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
Templates don't have key functions (cf computeKeyFunction() in
RecordLayoutBuilder.cpp), so don't have something that looks like one.
Also, instead of a vcall to force generation of the vtable, just construct
the object. This is how the repro on PR5557 (what the test is for) worked too.
llvm-svn: 225741
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
The FIXME in the test is caused by TemplateDeclInstantiator::VisitCXXRecordDecl
returning a nullptr instead of creating an invalid decl. This is a common
pattern across all of TemplateDeclInstantiator, so I'm not comfortable changing
it. The reason it's not invalid in the class template is due to support for an
MSVC extension, see r137573.
llvm-svn: 225071
Consider a template class with attributes on a method, and an explicit
specialization of that method:
template <int>
struct A {
void foo() final;
};
template <>
void A<0>::foo() {}
In this example, the attribute is `final`, but it might also be an
__attribute__((visibility("foo"))), noreturn, inline, etc. clang's current
behavior is to strip all attributes, which for some attributes is wrong
(the snippet above allows a subclass of A<0> to override the final method, for
example) and for others disagrees with gcc.
So stop dropping attributes. r95845 added this code without a test case, and
r176728 added the code for dropping attributes on parameters (with tests, but
they still pass).
As an additional wrinkle, do drop dllimport and dllexport, since that's how
these two attributes work. (This is covered by existing tests.)
Fixes PR21942.
The approach is by Richard Smith, initial analysis and typing was done by me.
With this, clang also matches GCC and EDG on all attributes Richard tested.
llvm-svn: 224651
This reverts commit r224451. It caused us to reject some valid existing
code.
This code appears to run in non-error cases as well as error cases. If
the scope of a DependentScopeDeclRefExpr is still incomplete it probably
means we still have more instantiation to do.
llvm-svn: 224526
exact type match for deduced template arguments, and be sure to produce correct
canonical TemplateArgument representations to enable correct redeclaration
matching.
llvm-svn: 224456
A DependentScopeDeclRefExpr should always have a nested name specifier.
During template instantiation, if we found that the named context was
incomplete, we would previously build a DependentScopeDeclRefExpr with
an empty qualifier.
This error recovery path has been asserting for some time. The other
error codepaths use ExprError, so we can do the same.
Fixes PR21864.
llvm-svn: 224451
ignore it during overload resolution when initializing
X from a value of type cv X.
Previously, our rule here only ignored specializations
of constructor templates. That's probably because the
standard says that constructors are outright ill-formed
if their first parameter is literally X and they're
callable with one argument. However, Clang only
enforces that prohibition against non-implicit
instantiations; I'm not sure why, but it seems to be
deliberate. Given that, the most sensible thing to
do is to just ignore the "illegal" constructor
regardless of where it came from.
Also, stop ignoring such constructors silently:
print a note explaining why they're being ignored.
Fixes <rdar://19199836>.
llvm-svn: 224205
We don't yet support pointer-to-member template arguments that have undergone
pointer-to-member conversions, mostly because we don't have a mangling for them yet.
llvm-svn: 222807
If there is more than one TypoExpr within the expr being transformed and
any but the last TypoExpr seen don't have any viable candidates, the
tree transform will be aborted early and the remaining TypoExprs are
never seen and hence never diagnosed. This adds a simple
RecursiveASTVisitor to find all of the TypoExprs to be diagnosed in the
case where typo correction of the entire expr fails (and the result of
the tree transform is an ExprError).
llvm-svn: 222465
Sema::ActOnIdExpression to use the new functionality.
Among other things, this allows recovery in several cases where it
wasn't possible before (e.g. correcting a mistyped static_cast<>).
llvm-svn: 222464
Specifically, when we have this situation:
struct A {
template <typename T> struct B {
int m1 = sizeof(A);
};
B<int> m2;
};
We can't parse m1's initializer eagerly because we need A to be
complete. Therefore we wait until the end of A's class scope to parse
it. However, we can trigger instantiation of B before the end of A,
which will attempt to instantiate the field decls eagerly, and it would
build a bad field decl instantiation that said it had an initializer but
actually lacked one.
Fixed by deferring instantiation of default member initializers until
they are needed during constructor analysis. This addresses a long
standing FIXME in the code.
Fixes PR19195.
