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 if (InternallyInconsistent) return;
98 plane_iterator PI = pmap.find(N->getType());
99 assert(PI != pmap.end() &&
100 "Trying to remove a value that doesn't have a type plane yet!");
101 removeEntry(PI, PI->second.find(N->getName()));
105 // removeEntry - Remove a value from the symbol table...
106 Value *SymbolTable::removeEntry(plane_iterator Plane, value_iterator Entry) {
107 if (InternallyInconsistent) return 0;
108 assert(Plane != pmap.end() &&
109 Entry != Plane->second.end() && "Invalid entry to remove!");
111 Value *Result = Entry->second;
112 const Type *Ty = Result->getType();
113 #if DEBUG_SYMBOL_TABLE
115 std::cerr << " Removing Value: " << Result->getName() << "\n";
118 // Remove the value from the plane...
119 Plane->second.erase(Entry);
121 // If the plane is empty, remove it now!
122 if (Plane->second.empty()) {
123 // If the plane represented an abstract type that we were interested in,
124 // unlink ourselves from this plane.
126 if (Plane->first->isAbstract()) {
128 std::cerr << "Plane Empty: Removing type: "
129 << Plane->first->getDescription() << "\n";
131 cast<DerivedType>(Plane->first)->removeAbstractTypeUser(this);
140 // remove - Remove a type
141 void SymbolTable::remove(Type* Ty ) {
142 type_iterator TI = this->type_begin();
143 type_iterator TE = this->type_end();
145 // Search for the entry
146 while ( TI != TE && TI->second != Ty )
150 this->removeEntry( TI );
154 // removeEntry - Remove a type from the symbol table...
155 Type* SymbolTable::removeEntry(type_iterator Entry) {
156 if (InternallyInconsistent) return 0;
157 assert( Entry != tmap.end() && "Invalid entry to remove!");
159 Type* Result = Entry->second;
161 #if DEBUG_SYMBOL_TABLE
163 std::cerr << " Removing Value: " << Result->getName() << "\n";
168 // If we are removing an abstract type, remove the symbol table from it's use
170 if (Result->isAbstract()) {
172 std::cerr << "Removing abstract type from symtab" << Result->getDescription()<<"\n";
174 cast<DerivedType>(Result)->removeAbstractTypeUser(this);
181 // insertEntry - Insert a value into the symbol table with the specified name.
182 void SymbolTable::insertEntry(const std::string &Name, const Type *VTy,
184 // Check to see if there is a naming conflict. If so, rename this value!
185 if (lookup(VTy, Name)) {
186 std::string UniqueName = getUniqueName(VTy, Name);
187 assert(InternallyInconsistent == false && "Infinite loop inserting value!");
188 InternallyInconsistent = true;
189 V->setName(UniqueName, this);
190 InternallyInconsistent = false;
194 #if DEBUG_SYMBOL_TABLE
196 std::cerr << " Inserting definition: " << Name << ": "
197 << VTy->getDescription() << "\n";
200 plane_iterator PI = pmap.find(VTy);
201 if (PI == pmap.end()) { // Not in collection yet... insert dummy entry
202 // Insert a new empty element. I points to the new elements.
203 PI = pmap.insert(make_pair(VTy, ValueMap())).first;
204 assert(PI != pmap.end() && "How did insert fail?");
206 // Check to see if the type is abstract. If so, it might be refined in the
207 // future, which would cause the plane of the old type to get merged into
210 if (VTy->isAbstract()) {
211 cast<DerivedType>(VTy)->addAbstractTypeUser(this);
213 std::cerr << "Added abstract type value: " << VTy->getDescription()
219 PI->second.insert(make_pair(Name, V));
223 // insertEntry - Insert a value into the symbol table with the specified
226 void SymbolTable::insertEntry(const std::string& Name, Type* T) {
228 // Check to see if there is a naming conflict. If so, rename this type!
229 std::string UniqueName = Name;
230 if (lookupType(Name))
231 UniqueName = getUniqueName(T, Name);
233 #if DEBUG_SYMBOL_TABLE
235 std::cerr << " Inserting type: " << UniqueName << ": "
236 << T->getDescription() << "\n";
239 // Insert the tmap entry
240 tmap.insert(make_pair(UniqueName, T));
242 // If we are adding an abstract type, add the symbol table to it's use list.
