Commit Graph

231 Commits

Author SHA1 Message Date
Peter Collingbourne a834166e48 Create a VTableContext class and start moving CodeGenVTables methods to it
llvm-svn: 140502
2011-09-26 01:56:30 +00:00
Douglas Gregor eb4089ad01 Only trigger the initialize-an-array-via-elementwise-copy/move code
generation when we're dealing with an implicitly-defined copy or move
constructor. And, actually set the implicitly-defined bit for
implicitly-defined constructors and destructors. Should fix self-host.

llvm-svn: 140334
2011-09-22 20:32:43 +00:00
Douglas Gregor 8a556ce512 Explicitly-defaulted copy/move constructors are not "implicit", but
they still need the logic to cope with array member
initialization. Fixes PR10720.

llvm-svn: 140302
2011-09-22 15:15:51 +00:00
Richard Smith 20104048be PR10304: Do not call destructors for data members from union destructors. Prior to C++11, this
has no effect since any such destructors must be trivial, and in C++11 such destructors must not
be called.

llvm-svn: 139997
2011-09-18 12:11:43 +00:00
John McCall 3b201b7d5f Sorry, that assertion actually already exists.
llvm-svn: 139770
2011-09-15 01:55:23 +00:00
John McCall 8f8f8d67ea We don't generate null initializer expressions anymore, and
we don't need to.

llvm-svn: 139769
2011-09-15 01:54:21 +00:00
Sebastian Redl 22653bac1a Declare and define implicit move constructor and assignment operator.
This makes the code duplication of implicit special member handling even worse,
but the cleanup will have to come later. For now, this works.
Follow-up with tests for explicit defaulting and enabling the __has_feature
flag to come.

llvm-svn: 138821
2011-08-30 19:58:05 +00:00
John McCall a5efa7386a Track whether an AggValueSlot is potentially aliased, and do not
emit call results into potentially aliased slots.  This allows us
to properly mark indirect return slots as noalias, at the cost
of requiring an extra memcpy when assigning an aggregate call
result into a l-value.  It also brings us into compliance with
the x86-64 ABI.

llvm-svn: 138599
2011-08-25 23:04:34 +00:00
John McCall 8d6fc9583d Use stronger typing for the flags on AggValueSlot and require
creators to tell us whether something needs GC barriers.
No functionality change.

llvm-svn: 138581
2011-08-25 20:40:09 +00:00
Eli Friedman f481ccafd8 Cleanup; no functionality change.
llvm-svn: 137126
2011-08-09 17:38:12 +00:00
Chris Lattner 0e62c1cc0b remove unneeded llvm:: namespace qualifiers on some core types now that LLVM.h imports
them into the clang namespace.

llvm-svn: 135852
2011-07-23 10:55:15 +00:00
Chris Lattner 2192fe50da de-constify llvm::Type, patch by David Blaikie!
llvm-svn: 135370
2011-07-18 04:24:23 +00:00
John McCall 6549b31fe9 Arrays are permitted to be zero-length in some situations.
llvm-svn: 135036
2011-07-13 07:37:11 +00:00
John McCall f677a8e99e Convert the standard default-construction loops to use phis and
partial destruction.

llvm-svn: 135033
2011-07-13 06:10:41 +00:00
John McCall f47c069162 Aggressive dead code elimination.
llvm-svn: 135029
2011-07-13 03:03:51 +00:00
John McCall 30317fda63 Generalize Cleanup::Emit's "isForEH" parameter into a set
of flags.  No functionality change.

llvm-svn: 134997
2011-07-12 20:27:29 +00:00
John McCall 4bd0fb1f09 Switch field destruction over to use the new destroyer-based API
and kill a lot of redundant code.

llvm-svn: 134988
2011-07-12 16:41:08 +00:00
John McCall 82fe67bb82 A number of array-related IR-gen cleanups.
- Emit default-initialization of arrays that were partially initialized
    with initializer lists with a loop, rather than emitting the default
    initializer N times;
  - support destroying VLAs of non-trivial type, although this is not
    yet exposed to users; and
  - support the partial destruction of arrays initialized with
    initializer lists when an initializer throws an exception.

llvm-svn: 134784
2011-07-09 01:37:26 +00:00
John McCall 55e1fbc848 LValue carries a type now, so simplify the main EmitLoad/Store APIs
by removing the redundant type parameter.

