//===-- Value.cpp - Implement the Value class -----------------------------===//
//
-// This file implements the Value and User classes.
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the Value and User classes.
//
//===----------------------------------------------------------------------===//
-#include "llvm/InstrTypes.h"
-#include "llvm/SymbolTable.h"
-#include "llvm/DerivedTypes.h"
#include "llvm/Constant.h"
-#include "Support/LeakDetector.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/InstrTypes.h"
+#include "llvm/Module.h"
+#include "llvm/ValueSymbolTable.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/LeakDetector.h"
#include <algorithm>
+using namespace llvm;
//===----------------------------------------------------------------------===//
// Value Class
return Ty;
}
-Value::Value(const Type *ty, ValueTy vty, const std::string &name)
- : Name(name), Ty(checkType(ty), this) {
- VTy = vty;
+Value::Value(const Type *ty, unsigned scid)
+ : SubclassID(scid), SubclassData(0), Ty(checkType(ty)),
+ UseList(0), Name(0) {
+ if (!isa<Constant>(this) && !isa<BasicBlock>(this))
+ assert((Ty->isFirstClassType() || Ty == Type::VoidTy ||
+ isa<OpaqueType>(ty)) &&
+ "Cannot create non-first-class values except for constants!");
}
Value::~Value() {
// Check to make sure that there are no uses of this value that are still
// around when the value is destroyed. If there are, then we have a dangling
// reference and something is wrong. This code is here to print out what is
- // still being referenced. The value in question should be printed as
+ // still being referenced. The value in question should be printed as
// a <badref>
//
- if (Uses.begin() != Uses.end()) {
- std::cerr << "While deleting: " << Ty << "%" << Name << "\n";
- for (use_const_iterator I = Uses.begin(); I != Uses.end(); ++I)
- std::cerr << "Use still stuck around after Def is destroyed:"
- << **I << "\n";
+ if (!use_empty()) {
+ DOUT << "While deleting: " << *Ty << " %" << Name << "\n";
+ for (use_iterator I = use_begin(), E = use_end(); I != E; ++I)
+ DOUT << "Use still stuck around after Def is destroyed:"
+ << **I << "\n";
}
#endif
- assert(Uses.begin() == Uses.end());
+ assert(use_empty() && "Uses remain when a value is destroyed!");
+ // If this value is named, destroy the name. This should not be in a symtab
+ // at this point.
+ if (Name)
+ Name->Destroy();
+
// There should be no uses of this object anymore, remove it.
LeakDetector::removeGarbageObject(this);
}
+/// hasNUses - Return true if this Value has exactly N users.
+///
+bool Value::hasNUses(unsigned N) const {
+ use_const_iterator UI = use_begin(), E = use_end();
+ for (; N; --N, ++UI)
+ if (UI == E) return false; // Too few.
+ return UI == E;
+}
+/// hasNUsesOrMore - Return true if this value has N users or more. This is
+/// logically equivalent to getNumUses() >= N.
+///
+bool Value::hasNUsesOrMore(unsigned N) const {
+ use_const_iterator UI = use_begin(), E = use_end();
-void Value::replaceAllUsesWith(Value *New) {
- assert(New && "Value::replaceAllUsesWith(<null>) is invalid!");
- assert(New != this && "this->replaceAllUsesWith(this) is NOT valid!");
- assert(New->getType() == getType() &&
- "replaceAllUses of value with new value of different type!");
- while (!Uses.empty()) {
- User *Use = Uses.back();
- // Must handle Constants specially, we cannot call replaceUsesOfWith on a
- // constant!
- if (Constant *C = dyn_cast<Constant>(Use)) {
- C->replaceUsesOfWithOnConstant(this, New);
- } else {
- Use->replaceUsesOfWith(this, New);
+ for (; N; --N, ++UI)
+ if (UI == E) return false; // Too few.
+
+ return true;
+}
+
+
+/// getNumUses - This method computes the number of uses of this Value. This
+/// is a linear time operation. Use hasOneUse or hasNUses to check for specific
+/// values.
