDoMsg() {
return "Enclosing DO CONCURRENT statement"_en_US;
}
static void SayWithDo(SemanticsContext &context, parser::CharBlock stmtLocation,
parser::MessageFixedText &&message, parser::CharBlock doLocation) {
context.Say(stmtLocation, message).Attach(doLocation, GetEnclosingDoMsg());
}
// 11.1.7.5 - enforce semantics constraints on a DO CONCURRENT loop body
class DoConcurrentBodyEnforce {
public:
DoConcurrentBodyEnforce(
SemanticsContext &context, parser::CharBlock doConcurrentSourcePosition)
: context_{context},
doConcurrentSourcePosition_{doConcurrentSourcePosition} {}
std::set<parser::Label> labels() { return labels_; }
template <typename T> bool Pre(const T &x) {
if (const auto *expr{GetExpr(context_, x)}) {
if (auto bad{FindImpureCall(context_.foldingContext(), *expr)}) {
context_.Say(currentStatementSourcePosition_,
"Impure procedure '%s' may not be referenced in DO CONCURRENT"_err_en_US,
*bad);
}
}
return true;
}
template <typename T> bool Pre(const parser::Statement<T> &statement) {
currentStatementSourcePosition_ = statement.source;
if (statement.label.has_value()) {
labels_.insert(*statement.label);
}
return true;
}
template <typename T> bool Pre(const parser::UnlabeledStatement<T> &stmt) {
currentStatementSourcePosition_ = stmt.source;
return true;
}
bool Pre(const parser::CallStmt &x) {
if (x.typedCall.get()) {
if (auto bad{FindImpureCall(context_.foldingContext(), *x.typedCall)}) {
context_.Say(currentStatementSourcePosition_,
"Impure procedure '%s' may not be referenced in DO CONCURRENT"_err_en_US,
*bad);
}
}
return true;
}
template <typename T> void Post(const T &) {}
// C1140 -- Can't deallocate a polymorphic entity in a DO CONCURRENT.
// Deallocation can be caused by exiting a block that declares an allocatable
// entity, assignment to an allocatable variable, or an actual DEALLOCATE
// statement
//
// Note also that the deallocation of a derived type entity might cause the
// invocation of an IMPURE final subroutine. (C1139)
//
// Predicate for deallocations caused by block exit and direct deallocation
static bool DeallocateAll(const Symbol &) { return true; }
// Predicate for deallocations caused by intrinsic assignment
static bool DeallocateNonCoarray(const Symbol &component) {
return !evaluate::IsCoarray(component);
}
static bool WillDeallocatePolymorphic(const Symbol &entity,
const std::function<bool(const Symbol &)> &WillDeallocate) {
return WillDeallocate(entity) && IsPolymorphicAllocatable(entity);
}
// Is it possible that we will we deallocate a polymorphic entity or one
// of its components?
static bool MightDeallocatePolymorphic(const Symbol &original,
const std::function<bool(const Symbol &)> &WillDeallocate) {
const Symbol &symbol{ResolveAssociations(original)};
// Check the entity itself, no coarray exception here
if (IsPolymorphicAllocatable(symbol)) {
return true;
}
// Check the components
if (const auto *details{symbol.detailsIf<ObjectEntityDetails>()}) {
if (const DeclTypeSpec * entityType{details->type()}) {
if (const DerivedTypeSpec * derivedType{entityType->AsDerived()}) {
UltimateComponentIterator ultimates{*derivedType};
for (const auto &ultimate : ultimates) {
if (WillDeallocatePolymorphic(ultimate, WillDeallocate)) {
return true;
}
}
}
}
}
return false;
}
void SayDeallocateWithImpureFinal(
const Symbol &entity, const char *reason, const Symbol &impure) {
context_.SayWithDecl(entity, currentStatementSourcePosition_,
"Deallocation of an entity with an IMPURE FINAL procedure '%s' caused by %s not allowed in DO CONCURRENT"_err_en_US,
impure.name(), reason);
}
void SayDeallocateOfPolymorph(
parser::CharBlock location, const Symbol &entity, const char *reason) {
context_.SayWithDecl(entity, location,
"Deallocation of a polymorphic entity caused by %s"
" not allowed in DO CONCURRENT"_err_en_US,
reason);
}
// Deallocation caused by block exit
// Allocatable entities and all of their allocatable subcomponents will be
// deallocated. This test is different from the other two because it does
// not deallocate in cases where the entity itself is not allocatable but
// has allocatable polymorphic components
void Post(const parser::BlockConstruct &blockConstruct) {
const auto &endBlockStmt{
std::get<parser::Statement<parser::EndBlockStmt>>(blockConstruct.t)};
const Scope &blockScope{context_.FindScope(endBlockStmt.source)};
const Scope &doScope{context_.FindScope(doConcurrentSourcePosition_)};
if (DoesScopeContain(&doScope, blockScope)) {
const char *reason{"block exit"};
for (auto &pair : blockScope) {
const Symbol &entity{*pair.second};
if (IsAllocatable(entity) && !IsSaved(entity) &&
MightDeallocatePolymorphic(entity, DeallocateAll)) {
SayDeallocateOfPolymorph(endBlockStmt.source, entity, reason);
}
if (const Symbol * impure{HasImpureFinal(entity)}) {
SayDeallocateWithImpureFinal(entity, reason, *impure);
}
}
}
}
// Deallocation caused by assignment
// Note that this case does not cause deallocation of coarray components
void Post(const parser::AssignmentStmt &stmt) {
const auto &variable{std::get<parser::Variable>(stmt.t)};
if (const Symbol * entity{GetLastName(variable).symbol}) {
const char *reason{"assignment"};
if (MightDeallocatePolymorphic(*entity, DeallocateNonCoarray)) {
SayDeallocateOfPolymorph(variable.GetSource(), *entity, reason);
}
if (const auto *assignment{GetAssignment(stmt)}) {
const auto &lhs{assignment->lhs};
if (const Symbol * impure{HasImpureFinal(*entity, lhs.Rank())}) {
SayDeallocateWithImpureFinal(*entity, reason, *impure);
