1 //===-- SymbolTable.cpp - Implement the SymbolTable class -----------------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and revised by Reid
6 // Spencer. It is distributed under the University of Illinois Open Source
7 // License. See LICENSE.TXT for details.
9 //===----------------------------------------------------------------------===//
11 // This file implements the SymbolTable class for the VMCore library.
13 //===----------------------------------------------------------------------===//
15 #include "llvm/SymbolTable.h"
16 #include "llvm/DerivedTypes.h"
17 #include "llvm/Module.h"
18 #include "Support/StringExtras.h"
23 #define DEBUG_SYMBOL_TABLE 0
24 #define DEBUG_ABSTYPE 0
26 SymbolTable::~SymbolTable() {
27 // Drop all abstract type references in the type plane...
28 for (type_iterator TI = tmap.begin(), TE = tmap.end(); TI != TE; ++TI) {
29 if (TI->second->isAbstract()) // If abstract, drop the reference...
30 cast<DerivedType>(TI->second)->removeAbstractTypeUser(this);
33 // TODO: FIXME: BIG ONE: This doesn't unreference abstract types for the
34 // planes that could still have entries!
36 #ifndef NDEBUG // Only do this in -g mode...
37 bool LeftoverValues = true;
38 for (plane_iterator PI = pmap.begin(); PI != pmap.end(); ++PI) {
39 for (value_iterator VI = PI->second.begin(); VI != PI->second.end(); ++VI)
40 if (!isa<Constant>(VI->second) ) {
41 std::cerr << "Value still in symbol table! Type = '"
42 << PI->first->getDescription() << "' Name = '"
43 << VI->first << "'\n";
44 LeftoverValues = false;
48 assert(LeftoverValues && "Values remain in symbol table!");
52 // getUniqueName - Given a base name, return a string that is either equal to
53 // it (or derived from it) that does not already occur in the symbol table for
54 // the specified type.
56 std::string SymbolTable::getUniqueName(const Type *Ty,
57 const std::string &BaseName) const {
59 plane_const_iterator PI = pmap.find(Ty);
60 if (PI == pmap.end()) return BaseName;
62 std::string TryName = BaseName;
63 const ValueMap& vmap = PI->second;
64 value_const_iterator End = vmap.end();
66 // See if the name exists
67 while (vmap.find(TryName) != End) // Loop until we find a free
68 TryName = BaseName + utostr(++LastUnique); // name in the symbol table
73 // lookup a value - Returns null on failure...
74 Value *SymbolTable::lookup(const Type *Ty, const std::string &Name) const {
75 plane_const_iterator PI = pmap.find(Ty);
76 if (PI != pmap.end()) { // We have symbols in that plane...
77 value_const_iterator VI = PI->second.find(Name);
78 if (VI != PI->second.end()) // and the name is in our hash table...
85 // lookup a type by name - returns null on failure
86 Type* SymbolTable::lookupType( const std::string& Name ) const {
87 type_const_iterator TI = tmap.find( Name );
88 if ( TI != tmap.end() )
94 void SymbolTable::remove(Value *N) {
95 assert(N->hasName() && "Value doesn't have name!");
96 assert(!isa<Type>(N) && "Can't remove types through this interface.");
97 if (InternallyInconsistent) return;
99 plane_iterator PI = pmap.find(N->getType());
100 assert(PI != pmap.end() &&
101 "Trying to remove a value that doesn't have a type plane yet!");
102 removeEntry(PI, PI->second.find(N->getName()));
106 // removeEntry - Remove a value from the symbol table...
107 Value *SymbolTable::removeEntry(plane_iterator Plane, value_iterator Entry) {
108 if (InternallyInconsistent) return 0;
109 assert(Plane != pmap.end() &&
110 Entry != Plane->second.end() && "Invalid entry to remove!");
112 Value *Result = Entry->second;
113 assert(!isa<Type>(Result) && "Can't remove types through this interface.");
114 #if DEBUG_SYMBOL_TABLE
116 std::cerr << " Removing Value: " << Result->getName() << "\n";
119 // Remove the value from the plane...
