and remove ASTContext reference (which was frequently bound to a dereferenced
null pointer) from the recursive lump of printPretty functions. In so doing,
fix (at least) one case where we intended to use the 'dump' mode, but that
failed because a null ASTContext reference had been passed in.
llvm-svn: 162011
things going on here that were problematic:
- We were missing the actual access check, or rather, it was suppressed
on account of being a redeclaration lookup.
- The access check would naturally happen during delay, which isn't
appropriate in this case.
- We weren't actually emitting dependent diagnostics associated with
class templates, which was unfortunate.
- Access was being propagated incorrectly for friend method declarations
that couldn't be matched at parse-time.
llvm-svn: 161652
for side-effects. Instead, check for side-effects after performing
initialization. Doing so also removes some strange corner cases and differences
between in-class initialization and constructor initialization.
llvm-svn: 161449
we know whether the function is virtual. But check it as soon as we do know;
in some cases we don't need to wait for an instantiation.
llvm-svn: 161316
sure to update the exception specification on the declaration as well as the
definition. If we're building in -fno-exceptions mode, nothing else will
trigger it to be updated.
llvm-svn: 161008
a defaulted special member function until the exception specification is needed
(using the same criteria used for the delayed instantiation of exception
specifications for function temploids).
EST_Delayed is now EST_Unevaluated (using 1330's terminology), and, like
EST_Uninstantiated, carries a pointer to the FunctionDecl which will be used to
resolve the exception specification.
This is enabled for all C++ modes: it's a little faster in the case where the
exception specification isn't used, allows our C++11-in-C++98 extensions to
work, and is still correct for C++98, since in that mode the computation of the
exception specification can't fail.
The diagnostics here aren't great (in particular, we should include implicit
evaluation of exception specifications for defaulted special members in the
template instantiation backtraces), but they're not much worse than before.
Our approach to the problem of cycles between in-class initializers and the
exception specification for a defaulted default constructor is modified a
little by this change -- we now reject any odr-use of a defaulted default
constructor if that constructor uses an in-class initializer and the use is in
an in-class initialzer which is declared lexically earlier. This is a closer
approximation to the current draft solution in core issue 1351, but isn't an
exact match (but the current draft wording isn't reasonable, so that's to be
expected).
llvm-svn: 160847
structor class under ARC, that struct/class does not have a trivial
move constructor or move assignment operator. Fixes the rest of
<rdar://problem/11738725>.
llvm-svn: 160615
be defined as deleted, take cv-qualifiers on class members into account when
looking up the copy or move constructor or assignment operator which will be
used for them.
llvm-svn: 160418
diagnostics implemented -- see testcases.
I created a new TableGen file for comment diagnostics,
DiagnosticCommentKinds.td, because comment diagnostics don't logically
fit into AST diagnostics file. But I don't feel strongly about it.
This also implements support for self-closing HTML tags in comment
lexer and parser (for example, <br />).
In order to issue precise diagnostics CommentSema needs to know the
declaration the comment is attached to. There is no easy way to find a decl by
comment, so we match comments and decls in lockstep: after parsing one
declgroup we check if we have any new, not yet attached comments. If we do --
then we do the usual comment-finding process.
It is interesting that this automatically handles trailing comments.
We pick up not only comments that precede the declaration, but also
comments that *follow* the declaration -- thanks to the lookahead in
the lexer: after parsing the declgroup we've consumed the semicolon
and looked ahead through comments.
Added -Wdocumentation-html flag for semantic HTML errors to allow the user to
disable only HTML warnings (but not HTML parse errors, which we emit as
warnings in -Wdocumentation).
llvm-svn: 160078
which will appear in the vtable as used, not just those ones which were
declared within the class itself. Fixes an issue reported as comment#3 in
PR12763 -- we sometimes assert in codegen if we try to emit a reference to a
function declaration which we've not marked as referenced. This also matches
gcc's observed behavior.
llvm-svn: 159895
template instantiation. I wasn't able to reproduce this down to
anything small enough to put in our test suite, but it's "obviously"
okay to set the invalid bit earlier and precludes a
known-broken-but-not-marked-broken class from being used elsewhere.
llvm-svn: 159584
This works around a quirk in the way that explicit template specializations are
handled in Clang. We generate an implicit declaration from the original
template which the explicit specialization is considered to redeclare. This
trips up the explicit delete logic.
This change only works around that strange representation. At some point it'd
be nice to remove those extra declarations to make the AST more accurately
reflect the C++ semantics.
Review by Doug Gregor.
llvm-svn: 159167
resulted in it being reverted. A test for that bug was added in r158950.
Original comment:
If an object (such as a std::string) with an appropriate c_str() member function
is passed to a variadic function in a position where a format string indicates
that c_str()'s return type is desired, provide a note suggesting that the user
may have intended to call the c_str() member.
Factor the non-POD-vararg checking out of DefaultVariadicArgumentPromotion and
move it to SemaChecking in order to facilitate this. Factor the call checking
out of function call checking and block call checking, and extend it to cover
constructor calls too.
Patch by Sam Panzer!
llvm-svn: 159159
Revert "If an object (such as a std::string) with an appropriate c_str() member function"
This reverts commit 7d96f6106bfbd85b1af06f34fdbf2834aad0e47e.
llvm-svn: 158949
is passed to a variadic function in a position where a format string indicates
that c_str()'s return type is desired, provide a note suggesting that the user
may have intended to call the c_str() member.
