resolved the -> to a call to a specific operator-> function. The particular
test case added here is actually being mishandled: the implicit member access
should not be type-dependent (because it's accessing a non-type-dependent
member of the current instantiation), but calls to a type-dependent operator->
that is a member of the current instantiation would be liable to hit the same
codepath.
llvm-svn: 284999
corresponding arguments are unexpanded pack expansions, we can compute the
result without substituting them. This significantly improves the memory usage
and performance of make_integer_sequence implementations that do this kind of
thing:
using result = integer_sequence<T, Ns ..., sizeof...(Ns) + Ns ...>;
... but note that such an implementation will still perform O(sizeof...(Ns)^2)
work while building the second pack expansion (we just have a somewhat lower
constant now).
In principle we could get this down to linear time by caching whether the
number of expansions of a pack is constant, or checking whether we're within an
alias template before scanning the pack for pack expansions (since that's the
only case in which we do substitutions within a dependent context at the
moment), but this patch doesn't attempt that.
llvm-svn: 284653
not instantiate exception specifications of functions if they were only used in
unevaluated contexts (other than 'noexcept' expressions).
In C++17 onwards, this becomes essential since the exception specification is
now part of the function's type.
Note that this means that constructs like the following no longer work:
struct A {
static T f() noexcept(...);
decltype(f()) *p;
};
... because the decltype expression now needs the exception specification of
'f', which has not yet been parsed.
llvm-svn: 284549
declaration has a dependent type.
This fixes a bug where clang errors out on a valid code.
rdar://problem/28051467
Differential Revision: https://reviews.llvm.org/D24110
llvm-svn: 280330
explicit specialization to a warning for C++98 mode (this is a defect report
resolution, so per our informal policy it should apply in C++98), and turn
the warning on by default for C++11 and later. In all cases where it fires, the
right thing to do is to remove the pointless explicit instantiation.
llvm-svn: 280308
within the instantiation of that same specialization. This could previously
happen for eagerly-instantiated function templates, variable templates,
exception specifications, default arguments, and a handful of other cases.
We still have an issue here for default template arguments that recursively
make use of themselves and likewise for substitution into the type of a
non-type template parameter, but in those cases we're producing a different
entity each time, so they should instead be caught by the instantiation depth
limit. However, currently we will typically run out of stack before we reach
it. :(
llvm-svn: 280190
per-frame stack usage enough to cause it to hit our stack limit. This is not
ideal; we should find a better way of dealing with this, such as increasing
our stack allocation when built with ASan.
llvm-svn: 279668
they're redeclarations. This is necessary in order for name lookup to correctly
find the most recent declaration of the name (which affects default template
argument lookup and cross-module merging, among other things).
llvm-svn: 275612
classes.
MSVC actively uses unqualified lookup in dependent bases, lookup at the
instantiation point (non-dependent names may be resolved on things
declared later) etc. and all this stuff is the main cause of
incompatibility between clang and MSVC.
Clang tries to emulate MSVC behavior but it may fail in many cases.
clang could store lexed tokens for member functions definitions within
ClassTemplateDecl for later parsing during template instantiation.
It will allow resolving many possible issues with lookup in dependent
base classes and removing many already existing MSVC-specific
hacks/workarounds from the clang code.
llvm-svn: 272774
The code had a typo it was doing:
Param->setUninstantiatedDefaultArg(Param->getUninstantiatedDefaultArg());
This is a no-op but may assert, we wanted to do:
Param->setUninstantiatedDefaultArg(OldParam->getUninstantiatedDefaultArg());
This fixes PR28082.
llvm-svn: 272425
Wilson.
An unqualified lookup for in base classes may cause stack overflow if
the base class is a specialization of current class.
Patch by Will Wilson.
llvm-svn: 271251
Also make explicit instantiation decls not apply to nested classes when
targeting MSVC. That dll attributes are not inherited by inner classes
might be the explanation for MSVC's behaviour here.
llvm-svn: 270897
Summary:
In dependent contexts where we know a type name is required, such as a
new expression, we can recover by forming a DependentNameType.
This generalizes our existing compatibility hack for default arguments
for template type parameters.
Works towards parsing atlctrlw.h, which is PR26748.
Reviewers: avt77, rsmith
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D20500
llvm-svn: 270615
This reversal is being done with r267453's author's (i.e. Richard Smith's) permission.
