Warn when a declaration uses an identifier that doesn't obey the reserved
identifier rule from C and/or C++.
Differential Revision: https://reviews.llvm.org/D93095
Create fix-it hints to fix the order of constructors.
To make this a lot simpler, I've grouped all the warnings for each out of order initializer into 1.
This is necessary as fixing one initializer would often interfere with other initializers.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D98745
There is no functional change here (hence no new tests). The only change
is to replace a couple uintptr_t members with llvm::PointerIntPair<> to
clean up the code, making it more readable and less error prone.
This cleanup highlighted that the old code was effectively casting away
const. This is fixed by changing some function signatures.
Reviewed By: rsmith
Differential Revision: https://reviews.llvm.org/D98889
The idiom:
```
DeclContext::lookup_result R = DeclContext::lookup(Name);
for (auto *D : R) {...}
```
is not safe when in the loop body we trigger deserialization from an AST file.
The deserialization can insert new declarations in the StoredDeclsList whose
underlying type is a vector. When the vector decides to reallocate its storage
the pointer we hold becomes invalid.
This patch replaces a SmallVector with an singly-linked list. The current
approach stores a SmallVector<NamedDecl*, 4> which is around 8 pointers.
The linked list is 3, 5, or 7. We do better in terms of memory usage for small
cases (and worse in terms of locality -- the linked list entries won't be near
each other, but will be near their corresponding declarations, and we were going
to fetch those memory pages anyway). For larger cases: the vector uses a
doubling strategy for reallocation, so will generally be between half-full and
full. Let's say it's 75% full on average, so there's N * 4/3 + 4 pointers' worth
of space allocated currently and will be 2N pointers with the linked list. So we
break even when there are N=6 entries and slightly lose in terms of memory usage
after that. We suspect that's still a win on average.
Thanks to @rsmith!
Differential revision: https://reviews.llvm.org/D91524
This patch just makes the error message clearer by reinforcing the cause
was a lack of viable **three-way** comparison function for the
**complete object**.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Reviewed By: rsmith
Differential Revision: https://reviews.llvm.org/D97990
See https://bugs.llvm.org/show_bug.cgi?id=42154.
GCC's __attribute__((align)) can reduce the alignment of a type when applied to
a typedef. However, functions which take a pointer or reference to the
original type are compiled assuming the original alignment. Therefore when any
such function is passed an object of the new, less-aligned type, an alignment
fault can occur. In particular, this applies to the constructor, which is
defined for the original type and called for the less-aligned object.
This change adds a warning whenever an pointer or reference to an object is
passed to a function that was defined for a more-aligned type.
The calls to ASTContext::getTypeAlignInChars seem change the order in which
record layouts are evaluated, which caused changes to the output of
-fdump-record-layouts. As such some tests needed to be updated:
* Use CHECK-LABEL rather than counting the number of "Dumping AST Record
Layout" headers.
* Check for end of line in labels, so that struct B1 doesn't match struct B
etc.
* Add --strict-whitespace, since the whitespace shows meaningful structure.
* The order in which record layouts are printed has changed in some cases.
* clang-format for regions changed
Differential Revision: https://reviews.llvm.org/D97187
See bug #48856
Definitions of classes with member function pointers and default
spaceship operator were getting accepted with no diagnostic on
release build, and triggering assert on builds with runtime checks
enabled. Diagnostics were only produced when actually comparing
instances of such classes.
This patch makes it so Spaceship and Less operators are not considered
as builtin operator candidates for function pointers, producing
equivalent diagnostics for the cases where pointers to member function
and pointers to data members are used instead.
Reviewed By: rsmith
Differential Revision: https://reviews.llvm.org/D95409
https://bugs.llvm.org/show_bug.cgi?id=40858
CheckShadow is now called for each binding in the structured binding to make sure it does not shadow any other variable in scope. This does use a custom implementation of getShadowedDeclaration though because a BindingDecl is not a VarDecl
Added a few unit tests for this. In theory though all the other shadow unit tests should be duplicated for the structured binding variables too but whether it is probably not worth it as they use common code. The MyTuple and std interface code has been copied from live-bindings-test.cpp
Reviewed By: rsmith
Differential Revision: https://reviews.llvm.org/D96147
This change affects 'SemaOpenCLCXX/newdelete.cl' test,
thus the patch contains adjustments in types validation of
operators new and delete
Reviewed By: Anastasia
Differential Revision: https://reviews.llvm.org/D96178
Similar to Windows Itanium, PS4 is also an Itanium C++ ABI variant
which shares the goal of semantic compatibility with Microsoft C++
code that uses dllimport/export.
