Per discussion with Eric and Joerg, this commit removes -Wpadded to
silence the warning about the padding inserted at the tail of struct
_Rep_base.
rdar://problem/23932550
llvm-svn: 258900
Summary:
This patch is similar to the <list> fix but it has a few differences. This patch doesn't use a `__link_pointer` typedef because we don't need to change the linked list pointers because `forward_list` never stores a `__forward_begin_node` in the linked list itself.
The issue with `forward_list` is that the iterators store pointers to `__forward_list_node` and not `__forward_begin_node`. This is incorrect because `before_begin()` and `cbefore_begin()` return iterators that point to a `__forward_begin_node`. This means we incorrectly downcast the `__forward_begin_node` pointer to a `__node_pointer`. This downcast itself is sometimes UB but it cannot be safely removed until ABI v2. The more common cause of UB is when we deference the downcast pointer. (for example `__ptr_->__next_`). This can be fixed without an ABI break by upcasting `__ptr_` before accessing it.
The fix is as follows:
1. Introduce a `__iter_node_pointer` typedef that works similar to `__link_pointer` in the last patch. In ABI v2 it is always a typedef for `__begin_node_pointer`.
2. Change the `__before_begin()` method to return the correct pointer type (`__begin_node_pointer`),
Previously it incorrectly downcasted the `__forward_begin_node` to a `__node_pointer` so it could be used to constructor the iterator types.
3. Change `__forward_list_iterator` and `__forward_list_const_iterator` in the following way:
1. Change `__node_pointer __ptr_;` member to have the `__iter_node_pointer` type instead.
2. Add additional private constructors that accept `__begin_node_pointer` in addition to `__node_pointer` and then correctly cast them to the stored `__iter_node_pointer` type.
3. Add `__get_begin()` and `__get_node_unchecked()` accessor methods that correctly cast `__ptr_` to the expected pointer type. `__get_begin()` is always safe to use and should be
preferred. `__get_node_unchecked()` can only be used on a deferencible iterator.
4. Replace direct access to `__forward_list_iterator::__ptr_` with the safe accessor methods.
Reviewers: mclow.lists, EricWF
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D15836
llvm-svn: 258888
This reverts commit r258575. EricWF sent me an email (no link since it
was off-list) requesting to review this pre-commit instead of
post-commit.
llvm-svn: 258625
An upcoming commit will add an optimization to insert() that avoids
unnecessary mallocs when we can safely extract the key type. This
commit shares code between emplace() and insert():
- if emplace() is given a single argument, and
- value_type is constructible from that argument
so that we have a single code path for the two.
I also updated the debug version of emplace_hint() to defer to
emplace(), like the non-debug version does.
In both cases, there should be NFC here.
llvm-svn: 258575
Rename the version of __construct_node() that takes a hash as an
argument to __construct_node_hash(), and use perfect-forwarding when
Rvalue references are available. The primary motivation is to allow
other types through, since unordered_map's value_type is different from
__hash_table's value_type -- a follow-up will take advantage of this --
but the rename is general "goodness".
There should be no functionality change here (aside from enabling the
follow-up).
llvm-svn: 258511
"__as_link()" can only be used safely on "__list_node" objects. This patch
moves the "__as_link()" member function from "__list_node_base" to "__list_node"
so it cannot be used incorrectly.
Unsafe downcasts now use a non-member function so we don't defer the type-punned
pointer.
llvm-svn: 256727
Summary:
This patch fixes std::list for builtin pointer types in the current ABI version and fixes std::list for all fancy pointer types in the next ABI version. The patch was designed to minimize the amount of code needed to support both ABI configurations. Currently only ~5 lines of code differ.
Reviewers: danalbert, jroelofs, mclow.lists
Subscribers: dexonsmith, awi, cfe-commits
Differential Revision: http://reviews.llvm.org/D12299
llvm-svn: 256652