involves extending implicit conversion sequences to model vector
conversions and vector splats, along with teaching the C++ conditional
operator-checking code about vector types.
Fixes <rdar://problem/7983501>.
llvm-svn: 104081
specific message that includes the template arguments, e.g.,
test/SemaTemplate/overload-candidates.cpp:27:20: note: candidate template
ignored: substitution failure [with T = int *]
typename T::type get_type(const T&); // expected-note{{candidate ...
^
llvm-svn: 103348
conflicting deduced template argument values, give a more specific
reason along with those values, e.g.,
test/SemaTemplate/overload-candidates.cpp:4:10: note: candidate template
ignored: deduced conflicting types for parameter 'T' ('int' vs. 'long')
const T& min(const T&, const T&);
^
llvm-svn: 103339
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
from a conversion function template specialization to one of exact
match rank. We only know how to test this in C++0x with default
function template arguments, but it's also in the C++03 spec. Fixes
PR6285.
llvm-svn: 101089
entity (if applicable) which was actually looked up. If a candidate was found
via a using declaration, this is the UsingShadowDecl; otherwise, if
the candidate is template specialization, this is the template; otherwise,
this is the function.
The point of this exercise is that "found declarations" are the entities
we do access control for, not their underlying declarations. Broadly speaking,
this patch fixes access control for using declarations.
There is a *lot* of redundant code calling into the overload-resolution APIs;
we really ought to clean that up.
llvm-svn: 98945
types. Rank these conversions below other conversions. This allows overload
resolution when the only distinction is between a complex and scalar type. It
also brings the complex overload resolutin in line with GCC's.
llvm-svn: 97128
sequences, where we would occasionally determine (incorrectly) that
one standard conversion sequence was a proper subset of another when,
in fact, they contained completely incomparable conversions.
This change records the types in each step within a standard
conversion sequence, so that we can check the specific comparison
types to determine when one sequence is a proper subset of the
other. Fixes this testcase (thanks, Anders!), which was distilled from
PR6095 (also thanks to Anders).
llvm-svn: 94660
conversions. To make this work, fill out all conversions for all candidates
(but only when diagnosing overload failure). Split out a few cases from
ovl_fail_bad_conversion which didn't actually involve a failed argument
conversion.
I'm pretty sure this is not a well-founded ordering, but I'm not sure it matters.
llvm-svn: 94283
information to feed diagnostics instead of regenerating it. Much room for
improvement here, but fixes some unfortunate problems reporting on method calls.
llvm-svn: 93316
sequence. Lots of small relevant changes. Fixes some serious problems with
ambiguous conversions; also possibly improves associated diagnostics.
llvm-svn: 93214
new notion of an "initialization sequence", which encapsulates the
computation of the initialization sequence along with diagnostic
information and the capability to turn the computed sequence into an
expression. At present, I've only switched one CheckReferenceInit
callers over to this new mechanism; more will follow.
Aside from (hopefully) being much more true to the standard, the
diagnostics provided by this reference-initialization code are a bit
better than before. Some examples:
p5-var.cpp:54:12: error: non-const lvalue reference to type 'struct
Derived'
cannot bind to a value of unrelated type 'struct Base'
Derived &dr2 = b; // expected-error{{non-const lvalue reference to
...
^ ~
p5-var.cpp:55:9: error: binding of reference to type 'struct Base' to
a value of
type 'struct Base const' drops qualifiers
Base &br3 = bc; // expected-error{{drops qualifiers}}
^ ~~
p5-var.cpp:57:15: error: ambiguous conversion from derived class
'struct Diamond' to base class 'struct Base':
struct Diamond -> struct Derived -> struct Base
struct Diamond -> struct Derived2 -> struct Base
Base &br5 = diamond; // expected-error{{ambiguous conversion from
...
^~~~~~~
p5-var.cpp:59:9: error: non-const lvalue reference to type 'long'
cannot bind to
a value of unrelated type 'int'
long &lr = i; // expected-error{{non-const lvalue reference to type
...
^ ~
p5-var.cpp:74:9: error: non-const lvalue reference to type 'struct
Base' cannot
bind to a temporary of type 'struct Base'
Base &br1 = Base(); // expected-error{{non-const lvalue reference to
...
^ ~~~~~~
p5-var.cpp:102:9: error: non-const reference cannot bind to bit-field
'i'
int & ir1 = (ib.i); // expected-error{{non-const reference cannot
...
^ ~~~~~~
p5-var.cpp:98:7: note: bit-field is declared here
int i : 17; // expected-note{{bit-field is declared here}}
^
llvm-svn: 90992
pointers thereof) to their corresponding non-noreturn function
types. This conversion is considered an exact match for
overload-resolution purposes. Note that we are a little more strict
that GCC is, because we encode noreturn in the type system, but that's
a Good Thing (TM) because it does not allow us to pretend that
potentially-returning function pointers are non-returning function
pointers.
Fxies PR5620.
llvm-svn: 90913
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
system. Since C99 doesn't have overloading and C++ doesn't have
_Complex, there is no specification for this. Here's what I think
makes sense.
