This makes Clang emit a linkonce_odr definition for 'val' in the code below,
to be compatible with MSVC-compiled code:
struct Foo {
static const int val = 1;
};
Differential Revision: http://llvm-reviews.chandlerc.com/D2233
llvm-svn: 195283
The original decls are created when used. The replacements are created at the
end of the TU in reverse order.
This makes the original order far better for testing. This is particularly
important since the replacement logic could be used even when
-mconstructor-aliases is not used, but that would make many tests hard to read.
This is a fixed version of r194357 which handles replacing a destructor with
another which is an alias to a third one.
llvm-svn: 194452
The original decls are created when used. The replacements are created at the
end of the TU in reverse order.
This makes the original order far better for testing. This is particularly
important since the replacement logic could be used even when
-mconstructor-aliases is not used, but that would make many tests hard to read.
llvm-svn: 194357
This is a small optimization on linux, but should help more on windows
where msvc only outputs one destructor if there would be two identical ones.
llvm-svn: 194095
deallocation function (and the corresponding unsized deallocation function has
been declared), emit a weak discardable definition of the function that
forwards to the corresponding unsized deallocation.
This allows a C++ standard library implementation to provide both a sized and
an unsized deallocation function, where the unsized one does not just call the
sized one, for instance by putting both in the same object file within an
archive.
llvm-svn: 194055
This is a fixed version of r193161. In order to handle
void foo() __attribute__((alias("bar")));
void bar() {}
void zed() __attribute__((alias("foo")));
it is not enough to delay aliases to the end of the TU, we have to do two
passes over them to find if they are defined or not.
This can be implemented by producing alias as we go and just doing the second
pass at the end. This has the advantage that other parts of clang that were
expecting alias to be processed in order don't have to be changed.
This patch also handles cyclic aliases.
llvm-svn: 193188
This reverts commit r193161.
It broke
void foo() __attribute__((alias("bar")));
void bar() {}
void zed() __attribute__((alias("foo")));
Looks like we have to fix pr17639 first :-(
llvm-svn: 193162
names. For example, with this patch we now reject
void f1(void) __attribute__((alias("g1")));
This patch is implemented in CodeGen. It is quiet a bit simpler and more
compatible with gcc than implementing it in Sema. The downside is that the
errors only fire during -emit-llvm.
llvm-svn: 193161
An updated version of r191586 with bug fix.
Struct-path aware TBAA generates tags to specify the access path,
while scalar TBAA only generates tags to scalar types.
We should not generate a TBAA tag with null being the first field. When
a TBAA type node is null, the tag should be null too. Make sure we
don't decorate an instruction with a null TBAA tag.
Added a testing case for the bug reported by Richard with -relaxed-aliasing
and -fsanitizer=thread.
llvm-svn: 192145
A quirk of AST representation leads to class template static data member
definitions being visited twice during Clang IRGen resulting in
duplicate (benign) initializers.
Discovered while investigating a possibly-related debug info bug tickled
by the duplicate emission of these members & their associated debug
info.
With thanks to Richard Smith for help investigating, understanding, and
helping with the fix.
llvm-svn: 189996
Refactor the underlying code a bit to remove unnecessary calls to
"hasErrorOccurred" & make them consistently at all the entry points to
the IRGen ASTConsumer.
llvm-svn: 188707
Summary:
We would crash in CodeGen::CodeGenModule::EmitUuidofInitializer
because our attempt to enter CodeGen::CodeGenModule::EmitConstantValue
will be foiled: the type of the constant value is incomplete.
Instead, create an unnamed type with the proper layout on all platforms.
Punt the problem of wrongly defined struct _GUID types to the user.
(It's impossible because the TU may never get to see the type and thus
we can't verify that it is suitable.)
This fixes PR16856.
Reviewers: rsmith, rnk, thakis
Reviewed By: rnk
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1375
llvm-svn: 188481
Summary:
It seems that __uuidof introduces a global extern "C" declaration of
type __s_GUID. However, our implementation of __uuidof does not provide
such a declaration and thus must open-code the mangling for __uuidof in
template parameters.
This allows us to codegen scoped COM pointers and other such things.
This fixes PR16836.
Depends on D1356.
Reviewers: rnk, cdavis5x, rsmith
Reviewed By: rnk
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1357
llvm-svn: 188252
We mangled them like:
L___uuid_12345678-1234-1234-1234-123456789abc
We should've mangled them like:
__GUID_12345678_1234_1234_1234_123456789abc
Furthermore, they are external symbols.
llvm-svn: 188053
Based on Peter Collingbourne's destructor patches.
