llvm-6502/lib/CodeGen/ShadowStackGC.cpp
Chandler Carruth 02d6288667 Re-sort #include lines using my handy dandy ./utils/sort_includes.py
script. This is in preparation for changes to lots of include lines.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229088 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 09:09:03 +00:00

56 lines
1.7 KiB
C++

//===-- ShadowStackGC.cpp - GC support for uncooperative targets ----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements lowering for the llvm.gc* intrinsics for targets that do
// not natively support them (which includes the C backend). Note that the code
// generated is not quite as efficient as algorithms which generate stack maps
// to identify roots.
//
// This pass implements the code transformation described in this paper:
// "Accurate Garbage Collection in an Uncooperative Environment"
// Fergus Henderson, ISMM, 2002
//
// In runtime/GC/SemiSpace.cpp is a prototype runtime which is compatible with
// ShadowStackGC.
//
// In order to support this particular transformation, all stack roots are
// coallocated in the stack. This allows a fully target-independent stack map
// while introducing only minor runtime overhead.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/GCs.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/CodeGen/GCStrategy.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Module.h"
using namespace llvm;
#define DEBUG_TYPE "shadowstackgc"
namespace {
class ShadowStackGC : public GCStrategy {
public:
ShadowStackGC();
};
}
static GCRegistry::Add<ShadowStackGC>
X("shadow-stack", "Very portable GC for uncooperative code generators");
void llvm::linkShadowStackGC() {}
ShadowStackGC::ShadowStackGC() {
InitRoots = true;
CustomRoots = true;
}