really shouldn't be optional. Fix the remaining place where a
temporary was being passed as potentially-aliased memory.
Fixes PR10756.
llvm-svn: 138627
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
to represent a fully-substituted non-type template parameter.
This should improve source fidelity, as well as being generically
useful for diagnostics and such.
llvm-svn: 135243
- an off-by-one error in emission of irregular array limits for
InitListExprs
- use an EH partial-destruction cleanup within the normal
array-destruction cleanup
- get the branch destinations right for the empty check
Also some refactoring which unfortunately obscures these changes.
llvm-svn: 134890
- 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
where we have an immediate need of a retained value.
As an exception, don't do this when the call is made as the immediate
operand of a __bridge retain. This is more in the way of a workaround
than an actual guarantee, so it's acceptable to be brittle here.
rdar://problem/9504800
llvm-svn: 134605
MaterializeTemporaryExpr captures a reference binding to a temporary
value, making explicit that the temporary value (a prvalue) needs to
be materialized into memory so that its address can be used. The
intended AST invariant here is that a reference will always bind to a
glvalue, and MaterializeTemporaryExpr will be used to convert prvalues
into glvalues for that binding to happen. For example, given
const int& r = 1.0;
The initializer of "r" will be a MaterializeTemporaryExpr whose
subexpression is an implicit conversion from the double literal "1.0"
to an integer value.
IR generation benefits most from this new node, since it was
previously guessing (badly) when to materialize temporaries for the
purposes of reference binding. There are likely more refactoring and
cleanups we could perform there, but the introduction of
MaterializeTemporaryExpr fixes PR9565, a case where IR generation
would effectively bind a const reference directly to a bitfield in a
struct. Addresses <rdar://problem/9552231>.
llvm-svn: 133521
separate aggregate temporary and then memcpy it over to the
destination. This fixes a regression I introduced with r133235, where
the compound literal on the RHS of an assignment makes use of the
structure on the LHS of the assignment.
I'm deeply suspicious of AggExprEmitter::VisitBinAssign()'s
optimization where it emits the RHS of an aggregate assignment
directly into the LHS lvalue without checking whether there is any
aliasing between the LHS/RHS. However, I'm not in a position to
revisit this now.
Big thanks to Eli for finding the regression!
llvm-svn: 133261
C++, which means:
- binding the temporary as needed in Sema, so that we generate the
appropriate call to the destructor, and
- emitting the compound literal into the appropriate location for
the aggregate, rather than trying to emit it as a temporary and
memcpy() it.
Fixes PR10138 / <rdar://problem/9615901>.
llvm-svn: 133235
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
-C++ objects with user-declared constructor don't need zero'ing.
-We can zero-initialize arrays of C++ objects in "bulk" now, in which case don't zero-initialize each object again.
llvm-svn: 130453
double data[20000000] = {0};
we would blow out the memory by creating 20M Exprs to fill out the initializer.
To fix this, if the initializer list initializes an array with more elements than
there are initializers in the list, have InitListExpr store a single 'ArrayFiller' expression
that specifies an expression to be used for value initialization of the rest of the elements.
Fixes rdar://9275920.
llvm-svn: 129896
because the result is ignored. The particular example here is with
property l-values, but there could be all sorts of lovely casts that this
isn't safe for. Sink the check into the one case that seems to actually
be capable of honoring this.
llvm-svn: 129397
for __unknown_anytype resolution to destructively modify the AST. So that's
what it does now, which significantly simplifies some of the implementation.
Normal member calls work pretty cleanly now, and I added support for
propagating unknown-ness through &.
llvm-svn: 129331
represents a dynamic cast where we know that the result is always null.
For example:
struct A {
virtual ~A();
};
struct B final : A { };
struct C { };
bool f(B* b) {
return dynamic_cast<C*>(b);
}
llvm-svn: 129256
The idea is that you can create a VarDecl with an unknown type, or a
FunctionDecl with an unknown return type, and it will still be valid to
access that object as long as you explicitly cast it at every use. I'm
still going back and forth about how I want to test this effectively, but
I wanted to go ahead and provide a skeletal implementation for the LLDB
folks' benefit and because it also improves some diagnostic goodness for
placeholder expressions.
llvm-svn: 129065
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
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
the LHS, or else the pointer might be invalid. This is kindof dumb, but
go ahead and make sure we're doing that for l-value scalar assignment,
which fixes a miscompile of obj-c++.dg/block-seq.mm.
