From: Alexander Kornienko <alexfh@google.com>
Date: Wed, 9 May 2018 12:27:21 +0000 (+0000)
Subject: Fixes issue introduced by r331556.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=80679644bf863c44b57f81d0f16600a3b2956148;p=clang

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

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@331870 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/StaticAnalyzer/Core/RegionStore.cpp b/lib/StaticAnalyzer/Core/RegionStore.cpp
index 557a89e626..be4b5aa918 100644
--- a/lib/StaticAnalyzer/Core/RegionStore.cpp
+++ b/lib/StaticAnalyzer/Core/RegionStore.cpp
@@ -1711,13 +1711,15 @@ SVal RegionStoreManager::getBindingForField(RegionBindingsConstRef B,
   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);
diff --git a/test/Analysis/initialization.c b/test/Analysis/initialization.c
new file mode 100644
index 0000000000..a6fe9be2b7
--- /dev/null
+++ b/test/Analysis/initialization.c
@@ -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
+}