#ifndef LLVM_ANALYSIS_VALUETRACKING_H
#define LLVM_ANALYSIS_VALUETRACKING_H
+#include <string>
+
namespace llvm {
class Value;
class Instruction;
const unsigned Idxs[1] = { Idx };
return FindInsertedValue(V, &Idxs[0], &Idxs[1], InsertBefore);
}
+
+ /// GetConstantStringInfo - This function computes the length of a
+ /// null-terminated C string pointed to by V. If successful, it returns true
+ /// and returns the string in Str. If unsuccessful, it returns false.
+ bool GetConstantStringInfo(Value *V, std::string &Str);
} // end namespace llvm
#endif
"implemented for all constants that have operands!");
assert(0 && "Constants that do not have operands cannot be using 'From'!");
}
-
- /// getStringValue - Turn an LLVM constant pointer that eventually points to a
- /// global into a string value. Return an empty string if we can't do it.
- /// Parameter Chop determines if the result is chopped at the first null
- /// terminator.
- ///
- std::string getStringValue(bool Chop = true, unsigned Offset = 0);
};
} // End llvm namespace
return unsigned(cast<ConstantInt>(getOperand(2))->getZExtValue());
}
- std::string getFileName() const;
- std::string getDirectory() const;
+ Value* getFileName() const;
+ Value* getDirectory() const;
// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const DbgStopPointInst *) { return true; }
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/Constants.h"
#include "llvm/Instructions.h"
+#include "llvm/GlobalVariable.h"
#include "llvm/IntrinsicInst.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Support/GetElementPtrTypeIterator.h"
// or load instruction)
return 0;
}
+
+/// GetConstantStringInfo - This function computes the length of a
+/// null-terminated C string pointed to by V. If successful, it returns true
+/// and returns the string in Str. If unsuccessful, it returns false.
+bool llvm::GetConstantStringInfo(Value *V, std::string &Str) {
+ // If V is NULL then return false;
+ if (V == NULL) return false;
+
+ // Look through bitcast instructions.
+ if (BitCastInst *BCI = dyn_cast<BitCastInst>(V))
+ return GetConstantStringInfo(BCI->getOperand(0), Str);
+
+ // If the value is not a GEP instruction nor a constant expression with a
+ // GEP instruction, then return false because ConstantArray can't occur
+ // any other way
+ User *GEP = 0;
+ if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(V)) {
+ GEP = GEPI;
+ } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
+ if (CE->getOpcode() != Instruction::GetElementPtr)
+ return false;
+ GEP = CE;
+ } else {
+ return false;
+ }
+
+ // Make sure the GEP has exactly three arguments.
+ if (GEP->getNumOperands() != 3)
+ return false;
+
+ // Check to make sure that the first operand of the GEP is an integer and
+ // has value 0 so that we are sure we're indexing into the initializer.
+ if (ConstantInt *Idx = dyn_cast<ConstantInt>(GEP->getOperand(1))) {
+ if (!Idx->isZero())
+ return false;
+ } else
+ return false;
+
+ // If the second index isn't a ConstantInt, then this is a variable index
+ // into the array. If this occurs, we can't say anything meaningful about
+ // the string.
+ uint64_t StartIdx = 0;
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(GEP->getOperand(2)))
+ StartIdx = CI->getZExtValue();
+ else
+ return false;
+
+ // The GEP instruction, constant or instruction, must reference a global
+ // variable that is a constant and is initialized. The referenced constant
+ // initializer is the array that we'll use for optimization.
+ GlobalVariable* GV = dyn_cast<GlobalVariable>(GEP->getOperand(0));
+ if (!GV || !GV->isConstant() || !GV->hasInitializer())
+ return false;
+ Constant *GlobalInit = GV->getInitializer();
+
+ // Handle the ConstantAggregateZero case
+ if (isa<ConstantAggregateZero>(GlobalInit)) {
+ // This is a degenerate case. The initializer is constant zero so the
+ // length of the string must be zero.
+ Str.clear();
+ return true;
+ }
+
+ // Must be a Constant Array
+ ConstantArray *Array = dyn_cast<ConstantArray>(GlobalInit);
+ if (Array == 0 || Array->getType()->getElementType() != Type::Int8Ty)
+ return false;
+
+ // Get the number of elements in the array
+ uint64_t NumElts = Array->getType()->getNumElements();
+
+ // Traverse the constant array from StartIdx (derived above) which is
+ // the place the GEP refers to in the array.
+ for (unsigned i = StartIdx; i < NumElts; ++i) {
+ Constant *Elt = Array->getOperand(i);
+ ConstantInt *CI = dyn_cast<ConstantInt>(Elt);
+ if (!CI) // This array isn't suitable, non-int initializer.
+ return false;
+ if (CI->isZero())
+ return true; // we found end of string, success!
+ Str += (char)CI->getZExtValue();
+ }
+
+ return false; // The array isn't null terminated.
