#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/SmallVector.h"
+#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/CaptureTracking.h"
+#include "llvm/IR/CallSite.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/Instructions.h"
+
using namespace llvm;
CaptureTracker::~CaptureTracker() {}
-bool CaptureTracker::shouldExplore(Use *U) { return true; }
+bool CaptureTracker::shouldExplore(const Use *U) { return true; }
namespace {
struct SimpleCaptureTracker : public CaptureTracker {
explicit SimpleCaptureTracker(bool ReturnCaptures)
: ReturnCaptures(ReturnCaptures), Captured(false) {}
- void tooManyUses() { Captured = true; }
+ void tooManyUses() override { Captured = true; }
- bool captured(Use *U) {
+ bool captured(const Use *U) override {
if (isa<ReturnInst>(U->getUser()) && !ReturnCaptures)
return false;
void llvm::PointerMayBeCaptured(const Value *V, CaptureTracker *Tracker) {
assert(V->getType()->isPointerTy() && "Capture is for pointers only!");
- SmallVector<Use*, Threshold> Worklist;
- SmallSet<Use*, Threshold> Visited;
+ SmallVector<const Use *, Threshold> Worklist;
+ SmallSet<const Use *, Threshold> Visited;
int Count = 0;
- for (Value::const_use_iterator UI = V->use_begin(), UE = V->use_end();
- UI != UE; ++UI) {
+ for (const Use &U : V->uses()) {
// If there are lots of uses, conservatively say that the value
// is captured to avoid taking too much compile time.
if (Count++ >= Threshold)
return Tracker->tooManyUses();
- Use *U = &UI.getUse();
- if (!Tracker->shouldExplore(U)) continue;
- Visited.insert(U);
- Worklist.push_back(U);
+ if (!Tracker->shouldExplore(&U)) continue;
+ Visited.insert(&U);
+ Worklist.push_back(&U);
}
while (!Worklist.empty()) {
- Use *U = Worklist.pop_back_val();
+ const Use *U = Worklist.pop_back_val();
Instruction *I = cast<Instruction>(U->getUser());
V = U->get();
case Instruction::GetElementPtr:
case Instruction::PHI:
case Instruction::Select:
+ case Instruction::AddrSpaceCast:
// The original value is not captured via this if the new value isn't.
- for (Instruction::use_iterator UI = I->use_begin(), UE = I->use_end();
- UI != UE; ++UI) {
- Use *U = &UI.getUse();
- if (Visited.insert(U))
- if (Tracker->shouldExplore(U))
- Worklist.push_back(U);
+ Count = 0;
+ for (Use &UU : I->uses()) {
+ // If there are lots of uses, conservatively say that the value
+ // is captured to avoid taking too much compile time.
+ if (Count++ >= Threshold)
+ return Tracker->tooManyUses();
+
+ if (Visited.insert(&UU))
+ if (Tracker->shouldExplore(&UU))
+ Worklist.push_back(&UU);
}
break;
case Instruction::ICmp:
// Don't count comparisons of a no-alias return value against null as
// captures. This allows us to ignore comparisons of malloc results
// with null, for example.
- if (isNoAliasCall(V->stripPointerCasts()))
- if (ConstantPointerNull *CPN =
- dyn_cast<ConstantPointerNull>(I->getOperand(1)))
- if (CPN->getType()->getAddressSpace() == 0)
+ if (ConstantPointerNull *CPN =
+ dyn_cast<ConstantPointerNull>(I->getOperand(1)))
+ if (CPN->getType()->getAddressSpace() == 0)
+ if (isNoAliasCall(V->stripPointerCasts()))
break;
// Otherwise, be conservative. There are crazy ways to capture pointers
// using comparisons.