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cling/lib/Interpreter/ASTNodeEraser.cpp
Axel Naumann fae0d4037f Follow changes in llvm/clang.
2014-02-18 08:29:38 +01:00

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//------------------------------------------------------------------------------
// 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.
//------------------------------------------------------------------------------
#include "ASTNodeEraser.h"
#include "cling/Interpreter/Transaction.h"
#include "cling/Utils/AST.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclVisitor.h"
#include "clang/AST/DependentDiagnostic.h"
#include "clang/AST/GlobalDecl.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/FileManager.h"
#include "clang/Sema/Scope.h"
#include "clang/Sema/Sema.h"
#include "clang/Lex/MacroInfo.h"
#include "clang/Lex/Preprocessor.h"
#include "llvm/ExecutionEngine/ExecutionEngine.h"
#include "llvm/ExecutionEngine/JIT.h" // For debugging the EE in gdb
#include "llvm/IR/Constants.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Module.h"
//#include "llvm/Transforms/IPO.h"
using namespace clang;
namespace cling {
///\brief The class does the actual work of removing a declaration and
/// resetting the internal structures of the compiler
///
class DeclReverter : public DeclVisitor<DeclReverter, bool> {
private:
typedef llvm::DenseSet<FileID> FileIDs;
///\brief The Sema object being reverted (contains the AST as well).
///
Sema* m_Sema;
///\brief The execution engine, either JIT or MCJIT, being recovered.
///
llvm::ExecutionEngine* m_EEngine;
///\brief The current transaction being reverted.
///
const Transaction* m_CurTransaction;
///\brief Reverted 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 reverted declarations
/// came from so that in the end they could be removed from clang's cache.
///
FileIDs m_FilesToUncache;
public:
DeclReverter(Sema* S, llvm::ExecutionEngine* EE, const Transaction* T)
: m_Sema(S), m_EEngine(EE), m_CurTransaction(T) { }
~DeclReverter();
///\brief Interface with nice name, forwarding to Visit.
///
///\param[in] D - The declaration to forward.
///\returns true on success.
///
bool RevertDecl(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 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 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;
void RemoveStaticInit(llvm::Function& F) 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 RevertMacro(Transaction::MacroDirectiveInfo MD) {
return VisitMacro(MD);
}
///\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) {
llvm::SmallVector<T*, 4> PrevDecls;
T* PrevDecl = R->getMostRecentDecl();
// [0]=>C [1]=>B [2]=>A ...
while (PrevDecl) { // Collect the redeclarations, except the one we remove
if (PrevDecl != R)
PrevDecls.push_back(PrevDecl);
PrevDecl = PrevDecl->getPreviousDecl();
}
if (!PrevDecls.empty()) {
// Make sure we update the lookup maps, because the removed decl might
// be registered in the lookup and again findable.
StoredDeclsMap* Map = DC->getPrimaryContext()->getLookupPtr();
if (Map) {
NamedDecl* ND = (NamedDecl*)((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();
for(DeclContext::lookup_result::iterator I = decls.begin(),
E = decls.end(); I != E; ++I) {
// FIXME: A decl meant to be added in the lookup already exists
// in the lookup table. My assumption is that the DeclReverted
// adds it here. This needs to be investigated mode. For now
// std::find gets promoted from assert to condition :)
if (*I == ND && std::find(decls.begin(), decls.end(),
PrevDecls[0]) == decls.end()) {
// The decl was registered in the lookup, update it.
*I = PrevDecls[0];
break;
}
}
}
}
}
// Put 0 in the end of the array so that the loop will reset the
// pointer to latest redeclaration in the chain to itself.
//
PrevDecls.push_back(0);
// 0 <- A <- B <- C
for(unsigned i = PrevDecls.size() - 1; i > 0; --i) {
PrevDecls[i-1]->setPreviousDecl(PrevDecls[i]);
}
}
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 reverted declaration.