120 Plane->second.erase(Entry);
122 // If the plane is empty, remove it now!
123 if (Plane->second.empty()) {
124 // If the plane represented an abstract type that we were interested in,
125 // unlink ourselves from this plane.
127 if (Plane->first->isAbstract()) {
129 std::cerr << "Plane Empty: Removing type: "
130 << Plane->first->getDescription() << "\n";
132 cast<DerivedType>(Plane->first)->removeAbstractTypeUser(this);
141 // remove - Remove a type
142 void SymbolTable::remove(Type* Ty ) {
143 type_iterator TI = this->type_begin();
144 type_iterator TE = this->type_end();
146 // Search for the entry
147 while ( TI != TE && TI->second != Ty )
151 this->removeEntry( TI );
155 // removeEntry - Remove a type from the symbol table...
156 Type* SymbolTable::removeEntry(type_iterator Entry) {
157 if (InternallyInconsistent) return 0;
158 assert( Entry != tmap.end() && "Invalid entry to remove!");
160 Type* Result = Entry->second;
162 #if DEBUG_SYMBOL_TABLE
164 std::cerr << " Removing Value: " << Result->getName() << "\n";
169 // If we are removing an abstract type, remove the symbol table from it's use
171 if (Result->isAbstract()) {
173 std::cerr << "Removing abstract type from symtab" << Result->getDescription()<<"\n";
175 cast<DerivedType>(Result)->removeAbstractTypeUser(this);
182 // insertEntry - Insert a value into the symbol table with the specified name.
183 void SymbolTable::insertEntry(const std::string &Name, const Type *VTy,
185 assert(!isa<Type>(V) && "Can't insert types through this interface.");
186 // Check to see if there is a naming conflict. If so, rename this value!
187 if (lookup(VTy, Name)) {
188 std::string UniqueName = getUniqueName(VTy, Name);
189 assert(InternallyInconsistent == false && "Infinite loop inserting value!");
190 InternallyInconsistent = true;
191 V->setName(UniqueName, this);
192 InternallyInconsistent = false;
196 #if DEBUG_SYMBOL_TABLE
198 std::cerr << " Inserting definition: " << Name << ": "
199 << VTy->getDescription() << "\n";
202 plane_iterator PI = pmap.find(VTy);
203 if (PI == pmap.end()) { // Not in collection yet... insert dummy entry
204 // Insert a new empty element. I points to the new elements.
205 PI = pmap.insert(make_pair(VTy, ValueMap())).first;
206 assert(PI != pmap.end() && "How did insert fail?");
208 // Check to see if the type is abstract. If so, it might be refined in the
209 // future, which would cause the plane of the old type to get merged into
212 if (VTy->isAbstract()) {
213 cast<DerivedType>(VTy)->addAbstractTypeUser(this);
215 std::cerr << "Added abstract type value: " << VTy->getDescription()
221 PI->second.insert(make_pair(Name, V));
225 // insertEntry - Insert a value into the symbol table with the specified
228 void SymbolTable::insertEntry(const std::string& Name, Type* T) {
230 // Check to see if there is a naming conflict. If so, rename this type!
231 std::string UniqueName = Name;
232 if (lookupType(Name))
233 UniqueName = getUniqueName(T, Name);
235 #if DEBUG_SYMBOL_TABLE
237 std::cerr << " Inserting type: " << UniqueName << ": "
238 << T->getDescription() << "\n";
241 // Insert the tmap entry
242 tmap.insert(make_pair(UniqueName, T));
244 // If we are adding an abstract type, add the symbol table to it's use list.
245 if (T->isAbstract()) {
246 cast<DerivedType>(T)->addAbstractTypeUser(this);
248 std::cerr << "Added abstract type to ST: " << T->getDescription() << "\n";
254 // Determine how many entries for a given type.