This change introduces a new function to determine from the triple
if an environment aims for compatibility with MS C++ code w.r.t to
these attributes and guards the relevant code paths using that
function.
Differential Revision: https://reviews.llvm.org/D90299
Since these are scoped enumerators, they have to be prefixed by DeclaratorContext, so lets remove Context from the name, and return some characters to the multiverse.
Patch was reviewed here: https://reviews.llvm.org/D91011
Thank you to aaron, bruno, wyatt and barry for indulging me.
friends.
When determining whether a function has a template instantiation
pattern, look for other declarations of that function that were
instantiated from a friend function definition, rather than assuming
that checking for member specialization information on whichever
declaration name lookup found will be sufficient.
As mentioned in the defect, the lambda static invoker does not follow
the calling convention of the lambda itself, which seems wrong. This
patch ensures that the calling convention of operator() is passed onto
the invoker and conversion-operator type.
This is accomplished by extracting the calling-convention determination
code out into a separate function in order to better reflect the 'thiscall'
work, as well as somewhat better support the future implementation of
https://devblogs.microsoft.com/oldnewthing/20150220-00/?p=44623
For any target (basically just win32) that has a different free and
static function calling convention, this generates BOTH alternatives.
This required some work to get the Windows mangler to work correctly for
this, as well as some tie-breaking for the unary operators.
Differential Revision: https://reviews.llvm.org/D89559
lambda-expression's captures.
The built-in structured binding rules for classes require that all
fields can be accessed by name, and the fields introduced for lambda
captures are unnamed, so decomposing a capturing lambda is ill-formed.
for which it matters.
This is a step towards separating checking for a constant initializer
(in which std::is_constant_evaluated returns true) and any other
evaluation of a variable initializer (in which it returns false).
folding to not constant folding.
Constant folding of ICEs is done as a GCC compatibility measure, but new
code was picking it up, presumably by accident, due to the bad default.
While here, also switch the flag from a bool to an enum to make it more
obvious what it means at call sites. This highlighted a couple of places
where our behavior is different between C++11 and C++14 due to switching
from checking for an ICE to checking for a converted constant
expression (where there is no 'fold' codepath).
We previously took a shortcut and said that weak variables never have
constant initializers (because those initializers are never correct to
use outside the variable). We now say that weak variables can have
constant initializers, but are never usable in constant expressions.
This changes some diagnostics to use terminology from the standard
rather than invented terminology, which improves consistency with other
diagnostics as well. There are no functional changes intended other
than wording and naming.
This is recommit of 6c8041aa0f, reverted in de044f7562 because of some
fails. Original commit message is below.
This change allow a CastExpr to have optional FPOptionsOverride object,
stored in trailing storage. Of all cast nodes only ImplicitCastExpr,
CStyleCastExpr, CXXFunctionalCastExpr and CXXStaticCastExpr are allowed
to have FPOptions.
Differential Revision: https://reviews.llvm.org/D85960
This change allow a CastExpr to have optional FPOptionsOverride object,
stored in trailing storage. Of all cast nodes only ImplicitCastExpr,
CStyleCastExpr, CXXFunctionalCastExpr and CXXStaticCastExpr are allowed
to have FPOptions.
Differential Revision: https://reviews.llvm.org/D85960
This patch adds override to several overriding virtual functions that were missing the keyword within the clang/ directory. These were found by the new -Wsuggest-override.
This patch adds `-Wsuggest-override`, which allows for more aggressive enforcement of modern C++ best practices, as well as better compatibility with gcc, which has had its own `-Wsuggest-override` since version 5.1.
Clang already has `-Winconsistent-missing-override`, which only warns in the case where there is at least one function already marked `override` in a class. This warning strengthens that warning by suggesting the `override` keyword regardless of whether it is already present anywhere.
The text between suggest-override and inconsistent-missing-override is now shared, using `TextSubstitution` for the entire diagnostic text.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D82728
be dependent if it names the right type.
