[cfe-commits] r71099 - in /cfe/branches/Apple/Dib: lib/Analysis/CFRefCount.cpp lib/Analysis/Store.cpp test/Analysis/pr_4164.c

[Mike Stump]

Author: mrs
Date: Wed May  6 13:32:48 2009
New Revision: 71099

URL: http://llvm.org/viewvc/llvm-project?rev=71099&view=rev
Log:
Merge in 71094:

Fix analyzer regression reported in PR 4164:
- Update the old StoreManager::CastRegion to strip off 'ElementRegions' when
  casting to void* (Zhongxing: please validate)
- Pass-by-reference argument invalidation logic in CFRefCount.cpp:
  - Strip ElementRegions when the ElementRegion is just a 'raw data' view
    on top of the underlying typed region.

Added:
    cfe/branches/Apple/Dib/test/Analysis/pr_4164.c
      - copied unchanged from r71094, cfe/trunk/test/Analysis/pr_4164.c
Modified:
    cfe/branches/Apple/Dib/lib/Analysis/CFRefCount.cpp
    cfe/branches/Apple/Dib/lib/Analysis/Store.cpp

Modified: cfe/branches/Apple/Dib/lib/Analysis/CFRefCount.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/branches/Apple/Dib/lib/Analysis/CFRefCount.cpp?rev=71099&r1=71098&r2=71099&view=diff

==============================================================================
--- cfe/branches/Apple/Dib/lib/Analysis/CFRefCount.cpp (original)
+++ cfe/branches/Apple/Dib/lib/Analysis/CFRefCount.cpp Wed May  6 13:32:48 2009
@@ -2606,7 +2606,29 @@
         
         const TypedRegion* R = dyn_cast<TypedRegion>(MR->getRegion());
 
-        if (R) {          
+        if (R) {
+          // Are we dealing with an ElementRegion?  If the element type is
+          // a basic integer type (e.g., char, int) and the underying region
+          // is also typed then strip off the ElementRegion.
+          // FIXME: We really need to think about this for the general case
+          //   as sometimes we are reasoning about arrays and other times
+          //   about (char*), etc., is just a form of passing raw bytes.
+          //   e.g., void *p = alloca(); foo((char*)p);
+          if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
+            // Checking for 'integral type' is probably too promiscuous, but
+            // we'll leave it in for now until we have a systematic way of
+            // handling all of these cases.  Eventually we need to come up
+            // with an interface to StoreManager so that this logic can be
+            // approriately delegated to the respective StoreManagers while
+            // still allowing us to do checker-specific logic (e.g.,
+            // invalidating reference counts), probably via callbacks.            
+            if (ER->getElementType()->isIntegralType())
+              if (const TypedRegion *superReg =
+                  dyn_cast<TypedRegion>(ER->getSuperRegion()))
+                R = superReg;
+            // FIXME: What about layers of ElementRegions?
+          }
+          
           // Is the invalidated variable something that we were tracking?
           SymbolRef Sym = state.GetSValAsScalarOrLoc(R).getAsLocSymbol();
           

Modified: cfe/branches/Apple/Dib/lib/Analysis/Store.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/branches/Apple/Dib/lib/Analysis/Store.cpp?rev=71099&r1=71098&r2=71099&view=diff

==============================================================================
--- cfe/branches/Apple/Dib/lib/Analysis/Store.cpp (original)
+++ cfe/branches/Apple/Dib/lib/Analysis/Store.cpp Wed May  6 13:32:48 2009
@@ -44,18 +44,37 @@
     QualType Pointee = PTy->getPointeeType();
     if (Pointee->isVoidType()) {
 
-      // Casts to void* only removes TypedViewRegion. If there is no
-      // TypedViewRegion, leave the region untouched. This happens when:
-      //
-      // void foo(void*);
-      // ...
-      // void bar() {
-      //   int x;
-      //   foo(&x);
-      // }
-
-      if (const TypedViewRegion *TR = dyn_cast<TypedViewRegion>(R))
-        R = TR->removeViews();
+      do {
+        if (const TypedViewRegion *TR = dyn_cast<TypedViewRegion>(R)) {
+          // Casts to void* removes TypedViewRegion. This happens when:
+          //
+          // void foo(void*);
+          // ...
+          // void bar() {
+          //   int x;
+          //   foo(&x);
+          // }
+          //
+          R = TR->removeViews();
+          continue;
+        }
+        else if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
+          // Casts to void* also removes ElementRegions. This happens when:
+          //
+          // void foo(void*);
+          // ...
+          // void bar() {
+          //   int x;
+          //   foo((char*)&x);
+          // }                
+          //
+          R = ER->getSuperRegion();
+          continue;
+        }
+        else
+          break;
+      }
+      while (0);
       
       return CastResult(state, R);
     }