Enhance RegionStore to lazily symbolicate fields and array elements for

structures passed-by-value as function arguments.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@74729 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 26 insertions, 10 deletions

diff --git a/lib/Analysis/MemRegion.cpp b/lib/Analysis/MemRegion.cpp
index 52e26238d9..4530540358 100644
--- a/lib/Analysis/MemRegion.cpp
+++ b/lib/Analysis/MemRegion.cpp
@@ -368,6 +368,13 @@ bool MemRegion::hasGlobalsStorage() const {
   return false;
 }
 
+bool MemRegion::hasParametersStorage() const {
+  if (const MemSpaceRegion *MS = getMemorySpace())
+    return MS == getMemRegionManager()->getStackArgumentsRegion();
+  
+  return false;
+}
+
 bool MemRegion::hasGlobalsOrParametersStorage() const {
   if (const MemSpaceRegion *MS = getMemorySpace()) {
     MemRegionManager *Mgr = getMemRegionManager();
diff --git a/lib/Analysis/RegionStore.cpp b/lib/Analysis/RegionStore.cpp
index 9c76265fa3..5729103fd3 100644
--- a/lib/Analysis/RegionStore.cpp
+++ b/lib/Analysis/RegionStore.cpp
@@ -959,7 +959,7 @@ SVal RegionStoreManager::RetrieveElement(const GRState* state,
     return UndefinedVal();
   }
 
-  if (R->hasStackStorage()) {
+  if (R->hasStackStorage() && !R->hasParametersStorage()) {
     // Currently we don't reason specially about Clang-style vectors.  Check
     // if superR is a vector and if so return Unknown.
     if (const TypedRegion *typedSuperR = dyn_cast<TypedRegion>(superR)) {
@@ -1006,7 +1006,11 @@ SVal RegionStoreManager::RetrieveField(const GRState* state,
     assert(0 && "Unknown default value");
   }
 
-  if (R->hasHeapOrStackStorage())
+  // FIXME: Is this correct?  Should it be UnknownVal?
+  if (R->hasHeapStorage())
+    return UndefinedVal();
+  
+  if (R->hasStackStorage() && !R->hasParametersStorage())
     return UndefinedVal();
 
   // If the region is already cast to another type, use that type to create the
diff --git a/test/Analysis/stack-addr-ps.c b/test/Analysis/stack-addr-ps.c
index 848adc8d9f..0d7a70373c 100644
--- a/test/Analysis/stack-addr-ps.c
+++ b/test/Analysis/stack-addr-ps.c
@@ -1,6 +1,5 @@
-// RUN: clang-cc -analyze -checker-cfref -analyzer-store=basic -verify %s
-
-// NOWORK: clang-cc -analyze -checker-cfref -analyzer-store=region -verify %s
+// RUN: clang-cc -analyze -checker-cfref -analyzer-store=basic -verify %s &&
+// RUN: clang-cc -analyze -checker-cfref -analyzer-store=region -verify %s
 
 #include <stdlib.h>
 
@@ -46,9 +45,15 @@ int array_test(int x[2]) {
   return x[0]; // no-warning
 }
 
-struct baz { int x; };
-
-int struct_test(struct baz byVal) {
-  return byVal.x; // no-warning;
+struct baz {
+  int x;
+  int y[2];
+};
+
+int struct_test(struct baz byVal, int flag) {
+  if (flag)  
+    return byVal.x; // no-warning
+  else {
+    return byVal.y[0]; // no-warning
+  }
 }
-