This fixes https://llvm.org/bugs/show_bug.cgi?id=27601
Also, per Richard's request the examples from the bug report have been added to our test suite.
llvm-svn: 270016
With this patch compiler emits warning if it tries to make implicit instantiation
of a template but cannot find the template definition. The warning can be suppressed
by explicit instantiation declaration or by command line options
-Wundefined-var-template and -Wundefined-func-template. The implementation follows
the discussion of http://reviews.llvm.org/D12326.
Differential Revision: http://reviews.llvm.org/D16396
llvm-svn: 266719
This is a fix for https://llvm.org/bugs/show_bug.cgi?id=25561 which was a
crash on invalid. Change the handling of invalid decls to have a catch-all
case to prevent unexpecting decls from triggering an assertion.
llvm-svn: 265467
This feature works outside of templates by forming a DeclRefExpr to a
FieldDecl instead of a MemberExpr, which requires a base object in
addition to the FieldDecl.
Previously, while building up the template AST before instantiation, we
formed a CXXDependentScopeMemberExpr, which always instantiates to a
MemberExpr. Now, in unevaluated contexts we form a
DependentScopeDeclRefExpr, which is a more flexible node that can
instantiate to either a MemberExpr or a DeclRefExpr depending on lookup
results.
Fixes PR26893.
llvm-svn: 263279
In VisitNonTypeTemplateParamDecl, before SubstExpr with the default argument,
we should create a ConstantEvaluated ExpressionEvaluationContext. Without this,
it is possible to use a PotentiallyEvaluated ExpressionEvaluationContext; and
MaybeODRUseExprs will not be cleared when popping the context, causing
assertion failure.
This is similar to how we handle the context before SubstExpr with the
default argument, in SubstDefaultTemplateArgument.
Part of PR13986.
rdar://24480205
Differential Revision: http://reviews.llvm.org/D17576
llvm-svn: 261803
Or, do not set Sema's CurContext to the template declaration's when substituting into default template arguments of said template declaration.
If we do push the template declaration context on to Sema, and the template declaration is at namespace scope, Sema can get confused and try and do odr analysis when substituting into default template arguments, even though the substitution could be occurring within a dependent context.
I'm not sure why this was being done, perhaps there was concern that if a default template argument referred to a previous template parameter, it might not be found during substitution - but all regression tests pass, and I can't craft a test that would cause it to fails (if some one does, please inform me, and i'll craft a different fix for the PR).
This patch removes a single line of code, but unfortunately adds more than it removes, because of the tests. Some day I still hope to commit a patch that removes far more lines than it adds, while leaving clang better for it ;)
Sorry that r253590 ("Change the expression evaluation context from Unevaluated to ConstantEvaluated while substituting into non-type template argument defaults") caused the PR!
llvm-svn: 258110
Covers significantly more code in the template template pack argument
test and fixes the resulting assert problem.
Differential Revision: http://reviews.llvm.org/D15743
llvm-svn: 257326
By storing the instantiated expression back in the ParmVarDecl,
we remove the last need for separately storing the sub-expression
of a CXXDefaultArgExpr. This makes PCH/Modules merging quite
simple: CXXDefaultArgExpr records are serialized as references
to the ParmVarDecl, and we ignore redundant attempts to overwrite
the instantiated expression.
This has some extremely marginal impact on user-facing semantics.
However, the major effect is that it avoids IRGen errors about
conflicting definitions due to lambdas in the argument being
instantiated multiple times while sharing the same mangling.
It should also slightly improve memory usage and module file size.
rdar://23810407
llvm-svn: 256983
This is the 5th Lit test patch.
Expanded expected diagnostics to vary by C++ dialect.
Expanded RUN line to: default, C++98/03 and C++11.
llvm-svn: 255196
This time, I went with the first approach from
http://reviews.llvm.org/D6700, where clang actually attempts to form an
implicit member reference from an UnresolvedLookupExpr. We know that
there are only two possible outcomes at this point, a DeclRefExpr of the
FieldDecl or an error, but its safer to reuse the existing machinery for
this.
llvm-svn: 250856
consider the following:
enum E *p;
enum E { e };
The above snippet is not ANSI C because 'enum E' has not bee defined
when we are processing the declaration of 'p'; however, it is a popular
extension to make the above work. This would fail using the Microsoft
enum semantics because the definition of 'E' would implicitly have a
fixed underlying type of 'int' which would trigger diagnostic messages
about a mismatch between the declaration and the definition.
