llvm-project/flang/lib/Semantics/data-to-inits.cpp
Peter Klausler 442ae603c5
[flang] Warn about inexact real literal implicit widening pitfall (#152799)
When a REAL or COMPLEX literal appears without an explicit kind suffix
or a kind-determining exponent letter, and the conversion of that
literal from decimal to binary is inexact, emit a warning if that
constant is later implicitly widened to a more precise kind, since it
will have a different value than was probably intended.

Values that convert exactly from decimal to default real, e.g. 1.0 and
0.125, do not elicit this warning.

There are many contexts in which Fortran implicitly converts constants.
This patch covers name constant values, variable and component
initialization, constants in expressions, structure constructor
components, and array constructors.

For example, "real(8) :: tenth = 0.1" is a common Fortran bug that's
hard to find, and is one that often trips up even experienced Fortran
programmers. Unlike C and C++, the literal constant 0.1 is *not* double
precision by default, and it does not have the same value as 0.1d0 or
0.1_8 do when it is converted from decimal to real(4) and then to
real(8).
2025-08-13 14:36:13 -07:00

954 lines
38 KiB
C++

//===-- lib/Semantics/data-to-inits.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
//
//===----------------------------------------------------------------------===//
// DATA statement object/value checking and conversion to static
// initializers
// - Applies specific checks to each scalar element initialization with a
// constant value or pointer target with class DataInitializationCompiler;
// - Collects the elemental initializations for each symbol and converts them
// into a single init() expression with member function
// DataChecker::ConstructInitializer().
#include "data-to-inits.h"
#include "pointer-assignment.h"
#include "flang/Evaluate/fold-designator.h"
#include "flang/Evaluate/tools.h"
#include "flang/Semantics/tools.h"
// The job of generating explicit static initializers for objects that don't
// have them in order to implement default component initialization is now being
// done in lowering, so don't do it here in semantics; but the code remains here
// in case we change our minds.
static constexpr bool makeDefaultInitializationExplicit{false};
// Whether to delete the original "init()" initializers from storage-associated
// objects and pointers.
static constexpr bool removeOriginalInits{false};
// Impose a hard limit that's more than large enough for real applications but
// small enough to cause artificial stress tests to fail reasonably instead of
// crashing the compiler with a memory allocation failure.
static constexpr auto maxDataInitBytes{std::size_t{1000000000}}; // 1GiB
namespace Fortran::semantics {
// Steps through a list of values in a DATA statement set; implements
// repetition.
template <typename DSV = parser::DataStmtValue> class ValueListIterator {
public:
ValueListIterator(SemanticsContext &context, const std::list<DSV> &list)
: context_{context}, end_{list.end()}, at_{list.begin()} {
SetRepetitionCount();
}
bool hasFatalError() const { return hasFatalError_; }
bool IsAtEnd() const { return at_ == end_; }
const SomeExpr *operator*() const { return GetExpr(context_, GetConstant()); }
std::optional<parser::CharBlock> LocateSource() const {
if (!hasFatalError_) {
return GetConstant().source;
}
return {};
}
ValueListIterator &operator++() {
if (repetitionsRemaining_ > 0) {
--repetitionsRemaining_;
} else if (at_ != end_) {
++at_;
SetRepetitionCount();
}
return *this;
}
private:
using listIterator = typename std::list<DSV>::const_iterator;
void SetRepetitionCount();
const parser::DataStmtValue &GetValue() const {
return DEREF(common::Unwrap<const parser::DataStmtValue>(*at_));
}
const parser::DataStmtConstant &GetConstant() const {
return std::get<parser::DataStmtConstant>(GetValue().t);
}
SemanticsContext &context_;
listIterator end_, at_;
ConstantSubscript repetitionsRemaining_{0};
bool hasFatalError_{false};
};
template <typename DSV> void ValueListIterator<DSV>::SetRepetitionCount() {
for (; at_ != end_; ++at_) {
auto repetitions{GetValue().repetitions};
if (repetitions < 0) {
hasFatalError_ = true;
} else if (repetitions > 0) {
repetitionsRemaining_ = repetitions - 1;
return;
}
}
repetitionsRemaining_ = 0;
}
// Collects all of the elemental initializations from DATA statements
// into a single image for each symbol that appears in any DATA.
// Expands the implied DO loops and array references.
