Files
swift-mirror/lib/SIL/SILDeclRef.cpp
Slava Pestov 75bd88968b SILGen: Allow extensions to define designated initializers of generic types
Previously, if a generic type had a stored property with
a generic type and an initializer expression, we would
emit the expression directly in the body of each designated
initializer.

This is a problem if the designated initializer is defined
within an extension (even in the same source file), because
extensions have a different set of generic parameters and
archetypes.

Also, we've had bugs in the past where emitting an
expression multiple times didn't work properly. While these
might currently all be fixed, this is a tricky case to test
and it would be best to avoid it.

Fix both problems by emitting the initializer expression
inside its own function at the SIL level, and call the
initializer function from each designated initializer.

I'm using the existing 'variable initializer' mangling for this;
it doesn't seem to be used for anything else right now.

Currently, the default memberwise initializer does not use
this, because the machinery for emitting it is somewhat
duplicated and separate from the initializer expressions in
user-defined constructors. I'll clean this up in an upcoming
patch.

Fixes <https://bugs.swift.org/browse/SR-488>.
2016-08-03 01:03:08 -07:00

661 lines
23 KiB
C++

//===--- SILDeclRef.cpp - Implements SILDeclRef ---------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2016 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
#include "swift/SIL/SILDeclRef.h"
#include "swift/SIL/SILLocation.h"
#include "swift/AST/AnyFunctionRef.h"
#include "swift/AST/ASTContext.h"
#include "swift/AST/Mangle.h"
#include "swift/Basic/Fallthrough.h"
#include "swift/ClangImporter/ClangImporter.h"
#include "swift/ClangImporter/ClangModule.h"
#include "swift/SIL/SILLinkage.h"
#include "llvm/Support/raw_ostream.h"
#include "clang/AST/Attr.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclObjC.h"
using namespace swift;
/// Get the method dispatch mechanism for a method.
MethodDispatch
swift::getMethodDispatch(AbstractFunctionDecl *method) {
// Final methods can be statically referenced.
if (method->isFinal())
return MethodDispatch::Static;
// Some methods are forced to be statically dispatched.
if (method->hasForcedStaticDispatch())
return MethodDispatch::Static;
// Import-as-member declarations are always statically referenced.
if (method->isImportAsMember())
return MethodDispatch::Static;
// If this declaration is in a class but not marked final, then it is
// always dynamically dispatched.
auto dc = method->getDeclContext();
if (isa<ClassDecl>(dc))
return MethodDispatch::Class;
// Class extension methods are only dynamically dispatched if they're
// dispatched by objc_msgSend, which happens if they're foreign or dynamic.
if (dc->getAsClassOrClassExtensionContext()) {
if (method->hasClangNode())
return MethodDispatch::Class;
if (auto fd = dyn_cast<FuncDecl>(method)) {
if (fd->isAccessor() && fd->getAccessorStorageDecl()->hasClangNode())
return MethodDispatch::Class;
}
if (method->getAttrs().hasAttribute<DynamicAttr>())
return MethodDispatch::Class;
}
// Otherwise, it can be referenced statically.
return MethodDispatch::Static;
}
bool swift::requiresForeignToNativeThunk(ValueDecl *vd) {
// Functions imported from C, Objective-C methods imported from Objective-C,
// as well as methods in @objc protocols (even protocols defined in Swift)
// require a foreign to native thunk.
auto dc = vd->getDeclContext();
if (auto proto = dyn_cast<ProtocolDecl>(dc))
if (proto->isObjC())
return true;
if (auto fd = dyn_cast<FuncDecl>(vd))
return fd->hasClangNode();
return false;
}
/// FIXME: merge requiresForeignEntryPoint() into getMethodDispatch() and add
/// an ObjectiveC case to the MethodDispatch enum.
bool swift::requiresForeignEntryPoint(ValueDecl *vd) {
if (vd->isImportAsMember())
return true;
// Final functions never require ObjC dispatch.
if (vd->isFinal())
return false;
if (requiresForeignToNativeThunk(vd))
return true;
if (auto *fd = dyn_cast<FuncDecl>(vd)) {
// Property accessors should be generated alongside the property.
