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llvm / llvm-project / c9ad356266f3c91d90bcb149d178423cb3e04c42 / . / flang / lib / Semantics / expression.cpp
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//===-- lib/Semantics/expression.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/Semantics/expression.h"
#include "check-call.h"
#include "pointer-assignment.h"
#include "resolve-names.h"
#include "flang/Common/Fortran.h"
#include "flang/Common/idioms.h"
#include "flang/Evaluate/common.h"
#include "flang/Evaluate/fold.h"
#include "flang/Evaluate/tools.h"
#include "flang/Parser/characters.h"
#include "flang/Parser/dump-parse-tree.h"
#include "flang/Parser/parse-tree-visitor.h"
#include "flang/Parser/parse-tree.h"
#include "flang/Semantics/scope.h"
#include "flang/Semantics/semantics.h"
#include "flang/Semantics/symbol.h"
#include "flang/Semantics/tools.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <functional>
#include <optional>
#include <set>
// Typedef for optional generic expressions (ubiquitous in this file)
using MaybeExpr =
std::optional<Fortran::evaluate::Expr<Fortran::evaluate::SomeType>>;
// Much of the code that implements semantic analysis of expressions is
// tightly coupled with their typed representations in lib/Evaluate,
// and appears here in namespace Fortran::evaluate for convenience.
namespace Fortran::evaluate {
using common::LanguageFeature;
using common::NumericOperator;
using common::TypeCategory;
static inline std::string ToUpperCase(const std::string &str) {
return parser::ToUpperCaseLetters(str);
}
struct DynamicTypeWithLength : public DynamicType {
explicit DynamicTypeWithLength(const DynamicType &t) : DynamicType{t} {}
std::optional<Expr<SubscriptInteger>> LEN() const;
std::optional<Expr<SubscriptInteger>> length;
};
std::optional<Expr<SubscriptInteger>> DynamicTypeWithLength::LEN() const {
if (length) {
return length;
} else {
return GetCharLength();
}
}
static std::optional<DynamicTypeWithLength> AnalyzeTypeSpec(
const std::optional<parser::TypeSpec> &spec) {
if (spec) {
if (const semantics::DeclTypeSpec * typeSpec{spec->declTypeSpec}) {
// Name resolution sets TypeSpec::declTypeSpec only when it's valid
// (viz., an intrinsic type with valid known kind or a non-polymorphic
// & non-ABSTRACT derived type).
if (const semantics::IntrinsicTypeSpec *
intrinsic{typeSpec->AsIntrinsic()}) {
TypeCategory category{intrinsic->category()};
if (auto optKind{ToInt64(intrinsic->kind())}) {
int kind{static_cast<int>(*optKind)};
if (category == TypeCategory::Character) {
const semantics::CharacterTypeSpec &cts{
typeSpec->characterTypeSpec()};
const semantics::ParamValue &len{cts.length()};
// N.B. CHARACTER(LEN=*) is allowed in type-specs in ALLOCATE() &
// type guards, but not in array constructors.
return DynamicTypeWithLength{DynamicType{kind, len}};
} else {
return DynamicTypeWithLength{DynamicType{category, kind}};
}
}
} else if (const semantics::DerivedTypeSpec *
derived{typeSpec->AsDerived()}) {
return DynamicTypeWithLength{DynamicType{*derived}};
}
}
}
return std::nullopt;
}
class ArgumentAnalyzer {
public:
explicit ArgumentAnalyzer(ExpressionAnalyzer &context)
: context_{context}, source_{context.GetContextualMessages().at()},
isProcedureCall_{false} {}
ArgumentAnalyzer(ExpressionAnalyzer &context, parser::CharBlock source,
bool isProcedureCall = false)
: context_{context}, source_{source}, isProcedureCall_{isProcedureCall} {}
bool fatalErrors() const { return fatalErrors_; }
ActualArguments &&GetActuals() {
CHECK(!fatalErrors_);
return std::move(actuals_);
}
const Expr<SomeType> &GetExpr(std::size_t i) const {
return DEREF(actuals_.at(i).value().UnwrapExpr());
}
Expr<SomeType> &&MoveExpr(std::size_t i) {
return std::move(DEREF(actuals_.at(i).value().UnwrapExpr()));
}
void Analyze(const common::Indirection<parser::Expr> &x) {
Analyze(x.value());
}
void Analyze(const parser::Expr &x) {
actuals_.emplace_back(AnalyzeExpr(x));
fatalErrors_ |= !actuals_.back();
}
void Analyze(const parser::Variable &);
void Analyze(const parser::ActualArgSpec &, bool isSubroutine);
void ConvertBOZ(std::optional<DynamicType> &thisType, std::size_t i,
std::optional<DynamicType> otherType);
bool IsIntrinsicRelational(
RelationalOperator, const DynamicType &, const DynamicType &) const;
bool IsIntrinsicLogical() const;
bool IsIntrinsicNumeric(NumericOperator) const;
bool IsIntrinsicConcat() const;
bool CheckConformance();
bool CheckForNullPointer(const char *where = "as an operand here");
// Find and return a user-defined operator or report an error.
// The provided message is used if there is no such operator.
MaybeExpr TryDefinedOp(const char *, parser::MessageFixedText,
const Symbol **definedOpSymbolPtr = nullptr, bool isUserOp = false);
template <typename E>
MaybeExpr TryDefinedOp(E opr, parser::MessageFixedText msg) {
return TryDefinedOp(
context_.context().languageFeatures().GetNames(opr), msg);
}
// Find and return a user-defined assignment
std::optional<ProcedureRef> TryDefinedAssignment();
std::optional<ProcedureRef> GetDefinedAssignmentProc();
std::optional<DynamicType> GetType(std::size_t) const;
void Dump(llvm::raw_ostream &);
private:
MaybeExpr TryDefinedOp(std::vector<const char *>, parser::MessageFixedText);
MaybeExpr TryBoundOp(const Symbol &, int passIndex);
std::optional<ActualArgument> AnalyzeExpr(const parser::Expr &);
MaybeExpr AnalyzeExprOrWholeAssumedSizeArray(const parser::Expr &);
bool AreConformable() const;
const Symbol *FindBoundOp(
parser::CharBlock, int passIndex, const Symbol *&definedOp);
void AddAssignmentConversion(
const DynamicType &lhsType, const DynamicType &rhsType);
bool OkLogicalIntegerAssignment(TypeCategory lhs, TypeCategory rhs);
int GetRank(std::size_t) const;
bool IsBOZLiteral(std::size_t i) const {
return evaluate::IsBOZLiteral(GetExpr(i));
}
void SayNoMatch(const std::string &, bool isAssignment = false);
std::string TypeAsFortran(std::size_t);
bool AnyUntypedOrMissingOperand();
ExpressionAnalyzer &context_;
ActualArguments actuals_;
parser::CharBlock source_;
bool fatalErrors_{false};
const bool isProcedureCall_; // false for user-defined op or assignment
};
// Wraps a data reference in a typed Designator<>, and a procedure
// or procedure pointer reference in a ProcedureDesignator.
MaybeExpr ExpressionAnalyzer::Designate(DataRef &&ref) {
const Symbol &last{ref.GetLastSymbol()};
const Symbol &symbol{BypassGeneric(last).GetUltimate()};
if (semantics::IsProcedure(symbol)) {
if (auto *component{std::get_if<Component>(&ref.u)}) {
return Expr<SomeType>{ProcedureDesignator{std::move(*component)}};
} else if (!std::holds_alternative<SymbolRef>(ref.u)) {
DIE("unexpected alternative in DataRef");
} else if (!symbol.attrs().test(semantics::Attr::INTRINSIC)) {
if (symbol.has<semantics::GenericDetails>()) {
Say("'%s' is not a specific procedure"_err_en_US, symbol.name());
} else {
return Expr<SomeType>{ProcedureDesignator{symbol}};
}
} else if (auto interface{context_.intrinsics().IsSpecificIntrinsicFunction(
symbol.name().ToString())};
interface && !interface->isRestrictedSpecific) {
SpecificIntrinsic intrinsic{
symbol.name().ToString(), std::move(*interface)};
intrinsic.isRestrictedSpecific = interface->isRestrictedSpecific;
return Expr<SomeType>{ProcedureDesignator{std::move(intrinsic)}};
} else {
Say("'%s' is not an unrestricted specific intrinsic procedure"_err_en_US,
symbol.name());
}
return std::nullopt;
} else if (MaybeExpr result{AsGenericExpr(std::move(ref))}) {
return result;
} else {
if (!context_.HasError(last) && !context_.HasError(symbol)) {
AttachDeclaration(
Say("'%s' is not an object that can appear in an expression"_err_en_US,
last.name()),
symbol);
context_.SetError(last);
}
return std::nullopt;
}
}
// Some subscript semantic checks must be deferred until all of the
// subscripts are in hand.
MaybeExpr ExpressionAnalyzer::CompleteSubscripts(ArrayRef &&ref) {
const Symbol &symbol{ref.GetLastSymbol().GetUltimate()};
int symbolRank{symbol.Rank()};
int subscripts{static_cast<int>(ref.size())};
if (subscripts == 0) {
return std::nullopt; // error recovery
} else if (subscripts != symbolRank) {
if (symbolRank != 0) {
Say("Reference to rank-%d object '%s' has %d subscripts"_err_en_US,
symbolRank, symbol.name(), subscripts);
}
return std::nullopt;
} else if (Component * component{ref.base().UnwrapComponent()}) {
int baseRank{component->base().Rank()};
if (baseRank > 0) {
int subscriptRank{0};
for (const auto &expr : ref.subscript()) {
subscriptRank += expr.Rank();
}
if (subscriptRank > 0) { // C919a
Say("Subscripts of component '%s' of rank-%d derived type "
"array have rank %d but must all be scalar"_err_en_US,
symbol.name(), baseRank, subscriptRank);
return std::nullopt;
}
}
} else if (const auto *object{
symbol.detailsIf<semantics::ObjectEntityDetails>()}) {
// C928 & C1002
if (Triplet * last{std::get_if<Triplet>(&ref.subscript().back().u)}) {
if (!last->upper() && object->IsAssumedSize()) {
Say("Assumed-size array '%s' must have explicit final "
"subscript upper bound value"_err_en_US,
symbol.name());
return std::nullopt;
}
}
} else {
// Shouldn't get here from Analyze(ArrayElement) without a valid base,
// which, if not an object, must be a construct entity from
// SELECT TYPE/RANK or ASSOCIATE.
CHECK(symbol.has<semantics::AssocEntityDetails>());
}
return Designate(DataRef{std::move(ref)});
}
// Applies subscripts to a data reference.
MaybeExpr ExpressionAnalyzer::ApplySubscripts(
DataRef &&dataRef, std::vector<Subscript> &&subscripts) {
if (subscripts.empty()) {
return std::nullopt; // error recovery
}
return std::visit(
common::visitors{
[&](SymbolRef &&symbol) {
return CompleteSubscripts(ArrayRef{symbol, std::move(subscripts)});
},
[&](Component &&c) {
return CompleteSubscripts(
ArrayRef{std::move(c), std::move(subscripts)});
},
[&](auto &&) -> MaybeExpr {
DIE("bad base for ArrayRef");
return std::nullopt;
},
},
std::move(dataRef.u));
}
// Top-level checks for data references.
