llvm-project/flang/lib/Lower/CallInterface.cpp
Daniel Chen af09219edd [Flang] Add partial support for lowering procedure pointer assignment. (#70461)
**Scope of the PR:**
1. Lowering global and local procedure pointer declaration statement
with explicit or implicit interface. The explicit interface can be from
an interface block, a module procedure or an internal procedure.
2. Lowering procedure pointer assignment, where the target procedure
could be external, module or internal procedures.
3. Lowering reference to procedure pointers so that it works end to end.

**PR notes:**
1. The first commit of the PR does not include testing. I would like to
collect some comments first, which may alter the output. Once I confirm
the implementation, I will add some testing as a follow up commit to
this PR.
2. No special handling of the host-associated entities when an internal
procedure is the target of a procedure pointer assignment in this PR.

**Implementation notes:**
1. The implementation is using the HLFIR path.
2. Flang currently uses `getUntypedBoxProcType` to get the
`fir::BoxProcType` for `ProcedureDesignator` when getting the address of
a procedure in order to pass it as an actual argument. This PR inherits
the same design decision for procedure pointer as the `fir::StoreOp`
requires the same memory type.

Note: this commit is actually resubmitting the original commit from
PR #70461 that was reverted. See PR #73221.
2023-11-23 13:43:35 +01:00

1560 lines
65 KiB
C++

//===-- CallInterface.cpp -- Procedure call interface ---------------------===//
//
// 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/Lower/CallInterface.h"
#include "flang/Evaluate/fold.h"
#include "flang/Lower/Bridge.h"
#include "flang/Lower/Mangler.h"
#include "flang/Lower/PFTBuilder.h"
#include "flang/Lower/StatementContext.h"
#include "flang/Lower/Support/Utils.h"
#include "flang/Optimizer/Builder/Character.h"
#include "flang/Optimizer/Builder/FIRBuilder.h"
#include "flang/Optimizer/Builder/Todo.h"
#include "flang/Optimizer/Dialect/FIRDialect.h"
#include "flang/Optimizer/Dialect/FIROpsSupport.h"
#include "flang/Optimizer/Support/InternalNames.h"
#include "flang/Semantics/symbol.h"
#include "flang/Semantics/tools.h"
#include <optional>
static mlir::FunctionType
getProcedureType(const Fortran::evaluate::characteristics::Procedure &proc,
Fortran::lower::AbstractConverter &converter);
mlir::Type Fortran::lower::getUntypedBoxProcType(mlir::MLIRContext *context) {
llvm::SmallVector<mlir::Type> resultTys;
llvm::SmallVector<mlir::Type> inputTys;
auto untypedFunc = mlir::FunctionType::get(context, inputTys, resultTys);
return fir::BoxProcType::get(context, untypedFunc);
}
/// Return the type of a dummy procedure given its characteristic (if it has
/// one).
static mlir::Type getProcedureDesignatorType(
const Fortran::evaluate::characteristics::Procedure *,
Fortran::lower::AbstractConverter &converter) {
// TODO: Get actual function type of the dummy procedure, at least when an
// interface is given. The result type should be available even if the arity
// and type of the arguments is not.
// In general, that is a nice to have but we cannot guarantee to find the
// function type that will match the one of the calls, we may not even know
// how many arguments the dummy procedure accepts (e.g. if a procedure
// pointer is only transiting through the current procedure without being
// called), so a function type cast must always be inserted.
return Fortran::lower::getUntypedBoxProcType(&converter.getMLIRContext());
}
//===----------------------------------------------------------------------===//
// Caller side interface implementation
//===----------------------------------------------------------------------===//
bool Fortran::lower::CallerInterface::hasAlternateReturns() const {
return procRef.hasAlternateReturns();
}
/// Return the binding label (from BIND(C...)) or the mangled name of the
/// symbol.
static std::string
getProcMangledName(const Fortran::evaluate::ProcedureDesignator &proc,
Fortran::lower::AbstractConverter &converter) {
if (const Fortran::semantics::Symbol *symbol = proc.GetSymbol())
return converter.mangleName(symbol->GetUltimate());
assert(proc.GetSpecificIntrinsic() &&
"expected intrinsic procedure in designator");
return proc.GetName();
}
std::string Fortran::lower::CallerInterface::getMangledName() const {
return getProcMangledName(procRef.proc(), converter);
}
const Fortran::semantics::Symbol *
Fortran::lower::CallerInterface::getProcedureSymbol() const {
return procRef.proc().GetSymbol();
}
bool Fortran::lower::CallerInterface::isIndirectCall() const {
if (const Fortran::semantics::Symbol *symbol = procRef.proc().GetSymbol())
return Fortran::semantics::IsPointer(*symbol) ||
Fortran::semantics::IsDummy(*symbol);
return false;
}
bool Fortran::lower::CallerInterface::requireDispatchCall() const {
// calls with NOPASS attribute still have their component so check if it is
// polymorphic.
if (const Fortran::evaluate::Component *component =
procRef.proc().GetComponent()) {
if (Fortran::semantics::IsPolymorphic(component->GetFirstSymbol()))
return true;
}
// calls with PASS attribute have the passed-object already set in its
// arguments. Just check if their is one.
std::optional<unsigned> passArg = getPassArgIndex();
if (passArg)
return true;
return false;
}
std::optional<unsigned>
Fortran::lower::CallerInterface::getPassArgIndex() const {
unsigned passArgIdx = 0;
std::optional<unsigned> passArg;
for (const auto &arg : getCallDescription().arguments()) {
if (arg && arg->isPassedObject()) {
passArg = passArgIdx;
break;
}
++passArgIdx;
}
if (!passArg)
return passArg;
// Take into account result inserted as arguments.
if (std::optional<Fortran::lower::CallInterface<
Fortran::lower::CallerInterface>::PassedEntity>
resultArg = getPassedResult()) {
if (resultArg->passBy == PassEntityBy::AddressAndLength)
passArg = *passArg + 2;
else if (resultArg->passBy == PassEntityBy::BaseAddress)
passArg = *passArg + 1;
}
return passArg;
}
const Fortran::semantics::Symbol *
Fortran::lower::CallerInterface::getIfIndirectCallSymbol() const {
if (const Fortran::semantics::Symbol *symbol = procRef.proc().GetSymbol())
if (Fortran::semantics::IsPointer(*symbol) ||
Fortran::semantics::IsDummy(*symbol))
return symbol;
return nullptr;
}
static mlir::Location
getProcedureDesignatorLoc(const Fortran::evaluate::ProcedureDesignator &proc,
Fortran::lower::AbstractConverter &converter) {
// Note: If the callee is defined in the same file but after the current
// unit we cannot get its location here and the funcOp is created at the
// wrong location (i.e, the caller location).
// To prevent this, it is up to the bridge to first declare all functions
// defined in the translation unit before lowering any calls or procedure
// designator references.
if (const Fortran::semantics::Symbol *symbol = proc.GetSymbol())
return converter.genLocation(symbol->name());
// Use current location for intrinsics.
return converter.getCurrentLocation();
}
mlir::Location Fortran::lower::CallerInterface::getCalleeLocation() const {
return getProcedureDesignatorLoc(procRef.proc(), converter);
}
// Get dummy argument characteristic for a procedure with implicit interface
// from the actual argument characteristic. The actual argument may not be a F77
// entity. The attribute must be dropped and the shape, if any, must be made
// explicit.