llvm-svn: 133860
2011-06-25 02:11:03 +00:00
John McCall 1553b19067 Restore correct use of GC barriers.
llvm-svn: 133144
2011-06-16 04:16:24 +00:00
John McCall 31168b077c Automatic Reference Counting.
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
2011-06-15 23:02:42 +00:00
Richard Smith 938f40b5aa Implement support for C++11 in-class initialization of non-static data members.
llvm-svn: 132878
2011-06-11 17:19:42 +00:00
Anders Carlsson d6f1518cc9 Fix another regression from the "skip vtable pointer initialization"
optimization. Make sure to require a vtable when trying to get the address
of a VTT, otherwise we would never end up emitting the VTT.

llvm-svn: 131400
2011-05-16 04:08:36 +00:00
Anders Carlsson 49c0bd2a25 Re-enable the fix for PR9181 now that all the edge cases are handled.
llvm-svn: 131385
2011-05-15 17:36:21 +00:00
Anders Carlsson b55c8c127e Disable the optimization until the bug noticed by Sean Hunt has been fixed.
llvm-svn: 131372
2011-05-15 01:50:14 +00:00
Anders Carlsson 9bd7d16440 When emitting the destructor for a class with a vtable, if we can determine
that the destructor body is trivial and that all member variables also have either
trivial destructors or trivial destructor bodies, we don't need to initialize the
vtable pointers since no virtual member functions will be called on the destructor.

Fixes PR9181.

llvm-svn: 131368
2011-05-14 23:26:09 +00:00
Anders Carlsson c36783e8b9 Move code to emit the callee of an CXXOperatorCallExpr out into a separate function in CGClass.cpp
llvm-svn: 131075
2011-05-08 20:32:23 +00:00
Alexis Hunt 9d47faf686 Ensure that destructors are properly inovked when an exception leaves
the body of a delegating constructor call.

This means that the delegating constructor implementation should be
complete and correct, though there are some rough edges (diagnostic
quality with the cycle detection and using a deleted destructor).

llvm-svn: 130803
2011-05-03 23:05:34 +00:00
Alexis Hunt 271c36811d Fix delegating constructors stylistic issues.
Material bugfixes to come this afternoon.

llvm-svn: 130782
2011-05-03 20:19:28 +00:00
Eli Friedman 43dca6a8d2 Simplify code a bit by using CallArgList::add. No intended functionality change.
llvm-svn: 130699
2011-05-02 17:57:46 +00:00
Alexis Hunt 61bc173784 Fully implement delegating constructors!
As far as I know, this implementation is complete but might be missing a
few optimizations. Exceptions and virtual bases are handled correctly.

Because I'm an optimist, the web page has appropriately been updated. If
I'm wrong, feel free to downgrade its support categories.

llvm-svn: 130642
2011-05-01 07:04:31 +00:00
John McCall a85af56e66 When block-capturing a variable with a non-trivial destructor,
make sure to mark the destructor.  This normally isn't required,
because the destructor should have been marked as part of the
declaration of the local, but it's necessary when the variable
is a parameter because it's the call sites that are responsible
for those destructors.

llvm-svn: 130372
2011-04-28 02:15:35 +00:00
Anders Carlsson 98981b10c8 Replace a couple of Builder.CreateICmpEQ with Builder.CreateIsNull. No functionality change.
llvm-svn: 129261
2011-04-11 00:30:07 +00:00
Ken Dyck bb4e977218 [Reapply r128776, modified so that it does not break debug info.]
Change the return type of CodeGenVTables::getVirtualBaseOffsetOffset() to
CharUnits. No change in functionality intended.

llvm-svn: 129072
2011-04-07 12:37:09 +00:00
Devang Patel 84852bbb42 Revert r128770, r128771, r128773 and r128776 for now. It breaks debug info.
llvm-svn: 128842
2011-04-04 20:36:06 +00:00
Ken Dyck 1473c9a7c4 Change the return type of CodeGenVTables::getVirtualBaseOffsetOffset() to
CharUnits. No change in functionality intended.

