1 //===- ReadConst.cpp - Code to constants and constant pools ---------------===//
3 // This file implements functionality to deserialize constants and entire
6 // Note that this library should be as fast as possible, reentrant, and
9 //===----------------------------------------------------------------------===//
11 #include "ReaderInternals.h"
12 #include "llvm/Module.h"
13 #include "llvm/Constants.h"
16 const Type *BytecodeParser::parseTypeConstant(const uchar *&Buf,
17 const uchar *EndBuf) {
19 if (read_vbr(Buf, EndBuf, PrimType)) return 0;
22 if ((Val = Type::getPrimitiveType((Type::PrimitiveID)PrimType)))
26 case Type::FunctionTyID: {
28 if (read_vbr(Buf, EndBuf, Typ)) return Val;
29 const Type *RetType = getType(Typ);
30 if (RetType == 0) return Val;
33 if (read_vbr(Buf, EndBuf, NumParams)) return Val;
35 std::vector<const Type*> Params;
37 if (read_vbr(Buf, EndBuf, Typ)) return Val;
38 const Type *Ty = getType(Typ);
39 if (Ty == 0) return Val;
43 bool isVarArg = Params.size() && Params.back() == Type::VoidTy;
44 if (isVarArg) Params.pop_back();
46 return FunctionType::get(RetType, Params, isVarArg);
48 case Type::ArrayTyID: {
50 if (read_vbr(Buf, EndBuf, ElTyp)) return Val;
51 const Type *ElementType = getType(ElTyp);
52 if (ElementType == 0) return Val;
55 if (read_vbr(Buf, EndBuf, NumElements)) return Val;
57 BCR_TRACE(5, "Array Type Constant #" << ElTyp << " size="
58 << NumElements << "\n");
59 return ArrayType::get(ElementType, NumElements);
61 case Type::StructTyID: {
63 std::vector<const Type*> Elements;
65 if (read_vbr(Buf, EndBuf, Typ)) return Val;
66 while (Typ) { // List is terminated by void/0 typeid
67 const Type *Ty = getType(Typ);
68 if (Ty == 0) return Val;
69 Elements.push_back(Ty);
71 if (read_vbr(Buf, EndBuf, Typ)) return Val;
74 return StructType::get(Elements);
76 case Type::PointerTyID: {
78 if (read_vbr(Buf, EndBuf, ElTyp)) return Val;
79 BCR_TRACE(5, "Pointer Type Constant #" << (ElTyp-14) << "\n");
80 const Type *ElementType = getType(ElTyp);
81 if (ElementType == 0) return Val;
82 return PointerType::get(ElementType);
85 case Type::OpaqueTyID: {
86 return OpaqueType::get();
90 std::cerr << __FILE__ << ":" << __LINE__
91 << ": Don't know how to deserialize"
92 << " primitive Type " << PrimType << "\n";
97 // refineAbstractType - The callback method is invoked when one of the
98 // elements of TypeValues becomes more concrete...
100 void BytecodeParser::refineAbstractType(const DerivedType *OldType,
101 const Type *NewType) {
102 if (OldType == NewType &&
103 OldType->isAbstract()) return; // Type is modified, but same
105 TypeValuesListTy::iterator I = find(FunctionTypeValues.begin(),
106 FunctionTypeValues.end(), OldType);
107 if (I == FunctionTypeValues.end()) {
108 I = find(ModuleTypeValues.begin(), ModuleTypeValues.end(), OldType);
109 assert(I != ModuleTypeValues.end() &&
110 "Can't refine a type I don't know about!");
113 if (OldType == NewType) {
114 assert(!OldType->isAbstract());
115 I->removeUserFromConcrete();
117 *I = NewType; // Update to point to new, more refined type.
123 // parseTypeConstants - We have to use this wierd code to handle recursive
124 // types. We know that recursive types will only reference the current slab of
125 // values in the type plane, but they can forward reference types before they
126 // have been read. For example, Type #0 might be '{ Ty#1 }' and Type #1 might
127 // be 'Ty#0*'. When reading Type #0, type number one doesn't exist. To fix
128 // this ugly problem, we pesimistically insert an opaque type for each type we
129 // are about to read. This means that forward references will resolve to
130 // something and when we reread the type later, we can replace the opaque type
131 // with a new resolved concrete type.
133 void debug_type_tables();
134 bool BytecodeParser::parseTypeConstants(const uchar *&Buf, const uchar *EndBuf,
135 TypeValuesListTy &Tab,
136 unsigned NumEntries) {
137 assert(Tab.size() == 0 && "should not have read type constants in before!");
139 // Insert a bunch of opaque types to be resolved later...
140 for (unsigned i = 0; i < NumEntries; ++i)
141 Tab.push_back(PATypeHandle<Type>(OpaqueType::get(), this));
143 // Loop through reading all of the types. Forward types will make use of the
144 // opaque types just inserted.