static Fortran::evaluate::characteristics::DummyDataObject
asImplicitArg(Fortran::evaluate::characteristics::DummyDataObject &&dummy) {
Fortran::evaluate::Shape shape =
dummy.type.attrs().none() ? dummy.type.shape()
: Fortran::evaluate::Shape(dummy.type.Rank());
return Fortran::evaluate::characteristics::DummyDataObject(
Fortran::evaluate::characteristics::TypeAndShape(dummy.type.type(),
std::move(shape)));
}
static Fortran::evaluate::characteristics::DummyArgument
asImplicitArg(Fortran::evaluate::characteristics::DummyArgument &&dummy) {
return std::visit(
Fortran::common::visitors{
[&](Fortran::evaluate::characteristics::DummyDataObject &obj) {
return Fortran::evaluate::characteristics::DummyArgument(
std::move(dummy.name), asImplicitArg(std::move(obj)));
},
[&](Fortran::evaluate::characteristics::DummyProcedure &proc) {
return Fortran::evaluate::characteristics::DummyArgument(
std::move(dummy.name), std::move(proc));
},
[](Fortran::evaluate::characteristics::AlternateReturn &x) {
return Fortran::evaluate::characteristics::DummyArgument(
std::move(x));
}},
dummy.u);
}
static bool isExternalDefinedInSameCompilationUnit(
const Fortran::evaluate::ProcedureDesignator &proc) {
if (const auto *symbol{proc.GetSymbol()})
return symbol->has<Fortran::semantics::SubprogramDetails>() &&
symbol->owner().IsGlobal();
return false;
}
Fortran::evaluate::characteristics::Procedure
Fortran::lower::CallerInterface::characterize() const {
Fortran::evaluate::FoldingContext &foldingContext =
converter.getFoldingContext();
std::optional<Fortran::evaluate::characteristics::Procedure> characteristic =
Fortran::evaluate::characteristics::Procedure::Characterize(
procRef.proc(), foldingContext);
assert(characteristic && "Failed to get characteristic from procRef");
// The characteristic may not contain the argument characteristic if the
// ProcedureDesignator has no interface, or may mismatch in case of implicit
// interface.
if (!characteristic->HasExplicitInterface() ||
(converter.getLoweringOptions().getLowerToHighLevelFIR() &&
isExternalDefinedInSameCompilationUnit(procRef.proc()) &&
characteristic->CanBeCalledViaImplicitInterface())) {
// In HLFIR lowering, calls to subprogram with implicit interfaces are
// always prepared according to the actual arguments. This is to support
// cases where the implicit interfaces are "abused" in old and not so old
// Fortran code (e.g, passing REAL(8) to CHARACTER(8), passing object
// pointers to procedure dummies, passing regular procedure dummies to
// character procedure dummies, omitted arguments....).
// In all those case, if the subprogram definition is in the same
// compilation unit, the "characteristic" from Characterize will be the one
// from the definition, in case of "abuses" (for which semantics raise a
// warning), lowering will be placed in a difficult position if it is given
// the dummy characteristic from the definition and an actual that has
// seemingly nothing to do with it: it would need to battle to anticipate
// and handle these mismatches (e.g., be able to prepare a fir.boxchar<>
// from a fir.real<> and so one). This was the approach of the lowering to
// FIR, and usually lead to compiler bug every time a new "abuse" was met in
// the wild.
// Instead, in HLFIR, the dummy characteristic is always computed from the
// actual for subprogram with implicit interfaces, and in case of call site
// vs fun.func MLIR function type signature mismatch, a function cast is
// done before placing the call. This is a hammer that should cover all
// cases and behave like existing compiler that "do not see" the definition
// when placing the call.
characteristic->dummyArguments.clear();
for (const std::optional<Fortran::evaluate::ActualArgument> &arg :
procRef.arguments()) {
// "arg" may be null if this is a call with missing arguments compared
// to the subprogram definition. Do not compute any characteristic
// in this case.
if (arg.has_value()) {
if (arg.value().isAlternateReturn()) {
characteristic->dummyArguments.emplace_back(
Fortran::evaluate::characteristics::AlternateReturn{});
} else {
// Argument cannot be optional with implicit interface
const Fortran::lower::SomeExpr *expr = arg.value().UnwrapExpr();
assert(expr && "argument in call with implicit interface cannot be "
"assumed type");
std::optional<Fortran::evaluate::characteristics::DummyArgument>
argCharacteristic =
Fortran::evaluate::characteristics::DummyArgument::FromActual(
"actual", *expr, foldingContext,
/*forImplicitInterface=*/true);
assert(argCharacteristic &&
"failed to characterize argument in implicit call");
characteristic->dummyArguments.emplace_back(
asImplicitArg(std::move(*argCharacteristic)));
}
}
}
}
return *characteristic;
}
void Fortran::lower::CallerInterface::placeInput(
const PassedEntity &passedEntity, mlir::Value arg) {
assert(static_cast<int>(actualInputs.size()) > passedEntity.firArgument &&
passedEntity.firArgument >= 0 &&
passedEntity.passBy != CallInterface::PassEntityBy::AddressAndLength &&
"bad arg position");
actualInputs[passedEntity.firArgument] = arg;
}
void Fortran::lower::CallerInterface::placeAddressAndLengthInput(
const PassedEntity &passedEntity, mlir::Value addr, mlir::Value len) {
assert(static_cast<int>(actualInputs.size()) > passedEntity.firArgument &&
static_cast<int>(actualInputs.size()) > passedEntity.firLength &&
passedEntity.firArgument >= 0 && passedEntity.firLength >= 0 &&
passedEntity.passBy == CallInterface::PassEntityBy::AddressAndLength &&
"bad arg position");
actualInputs[passedEntity.firArgument] = addr;
actualInputs[passedEntity.firLength] = len;
}
bool Fortran::lower::CallerInterface::verifyActualInputs() const {
if (getNumFIRArguments() != actualInputs.size())
return false;
for (mlir::Value arg : actualInputs) {
if (!arg)
return false;
}
return true;
}
void Fortran::lower::CallerInterface::walkResultLengths(
ExprVisitor visitor) const {
assert(characteristic && "characteristic was not computed");
const Fortran::evaluate::characteristics::FunctionResult &result =
characteristic->functionResult.value();
const Fortran::evaluate::characteristics::TypeAndShape *typeAndShape =
result.GetTypeAndShape();
assert(typeAndShape && "no result type");
Fortran::evaluate::DynamicType dynamicType = typeAndShape->type();
// Visit result length specification expressions that are explicit.
if (dynamicType.category() == Fortran::common::TypeCategory::Character) {
if (std::optional<Fortran::evaluate::ExtentExpr> length =
dynamicType.GetCharLength())
visitor(toEvExpr(*length));
} else if (dynamicType.category() == common::TypeCategory::Derived &&
!dynamicType.IsUnlimitedPolymorphic()) {
const Fortran::semantics::DerivedTypeSpec &derivedTypeSpec =
dynamicType.GetDerivedTypeSpec();
if (Fortran::semantics::CountLenParameters(derivedTypeSpec) > 0)
TODO(converter.getCurrentLocation(),
"function result with derived type length parameters");
}
}
// Compute extent expr from shapeSpec of an explicit shape.
// TODO: Allow evaluate shape analysis to work in a mode where it disregards
// the non-constant aspects when building the shape to avoid having this here.
static Fortran::evaluate::ExtentExpr
getExtentExpr(const Fortran::semantics::ShapeSpec &shapeSpec) {
const auto &ubound = shapeSpec.ubound().GetExplicit();
const auto &lbound = shapeSpec.lbound().GetExplicit();
assert(lbound && ubound && "shape must be explicit");
return Fortran::common::Clone(*ubound) - Fortran::common::Clone(*lbound) +
Fortran::evaluate::ExtentExpr{1};
}
void Fortran::lower::CallerInterface::walkResultExtents(
ExprVisitor visitor) const {
// Walk directly the result symbol shape (the characteristic shape may contain
// descriptor inquiries to it that would fail to lower on the caller side).