///
void CollectFilesToUncache(SourceLocation Loc);
};
DeclReverter::~DeclReverter() {
SourceManager& SM = m_Sema->getSourceManager();
for (FileIDs::iterator I = m_FilesToUncache.begin(),
E = m_FilesToUncache.end(); I != E; ++I) {
const SrcMgr::FileInfo& fInfo = SM.getSLocEntry(*I).getFile();
// We need to reset the cache
SrcMgr::ContentCache* cache
= const_cast<SrcMgr::ContentCache*>(fInfo.getContentCache());
FileEntry* entry = const_cast<FileEntry*>(cache->ContentsEntry);
// We have to reset the file entry size to keep the cache and the file
// entry in sync.
if (entry) {
cache->replaceBuffer(0,/*free*/true);
FileManager::modifyFileEntry(entry, /*size*/0, 0);
}
}
// Clean up the pending instantiations
m_Sema->PendingInstantiations.clear();
m_Sema->PendingLocalImplicitInstantiations.clear();
}
void DeclReverter::CollectFilesToUncache(SourceLocation Loc) {
const SourceManager& SM = m_Sema->getSourceManager();
FileID FID = SM.getFileID(SM.getSpellingLoc(Loc));
if (!FID.isInvalid() && FID >= m_CurTransaction->getBufferFID()
&& !m_FilesToUncache.count(FID))
m_FilesToUncache.insert(FID);
}
bool DeclReverter::VisitDecl(Decl* D) {
assert(D && "The Decl is null");
CollectFilesToUncache(D->getLocStart());
DeclContext* DC = D->getLexicalDeclContext();
bool Successful = true;
if (DC->containsDecl(D))
DC->removeDecl(D);
// With the bump allocator this is nop.
if (Successful)
m_Sema->getASTContext().Deallocate(D);
return Successful;
}
bool DeclReverter::VisitNamedDecl(NamedDecl* ND) {
bool Successful = VisitDecl(ND);
DeclContext* DC = ND->getDeclContext();
while (DC->isTransparentContext())
DC = DC->getLookupParent();
// if the decl was anonymous we are done.
if (!ND->getIdentifier())
return Successful;
// If the decl was removed make sure that we fix the lookup
if (Successful) {
if (Scope* S = m_Sema->getScopeForContext(DC))
S->RemoveDecl(ND);
if (utils::Analyze::isOnScopeChains(ND, *m_Sema))
m_Sema->IdResolver.RemoveDecl(ND);
}
// Cleanup the lookup tables.
StoredDeclsMap *Map = DC->getPrimaryContext()->getLookupPtr();
if (Map) { // DeclContexts like EnumDecls don't have lookup maps.
// Make sure we the decl doesn't exist in the lookup tables.
StoredDeclsMap::iterator Pos = Map->find(ND->getDeclName());
if ( Pos != Map->end()) {
// Most decls only have one entry in their list, special case it.
if (Pos->second.getAsDecl() == ND)
Pos->second.remove(ND);
else if (StoredDeclsList::DeclsTy* Vec = Pos->second.getAsVector()) {
// Otherwise iterate over the list with entries with the same name.
for (StoredDeclsList::DeclsTy::const_iterator I = Vec->begin(),
E = Vec->end(); I != E; ++I)
if (*I == ND)
Pos->second.remove(ND);
}
if (Pos->second.isNull() ||
(Pos->second.getAsVector() && !Pos->second.getAsVector()->size()))
Map->erase(Pos);
}
}
#ifndef NDEBUG
if (Map) { // DeclContexts like EnumDecls don't have lookup maps.
// Make sure we the decl doesn't exist in the lookup tables.
StoredDeclsMap::iterator Pos = Map->find(ND->getDeclName());
if ( Pos != Map->end()) {
// Most decls only have one entry in their list, special case it.
if (NamedDecl *OldD = Pos->second.getAsDecl())
assert(OldD != ND && "Lookup entry still exists.");
else if (StoredDeclsList::DeclsTy* Vec = Pos->second.getAsVector()) {
// Otherwise iterate over the list with entries with the same name.
// TODO: Walk the redeclaration chain if the entry was a redeclaration.
for (StoredDeclsList::DeclsTy::const_iterator I = Vec->begin(),
E = Vec->end(); I != E; ++I)
assert(*I != ND && "Lookup entry still exists.");
}
else
assert(Pos->second.isNull() && "!?");
}
}
#endif
return Successful;
}
bool DeclReverter::VisitUsingShadowDecl(UsingShadowDecl* USD) {
// UsingShadowDecl: NamedDecl, Redeclarable
bool Successful = false;
// FIXME: This is needed when we have newest clang:
//Successful = VisitRedeclarable(USD, USD->getDeclContext());
Successful &= VisitNamedDecl(USD);
// Unregister from the using decl that it shadows.
