copy-initialization. We previously got this wrong in a couple of ways:
- we only looked for copy / move constructors and constructor templates for
this copy, and thus would fail to copy in cases where doing so should use
some other constructor (but see core issue 670),
- we mishandled the special case for disabling user-defined conversions that
blocks infinite recursion through repeated application of a copy constructor
(applying it in slightly too many cases) -- though as far as I can tell,
this does not ever actually affect the result of overload resolution, and
- we misapplied the special-case rules for constructors taking a parameter
whose type is a (reference to) the same class type by incorrectly assuming
that only happens for copy/move constructors (it also happens for
constructors instantiated from templates and those inherited from base
classes).
These changes should only affect strange corner cases (for instance, where the
copy constructor exists but has a non-const-qualified parameter type), so for
the most part it only causes us to produce more 'candidate' notes, but see the
test changes for other cases whose behavior is affected.
llvm-svn: 280776
clang would incorrectly not allow the following:
int x = true ? (throw 1) : 2;
The problem exists because we don't see beyond the parens.
This, in turn, causes us to believe that we are choosing between void
and int which we diagnose as an error.
Instead, allow clang to see the 'throw' inside the parens.
llvm-svn: 183085
designator" diagnostic with more correct and more human-friendly "cannot take
address of rvalue of type 'T'".
For the case of & &T::f, provide a custom diagnostic, rather than unhelpfully
saying "cannot take address of rvalue of type '<overloaded function type>'".
For the case of &array_temporary, treat it just like a class temporary
(including allowing it as an extension); the existing diagnostic wording
for the class temporary case works fine.
llvm-svn: 174262
A couple of missing "RequireNonAbstractType" calls in conditional operator
handling. I looked for opportunities to tie this check in to all relevant
callers of PerformCopyInitialization (couldn't be all callers since this is
called for base subobject copying too, where it's acceptable to copy abstract
types) but the callers varied too much & in many cases had substantial code
or conditionals on the RequireNonAbstractType call, the
PerformCopyInitialization call, or the code between the two calls.
llvm-svn: 163555
A conditional operator between glvalues of types cv1 T and cv2 T produces a
glvalue if the expressions are of the same value kind and one of cv1 and cv2
is a subset of the other.
A conditional operator between two null pointer constants is permitted if one
of them is of type std::nullptr_t.
llvm-svn: 161476
- If the declarator is at the start of a line, and the previous line contained
another declarator and ended with a comma, then that comma was probably a
typo for a semicolon:
int n = 0, m = 1, l = 2, // k = 5;
myImportantFunctionCall(); // oops!
- If removing the parentheses would correctly initialize the object, then
produce a note suggesting that fix.
- Otherwise, if there is a simple initializer we can suggest which performs
value-initialization, then provide a note suggesting a correction to that
initializer.
Sema::Declarator now tracks the location of the comma prior to the declarator in
the declaration, if there is one, to facilitate providing the note. The code to
determine an appropriate initializer from the -Wuninitialized warning has been
factored out to allow use in both that and -Wvexing-parse.
llvm-svn: 148072
scope, when no other indication is provided that the user intended to declare a
function rather than a variable.
Remove some false positives from the existing 'parentheses disambiguated as a
function' warning by suppressing it when the declaration is marked as 'typedef'
or 'extern'.
Add a new warning group -Wvexing-parse containing both of these warnings.
The new warning is enabled by default; despite a number of false positives (and
one bug) in clang's test-suite, I have only found genuine bugs with it when
running it over a significant quantity of real C++ code.
llvm-svn: 147599
implementation used by overload resolution to support rvalue
references. The original commits caused PR9026 and some
hard-to-reproduce self-host breakage.
The only (crucial!) difference between this commit and the previous
commits is that we now properly check the SuppressUserConversions flag
before attempting to perform a second user-defined conversion in
reference binding, breaking the infinite recursion chain of
user-defined conversions.
Rvalue references should be working a bit better now.
llvm-svn: 124121
resolution to match the latest C++0x working paper's semantics. The
implementation now matching up with the reference-binding
implementation used for initialization.
llvm-svn: 123977
This flag and warning match GCC semantics. Also, move it to -Wextra as this is
a largely cosmetic issue and doesn't seem to mask problems. Subsequent fixes to
the tests which no longer by default emit the warning. Added explicit test
cases for both C and C++ behavior with the warning turned on.
llvm-svn: 108325
effect warning" by printing the qualifiers we saw and correctly
pluralizing the message, e.g.,
test/SemaCXX/conditional-expr.cpp:295:3: warning: 'const volatile' type
qualifiers on return type have no effect
const volatile Enum g2() {
^~~~~ ~~~~~~~~
llvm-svn: 108236
strip cv-qualifiers from the expression's type when the language calls
for it: in C, that's all the time, while C++ only does it for
non-class types.
Centralized the computation of the call expression type in
QualType::getCallResultType() and some helper functions in other nodes
(FunctionDecl, ObjCMethodDecl, FunctionType), and updated all relevant
callers of getResultType() to getCallResultType().