llvm-svn: 128776
2011-04-02 17:52:22 +00:00
Jay Foad 20c0f02cc5 Remove PHINode::reserveOperandSpace(). Instead, add a parameter to
PHINode::Create() giving the (known or expected) number of operands.

llvm-svn: 128538
2011-03-30 11:28:58 +00:00
Ken Dyck 16ffcac1a2 Convert the BaseOffset member of BaseSubobject to CharUnits from bits. No
change in functionality intended.

llvm-svn: 128190
2011-03-24 01:21:01 +00:00
Ken Dyck 3fb4c8920d Convert OffsetFromNearestVBast parameter of InitializeVTablePointer(s) to
CharUnits. No change in functionality intended.

llvm-svn: 128129
2011-03-23 01:04:18 +00:00
Ken Dyck cfc332cc43 Convert NonVirtual parameter of ApplyNonVirtualAndVirtualOffset() to
CharUnits. No change in functionality intended.

llvm-svn: 128126
2011-03-23 00:45:26 +00:00
Ken Dyck 6aa767c18e Convert Offset variable in GetAddressOfDirectBaseInCompleteClass() to
CharUnits. No change in functionality intended.

llvm-svn: 128060
2011-03-22 01:21:15 +00:00
Ken Dyck a1a4ae34d0 Change return value of ComputeNonVirtualBaseClassOffset() to CharUnits. No
change in functionality intended.

llvm-svn: 128050
2011-03-22 00:53:26 +00:00
John McCall 32ea969415 Use a slightly more semantic interface for emitting call arguments.
llvm-svn: 127494
2011-03-11 20:59:21 +00:00
John McCall a738c25f5e Use the "undergoes default argument promotion" bit on parameters to
simplify the logic of initializing function parameters so that we don't need
both a variable declaration and a type in FunctionArgList.  This also means
that we need to propagate the CGFunctionInfo down in a lot of places rather
than recalculating it from the FAL.  There's more we can do to eliminate
redundancy here, and I've left FIXMEs behind to do it.

llvm-svn: 127314
2011-03-09 04:27:21 +00:00
Anders Carlsson 6dc07d4e56 Get rid of the areExceptionsEnabled() getter from LangOptions.
llvm-svn: 126598
2011-02-28 00:33:03 +00:00
Devang Patel b6ed369e77 A constructor call should force class's debug info even if -flimit-debug-info is enabled.
llvm-svn: 126246
2011-02-22 20:55:26 +00:00
Anders Carlsson 08ce5ed1b1 Add a LangOptions::areExceptionsEnabled and start using it.
llvm-svn: 126062
2011-02-20 00:20:27 +00:00
John McCall ad7c5c1657 Reorganize CodeGen{Function,Module} to eliminate the unfortunate
Block{Function,Module} base class.  Minor other refactorings.

Fixed a few address-space bugs while I was there.

llvm-svn: 125085
2011-02-08 08:22:06 +00:00
Fariborz Jahanian 7f6f81ba9b Clean up of -fapple-kext abi code. No change otherwise.
llvm-svn: 124807
2011-02-03 19:27:17 +00:00
Fariborz Jahanian 0c12ed1429 -fapple-kext, elimination of all direct calls to virtual dtors.
llvm-svn: 124757
2011-02-02 23:12:46 +00:00
Fariborz Jahanian 265c325ef3 -fapple-kext support for indirect call to virtuals dtors - wip.
llvm-svn: 124701
2011-02-01 23:22:34 +00:00
Anders Carlsson 883fc72c3c Make emitting a VTT a two-step process, much like emitting a VTable. You first get the address of the VTT, and then pass it to EmitVTTDefinition.
llvm-svn: 124539
2011-01-29 19:16:51 +00:00
Anders Carlsson a376b53695 When doing a derived-to-base class through a virtual class, we don't have to get the vbase offset from the vtable if the derived class is marked final.
llvm-svn: 124523
2011-01-29 03:18:56 +00:00
Alexis Hunt 1d7926502f Renamed CXXBaseOrMemberInitializer to CXXCtorInitializer. This is both shorter,
more accurate, and makes it make sense for it to hold a delegating constructor
call.

llvm-svn: 123084
2011-01-08 20:30:50 +00:00
Francois Pichet d583da04d0 More anonymous struct/union redesign. This one deals with anonymous field used in a constructor initializer list:
struct X {
  X() : au_i1(123) {}
  union {
    int au_i1;
    float au_f1;
  };
};

clang will now deal with au_i1 explicitly as an IndirectFieldDecl.

