Add support for reading ConstantExpr nodes.
Add class ConstantFwdRefs to resolve forward references to constants
and to globals. (Hmm... this class could be renamed I guess.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@2896 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Bytecode/Reader/ConstantReader.cpp b/lib/Bytecode/Reader/ConstantReader.cpp
index 7e00cd2..2fa392e 100644
--- a/lib/Bytecode/Reader/ConstantReader.cpp
+++ b/lib/Bytecode/Reader/ConstantReader.cpp
@@ -179,6 +179,54 @@
bool BytecodeParser::parseConstantValue(const uchar *&Buf, const uchar *EndBuf,
const Type *Ty, Constant *&V) {
+
+ // We must check for a ConstantExpr before switching by type because
+ // a ConstantExpr can be of any type, and has no explicit value.
+ //
+ unsigned isExprNumArgs; // 0 if not expr; numArgs if is expr
+ if (read_vbr(Buf, EndBuf, isExprNumArgs)) return failure(true);
+ if (isExprNumArgs) {
+ unsigned opCode;
+ vector<Constant*> argVec;
+ argVec.reserve(isExprNumArgs);
+
+ if (read_vbr(Buf, EndBuf, opCode)) return failure(true);
+
+ // Read the slot number and types of each of the arguments
+ for (unsigned i=0; i < isExprNumArgs; ++i) {
+ unsigned argValSlot, argTypeSlot;
+ if (read_vbr(Buf, EndBuf, argValSlot)) return failure(true);
+ if (read_vbr(Buf, EndBuf, argTypeSlot)) return failure(true);
+ const Type *argTy = getType(argTypeSlot);
+ if (argTy == 0) return failure(true);
+
+ BCR_TRACE(4, "CE Arg " << i << ": Type: '" << argTy << "' slot: " << argValSlot << "\n");
+
+ // Get the arg value from its slot if it exists, otherwise a placeholder
+ Value *Val = getValue(argTy, argValSlot, false);
+ Constant* C;
+ if (Val) {
+ if (!(C = dyn_cast<Constant>(Val))) return failure(true);
+ BCR_TRACE(5, "Constant Found in ValueTable!\n");
+ } else { // Nope... find or create a forward ref. for it
+ C = fwdRefs.GetFwdRefToConstant(argTy, argValSlot);
+ }
+ argVec.push_back(C);
+ }
+
+ // Construct a ConstantExpr of the appropriate kind
+ if (isExprNumArgs == 1) { // All one-operand expressions
+ V = ConstantExpr::get(opCode, argVec[0], Ty);
+ } else if (opCode == Instruction::GetElementPtr) { // GetElementPtr
+ vector<Value*> IdxList(argVec.begin()+1, argVec.end());
+ V = ConstantExpr::get(opCode, argVec[0], IdxList, Ty);
+ } else { // All other 2-operand expressions
+ V = ConstantExpr::get(opCode, argVec[0], argVec[1], Ty);
+ }
+ return false;
+ }
+
+ // Ok, not an ConstantExpr. We now know how to read the given type...
switch (Ty->getPrimitiveID()) {
case Type::BoolTyID: {
unsigned Val;
@@ -286,38 +334,21 @@
case 1: { // ConstantPointerRef value...
unsigned Slot;
if (read_vbr(Buf, EndBuf, Slot)) return failure(true);
- BCR_TRACE(4, "CPPR: Type: '" << Ty << "' slot: " << Slot << "\n");
+ BCR_TRACE(4, "CPR: Type: '" << Ty << "' slot: " << Slot << "\n");
// Check to see if we have already read this global variable yet...
Value *Val = getValue(PT, Slot, false);
- GlobalValue *GV;
+ GlobalValue* GV;
if (Val) {
- if (!(GV = dyn_cast<GlobalValue>(Val))) return failure(true);
- BCR_TRACE(5, "Value Found in ValueTable!\n");
- } else { // Nope... see if we have previously forward ref'd it
- GlobalRefsType::iterator I = GlobalRefs.find(make_pair(PT, Slot));
- if (I != GlobalRefs.end()) {
- BCR_TRACE(5, "Previous forward ref found!\n");
- GV = I->second;
- } else {
- BCR_TRACE(5, "Creating new forward ref variable!\n");
-
- // Create a placeholder for the global variable reference...
- GlobalVariable *GVar =
- new GlobalVariable(PT->getElementType(), false, true);
-
- // Keep track of the fact that we have a forward ref to recycle it
- GlobalRefs.insert(make_pair(make_pair(PT, Slot), GVar));
-
- // Must temporarily push this value into the module table...
- TheModule->getGlobalList().push_back(GVar);
- GV = GVar;
- }
+ if (!(GV = dyn_cast<GlobalValue>(Val))) return failure(true);
+ BCR_TRACE(5, "Value Found in ValueTable!\n");
+ } else { // Nope... find or create a forward ref. for it
+ GV = fwdRefs.GetFwdRefToGlobal(PT, Slot);
}
-
V = ConstantPointerRef::get(GV);
break;
}
+
default:
BCR_TRACE(5, "UNKNOWN Pointer Constant Type!\n");
return failure(true);
@@ -352,9 +383,12 @@
} else {
for (unsigned i = 0; i < NumEntries; ++i) {
Constant *I;
+ int Slot;
if (parseConstantValue(Buf, EndBuf, Ty, I)) return failure(true);
+ assert(I && "parseConstantValue returned `!failure' and NULL result");
BCR_TRACE(4, "Read Constant: '" << I << "'\n");
- if (insertValue(I, Tab) == -1) return failure(true);
+ if ((Slot = insertValue(I, Tab)) < 0) return failure(true);
+ resolveRefsToConstant(I, (unsigned) Slot);
}
}
}