146 for (unsigned i = 0; i < NumEntries; ++i) {
147 const Type *NewTy = parseTypeConstant(Buf, EndBuf), *OldTy = Tab[i].get();
148 if (NewTy == 0) return true;
149 BCR_TRACE(4, "#" << i << ": Read Type Constant: '" << NewTy <<
150 "' Replacing: " << OldTy << "\n");
152 // Don't insertValue the new type... instead we want to replace the opaque
153 // type with the new concrete value...
156 // Refine the abstract type to the new type. This causes all uses of the
157 // abstract type to use the newty. This also will cause the opaque type
160 ((DerivedType*)Tab[i].get())->refineAbstractTypeTo(NewTy);
162 // This should have replace the old opaque type with the new type in the
163 // value table... or with a preexisting type that was already in the system
164 assert(Tab[i] != OldTy && "refineAbstractType didn't work!");
167 BCR_TRACE(5, "Resulting types:\n");
168 for (unsigned i = 0; i < NumEntries; ++i) {
169 BCR_TRACE(5, (void*)Tab[i].get() << " - " << Tab[i].get() << "\n");
176 bool BytecodeParser::parseConstantValue(const uchar *&Buf, const uchar *EndBuf,
177 const Type *Ty, Constant *&V) {
179 // We must check for a ConstantExpr before switching by type because
180 // a ConstantExpr can be of any type, and has no explicit value.
182 unsigned isExprNumArgs; // 0 if not expr; numArgs if is expr
183 if (read_vbr(Buf, EndBuf, isExprNumArgs)) return true;
185 // FIXME: Encoding of constant exprs could be much more compact!
187 std::vector<Constant*> ArgVec;
188 ArgVec.reserve(isExprNumArgs);
189 if (read_vbr(Buf, EndBuf, Opcode)) return true;
191 // Read the slot number and types of each of the arguments
192 for (unsigned i = 0; i != isExprNumArgs; ++i) {
193 unsigned ArgValSlot, ArgTypeSlot;
194 if (read_vbr(Buf, EndBuf, ArgValSlot)) return true;
195 if (read_vbr(Buf, EndBuf, ArgTypeSlot)) return true;
196 const Type *ArgTy = getType(ArgTypeSlot);
197 if (ArgTy == 0) return true;
199 BCR_TRACE(4, "CE Arg " << i << ": Type: '" << ArgTy << "' slot: "
200 << ArgValSlot << "\n");
202 // Get the arg value from its slot if it exists, otherwise a placeholder
203 Constant *C = getConstantValue(ArgTy, ArgValSlot);
204 if (C == 0) return true;
208 // Construct a ConstantExpr of the appropriate kind
209 if (isExprNumArgs == 1) { // All one-operand expressions
210 assert(Opcode == Instruction::Cast);
211 V = ConstantExpr::getCast(ArgVec[0], Ty);
212 } else if (Opcode == Instruction::GetElementPtr) { // GetElementPtr
213 std::vector<Constant*> IdxList(ArgVec.begin()+1, ArgVec.end());
214 V = ConstantExpr::getGetElementPtr(ArgVec[0], IdxList);
215 } else { // All other 2-operand expressions
216 V = ConstantExpr::get(Opcode, ArgVec[0], ArgVec[1]);
221 // Ok, not an ConstantExpr. We now know how to read the given type...
222 switch (Ty->getPrimitiveID()) {
223 case Type::BoolTyID: {
225 if (read_vbr(Buf, EndBuf, Val)) return true;
226 if (Val != 0 && Val != 1) return true;
227 V = ConstantBool::get(Val == 1);
231 case Type::UByteTyID: // Unsigned integer types...
232 case Type::UShortTyID:
233 case Type::UIntTyID: {
235 if (read_vbr(Buf, EndBuf, Val)) return true;
236 if (!ConstantUInt::isValueValidForType(Ty, Val)) return true;
237 V = ConstantUInt::get(Ty, Val);
241 case Type::ULongTyID: {
243 if (read_vbr(Buf, EndBuf, Val)) return true;
244 V = ConstantUInt::get(Ty, Val);
248 case Type::SByteTyID: // Unsigned integer types...
249 case Type::ShortTyID:
250 case Type::IntTyID: {
252 if (read_vbr(Buf, EndBuf, Val)) return true;
253 if (!ConstantSInt::isValueValidForType(Ty, Val)) return true;
254 V = ConstantSInt::get(Ty, Val);
258 case Type::LongTyID: {
260 if (read_vbr(Buf, EndBuf, Val)) return true;
261 V = ConstantSInt::get(Ty, Val);
265 case Type::FloatTyID: {
267 if (input_data(Buf, EndBuf, &F, &F+1)) return true;
268 V = ConstantFP::get(Ty, F);
272 case Type::DoubleTyID: {
274 if (input_data(Buf, EndBuf, &Val, &Val+1)) return true;
275 V = ConstantFP::get(Ty, Val);
280 assert(0 && "Type constants should be handled seperately!!!");
283 case Type::ArrayTyID: {
284 const ArrayType *AT = cast<const ArrayType>(Ty);
285 unsigned NumElements = AT->getNumElements();
287 std::vector<Constant*> Elements;
288 while (NumElements--) { // Read all of the elements of the constant.