const Fortran::semantics::SubprogramDetails *interfaceDetails =
getInterfaceDetails();
if (interfaceDetails) {
const Fortran::semantics::Symbol &result = interfaceDetails->result();
if (const auto *objectDetails =
result.detailsIf<Fortran::semantics::ObjectEntityDetails>())
if (objectDetails->shape().IsExplicitShape())
for (const Fortran::semantics::ShapeSpec &shapeSpec :
objectDetails->shape())
visitor(Fortran::evaluate::AsGenericExpr(getExtentExpr(shapeSpec)));
} else {
if (procRef.Rank() != 0)
fir::emitFatalError(
converter.getCurrentLocation(),
"only scalar functions may not have an interface symbol");
}
}
bool Fortran::lower::CallerInterface::mustMapInterfaceSymbols() const {
assert(characteristic && "characteristic was not computed");
const std::optional<Fortran::evaluate::characteristics::FunctionResult>
&result = characteristic->functionResult;
if (!result || result->CanBeReturnedViaImplicitInterface() ||
!getInterfaceDetails())
return false;
bool allResultSpecExprConstant = true;
auto visitor = [&](const Fortran::lower::SomeExpr &e) {
allResultSpecExprConstant &= Fortran::evaluate::IsConstantExpr(e);
};
walkResultLengths(visitor);
walkResultExtents(visitor);
return !allResultSpecExprConstant;
}
mlir::Value Fortran::lower::CallerInterface::getArgumentValue(
const semantics::Symbol &sym) const {
mlir::Location loc = converter.getCurrentLocation();
const Fortran::semantics::SubprogramDetails *ifaceDetails =
getInterfaceDetails();
if (!ifaceDetails)
fir::emitFatalError(
loc, "mapping actual and dummy arguments requires an interface");
const std::vector<Fortran::semantics::Symbol *> &dummies =
ifaceDetails->dummyArgs();
auto it = std::find(dummies.begin(), dummies.end(), &sym);
if (it == dummies.end())
fir::emitFatalError(loc, "symbol is not a dummy in this call");
FirValue mlirArgIndex = passedArguments[it - dummies.begin()].firArgument;
return actualInputs[mlirArgIndex];
}
mlir::Type Fortran::lower::CallerInterface::getResultStorageType() const {
if (passedResult)
return fir::dyn_cast_ptrEleTy(inputs[passedResult->firArgument].type);
assert(saveResult && !outputs.empty());
return outputs[0].type;
}
const Fortran::semantics::Symbol &
Fortran::lower::CallerInterface::getResultSymbol() const {
mlir::Location loc = converter.getCurrentLocation();
const Fortran::semantics::SubprogramDetails *ifaceDetails =
getInterfaceDetails();
if (!ifaceDetails)
fir::emitFatalError(
loc, "mapping actual and dummy arguments requires an interface");
return ifaceDetails->result();
}
const Fortran::semantics::SubprogramDetails *
Fortran::lower::CallerInterface::getInterfaceDetails() const {
if (const Fortran::semantics::Symbol *iface =
procRef.proc().GetInterfaceSymbol())
return iface->GetUltimate()
.detailsIf<Fortran::semantics::SubprogramDetails>();
return nullptr;
}
//===----------------------------------------------------------------------===//
// Callee side interface implementation
//===----------------------------------------------------------------------===//
bool Fortran::lower::CalleeInterface::hasAlternateReturns() const {
return !funit.isMainProgram() &&
Fortran::semantics::HasAlternateReturns(funit.getSubprogramSymbol());
}
std::string Fortran::lower::CalleeInterface::getMangledName() const {
if (funit.isMainProgram())
return fir::NameUniquer::doProgramEntry().str();
return converter.mangleName(funit.getSubprogramSymbol());
}
const Fortran::semantics::Symbol *
Fortran::lower::CalleeInterface::getProcedureSymbol() const {
if (funit.isMainProgram())
return funit.getMainProgramSymbol();
return &funit.getSubprogramSymbol();
}
mlir::Location Fortran::lower::CalleeInterface::getCalleeLocation() const {
// FIXME: do NOT use unknown for the anonymous PROGRAM case. We probably
// should just stash the location in the funit regardless.
return converter.genLocation(funit.getStartingSourceLoc());
}
Fortran::evaluate::characteristics::Procedure
Fortran::lower::CalleeInterface::characterize() const {
Fortran::evaluate::FoldingContext &foldingContext =
converter.getFoldingContext();
std::optional<Fortran::evaluate::characteristics::Procedure> characteristic =
Fortran::evaluate::characteristics::Procedure::Characterize(
funit.getSubprogramSymbol(), foldingContext);
assert(characteristic && "Fail to get characteristic from symbol");
return *characteristic;
}
bool Fortran::lower::CalleeInterface::isMainProgram() const {
return funit.isMainProgram();
}
mlir::func::FuncOp
Fortran::lower::CalleeInterface::addEntryBlockAndMapArguments() {
// Check for bugs in the front end. The front end must not present multiple
// definitions of the same procedure.
if (!func.getBlocks().empty())
fir::emitFatalError(func.getLoc(),
"cannot process subprogram that was already processed");
// On the callee side, directly map the mlir::value argument of the function
// block to the Fortran symbols.
func.addEntryBlock();
mapPassedEntities();
return func;
}
bool Fortran::lower::CalleeInterface::hasHostAssociated() const {
return funit.parentHasTupleHostAssoc();
}
mlir::Type Fortran::lower::CalleeInterface::getHostAssociatedTy() const {
assert(hasHostAssociated());
return funit.parentHostAssoc().getArgumentType(converter);
}
mlir::Value Fortran::lower::CalleeInterface::getHostAssociatedTuple() const {
assert(hasHostAssociated() || !funit.getHostAssoc().empty());
return converter.hostAssocTupleValue();
}
void Fortran::lower::CalleeInterface::setFuncAttrs(
mlir::func::FuncOp func) const {
if (funit.parentHasHostAssoc())
func->setAttr(fir::getInternalProcedureAttrName(),
mlir::UnitAttr::get(func->getContext()));
}
//===----------------------------------------------------------------------===//
// CallInterface implementation: this part is common to both caller and callee.
//===----------------------------------------------------------------------===//
static void addSymbolAttribute(mlir::func::FuncOp func,
const Fortran::semantics::Symbol &sym,
mlir::MLIRContext &mlirContext) {
// Only add this on bind(C) functions for which the symbol is not reflected in
// the current context.
if (!Fortran::semantics::IsBindCProcedure(sym))
return;
std::string name =
Fortran::lower::mangle::mangleName(sym, /*keepExternalInScope=*/true);
func->setAttr(fir::getSymbolAttrName(),
mlir::StringAttr::get(&mlirContext, name));
}
/// Declare drives the different actions to be performed while analyzing the
/// signature and building/finding the mlir::func::FuncOp.
template <typename T>
void Fortran::lower::CallInterface<T>::declare() {
if (!side().isMainProgram()) {
characteristic.emplace(side().characterize());
bool isImplicit = characteristic->CanBeCalledViaImplicitInterface();
determineInterface(isImplicit, *characteristic);
}
// No input/output for main program
// Create / get funcOp for direct calls. For indirect calls (only meaningful
// on the caller side), no funcOp has to be created here. The mlir::Value
// holding the indirection is used when creating the fir::CallOp.
if (!side().isIndirectCall()) {
std::string name = side().getMangledName();
mlir::ModuleOp module = converter.getModuleOp();
func = fir::FirOpBuilder::getNamedFunction(module, name);
if (!func) {
mlir::Location loc = side().getCalleeLocation();
mlir::FunctionType ty = genFunctionType();
func = fir::FirOpBuilder::createFunction(loc, module, name, ty);
if (const Fortran::semantics::Symbol *sym = side().getProcedureSymbol()) {
if (side().isMainProgram()) {
func->setAttr(fir::getSymbolAttrName(),
mlir::StringAttr::get(&converter.getMLIRContext(),
sym->name().ToString()));
} else {
addSymbolAttribute(func, *sym, converter.getMLIRContext());
}
}
for (const auto &placeHolder : llvm::enumerate(inputs))
if (!placeHolder.value().attributes.empty())
func.setArgAttrs(placeHolder.index(), placeHolder.value().attributes);
side().setFuncAttrs(func);
}
}
}
/// Once the signature has been analyzed and the mlir::func::FuncOp was
/// built/found, map the fir inputs to Fortran entities (the symbols or
/// expressions).
template <typename T>
void Fortran::lower::CallInterface<T>::mapPassedEntities() {
// map back fir inputs to passed entities
if constexpr (std::is_same_v<T, Fortran::lower::CalleeInterface>) {
assert(inputs.size() == func.front().getArguments().size() &&
"function previously created with different number of arguments");
for (auto [fst, snd] : llvm::zip(inputs, func.front().getArguments()))
mapBackInputToPassedEntity(fst, snd);
} else {
// On the caller side, map the index of the mlir argument position
// to Fortran ActualArguments.
