Commit Graph

5 Commits

Author SHA1 Message Date
Hans Wennborg 3d79154aec [Win32 ABI] Defer operator delete checks until vtable is marked used
We were previously checking at every destructor declaration, but that was a bit
excessive. Since the deleting destructor is emitted with the vtable, do the
check when the vtable is marked used.

Differential Revision: http://llvm-reviews.chandlerc.com/D2851

llvm-svn: 202046
2014-02-24 15:58:24 +00:00
Hans Wennborg c9bd88e681 Remove the -cxx-abi command-line flag.
This makes the C++ ABI depend entirely on the target: MS ABI for -win32 triples,
Itanium otherwise. It's no longer possible to do weird combinations.

To be able to run a test with a specific ABI without constraining it to a
specific triple, new substitutions are added to lit: %itanium_abi_triple and
%ms_abi_triple can be used to get the current target triple adjusted to the
desired ABI. For example, if the test suite is running with the i686-pc-win32
target, %itanium_abi_triple will expand to i686-pc-mingw32.

Differential Revision: http://llvm-reviews.chandlerc.com/D2545

llvm-svn: 199250
2014-01-14 19:35:09 +00:00
Hans Wennborg 0f3c10cb8a [ms-cxxabi] Elide dtor access checks for pass-by-val objects in callees
The ABI requires the destructor to be invoked in the callee, but the
standard does not require access checks here so we avoid doing direct
access checks on the destructor.

If we end up needing to define an implicit destructor, we don't skip
access checks for the base class, etc. Those checks are effectively part
of generating the destructor definition, and aren't affected by which TU
the check is performed in.

Differential Revision: http://llvm-reviews.chandlerc.com/D2409

llvm-svn: 199120
2014-01-13 17:23:24 +00:00
Reid Kleckner 23f4c4b64f [ms-cxxabi] Destroy temporary record arguments in the callee
Itanium destroys them in the caller at the end of the full expression,
but MSVC destroys them in the callee.  This is further complicated by
the need to emit EH-only destructor cleanups in the caller.

This should help clang compile MSVC's debug iterators more correctly.
There is still an outstanding issue in PR5064 of a memcpy emitted by the
LLVM backend, which is not correct for C++ records.

Fixes PR16226.

Reviewers: rjmccall

Differential Revision: http://llvm-reviews.chandlerc.com/D929

llvm-svn: 184543
2013-06-21 12:45:15 +00:00
Peter Collingbourne b289fe64c1 [ms-cxxabi] Look up operator delete() at every virtual dtor declaration.
While the C++ standard requires that this lookup take place only at the
definition point of a virtual destructor (C++11 [class.dtor]p12), the
Microsoft ABI may require the compiler to emit a deleting destructor
for any virtual destructor declared in the TU, including ones without
a body, requiring an operator delete() lookup for every virtual
destructor declaration.  The result of the lookup should be the same
no matter which declaration is used (except in weird corner cases).

This change will cause us to reject some valid TUs in Microsoft ABI
mode, e.g.:

struct A {
  void operator delete(void *);
};

struct B {
  void operator delete(void *);
};

struct C : A, B {
  virtual ~C();
};

As Richard points out, every virtual function declared in a TU
(including this virtual destructor) is odr-used, so it must be defined
in any program which declares it, or the program is ill formed, no
diagnostic required.  Because we know that any definition of this
destructor will cause the lookup to fail, the compiler can choose to
issue a diagnostic here.

Differential Revision: http://llvm-reviews.chandlerc.com/D822

llvm-svn: 182270
2013-05-20 14:12:25 +00:00