// Applies checks that validate each distinct elemental initialization
// of the variables in a data-stmt-set, as well as those that apply
// to the corresponding values being used to initialize each element.
template <typename DSV = parser::DataStmtValue>
class DataInitializationCompiler {
public:
DataInitializationCompiler(DataInitializations &inits,
evaluate::ExpressionAnalyzer &a, const std::list<DSV> &list)
: inits_{inits}, exprAnalyzer_{a}, values_{a.context(), list} {}
const DataInitializations &inits() const { return inits_; }
bool HasSurplusValues() const { return !values_.IsAtEnd(); }
bool Scan(const parser::DataStmtObject &);
// Initializes all elements of whole variable or component
bool Scan(const Symbol &);
private:
bool Scan(const parser::Variable &);
bool Scan(const parser::Designator &);
bool Scan(const parser::DataImpliedDo &);
bool Scan(const parser::DataIDoObject &);
// Initializes all elements of a designator, which can be an array or section.
bool InitDesignator(const SomeExpr &, const Scope &);
// Initializes a single scalar object.
bool InitElement(const evaluate::OffsetSymbol &, const SomeExpr &designator,
const Scope &);
// If the returned flag is true, emit a warning about CHARACTER misusage.
std::optional<std::pair<SomeExpr, bool>> ConvertElement(
const SomeExpr &, const evaluate::DynamicType &);
DataInitializations &inits_;
evaluate::ExpressionAnalyzer &exprAnalyzer_;
ValueListIterator<DSV> values_;
};
template <typename DSV>
bool DataInitializationCompiler<DSV>::Scan(
const parser::DataStmtObject &object) {
return common::visit(
common::visitors{
[&](const common::Indirection<parser::Variable> &var) {
return Scan(var.value());
},
[&](const parser::DataImpliedDo &ido) { return Scan(ido); },
},
object.u);
}
template <typename DSV>
bool DataInitializationCompiler<DSV>::Scan(const parser::Variable &var) {
if (const auto *expr{GetExpr(exprAnalyzer_.context(), var)}) {
parser::CharBlock at{var.GetSource()};
exprAnalyzer_.GetFoldingContext().messages().SetLocation(at);
if (InitDesignator(*expr, exprAnalyzer_.context().FindScope(at))) {
return true;
}
}
return false;
}
template <typename DSV>
bool DataInitializationCompiler<DSV>::Scan(
const parser::Designator &designator) {
MaybeExpr expr;
{ // The out-of-range subscript errors from the designator folder are a
// more specific than the default ones from expression semantics, so
// disable those to avoid piling on.
auto restorer{exprAnalyzer_.GetContextualMessages().DiscardMessages()};
expr = exprAnalyzer_.Analyze(designator);
}
if (expr) {
parser::CharBlock at{parser::FindSourceLocation(designator)};
exprAnalyzer_.GetFoldingContext().messages().SetLocation(at);
if (InitDesignator(*expr, exprAnalyzer_.context().FindScope(at))) {
return true;
}
}
return false;
}
template <typename DSV>
bool DataInitializationCompiler<DSV>::Scan(const parser::DataImpliedDo &ido) {
const auto &bounds{std::get<parser::DataImpliedDo::Bounds>(ido.t)};
auto name{bounds.name.thing.thing};
const auto *lowerExpr{
GetExpr(exprAnalyzer_.context(), bounds.lower.thing.thing)};
const auto *upperExpr{
GetExpr(exprAnalyzer_.context(), bounds.upper.thing.thing)};
const auto *stepExpr{bounds.step
? GetExpr(exprAnalyzer_.context(), bounds.step->thing.thing)
: nullptr};
if (lowerExpr && upperExpr) {
// Fold the bounds expressions (again) in case any of them depend
// on outer implied DO loops.
evaluate::FoldingContext &context{exprAnalyzer_.GetFoldingContext()};
std::int64_t stepVal{1};
if (stepExpr) {
auto foldedStep{evaluate::Fold(context, SomeExpr{*stepExpr})};
stepVal = ToInt64(foldedStep).value_or(1);
if (stepVal == 0) {
exprAnalyzer_.Say(name.source,
"DATA statement implied DO loop has a step value of zero"_err_en_US);
return false;
}
}
auto foldedLower{evaluate::Fold(context, SomeExpr{*lowerExpr})};
auto lower{ToInt64(foldedLower)};
auto foldedUpper{evaluate::Fold(context, SomeExpr{*upperExpr})};
auto upper{ToInt64(foldedUpper)};
if (lower && upper) {
int kind{evaluate::ResultType<evaluate::ImpliedDoIndex>::kind};
if (const auto dynamicType{evaluate::DynamicType::From(*name.symbol)}) {
if (dynamicType->category() == TypeCategory::Integer) {
