consider C++ that looks like:
inline int &f(bool b) {
if (b) {
static int i;
return i;
}
static int i;
return i;
}
Both 'i' variables must have distinct (and stable) names for linkage
purposes. The MSVC 2013 ABI would number the variables using a count of
the number of scopes that have been created. However, the final 'i'
returns to a scope that has already been created leading to a mangling
collision.
MSVC 2015 fixes this by giving the second 'i' the name it would have if
it were declared before the 'if'. However, this results in ABI breakage
because the mangled name, in cases where there was no ambiguity, would
now be different.
We implement the new behavior and only enable it if we are targeting the
MSVC 2015 ABI, otherwise the old behavior will be used.
This fixes PR18131.
llvm-svn: 232766
Now that SmallString is a first-class citizen, most SmallString::str()
calls are not required. This patch removes a whole bunch of them, yet
there are lots more.
There are two use cases where str() is really needed:
1) To use one of StringRef member functions which is not available in
SmallString.
2) To convert to std::string, as StringRef implicitly converts while
SmallString do not. We may wish to change this, but it may introduce
ambiguity.
llvm-svn: 232622
contained a typo correction (the auto decl was being marked as dependent
unnecessarily, which triggered an assertion in cases where the size of
the type is needed).
llvm-svn: 232568
Previously, we would error out on this code because the default argument
wasn't parsed until the end of Outer:
struct __declspec(dllexport) Outer {
struct __declspec(dllexport) Inner {
Inner(void *p = 0);
};
};
Now we do the checking on the closing brace of Outer instead of Inner.
llvm-svn: 232519
The MS ABI utilizes a compiler generated function called the "vector
constructor iterator" to construct arrays of objects with
non-trivial constructors/destructors. For this to work, the constructor
must follow a specific calling convention. A thunk must be created if
the default constructor has default arguments, is variadic or is
otherwise incompatible. This thunk is called the default constructor
closure.
N.B. Default constructor closures are only generated if the default
constructor is exported because clang itself does not utilize vector
constructor iterators. Failing to export the default constructor
closure will result in link/load failure if a translation unit compiled
with MSVC is on the import side.
Differential Revision: http://reviews.llvm.org/D8331
llvm-svn: 232229
This is a bit more involved than I anticipated, so here's a breakdown
of the changes:
1. Call ActOnFinishFunctionBody _after_ we parsed =default and
=delete specifiers. Saying that we finished the body before parsing
=default is just wrong. Changing this allows us to use isDefaulted
and isDeleted on a decl in ActOnFinishFunctionBody.
2. Check for -Wmissing-prototypes after we parsed the function body.
3. Disable -Wmissing-prototypes when the Decl isDeleted.
llvm-svn: 232040
Using declarations which are aliases to struct types have their name
used as the struct type's name for linkage purposes. Otherwise, make
sure to give an anonymous struct defined inside a using declaration a
mangling number to disambiguate it from other anonymous structs in the
same context.
This fixes PR22809.
llvm-svn: 231909
of extern "C" declarations. This is simpler and vastly more efficient for
modules builds (we no longer need to load *all* extern "C" declarations to
determine if we have a redeclaration).
No functionality change intended.
llvm-svn: 231538
`isTrackedVar` has been updated to also track records.
`DeclRefExpr`s appearing on the left side of a comma operator are
ignored, while those appearing on the right side are classified as
`Use`.
Patch by Enrico Pertoso.
llvm-svn: 231068
dynamic classes in the translation unit and check whether each one's key
function is defined when we got to the end of the TU (and when we got to the
end of each module). This is really terrible for modules performance, since it
causes unnecessary deserialization of every dynamic class in every compilation.
We now use a much simpler (and, in a modules build, vastly more efficient)
system: when we see an out-of-line definition of a virtual function, we check
whether that function was in fact its class's key function. (If so, we need to
emit the vtable.)
llvm-svn: 230830
Patch improves lookup into dependendt bases of dependent class and adds lookup
into non-dependent bases.
Differential Revision: http://reviews.llvm.org/D7173
llvm-svn: 229817
This fixes PR22492, which is in response to CWG issue #1204.
Per the CWG issue 'contexpr' variables are now allowed in
for range loops.
llvm-svn: 229716
The motivation is to fix a crash on
struct S {} s;
Foo S::~S() { s.~S(); }
What was happening here was that S::~S() was marked as invalid since its
return type is invalid, and as a consequence CheckFunctionDeclaration() wasn't
called and S::~S() didn't get merged into S's implicit destructor. This way,
the class ended up with two destructors, which confused the overload printer
when it suddenly had to print two possible destructors for `s.~S()`.
In addition to fixing the crash, this change also seems to improve diagnostics
in a few other places, see test changes.
Crash found by SLi's bot.
llvm-svn: 229639
This fixes PR22492, which is in response to CWG issue #1204.
Per the CWG issue 'contexpr' variables are now allowed in
for range loops.
llvm-svn: 229543
(or of a lambda init-capture, which is sort-of such a variable). The semantics
of such constructs will change when we implement N3922, so we intend to warn on
this in Clang 3.6 then change the semantics in Clang 3.7.
llvm-svn: 228792
We'd give the VarDecl a CXXConstructExpr even though it is annotated
with an alias attribute. This would make us trip over sanity checking
asserts.
This fixes PR22493.
llvm-svn: 228523
Some standard header files from MSVC2012 use 'mutable' on references, though it is directly prohibited by the standard.
Fix for http://llvm.org/PR22444
Differential Revision: http://reviews.llvm.org/D7370
llvm-svn: 228113
be corrected.
