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cling/lib/Interpreter/TransactionUnloader.cpp
Philippe Canal 36e5b1eec0 Use isa (instead of dync_cast) for type testing
2015-10-23 18:22:26 +02:00

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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 "TransactionUnloader.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/CodeGen/ModuleBuilder.h"
#include "clang/Sema/Scope.h"
#include "clang/Sema/Sema.h"
#include "clang/Lex/MacroInfo.h"
#include "clang/Lex/Preprocessor.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Module.h"
//#include "llvm/Transforms/IPO.h"
using namespace clang;
// FIXME: rename back to cling when gcc fix the
// namespace cling { using cling::DeclUnloader DeclUnloader} bug
namespace clang {
using namespace cling;
// Copied and adapted from GlobalDCE.cpp
class GlobalValueEraser {
private:
typedef llvm::SmallPtrSet<llvm::GlobalValue*, 32> Globals;
Globals VisitedGlobals;
llvm::SmallPtrSet<llvm::Constant *, 8> SeenConstants;
clang::CodeGenerator* m_CodeGen;
public:
GlobalValueEraser(clang::CodeGenerator* CG)
: m_CodeGen(CG) { }
///\brief Erases the given global value and all unused leftovers
///
///\param[in] GV - The removal starting point.
///
///\returns true if something was erased.
///
bool EraseGlobalValue(llvm::GlobalValue* GV) {
using namespace llvm;
bool Changed = false;
Changed |= RemoveUnusedGlobalValue(*GV);
// Collect all uses of globals by GV
CollectAllUsesOfGlobals(GV);
FindUsedValues(*GV->getParent());
// The first pass is to drop initializers of global vars which are dead.
for (Globals::iterator I = VisitedGlobals.begin(),
E = VisitedGlobals.end(); I != E; ++I)
if (GlobalVariable* GV = dyn_cast<GlobalVariable>(*I)) {
GV->setInitializer(0);
}
else if (GlobalAlias* GA = dyn_cast<GlobalAlias>(*I)) {
GA->setAliasee(0);
}
else {
Function* F = cast<Function>(*I);
if (!F->isDeclaration())
F->deleteBody();
}
if (!VisitedGlobals.empty()) {
// Now that all interferences have been dropped, delete the actual
// objects themselves.
for (Globals::iterator I = VisitedGlobals.begin(),
E = VisitedGlobals.end(); I != E; ++I) {
RemoveUnusedGlobalValue(**I);
if ((*I)->getNumUses())
continue;
// Required by ::DwarfEHPrepare::InsertUnwindResumeCalls (in the JIT)
if ((*I)->getName().equals("_Unwind_Resume"))
continue;
m_CodeGen->forgetGlobal(*I);
(*I)->eraseFromParent();
}
Changed = true;
}
// Make sure that all memory is released
VisitedGlobals.clear();
SeenConstants.clear();
return Changed;
}
private:
/// Find values that are marked as llvm.used.
void FindUsedValues(const llvm::Module& m) {
for (const llvm::GlobalVariable& GV : m.globals()) {
if (!GV.getName().startswith("llvm.used"))
continue;
const llvm::ConstantArray* Inits
= cast<llvm::ConstantArray>(GV.getInitializer());
for (unsigned i = 0, e = Inits->getNumOperands(); i != e; ++i) {
llvm::Value *Operand
= Inits->getOperand(i)->stripPointerCastsNoFollowAliases();
VisitedGlobals.erase(cast<llvm::GlobalValue>(Operand));
}
}
}
/// CollectAllUsesOfGlobals - collects recursively all referenced globals by
/// GV.
void CollectAllUsesOfGlobals(llvm::GlobalValue *G) {
using namespace llvm;
// If the global is already in the set, no need to reprocess it.
if (!VisitedGlobals.insert(G).second)
return;
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(G)) {
// If this is a global variable, we must make sure to add any global
// values referenced by the initializer to the collection set.
if (GV->hasInitializer())
MarkConstant(GV->getInitializer());
} else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(G)) {
// The target of a global alias as referenced.
MarkConstant(GA->getAliasee());
} else {
// Otherwise this must be a function object. We have to scan the body
// of the function looking for constants and global values which are
// used as operands. Any operands of these types must be processed to
// ensure that any globals used will be marked as collected.
