r331870 - Fixes issue introduced by r331556.

[Alexander Kornienko via cfe-commits]

Author: alexfh
Date: Wed May  9 05:27:21 2018
New Revision: 331870

URL: http://llvm.org/viewvc/llvm-project?rev=331870&view=rev
Log:
Fixes issue introduced by r331556.

Closes bug: https://bugs.llvm.org/show_bug.cgi?id=37357

Patch by Rafael Stahl!

Differential revision: https://reviews.llvm.org/D46633

Added:
    cfe/trunk/test/Analysis/initialization.c
Modified:
    cfe/trunk/lib/StaticAnalyzer/Core/RegionStore.cpp

Modified: cfe/trunk/lib/StaticAnalyzer/Core/RegionStore.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Core/RegionStore.cpp?rev=331870&r1=331869&r2=331870&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Core/RegionStore.cpp (original)
+++ cfe/trunk/lib/StaticAnalyzer/Core/RegionStore.cpp Wed May  9 05:27:21 2018
@@ -1711,13 +1711,15 @@ SVal RegionStoreManager::getBindingForFi
   if (const auto *VR = dyn_cast<VarRegion>(superR)) {
     const VarDecl *VD = VR->getDecl();
     QualType RecordVarTy = VD->getType();
+    unsigned Index = FD->getFieldIndex();
     // Either the record variable or the field has to be const qualified.
     if (RecordVarTy.isConstQualified() || Ty.isConstQualified())
       if (const Expr *Init = VD->getInit())
         if (const auto *InitList = dyn_cast<InitListExpr>(Init))
-          if (const Expr *FieldInit = InitList->getInit(FD->getFieldIndex()))
-            if (Optional<SVal> V = svalBuilder.getConstantVal(FieldInit))
-              return *V;
+          if (Index < InitList->getNumInits())
+            if (const Expr *FieldInit = InitList->getInit(Index))
+              if (Optional<SVal> V = svalBuilder.getConstantVal(FieldInit))
+                return *V;
   }
 
   return getBindingForFieldOrElementCommon(B, R, Ty);

Added: cfe/trunk/test/Analysis/initialization.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/initialization.c?rev=331870&view=auto
==============================================================================
--- cfe/trunk/test/Analysis/initialization.c (added)
+++ cfe/trunk/test/Analysis/initialization.c Wed May  9 05:27:21 2018
@@ -0,0 +1,7 @@
+// RUN: %clang_analyze_cc1 -analyzer-checker=core -verify %s
+// expected-no-diagnostics
+
+void initbug() {
+  const union { float a; } u = {};
+  (void)u.a; // no-crash
+}