Clang recently changed the way it outputs static assert diagnostics.
This patch fixes libc++'s -verify tests so they tolerate both the old
and new message format.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@313499 91177308-0d34-0410-b5e6-96231b3b80d8
path::iterator isn't a strictly conforming iterator. Specifically
it stashes the current element inside the iterator. This leads to
UB when used with reverse_iterator since it requires the element
to outlive the lifetime of the iterator.
This patch adds a static_assert inside reverse_iterator to disallow
"stashing iterator types", and it tags path::iterator as such a type.
Additionally this patch removes all uses of reverse_iterator<path::iterator>
within the tests.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@300164 91177308-0d34-0410-b5e6-96231b3b80d8
This patch entirely rewrites the parsing logic for paths. Unlike the previous
implementation this one stores information about the current state; For example
if we are in a trailing separator or a root separator. This avoids the need for
extra lookahead (and extra work) when incrementing or decrementing an iterator.
Roughly this gives us a 15% speedup over the previous implementation.
Unfortunately this implementation is still a lot slower than libstdc++'s.
Because libstdc++ pre-parses and splits the path upon construction their
iterators are trivial to increment/decrement. This makes libc++ lazy parsing
100x slower than libstdc++. However the pre-parsing libstdc++ causes a ton
of extra and unneeded allocations when constructing the string. For example
`path("/foo/bar/")` would require at least 5 allocations with libstdc++
whereas libc++ uses only one. The non-allocating behavior is much preferable
when you consider filesystem usages like 'exists("/foo/bar/")'.
Even then libc++'s path seems to be twice as slow to simply construct compared
to libstdc++. More investigation is needed about this.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@285526 91177308-0d34-0410-b5e6-96231b3b80d8
