diff lib/Analysis/AliasDebugger.cpp @ 0:95c75e76d11b LLVM3.4

LLVM 3.4
author Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
date Thu, 12 Dec 2013 13:56:28 +0900
parents
children 54457678186b
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/Analysis/AliasDebugger.cpp	Thu Dec 12 13:56:28 2013 +0900
@@ -0,0 +1,138 @@
+//===- 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/Analysis/AliasAnalysis.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Pass.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) {
+      initializeAliasDebuggerPass(*PassRegistry::getPassRegistry());
+    }
+
+    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 (User::const_op_iterator OI = I->op_begin(),
+             OE = I->op_end(); OI != OE; ++OI)
+          Vals.insert(*OI);
+      }
+
+      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);
+              for (User::const_op_iterator OI = BI->op_begin(),
+                   OE = BI->op_end(); OI != OE; ++OI)
+                Vals.insert(*OI);
+            }
+        }
+        
+      }
+      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(AnalysisID PI) {
+      if (PI == &AliasAnalysis::ID)
+        return (AliasAnalysis*)this;
+      return this;
+    }
+    
+    //------------------------------------------------
+    // Implement the AliasAnalysis API
+    //
+    AliasResult alias(const Location &LocA, const Location &LocB) {
+      assert(Vals.find(LocA.Ptr) != Vals.end() &&
+             "Never seen value in AA before");
+      assert(Vals.find(LocB.Ptr) != Vals.end() &&
+             "Never seen value in AA before");
+      return AliasAnalysis::alias(LocA, LocB);
+    }
+
+    ModRefResult getModRefInfo(ImmutableCallSite CS,
+                               const Location &Loc) {
+      assert(Vals.find(Loc.Ptr) != Vals.end() && "Never seen value in AA before");
+      return AliasAnalysis::getModRefInfo(CS, Loc);
+    }
+
+    ModRefResult getModRefInfo(ImmutableCallSite CS1,
+                               ImmutableCallSite CS2) {
+      return AliasAnalysis::getModRefInfo(CS1,CS2);
+    }
+    
+    bool pointsToConstantMemory(const Location &Loc, bool OrLocal) {
+      assert(Vals.find(Loc.Ptr) != Vals.end() && "Never seen value in AA before");
+      return AliasAnalysis::pointsToConstantMemory(Loc, OrLocal);
+    }
+
+    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;
+INITIALIZE_AG_PASS(AliasDebugger, AliasAnalysis, "debug-aa",
+                   "AA use debugger", false, true, false)
+
+Pass *llvm::createAliasDebugger() { return new AliasDebugger(); }
+