This matches the GCC behavior, but no longer matches the standard
wording. However, the standard wording in this case is not in line with
the intent, which was to require the enclosing class type to be named
directly. I've reported this wording oversight to the committee.
This reverts commit defd43a5b3.
with correction to solve msan report
To solve https://bugs.llvm.org/show_bug.cgi?id=46166 where the
floating point settings in PCH files aren't compatible, rewrite
FPFeatures to use a delta in the settings rather than absolute settings.
With this patch, these floating point options can be benign.
Reviewers: rjmccall
Differential Revision: https://reviews.llvm.org/D81869
This reverts commit b55d723ed6.
Reapply Modify FPFeatures to use delta not absolute settings
To solve https://bugs.llvm.org/show_bug.cgi?id=46166 where the
floating point settings in PCH files aren't compatible, rewrite
FPFeatures to use a delta in the settings rather than absolute settings.
With this patch, these floating point options can be benign.
Reviewers: rjmccall
Differential Revision: https://reviews.llvm.org/D81869
Summary:
otherwise we'll run into code path which expects a good base specifiers,
and lead to crashes.
The crash only occurs in template instantiations (in non-template case,
the bad base specifiers are dropped during parsing.)
crash stacktrace:
```
clang: llvm-project/clang/lib/Sema/SemaInit.cpp:7864: clang::ExprResult clang::InitializationSequence::Perform(clang::Sema &, const clang::InitializedEntity &, const clang::InitializationKind &, clang::MultiExprArg, clang::QualType *): Assertion `Kind.getKind() == InitializationKind::IK_Copy || Kind.isExplicitCast() || Kind.getKind() == InitializationKind::IK_DirectList' failed.
PLEASE submit a bug report to https://bugs.llvm.org/ and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
```
Reviewers: sammccall
Reviewed By: sammccall
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D82086
C++ unqualified name lookup searches template parameter scopes
immediately after finishing searching the entity the parameters belong
to. (Eg, for a class template, you search the template parameter scope
after looking in that class template and its base classes and before
looking in the scope containing the class template.) This is complicated
by the fact that scope lookup within a template parameter scope looks in
a different sequence of places prior to reaching the end of the
declarator-id in the template declaration.
We used to approximate the proper lookup rule with a hack in the scope /
decl context walk inside name lookup. Now we instead compute the lookup
parent for each template parameter scope.
In order to get this right, we now make sure to enter a distinct Scope
for each template parameter scope, and make sure to re-enter the
enclosing class scopes properly when handling delay-parsed regions
within a class.
templated class.
When a defaulted operator<=> results in the injection of a defaulted
operator==, that operator== can be named by unqualified name within the
same class, even if the class is templated. To make this work, perform
the transform from defaulted operator<=> to defaulted operator== in the
template definition context instead of the template instantiation
context.
This results in our substituting into a declaration from a context where
we don't have a full list of template arguments (or indeed any), for
which we are now more careful to not spuriously instantiate declarations
that are not dependent on the arguments we're substituting.
templated class.
When a defaulted operator<=> results in the injection of a defaulted
operator==, that operator== can be named by unqualified name within the
same class, even if the class is templated. To make this work, perform
the transform from defaulted operator<=> to defaulted operator== in the
template definition context instead of the template instantiation
context.
This results in our substituting into a declaration from a context where
we don't have a full list of template arguments (or indeed any), for
which we are now more careful to not spuriously instantiate declarations
that are not dependent on the arguments we're substituting.
This diagnostic (which defaults to an error, added in
95833f33bd) was intended to clearly
point out cases where the C++ ABI won't match the Microsoft C++ ABI,
for cases when this is enabled via a pragma over a region of code.
The MSVC compatible struct layout feature can also be enabled via a
compiler option (-mms-bitfields). If enabled that way, one essentially
can't compile any C++ code unless also building with
-Wno-incompatible-ms-struct (which GCC doesn't support, and projects
developed with GCC aren't setting).
For the MinGW target, it's expected that the C++ ABI won't match
the MSVC one, if this option is used for getting the struct
layout to match MSVC.
Differential Revision: https://reviews.llvm.org/D81794
declaration is not visible.
In passing, add a test for a similar case of conflicting redeclarations
of internal-linkage structured bindings. (This case already works).