kind = dynamicType->kind();
}
}
if (exprAnalyzer_.AddImpliedDo(name.source, kind)) {
auto &value{context.StartImpliedDo(name.source, *lower)};
bool result{true};
for (auto n{(*upper - value + stepVal) / stepVal}; n > 0;
--n, value += stepVal) {
for (const auto &object :
std::get<std::list<parser::DataIDoObject>>(ido.t)) {
if (!Scan(object)) {
result = false;
break;
}
}
}
context.EndImpliedDo(name.source);
exprAnalyzer_.RemoveImpliedDo(name.source);
return result;
}
}
}
return false;
}
template <typename DSV>
bool DataInitializationCompiler<DSV>::Scan(
const parser::DataIDoObject &object) {
return common::visit(
common::visitors{
[&](const parser::Scalar<common::Indirection<parser::Designator>>
&var) { return Scan(var.thing.value()); },
[&](const common::Indirection<parser::DataImpliedDo> &ido) {
return Scan(ido.value());
},
},
object.u);
}
template <typename DSV>
bool DataInitializationCompiler<DSV>::Scan(const Symbol &symbol) {
auto designator{exprAnalyzer_.Designate(evaluate::DataRef{symbol})};
CHECK(designator.has_value());
return InitDesignator(*designator, symbol.owner());
}
template <typename DSV>
bool DataInitializationCompiler<DSV>::InitDesignator(
const SomeExpr &designator, const Scope &scope) {
evaluate::FoldingContext &context{exprAnalyzer_.GetFoldingContext()};
evaluate::DesignatorFolder folder{context};
while (auto offsetSymbol{folder.FoldDesignator(designator)}) {
if (folder.isOutOfRange()) {
if (auto bad{evaluate::OffsetToDesignator(context, *offsetSymbol)}) {
exprAnalyzer_.context().Say(
"DATA statement designator '%s' is out of range"_err_en_US,
bad->AsFortran());
} else {
exprAnalyzer_.context().Say(
"DATA statement designator '%s' is out of range"_err_en_US,
designator.AsFortran());
}
return false;
} else if (!InitElement(*offsetSymbol, designator, scope)) {
return false;
} else {
++values_;
}
}
return folder.isEmpty();
}
template <typename DSV>
std::optional<std::pair<SomeExpr, bool>>
DataInitializationCompiler<DSV>::ConvertElement(
const SomeExpr &expr, const evaluate::DynamicType &type) {
evaluate::FoldingContext &foldingContext{exprAnalyzer_.GetFoldingContext()};
evaluate::CheckRealWidening(expr, type, foldingContext);
if (auto converted{evaluate::ConvertToType(type, SomeExpr{expr})}) {
return {std::make_pair(std::move(*converted), false)};
}
// Allow DATA initialization with Hollerith and kind=1 CHARACTER like
// (most) other Fortran compilers do.
if (auto converted{evaluate::HollerithToBOZ(foldingContext, expr, type)}) {
return {std::make_pair(std::move(*converted), true)};
}
SemanticsContext &context{exprAnalyzer_.context()};
if (context.IsEnabled(common::LanguageFeature::LogicalIntegerAssignment)) {
if (MaybeExpr converted{evaluate::DataConstantConversionExtension(
foldingContext, type, expr)}) {
context.Warn(common::LanguageFeature::LogicalIntegerAssignment,
foldingContext.messages().at(),
"nonstandard usage: initialization of %s with %s"_port_en_US,
type.AsFortran(), expr.GetType().value().AsFortran());
return {std::make_pair(std::move(*converted), false)};
}
}
return std::nullopt;
}
template <typename DSV>
bool DataInitializationCompiler<DSV>::InitElement(
const evaluate::OffsetSymbol &offsetSymbol, const SomeExpr &designator,
const Scope &scope) {
const Symbol &symbol{offsetSymbol.symbol()};
const Symbol *lastSymbol{GetLastSymbol(designator)};
bool isPointer{lastSymbol && IsPointer(*lastSymbol)};
bool isProcPointer{lastSymbol && IsProcedurePointer(*lastSymbol)};
evaluate::FoldingContext &context{exprAnalyzer_.GetFoldingContext()};
const auto DescribeElement{[&]() {
if (auto badDesignator{
evaluate::OffsetToDesignator(context, offsetSymbol)}) {
return badDesignator->AsFortran();
} else {
// Error recovery
std::string buf;
llvm::raw_string_ostream ss{buf};
ss << offsetSymbol.symbol().name() << " offset " << offsetSymbol.offset()
<< " bytes for " << offsetSymbol.size() << " bytes";
return ss.str();
}
}};
const auto GetImage{[&]() -> evaluate::InitialImage & {
// This could be (and was) written to always call std::map<>::emplace(),
// which should handle duplicate entries gracefully, but it was still
// causing memory allocation & deallocation with gcc.