}
}
}
if (const auto *assignment{GetAssignment(stmt)}) {
if (const auto *call{
std::get_if<evaluate::ProcedureRef>(&assignment->u)}) {
if (auto bad{FindImpureCall(context_.foldingContext(), *call)}) {
context_.Say(currentStatementSourcePosition_,
"The defined assignment subroutine '%s' is not pure"_err_en_US,
*bad);
}
}
}
}
// Deallocation from a DEALLOCATE statement
// This case is different because DEALLOCATE statements deallocate both
// ALLOCATABLE and POINTER entities
void Post(const parser::DeallocateStmt &stmt) {
const auto &allocateObjectList{
std::get<std::list<parser::AllocateObject>>(stmt.t)};
for (const auto &allocateObject : allocateObjectList) {
const parser::Name &name{GetLastName(allocateObject)};
const char *reason{"a DEALLOCATE statement"};
if (name.symbol) {
const Symbol &entity{*name.symbol};
const DeclTypeSpec *entityType{entity.GetType()};
if ((entityType && entityType->IsPolymorphic()) || // POINTER case
MightDeallocatePolymorphic(entity, DeallocateAll)) {
SayDeallocateOfPolymorph(
currentStatementSourcePosition_, entity, reason);
}
if (const Symbol * impure{HasImpureFinal(entity)}) {
SayDeallocateWithImpureFinal(entity, reason, *impure);
}
}
}
}
// C1137 -- No image control statements in a DO CONCURRENT
void Post(const parser::ExecutableConstruct &construct) {
if (IsImageControlStmt(construct)) {
const parser::CharBlock statementLocation{
GetImageControlStmtLocation(construct)};
auto &msg{context_.Say(statementLocation,
"An image control statement is not allowed in DO CONCURRENT"_err_en_US)};
if (auto coarrayMsg{GetImageControlStmtCoarrayMsg(construct)}) {
msg.Attach(statementLocation, *coarrayMsg);
}
msg.Attach(doConcurrentSourcePosition_, GetEnclosingDoMsg());
}
}
// C1136 -- No RETURN statements in a DO CONCURRENT
void Post(const parser::ReturnStmt &) {
context_
.Say(currentStatementSourcePosition_,
"RETURN is not allowed in DO CONCURRENT"_err_en_US)
.Attach(doConcurrentSourcePosition_, GetEnclosingDoMsg());
}
// C1145, C1146: cannot call ieee_[gs]et_flag, ieee_[gs]et_halting_mode,
// ieee_[gs]et_status, ieee_set_rounding_mode, or ieee_set_underflow_mode
void Post(const parser::ProcedureDesignator &procedureDesignator) {
if (auto *name{std::get_if<parser::Name>(&procedureDesignator.u)}) {
if (name->symbol) {
const Symbol &ultimate{name->symbol->GetUltimate()};
const Scope &scope{ultimate.owner()};
if (const Symbol * module{scope.IsModule() ? scope.symbol() : nullptr};
module &&
(module->name() == "__fortran_ieee_arithmetic" ||
module->name() == "__fortran_ieee_exceptions")) {
std::string s{ultimate.name().ToString()};
static constexpr const char *badName[]{"ieee_get_flag",
"ieee_set_flag", "ieee_get_halting_mode", "ieee_set_halting_mode",
"ieee_get_status", "ieee_set_status", "ieee_set_rounding_mode",
"ieee_set_underflow_mode", nullptr};
for (std::size_t j{0}; badName[j]; ++j) {
if (s.find(badName[j]) != s.npos) {
context_
.Say(name->source,
"'%s' may not be called in DO CONCURRENT"_err_en_US,
badName[j])
.Attach(doConcurrentSourcePosition_, GetEnclosingDoMsg());
break;
}
}
}
}
}
}
// 11.1.7.5, paragraph 5, no ADVANCE specifier in a DO CONCURRENT
void Post(const parser::IoControlSpec &ioControlSpec) {
if (auto *charExpr{
std::get_if<parser::IoControlSpec::CharExpr>(&ioControlSpec.u)}) {
if (std::get<parser::IoControlSpec::CharExpr::Kind>(charExpr->t) ==
parser::IoControlSpec::CharExpr::Kind::Advance) {
SayWithDo(context_, currentStatementSourcePosition_,
"ADVANCE specifier is not allowed in DO"
" CONCURRENT"_err_en_US,
doConcurrentSourcePosition_);
}
}
}
private:
std::set<parser::Label> labels_;
parser::CharBlock currentStatementSourcePosition_;
SemanticsContext &context_;
parser::CharBlock doConcurrentSourcePosition_;
}; // class DoConcurrentBodyEnforce
// Class for enforcing C1130 -- in a DO CONCURRENT with DEFAULT(NONE),
// variables from enclosing scopes must have their locality specified
class DoConcurrentVariableEnforce {
public:
DoConcurrentVariableEnforce(
SemanticsContext &context, parser::CharBlock doConcurrentSourcePosition)
: context_{context},
doConcurrentSourcePosition_{doConcurrentSourcePosition},
blockScope_{context.FindScope(doConcurrentSourcePosition_)} {}
template <typename T> bool Pre(const T &) { return true; }
template <typename T> void Post(const T &) {}
// Check to see if the name is a variable from an enclosing scope
void Post(const parser::Name &name) {
if (const Symbol * symbol{name.symbol}) {
if (IsVariableName(*symbol)) {
const Scope &variableScope{symbol->owner()};
if (DoesScopeContain(&variableScope, blockScope_)) {
context_.SayWithDecl(*symbol, name.source,
"Variable '%s' from an enclosing scope referenced in DO "
"CONCURRENT with DEFAULT(NONE) must appear in a "
"locality-spec"_err_en_US,
symbol->name());
}
}
}
}
private:
SemanticsContext &context_;
parser::CharBlock doConcurrentSourcePosition_;
const Scope &blockScope_;
}; // class DoConcurrentVariableEnforce
// Find a DO or FORALL and enforce semantics checks on its body
class DoContext {
public:
DoContext(SemanticsContext &context, IndexVarKind kind, bool isNested)
: context_{context}, kind_{kind}, isNested_{isNested} {}
// Mark this DO construct as a point of definition for the DO variables
// or index-names it contains. If they're already defined, emit an error
// message. We need to remember both the variable and the source location of
// the variable in the DO construct so that we can remove it when we leave
// the DO construct and use its location in error messages.