Instead, treat fixed underlying types as not fixed for the purposes of
the diagnostic.
llvm-svn: 249674
Our self hosting buildbots found a few more tests which weren't updated
to reflect that the enum semantics are part of the Microsoft ABI.
llvm-svn: 249670
that change turns out to not be reasonable: mutating the AST of a parsed
template during instantiation is not a sound thing to do, does not work across
chained PCH / modules builds, and is in any case a special-case workaround to a
more general problem that should be solved centrally.
llvm-svn: 249342
partial specialization can perform conversions on the argument. Be sure we
start again from the original argument when checking each possible template.
llvm-svn: 249114
We get into this bad state when someone defines a new member function
for a class but forgets to add the declaration to the class body.
Calling the new member function from a member function template of the
class will crash during instantiation.
llvm-svn: 248925
This doesn't quite get alias template equivalence right yet, but handles the
egregious cases where we would silently give the wrong answers.
llvm-svn: 248431
Summary:
This change adds support for `__builtin_ms_va_list`, a GCC extension for
variadic `ms_abi` functions. The existing `__builtin_va_list` support is
inadequate for this because `va_list` is defined differently in the Win64
ABI vs. the System V/AMD64 ABI.
Depends on D1622.
Reviewers: rsmith, rnk, rjmccall
CC: cfe-commits
Differential Revision: http://reviews.llvm.org/D1623
llvm-svn: 247941
Summary:
`OpaqueValueExpr`s may not have a source expression (as in the case when
they are created due to a default argument error).
This can cause an assertion failure in `TransformOpaqueValueExpr` during
template instantiation.
This patch fixes the assertion failure.
Reviewers: hfinkel, rsmith
Subscribers: fraggamuffin, cfe-commits
Differential Revision: http://reviews.llvm.org/D11582
Patch by Rachel Craik!
llvm-svn: 246600
If a function declaration is found inside a template function as in:
template<class T> void f() {
void g(int x = T::v) except(T::w);
}
it must be instantiated along with the enclosing template function,
including default arguments and exception specification.
Together with the patch committed in r240974 this implements DR1484.
Differential Revision: http://reviews.llvm.org/D11194
llvm-svn: 245810
If a function containing a local class is instantiated, instantiate
all of local class member, including default arguments and exception
specifications.
This change fixes PR21332 and thus implements DR1484.
Differential Revision: http://reviews.llvm.org/D9990
llvm-svn: 240974
Get rid of code-path that (according to Richard Smith) is not needed but
leads to a crasher bug when assuming a template has been fully
instantiated and thus has a definition.
llvm-svn: 240752
The underlying problem in PR23823 already existed before my recent change
in r239558, but that change made it worse (failing not only for undeclared
symbols, but also failed overload resolution). This makes Clang not try to
delay the lookup in SFINAE context. I assume no current code is relying on
SFINAE working with lookups that need to be delayed, because that never
seems to have worked.
Differential Revision: http://reviews.llvm.org/D10417
llvm-svn: 239639
This patch does two things in order to enable compilation of the problematic code in PR23810:
1. In Sema::buildOverloadedCallSet, it postpones lookup for MS mode when no
viable candidate is found in the overload set. Previously, lookup would only
be postponed here if the overload set was empty.
2. Make BuildRecoveryCallExpr call Sema::DiagnoseEmptyLookup under more circumstances.
There is a comment in DiagnoseTwoPhaseLookup that says "Don't diagnose names we find in
classes; we get much better diagnostics for these from DiagnoseEmptyLookup." The problem
was that DiagnoseEmptyLookup might not get called later, and we failed to recover.
Differential Revision: http://reviews.llvm.org/D10369
llvm-svn: 239558
Starting from r236426 FindInstantiatedDecl may instantiate types that
are referenced before definition. This change limit the set of types
that can be instantiated by this function.
llvm-svn: 237434
This is necessary in order to allow the use of a constexpr member function, or
a member function with deduced return type, of a local class within a
surrounding instantiated function template specialization.
Patch by Michael Park!
This re-commits r236063, which was reverted in r236134, along with a fix for a
delayed template parsing bug that was exposed by this change.
llvm-svn: 237064
If a class is absent from instantiation and is incomplete, instantiate it as
an incomplete class thus avoiding compiler crash.
This change fixes PR18653.
Differential Revision: http://reviews.llvm.org/D8281
llvm-svn: 236426
This is necessary in order to allow the use of a constexpr member function, or
a member function with deduced return type, of a local class within a
surrounding instantiated function template specialization.
Patch by Michael Park!
llvm-svn: 236063
Inclass initializer is instantiated in its own LocalInstantiationScope. It
causes problems when instantiating local classes - when instantiation scope
is searched for DeclContext of the field, the search fails. As a solution,
the instantiation scope of field initializer is combined with its outer
scope.