if (fd->isGetterOrSetter())
return requiresForeignEntryPoint(fd->getAccessorStorageDecl());
return fd->getAttrs().hasAttribute<DynamicAttr>();
}
if (auto *cd = dyn_cast<ConstructorDecl>(vd)) {
if (cd->hasClangNode())
return true;
return cd->getAttrs().hasAttribute<DynamicAttr>();
}
if (auto *asd = dyn_cast<AbstractStorageDecl>(vd))
return asd->requiresForeignGetterAndSetter();
return vd->getAttrs().hasAttribute<DynamicAttr>();
}
static unsigned getFuncNaturalUncurryLevel(AnyFunctionRef AFR) {
assert(AFR.getParameterLists().size() >= 1 && "no arguments for func?!");
unsigned Level = AFR.getParameterLists().size() - 1;
// Functions with captures have an extra uncurry level for the capture
// context.
if (AFR.getCaptureInfo().hasLocalCaptures())
Level += 1;
return Level;
}
SILDeclRef::SILDeclRef(ValueDecl *vd, SILDeclRef::Kind kind,
ResilienceExpansion expansion,
unsigned atUncurryLevel, bool isForeign)
: loc(vd), kind(kind), Expansion(unsigned(expansion)),
isForeign(isForeign), isDirectReference(0), defaultArgIndex(0)
{
unsigned naturalUncurryLevel;
// FIXME: restructure to use a "switch".
if (auto *func = dyn_cast<FuncDecl>(vd)) {
assert(kind == Kind::Func &&
"can only create a Func SILDeclRef for a func decl");
naturalUncurryLevel = getFuncNaturalUncurryLevel(func);
} else if (isa<ConstructorDecl>(vd)) {
assert((kind == Kind::Allocator || kind == Kind::Initializer)
&& "can only create Allocator or Initializer SILDeclRef for ctor");
naturalUncurryLevel = 1;
} else if (auto *ed = dyn_cast<EnumElementDecl>(vd)) {
assert(kind == Kind::EnumElement
&& "can only create EnumElement SILDeclRef for enum element");
naturalUncurryLevel = ed->hasArgumentType() ? 1 : 0;
} else if (isa<DestructorDecl>(vd)) {
assert((kind == Kind::Destroyer || kind == Kind::Deallocator)
&& "can only create destroyer/deallocator SILDeclRef for dtor");
naturalUncurryLevel = 0;
} else if (isa<ClassDecl>(vd)) {
assert((kind == Kind::IVarInitializer || kind == Kind::IVarDestroyer) &&
"can only create ivar initializer/destroyer SILDeclRef for class");
naturalUncurryLevel = 1;
} else if (auto *var = dyn_cast<VarDecl>(vd)) {
assert((kind == Kind::GlobalAccessor ||
kind == Kind::GlobalGetter ||
kind == Kind::StoredPropertyInitializer) &&
"can only create GlobalAccessor, GlobalGetter or "
"StoredPropertyInitializer SILDeclRef for var");
naturalUncurryLevel = 0;
assert(!var->getDeclContext()->isLocalContext() &&
"can't reference local var as global var");
assert(var->hasStorage() && "can't reference computed var as global var");
(void)var;
} else {
llvm_unreachable("Unhandled ValueDecl for SILDeclRef");
}
assert((atUncurryLevel == ConstructAtNaturalUncurryLevel
|| atUncurryLevel <= naturalUncurryLevel)
&& "can't emit SILDeclRef below natural uncurry level");
uncurryLevel = atUncurryLevel == ConstructAtNaturalUncurryLevel
? naturalUncurryLevel
: atUncurryLevel;
isCurried = uncurryLevel != naturalUncurryLevel;
}
SILDeclRef::SILDeclRef(SILDeclRef::Loc baseLoc,
ResilienceExpansion expansion,
unsigned atUncurryLevel, bool asForeign)
: isDirectReference(0), defaultArgIndex(0)
{
unsigned naturalUncurryLevel;
if (ValueDecl *vd = baseLoc.dyn_cast<ValueDecl*>()) {
if (FuncDecl *fd = dyn_cast<FuncDecl>(vd)) {
// Map FuncDecls directly to Func SILDeclRefs.