auto iter{inits_.find(&symbol)};
if (iter == inits_.end()) {
iter = inits_.emplace(&symbol, symbol.size()).first;
}
auto &symbolInit{iter->second};
symbolInit.NoteInitializedRange(offsetSymbol);
return symbolInit.image;
}};
const auto OutOfRangeError{[&]() {
evaluate::AttachDeclaration(
exprAnalyzer_.context().Say(
"DATA statement designator '%s' is out of range for its variable '%s'"_err_en_US,
DescribeElement(), symbol.name()),
symbol);
}};
if (values_.hasFatalError()) {
return false;
} else if (values_.IsAtEnd()) {
exprAnalyzer_.context().Say(
"DATA statement set has no value for '%s'"_err_en_US,
DescribeElement());
return false;
} else if (static_cast<std::size_t>(
offsetSymbol.offset() + offsetSymbol.size()) > symbol.size()) {
OutOfRangeError();
return false;
}
auto &messages{context.messages()};
auto restorer{
messages.SetLocation(values_.LocateSource().value_or(messages.at()))};
const SomeExpr *expr{*values_};
if (!expr) {
CHECK(exprAnalyzer_.context().AnyFatalError());
} else if (symbol.size() > maxDataInitBytes) {
evaluate::AttachDeclaration(
exprAnalyzer_.context().Say(
"'%s' is too large to initialize with a DATA statement"_todo_en_US,
symbol.name()),
symbol);
return false;
} else if (isPointer) {
if (static_cast<std::size_t>(offsetSymbol.offset() + offsetSymbol.size()) >
symbol.size()) {
OutOfRangeError();
} else if (evaluate::IsNullPointer(expr)) {
// nothing to do; rely on zero initialization
return true;
} else if (isProcPointer) {
if (evaluate::IsProcedureDesignator(*expr)) {
if (CheckPointerAssignment(exprAnalyzer_.context(), designator, *expr,
scope,
/*isBoundsRemapping=*/false, /*isAssumedRank=*/false)) {
if (lastSymbol->has<ProcEntityDetails>()) {
GetImage().AddPointer(offsetSymbol.offset(), *expr);
return true;
} else {
evaluate::AttachDeclaration(
exprAnalyzer_.context().Say(
"DATA statement initialization of procedure pointer '%s' declared using a POINTER statement and an INTERFACE instead of a PROCEDURE statement"_todo_en_US,
DescribeElement()),
*lastSymbol);
}
}
} else {
exprAnalyzer_.Say(
"Data object '%s' may not be used to initialize '%s', which is a procedure pointer"_err_en_US,
expr->AsFortran(), DescribeElement());
}
} else if (evaluate::IsProcedure(*expr)) {
exprAnalyzer_.Say(
"Procedure '%s' may not be used to initialize '%s', which is not a procedure pointer"_err_en_US,
expr->AsFortran(), DescribeElement());
} else if (CheckInitialDataPointerTarget(
exprAnalyzer_.context(), designator, *expr, scope)) {
GetImage().AddPointer(offsetSymbol.offset(), *expr);
return true;
}
} else if (evaluate::IsNullPointer(expr)) {
exprAnalyzer_.Say("Initializer for '%s' must not be a pointer"_err_en_US,
DescribeElement());
} else if (evaluate::IsProcedureDesignator(*expr)) {
exprAnalyzer_.Say("Initializer for '%s' must not be a procedure"_err_en_US,
DescribeElement());
} else if (auto designatorType{designator.GetType()}) {
if (expr->Rank() > 0) {
// Because initial-data-target is ambiguous with scalar-constant and
// scalar-constant-subobject at parse time, enforcement of scalar-*
// must be deferred to here.
exprAnalyzer_.Say(
"DATA statement value initializes '%s' with an array"_err_en_US,
DescribeElement());
} else if (auto converted{ConvertElement(*expr, *designatorType)}) {
// value non-pointer initialization
if (IsBOZLiteral(*expr) &&
designatorType->category() != TypeCategory::Integer) { // 8.6.7(11)
exprAnalyzer_.Warn(common::LanguageFeature::DataStmtExtensions,
"BOZ literal should appear in a DATA statement only as a value for an integer object, but '%s' is '%s'"_port_en_US,
DescribeElement(), designatorType->AsFortran());
} else if (converted->second) {
exprAnalyzer_.Warn(common::LanguageFeature::DataStmtExtensions,
"DATA statement value initializes '%s' of type '%s' with CHARACTER"_port_en_US,
DescribeElement(), designatorType->AsFortran());
}
auto folded{evaluate::Fold(context, std::move(converted->first))};
// Rewritten from a switch() in order to avoid getting complaints
// about a missing "default:" from some compilers and complaints
// about a redundant "default:" from others.
