existence by always threading an edge from the catchall. Not doing
this was previously causing a crash in the very extreme case where
neither the normal cleanup nor the EH catchall was actually reachable:
we would delete the catchall entry block, which would cause us to
delete the entry block of the finally cleanup as well because the
cleanup logic would merge the blocks, which in turn triggered an assert
because later blocks in the finally would still be using values from the
entry. Laziness turns out to be the most elegant solution to the problem.
llvm-svn: 133601
Language-design credit goes to a lot of people, but I particularly want
to single out Blaine Garst and Patrick Beard for their contributions.
Compiler implementation credit goes to Argyrios, Doug, Fariborz, and myself,
in no particular order.
llvm-svn: 133103
to be careful to emit landing pads that are always prepared to handle a
cleanup path. This is correct mostly because of the fix to the LLVM
inliner, r132200.
llvm-svn: 132209
Change the interface to expose the new information and deal with the enormous fallout.
Introduce the new ExceptionSpecificationType value EST_DynamicNone to more easily deal with empty throw specifications.
Update the tests for noexcept and fix the various bugs uncovered, such as lack of tentative parsing support.
llvm-svn: 127537
C++ exceptions, even when exceptions have been turned off using -fno-exceptions.
Make the -fobjc-exceptions flag do the same thing, but for Objective-C exceptions.
C++ and Objective-C exceptions can also be disabled using -fno-cxx-excptions and
-fno-objc-exceptions.
llvm-svn: 126630
class and to bind the shared value using OpaqueValueExpr. This fixes an
unnoticed problem with deserialization of these expressions where the
deserialized form would lose the vital pointer-equality trait; or rather,
it fixes it because this patch also does the right thing for deserializing
OVEs.
Change OVEs to not be a "temporary object" in the sense that copy elision is
permitted.
This new representation is not totally unawkward to work with, but I think
that's really part and parcel with the semantics we're modelling here. In
particular, it's much easier to fix things like the copy elision bug and to
make the CFG look right.
I've tried to update the analyzer to deal with this in at least some
obvious cases, and I think we get a much better CFG out, but the printing
of OpaqueValueExprs probably needs some work.
llvm-svn: 125744
fixing a crash which probably nobody was ever going to see. In doing so,
fix a horrendous number of problems with the conditional-cleanups code.
Also, make conditional cleanups re-use the cleanup's activation variable,
which avoids some unfortunate repetitiveness.
llvm-svn: 124481
I'm separately committing this because it incidentally changes some
block orderings and minor IR issues, like using a phi instead of
an unnecessary alloca.
llvm-svn: 124277
delete the block we began emitting into if it had no predecessors. We never
want to do this, because there are several valid cases during statement
emission where an existing block has no known predecessors but will acquire
some later. The case in my test case doesn't inherently fall into this
category, because we could safely emit the case-range code before the statement
body, but there are examples with labels that can't be fallen into
that would also demonstrate this bug.
rdar://problem/8837067
llvm-svn: 123303
slot. The easiest way to do that was to bundle up the information
we care about for aggregate slots into a new structure which demands
that its creators at least consider the question.
I could probably be convinced that the ObjC 'needs GC' bit should
be rolled into this structure.
Implement generalized copy elision. The main obstacle here is that
IR-generation must be much more careful about making sure that exactly
llvm-svn: 113962
update callers as best I can.
- This is a work in progress, our alignment handling is very horrible / sketchy -- I am just aiming for monotonic improvement.
- Serious review appreciated.
llvm-svn: 111707
instead of _Unwind_Resume. With SJLJ exceptions, this is spelled
"_Unwind_SjLj_Resume_or_Rethrow", not "_Unwind_SjLj_Resume", which has
significantly different semantics.
We should actually never be generating a call to _Unwind_SjLj_Resume directly;
even if we were generating true cleanups (which we aren't because of the
horrible hack), we should be calling __cxa_end_cleanup() on ARM. I
haven't implemented this because there's little point as long as the HH is
present.
I believe this fixes <rdar://problem/8281377>.
llvm-svn: 110851
where we weren't accounting for the possibility that a @finally block might
have internal cleanups and therefore might write to the cleanup destination slot.
Fixes <rdar://problem/8293901>.
llvm-svn: 110760
mostly in avoiding unnecessary work at compile time but also in producing more
sensible block orderings.