USD->getUsingDecl()->removeShadowDecl(USD);
return Successful;
}
bool DeclReverter::VisitTypedefNameDecl(TypedefNameDecl* TND) {
// TypedefNameDecl: TypeDecl, Redeclarable
bool Successful = VisitRedeclarable(TND, TND->getDeclContext());
Successful &= VisitTypeDecl(TND);
return Successful;
}
bool DeclReverter::VisitVarDecl(VarDecl* VD) {
// llvm::Module cannot contain:
// * variables and parameters with dependent context;
// * mangled names for parameters;
if (!isa<ParmVarDecl>(VD) && !VD->getDeclContext()->isDependentContext()) {
// Cleanup the module if the transaction was committed and code was
// generated. This has to go first, because it may need the AST
// information which we will remove soon. (Eg. mangleDeclName iterates the
// redecls)
GlobalDecl GD(VD);
MaybeRemoveDeclFromModule(GD);
}
// VarDecl : DeclaratiorDecl, Redeclarable
bool Successful = VisitRedeclarable(VD, VD->getDeclContext());
Successful &= VisitDeclaratorDecl(VD);
return Successful;
}
namespace {
typedef llvm::SmallVector<VarDecl*, 2> Vars;
class StaticVarCollector : public RecursiveASTVisitor<StaticVarCollector> {
Vars& m_V;
public:
StaticVarCollector(FunctionDecl* FD, Vars& V) : m_V(V) {
TraverseStmt(FD->getBody());
}
bool VisitDeclStmt(DeclStmt* DS) {
for(DeclStmt::decl_iterator I = DS->decl_begin(), E = DS->decl_end();
I != E; ++I)
if (VarDecl* VD = dyn_cast<VarDecl>(*I))
if (VD->isStaticLocal())
m_V.push_back(VD);
return true;
}
};
}
bool DeclReverter::VisitFunctionDecl(FunctionDecl* FD) {
// The Structors need to be handled differently.
if (!isa<CXXConstructorDecl>(FD) && !isa<CXXDestructorDecl>(FD)) {
// Cleanup the module if the transaction was committed and code was
// generated. This has to go first, because it may need the AST info
// which we will remove soon. (Eg. mangleDeclName iterates the redecls)
GlobalDecl GD(FD);
MaybeRemoveDeclFromModule(GD);
// Handle static locals. void func() { static int var; } is represented in
// the llvm::Module is a global named @func.var
Vars V;
StaticVarCollector c(FD, V);
for (Vars::iterator I = V.begin(), E = V.end(); I != E; ++I) {
GlobalDecl GD(*I);
MaybeRemoveDeclFromModule(GD);
}
}
// FunctionDecl : DeclaratiorDecl, DeclContext, Redeclarable
// We start with the decl context first, because parameters are part of the
// DeclContext and when trying to remove them we need the full redecl chain
// still in place.
bool Successful = VisitDeclContext(FD);
Successful &= VisitRedeclarable(FD, FD->getDeclContext());
Successful &= VisitDeclaratorDecl(FD);
// Template instantiation of templated function first creates a canonical
// declaration and after the actual template specialization. For example:
// template<typename T> T TemplatedF(T t);
// template<> int TemplatedF(int i) { return i + 1; } creates:
// 1. Canonical decl: int TemplatedF(int i);
// 2. int TemplatedF(int i){ return i + 1; }
//
// The template specialization is attached to the list of specialization of
// the templated function.
// When TemplatedF is looked up it finds the templated function and the
// lookup is extended by the templated function with its specializations.
// In the end we don't need to remove the canonical decl because, it
// doesn't end up in the lookup table.