Reviewed By: rsmith
Differential Revision: http://reviews.llvm.org/D5690
llvm-svn: 222192
expansion into a parameter pack; we know that we're still filling in that
parameter's arguments. Previously, if we hit this case for an alias template,
we'd try to substitute using non-canonical template arguments.
llvm-svn: 221832
than the type of a function declaration). We previously didn't instantiate
these at all! This also covers the pathological case where the only mention of
a parameter pack is within the exception specification; this gives us a second
way (other than alias templates) to reach the horrible state where a type
contains an unexpanded pack, but its canonical type does not.
This is a re-commit of r219977:
r219977 was reverted in r220038 because it hit a wrong-code bug in GCC 4.7.2.
(That's gcc.gnu.org/PR56135, and affects any implicit lambda-capture of
'this' within a template.)
r219977 was a re-commit of r217995, r218011, and r218053:
r217995 was reverted in r218058 because it hit a rejects-valid bug in MSVC.
(Incorrect overload resolution in the presence of using-declarations.)
It was re-committed in r219977 with a workaround for the MSVC rejects-valid.
r218011 was a workaround for an MSVC parser bug. (Incorrect desugaring of
unbraced range-based for loop).
llvm-svn: 221750
penultimate parameter of a template parameter list, where the last parameter is
itself a pack, and build a bogus empty final pack argument.
llvm-svn: 221748
This is a new form of expression of the form:
(expr op ... op expr)
where one of the exprs is a parameter pack. It expands into
(expr1 op (expr2onwards op ... op expr))
(and likewise if the pack is on the right). The non-pack operand can be
omitted; in that case, an empty pack gives a fallback value or an error,
depending on the operator.
llvm-svn: 221573
According to C++ standard if an exception-specification is specified in an explicit instantiation directive, it shall be compatible with the exception-specifications of other declarations of that function. This patch adds checks for this.
Differential Revision: http://reviews.llvm.org/D5822
llvm-svn: 221448
template specialization type dependent, even if it has no dependent template
arguments. I've filed a corresponding bug against the C++ standard.
llvm-svn: 220088
of a member function of a class template that is defined outside the template.
This substitution can actually fail in some weird cases.
llvm-svn: 220085
It broke some builders. I guess it'd be reproducible with --vg.
Failing Tests (3):
Clang :: CXX/except/except.spec/p1.cpp
Clang :: SemaTemplate/instantiate-exception-spec-cxx11.cpp
Clang :: SemaTemplate/instantiate-exception-spec.cpp
llvm-svn: 220038
reverted in r218058 because they triggered a rejects-valid bug in MSVC.
Original commit message from r217995:
Instantiate exception specifications when instantiating function types (other
than the type of a function declaration). We previously didn't instantiate
these at all! This also covers the pathological case where the only mention of
a parameter pack is within the exception specification; this gives us a second
way (other than alias templates) to reach the horrible state where a type
contains an unexpanded pack, but its canonical type does not.
llvm-svn: 219977
Fix for clang crash when instantiating a template with qualified lookup for members in non-class types.
Differential Revision: http://reviews.llvm.org/D5769
llvm-svn: 219897
r218053: Use exceptions() instead of getNumExceptions()/getExceptionType() to avoid
r218011: Work around MSVC parser bug by putting redundant braces around the body of
r217997: Skip parens when detecting whether we're instantiating a function declaration.
r217995: Instantiate exception specifications when instantiating function types (other
The Windows build was broken for 16 hours and no one had any good ideas of how to
fix it. Reverting for now to make the builders green. See the cfe-commits thread [1] for
more info.