Move the destructor cleanups for local variables over to use lazy cleanups.
Eventually all cleanups will do this; for now we have some awkward code
duplication.
Tell IR generation just to never produce landing pads in -fno-exceptions.
This is a much more comprehensive solution to a problem which previously was
half-solved by checks in most cleanup-generation spots.
llvm-svn: 108270
self-host. Hopefully these results hold up on different platforms.
I tried to keep the GNU ObjC runtime happy, but it's hard for me to test.
Reimplement how clang generates IR for exceptions. Instead of creating new
invoke destinations which sequentially chain to the previous destination,
push a more semantic representation of *why* we need the cleanup/catch/filter
behavior, then collect that information into a single landing pad upon request.
Also reorganizes how normal cleanups (i.e. cleanups triggered by non-exceptional
control flow) are generated, since it's actually fairly closely tied in with
the former. Remove the need to track which cleanup scope a block is associated
with.
Document a lot of previously poorly-understood (by me, at least) behavior.
The new framework implements the Horrible Hack (tm), which requires every
landing pad to have a catch-all so that inlining will work. Clang no longer
requires the Horrible Hack just to make exceptions flow correctly within
a function, however. The HH is an unfortunate requirement of LLVM's EH IR.
llvm-svn: 107631
have CGF create and make accessible standard int32,int64 and
intptr types. This fixes a ton of 80 column violations
introduced by LLVMContextification and cleans up stuff a lot.
llvm-svn: 106977
This is still probably wrong for Objective-C++ and adds a couple of lines in CGException that should probably be in the CGObjCRuntime subclass. The personality function is now only looked up in one place in CGException though, so this should be easier to fix in the future.
llvm-svn: 103938
__cxa_guard_abort along the exceptional edge into (in effect) a nested
"try" that rethrows after aborting. Fixes PR7144 and the remaining
Boost.ProgramOptions failures, along with the regressions that r103880
caused.
The crucial difference between this and r103880 is that we now follow
LLVM's little dance with the llvm.eh.exception and llvm.eh.selector
calls, then use _Unwind_Resume_or_Rethrow to rethrow.
llvm-svn: 103892
__cxa_guard_abort along the exceptional edge into (in effect) a nested
"try" that rethrows after aborting. Fixes PR7144 and the remaining
Boost.ProgramOptions failures.
llvm-svn: 103880
in a throw expression. Use EmitAnyExprToMem to emit the throw expression,
which magically elides the final copy-constructor call (which raises a new
strict-compliance bug, but baby steps). Give __cxa_throw a destructor pointer
if the exception type has a non-trivial destructor.
llvm-svn: 102039
Fix some bugs with function-try-blocks and simplify normal try-block
code generation.
This implementation excludes a deleting destructor's call to
operator delete() from the function-try-block, which I believe
is correct but which I can't find straightforward support for at
a moment's glance.
llvm-svn: 96670
follows (as conservatively as possible) gcc's current behavior: attributes
written on return types that don't apply there are applied to the function
instead, etc. Only parse CC attributes as type attributes, not as decl attributes;
don't accepet noreturn as a decl attribute on ValueDecls, either (it still
needs to apply to other decls, like blocks). Consistently consume CC/noreturn
information throughout codegen; enforce this by removing their default values
in CodeGenTypes::getFunctionInfo().
llvm-svn: 95436
that this is true when mangling, then fix up the various places in
Sema and/or CodeGen that need to remove qualifiers. Addresses a
linking issue when building LLVM with Clang.
llvm-svn: 92064
Highlights include:
Add a helper to generate __cxa_free_exception and _ZSt9terminatev.
Add a region to handle EH object deallocation for ctor failures for throw.
Add a terminate handler for __cxa_end_catch.
A framework for adding cleanup actions for the exceptional edges only.
llvm-svn: 90305
Highlights include:
Fix __cxa_begin_catch so it now returns a value.
Added getUnwindResumeOrRethrowFn helper to build up calls to
_Unwind_Resume_or_Rethrow.
Broke out object copying code into CopyObject from EmitCXXThrowExpr.
Built up another version of CopyObject that can copy from memory for
use in the catch parameter code.
RTTI generation for type matching for catch.
Code to check for the type match for catch.
Code to generate the catch parameter, WIP, need make sure references
and pointers and copy ctors work.
llvm-svn: 90205
Chris Lattner