Summary: This fixes PR20883.
Test Plan: The patch includes an automated test.
Reviewers: hansw
Differential Revision: http://reviews.llvm.org/D5256
llvm-svn: 217413
The warning warns on TypedefNameDecls -- typedefs and C++11 using aliases --
that are !isReferenced(). Since the isReferenced() bit on TypedefNameDecls
wasn't used for anything before this warning it wasn't always set correctly,
so this patch also adds a few missing MarkAnyDeclReferenced() calls in
various places for TypedefNameDecls.
This is made a bit complicated due to local typedefs possibly being used only
after their local scope has closed. Consider:
template <class T>
void template_fun(T t) {
typename T::Foo s3foo; // YYY
(void)s3foo;
}
void template_fun_user() {
struct Local {
typedef int Foo; // XXX
} p;
template_fun(p);
}
Here the typedef in XXX is only used at end-of-translation unit, when YYY in
template_fun() gets instantiated. To handle this, typedefs that are unused when
their scope exits are added to a set of potentially unused typedefs, and that
set gets checked at end-of-TU. Typedefs that are still unused at that point then
get warned on. There's also serialization code for this set, so that the
warning works with precompiled headers and modules. For modules, the warning
is emitted when the module is built, for precompiled headers each time the
header gets used.
Finally, consider a function using C++14 auto return types to return a local
type defined in a header:
auto f() {
struct S { typedef int a; };
return S();
}
Here, the typedef escapes its local scope and could be used by only some
translation units including the header. To not warn on this, add a
RecursiveASTVisitor that marks all delcs on local types returned from auto
functions as referenced. (Except if it's a function with internal linkage, or
the decls are private and the local type has no friends -- in these cases, it
_is_ safe to warn.)
Several of the included testcases (most of the interesting ones) were provided
by Richard Smith.
(gcc's spelling -Wunused-local-typedefs is supported as an alias for this
warning.)
llvm-svn: 217298
Originally, self reference checking made a double pass over some expressions
to handle reference type checking. Now, allow HandleValue to also check
reference types, and fallback to Visit for unhandled expressions.
llvm-svn: 217203
Naked functions don't have prologues or epilogues, so doing
codegen for anything other than inline assembly would be completely
hit or miss.
Differential Revision: http://reviews.llvm.org/D5183
llvm-svn: 217199
Fix r216438 to catch more complicated self-initialized in std::move. For
instance, "Foo f = std::move(cond ? OtherFoo : (UNUSED_VALUE, f));"
Make sure that BinaryConditionalOperator, ConditionalOperator, BinaryOperator
with comma operator, and OpaqueValueExpr perform the correct usage forwarding
across the three uninitialized value checkers.
llvm-svn: 216627
This shouldn't really be allowed, but it comes up in real code (see PR). As
long as the decl hasn't been used there's no technical difficulty in supporting
it, so downgrade the error to a warning.
Differential Revision: http://reviews.llvm.org/D5087
llvm-svn: 216619
feature is c11 about nested struct declarations must have
struct-declarator-list. Without this change, code
which was meant for c99 breaks. rdar://18125536
llvm-svn: 216469
Changes diagnostic options, language standard options, diagnostic identifiers, diagnostic wording to use c++14 instead of c++1y. It also modifies related test cases to use the updated diagnostic wording.
llvm-svn: 215982
We had two bugs:
- We wouldn't properly warn when a struct/union/enum was mentioned
inside of a record definition if no declarator was provided. We
should have mentioned that this declaration declares nothing.
- We didn't properly support Microsoft's extension where certain
declspecs without declarators would act as anonymous structs/unions.
* We completely ignored the case where such a declspec could be a
union.
* We didn't properly handle the case where a record was defined inside
another record:
struct X {
int a;
struct Y {
int b;
};
};
llvm-svn: 215347
one, perform the import if the types match even if the imported declaration is
hidden. Otherwise, NamedDecl::declarationReplaces will drop one of the name
lookup entries, making the typedef effectively inaccessible from one of the
modules that declared it.
llvm-svn: 215306
This matches MSVC's logic, which seems to be that when the friend
declaration is qualified, it cannot be a declaration of a new symbol
and so the dll linkage doesn't change.
Differential Revision: http://reviews.llvm.org/D4764
llvm-svn: 214774
FunctionProtoType::ExtProtoInfo. Most of the users of these fields don't care
about the other ExtProtoInfo bits and just want to talk about the exception
specification.
llvm-svn: 214450
This flag specifies that we are building an implementation file of the
module <name>, preventing importing <name> as a module. This does not
consider this to be the 'current module' for the purposes of doing
modular checks like decluse or non-modular-include warnings, unlike
-fmodule-name.
This is needed as a stopgap until:
1) we can resolve relative includes to a VFS-mapped module (or can
safely import a header textually and as part of a module)
and ideally
2) we can safely do incremental rebuilding when implementation files
import submodules.
llvm-svn: 213767
Summary:
This pragma is very rare. We could *hypothetically* lower some uses of
it down to @llvm.global_ctors, but given that GlobalOpt isn't able to
optimize prioritized global ctors today, there's really no point.
If we wanted to do this in the future, I would check if the section used
in the pragma started with ".CRT$XC" and had up to two characters after
it. Those two characters could form the 16-bit initialization priority
that we support in @llvm.global_ctors. We would have to teach LLVM to
lower prioritized global ctors on COFF as well.
This should let us compile some silly uses of this pragma in WebKit /
Blink.
