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-rw-r--r--lib/Bitcode/Reader/BitcodeReader.cpp109
1 files changed, 8 insertions, 101 deletions
diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index ee9e115..a842bd3 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -133,15 +133,6 @@ namespace {
: ConstantExpr(Ty, Instruction::UserOp1, &Op<0>(), 1) {
Op<0>() = UndefValue::get(Type::Int32Ty);
}
-
- /// @brief Methods to support type inquiry through isa, cast, and dyn_cast.
- static inline bool classof(const ConstantPlaceHolder *) { return true; }
- static bool classof(const Value *V) {
- return isa<ConstantExpr>(V) &&
- cast<ConstantExpr>(V)->getOpcode() == Instruction::UserOp1;
- }
-
-
/// Provide fast operand accessors
DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
};
@@ -214,85 +205,6 @@ Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, const Type *Ty) {
return V;
}
-/// ResolveConstantForwardRefs - Once all constants are read, this method bulk
-/// resolves any forward references. The idea behind this is that we sometimes
-/// get constants (such as large arrays) which reference *many* forward ref
-/// constants. Replacing each of these causes a lot of thrashing when
-/// building/reuniquing the constant. Instead of doing this, we look at all the
-/// uses and rewrite all the place holders at once for any constant that uses
-/// a placeholder.
-void BitcodeReaderValueList::ResolveConstantForwardRefs() {
- // Sort the values by-pointer so that they are efficient to look up with a
- // binary search.
- std::sort(ResolveConstants.begin(), ResolveConstants.end());
-
- SmallVector<Constant*, 64> NewOps;
-
- while (!ResolveConstants.empty()) {
- Value *RealVal = getOperand(ResolveConstants.back().second);
- Constant *Placeholder = ResolveConstants.back().first;
- ResolveConstants.pop_back();
-
- // Loop over all users of the placeholder, updating them to reference the
- // new value. If they reference more than one placeholder, update them all
- // at once.
- while (!Placeholder->use_empty()) {
- User *U = Placeholder->use_back();
- // If the using object isn't uniqued, just update the operands. This
- // handles instructions and initializers for global variables.
- if (!isa<Constant>(U) || isa<GlobalValue>(U)) {
- U->replaceUsesOfWith(Placeholder, RealVal);
- continue;
- }
-
- // Otherwise, we have a constant that uses the placeholder. Replace that
- // constant with a new constant that has *all* placeholder uses updated.
- Constant *UserC = cast<Constant>(U);
- for (User::op_iterator I = UserC->op_begin(), E = UserC->op_end();
- I != E; ++I) {
- Value *NewOp;
- if (!isa<ConstantPlaceHolder>(*I)) {
- // Not a placeholder reference.
- NewOp = *I;
- } else if (*I == Placeholder) {
- // Common case is that it just references this one placeholder.
- NewOp = RealVal;
- } else {
- // Otherwise, look up the placeholder in ResolveConstants.
- ResolveConstantsTy::iterator It =
- std::lower_bound(ResolveConstants.begin(), ResolveConstants.end(),
- std::pair<Constant*, unsigned>(cast<Constant>(*I),
- 0));
- assert(It != ResolveConstants.end() && It->first == *I);
- NewOp = this->getOperand(It->second);
- }
-
- NewOps.push_back(cast<Constant>(NewOp));
- }
-
- // Make the new constant.
- Constant *NewC;
- if (ConstantArray *UserCA = dyn_cast<ConstantArray>(UserC)) {
- NewC = ConstantArray::get(UserCA->getType(), &NewOps[0], NewOps.size());
- } else if (isa<ConstantStruct>(UserC)) {
- NewC = ConstantStruct::get(&NewOps[0], NewOps.size());
- } else if (isa<ConstantVector>(UserC)) {
- NewC = ConstantVector::get(&NewOps[0], NewOps.size());
- } else {
- // Must be a constant expression.
- NewC = cast<ConstantExpr>(UserC)->getWithOperands(&NewOps[0],
- NewOps.size());
- }
-
- UserC->replaceAllUsesWith(NewC);
- UserC->destroyConstant();
- NewOps.clear();
- }
-
- delete Placeholder;
- }
-}
-
const Type *BitcodeReader::getTypeByID(unsigned ID, bool isTypeTable) {
// If the TypeID is in range, return it.
@@ -690,8 +602,14 @@ bool BitcodeReader::ParseConstants() {
unsigned NextCstNo = ValueList.size();
while (1) {
unsigned Code = Stream.ReadCode();
- if (Code == bitc::END_BLOCK)
- break;
+ if (Code == bitc::END_BLOCK) {
+ if (NextCstNo != ValueList.size())
+ return Error("Invalid constant reference!");
+
+ if (Stream.ReadBlockEnd())
+ return Error("Error at end of constants block");
+ return false;
+ }
if (Code == bitc::ENTER_SUBBLOCK) {
// No known subblocks, always skip them.
@@ -934,17 +852,6 @@ bool BitcodeReader::ParseConstants() {
ValueList.AssignValue(V, NextCstNo);
++NextCstNo;
}
-
- if (NextCstNo != ValueList.size())
- return Error("Invalid constant reference!");
-
- if (Stream.ReadBlockEnd())
- return Error("Error at end of constants block");
-
- // Once all the constants have been read, go through and resolve forward
- // references.
- ValueList.ResolveConstantForwardRefs();
- return false;
}
/// RememberAndSkipFunctionBody - When we see the block for a function body,