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
field to be memcpy'd, rather instead of ASTContext::getTypeAlign(<Field Type>).
For packed structs the alignment of a field may be less than the alignment of
the field's type.
<rdar://problem/13338585>
llvm-svn: 176512
[[noreturn]] function are not required to also be [[noreturn]]. We still emit
calls to virtual __attribute__((noreturn)) functions as noreturn; unlike GCC,
we do require overriders to also be noreturn for that attribute.
llvm-svn: 176476
calls and declarations.
LLVM has a default CC determined by the target triple. This is
not always the actual default CC for the ABI we've been asked to
target, and so we sometimes find ourselves annotating all user
functions with an explicit calling convention. Since these
calling conventions usually agree for the simple set of argument
types passed to most runtime functions, using the LLVM-default CC
in principle has no effect. However, the LLVM optimizer goes
into histrionics if it sees this kind of formal CC mismatch,
since it has no concept of CC compatibility. Therefore, if this
module happens to define the "runtime" function, or got LTO'ed
with such a definition, we can miscompile; so it's quite
important to get this right.
Defining runtime functions locally is quite common in embedded
applications.
llvm-svn: 176286
Since r175326 an implicitly hidden template argument can cause a template
installation to become hidden, even if the template itself has an explicit
default visibility. This requires that we keep track of "late" additions
of the visibility attribute.
This is hopefully the last followup change. It just removes the caching of
visibilities from types so that we can see new attributes even after a type has
been used.
llvm-svn: 176164
bitfield. CGBitField::StorageAlignment holds the alignment in chars, but
emitMemcpy had been treating it as if it were held in bits, leading to
underaligned memcpys.
Related to PR15348.
Thanks very much to Chandler for the diagnosis.
llvm-svn: 176163
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
GCC applies a pragma weak to a decl if it matches the mangled name. We used
to apply if it matched the plain name.
This patch is a compromise: we apply the pragma only if it matches the name
and the decl has C language linkage.
llvm-svn: 176110
Weather we should give C language linkage to functions and variables with
internal linkage probably depends on how much code assumes it. The standard
says they should have no language linkage, but gcc and msvc assign them
C language linkage.
This commit removes the hack that was preventing the mangling on static
functions declare in extern C contexts. It is an experiment to see if we
can implement the rules in the standard.
If it turns out that many users depend on these functions and variables
having C language linkage, we should change isExternC instead and try
to convince the CWG to change the standard.
llvm-svn: 175937
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
bitfield related issues.
The original commit broke Takumi's builder. The bug was caused by bitfield sizes
being determined by their underlying type, rather than the field info. A similar
issue with bitfield alignments showed up on closer testing. Both have been fixed
in this patch.
llvm-svn: 175389
linkonce_odr. Emit construction vtables as internal in this case, since the ABI
does not guarantee that they will be availble externally.
llvm-svn: 175330
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
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
move-constructors and move-assignment operators, use memcpy to copy adjacent
POD members.
Previously, classes with one or more Non-POD members would fall back on
element-wise copies for all members, including POD members. This often
generated a lot of IR. Without padding metadata, it wasn't often possible
for the LLVM optimizers to turn the element-wise copies into a memcpy.
This code hasn't yet received any serious tuning. I didn't see any serious
regressions on a self-hosted clang build, or any of the nightly tests, but
I think it's important to get this out in the wild to get more testing.
Insights, feedback and comments welcome.
Many thanks to David Blaikie, Richard Smith, and especially John McCall for
their help and feedback on this work.
llvm-svn: 174919
Adrian Prantl