Reviewers: rsmith, majnemer
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D4549
llvm-svn: 213593
ExtWarn/Warnings. Mostly the name of the warning was changed to match the
semantics, but in the PR20356 cases, the warning was about valid code, so the
diagnostic was changed from ExtWarn to Warning instead.
llvm-svn: 213443
The relevant portion of C++ standard says [namespace.memdef]p3:
If the name in a friend declaration is neither qualified nor a
template-id and the declaration is a function or an
elaborated-type-specifier, the lookup to determine whether the entity
has been previously declared shall not consider any scopes outside the
innermost enclosing namespace.
MSVC does not implement that rule for types. If there is a type in an
enclosing namespace, they consider an unqualified tag declaration with
the same name to be a redeclaration of the type from another namespace.
Implementing compatibility is a simple matter of disabling our
implementation of this rule for types, which was added in r177473.
Reviewers: rsmith
Differential Revision: http://reviews.llvm.org/D4443
llvm-svn: 212784
gcc supports this behavior and it is pervasively used inside the Linux
kernel.
Note that both gcc and clang will reject code that attempts to do this
in a C++ language mode.
This fixes PR17998.
llvm-svn: 212631
If we want to resolve the remaining FIXMEs here, we probably want to
extend the main lookup mechanism to perform lookup into dependent bases,
but we would have to tread lightly. Adding more name lookup has major
impact on compile time.
If we did extend the main mechanism, we would add a flag to LookupResult
that allows us to find names from dependent base classes where the base
is a specialization of a known template. The final LookupResult would
still return LookupResult::NotFoundInCurrentInstantiation, but it would
have a collection of Decls. If we find a real lookup result, we would
clear the flag and the existing lookup results and begin accumulating
only real lookup results.
We would structure the lookup as a secondary lookup between normal
lookup and typo correction for normal compilation, but for MSVC
compatibility mode, we would always enable this extra lookup into
dependent bases.
llvm-svn: 212566
MSVC appears to perform name lookup into dependent base classes when the
dependent base class has a known primary template. This allows them to
know whether some unqualified ids are types or not, which allows them to
parse more class templates without typename keywords.
We can do the same thing when type name lookup fails, and if we find a
single type decl in one of our dependent base classes, recover as though
the user wrote 'typename MyClass::TypeFromBase'.
This allows us to parse some COM smart pointer classes in wrl/client.h
from the Windows 8 SDK.
Reviewers: rsmith
Differential Revision: http://reviews.llvm.org/D4237
llvm-svn: 212561
C++ [basic.start.main]p1: "It shall have a return type of type int"
ISO C is also clear about this, so only accept 'int' with qualifiers in GNUMode
C.
llvm-svn: 212171
This source range is useful for all kinds of diagnostic QOI and refactoring
work, so let's make it more discoverable.
This commit also makes use of the new function to enhance various diagnostics
relating to return types and resolves an old FIXME.
llvm-svn: 212154
Types defined in function prototype are diagnosed earlier in C++ compilation.
They are put into declaration context where the prototype is introduced. Later on,
when FunctionDecl object is created, these types are moved into the function context.
This patch fixes PR19018 and PR18963.
Differential Revision: http://reviews.llvm.org/D4145
llvm-svn: 211718
Make it return void and delete the dead code in the parser that handled
the case where it might return false. This has been dead since 2010
when John deleted Action.h.
llvm-svn: 211248
CL permits static redeclarations to follow extern declarations. The
storage specifier on the latter declaration has no effect.
This fixes PR20034.
Differential Revision: http://reviews.llvm.org/D4149
llvm-svn: 211238
The compilation pipeline doesn't actually need to know about the high-level
concept of diagnostic mappings, and hiding the final computed level presents
several simplifications and other potential benefits.
The only exceptions are opportunistic checks to see whether expensive code
paths can be avoided for diagnostics that are guaranteed to be ignored at a
certain SourceLocation.
This commit formalizes that invariant by introducing and using
DiagnosticsEngine::isIgnored() in place of individual level checks throughout
lex, parse and sema.
llvm-svn: 211005
Summary:
'sizeof' is a UnaryExprOrTypeTrait, and it can contain either a type or
an expression. This change threads a RecoveryTSI parameter through the
layers between TransformUnaryExprOrTypeTrait the point at which we look
up the type. If lookup finds a single type result after instantiation,
we now build TypeSourceInfo for it just like a normal transformation
would.
This fixes the last error in the hello world ATL app that I've been
working with, and it now links and runs with clang. Please try it and
file bugs!
Reviewers: rsmith
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D4108
llvm-svn: 210855
MSVC delays parsing of default arguments until instantiation. If the
default argument is never used, it is never parsed. We don't model
this.
Instead, if lookup of a type name fails in a template argument context,
we form a DependentNameType, which will be looked up at instantiation
time.
This fixes errors about 'CControlWinTraits' in atlwin.h.
Reviewers: rsmith
Differential Revision: http://reviews.llvm.org/D3995
llvm-svn: 210382
This patch adds support for pointer types in global named registers variables.
It'll be lowered as a pair of read/write_register and inttoptr/ptrtoint calls.
Also adds some early checks on types on SemaDecl to avoid the assert.
Tests changed accordingly. (PR19837)
llvm-svn: 210274
This allows us to compile the following kind of code, which occurs in MSVC
headers:
template <typename> struct S {
__declspec(dllimport) static int x;
};
template <typename T> int S<T>::x;
The definition works similarly to a dllimport inline function definition and
gets available_externally linkage.
Differential Revision: http://reviews.llvm.org/D3998
llvm-svn: 210141