This was the build error (from [2]):
C:\bb-win7\ninja-clang-i686-msc17-R\llvm-project\clang\lib\Sema\SemaTemplateInstantiate.cpp(1590) : error C2668: '`anonymous-namespace'::TemplateInstantiator::TransformFunctionProtoType' : ambiguous call to overloaded function
C:\bb-win7\ninja-clang-i686-msc17-R\llvm-project\clang\lib\Sema\SemaTemplateInstantiate.cpp(1313): could be 'clang::QualType `anonymous-namespace'::TemplateInstantiator::TransformFunctionProtoType<clang::Sema::SubstFunctionDeclType::<lambda_756edcbe7bd5c7584849a6e3a1491735>>(clang::TypeLocBuilder &,clang::FunctionProtoTypeLoc,clang::CXXRecordDecl *,unsigned int,Fn)'
with
[
Fn=clang::Sema::SubstFunctionDeclType::<lambda_756edcbe7bd5c7584849a6e3a1491735>
]
c:\bb-win7\ninja-clang-i686-msc17-r\llvm-project\clang\lib\sema\TreeTransform.h(4532): or 'clang::QualType clang::TreeTransform<Derived>::TransformFunctionProtoType<clang::Sema::SubstFunctionDeclType::<lambda_756edcbe7bd5c7584849a6e3a1491735>>(clang::TypeLocBuilder &,clang::FunctionProtoTypeLoc,clang::CXXRecordDecl *,unsigned int,Fn)'
with
[
Derived=`anonymous-namespace'::TemplateInstantiator,
Fn=clang::Sema::SubstFunctionDeclType::<lambda_756edcbe7bd5c7584849a6e3a1491735>
]
while trying to match the argument list '(clang::TypeLocBuilder, clang::FunctionProtoTypeLoc, clang::CXXRecordDecl *, unsigned int, clang::Sema::SubstFunctionDeclType::<lambda_756edcbe7bd5c7584849a6e3a1491735>)'
1. http://lists.cs.uiuc.edu/pipermail/cfe-commits/Week-of-Mon-20140915/115011.html
2. http://bb.pgr.jp/builders/ninja-clang-i686-msc17-R/builds/10515/steps/build_clang_tools_1/logs/stdio
llvm-svn: 218058
than the type of a function declaration). We previously didn't instantiate
these at all! This also covers the pathological case where the only mention of
a parameter pack is within the exception specification; this gives us a second
way (other than alias templates) to reach the horrible state where a type
contains an unexpanded pack, but its canonical type does not.
llvm-svn: 217995
Changes diagnostic options, language standard options, diagnostic identifiers, diagnostic wording to use c++14 instead of c++1y. It also modifies related test cases to use the updated diagnostic wording.
llvm-svn: 215982
Previously, any undeclared unqualified id starting a nested name
specifier in a dependent context would have its lookup retried during
template instantiation. Now we limit that retry hack to methods of a
class with dependent bases. Free function templates in particular are
no longer affected by this hack.
Also, diagnose this as a Microsoft extension. This has the downside that
template authors may see this warning *and* an error during
instantiation time about this identifier. Fixing that will probably
require formalizing some kind of "delayed" identifier, instead of our
ad-hoc solutions of forming dependent AST nodes when lookup fails.
Based on a patch by Kim Gräsman!
Differential Revision: http://reviews.llvm.org/D4854
llvm-svn: 215683
Commit r213935 added additional validation of register constants/size for AArch64 and because these tests which contain Intel assembler the new validation caused these tests to fail when the default target is changed to an AArch64 target.
llvm-svn: 214706
If, during the initial parse of a template, we perform aggregate initialization
and form an implicit value initialization for an array type, then when we come
to instantiate the template and redo the initialization step, we would try to
match the implicit value initialization up against an array *element*, not to
the complete array.
Remarkably, we've had this bug since ~the dawn of time, but only noticed it
recently.
llvm-svn: 213332
This fixes compilation errors about incomplete types used with WebKit's
RefPtr template. Simply calling an out of line constructor should not
instantiate all inline and defaulted virtual methods.
Tested by building and testing several big piles of code on Linux.
Reviewers: rsmith
Differential Revision: http://reviews.llvm.org/D4429
llvm-svn: 213109
If we want to resolve the remaining FIXMEs here, we probably want to
extend the main lookup mechanism to perform lookup into dependent bases,
but we would have to tread lightly. Adding more name lookup has major
impact on compile time.
If we did extend the main mechanism, we would add a flag to LookupResult
that allows us to find names from dependent base classes where the base
is a specialization of a known template. The final LookupResult would
still return LookupResult::NotFoundInCurrentInstantiation, but it would
have a collection of Decls. If we find a real lookup result, we would
clear the flag and the existing lookup results and begin accumulating
only real lookup results.
We would structure the lookup as a secondary lookup between normal
lookup and typo correction for normal compilation, but for MSVC
compatibility mode, we would always enable this extra lookup into
dependent bases.
llvm-svn: 212566
MSVC appears to perform name lookup into dependent base classes when the
dependent base class has a known primary template. This allows them to
know whether some unqualified ids are types or not, which allows them to
parse more class templates without typename keywords.