243 if (T->isAbstract()) {
244 cast<DerivedType>(T)->addAbstractTypeUser(this);
246 std::cerr << "Added abstract type to ST: " << T->getDescription() << "\n";
252 // Determine how many entries for a given type.
253 unsigned SymbolTable::type_size(const Type *Ty) const {
254 plane_const_iterator PI = pmap.find(Ty);
255 if ( PI == pmap.end() ) return 0;
256 return PI->second.size();
260 // Get the name of a value
261 std::string SymbolTable::get_name( const Value* V ) const {
262 value_const_iterator VI = this->value_begin( V->getType() );
263 value_const_iterator VE = this->value_end( V->getType() );
265 // Search for the entry
266 while ( VI != VE && VI->second != V )
276 // Get the name of a type
277 std::string SymbolTable::get_name( const Type* T ) const {
278 if (tmap.empty()) return ""; // No types at all.
280 type_const_iterator TI = tmap.begin();
281 type_const_iterator TE = tmap.end();
283 // Search for the entry
284 while (TI != TE && TI->second != T )
287 if (TI != TE) // Must have found an entry!
289 return ""; // Must not have found anything...
293 // Strip the symbol table of its names.
294 bool SymbolTable::strip( void ) {
295 bool RemovedSymbol = false;
296 for (plane_iterator I = pmap.begin(); I != pmap.end();) {
297 // Removing items from the plane can cause the plane itself to get deleted.
298 // If this happens, make sure we incremented our plane iterator already!
299 ValueMap &Plane = (I++)->second;
300 value_iterator B = Plane.begin(), Bend = Plane.end();
301 while (B != Bend) { // Found nonempty type plane!
302 Value *V = B->second;
303 if (isa<Constant>(V)) {
305 RemovedSymbol = true;
307 if (!isa<GlobalValue>(V) || cast<GlobalValue>(V)->hasInternalLinkage()){
308 // Set name to "", removing from symbol table!
309 V->setName("", this);
310 RemovedSymbol = true;
317 for (type_iterator TI = tmap.begin(); TI != tmap.end(); ) {
318 Type* T = (TI++)->second;
320 RemovedSymbol = true;
323 return RemovedSymbol;
327 // This function is called when one of the types in the type plane are refined
328 void SymbolTable::refineAbstractType(const DerivedType *OldType,
329 const Type *NewType) {
331 // Search to see if we have any values of the type Oldtype. If so, we need to
332 // move them into the newtype plane...
333 plane_iterator PI = pmap.find(OldType);
334 if (PI != pmap.end()) {
335 // Get a handle to the new type plane...
336 plane_iterator NewTypeIt = pmap.find(NewType);
337 if (NewTypeIt == pmap.end()) { // If no plane exists, add one
338 NewTypeIt = pmap.insert(make_pair(NewType, ValueMap())).first;
340 if (NewType->isAbstract()) {
341 cast<DerivedType>(NewType)->addAbstractTypeUser(this);
343 std::cerr << "[Added] refined to abstype: " << NewType->getDescription()
349 ValueMap &NewPlane = NewTypeIt->second;
350 ValueMap &OldPlane = PI->second;
351 while (!OldPlane.empty()) {
352 std::pair<const std::string, Value*> V = *OldPlane.begin();
354 // Check to see if there is already a value in the symbol table that this
355 // would collide with.
356 value_iterator VI = NewPlane.find(V.first);
357 if (VI != NewPlane.end() && VI->second == V.second) {
360 } else if (VI != NewPlane.end()) {
361 // The only thing we are allowing for now is two external global values
364 GlobalValue *ExistGV = dyn_cast<GlobalValue>(VI->second);
365 GlobalValue *NewGV = dyn_cast<GlobalValue>(V.second);
367 if (ExistGV && NewGV) {
368 assert((ExistGV->isExternal() || NewGV->isExternal()) &&
369 "Two planes folded together with overlapping value names!");
371 // Make sure that ExistGV is the one we want to keep!
