Blocks, like lambdas, can be written in contexts which are required to be
treated as the same under ODR. Unlike lambdas, it isn't possible to actually
take the address of a block, so the mangling of the block itself doesn't
matter. However, objects like static variables inside a block do need to
be mangled in a consistent way.
There are basically three components here. One, block literals need a
consistent numbering. Two, objects/types inside a block literal need
to be mangled using it. Three, objects/types inside a block literal need
to have their linkage computed correctly.
llvm-svn: 185372
The old implementation of ms_struct in RecordLayoutBuilder was a
complete mess: it depended on complicated conditionals which didn't
really reflect the underlying logic, and placed a burden on users of
the resulting RecordLayout. This commit rips out almost all of the
old code, and replaces it with simple checks in
RecordLayoutBuilder::LayoutBitField.
This commit also fixes <rdar://problem/14252115>, a bug where class
inheritance would cause us to lay out bitfields incorrectly.
llvm-svn: 185018
The goal of this sugar node is to be able to look at an arbitrary
FunctionType and tell if any of the parameters were decayed from an
array or function type. Ultimately this is necessary to implement
Microsoft's C++ name mangling scheme, which mangles decayed arrays
differently from normal pointers.
Reviewers: rsmith
Differential Revision: http://llvm-reviews.chandlerc.com/D1014
llvm-svn: 184763
Template functions (and member functions of class templates) present the same
problem as inline functions. They need to be uniqued, so we need to assign
VisibleNoLinkage linkage to types defined in them.
llvm-svn: 183222
This patch ensures that APValues are deallocated with the ASTContext by
registering a deallocation function for APValues to the ASTContext.
Original version of the patch by James Dennett.
llvm-svn: 183101
The testcase in PR16060 points out that while template arguments can
show that a type is not externally visible, the standards still says
they have external linkage.
In terms of our implementation, it means that we should merge just the
isExternallyVisible bit, not the formal linkage.
llvm-svn: 182962
This brings the number of linkage computations in "clang -cc1" in SemaExpr.ii
from 58426 to 43134. With -emit-llvm the number goes from 161045 to 145461.
llvm-svn: 182823
Before this patch the linkage cache was only used by the entry level function
(getLinkage). The function that does the actual computation (getLVForDecl),
never looked at it.
This means that we would not reuse an entry in the cache when getLVForDecl did
a recursive call. This patch fixes that by adding another computation enum
value for when we don't care about the linkage at all and having getLVForDecl
check the cache in that case.
When running "clang -cc1" over SemaExpr.ii this brings the number of linkage
computations from 93749 to 58426. When running "clang -cc1 -emit-llvm -O3" it
goes from 198708 to 161444.
For SemaExpr.ii at least linkage computation is a small enough percentage of
the work that the time difference was in the noise.
When asserts are enabled this patch also causes clang to check the linkage
cache even on recursive calls.
llvm-svn: 182799
John noticed that the fix for pr15930 (r181981) didn't handle indirect
uses of local types. For example, a pointer to local struct, or a
function that returns it.
One way to implement this would be to recursively look for local
types. This would look a lot like the linkage computation itself for
types.
To avoid code duplication and utilize the existing linkage cache, this
patch just makes the computation of "type with no linkage but
externally visible because it is from an inline function" part of the
linkage computation itself.
llvm-svn: 182711
In the case of inline functions, we have to special case local types
when they are used as template arguments to make sure the template
instantiations are still uniqued in case the function itself is inlined.
llvm-svn: 181981
The most common (non-buggy) case are where such objects are used as
return expressions in bool-returning functions or as boolean function
arguments. In those cases I've used (& added if necessary) a named
function to provide the equivalent (or sometimes negative, depending on
convenient wording) test.
DiagnosticBuilder kept its implicit conversion operator owing to the
prevalent use of it in return statements.