auto status{GetImage().Add(
offsetSymbol.offset(), offsetSymbol.size(), folded, context)};
if (status == evaluate::InitialImage::Ok) {
return true;
} else if (status == evaluate::InitialImage::NotAConstant) {
exprAnalyzer_.Say(
"DATA statement value '%s' for '%s' is not a constant"_err_en_US,
folded.AsFortran(), DescribeElement());
} else if (status == evaluate::InitialImage::OutOfRange) {
OutOfRangeError();
} else if (status == evaluate::InitialImage::LengthMismatch) {
exprAnalyzer_.Warn(common::UsageWarning::DataLength,
"DATA statement value '%s' for '%s' has the wrong length"_warn_en_US,
folded.AsFortran(), DescribeElement());
return true;
} else if (status == evaluate::InitialImage::TooManyElems) {
exprAnalyzer_.Say("DATA statement has too many elements"_err_en_US);
} else {
CHECK(exprAnalyzer_.context().AnyFatalError());
}
} else {
exprAnalyzer_.context().Say(
"DATA statement value could not be converted to the type '%s' of the object '%s'"_err_en_US,
designatorType->AsFortran(), DescribeElement());
}
} else {
CHECK(exprAnalyzer_.context().AnyFatalError());
}
return false;
}
void AccumulateDataInitializations(DataInitializations &inits,
evaluate::ExpressionAnalyzer &exprAnalyzer,
const parser::DataStmtSet &set) {
DataInitializationCompiler scanner{
inits, exprAnalyzer, std::get<std::list<parser::DataStmtValue>>(set.t)};
for (const auto &object :
std::get<std::list<parser::DataStmtObject>>(set.t)) {
if (!scanner.Scan(object)) {
return;
}
}
if (scanner.HasSurplusValues()) {
exprAnalyzer.context().Say(
"DATA statement set has more values than objects"_err_en_US);
}
}
void AccumulateDataInitializations(DataInitializations &inits,
evaluate::ExpressionAnalyzer &exprAnalyzer, const Symbol &symbol,
const std::list<common::Indirection<parser::DataStmtValue>> &list) {
DataInitializationCompiler<common::Indirection<parser::DataStmtValue>>
scanner{inits, exprAnalyzer, list};
if (scanner.Scan(symbol) && scanner.HasSurplusValues()) {
exprAnalyzer.context().Say(
"DATA statement set has more values than objects"_err_en_US);
}
}
// Looks for default derived type component initialization -- but
// *not* allocatables.
static const DerivedTypeSpec *HasDefaultInitialization(const Symbol &symbol) {
if (const auto *object{symbol.detailsIf<ObjectEntityDetails>()}) {
if (object->init().has_value()) {
return nullptr; // init is explicit, not default
} else if (!object->isDummy() && object->type()) {
if (const DerivedTypeSpec * derived{object->type()->AsDerived()}) {
DirectComponentIterator directs{*derived};
if (llvm::any_of(directs, [](const Symbol &component) {
return !IsAllocatable(component) &&
HasDeclarationInitializer(component);
})) {
return derived;
}
}
}
}
return nullptr;
}
// PopulateWithComponentDefaults() adds initializations to an instance
// of SymbolDataInitialization containing all of the default component
// initializers
static void PopulateWithComponentDefaults(SymbolDataInitialization &init,
std::size_t offset, const DerivedTypeSpec &derived,
evaluate::FoldingContext &foldingContext);
static void PopulateWithComponentDefaults(SymbolDataInitialization &init,
std::size_t offset, const DerivedTypeSpec &derived,
evaluate::FoldingContext &foldingContext, const Symbol &symbol) {
if (auto extents{evaluate::GetConstantExtents(foldingContext, symbol)}) {
const Scope &scope{derived.scope() ? *derived.scope()
: DEREF(derived.typeSymbol().scope())};
std::size_t stride{scope.size()};
if (std::size_t alignment{scope.alignment().value_or(0)}) {
stride = ((stride + alignment - 1) / alignment) * alignment;
}
for (auto elements{evaluate::GetSize(*extents)}; elements-- > 0;
offset += stride) {
PopulateWithComponentDefaults(init, offset, derived, foldingContext);
}
}
}
// F'2018 19.5.3(10) allows storage-associated default component initialization
// when the values are identical.