//
class FunctionTemplateDeclExt : public FunctionTemplateDecl {
public:
static void removeSpecialization(FunctionTemplateDecl* self,
const FunctionDecl* specialization) {
assert(self && specialization && "Cannot be null!");
assert(specialization == specialization->getCanonicalDecl()
&& "Not the canonical specialization!?");
typedef llvm::SmallVector<FunctionDecl*, 4> Specializations;
typedef llvm::FoldingSetVector< FunctionTemplateSpecializationInfo> Set;
FunctionTemplateDeclExt* This = (FunctionTemplateDeclExt*) self;
Specializations specializations;
const Set& specs = This->getSpecializations();
if (!specs.size()) // nothing to remove
return;
// Collect all the specializations without the one to remove.
for(Set::const_iterator I = specs.begin(),E = specs.end(); I != E; ++I){
assert(I->Function && "Must have a specialization.");
if (I->Function != specialization)
specializations.push_back(I->Function);
}
This->getSpecializations().clear();
//Readd the collected specializations.
void* InsertPos = 0;
FunctionTemplateSpecializationInfo* FTSI = 0;
for (size_t i = 0, e = specializations.size(); i < e; ++i) {
FTSI = specializations[i]->getTemplateSpecializationInfo();
assert(FTSI && "Must not be null.");
// Avoid assertion on add.
FTSI->SetNextInBucket(0);
This->addSpecialization(FTSI, InsertPos);
}
#ifndef NDEBUG
const TemplateArgumentList* args
= specialization->getTemplateSpecializationArgs();
assert(!self->findSpecialization(args->data(), args->size(), InsertPos)
&& "Finds the removed decl again!");
#endif
}
};
if (FD->isFunctionTemplateSpecialization() && FD->isCanonicalDecl()) {
// Only the canonical declarations are registered in the list of the
// specializations.
FunctionTemplateDecl* FTD
= FD->getTemplateSpecializationInfo()->getTemplate();
// The canonical declaration of every specialization is registered with
// the FunctionTemplateDecl.
// Note this might revert too much in the case:
// template<typename T> T f(){ return T();}
// template<> int f();
// template<> int f() { return 0;}
// when the template specialization was forward declared the canonical
// becomes the first forward declaration. If the canonical forward
// declaration was declared outside the set of the decls to revert we have
// to keep it registered as a template specialization.
//
// In order to diagnose mismatches of the specializations, clang 'injects'
// a implicit forward declaration making it very hard distinguish between
// the explicit and the implicit forward declaration. So far the only way
// to distinguish is by source location comparison.
// FIXME: When the misbehavior of clang is fixed we must avoid relying on
// source locations
FunctionTemplateDeclExt::removeSpecialization(FTD, FD);
}
return Successful;
}
bool DeclReverter::VisitCXXConstructorDecl(CXXConstructorDecl* CXXCtor) {
// Cleanup the module if the transaction was committed and code was
// generated. This has to go first, because it may need the AST information
// which we will remove soon. (Eg. mangleDeclName iterates the redecls)
// Brute-force all possibly generated ctors.
// Ctor_Complete Complete object ctor.
// Ctor_Base Base object ctor.
// Ctor_CompleteAllocating Complete object allocating ctor.
GlobalDecl GD(CXXCtor, Ctor_Complete);
MaybeRemoveDeclFromModule(GD);
GD = GlobalDecl(CXXCtor, Ctor_Base);
MaybeRemoveDeclFromModule(GD);
GD = GlobalDecl(CXXCtor, Ctor_CompleteAllocating);
MaybeRemoveDeclFromModule(GD);
bool Successful = VisitCXXMethodDecl(CXXCtor);
return Successful;
}
bool DeclReverter::VisitDeclContext(DeclContext* DC) {
bool Successful = true;
typedef llvm::SmallVector<Decl*, 64> Decls;
Decls declsToErase;
// Removing from single-linked list invalidates the iterators.
for (DeclContext::decl_iterator I = DC->decls_begin();
I != DC->decls_end(); ++I) {
declsToErase.push_back(*I);
}
for(Decls::iterator I = declsToErase.begin(), E = declsToErase.end();
I != E; ++I)
Successful = Visit(*I) && Successful;
return Successful;
}
bool DeclReverter::VisitNamespaceDecl(NamespaceDecl* NSD) {
// NamespaceDecl: NamedDecl, DeclContext, Redeclarable
bool Successful = VisitRedeclarable(NSD, NSD->getDeclContext());
Successful &= VisitDeclContext(NSD);
Successful &= VisitNamedDecl(NSD);
return Successful;
}
bool DeclReverter::VisitTagDecl(TagDecl* TD) {
// TagDecl: TypeDecl, DeclContext, Redeclarable
bool Successful = VisitRedeclarable(TD, TD->getDeclContext());
Successful &= VisitDeclContext(TD);
Successful &= VisitTypeDecl(TD);
return Successful;
}
bool DeclReverter::VisitRecordDecl(RecordDecl* RD) {
if (RD->isInjectedClassName())
return true;
/// The injected class name in C++ is the name of the class that
/// appears inside the class itself. For example:
///
/// \code
/// struct C {
/// // C is implicitly declared here as a synonym for the class name.