void DefineDoVariables(const parser::DoConstruct &doConstruct) {
if (doConstruct.IsDoNormal()) {
context_.ActivateIndexVar(GetDoVariable(doConstruct), IndexVarKind::DO);
} else if (doConstruct.IsDoConcurrent()) {
if (const auto &loopControl{doConstruct.GetLoopControl()}) {
ActivateIndexVars(GetControls(*loopControl));
}
}
}
// Called at the end of a DO construct to deactivate the DO construct
void ResetDoVariables(const parser::DoConstruct &doConstruct) {
if (doConstruct.IsDoNormal()) {
context_.DeactivateIndexVar(GetDoVariable(doConstruct));
} else if (doConstruct.IsDoConcurrent()) {
if (const auto &loopControl{doConstruct.GetLoopControl()}) {
DeactivateIndexVars(GetControls(*loopControl));
}
}
}
void ActivateIndexVars(const std::list<parser::ConcurrentControl> &controls) {
for (const auto &control : controls) {
context_.ActivateIndexVar(std::get<parser::Name>(control.t), kind_);
}
}
void DeactivateIndexVars(
const std::list<parser::ConcurrentControl> &controls) {
for (const auto &control : controls) {
context_.DeactivateIndexVar(std::get<parser::Name>(control.t));
}
}
void Check(const parser::DoConstruct &doConstruct) {
if (doConstruct.IsDoConcurrent()) {
CheckDoConcurrent(doConstruct);
} else if (doConstruct.IsDoNormal()) {
CheckDoNormal(doConstruct);
} else {
// TODO: handle the other cases
}
}
void Check(const parser::ForallStmt &stmt) {
CheckConcurrentHeader(GetConcurrentHeader(stmt));
}
void Check(const parser::ForallConstruct &construct) {
CheckConcurrentHeader(GetConcurrentHeader(construct));
}
void Check(const parser::ForallAssignmentStmt &stmt) {
if (const evaluate::Assignment *
assignment{common::visit(
common::visitors{[&](const auto &x) { return GetAssignment(x); }},
stmt.u)}) {
CheckForallIndexesUsed(*assignment);
CheckForImpureCall(assignment->lhs);
CheckForImpureCall(assignment->rhs);
if (IsVariable(assignment->lhs)) {
if (const Symbol * symbol{GetLastSymbol(assignment->lhs)}) {
if (auto impureFinal{
HasImpureFinal(*symbol, assignment->lhs.Rank())}) {
context_.SayWithDecl(*symbol, parser::FindSourceLocation(stmt),
"Impure procedure '%s' is referenced by finalization in a %s"_err_en_US,
impureFinal->name(), LoopKindName());
}
}
}
if (const auto *proc{
std::get_if<evaluate::ProcedureRef>(&assignment->u)}) {
CheckForImpureCall(*proc);
}
common::visit(
common::visitors{
[](const evaluate::Assignment::Intrinsic &) {},
[&](const evaluate::ProcedureRef &proc) {
CheckForImpureCall(proc);
},
[&](const evaluate::Assignment::BoundsSpec &bounds) {
for (const auto &bound : bounds) {
CheckForImpureCall(SomeExpr{bound});
}
},
[&](const evaluate::Assignment::BoundsRemapping &bounds) {
for (const auto &bound : bounds) {
CheckForImpureCall(SomeExpr{bound.first});
CheckForImpureCall(SomeExpr{bound.second});
}
},
},
assignment->u);
}
}
private:
void SayBadDoControl(parser::CharBlock sourceLocation) {
context_.Say(sourceLocation, "DO controls should be INTEGER"_err_en_US);
}
void CheckDoControl(const parser::CharBlock &sourceLocation, bool isReal) {
if (isReal) {
if (context_.ShouldWarn(common::LanguageFeature::RealDoControls)) {
context_.Say(
sourceLocation, "DO controls should be INTEGER"_port_en_US);
}
} else {
SayBadDoControl(sourceLocation);
}
}
void CheckDoVariable(const parser::ScalarName &scalarName) {
const parser::CharBlock &sourceLocation{scalarName.thing.source};
if (const Symbol * symbol{scalarName.thing.symbol}) {
if (!IsVariableName(*symbol)) {
context_.Say(
sourceLocation, "DO control must be an INTEGER variable"_err_en_US);
} else if (auto why{WhyNotDefinable(sourceLocation,
context_.FindScope(sourceLocation), DefinabilityFlags{},
*symbol)}) {
context_
.Say(sourceLocation,
"'%s' may not be used as a DO variable"_err_en_US,
symbol->name())
.Attach(std::move(why->set_severity(parser::Severity::Because)));
} else {
const DeclTypeSpec *symType{symbol->GetType()};
if (!symType) {
SayBadDoControl(sourceLocation);
} else {
if (!symType->IsNumeric(TypeCategory::Integer)) {
CheckDoControl(
sourceLocation, symType->IsNumeric(TypeCategory::Real));
}
}
} // No messages for INTEGER
}
}
// Semantic checks for the limit and step expressions