loc = fd;
kind = Kind::Func;
naturalUncurryLevel = getFuncNaturalUncurryLevel(fd);
}
// Map ConstructorDecls to the Allocator SILDeclRef of the constructor.
else if (ConstructorDecl *cd = dyn_cast<ConstructorDecl>(vd)) {
loc = cd;
kind = Kind::Allocator;
naturalUncurryLevel = 1;
}
// Map EnumElementDecls to the EnumElement SILDeclRef of the element.
else if (EnumElementDecl *ed = dyn_cast<EnumElementDecl>(vd)) {
loc = ed;
kind = Kind::EnumElement;
naturalUncurryLevel = ed->hasArgumentType() ? 1 : 0;
}
// VarDecl constants require an explicit kind.
else if (isa<VarDecl>(vd)) {
llvm_unreachable("must create SILDeclRef for VarDecl with explicit kind");
}
// Map DestructorDecls to the Deallocator of the destructor.
else if (auto dtor = dyn_cast<DestructorDecl>(vd)) {
loc = dtor;
kind = Kind::Deallocator;
naturalUncurryLevel = 0;
}
else {
llvm_unreachable("invalid loc decl for SILDeclRef!");
}
} else if (auto *ACE = baseLoc.dyn_cast<AbstractClosureExpr *>()) {
loc = ACE;
kind = Kind::Func;
assert(ACE->getParameterLists().size() >= 1 &&
"no param patterns for function?!");
naturalUncurryLevel = getFuncNaturalUncurryLevel(ACE);
} else {
llvm_unreachable("impossible SILDeclRef loc");
}
// Set the uncurry level.
assert((atUncurryLevel == ConstructAtNaturalUncurryLevel
|| atUncurryLevel <= naturalUncurryLevel)
&& "can't emit SILDeclRef below natural uncurry level");
uncurryLevel = atUncurryLevel == ConstructAtNaturalUncurryLevel
? naturalUncurryLevel
: atUncurryLevel;
Expansion = (unsigned) expansion;
isCurried = uncurryLevel != naturalUncurryLevel;
isForeign = asForeign;
}
Optional<AnyFunctionRef> SILDeclRef::getAnyFunctionRef() const {
if (auto vd = loc.dyn_cast<ValueDecl*>()) {
if (auto afd = dyn_cast<AbstractFunctionDecl>(vd)) {
return AnyFunctionRef(afd);
} else {
return None;
}
}
return AnyFunctionRef(loc.get<AbstractClosureExpr*>());
}
bool SILDeclRef::isThunk() const {
return isCurried || isForeignToNativeThunk() || isNativeToForeignThunk();
}
bool SILDeclRef::isClangImported() const {
if (!hasDecl())
return false;
ValueDecl *d = getDecl();
DeclContext *moduleContext = d->getDeclContext()->getModuleScopeContext();
if (isa<ClangModuleUnit>(moduleContext)) {
if (isClangGenerated())
return true;
if (isa<ConstructorDecl>(d) || isa<EnumElementDecl>(d))
return !isForeign;
if (auto *FD = dyn_cast<FuncDecl>(d))
if (FD->isAccessor() ||
isa<NominalTypeDecl>(d->getDeclContext()))
return !isForeign;
}
return false;
}
bool SILDeclRef::isClangGenerated() const {
if (!hasDecl())
return false;
return isClangGenerated(getDecl()->getClangNode());
}
// FIXME: this is a weird predicate.
bool SILDeclRef::isClangGenerated(ClangNode node) {
if (auto nd = dyn_cast_or_null<clang::NamedDecl>(node.getAsDecl())) {
// ie, 'static inline' functions for which we must ask Clang to emit a body
// for explicitly
if (!nd->isExternallyVisible())
return true;
}
return false;
}
SILLinkage SILDeclRef::getLinkage(ForDefinition_t forDefinition) const {
// Anonymous functions have shared linkage.
// FIXME: This should really be the linkage of the parent function.
if (getAbstractClosureExpr())
return SILLinkage::Shared;
// Native function-local declarations have shared linkage.
// FIXME: @objc declarations should be too, but we currently have no way
// of marking them "used" other than making them external.