This fixes PR22250, which exposed the bug where if there's more than one
TypoExpr in the arguments, once one failed to be corrected none of the
TypoExprs after it would be handled at all thanks to an early return.
llvm-svn: 226624
Things that are OK:
extern int var1 __attribute((alias("v1")));
static int var2 __attribute((alias("v2")));
Things that are not OK:
int var3 __attribute((alias("v3")));
extern int var4 __attribute((alias("v4"))) = 4;
We choose to accpet:
struct S { static int var5 __attribute((alias("v5"))); };
This code causes assertion failues in GCC 4.8 and ICC 13.0.1, we have
no reason to reject it.
This partially fixes PR22217.
llvm-svn: 226436
Clang currently crashes on
class C {
C() = default;
C() = delete;
};
My cunning plan for fixing this was to change the `if (!FnD)` in
Parser::ParseCXXInlineMethodDef() to `if (!FnD || FnD->isInvalidDecl)` – but
alas, the second constructor decl wasn't marked as invalid. This lets
Sema::MergeFunctionDecl() return true on function redeclarations, which leads
to them being marked invalid.
This also improves error messages when functions are redeclared.
llvm-svn: 226365
We would check the type information from the declaration found by lookup
but we would neglect checking compatibility with the most recent
declaration. This would make it possible for us to not correctly
diagnose inconsistencies with declarations which were made in a
different scope.
llvm-svn: 225934
In the following:
void f(int x) { extern int x; }
The second declaration of 'x' shouldn't be considered a redeclaration of
the parameter.
This is a different approach to r225780.
llvm-svn: 225875
conflicting attribute, warn about the conflict and pick a "winning"
attribute to preserve, instead of emitting an error. This matches the
behavior when the conflicting attributes are on different declarations.
Along the way I discovered that conflicts involving __forceinline were
reported as 'always_inline' (alternate spelling, same attribute) so
fixed that up to report the attribute as spelled in the source.
llvm-svn: 225813
In the following:
void f(int x) { extern int x; }
The second declaration of 'x' shouldn't be considered a redeclaration of
the parameter.
llvm-svn: 225780
There are two things in a C++ program that need to read the vtable pointer:
Constructors and destructors. (A few other operations -- virtual calls,
dynamic cast, rtti -- read the vtable pointer off a this pointer, but for
this they don't need the vtable symbol.) Implicit constructors and destructors
and explicit constructors already marked the vtable as used, but explicit
destructors didn't.
Note that the only thing sema's "mark a class's vtable used" does is to mark all
final overriders of the class as referenced, it does _not_ cause emission of
the vtable itself. This is done on demand by codegen, independent of sema,
since sema might emit functions that are not referenced. (The exception are
vtables that are forced via key functions -- these are forced onto codegen
by sema.)
This bug went unnoticed for years because it doesn't have observable effects
(yet -- I want to change this in PR20337, which is why I noticed this).
r213109 made it so that _calls_ to constructors don't mark the vtable used.
Currently, _calls_ to destructors still mark the vtable used. If that
wasn't the case, this program would tickle the problem:
test.h:
template <typename T>
struct B {
int* p;
virtual ~B() { delete p; }
virtual void f() {}
};
struct __attribute__((visibility("default"))) C {
C();
B<int> m;
};
test2.cc:
#include "test.h"
int main() {
C* c = new C;
delete c;
}
test3.cc:
#include "test.h"
C::C() {}
# This bin/clang++ binary doesn't MarkVTableUsed() for virtual dtor calls:
$ bin/clang++ -shared test3.cc -std=c++11 -O2 -fvisibility=hidden \
-fvisibility-inlines-hidden -o libtest3.dylib
$ bin/clang++ test2.cc -std=c++11 -O2 -fvisibility=hidden \
-fvisibility-inlines-hidden libtest3.dylib
Undefined symbols for architecture x86_64:
"B<int>::f()", referenced from:
vtable for B<int> in test2-af8f4f.o
ld: symbol(s) not found for architecture x86_64
What's happening here is that there's a copy of B's vtable hidden in
libtest3.dylib, because C's constructor caused an implicit instantiation of that
(and implicit constructors generate vtables).
test2.cc calls C's destructDr, which destroys the B<int> member,
which wants to overwrite the vtable back to B (think of B as the base of a class
hierarchy, and of hierarchical destruction -- maybe we shouldn't do the vtable
writing in destructors of final classes), but there's nothing in test2.cc that
marks B's vtable used. So codegen writes out the vtable, but since it wasn't
marked used, sema didn't mark all the virtual functions (in particular f())
as used.
Note that this change makes us reject programs we didn't reject before (see
the included Sema test case), but both gcc and cl also reject this code, and
clang used to reject it before r213109.
llvm-svn: 225761
We have a diagnostic describing that constexpr changed in C++14 when
compiling in C++11 mode. While doing this, it examines the previous
declaration and assumes that it is a function. However it is possible,
in the context of error recovery, for this to not be the case.
llvm-svn: 225518
We assumed that class-scope specializations would result in a
CXXMethodDecl for that class. However, globally qualified functions
will result in normal FunctionDecls.
llvm-svn: 225508
transform.
Also diagnose typos in the initializer of an invalid C++ declaration.
Both issues were hit using the same line of test code, depending on
whether the code was treated as C or C++.
Fixes PR22092.
llvm-svn: 225389
hasDeclaratorForAnonDecl, getDeclaratorForAnonDecl and
getTypedefNameForAnonDecl are expected to handle the case where
NamedDeclOrQualifier holds the wrong type or nothing at all.
llvm-svn: 224912
We expected the type of a TagDecl to be a TagType, not an
InjectedClassNameType. Introduced a helper method, Type::getAsTagDecl,
to abstract away the difference; redefine Type::getAsCXXRecordDecl to be
in terms of it.
llvm-svn: 224898