Complex conversions come in several flavors:
- Complex promotions: a complex -> complex conversion where the
underlying real-type conversion is a floating-point promotion. GCC
seems to call this a promotion, EDG does something else. This is
given "promotion" rank for determining the best viable function.
- Complex conversions: a complex -> complex conversion that is
not a complex promotion. This is given "conversion" rank for
determining the best viable function.
- Complex-real conversions: a real -> complex or complex -> real
conversion. This is given "conversion" rank for determining the
best viable function.
These rules are the same for C99 (when using the "overloadable"
attribute) and C++. However, there is one difference in the handling
of floating-point promotions: in C99, float -> long double and double
-> long double are considered promotions (so we give them "promotion"
rank), while C++ considers these conversions ("conversion" rank).
llvm-svn: 64343
This commit adds a new attribute, "overloadable", that enables C++
function overloading in C. The attribute can only be added to function
declarations, e.g.,
int *f(int) __attribute__((overloadable));
If the "overloadable" attribute exists on a function with a given
name, *all* functions with that name (and in that scope) must have the
"overloadable" attribute. Sets of overloaded functions with the
"overloadable" attribute then follow the normal C++ rules for
overloaded functions, e.g., overloads must have different
parameter-type-lists from each other.
When calling an overloaded function in C, we follow the same
overloading rules as C++, with three extensions to the set of standard
conversions:
- A value of a given struct or union type T can be converted to the
type T. This is just the identity conversion. (In C++, this would
go through a copy constructor).
- A value of pointer type T* can be converted to a value of type U*
if T and U are compatible types. This conversion has Conversion
rank (it's considered a pointer conversion in C).
- A value of type T can be converted to a value of type U if T and U
are compatible (and are not both pointer types). This conversion
has Conversion rank (it's considered to be a new kind of
conversion unique to C, a "compatible" conversion).
Known defects (and, therefore, next steps):
1) The standard-conversion handling does not understand conversions
involving _Complex or vector extensions, so it is likely to get
these wrong. We need to add these conversions.
2) All overloadable functions with the same name will have the same
linkage name, which means we'll get a collision in the linker (if
not sooner). We'll need to mangle the names of these functions.
llvm-svn: 64336
- Overloading has to cope with having both static and non-static
member functions in the overload set.
- The call may or may not have an implicit object argument,
depending on the syntax (x.f() vs. f()) and the context (static
vs. non-static member function).
- We now generate MemberExprs for implicit member access expression.
- We now cope with mutable whenever we're building MemberExprs.
llvm-svn: 61329
being called to be converted to a reference-to-function,
pointer-to-function, or reference-to-pointer-to-function. This is done
through "surrogate" candidate functions that model the conversions
from the object to the function (reference/pointer) and the
conversions in the arguments.
llvm-svn: 59674
functions for built-in operators, e.g., the builtin
bool operator==(int const*, int const*)
can be used for the expression "x1 == x2" given:
struct X {
operator int const*();
} x1, x2;
The scheme for handling these built-in operators is relatively simple:
for each candidate required by the standard, create a special kind of
candidate function for the built-in. If overload resolution picks the
built-in operator, we perform the appropriate conversions on the
arguments and then let the normal built-in operator take care of it.
There may be some optimization opportunity left: if we can reduce the
number of built-in operator overloads we generate, overload resolution
for these cases will go faster. However, one must be careful when
doing this: GCC generates too few operator overloads in our little
test program, and fails to compile it because none of the overloads it
generates match.
Note that we only support operator overload for non-member binary
operators at the moment. The other operators will follow.
As part of this change, ImplicitCastExpr can now be an lvalue.
llvm-svn: 59148
cope with the case where a user-defined conversion is actually a copy
construction, and therefore can be compared against other standard
conversion sequences. While I called this a hack before, now I'm
convinced that it's the right way to go.
Compare overloads based on derived-to-base conversions that invoke
copy constructors.
Suppress user-defined conversions when attempting to call a
user-defined conversion.
llvm-svn: 58629
conversions.
Notes:
- Overload resolution for converting constructors need to prohibit
user-defined conversions (hence, the test isn't -verify safe yet).
- We still use hacks for conversions from a class type to itself.
This will be the case until we start implicitly declaring the appropriate
special member functions. (That's next on my list)
llvm-svn: 58513
ImplicitConversionSequence and, when doing so, following the specific
rules of [over.best.ics].
The computation of the implicit conversion sequences implements C++
[over.ics.ref], but we do not (yet) have ranking for implicit
conversion sequences that use reference binding.
llvm-svn: 58357
pointer-to-base. Also, add overload ranking for pointer conversions
(for both pointer-to-void and derived-to-base pointer conversions).
Note that we do not yet diagnose derived-to-base pointer conversion
errors that stem from ambiguous or inacessible base classes. These
aren't handled during overload resolution; rather, when the conversion
is actually used we go ahead and diagnose the error.
llvm-svn: 58017
conversions (e.g., comparing int* -> const int* against
int* -> const volatile int*); see C++ 13.3.3.2p3 bullet 3.
Add Sema::UnwrapSimilarPointerTypes to simplify the control flow of
IsQualificationConversion and CompareQualificationConversion (and fix
the handling of the int* -> volatile int* conversion in the former).
llvm-svn: 57978
Douglas Gregor