This patch fixes PR23194.
Differential Revision: http://reviews.llvm.org/D9258
llvm-svn: 236005
Previously, many error messages would simply be "read-only variable is not
assignable" This change provides more information about why the variable is
not assignable, as well as note to where the const is located.
Differential Revision: http://reviews.llvm.org/D4479
llvm-svn: 234677
This affects this test case:
void foo();
template <typename T> class C {
friend inline void foo();
};
inline void foo() {}
C<int> c;
Here, we instantiate the foo friend decl and add it to foo's redecl
chain. However, our previous decl pointer happens to reference the first
declaration of foo, which is not marked inline. When we check to see if
foo was already defined, we implicitly search all previous decls. We
should do the same for the inline check, instead of just checking this
particular previous decl.
Reviewers: rsmith
Differential Revision: http://reviews.llvm.org/D8872
llvm-svn: 234374
MS compiler emits no errors in case of explicit specializations outside declaration enclosing namespaces, even when language extensions are disabled.
The patch is to suppress errors and emit extension warnings if explicit specializations are not declared in the corresponding namespaces.
This fixes PR13738.
Patch by Alexey Frolov.
Differential Revision: http://reviews.llvm.org/D8283
llvm-svn: 232800
the presence of an abstract declarator with a ptr-operator as proof that a
construct cannot parse as an expression to improve diagnostics along error
recovery paths.
llvm-svn: 230261
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
... when the variable's type is a typedef of a ConstantArrayType. Just
look through the typedef (and any other sugar). We only use the
constant array type here to get the element count.
llvm-svn: 227115
clang currently calls MarkVTableUsed() for classes that get their virtual
methods called or that participate in a dynamic_cast. This is unnecessary,
since CodeGen only emits vtables when it generates constructor, destructor, and
vtt code. (*)
Note that Sema::MarkVTableUsed() doesn't cause the emission of a vtable.
Its main user-visible effect is that it instantiates virtual member functions
of template classes, to make sure that if codegen decides to write a vtable
all the entries in the vtable are defined.
While this shouldn't change the behavior of codegen (other than being faster),
it does make clang more permissive: virtual methods of templates (in particular
destructors) end up being instantiated less often. In particular, classes that
have members that are smart pointers to incomplete types will now get their
implicit virtual destructor instantiated less frequently. For example, this
used to not compile but does now compile:
template <typename T> struct OwnPtr {
~OwnPtr() { static_assert((sizeof(T) > 0), "TypeMustBeComplete"); }
};
class ScriptLoader;
struct Base { virtual ~Base(); };
struct Sub : public Base {
virtual void someFun() const {}
OwnPtr<ScriptLoader> m_loader;
};
void f(Sub *s) { s->someFun(); }
The more permissive behavior matches both gcc (where this is not often
observable, since in practice most things with virtual methods have a key
function, and Sema::DefineUsedVTables() skips vtables for classes with key
functions) and cl (which is my motivation for this change) – this fixes
PR20337. See this issue and the review thread for some discussions about
optimizations.
This is similar to r213109 in spirit. r225761 was a prerequisite for this
change.
Various tests relied on "a->f()" marking a's vtable as used (in the sema
sense), switch these to just construct a on the stack. This forces
instantiation of the implicit constructor, which will mark the vtable as used.
(*) The exception is -fapple-kext mode: In this mode, qualified calls to
virtual functions (`a->Base::f()`) still go through the vtable, and since the
vtable pointer off this doesn't point to Base's vtable, this needs to reference
Base's vtable directly. To keep this working, keep referencing the vtable for
virtual calls in apple kext mode.
llvm-svn: 227073
and only update the orginal list on a valid arugment list. When checking an
individual expression template argument, and conversions are required, update
the expression in the template argument. Since template arguments are
speculatively checked, the copying of the template argument list prevents
updating the template arguments when the list does not match the template.
Additionally, clean up the integer checking code in the template diffing code.
The code performs unneccessary conversions from APSInt to APInt.
Fixes PR21758.
This essentially reverts r224770 to recommits r224667 and r224668 with extra
changes to prevent the template instantiation problems seen in PR22006.
A test to catch the discovered problem is also added.
llvm-svn: 226983
Previously if an enumeration was used in a nested name specifier in pre-C++11
language dialect, error message was 'XXX is not a class, namespace, or scoped
enumeration'. This patch removes the word 'scoped' as in C++11 any enumeration
may be used in this context.
llvm-svn: 226410
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
Richard Smith