This makes use of the recently-added @llvm.assume intrinsic to implement a
__builtin_assume(bool) intrinsic (to provide additional information to the
optimizer). This hooks up __assume in MS-compatibility mode to mirror
__builtin_assume (the semantics have been intentionally kept compatible), and
implements GCC's __builtin_assume_aligned as assume((p - o) & mask == 0). LLVM
now contains special logic to deal with assumptions of this form.
llvm-svn: 217349
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
This innocuous statement to get the identifier info for __va_list_tag
was causing an assertion failure:
NextIsPrevious() && "decl became non-canonical unexpectedly"
if the __va_list_tag identifier was found in a PCH in some
circumstances, because it was looked up before the ASTReader had a Sema
object to use to find existing decls to merge with.
We could possibly move getting the identifier info even later, or make
it lazy if we wanted to, but this seemed like the minimal change.
Now why a PCH would have this identifier in the first place is a bit
mysterious. This seems to be related to the global module index in some
way, because when the test case is built without the global module index
it will not emit an identifier for __va_list_tag into the PCH, but with
the global module index it does.
llvm-svn: 217275
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
before retrying the initialization to produce diagnostics. Otherwise, we may
fail to produce any diagnostics, and silently produce invalid AST in a -Asserts
build. Also add a note to this codepath to make it more clear why we were
trying to create a temporary.
llvm-svn: 217197
In line with SemaOpenMP.cpp, etc. CUDA-specific semantic analysis code goes into
a separate file. This is in anticipation of adding extra functionality here in
the near future.
No change in functionality.
Review: http://reviews.llvm.org/D5160
llvm-svn: 217043
in the super class, do not issue the warning about property
in current class's protocol will not be auto synthesized.
// rdar://18179833
llvm-svn: 216769
Do not warn when property declared in class's protocol will be auto-synthesized
by its uper class implementation because super class has also declared this
property while this class has not. Continue to warn if current class
has declared the property also (because this declaration will not result
in a 2nd synthesis).
rdar://18152478
llvm-svn: 216753
don't mark the field as initialized until the next initializer instead of
instantly. Since this checker is AST based, statements are processed in tree
order instead of following code flow. This can result in different warnings
from just reordering the code. Also changed to use one checker per constructor
instead of creating a new checker per field.
class T {
int x, y;
// Already warns
T(bool b) : x(!b ? (1 + y) : (y = 5)) {}
// New warning added here, previously (1 + y) comes after (y = 5) in the AST
// preventing the warning.
T(bool b) : x(b ? (y = 5) : (1 + y)) {}
};
llvm-svn: 216641
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
In C++11, instantiation of exception specs is deferred. The instantiation is
done in MarkFunctionReferenced(), which wasn't called for non-OdrUsed functions,
which then caused an assert in codegen. Fixes PR19190, see the bug for details.
llvm-svn: 216562
global pool in the course of method selection for
a messaging expression, select one with the most general
return type of 'id'. This is to remove type-mismatch
warning (which is useless) as result of random selection of
method with more restrictive return type. rdar://18095772
llvm-svn: 216560
ACLE 2.0 allows __fp16 to be used as a function argument or return
type. This enables this for AArch64.
This also fixes an existing bug that causes clang to not allow
homogeneous floating-point aggregates with a base type of __fp16. This
is valid for AAPCS64, but not for AAPCS-VFP.
llvm-svn: 216558
the no-arguments case. Don't expand this to an __attribute__((nonnull(A, B,
C))) attribute, since that does the wrong thing for function templates and
varargs functions.
In passing, fix a grammar error in the diagnostic, a crash if
__attribute__((nonnull(N))) is applied to a varargs function,
a bug where the same null argument could be diagnosed multiple
times if there were multiple nonnull attributes referring to it,
and a bug where nonnull attributes would not be accumulated correctly
across redeclarations.
llvm-svn: 216520
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
pattern of an alias template declaration. Use this to merge alias templates
properly when they're members of class template specializations.
llvm-svn: 216437
__vector long is deprecated, but __vector long long is not. As a result, we
cannot check for __vector long (to issue the deprecation warning) as we parse
the type because we need to know how many 'long's we have first.
DeclSpec::Finish seems like a more-appropriate place to perform the check
(which places it with several other similar Altivec vector checks).
Fixes PR20720.
llvm-svn: 216342
We would previously assert (a decl cannot have two DLL attributes) on this code:
template <typename T> struct __declspec(dllimport) S { T f() { return T(); } };
template struct __declspec(dllexport) S<int>;
The problem was that when instantiating, we would take the attribute from the
template even if the instantiation itself already had an attribute.
Also, don't inherit DLL attributes from the template to its members before
instantiation, as the attribute may change.
I couldn't figure out what MinGW does here, so I'm leaving that open. At least
we're not asserting anymore.
llvm-svn: 216340
declared, rather than putting them into the template parameter scope. We
previously had *no record* in the scope for class template declarations, once
those declarations completed and their template parameter scopes were popped.
This in turn caused us to be unable to merge class template declarations that
were declared in the global scope (where we use scope lookup rather than
DeclContext lookup for merging), when loading a module.
llvm-svn: 216311
variable that has regiser constraint "r" is not 64-bit.
General register operands are output using 64-bit "x" register names, regardless
of the size of the variable, unless the asm operand is prefixed with the "%w"
modifier. This surprises and confuses many users who aren't familiar with
aarch64 inline assembly rules.
With this commit, a note and fixit hint are printed which tell the users that
they need modifier "%w" in order to output a "w" register instead of an "x"
register.
<rdar://problem/12764785>
llvm-svn: 216260
Hal Finkel