DeclIsRequiredFunctionOrFileScopedVar.
This function is part of the public CodeGen interface since it's essentially a CodeGen predicate that is also
needed by the PCH mechanism to determine whether a decl needs to be deserialized during PCH loading for codegen purposes.
This fixes current (and avoids future) codegen-from-PCH bugs.
llvm-svn: 109546
- This issue here is that /usr/include/Blocks.h wants to define some of the
block runtime globals as weak, depending on the target. This doesn't work in
Clang because we aren't using the AST decl for these globals.
- The fix is a pretty gross hack which just watches all the decls for the
specific blocks globals we need to know about; if we see one we use it,
otherwise we use the hand coded type.
In time, I would like to clean this up by changing IRgen to ask Sema/AST for
the decl, which would then be lazily loaded from the builtin table if
necessary. This could be used in a whole host of places in IRgen and would
get rid of a lot of grotty hand coding of LLVM IR; however, we need some
extra Sema support for this as well as support for builtin global variables.
llvm-svn: 108482
at -O0. The only change from the previous patch is that we don't try
to generate virtual method thunks for an available_externally
function.
llvm-svn: 108230
-O0, since we won't be using the definitions for anything anyway. For
lib/System/Path.o when built in Debug+Asserts mode, this leads to a 4%
improvement in compile time (and suppresses 440 function bodies).
<rdar://problem/7987644>
llvm-svn: 108156
emit metadata associating allocas and global values with a Decl*. This feature
is controlled by an option that (intentionally) cannot be enabled on the command
line.
To use this feature, simply set
CodeGenOptions.EmitDeclMetadata = true;
and then interpret the completely underspecified metadata. :)
llvm-svn: 107739
r107173, "fix PR7519: after thrashing around and remembering how all this stuff"
r107216, "fix PR7523, which was caused by the ABI code calling ConvertType instead"
This includes a fix to make ConvertTypeForMem handle the "recursive" case, and call
it as such when lowering function types which have an indirect result.
llvm-svn: 107310
This class only supports name mangling (which is apparently used during C/ObjC
codegen). For now only the Itanium C++ ABI is supported. Patches to add a
second C++ ABI are forthcoming.
llvm-svn: 104630
variables should have that linkage. Otherwise, its static local
variables should have internal linkage. To avoid computing this excessively,
set a function's linkage before we emit code for it.
Previously we were assigning weak linkage to the static variables of
static inline functions in C++, with predictably terrible results. This
fixes that and also gives better linkage than 'weak' when merging is required.
llvm-svn: 104581
methods for which the key function is guaranteed to be in another
translation unit. Unfortunately, this guarantee isn't the case when
dealing with shared libraries that fail to export these virtual method
definitions.
I'm reopening PR6747 so we can consider this again at a later point in
time.
llvm-svn: 103741
"used" (e.g., we will refer to the vtable in the generated code) and
when they are defined (i.e., because we've seen the key function
definition). Previously, we were effectively tracking "potential
definitions" rather than uses, so we were a bit too eager about emitting
vtables for classes without key functions.
The new scheme:
- For every use of a vtable, Sema calls MarkVTableUsed() to indicate
the use. For example, this occurs when calling a virtual member
function of the class, defining a constructor of that class type,
dynamic_cast'ing from that type to a derived class, casting
to/through a virtual base class, etc.
- For every definition of a vtable, Sema calls MarkVTableUsed() to
indicate the definition. This happens at the end of the translation
unit for classes whose key function has been defined (so we can
delay computation of the key function; see PR6564), and will also
occur with explicit template instantiation definitions.
- For every vtable defined/used, we mark all of the virtual member
functions of that vtable as defined/used, unless we know that the key
function is in another translation unit. This instantiates virtual
member functions when needed.
- At the end of the translation unit, Sema tells CodeGen (via the
ASTConsumer) which vtables must be defined (CodeGen will define
them) and which may be used (for which CodeGen will define the
vtables lazily).
From a language perspective, both the old and the new schemes are
permissible: we're allowed to instantiate virtual member functions
whenever we want per the standard. However, all other C++ compilers
were more lazy than we were, and our eagerness was both a performance
issue (we instantiated too much) and a portability problem (we broke
Boost test cases, which now pass).
Notes:
(1) There's a ton of churn in the tests, because the order in which
vtables get emitted to IR has changed. I've tried to isolate some of
the larger tests from these issues.
(2) Some diagnostics related to
implicitly-instantiated/implicitly-defined virtual member functions
have moved to the point of first use/definition. It's better this
way.
(3) I could use a review of the places where we MarkVTableUsed, to
see if I missed any place where the language effectively requires a
vtable.
Fixes PR7114 and PR6564.
llvm-svn: 103718
available_externally linkage, since they may not have been given a
strong definition in another translation unit. Without this patch, the
following test case fails to link with a GCC-compiled libstdc++:
#include <sstream>
int main() { std::basic_stringbuf<char> bs; }
Fixes the last problem with the Boost.IO library.
llvm-svn: 103208
reference type, make sure that the initializer we build is the
of the appropriate type for the *reference*, not for the thing that it
refers to. Fixes PR7050.
llvm-svn: 103115
__cxxabiv1::__fundamental_type_info in every translation
unit. Previously, we would perform name lookup for
__cxxabiv1::__fundamental_type_info at the end of IRGen for a each
translation unit, to determine whether it was present. If so, we we
produce type information for all of the fundamental types. However,
this name lookup causes PCH deserialization of a significant part of the
translation unit, which has a woeful impact on performance.
