commit 68b6ce96347d2cf954ebbc9c034aab190338a9ca
author swift-ci <swift-ci@users.noreply.github.com> Wed Oct 25 08:28:17 2017 -0700
committer swift-ci <swift-ci@users.noreply.github.com> Wed Oct 25 08:28:17 2017 -0700
tree 532a178a3f2ddce1392bf3b0f65e1eb1d8895188
parent bb20a94e8665dad7f49b7d0979d527923c7efefe
parent dfaf801b7f27a29ec52da8f20a479512c1786954

Merge remote-tracking branch 'origin/swift-4.1-branch' into stable

lib/AST/ExprConstant.cpp

diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index a26b608..419e9a7 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -1758,6 +1758,9 @@
       }
     }
     for (const auto *I : RD->fields()) {
+      if (I->isUnnamedBitfield())
+        continue;
+
       if (!CheckConstantExpression(Info, DiagLoc, I->getType(),
                                    Value.getStructField(I->getFieldIndex())))
         return false;

test/SemaCXX/constant-expression-cxx11.cpp

diff --git a/test/SemaCXX/constant-expression-cxx11.cpp b/test/SemaCXX/constant-expression-cxx11.cpp
index 3fda2d0..c834da7 100644
--- a/test/SemaCXX/constant-expression-cxx11.cpp
+++ b/test/SemaCXX/constant-expression-cxx11.cpp
@@ -1904,6 +1904,22 @@
     };
     static_assert(X::f(3) == -1, "3 should truncate to -1");
   }
+
+  struct HasUnnamedBitfield {
+    unsigned a;
+    unsigned : 20;
+    unsigned b;
+
+    constexpr HasUnnamedBitfield() : a(), b() {}
+    constexpr HasUnnamedBitfield(unsigned a, unsigned b) : a(a), b(b) {}
+  };
+
+  void testUnnamedBitfield() {
+    const HasUnnamedBitfield zero{};
+    int a = 1 / zero.b; // expected-warning {{division by zero is undefined}}
+    const HasUnnamedBitfield oneZero{1, 0};
+    int b = 1 / oneZero.b; // expected-warning {{division by zero is undefined}}
+  }
 }
 
 namespace ZeroSizeTypes {

test/SemaCXX/warn-global-constructors.cpp

diff --git a/test/SemaCXX/warn-global-constructors.cpp b/test/SemaCXX/warn-global-constructors.cpp
index 8568264..430f239 100644
--- a/test/SemaCXX/warn-global-constructors.cpp
+++ b/test/SemaCXX/warn-global-constructors.cpp
@@ -126,3 +126,22 @@
 void *array_storage[1];
 const int &global_reference = *(int *)array_storage;
 }
+
+namespace bitfields {
+  struct HasUnnamedBitfield {
+    unsigned a;
+    unsigned : 20;
+    unsigned b;
+
+    constexpr HasUnnamedBitfield() : a(), b() {}
+    constexpr HasUnnamedBitfield(unsigned a, unsigned b) : a(a), b(b) {}
+    explicit HasUnnamedBitfield(unsigned a) {}
+  };
+
+  const HasUnnamedBitfield zeroConst{};
+  HasUnnamedBitfield zeroMutable{};
+  const HasUnnamedBitfield explicitConst{1, 2};
+  HasUnnamedBitfield explicitMutable{1, 2};
+  const HasUnnamedBitfield nonConstexprConst{1}; // expected-warning {{global constructor}}
+  HasUnnamedBitfield nonConstexprMutable{1}; // expected-warning {{global constructor}}
+}