llvm-svn: 120900
2010-12-04 09:14:42 +00:00
Fariborz Jahanian e988bdac44 Block API patch to do copy ctor of copied-in cxx objects in
copy helper function and dtor of copied cxx objects
in dispose helper functions. __block variables
TBD next.

llvm-svn: 119011
2010-11-13 21:53:34 +00:00
Anders Carlsson fd88a6160d Rename getBaseClassOffset to getBaseClassOffsetInBits and introduce a getBaseClassOffset which returns the offset in CharUnits. Do the same thing for getVBaseClassOffset.
llvm-svn: 117881
2010-10-31 23:22:37 +00:00
Dan Gohman 8fc50c296a Factor out the code for emitting code to load vtable pointer members
so that it's done in one place.

llvm-svn: 117386
2010-10-26 18:44:08 +00:00
John McCall 1c9c3fd50a Death to blocks, or at least the word "block" in one particular obnoxiously
ambiguous context.

llvm-svn: 116567
2010-10-15 04:57:14 +00:00
John McCall 769250ea70 Currently we're initializing the vtable pointers of a class only after
the bases are completely initialized.  This won't work --- base
initializer expressions can rely on the vtables having been set up.
Check for uses of 'this' in the initializers and force a vtable
initialization if found.

This might not be good enough;  we might need to extend this to handle
the possibility of arbitrary code finding an external reference to this
(not yet completely-constructed!) object and accessing through it,
in which case we'll probably find ourselves doing a lot more unnecessary
stores.

llvm-svn: 114153
2010-09-17 02:31:44 +00:00
John McCall 7a626f63f7 one piece of code is responsible for the lifetime of every aggregate
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
2010-09-15 10:14:12 +00:00
Daniel Dunbar f6fb7e2b53 IRgen: Switch a bunch of trivial MakeAddr calls to use MakeAddrLValue.
llvm-svn: 111716
2010-08-21 03:08:16 +00:00
Devang Patel d76c1dbe39 Emit a stop point for delegate constructor call. This gives user a chance to step into constructor body.
llvm-svn: 110853
2010-08-11 21:04:37 +00:00
John McCall cf14216509 Store inheritance paths after CastExprs instead of inside them.
This takes some trickery since CastExpr has subclasses (and indeed,
is abstract).

Also, smoosh the CastKind into the bitfield from Expr.

Drops two words of storage from Expr in the common case of expressions
which don't need inheritance paths.  Avoids a separate allocation and
another word of overhead in cases needing inheritance paths.  Also has
the advantage of not leaking memory, since destructors for AST nodes are
never run.

llvm-svn: 110507
2010-08-07 06:22:56 +00:00
John McCall cda666ccd8 Rename LazyCleanup -> Cleanup. No functionality change for these last three
commits.

llvm-svn: 109000
2010-07-21 07:22:38 +00:00
John McCall 8680f87d99 Switch the destructor for a temporary arising from a reference binding over to
using a lazy cleanup.

llvm-svn: 108994
2010-07-21 06:29:51 +00:00
John McCall f99a631e4e Implement proper base/member destructor EH chaining.
llvm-svn: 108989
2010-07-21 05:30:47 +00:00
John McCall 53cad2ef04 Change PushDestructorCleanup to use lazy cleanups.
llvm-svn: 108979
2010-07-21 01:41:18 +00:00
John McCall 1d9875654f Convert the EH cleanups for base and member destructors in a constructor into
lazy cleanups.

llvm-svn: 108978
2010-07-21 01:23:41 +00:00
Douglas Gregor 05fc5be32f Implement zero-initialization for array new when there is an
initializer of (). Make sure to use a simple memset() when we can, or
fall back to generating a loop when a simple memset will not
suffice. Fixes <rdar://problem/8212208>, a regression due to my work
in r107857.

