If a function or variable has a type with no linkage (and is not extern "C"),
any use of it requires a definition within the same translation unit; the idea
is that it is not possible to define the entity elsewhere, so any such use is
necessarily an error.
There is an exception, though: some types formally have no linkage but
nonetheless can be referenced from other translation units (for example, this
happens to anonymous structures defined within inline functions). For entities
with those types, we suppress the diagnostic except under -pedantic.
llvm-svn: 313729
This follows the scheme agreed with Nathan Sidwell, which can be found here:
https://gcc.gnu.org/wiki/cxx-modules?action=AttachFile
This will be proposed to the itanium-cxx-abi list once we have some experience
with how well it works; the ABI for this TS should be considered unstable until
it is part of the Itanium C++ ABI.
llvm-svn: 312467
This is a follow-up to r310436 with actual functional changes. Please
see that commit message for a description of why a cache is appearing
here.
Suggestions for less-bad ways of testing this are appreciated. :)
This fixes PR29160.
llvm-svn: 310437
This is patch 1 in a 2 patch series that aims to fix PR29160. Its goal
is to cache decl visibility/linkage for the duration of each
visibility+linkage query.
The simplest way I can see to do this is to put the visibility
calculation code that needs to (transitively) access this cache into a
class, which is what this patch does. Actual caching will come in patch
2. (Another way would be to keep the cache in ASTContext + manually
invalidate it or something, but that felt way too subtle to me.)
Caching visibility results across multiple queries seems a bit tricky,
since the user can add visibility attributes ~whenever they want, and
these attributes can apparently have far-reaching effects (e.g. class
visibility extends to its members, ...). Because a cache that's dropped
at the end of each top-level query seems to work nearly as well and
doesn't require any eviction logic, I opted for that design.
llvm-svn: 310436
In addition to the formal linkage rules, the Modules TS includes cases where
internal-linkage symbols within a module interface unit can be referenced from
outside the module via exported inline functions / templates. We give such
declarations "module-internal linkage", which is formally internal linkage, but
results in an externally-visible symbol.
llvm-svn: 307434
In C mode clang fails to merge the textually included definition with the one imported from a module. The C lookup rules fail to find the imported definition because its linkage is internal in non C++ mode.
This patch reinstates some of the ODR merging rules for typedefs of anonymous tags for languages other than C++.
Patch by Raphael Isemann and me (D34510).
llvm-svn: 306964
Redeclaration lookup should never find hidden enumerators in C, because
they do not have linkage (C11 6.2.2/6)
The linkage of an enumerator should be VisibleNoLinkage, and
isHiddenDeclarationVisible should be checking hasExternalFormalLinkage.
This is was reviewed as part of D31778, but splitted into a different
commit for clarity.
rdar://problem/31909368
llvm-svn: 306917
a c++17 aligned allocation/deallocation function that is unavailable in
the standard library on Apple platforms.
The aligned functions are implemented only in the following versions or
later versions of the OSes, so clang issues diagnostics if the deployment
target being targeted is older than these:
macosx: 10.13
ios: 11.0
tvos: 11.0
watchos: 4.0
The diagnostics are issued whenever the aligned functions are selected
except when the selected function has a definition in the same file.
If there is a user-defined function available somewhere else, option
-Wno-aligned-allocation-unavailable can be used to silence the
diagnostics.
rdar://problem/32664169
Differential Revision: https://reviews.llvm.org/D34574
llvm-svn: 306722
Summary:
If the first parameter of the function is the ImplicitParamDecl, codegen
automatically marks it as an implicit argument with `this` or `self`
pointer. Added internal kind of the ImplicitParamDecl to separate
'this', 'self', 'vtt' and other implicit parameters from other kind of
parameters.
Reviewers: rjmccall, aaron.ballman
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D33735
llvm-svn: 305075
Modifies FunctionDecl::isThisDeclarationADefinition so that it covers
all the cases checked by FunctionDecl::isDefined. Implements the latter
method by call to isThisDeclarationADefinition.
This change is a part of the patch D30170.
llvm-svn: 304684
rather than waiting until it's queried.
Currently this is only applied to local submodule visibility mode, as we don't
yet allocate storage for the owning module in non-local-visibility modules
compilations.