int firPosition = 0;
for (const FirPlaceHolder &placeHolder : inputs)
mapBackInputToPassedEntity(placeHolder, firPosition++);
}
}
template <typename T>
void Fortran::lower::CallInterface<T>::mapBackInputToPassedEntity(
const FirPlaceHolder &placeHolder, FirValue firValue) {
PassedEntity &passedEntity =
placeHolder.passedEntityPosition == FirPlaceHolder::resultEntityPosition
? passedResult.value()
: passedArguments[placeHolder.passedEntityPosition];
if (placeHolder.property == Property::CharLength)
passedEntity.firLength = firValue;
else
passedEntity.firArgument = firValue;
}
/// Helpers to access ActualArgument/Symbols
static const Fortran::evaluate::ActualArguments &
getEntityContainer(const Fortran::evaluate::ProcedureRef &proc) {
return proc.arguments();
}
static const std::vector<Fortran::semantics::Symbol *> &
getEntityContainer(Fortran::lower::pft::FunctionLikeUnit &funit) {
return funit.getSubprogramSymbol()
.get<Fortran::semantics::SubprogramDetails>()
.dummyArgs();
}
static const Fortran::evaluate::ActualArgument *getDataObjectEntity(
const std::optional<Fortran::evaluate::ActualArgument> &arg) {
if (arg)
return &*arg;
return nullptr;
}
static const Fortran::semantics::Symbol &
getDataObjectEntity(const Fortran::semantics::Symbol *arg) {
assert(arg && "expect symbol for data object entity");
return *arg;
}
static const Fortran::evaluate::ActualArgument *
getResultEntity(const Fortran::evaluate::ProcedureRef &) {
return nullptr;
}
static const Fortran::semantics::Symbol &
getResultEntity(Fortran::lower::pft::FunctionLikeUnit &funit) {
return funit.getSubprogramSymbol()
.get<Fortran::semantics::SubprogramDetails>()
.result();
}
/// Bypass helpers to manipulate entities since they are not any symbol/actual
/// argument to associate. See SignatureBuilder below.
using FakeEntity = bool;
using FakeEntities = llvm::SmallVector<FakeEntity>;
static FakeEntities
getEntityContainer(const Fortran::evaluate::characteristics::Procedure &proc) {
FakeEntities enities(proc.dummyArguments.size());
return enities;
}
static const FakeEntity &getDataObjectEntity(const FakeEntity &e) { return e; }
static FakeEntity
getResultEntity(const Fortran::evaluate::characteristics::Procedure &proc) {
return false;
}
/// This is the actual part that defines the FIR interface based on the
/// characteristic. It directly mutates the CallInterface members.
template <typename T>
class Fortran::lower::CallInterfaceImpl {
using CallInterface = Fortran::lower::CallInterface<T>;
using PassEntityBy = typename CallInterface::PassEntityBy;
using PassedEntity = typename CallInterface::PassedEntity;
using FirValue = typename CallInterface::FirValue;
using FortranEntity = typename CallInterface::FortranEntity;
using FirPlaceHolder = typename CallInterface::FirPlaceHolder;
using Property = typename CallInterface::Property;
using TypeAndShape = Fortran::evaluate::characteristics::TypeAndShape;
using DummyCharacteristics =
Fortran::evaluate::characteristics::DummyArgument;
public:
CallInterfaceImpl(CallInterface &i)
: interface(i), mlirContext{i.converter.getMLIRContext()} {}
void buildImplicitInterface(
const Fortran::evaluate::characteristics::Procedure &procedure) {
// Handle result
if (const std::optional<Fortran::evaluate::characteristics::FunctionResult>
&result = procedure.functionResult)
handleImplicitResult(*result, procedure.IsBindC());
else if (interface.side().hasAlternateReturns())
addFirResult(mlir::IndexType::get(&mlirContext),
FirPlaceHolder::resultEntityPosition, Property::Value);
// Handle arguments
const auto &argumentEntities =
getEntityContainer(interface.side().getCallDescription());
for (auto pair : llvm::zip(procedure.dummyArguments, argumentEntities)) {
const Fortran::evaluate::characteristics::DummyArgument
&argCharacteristics = std::get<0>(pair);
std::visit(
Fortran::common::visitors{
[&](const auto &dummy) {
const auto &entity = getDataObjectEntity(std::get<1>(pair));
handleImplicitDummy(&argCharacteristics, dummy, entity);
},
[&](const Fortran::evaluate::characteristics::AlternateReturn &) {
// nothing to do
},
},
argCharacteristics.u);
}
}
void buildExplicitInterface(
const Fortran::evaluate::characteristics::Procedure &procedure) {
bool isBindC = procedure.IsBindC();
// Handle result
if (const std::optional<Fortran::evaluate::characteristics::FunctionResult>
&result = procedure.functionResult) {
if (result->CanBeReturnedViaImplicitInterface())
handleImplicitResult(*result, isBindC);
else
handleExplicitResult(*result);
} else if (interface.side().hasAlternateReturns()) {
addFirResult(mlir::IndexType::get(&mlirContext),
FirPlaceHolder::resultEntityPosition, Property::Value);
}
// Handle arguments
const auto &argumentEntities =
getEntityContainer(interface.side().getCallDescription());
for (auto pair : llvm::zip(procedure.dummyArguments, argumentEntities)) {
const Fortran::evaluate::characteristics::DummyArgument
&argCharacteristics = std::get<0>(pair);
std::visit(
Fortran::common::visitors{
[&](const Fortran::evaluate::characteristics::DummyDataObject
&dummy) {
const auto &entity = getDataObjectEntity(std::get<1>(pair));
if (!isBindC && dummy.CanBePassedViaImplicitInterface())
handleImplicitDummy(&argCharacteristics, dummy, entity);
else
handleExplicitDummy(&argCharacteristics, dummy, entity,
isBindC);
},
[&](const Fortran::evaluate::characteristics::DummyProcedure
&dummy) {
const auto &entity = getDataObjectEntity(std::get<1>(pair));
handleImplicitDummy(&argCharacteristics, dummy, entity);
},
[&](const Fortran::evaluate::characteristics::AlternateReturn &) {
// nothing to do
},
},
argCharacteristics.u);
}
}
void appendHostAssocTupleArg(mlir::Type tupTy) {
mlir::MLIRContext *ctxt = tupTy.getContext();
addFirOperand(tupTy, nextPassedArgPosition(), Property::BaseAddress,
{mlir::NamedAttribute{
mlir::StringAttr::get(ctxt, fir::getHostAssocAttrName()),
mlir::UnitAttr::get(ctxt)}});
interface.passedArguments.emplace_back(
PassedEntity{PassEntityBy::BaseAddress, std::nullopt,
interface.side().getHostAssociatedTuple(), emptyValue()});
}
static std::optional<Fortran::evaluate::DynamicType> getResultDynamicType(
const Fortran::evaluate::characteristics::Procedure &procedure) {
if (const std::optional<Fortran::evaluate::characteristics::FunctionResult>
&result = procedure.functionResult)
if (const auto *resultTypeAndShape = result->GetTypeAndShape())
return resultTypeAndShape->type();
return std::nullopt;
}
static bool mustPassLengthWithDummyProcedure(
const Fortran::evaluate::characteristics::Procedure &procedure) {
// When passing a character function designator `bar` as dummy procedure to
// `foo` (e.g. `foo(bar)`), pass the result length of `bar` to `foo` so that
// `bar` can be called inside `foo` even if its length is assumed there.
// From an ABI perspective, the extra length argument must be handled
// exactly as if passing a character object. Using an argument of
// fir.boxchar type gives the expected behavior: after codegen, the
// fir.boxchar lengths are added after all the arguments as extra value
// arguments (the extra arguments order is the order of the fir.boxchar).