Function *F = cast<Function>(G);
if (F->hasPrefixData())
MarkConstant(F->getPrefixData());
for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
for (User::op_iterator U = I->op_begin(), E = I->op_end();U!=E; ++U)
if (GlobalValue *GV = dyn_cast<GlobalValue>(*U))
CollectAllUsesOfGlobals(GV);
else if (Constant *C = dyn_cast<Constant>(*U))
MarkConstant(C);
}
}
void MarkConstant(llvm::Constant *C) {
using namespace llvm;
if (GlobalValue *GV = dyn_cast<GlobalValue>(C))
return CollectAllUsesOfGlobals(GV);
// Loop over all of the operands of the constant, adding any globals they
// use to the list of needed globals.
for (User::op_iterator I = C->op_begin(), E = C->op_end(); I != E; ++I) {
Constant *Op = dyn_cast<Constant>(*I);
// We already processed this constant there's no need to do it again.
if (Op && SeenConstants.insert(Op).second)
MarkConstant(Op);
}
}
// RemoveUnusedGlobalValue - Loop over all of the uses of the specified
// GlobalValue, looking for the constant pointer ref that may be pointing to
// it. If found, check to see if the constant pointer ref is safe to
// destroy, and if so, nuke it. This will reduce the reference count on the
// global value, which might make it deader.
//
bool RemoveUnusedGlobalValue(llvm::GlobalValue &GV) {
using namespace llvm;
if (GV.use_empty())
return false;
GV.removeDeadConstantUsers();
return GV.use_empty();
}
};
///\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 = canon;
}
}
// 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;
static DeclLink& 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(DeclLink::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 again 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();
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 DeclUnloader
// 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(),
MostRecentNotThis)
== decls.end()) {
// The decl was registered in the lookup, update it.
*I = MostRecentNotThis;
break;
}
}
}
}
}
// 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);
};
DeclUnloader::~DeclUnloader() {
SourceManager& SM = m_Sema->getSourceManager();
for (FileIDs::iterator I = m_FilesToUncache.begin(),
E = m_FilesToUncache.end(); I != E; ++I) {
// We need to reset the cache
SM.invalidateCache(*I);
}
}
void DeclUnloader::CollectFilesToUncache(SourceLocation Loc) {
if (!m_CurTransaction)
return;
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 DeclUnloader::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 DeclUnloader::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 DeclUnloader::VisitDeclaratorDecl(DeclaratorDecl* DD) {
// VisitDeclaratorDecl: ValueDecl
auto found = std::find(m_Sema->UnusedFileScopedDecls.begin(/*ExtSource*/0,
/*Local*/true),
m_Sema->UnusedFileScopedDecls.end(), DD);
if (found != m_Sema->UnusedFileScopedDecls.end())
m_Sema->UnusedFileScopedDecls.erase(found,
m_Sema->UnusedFileScopedDecls.end());
return VisitValueDecl(DD);
}
bool DeclUnloader::VisitUsingShadowDecl(UsingShadowDecl* USD) {
// UsingShadowDecl: NamedDecl, Redeclarable
bool Successful = true;
// 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 DeclUnloader::VisitTypedefNameDecl(TypedefNameDecl* TND) {
// TypedefNameDecl: TypeDecl, Redeclarable
bool Successful = VisitRedeclarable(TND, TND->getDeclContext());
Successful &= VisitTypeDecl(TND);
return Successful;
}
bool DeclUnloader::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 DeclUnloader::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);
}
}
// VisitRedeclarable() will mess around with this!
bool wasCanonical = FD->isCanonicalDecl();
// 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->asArray(), InsertPos)
&& "Finds the removed decl again!");
#endif
}
};
if (FD->isFunctionTemplateSpecialization() && wasCanonical) {
// 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 unload 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 unload 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 DeclUnloader::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_Comdat The COMDAT used for ctors.
GlobalDecl GD(CXXCtor, Ctor_Complete);
MaybeRemoveDeclFromModule(GD);
GD = GlobalDecl(CXXCtor, Ctor_Base);
MaybeRemoveDeclFromModule(GD);
GD = GlobalDecl(CXXCtor, Ctor_Comdat);
MaybeRemoveDeclFromModule(GD);
bool Successful = VisitCXXMethodDecl(CXXCtor);
return Successful;
}
bool DeclUnloader::VisitCXXDestructorDecl(CXXDestructorDecl* CXXDtor) {
// 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 dtors.