/// };
///
/// C::C c; // same as "C c;"
/// \endcode
// It is another question why it is on the redecl chain.
// The test show it can be either:
// ... <- InjectedC <- C <- ..., i.e previous decl or
// ... <- C <- InjectedC <- ...
RecordDecl* InjectedRD = RD->getPreviousDecl();
if (!(InjectedRD && InjectedRD->isInjectedClassName())) {
InjectedRD = RD->getMostRecentDecl();
while (InjectedRD) {
if (InjectedRD->isInjectedClassName()
&& InjectedRD->getPreviousDecl() == RD)
break;
InjectedRD = InjectedRD->getPreviousDecl();
}
}
bool Successful = true;
if (InjectedRD) {
assert(InjectedRD->isInjectedClassName() && "Not injected classname?");
Successful &= VisitRedeclarable(InjectedRD, InjectedRD->getDeclContext());
}
Successful &= VisitTagDecl(RD);
return Successful;
}
void DeclReverter::MaybeRemoveDeclFromModule(GlobalDecl& GD) const {
if (!m_CurTransaction->getModule()) // syntax-only mode exit
return;
using namespace llvm;
// if it was successfully removed from the AST we have to check whether
// code was generated and remove it.
// From llvm's mailing list, explanation of the RAUW'd assert:
//
// The problem isn't with your call to
// replaceAllUsesWith per se, the problem is that somebody (I would guess
// the JIT?) is holding it in a ValueMap.
//
// We used to have a problem that some parts of the code would keep a
// mapping like so:
// std::map<Value *, ...>
// while somebody else would modify the Value* without them noticing,
// leading to a dangling pointer in the map. To fix that, we invented the
// ValueMap which puts a Use that doesn't show up in the use_iterator on
// the Value it holds. When the Value is erased or RAUW'd, the ValueMap is
// notified and in this case decides that's not okay and terminates the
// program.
//
// Probably what's happened here is that the calling function has had its
// code generated by the JIT, but not the callee. Thus the JIT emitted a
// call to a generated stub, and will do the codegen of the callee once
// that stub is reached. Of course, once the JIT is in this state, it holds
// on to the Function with a ValueMap in order to prevent things from
// getting out of sync.
//
if (m_CurTransaction->getState() == Transaction::kCommitted) {
std::string mangledName;
utils::Analyze::maybeMangleDeclName(GD, mangledName);
// Handle static locals. void func() { static int var; } is represented in
// the llvm::Module is a global named @func.var
if (const VarDecl* VD = dyn_cast<VarDecl>(GD.getDecl()))
if (VD->isStaticLocal()) {
std::string functionMangledName;
GlobalDecl FDGD(cast<FunctionDecl>(VD->getDeclContext()));
utils::Analyze::maybeMangleDeclName(FDGD, functionMangledName);
mangledName = functionMangledName + "." + mangledName;
}
GlobalValue* GV
= m_CurTransaction->getModule()->getNamedValue(mangledName);
if (GV) { // May be deferred decl and thus 0
// createGVExtractionPass - If deleteFn is true, this pass deletes
// the specified global values. Otherwise, it deletes as much of the
// module as possible, except for the global values specified.
//
//std::vector<GlobalValue*> GVs;
//GVs.push_back(GV);
//llvm::ModulePass* GVExtract = llvm::createGVExtractionPass(GVs, true);
//GVExtract->runOnModule(*m_CurTransaction->getModule());
GV->removeDeadConstantUsers();
if (!GV->use_empty()) {
// Assert that if there was a use it is not coming from the explicit
// AST node, but from the implicitly generated functions, which ensure
// the initialization order semantics. Such functions are:
// _GLOBAL__I* and __cxx_global_var_init*
//
// We can 'afford' to drop all the references because we know that the
// static init functions must be called only once, and that was
// already done.