Leave a FIXME for how to solve this problem for agg __blocks.
llvm-svn: 120992
Fix a bug in the emission of complex compound assignment l-values.
Introduce a method to emit an expression whose value isn't relevant.
Make that method evaluate its operand as an l-value if it is one.
Fixes our volatile compliance in C++.
llvm-svn: 120931
not actually frequently used, because ImpCastExprToType only creates a node
if the types differ. So explicitly create an ICE in the lvalue-to-rvalue
conversion code in DefaultFunctionArrayLvalueConversion() as well as several
other new places, and consistently deal with the consequences throughout the
compiler.
In addition, introduce a new cast kind for loading an ObjCProperty l-value,
and make sure we emit those nodes whenever an ObjCProperty l-value appears
that's not on the LHS of an assignment operator.
This breaks a couple of rewriter tests, which I've x-failed until future
development occurs on the rewriter.
Ted Kremenek kindly contributed the analyzer workarounds in this patch.
llvm-svn: 120890
when an initializer is variable (I handled the constant case in a previous
patch). This has three pieces:
1. Enhance AggValueSlot to have a 'isZeroed' bit to tell CGExprAgg that
the memory being stored into has previously been memset to zero.
2. Teach CGExprAgg to not emit stores of zero to isZeroed memory.
3. Teach CodeGenFunction::EmitAggExpr to scan initializers to determine
whether they are profitable to emit a memset + inividual stores vs
stores for everything.
The heuristic used is that a global has to be more than 16 bytes and
has to be 3/4 zero to be candidate for this xform. The two testcases
are illustrative of the scenarios this catches. We now codegen test9 into:
call void @llvm.memset.p0i8.i64(i8* %0, i8 0, i64 400, i32 4, i1 false)
%.array = getelementptr inbounds [100 x i32]* %Arr, i32 0, i32 0
%tmp = load i32* %X.addr, align 4
store i32 %tmp, i32* %.array
and test10 into:
call void @llvm.memset.p0i8.i64(i8* %0, i8 0, i64 392, i32 8, i1 false)
%tmp = getelementptr inbounds %struct.b* %S, i32 0, i32 0
%tmp1 = getelementptr inbounds %struct.a* %tmp, i32 0, i32 0
%tmp2 = load i32* %X.addr, align 4
store i32 %tmp2, i32* %tmp1, align 4
%tmp5 = getelementptr inbounds %struct.b* %S, i32 0, i32 3
%tmp10 = getelementptr inbounds %struct.a* %tmp5, i32 0, i32 4
%tmp11 = load i32* %X.addr, align 4
store i32 %tmp11, i32* %tmp10, align 4
Previously we produced 99 stores of zero for test9 and also tons for test10.
This xforms should substantially speed up -O0 builds when it kicks in as well
as reducing code size and optimizer heartburn on insane cases. This resolves
PR279.
llvm-svn: 120692
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
but not in C++, so don't emit aggregate loads of volatile references
in null context in C++. Happens to have been caught by an assertion.
We do not get the scalar case right. Volatiles are really broken.
llvm-svn: 112019
implicitly-defined default constructor, zero-initialize the memory
before calling the default constructor. Previously, we would only
zero-initialize in the case of a trivial default constructor.
Also, simplify the hideous logic that determines when we have a
trivial default constructor and, therefore, don't need to emit any
call at all.
llvm-svn: 111779
pointers. I find the resulting code to be substantially cleaner, and it
makes it very easy to use the same APIs for data member pointers (which I have
conscientiously avoided here), and it avoids a plethora of potential
inefficiencies due to excessive memory copying, but we'll have to see if it
actually works.
llvm-svn: 111776
duplication between the constant and non-constant paths in all of this.
Implement ARM ABI semantics for member pointer constants and conversion.
llvm-svn: 111772
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
reinterpret_casts (possibly indirectly via C-style/functional casts)
on values, e.g.,
int i;
reinterpret_cast<short&>(i);
The IR generated for this is essentially the same as for
*reinterpret_cast<short*>(&i).
Fixes PR6437, PR7593, and PR7344.
llvm-svn: 108294
was not producing a memcpy with the right address
spaces because of two places in it doing casts of
the arguments to i8, one of which that didn't
preserve the address space.
There is also an optimizer bug here.
llvm-svn: 107842
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
objective-c++ class objects which have GC'able objc object
pointers and need to use ObjC's objc_memmove_collectable
API (radar 8070772).
llvm-svn: 106061
isn't possible to compute.