// Dtor_Deleting Deleting dtor.
// Dtor_Complete Complete object dtor.
// Dtor_Base Base object dtor.
// Dtor_Comdat The COMDAT used for dtors.
GlobalDecl GD(CXXDtor, Dtor_Deleting);
MaybeRemoveDeclFromModule(GD);
GD = GlobalDecl(CXXDtor, Dtor_Complete);
MaybeRemoveDeclFromModule(GD);
GD = GlobalDecl(CXXDtor, Dtor_Base);
MaybeRemoveDeclFromModule(GD);
GD = GlobalDecl(CXXDtor, Dtor_Comdat);
MaybeRemoveDeclFromModule(GD);
bool Successful = VisitCXXMethodDecl(CXXDtor);
return Successful;
}
bool DeclUnloader::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->noload_decls_begin();
I != DC->noload_decls_end(); ++I) {
declsToErase.push_back(*I);
}
for(Decls::reverse_iterator I = declsToErase.rbegin(),
E = declsToErase.rend(); I != E; ++I) {
Successful = Visit(*I) && Successful;
assert(Successful);
}
return Successful;
}
bool DeclUnloader::VisitNamespaceDecl(NamespaceDecl* NSD) {
// NamespaceDecl: NamedDecl, DeclContext, Redeclarable
bool Successful = VisitDeclContext(NSD);
Successful &= VisitRedeclarable(NSD, NSD->getDeclContext());
Successful &= VisitNamedDecl(NSD);
return Successful;
}
bool DeclUnloader::VisitTagDecl(TagDecl* TD) {
// TagDecl: TypeDecl, DeclContext, Redeclarable
bool Successful = VisitDeclContext(TD);
Successful &= VisitRedeclarable(TD, TD->getDeclContext());
Successful &= VisitTypeDecl(TD);
return Successful;
}
bool DeclUnloader::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 DeclUnloader::MaybeRemoveDeclFromModule(GlobalDecl& GD) const {
if (!m_CurTransaction
|| !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;
}
llvm::Module* M = m_CurTransaction->getModule();
GlobalValue* GV = M->getNamedValue(mangledName);
if (GV) { // May be deferred decl and thus 0
GlobalValueEraser GVEraser(m_CodeGen);
GVEraser.EraseGlobalValue(GV);
}
}
}
bool DeclUnloader::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 DeclUnloader::VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl* R){
// RedeclarableTemplateDecl: TemplateDecl, Redeclarable
bool Successful = VisitRedeclarable(R, R->getDeclContext());
Successful &= VisitTemplateDecl(R);
return Successful;
}
bool DeclUnloader::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 DeclUnloader::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;
}
namespace {
// 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(!isa<ClassTemplatePartialSpecializationDecl>(spec) &&
"Use removePartialSpecialization");
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);
}
}
static void removePartialSpecialization(ClassTemplateDecl* self,
ClassTemplatePartialSpecializationDecl* spec) {
assert(self && spec && "Cannot be null!");
assert(spec == spec->getCanonicalDecl()
&& "Not the canonical specialization!?");
typedef llvm::SmallVector<ClassTemplatePartialSpecializationDecl*, 4>
Specializations;
typedef llvm::FoldingSetVector<ClassTemplatePartialSpecializationDecl> Set;
ClassTemplateDeclExt* This = (ClassTemplateDeclExt*) self;
Specializations specializations;
Set& specs = This->getPartialSpecializations();
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->getPartialSpecializations().clear();
//Readd the collected specializations.
void* InsertPos = 0;
ClassTemplatePartialSpecializationDecl* CTPSD = 0;
for (size_t i = 0, e = specializations.size(); i < e; ++i) {
CTPSD = specializations[i];
assert(CTPSD && "Must not be null.");
// Avoid assertion on add.