This reinstates r302965, reverted in r303037, with a fix for the reported
crash, which occurred when reparenting a local declaration to be a child of
a hidden imported declaration (specifically during template instantiation).
llvm-svn: 303224
module immediately
Also revert dependent r302969. This is leading to crashes.
Will provide more details reproduction instructions to Richard.
llvm-svn: 303037
rather than waiting until it's queried.
Currently this is only applied to local submodule visibility mode, as we don't
yet allocate storage for the owning module in non-local-visibility modules
compilations.
llvm-svn: 302965
When looking for the template instantiation pattern of a templated entity,
consistently select the definition of the pattern if there is one. This means
we'll pick the same owning module when we start instantiating a template that
we'll later pick when determining which modules are visible during that
instantiation.
This reinstates r300650, reverted in r300659, with a fix for a regression
reported by Chandler after commit.
llvm-svn: 300938
The original idea was that if the attribute on an operator,
that the return-value unused-ness wouldn't matter. However,
all of the operators except postfix inc/dec return
references! References don't result in this warning
anyway, so those are already excluded.
Differential Revision: https://reviews.llvm.org/D32207
llvm-svn: 300764
modules but exposes much more widespread issues. Example and more
information is on the review thread for r300650.
Original commit summary:
[modules] Properly look up the owning module for an instantiation of a merged template.
llvm-svn: 300659
When looking for the template instantiation pattern of a templated entity,
consistently select the definition of the pattern if there is one. This means
we'll pick the same owning module when we start instantiating a template that
we'll later pick when determining which modules are visible during that
instantiation.
llvm-svn: 300650
The code implements Richard Smith suggestion in comment 3 of the PR.
reviewer: Vassil Vassilev
Differential Revision: https://reviews.llvm.org/D31540
llvm-svn: 300443
In such a case, as when using the NS_ENUM macro, for indexing purposes treat the typedef as 'transparent',
meaning we treat its references as symbols of the underlying tag symbol.
Also provide a libclang API to check for such typedefs.
llvm-svn: 298392
This commit adds support for a new attribute that will be used to
distinguish between extensible and inextensible enums. There are three
main purposes of this attribute:
1. Give better control over when enum-related warnings are issued.
For example, in the code below, clang will not issue a -Wassign-enum
warning if the enum is marked "open":
enum __attribute__((enum_extensibility(closed))) EnumClosed {
B0 = 1, B1 = 10
};
enum __attribute__((enum_extensibility(open))) EnumOpen {
C0 = 1, C1 = 10
};
enum EnumClosed ec = 100; // warning issued
enum EnumOpen eo = 100; // no warning
2. Enable code-completion and debugging tools to offer better
suggestions.
3. Make it easier for swift's clang importer to determine which swift
type an enum should be mapped to.
For more details, see the discussion I started on cfe-dev:
http://lists.llvm.org/pipermail/cfe-dev/2017-February/052748.html
rdar://problem/12764379
rdar://problem/23145650
Differential Revision: https://reviews.llvm.org/D30766
llvm-svn: 298332
It looks like the only use of AddDeallocation is to indirectly call the
destructors of objects. In one case I found
(TypeAliasTemplateDecl::Common), the destructor is a nop, so registering
it to run later seems pointless.
All of the other *::Common types have non-trivial dtors, so deleting the
useless AddDeallocation felt somewhat fragile. Happy to kill it + turn
the is_trivial_dtor check into a static_assert if people think that'd be
better.
llvm-svn: 295029
Summary:
We do not currently track the source locations for exception specifications such
that their source range can be queried through the AST. This leads to trying to
write more complex code to determine the source range for uses like FixItHints
(see D18575 for an example). In addition to use within tools like clang-tidy, I
think this information may become more important to track as exception
specifications become more integrated into the type system.
Patch by Don Hinton.
