[cfe-commits] r63110 - in /cfe/trunk: lib/Analysis/BasicStore.cpp test/Analysis/misc-ps.m

[Ted Kremenek]

Author: kremenek
Date: Tue Jan 27 12:29:03 2009
New Revision: 63110

URL: http://llvm.org/viewvc/llvm-project?rev=63110&view=rev
Log:
Fix bug in BasicStore::getLValueElement where if the base of an array subscript expression was an ElementRegion we stacked another ElementRegion on top of that.

This fixes PR 3422.

Modified:
    cfe/trunk/lib/Analysis/BasicStore.cpp
    cfe/trunk/test/Analysis/misc-ps.m

Modified: cfe/trunk/lib/Analysis/BasicStore.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Analysis/BasicStore.cpp?rev=63110&r1=63109&r2=63110&view=diff

==============================================================================
--- cfe/trunk/lib/Analysis/BasicStore.cpp (original)
+++ cfe/trunk/lib/Analysis/BasicStore.cpp Tue Jan 27 12:29:03 2009
@@ -203,7 +203,6 @@
 SVal BasicStoreManager::getLValueElement(const GRState* St, SVal Base,
                                          SVal Offset) {
 
-  
   if (Base.isUnknownOrUndef())
     return Base;
   
@@ -233,6 +232,17 @@
       
     case loc::MemRegionKind: {
       const MemRegion *R = cast<loc::MemRegionVal>(BaseL).getRegion();
+      
+      if (isa<ElementRegion>(R)) {
+        // Basic example:
+        //   char buf[100];
+        //   char *q = &buf[1];  // p points to ElementRegion(buf,Unknown)
+        //   &q[10]
+        assert(cast<ElementRegion>(R)->getIndex().isUnknown());
+        return Base;
+      }
+      
+      
       if (const TypedRegion *TR = dyn_cast<TypedRegion>(R)) {
         BaseR = TR;
         break;
@@ -244,7 +254,7 @@
       
       break;
     }
-      
+
     case loc::ConcreteIntKind:
       // While these seem funny, this can happen through casts.
       // FIXME: What we should return is the field offset.  For example,

Modified: cfe/trunk/test/Analysis/misc-ps.m
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/misc-ps.m?rev=63110&r1=63109&r2=63110&view=diff

==============================================================================
--- cfe/trunk/test/Analysis/misc-ps.m (original)
+++ cfe/trunk/test/Analysis/misc-ps.m Tue Jan 27 12:29:03 2009
@@ -100,3 +100,11 @@
   *p = 1; // no-warning
 }
 
+// PR 3422
+void pr3422_helper(char *p);
+void pr3422() {
+  char buf[100];
+  char *q = &buf[10];
+  pr3422_helper(&q[1]);
+}
+