We can do the same thing when type name lookup fails, and if we find a
single type decl in one of our dependent base classes, recover as though
the user wrote 'typename MyClass::TypeFromBase'.
This allows us to parse some COM smart pointer classes in wrl/client.h
from the Windows 8 SDK.
Reviewers: rsmith
Differential Revision: http://reviews.llvm.org/D4237
llvm-svn: 212561
When adding the implicit compound statement (required for Codegen?), the
end location was previously overridden by the start location, probably
based on the assumptions:
* The location of the compound statement should be the member's location
* The compound statement if present is the last element of a FunctionDecl
This patch changes the location of the compound statement to the
member's end location.
Code review: http://reviews.llvm.org/D4175
llvm-svn: 211344
Summary:
'sizeof' is a UnaryExprOrTypeTrait, and it can contain either a type or
an expression. This change threads a RecoveryTSI parameter through the
layers between TransformUnaryExprOrTypeTrait the point at which we look
up the type. If lookup finds a single type result after instantiation,
we now build TypeSourceInfo for it just like a normal transformation
would.
This fixes the last error in the hello world ATL app that I've been
working with, and it now links and runs with clang. Please try it and
file bugs!
Reviewers: rsmith
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D4108
llvm-svn: 210855
We currently allow unqualified lookup for instance methods but not
static methods because we can't recover with a semantic 'this->'
insertion.
ATL headers have static methods that do unqualified lookup into
dependent base classes. The pattern looks like:
template <typename T> struct Foo : T {
static int *getBarFromT() { return Bar; }
};
Now we recover as if the user had written:
template <typename T> struct Foo : T {
static int *getBarFromT() { return Foo::Bar; }
};
... which will eventually look up Bar in T at instantiation time.
Now we emit a diagnostic in both cases, and delay lookup in other
contexts where 'this' is available and refers to a class with dependent
bases.
Reviewed by: rsmith
Differential Revision: http://reviews.llvm.org/D4079
llvm-svn: 210611
While matching a non-type template argument against a known template
type parameter we now modify the AST's TemplateArgumentLoc to assume the
user wrote typename. Under -fms-compatibility, we downgrade our
diagnostic from an error to an extwarn.
Reviewed by: rsmith
Differential Revision: http://reviews.llvm.org/D4049
llvm-svn: 210607
MSVC delays parsing of default arguments until instantiation. If the
default argument is never used, it is never parsed. We don't model
this.
Instead, if lookup of a type name fails in a template argument context,
we form a DependentNameType, which will be looked up at instantiation
time.
This fixes errors about 'CControlWinTraits' in atlwin.h.
Reviewers: rsmith
Differential Revision: http://reviews.llvm.org/D3995
llvm-svn: 210382
results in a template having too many arguments, but all the trailing arguments
are packs, that's OK if we have a partial pack substitution: the trailing pack
expansions may end up empty.
llvm-svn: 210350
The conventional form is '<action> to silence this warning'.
Also call the diagnostic an 'issue' rather than a 'message' because the latter
term is more widely used with reference to message expressions.
llvm-svn: 209052
that looks like it might be an explicit specialization, don't recover as an
explicit specialization (bypassing the check that would reject that).
llvm-svn: 206444
Summary:
Declaring a function as inline after it has been defined is in violation
of [dcl.fct.spec]p4. The program would get a strong definition instead
of getting a function with linkonce_odr linkage.
Reviewers: rsmith
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D3220
llvm-svn: 205129
const-qualified parameter type and the defined with a non-const-qualified
parameter type, the parameter is not const inside its body. Ensure that
the type we use when instantiating the body is the right one. Patch by
suyog sarda!
This is still rather unsatisfactory; it seems like it might be better to
instantiate at least the function parameters, and maybe the complete function
declaration, when we instantiate the definition for such a member function
(instead of reusing the declaration from inside the instantiated class
definition).
llvm-svn: 203741
null comparison when the pointer is known to be non-null.
This catches the array to pointer decay, function to pointer decay and
address of variables. This does not catch address of function since this
has been previously used to silence a warning.
Pointer to bool conversion is under -Wbool-conversion.