255 unsigned SymbolTable::type_size(const Type *Ty) const {
256 plane_const_iterator PI = pmap.find(Ty);
257 if ( PI == pmap.end() ) return 0;
258 return PI->second.size();
262 // Get the name of a value
263 std::string SymbolTable::get_name( const Value* V ) const {
264 assert(!isa<Type>(V) && "Can't get name of types through this interface.");
265 value_const_iterator VI = this->value_begin( V->getType() );
266 value_const_iterator VE = this->value_end( V->getType() );
268 // Search for the entry
269 while ( VI != VE && VI->second != V )
279 // Get the name of a type
280 std::string SymbolTable::get_name( const Type* T ) const {
281 if (tmap.empty()) return ""; // No types at all.
283 type_const_iterator TI = tmap.begin();
284 type_const_iterator TE = tmap.end();
286 // Search for the entry
287 while (TI != TE && TI->second != T )
290 if (TI != TE) // Must have found an entry!
292 return ""; // Must not have found anything...
296 // Strip the symbol table of its names.
297 bool SymbolTable::strip( void ) {
298 bool RemovedSymbol = false;
299 for (plane_iterator I = pmap.begin(); I != pmap.end();) {
300 // Removing items from the plane can cause the plane itself to get deleted.
301 // If this happens, make sure we incremented our plane iterator already!
302 ValueMap &Plane = (I++)->second;
303 value_iterator B = Plane.begin(), Bend = Plane.end();
304 while (B != Bend) { // Found nonempty type plane!
305 Value *V = B->second;
306 if (isa<Constant>(V)) {
308 RemovedSymbol = true;
310 if (!isa<GlobalValue>(V) || cast<GlobalValue>(V)->hasInternalLinkage()){
311 // Set name to "", removing from symbol table!
312 V->setName("", this);
313 RemovedSymbol = true;
320 for (type_iterator TI = tmap.begin(); TI != tmap.end(); ) {
321 Type* T = (TI++)->second;
323 RemovedSymbol = true;
326 return RemovedSymbol;
330 // This function is called when one of the types in the type plane are refined
331 void SymbolTable::refineAbstractType(const DerivedType *OldType,
332 const Type *NewType) {
334 // Search to see if we have any values of the type Oldtype. If so, we need to
335 // move them into the newtype plane...
336 plane_iterator PI = pmap.find(OldType);
337 if (PI != pmap.end()) {
338 // Get a handle to the new type plane...
339 plane_iterator NewTypeIt = pmap.find(NewType);
340 if (NewTypeIt == pmap.end()) { // If no plane exists, add one
341 NewTypeIt = pmap.insert(make_pair(NewType, ValueMap())).first;
343 if (NewType->isAbstract()) {
344 cast<DerivedType>(NewType)->addAbstractTypeUser(this);
346 std::cerr << "[Added] refined to abstype: " << NewType->getDescription()
352 ValueMap &NewPlane = NewTypeIt->second;
353 ValueMap &OldPlane = PI->second;
354 while (!OldPlane.empty()) {
355 std::pair<const std::string, Value*> V = *OldPlane.begin();
357 // Check to see if there is already a value in the symbol table that this
358 // would collide with.
359 value_iterator VI = NewPlane.find(V.first);
360 if (VI != NewPlane.end() && VI->second == V.second) {
363 } else if (VI != NewPlane.end()) {
364 // The only thing we are allowing for now is two external global values
367 GlobalValue *ExistGV = dyn_cast<GlobalValue>(VI->second);
368 GlobalValue *NewGV = dyn_cast<GlobalValue>(V.second);
370 if (ExistGV && NewGV) {
371 assert((ExistGV->isExternal() || NewGV->isExternal()) &&
372 "Two planes folded together with overlapping value names!");
374 // Make sure that ExistGV is the one we want to keep!
375 if (!NewGV->isExternal())
376 std::swap(NewGV, ExistGV);
378 // Ok we have two external global values. Make all uses of the new
379 // one use the old one...
