[analyzer] Canonicalize declarations within variable regions.

Memory region that correspond to a variable is identified by the variable's
declaration and, in case of local variables, the stack frame it belongs to.

The declaration needs to be canonical, otherwise we'd have two different
memory regions that correspond to the same variable.

Fix such bug for global variables with forward declarations and assert
that no other problems of this kind happen.

Differential Revision: https://reviews.llvm.org/D57619

llvm-svn: 353353

1 files changed, 2 insertions, 0 deletions

diff --git a/clang/lib/StaticAnalyzer/Core/MemRegion.cpp b/clang/lib/StaticAnalyzer/Core/MemRegion.cpp
index fd08f92a658..b9619d173dd 100644
--- a/clang/lib/StaticAnalyzer/Core/MemRegion.cpp
+++ b/clang/lib/StaticAnalyzer/Core/MemRegion.cpp
@@ -844,6 +844,7 @@ getStackOrCaptureRegionForDeclContext(const LocationContext *LC,
 
 const VarRegion* MemRegionManager::getVarRegion(const VarDecl *D,
                                                 const LocationContext *LC) {
+  D = D->getCanonicalDecl();
   const MemRegion *sReg = nullptr;
 
   if (D->hasGlobalStorage() && !D->isStaticLocal()) {
@@ -930,6 +931,7 @@ const VarRegion* MemRegionManager::getVarRegion(const VarDecl *D,
 
 const VarRegion *MemRegionManager::getVarRegion(const VarDecl *D,
                                                 const MemRegion *superR) {
+  D = D->getCanonicalDecl();
   return getSubRegion<VarRegion>(D, superR);
 }