+unsigned Value::getNumUses() const {
+ return (unsigned)std::distance(use_begin(), use_end());
+}
+
+static bool getSymTab(Value *V, ValueSymbolTable *&ST) {
+ ST = 0;
+ if (Instruction *I = dyn_cast<Instruction>(V)) {
+ if (BasicBlock *P = I->getParent())
+ if (Function *PP = P->getParent())
+ ST = &PP->getValueSymbolTable();
+ } else if (BasicBlock *BB = dyn_cast<BasicBlock>(V)) {
+ if (Function *P = BB->getParent())
+ ST = &P->getValueSymbolTable();
+ } else if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
+ if (Module *P = GV->getParent())
+ ST = &P->getValueSymbolTable();
+ } else if (Argument *A = dyn_cast<Argument>(V)) {
+ if (Function *P = A->getParent())
+ ST = &P->getValueSymbolTable();
+ } else {
+ assert(isa<Constant>(V) && "Unknown value type!");
+ return true; // no name is setable for this.
+ }
+ return false;
+}
+
+/// getNameStart - Return a pointer to a null terminated string for this name.
+/// Note that names can have null characters within the string as well as at
+/// their end. This always returns a non-null pointer.
+const char *Value::getNameStart() const {
+ if (Name == 0) return "";
+ return Name->getKeyData();
+}
+
+/// getNameLen - Return the length of the string, correctly handling nul
+/// characters embedded into them.
+unsigned Value::getNameLen() const {
+ return Name ? Name->getKeyLength() : 0;
+}
+
+
+std::string Value::getNameStr() const {
+ if (Name == 0) return "";
+ return std::string(Name->getKeyData(),
+ Name->getKeyData()+Name->getKeyLength());
+}
+
+void Value::setName(const std::string &name) {
+ setName(&name[0], name.size());
+}
+
+void Value::setName(const char *Name) {
+ setName(Name, Name ? strlen(Name) : 0);
+}
+
+void Value::setName(const char *NameStr, unsigned NameLen) {
+ if (NameLen == 0 && !hasName()) return;
+ assert(getType() != Type::VoidTy && "Cannot assign a name to void values!");
+
+ // Get the symbol table to update for this object.
+ ValueSymbolTable *ST;
+ if (getSymTab(this, ST))
+ return; // Cannot set a name on this value (e.g. constant).
+
+ if (!ST) { // No symbol table to update? Just do the change.
+ if (NameLen == 0) {
+ // Free the name for this value.
+ Name->Destroy();
+ Name = 0;
+ return;
+ }
+
+ if (Name) {
+ // Name isn't changing?
+ if (NameLen == Name->getKeyLength() &&
+ !memcmp(Name->getKeyData(), NameStr, NameLen))
+ return;
+ Name->Destroy();
}
+
+ // NOTE: Could optimize for the case the name is shrinking to not deallocate
+ // then reallocated.
+
+ // Create the new name.
+ Name = ValueName::Create(NameStr, NameStr+NameLen);
+ Name->setValue(this);
+ return;
}
+
+ // NOTE: Could optimize for the case the name is shrinking to not deallocate
+ // then reallocated.
+ if (hasName()) {
+ // Name isn't changing?
+ if (NameLen == Name->getKeyLength() &&
+ !memcmp(Name->getKeyData(), NameStr, NameLen))
+ return;
+
+ // Remove old name.
+ ST->removeValueName(Name);
+ Name->Destroy();
+ Name = 0;
+
+ if (NameLen == 0)
+ return;
+ }
+
+ // Name is changing to something new.
+ Name = ST->createValueName(NameStr, NameLen, this);
}
-// refineAbstractType - This function is implemented because we use
-// potentially abstract types, and these types may be resolved to more
-// concrete types after we are constructed. For the value class, we simply
-// change Ty to point to the right type. :)
-//
-void Value::refineAbstractType(const DerivedType *OldTy, const Type *NewTy) {
- assert(Ty.get() == OldTy && "Can't refine anything but my type!");
- if (OldTy == NewTy && !OldTy->isAbstract())
- Ty.removeUserFromConcrete();
- Ty = NewTy;
+
+/// takeName - transfer the name from V to this value, setting V's name to
+/// empty. It is an error to call V->takeName(V).