void CheckDoExpression(const parser::ScalarExpr &scalarExpression) {
if (const SomeExpr * expr{GetExpr(context_, scalarExpression)}) {
if (!ExprHasTypeCategory(*expr, TypeCategory::Integer)) {
// No warnings or errors for type INTEGER
const parser::CharBlock &loc{scalarExpression.thing.value().source};
CheckDoControl(loc, ExprHasTypeCategory(*expr, TypeCategory::Real));
}
}
}
void CheckDoNormal(const parser::DoConstruct &doConstruct) {
// C1120 -- types of DO variables must be INTEGER, extended by allowing
// REAL and DOUBLE PRECISION
const Bounds &bounds{GetBounds(doConstruct)};
CheckDoVariable(bounds.name);
CheckDoExpression(bounds.lower);
CheckDoExpression(bounds.upper);
if (bounds.step) {
CheckDoExpression(*bounds.step);
if (IsZero(*bounds.step) &&
context_.ShouldWarn(common::UsageWarning::ZeroDoStep)) {
context_.Say(bounds.step->thing.value().source,
"DO step expression should not be zero"_warn_en_US);
}
}
}
void CheckDoConcurrent(const parser::DoConstruct &doConstruct) {
auto &doStmt{
std::get<parser::Statement<parser::NonLabelDoStmt>>(doConstruct.t)};
currentStatementSourcePosition_ = doStmt.source;
const parser::Block &block{std::get<parser::Block>(doConstruct.t)};
DoConcurrentBodyEnforce doConcurrentBodyEnforce{context_, doStmt.source};
parser::Walk(block, doConcurrentBodyEnforce);
LabelEnforce doConcurrentLabelEnforce{context_,
doConcurrentBodyEnforce.labels(), currentStatementSourcePosition_,
"DO CONCURRENT"};
parser::Walk(block, doConcurrentLabelEnforce);
const auto &loopControl{doConstruct.GetLoopControl()};
CheckConcurrentLoopControl(*loopControl);
CheckLocalitySpecs(*loopControl, block);
}
// Return a set of symbols whose names are in a Local locality-spec. Look
// the names up in the scope that encloses the DO construct to avoid getting
// the local versions of them. Then follow the host-, use-, and
// construct-associations to get the root symbols
UnorderedSymbolSet GatherLocals(
const std::list<parser::LocalitySpec> &localitySpecs) const {
UnorderedSymbolSet symbols;
const Scope &parentScope{
context_.FindScope(currentStatementSourcePosition_).parent()};
// Loop through the LocalitySpec::Local locality-specs
for (const auto &ls : localitySpecs) {
if (const auto *names{std::get_if<parser::LocalitySpec::Local>(&ls.u)}) {
// Loop through the names in the Local locality-spec getting their
// symbols
for (const parser::Name &name : names->v) {
if (const Symbol * symbol{parentScope.FindSymbol(name.source)}) {
symbols.insert(ResolveAssociations(*symbol));
}
}
}
}
return symbols;
}
UnorderedSymbolSet GatherSymbolsFromExpression(
const parser::Expr &expression) const {
UnorderedSymbolSet result;
if (const auto *expr{GetExpr(context_, expression)}) {
for (const Symbol &symbol : evaluate::CollectSymbols(*expr)) {
result.insert(ResolveAssociations(symbol));
}
}
return result;
}
// C1121 - procedures in mask must be pure
void CheckMaskIsPure(const parser::ScalarLogicalExpr &mask) const {
UnorderedSymbolSet references{
GatherSymbolsFromExpression(mask.thing.thing.value())};
for (const Symbol &ref : OrderBySourcePosition(references)) {
if (IsProcedure(ref) && !IsPureProcedure(ref)) {
context_.SayWithDecl(ref, parser::Unwrap<parser::Expr>(mask)->source,
"%s mask expression may not reference impure procedure '%s'"_err_en_US,
LoopKindName(), ref.name());
return;
}
}
}
void CheckNoCollisions(const UnorderedSymbolSet &refs,
const UnorderedSymbolSet &uses, parser::MessageFixedText &&errorMessage,
const parser::CharBlock &refPosition) const {
for (const Symbol &ref : OrderBySourcePosition(refs)) {
if (uses.find(ref) != uses.end()) {
context_.SayWithDecl(ref, refPosition, std::move(errorMessage),
LoopKindName(), ref.name());
return;
}
}
}
void HasNoReferences(const UnorderedSymbolSet &indexNames,
const parser::ScalarIntExpr &expr) const {
CheckNoCollisions(GatherSymbolsFromExpression(expr.thing.thing.value()),
indexNames,
"%s limit expression may not reference index variable '%s'"_err_en_US,
expr.thing.thing.value().source);
}
// C1129, names in local locality-specs can't be in mask expressions
void CheckMaskDoesNotReferenceLocal(const parser::ScalarLogicalExpr &mask,