MaybeExpr ExpressionAnalyzer::TopLevelChecks(DataRef &&dataRef) {
if (Component * component{std::get_if<Component>(&dataRef.u)}) {
const Symbol &symbol{component->GetLastSymbol()};
int componentRank{symbol.Rank()};
if (componentRank > 0) {
int baseRank{component->base().Rank()};
if (baseRank > 0) { // C919a
Say("Reference to whole rank-%d component '%%%s' of "
"rank-%d array of derived type is not allowed"_err_en_US,
componentRank, symbol.name(), baseRank);
}
}
}
return Designate(std::move(dataRef));
}
// Parse tree correction after a substring S(j:k) was misparsed as an
// array section. N.B. Fortran substrings have to have a range, not a
// single index.
static void FixMisparsedSubstring(const parser::Designator &d) {
auto &mutate{const_cast<parser::Designator &>(d)};
if (auto *dataRef{std::get_if<parser::DataRef>(&mutate.u)}) {
if (auto *ae{std::get_if<common::Indirection<parser::ArrayElement>>(
&dataRef->u)}) {
parser::ArrayElement &arrElement{ae->value()};
if (!arrElement.subscripts.empty()) {
auto iter{arrElement.subscripts.begin()};
if (auto *triplet{std::get_if<parser::SubscriptTriplet>(&iter->u)}) {
if (!std::get<2>(triplet->t) /* no stride */ &&
++iter == arrElement.subscripts.end() /* one subscript */) {
if (Symbol *
symbol{std::visit(
common::visitors{
[](parser::Name &n) { return n.symbol; },
[](common::Indirection<parser::StructureComponent>
&sc) { return sc.value().component.symbol; },
[](auto &) -> Symbol * { return nullptr; },
},
arrElement.base.u)}) {
const Symbol &ultimate{symbol->GetUltimate()};
if (const semantics::DeclTypeSpec * type{ultimate.GetType()}) {
if (!ultimate.IsObjectArray() &&
type->category() == semantics::DeclTypeSpec::Character) {
// The ambiguous S(j:k) was parsed as an array section
// reference, but it's now clear that it's a substring.
// Fix the parse tree in situ.
mutate.u = arrElement.ConvertToSubstring();
}
}
}
}
}
}
}
}
}
MaybeExpr ExpressionAnalyzer::Analyze(const parser::Designator &d) {
auto restorer{GetContextualMessages().SetLocation(d.source)};
FixMisparsedSubstring(d);
// These checks have to be deferred to these "top level" data-refs where
// we can be sure that there are no following subscripts (yet).
// Substrings have already been run through TopLevelChecks() and
// won't be returned by ExtractDataRef().
if (MaybeExpr result{Analyze(d.u)}) {
if (std::optional<DataRef> dataRef{ExtractDataRef(std::move(result))}) {
return TopLevelChecks(std::move(*dataRef));
}
return result;
}
return std::nullopt;
}
// A utility subroutine to repackage optional expressions of various levels
// of type specificity as fully general MaybeExpr values.
template <typename A> common::IfNoLvalue<MaybeExpr, A> AsMaybeExpr(A &&x) {
return AsGenericExpr(std::move(x));
}
template <typename A> MaybeExpr AsMaybeExpr(std::optional<A> &&x) {
if (x) {
return AsMaybeExpr(std::move(*x));
}
return std::nullopt;
}
// Type kind parameter values for literal constants.
int ExpressionAnalyzer::AnalyzeKindParam(
const std::optional<parser::KindParam> &kindParam, int defaultKind) {
if (!kindParam) {
return defaultKind;
}
return std::visit(
common::visitors{
[](std::uint64_t k) { return static_cast<int>(k); },
[&](const parser::Scalar<
parser::Integer<parser::Constant<parser::Name>>> &n) {
if (MaybeExpr ie{Analyze(n)}) {
if (std::optional<std::int64_t> i64{ToInt64(*ie)}) {
int iv = *i64;
if (iv == *i64) {
return iv;
}
}
}
return defaultKind;
},
},
kindParam->u);
}
// Common handling of parser::IntLiteralConstant and SignedIntLiteralConstant
struct IntTypeVisitor {
using Result = MaybeExpr;
using Types = IntegerTypes;
template <typename T> Result Test() {
if (T::kind >= kind) {
const char *p{digits.begin()};
auto value{T::Scalar::Read(p, 10, true /*signed*/)};
if (!value.overflow) {
if (T::kind > kind) {
if (!isDefaultKind ||
!analyzer.context().IsEnabled(LanguageFeature::BigIntLiterals)) {
return std::nullopt;
} else if (analyzer.context().ShouldWarn(
LanguageFeature::BigIntLiterals)) {
analyzer.Say(digits,
"Integer literal is too large for default INTEGER(KIND=%d); "
"assuming INTEGER(KIND=%d)"_en_US,
kind, T::kind);
}
}
return Expr<SomeType>{
Expr<SomeInteger>{Expr<T>{Constant<T>{std::move(value.value)}}}};
}
}
return std::nullopt;
}
ExpressionAnalyzer &analyzer;
parser::CharBlock digits;
int kind;
bool isDefaultKind;
};
template <typename PARSED>
MaybeExpr ExpressionAnalyzer::IntLiteralConstant(const PARSED &x) {
const auto &kindParam{std::get<std::optional<parser::KindParam>>(x.t)};
bool isDefaultKind{!kindParam};
int kind{AnalyzeKindParam(kindParam, GetDefaultKind(TypeCategory::Integer))};
if (CheckIntrinsicKind(TypeCategory::Integer, kind)) {
auto digits{std::get<parser::CharBlock>(x.t)};
if (MaybeExpr result{common::SearchTypes(
IntTypeVisitor{*this, digits, kind, isDefaultKind})}) {
return result;
} else if (isDefaultKind) {
Say(digits,
"Integer literal is too large for any allowable "
"kind of INTEGER"_err_en_US);
} else {
Say(digits, "Integer literal is too large for INTEGER(KIND=%d)"_err_en_US,
kind);
}
}
return std::nullopt;
}
MaybeExpr ExpressionAnalyzer::Analyze(const parser::IntLiteralConstant &x) {
auto restorer{
GetContextualMessages().SetLocation(std::get<parser::CharBlock>(x.t))};
return IntLiteralConstant(x);
}
MaybeExpr ExpressionAnalyzer::Analyze(
const parser::SignedIntLiteralConstant &x) {
auto restorer{GetContextualMessages().SetLocation(x.source)};
return IntLiteralConstant(x);
}
template <typename TYPE>
Constant<TYPE> ReadRealLiteral(
parser::CharBlock source, FoldingContext &context) {
const char *p{source.begin()};
auto valWithFlags{Scalar<TYPE>::Read(p, context.rounding())};
CHECK(p == source.end());
RealFlagWarnings(context, valWithFlags.flags, "conversion of REAL literal");
auto value{valWithFlags.value};
if (context.flushSubnormalsToZero()) {
value = value.FlushSubnormalToZero();
}
return {value};
}
struct RealTypeVisitor {
using Result = std::optional<Expr<SomeReal>>;
using Types = RealTypes;
RealTypeVisitor(int k, parser::CharBlock lit, FoldingContext &ctx)
: kind{k}, literal{lit}, context{ctx} {}
template <typename T> Result Test() {
if (kind == T::kind) {
return {AsCategoryExpr(ReadRealLiteral<T>(literal, context))};
}
return std::nullopt;
}
int kind;
parser::CharBlock literal;
FoldingContext &context;
};
// Reads a real literal constant and encodes it with the right kind.
MaybeExpr ExpressionAnalyzer::Analyze(const parser::RealLiteralConstant &x) {
// Use a local message context around the real literal for better
// provenance on any messages.
auto restorer{GetContextualMessages().SetLocation(x.real.source)};
// If a kind parameter appears, it defines the kind of the literal and the
// letter used in an exponent part must be 'E' (e.g., the 'E' in
// "6.02214E+23"). In the absence of an explicit kind parameter, any
// exponent letter determines the kind. Otherwise, defaults apply.
auto &defaults{context_.defaultKinds()};
int defaultKind{defaults.GetDefaultKind(TypeCategory::Real)};
const char *end{x.real.source.end()};
char expoLetter{' '};
std::optional<int> letterKind;
for (const char *p{x.real.source.begin()}; p < end; ++p) {
if (parser::IsLetter(*p)) {
expoLetter = *p;
switch (expoLetter) {
case 'e':
letterKind = defaults.GetDefaultKind(TypeCategory::Real);
break;
case 'd':
letterKind = defaults.doublePrecisionKind();
break;
case 'q':
letterKind = defaults.quadPrecisionKind();
break;
default:
Say("Unknown exponent letter '%c'"_err_en_US, expoLetter);
}
break;
}
}
if (letterKind) {
defaultKind = *letterKind;
}
// C716 requires 'E' as an exponent, but this is more useful
auto kind{AnalyzeKindParam(x.kind, defaultKind)};
if (letterKind && kind != *letterKind && expoLetter != 'e') {
Say("Explicit kind parameter on real constant disagrees with "
"exponent letter '%c'"_en_US,
expoLetter);
}
auto result{common::SearchTypes(
RealTypeVisitor{kind, x.real.source, GetFoldingContext()})};
if (!result) { // C717
Say("Unsupported REAL(KIND=%d)"_err_en_US, kind);
}
return AsMaybeExpr(std::move(result));
}
MaybeExpr ExpressionAnalyzer::Analyze(
const parser::SignedRealLiteralConstant &x) {
if (auto result{Analyze(std::get<parser::RealLiteralConstant>(x.t))}) {
auto &realExpr{std::get<Expr<SomeReal>>(result->u)};
if (auto sign{std::get<std::optional<parser::Sign>>(x.t)}) {
if (sign == parser::Sign::Negative) {
return AsGenericExpr(-std::move(realExpr));
}
}
return result;
}
return std::nullopt;
}
MaybeExpr ExpressionAnalyzer::Analyze(
const parser::SignedComplexLiteralConstant &x) {
auto result{Analyze(std::get<parser::ComplexLiteralConstant>(x.t))};
if (!result) {
return std::nullopt;
} else if (std::get<parser::Sign>(x.t) == parser::Sign::Negative) {
return AsGenericExpr(-std::move(std::get<Expr<SomeComplex>>(result->u)));
} else {
return result;
}
}
MaybeExpr ExpressionAnalyzer::Analyze(const parser::ComplexPart &x) {
return Analyze(x.u);
}
MaybeExpr ExpressionAnalyzer::Analyze(const parser::ComplexLiteralConstant &z) {
return AsMaybeExpr(
ConstructComplex(GetContextualMessages(), Analyze(std::get<0>(z.t)),
Analyze(std::get<1>(z.t)), GetDefaultKind(TypeCategory::Real)));
}
// CHARACTER literal processing.