// This ABI is compatible with ifort, nag, nvfortran, and xlf, but not
// gfortran. Gfortran does not pass the length and is therefore unable to
// handle later call to `bar` in `foo` where the length would be assumed. If
// the result is an array, nag and ifort and xlf still pass the length, but
// not nvfortran (and gfortran). It is not clear it is possible to call an
// array function with assumed length (f18 forbides defining such
// interfaces). Hence, passing the length is most likely useless, but stick
// with ifort/nag/xlf interface here.
if (std::optional<Fortran::evaluate::DynamicType> type =
getResultDynamicType(procedure))
return type->category() == Fortran::common::TypeCategory::Character;
return false;
}
private:
void handleImplicitResult(
const Fortran::evaluate::characteristics::FunctionResult &result,
bool isBindC) {
if (result.IsProcedurePointer())
TODO(interface.converter.getCurrentLocation(),
"procedure pointer result not yet handled");
const Fortran::evaluate::characteristics::TypeAndShape *typeAndShape =
result.GetTypeAndShape();
assert(typeAndShape && "expect type for non proc pointer result");
Fortran::evaluate::DynamicType dynamicType = typeAndShape->type();
// Character result allocated by caller and passed as hidden arguments
if (dynamicType.category() == Fortran::common::TypeCategory::Character) {
if (isBindC) {
mlir::Type mlirType = translateDynamicType(dynamicType);
addFirResult(mlirType, FirPlaceHolder::resultEntityPosition,
Property::Value);
} else {
handleImplicitCharacterResult(dynamicType);
}
} else if (dynamicType.category() ==
Fortran::common::TypeCategory::Derived) {
if (!dynamicType.GetDerivedTypeSpec().IsVectorType()) {
// Derived result need to be allocated by the caller and the result
// value must be saved. Derived type in implicit interface cannot have
// length parameters.
setSaveResult();
}
mlir::Type mlirType = translateDynamicType(dynamicType);
addFirResult(mlirType, FirPlaceHolder::resultEntityPosition,
Property::Value);
} else {
// All result other than characters/derived are simply returned by value
// in implicit interfaces
mlir::Type mlirType =
getConverter().genType(dynamicType.category(), dynamicType.kind());
addFirResult(mlirType, FirPlaceHolder::resultEntityPosition,
Property::Value);
}
}
void
handleImplicitCharacterResult(const Fortran::evaluate::DynamicType &type) {
int resultPosition = FirPlaceHolder::resultEntityPosition;
setPassedResult(PassEntityBy::AddressAndLength,
getResultEntity(interface.side().getCallDescription()));
mlir::Type lenTy = mlir::IndexType::get(&mlirContext);
std::optional<std::int64_t> constantLen = type.knownLength();
fir::CharacterType::LenType len =
constantLen ? *constantLen : fir::CharacterType::unknownLen();
mlir::Type charRefTy = fir::ReferenceType::get(
fir::CharacterType::get(&mlirContext, type.kind(), len));
mlir::Type boxCharTy = fir::BoxCharType::get(&mlirContext, type.kind());
addFirOperand(charRefTy, resultPosition, Property::CharAddress);
addFirOperand(lenTy, resultPosition, Property::CharLength);
/// For now, also return it by boxchar
addFirResult(boxCharTy, resultPosition, Property::BoxChar);
}
/// Return a vector with an attribute with the name of the argument if this
/// is a callee interface and the name is available. Otherwise, just return
/// an empty vector.
llvm::SmallVector<mlir::NamedAttribute>
dummyNameAttr(const FortranEntity &entity) {
if constexpr (std::is_same_v<FortranEntity,
std::optional<Fortran::common::Reference<
const Fortran::semantics::Symbol>>>) {
if (entity.has_value()) {
const Fortran::semantics::Symbol *argument = &*entity.value();
// "fir.bindc_name" is used for arguments for the sake of consistency
// with other attributes carrying surface syntax names in FIR.
return {mlir::NamedAttribute(
mlir::StringAttr::get(&mlirContext, "fir.bindc_name"),
mlir::StringAttr::get(&mlirContext,
toStringRef(argument->name())))};
}
}
return {};
}
mlir::Type
getRefType(Fortran::evaluate::DynamicType dynamicType,
const Fortran::evaluate::characteristics::DummyDataObject &obj) {
mlir::Type type = translateDynamicType(dynamicType);
fir::SequenceType::Shape bounds = getBounds(obj.type.shape());
if (!bounds.empty())
type = fir::SequenceType::get(bounds, type);
return fir::ReferenceType::get(type);
}
void handleImplicitDummy(
const DummyCharacteristics *characteristics,
const Fortran::evaluate::characteristics::DummyDataObject &obj,
const FortranEntity &entity) {
Fortran::evaluate::DynamicType dynamicType = obj.type.type();
if constexpr (std::is_same_v<FortranEntity,
const Fortran::evaluate::ActualArgument *>) {
if (entity) {
if (entity->isPercentVal()) {
mlir::Type type = translateDynamicType(dynamicType);
addFirOperand(type, nextPassedArgPosition(), Property::Value,
dummyNameAttr(entity));
addPassedArg(PassEntityBy::Value, entity, characteristics);
return;
}
if (entity->isPercentRef()) {
mlir::Type refType = getRefType(dynamicType, obj);
addFirOperand(refType, nextPassedArgPosition(), Property::BaseAddress,
dummyNameAttr(entity));
addPassedArg(PassEntityBy::BaseAddress, entity, characteristics);
return;
}
}
}
if (dynamicType.category() == Fortran::common::TypeCategory::Character) {
mlir::Type boxCharTy =
fir::BoxCharType::get(&mlirContext, dynamicType.kind());
addFirOperand(boxCharTy, nextPassedArgPosition(), Property::BoxChar,
dummyNameAttr(entity));
addPassedArg(PassEntityBy::BoxChar, entity, characteristics);
} else {
// non-PDT derived type allowed in implicit interface.
mlir::Type refType = getRefType(dynamicType, obj);
addFirOperand(refType, nextPassedArgPosition(), Property::BaseAddress,
dummyNameAttr(entity));
addPassedArg(PassEntityBy::BaseAddress, entity, characteristics);
}
}
// Define when an explicit argument must be passed in a fir.box.
bool dummyRequiresBox(
const Fortran::evaluate::characteristics::DummyDataObject &obj,
bool isBindC) {
using ShapeAttr = Fortran::evaluate::characteristics::TypeAndShape::Attr;
using ShapeAttrs = Fortran::evaluate::characteristics::TypeAndShape::Attrs;
constexpr ShapeAttrs shapeRequiringBox = {
ShapeAttr::AssumedShape, ShapeAttr::DeferredShape,
ShapeAttr::AssumedRank, ShapeAttr::Coarray};
if ((obj.type.attrs() & shapeRequiringBox).any())
// Need to pass shape/coshape info in fir.box.
return true;
if (obj.type.type().IsPolymorphic() && !obj.type.type().IsAssumedType())
// Need to pass dynamic type info in fir.box.
return true;
if (const Fortran::semantics::DerivedTypeSpec *derived =
Fortran::evaluate::GetDerivedTypeSpec(obj.type.type()))
if (const Fortran::semantics::Scope *scope = derived->scope())
// Need to pass length type parameters in fir.box if any.
return scope->IsDerivedTypeWithLengthParameter();
if (isBindC && obj.type.type().IsAssumedLengthCharacter())
return true; // Fortran 2018 18.3.6 point 2 (5)
return false;
}
mlir::Type
translateDynamicType(const Fortran::evaluate::DynamicType &dynamicType) {
Fortran::common::TypeCategory cat = dynamicType.category();
// DERIVED
if (cat == Fortran::common::TypeCategory::Derived) {
// TODO is kept under experimental flag until feature is complete.
if (dynamicType.IsPolymorphic() &&
!getConverter().getLoweringOptions().getPolymorphicTypeImpl())
TODO(interface.converter.getCurrentLocation(),
"support for polymorphic types");
if (dynamicType.IsUnlimitedPolymorphic())
return mlir::NoneType::get(&mlirContext);
return getConverter().genType(dynamicType.GetDerivedTypeSpec());
}
// CHARACTER with compile time constant length.
if (cat == Fortran::common::TypeCategory::Character)
if (std::optional<std::int64_t> constantLen =
toInt64(dynamicType.GetCharLength()))
return getConverter().genType(cat, dynamicType.kind(), {*constantLen});
// INTEGER, REAL, LOGICAL, COMPLEX, and CHARACTER with dynamic length.