ValueDecl *d = getDecl();
DeclContext *moduleContext = d->getDeclContext();
while (!moduleContext->isModuleScopeContext()) {
if (!isForeign && moduleContext->isLocalContext())
return SILLinkage::Shared;
moduleContext = moduleContext->getParent();
}
// Currying and calling convention thunks have shared linkage.
if (isThunk())
// If a function declares a @_cdecl name, its native-to-foreign thunk
// is exported with the visibility of the function.
if (!isNativeToForeignThunk() || !d->getAttrs().hasAttribute<CDeclAttr>())
return SILLinkage::Shared;
// Enum constructors are essentially the same as thunks, they are
// emitted by need and have shared linkage.
if (isEnumElement())
return SILLinkage::Shared;
// Stored property initializers have hidden linkage, since they are
// not meant to be used from outside of their module.
if (isStoredPropertyInitializer())
return SILLinkage::Hidden;
// Declarations imported from Clang modules have shared linkage.
const SILLinkage ClangLinkage = SILLinkage::Shared;
if (isClangImported())
return ClangLinkage;
// Otherwise, we have external linkage.
switch (d->getEffectiveAccess()) {
case Accessibility::Private:
case Accessibility::FilePrivate:
return (forDefinition ? SILLinkage::Private : SILLinkage::PrivateExternal);
case Accessibility::Internal:
return (forDefinition ? SILLinkage::Hidden : SILLinkage::HiddenExternal);
default:
return (forDefinition ? SILLinkage::Public : SILLinkage::PublicExternal);
}
}
SILDeclRef SILDeclRef::getDefaultArgGenerator(Loc loc,
unsigned defaultArgIndex) {
SILDeclRef result;
result.loc = loc;
result.kind = Kind::DefaultArgGenerator;
result.defaultArgIndex = defaultArgIndex;
return result;
}
/// \brief True if the function should be treated as transparent.
bool SILDeclRef::isTransparent() const {
if (isEnumElement())
return true;
if (isStoredPropertyInitializer())
return true;
if (hasAutoClosureExpr())
return true;
return hasDecl() ? getDecl()->isTransparent() : false;
}
/// \brief True if the function should have its body serialized.
bool SILDeclRef::isFragile() const {
DeclContext *dc;
if (auto closure = getAbstractClosureExpr())
dc = closure->getLocalContext();
else
dc = getDecl()->getInnermostDeclContext();
// This is stupid
return (dc->getResilienceExpansion() == ResilienceExpansion::Minimal);
}
/// \brief True if the function has noinline attribute.
bool SILDeclRef::isNoinline() const {
if (!hasDecl())
return false;
if (auto InlineA = getDecl()->getAttrs().getAttribute<InlineAttr>())
if (InlineA->getKind() == InlineKind::Never)
return true;
return false;
}
/// \brief True if the function has noinline attribute.
bool SILDeclRef::isAlwaysInline() const {
if (!hasDecl())
return false;
if (auto InlineA = getDecl()->getAttrs().getAttribute<InlineAttr>())
if (InlineA->getKind() == InlineKind::Always)
return true;
return false;
}
bool SILDeclRef::hasEffectsAttribute() const {
if (!hasDecl())
return false;
return getDecl()->getAttrs().hasAttribute<EffectsAttr>();
}
EffectsKind SILDeclRef::getEffectsAttribute() const {
assert(hasEffectsAttribute());
EffectsAttr *MA = getDecl()->getAttrs().getAttribute<EffectsAttr>();
return MA->getKind();
}
bool SILDeclRef::isForeignToNativeThunk() const {
// Non-decl entry points are never natively foreign, so they would never
// have a foreign-to-native thunk.
if (!hasDecl())
return false;
if (requiresForeignToNativeThunk(getDecl()))
return !isForeign;
// ObjC initializing constructors and factories are foreign.
// We emit a special native allocating constructor though.
if (isa<ConstructorDecl>(getDecl())
&& (kind == Kind::Initializer
|| cast<ConstructorDecl>(getDecl())->isFactoryInit())
&& getDecl()->hasClangNode())
return !isForeign;
return false;
}
bool SILDeclRef::isNativeToForeignThunk() const {
// We can have native-to-foreign thunks over closures.
if (!hasDecl())
return isForeign;
// We can have native-to-foreign thunks over global or local native functions.