MaybeExpr ExpressionAnalyzer::AnalyzeString(std::string &&string, int kind) {
if (!CheckIntrinsicKind(TypeCategory::Character, kind)) {
return std::nullopt;
}
switch (kind) {
case 1:
return AsGenericExpr(Constant<Type<TypeCategory::Character, 1>>{
parser::DecodeString<std::string, parser::Encoding::LATIN_1>(
string, true)});
case 2:
return AsGenericExpr(Constant<Type<TypeCategory::Character, 2>>{
parser::DecodeString<std::u16string, parser::Encoding::UTF_8>(
string, true)});
case 4:
return AsGenericExpr(Constant<Type<TypeCategory::Character, 4>>{
parser::DecodeString<std::u32string, parser::Encoding::UTF_8>(
string, true)});
default:
CRASH_NO_CASE;
}
}
MaybeExpr ExpressionAnalyzer::Analyze(const parser::CharLiteralConstant &x) {
int kind{
AnalyzeKindParam(std::get<std::optional<parser::KindParam>>(x.t), 1)};
auto value{std::get<std::string>(x.t)};
return AnalyzeString(std::move(value), kind);
}
MaybeExpr ExpressionAnalyzer::Analyze(
const parser::HollerithLiteralConstant &x) {
int kind{GetDefaultKind(TypeCategory::Character)};
auto value{x.v};
return AnalyzeString(std::move(value), kind);
}
// .TRUE. and .FALSE. of various kinds
MaybeExpr ExpressionAnalyzer::Analyze(const parser::LogicalLiteralConstant &x) {
auto kind{AnalyzeKindParam(std::get<std::optional<parser::KindParam>>(x.t),
GetDefaultKind(TypeCategory::Logical))};
bool value{std::get<bool>(x.t)};
auto result{common::SearchTypes(
TypeKindVisitor<TypeCategory::Logical, Constant, bool>{
kind, std::move(value)})};
if (!result) {
Say("unsupported LOGICAL(KIND=%d)"_err_en_US, kind); // C728
}
return result;
}
// BOZ typeless literals
MaybeExpr ExpressionAnalyzer::Analyze(const parser::BOZLiteralConstant &x) {
const char *p{x.v.c_str()};
std::uint64_t base{16};
switch (*p++) {
case 'b':
base = 2;
break;
case 'o':
base = 8;
break;
case 'z':
break;
case 'x':
break;
default:
CRASH_NO_CASE;
}
CHECK(*p == '"');
++p;
auto value{BOZLiteralConstant::Read(p, base, false /*unsigned*/)};
if (*p != '"') {
Say("Invalid digit ('%c') in BOZ literal '%s'"_err_en_US, *p,
x.v); // C7107, C7108
return std::nullopt;
}
if (value.overflow) {
Say("BOZ literal '%s' too large"_err_en_US, x.v);
return std::nullopt;
}
return AsGenericExpr(std::move(value.value));
}
// Names and named constants
MaybeExpr ExpressionAnalyzer::Analyze(const parser::Name &n) {
auto restorer{GetContextualMessages().SetLocation(n.source)};
if (std::optional<int> kind{IsImpliedDo(n.source)}) {
return AsMaybeExpr(ConvertToKind<TypeCategory::Integer>(
*kind, AsExpr(ImpliedDoIndex{n.source})));
} else if (context_.HasError(n)) {
return std::nullopt;
} else if (!n.symbol) {
SayAt(n, "Internal error: unresolved name '%s'"_err_en_US, n.source);
return std::nullopt;
} else {
const Symbol &ultimate{n.symbol->GetUltimate()};
if (ultimate.has<semantics::TypeParamDetails>()) {
// A bare reference to a derived type parameter (within a parameterized
// derived type definition)
return Fold(ConvertToType(
ultimate, AsGenericExpr(TypeParamInquiry{std::nullopt, ultimate})));
} else {
if (n.symbol->attrs().test(semantics::Attr::VOLATILE)) {
if (const semantics::Scope *
pure{semantics::FindPureProcedureContaining(
context_.FindScope(n.source))}) {
SayAt(n,
"VOLATILE variable '%s' may not be referenced in pure subprogram '%s'"_err_en_US,
n.source, DEREF(pure->symbol()).name());
n.symbol->attrs().reset(semantics::Attr::VOLATILE);
}
}
if (!isWholeAssumedSizeArrayOk_ &&
semantics::IsAssumedSizeArray(*n.symbol)) { // C1002, C1014, C1231
AttachDeclaration(
SayAt(n,
"Whole assumed-size array '%s' may not appear here without subscripts"_err_en_US,
n.source),
*n.symbol);
}
return Designate(DataRef{*n.symbol});
}
}
}
MaybeExpr ExpressionAnalyzer::Analyze(const parser::NamedConstant &n) {
auto restorer{GetContextualMessages().SetLocation(n.v.source)};
if (MaybeExpr value{Analyze(n.v)}) {
Expr<SomeType> folded{Fold(std::move(*value))};
if (IsConstantExpr(folded)) {
return folded;
}
Say(n.v.source, "must be a constant"_err_en_US); // C718
}
return std::nullopt;
}
MaybeExpr ExpressionAnalyzer::Analyze(const parser::NullInit &n) {
if (MaybeExpr value{Analyze(n.v)}) {
// Subtle: when the NullInit is a DataStmtConstant, it might
// be a misparse of a structure constructor without parameters
// or components (e.g., T()). Checking the result to ensure
// that a "=>" data entity initializer actually resolved to
// a null pointer has to be done by the caller.
return Fold(std::move(*value));
}
return std::nullopt;
}
MaybeExpr ExpressionAnalyzer::Analyze(const parser::InitialDataTarget &x) {
return Analyze(x.value());
}
MaybeExpr ExpressionAnalyzer::Analyze(const parser::DataStmtValue &x) {
if (const auto &repeat{
std::get<std::optional<parser::DataStmtRepeat>>(x.t)}) {
x.repetitions = -1;
if (MaybeExpr expr{Analyze(repeat->u)}) {
Expr<SomeType> folded{Fold(std::move(*expr))};
if (auto value{ToInt64(folded)}) {
if (*value >= 0) { // C882
x.repetitions = *value;
} else {
Say(FindSourceLocation(repeat),
"Repeat count (%jd) for data value must not be negative"_err_en_US,
*value);
}
}
}
}
return Analyze(std::get<parser::DataStmtConstant>(x.t));
}
// Substring references
std::optional<Expr<SubscriptInteger>> ExpressionAnalyzer::GetSubstringBound(
const std::optional<parser::ScalarIntExpr> &bound) {
if (bound) {
if (MaybeExpr expr{Analyze(*bound)}) {
if (expr->Rank() > 1) {
Say("substring bound expression has rank %d"_err_en_US, expr->Rank());
}
if (auto *intExpr{std::get_if<Expr<SomeInteger>>(&expr->u)}) {
if (auto *ssIntExpr{std::get_if<Expr<SubscriptInteger>>(&intExpr->u)}) {
return {std::move(*ssIntExpr)};
}
return {Expr<SubscriptInteger>{
Convert<SubscriptInteger, TypeCategory::Integer>{
std::move(*intExpr)}}};
} else {
Say("substring bound expression is not INTEGER"_err_en_US);
}
}
}
return std::nullopt;
}
MaybeExpr ExpressionAnalyzer::Analyze(const parser::Substring &ss) {
if (MaybeExpr baseExpr{Analyze(std::get<parser::DataRef>(ss.t))}) {
if (std::optional<DataRef> dataRef{ExtractDataRef(std::move(*baseExpr))}) {
if (MaybeExpr newBaseExpr{TopLevelChecks(std::move(*dataRef))}) {
if (std::optional<DataRef> checked{
ExtractDataRef(std::move(*newBaseExpr))}) {
const parser::SubstringRange &range{
std::get<parser::SubstringRange>(ss.t)};
std::optional<Expr<SubscriptInteger>> first{
GetSubstringBound(std::get<0>(range.t))};
std::optional<Expr<SubscriptInteger>> last{
GetSubstringBound(std::get<1>(range.t))};
const Symbol &symbol{checked->GetLastSymbol()};
if (std::optional<DynamicType> dynamicType{
DynamicType::From(symbol)}) {
if (dynamicType->category() == TypeCategory::Character) {
return WrapperHelper<TypeCategory::Character, Designator,
Substring>(dynamicType->kind(),
Substring{std::move(checked.value()), std::move(first),
std::move(last)});
}
}
Say("substring may apply only to CHARACTER"_err_en_US);
}
}
}
}
return std::nullopt;
}
// CHARACTER literal substrings
MaybeExpr ExpressionAnalyzer::Analyze(
const parser::CharLiteralConstantSubstring &x) {
const parser::SubstringRange &range{std::get<parser::SubstringRange>(x.t)};
std::optional<Expr<SubscriptInteger>> lower{
GetSubstringBound(std::get<0>(range.t))};
std::optional<Expr<SubscriptInteger>> upper{
GetSubstringBound(std::get<1>(range.t))};
if (MaybeExpr string{Analyze(std::get<parser::CharLiteralConstant>(x.t))}) {
if (auto *charExpr{std::get_if<Expr<SomeCharacter>>(&string->u)}) {
Expr<SubscriptInteger> length{
std::visit([](const auto &ckExpr) { return ckExpr.LEN().value(); },
charExpr->u)};
if (!lower) {
lower = Expr<SubscriptInteger>{1};
}
if (!upper) {
upper = Expr<SubscriptInteger>{
static_cast<std::int64_t>(ToInt64(length).value())};
}
return std::visit(
[&](auto &&ckExpr) -> MaybeExpr {
using Result = ResultType<decltype(ckExpr)>;
auto *cp{std::get_if<Constant<Result>>(&ckExpr.u)};
CHECK(DEREF(cp).size() == 1);
StaticDataObject::Pointer staticData{StaticDataObject::Create()};
staticData->set_alignment(Result::kind)
.set_itemBytes(Result::kind)
.Push(cp->GetScalarValue().value());
Substring substring{std::move(staticData), std::move(lower.value()),
std::move(upper.value())};
return AsGenericExpr(
Expr<Result>{Designator<Result>{std::move(substring)}});
},
std::move(charExpr->u));
}
}
return std::nullopt;
}
// Subscripted array references
std::optional<Expr<SubscriptInteger>> ExpressionAnalyzer::AsSubscript(
MaybeExpr &&expr) {
if (expr) {
if (expr->Rank() > 1) {
Say("Subscript expression has rank %d greater than 1"_err_en_US,
expr->Rank());
}
if (auto *intExpr{std::get_if<Expr<SomeInteger>>(&expr->u)}) {
if (auto *ssIntExpr{std::get_if<Expr<SubscriptInteger>>(&intExpr->u)}) {
return std::move(*ssIntExpr);
} else {
return Expr<SubscriptInteger>{
Convert<SubscriptInteger, TypeCategory::Integer>{
std::move(*intExpr)}};
}
} else {
Say("Subscript expression is not INTEGER"_err_en_US);
}
}
return std::nullopt;
}
std::optional<Expr<SubscriptInteger>> ExpressionAnalyzer::TripletPart(
const std::optional<parser::Subscript> &s) {
if (s) {
return AsSubscript(Analyze(*s));
} else {
return std::nullopt;
}
}
std::optional<Subscript> ExpressionAnalyzer::AnalyzeSectionSubscript(
const parser::SectionSubscript &ss) {
return std::visit(
common::visitors{
[&](const parser::SubscriptTriplet &t) -> std::optional<Subscript> {
const auto &lower{std::get<0>(t.t)};
const auto &upper{std::get<1>(t.t)};
const auto &stride{std::get<2>(t.t)};
auto result{Triplet{
TripletPart(lower), TripletPart(upper), TripletPart(stride)}};
if ((lower && !result.lower()) || (upper && !result.upper())) {
return std::nullopt;
} else {
return std::make_optional<Subscript>(result);
}
},
[&](const auto &s) -> std::optional<Subscript> {
if (auto subscriptExpr{AsSubscript(Analyze(s))}) {
return Subscript{std::move(*subscriptExpr)};
} else {
return std::nullopt;
}
},
},
ss.u);
}
// Empty result means an error occurred
std::vector<Subscript> ExpressionAnalyzer::AnalyzeSectionSubscripts(
const std::list<parser::SectionSubscript> &sss) {
bool error{false};
std::vector<Subscript> subscripts;
for (const auto &s : sss) {
if (auto subscript{AnalyzeSectionSubscript(s)}) {
subscripts.emplace_back(std::move(*subscript));
} else {
error = true;
}
}
return !error ? subscripts : std::vector<Subscript>{};
}
MaybeExpr ExpressionAnalyzer::Analyze(const parser::ArrayElement &ae) {
MaybeExpr baseExpr;
{
auto restorer{AllowWholeAssumedSizeArray()};
baseExpr = Analyze(ae.base);
}
if (baseExpr) {
if (ae.subscripts.empty()) {
// will be converted to function call later or error reported
} else if (baseExpr->Rank() == 0) {
if (const Symbol * symbol{GetLastSymbol(*baseExpr)}) {
if (!context_.HasError(symbol)) {
if (inDataStmtConstant_) {
// Better error for NULL(X) with a MOLD= argument
Say("'%s' must be an array or structure constructor if used with non-empty parentheses as a DATA statement constant"_err_en_US,
symbol->name());
} else {
Say("'%s' is not an array"_err_en_US, symbol->name());
}
context_.SetError(*symbol);
}
}
} else if (std::optional<DataRef> dataRef{
ExtractDataRef(std::move(*baseExpr))}) {
return ApplySubscripts(
std::move(*dataRef), AnalyzeSectionSubscripts(ae.subscripts));
} else {
Say("Subscripts may be applied only to an object, component, or array constant"_err_en_US);
}
}
// error was reported: analyze subscripts without reporting more errors
auto restorer{GetContextualMessages().DiscardMessages()};
AnalyzeSectionSubscripts(ae.subscripts);
return std::nullopt;
}
// Type parameter inquiries apply to data references, but don't depend
// on any trailing (co)subscripts.
