cling/lib/Interpreter/DeclUnloader.h

420 lines
14 KiB
C++

//--------------------------------------------------------------------*- C++ -*-
// CLING - the C++ LLVM-based InterpreterG :)
// author: Vassil Vassilev <vvasilev@cern.ch>
//
// This file is dual-licensed: you can choose to license it under the University
// of Illinois Open Source License or the GNU Lesser General Public License. See
// LICENSE.TXT for details.
//------------------------------------------------------------------------------
#ifndef CLING_DECL_UNLOADER
#define CLING_DECL_UNLOADER
#include "cling/Interpreter/Transaction.h"
#include "clang/AST/DeclContextInternals.h"
#include "clang/AST/DeclVisitor.h"
namespace clang {
class CodeGenerator;
class GlobalDecl;
using cling::Transaction;
///\brief The class does the actual work of removing a declaration and
/// resetting the internal structures of the compiler
///
class DeclUnloader : public DeclVisitor<DeclUnloader, bool> {
private:
typedef llvm::DenseSet<FileID> FileIDs;
///\brief The Sema object being unloaded (contains the AST as well).
///
Sema* m_Sema;
///\brief The clang code generator, being recovered.
///
clang::CodeGenerator* m_CodeGen;
///\brief The current transaction being unloaded.
///
const Transaction* m_CurTransaction;
///\brief Unloaded declaration contains a SourceLocation, representing a
/// place in the file where it was seen. Clang caches that file and even if
/// a declaration is removed and the file is edited we hit the cached entry.
/// This ADT keeps track of the files from which the unloaded declarations
/// came from so that in the end they could be removed from clang's cache.
///
FileIDs m_FilesToUncache;
public:
DeclUnloader(Sema* S, clang::CodeGenerator* CG, const Transaction* T)
: m_Sema(S), m_CodeGen(CG), m_CurTransaction(T) { }
~DeclUnloader();
///\brief Interface with nice name, forwarding to Visit.
///
///\param[in] D - The declaration to forward.
///\returns true on success.
///
bool UnloadDecl(Decl* D) { return Visit(D); }
///\brief If it falls back in the base class just remove the declaration
/// only from the declaration context.
/// @param[in] D - The declaration to be removed.
///
///\returns true on success.
///
bool VisitDecl(Decl* D);
///\brief Removes the declaration from the lookup chains and from the
/// declaration context.
/// @param[in] ND - The declaration to be removed.
///
///\returns true on success.
///
bool VisitNamedDecl(NamedDecl* ND);
///\brief Removes the declaration from Sema's unused decl registry
/// @param[in] DD - The declaration to be removed.
///
///\returns true on success.
///
bool VisitDeclaratorDecl(DeclaratorDecl* DD);
///\brief Removes a using shadow declaration, created in the cases:
///\code
/// namespace A {
/// void foo();
/// }
/// namespace B {
/// using A::foo; // <- a UsingDecl
/// // Also creates a UsingShadowDecl for A::foo() in B
/// }
///\endcode
///\param[in] USD - The declaration to be removed.
///
///\returns true on success.
///
bool VisitUsingShadowDecl(UsingShadowDecl* USD);
///\brief Removes a typedef name decls. A base class for TypedefDecls and
/// TypeAliasDecls.
///\param[in] TND - The declaration to be removed.
///
///\returns true on success.
///
bool VisitTypedefNameDecl(TypedefNameDecl* TND);
///\brief Removes the declaration from the lookup chains and from the
/// declaration context and it rebuilds the redeclaration chain.
/// @param[in] VD - The declaration to be removed.
///
///\returns true on success.
///
bool VisitVarDecl(VarDecl* VD);
///\brief Removes the declaration from the lookup chains and from the
/// declaration context and it rebuilds the redeclaration chain.
/// @param[in] FD - The declaration to be removed.
///
///\returns true on success.
///
bool VisitFunctionDecl(FunctionDecl* FD);
///\brief Specialize the removal of constructors due to the fact the we need
/// the constructor type (aka CXXCtorType). The information is located in
/// the CXXConstructExpr of usually VarDecls.
/// See clang::CodeGen::CodeGenFunction::EmitCXXConstructExpr.
///
/// What we will do instead is to brute-force and try to remove from the
/// llvm::Module all ctors of this class with all the types.
///
///\param[in] CXXCtor - The declaration to be removed.
///
///\returns true on success.
///
bool VisitCXXConstructorDecl(CXXConstructorDecl* CXXCtor);
///\brief Specialize the removal of destructors due to the fact the we need
/// the to erase the dtor decl and the deleting operator.
