implicitly perform an lvalue-to-rvalue conversion if used on an lvalue
expression. Also improve the documentation of Expr::Evaluate* to indicate which
of them will accept expressions with side-effects.
llvm-svn: 143263
rvalue. An assertion to catch this is in ImpCastExprToType will follow, but
vector operations currently trip over this (due to omitting the usual arithmetic
conversions). Also add an assert to catch missing lvalue-to-rvalue conversions
on the LHS of ->.
llvm-svn: 143155
expressions: expressions which refer to a logical rather
than a physical l-value, where the logical object is
actually accessed via custom getter/setter code.
A subsequent patch will generalize the AST for these
so that arbitrary "implementing" sub-expressions can
be provided.
Right now the only client is ObjC properties, but
this should be generalizable to similar language
features, e.g. Managed C++'s __property methods.
llvm-svn: 142914
statements. As noted in the documentation for the AST node, the
semantics of __if_exists/__if_not_exists are somewhat different from
the way Visual C++ implements them, because our parsed-template
representation can't accommodate VC++ semantics without serious
contortions. Hopefully this implementation is "good enough".
llvm-svn: 142901
- Remodel Expr::EvaluateAsInt to behave like the other EvaluateAs* functions,
and add Expr::EvaluateKnownConstInt to capture the current fold-or-assert
behaviour.
- Factor out evaluation of bitfield bit widths.
- Fix a few places which would evaluate an expression twice: once to determine
whether it is a constant expression, then again to get the value.
llvm-svn: 141561
builtin types (When requested). This is another step toward making
ASTUnit build the ASTContext as needed when loading an AST file,
rather than doing so after the fact. No actual functionality change (yet).
llvm-svn: 138985
-Wunused was a mistake. It resulted in duplicate warnings and lots of
other hacks. Instead, this should be a special sub-category to
-Wunused-value, much like -Wunused-result is.
Moved to -Wunused-comparison, moved the implementation to piggy back on
the -Wunused-value implementation instead of rolling its own, different
mechanism for catching all of the "interesting" statements.
I like the unused-value mechanism for this better, but its currently
missing several top-level statements. For now, I've FIXME-ed out those
test cases. I'll enhance the generic infrastructure to catch these
statements in a subsequent patch.
This patch also removes the cast-to-void fixit hint. This hint isn't
available on any of the other -Wunused-value diagnostics, and if we want
it to be, we should add it generically rather than in one specific case.
llvm-svn: 137822
code is very likely to be buggy, but its going to require more
significant changes on the part of the user to correct it in this case.
llvm-svn: 137820
a complement to the warnings we provide in condition expressions. Much
like we warn on conditions such as:
int x, y;
...
if (x = y) ... // Almost always a typo of '=='
This warning applies the complementary logic to "top-level" statements,
or statements whose value is not consumed or used in some way:
int x, y;
...
x == y; // Almost always a type for '='
We also mirror the '!=' vs. '|=' logic.
The warning is designed to fire even for overloaded operators for two reasons:
1) Especially in the presence of widespread templates that assume
operator== and operator!= perform the expected comparison operations,
it seems unreasonable to suppress warnings on the offchance that
a user has written a class that abuses these operators, embedding
side-effects or other magic within them.
2) There is a trivial source modification to silence the warning for
truly exceptional cases:
(void)(x == y); // No warning
A (greatly reduced) form of this warning has already caught a number of
bugs in our codebase, so there is precedent for it actually firing. That
said, its currently off by default, but enabled under -Wall.
There are several fixmes left here that I'm working on in follow-up
patches, including de-duplicating warnings from -Wunused, sharing code
with -Wunused's implementation (and creating a nice place to hook
diagnostics on "top-level" statements), and handling cases where a proxy
object with a bool conversion is returned, hiding the operation in the
cleanup AST nodes.
Suggestions for any of this code more than welcome. Also, I'd really
love suggestions for better naming than "top-level".
llvm-svn: 137819
ActOnStartOfSwitchStmt (i.e. before binding up a full-expression)
instead of ActOnFinishSwitchStmt.
Among other things, this means that property l-values are properly
converted inside the full-expression.
llvm-svn: 137014
for-in statements; specifically, make sure to close over any
temporaries or cleanups it might require. In ARC, this has
implications for the lifetime of the collection, so emit it
with a retain and release it upon exit from the loop.
rdar://problem/9817306
llvm-svn: 136204
throw-expressions, such that we don't consider the NRVO when the
non-volatile automatic object comes from outside the innermost try
scope (C++0x [class.copymove]p13). In C++98/03, our ASTs were
incorrect but it didn't matter because IR generation doesn't actually
apply the NRVO here. In C++0x, however, we were moving from an object
when in fact we should have copied from it. Fixes PR10142 /
<rdar://problem/9714312>.
llvm-svn: 134548
they should still be officially __strong for the purposes of errors,
block capture, etc. Make a new bit on variables, isARCPseudoStrong(),
and set this for 'self' and these enumeration-loop variables. Change
the code that was looking for the old patterns to look for this bit,
and change IR generation to find this bit and treat the resulting
variable as __unsafe_unretained for the purposes of init/destroy in
the two places it can come up.
llvm-svn: 133243
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
Related result types apply Cocoa conventions to the type of message
sends and property accesses to Objective-C methods that are known to
always return objects whose type is the same as the type of the
receiving class (or a subclass thereof), such as +alloc and
-init. This tightens up static type safety for Objective-C, so that we
now diagnose mistakes like this:
t.m:4:10: warning: incompatible pointer types initializing 'NSSet *'
with an
expression of type 'NSArray *' [-Wincompatible-pointer-types]
NSSet *array = [[NSArray alloc] init];
^ ~~~~~~~~~~~~~~~~~~~~~~
/System/Library/Frameworks/Foundation.framework/Headers/NSObject.h:72:1:
note:
instance method 'init' is assumed to return an instance of its
receiver
type ('NSArray *')
- (id)init;
^
It also means that we get decent type inference when writing code in
Objective-C++0x:
auto array = [[NSMutableArray alloc] initWithObjects:@"one", @"two",nil];
// ^ now infers NSMutableArray* rather than id
llvm-svn: 132868
return <expression> ;
in blocks with a 'void' result type, so long as <expression> has type
'void'. This follows the rules for C++ functions.
llvm-svn: 132658
with a type-dependent expression, infer the placeholder type
'Context.DependentTy' to indicate that this is just a
placeholder. Fixes PR9982 / <rdar://problem/9486685>.
llvm-svn: 132657
Type::isUnsignedIntegerOrEnumerationType(), which are like
Type::isSignedIntegerType() and Type::isUnsignedIntegerType() but also
consider the underlying type of a C++0x scoped enumeration type.
Audited all callers to the existing functions, switching those that
need to also handle scoped enumeration types (e.g., those that deal
with constant values) over to the new functions. Fixes PR9923 /
<rdar://problem/9447851>.
llvm-svn: 131735
Changed the integer type that range-based for-loops used. Switched to pointer difference type, which satisfies the new assert in IntegerLiteral.
llvm-svn: 130739
member function, i.e. something of the form 'x.f' where 'f' is a non-static
member function. Diagnose this in the general case. Some of the new diagnostics
are probably worse than the old ones, but we now get this right much more
universally, and there's certainly room for improvement in the diagnostics.
llvm-svn: 130239
Richard Smith