372 if (!NewGV->isExternal())
373 std::swap(NewGV, ExistGV);
375 // Ok we have two external global values. Make all uses of the new
376 // one use the old one...
377 NewGV->uncheckedReplaceAllUsesWith(ExistGV);
379 // Now we just convert it to an unnamed method... which won't get
380 // added to our symbol table. The problem is that if we call
381 // setName on the method that it will try to remove itself from
382 // the symbol table and die... because it's not in the symtab
383 // right now. To fix this, we have an internally consistent flag
384 // that turns remove into a noop. Thus the name will get null'd
385 // out, but the symbol table won't get upset.
387 assert(InternallyInconsistent == false &&
388 "Symbol table already inconsistent!");
389 InternallyInconsistent = true;
391 // Remove newM from the symtab
393 InternallyInconsistent = false;
395 // Now we can remove this global from the module entirely...
396 Module *M = NewGV->getParent();
397 if (Function *F = dyn_cast<Function>(NewGV))
398 M->getFunctionList().remove(F);
400 M->getGlobalList().remove(cast<GlobalVariable>(NewGV));
403 // If they are not global values, they must be just random values who
404 // happen to conflict now that types have been resolved. If this is
405 // the case, reinsert the value into the new plane, allowing it to get
407 assert(V.second->getType() == NewType &&"Type resolution is broken!");
411 insertEntry(V.first, NewType, V.second);
414 // Remove the item from the old type plane
415 OldPlane.erase(OldPlane.begin());
418 // Ok, now we are not referencing the type anymore... take me off your user
421 std::cerr << "Removing type " << OldType->getDescription() << "\n";
423 OldType->removeAbstractTypeUser(this);
425 // Remove the plane that is no longer used
429 // Loop over all of the types in the symbol table, replacing any references
430 // to OldType with references to NewType. Note that there may be multiple
431 // occurrences, and although we only need to remove one at a time, it's
432 // faster to remove them all in one pass.
434 for (type_iterator I = type_begin(), E = type_end(); I != E; ++I) {
435 if (I->second == (Type*)OldType) { // FIXME when Types aren't const.
437 std::cerr << "Removing type " << OldType->getDescription() << "\n";
439 OldType->removeAbstractTypeUser(this);
441 I->second = (Type*)NewType; // TODO FIXME when types aren't const
442 if (NewType->isAbstract()) {
444 std::cerr << "Added type " << NewType->getDescription() << "\n";
446 cast<DerivedType>(NewType)->addAbstractTypeUser(this);
453 // Handle situation where type becomes Concreate from Abstract
454 void SymbolTable::typeBecameConcrete(const DerivedType *AbsTy) {
455 plane_iterator PI = pmap.find(AbsTy);
457 // If there are any values in the symbol table of this type, then the type
458 // plane is a use of the abstract type which must be dropped.
459 if (PI != pmap.end())
460 AbsTy->removeAbstractTypeUser(this);
462 // Loop over all of the types in the symbol table, dropping any abstract
463 // type user entries for AbsTy which occur because there are names for the
465 for (type_iterator TI = type_begin(), TE = type_end(); TI != TE; ++TI)
466 if (TI->second == (Type*)AbsTy) // FIXME when Types aren't const.
467 AbsTy->removeAbstractTypeUser(this);
470 static void DumpVal(const std::pair<const std::string, Value *> &V) {
471 std::cerr << " '" << V.first << "' = ";
476 static void DumpPlane(const std::pair<const Type *,
477 std::map<const std::string, Value *> >&P){
480 for_each(P.second.begin(), P.second.end(), DumpVal);
483 static void DumpTypes(const std::pair<const std::string, Type*>& T ) {
484 std::cerr << " '" << T.first << "' = ";
489 void SymbolTable::dump() const {
490 std::cerr << "Symbol table dump:\n Plane:";
491 for_each(pmap.begin(), pmap.end(), DumpPlane);
492 std::cerr << " Types: ";
493 for_each(tmap.begin(), tmap.end(), DumpTypes);