290 if (read_vbr(Buf, EndBuf, Slot)) return true;
291 Constant *C = getConstantValue(AT->getElementType(), Slot);
293 Elements.push_back(C);
295 V = ConstantArray::get(AT, Elements);
299 case Type::StructTyID: {
300 const StructType *ST = cast<StructType>(Ty);
301 const StructType::ElementTypes &ET = ST->getElementTypes();
303 std::vector<Constant *> Elements;
304 for (unsigned i = 0; i < ET.size(); ++i) {
306 if (read_vbr(Buf, EndBuf, Slot)) return true;
307 Constant *C = getConstantValue(ET[i], Slot);
309 Elements.push_back(C);
312 V = ConstantStruct::get(ST, Elements);
316 case Type::PointerTyID: {
317 const PointerType *PT = cast<const PointerType>(Ty);
319 if (HasImplicitZeroInitializer)
322 if (read_vbr(Buf, EndBuf, SubClass)) return true;
325 case 0: // ConstantPointerNull value...
326 V = ConstantPointerNull::get(PT);
329 case 1: { // ConstantPointerRef value...
331 if (read_vbr(Buf, EndBuf, Slot)) return true;
332 BCR_TRACE(4, "CPR: Type: '" << Ty << "' slot: " << Slot << "\n");
334 // Check to see if we have already read this global variable...
335 Value *Val = getValue(PT, Slot, false);
338 if (!(GV = dyn_cast<GlobalValue>(Val))) return true;
339 BCR_TRACE(5, "Value Found in ValueTable!\n");
340 } else if (RevisionNum > 0) {
341 // Revision #0 could have forward references to globals that were wierd.
342 // We got rid of this in subsequent revs.
344 } else { // Nope... find or create a forward ref. for it
345 GlobalRefsType::iterator I = GlobalRefs.find(std::make_pair(PT, Slot));
347 if (I != GlobalRefs.end()) {
348 BCR_TRACE(5, "Previous forward ref found!\n");
349 GV = cast<GlobalValue>(I->second);
351 BCR_TRACE(5, "Creating new forward ref to a global variable!\n");
353 // Create a placeholder for the global variable reference...
354 GlobalVariable *GVar =
355 new GlobalVariable(PT->getElementType(), false,
356 GlobalValue::InternalLinkage);
358 // Keep track of the fact that we have a forward ref to recycle it
359 GlobalRefs.insert(std::make_pair(std::make_pair(PT, Slot), GVar));
361 // Must temporarily push this value into the module table...
362 TheModule->getGlobalList().push_back(GVar);
367 V = ConstantPointerRef::get(GV);
372 BCR_TRACE(5, "UNKNOWN Pointer Constant Type!\n");
379 std::cerr << __FILE__ << ":" << __LINE__
380 << ": Don't know how to deserialize constant value of type '"
381 << Ty->getName() << "'\n";
388 bool BytecodeParser::ParseGlobalTypes(const uchar *&Buf, const uchar *EndBuf) {
390 return ParseConstantPool(Buf, EndBuf, T, ModuleTypeValues);
393 bool BytecodeParser::ParseConstantPool(const uchar *&Buf, const uchar *EndBuf,
395 TypeValuesListTy &TypeTab) {
396 while (Buf < EndBuf) {
397 unsigned NumEntries, Typ;
399 if (read_vbr(Buf, EndBuf, NumEntries) ||
400 read_vbr(Buf, EndBuf, Typ)) return true;
401 const Type *Ty = getType(Typ);
402 if (Ty == 0) return true;
403 BCR_TRACE(3, "Type: '" << Ty << "' NumEntries: " << NumEntries << "\n");
405 if (Typ == Type::TypeTyID) {
406 if (parseTypeConstants(Buf, EndBuf, TypeTab, NumEntries)) return true;
408 for (unsigned i = 0; i < NumEntries; ++i) {
411 if (parseConstantValue(Buf, EndBuf, Ty, C)) return true;
412 assert(C && "parseConstantValue returned NULL!");
413 BCR_TRACE(4, "Read Constant: '" << *C << "'\n");
414 if ((Slot = insertValue(C, Tab)) == -1) return true;
416 // If we are reading a function constant table, make sure that we adjust
417 // the slot number to be the real global constant number.
419 if (&Tab != &ModuleValues && Typ < ModuleValues.size())
420 Slot += ModuleValues[Typ]->size();
421 ResolveReferencesToValue(C, (unsigned)Slot);
426 if (Buf > EndBuf) return true;