merged type info names.
Previously std::type_info always expected type info string to be unique.
But this isn't always the case. Like when -Bsymbolic is passed to the
linker or due to llvm.org/PR37398.
This patch adds the LIBCXX_HAS_MERGED_TYPEINFO_NAMES_DEFAULT CMake
option which, when specified, overrides the default configuration for
the library.
The current defaults still assume unique names even though this isn't
strictly correct for ELF binaries. We should consider changing the
default in a follow up commit.
llvm-svn: 361913
Summary:
On Windows we currently provide two separate ABI configurations. One which defers to `vcruntime` to provide the C++ runtime and another which doesn't.
Using `vcruntime` allows interoperability which programs compiled against the MSVC STL, and should be preferred whenever possible.
When deferring to `vcruntime` much of the ABI we provide changes. Including the layout of `<stdexcept>` types, their vtables, and how the linkage of their members.
This patch introduces the `_LIBCPP_ABI_VCRUNTIME` macro to denote this configuration. It also cleans up the existing configuration for using `vcruntime`.
This cleanup lays the groundwork for fixing a number of ABI and interoperability bugs in `<stdexcept>`.
Reviewers: thomasanderson, ldionne, smeenai
Reviewed By: smeenai
Subscribers: jdoerfert, libcxx-commits, #libc
Differential Revision: https://reviews.llvm.org/D58942
llvm-svn: 355366
Summary:
We currently have effectively 3 implementations of type_info: one for
the Microsoft ABI, one that does not assume that there's a unique copy
of each RTTI in a progran, and one that assumes a unique copy.
Those 3 implementations are entangled into the same class with nested
ifdefs, which makes it very difficult to understand. Furthermore, the
benefit of doing this is rather small since the code that is duplicated
across implementations is just a couple of trivial lines.
This patch stamps out the 3 versions of type_info explicitly to increase
readability. It also explains what's going on with short comments, because
it's far from obvious.
Reviewers: EricWF, mclow.lists
Subscribers: christof, jkorous, dexonsmith
Differential Revision: https://reviews.llvm.org/D57606
llvm-svn: 352905
to reflect the new license. These used slightly different spellings that
defeated my regular expressions.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351648
Summary:
We already have the negation of that as _LIBCPP_HAS_NONUNIQUE_TYPEINFO.
Having both defined is confusing, since only one of them is used.
Reviewers: EricWF, mclow.lists
Subscribers: christof, jkorous, dexonsmith, libcxx-commits
Differential Revision: https://reviews.llvm.org/D54537
llvm-svn: 349947
Summary:
We never actually mean to always inline a function -- all the uses of
the macro I could find are actually attempts to control the visibility
of symbols. This is better described by _LIBCPP_INLINE_VISIBILITY, which
is actually always defined the same.
This change is orthogonal to the decision of what we're actually going
to do with _LIBCPP_INLINE_VISIBILITY -- it just simplifies things by
having one canonical way of doing things.
Note that this commit had originally been applied in r336369 and then
reverted in r336382 because of unforeseen problems. Both of these problems
have now been fixed.
Reviewers: EricWF, mclow.lists
Subscribers: christof, dexonsmith, erikvanderpoel
Differential Revision: https://reviews.llvm.org/D48892
llvm-svn: 336866
This reverts commit r336369. The commit had two problems:
1. __pbump was marked as _LIBCPP_EXTERN_TEMPLATE_INLINE_VISIBILITY instead of
_LIBCPP_INLINE_VISIBILITY, which lead to two symbols being added in the
dylib and the check-cxx-abilist failing.
2. The LLDB tests started failing because they undefine
`_LIBCPP_INLINE_VISIBILITY`. I need to figure out why they do that and
fix the tests before we can go forward with this change.
llvm-svn: 336382
Summary:
We never actually mean to always inline a function -- all the uses of
the macro I could find are actually attempts to control the visibility
of symbols. This is better described by _LIBCPP_INLINE_VISIBILITY, which
is actually always defined the same.
This change is orthogonal to the decision of what we're actually going
to do with _LIBCPP_INLINE_VISIBILITY -- it just simplifies things by
having one canonical way of doing things.