const UnorderedSymbolSet &localVars) const {
CheckNoCollisions(GatherSymbolsFromExpression(mask.thing.thing.value()),
localVars,
"%s mask expression references variable '%s'"
" in LOCAL locality-spec"_err_en_US,
mask.thing.thing.value().source);
}
// C1129, names in local locality-specs can't be in limit or step
// expressions
void CheckExprDoesNotReferenceLocal(const parser::ScalarIntExpr &expr,
const UnorderedSymbolSet &localVars) const {
CheckNoCollisions(GatherSymbolsFromExpression(expr.thing.thing.value()),
localVars,
"%s expression references variable '%s'"
" in LOCAL locality-spec"_err_en_US,
expr.thing.thing.value().source);
}
// C1130, DEFAULT(NONE) locality requires names to be in locality-specs to
// be used in the body of the DO loop
void CheckDefaultNoneImpliesExplicitLocality(
const std::list<parser::LocalitySpec> &localitySpecs,
const parser::Block &block) const {
bool hasDefaultNone{false};
for (auto &ls : localitySpecs) {
if (std::holds_alternative<parser::LocalitySpec::DefaultNone>(ls.u)) {
if (hasDefaultNone) {
// F'2023 C1129, you can only have one DEFAULT(NONE)
if (context_.ShouldWarn(common::LanguageFeature::BenignRedundancy)) {
context_.Say(currentStatementSourcePosition_,
"Only one DEFAULT(NONE) may appear"_port_en_US);
}
break;
}
hasDefaultNone = true;
}
}
if (hasDefaultNone) {
DoConcurrentVariableEnforce doConcurrentVariableEnforce{
context_, currentStatementSourcePosition_};
parser::Walk(block, doConcurrentVariableEnforce);
}
}
void CheckReduce(const parser::LocalitySpec::Reduce &reduce) const {
const parser::ReductionOperator &reductionOperator{
std::get<parser::ReductionOperator>(reduce.t)};
// F'2023 C1132, reduction variables should have suitable intrinsic type
for (const parser::Name &x : std::get<std::list<parser::Name>>(reduce.t)) {
bool supportedIdentifier{false};
if (x.symbol && x.symbol->GetType()) {
const auto *type{x.symbol->GetType()};
auto typeMismatch{[&](const char *suitable_types) {
context_.Say(currentStatementSourcePosition_,
"Reduction variable '%s' ('%s') does not have a suitable type ('%s')."_err_en_US,
x.symbol->name(), type->AsFortran(), suitable_types);
}};
supportedIdentifier = true;
switch (reductionOperator.v) {
case parser::ReductionOperator::Operator::Plus:
case parser::ReductionOperator::Operator::Multiply:
if (!(type->IsNumeric(TypeCategory::Complex) ||
type->IsNumeric(TypeCategory::Integer) ||
type->IsNumeric(TypeCategory::Real))) {
typeMismatch("COMPLEX', 'INTEGER', or 'REAL");
}
break;
case parser::ReductionOperator::Operator::And:
case parser::ReductionOperator::Operator::Or:
case parser::ReductionOperator::Operator::Eqv:
case parser::ReductionOperator::Operator::Neqv:
if (type->category() != DeclTypeSpec::Category::Logical) {
typeMismatch("LOGICAL");
}
break;
case parser::ReductionOperator::Operator::Max:
case parser::ReductionOperator::Operator::Min:
if (!(type->IsNumeric(TypeCategory::Integer) ||
type->IsNumeric(TypeCategory::Real))) {
typeMismatch("INTEGER', or 'REAL");
}
break;
case parser::ReductionOperator::Operator::Iand:
case parser::ReductionOperator::Operator::Ior:
case parser::ReductionOperator::Operator::Ieor:
if (!type->IsNumeric(TypeCategory::Integer)) {
typeMismatch("INTEGER");
}
break;
}
}
if (!supportedIdentifier) {
context_.Say(currentStatementSourcePosition_,
"Invalid identifier in REDUCE clause."_err_en_US);
}
}
}
// C1123, concurrent limit or step expressions can't reference index-names
void CheckConcurrentHeader(const parser::ConcurrentHeader &header) const {
if (const auto &mask{
std::get<std::optional<parser::ScalarLogicalExpr>>(header.t)}) {
CheckMaskIsPure(*mask);
}
const auto &controls{
std::get<std::list<parser::ConcurrentControl>>(header.t)};
UnorderedSymbolSet indexNames;
for (const parser::ConcurrentControl &control : controls) {
const auto &indexName{std::get<parser::Name>(control.t)};
if (indexName.symbol) {
indexNames.insert(*indexName.symbol);
}
if (isNested_) {
CheckForImpureCall(std::get<1>(control.t));
CheckForImpureCall(std::get<2>(control.t));
if (const auto &stride{std::get<3>(control.t)}) {