static NamedEntity IgnoreAnySubscripts(Designator<SomeDerived> &&designator) {
return std::visit(
common::visitors{
[](SymbolRef &&symbol) { return NamedEntity{symbol}; },
[](Component &&component) {
return NamedEntity{std::move(component)};
},
[](ArrayRef &&arrayRef) { return std::move(arrayRef.base()); },
[](CoarrayRef &&coarrayRef) {
return NamedEntity{coarrayRef.GetLastSymbol()};
},
},
std::move(designator.u));
}
// Components of parent derived types are explicitly represented as such.
std::optional<Component> ExpressionAnalyzer::CreateComponent(
DataRef &&base, const Symbol &component, const semantics::Scope &scope) {
if (IsAllocatableOrPointer(component) && base.Rank() > 0) { // C919b
Say("An allocatable or pointer component reference must be applied to a scalar base"_err_en_US);
}
if (&component.owner() == &scope) {
return Component{std::move(base), component};
}
if (const semantics::Scope * parentScope{scope.GetDerivedTypeParent()}) {
if (const Symbol * parentComponent{parentScope->GetSymbol()}) {
return CreateComponent(
DataRef{Component{std::move(base), *parentComponent}}, component,
*parentScope);
}
}
return std::nullopt;
}
// Derived type component references and type parameter inquiries
MaybeExpr ExpressionAnalyzer::Analyze(const parser::StructureComponent &sc) {
MaybeExpr base{Analyze(sc.base)};
Symbol *sym{sc.component.symbol};
if (!base || !sym || context_.HasError(sym)) {
return std::nullopt;
}
const auto &name{sc.component.source};
if (auto *dtExpr{UnwrapExpr<Expr<SomeDerived>>(*base)}) {
const auto *dtSpec{GetDerivedTypeSpec(dtExpr->GetType())};
if (sym->detailsIf<semantics::TypeParamDetails>()) {
if (auto *designator{UnwrapExpr<Designator<SomeDerived>>(*dtExpr)}) {
if (std::optional<DynamicType> dyType{DynamicType::From(*sym)}) {
if (dyType->category() == TypeCategory::Integer) {
auto restorer{GetContextualMessages().SetLocation(name)};
return Fold(ConvertToType(*dyType,
AsGenericExpr(TypeParamInquiry{
IgnoreAnySubscripts(std::move(*designator)), *sym})));
}
}
Say(name, "Type parameter is not INTEGER"_err_en_US);
} else {
Say(name,
"A type parameter inquiry must be applied to "
"a designator"_err_en_US);
}
} else if (!dtSpec || !dtSpec->scope()) {
CHECK(context_.AnyFatalError() || !foldingContext_.messages().empty());
return std::nullopt;
} else if (std::optional<DataRef> dataRef{
ExtractDataRef(std::move(*dtExpr))}) {
if (auto component{
CreateComponent(std::move(*dataRef), *sym, *dtSpec->scope())}) {
return Designate(DataRef{std::move(*component)});
} else {
Say(name, "Component is not in scope of derived TYPE(%s)"_err_en_US,
dtSpec->typeSymbol().name());
}
} else {
Say(name,
"Base of component reference must be a data reference"_err_en_US);
}
} else if (auto *details{sym->detailsIf<semantics::MiscDetails>()}) {
// special part-ref: %re, %im, %kind, %len
// Type errors are detected and reported in semantics.
using MiscKind = semantics::MiscDetails::Kind;
MiscKind kind{details->kind()};
if (kind == MiscKind::ComplexPartRe || kind == MiscKind::ComplexPartIm) {
if (auto *zExpr{std::get_if<Expr<SomeComplex>>(&base->u)}) {
if (std::optional<DataRef> dataRef{ExtractDataRef(std::move(*zExpr))}) {
Expr<SomeReal> realExpr{std::visit(
[&](const auto &z) {
using PartType = typename ResultType<decltype(z)>::Part;
auto part{kind == MiscKind::ComplexPartRe
? ComplexPart::Part::RE
: ComplexPart::Part::IM};
return AsCategoryExpr(Designator<PartType>{
ComplexPart{std::move(*dataRef), part}});
},
zExpr->u)};
return AsGenericExpr(std::move(realExpr));
}
}
} else if (kind == MiscKind::KindParamInquiry ||
kind == MiscKind::LenParamInquiry) {
// Convert x%KIND -> intrinsic KIND(x), x%LEN -> intrinsic LEN(x)
return MakeFunctionRef(
name, ActualArguments{ActualArgument{std::move(*base)}});
} else {
DIE("unexpected MiscDetails::Kind");
}
} else {
Say(name, "derived type required before component reference"_err_en_US);
}
return std::nullopt;
}
MaybeExpr ExpressionAnalyzer::Analyze(const parser::CoindexedNamedObject &x) {
if (auto maybeDataRef{ExtractDataRef(Analyze(x.base))}) {
DataRef *dataRef{&*maybeDataRef};
std::vector<Subscript> subscripts;
SymbolVector reversed;
if (auto *aRef{std::get_if<ArrayRef>(&dataRef->u)}) {
subscripts = std::move(aRef->subscript());
reversed.push_back(aRef->GetLastSymbol());
if (Component * component{aRef->base().UnwrapComponent()}) {
dataRef = &component->base();
} else {
dataRef = nullptr;
}
}
if (dataRef) {
while (auto *component{std::get_if<Component>(&dataRef->u)}) {
reversed.push_back(component->GetLastSymbol());
dataRef = &component->base();
}
if (auto *baseSym{std::get_if<SymbolRef>(&dataRef->u)}) {
reversed.push_back(*baseSym);
} else {
Say("Base of coindexed named object has subscripts or cosubscripts"_err_en_US);
}
}
std::vector<Expr<SubscriptInteger>> cosubscripts;
bool cosubsOk{true};
for (const auto &cosub :
std::get<std::list<parser::Cosubscript>>(x.imageSelector.t)) {
MaybeExpr coex{Analyze(cosub)};
if (auto *intExpr{UnwrapExpr<Expr<SomeInteger>>(coex)}) {
cosubscripts.push_back(
ConvertToType<SubscriptInteger>(std::move(*intExpr)));
} else {
cosubsOk = false;
}
}
if (cosubsOk && !reversed.empty()) {
int numCosubscripts{static_cast<int>(cosubscripts.size())};
const Symbol &symbol{reversed.front()};
if (numCosubscripts != symbol.Corank()) {
Say("'%s' has corank %d, but coindexed reference has %d cosubscripts"_err_en_US,
symbol.name(), symbol.Corank(), numCosubscripts);
}
}
for (const auto &imageSelSpec :
std::get<std::list<parser::ImageSelectorSpec>>(x.imageSelector.t)) {
std::visit(
common::visitors{
[&](const auto &x) { Analyze(x.v); },
},
imageSelSpec.u);
}
// Reverse the chain of symbols so that the base is first and coarray
// ultimate component is last.
if (cosubsOk) {
return Designate(
DataRef{CoarrayRef{SymbolVector{reversed.crbegin(), reversed.crend()},
std::move(subscripts), std::move(cosubscripts)}});
}
}
return std::nullopt;
}
int ExpressionAnalyzer::IntegerTypeSpecKind(
const parser::IntegerTypeSpec &spec) {
Expr<SubscriptInteger> value{
AnalyzeKindSelector(TypeCategory::Integer, spec.v)};
if (auto kind{ToInt64(value)}) {
return static_cast<int>(*kind);
}
SayAt(spec, "Constant INTEGER kind value required here"_err_en_US);
return GetDefaultKind(TypeCategory::Integer);
}
// Array constructors
// Inverts a collection of generic ArrayConstructorValues<SomeType> that
// all happen to have the same actual type T into one ArrayConstructor<T>.
template <typename T>
ArrayConstructorValues<T> MakeSpecific(
ArrayConstructorValues<SomeType> &&from) {
ArrayConstructorValues<T> to;
for (ArrayConstructorValue<SomeType> &x : from) {
std::visit(
common::visitors{
[&](common::CopyableIndirection<Expr<SomeType>> &&expr) {
auto *typed{UnwrapExpr<Expr<T>>(expr.value())};
to.Push(std::move(DEREF(typed)));
},
[&](ImpliedDo<SomeType> &&impliedDo) {
to.Push(ImpliedDo<T>{impliedDo.name(),
std::move(impliedDo.lower()), std::move(impliedDo.upper()),
std::move(impliedDo.stride()),
MakeSpecific<T>(std::move(impliedDo.values()))});
},
},
std::move(x.u));
}
return to;
}
class ArrayConstructorContext {
public:
ArrayConstructorContext(
ExpressionAnalyzer &c, std::optional<DynamicTypeWithLength> &&t)
: exprAnalyzer_{c}, type_{std::move(t)} {}
void Add(const parser::AcValue &);
MaybeExpr ToExpr();
// These interfaces allow *this to be used as a type visitor argument to
// common::SearchTypes() to convert the array constructor to a typed
// expression in ToExpr().
using Result = MaybeExpr;
using Types = AllTypes;
template <typename T> Result Test() {
if (type_ && type_->category() == T::category) {
if constexpr (T::category == TypeCategory::Derived) {
if (!type_->IsUnlimitedPolymorphic()) {
return AsMaybeExpr(ArrayConstructor<T>{type_->GetDerivedTypeSpec(),
MakeSpecific<T>(std::move(values_))});
}
} else if (type_->kind() == T::kind) {
if constexpr (T::category == TypeCategory::Character) {
if (auto len{type_->LEN()}) {
return AsMaybeExpr(ArrayConstructor<T>{
*std::move(len), MakeSpecific<T>(std::move(values_))});
}
} else {
return AsMaybeExpr(
ArrayConstructor<T>{MakeSpecific<T>(std::move(values_))});
}
}
}
return std::nullopt;
}
private:
using ImpliedDoIntType = ResultType<ImpliedDoIndex>;
void Push(MaybeExpr &&);
void Add(const parser::AcValue::Triplet &);
void Add(const parser::Expr &);
void Add(const parser::AcImpliedDo &);
void UnrollConstantImpliedDo(const parser::AcImpliedDo &,
parser::CharBlock name, std::int64_t lower, std::int64_t upper,
std::int64_t stride);
template <int KIND, typename A>
std::optional<Expr<Type<TypeCategory::Integer, KIND>>> GetSpecificIntExpr(
const A &x) {
if (MaybeExpr y{exprAnalyzer_.Analyze(x)}) {
Expr<SomeInteger> *intExpr{UnwrapExpr<Expr<SomeInteger>>(*y)};
return Fold(exprAnalyzer_.GetFoldingContext(),
ConvertToType<Type<TypeCategory::Integer, KIND>>(
std::move(DEREF(intExpr))));
}
return std::nullopt;
}
// Nested array constructors all reference the same ExpressionAnalyzer,
// which represents the nest of active implied DO loop indices.