return getConverter().genType(cat, dynamicType.kind());
}
void handleExplicitDummy(
const DummyCharacteristics *characteristics,
const Fortran::evaluate::characteristics::DummyDataObject &obj,
const FortranEntity &entity, bool isBindC) {
using Attrs = Fortran::evaluate::characteristics::DummyDataObject::Attr;
bool isValueAttr = false;
[[maybe_unused]] mlir::Location loc =
interface.converter.getCurrentLocation();
llvm::SmallVector<mlir::NamedAttribute> attrs = dummyNameAttr(entity);
auto addMLIRAttr = [&](llvm::StringRef attr) {
attrs.emplace_back(mlir::StringAttr::get(&mlirContext, attr),
mlir::UnitAttr::get(&mlirContext));
};
if (obj.attrs.test(Attrs::Optional))
addMLIRAttr(fir::getOptionalAttrName());
if (obj.attrs.test(Attrs::Asynchronous))
TODO(loc, "ASYNCHRONOUS in procedure interface");
if (obj.attrs.test(Attrs::Contiguous))
addMLIRAttr(fir::getContiguousAttrName());
if (obj.attrs.test(Attrs::Value))
isValueAttr = true; // TODO: do we want an mlir::Attribute as well?
if (obj.attrs.test(Attrs::Volatile))
TODO(loc, "VOLATILE in procedure interface");
if (obj.attrs.test(Attrs::Target))
addMLIRAttr(fir::getTargetAttrName());
// TODO: intents that require special care (e.g finalization)
using ShapeAttr = Fortran::evaluate::characteristics::TypeAndShape::Attr;
const Fortran::evaluate::characteristics::TypeAndShape::Attrs &shapeAttrs =
obj.type.attrs();
if (shapeAttrs.test(ShapeAttr::AssumedRank))
TODO(loc, "assumed rank in procedure interface");
if (shapeAttrs.test(ShapeAttr::Coarray))
TODO(loc, "coarray: dummy argument coarray in procedure interface");
// So far assume that if the argument cannot be passed by implicit interface
// it must be by box. That may no be always true (e.g for simple optionals)
Fortran::evaluate::DynamicType dynamicType = obj.type.type();
mlir::Type type = translateDynamicType(dynamicType);
fir::SequenceType::Shape bounds = getBounds(obj.type.shape());
if (!bounds.empty())
type = fir::SequenceType::get(bounds, type);
if (obj.attrs.test(Attrs::Allocatable))
type = fir::HeapType::get(type);
if (obj.attrs.test(Attrs::Pointer))
type = fir::PointerType::get(type);
mlir::Type boxType = fir::wrapInClassOrBoxType(
type, obj.type.type().IsPolymorphic(), obj.type.type().IsAssumedType());
if (obj.attrs.test(Attrs::Allocatable) || obj.attrs.test(Attrs::Pointer)) {
// Pass as fir.ref<fir.box> or fir.ref<fir.class>
mlir::Type boxRefType = fir::ReferenceType::get(boxType);
addFirOperand(boxRefType, nextPassedArgPosition(), Property::MutableBox,
attrs);
addPassedArg(PassEntityBy::MutableBox, entity, characteristics);
} else if (dummyRequiresBox(obj, isBindC)) {
// Pass as fir.box or fir.class
if (isValueAttr &&
!getConverter().getLoweringOptions().getLowerToHighLevelFIR())
TODO(loc, "assumed shape dummy argument with VALUE attribute");
addFirOperand(boxType, nextPassedArgPosition(), Property::Box, attrs);
addPassedArg(PassEntityBy::Box, entity, characteristics);
} else if (dynamicType.category() ==
Fortran::common::TypeCategory::Character) {
// Pass as fir.box_char
mlir::Type boxCharTy =
fir::BoxCharType::get(&mlirContext, dynamicType.kind());
addFirOperand(boxCharTy, nextPassedArgPosition(), Property::BoxChar,
attrs);
addPassedArg(isValueAttr ? PassEntityBy::CharBoxValueAttribute
: PassEntityBy::BoxChar,
entity, characteristics);
} else {
// Pass as fir.ref unless it's by VALUE and BIND(C). Also pass-by-value
// for numerical/logical scalar without OPTIONAL so that the behavior is
// consistent with gfortran/nvfortran.
// TODO: pass-by-value for derived type is not supported yet
mlir::Type passType = fir::ReferenceType::get(type);
PassEntityBy passBy = PassEntityBy::BaseAddress;
Property prop = Property::BaseAddress;
if (isValueAttr) {
bool isBuiltinCptrType = fir::isa_builtin_cptr_type(type);
if (isBindC || (!type.isa<fir::SequenceType>() &&
!obj.attrs.test(Attrs::Optional) &&
(dynamicType.category() !=
Fortran::common::TypeCategory::Derived ||
isBuiltinCptrType))) {
passBy = PassEntityBy::Value;
prop = Property::Value;
if (isBuiltinCptrType) {
auto recTy = type.dyn_cast<fir::RecordType>();
mlir::Type fieldTy = recTy.getTypeList()[0].second;
passType = fir::ReferenceType::get(fieldTy);
} else {
passType = type;
}
} else {
passBy = PassEntityBy::BaseAddressValueAttribute;
}
}
addFirOperand(passType, nextPassedArgPosition(), prop, attrs);
addPassedArg(passBy, entity, characteristics);
}
}
void handleImplicitDummy(
const DummyCharacteristics *characteristics,
const Fortran::evaluate::characteristics::DummyProcedure &proc,
const FortranEntity &entity) {
if (!interface.converter.getLoweringOptions().getLowerToHighLevelFIR() &&
proc.attrs.test(
Fortran::evaluate::characteristics::DummyProcedure::Attr::Pointer))
TODO(interface.converter.getCurrentLocation(),
"procedure pointer arguments");
const Fortran::evaluate::characteristics::Procedure &procedure =
proc.procedure.value();
mlir::Type funcType =
getProcedureDesignatorType(&procedure, interface.converter);
if (proc.attrs.test(Fortran::evaluate::characteristics::DummyProcedure::
Attr::Pointer)) {
// Prodecure pointer dummy argument.
funcType = fir::ReferenceType::get(funcType);
addFirOperand(funcType, nextPassedArgPosition(), Property::BoxProcRef);
addPassedArg(PassEntityBy::BoxProcRef, entity, characteristics);
return;
}
// Otherwise, it is a dummy procedure.
std::optional<Fortran::evaluate::DynamicType> resultTy =
getResultDynamicType(procedure);
if (resultTy && mustPassLengthWithDummyProcedure(procedure)) {
// The result length of dummy procedures that are character functions must
// be passed so that the dummy procedure can be called if it has assumed
// length on the callee side.
mlir::Type tupleType =
fir::factory::getCharacterProcedureTupleType(funcType);
llvm::StringRef charProcAttr = fir::getCharacterProcedureDummyAttrName();
addFirOperand(tupleType, nextPassedArgPosition(), Property::CharProcTuple,
{mlir::NamedAttribute{
mlir::StringAttr::get(&mlirContext, charProcAttr),
mlir::UnitAttr::get(&mlirContext)}});
addPassedArg(PassEntityBy::CharProcTuple, entity, characteristics);
return;
}
addFirOperand(funcType, nextPassedArgPosition(), Property::BaseAddress);
addPassedArg(PassEntityBy::BaseAddress, entity, characteristics);
}
void handleExplicitResult(
const Fortran::evaluate::characteristics::FunctionResult &result) {
using Attr = Fortran::evaluate::characteristics::FunctionResult::Attr;
mlir::Type mlirType;
if (auto proc{result.IsProcedurePointer()})
mlirType = fir::BoxProcType::get(
&mlirContext, getProcedureType(*proc, interface.converter));
else {
const Fortran::evaluate::characteristics::TypeAndShape *typeAndShape =
result.GetTypeAndShape();
assert(typeAndShape && "expect type for non proc pointer result");
mlirType = translateDynamicType(typeAndShape->type());
fir::SequenceType::Shape bounds = getBounds(typeAndShape->shape());
const auto *resTypeAndShape{result.GetTypeAndShape()};
bool resIsPolymorphic =
resTypeAndShape && resTypeAndShape->type().IsPolymorphic();
bool resIsAssumedType =
resTypeAndShape && resTypeAndShape->type().IsAssumedType();
if (!bounds.empty())
mlirType = fir::SequenceType::get(bounds, mlirType);
if (result.attrs.test(Attr::Allocatable))
mlirType = fir::wrapInClassOrBoxType(
fir::HeapType::get(mlirType), resIsPolymorphic, resIsAssumedType);
if (result.attrs.test(Attr::Pointer))
mlirType =
fir::wrapInClassOrBoxType(fir::PointerType::get(mlirType),
resIsPolymorphic, resIsAssumedType);
if (fir::isa_char(mlirType)) {
// Character scalar results must be passed as arguments in lowering so
// that an assumed length character function callee can access the
// result length. A function with a result requiring an explicit
// interface does not have to be compatible with assumed length
// function, but most compilers supports it.