CTPSD->SetNextInBucket(0);
This->AddPartialSpecialization(CTPSD, InsertPos);
}
}
};
} // end anonymous namespace
bool DeclUnloader::VisitClassTemplateSpecializationDecl(
ClassTemplateSpecializationDecl* CTSD) {
// ClassTemplateSpecializationDecl: CXXRecordDecl, FoldingSet
bool Successful = VisitCXXRecordDecl(CTSD);
ClassTemplateSpecializationDecl* CanonCTSD =
static_cast<ClassTemplateSpecializationDecl*>(CTSD->getCanonicalDecl());
if (auto D = dyn_cast<ClassTemplatePartialSpecializationDecl>(CanonCTSD))
ClassTemplateDeclExt::removePartialSpecialization(
D->getSpecializedTemplate(),
D);
else
ClassTemplateDeclExt::removeSpecialization(CTSD->getSpecializedTemplate(),
CanonCTSD);
return Successful;
}
} // end namespace clang
namespace cling {
TransactionUnloader::TransactionUnloader(Sema* S, clang::CodeGenerator* CG)
: m_Sema(S), m_CodeGen(CG) {
}
TransactionUnloader::~TransactionUnloader() {
}
bool TransactionUnloader::RevertTransaction(Transaction* T) {
if (Transaction* Parent = T->getParent()) {
Parent->removeNestedTransaction(T);
T->setParent(0);
}
DeclUnloader DeclU(m_Sema, m_CodeGen, T);
bool Successful = true;
for (Transaction::const_reverse_iterator I = T->rdecls_begin(),
E = T->rdecls_end(); I != E; ++I) {
const Transaction::ConsumerCallInfo& Call = I->m_Call;
const DeclGroupRef& DGR = (*I).m_DGR;
if (Call == Transaction::kCCIHandleVTable)
continue;
// The non templated classes come through HandleTopLevelDecl and
// HandleTagDeclDefinition, this is why we need to filter.
if (Call == Transaction::kCCIHandleTagDeclDefinition)
if (const CXXRecordDecl* D
= dyn_cast<CXXRecordDecl>(DGR.getSingleDecl()))
if (D->getTemplateSpecializationKind() == TSK_Undeclared)
continue;
if (Call == Transaction::kCCINone)
RevertTransaction(*T->rnested_begin());
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 = DeclU.UnloadDecl(*Di) && Successful;
#ifndef NDEBUG
assert(Successful && "Cannot handle that yet!");
#endif
}
}
assert(T->rnested_begin() == T->rnested_end() && "nested transactions mismatch");
for (Transaction::const_reverse_macros_iterator MI = T->rmacros_begin(),
ME = T->rmacros_end(); MI != ME; ++MI) {
// Get rid of the macro definition
Successful = DeclU.UnloadMacro(*MI) && Successful;
#ifndef NDEBUG
assert(Successful && "Cannot handle that yet!");
#endif
}
#ifndef NDEBUG
//FIXME: Move the nested transaction marker out of the decl lists and
// reenable this assertion.
//size_t DeclSize = std::distance(T->decls_begin(), T->decls_end());
//if (T->getCompilationOpts().CodeGenerationForModule)
// assert (!DeclSize && "No parsed decls must happen in parse for module");
#endif
//FIXME: Terrible hack, we *must* get rid of parseForModule by implementing
// a header file generator in cling.
for (Transaction::const_reverse_iterator I = T->deserialized_rdecls_begin(),
E = T->deserialized_rdecls_end(); I != E; ++I) {
const DeclGroupRef& DGR = (*I).m_DGR;
for (DeclGroupRef::const_iterator
Di = DGR.end() - 1, E = DGR.begin() - 1; Di != E; --Di) {
// We only want to revert all that came through parseForModule, and
// not the PCH.
if (!(*Di)->isFromASTFile())
Successful = DeclU.UnloadDecl(*Di) && Successful;
#ifndef NDEBUG
assert(Successful && "Cannot handle that yet!");
#endif
}
}
// Clean up the pending instantiations
m_Sema->PendingInstantiations.clear();
m_Sema->PendingLocalImplicitInstantiations.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;
}
bool TransactionUnloader::UnloadDecl(Decl* D) {
DeclUnloader DeclU(m_Sema, m_CodeGen, 0);
return DeclU.UnloadDecl(D);
}
} // end namespace cling
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