...before checking that the default argument is valid with
CheckDefaultArgumentVisitor.
Currently the restrictions on a default argument are checked with the visitor
CheckDefaultArgumentVisitor in ActOnParamDefaultArgument before
performing the conversion to the parameter type in SetParamDefaultArgument.
This was fine before the previous patch but now some valid code post-CWG 2346
is rejected:
void test() {
const int i2 = 0;
extern void h2a(int x = i2); // FIXME: ok, not odr-use
extern void h2b(int x = i2 + 0); // ok, not odr-use
}
This is because the reference to i2 in h2a has not been marked yet with
NOUR_Constant. i2 is marked NOUR_Constant when the conversion to the parameter
type is done, which is done just after.
The solution is to do the conversion to the parameter type before checking
the restrictions on default arguments with CheckDefaultArgumentVisitor.
This has the side-benefit of improving some diagnostics.
Differential Revision: https://reviews.llvm.org/D81616
Reviewed By: rsmith
This patch implements the resolution of CWG 2082 and CWG 2346.
The resolution of CWG 2082 changed [dcl.fct.default]p7 and p9 to allow
a parameter or local variable to appear in a default argument if not
in a potentially-evaluated expression.
The resolution of CWG 2346 changed [dcl.fct.default]p7 to allow a local
variable to appear in a default argument if not odr-used.
An issue remains after this patch
(see the FIXME in test/CXX/dcl.decl/dcl.meaning/dcl.fct.default/p7.cpp).
This is addressed by the next patch.
Differential Revision: https://reviews.llvm.org/D81615
Reviewed By: rsmith, erichkeane
Before the next patches do the following NFCs:
- Make it a const visitor; CheckDefaultArgumentVisitor should
really not modify the visited nodes.
- clang-format
- Take a reference to Sema instead of a pointer and pass it
as the first argument to the constructor. This is for
consistency with the other similar visitors.
- Use range for loops when appropriate as per the style guide.
- Use `const auto *" when appropriate as per the style guide.
DiagnosticErrorTrap is usually inappropriate because it indicates
whether an error message was rendered in a given region (and is
therefore affected by -ferror-limit and by suppression of errors if we
see an invalid declaration).
hasErrorOccurred() is usually inappropriate because it indicates
whethere an "error:" message was displayed, regardless of whether the
message was a warning promoted to an error, and therefore depends on
things like -Werror that are usually irrelevant.
Where applicable, CodeSynthesisContexts are used to attach notes to
the first diagnostic produced in a region of code, isnstead of using an
error trap and then attaching a note to whichever diagnostic happened to
be produced last (or suppressing the note if the final diagnostic is a
disabled warning!).
This is mostly NFC.
trivial.
We previously took a shortcut by assuming that if a subobject had a
trivial copy assignment operator (with a few side-conditions), we would
always invoke it, and could avoid going through overload resolution.
That turns out to not be correct in the presenve of ref-qualifiers (and
also won't be the case for copy-assignments with requires-clauses
either). Use the same logic for lazy declaration of copy-assignments
that we use for all other special member functions.
Previously committed as c57f8a3a20. This
now also includes an extension of LLDB's workaround for handling special
members without the help of Sema to cover copy assignments.
trivial.
We previously took a shortcut by assuming that if a subobject had a
trivial copy assignment operator (with a few side-conditions), we would
always invoke it, and could avoid going through overload resolution.
That turns out to not be correct in the presenve of ref-qualifiers (and
also won't be the case for copy-assignments with requires-clauses
either). Use the same logic for lazy declaration of copy-assignments
that we use for all other special member functions.
parameters with default arguments.
Directly follow the wording by relaxing the AST invariant that all
parameters after one with a default arguemnt also have default
arguments, and removing the diagnostic on missing default arguments
on a pack-expanded parameter following a parameter with a default
argument.
Testing also revealed that we need to special-case explicit
specializations of templates with a pack following a parameter with a
default argument, as such explicit specializations are otherwise
impossible to write. The standard wording doesn't address this case; a
issue has been filed.
This exposed a bug where we would briefly consider a parameter to have
no default argument while we parse a delay-parsed default argument for
that parameter, which is also fixed.
Partially incorporates a patch by Raul Tambre.
Summary:
Diagnostic is emitted if some declaration of unsupported type
declaration is used inside device code.