One bug was found in ExprConstant.cpp involving a comparison of two
PointerUnions (PointerUnion did not previously have an operator==, so
instead both operands were converted to bool & then compared). A test
is included in test/SemaCXX/constant-expression-cxx1y.cpp for the fix
(adding operator== to PointerUnion in LLVM).
llvm-svn: 181869
This patch renames getLinkage to getLinkageInternal. Only code that
needs to handle UniqueExternalLinkage specially should call this.
Linkage, as defined in the c++ standard, is provided by
getFormalLinkage. It maps UniqueExternalLinkage to ExternalLinkage.
Most places in the compiler actually want isExternallyVisible, which
handles UniqueExternalLinkage as internal.
llvm-svn: 181677
type returns a lambda defined within itself. The computation of linkage for the
function looked at the linkage of the lambda, and vice versa.
This is solved by not checking whether an 'auto' in a function return type
deduces to a type with unique external linkage. We don't need this check,
because the type deduced for 'auto' doesn't affect whether two
otherwise-identical declarations would name different functions, so we don't
need to give an ostensibly external-linkage function internal linkage for this
reason. (We also don't need unique-external linkage in C++11 onwards at all,
but that's not implemented yet.)
llvm-svn: 181675
I was not able to find a case (other than the fix in r181163) where this
makes a difference, but it is a more obviously correct API to have.
llvm-svn: 181165
Add serialization for captured statements and captured decls. Also add
a const_capture_iterator to CapturedStmt.
Test contributed by Wei Pan
Differential Revision: http://llvm-reviews.chandlerc.com/D727
llvm-svn: 181048
Move the creation of CapturedStmt parameters out of CodeGen and into
Sema, making it easier to customize the outlined function. The
ImplicitParamDecls are stored in the CapturedDecl using an
ASTContext-allocated array.
Differential Revision: http://llvm-reviews.chandlerc.com/D722
llvm-svn: 181043
Instead, we check for one line extern "C" context in linkage computation and
when deciding if a variable is a definition.
This hopefully completes the transition to having "as written" semantics for
hasExternalStorage.
llvm-svn: 180258
For a parameter in a method like this:
-(int)methodWithFn:(void (*)(int *p))fn;
we would return the source range of the type and not include the parameter name.
Fixes rdar://13668626.
llvm-svn: 179660
Add CapturedDecl to be the DeclContext for CapturedStmt, and perform semantic
analysis. Currently captures all variables by reference.
TODO: templates
Author: Ben Langmuir <ben.langmuir@intel.com>
Differential Revision: http://llvm-reviews.chandlerc.com/D433
llvm-svn: 179618
It was being used correctly, but it is a very dangerous API to have around.
Instead, move the logic from the filtering to when we are deciding if we should
link two decls.
llvm-svn: 179523
This mostly reverts 178733, but keeps the tests.
I don't claim to understand how hidden sub modules work or when we need to see
them (is that documented?), but this has the same semantics and avoids adding
hasExternalLinkageUncached which has the same foot gun potential as the old
hasExternalLinkage.
Last but not least, not computing linkage when it is not needed is more
efficient.
llvm-svn: 178739
caching the linkage for a declaration before we set up its redeclaration chain,
when determining whether a declaration could be a redeclaration of something
from an unimported submodule. We actually want to look at the declaration as if
it were not a redeclaration here, so compute the linkage but don't cache it.
llvm-svn: 178733
http://lab.llvm.org:8011/builders/clang-x86_64-darwin10-gdb went back green
before it processed the reverted 178663, so it could not have been the culprit.
Revert "Revert 178663."
This reverts commit 4f8a3eb2ce5d4ba422483439e20c8cbb4d953a41.
llvm-svn: 178682
For variables and functions clang used to store two storage classes. The one
"as written" in the code and a patched one, which, for example, propagates
static to the following decls.
This apparently is from the days clang lacked linkage computation. It is now
redundant and this patch removes it.
llvm-svn: 178663
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
Eli Friedman