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
I'm not sure if libcxx is asserting UTF-8 here; but on Windows the full char value is always passed through in its entirety, since the default codepage is something like Windows-1252. The replacement character is only used for non-chars there; and that should be a more portable test everywhere.
(Still pending review at https://reviews.llvm.org/D47395 which has been open since may; will ask for forgiveness rather than permission :) )
llvm-svn: 339213
There were two problems with the initial fix.
1. The added tests flushed out that we misconfigured _LIBCPP_EXPLICIT with GCC.
2. Because the boolean type was a member function template it caused weird link
errors. I'm assuming due to the vague linkage rules. This time the bool type
is a non-template member function pointer. That seems to have fixed the
failing tests. Plus it will end up generating less symbols overall, since
the bool type is no longer per instantiation.
original commit message below
-----------------------------
std::basic_ios has an operator bool(). In C++11 and later
it is explicit, and only allows contextual implicit conversions.
However explicit isn't available in C++03 which causes std::istream (et al)
to have an implicit conversion to int. This can easily cause ambiguities
when calling operator<< and operator>>.
This patch uses a "bool-like" type in C++03 to work around this. The
"bool-like" type is an arbitrary pointer to member function type. It
will not convert to either int or void*, but will convert to bool.
llvm-svn: 290754
std::basic_ios has an operator bool(). In C++11 and later
it is explicit, and only allows contextual implicit conversions.
However explicit isn't available in C++03 which causes std::istream (et al)
to have an implicit conversion to int. This can easily cause ambiguities
when calling operator<< and operator>>.
This patch uses a "bool-like" type in C++03 to work around this. The
"bool-like" type is an arbitrary pointer to member function type. It
will not convert to either int or void*, but will convert to bool.
llvm-svn: 290750
Skip tests that expect an exception be thrown. Also add
some missing asserts in the original test.
Differential Revision: https://reviews.llvm.org/D26512
llvm-svn: 286823
The initial buildbot run found a few missing bits in the initial XFAIL list
for the no-exceptions libc++ variant. These discrepancies are as follows:
[1] Following two tests need XFAILs on the no-exceptions library variant.
My local runs had these two disabled for other reasons (unsupported):
- localization/locales/locale/locale.cons/char_pointer.pass.cpp
- numerics/complex.number/complex.ops/complex_divide_complex.pass.cpp
[2] These three does not need XFAILs, they were failing on my local runs for
other reasons:
- depr/depr.c.headers/uchar_h.pass.cpp
- input.output/iostreams.base/ios/basic.ios.members/copyfmt.pass.cpp
- .../category.collate/locale.collate.byname/transform.pass.cpp
(these are failing on my box for the default build as well)
The current patch fixes both the cases above. Additionally, I've run the
following scan to make sure I've covered all the cases:
> grep ' catch \| try \| throw ' -R . | perl -pe 's|(.*?):.*|\1|' | sort | \
uniq > 1.txt
> grep 'libcpp-no-exceptions' -R . | perl -pe 's|(.*?):.*|\1|' | sort | \
uniq > 2.txt
> diff 1.txt 2.txt
This showed up a few extra interesting cases:
[3] These two tests do not use try/catch/throw statements, but they fail at
runtime. Need to be investigated, I've left the XFAILs in.
- std/thread/futures/futures.shared_future/dtor.pass.cpp
- std/thread/futures/futures.unique_future/dtor.pass.cpp
[4] These tests use a macro named TEST_HAS_NO_EXCEPTIONS to conditionally
exclude try/catch/throw statements when running without exceptions. I'm not
entirely sure why this was needed (AFAIK, we didn't have a no-exceptions
library build before). The macro's defintion is quite similar to that of
_LIBCPP_NO_EXCEPTIONS. I will investigate if this can be reused for my test
fixes or if it should be replaced with _LIBCPP_NO_EXCEPTIONS.
- std/experimental/any/*
Change-Id: I9ad1e0edd78f305406eaa0ab148b1ab693f7e26a
llvm-svn: 252870
Fixes a small omission in libcxx that prevents libcxx being built when
-DLIBCXX_ENABLE_EXCEPTIONS=0 is specified.
This patch adds XFAILS to all those tests that are currently failing
on the new -fno-exceptions library variant. Follow-up patches will
update the tests (progressively) to cope with the new library variant.
Change-Id: I4b801bd8d8e4fe7193df9e55f39f1f393a8ba81a
llvm-svn: 252598
Marshall Clow