With this change, we now look at each record type after we've
generated its vtable to see if it is
__cxxabiv1::__fundamental_type_info. If so, we generate type info for
all of the fundamental types. This works because
__cxxabiv1::__fundamental_type_info should always have a key function
(typically the virtual destructor), that will be defined once in the
support library. The fundamental type information will end up there.
Fixes <rdar://problem/7840011>.
llvm-svn: 100772
shadowing it in the GlobalDeclMap. Eliminates the string-uniquing
requirement for mangled names, which should help C++ codegen times a little.
Forces us to do string lookups instead of pointer lookups, which might hurt
codegen times a little across the board. We'll see how it plays out.
Removing the string-uniquing requirement implicitly fixes any bugs like
PR6635 which arose from the fact that we had multiple uniquing tables for
different kinds of identifiers.
llvm-svn: 99012
iterations of this patch gave explicit template instantiation
link-once ODR linkage, which permitted the back end to eliminate
unused symbols. Weak ODR linkage still requires the symbols to be
generated.
llvm-svn: 98441
Clang's support for weakref is now better than llvm-gcc's :-)
We don't introduce a new symbol and we correctly mark undefined references weak only if there is no
definition or regular undefined references in the same file.
llvm-svn: 97733
1) emit base destructors as aliases to their unique base class destructors
under some careful conditions. This is enabled for the same targets that can
support complete-to-base aliases, i.e. not darwin.
2) Emit non-variadic complete constructors for classes with no virtual bases
as calls to the base constructor. This is enabled on all targets and in
theory can trigger in situations that the alias optimization can't (mostly
involving virtual bases, mostly not yet supported).
These are bundled together because I didn't think it worthwhile to split them,
not because they really need to be.
llvm-svn: 96842
and destructors when the two entities are semantically identical, i.e. when
the class has no virtual base classes. We only do this for linkage types
for which aliases are supported, i.e. internal and external, i.e. not linkonce.
llvm-svn: 96451
array allocated using the allocator in ASTContext. This addresses
these strings getting leaked when using a BumpPtrAllocator (in
ASTContext).
Fixes: <rdar://problem/7636765>
llvm-svn: 95853
The standard actually says that such references should have internal linkage,
but gcc doesn't do that, so we probably can't get away with it.
llvm-svn: 95577
over to VarDecl::isThisDeclarationADefinition(), which handles
variables declared with linkage specifications better (among other
things). CMake 2.9 (from CVS) now builds with clang++ and is somewhat
functional.
llvm-svn: 95486
that is in an anonymous namespace, give that function or variable
internal linkage.
This change models an oddity of the C++ standard, where names declared
in an anonymous namespace have external linkage but, because anonymous
namespace are really "uniquely-named" namespaces, the names cannot be
referenced from other translation units. That means that they have
external linkage for semantic analysis, but the only sensible
implementation for code generation is to give them internal
linkage. We now model this notion via the UniqueExternalLinkage
linkage type. There are several changes here:
- Extended NamedDecl::getLinkage() to produce UniqueExternalLinkage
when the declaration is in an anonymous namespace.
- Added Type::getLinkage() to determine the linkage of a type, which
is defined as the minimum linkage of the types (when we're dealing
with a compound type that is not a struct/class/union).
- Extended NamedDecl::getLinkage() to consider the linkage of the
template arguments and template parameters of function template
specializations and class template specializations.
- Taught code generation to rely on NamedDecl::getLinkage() when
determining the linkage of variables and functions, also
considering the linkage of the types of those variables and
functions (C++ only). Map UniqueExternalLinkage to internal
linkage, taking out the explicit checks for
isInAnonymousNamespace().
This fixes much of PR5792, which, as discovered by Anders Carlsson, is
actually the reason behind the pass-manager assertion that causes the
majority of clang-on-clang regression test failures. With this fix,
Clang-built-Clang+LLVM passes 88% of its regression tests (up from
67%). The specific numbers are:
LLVM:
Expected Passes : 4006
Expected Failures : 32
Unsupported Tests : 40
Unexpected Failures: 736
Clang:
Expected Passes : 1903
Expected Failures : 14
Unexpected Failures: 75
Overall:
Expected Passes : 5909
Expected Failures : 46
Unsupported Tests : 40
Unexpected Failures: 811
Still to do:
- Improve testing
- Check whether we should allow the presence of types with
InternalLinkage (in addition to UniqueExternalLinkage) given
variables/functions internal linkage in C++, as mentioned in
PR5792.
- Determine how expensive the getLinkage() calls are in practice;
consider caching the result in NamedDecl.
- Assess the feasibility of Chris's idea in comment #1 of PR5792.
llvm-svn: 95216
by setting the section of the generated global. This is an
optimization done by the code generator, and the code being
removed didn't handle the case when the string contained an
embedded nul (which the code generator does correctly
handle). This is rdar://7589850
llvm-svn: 95003
1. Add helper class for sema checks for target attributes
2. Add helper class for codegen of target attributes
As a proof-of-concept - implement msp430's 'interrupt' attribute.
llvm-svn: 93118
linkage of vtables. Before this, we were emitting RTTI names for
template instantiations with strong external linkage rather than with
weak ODR linkage.
llvm-svn: 92857
- All classes can have a key function; templates don't change that.
non-template classes when computing the key function.
- We always mark all of the virtual member functions of class
template instantiations.
- The vtable for an instantiation of a class template has weak
linkage.
We could probably use available_externally linkage for vtables of
classes instantiated by explicit instantiation declarations (extern
templates), but GCC doesn't do this and I'm not 100% that the ABI
permits it.
llvm-svn: 92753
Argyrios Kyrtzidis