From: Zhongxing Xu <xuzhongxing@gmail.com>
Date: Wed, 6 May 2009 08:08:27 +0000 (+0000)
Subject: Implement a heuristic type size comparison method for now.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=ccb161603c3c280c378e6701986e9f3646898277;p=clang

Implement a heuristic type size comparison method for now.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@71074 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Analysis/RegionStore.cpp b/lib/Analysis/RegionStore.cpp
index 145559e8b8..5f8e6c3f92 100644
--- a/lib/Analysis/RegionStore.cpp
+++ b/lib/Analysis/RegionStore.cpp
@@ -554,6 +554,10 @@ SVal RegionStoreManager::getSizeInElements(const GRState* St,
     return UnknownVal();
   }
 
+  if (isa<ElementRegion>(R)) {
+    return UnknownVal();
+  }
+
   assert(0 && "Other regions are not supported yet.");
   return UnknownVal();
 }
@@ -585,6 +589,13 @@ SVal RegionStoreManager::ArrayToPointer(Loc Array) {
   return loc::MemRegionVal(ER);                    
 }
 
+static bool isSmallerThan(QualType T1, QualType T2) {
+  if (T1->isCharType())
+    return true;
+  else
+    return false;
+}
+
 RegionStoreManager::CastResult
 RegionStoreManager::CastRegion(const GRState* state, const MemRegion* R,
                          QualType CastToTy) {
@@ -637,9 +648,14 @@ RegionStoreManager::CastRegion(const GRState* state, const MemRegion* R,
   // VarRegion.
   if (isa<VarRegion>(R) || isa<ElementRegion>(R) || isa<FieldRegion>(R)
       || isa<ObjCIvarRegion>(R) || isa<CompoundLiteralRegion>(R)) {
-    // FIXME: create an ElementRegion when the size of the pointee type is
-    // smaller than the region.
-    return CastResult(state, R);
+    if (isSmallerThan(PointeeTy, 
+                      cast<TypedRegion>(R)->getRValueType(getContext()))) {
+      SVal Idx = ValMgr.makeZeroArrayIndex();
+      ElementRegion* ER = MRMgr.getElementRegion(PointeeTy, Idx, 
+                                                 cast<TypedRegion>(R));
+      return CastResult(state, ER);
+    } else
+      return CastResult(state, R);
   }
 
   if (isa<TypedViewRegion>(R)) {
diff --git a/test/Analysis/rdar-6541136-region.c b/test/Analysis/rdar-6541136-region.c
index 59ee313f45..1e7a2d974b 100644
--- a/test/Analysis/rdar-6541136-region.c
+++ b/test/Analysis/rdar-6541136-region.c
@@ -13,5 +13,7 @@ void foo( void )
   struct load_wine *cmd = (void*) &wonky[1];
   cmd = cmd;
   char *p = (void*) &wonky[1];
-  *p = 1; // expected-warning{{Load or store into an out-of-bound memory}}
+  *p = 1; 
+  kernel_tea_cheese_t *q = &wonky[1];
+  kernel_tea_cheese_t r = *q; // expected-warning{{out-of-bound memory position}}
 }