[libcxx] r298937 - [libc++] Add a key function for bad_function_call

[Shoaib Meenai via cfe-commits]

Author: smeenai
Date: Tue Mar 28 14:33:31 2017
New Revision: 298937

URL: http://llvm.org/viewvc/llvm-project?rev=298937&view=rev
Log:
[libc++] Add a key function for bad_function_call

Summary:
bad_function_call is currently an empty class, so any object files using
that class will end up with their own copy of its typeinfo, typeinfo
name and vtable, leading to unnecessary duplication that has to be
resolved by the dynamic linker. Instead, give bad_function_call a key
function and put a definition for that key function in libc++ itself, to
centralize the typeinfo and vtable.

This is consistent with the behavior for other exception classes. The
key functions are defined in libc++ rather than libc++abi since the
class is defined in the libc++ versioning namespace, so ABI
compatibility with libstdc++ is not a concern.

Guard this change behind an ABI macro, since it isn't backwards
compatible (i.e., clients built against the new libc++ headers wouldn't
be able to run against an older libc++ library).

Reviewers: mclow.lists, EricWF

Subscribers: mgorny, cfe-commits

Differential Revision: https://reviews.llvm.org/D27387

Added:
    libcxx/trunk/src/functional.cpp
Modified:
    libcxx/trunk/include/__config
    libcxx/trunk/include/functional
    libcxx/trunk/lib/CMakeLists.txt

Modified: libcxx/trunk/include/__config
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/__config?rev=298937&r1=298936&r2=298937&view=diff
==============================================================================
--- libcxx/trunk/include/__config (original)
+++ libcxx/trunk/include/__config Tue Mar 28 14:33:31 2017
@@ -58,6 +58,10 @@
 // `pointer_safety` and `get_pointer_safety()` will no longer be available
 // in C++03.
 #define _LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE
+// Define a key function for `bad_function_call` in the library, to centralize
+// its vtable and typeinfo to libc++ rather than having all other libraries
+// using that class define their own copies.
+#define _LIBCPP_ABI_BAD_FUNCTION_CALL_KEY_FUNCTION
 #elif _LIBCPP_ABI_VERSION == 1
 #if !defined(_WIN32)
 // Enable compiling copies of now inline methods into the dylib to support

Modified: libcxx/trunk/include/functional
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/functional?rev=298937&r1=298936&r2=298937&view=diff
==============================================================================
--- libcxx/trunk/include/functional (original)
+++ libcxx/trunk/include/functional Tue Mar 28 14:33:31 2017
@@ -1389,6 +1389,12 @@ mem_fn(_Rp _Tp::* __pm) _NOEXCEPT
 class _LIBCPP_EXCEPTION_ABI bad_function_call
     : public exception
 {
+#ifdef _LIBCPP_ABI_BAD_FUNCTION_CALL_KEY_FUNCTION
+public:
+    virtual ~bad_function_call() _NOEXCEPT;
+
+    virtual const char* what() const _NOEXCEPT;
+#endif
 };
 
 _LIBCPP_NORETURN inline _LIBCPP_ALWAYS_INLINE

Modified: libcxx/trunk/lib/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/lib/CMakeLists.txt?rev=298937&r1=298936&r2=298937&view=diff
==============================================================================
--- libcxx/trunk/lib/CMakeLists.txt (original)
+++ libcxx/trunk/lib/CMakeLists.txt Tue Mar 28 14:33:31 2017
@@ -177,7 +177,7 @@ endif()
 split_list(LIBCXX_COMPILE_FLAGS)
 split_list(LIBCXX_LINK_FLAGS)
 
-# Add a object library that contains the compiled source files.
+# Add an object library that contains the compiled source files.
 add_library(cxx_objects OBJECT ${exclude_from_all} ${LIBCXX_SOURCES} ${LIBCXX_HEADERS})
 if(WIN32 AND NOT MINGW)
   target_compile_definitions(cxx_objects

Added: libcxx/trunk/src/functional.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/src/functional.cpp?rev=298937&view=auto
==============================================================================
--- libcxx/trunk/src/functional.cpp (added)
+++ libcxx/trunk/src/functional.cpp Tue Mar 28 14:33:31 2017
@@ -0,0 +1,26 @@
+//===----------------------- functional.cpp -------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "functional"
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#ifdef _LIBCPP_ABI_BAD_FUNCTION_CALL_KEY_FUNCTION
+bad_function_call::~bad_function_call() _NOEXCEPT
+{
+}
+
+const char*
+bad_function_call::what() const _NOEXCEPT
+{
+    return "std::bad_function_call";
+}
+#endif
+
+_LIBCPP_END_NAMESPACE_STD