static void PopulateWithComponentDefaults(SymbolDataInitialization &init,
std::size_t offset, const DerivedTypeSpec &derived,
evaluate::FoldingContext &foldingContext) {
const Scope &scope{
derived.scope() ? *derived.scope() : DEREF(derived.typeSymbol().scope())};
for (const auto &pair : scope) {
const Symbol &component{*pair.second};
std::size_t componentOffset{offset + component.offset()};
if (const auto *object{component.detailsIf<ObjectEntityDetails>()}) {
if (!IsAllocatable(component) && !IsAutomatic(component)) {
bool initialized{false};
if (object->init()) {
initialized = true;
if (IsPointer(component)) {
if (auto extant{init.image.AsConstantPointer(componentOffset)}) {
initialized = !(*extant == *object->init());
}
if (initialized) {
init.image.AddPointer(componentOffset, *object->init());
}
} else { // data, not pointer
if (auto dyType{evaluate::DynamicType::From(component)}) {
if (auto extents{evaluate::GetConstantExtents(
foldingContext, component)}) {
if (auto extant{init.image.AsConstant(foldingContext, *dyType,
std::nullopt, *extents, false /*don't pad*/,
componentOffset)}) {
initialized = !(*extant == *object->init());
}
}
}
if (initialized) {
init.image.Add(componentOffset, component.size(), *object->init(),
foldingContext);
}
}
} else if (const DeclTypeSpec * type{component.GetType()}) {
if (const DerivedTypeSpec * componentDerived{type->AsDerived()}) {
PopulateWithComponentDefaults(init, componentOffset,
*componentDerived, foldingContext, component);
}
}
if (initialized) {
init.NoteInitializedRange(componentOffset, component.size());
}
}
} else if (const auto *proc{component.detailsIf<ProcEntityDetails>()}) {
if (proc->init() && *proc->init()) {
SomeExpr procPtrInit{evaluate::ProcedureDesignator{**proc->init()}};
auto extant{init.image.AsConstantPointer(componentOffset)};
if (!extant || !(*extant == procPtrInit)) {
init.NoteInitializedRange(componentOffset, component.size());
init.image.AddPointer(componentOffset, std::move(procPtrInit));
}
}
}
}
}
static bool CheckForOverlappingInitialization(
const std::list<SymbolRef> &symbols,
SymbolDataInitialization &initialization,
evaluate::ExpressionAnalyzer &exprAnalyzer, const std::string &what) {
bool result{true};
auto &context{exprAnalyzer.GetFoldingContext()};
initialization.initializedRanges.sort();
ConstantSubscript next{0};
for (const auto &range : initialization.initializedRanges) {
if (range.start() < next) {
result = false; // error: overlap
bool hit{false};
for (const Symbol &symbol : symbols) {
auto offset{range.start() -
static_cast<ConstantSubscript>(
symbol.offset() - symbols.front()->offset())};
if (offset >= 0) {
if (auto badDesignator{evaluate::OffsetToDesignator(
context, symbol, offset, range.size())}) {
hit = true;
exprAnalyzer.Say(symbol.name(),
"%s affect '%s' more than once"_err_en_US, what,
badDesignator->AsFortran());
}
}
}
CHECK(hit);
}
next = range.start() + range.size();
CHECK(next <= static_cast<ConstantSubscript>(initialization.image.size()));
}
return result;
}
static void IncorporateExplicitInitialization(
SymbolDataInitialization &combined, DataInitializations &inits,
const Symbol &symbol, ConstantSubscript firstOffset,
evaluate::FoldingContext &foldingContext) {
auto iter{inits.find(&symbol)};
const auto offset{symbol.offset() - firstOffset};
if (iter != inits.end()) { // DATA statement initialization
for (const auto &range : iter->second.initializedRanges) {
auto at{offset + range.start()};
combined.NoteInitializedRange(at, range.size());
combined.image.Incorporate(
at, iter->second.image, range.start(), range.size());
}
if (removeOriginalInits) {
inits.erase(iter);
}
} else { // Declaration initialization
Symbol &mutableSymbol{const_cast<Symbol &>(symbol)};
if (IsPointer(mutableSymbol)) {
if (auto *object{mutableSymbol.detailsIf<ObjectEntityDetails>()}) {
if (object->init()) {
combined.NoteInitializedRange(offset, mutableSymbol.size());
combined.image.AddPointer(offset, *object->init());
if (removeOriginalInits) {
object->init().reset();
}
}
} else if (auto *proc{mutableSymbol.detailsIf<ProcEntityDetails>()}) {
if (proc->init() && *proc->init()) {
combined.NoteInitializedRange(offset, mutableSymbol.size());
combined.image.AddPointer(
offset, SomeExpr{evaluate::ProcedureDesignator{**proc->init()}});
if (removeOriginalInits) {
proc->init().reset();
}
}
}
} else if (auto *object{mutableSymbol.detailsIf<ObjectEntityDetails>()}) {
if (!IsNamedConstant(mutableSymbol) && object->init()) {
combined.NoteInitializedRange(offset, mutableSymbol.size());
combined.image.Add(
offset, mutableSymbol.size(), *object->init(), foldingContext);
if (removeOriginalInits) {
object->init().reset();
}
}
}
}
}
// Finds the size of the smallest element type in a list of
// storage-associated objects.
static std::size_t ComputeMinElementBytes(
const std::list<SymbolRef> &associated,
evaluate::FoldingContext &foldingContext) {
std::size_t minElementBytes{1};
const Symbol &first{*associated.front()};
for (const Symbol &s : associated) {
if (auto dyType{evaluate::DynamicType::From(s)}) {
auto size{static_cast<std::size_t>(
evaluate::ToInt64(dyType->MeasureSizeInBytes(foldingContext, true))
.value_or(1))};
if (std::size_t alignment{
dyType->GetAlignment(foldingContext.targetCharacteristics())}) {
size = ((size + alignment - 1) / alignment) * alignment;
}
if (&s == &first) {
minElementBytes = size;
} else {
minElementBytes = std::min(minElementBytes, size);
}
} else {
minElementBytes = 1;
}
}
return minElementBytes;
}
// Checks for overlapping initialization errors in a list of
// storage-associated objects. Default component initializations
// are allowed to be overridden by explicit initializations.
