[llvm-commits] CVS: llvm/lib/Analysis/AliasDebugger.cpp

[Andrew Lenharth]

Changes in directory llvm/lib/Analysis:

AliasDebugger.cpp added (r1.1)
---
Log message:

A shim over other AA impls to catch incorrect uses

---
Diffs of the changes:  (+125 -0)

 AliasDebugger.cpp |  125 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 125 insertions(+)


Index: llvm/lib/Analysis/AliasDebugger.cpp
diff -c /dev/null llvm/lib/Analysis/AliasDebugger.cpp:1.1
*** /dev/null	Mon Nov 13 23:20:38 2006
--- llvm/lib/Analysis/AliasDebugger.cpp	Mon Nov 13 23:20:28 2006
***************
*** 0 ****
--- 1,125 ----
+ //===- AliasDebugger.cpp - Simple Alias Analysis Use Checker --------------===//
+ //
+ //                     The LLVM Compiler Infrastructure
+ //
+ // This file was developed by Andrew Lenharth and 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:
+     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->isExternal()) {
+           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
+     }
+ 
+     //------------------------------------------------
+     // 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);
+     }
+     
+     void getMustAliases(Value *P, std::vector<Value*> &RetVals) {
+       assert(Vals.find(P) != Vals.end() && "Never seen value in AA before");
+       return AliasAnalysis::getMustAliases(P, RetVals);
+     }
+ 
+     bool pointsToConstantMemory(const Value *P) {
+       assert(Vals.find(P) != Vals.end() && "Never seen value in AA before");
+       return AliasAnalysis::pointsToConstantMemory(P);
+     }
+ 
+     /// getModRefBehavior - Return the behavior of the specified function if
+     /// called from the specified call site.  The call site may be null in which
+     /// case the most generic behavior of this function should be returned.
+     virtual ModRefBehavior getModRefBehavior(Function *F, CallSite CS,
+                                          std::vector<PointerAccessInfo> *Info) {
+       assert(Vals.find(F) != Vals.end() && "Never seen value in AA before");
+       return AliasAnalysis::getModRefBehavior(F, CS, Info);
+     }
+ 
+     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);
+     }
+ 
+   };
+ 
+   RegisterPass<AliasDebugger> X("debug-aa", "AA use debugger");
+   RegisterAnalysisGroup<AliasAnalysis> Y(X);
+ }
+ 
+ Pass *llvm::createAliasDebugger() { return new AliasDebugger(); }
+