teak-llvm/clang/test/SemaCXX/warn-msvc-enum-bitfield.cpp
Reid Kleckner ad425626d2 Add warning when assigning enums to bitfields without an explicit unsigned underlying type
Summary:
Add a warning when assigning enums to bitfields without an explicit
unsigned underlying type. This is to prevent problems with MSVC
compatibility, since the Microsoft ABI defaults to storing enums with a
signed type, causing inconsistencies with saving to/reading from
bitfields.

Also disabled the warning in the dr0xx.cpp test which throws the error,
and added a test for the warning.

The warning can be disabled with -Wno-signed-enum-bitfield.

Patch by Sasha Bermeister!

Reviewers: rnk, aaron.ballman

Subscribers: mehdi_amini, aaron.ballman, cfe-commits, thakis, dcheng

Differential Revision: https://reviews.llvm.org/D24289

llvm-svn: 287177
2016-11-16 23:40:00 +00:00

41 lines
1.1 KiB
C++

// RUN: %clang_cc1 -fsyntax-only -Wsigned-enum-bitfield -verify %s --std=c++11
// Enums used in bitfields with no explicitly specified underlying type.
void test0() {
enum E { E1, E2 };
enum F { F1, F2 };
struct { E e1 : 1; E e2; F f1 : 1; F f2; } s;
s.e1 = E1; // expected-warning {{enums in the Microsoft ABI are signed integers by default; consider giving the enum E an unsigned underlying type to make this code portable}}
s.f1 = F1; // expected-warning {{enums in the Microsoft ABI are signed integers by default; consider giving the enum F an unsigned underlying type to make this code portable}}
s.e2 = E2;
s.f2 = F2;
}
// Enums used in bitfields with an explicit signed underlying type.
void test1() {
enum E : signed { E1, E2 };
enum F : long { F1, F2 };
struct { E e1 : 1; E e2; F f1 : 1; F f2; } s;
s.e1 = E1;
s.f1 = F1;
s.e2 = E2;
s.f2 = F2;
}
// Enums used in bitfields with an explicitly unsigned underlying type.
void test3() {
enum E : unsigned { E1, E2 };
enum F : unsigned long { F1, F2 };
struct { E e1 : 1; E e2; F f1 : 1; F f2; } s;
s.e1 = E1;
s.f1 = F1;
s.e2 = E2;
s.f2 = F2;
}