The patch is generated using this command:
$ tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
-checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
work/llvm/tools/clang
To reduce churn, not touching namespaces spanning less than 10 lines.
llvm-svn: 240270
Handle some common cases quickly when deeper introspection into the path
has no effect on the final result.
No functional change intended.
llvm-svn: 236475
I discovered a case where the old algorithm would crash. Instead of
trying to patch the algorithm, rewrite it. The new algorithm operates
in three phases:
1. Find all paths to the subobject with the vptr.
2. Remove paths which are subsets of other paths.
3. Select the best path where 'best' is defined as introducing the most
covariant overriders. If two paths introduce different overriders,
raise a diagnostic.
llvm-svn: 236444
The MSVC ABI has a bug introduced by appending to the end of vftables
which come from virtual bases: covariant thunks introduces via
non-overlapping regions of the inheritance lattice both append to the
same slot in the vftable.
It is possible to generate correct vftables in cases where one node in
the lattice completely dominates the other on the way to the base with
the vfptr; in all other cases, we must raise a diagnostic in order to
prevent the illusion that we succeeded in laying out the vftable.
This fixes PR16759.
llvm-svn: 236354
A class might contain multiple ways of getting to a vbase, some of which
are virtual and other non-virtual. It may be the case that a
non-virtual base contains an override of a method in a vbase. This
means that we must carefully pick between a set of nvbases to determine
which is the best.
As a consequence, the findPathForVPtr algorithm is considerably simpler.
llvm-svn: 236353
There can be multiple virtual bases which are on the path to a vfptr
when one vbase virtually inherits from another. We should prefer the
most derived virtual base which covariantly overrides a method in the
vfptr class; if we do not lengthen the path this way, we will end up
with too few vftable entries.
This fixes PR21073.
llvm-svn: 236239
This was a bug in r218285 that prevented us from seeing subsequent
virtual bases in the class hierarchy, leading to crashes later.
Also add some comments to this function, now that we better understand
what it's trying to do.
Fixes PR21062 and PR21064.
llvm-svn: 235899
There will be an explicit template instantiation in another translation
unit which will provide the definition of the VF/VB-Tables.
This fixes PR22932.
llvm-svn: 232680
We need to walk the class hierarchy twice: once in depth-first base
specifier order for mangling and again in depth-first layout order for
vftable layout.
Vftable layout seems to depend on the full path from the most derived
class to the base containing the vfptr.
Fixes PR21031.
llvm-svn: 218285
Deleted virtual functions get _purecall inserted into the vftable.
Earlier CTPs would simply stick nullptr in there.
N.B. MSVC can't handle deleted virtual functions which require return
adjusting thunks, they give an error that a deleted function couldn't be
called inside of a compiler generated function. We get this correct by
making the thunk have a __purecall entry as well.
llvm-svn: 217654
There are slight differences between /GR- and -fno-rtti which made
mapping one to the other inappropriate.
-fno-rtti disables dynamic_cast, typeid, and does not emit RTTI related
information for the v-table.
/GR- does not generate complete object locators and thus will not
reference them in vftables. However, constructs like dynamic_cast and
typeid are permitted.
This should bring our implementation of RTTI up to semantic parity with
MSVC modulo bugs.
llvm-svn: 212138
The pointer for a class's RTTI data comes right before the VFTable but
has no name. To be properly compatible with this, we do the following:
* Create a single GlobalVariable which holds the contents of the VFTable
_and_ the pointer to the RTTI data.
* Create a GlobalAlias, with appropriate linkage/visibility, that points
just after the RTTI data pointer. This ensures that the VFTable
symbol will always refer to VFTable data.
* Create a Comdat with a "Largest" SelectionKind and stick the private
GlobalVariable in it. By transitivity, the GlobalAlias will be a
member of the Comdat group. Using "Largest" ensures that foreign
definitions without an RTTI data pointer will _not_ be chosen in the
final linked image.
Whether or not we emit RTTI data depends on several things:
* The -fno-rtti flag implies that we should never not emit a pointer to
RTTI data before the VFTable.
* __declspec(dllimport) brings in the VFTable from a remote DLL. Use an
available_externally GlobalVariable to provide a local definition of
the VFTable. This means that we won't have any available_externally
definitions of things like complete object locators. This is
acceptable because they are never directly referenced.
To my knowledge, this completes the implementation of MSVC RTTI code
generation.
Further semantic work should be done to properly support /GR-.
llvm-svn: 212125
Alexander Kornienko