From: Richard Smith <richard-llvm@metafoo.co.uk>
Date: Wed, 15 Nov 2017 03:03:56 +0000 (+0000)
Subject: PR35214: don't crash if we see an array of unknown bound added to an empty but invali... 
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=7c604e87f1f22aa9605faab1dce762dad85a4cff;p=clang

PR35214: don't crash if we see an array of unknown bound added to an empty but invalid designator.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@318258 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index c09c99386c..e899b7ca16 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -1351,10 +1351,11 @@ namespace {
         Designator.setInvalid();
         return;
       }
-
-      assert(getType(Base)->isPointerType() || getType(Base)->isArrayType());
-      Designator.FirstEntryIsAnUnsizedArray = true;
-      Designator.addUnsizedArrayUnchecked(ElemTy);
+      if (checkSubobject(Info, E, CSK_ArrayToPointer)) {
+        assert(getType(Base)->isPointerType() || getType(Base)->isArrayType());
+        Designator.FirstEntryIsAnUnsizedArray = true;
+        Designator.addUnsizedArrayUnchecked(ElemTy);
+      }
     }
     void addArray(EvalInfo &Info, const Expr *E, const ConstantArrayType *CAT) {
       if (checkSubobject(Info, E, CSK_ArrayToPointer))
diff --git a/test/Sema/const-eval.c b/test/Sema/const-eval.c
index 1b0a325dd1..d60296f279 100644
--- a/test/Sema/const-eval.c
+++ b/test/Sema/const-eval.c
@@ -144,3 +144,11 @@ void *PR28739a = (__int128)(unsigned long)-1 + &PR28739a;
 void *PR28739b = &PR28739b + (__int128)(unsigned long)-1;
 __int128 PR28739c = (&PR28739c + (__int128)(unsigned long)-1) - &PR28739c;
 void *PR28739d = &(&PR28739d)[(__int128)(unsigned long)-1];
+
+struct PR35214_X {
+  int k;
+  int arr[];
+};
+int PR35214_x;
+int PR35214_y = ((struct PR35214_X *)&PR35214_x)->arr[1]; // expected-error {{not a compile-time constant}}
+int *PR35214_z = &((struct PR35214_X *)&PR35214_x)->arr[1]; // ok, &PR35214_x + 2