///
/// We will brute-force and try to remove from the llvm::Module all dtors of
/// this class with all the types.
///
///\param[in] CXXDtor - The declaration to be removed.
///
///\returns true on success.
///
bool VisitCXXDestructorDecl(CXXDestructorDecl* CXXDtor);
///\brief Removes the DeclCotnext and its decls.
/// @param[in] DC - The declaration to be removed.
///
///\returns true on success.
///
bool VisitDeclContext(DeclContext* DC);
///\brief Removes the namespace.
/// @param[in] NSD - The declaration to be removed.
///
///\returns true on success.
///
bool VisitNamespaceDecl(NamespaceDecl* NSD);
///\brief Removes a Tag (class/union/struct/enum). Most of the other
/// containers fall back into that case.
/// @param[in] TD - The declaration to be removed.
///
///\returns true on success.
///
bool VisitTagDecl(TagDecl* TD);
///\brief Removes a RecordDecl. We shouldn't remove the implicit class
/// declaration.
///\param[in] RD - The declaration to be removed.
///
///\returns true on success.
///
bool VisitRecordDecl(RecordDecl* RD);
///\brief Remove the macro from the Preprocessor.
/// @param[in] MD - The MacroDirectiveInfo containing the IdentifierInfo and
/// MacroDirective to forward.
///
///\returns true on success.
///
bool VisitMacro(const Transaction::MacroDirectiveInfo MD);
///@name Templates
///@{
///\brief Removes template from the redecl chain. Templates are
/// redeclarables also.
/// @param[in] R - The declaration to be removed.
///
///\returns true on success.
///
bool VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl* R);
///\brief Removes the declaration clang's internal structures. This case
/// looks very much to VisitFunctionDecl, but FunctionTemplateDecl doesn't
/// derive from FunctionDecl and thus we need to handle it 'by hand'.
/// @param[in] FTD - The declaration to be removed.
///
///\returns true on success.
///
bool VisitFunctionTemplateDecl(FunctionTemplateDecl* FTD);
///\brief Removes a class template declaration from clang's internal
/// structures.
/// @param[in] CTD - The declaration to be removed.
///
///\returns true on success.
///
bool VisitClassTemplateDecl(ClassTemplateDecl* CTD);
///\brief Removes a class template specialization declaration from clang's
/// internal structures.
/// @param[in] CTSD - The declaration to be removed.
///
///\returns true on success.
///
bool VisitClassTemplateSpecializationDecl(ClassTemplateSpecializationDecl*
CTSD);
///@}
void MaybeRemoveDeclFromModule(GlobalDecl& GD) const;
/// @name Helpers
/// @{
///\brief Interface with nice name, forwarding to Visit.
///
///\param[in] MD - The MacroDirectiveInfo containing the IdentifierInfo and
/// MacroDirective to forward.
///\returns true on success.
///
bool UnloadMacro(Transaction::MacroDirectiveInfo MD) {
return VisitMacro(MD);
}
template <typename T>
constexpr static bool isDefinition(T*) {
return false;
}
static bool isDefinition(TagDecl* R) {
return R->isCompleteDefinition() && isa<CXXRecordDecl>(R);
}
template <typename T>
static void resetDefinitionData(T*) {
llvm_unreachable("resetDefinitionData on non-cxx record declaration");
}
static void resetDefinitionData(TagDecl *decl) {
auto canon = dyn_cast<CXXRecordDecl>(decl->getCanonicalDecl());
assert(canon && "Only CXXRecordDecl have DefinitionData");
for (auto iter = canon->getMostRecentDecl(); iter;
iter = iter->getPreviousDecl()) {
auto declcxx = dyn_cast<CXXRecordDecl>(iter);
assert(declcxx && "Only CXXRecordDecl have DefinitionData");
declcxx->DefinitionData = nullptr;
}
}
// Copied and adapted from: ASTReaderDecl.cpp
template<typename DeclT>
void removeRedeclFromChain(DeclT* R) {
//RedeclLink is a protected member.
struct RedeclDerived : public Redeclarable<DeclT> {
typedef typename Redeclarable<DeclT>::DeclLink DeclLink_t;
static DeclLink_t& getLink(DeclT* R) {
Redeclarable<DeclT>* D = R;
return ((RedeclDerived*)D)->RedeclLink;
}
static void setLatest(DeclT* Latest) {
// Convert A -> Latest -> B into A -> Latest
getLink(Latest->getFirstDecl()).setLatest(Latest);
}
static void skipPrev(DeclT* Next) {
// Convert A -> B -> Next into A -> Next
DeclT* Skip = Next->getPreviousDecl();
getLink(Next).setPrevious(Skip->getPreviousDecl());
}
static void setFirst(DeclT* First) {
// Convert A -> First -> B into First -> B
DeclT* Latest = First->getMostRecentDecl();
getLink(First)
= DeclLink_t(DeclLink_t::LatestLink, First->getASTContext());
getLink(First).setLatest(Latest);
}
};
assert(R != R->getFirstDecl() && "Cannot remove only redecl from chain");
const bool isdef = isDefinition(R);
// In the following cases, A marks the first, Z the most recent and
// R the decl to be removed from the chain.
