forked from OSchip/llvm-project
				
			
		
			
				
	
	
		
			132 lines
		
	
	
		
			4.7 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			132 lines
		
	
	
		
			4.7 KiB
		
	
	
	
		
			C++
		
	
	
	
//===- AliasDebugger.cpp - Simple Alias Analysis Use Checker --------------===//
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//
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//                     The LLVM Compiler Infrastructure
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//
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// This file was developed by Andrew Lenharth and is distributed under
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// the University of Illinois Open Source License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This simple pass checks alias analysis users to ensure that if they
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// create a new value, they do not query AA without informing it of the value.
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// It acts as a shim over any other AA pass you want.
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//
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// Yes keeping track of every value in the program is expensive, but this is 
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// a debugging pass.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Analysis/Passes.h"
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#include "llvm/Module.h"
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#include "llvm/Pass.h"
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#include "llvm/Instructions.h"
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#include "llvm/Constants.h"
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#include "llvm/DerivedTypes.h"
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#include "llvm/Analysis/AliasAnalysis.h"
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#include "llvm/Support/Compiler.h"
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#include <set>
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using namespace llvm;
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namespace {
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  class VISIBILITY_HIDDEN AliasDebugger 
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      : public ModulePass, public AliasAnalysis {
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    //What we do is simple.  Keep track of every value the AA could
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    //know about, and verify that queries are one of those.
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    //A query to a value that didn't exist when the AA was created
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    //means someone forgot to update the AA when creating new values
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    std::set<const Value*> Vals;
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  public:
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    static char ID; // Class identification, replacement for typeinfo
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    AliasDebugger() : ModulePass((intptr_t)&ID) {}
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    bool runOnModule(Module &M) {
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      InitializeAliasAnalysis(this);                 // set up super class
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      for(Module::global_iterator I = M.global_begin(),
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            E = M.global_end(); I != E; ++I)
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        Vals.insert(&*I);
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      for(Module::iterator I = M.begin(),
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            E = M.end(); I != E; ++I){
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        Vals.insert(&*I);
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        if(!I->isDeclaration()) {
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          for (Function::arg_iterator AI = I->arg_begin(), AE = I->arg_end();
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               AI != AE; ++AI) 
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            Vals.insert(&*AI);     
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          for (Function::const_iterator FI = I->begin(), FE = I->end();
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               FI != FE; ++FI) 
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            for (BasicBlock::const_iterator BI = FI->begin(), BE = FI->end();
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                 BI != BE; ++BI)
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              Vals.insert(&*BI);
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        }
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      }
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      return false;
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    }
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    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
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      AliasAnalysis::getAnalysisUsage(AU);
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      AU.setPreservesAll();                         // Does not transform code
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    }
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    //------------------------------------------------
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    // Implement the AliasAnalysis API
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    //
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    AliasResult alias(const Value *V1, unsigned V1Size,
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                      const Value *V2, unsigned V2Size) {
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      assert(Vals.find(V1) != Vals.end() && "Never seen value in AA before");
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      assert(Vals.find(V2) != Vals.end() && "Never seen value in AA before");    
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      return AliasAnalysis::alias(V1, V1Size, V2, V2Size);
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    }
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    ModRefResult getModRefInfo(CallSite CS, Value *P, unsigned Size) {
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      assert(Vals.find(P) != Vals.end() && "Never seen value in AA before");
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      return AliasAnalysis::getModRefInfo(CS, P, Size);
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    }
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    ModRefResult getModRefInfo(CallSite CS1, CallSite CS2) {
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      return AliasAnalysis::getModRefInfo(CS1,CS2);
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    }
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    void getMustAliases(Value *P, std::vector<Value*> &RetVals) {
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      assert(Vals.find(P) != Vals.end() && "Never seen value in AA before");
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      return AliasAnalysis::getMustAliases(P, RetVals);
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    }
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    bool pointsToConstantMemory(const Value *P) {
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      assert(Vals.find(P) != Vals.end() && "Never seen value in AA before");
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      return AliasAnalysis::pointsToConstantMemory(P);
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    }
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    /// getModRefBehavior - Return the behavior of the specified function if
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    /// called from the specified call site.  The call site may be null in which
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    /// case the most generic behavior of this function should be returned.
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    virtual ModRefBehavior getModRefBehavior(Function *F, CallSite CS,
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                                         std::vector<PointerAccessInfo> *Info) {
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      assert(Vals.find(F) != Vals.end() && "Never seen value in AA before");
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      return AliasAnalysis::getModRefBehavior(F, CS, Info);
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    }
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    virtual void deleteValue(Value *V) {
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      assert(Vals.find(V) != Vals.end() && "Never seen value in AA before");
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      AliasAnalysis::deleteValue(V);
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    }
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    virtual void copyValue(Value *From, Value *To) {
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      Vals.insert(To);
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      AliasAnalysis::copyValue(From, To);
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    }
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  };
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  char AliasDebugger::ID = 0;
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  RegisterPass<AliasDebugger> X("debug-aa", "AA use debugger");
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  RegisterAnalysisGroup<AliasAnalysis> Y(X);
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}
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Pass *llvm::createAliasDebugger() { return new AliasDebugger(); }
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