Before this patch we would compute the linkage lazily and cache it. When the
AST was modified in ways that could change the value, we would invalidate the
cache.
That was fairly brittle, since any code could ask for the a linkage before
the correct value was available.
We should change the API to one where the linkage is computed explicitly and
trying to get it when it is not available asserts.
This patch is a first step in that direction. We still compute the linkage
lazily, but instead of invalidating a cache, we assert that the AST
modifications didn't change the result.
llvm-svn: 176999
This fixes a crash in
namespace {
struct X {};
}
extern "C" X test2_b;
X test2_b
before we would assign different linkages to each of the test2_b decls.
llvm-svn: 176869
It is possible that some of the current uses of
"getStorageClassAsWritten() == SC_Extern" should use this but I don't know
enough about SC_PrivateExtern to change and test them.
llvm-svn: 176606
Now that implicitly hidden template arguments can make an instantiation hidden,
it is important to look at more than just the canonical decl of the argument
in order to see if an attribute is available in a more recent decl.
This has the disadvantage of exposing when getExplicitVisibility is called,
but lets us handle cases like
template <typename T>
struct __attribute__((visibility("default"))) barT {
static void zed() {}
};
class foo;
class __attribute__((visibility("default"))) foo;
template struct barT<foo>;
llvm-svn: 176112
Introduce a new AST Decl node "EmptyDecl" to model empty-declaration. Have attributes from attribute-declaration appertain
to the EmptyDecl node by creating the AST representations of these attributes and attach them to the EmptyDecl node so these
attributes can be sema checked just as attributes attached to "normal" declarations.
llvm-svn: 175900
control the visibility of a type for the purposes of RTTI
and template argument restrictions independently of how
visibility propagates to its non-type member declarations.
Also fix r175326 to not ignore template argument visibility
on a template explicit instantiation when a member has
an explicit attribute but the instantiation does not.
The type_visibility work is rdar://11880378
llvm-svn: 175587
We treat this as an alternative to -fvisibility=<?>
which changes the default value visibility to "hidden"
and the default type visibility to "default".
Expose a -cc1 option for changing the default type
visibility, repurposing -fvisibility as the default
value visibility option (also setting type visibility
from it in the absence of a specific option).
rdar://13079314
llvm-svn: 175480
for distinguishing type vs. value visibility.
The changes to the visibility of explicit specializations
are intentional. The change to the "ugly" test case is
a consequence of a sensible implementation, and I am happy
to argue that this is better behavior. Other changes may
or may not be intended; it is quite difficult to divine
intent from some of the code I altered.
I've left behind a comment which I hope explains the
philosophy behind visibility computation.
llvm-svn: 175326
I added hasCLanguageLinkage while fixing some language linkage bugs some
time ago so that I wouldn't have to check all users of isExternC. It turned
out to be a much longer detour than expected, but this patch finally
merges the two again. The isExternC function now implements just the
standard notion of having C language linkage.
llvm-svn: 175119
some cases where functions with no language linkage were being treated as having
C language linkage. In particular, don't warn in
extern "C" {
static NonPod foo();
}
Since getLanguageLinkage checks the language linkage, the linkage computation
cannot use the language linkage. Break the loop by checking just the context
in the linkage computation.
llvm-svn: 175117
the linkage of functions and variables while merging declarations from modules,
and we don't necessarily have enough of the rest of the AST loaded at that
point to allow us to compute linkage, so serialize it instead.
llvm-svn: 174943
visible.
The basic problem here is that a given translation unit can use
forward declarations to form pointers to a given type, say,
class X;
X *x;
and then import a module that includes a definition of X:
import XDef;
We will then fail when attempting to access a member of X, e.g.,
x->method()
because the AST reader did not know to look for a default of a class
named X within the new module.
This implementation is a bit of a C-centric hack, because the only
definitions that can have this property are enums, structs, unions,
Objective-C classes, and Objective-C protocols, and all of those are
either visible at the top-level or can't be defined later. Hence, we
can use the out-of-date-ness of the name and the identifier-update
mechanism to force the update.
In C++, we will not be so lucky, and will need a more advanced
solution, because the definitions could be in namespaces defined in
two different modules, e.g.,
// module 1
namespace N { struct X; }
// module 2
namespace N { struct X { /* ... */ }; }
One possible implementation here is for C++ to extend the information
associated with each identifier table to include the declaration IDs
of any definitions associated with that name, regardless of
context. We would have to eagerly load those definitions.
llvm-svn: 174794
Title: [PR9027] volatile struct bug: member is not loaded at -O;
This is caused by last flag passed to @llvm.memcpy being false,
not honoring that aggregate has at least one 'volatile' data member
(even though aggregate itself has not been qualified as 'volatile'.
As a result, optimization optimizes away the memcpy altogether.
Patch review by John MaCall (I still need to fix up a test though).
llvm-svn: 173535
for template instantiations, and use it to simplify the implementation of
FunctionDecl::isInlined().
This incidentally changes the result of isInlined on a declared-but-not-defined
non-inline member function from true to false. This is sort of a bug fix, but
currently isInlined is only called on function definitions, so it has no visible
effects.
llvm-svn: 173397
it apart from [[gnu::noreturn]] / __attribute__((noreturn)), since their
semantics are not equivalent (for instance, we treat [[gnu::noreturn]] as
affecting the function type, whereas [[noreturn]] does not).
llvm-svn: 172691
The testcase in pr14929 shows that this is extremely hard to do. If we choose
to apply the attribute, that causes the visibility of some decls to change and
that can happen really late (during codegen).
Current gcc warns and ignores the attribute in this testcase with a warning.
This suggest that the correct solution is to find a point in the compilation
where we can compute the visibility and
* assert it was never computed before
* reject any attempts to compute it again in the future (with warnings).
llvm-svn: 172305
It is somewhat hard to test linkage, so I decided to try to add an assert. This
already found some interesting cases where there were different.
llvm-svn: 171585
This patch moves hasCLanguageLinkage to be VarDecl and FunctionDecl methods
so that they can be used from SemaOverload.cpp and then fixes the logic
in Sema::IsOverload.
llvm-svn: 171193
the body of a functions. The problem was that hasBody looks at the entire chain
and causes problems to -fvisibility-inlines-hidden if the cache was not
invalidated.
Original message:
Cache visibility of decls.
This unifies the linkage and visibility caching. I first implemented this when
working on pr13844, but the previous fixes removed the performance advantage of
this one.
This is still a step in the right direction for making linkage and visibility
cheap to use.
llvm-svn: 171053
This unifies the linkage and visibility caching. I first implemented this when
working on pr13844, but the previous fixes removed the performance advantage of
this one.
This is still a step in the right direction for making linkage and visibility
cheap to use.
llvm-svn: 171048
This fixes the storage class of extern decls that are merged with file level
statics. The patch also fixes the linkage computation so that they are
considered internal.
llvm-svn: 170406
Remove pre-standard restriction on explicitly-defaulted copy constructors with
'incorrect' parameter types, and instead just make those special members
non-trivial as the standard requires.
This required making CXXRecordDecl correctly handle classes which have both a
trivial and a non-trivial special member of the same kind.
This also fixes PR13217 by reimplementing DiagnoseNontrivial in terms of the
new triviality computation technology.
llvm-svn: 169667
uncovered.
This required manually correcting all of the incorrect main-module
headers I could find, and running the new llvm/utils/sort_includes.py
script over the files.
I also manually added quite a few missing headers that were uncovered by
shuffling the order or moving headers up to be main-module-headers.
llvm-svn: 169237
Rafael Espindola