Reviewers: rsmith
Subscribers: malcolm.parsons, sbarzowski, alexfh, hintonda, cfe-commits
Differential Revision: https://reviews.llvm.org/D20428
llvm-svn: 291771
This saves two pointers from FunctionDecl that were being used for some
rare and questionable C-only functionality. The DeclsInPrototypeScope
ArrayRef was added in r151712 in order to parse this kind of C code:
enum e {x, y};
int f(enum {y, x} n) {
return x; // should return 1, not 0
}
The challenge is that we parse 'int f(enum {y, x} n)' it its own
function prototype scope that gets popped before we build the
FunctionDecl for 'f'. The original change was doing two questionable
things:
1. Saving all tag decls introduced in prototype scope on a TU-global
Sema variable. This is problematic when you have cases like this, where
'x' and 'y' shouldn't be visible in 'f':
void f(void (*fp)(enum { x, y } e)) { /* no x */ }
This patch fixes that, so now 'f' can't see 'x', which is consistent
with GCC.
2. Storing the decls in FunctionDecl in ActOnFunctionDeclarator so that
they could be used in ActOnStartOfFunctionDef. This is just an
inefficient way to move information around. The AST lives forever, but
the list of non-parameter decls in prototype scope is short lived.
Moving these things to the Declarator solves both of these issues.
Reviewers: rsmith
Subscribers: jmolloy, cfe-commits
Differential Revision: https://reviews.llvm.org/D27279
llvm-svn: 289225
Previously we were asserting that this declaration doesn't have a body
*and* won't have a body after we continue parsing. This is too strong
and breaks the go-bindings test during codegen.
llvm-svn: 285412
Summary:
In CUDA compilation, we call isInlineDefinitionExternallyVisible (via
getGVALinkageForFunction) on functions while parsing their definitions.
At the point in time when we call getGVALinkageForFunction, we haven't
yet added the body to the function, so we trip this assert. But as far
as I can tell, this is harmless.
To work around this, we add a new flag to FunctionDecl, "WillHaveBody".
There was other code that was working around the existing assert with a
really awful hack -- this change lets us get rid of that hack.
Reviewers: rsmith, tra
Subscribers: aemerson, cfe-commits
Differential Revision: https://reviews.llvm.org/D25640
llvm-svn: 285410
1) Merge and demote variable definitions when we find a redefinition in
MergeVarDecls, not only when we find one in AddInitializerToDecl (we only reach
the second case if it's the addition of the initializer itself that converts an
existing declaration into a definition).
2) When rebuilding a redeclaration chain for a variable, if we merge two
definitions together, mark the definitions as merged so the retained definition
is made visible whenever the demoted definition would have been.
Original commit message (from r283882):
[modules] PR28752: Do not instantiate variable declarations which are not visible.
Original patch by Vassil Vassilev! Changes listed above are mine.
llvm-svn: 284284
Summary:
Emitting deferred diagnostics during codegen was a hack. It did work,
but usability was poor, both for us as compiler devs and for users. We
don't codegen if there are any sema errors, so for users this meant that
they wouldn't see deferred errors if there were any non-deferred errors.
For devs, this meant that we had to carefully split up our tests so that
when we tested deferred errors, we didn't emit any non-deferred errors.
This change moves checking for deferred errors into Sema. See the big
comment in SemaCUDA.cpp for an overview of the idea.
This checking adds overhead to compilation, because we have to maintain
a partial call graph. As a result, this change makes deferred errors a
CUDA-only concept (whereas before they were a general concept). If
anyone else wants to use this framework for something other than CUDA,
we can generalize at that time.
This patch makes the minimal set of test changes -- after this lands,
I'll go back through and do a cleanup of the tests that we no longer
have to split up.
Reviewers: rnk
Subscribers: cfe-commits, rsmith, tra
Differential Revision: https://reviews.llvm.org/D25541
llvm-svn: 284158
Original message:
"[modules] PR28752: Do not instantiate variable declarations which are not visible.
https://reviews.llvm.org/D24508
Patch developed in collaboration with Richard Smith!"
llvm-svn: 284008
This affects functions with the C++11 [[ noreturn ]] and C11 _Noreturn
specifiers.
Patch by Victor Leschuk!
https://reviews.llvm.org/D23168
llvm-svn: 278942
Summary:
This patch lets you create diagnostics that are emitted if and only if a
particular FunctionDecl is codegen'ed.
This is necessary for CUDA, where some constructs -- e.g. calls from
host+device functions to host functions when compiling for device -- are
allowed to appear in semantically-correct programs, but only if they're
never codegen'ed.
Reviewers: rnk
Subscribers: cfe-commits, tra
Differential Revision: https://reviews.llvm.org/D23241
llvm-svn: 278735
Richard Smith