While doing this, I also found a few tests that were either clearly
incorrect (e.g. testing the wrong function) or that lacked basic test
coverage like testing std::string itself (e.g. the test was only checking
std::basic_string with a custom allocator). In these cases, I did a few
conservative drive-by changes.
Differential Revision: https://reviews.llvm.org/D140550
Co-authored-by: Brendan Emery <brendan.emery@esrlabs.com>
Previously, assignment to a std::basic_string type with a _custom_
allocator could under certain conditions attempt to interpret part of
the target string's "short" string-content as if it was a "long" data
pointer, and attempt to deallocate a garbage value.
This is a serious bug, but code in which it might happen is rare. It
required:
1. the basic_string must be using a custom allocator type which sets the
propagate_on_container_copy_assignment trait to true (thus, it does not
affect the default allocator, nor most custom allocators).
2. the allocator for the target string must compare not equal to the
allocator for the source string (many allocators always compare equal).
3. the source of the copy must currently contain a "long" string, and
the assignment-target must currently contain a "short" string.
Finally, the issue would've typically been innocuous when the bytes
misinterpreted as a pointer were all zero, as deallocating a nullptr is
typically a no-op. This is why existing test cases did not exhibit an
issue: they were all zero-length strings, which do not have data in the
bytes interpreted as a pointer.
Avoids using operator& in basic_string since an evil char-like type can
hijack this operator. Added some more evil operators, this found a place
where equality was compared directly and not via the traits.
This adds a helper test string. This is now only used in a few tests,
but the intention is to use this in more tests for basic_string.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D145257
This patch switches the build compiler for AIX from ibm-clang to clang. ibm-clang++_r has `-pthread` by default, but clang for AIX doesn't, so `-pthread` had to be added to the test config. A bunch of tests now pass, so the `XFAIL` was removed. This patch also switch the build to use the visibility support available in clang-15 to control symbols exported by the shared library (AIX traditionally uses explicit export lists for this purpose).
Reviewed By: #libc, #libc_abi, daltenty, #libunwind, ldionne
Differential Revision: https://reviews.llvm.org/D127470
Summary:
Freestanding is *weird*. The standard allows it to differ in a bunch of odd
manners from regular C++, and the committee would like to improve that
situation. I'd like to make libc++ behave better with what freestanding should
be, so that it can be a tool we use in improving the standard. To do that we
need to try stuff out, both with "freestanding the language mode" and
"freestanding the library subset".
Let's start with the super basic: run the libc++ tests in freestanding, using
clang as the compiler, and see what works. The easiest hack to do this:
In utils/libcxx/test/config.py add:
self.cxx.compile_flags += ['-ffreestanding']
Run the tests and they all fail.
Why? Because in freestanding `main` isn't special. This "not special" property
has two effects: main doesn't get mangled, and main isn't allowed to omit its
`return` statement. The first means main gets mangled and the linker can't
create a valid executable for us to test. The second means we spew out warnings
(ew) and the compiler doesn't insert the `return` we omitted, and main just
falls of the end and does whatever undefined behavior (if you're luck, ud2
leading to non-zero return code).
Let's start my work with the basics. This patch changes all libc++ tests to
declare `main` as `int main(int, char**` so it mangles consistently (enabling us
to declare another `extern "C"` main for freestanding which calls the mangled
one), and adds `return 0;` to all places where it was missing. This touches 6124
files, and I apologize.
The former was done with The Magic Of Sed.
The later was done with a (not quite correct but decent) clang tool:
https://gist.github.com/jfbastien/793819ff360baa845483dde81170feed
This works for most tests, though I did have to adjust a few places when e.g.
the test runs with `-x c`, macros are used for main (such as for the filesystem
tests), etc.
Once this is in we can create a freestanding bot which will prevent further
regressions. After that, we can start the real work of supporting C++
freestanding fairly well in libc++.
<rdar://problem/47754795>
Reviewers: ldionne, mclow.lists, EricWF
Subscribers: christof, jkorous, dexonsmith, arphaman, miyuki, libcxx-commits
Differential Revision: https://reviews.llvm.org/D57624
llvm-svn: 353086
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
