llvm/lib/IR/LeaksContext.h
Duncan P. N. Exon Smith da75f7277e IR: Store MDNodes in a separate LeakDetector container
This gives us better leak detection messages, like `Value` has.

This also has the side effect of papering over a problem where
`MachineInstr`s are added as garbage to the leak detector and then
deleted without being removed.  If `MDNode::getTemporary()` allocates an
`MDNodeFwdDecl` in the same spot, the leak detector asserts.  By
separating `MDNode`s into their own container we lose that assertion.

Since `MachineInstr` is required to have a trivial destructor, its usage
of `LeakDetector` at all is pretty suspect.  I'll be sending a patch
soon to strip that out.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224060 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-11 21:39:39 +00:00

104 lines
2.5 KiB
C++

//===- LeaksContext.h - LeadDetector Implementation ------------*- C++ -*--===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines various helper methods and classes used by
// LLVMContextImpl for leaks detectors.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_IR_LEAKSCONTEXT_H
#define LLVM_LIB_IR_LEAKSCONTEXT_H
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/Value.h"
#include "llvm/Support/raw_ostream.h"
namespace llvm {
template <class T>
struct PrinterTrait {
static void print(const T* P) { errs() << P; }
};
template<>
struct PrinterTrait<Value> {
static void print(const Value* P) { errs() << *P; }
};
template <> struct PrinterTrait<Metadata> {
static void print(const Metadata *P) { P->print(errs()); }
};
template <typename T>
struct LeakDetectorImpl {
explicit LeakDetectorImpl(const char* const name = "") :
Cache(nullptr), Name(name) { }
void clear() {
Cache = nullptr;
Ts.clear();
}
void setName(const char* n) {
Name = n;
}
// Because the most common usage pattern, by far, is to add a
// garbage object, then remove it immediately, we optimize this
// case. When an object is added, it is not added to the set
// immediately, it is added to the CachedValue Value. If it is
// immediately removed, no set search need be performed.
void addGarbage(const T* o) {
assert(Ts.count(o) == 0 && "Object already in set!");
if (Cache) {
assert(Cache != o && "Object already in set!");
Ts.insert(Cache);
}
Cache = o;
}
void removeGarbage(const T* o) {
if (o == Cache)
Cache = nullptr; // Cache hit
else
Ts.erase(o);
}
bool hasGarbage(const std::string& Message) {
addGarbage(nullptr); // Flush the Cache
assert(!Cache && "No value should be cached anymore!");
if (!Ts.empty()) {
errs() << "Leaked " << Name << " objects found: " << Message << ":\n";
for (typename SmallPtrSet<const T*, 8>::iterator I = Ts.begin(),
E = Ts.end(); I != E; ++I) {
errs() << '\t';
PrinterTrait<T>::print(*I);
errs() << '\n';
}
errs() << '\n';
return true;
}
return false;
}
private:
SmallPtrSet<const T*, 8> Ts;
const T* Cache;
const char* Name;
};
}
#endif