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