// TODO: Static functions too.
if (auto func = dyn_cast<FuncDecl>(getDecl())) {
if (!func->getDeclContext()->isTypeContext()
&& !func->hasClangNode())
return isForeign;
}
return false;
}
/// Use the Clang importer to mangle a Clang declaration.
static void mangleClangDecl(raw_ostream &buffer,
const clang::NamedDecl *clangDecl,
ASTContext &ctx) {
auto *importer = static_cast<ClangImporter *>(ctx.getClangModuleLoader());
importer->getMangledName(buffer, clangDecl);
}
static std::string mangleConstant(SILDeclRef c, StringRef prefix) {
using namespace Mangle;
Mangler mangler;
// Almost everything below gets one of the common prefixes:
// mangled-name ::= '_T' global // Native symbol
// mangled-name ::= '_TTo' global // ObjC interop thunk
// mangled-name ::= '_TTO' global // Foreign function thunk
// mangled-name ::= '_TTd' global // Direct
StringRef introducer = "_T";
if (!prefix.empty()) {
introducer = prefix;
} else if (c.isForeign) {
assert(prefix.empty() && "can't have custom prefix on thunk");
introducer = "_TTo";
} else if (c.isDirectReference) {
introducer = "_TTd";
} else if (c.isForeignToNativeThunk()) {
assert(prefix.empty() && "can't have custom prefix on thunk");
introducer = "_TTO";
}
// As a special case, Clang functions and globals don't get mangled at all.
if (c.hasDecl()) {
if (auto clangDecl = c.getDecl()->getClangDecl()) {
if (!c.isForeignToNativeThunk() && !c.isNativeToForeignThunk()
&& !c.isCurried) {
if (auto namedClangDecl = dyn_cast<clang::DeclaratorDecl>(clangDecl)) {
if (auto asmLabel = namedClangDecl->getAttr<clang::AsmLabelAttr>()) {
mangler.append('\01');
mangler.append(asmLabel->getLabel());
} else if (namedClangDecl->hasAttr<clang::OverloadableAttr>()) {
std::string storage;
llvm::raw_string_ostream SS(storage);
// FIXME: When we can import C++, use Clang's mangler all the time.
mangleClangDecl(SS, namedClangDecl,
c.getDecl()->getASTContext());
mangler.append(SS.str());
} else {
mangler.append(namedClangDecl->getName());
}
return mangler.finalize();
}
}
}
}
switch (c.kind) {
// entity ::= declaration // other declaration
case SILDeclRef::Kind::Func:
if (!c.hasDecl()) {
mangler.append(introducer);
mangler.mangleClosureEntity(c.getAbstractClosureExpr(),
c.uncurryLevel);
return mangler.finalize();
}
// As a special case, functions can have manually mangled names.
// Use the SILGen name only for the original non-thunked, non-curried entry
// point.
if (auto NameA = c.getDecl()->getAttrs().getAttribute<SILGenNameAttr>())
if (!c.isForeignToNativeThunk() && !c.isNativeToForeignThunk()
&& !c.isCurried) {
mangler.append(NameA->Name);
return mangler.finalize();
}
// Use a given cdecl name for native-to-foreign thunks.
if (auto CDeclA = c.getDecl()->getAttrs().getAttribute<CDeclAttr>())
if (c.isNativeToForeignThunk()) {
mangler.append(CDeclA->Name);
return mangler.finalize();
}
// Otherwise, fall through into the 'other decl' case.