This patch is mostly refactoring; the key change is the addition of the code
starting with the comment, "Check whether the function has a computable LLVM
signature." The solution here is essentially the same as the way the
vtable code handles such functions.
llvm-svn: 105151
temporaries. There are actually several interrelated fixes here:
- When converting an object to a base class, it's only an lvalue
cast when the original object was an lvalue and we aren't casting
pointer-to-derived to pointer-to-base. Previously, we were
misclassifying derived-to-base casts of class rvalues as lvalues,
causing various oddities (including problems with reference binding
not extending the lifetimes of some temporaries).
- Teach the code for emitting a reference binding how to look
through no-op casts and parentheses directly, since
Expr::IgnoreParenNoOpCasts is just plain wrong for this. Also, make
sure that we properly look through multiple levels of indirection
from the temporary object, but destroy the actual temporary object;
this fixes the reference-binding issue mentioned above.
- Teach Objective-C message sends to bind the result as a temporary
when needed. This is actually John's change, but it triggered the
reference-binding problem above, so it's included here. Now John
can actually test his return-slot improvements.
llvm-svn: 104434
particular issue was the cause of the Boost.Interprocess failures, and
in general will lead to horrendous, hard-to-diagnose miscompiles. The
assertion itself has survives self-host and a full Boost build, so we
are close to eradicating this problem in C++.
Note that the assertion is *not* turned on for Objective-C++, where we
still have problems with introducing memcpy's of non-POD class
types. That part of the assertion will go away as soon as we fix the
known issues in Objective-C++.
llvm-svn: 104227
CXXExprWithTemporaries.
Not emitting the expression as an aggregate might be the right thing to do,
but is orthogonal. Emitting it as an scalar expression will still try to
create a temporary for the incomplete type of the CXXExprWithTemporaries and
fail.
llvm-svn: 99134
- This fixes many many more places than the test case, but my feeling is we need to audit alignment systematically so I'm not inclined to try hard to test the individual fixes in this patch. If this bothers you, patches welcome!
PR6240.
llvm-svn: 95648
qualified reference to a declaration that is not a non-static data
member or non-static member function, e.g.,
namespace N { int i; }
int j = N::i;
Instead, extend DeclRefExpr to optionally store the qualifier. Most
clients won't see or care about the difference (since
QualifierDeclRefExpr inherited DeclRefExpr). However, this reduces the
number of top-level expression types that clients need to cope with,
brings the implementation of DeclRefExpr into line with MemberExpr,
and simplifies and unifies our handling of declaration references.
Extended DeclRefExpr to (optionally) store explicitly-specified
template arguments. This occurs when naming a declaration via a
template-id (which will be stored in a TemplateIdRefExpr) that,
following template argument deduction and (possibly) overload
resolution, is replaced with a DeclRefExpr that refers to a template
specialization but maintains the template arguments as written.
llvm-svn: 84962
Type hierarchy. Demote 'volatile' to extended-qualifier status. Audit our
use of qualifiers and fix a few places that weren't dealing with qualifiers
quite right; many more remain.
llvm-svn: 82705
Type::getAsReferenceType() -> Type::getAs<ReferenceType>()
Type::getAsRecordType() -> Type::getAs<RecordType>()
Type::getAsPointerType() -> Type::getAs<PointerType>()
Type::getAsBlockPointerType() -> Type::getAs<BlockPointerType>()
Type::getAsLValueReferenceType() -> Type::getAs<LValueReferenceType>()
Type::getAsRValueReferenceType() -> Type::getAs<RValueReferenceType>()
Type::getAsMemberPointerType() -> Type::getAs<MemberPointerType>()
Type::getAsReferenceType() -> Type::getAs<ReferenceType>()
Type::getAsTagType() -> Type::getAs<TagType>()
And remove Type::getAsReferenceType(), etc.
This change is similar to one I made a couple weeks ago, but that was partly
reverted pending some additional design discussion. With Doug's pending smart
pointer changes for Types, it seemed natural to take this approach.
llvm-svn: 77510
until Doug Gregor's Type smart pointer code lands (or more discussion occurs).
These methods just call the new Type::getAs<XXX> methods, so we still have
reduced implementation redundancy. Having explicit getAsXXXType() methods makes
it easier to set breakpoints in the debugger.
llvm-svn: 76193
Remove ASTContext parameter from DeclContext's methods. This change cascaded down to other Decl's methods and changes to call sites started "escalating".
Timings using pre-tokenized "cocoa.h" showed only a ~1% increase in time run between and after this commit.
llvm-svn: 74506
John McCall