ExpressionAnalyzer &exprAnalyzer_;
std::optional<DynamicTypeWithLength> type_;
bool explicitType_{type_.has_value()};
std::optional<std::int64_t> constantLength_;
ArrayConstructorValues<SomeType> values_;
std::uint64_t messageDisplayedSet_{0};
};
void ArrayConstructorContext::Push(MaybeExpr &&x) {
if (!x) {
return;
}
if (!type_) {
if (auto *boz{std::get_if<BOZLiteralConstant>(&x->u)}) {
// Treat an array constructor of BOZ as if default integer.
if (exprAnalyzer_.context().ShouldWarn(
common::LanguageFeature::BOZAsDefaultInteger)) {
exprAnalyzer_.Say(
"BOZ literal in array constructor without explicit type is assumed to be default INTEGER"_en_US);
}
x = AsGenericExpr(ConvertToKind<TypeCategory::Integer>(
exprAnalyzer_.GetDefaultKind(TypeCategory::Integer),
std::move(*boz)));
}
}
std::optional<DynamicType> dyType{x->GetType()};
if (!dyType) {
if (auto *boz{std::get_if<BOZLiteralConstant>(&x->u)}) {
if (!type_) {
// Treat an array constructor of BOZ as if default integer.
if (exprAnalyzer_.context().ShouldWarn(
common::LanguageFeature::BOZAsDefaultInteger)) {
exprAnalyzer_.Say(
"BOZ literal in array constructor without explicit type is assumed to be default INTEGER"_en_US);
}
x = AsGenericExpr(ConvertToKind<TypeCategory::Integer>(
exprAnalyzer_.GetDefaultKind(TypeCategory::Integer),
std::move(*boz)));
dyType = x.value().GetType();
} else if (auto cast{ConvertToType(*type_, std::move(*x))}) {
x = std::move(cast);
dyType = *type_;
} else {
if (!(messageDisplayedSet_ & 0x80)) {
exprAnalyzer_.Say(
"BOZ literal is not suitable for use in this array constructor"_err_en_US);
messageDisplayedSet_ |= 0x80;
}
return;
}
} else { // procedure name, &c.
if (!(messageDisplayedSet_ & 0x40)) {
exprAnalyzer_.Say(
"Item is not suitable for use in an array constructor"_err_en_US);
messageDisplayedSet_ |= 0x40;
}
return;
}
} else if (dyType->IsUnlimitedPolymorphic()) {
if (!(messageDisplayedSet_ & 8)) {
exprAnalyzer_.Say("Cannot have an unlimited polymorphic value in an "
"array constructor"_err_en_US); // C7113
messageDisplayedSet_ |= 8;
}
return;
}
DynamicTypeWithLength xType{dyType.value()};
if (Expr<SomeCharacter> * charExpr{UnwrapExpr<Expr<SomeCharacter>>(*x)}) {
CHECK(xType.category() == TypeCategory::Character);
xType.length =
std::visit([](const auto &kc) { return kc.LEN(); }, charExpr->u);
}
if (!type_) {
// If there is no explicit type-spec in an array constructor, the type
// of the array is the declared type of all of the elements, which must
// be well-defined and all match.
// TODO: Possible language extension: use the most general type of
// the values as the type of a numeric constructed array, convert all
// of the other values to that type. Alternative: let the first value
// determine the type, and convert the others to that type.
CHECK(!explicitType_);
type_ = std::move(xType);
constantLength_ = ToInt64(type_->length);
values_.Push(std::move(*x));
} else if (!explicitType_) {
if (type_->IsTkCompatibleWith(xType) && xType.IsTkCompatibleWith(*type_)) {
values_.Push(std::move(*x));
if (auto thisLen{ToInt64(xType.LEN())}) {
if (constantLength_) {
if (exprAnalyzer_.context().warnOnNonstandardUsage() &&
*thisLen != *constantLength_) {
if (!(messageDisplayedSet_ & 1)) {
exprAnalyzer_.Say(
"Character literal in array constructor without explicit "
"type has different length than earlier elements"_en_US);
messageDisplayedSet_ |= 1;
}
}
if (*thisLen > *constantLength_) {
// Language extension: use the longest literal to determine the
// length of the array constructor's character elements, not the
// first, when there is no explicit type.
*constantLength_ = *thisLen;
type_->length = xType.LEN();
}
} else {
constantLength_ = *thisLen;
type_->length = xType.LEN();
}
}
} else {
if (!(messageDisplayedSet_ & 2)) {
exprAnalyzer_.Say(
"Values in array constructor must have the same declared type "
"when no explicit type appears"_err_en_US); // C7110
messageDisplayedSet_ |= 2;
}
}
} else {
if (auto cast{ConvertToType(*type_, std::move(*x))}) {
values_.Push(std::move(*cast));
} else if (!(messageDisplayedSet_ & 4)) {
exprAnalyzer_.Say("Value in array constructor of type '%s' could not "
"be converted to the type of the array '%s'"_err_en_US,
x->GetType()->AsFortran(), type_->AsFortran()); // C7111, C7112
messageDisplayedSet_ |= 4;
}
}
}
void ArrayConstructorContext::Add(const parser::AcValue &x) {
std::visit(
common::visitors{
[&](const parser::AcValue::Triplet &triplet) { Add(triplet); },
[&](const common::Indirection<parser::Expr> &expr) {
Add(expr.value());
},
[&](const common::Indirection<parser::AcImpliedDo> &impliedDo) {
Add(impliedDo.value());
},
},
x.u);
}
// Transforms l:u(:s) into (_,_=l,u(,s)) with an anonymous index '_'
void ArrayConstructorContext::Add(const parser::AcValue::Triplet &triplet) {
std::optional<Expr<ImpliedDoIntType>> lower{
GetSpecificIntExpr<ImpliedDoIntType::kind>(std::get<0>(triplet.t))};
std::optional<Expr<ImpliedDoIntType>> upper{
GetSpecificIntExpr<ImpliedDoIntType::kind>(std::get<1>(triplet.t))};
std::optional<Expr<ImpliedDoIntType>> stride{
GetSpecificIntExpr<ImpliedDoIntType::kind>(std::get<2>(triplet.t))};
if (lower && upper) {
if (!stride) {
stride = Expr<ImpliedDoIntType>{1};
}
if (!type_) {
type_ = DynamicTypeWithLength{ImpliedDoIntType::GetType()};
}
auto v{std::move(values_)};
parser::CharBlock anonymous;
Push(Expr<SomeType>{
Expr<SomeInteger>{Expr<ImpliedDoIntType>{ImpliedDoIndex{anonymous}}}});
std::swap(v, values_);
values_.Push(ImpliedDo<SomeType>{anonymous, std::move(*lower),
std::move(*upper), std::move(*stride), std::move(v)});
}
}
void ArrayConstructorContext::Add(const parser::Expr &expr) {
auto restorer{exprAnalyzer_.GetContextualMessages().SetLocation(expr.source)};
Push(exprAnalyzer_.Analyze(expr));
}
void ArrayConstructorContext::Add(const parser::AcImpliedDo &impliedDo) {
const auto &control{std::get<parser::AcImpliedDoControl>(impliedDo.t)};
const auto &bounds{std::get<parser::AcImpliedDoControl::Bounds>(control.t)};
exprAnalyzer_.Analyze(bounds.name);
parser::CharBlock name{bounds.name.thing.thing.source};
const Symbol *symbol{bounds.name.thing.thing.symbol};
int kind{ImpliedDoIntType::kind};
if (const auto dynamicType{DynamicType::From(symbol)}) {
kind = dynamicType->kind();
}
std::optional<Expr<ImpliedDoIntType>> lower{
GetSpecificIntExpr<ImpliedDoIntType::kind>(bounds.lower)};
std::optional<Expr<ImpliedDoIntType>> upper{
GetSpecificIntExpr<ImpliedDoIntType::kind>(bounds.upper)};
if (lower && upper) {
std::optional<Expr<ImpliedDoIntType>> stride{
GetSpecificIntExpr<ImpliedDoIntType::kind>(bounds.step)};
if (!stride) {
stride = Expr<ImpliedDoIntType>{1};
}
if (exprAnalyzer_.AddImpliedDo(name, kind)) {
// Check for constant bounds; the loop may require complete unrolling
// of the parse tree if all bounds are constant in order to allow the
// implied DO loop index to qualify as a constant expression.
auto cLower{ToInt64(lower)};
auto cUpper{ToInt64(upper)};
auto cStride{ToInt64(stride)};
if (!(messageDisplayedSet_ & 0x10) && cStride && *cStride == 0) {
exprAnalyzer_.SayAt(bounds.step.value().thing.thing.value().source,
"The stride of an implied DO loop must not be zero"_err_en_US);
messageDisplayedSet_ |= 0x10;
}
bool isConstant{cLower && cUpper && cStride && *cStride != 0};
bool isNonemptyConstant{isConstant &&
((*cStride > 0 && *cLower <= *cUpper) ||
(*cStride < 0 && *cLower >= *cUpper))};
bool unrollConstantLoop{false};
parser::Messages buffer;
auto saveMessagesDisplayed{messageDisplayedSet_};
{
auto messageRestorer{
exprAnalyzer_.GetContextualMessages().SetMessages(buffer)};
auto v{std::move(values_)};
for (const auto &value :
std::get<std::list<parser::AcValue>>(impliedDo.t)) {
Add(value);
}
std::swap(v, values_);
if (isNonemptyConstant && buffer.AnyFatalError()) {
unrollConstantLoop = true;
} else {
values_.Push(ImpliedDo<SomeType>{name, std::move(*lower),
std::move(*upper), std::move(*stride), std::move(v)});
}
}
if (unrollConstantLoop) {
messageDisplayedSet_ = saveMessagesDisplayed;
UnrollConstantImpliedDo(impliedDo, name, *cLower, *cUpper, *cStride);
} else if (auto *messages{
exprAnalyzer_.GetContextualMessages().messages()}) {
messages->Annex(std::move(buffer));
}
exprAnalyzer_.RemoveImpliedDo(name);
} else if (!(messageDisplayedSet_ & 0x20)) {
exprAnalyzer_.SayAt(name,
"Implied DO index '%s' is active in a surrounding implied DO loop "
"and may not have the same name"_err_en_US,
name); // C7115
messageDisplayedSet_ |= 0x20;
}
}
}
// Fortran considers an implied DO index of an array constructor to be
// a constant expression if the bounds of the implied DO loop are constant.
// Usually this doesn't matter, but if we emitted spurious messages as a
// result of not using constant values for the index while analyzing the
// items, we need to do it again the "hard" way with multiple iterations over
// the parse tree.
void ArrayConstructorContext::UnrollConstantImpliedDo(
const parser::AcImpliedDo &impliedDo, parser::CharBlock name,
std::int64_t lower, std::int64_t upper, std::int64_t stride) {
auto &foldingContext{exprAnalyzer_.GetFoldingContext()};
auto restorer{exprAnalyzer_.DoNotUseSavedTypedExprs()};
for (auto &at{foldingContext.StartImpliedDo(name, lower)};
(stride > 0 && at <= upper) || (stride < 0 && at >= upper);
at += stride) {
for (const auto &value :
std::get<std::list<parser::AcValue>>(impliedDo.t)) {
Add(value);
}
}
foldingContext.EndImpliedDo(name);
}
MaybeExpr ArrayConstructorContext::ToExpr() {
return common::SearchTypes(std::move(*this));
}
MaybeExpr ExpressionAnalyzer::Analyze(const parser::ArrayConstructor &array) {
const parser::AcSpec &acSpec{array.v};
ArrayConstructorContext acContext{*this, AnalyzeTypeSpec(acSpec.type)};
for (const parser::AcValue &value : acSpec.values) {
acContext.Add(value);
}
return acContext.ToExpr();
}
MaybeExpr ExpressionAnalyzer::Analyze(
const parser::StructureConstructor &structure) {
auto &parsedType{std::get<parser::DerivedTypeSpec>(structure.t)};
parser::Name structureType{std::get<parser::Name>(parsedType.t)};
parser::CharBlock &typeName{structureType.source};
if (semantics::Symbol * typeSymbol{structureType.symbol}) {
if (typeSymbol->has<semantics::DerivedTypeDetails>()) {
semantics::DerivedTypeSpec dtSpec{typeName, typeSymbol->GetUltimate()};
if (!CheckIsValidForwardReference(dtSpec)) {
return std::nullopt;
}
}
}
if (!parsedType.derivedTypeSpec) {
return std::nullopt;
}
const auto &spec{*parsedType.derivedTypeSpec};
const Symbol &typeSymbol{spec.typeSymbol()};
if (!spec.scope() || !typeSymbol.has<semantics::DerivedTypeDetails>()) {
return std::nullopt; // error recovery
}
const auto &typeDetails{typeSymbol.get<semantics::DerivedTypeDetails>()};
const Symbol *parentComponent{typeDetails.GetParentComponent(*spec.scope())};
if (typeSymbol.attrs().test(semantics::Attr::ABSTRACT)) { // C796
AttachDeclaration(Say(typeName,
"ABSTRACT derived type '%s' may not be used in a "
"structure constructor"_err_en_US,
typeName),
typeSymbol); // C7114
}
// This iterator traverses all of the components in the derived type and its
// parents. The symbols for whole parent components appear after their
// own components and before the components of the types that extend them.