CheckForImpureCall(*stride);
}
}
}
if (!indexNames.empty()) {
for (const parser::ConcurrentControl &control : controls) {
HasNoReferences(indexNames, std::get<1>(control.t));
HasNoReferences(indexNames, std::get<2>(control.t));
if (const auto &intExpr{
std::get<std::optional<parser::ScalarIntExpr>>(control.t)}) {
const parser::Expr &expr{intExpr->thing.thing.value()};
CheckNoCollisions(GatherSymbolsFromExpression(expr), indexNames,
"%s step expression may not reference index variable '%s'"_err_en_US,
expr.source);
if (IsZero(expr)) {
context_.Say(expr.source,
"%s step expression may not be zero"_err_en_US, LoopKindName());
}
}
}
}
}
void CheckLocalitySpecs(
const parser::LoopControl &control, const parser::Block &block) const {
const auto &concurrent{
std::get<parser::LoopControl::Concurrent>(control.u)};
const auto &header{std::get<parser::ConcurrentHeader>(concurrent.t)};
const auto &localitySpecs{
std::get<std::list<parser::LocalitySpec>>(concurrent.t)};
if (!localitySpecs.empty()) {
const UnorderedSymbolSet &localVars{GatherLocals(localitySpecs)};
for (const auto &c : GetControls(control)) {
CheckExprDoesNotReferenceLocal(std::get<1>(c.t), localVars);
CheckExprDoesNotReferenceLocal(std::get<2>(c.t), localVars);
if (const auto &expr{
std::get<std::optional<parser::ScalarIntExpr>>(c.t)}) {
CheckExprDoesNotReferenceLocal(*expr, localVars);
}
}
if (const auto &mask{
std::get<std::optional<parser::ScalarLogicalExpr>>(header.t)}) {
CheckMaskDoesNotReferenceLocal(*mask, localVars);
}
for (auto &ls : localitySpecs) {
if (const auto *reduce{
std::get_if<parser::LocalitySpec::Reduce>(&ls.u)}) {
CheckReduce(*reduce);
}
}
CheckDefaultNoneImpliesExplicitLocality(localitySpecs, block);
}
}
// check constraints [C1121 .. C1130]
void CheckConcurrentLoopControl(const parser::LoopControl &control) const {
const auto &concurrent{
std::get<parser::LoopControl::Concurrent>(control.u)};
CheckConcurrentHeader(std::get<parser::ConcurrentHeader>(concurrent.t));
}
template <typename T> void CheckForImpureCall(const T &x) const {
if (auto bad{FindImpureCall(context_.foldingContext(), x)}) {
context_.Say(
"Impure procedure '%s' may not be referenced in a %s"_err_en_US, *bad,
LoopKindName());
}
}
void CheckForImpureCall(const parser::ScalarIntExpr &x) const {
const auto &parsedExpr{x.thing.thing.value()};
auto oldLocation{context_.location()};
context_.set_location(parsedExpr.source);
if (const auto &typedExpr{parsedExpr.typedExpr}) {
if (const auto &expr{typedExpr->v}) {
CheckForImpureCall(*expr);
}
}
context_.set_location(oldLocation);
}
// Each index should be used on the LHS of each assignment in a FORALL
void CheckForallIndexesUsed(const evaluate::Assignment &assignment) {
SymbolVector indexVars{context_.GetIndexVars(IndexVarKind::FORALL)};
if (!indexVars.empty()) {
UnorderedSymbolSet symbols{evaluate::CollectSymbols(assignment.lhs)};
common::visit(
common::visitors{
[&](const evaluate::Assignment::BoundsSpec &spec) {
for (const auto &bound : spec) {
// TODO: this is working around missing std::set::merge in some versions of
// clang that we are building with
#ifdef __clang__
auto boundSymbols{evaluate::CollectSymbols(bound)};
symbols.insert(boundSymbols.begin(), boundSymbols.end());
#else
symbols.merge(evaluate::CollectSymbols(bound));
#endif
}
},
[&](const evaluate::Assignment::BoundsRemapping &remapping) {
for (const auto &bounds : remapping) {
#ifdef __clang__
auto lbSymbols{evaluate::CollectSymbols(bounds.first)};
symbols.insert(lbSymbols.begin(), lbSymbols.end());
auto ubSymbols{evaluate::CollectSymbols(bounds.second)};
symbols.insert(ubSymbols.begin(), ubSymbols.end());
#else
symbols.merge(evaluate::CollectSymbols(bounds.first));
symbols.merge(evaluate::CollectSymbols(bounds.second));
#endif
}
},
[](const auto &) {},
},
assignment.u);
for (const Symbol &index : indexVars) {
if (symbols.count(index) == 0 &&
context_.ShouldWarn(common::UsageWarning::UnusedForallIndex)) {
context_.Say("FORALL index variable '%s' not used on left-hand side"
" of assignment"_warn_en_US,
index.name());
}
}
}
}
// For messages where the DO loop must be DO CONCURRENT, make that explicit.