Prior to this change, clang was considering ?1 to be the complete
destructor and the base destructor, which was wrong. This lead to
crashes when clang tried to emit two LLVM functions with the same name.
In this ABI, TUs with non-inline dtors might not emit a complete
destructor. They are emitted as inline thunks in TUs that need them,
and they always delegate to the base dtors of the complete class and its
virtual bases. This change uses the DeferredDecls machinery to emit
complete dtors as needed.
Currently in clang try body destructors can catch exceptions thrown by
virtual base destructors. In the Microsoft C++ ABI, clang may not have
the destructor definition, in which case clang won't wrap the virtual
virtual base destructor calls in a try-catch. Diagnosing this in user
code is TODO.
Finally, for classes that don't use virtual inheritance, MSVC always
calls the base destructor (?1) directly. This is a useful code size
optimization that avoids emitting lots of extra thunks or aliases.
Implementing it also means our existing tests continue to pass, and is
consistent with MSVC's output.
We can do the same for Itanium by tweaking GetAddrOfCXXDestructor, but
it will require further testing.
Reviewers: rjmccall
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1066
llvm-svn: 186828
optimize, to follow the permissions granted in N3664. Under those rules, only
calls generated by new-expressions and delete-expressions are permitted to be
optimized, and direct calls to ::operator new and ::operator delete must be
treated as normal calls.
llvm-svn: 186799
The key insight here is that weak linkage for a static local variable
should always mean linkonce_odr, because every file that needs it will
generate a definition. We don't actually care about the precise linkage
of the parent context. I feel a bit silly that I didn't realize this before.
llvm-svn: 185381
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
This allows clang to use the backend parameter attribute 'returned' when generating 'this'-returning constructors and destructors in ARM and MSVC C++ ABIs.
llvm-svn: 185291
These options will add a module flag with name "Dwarf Version".
The behavior flag is currently set to Warning, so when two values disagree,
a warning will be emitted.
llvm-svn: 184276
The backend will now use the generic 'returned' attribute to form tail calls where possible, as well as avoid save-restores of 'this' in some cases (specifically the cases that matter for the ARM C++ ABI).
This patch also reverts a prior front-end only partial implementation of these optimizations, since it's no longer required.
llvm-svn: 184205
Introduce CXXStdInitializerListExpr node, representing the implicit
construction of a std::initializer_list<T> object from its underlying array.
The AST representation of such an expression goes from an InitListExpr with a
flag set, to a CXXStdInitializerListExpr containing a MaterializeTemporaryExpr
containing an InitListExpr (possibly wrapped in a CXXBindTemporaryExpr).
This more detailed representation has several advantages, the most important of
which is that the new MaterializeTemporaryExpr allows us to directly model
lifetime extension of the underlying temporary array. Using that, this patch
*drastically* simplifies the IR generation of this construct, provides IR
generation support for nested global initializer_list objects, fixes several
bugs where the destructors for the underlying array would accidentally not get
invoked, and provides constant expression evaluation support for
std::initializer_list objects.
llvm-svn: 183872
handle temporaries which have been lifetime-extended to static storage duration
within constant expressions. This correctly handles nested lifetime extension
(through reference members of aggregates in aggregate initializers) but
non-constant-expression emission hasn't yet been updated to do the same.
llvm-svn: 183283
This removes a FIXME in CodeGenModule::SetLLVMFunctionAttributesForDefinition.
When a function is declared cold we can now generate the IR attribute in
addition to marking the function to be optimized for size.
I tried adding a separate CHECK in the existing test, but it was
failing. I suppose CHECK matches one line exactly once? This would be
a problem if the attributes are listed in a different order, though they
seem to be sorted.
llvm-svn: 182666
This resolves the last of the PR14606 failures in the GDB 7.5 test
suite. (but there are still unresolved issues in the imported_decl case
- we need to implement optional/lazy decls for functions & variables
like we already do for types)
llvm-svn: 182329
selectany only applies to externally visible global variables. It has
the effect of making the data weak_odr.
The MSDN docs suggest that unused definitions can only be dropped at
linktime, so Clang uses weak instead of linkonce. MSVC optimizes away
references to constant selectany data, so it must assume that there is
only one definition, hence weak_odr.
Reviewers: espindola
Differential Revision: http://llvm-reviews.chandlerc.com/D814
llvm-svn: 182266
