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