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[libc++] Make _LIBCPP_TYPE_VIS export members

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Summary:
Most classes annotated with _LIBCPP_TYPE_VIS need to have at least some
of their members exported, otherwise we have a lot of link errors when
linking against a libc++ built with hidden visibility. This also makes
_LIBCPP_TYPE_VIS be consistent across platforms, since on Windows it
already exports members.

With this change made, any template methods of a class marked
_LIBCPP_TYPE_VIS will also get default visibility when instantiatied,
which is not desirable for clients of libc++ headers who wish to control
their visibility; this is the same issue as PR30642. Annotate all
problematic methods with an explicit visibility specifier to avoid this.

The problematic methods were found by running bad-visibility-finder [1]
against the libc++ headers after making the _LIBCPP_TYPE_VIS change. The
small methods were marked for inlining; the larger ones hidden.

[1] https://github.com/smeenai/bad-visibility-finder

Reviewers: mclow.lists, EricWF

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D25208

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@296732 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Shoaib Meenai
2017-03-02 03:22:18 +00:00
parent 24e8dbdd2d
commit 6b7349243e
9 changed files with 35 additions and 14 deletions
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11
docs/DesignDocs/VisibilityMacros.rst
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@@ -47,18 +47,17 @@ Visibility Macros
A synonym for `_LIBCPP_INLINE_VISIBILITY`
**_LIBCPP_TYPE_VIS**
Mark a type's typeinfo, vtable and members as having default visibility.
This attribute cannot be used on class templates.
**_LIBCPP_TEMPLATE_VIS**
Mark a type's typeinfo and vtable as having default visibility.
`_LIBCPP_TYPE_VIS`. This macro has no effect on the visibility of the
type's member functions. This attribute cannot be used on class templates.
This macro has no effect on the visibility of the type's member functions.
**GCC Behavior**: GCC does not support Clang's `type_visibility(...)`
attribute. With GCC the `visibility(...)` attribute is used and member
functions are affected.
**_LIBCPP_TEMPLATE_VIS**
The same as `_LIBCPP_TYPE_VIS` except that it may be applied to class
templates.
**Windows Behavior**: DLLs do not support dllimport/export on class templates.
The macro has an empty definition on this platform.