Memcpy operations for structs containing member with unsupported type
are allowed. Fixed crash on attempt to emit diagnostic outside of the
functions.
The approach is generalized between SYCL and OpenMP.
CUDA/OMP deferred diagnostic interface is going to be used for SYCL device.
Reviewers: rsmith, rjmccall, ABataev, erichkeane, bader, jdoerfert, aaron.ballman
Reviewed By: jdoerfert
Subscribers: guansong, sstefan1, yaxunl, mgorny, bader, ebevhan, Anastasia, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D74387
Summary: This allows for suppressing warnings about the conversion function never being called if it overrides a virtual function in a base class.
Differential Revision: https://reviews.llvm.org/D78444
test cases
Add support for #pragma float_control
Reviewers: rjmccall, erichkeane, sepavloff
Differential Revision: https://reviews.llvm.org/D72841
This reverts commit 85dc033cac, and makes
corrections to the test cases that failed on buildbots.
In the MS C++ ABI, the complete destructor variant for a class with
virtual bases is emitted whereever it is needed, instead of directly
alongside the base destructor variant. The complete destructor calls the
base destructor of the current class and the base destructors of each
virtual base. In order for this to work reliably, translation units that
use the destructor of a class also need to mark destructors of virtual
bases of that class used.
Fixes PR38521
Reviewed By: rsmith
Differential Revision: https://reviews.llvm.org/D77081
Summary:
- Even though the bindless surface/texture interfaces are promoted,
there are still code using surface/texture references. For example,
[PR#26400](https://bugs.llvm.org/show_bug.cgi?id=26400) reports the
compilation issue for code using `tex2D` with texture references. For
better compatibility, this patch proposes the support of
surface/texture references.
- Due to the absent documentation and magic headers, it's believed that
`nvcc` does use builtins for texture support. From the limited NVVM
documentation[^nvvm] and NVPTX backend texture/surface related
tests[^test], it's believed that surface/texture references are
supported by replacing their reference types, which are annotated with
`device_builtin_surface_type`/`device_builtin_texture_type`, with the
corresponding handle-like object types, `cudaSurfaceObject_t` or
`cudaTextureObject_t`, in the device-side compilation. On the host
side, that global handle variables are registered and will be
established and updated later when corresponding binding/unbinding
APIs are called[^bind]. Surface/texture references are most like
device global variables but represented in different types on the host
and device sides.
- In this patch, the following changes are proposed to support that
behavior:
+ Refine `device_builtin_surface_type` and
`device_builtin_texture_type` attributes to be applied on `Type`
decl only to check whether a variable is of the surface/texture
reference type.
+ Add hooks in code generation to replace that reference types with
the correponding object types as well as all accesses to them. In
particular, `nvvm.texsurf.handle.internal` should be used to load
object handles from global reference variables[^texsurf] as well as
metadata annotations.
+ Generate host-side registration with proper template argument
parsing.
---
[^nvvm]: https://docs.nvidia.com/cuda/pdf/NVVM_IR_Specification.pdf
[^test]: https://raw.githubusercontent.com/llvm/llvm-project/master/llvm/test/CodeGen/NVPTX/tex-read-cuda.ll
[^bind]: See section 3.2.11.1.2 ``Texture reference API` in [CUDA C Programming Guide](https://docs.nvidia.com/cuda/pdf/CUDA_C_Programming_Guide.pdf).
[^texsurf]: According to NVVM IR, `nvvm.texsurf.handle` should be used. But, the current backend doesn't have that supported. We may revise that later.
Reviewers: tra, rjmccall, yaxunl, a.sidorin
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D76365
Summary:
Changes:
- handle immediate invocations for constructors.
- add tests
after this patch i believe the implementation of consteval is nearly standard compliant, but IR-gen still needs to be taught not to emit consteval declarations.
Reviewers: rsmith
Reviewed By: rsmith
Subscribers: wchilders
Differential Revision: https://reviews.llvm.org/D74007
In the current SVE ACLE spec, the usual rules for throwing and
catching incomplete types also apply to sizeless types. However,
throwing pointers to sizeless types should not pose any real difficulty,
so as an extension, the clang implementation allows that.
This patch enforces these rules for catch statements.
