[all-commits] [llvm/llvm-project] 8c8a26: [clang][AIX] add option mdefault-visibility-export...

[David Tenty via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 8c8a2679a20f621994fa904bcfc68775e7345edc
      https://github.com/llvm/llvm-project/commit/8c8a2679a20f621994fa904bcfc68775e7345edc
  Author: David Tenty <daltenty at ibm.com>
  Date:   2022-06-01 (Wed, 01 Jun 2022)

  Changed paths:
    M clang/docs/UsersManual.rst
    M clang/include/clang/Basic/LangOptions.def
    M clang/include/clang/Basic/LangOptions.h
    M clang/include/clang/Driver/Options.td
    M clang/lib/CodeGen/CodeGenModule.cpp
    M clang/lib/CodeGen/CodeGenModule.h
    M clang/lib/CodeGen/ItaniumCXXABI.cpp
    M clang/lib/CodeGen/MicrosoftCXXABI.cpp
    M clang/lib/Driver/ToolChains/Clang.cpp
    A clang/test/CodeGen/mdefault-visibility-export-mapping.c
    A clang/test/CodeGenCXX/mdefault-visibility-export-mapping-alias.cpp
    A clang/test/CodeGenCXX/mdefault-visibility-export-mapping-rtti.cpp
    A clang/test/CodeGenCXX/mdefault-visibility-export-mapping.cpp

  Log Message:
  -----------
  [clang][AIX] add option mdefault-visibility-export-mapping

The option mdefault-visibility-export-mapping is created to allow
mapping default visibility to an explicit shared library export
(e.g. dllexport). Exactly how and if this is manifested is target
dependent (since it depends on how they map dllexport in the IR).

Three values are provided for the option:

* none: the default and behavior without the option, no additional export linkage information is created.
* explicit: add the export for entities with explict default visibility from the source, including RTTI
* all: add the export for all entities with default visibility

This option is useful for targets which do not export symbols as part of
their usual default linkage behaviour (e.g. AIX), such targets
traditionally specified such information in external files (e.g. export
lists), but this mapping allows them to use the visibility information
typically used for this purpose on other (e.g. ELF) platforms.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D126340