DeclT* Prev = R->getPreviousDecl();
if (R == R->getMostRecentDecl()) {
// A -> .. -> R
RedeclDerived::setLatest(Prev);
} else {
// Find the next redecl, starting at the end
DeclT* Next = R->getMostRecentDecl();
while (Next && Next->getPreviousDecl() != R)
Next = Next->getPreviousDecl();
if (!Next) {
// R is not (yet?) wired up.
return;
}
if (R->getPreviousDecl()) {
// A -> .. -> R -> .. -> Z
RedeclDerived::skipPrev(Next);
} else {
assert(R->getFirstDecl() == R && "Logic error");
// R -> .. -> Z
RedeclDerived::setFirst(Next);
}
}
// If the decl was the definition, the other decl might have their
// DefinitionData pointing to it.
// This is really need only if DeclT is a TagDecl or derived.
if (isdef) {
resetDefinitionData(Prev);
}
}
void removeRedeclFromChain(...) {
llvm_unreachable("setLatestDeclImpl on non-redeclarable declaration");
}
///\brief Removes given declaration from the chain of redeclarations.
/// Rebuilds the chain and sets properly first and last redeclaration.
/// @param[in] R - The redeclarable, its chain to be rebuilt.
/// @param[in] DC - Remove the redecl's lookup entry from this DeclContext.
///
///\returns the most recent redeclaration in the new chain.
///
template <typename T>
bool VisitRedeclarable(clang::Redeclarable<T>* R, DeclContext* DC) {
if (R->getFirstDecl() == R) {
// This is the only element in the chain.
return true;
}
T* MostRecent = R->getMostRecentDecl();
T* MostRecentNotThis = MostRecent;
if (MostRecentNotThis == R)
MostRecentNotThis = R->getPreviousDecl();
if (StoredDeclsMap* Map = DC->getPrimaryContext()->getLookupPtr()) {
// Make sure we update the lookup maps, because the removed decl might
// be registered in the lookup and still findable.
NamedDecl* ND = (T*)R;
DeclarationName Name = ND->getDeclName();
if (!Name.isEmpty()) {
StoredDeclsMap::iterator Pos = Map->find(Name);
if (Pos != Map->end() && !Pos->second.isNull()) {
DeclContext::lookup_result decls = Pos->second.getLookupResult();
// FIXME: A decl meant to be added in the lookup already exists
// in the lookup table. My assumption is that the DeclUnloader
// adds it here. This needs to be investigated mode. For now
// std::find gets promoted from assert to condition :)
// DeclContext::lookup_result::iterator is not an InputIterator
// (const member, thus no op=(const iterator&)), thus we cannot use
// std::find. MSVC actually cares!
auto hasDecl = [](const DeclContext::lookup_result& Result,
const NamedDecl* Needle) -> bool {
for (auto IDecl: Result) {
if (IDecl == Needle)
return true;
}
return false;
};
if (!hasDecl(decls, MostRecentNotThis) && hasDecl(decls, ND)) {
// The decl was registered in the lookup, update it.
Pos->second.HandleRedeclaration(MostRecentNotThis,
/*IsKnownNewer*/ true);
}
}
}
}
// Set a new latest redecl.
removeRedeclFromChain((T*)R);
#ifndef NDEBUG
// Validate redecl chain by iterating through it.
std::set<clang::Redeclarable<T>*> CheckUnique;
(void)CheckUnique;
for (auto RD: MostRecentNotThis->redecls()) {
assert(CheckUnique.insert(RD).second && "Dupe redecl chain element");
(void)RD;
}
#endif
return true;
}
/// @}
private:
///\brief Function that collects the files which we must reread from disk.
///
/// For example: We must uncache the cached include, which brought a
/// declaration or a macro diretive definition in the AST.
///\param[in] Loc - The source location of the unloaded declaration.
///
void CollectFilesToUncache(SourceLocation Loc);
};
} // namespace clang
namespace cling {
using clang::DeclUnloader;
} // namespace cling
#endif // CLING_DECL_UNLOADER