// If the objects are static, save the combined initializer as
// a compiler-created object that covers all of them.
static bool CombineEquivalencedInitialization(
const std::list<SymbolRef> &associated,
evaluate::ExpressionAnalyzer &exprAnalyzer, DataInitializations &inits) {
// Compute the minimum common granularity and total size
const Symbol &first{*associated.front()};
std::size_t maxLimit{0};
for (const Symbol &s : associated) {
CHECK(s.offset() >= first.offset());
auto limit{s.offset() + s.size()};
if (limit > maxLimit) {
maxLimit = limit;
}
}
auto bytes{static_cast<common::ConstantSubscript>(maxLimit - first.offset())};
Scope &scope{const_cast<Scope &>(first.owner())};
// Combine the initializations of the associated objects.
// Apply all default initializations first.
SymbolDataInitialization combined{static_cast<std::size_t>(bytes)};
auto &foldingContext{exprAnalyzer.GetFoldingContext()};
for (const Symbol &s : associated) {
if (!IsNamedConstant(s)) {
if (const auto *derived{HasDefaultInitialization(s)}) {
PopulateWithComponentDefaults(
combined, s.offset() - first.offset(), *derived, foldingContext, s);
}
}
}
if (!CheckForOverlappingInitialization(associated, combined, exprAnalyzer,
"Distinct default component initializations of equivalenced objects"s)) {
return false;
}
// Don't complain about overlap between explicit initializations and
// default initializations.
combined.initializedRanges.clear();
// Now overlay all explicit initializations from DATA statements and
// from initializers in declarations.
for (const Symbol &symbol : associated) {
IncorporateExplicitInitialization(
combined, inits, symbol, first.offset(), foldingContext);
}
if (!CheckForOverlappingInitialization(associated, combined, exprAnalyzer,
"Explicit initializations of equivalenced objects"s)) {
return false;
}
// If the items are in static storage, save the final initialization.
if (llvm::any_of(associated, [](SymbolRef ref) { return IsSaved(*ref); })) {
// Create a compiler array temp that overlaps all the items.
SourceName name{exprAnalyzer.context().GetTempName(scope)};
auto emplaced{
scope.try_emplace(name, Attrs{Attr::SAVE}, ObjectEntityDetails{})};
CHECK(emplaced.second);
Symbol &combinedSymbol{*emplaced.first->second};
combinedSymbol.set(Symbol::Flag::CompilerCreated);
inits.emplace(&combinedSymbol, std::move(combined));
auto &details{combinedSymbol.get<ObjectEntityDetails>()};
combinedSymbol.set_offset(first.offset());
combinedSymbol.set_size(bytes);
std::size_t minElementBytes{
ComputeMinElementBytes(associated, foldingContext)};
if (!exprAnalyzer.GetFoldingContext().targetCharacteristics().IsTypeEnabled(
TypeCategory::Integer, minElementBytes) ||
(bytes % minElementBytes) != 0) {
minElementBytes = 1;
}
const DeclTypeSpec &typeSpec{scope.MakeNumericType(
TypeCategory::Integer, KindExpr{minElementBytes})};
details.set_type(typeSpec);
ArraySpec arraySpec;
arraySpec.emplace_back(ShapeSpec::MakeExplicit(Bound{
bytes / static_cast<common::ConstantSubscript>(minElementBytes)}));
details.set_shape(arraySpec);
if (const auto *commonBlock{FindCommonBlockContaining(first)}) {
details.set_commonBlock(*commonBlock);
}
// Add an EQUIVALENCE set to the scope so that the new object appears in
// the results of GetStorageAssociations().
auto &newSet{scope.equivalenceSets().emplace_back()};
newSet.emplace_back(combinedSymbol);
newSet.emplace_back(const_cast<Symbol &>(first));
}
return true;
}
// When a statically-allocated derived type variable has no explicit
// initialization, but its type has at least one nonallocatable ultimate
// component with default initialization, make its initialization explicit.
[[maybe_unused]] static void MakeDefaultInitializationExplicit(
const Scope &scope, const std::list<std::list<SymbolRef>> &associations,
evaluate::FoldingContext &foldingContext, DataInitializations &inits) {
UnorderedSymbolSet equivalenced;
for (const std::list<SymbolRef> &association : associations) {
for (const Symbol &symbol : association) {
equivalenced.emplace(symbol);
}
}
for (const auto &pair : scope) {
const Symbol &symbol{*pair.second};
if (!symbol.test(Symbol::Flag::InDataStmt) &&
!HasDeclarationInitializer(symbol) && IsSaved(symbol) &&
equivalenced.find(symbol) == equivalenced.end()) {
// Static object, no local storage association, no explicit initialization
if (const DerivedTypeSpec * derived{HasDefaultInitialization(symbol)}) {
auto newInitIter{inits.emplace(&symbol, symbol.size())};
CHECK(newInitIter.second);
auto &newInit{newInitIter.first->second};
PopulateWithComponentDefaults(
newInit, 0, *derived, foldingContext, symbol);
}
}
}
}
// Traverses the Scopes to:
// 1) combine initialization of equivalenced objects, &
// 2) optionally make initialization explicit for otherwise uninitialized static
// objects of derived types with default component initialization
// Returns false on error.