SmallVector<User*, 4> uses;
for(llvm::Value::use_iterator I = GV->use_begin(), E = GV->use_end();
I != E; ++I) {
uses.push_back(*I);
}
for(SmallVector<User*, 4>::iterator I = uses.begin(), E = uses.end();
I != E; ++I)
if (llvm::Instruction* instr = dyn_cast<llvm::Instruction>(*I)) {
llvm::Function* F = instr->getParent()->getParent();
if (F->getName().startswith("__cxx_global_var_init"))
RemoveStaticInit(*F);
}
}
// Cleanup the jit mapping of GV->addr.
m_EEngine->updateGlobalMapping(GV, 0);
GV->dropAllReferences();
if (!GV->use_empty()) {
if (Function* F = dyn_cast<Function>(GV)) {
Function* dummy
= Function::Create(F->getFunctionType(), F->getLinkage());
F->replaceAllUsesWith(dummy);
}
else
GV->replaceAllUsesWith(UndefValue::get(GV->getType()));
}
GV->eraseFromParent();
}
}
}
void DeclReverter::RemoveStaticInit(llvm::Function& F) const {
// In our very controlled case the parent of the BasicBlock is the
// static init llvm::Function.
assert(F.getName().startswith("__cxx_global_var_init")
&& "Not a static init");
assert(F.hasInternalLinkage() && "Not a static init");
// The static init functions have the layout:
// declare internal void @__cxx_global_var_init1() section "..."
//
// define internal void @_GLOBAL__I_a2() section "..." {
// entry:
// call void @__cxx_global_var_init1()
// ret void
// }
//
assert(F.hasOneUse() && "Must have only one use");
// erase _GLOBAL__I* first
llvm::BasicBlock* BB = cast<llvm::Instruction>(F.use_back())->getParent();
BB->getParent()->eraseFromParent();
F.eraseFromParent();
}
bool DeclReverter::VisitMacro(Transaction::MacroDirectiveInfo MacroD) {
assert(MacroD.m_MD && "The MacroDirective is null");
assert(MacroD.m_II && "The IdentifierInfo is null");
CollectFilesToUncache(MacroD.m_MD->getLocation());
Preprocessor& PP = m_Sema->getPreprocessor();
#ifndef NDEBUG
bool ExistsInPP = false;
// Make sure the macro is in the Preprocessor. Not sure if not redundant
// because removeMacro looks for the macro anyway in the DenseMap Macros[]
for (Preprocessor::macro_iterator
I = PP.macro_begin(/*IncludeExternalMacros*/false),
E = PP.macro_end(/*IncludeExternalMacros*/false); E !=I; ++I) {
if ((*I).first == MacroD.m_II) {
// FIXME:check whether we have the concrete directive on the macro chain
// && (*I).second == MacroD.m_MD
ExistsInPP = true;
break;
}
}
assert(ExistsInPP && "Not in the Preprocessor?!");
#endif
const MacroDirective* MD = MacroD.m_MD;
// Undef the definition
const MacroInfo* MI = MD->getMacroInfo();
// If the macro is not defined, this is a noop undef, just return.
if (MI == 0)
return false;
// Remove the pair from the macros
PP.removeMacro(MacroD.m_II, const_cast<MacroDirective*>(MacroD.m_MD));
return true;
}
bool DeclReverter::VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl* R){
// RedeclarableTemplateDecl: TemplateDecl, Redeclarable
bool Successful = VisitRedeclarable(R, R->getDeclContext());
Successful &= VisitTemplateDecl(R);
return Successful;
}
bool DeclReverter::VisitFunctionTemplateDecl(FunctionTemplateDecl* FTD) {
bool Successful = true;
// Remove specializations:
for (FunctionTemplateDecl::spec_iterator I = FTD->spec_begin(),
E = FTD->spec_end(); I != E; ++I)
Successful &= Visit(*I);
Successful &= VisitRedeclarableTemplateDecl(FTD);
Successful &= VisitFunctionDecl(FTD->getTemplatedDecl());
return Successful;
}
bool DeclReverter::VisitClassTemplateDecl(ClassTemplateDecl* CTD) {
// ClassTemplateDecl: TemplateDecl, Redeclarable
bool Successful = true;
// Remove specializations:
for (ClassTemplateDecl::spec_iterator I = CTD->spec_begin(),
E = CTD->spec_end(); I != E; ++I)
Successful &= Visit(*I);
Successful &= VisitRedeclarableTemplateDecl(CTD);
Successful &= Visit(CTD->getTemplatedDecl());
return Successful;
}
bool DeclReverter::VisitClassTemplateSpecializationDecl(
ClassTemplateSpecializationDecl* CTSD) {
// A template specialization is attached to the list of specialization of
// the templated class.