const char *LoopKindName() const {
return kind_ == IndexVarKind::DO ? "DO CONCURRENT" : "FORALL";
}
SemanticsContext &context_;
const IndexVarKind kind_;
parser::CharBlock currentStatementSourcePosition_;
bool isNested_{false};
}; // class DoContext
void DoForallChecker::Enter(const parser::DoConstruct &doConstruct) {
DoContext doContext{context_, IndexVarKind::DO, constructNesting_ > 0};
doContext.DefineDoVariables(doConstruct);
}
void DoForallChecker::Leave(const parser::DoConstruct &doConstruct) {
DoContext doContext{context_, IndexVarKind::DO, constructNesting_ > 0};
++constructNesting_;
doContext.Check(doConstruct);
doContext.ResetDoVariables(doConstruct);
--constructNesting_;
}
void DoForallChecker::Enter(const parser::ForallConstruct &construct) {
DoContext doContext{context_, IndexVarKind::FORALL, constructNesting_ > 0};
doContext.ActivateIndexVars(GetControls(construct));
++constructNesting_;
doContext.Check(construct);
}
void DoForallChecker::Leave(const parser::ForallConstruct &construct) {
DoContext doContext{context_, IndexVarKind::FORALL, constructNesting_ > 0};
doContext.DeactivateIndexVars(GetControls(construct));
--constructNesting_;
}
void DoForallChecker::Enter(const parser::ForallStmt &stmt) {
DoContext doContext{context_, IndexVarKind::FORALL, constructNesting_ > 0};
++constructNesting_;
doContext.Check(stmt);
doContext.ActivateIndexVars(GetControls(stmt));
}
void DoForallChecker::Leave(const parser::ForallStmt &stmt) {
DoContext doContext{context_, IndexVarKind::FORALL, constructNesting_ > 0};
doContext.DeactivateIndexVars(GetControls(stmt));
--constructNesting_;
}
void DoForallChecker::Leave(const parser::ForallAssignmentStmt &stmt) {
DoContext doContext{context_, IndexVarKind::FORALL, constructNesting_ > 0};
doContext.Check(stmt);
}
template <typename A>
static parser::CharBlock GetConstructPosition(const A &a) {
return std::get<0>(a.t).source;
}
static parser::CharBlock GetNodePosition(const ConstructNode &construct) {
return common::visit(
[&](const auto &x) { return GetConstructPosition(*x); }, construct);
}
void DoForallChecker::SayBadLeave(StmtType stmtType,
const char *enclosingStmtName, const ConstructNode &construct) const {
context_
.Say("%s must not leave a %s statement"_err_en_US, EnumToString(stmtType),
enclosingStmtName)
.Attach(GetNodePosition(construct), "The construct that was left"_en_US);
}
static const parser::DoConstruct *MaybeGetDoConstruct(
const ConstructNode &construct) {
if (const auto *doNode{
std::get_if<const parser::DoConstruct *>(&construct)}) {
return *doNode;
} else {
return nullptr;
}
}
static bool ConstructIsDoConcurrent(const ConstructNode &construct) {
const parser::DoConstruct *doConstruct{MaybeGetDoConstruct(construct)};
return doConstruct && doConstruct->IsDoConcurrent();
}
// Check that CYCLE and EXIT statements do not cause flow of control to
// leave DO CONCURRENT, CRITICAL, or CHANGE TEAM constructs.
void DoForallChecker::CheckForBadLeave(
StmtType stmtType, const ConstructNode &construct) const {
common::visit(common::visitors{
[&](const parser::DoConstruct *doConstructPtr) {
if (doConstructPtr->IsDoConcurrent()) {
// C1135 and C1167 -- CYCLE and EXIT statements can't
// leave a DO CONCURRENT
SayBadLeave(stmtType, "DO CONCURRENT", construct);
}
},
[&](const parser::CriticalConstruct *) {
// C1135 and C1168 -- similarly, for CRITICAL
SayBadLeave(stmtType, "CRITICAL", construct);
},
[&](const parser::ChangeTeamConstruct *) {
// C1135 and C1168 -- similarly, for CHANGE TEAM
SayBadLeave(stmtType, "CHANGE TEAM", construct);
},
[](const auto *) {},
},
construct);
}
static bool StmtMatchesConstruct(const parser::Name *stmtName,
StmtType stmtType, const std::optional<parser::Name> &constructName,
const ConstructNode &construct) {
bool inDoConstruct{MaybeGetDoConstruct(construct) != nullptr};
if (!stmtName) {
return inDoConstruct; // Unlabeled statements match all DO constructs
} else if (constructName && constructName->source == stmtName->source) {
return stmtType == StmtType::EXIT || inDoConstruct;
} else {
return false;
}
}
// C1167 Can't EXIT from a DO CONCURRENT
void DoForallChecker::CheckDoConcurrentExit(
StmtType stmtType, const ConstructNode &construct) const {
if (stmtType == StmtType::EXIT && ConstructIsDoConcurrent(construct)) {
SayBadLeave(StmtType::EXIT, "DO CONCURRENT", construct);
}
}
// Check nesting violations for a CYCLE or EXIT statement. Loop up the
// nesting levels looking for a construct that matches the CYCLE or EXIT
// statment. At every construct, check for a violation. If we find a match
// without finding a violation, the check is complete.