Fixes PR7598 and PR7463, along with a bunch of getResultType() call
sites that weren't stripping references off the result type (nothing
stripped cv-qualifiers properly before this change).
llvm-svn: 108234
create a temporary copy of both the "true" and "false" results. Fixes
the Boost.Interprocess failures.
Daniel did all the hard work of tracking down the issue, I get to type
up the trivial fix for this horrible miscompile.
llvm-svn: 104184
"bottom-up" when implicit casts and comparisons are inserted, compute them
"top-down" when the full expression is finished. Makes it easier to
coordinate warnings and thus implement -Wconversion for signedness
conversions without double-warning with -Wsign-compare. Also makes it possible
to realize that a signedness conversion is okay because the context is
performing the inverse conversion. Also simplifies some logic that was
trying to calculate the ultimate comparison/result type and getting it wrong.
Also fixes a problem with the C++ explicit casts which are often "implemented"
in the AST with a series of implicit cast expressions.
llvm-svn: 103174
copy constructor, suppress user-defined conversions on the
argument. Otherwise, we can end up in a recursion loop where the
bind the argument of the copy constructor to another copy constructor call,
whose argument is then a copy constructor call...
Found by Boost.Regex which, alas, still isn't building.
llvm-svn: 102269
resolution. There are two sources of problems involving user-defined
conversions that this change eliminates, along with providing simpler
interfaces for checking implicit conversions:
- It eliminates a case of infinite recursion found in Boost.
- It eliminates the search for the constructor needed to copy a temporary
generated by an implicit conversion from overload
resolution. Overload resolution assumes that, if it gets a value
of the parameter's class type (or a derived class thereof), there
is a way to copy if... even if there isn't. We now model this
properly.
llvm-svn: 101680
Remove -faccess-control from -cc1; add -fno-access-control.
Make the driver pass -fno-access-control by default.
Update a bunch of tests to be correct under access control.
llvm-svn: 100880
poor (and wrong) approximation of the actual rules governing when to
build a copy and when it can be elided.
The correct implementation is actually simpler than the
approximation. When we only enumerate constructors as part of
initialization (e.g., for direct initialization or when we're copying
from a class type or one of its derived classes), we don't create a
copy. When we enumerate all conversion functions, we do create a
copy. Before, we created some extra copies and missed some
others. The new test copy-initialization.cpp shows a case where we
missed creating a (required, non-elidable) copy as part of a
user-defined conversion, which resulted in a miscompile. This commit
also fixes PR6757, where the missing copy made us reject well-formed
code in the ternary operator.
This commit also cleans up our handling of copy elision in the case
where we create an extra copy of a temporary object, which became
necessary now that we produce the right copies. The code that seeks to
find the temporary object being copied has moved into
Expr::getTemporaryObject(); it used to have two different
not-quite-the-same implementations, one in Sema and one in CodeGen.
Note that we still do not attempt to perform the named return value
optimization, so we miss copy elisions for return values and throw
expressions.
llvm-svn: 100196
expression can be converted to the type of another, only apply the
lvalue-to-rvalue conversion to the type of the expression we're
converting, *not* the array-to-pointer or function-to-pointer
conversions. Fixes PR6595.
llvm-svn: 99652
therefore not creating ElaboratedTypes, which are still pretty-printed
with the written tag).
Most of these testcase changes were done by script, so don't feel too
sorry for my fingers.
llvm-svn: 98149
conversions. Fix an access-control bug where privileges were not considered
at intermediate points along the inheritance path. Prepare for friends.
llvm-svn: 95775
sequence. Lots of small relevant changes. Fixes some serious problems with
ambiguous conversions; also possibly improves associated diagnostics.
llvm-svn: 93214
InitializationSequence (when a FunctionDecl is present). This required
a few small fixes to initialization sequences:
- Make sure to use the adjusted parameter type for initialization of
function parameters.
- Implement transparent union calling semantics in C
llvm-svn: 91902
- This is designed to make it obvious that %clang_cc1 is a "test variable"
which is substituted. It is '%clang_cc1' instead of '%clang -cc1' because it
can be useful to redefine what gets run as 'clang -cc1' (for example, to set
a default target).
llvm-svn: 91446
DiagnoseSignCompare into Sema::CheckSignCompare and call it from more places.
Add some enumerator tests. These seem to expose some oddities in the
types we're converting C++ enumerators to; in particular, they're converting
to unsigned before int, which seems to contradict 4.5 [conv.prom] p2.
Note to self: stop baiting Doug in my commit messages.
llvm-svn: 86128
pointers, by extending the "composite pointer type" logic to include
member pointer types.
Introduce test cases for member pointer comparisons, including those
that involve the builtin operator candidates implemented earlier.
llvm-svn: 79925
Remove an atrocious amount of trailing whitespace in the overloaded operator mangler. Sorry, couldn't help myself.
Change the DeclType parameter of Sema::CheckReferenceInit to be passed by value instead of reference. It wasn't changed anywhere.
Let the parser handle C++'s irregular grammar around assignment-expression and conditional-expression.
And finally, the reason for all this stuff: implement C++ semantics for the conditional operator. The implementation is complete except for determining lvalueness.
llvm-svn: 69299
Richard Smith