[Sema] Correct nothrow inherited by noexcept

As reported in https://bugs.llvm.org/show_bug.cgi?id=33235,
a noexcept function was unable to inherit from a nothrow defaulted
constructor. Attribute "nothrow" is supposed to be semantically
identical to noexcept, and in fact, a number of other places in the
code treat them identically.

This patch simply checks the RecordDecl for the correct attribute in
the case where no other exception specifier was set.

Differential Revision: https://reviews.llvm.org/D38209

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@314462 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index 492694d07ef08c3a3c20753a572cc6ac58fa62c7..82e112bb3f92a33d1c599bb308078df5043f4a63 100644 (file)
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -167,6 +167,9 @@ Sema::ImplicitExceptionSpecification::CalledDecl(SourceLocation CallLoc,
   if (ComputedEST == EST_None)
     return;
 
+  if (EST == EST_None && Method->hasAttr<NoThrowAttr>())
+    EST = EST_BasicNoexcept;
+
   switch(EST) {
   // If this function can throw any exceptions, make a note of that.
   case EST_MSAny:

diff --git a/test/SemaCXX/nothrow-as-noexcept-ctor.cpp b/test/SemaCXX/nothrow-as-noexcept-ctor.cpp
new file mode 100644 (file)
index 0000000..7cca414
--- /dev/null
+++ b/test/SemaCXX/nothrow-as-noexcept-ctor.cpp
@@ -0,0 +1,26 @@
+// RUN: %clang_cc1 %s -fcxx-exceptions -fsyntax-only -Wexceptions -verify -std=c++14
+
+// expected-no-diagnostics
+struct Base {
+  __attribute__((nothrow)) Base() {}
+};
+
+struct Derived : Base {
+  Derived() noexcept = default;
+};
+
+struct Base2 {
+   Base2() noexcept {}
+};
+
+struct Derived2 : Base2 {
+  __attribute__((nothrow)) Derived2() = default;
+};
+
+struct Base3 {
+  __attribute__((nothrow)) Base3() {}
+};
+
+struct Derived3 : Base3 {
+  __attribute__((nothrow)) Derived3() = default;
+};