Pointer to null comparison is under -Wtautological-pointer-compare, a sub-group
of -Wtautological-compare.
void foo() {
int arr[5];
int x;
// warn on these conditionals
if (foo);
if (arr);
if (&x);
if (foo == null);
if (arr == null);
if (&x == null);
if (&foo); // no warning
}
llvm-svn: 202216
The language forbids defining enums in prototypes, so this check is normally
redundant, but if an enum is defined during template instantiation it should
not be added to the prototype scope.
While at it, clean up the code that deals with tag definitions in prototype
scope and expand the visibility warning to cover the case where an anonymous
enum is defined.
Differential Revision: http://llvm-reviews.chandlerc.com/D2742
llvm-svn: 201927
It was previously thought that Sema::InstantiateClass could not fail
from within this point in instantiate.
However, it can happen if the class is invalid some way (i.e. invalid
base specifier).
This fixes PR18907.
Differential Revision: http://llvm-reviews.chandlerc.com/D2850
llvm-svn: 201913
template parameters, don't look for parameters of outer templates. If a problem
is found in a default template argument, point the diagnostic at the partial
specialization (with a note pointing at the default argument) instead of
pointing it at the default argument and leaving it unclear which partial
specialization os problematic.
llvm-svn: 201031
This makes the C++ ABI depend entirely on the target: MS ABI for -win32 triples,
Itanium otherwise. It's no longer possible to do weird combinations.
To be able to run a test with a specific ABI without constraining it to a
specific triple, new substitutions are added to lit: %itanium_abi_triple and
%ms_abi_triple can be used to get the current target triple adjusted to the
desired ABI. For example, if the test suite is running with the i686-pc-win32
target, %itanium_abi_triple will expand to i686-pc-mingw32.
Differential Revision: http://llvm-reviews.chandlerc.com/D2545
llvm-svn: 199250
In preparation for making the Win32 triple imply MS ABI mode,
make all tests pass in this mode, or make them use the Itanium
mode explicitly.
Differential Revision: http://llvm-reviews.chandlerc.com/D2401
llvm-svn: 199130
is specialized by an explicit specialization, start from the first declaration
in case we've got a member of a class template (redeclarations might not number
the template parameters the same way).
Our recover here is still far from ideal.
llvm-svn: 197305
This patch was submitted to the list for review and didn't receive a LGTM.
(In fact one explicit objection and one query were raised.)
This reverts commit r197295.
llvm-svn: 197299
The tests were perhaps made too relaxed in r197164 when we switched to the new
MinGW ABI. This makes sure we check explicitly for an optional thiscall
attribute and nothing else.
We should still look into whether we should print these attributes at all in
these cases.
llvm-svn: 197252
Previously, a line like
// expected-error-re {{foo}}
treats the entirety of foo as a regex. This is inconvenient when matching type
names containing regex characters. For example, to match
"void *(class test8::A::*)(void)" inside such a regex, one would have to type
"void \*\(class test8::A::\*\)\(void\)".
This patch changes the semantics of expected-error-re to only treat the parts
of the directive wrapped in double curly braces as regexes. This avoids the
escaping problem and leads to nicer patterns for those cases; see e.g. the
change to test/Sema/format-strings-scanf.c.
(The balanced search for closing }} of a directive also makes us handle the
full directive in test\SemaCXX\constexpr-printing.cpp:41 and :53.)
Differential Revision: http://llvm-reviews.chandlerc.com/D2388
llvm-svn: 197092
The standard is pretty clear on what it allows inside of template
arguments for non-type template parameters of pointer-to-member.
They must be of the form &qualified-id and cannot come from sources like
constexpr VarDecls or things of that nature.
This fixes PR18192.
llvm-svn: 196852
We wouldn't properly save and restore the pending local instantiations
we had built up prior to instantiation of a variable definition. This
would lead to us instantiating too much causing crashes and other
general badness.
This fixes PR14374.
llvm-svn: 195887
We would fail to instantiate them when the surrounding function was
instantiated. Instantiate the class and add it's members to the list of
pending instantiations, they should be resolved when we are finished
with the function's body.
This fixes PR9685.
llvm-svn: 195827
We only considered FieldDecl and CXXMethodDecl as appropriate which
would cause us to believe the IndirectFieldDecl corresponded to an
argument of it's field type instead of a pointer-to-member type.
This fixes PR17696.
llvm-svn: 193461
David Majnemer