#include "llvm/Support/Dwarf.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
-#include "llvm/ADT/SmallString.h"
using namespace llvm;
//===----------------------------------------------------------------------===//
/// IsNullTerminatedString - Return true if the specified constant (which is
/// known to have a type that is an array of 1/2/4 byte elements) ends with a
-/// nul value and contains no other nuls in it.
+/// nul value and contains no other nuls in it. Note that this is more general
+/// than ConstantDataSequential::isString because we allow 2 & 4 byte strings.
static bool IsNullTerminatedString(const Constant *C) {
- ArrayType *ATy = cast<ArrayType>(C->getType());
-
- // First check: is we have constant array of i8 terminated with zero
- if (const ConstantArray *CVA = dyn_cast<ConstantArray>(C)) {
- if (ATy->getNumElements() == 0) return false;
-
- ConstantInt *Null =
- dyn_cast<ConstantInt>(CVA->getOperand(ATy->getNumElements()-1));
- if (Null == 0 || !Null->isZero())
+ // First check: is we have constant array terminated with zero
+ if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(C)) {
+ unsigned NumElts = CDS->getNumElements();
+ assert(NumElts != 0 && "Can't have an empty CDS");
+
+ if (CDS->getElementAsInteger(NumElts-1) != 0)
return false; // Not null terminated.
-
+
// Verify that the null doesn't occur anywhere else in the string.
- for (unsigned i = 0, e = ATy->getNumElements()-1; i != e; ++i)
- // Reject constantexpr elements etc.
- if (!isa<ConstantInt>(CVA->getOperand(i)) ||
- CVA->getOperand(i) == Null)
+ for (unsigned i = 0; i != NumElts-1; ++i)
+ if (CDS->getElementAsInteger(i) == 0)
return false;
return true;
}
// Another possibility: [1 x i8] zeroinitializer
if (isa<ConstantAggregateZero>(C))
- return ATy->getNumElements() == 1;
+ return cast<ArrayType>(C->getType())->getNumElements() == 1;
return false;
}
// a mergable string section, or general .data if it contains relocations.
if (GVar->isConstant()) {
// If the initializer for the global contains something that requires a
- // relocation, then we may have to drop this into a wriable data section
+ // relocation, then we may have to drop this into a writable data section
// even though it is marked const.
switch (C->getRelocationInfo()) {
case Constant::NoRelocation: