Fold -Wreturn-stack-address into general initialization lifetime
checking.

llvm-svn: 337743

[Sema] Allow static_cast<T&&>(e) to check explicit conversions for non-reference-related types.

Summary:
[expr.cast.static] states:
> 3. A glvalue of type “cv1 T1” can be cast to type “rvalue refere

[Sema] Allow static_cast<T&&>(e) to check explicit conversions for non-reference-related types.

Summary:
[expr.cast.static] states:
> 3. A glvalue of type “cv1 T1” can be cast to type “rvalue reference to cv2 T2” if “cv2 T2” is reference-compatible
> with “cv1 T1”. The result refers to the object or the specified base class subobject thereof. If T2 is
> an inaccessible or ambiguous base class of T1, a program that necessitates such a cast is
> ill-formed.
>
> 4. Otherwise, an expression e can be explicitly converted to a type T using a static_cast of the form static_-
> cast<T>(e) if the declaration T t(e); is well-formed, for some invented temporary variable t. [...]

Currently when checking p3 Clang will diagnose `static_cast<T&&>(e)` as invalid if the argument is not reference compatible with `T`. However I believe the correct behavior is to also check p4 in those cases. For example:

```
double y = 42;
static_cast<int&&>(y); // this should be OK. 'int&& t(y)' is well formed
```

Note that we still don't check p4 for non-reference-compatible types which are reference-related since `T&& t(e);` should never be well formed in those cases.


Reviewers: rsmith

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D26231

llvm-svn: 285872

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[Sema] Implement C++14's DR1579: Prefer returning by converting move constructor

Fixes PR28096.

Differential Revision: http://reviews.llvm.org/D21619

llvm-svn: 274291

Clarify the error message when the reason the conversion is not viable is because the returned value does not match the function return type.

llvm-svn: 245979

Update all tests other than Driver/std.cpp to use -std=c++11 rather than
-std=c++0x. Patch by Ahmed Charles!

llvm-svn: 141900

Move test, so it actually tests what it is supposed to (given that we don't have an AST verifier).

llvm-svn: 140620

PR11009: Fix a FIXME which was leading to an assertion failure with rvalue references.

llvm-svn: 140594

Add -fcxx-exceptions to all tests that use C++ exceptions.

llvm-svn: 126599

Pass -fexceptions to all tests that use try/catch/throw.

llvm-svn: 126037

Improve the diagnostic that complains about binding an rvalue
reference to an lvalue.

llvm-svn: 123953

More work to bring reference binding up to the latest C++0x
specification. In particular, an rvalue reference can bind to an
initializer expression that is an lvalue if the referent type and the
init

More work to bring reference binding up to the latest C++0x
specification. In particular, an rvalue reference can bind to an
initializer expression that is an lvalue if the referent type and the
initializer expression type are not reference-related. This is a newer
formulation to the previous "rvalue references can never bind to
lvalues" rule.

llvm-svn: 123952

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Follow through references to catch returned stack addresses, local blocks, label addresses or references to temporaries, e.g:

const int& g2() {
int s1;
int &s2 = s1; // expected-note {{binding r

Follow through references to catch returned stack addresses, local blocks, label addresses or references to temporaries, e.g:

const int& g2() {
int s1;
int &s2 = s1; // expected-note {{binding reference variable 's2' here}}
return s2; // expected-warning {{reference to stack memory associated with local variable 's1' returned}}
}

llvm-svn: 120483

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Revert r120331 since it causes spurious warnings and a possible assertion hit when self-host.

llvm-svn: 120351

Emit warnings if we are returning a reference to a local temporary.
The issue was brought to our attention by Matthieu Monrocq.

llvm-svn: 120331

Make both old and new versions of reference binding use the new classification functions, and updated them for N3092.

llvm-svn: 107301

When pretty-printing tag types, only print the tag if we're in C (and
therefore not creating ElaboratedTypes, which are still pretty-printed
with the written tag).

Most of these testcase changes wer

When pretty-printing tag types, only print the tag if we're in C (and
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

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Change the printing of OR_Deleted overload results to print all the candidates,
not just the viable ones. This is reasonable because the most common use of
deleted functions is to exclude some impli

Change the printing of OR_Deleted overload results to print all the candidates,
not just the viable ones. This is reasonable because the most common use of
deleted functions is to exclude some implicit conversion during calls; users
therefore will want to figure out why some other options were excluded.

Started sorting overload results. Right now it just sorts by location in the
translation unit (after putting viable functions first), but we can do better than
that.

Changed bool OnlyViable parameter to PrintOverloadCandidates to an enum for better
self-documentation.

llvm-svn: 92990

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Improve the diagnostics used to report implicitly-generated class members
as parts of overload sets. Also, refer to constructors as 'constructors'
rather than functions.

Adjust a lot of tests.

llv

Improve the diagnostics used to report implicitly-generated class members
as parts of overload sets. Also, refer to constructors as 'constructors'
rather than functions.

Adjust a lot of tests.

llvm-svn: 92832

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Switch the initialization required by return statements over to the
new InitializationSequence. This fixes some bugs (e.g., PR5808),
changed some diagnostics, and caused more churn than expected. Wha

Switch the initialization required by return statements over to the
new InitializationSequence. This fixes some bugs (e.g., PR5808),
changed some diagnostics, and caused more churn than expected. What's
new:

- InitializationSequence now has a "C conversion sequence" category
and step kind, which falls back to
- Changed the diagnostics for returns to always have the result type
of the function first and the type of the expression second.
CheckSingleAssignmentConstraints to peform checking in C.
- Improved ASTs for initialization of return values. The ASTs now
capture all of the temporaries we need to create, but
intentionally do not bind the tempoary that is actually returned,
so that it won't get destroyed twice.
- Make sure to perform an (elidable!) copy of the class object that
is returned from a class.
- Fix copy elision in CodeGen to properly see through the
subexpressions that occur with elidable copies.
- Give "new" its own entity kind; as with return values and thrown
objects, we don't bind the expression so we don't call a
destructor for it.

Note that, with this patch, I've broken returning move-only types in
C++0x. We'll fix it later, when we tackle NRVO.

llvm-svn: 91669

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Update tests to use %clang_cc1 instead of 'clang-cc' or 'clang -cc1'.
- This is designed to make it obvious that %clang_cc1 is a "test variable"
which is substituted. It is '%clang_cc1' instead o

Update tests to use %clang_cc1 instead of 'clang-cc' or 'clang -cc1'.
- 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

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Reimplement reference initialization (C++ [dcl.init.ref]) using the
new notion of an "initialization sequence", which encapsulates the
computation of the initialization sequence along with diagnostic

Reimplement reference initialization (C++ [dcl.init.ref]) using the
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

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Improve on diagnosing type mismatches because of
lack of viable convesion functions.

llvm-svn: 89216

Parse deleted member functions. Parsing member declarations goes through a different code path that I forgot previously.
Implement the rvalue reference overload dance for returning local objects. Ret

Parse deleted member functions. Parsing member declarations goes through a different code path that I forgot previously.
Implement the rvalue reference overload dance for returning local objects. Returning a local object first tries to find a move constructor now.
The error message when no move constructor is defined (or is not applicable) and the copy constructor is deleted is quite ugly, though.

llvm-svn: 68902

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Reintroduce r67870 (rval ref overloading), since I can't reproduce any test failures on i386 or x86_64. If this fails for someone, please contact me.

llvm-svn: 67999

Revert Sebastian's rvalue patch (r67870) since it caused test failures in

SemaCXX//overload-member-call.cpp
SemaCXX//overloaded-operator.cpp
SemaTemplate//instantiate-method.cpp

llvm-svn: 67912