SWIFT_FALLTHROUGH;
case SILDeclRef::Kind::EnumElement:
mangler.append(introducer);
mangler.mangleEntity(c.getDecl(), c.uncurryLevel);
return mangler.finalize();
// entity ::= context 'D' // deallocating destructor
case SILDeclRef::Kind::Deallocator:
mangler.append(introducer);
mangler.mangleDestructorEntity(cast<DestructorDecl>(c.getDecl()),
/*isDeallocating*/ true);
return mangler.finalize();
// entity ::= context 'd' // destroying destructor
case SILDeclRef::Kind::Destroyer:
mangler.append(introducer);
mangler.mangleDestructorEntity(cast<DestructorDecl>(c.getDecl()),
/*isDeallocating*/ false);
return mangler.finalize();
// entity ::= context 'C' type // allocating constructor
case SILDeclRef::Kind::Allocator:
mangler.append(introducer);
mangler.mangleConstructorEntity(cast<ConstructorDecl>(c.getDecl()),
/*allocating*/ true,
c.uncurryLevel);
return mangler.finalize();
// entity ::= context 'c' type // initializing constructor
case SILDeclRef::Kind::Initializer:
mangler.append(introducer);
mangler.mangleConstructorEntity(cast<ConstructorDecl>(c.getDecl()),
/*allocating*/ false,
c.uncurryLevel);
return mangler.finalize();
// entity ::= declaration 'e' // ivar initializer
// entity ::= declaration 'E' // ivar destroyer
case SILDeclRef::Kind::IVarInitializer:
case SILDeclRef::Kind::IVarDestroyer:
mangler.append(introducer);
mangler.mangleIVarInitDestroyEntity(
cast<ClassDecl>(c.getDecl()),
c.kind == SILDeclRef::Kind::IVarDestroyer);
return mangler.finalize();
// entity ::= declaration 'a' // addressor
case SILDeclRef::Kind::GlobalAccessor:
mangler.append(introducer);
mangler.mangleAddressorEntity(c.getDecl());
return mangler.finalize();
// entity ::= declaration 'G' // getter
case SILDeclRef::Kind::GlobalGetter:
mangler.append(introducer);
mangler.mangleGlobalGetterEntity(c.getDecl());
return mangler.finalize();
// entity ::= context 'e' index // default arg generator
case SILDeclRef::Kind::DefaultArgGenerator:
mangler.append(introducer);
mangler.mangleDefaultArgumentEntity(cast<AbstractFunctionDecl>(c.getDecl()),
c.defaultArgIndex);
return mangler.finalize();
// entity ::= 'I' declaration 'i' // stored property initializer
case SILDeclRef::Kind::StoredPropertyInitializer:
mangler.append(introducer);
mangler.mangleInitializerEntity(cast<VarDecl>(c.getDecl()));
return mangler.finalize();
}
llvm_unreachable("bad entity kind!");
}
std::string SILDeclRef::mangle(StringRef prefix) const {
return mangleConstant(*this, prefix);
}
SILDeclRef SILDeclRef::getNextOverriddenVTableEntry() const {
if (auto overridden = getOverridden()) {
// If we overrode a foreign decl, a dynamic method, this is an
// accessor for a property that overrides an ObjC decl, or if it is an
// @NSManaged property, then it won't be in the vtable.
if (overridden.getDecl()->hasClangNode())
return SILDeclRef();
if (overridden.getDecl()->getAttrs().hasAttribute<DynamicAttr>())
return SILDeclRef();
if (auto *ovFD = dyn_cast<FuncDecl>(overridden.getDecl()))
if (auto *asd = ovFD->getAccessorStorageDecl()) {
if (asd->hasClangNode())
return SILDeclRef();
}
// If we overrode a decl from an extension, it won't be in a vtable
// either. This can occur for extensions to ObjC classes.
if (isa<ExtensionDecl>(overridden.getDecl()->getDeclContext()))
return SILDeclRef();
// If we overrode a non-required initializer, there won't be a vtable
// slot for the allocator.
if (overridden.kind == SILDeclRef::Kind::Allocator &&
!cast<ConstructorDecl>(overridden.getDecl())->isRequired()) {
return SILDeclRef();
}
return overridden;
}
return SILDeclRef();
}
SILDeclRef SILDeclRef::getBaseOverriddenVTableEntry() const {
// 'method' is the most final method in the hierarchy which we
// haven't yet found a compatible override for. 'cur' is the method
// we're currently looking at. Compatibility is transitive,
// so we can forget our original method and just keep going up.
SILDeclRef method = *this;
SILDeclRef cur = method;
while ((cur = cur.getNextOverriddenVTableEntry())) {
method = cur;
}
return method;
}
SILLocation SILDeclRef::getAsRegularLocation() const {
if (hasDecl())
return RegularLocation(getDecl());
return RegularLocation(getAbstractClosureExpr());
}