//
class ClassTemplateDeclExt : public ClassTemplateDecl {
public:
static void removeSpecialization(ClassTemplateDecl* self,
ClassTemplateSpecializationDecl* spec) {
assert(self && spec && "Cannot be null!");
assert(spec == spec->getCanonicalDecl()
&& "Not the canonical specialization!?");
typedef llvm::SmallVector<ClassTemplateSpecializationDecl*, 4> Specializations;
typedef llvm::FoldingSetVector<ClassTemplateSpecializationDecl> Set;
ClassTemplateDeclExt* This = (ClassTemplateDeclExt*) self;
Specializations specializations;
Set& specs = This->getSpecializations();
if (!specs.size()) // nothing to remove
return;
// Collect all the specializations without the one to remove.
for(Set::iterator I = specs.begin(),E = specs.end(); I != E; ++I){
if (&*I != spec)
specializations.push_back(&*I);
}
This->getSpecializations().clear();
//Readd the collected specializations.
void* InsertPos = 0;
ClassTemplateSpecializationDecl* CTSD = 0;
for (size_t i = 0, e = specializations.size(); i < e; ++i) {
CTSD = specializations[i];
assert(CTSD && "Must not be null.");
// Avoid assertion on add.
CTSD->SetNextInBucket(0);
This->AddSpecialization(CTSD, InsertPos);
}
}
};
ClassTemplateSpecializationDecl* CanonCTSD =
static_cast<ClassTemplateSpecializationDecl*>(CTSD->getCanonicalDecl());
ClassTemplateDeclExt::removeSpecialization(CTSD->getSpecializedTemplate(),
CanonCTSD);
// ClassTemplateSpecializationDecl: CXXRecordDecl, FoldingSet
return VisitCXXRecordDecl(CTSD);
}
ASTNodeEraser::ASTNodeEraser(Sema* S, llvm::ExecutionEngine* EE)
: m_Sema(S), m_EEngine(EE) {
}
ASTNodeEraser::~ASTNodeEraser() {
}
bool ASTNodeEraser::RevertTransaction(Transaction* T) {
DeclReverter DeclRev(m_Sema, m_EEngine, T);
bool Successful = true;
for (Transaction::const_reverse_iterator I = T->rdecls_begin(),
E = T->rdecls_end(); I != E; ++I) {
if ((*I).m_Call != Transaction::kCCIHandleTopLevelDecl)
continue;
const DeclGroupRef& DGR = (*I).m_DGR;
for (DeclGroupRef::const_iterator
Di = DGR.end() - 1, E = DGR.begin() - 1; Di != E; --Di) {
// Get rid of the declaration. If the declaration has name we should
// heal the lookup tables as well
Successful = DeclRev.RevertDecl(*Di) && Successful;
#ifndef NDEBUG
assert(Successful && "Cannot handle that yet!");
#endif
}
}
for (Transaction::const_reverse_macros_iterator MI = T->rmacros_begin(),
ME = T->rmacros_end(); MI != ME; ++MI) {
// Get rid of the macro definition
Successful = DeclRev.RevertMacro(*MI) && Successful;
#ifndef NDEBUG
assert(Successful && "Cannot handle that yet!");
#endif
}
m_Sema->getDiagnostics().Reset();
m_Sema->getDiagnostics().getClient()->clear();
// Cleanup the module from unused global values.
// if (T->getModule()) {
// llvm::ModulePass* globalDCE = llvm::createGlobalDCEPass();
// globalDCE->runOnModule(*T->getModule());
// }
if (Successful)
T->setState(Transaction::kRolledBack);
else
T->setState(Transaction::kRolledBackWithErrors);
return Successful;
}
} // end namespace cling
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