handleImplicitCharacterResult(typeAndShape->type());
return;
}
}
addFirResult(mlirType, FirPlaceHolder::resultEntityPosition,
Property::Value);
// Explicit results require the caller to allocate the storage and save the
// function result in the storage with a fir.save_result.
setSaveResult();
}
fir::SequenceType::Shape getBounds(const Fortran::evaluate::Shape &shape) {
fir::SequenceType::Shape bounds;
for (const std::optional<Fortran::evaluate::ExtentExpr> &extent : shape) {
fir::SequenceType::Extent bound = fir::SequenceType::getUnknownExtent();
if (std::optional<std::int64_t> i = toInt64(extent))
bound = *i;
bounds.emplace_back(bound);
}
return bounds;
}
std::optional<std::int64_t>
toInt64(std::optional<
Fortran::evaluate::Expr<Fortran::evaluate::SubscriptInteger>>
expr) {
if (expr)
return Fortran::evaluate::ToInt64(Fortran::evaluate::Fold(
getConverter().getFoldingContext(), toEvExpr(*expr)));
return std::nullopt;
}
void addFirOperand(
mlir::Type type, int entityPosition, Property p,
llvm::ArrayRef<mlir::NamedAttribute> attributes = std::nullopt) {
interface.inputs.emplace_back(
FirPlaceHolder{type, entityPosition, p, attributes});
}
void
addFirResult(mlir::Type type, int entityPosition, Property p,
llvm::ArrayRef<mlir::NamedAttribute> attributes = std::nullopt) {
interface.outputs.emplace_back(
FirPlaceHolder{type, entityPosition, p, attributes});
}
void addPassedArg(PassEntityBy p, FortranEntity entity,
const DummyCharacteristics *characteristics) {
interface.passedArguments.emplace_back(
PassedEntity{p, entity, emptyValue(), emptyValue(), characteristics});
}
void setPassedResult(PassEntityBy p, FortranEntity entity) {
interface.passedResult =
PassedEntity{p, entity, emptyValue(), emptyValue()};
}
void setSaveResult() { interface.saveResult = true; }
int nextPassedArgPosition() { return interface.passedArguments.size(); }
static FirValue emptyValue() {
if constexpr (std::is_same_v<Fortran::lower::CalleeInterface, T>) {
return {};
} else {
return -1;
}
}
Fortran::lower::AbstractConverter &getConverter() {
return interface.converter;
}
CallInterface &interface;
mlir::MLIRContext &mlirContext;
};
template <typename T>
bool Fortran::lower::CallInterface<T>::PassedEntity::isOptional() const {
if (!characteristics)
return false;
return characteristics->IsOptional();
}
template <typename T>
bool Fortran::lower::CallInterface<T>::PassedEntity::mayBeModifiedByCall()
const {
if (!characteristics)
return true;
if (characteristics->GetIntent() == Fortran::common::Intent::In)
return false;
return !hasValueAttribute();
}
template <typename T>
bool Fortran::lower::CallInterface<T>::PassedEntity::mayBeReadByCall() const {
if (!characteristics)
return true;
return characteristics->GetIntent() != Fortran::common::Intent::Out;
}
template <typename T>
bool Fortran::lower::CallInterface<T>::PassedEntity::testTKR(
Fortran::common::IgnoreTKR flag) const {
if (!characteristics)
return false;
const auto *dummy =
std::get_if<Fortran::evaluate::characteristics::DummyDataObject>(
&characteristics->u);
if (!dummy)
return false;
return dummy->ignoreTKR.test(flag);
}
template <typename T>
bool Fortran::lower::CallInterface<T>::PassedEntity::isIntentOut() const {
if (!characteristics)
return true;
return characteristics->GetIntent() == Fortran::common::Intent::Out;
}
template <typename T>
bool Fortran::lower::CallInterface<T>::PassedEntity::mustBeMadeContiguous()
const {
if (!characteristics)
return true;
const auto *dummy =
std::get_if<Fortran::evaluate::characteristics::DummyDataObject>(
&characteristics->u);
if (!dummy)
return false;
const auto &shapeAttrs = dummy->type.attrs();
using ShapeAttrs = Fortran::evaluate::characteristics::TypeAndShape::Attr;
if (shapeAttrs.test(ShapeAttrs::AssumedRank) ||
shapeAttrs.test(ShapeAttrs::AssumedShape))
return dummy->attrs.test(
Fortran::evaluate::characteristics::DummyDataObject::Attr::Contiguous);
if (shapeAttrs.test(ShapeAttrs::DeferredShape))
return false;
// Explicit shape arrays are contiguous.
return dummy->type.Rank() > 0;
}
template <typename T>
bool Fortran::lower::CallInterface<T>::PassedEntity::hasValueAttribute() const {
if (!characteristics)
return false;
const auto *dummy =
std::get_if<Fortran::evaluate::characteristics::DummyDataObject>(
&characteristics->u);
return dummy &&
dummy->attrs.test(
Fortran::evaluate::characteristics::DummyDataObject::Attr::Value);
}
template <typename T>
bool Fortran::lower::CallInterface<T>::PassedEntity::hasAllocatableAttribute()
const {
if (!characteristics)
return false;
const auto *dummy =
std::get_if<Fortran::evaluate::characteristics::DummyDataObject>(
&characteristics->u);
using Attrs = Fortran::evaluate::characteristics::DummyDataObject::Attr;
return dummy && dummy->attrs.test(Attrs::Allocatable);
}
template <typename T>
bool Fortran::lower::CallInterface<
T>::PassedEntity::mayRequireIntentoutFinalization() const {
// Conservatively assume that the finalization is needed.
if (!characteristics)
return true;
// No INTENT(OUT) dummy arguments do not require finalization on entry.
if (!isIntentOut())
return false;
const auto *dummy =
std::get_if<Fortran::evaluate::characteristics::DummyDataObject>(
&characteristics->u);
if (!dummy)
return true;
// POINTER/ALLOCATABLE dummy arguments do not require finalization.
using Attrs = Fortran::evaluate::characteristics::DummyDataObject::Attr;
if (dummy->attrs.test(Attrs::Allocatable) ||
dummy->attrs.test(Attrs::Pointer))
return false;
// Polymorphic and unlimited polymorphic INTENT(OUT) dummy arguments
// may need finalization.
const Fortran::evaluate::DynamicType &type = dummy->type.type();
if (type.IsPolymorphic() || type.IsUnlimitedPolymorphic())
return true;
// INTENT(OUT) dummy arguments of derived types require finalization,
// if their type has finalization.
const Fortran::semantics::DerivedTypeSpec *derived =
Fortran::evaluate::GetDerivedTypeSpec(type);
if (!derived)
return false;
return Fortran::semantics::IsFinalizable(*derived);
}
template <typename T>
void Fortran::lower::CallInterface<T>::determineInterface(
bool isImplicit,
const Fortran::evaluate::characteristics::Procedure &procedure) {
CallInterfaceImpl<T> impl(*this);
if (isImplicit)
impl.buildImplicitInterface(procedure);
else
impl.buildExplicitInterface(procedure);
// We only expect the extra host asspciations argument from the callee side as
// the definition of internal procedures will be present, and we'll always
// have a FuncOp definition in the ModuleOp, when lowering.