+}
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/Constants.h"
+#include "llvm/Analysis/ValueTracking.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineLocation.h"
}
virtual void Apply(std::string &Field) {
Constant *C = CI->getOperand(I++);
- Field = C->getStringValue();
+ std::string S;
+ if (GetConstantStringInfo(C, S))
+ Field = S;
+ else
+ Field = "";
}
virtual void Apply(DebugInfoDesc *&Field) {
Constant *C = CI->getOperand(I++);
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/Constants.h"
+#include "llvm/Analysis/ValueTracking.h"
#include "llvm/GlobalAlias.h"
#include "llvm/GlobalVariable.h"
#include "llvm/Intrinsics.h"
GlobalVariable *GV = dyn_cast<GlobalVariable>(G->getGlobal());
if (GV && GV->isConstant()) {
- Str = GV->getStringValue(false);
- if (!Str.empty()) {
+ if (GetConstantStringInfo(GV, Str)) {
SrcOff += SrcDelta;
return true;
}
#include "llvm/Debugger/ProgramInfo.h"
#include "llvm/Constants.h"
+#include "llvm/Analysis/ValueTracking.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Intrinsics.h"
#include "llvm/IntrinsicInst.h"
if (ConstantInt *CUI = dyn_cast<ConstantInt>(CS->getOperand(1)))
Version = CUI->getZExtValue();
- BaseName = CS->getOperand(3)->getStringValue();
- Directory = CS->getOperand(4)->getStringValue();
+ if (!GetConstantStringInfo(CS->getOperand(3), BaseName))
+ BaseName = "";
+ if (!GetConstantStringInfo(CS->getOperand(4), Directory))
+ Directory = "";
}
}
SourceFile = &PI.getSourceFile(GV);
// Entry #2 is the function name.
- Name = CS->getOperand(2)->getStringValue();
+ if (!GetConstantStringInfo(CS->getOperand(2), Name))
+ Name = "";
}
}
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(CI)) {
// Instead of loading constant c string, use corresponding integer value
// directly if string length is small enough.
- const std::string &Str = CE->getOperand(0)->getStringValue();
- if (!Str.empty()) {
+ std::string Str;
+ if (GetConstantStringInfo(CE->getOperand(0), Str) && !Str.empty()) {
unsigned len = Str.length();
const Type *Ty = cast<PointerType>(CE->getType())->getElementType();
unsigned numBits = Ty->getPrimitiveSizeInBits();
// Delete the old constant!
destroyConstant();
-}
-
-
-/// getStringValue - Turn an LLVM constant pointer that eventually points to a
-/// global into a string value. Return an empty string if we can't do it.
-/// Parameter Chop determines if the result is chopped at the first null
-/// terminator.
-///
-std::string Constant::getStringValue(bool Chop, unsigned Offset) {
- if (GlobalVariable *GV = dyn_cast<GlobalVariable>(this)) {
- if (GV->hasInitializer() && isa<ConstantArray>(GV->getInitializer())) {
- ConstantArray *Init = cast<ConstantArray>(GV->getInitializer());
- if (Init->isString()) {
- std::string Result = Init->getAsString();
- if (Offset < Result.size()) {
- // If we are pointing INTO The string, erase the beginning...
- Result.erase(Result.begin(), Result.begin()+Offset);
-
- // Take off the null terminator, and any string fragments after it.
- if (Chop) {
- std::string::size_type NullPos = Result.find_first_of((char)0);
- if (NullPos != std::string::npos)
- Result.erase(Result.begin()+NullPos, Result.end());
- }
- return Result;
- }
- }
- }
- } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(this)) {
- if (CE->getOpcode() == Instruction::GetElementPtr) {
- // Turn a gep into the specified offset.
- if (CE->getNumOperands() == 3 &&
- cast<Constant>(CE->getOperand(1))->isNullValue() &&
- isa<ConstantInt>(CE->getOperand(2))) {
- Offset += cast<ConstantInt>(CE->getOperand(2))->getZExtValue();
- return CE->getOperand(0)->getStringValue(Chop, Offset);
- }
- }
- }
- return "";
-}
+}
\ No newline at end of file
#include "llvm/IntrinsicInst.h"
#include "llvm/Constants.h"
#include "llvm/GlobalVariable.h"
+#include "llvm/Analysis/ValueTracking.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
using namespace llvm;
/// DbgStopPointInst - This represents the llvm.dbg.stoppoint instruction.
///
-std::string DbgStopPointInst::getFileName() const {
+Value *DbgStopPointInst::getFileName() const {
// Once the operand indices are verified, update this assert
assert(LLVMDebugVersion == (6 << 16) && "Verify operand indices");
GlobalVariable *GV = cast<GlobalVariable>(getContext());
- if (!GV->hasInitializer()) return "";
+ if (!GV->hasInitializer()) return NULL;
ConstantStruct *CS = cast<ConstantStruct>(GV->getInitializer());
- return CS->getOperand(3)->getStringValue();
+ return CS->getOperand(4);
}
-std::string DbgStopPointInst::getDirectory() const {
+Value *DbgStopPointInst::getDirectory() const {
// Once the operand indices are verified, update this assert
assert(LLVMDebugVersion == (6 << 16) && "Verify operand indices");
GlobalVariable *GV = cast<GlobalVariable>(getContext());
- if (!GV->hasInitializer()) return "";
+ if (!GV->hasInitializer()) return NULL;
ConstantStruct *CS = cast<ConstantStruct>(GV->getInitializer());
- return CS->getOperand(4)->getStringValue();
+ return CS->getOperand(4);
}
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