static bool ProcessScopes(const Scope &scope,
evaluate::ExpressionAnalyzer &exprAnalyzer, DataInitializations &inits) {
bool result{true}; // no error
switch (scope.kind()) {
case Scope::Kind::Global:
case Scope::Kind::Module:
case Scope::Kind::MainProgram:
case Scope::Kind::Subprogram:
case Scope::Kind::BlockData:
case Scope::Kind::BlockConstruct: {
std::list<std::list<SymbolRef>> associations{GetStorageAssociations(scope)};
for (const std::list<SymbolRef> &associated : associations) {
if (std::find_if(associated.begin(), associated.end(), [](SymbolRef ref) {
return IsInitialized(*ref);
}) != associated.end()) {
result &=
CombineEquivalencedInitialization(associated, exprAnalyzer, inits);
}
}
if constexpr (makeDefaultInitializationExplicit) {
MakeDefaultInitializationExplicit(
scope, associations, exprAnalyzer.GetFoldingContext(), inits);
}
for (const Scope &child : scope.children()) {
result &= ProcessScopes(child, exprAnalyzer, inits);
}
} break;
default:;
}
return result;
}
// Converts the static initialization image for a single symbol with
// one or more DATA statement appearances.
void ConstructInitializer(const Symbol &symbol,
SymbolDataInitialization &initialization,
evaluate::ExpressionAnalyzer &exprAnalyzer) {
std::list<SymbolRef> symbols{symbol};
CheckForOverlappingInitialization(
symbols, initialization, exprAnalyzer, "DATA statement initializations"s);
auto &context{exprAnalyzer.GetFoldingContext()};
if (const auto *proc{symbol.detailsIf<ProcEntityDetails>()}) {
CHECK(IsProcedurePointer(symbol));
auto &mutableProc{const_cast<ProcEntityDetails &>(*proc)};
if (MaybeExpr expr{initialization.image.AsConstantPointer()}) {
if (const auto *procDesignator{
std::get_if<evaluate::ProcedureDesignator>(&expr->u)}) {
CHECK(!procDesignator->GetComponent());
if (const auto *intrin{procDesignator->GetSpecificIntrinsic()}) {
const Symbol *intrinSymbol{
symbol.owner().FindSymbol(SourceName{intrin->name})};
mutableProc.set_init(DEREF(intrinSymbol));
} else {
mutableProc.set_init(DEREF(procDesignator->GetSymbol()));
}
} else {
CHECK(evaluate::IsNullProcedurePointer(&*expr));
mutableProc.set_init(nullptr);
}
} else {
mutableProc.set_init(nullptr);
}
} else if (const auto *object{symbol.detailsIf<ObjectEntityDetails>()}) {
auto &mutableObject{const_cast<ObjectEntityDetails &>(*object)};
if (IsPointer(symbol)) {
if (auto ptr{initialization.image.AsConstantPointer()}) {
mutableObject.set_init(*ptr);
} else {
mutableObject.set_init(SomeExpr{evaluate::NullPointer{}});
}
} else if (auto symbolType{evaluate::DynamicType::From(symbol)}) {
if (auto extents{evaluate::GetConstantExtents(context, symbol)}) {
mutableObject.set_init(initialization.image.AsConstant(
context, *symbolType, std::nullopt, *extents));
} else {
exprAnalyzer.Say(symbol.name(),
"internal: unknown shape for '%s' while constructing initializer from DATA"_err_en_US,
symbol.name());
return;
}
} else {
exprAnalyzer.Say(symbol.name(),
"internal: no type for '%s' while constructing initializer from DATA"_err_en_US,
symbol.name());
return;
}
if (!object->init()) {
exprAnalyzer.Say(symbol.name(),
"internal: could not construct an initializer from DATA statements for '%s'"_err_en_US,
symbol.name());
}
} else {
CHECK(exprAnalyzer.context().AnyFatalError());
}
}
void ConvertToInitializers(
DataInitializations &inits, evaluate::ExpressionAnalyzer &exprAnalyzer) {
if (ProcessScopes(
exprAnalyzer.context().globalScope(), exprAnalyzer, inits)) {
for (auto &[symbolPtr, initialization] : inits) {
ConstructInitializer(*symbolPtr, initialization, exprAnalyzer);
}
}
}
} // namespace Fortran::semantics