Differential Revision: https://reviews.llvm.org/D76090
function and an overridden function until we know whether the overriding
function is deleted.
We previously did these checks when we first built the declaration,
which was too soon in some cases. We now defer all these checks to the
end of the class.
Also add missing check that a consteval function cannot override a
non-consteval function and vice versa.
1) Fix a regression in llvmorg-11-init-2485-g0e3a4877840 that would
reject some cases where a class name is shadowed by a typedef-name
causing a destructor declaration to be rejected. Prefer a tag type over
a typedef in destructor name lookup.
2) Convert the "type in destructor declaration is a typedef" error to an
error-by-default ExtWarn to allow codebases to turn it off. GCC and MSVC
do not enforce this rule.
constant initialization.
Removing this zeroing regressed our code generation in a few cases, also
fixed here. We now compute whether a variable has constant destruction
even if it doesn't have a constant initializer, by trying to destroy a
default-initialized value, and skip emitting a trivial default
constructor for a variable even if it has non-trivial (but perhaps
constant) destruction.
Summary:
Changes:
- Calls to consteval function are now evaluated in constant context but IR is still generated for them.
- Add diagnostic for taking address of a consteval function in non-constexpr context.
- Add diagnostic for address of consteval function accessible at runtime.
- Add tests
Reviewers: rsmith, aaron.ballman
Reviewed By: rsmith
Subscribers: mgrang, riccibruno, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D63960
types are needed to compute the return type of a defaulted operator<=>.
This raises the question of what to do if return type deduction fails.
The standard doesn't say, and implementations vary, so for now reject
that case eagerly to keep our options open.
when building a defaulted comparison.
As a convenient way of asking whether `x @ y` is valid and building it,
we previouly always performed overload resolution and built an
overloaded expression, which would both end up picking a builtin
operator candidate when given a non-overloadable type. But that's not
quite right, because it can result in our finding a user-declared
operator overload, which we should never do when applying operators
non-overloadable types.
Handle this more correctly: skip overload resolution when building
`x @ y` if the operands are not overloadable. But still perform overload
resolution (considering only builtin candidates) when checking validity,
as we don't have any other good way to ask whether a binary operator
expression would be valid.
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.
This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.
This doesn't actually modify StringRef yet, I'll do that in a follow-up.
This patch implements P1141R2 "Yet another approach for constrained declarations".
General strategy for this patch was:
- Expand AutoType to include optional type-constraint, reflecting the wording and easing the integration of constraints.
- Replace autos in parameter type specifiers with invented parameters in GetTypeSpecTypeForDeclarator, using the same logic
previously used for generic lambdas, now unified with abbreviated templates, by:
- Tracking the template parameter lists in the Declarator object
- Tracking the template parameter depth before parsing function declarators (at which point we can match template
parameters against scope specifiers to know if we have an explicit template parameter list to append invented parameters
to or not).
- When encountering an AutoType in a parameter context we check a stack of InventedTemplateParameterInfo structures that
contain the info required to create and accumulate invented template parameters (fields that were already present in
LambdaScopeInfo, which now inherits from this class and is looked up when an auto is encountered in a lambda context).
Resubmit after fixing MSAN failures caused by incomplete initialization of AutoTypeLocs in TypeSpecLocFiller.
Differential Revision: https://reviews.llvm.org/D65042
This patch implements P1141R2 "Yet another approach for constrained declarations".
General strategy for this patch was:
- Expand AutoType to include optional type-constraint, reflecting the wording and easing the integration of constraints.
- Replace autos in parameter type specifiers with invented parameters in GetTypeSpecTypeForDeclarator, using the same logic
previously used for generic lambdas, now unified with abbreviated templates, by:
- Tracking the template parameter lists in the Declarator object
- Tracking the template parameter depth before parsing function declarators (at which point we can match template
parameters against scope specifiers to know if we have an explicit template parameter list to append invented parameters
to or not).
- When encountering an AutoType in a parameter context we check a stack of InventedTemplateParameterInfo structures that
contain the info required to create and accumulate invented template parameters (fields that were already present in
LambdaScopeInfo, which now inherits from this class and is looked up when an auto is encountered in a lambda context).
Resubmit after incorrect check in NonTypeTemplateParmDecl broke lldb.
Differential Revision: https://reviews.llvm.org/D65042
serge-sans-paille