380 NewGV->uncheckedReplaceAllUsesWith(ExistGV);
382 // Now we just convert it to an unnamed method... which won't get
383 // added to our symbol table. The problem is that if we call
384 // setName on the method that it will try to remove itself from
385 // the symbol table and die... because it's not in the symtab
386 // right now. To fix this, we have an internally consistent flag
387 // that turns remove into a noop. Thus the name will get null'd
388 // out, but the symbol table won't get upset.
390 assert(InternallyInconsistent == false &&
391 "Symbol table already inconsistent!");
392 InternallyInconsistent = true;
394 // Remove newM from the symtab
396 InternallyInconsistent = false;
398 // Now we can remove this global from the module entirely...
399 Module *M = NewGV->getParent();
400 if (Function *F = dyn_cast<Function>(NewGV))
401 M->getFunctionList().remove(F);
403 M->getGlobalList().remove(cast<GlobalVariable>(NewGV));
406 // If they are not global values, they must be just random values who
407 // happen to conflict now that types have been resolved. If this is
408 // the case, reinsert the value into the new plane, allowing it to get
410 assert(V.second->getType() == NewType &&"Type resolution is broken!");
414 insertEntry(V.first, NewType, V.second);
417 // Remove the item from the old type plane
418 OldPlane.erase(OldPlane.begin());
421 // Ok, now we are not referencing the type anymore... take me off your user
424 std::cerr << "Removing type " << OldType->getDescription() << "\n";
426 OldType->removeAbstractTypeUser(this);
428 // Remove the plane that is no longer used
432 // Loop over all of the types in the symbol table, replacing any references
433 // to OldType with references to NewType. Note that there may be multiple
434 // occurrences, and although we only need to remove one at a time, it's
435 // faster to remove them all in one pass.
437 for (type_iterator I = type_begin(), E = type_end(); I != E; ++I) {
438 if (I->second == (Type*)OldType) { // FIXME when Types aren't const.
440 std::cerr << "Removing type " << OldType->getDescription() << "\n";
442 OldType->removeAbstractTypeUser(this);
444 I->second = (Type*)NewType; // TODO FIXME when types aren't const
445 if (NewType->isAbstract()) {
447 std::cerr << "Added type " << NewType->getDescription() << "\n";
449 cast<DerivedType>(NewType)->addAbstractTypeUser(this);
456 // Handle situation where type becomes Concreate from Abstract
457 void SymbolTable::typeBecameConcrete(const DerivedType *AbsTy) {
458 plane_iterator PI = pmap.find(AbsTy);
460 // If there are any values in the symbol table of this type, then the type
461 // plane is a use of the abstract type which must be dropped.
462 if (PI != pmap.end())
463 AbsTy->removeAbstractTypeUser(this);
465 // Loop over all of the types in the symbol table, dropping any abstract
466 // type user entries for AbsTy which occur because there are names for the
468 for (type_iterator TI = type_begin(), TE = type_end(); TI != TE; ++TI)
469 if (TI->second == (Type*)AbsTy) // FIXME when Types aren't const.
470 AbsTy->removeAbstractTypeUser(this);
473 static void DumpVal(const std::pair<const std::string, Value *> &V) {
474 std::cerr << " '" << V.first << "' = ";
479 static void DumpPlane(const std::pair<const Type *,
480 std::map<const std::string, Value *> >&P){
483 for_each(P.second.begin(), P.second.end(), DumpVal);
486 static void DumpTypes(const std::pair<const std::string, Type*>& T ) {
487 std::cerr << " '" << T.first << "' = ";
492 void SymbolTable::dump() const {
493 std::cerr << "Symbol table dump:\n Plane:";
494 for_each(pmap.begin(), pmap.end(), DumpPlane);
495 std::cerr << " Types: ";
496 for_each(tmap.begin(), tmap.end(), DumpTypes);