// E.g., TYPE :: A; REAL X; END TYPE
// TYPE, EXTENDS(A) :: B; REAL Y; END TYPE
// produces the component list X, A, Y.
// The order is important below because a structure constructor can
// initialize X or A by name, but not both.
auto components{semantics::OrderedComponentIterator{spec}};
auto nextAnonymous{components.begin()};
std::set<parser::CharBlock> unavailable;
bool anyKeyword{false};
StructureConstructor result{spec};
bool checkConflicts{true}; // until we hit one
auto &messages{GetContextualMessages()};
for (const auto &component :
std::get<std::list<parser::ComponentSpec>>(structure.t)) {
const parser::Expr &expr{
std::get<parser::ComponentDataSource>(component.t).v.value()};
parser::CharBlock source{expr.source};
auto restorer{messages.SetLocation(source)};
const Symbol *symbol{nullptr};
MaybeExpr value{Analyze(expr)};
std::optional<DynamicType> valueType{DynamicType::From(value)};
if (const auto &kw{std::get<std::optional<parser::Keyword>>(component.t)}) {
anyKeyword = true;
source = kw->v.source;
symbol = kw->v.symbol;
if (!symbol) {
auto componentIter{std::find_if(components.begin(), components.end(),
[=](const Symbol &symbol) { return symbol.name() == source; })};
if (componentIter != components.end()) {
symbol = &*componentIter;
}
}
if (!symbol) { // C7101
Say(source,
"Keyword '%s=' does not name a component of derived type '%s'"_err_en_US,
source, typeName);
}
} else {
if (anyKeyword) { // C7100
Say(source,
"Value in structure constructor lacks a component name"_err_en_US);
checkConflicts = false; // stem cascade
}
// Here's a regrettably common extension of the standard: anonymous
// initialization of parent components, e.g., T(PT(1)) rather than
// T(1) or T(PT=PT(1)).
if (nextAnonymous == components.begin() && parentComponent &&
valueType == DynamicType::From(*parentComponent) &&
context().IsEnabled(LanguageFeature::AnonymousParents)) {
auto iter{
std::find(components.begin(), components.end(), *parentComponent)};
if (iter != components.end()) {
symbol = parentComponent;
nextAnonymous = ++iter;
if (context().ShouldWarn(LanguageFeature::AnonymousParents)) {
Say(source,
"Whole parent component '%s' in structure "
"constructor should not be anonymous"_en_US,
symbol->name());
}
}
}
while (!symbol && nextAnonymous != components.end()) {
const Symbol &next{*nextAnonymous};
++nextAnonymous;
if (!next.test(Symbol::Flag::ParentComp)) {
symbol = &next;
}
}
if (!symbol) {
Say(source, "Unexpected value in structure constructor"_err_en_US);
}
}
if (symbol) {
if (const auto *currScope{context_.globalScope().FindScope(source)}) {
if (auto msg{CheckAccessibleComponent(*currScope, *symbol)}) {
Say(source, *msg);
}
}
if (checkConflicts) {
auto componentIter{
std::find(components.begin(), components.end(), *symbol)};
if (unavailable.find(symbol->name()) != unavailable.cend()) {
// C797, C798
Say(source,
"Component '%s' conflicts with another component earlier in "
"this structure constructor"_err_en_US,
symbol->name());
} else if (symbol->test(Symbol::Flag::ParentComp)) {
// Make earlier components unavailable once a whole parent appears.
for (auto it{components.begin()}; it != componentIter; ++it) {
unavailable.insert(it->name());
}
} else {
// Make whole parent components unavailable after any of their
// constituents appear.
for (auto it{componentIter}; it != components.end(); ++it) {
if (it->test(Symbol::Flag::ParentComp)) {
unavailable.insert(it->name());
}
}
}
}
unavailable.insert(symbol->name());
if (value) {
if (symbol->has<semantics::ProcEntityDetails>()) {
CHECK(IsPointer(*symbol));
} else if (symbol->has<semantics::ObjectEntityDetails>()) {
// C1594(4)
const auto &innermost{context_.FindScope(expr.source)};
if (const auto *pureProc{FindPureProcedureContaining(innermost)}) {
if (const Symbol * pointer{FindPointerComponent(*symbol)}) {
if (const Symbol *
object{FindExternallyVisibleObject(*value, *pureProc)}) {
if (auto *msg{Say(expr.source,
"Externally visible object '%s' may not be "
"associated with pointer component '%s' in a "
"pure procedure"_err_en_US,
object->name(), pointer->name())}) {
msg->Attach(object->name(), "Object declaration"_en_US)
.Attach(pointer->name(), "Pointer declaration"_en_US);
}
}
}
}
} else if (symbol->has<semantics::TypeParamDetails>()) {
Say(expr.source,
"Type parameter '%s' may not appear as a component "
"of a structure constructor"_err_en_US,
symbol->name());
continue;
} else {
Say(expr.source,
"Component '%s' is neither a procedure pointer "
"nor a data object"_err_en_US,
symbol->name());
continue;
}
if (IsPointer(*symbol)) {
semantics::CheckPointerAssignment(
GetFoldingContext(), *symbol, *value); // C7104, C7105
result.Add(*symbol, Fold(std::move(*value)));
} else if (MaybeExpr converted{
ConvertToType(*symbol, std::move(*value))}) {
if (auto componentShape{GetShape(GetFoldingContext(), *symbol)}) {
if (auto valueShape{GetShape(GetFoldingContext(), *converted)}) {
if (GetRank(*componentShape) == 0 && GetRank(*valueShape) > 0) {
AttachDeclaration(
Say(expr.source,
"Rank-%d array value is not compatible with scalar component '%s'"_err_en_US,
GetRank(*valueShape), symbol->name()),
*symbol);
} else {
auto checked{
CheckConformance(messages, *componentShape, *valueShape,
CheckConformanceFlags::RightIsExpandableDeferred,
"component", "value")};
if (checked && *checked && GetRank(*componentShape) > 0 &&
GetRank(*valueShape) == 0 &&
!IsExpandableScalar(*converted)) {
AttachDeclaration(
Say(expr.source,
"Scalar value cannot be expanded to shape of array component '%s'"_err_en_US,
symbol->name()),
*symbol);
}
if (checked.value_or(true)) {
result.Add(*symbol, std::move(*converted));
}
}
} else {
Say(expr.source, "Shape of value cannot be determined"_err_en_US);
}
} else {
AttachDeclaration(
Say(expr.source,
"Shape of component '%s' cannot be determined"_err_en_US,
symbol->name()),
*symbol);
}
} else if (IsAllocatable(*symbol) && IsBareNullPointer(&*value)) {
// NULL() with no arguments allowed by 7.5.10 para 6 for ALLOCATABLE
} else if (auto symType{DynamicType::From(symbol)}) {
if (valueType) {
AttachDeclaration(
Say(expr.source,
"Value in structure constructor of type %s is "
"incompatible with component '%s' of type %s"_err_en_US,
valueType->AsFortran(), symbol->name(),
symType->AsFortran()),
*symbol);
} else {
AttachDeclaration(
Say(expr.source,
"Value in structure constructor is incompatible with "
" component '%s' of type %s"_err_en_US,
symbol->name(), symType->AsFortran()),
*symbol);
}
}
}
}
}
// Ensure that unmentioned component objects have default initializers.
for (const Symbol &symbol : components) {
if (!symbol.test(Symbol::Flag::ParentComp) &&
unavailable.find(symbol.name()) == unavailable.cend() &&
!IsAllocatable(symbol)) {
if (const auto *details{
symbol.detailsIf<semantics::ObjectEntityDetails>()}) {
if (details->init()) {
result.Add(symbol, common::Clone(*details->init()));
} else { // C799
AttachDeclaration(Say(typeName,
"Structure constructor lacks a value for "
"component '%s'"_err_en_US,
symbol.name()),
symbol);
}
}
}
}
return AsMaybeExpr(Expr<SomeDerived>{std::move(result)});
}
static std::optional<parser::CharBlock> GetPassName(
const semantics::Symbol &proc) {
return std::visit(
[](const auto &details) {
if constexpr (std::is_base_of_v<semantics::WithPassArg,
std::decay_t<decltype(details)>>) {
return details.passName();
} else {
return std::optional<parser::CharBlock>{};
}
},
proc.details());
}
static int GetPassIndex(const Symbol &proc) {
CHECK(!proc.attrs().test(semantics::Attr::NOPASS));
std::optional<parser::CharBlock> passName{GetPassName(proc)};
const auto *interface{semantics::FindInterface(proc)};
if (!passName || !interface) {
return 0; // first argument is passed-object
}
const auto &subp{interface->get<semantics::SubprogramDetails>()};
int index{0};
for (const auto *arg : subp.dummyArgs()) {
if (arg && arg->name() == passName) {
return index;
}
++index;
}
DIE("PASS argument name not in dummy argument list");
}
// Injects an expression into an actual argument list as the "passed object"
// for a type-bound procedure reference that is not NOPASS. Adds an
// argument keyword if possible, but not when the passed object goes
// before a positional argument.
// e.g., obj%tbp(x) -> tbp(obj,x).
static void AddPassArg(ActualArguments &actuals, const Expr<SomeDerived> &expr,
const Symbol &component, bool isPassedObject = true) {
if (component.attrs().test(semantics::Attr::NOPASS)) {
return;
}
int passIndex{GetPassIndex(component)};
auto iter{actuals.begin()};
int at{0};
while (iter < actuals.end() && at < passIndex) {
if (*iter && (*iter)->keyword()) {
iter = actuals.end();
break;
}
++iter;
++at;
}
ActualArgument passed{AsGenericExpr(common::Clone(expr))};
passed.set_isPassedObject(isPassedObject);
if (iter == actuals.end()) {
if (auto passName{GetPassName(component)}) {
passed.set_keyword(*passName);
}
}
actuals.emplace(iter, std::move(passed));
}
// Return the compile-time resolution of a procedure binding, if possible.