void DoForallChecker::CheckNesting(
StmtType stmtType, const parser::Name *stmtName) const {
const ConstructStack &stack{context_.constructStack()};
for (auto iter{stack.cend()}; iter-- != stack.cbegin();) {
const ConstructNode &construct{*iter};
const std::optional<parser::Name> &constructName{
MaybeGetNodeName(construct)};
if (StmtMatchesConstruct(stmtName, stmtType, constructName, construct)) {
CheckDoConcurrentExit(stmtType, construct);
return; // We got a match, so we're finished checking
}
CheckForBadLeave(stmtType, construct);
}
// We haven't found a match in the enclosing constructs
if (stmtType == StmtType::EXIT) {
context_.Say("No matching construct for EXIT statement"_err_en_US);
} else {
context_.Say("No matching DO construct for CYCLE statement"_err_en_US);
}
}
// C1135 -- Nesting for CYCLE statements
void DoForallChecker::Enter(const parser::CycleStmt &cycleStmt) {
CheckNesting(StmtType::CYCLE, common::GetPtrFromOptional(cycleStmt.v));
}
// C1167 and C1168 -- Nesting for EXIT statements
void DoForallChecker::Enter(const parser::ExitStmt &exitStmt) {
CheckNesting(StmtType::EXIT, common::GetPtrFromOptional(exitStmt.v));
}
void DoForallChecker::Leave(const parser::AssignmentStmt &stmt) {
const auto &variable{std::get<parser::Variable>(stmt.t)};
context_.CheckIndexVarRedefine(variable);
}
static void CheckIfArgIsDoVar(const evaluate::ActualArgument &arg,
const parser::CharBlock location, SemanticsContext &context) {
common::Intent intent{arg.dummyIntent()};
if (intent == common::Intent::Out || intent == common::Intent::InOut) {
if (const SomeExpr * argExpr{arg.UnwrapExpr()}) {
if (const Symbol * var{evaluate::UnwrapWholeSymbolDataRef(*argExpr)}) {
if (intent == common::Intent::Out) {
context.CheckIndexVarRedefine(location, *var);
} else {
context.WarnIndexVarRedefine(location, *var); // INTENT(INOUT)
}
}
}
}
}
// Check to see if a DO variable is being passed as an actual argument to a
// dummy argument whose intent is OUT or INOUT. To do this, we need to find
// the expressions for actual arguments which contain DO variables. We get the
// intents of the dummy arguments from the ProcedureRef in the "typedCall"
// field of the CallStmt which was filled in during expression checking. At
// the same time, we need to iterate over the parser::Expr versions of the
// actual arguments to get their source locations of the arguments for the
// messages.
void DoForallChecker::Leave(const parser::CallStmt &callStmt) {
if (const auto &typedCall{callStmt.typedCall}) {
const auto &parsedArgs{
std::get<std::list<parser::ActualArgSpec>>(callStmt.call.t)};
auto parsedArgIter{parsedArgs.begin()};
const evaluate::ActualArguments &checkedArgs{typedCall->arguments()};
for (const auto &checkedOptionalArg : checkedArgs) {
if (parsedArgIter == parsedArgs.end()) {
break; // No more parsed arguments, we're done.
}
const auto &parsedArg{std::get<parser::ActualArg>(parsedArgIter->t)};
++parsedArgIter;
if (checkedOptionalArg) {
const evaluate::ActualArgument &checkedArg{*checkedOptionalArg};
if (const auto *parsedExpr{
std::get_if<common::Indirection<parser::Expr>>(&parsedArg.u)}) {
CheckIfArgIsDoVar(checkedArg, parsedExpr->value().source, context_);
}
}
}
}
}
void DoForallChecker::Leave(const parser::ConnectSpec &connectSpec) {
const auto *newunit{
std::get_if<parser::ConnectSpec::Newunit>(&connectSpec.u)};
if (newunit) {
context_.CheckIndexVarRedefine(newunit->v.thing.thing);
}
}
using ActualArgumentSet = std::set<evaluate::ActualArgumentRef>;
struct CollectActualArgumentsHelper
: public evaluate::SetTraverse<CollectActualArgumentsHelper,
ActualArgumentSet> {
using Base = SetTraverse<CollectActualArgumentsHelper, ActualArgumentSet>;
CollectActualArgumentsHelper() : Base{*this} {}
using Base::operator();
ActualArgumentSet operator()(const evaluate::ActualArgument &arg) const {
return Combine(ActualArgumentSet{arg},
CollectActualArgumentsHelper{}(arg.UnwrapExpr()));
}
};
template <typename A> ActualArgumentSet CollectActualArguments(const A &x) {
return CollectActualArgumentsHelper{}(x);
}
template ActualArgumentSet CollectActualArguments(const SomeExpr &);
void DoForallChecker::Enter(const parser::Expr &parsedExpr) { ++exprDepth_; }
void DoForallChecker::Leave(const parser::Expr &parsedExpr) {
CHECK(exprDepth_ > 0);
if (--exprDepth_ == 0) { // Only check top level expressions
if (const SomeExpr * expr{GetExpr(context_, parsedExpr)}) {
ActualArgumentSet argSet{CollectActualArguments(*expr)};
for (const evaluate::ActualArgumentRef &argRef : argSet) {
CheckIfArgIsDoVar(*argRef, parsedExpr.source, context_);
}
}
}
}
void DoForallChecker::Leave(const parser::InquireSpec &inquireSpec) {
const auto *intVar{std::get_if<parser::InquireSpec::IntVar>(&inquireSpec.u)};
if (intVar) {
const auto &scalar{std::get<parser::ScalarIntVariable>(intVar->t)};
context_.CheckIndexVarRedefine(scalar.thing.thing);
}
}
void DoForallChecker::Leave(const parser::IoControlSpec &ioControlSpec) {
const auto *size{std::get_if<parser::IoControlSpec::Size>(&ioControlSpec.u)};
if (size) {
context_.CheckIndexVarRedefine(size->v.thing.thing);
}
}
void DoForallChecker::Leave(const parser::OutputImpliedDo &outputImpliedDo) {
const auto &control{std::get<parser::IoImpliedDoControl>(outputImpliedDo.t)};
const parser::Name &name{control.name.thing.thing};
context_.CheckIndexVarRedefine(name.source, *name.symbol);
}
void DoForallChecker::Leave(const parser::StatVariable &statVariable) {
context_.CheckIndexVarRedefine(statVariable.v.thing.thing);
}
} // namespace Fortran::semantics
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