+void Value::takeName(Value *V) {
+ ValueSymbolTable *ST = 0;
+ // If this value has a name, drop it.
+ if (hasName()) {
+ // Get the symtab this is in.
+ if (getSymTab(this, ST)) {
+ // We can't set a name on this value, but we need to clear V's name if
+ // it has one.
+ if (V->hasName()) V->setName(0, 0);
+ return; // Cannot set a name on this value (e.g. constant).
+ }
+
+ // Remove old name.
+ if (ST)
+ ST->removeValueName(Name);
+ Name->Destroy();
+ Name = 0;
+ }
+
+ // Now we know that this has no name.
+
+ // If V has no name either, we're done.
+ if (!V->hasName()) return;
+
+ // Get this's symtab if we didn't before.
+ if (!ST) {
+ if (getSymTab(this, ST)) {
+ // Clear V's name.
+ V->setName(0, 0);
+ return; // Cannot set a name on this value (e.g. constant).
+ }
+ }
+
+ // Get V's ST, this should always succed, because V has a name.
+ ValueSymbolTable *VST;
+ bool Failure = getSymTab(V, VST);
+ assert(!Failure && "V has a name, so it should have a ST!");
+
+ // If these values are both in the same symtab, we can do this very fast.
+ // This works even if both values have no symtab yet.
+ if (ST == VST) {
+ // Take the name!
+ Name = V->Name;
+ V->Name = 0;
+ Name->setValue(this);
+ return;
+ }
+
+ // Otherwise, things are slightly more complex. Remove V's name from VST and
+ // then reinsert it into ST.
+
+ if (VST)
+ VST->removeValueName(V->Name);
+ Name = V->Name;
+ V->Name = 0;
+ Name->setValue(this);
+
+ if (ST)
+ ST->reinsertValue(this);
}
-void Value::killUse(User *U) {
- if (U == 0) return;
- unsigned i;
- // Scan backwards through the uses list looking for the user. We do this
- // because vectors like to be accessed on the end. This is incredibly
- // important from a performance perspective.
- for (i = Uses.size()-1; Uses[i] != U; --i)
- /* empty */;
+// uncheckedReplaceAllUsesWith - This is exactly the same as replaceAllUsesWith,
+// except that it doesn't have all of the asserts. The asserts fail because we
+// are half-way done resolving types, which causes some types to exist as two
+// different Type*'s at the same time. This is a sledgehammer to work around
+// this problem.
+//
+void Value::uncheckedReplaceAllUsesWith(Value *New) {
+ while (!use_empty()) {
+ Use &U = *UseList;
+ // Must handle Constants specially, we cannot call replaceUsesOfWith on a
+ // constant because they are uniqued.
+ if (Constant *C = dyn_cast<Constant>(U.getUser())) {
+ if (!isa<GlobalValue>(C)) {
+ C->replaceUsesOfWithOnConstant(this, New, &U);
+ continue;
+ }
+ }
+
+ U.set(New);
+ }
+}
- assert(i < Uses.size() && "Use not in uses list!!");
- Uses.erase(Uses.begin()+i);
+void Value::replaceAllUsesWith(Value *New) {
+ assert(New && "Value::replaceAllUsesWith(<null>) is invalid!");
+ assert(New != this && "this->replaceAllUsesWith(this) is NOT valid!");
+ assert(New->getType() == getType() &&
+ "replaceAllUses of value with new value of different type!");
+
+ uncheckedReplaceAllUsesWith(New);
}
//===----------------------------------------------------------------------===//
// User Class
//===----------------------------------------------------------------------===//
-User::User(const Type *Ty, ValueTy vty, const std::string &name)
- : Value(Ty, vty, name) {
-}
-
// replaceUsesOfWith - Replaces all references to the "From" definition with
// references to the "To" definition.
//
void User::replaceUsesOfWith(Value *From, Value *To) {
if (From == To) return; // Duh what?
- assert(!isa<Constant>(this) &&
+ assert(!isa<Constant>(this) || isa<GlobalValue>(this) &&
"Cannot call User::replaceUsesofWith on a constant!");
for (unsigned i = 0, E = getNumOperands(); i != E; ++i)
setOperand(i, To); // Fix it now...
}
}
+