Fix or suppress GCC warnings during build.
Summary:
Currently a number of GCC warnings are emitted when building libc++. This patch fixes or ignores all of them. The primary changes are:
* Work around strict aliasing issues in `typeinfo::hash_code()` by using __attribute__((may_alias)). However I think a non-aliasing `hash_code()` implementation is possible. Further investigation needed.
* Add `_LIBCPP_UNREACHABLE()` to switch in `strstream.cpp` to avoid -Wpotentially-uninitialized.
* Fix -Wunused-value warning in `__all` by adding a void cast.
* Ignore -Wattributes for now. There are a number of real attribute issues when using GCC but enabling the warning is too noisy.
* Ignore -Wliteral-suffix since it warns about the use of reserved identifiers. Note Only GCC 7.0 supports disabling this warning.
* Ignore -Wc++14-compat since it warns about the sized new/delete overloads.
Reviewers: EricWF
Differential Revision: https://reviews.llvm.org/D24003
llvm-svn: 280007
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: f6ac565031343554370a6a3139f88341765fa32d
diff --git a/src/strstream.cpp b/src/strstream.cpp
index 0e2d7ff..be94f9c 100644
--- a/src/strstream.cpp
+++ b/src/strstream.cpp
@@ -11,6 +11,7 @@
#include "algorithm"
#include "climits"
#include "cstring"
+#include "cstdlib"
#include "__debug"
_LIBCPP_BEGIN_NAMESPACE_STD
@@ -266,6 +267,8 @@
case ios::end:
newoff = seekhigh - eback();
break;
+ default:
+ _LIBCPP_UNREACHABLE();
}
newoff += __off;
if (0 <= newoff && newoff <= seekhigh - eback())