diff options
| author |  Derek Mauro <dmauro@google.com> | 2024-01-03 13:00:42 -0800 |
|---|---|---|
| committer |  Copybara-Service <copybara-worker@google.com> | 2024-01-03 13:01:46 -0800 |
| commit | 2a636651729cec997a433ce8e363c6344130944e (patch) | |
| tree | f039cfa461d15224bc67fd74b8dcbd4fa4f0065b /absl/strings | |
| parent | 98156bb8e0337cc8c2e0480ebc14fee208a2f08c (diff) | |
Avoid a empty library build failure on Apple platforms
https://github.com/abseil/abseil-cpp/issues/1465 reports that
some CMake builds on Apply platforms issue
```
warning: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ranlib: archive library: libabsl_bad_any_cast_impl.a the table of contents is empty (no object file members in the library define global symbols)
```
Our CMake build handles this problem for header-only libraries by not
building a library at all. For some libraries, for example our polyfills,
the library is only conditionally empty. In these libraries, I added
a single char variable on Apple platforms as a workaround.
I have been able to reproduce the warnings reported in
https://github.com/abseil/abseil-cpp/issues/1465, but they don't fail the
build for me. I don't see them any more after this change.
PiperOrigin-RevId: 595480705
Change-Id: Ie48637e84ebae2f2aea4e2de83b146f30f6a76b9
Diffstat (limited to 'absl/strings')
| -rw-r--r-- | absl/strings/string_view.cc | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/absl/strings/string_view.cc b/absl/strings/string_view.cc index 0500ef5c..97025c32 100644 --- a/absl/strings/string_view.cc +++ b/absl/strings/string_view.cc @@ -241,4 +241,22 @@ constexpr string_view::size_type string_view::kMaxSize; ABSL_NAMESPACE_END } // namespace absl +#else + +// https://github.com/abseil/abseil-cpp/issues/1465 +// CMake builds on Apple platforms error when libraries are empty. +// Our CMake configuration can avoid this error on header-only libraries, +// but since this library is conditionally empty, including a single +// variable is an easy workaround. +#ifdef __APPLE__ +namespace absl { +ABSL_NAMESPACE_BEGIN +namespace strings_internal { +extern const char kAvoidEmptyStringViewLibraryWarning; +const char kAvoidEmptyStringViewLibraryWarning = 0; +} // namespace strings_internal +ABSL_NAMESPACE_END +} // namespace absl +#endif // __APPLE__ + #endif // ABSL_USES_STD_STRING_VIEW |