the result of a cast-to-reference-type lifetime-extends the object to which the
reference inside the cast binds.
This requires us to look for subobject adjustments on both the inside and the
outside of the MaterializeTemporaryExpr when looking for a temporary to
lifetime-extend (which we also need for core issue 616, and possibly 1213).
llvm-svn: 184024
Introduce CXXStdInitializerListExpr node, representing the implicit
construction of a std::initializer_list<T> object from its underlying array.
The AST representation of such an expression goes from an InitListExpr with a
flag set, to a CXXStdInitializerListExpr containing a MaterializeTemporaryExpr
containing an InitListExpr (possibly wrapped in a CXXBindTemporaryExpr).
This more detailed representation has several advantages, the most important of
which is that the new MaterializeTemporaryExpr allows us to directly model
lifetime extension of the underlying temporary array. Using that, this patch
*drastically* simplifies the IR generation of this construct, provides IR
generation support for nested global initializer_list objects, fixes several
bugs where the destructors for the underlying array would accidentally not get
invoked, and provides constant expression evaluation support for
std::initializer_list objects.
llvm-svn: 183872
which is lifetime-extended by a reference binding. An additional temporary is
created for such a bitfield access (although we have no explicit AST
representation for it).
llvm-svn: 183095
The most common (non-buggy) case are where such objects are used as
return expressions in bool-returning functions or as boolean function
arguments. In those cases I've used (& added if necessary) a named
function to provide the equivalent (or sometimes negative, depending on
convenient wording) test.
DiagnosticBuilder kept its implicit conversion operator owing to the
prevalent use of it in return statements.
One bug was found in ExprConstant.cpp involving a comparison of two
PointerUnions (PointerUnion did not previously have an operator==, so
instead both operands were converted to bool & then compared). A test
is included in test/SemaCXX/constant-expression-cxx1y.cpp for the fix
(adding operator== to PointerUnion in LLVM).
llvm-svn: 181869
- References to ObjC bit-field ivars are bit-field lvalues;
fixes rdar://13794269, which got me started down this.
- Introduce Expr::refersToBitField, switch a couple users to
it where semantically important, and comment the difference
between this and the existing API.
- Discourage Expr::getBitField by making it a bit longer and
less general-sounding.
- Lock down on const_casts of bit-field gl-values until we
hear back from the committee as to whether they're allowed.
llvm-svn: 181252
statement in constexpr functions. Everything which doesn't require variable
mutation is also allowed as an extension in C++11. 'void' becomes a literal
type to support constexpr functions which return 'void'.
llvm-svn: 180022
Add a CXXDefaultInitExpr, analogous to CXXDefaultArgExpr, and use it both in
CXXCtorInitializers and in InitListExprs to represent a default initializer.
There's an additional complication here: because the default initializer can
refer to the initialized object via its 'this' pointer, we need to make sure
that 'this' points to the right thing within the evaluation.
llvm-svn: 179958
This change also makes the serialisation store the required semantics,
fixing an issue where PPC128 was always assumed when re-reading a
128-bit value.
llvm-svn: 173139
This is inspired by a number of false positives in real code, including
PR14968. I've added test cases reduced from these false positives to
test/Sema/unused-expr.c, as well as corresponding test cases that pass the
offending expressions as arguments to a no-op macro to ensure that we do warn
there.
This also removes my previous tweak from r166522/r166534, so that we warn on
unused cast expressions in macro arguments.
There were several test cases that were using -Wunused-value to test general
diagnostic emission features; I changed those to use other warnings or warn on
a macro argument expression. I stared at the test case for PR14399 for a while
with Richard Smith and we believe the new test case exercises the same
codepaths as before.
llvm-svn: 172696
Changed getLocStart() and getLocEnd() to be required for Stmts, and make
getSourceRange() optional. The default implementation for getSourceRange()
is build the range by calling getLocStart() and getLocEnd().
llvm-svn: 171067
of a member function with parenthesized declarator.
Like this test case:
class Foo {
const char *(baz)() {
return __PRETTY_FUNCTION__;
}
};
llvm-svn: 170233
bytes of the buffer and not the size of the string, otherwise we
may overwrite the buffer if there is a mismatch between the size
of the string and the CharByteWidth, and assertions are disabled.
The bug where this could occur was fixed in r163931.
Related to rdar://12069503
llvm-svn: 163939
(__builtin_* etc.) so that it isn't possible to take their address.
Specifically, introduce a new type to represent a reference to a builtin
function, and a new cast kind to convert it to a function pointer in the
operand of a call. Fixes PR13195.
llvm-svn: 162962
This also provides isConst/Volatile/Restrict on FunctionTypes to coalesce
the implementation with other callers (& update those other callers).
Patch contributed by Sam Panzer (panzer@google.com).
llvm-svn: 161647
This is effectively a warning for code that violates core issue 903 & thus will
become standard error in the future, hopefully. It catches strange null
pointers such as: '\0', 1 - 1, const int null = 0; etc...
There's currently a flaw in this warning (& the warning for 'false' as a null
pointer literal as well) where it doesn't trigger on comparisons (ptr == '\0'
for example). Fix to come in a future patch.
Also, due to this only being a warning, not an error, it triggers quite
frequently on gtest code which tests expressions for null-pointer-ness in a
SFINAE context (so it wouldn't be a problem if this was an error as in an
actual implementation of core issue 903). To workaround this for now, the
diagnostic does not fire in unevaluated contexts.
Review by Sean Silva and Richard Smith.
llvm-svn: 161501
update implementation to match. An elidable, non-trivial constructor call is a
side-effect under this definition, but wasn't under the old one, because we are
not required to evaluate it even though it may have an effect.
Also rationalize checking for volatile reads: just look for lvalue-to-rvalue
conversions on volatile glvalues, and ignore whether a DeclRefExpr etc is for
a volatile variable.
llvm-svn: 161393
was mistakenly classifying dynamic_casts which might throw as having no side
effects.
Switch it from a visitor to a switch, so it is kept up-to-date as future Expr
nodes are added. Move it from ExprConstant.cpp to Expr.cpp, since it's not
really related to constant expression evaluation.
Since we use HasSideEffect to determine whether to emit an unused global with
internal linkage, this has the effect of suppressing emission of globals in
some cases.
I've left many of the Objective-C cases conservatively assuming that the
expression has side-effects. I'll leave it to someone with better knowledge
of Objective-C than mine to improve them.
llvm-svn: 161388
This required moving the ctors for IntegerLiteral and FloatingLiteral out of
line which shouldn't change anything as they are usually called through Create
methods that are already out of line.
ASTContext::Deallocate has been a nop for a long time, drop it from ASTVector
and make it independent from ASTContext.h
Pass the StorageAllocator directly to AccessedEntity so it doesn't need to
have a definition of ASTContext around.
llvm-svn: 159718
the correct this pointer. There is some potential for sharing a bit more
code with canDevirtualizeMemberFunctionCalls, but that can be done in an
independent patch.
llvm-svn: 159326
Richard Smith