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
-When parsing declarators, don't depend on "CurScope->isCXXClassScope() == true" for constructors/destructors
-For C++ member declarations, don't depend on "Declarator.getContext() == Declarator::MemberContext"
llvm-svn: 58866
functions in C++, e.g.,
struct X {
operator bool() const;
};
Note that these conversions don't actually do anything, since we don't
yet have the ability to use them for implicit or explicit conversions.
llvm-svn: 58860
operators. For example, one can now write "x + y" where x or y is a
class or enumeration type, and Clang will perform overload resolution
for "+" based on the overloaded operators it finds.
The other kinds of overloadable operators in C++ will follow this same
approach.
Three major issues remain:
1) We don't find member operators
2) Since we don't have user-defined conversion operators, we can't
call any of the built-in overloaded operators in C++ [over.built].
3) Once we've done the semantic checks, we drop the overloaded
operator on the floor; it doesn't get into the AST at all.
llvm-svn: 58821
operators in C++. Overloaded operators can be called directly via
their operator-function-ids, e.g., "operator+(foo, bar)", but we don't
yet implement the semantics of operator overloading to handle, e.g.,
"foo + bar".
llvm-svn: 58817
Implicit declaration of destructors (when necessary).
Extended Declarator to store information about parsed constructors
and destructors; this will be extended to deal with declarators that
name overloaded operators (e.g., "operator +") and user-defined
conversion operators (e.g., "operator int").
llvm-svn: 58767
duplication in the handling of copy-initialization by constructor,
which occurs both for initialization of a declaration and for
overloading. The initialization code is due for some refactoring.
llvm-svn: 58756
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
when appropriate.
Conversions for class types now make use of copy constructors. I've
replaced the egregious hack allowing class-to-class conversions with a
slightly less egregious hack calling these conversions standard
conversions (for overloading reasons).
llvm-svn: 58622
reference-collapsing.
Implement diagnostic for formation of a reference to cv void.
Drop cv-qualifiers added to a reference type when the reference type
comes from a typedef.
llvm-svn: 58612
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
Notes:
- Constructors are never found by name lookup, so they'll never get
pushed into any scope. Instead, they are stored as an
OverloadedFunctionDecl in CXXRecordDecl for easy overloading.
- There's a new action isCurrentClassName that determines whether an
identifier is the name of the innermost class currently being defined;
we use this to identify the declarator-id grammar rule that refers to
a type-name.
- MinimalAction does *not* support parsing constructors.
- We now handle virtual and explicit function specifiers.
llvm-svn: 58499
- Allows definitions of overloaded functions :)
- Eliminates extraneous error messages when we have a definition of a
function that isn't an overload but doesn't have exactly the same type
as the original.
llvm-svn: 58382
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
of copy initialization. Other pieces of the puzzle:
- Try/Perform-ImplicitConversion now handles implicit conversions
that don't involve references.
- Try/Perform-CopyInitialization uses
CheckSingleAssignmentConstraints for C. PerformCopyInitialization
is now used for all argument passing and returning values from a
function.
- Diagnose errors with declaring references and const values without
an initializer. (Uses a new Action callback, ActOnUninitializedDecl).
We do not yet have implicit conversion sequences for reference
binding, which means that we don't have any overloading support for
reference parameters yet.
llvm-svn: 58353
- CastExpr is the root of all casts
- ImplicitCastExpr is (still) used for all explicit casts
- ExplicitCastExpr is now the root of all *explicit* casts
- ExplicitCCastExpr (new name needed!?) is a C-style cast in C or C++
- CXXFunctionalCastExpr inherits from ExplicitCastExpr
- CXXNamedCastExpr inherits from ExplicitCastExpr and is the root of all
of the C++ named cast expression types (static_cast, dynamic_cast, etc.)
- Added classes CXXStaticCastExpr, CXXDynamicCastExpr,
CXXReinterpretCastExpr, and CXXConstCastExpr to
Also, fixed returned-stack-addr.cpp, which broke once when we fixed
reinterpret_cast to diagnose double->int* conversions and again when
we eliminated implicit conversions to reference types. The fix is in
both testcase and SemaChecking.cpp.
Most of this patch is simply support for the renaming. There's very
little actual change in semantics.
llvm-svn: 58264
conversions.
Added PerformImplicitConversion, which follows an implicit conversion sequence
computed by TryCopyInitialization and actually performs the implicit
conversions, including the extra check for ambiguity mentioned above.
llvm-svn: 58071
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
Changes:
- Sema::IsQualificationConversion determines whether we have a qualification
conversion.
- Sema::CheckSingleAssignment constraints now follows the C++ rules in C++,
performing an implicit conversion from the right-hand side to the type of
the left-hand side rather than checking based on the C notion of
"compatibility". We now rely on the implicit-conversion code to
determine whether the conversion can happen or
not. Sema::TryCopyInitialization has an ugly reference-related
hack to cope with the initialization of references, for now.
- When building DeclRefExprs, strip away the reference type, since
there are no expressions whose type is a reference. We'll need to
do this throughout Sema.
- Expr::isLvalue now permits functions to be lvalues in C++ (but not
in C).
llvm-svn: 57935
class C {
static const int number = 50;
static int arr[number];
};
Here's how it worked:
-GetTypeForDeclarator was called from both Sema::ActOnCXXMemberDeclarator and Sema::ActOnDeclarator.
-VariableArrayTypes are not uniqued so two VariableArrayTypes were created with the same DeclRefExpr.
-On exit they both tried to destroy that one DeclRefExpr.
The fix is not to use GetTypeForDeclarator from the Sema::ActOnCXXMemberDeclarator.
llvm-svn: 57313
This is how this kind of initializers appear in the AST:
-The Init expression of the VarDecl is a functional type construction (of the VarDecl's type).
-The new VarDecl::hasCXXDirectInitializer() returns true.
e.g, for "int x(1);":
-VarDecl 'x' has Init with expression "int(1)" (CXXFunctionalCastExpr).
-hasCXXDirectInitializer() of VarDecl 'x' returns true.
A major benefit is that clients that don't particularly care about which exactly form was the initializer can handle both cases without special case code.
Note that codegening works now for "int x(1);" without any changes to CodeGen.
llvm-svn: 57178
This was the motivation of the following changes:
-'TentativeParsingResult' enum is replaced by a 'TPResult' class that basically encapsulates the enum.
-TPR_true, TPR_false, TPR_ambiguous, and TPR_error enum constants are replaced by TPResult::True(), TPResult::False(), etc. calls that return a TPResult object.
-Also fixed the subtle bug in Parser::isCXXFunctionDeclarator (caught by the above changes as a compilation error).
llvm-svn: 57125
'ParseTentative.cpp' implements the functionality needed to resolve ambiguous C++ statements, to either a declaration or an expression, by "tentatively parsing" them.
llvm-svn: 57084
-The Parser calls a new "ActOnCXXTypeConstructExpr" action.
-Sema, depending on the type and expressions number:
-If the type is a class, it will treat it as a class constructor. [TODO]
-If there's only one expression (i.e. "int(0.5)" ), creates a new "CXXFunctionalCastExpr" Expr node
-If there are no expressions (i.e "int()" ), creates a new "CXXZeroInitValueExpr" Expr node.
llvm-svn: 55177
Douglas Gregor