Reviewers: EricWF
Subscribers: christof, llvm-commits, dexonsmith, erikvanderpoel, mclow.lists
Differential Revision: https://reviews.llvm.org/D48892
llvm-svn: 336369
We need to use the vcruntime declarations on Windows to avoid an
ODR violation involving rtti.obj, which provides the definition of
the runtime function implementing dynamic_cast and depends on the
vcruntime implementations of bad_cast and bad_typeid.
Differential Revision: https://reviews.llvm.org/D42220
llvm-svn: 323491
The RTTI structure is different on Windows when building under MS ABI.
Update the definition to reflect this. The structure itself contains an
area for caching the undecorated name (which is 0-initialized). The
decorated name has a bitfield followed by the linkage name. When
std::type_info::name is invoked for the first time, the runtime should
undecorate the name, cache it, and return the undecorated name. This
requires access to an implementation of __unDName. For now, return
the raw name.
This uses the fnv-1a hash to hash the name of the RTTI. We could use an
alternate hash (murmur? city?), but, this was the quickest to throw
together.
llvm-svn: 313344
Libc++ is used as a system library on macOS and iOS (amongst others). In order
for users to be able to compile a binary that is intended to be deployed to an
older version of the platform, clang provides the
availability attribute <https://clang.llvm.org/docs/AttributeReference.html#availability>_
that can be placed on declarations to describe the lifecycle of a symbol in the
library.
See docs/DesignDocs/AvailabilityMarkup.rst for more information.
Differential Revision: https://reviews.llvm.org/D31739
llvm-svn: 302172
This recommits r294707 with additional fixes. The main difference is
libc++ now correctly builds without any ABI library.
exception.cpp is a bloody mess. It's full of confusing #ifdef branches for
each different ABI library we support, and it's getting unmaintainable.
This patch breaks down exception.cpp into multiple different header files,
roughly one per implementation. Additionally it moves the definitions of
exceptions in new.cpp into the correct implementation header.
This patch also removes an unmaintained libc++abi configuration.
This configuration may still be used by Apple internally but there
are no other possible users. If it turns out that Apple still uses
this configuration internally I will re-add it in a later commit.
See http://llvm.org/PR31904.
llvm-svn: 294730
exception.cpp is a bloody mess. It's full of confusing #ifdef branches for
each different ABI library we support, and it's getting unmaintainable.
This patch breaks down exception.cpp into multiple different header files,
roughly one per implementation. Additionally it moves the definitions of
exceptions in new.cpp into the correct implementation header.
This patch also removes an unmaintained libc++abi configuration.
This configuration may still be used by Apple internally but there
are no other possible users. If it turns out that Apple still uses
this configuration internally I will re-add it in a later commit.
See http://llvm.org/PR31904.
llvm-svn: 294707
This is motivated by adding a third RTTI scheme to libc++. Split out
the two forms of the itanium RTTI representation. This is based on
suggestions from Eric Fiselier. NFC
llvm-svn: 291174
Summary:
The current implementation of `hash_code()` for uniqued RTTI strings violates strict aliasing by dereferencing a type-punned pointer. Specifically it generates a `const char**` pointer from the address of the `__name` member before casting it to `const size_t*` and dereferencing it to get the hash. This is really just a complex and incorrect way of writing `reinterpret_cast<size_t>(__name)`.
This patch changes the conversion sequence so that it no longer contains UB.
Reviewers: howard.hinnant, mclow.lists
Subscribers: rjmccall, cfe-commits
Differential Revision: https://reviews.llvm.org/D24012
llvm-svn: 283408
This patch removes the `<cstdlib>` include from exception where it is no longer
needed. Unlike my previous attempt this patch also adds <cstdlib> where needed
in other headers like <new> and <typeinfo>.
This won't fix the Firefox build issues discussed on IRC but it is more correct
for libc++.
llvm-svn: 280754
Apparently I missed a number of additional include which need to be added.
Reverting so I can recommit as a single patch with all of the required includes.
llvm-svn: 280752
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
It's identical to name() these days. (At one point it avoided masking
of the RTTI uniqueness bit because ARM64 ignored it architecturally,
but no longer).
llvm-svn: 205518
ARM64 generates RTTI with hidden visibility, which means that typeinfo
must be compared char-by-char since it's not guaranteed to be uniqued
across the whole program.
llvm-svn: 205139
Eric Fiselier