[llvm-commits] [llvm] r104970 - in /llvm/trunk: lib/Analysis/Lint.cpp test/Other/lint.ll

[Dan Gohman]

Author: djg
Date: Fri May 28 12:44:00 2010
New Revision: 104970

URL: http://llvm.org/viewvc/llvm-project?rev=104970&view=rev
Log:
Fix lint's memcpy and memmove checks, and its basic block traversal.

Modified:
    llvm/trunk/lib/Analysis/Lint.cpp
    llvm/trunk/test/Other/lint.ll

Modified: llvm/trunk/lib/Analysis/Lint.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/Lint.cpp?rev=104970&r1=104969&r2=104970&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/Lint.cpp (original)
+++ llvm/trunk/lib/Analysis/Lint.cpp Fri May 28 12:44:00 2010
@@ -248,9 +248,9 @@
 
     case Intrinsic::memcpy: {
       MemCpyInst *MCI = cast<MemCpyInst>(&I);
-      visitMemoryReference(I, MCI->getSource(), MCI->getAlignment(), 0,
-                           MemRef::Write);
       visitMemoryReference(I, MCI->getDest(), MCI->getAlignment(), 0,
+                           MemRef::Write);
+      visitMemoryReference(I, MCI->getSource(), MCI->getAlignment(), 0,
                            MemRef::Read);
 
       // Check that the memcpy arguments don't overlap. The AliasAnalysis API
@@ -269,9 +269,9 @@
     }
     case Intrinsic::memmove: {
       MemMoveInst *MMI = cast<MemMoveInst>(&I);
-      visitMemoryReference(I, MMI->getSource(), MMI->getAlignment(), 0,
-                           MemRef::Write);
       visitMemoryReference(I, MMI->getDest(), MMI->getAlignment(), 0,
+                           MemRef::Write);
+      visitMemoryReference(I, MMI->getSource(), MMI->getAlignment(), 0,
                            MemRef::Read);
       break;
     }
@@ -519,11 +519,14 @@
   if (LoadInst *L = dyn_cast<LoadInst>(V)) {
     BasicBlock::iterator BBI = L;
     BasicBlock *BB = L->getParent();
+    SmallPtrSet<BasicBlock *, 4> VisitedBlocks;
     for (;;) {
+      if (!VisitedBlocks.insert(BB)) break;
       if (Value *U = FindAvailableLoadedValue(L->getPointerOperand(),
                                               BB, BBI, 6, AA))
         return findValueImpl(U, OffsetOk, Visited);
-      BB = L->getParent()->getUniquePredecessor();
+      if (BBI != BB->begin()) break;
+      BB = BB->getUniquePredecessor();
       if (!BB) break;
       BBI = BB->end();
     }

Modified: llvm/trunk/test/Other/lint.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Other/lint.ll?rev=104970&r1=104969&r2=104970&view=diff
==============================================================================
--- llvm/trunk/test/Other/lint.ll (original)
+++ llvm/trunk/test/Other/lint.ll Fri May 28 12:44:00 2010
@@ -3,6 +3,7 @@
 
 declare fastcc void @bar()
 declare void @llvm.stackrestore(i8*)
+declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind
 
 @CG = constant i32 7
 
@@ -54,6 +55,9 @@
 ; CHECK: Undefined behavior: Null pointer dereference
   call void @llvm.stackrestore(i8* null)
 
+; CHECK: Write to read-only memory
+  call void @llvm.memcpy.p0i8.p0i8.i64(i8* bitcast (i32* @CG to i8*), i8* bitcast (i32* @CG to i8*), i64 1, i32 1, i1 0)
+
   br label %next
 
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