llvm-svn: 108977
2010-07-21 01:10:17 +00:00
John McCall 2b7fc3828e Teach IR generation how to lazily emit cleanups. This has a lot of advantages,
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
2010-07-13 20:32:21 +00:00
John McCall b609d3f5f9 Teach function-try-blocks on constructors and destructors to implicitly
rethrow.  Fixes rdar://problem/7696603

llvm-svn: 107757
2010-07-07 06:56:46 +00:00
John McCall bd30929e4d Validated by nightly-test runs on x86 and x86-64 darwin, including after
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
2010-07-06 01:34:17 +00:00
Douglas Gregor bac7490ffc Remove unnecessary ASTContext parameter from
CXXRecordDecl::getDestructor(); no functionality change.

llvm-svn: 107394
2010-07-01 14:13:13 +00:00
Anders Carlsson 04775f8413 Change EmitReferenceBindingToExpr to take a decl instead of a boolean.
llvm-svn: 106949
2010-06-26 16:35:32 +00:00
Anders Carlsson 282bc10eaa Move GenerateCXXAggrDestructorHelper to CGDeclCXX.cpp where it belongs.
llvm-svn: 105647
2010-06-08 22:17:27 +00:00
Anders Carlsson 165ec0a04f Simplify GenerateCXXAggrDestructorHelper.
llvm-svn: 105646
2010-06-08 22:14:59 +00:00
Eli Friedman cce5b81ce1 Don't intentionally try to ignore the value of a scalar expression when we
actually care about it. Fixes PR7291.

llvm-svn: 105404
2010-06-03 19:58:07 +00:00
John McCall 23f6626262 Correctly pass aggregates by reference when emitting thunks.
llvm-svn: 104778
2010-05-26 22:34:26 +00:00
Anders Carlsson c0964b60e5 Re-land the fix for PR7139.
llvm-svn: 104446
2010-05-22 17:35:42 +00:00
Anders Carlsson c866eb5ba9 Unbreak self-host.
llvm-svn: 104390
2010-05-21 22:17:48 +00:00
Anders Carlsson da1641cd12 Rename CodeGenFunction::EmitMemSetToZero to EmitNullInitialization. Handle setting null data member pointers correctly. Fixes PR7139.
llvm-svn: 104387
2010-05-21 21:45:41 +00:00
John McCall c4094935c0 When emitting an lvalue for an anonymous struct or union member during
class initialization, drill down through an arbitrary number of anonymous
records.

llvm-svn: 104310
2010-05-21 01:18:57 +00:00
Chris Lattner 44456d294c simplify EmitAggMemberInitializer a bit and make it work in 32-bit mode,
fixing PR7063.

llvm-svn: 103171
2010-05-06 06:35:23 +00:00
Douglas Gregor 94f9a4820a Reimplement code generation for copying fields in the
implicitly-generated copy constructor. Previously, Sema would perform
some checking and instantiation to determine which copy constructors,
etc., would be called, then CodeGen would attempt to figure out which
copy constructor to call... but would get it wrong, or poke at an
uninstantiated default argument, or fail in other ways.

The new scheme is similar to what we now do for the implicit
copy-assignment operator, where Sema performs all of the semantic
analysis and builds specific ASTs that look similar to the ASTs we'd
get from explicitly writing the copy constructor, so that CodeGen need
only do a direct translation.

However, it's not quite that simple because one cannot explicit write
elementwise copy-construction of an array. So, I've extended
CXXBaseOrMemberInitializer to contain a list of indexing variables
used to copy-construct the elements. For example, if we have:

  struct A { A(const A&); };
  
  struct B {
    A array[2][3];
  };

then we generate an implicit copy assignment operator for B that looks
something like this:

  B::B(const B &other) : array[i0][i1](other.array[i0][i1]) { }

CodeGen will loop over the invented variables i0 and i1 to visit all
elements in the array, so that each element in the destination array
will be copy-constructed from the corresponding element in the source
array. Of course, if we're dealing with arrays of scalars or class
types with trivial copy-assignment operators, we just generate a
memcpy rather than a loop.

Fixes PR6928, PR5989, and PR6887. Boost.Regex now compiles and passes
all of its regression tests.

Conspicuously missing from this patch is handling for the exceptional
case, where we need to destruct those objects that we have
constructed. I'll address that case separately.

llvm-svn: 103079
2010-05-05 05:51:00 +00:00
John McCall e61b02bcaf When inheriting a default argument expression, inherit the full expression,
not just the inner expression.  This is important if the expression has any
temporaries.  Fixes PR 7028.