static const Symbol *GetBindingResolution(
const std::optional<DynamicType> &baseType, const Symbol &component) {
const auto *binding{component.detailsIf<semantics::ProcBindingDetails>()};
if (!binding) {
return nullptr;
}
if (!component.attrs().test(semantics::Attr::NON_OVERRIDABLE) &&
(!baseType || baseType->IsPolymorphic())) {
return nullptr;
}
return &binding->symbol();
}
auto ExpressionAnalyzer::AnalyzeProcedureComponentRef(
const parser::ProcComponentRef &pcr, ActualArguments &&arguments)
-> std::optional<CalleeAndArguments> {
const parser::StructureComponent &sc{pcr.v.thing};
if (MaybeExpr base{Analyze(sc.base)}) {
if (const Symbol * sym{sc.component.symbol}) {
if (context_.HasError(sym)) {
return std::nullopt;
}
if (!IsProcedure(*sym)) {
AttachDeclaration(
Say(sc.component.source, "'%s' is not a procedure"_err_en_US,
sc.component.source),
*sym);
return std::nullopt;
}
if (auto *dtExpr{UnwrapExpr<Expr<SomeDerived>>(*base)}) {
if (sym->has<semantics::GenericDetails>()) {
AdjustActuals adjustment{
[&](const Symbol &proc, ActualArguments &actuals) {
if (!proc.attrs().test(semantics::Attr::NOPASS)) {
AddPassArg(actuals, std::move(*dtExpr), proc);
}
return true;
}};
auto pair{ResolveGeneric(*sym, arguments, adjustment)};
sym = pair.first;
if (!sym) {
EmitGenericResolutionError(*sc.component.symbol, pair.second);
return std::nullopt;
}
}
if (const Symbol *
resolution{GetBindingResolution(dtExpr->GetType(), *sym)}) {
AddPassArg(arguments, std::move(*dtExpr), *sym, false);
return CalleeAndArguments{
ProcedureDesignator{*resolution}, std::move(arguments)};
} else if (std::optional<DataRef> dataRef{
ExtractDataRef(std::move(*dtExpr))}) {
if (sym->attrs().test(semantics::Attr::NOPASS)) {
return CalleeAndArguments{
ProcedureDesignator{Component{std::move(*dataRef), *sym}},
std::move(arguments)};
} else {
AddPassArg(arguments,
Expr<SomeDerived>{Designator<SomeDerived>{std::move(*dataRef)}},
*sym);
return CalleeAndArguments{
ProcedureDesignator{*sym}, std::move(arguments)};
}
}
}
Say(sc.component.source,
"Base of procedure component reference is not a derived-type object"_err_en_US);
}
}
CHECK(context_.AnyFatalError());
return std::nullopt;
}
// Can actual be argument associated with dummy?
static bool CheckCompatibleArgument(bool isElemental,
const ActualArgument &actual, const characteristics::DummyArgument &dummy) {
const auto *expr{actual.UnwrapExpr()};
return std::visit(
common::visitors{
[&](const characteristics::DummyDataObject &x) {
if (x.attrs.test(characteristics::DummyDataObject::Attr::Pointer) &&
IsBareNullPointer(expr)) {
// NULL() without MOLD= is compatible with any dummy data pointer
// but cannot be allowed to lead to ambiguity.
return true;
} else if (!isElemental && actual.Rank() != x.type.Rank() &&
!x.type.attrs().test(
characteristics::TypeAndShape::Attr::AssumedRank)) {
return false;
} else if (auto actualType{actual.GetType()}) {
return x.type.type().IsTkCompatibleWith(*actualType);
}
return false;
},
[&](const characteristics::DummyProcedure &) {
return expr && IsProcedurePointerTarget(*expr);
},
[&](const characteristics::AlternateReturn &) {
return actual.isAlternateReturn();
},
},
dummy.u);
}
// Are the actual arguments compatible with the dummy arguments of procedure?
static bool CheckCompatibleArguments(
const characteristics::Procedure &procedure,
const ActualArguments &actuals) {
bool isElemental{procedure.IsElemental()};
const auto &dummies{procedure.dummyArguments};
CHECK(dummies.size() == actuals.size());
for (std::size_t i{0}; i < dummies.size(); ++i) {
const characteristics::DummyArgument &dummy{dummies[i]};
const std::optional<ActualArgument> &actual{actuals[i]};
if (actual && !CheckCompatibleArgument(isElemental, *actual, dummy)) {
return false;
}
}
return true;
}
// Handles a forward reference to a module function from what must
// be a specification expression. Return false if the symbol is
// an invalid forward reference.
bool ExpressionAnalyzer::ResolveForward(const Symbol &symbol) {
if (context_.HasError(symbol)) {
return false;
}
if (const auto *details{
symbol.detailsIf<semantics::SubprogramNameDetails>()}) {
if (details->kind() == semantics::SubprogramKind::Module) {
// If this symbol is still a SubprogramNameDetails, we must be
// checking a specification expression in a sibling module
// procedure. Resolve its names now so that its interface
// is known.
semantics::ResolveSpecificationParts(context_, symbol);
if (symbol.has<semantics::SubprogramNameDetails>()) {
// When the symbol hasn't had its details updated, we must have
// already been in the process of resolving the function's
// specification part; but recursive function calls are not
// allowed in specification parts (10.1.11 para 5).
Say("The module function '%s' may not be referenced recursively in a specification expression"_err_en_US,
symbol.name());
context_.SetError(symbol);
return false;
}
} else { // 10.1.11 para 4
Say("The internal function '%s' may not be referenced in a specification expression"_err_en_US,
symbol.name());
context_.SetError(symbol);
return false;
}
}
return true;
}
// Resolve a call to a generic procedure with given actual arguments.
// adjustActuals is called on procedure bindings to handle pass arg.
std::pair<const Symbol *, bool> ExpressionAnalyzer::ResolveGeneric(
const Symbol &symbol, const ActualArguments &actuals,
const AdjustActuals &adjustActuals, bool mightBeStructureConstructor) {
const Symbol *elemental{nullptr}; // matching elemental specific proc
const Symbol *nonElemental{nullptr}; // matching non-elemental specific
const auto &details{symbol.GetUltimate().get<semantics::GenericDetails>()};
bool anyBareNullActual{
std::find_if(actuals.begin(), actuals.end(), [](auto iter) {
return IsBareNullPointer(iter->UnwrapExpr());
}) != actuals.end()};
for (const Symbol &specific : details.specificProcs()) {
if (!ResolveForward(specific)) {
continue;
}
if (std::optional<characteristics::Procedure> procedure{
characteristics::Procedure::Characterize(
ProcedureDesignator{specific}, context_.foldingContext())}) {
ActualArguments localActuals{actuals};
if (specific.has<semantics::ProcBindingDetails>()) {
if (!adjustActuals.value()(specific, localActuals)) {
continue;
}
}
if (semantics::CheckInterfaceForGeneric(*procedure, localActuals,
GetFoldingContext(), false /* no integer conversions */) &&
CheckCompatibleArguments(*procedure, localActuals)) {
if ((procedure->IsElemental() && elemental) ||
(!procedure->IsElemental() && nonElemental)) {
// 16.9.144(6): a bare NULL() is not allowed as an actual
// argument to a generic procedure if the specific procedure
// cannot be unambiguously distinguished
return {nullptr, true /* due to NULL actuals */};
}
if (!procedure->IsElemental()) {
// takes priority over elemental match
nonElemental = &specific;
if (!anyBareNullActual) {
break; // unambiguous case
}
} else {
elemental = &specific;
}
}
}
}
if (nonElemental) {
return {&AccessSpecific(symbol, *nonElemental), false};
} else if (elemental) {
return {&AccessSpecific(symbol, *elemental), false};
}
// Check parent derived type
if (const auto *parentScope{symbol.owner().GetDerivedTypeParent()}) {
if (const Symbol * extended{parentScope->FindComponent(symbol.name())}) {
if (extended->GetUltimate().has<semantics::GenericDetails>()) {
auto pair{ResolveGeneric(*extended, actuals, adjustActuals, false)};
if (pair.first) {
return pair;
}
}
}
}
if (mightBeStructureConstructor && details.derivedType()) {
return {details.derivedType(), false};
}
return {nullptr, false};
}
const Symbol &ExpressionAnalyzer::AccessSpecific(
const Symbol &originalGeneric, const Symbol &specific) {
if (const auto *hosted{
originalGeneric.detailsIf<semantics::HostAssocDetails>()}) {
return AccessSpecific(hosted->symbol(), specific);
} else if (const auto *used{
originalGeneric.detailsIf<semantics::UseDetails>()}) {
const auto &scope{originalGeneric.owner()};
if (auto iter{scope.find(specific.name())}; iter != scope.end()) {
if (const auto *useDetails{
iter->second->detailsIf<semantics::UseDetails>()}) {
const Symbol &usedSymbol{useDetails->symbol()};
const auto *usedGeneric{
usedSymbol.detailsIf<semantics::GenericDetails>()};
if (&usedSymbol == &specific ||
(usedGeneric && usedGeneric->specific() == &specific)) {
return specific;
}
}
}
// Create a renaming USE of the specific procedure.
auto rename{context_.SaveTempName(
used->symbol().owner().GetName().value().ToString() + "$" +
specific.name().ToString())};
return *const_cast<semantics::Scope &>(scope)
.try_emplace(rename, specific.attrs(),
semantics::UseDetails{rename, specific})
.first->second;
} else {
return specific;
}
}
void ExpressionAnalyzer::EmitGenericResolutionError(
const Symbol &symbol, bool dueToNullActuals) {
Say(dueToNullActuals
? "One or more NULL() actual arguments to the generic procedure '%s' requires a MOLD= for disambiguation"_err_en_US
: semantics::IsGenericDefinedOp(symbol)
? "No specific procedure of generic operator '%s' matches the actual arguments"_err_en_US
: "No specific procedure of generic '%s' matches the actual arguments"_err_en_US,
symbol.name());
}
auto ExpressionAnalyzer::GetCalleeAndArguments(
const parser::ProcedureDesignator &pd, ActualArguments &&arguments,
bool isSubroutine, bool mightBeStructureConstructor)
-> std::optional<CalleeAndArguments> {
return std::visit(
common::visitors{
[&](const parser::Name &name) {
return GetCalleeAndArguments(name, std::move(arguments),
isSubroutine, mightBeStructureConstructor);
},
[&](const parser::ProcComponentRef &pcr) {
return AnalyzeProcedureComponentRef(pcr, std::move(arguments));
},
},
pd.u);
}
auto ExpressionAnalyzer::GetCalleeAndArguments(const parser::Name &name,
ActualArguments &&arguments, bool isSubroutine,
bool mightBeStructureConstructor) -> std::optional<CalleeAndArguments> {
const Symbol *symbol{name.symbol};
if (context_.HasError(symbol)) {
return std::nullopt; // also handles null symbol
}
const Symbol &ultimate{DEREF(symbol).GetUltimate()};
if (ultimate.attrs().test(semantics::Attr::INTRINSIC)) {
if (std::optional<SpecificCall> specificCall{context_.intrinsics().Probe(
CallCharacteristics{ultimate.name().ToString(), isSubroutine},
arguments, GetFoldingContext())}) {
CheckBadExplicitType(*specificCall, *symbol);
return CalleeAndArguments{
ProcedureDesignator{std::move(specificCall->specificIntrinsic)},
std::move(specificCall->arguments)};
}
} else {
CheckForBadRecursion(name.source, ultimate);
bool dueToNullActual{false};
if (ultimate.has<semantics::GenericDetails>()) {
ExpressionAnalyzer::AdjustActuals noAdjustment;
auto pair{ResolveGeneric(
*symbol, arguments, noAdjustment, mightBeStructureConstructor)};
symbol = pair.first;
dueToNullActual = pair.second;
}
if (symbol) {
if (symbol->GetUltimate().has<semantics::DerivedTypeDetails>()) {
if (mightBeStructureConstructor) {
return CalleeAndArguments{
semantics::SymbolRef{*symbol}, std::move(arguments)};
}
} else if (IsProcedure(*symbol)) {
return CalleeAndArguments{
ProcedureDesignator{*symbol}, std::move(arguments)};
}
if (!context_.HasError(*symbol)) {
AttachDeclaration(
Say(name.source, "'%s' is not a callable procedure"_err_en_US,
name.source),
*symbol);
}
} else if (std::optional<SpecificCall> specificCall{
context_.intrinsics().Probe(
CallCharacteristics{
ultimate.name().ToString(), isSubroutine},
arguments, GetFoldingContext())}) {
// Generics can extend intrinsics
return CalleeAndArguments{
ProcedureDesignator{std::move(specificCall->specificIntrinsic)},
std::move(specificCall->arguments)};
} else {
EmitGenericResolutionError(*name.symbol, dueToNullActual);
}
}
return std::nullopt;
}
// Fortran 2018 expressly states (8.2 p3) that any declared type for a
// generic intrinsic function "has no effect" on the result type of a
// call to that intrinsic. So one can declare "character*8 cos" and
// still get a real result from "cos(1.)". This is a dangerous feature,
// especially since implementations are free to extend their sets of
// intrinsics, and in doing so might clash with a name in a program.