if constexpr (std::is_same_v<T, Fortran::lower::CalleeInterface>) {
if (side().hasHostAssociated())
impl.appendHostAssocTupleArg(side().getHostAssociatedTy());
}
}
template <typename T>
mlir::FunctionType Fortran::lower::CallInterface<T>::genFunctionType() {
llvm::SmallVector<mlir::Type> returnTys;
llvm::SmallVector<mlir::Type> inputTys;
for (const FirPlaceHolder &placeHolder : outputs)
returnTys.emplace_back(placeHolder.type);
for (const FirPlaceHolder &placeHolder : inputs)
inputTys.emplace_back(placeHolder.type);
return mlir::FunctionType::get(&converter.getMLIRContext(), inputTys,
returnTys);
}
template <typename T>
llvm::SmallVector<mlir::Type>
Fortran::lower::CallInterface<T>::getResultType() const {
llvm::SmallVector<mlir::Type> types;
for (const FirPlaceHolder &out : outputs)
types.emplace_back(out.type);
return types;
}
template class Fortran::lower::CallInterface<Fortran::lower::CalleeInterface>;
template class Fortran::lower::CallInterface<Fortran::lower::CallerInterface>;
//===----------------------------------------------------------------------===//
// Function Type Translation
//===----------------------------------------------------------------------===//
/// Build signature from characteristics when there is no Fortran entity to
/// associate with the arguments (i.e, this is not a call site or a procedure
/// declaration. This is needed when dealing with function pointers/dummy
/// arguments.
class SignatureBuilder;
template <>
struct Fortran::lower::PassedEntityTypes<SignatureBuilder> {
using FortranEntity = FakeEntity;
using FirValue = int;
};
/// SignatureBuilder is a CRTP implementation of CallInterface intended to
/// help translating characteristics::Procedure to mlir::FunctionType using
/// the CallInterface translation.
class SignatureBuilder
: public Fortran::lower::CallInterface<SignatureBuilder> {
public:
SignatureBuilder(const Fortran::evaluate::characteristics::Procedure &p,
Fortran::lower::AbstractConverter &c, bool forceImplicit)
: CallInterface{c}, proc{p} {
bool isImplicit = forceImplicit || proc.CanBeCalledViaImplicitInterface();
determineInterface(isImplicit, proc);
}
SignatureBuilder(const Fortran::evaluate::ProcedureDesignator &procDes,
Fortran::lower::AbstractConverter &c)
: CallInterface{c}, procDesignator{&procDes},
proc{Fortran::evaluate::characteristics::Procedure::Characterize(
procDes, converter.getFoldingContext())
.value()} {}
/// Does the procedure characteristics being translated have alternate
/// returns ?
bool hasAlternateReturns() const {
for (const Fortran::evaluate::characteristics::DummyArgument &dummy :
proc.dummyArguments)
if (std::holds_alternative<
Fortran::evaluate::characteristics::AlternateReturn>(dummy.u))
return true;
return false;
};
/// This is only here to fulfill CRTP dependencies and should not be called.
std::string getMangledName() const {
if (procDesignator)
return getProcMangledName(*procDesignator, converter);
fir::emitFatalError(
converter.getCurrentLocation(),
"should not query name when only building function type");
}
/// This is only here to fulfill CRTP dependencies and should not be called.
mlir::Location getCalleeLocation() const {
if (procDesignator)
return getProcedureDesignatorLoc(*procDesignator, converter);
return converter.getCurrentLocation();
}
const Fortran::semantics::Symbol *getProcedureSymbol() const {
if (procDesignator)
return procDesignator->GetSymbol();
return nullptr;
};
Fortran::evaluate::characteristics::Procedure characterize() const {
return proc;
}
/// SignatureBuilder cannot be used on main program.
static constexpr bool isMainProgram() { return false; }
/// Return the characteristics::Procedure that is being translated to
/// mlir::FunctionType.
const Fortran::evaluate::characteristics::Procedure &
getCallDescription() const {
return proc;
}
/// Set internal procedure attribute on MLIR function. Internal procedure
/// are defined in the current file and will not go through SignatureBuilder.
void setFuncAttrs(mlir::func::FuncOp) const {}
/// This is not the description of an indirect call.
static constexpr bool isIndirectCall() { return false; }
/// Return the translated signature.
mlir::FunctionType getFunctionType() {
if (interfaceDetermined)
fir::emitFatalError(converter.getCurrentLocation(),
"SignatureBuilder should only be used once");
// Most unrestricted intrinsic characteristics have the Elemental attribute
// which triggers CanBeCalledViaImplicitInterface to return false. However,
// using implicit interface rules is just fine here.
bool forceImplicit =
procDesignator && procDesignator->GetSpecificIntrinsic();
bool isImplicit = forceImplicit || proc.CanBeCalledViaImplicitInterface();
determineInterface(isImplicit, proc);
interfaceDetermined = true;
return genFunctionType();
}
mlir::func::FuncOp getOrCreateFuncOp() {
if (interfaceDetermined)
fir::emitFatalError(converter.getCurrentLocation(),
"SignatureBuilder should only be used once");
declare();
interfaceDetermined = true;
return getFuncOp();
}
// Copy of base implementation.
static constexpr bool hasHostAssociated() { return false; }
mlir::Type getHostAssociatedTy() const {
llvm_unreachable("getting host associated type in SignatureBuilder");
}
private:
const Fortran::evaluate::ProcedureDesignator *procDesignator = nullptr;
Fortran::evaluate::characteristics::Procedure proc;
bool interfaceDetermined = false;
};
mlir::FunctionType Fortran::lower::translateSignature(
const Fortran::evaluate::ProcedureDesignator &proc,
Fortran::lower::AbstractConverter &converter) {
return SignatureBuilder{proc, converter}.getFunctionType();
}
mlir::func::FuncOp Fortran::lower::getOrDeclareFunction(
const Fortran::evaluate::ProcedureDesignator &proc,
Fortran::lower::AbstractConverter &converter) {
mlir::ModuleOp module = converter.getModuleOp();
std::string name = getProcMangledName(proc, converter);
mlir::func::FuncOp func = fir::FirOpBuilder::getNamedFunction(module, name);
if (func)
return func;
// getOrDeclareFunction is only used for functions not defined in the current
// program unit, so use the location of the procedure designator symbol, which
// is the first occurrence of the procedure in the program unit.
return SignatureBuilder{proc, converter}.getOrCreateFuncOp();
}
// Is it required to pass a dummy procedure with \p characteristics as a tuple
// containing the function address and the result length ?
static bool mustPassLengthWithDummyProcedure(
const std::optional<Fortran::evaluate::characteristics::Procedure>
&characteristics) {
return characteristics &&
Fortran::lower::CallInterfaceImpl<SignatureBuilder>::
mustPassLengthWithDummyProcedure(*characteristics);
}
bool Fortran::lower::mustPassLengthWithDummyProcedure(
const Fortran::evaluate::ProcedureDesignator &procedure,
Fortran::lower::AbstractConverter &converter) {
std::optional<Fortran::evaluate::characteristics::Procedure> characteristics =
Fortran::evaluate::characteristics::Procedure::Characterize(
procedure, converter.getFoldingContext());
return ::mustPassLengthWithDummyProcedure(characteristics);
}
mlir::Type Fortran::lower::getDummyProcedureType(
const Fortran::semantics::Symbol &dummyProc,
Fortran::lower::AbstractConverter &converter) {
std::optional<Fortran::evaluate::characteristics::Procedure> iface =
Fortran::evaluate::characteristics::Procedure::Characterize(
dummyProc, converter.getFoldingContext());
mlir::Type procType = getProcedureDesignatorType(
iface.has_value() ? &*iface : nullptr, converter);
if (::mustPassLengthWithDummyProcedure(iface))
return fir::factory::getCharacterProcedureTupleType(procType);
return procType;
}
bool Fortran::lower::isCPtrArgByValueType(mlir::Type ty) {
return ty.isa<fir::ReferenceType>() &&
fir::isa_integer(fir::unwrapRefType(ty));
}
// Return the mlir::FunctionType of a procedure
static mlir::FunctionType
getProcedureType(const Fortran::evaluate::characteristics::Procedure &proc,
Fortran::lower::AbstractConverter &converter) {
return SignatureBuilder{proc, converter, false}.genFunctionType();
}