Basically a symptom of really tragic method names.

llvm-svn: 102998
2010-05-04 01:53:42 +00:00
Anders Carlsson f4da2cf20a Remove OldGetAddressOfBaseClass - bye bye ambiguities.
llvm-svn: 102889
2010-05-03 00:32:27 +00:00
Anders Carlsson c58fb552f3 Get rid of the last caller of OldGetAddressOfBaseClass.
llvm-svn: 102888
2010-05-03 00:29:58 +00:00
Anders Carlsson c4d0d0fed1 More work towards getting rid of OldGetAddressOfBaseClass.
llvm-svn: 102887
2010-05-03 00:07:07 +00:00
Anders Carlsson e089060fd0 Get rid of a call to GetAddressOfDirectBaseInCompleteClass.
llvm-svn: 102886
2010-05-02 23:57:15 +00:00
Anders Carlsson 859b3064cb Have getSubVTTIndex take a BaseSubobject instead of just a base.
llvm-svn: 102885
2010-05-02 23:53:25 +00:00
Anders Carlsson 4d205ba87f Pass ForVirtualBase all the way to GetVTTParameter.
llvm-svn: 102883
2010-05-02 23:33:10 +00:00
Anders Carlsson f8a71f08d1 Add the same 'ForVirtualBase' parameter to EmitCXXDestructorCall.
llvm-svn: 102882
2010-05-02 23:29:11 +00:00
Anders Carlsson e11f9ce9dc Revert my last change and add a 'ForVirtualBase' parameter to EmitCXXConstructorCall instead.
llvm-svn: 102881
2010-05-02 23:20:53 +00:00
Anders Carlsson 4c638f1217 Pass the construction kind down to EmitCXXConstructorCall.
llvm-svn: 102880
2010-05-02 23:01:10 +00:00
Anders Carlsson 245820b9d9 Remove another unused function.
llvm-svn: 102871
2010-05-02 18:13:35 +00:00
Anders Carlsson 54eb4843b1 Remove an unused function.
llvm-svn: 102870
2010-05-02 18:12:22 +00:00
Douglas Gregor b139cd5843 Complete reimplementation of the synthesis for implicitly-defined copy
assignment operators. 

Previously, Sema provided type-checking and template instantiation for
copy assignment operators, then CodeGen would synthesize the actual
body of the copy constructor. Unfortunately, the two were not in sync,
and CodeGen might pick a copy-assignment operator that is different
from what Sema chose, leading to strange failures, e.g., link-time
failures when CodeGen called a copy-assignment operator that was not
instantiation, run-time failures when copy-assignment operators were
overloaded for const/non-const references and the wrong one was
picked, and run-time failures when by-value copy-assignment operators
did not have their arguments properly copy-initialized.

This implementation synthesizes the implicitly-defined copy assignment
operator bodies in Sema, so that the resulting ASTs encode exactly
what CodeGen needs to do; there is no longer any special code in
CodeGen to synthesize copy-assignment operators. The synthesis of the
body is relatively simple, and we generate one of three different
kinds of copy statements for each base or member:

  - For a class subobject, call the appropriate copy-assignment
    operator, after overload resolution has determined what that is.
  - For an array of scalar types or an array of class types that have
    trivial copy assignment operators, construct a call to
    __builtin_memcpy.
  - For an array of class types with non-trivial copy assignment
    operators, synthesize a (possibly nested!) for loop whose inner
    statement calls the copy constructor.
  - For a scalar type, use built-in assignment.

This patch fixes at least a few tests cases in Boost.Spirit that were
failing because CodeGen picked the wrong copy-assignment operator
(leading to link-time failures), and I suspect a number of undiagnosed
problems will also go away with this change.

Some of the diagnostics we had previously have gotten worse with this
change, since we're going through generic code for our
type-checking. I will improve this in a subsequent patch.

llvm-svn: 102853
2010-05-01 20:49:11 +00:00
Anders Carlsson b136e626ea Simplify EmitCopyCtorCall.
llvm-svn: 102849
2010-05-01 17:07:40 +00:00
Anders Carlsson aab3b57359 Simplify EmitClassAggrMemberwiseCopy.
llvm-svn: 102848
2010-05-01 17:02:18 +00:00