// So we emit a warning in this situation, and perhaps it should be an
// error -- any correctly working program can silence the message by
// simply deleting the pointless type declaration.
void ExpressionAnalyzer::CheckBadExplicitType(
const SpecificCall &call, const Symbol &intrinsic) {
if (intrinsic.GetUltimate().GetType()) {
const auto &procedure{call.specificIntrinsic.characteristics.value()};
if (const auto &result{procedure.functionResult}) {
if (const auto *typeAndShape{result->GetTypeAndShape()}) {
if (auto declared{
typeAndShape->Characterize(intrinsic, GetFoldingContext())}) {
if (!declared->type().IsTkCompatibleWith(typeAndShape->type())) {
if (auto *msg{Say(
"The result type '%s' of the intrinsic function '%s' is not the explicit declared type '%s'"_en_US,
typeAndShape->AsFortran(), intrinsic.name(),
declared->AsFortran())}) {
msg->Attach(intrinsic.name(),
"Ignored declaration of intrinsic function '%s'"_en_US,
intrinsic.name());
}
}
}
}
}
}
}
void ExpressionAnalyzer::CheckForBadRecursion(
parser::CharBlock callSite, const semantics::Symbol &proc) {
if (const auto *scope{proc.scope()}) {
if (scope->sourceRange().Contains(callSite)) {
parser::Message *msg{nullptr};
if (proc.attrs().test(semantics::Attr::NON_RECURSIVE)) { // 15.6.2.1(3)
msg = Say("NON_RECURSIVE procedure '%s' cannot call itself"_err_en_US,
callSite);
} else if (IsAssumedLengthCharacter(proc) && IsExternal(proc)) {
msg = Say( // 15.6.2.1(3)
"Assumed-length CHARACTER(*) function '%s' cannot call itself"_err_en_US,
callSite);
}
AttachDeclaration(msg, proc);
}
}
}
template <typename A> static const Symbol *AssumedTypeDummy(const A &x) {
if (const auto *designator{
std::get_if<common::Indirection<parser::Designator>>(&x.u)}) {
if (const auto *dataRef{
std::get_if<parser::DataRef>(&designator->value().u)}) {
if (const auto *name{std::get_if<parser::Name>(&dataRef->u)}) {
return AssumedTypeDummy(*name);
}
}
}
return nullptr;
}
template <>
const Symbol *AssumedTypeDummy<parser::Name>(const parser::Name &name) {
if (const Symbol * symbol{name.symbol}) {
if (const auto *type{symbol->GetType()}) {
if (type->category() == semantics::DeclTypeSpec::TypeStar) {
return symbol;
}
}
}
return nullptr;
}
template <typename A>
static const Symbol *AssumedTypePointerOrAllocatableDummy(const A &object) {
// It is illegal for allocatable of pointer objects to be TYPE(*), but at that
// point it is is not guaranteed that it has been checked the object has
// POINTER or ALLOCATABLE attribute, so do not assume nullptr can be directly
// returned.
return std::visit(
common::visitors{
[&](const parser::StructureComponent &x) {
return AssumedTypeDummy(x.component);
},
[&](const parser::Name &x) { return AssumedTypeDummy(x); },
},
object.u);
}
template <>
const Symbol *AssumedTypeDummy<parser::AllocateObject>(
const parser::AllocateObject &x) {
return AssumedTypePointerOrAllocatableDummy(x);
}
template <>
const Symbol *AssumedTypeDummy<parser::PointerObject>(
const parser::PointerObject &x) {
return AssumedTypePointerOrAllocatableDummy(x);
}
bool ExpressionAnalyzer::CheckIsValidForwardReference(
const semantics::DerivedTypeSpec &dtSpec) {
if (dtSpec.IsForwardReferenced()) {
Say("Cannot construct value for derived type '%s' "
"before it is defined"_err_en_US,
dtSpec.name());
return false;
}
return true;
}
MaybeExpr ExpressionAnalyzer::Analyze(const parser::FunctionReference &funcRef,
std::optional<parser::StructureConstructor> *structureConstructor) {
const parser::Call &call{funcRef.v};
auto restorer{GetContextualMessages().SetLocation(call.source)};
ArgumentAnalyzer analyzer{*this, call.source, true /* isProcedureCall */};
for (const auto &arg : std::get<std::list<parser::ActualArgSpec>>(call.t)) {
analyzer.Analyze(arg, false /* not subroutine call */);
}
if (analyzer.fatalErrors()) {
return std::nullopt;
}
if (std::optional<CalleeAndArguments> callee{
GetCalleeAndArguments(std::get<parser::ProcedureDesignator>(call.t),
analyzer.GetActuals(), false /* not subroutine */,
true /* might be structure constructor */)}) {
if (auto *proc{std::get_if<ProcedureDesignator>(&callee->u)}) {
return MakeFunctionRef(
call.source, std::move(*proc), std::move(callee->arguments));
}
CHECK(std::holds_alternative<semantics::SymbolRef>(callee->u));
const Symbol &symbol{*std::get<semantics::SymbolRef>(callee->u)};
if (structureConstructor) {
// Structure constructor misparsed as function reference?
const auto &designator{std::get<parser::ProcedureDesignator>(call.t)};
if (const auto *name{std::get_if<parser::Name>(&designator.u)}) {
semantics::Scope &scope{context_.FindScope(name->source)};
semantics::DerivedTypeSpec dtSpec{name->source, symbol.GetUltimate()};
if (!CheckIsValidForwardReference(dtSpec)) {
return std::nullopt;
}
const semantics::DeclTypeSpec &type{
semantics::FindOrInstantiateDerivedType(scope, std::move(dtSpec))};
auto &mutableRef{const_cast<parser::FunctionReference &>(funcRef)};
*structureConstructor =
mutableRef.ConvertToStructureConstructor(type.derivedTypeSpec());
return Analyze(structureConstructor->value());
}
}
if (!context_.HasError(symbol)) {
AttachDeclaration(
Say("'%s' is called like a function but is not a procedure"_err_en_US,
symbol.name()),
symbol);
context_.SetError(symbol);
}
}
return std::nullopt;
}
static bool HasAlternateReturns(const evaluate::ActualArguments &args) {
for (const auto &arg : args) {
if (arg && arg->isAlternateReturn()) {
return true;
}
}
return false;
}
void ExpressionAnalyzer::Analyze(const parser::CallStmt &callStmt) {
const parser::Call &call{callStmt.v};
auto restorer{GetContextualMessages().SetLocation(call.source)};
ArgumentAnalyzer analyzer{*this, call.source, true /* isProcedureCall */};
const auto &actualArgList{std::get<std::list<parser::ActualArgSpec>>(call.t)};
for (const auto &arg : actualArgList) {
analyzer.Analyze(arg, true /* is subroutine call */);
}
if (!analyzer.fatalErrors()) {
if (std::optional<CalleeAndArguments> callee{
GetCalleeAndArguments(std::get<parser::ProcedureDesignator>(call.t),
analyzer.GetActuals(), true /* subroutine */)}) {
ProcedureDesignator *proc{std::get_if<ProcedureDesignator>(&callee->u)};
CHECK(proc);
if (CheckCall(call.source, *proc, callee->arguments)) {
bool hasAlternateReturns{HasAlternateReturns(callee->arguments)};
callStmt.typedCall.Reset(
new ProcedureRef{std::move(*proc), std::move(callee->arguments),
hasAlternateReturns},
ProcedureRef::Deleter);
}
}
}
}
const Assignment *ExpressionAnalyzer::Analyze(const parser::AssignmentStmt &x) {
if (!x.typedAssignment) {
ArgumentAnalyzer analyzer{*this};
analyzer.Analyze(std::get<parser::Variable>(x.t));
analyzer.Analyze(std::get<parser::Expr>(x.t));
std::optional<Assignment> assignment;
if (!analyzer.fatalErrors()) {
std::optional<ProcedureRef> procRef{analyzer.TryDefinedAssignment()};
if (!procRef) {
analyzer.CheckForNullPointer(
"in a non-pointer intrinsic assignment statement");
}
assignment.emplace(analyzer.MoveExpr(0), analyzer.MoveExpr(1));
if (procRef) {
assignment->u = std::move(*procRef);
}
}
x.typedAssignment.Reset(new GenericAssignmentWrapper{std::move(assignment)},
GenericAssignmentWrapper::Deleter);
}
return common::GetPtrFromOptional(x.typedAssignment->v);
}
const Assignment *ExpressionAnalyzer::Analyze(
const parser::PointerAssignmentStmt &x) {
if (!x.typedAssignment) {
MaybeExpr lhs{Analyze(std::get<parser::DataRef>(x.t))};
MaybeExpr rhs{Analyze(std::get<parser::Expr>(x.t))};
if (!lhs || !rhs) {
x.typedAssignment.Reset(
new GenericAssignmentWrapper{}, GenericAssignmentWrapper::Deleter);
} else {
Assignment assignment{std::move(*lhs), std::move(*rhs)};
std::visit(common::visitors{
[&](const std::list<parser::BoundsRemapping> &list) {
Assignment::BoundsRemapping bounds;
for (const auto &elem : list) {
auto lower{AsSubscript(Analyze(std::get<0>(elem.t)))};
auto upper{AsSubscript(Analyze(std::get<1>(elem.t)))};
if (lower && upper) {
bounds.emplace_back(Fold(std::move(*lower)),
Fold(std::move(*upper)));
}
}
assignment.u = std::move(bounds);
},
[&](const std::list<parser::BoundsSpec> &list) {
Assignment::BoundsSpec bounds;
for (const auto &bound : list) {
if (auto lower{AsSubscript(Analyze(bound.v))}) {
bounds.emplace_back(Fold(std::move(*lower)));
}
}
assignment.u = std::move(bounds);
},
},
std::get<parser::PointerAssignmentStmt::Bounds>(x.t).u);
x.typedAssignment.Reset(
new GenericAssignmentWrapper{std::move(assignment)},
GenericAssignmentWrapper::Deleter);
}
}
return common::GetPtrFromOptional(x.typedAssignment->v);
}
static bool IsExternalCalledImplicitly(
parser::CharBlock callSite, const ProcedureDesignator &proc) {
if (const auto *symbol{proc.GetSymbol()}) {
return symbol->has<semantics::SubprogramDetails>() &&
symbol->owner().IsGlobal() &&
(!symbol->scope() /*ENTRY*/ ||
!symbol->scope()->sourceRange().Contains(callSite));
} else {
return false;
}
}
std::optional<characteristics::Procedure> ExpressionAnalyzer::CheckCall(
parser::CharBlock callSite, const ProcedureDesignator &proc,
ActualArguments &arguments) {
auto chars{characteristics::Procedure::Characterize(
proc, context_.foldingContext())};
if (chars) {
bool treatExternalAsImplicit{IsExternalCalledImplicitly(callSite, proc)};
if (treatExternalAsImplicit && !chars->CanBeCalledViaImplicitInterface()) {
Say(callSite,
"References to the procedure '%s' require an explicit interface"_en_US,
DEREF(proc.GetSymbol()).name());
}
// Checks for ASSOCIATED() are done in intrinsic table processing
bool procIsAssociated{false};
if (const SpecificIntrinsic *
specificIntrinsic{proc.GetSpecificIntrinsic()}) {
if (specificIntrinsic->name == "associated") {
procIsAssociated = true;
}
}
if (!procIsAssociated) {
semantics::CheckArguments(*chars, arguments, GetFoldingContext(),
context_.FindScope(callSite), treatExternalAsImplicit,
proc.GetSpecificIntrinsic());
const Symbol *procSymbol{proc.GetSymbol()};
if (procSymbol && !IsPureProcedure(*procSymbol)) {
if (const semantics::Scope *
pure{semantics::FindPureProcedureContaining(
context_.FindScope(callSite))}) {
Say(callSite,
"Procedure '%s' referenced in pure subprogram '%s' must be pure too"_err_en_US,
procSymbol->name(), DEREF(pure->symbol()).name());