Factor the non-POD-vararg checking out of DefaultVariadicArgumentPromotion and
move it to SemaChecking in order to facilitate this. Factor the call checking
out of function call checking and block call checking, and extend it to cover
constructor calls too.
Patch by Sam Panzer!
llvm-svn: 158887
target Objective-C runtime down to the frontend: break this
down into a single target runtime kind and version, and compute
all the relevant information from that. This makes it
relatively painless to add support for new runtimes to the
compiler. Make the new -cc1 flag, -fobjc-runtime=blah-x.y.z,
available at the driver level as a better and more general
alternative to -fgnu-runtime and -fnext-runtime. This new
concept of an Objective-C runtime also encompasses what we
were previously separating out as the "Objective-C ABI", so
fragile vs. non-fragile runtimes are now really modelled as
different kinds of runtime, paving the way for better overall
differentiation.
As a sort of special case, continue to accept the -cc1 flag
-fobjc-runtime-has-weak, as a sop to PLCompatibilityWeak.
I won't go so far as to say "no functionality change", even
ignoring the new driver flag, but subtle changes in driver
semantics are almost certainly not intended.
llvm-svn: 158793
* Escaped "::" and "<" as needed in Doxygen comments;
* Marked up code examples with \code...\endcode;
* Documented a \param that is current, instead of a few that aren't;
* Fixed up some \file and \brief comments.
llvm-svn: 158562
We need an efficient mechanism to determine whether a defaulted default
constructor is constexpr, in order to determine whether a class is a literal
type, so keep the incrementally-built form on CXXRecordDecl. Remove the
on-demand computation of same, so that we only have one method for determining
whether a default constructor is constexpr. This doesn't affect correctness,
since default constructor lookup is much simpler than selecting a constructor
for copying or moving.
We don't need a corresponding mechanism for defaulted copy or move constructors,
since they can't affect whether a type is a literal type. Conversely, checking
whether such functions are constexpr can require non-trivial effort, so we defer
such checks until the copy or move constructor is required.
Thus we now only compute whether a copy or move constructor is constexpr on
demand, and only compute whether a default constructor is constexpr in advance.
This is unfortunate, but seems like the best solution.
llvm-svn: 158290
an explicitly-defaulted default constructor would be constexpr. This is
necessary in weird (but well-formed) cases where a class has more than one copy
or move constructor.
Cleanup of now-unused parts of CXXRecordDecl to follow.
llvm-svn: 158289
In addition, I've made the pointer and reference typedef 'void' rather than T*
just so they can't get misused. I would've omitted them entirely but
std::distance likes them to be there even if it doesn't use them.
This rolls back r155808 and r155869.
Review by Doug Gregor incorporating feedback from Chandler Carruth.
llvm-svn: 158104
into one. These were all performing almost identical checks, with different bugs
in each of them.
This fixes PR12806 (we weren't setting the exception specification for an
explicitly-defaulted, non-user-provided default constructor) and enforces
8.4.2/2's rule that an in-class defaulted member must exactly match the implicit
parameter type.
llvm-svn: 156802
Sema::ConvertToIntegralOrEnumerationType() from PartialDiagnostics to
abstract "diagnoser" classes. Not much of a win here, but we're
-several PartialDiagnostics.
llvm-svn: 156217
off PartialDiagnostic. PartialDiagnostic is rather heavyweight for
something that is in the critical path and is rarely used. So, switch
over to an abstract-class-based callback mechanism that delays most of
the work until a diagnostic is actually produced. Good for ~11k code
size reduction in the compiler and 1% speedup in -fsyntax-only on the
code in <rdar://problem/11004361>.
llvm-svn: 156176
refactorings in that revision, and some of the subsequent bugfixes, which
seem to be relevant even without delayed exception specification parsing.
llvm-svn: 156031
filter_decl_iterator had a weird mismatch where both op* and op-> returned T*
making it difficult to generalize this filtering behavior into a reusable
library of any kind.
This change errs on the side of value, making op-> return T* and op* return
T&.
(reviewed by Richard Smith)
llvm-svn: 155808
Don't try to query whether an incomplete type has a trivial copy constructor
when determining whether a move constructor should be declared.
llvm-svn: 155575
non-const reference parameter type if the class had any subobjects with deleted
copy constructors. This causes a rejects-valid if the class's copy constructor
is explicitly defaulted (as happens for some implementations of std::pair etc).
llvm-svn: 155218
We have a new flavor of exception specification, EST_Uninstantiated. A function
type with this exception specification carries a pointer to a FunctionDecl, and
the exception specification for that FunctionDecl is instantiated (if needed)
and used in the place of the function type's exception specification.
When a function template declaration with a non-trivial exception specification
is instantiated, the specialization's exception specification is set to this
new 'uninstantiated' kind rather than being instantiated immediately.
Expr::CanThrow has migrated onto Sema, so it can instantiate exception specs
on-demand. Also, any odr-use of a function triggers the instantiation of its
exception specification (the exception specification could be needed by IRGen).
In passing, fix two places where a DeclRefExpr was created but the corresponding
function was not actually marked odr-used. We used to get away with this, but
don't any more.
Also fix a bug where instantiating an exception specification which refers to
function parameters resulted in a crash. We still have the same bug in default
arguments, which I'll be looking into next.
This, plus a tiny patch to fix libstdc++'s common_type, is enough for clang to
parse (and, in very limited testing, support) all of libstdc++4.7's standard
headers.
llvm-svn: 154886
exception specifications on member functions until after the closing
'}' for the containing class. This allows, for example, a member
function to throw an instance of its own class. Fixes PR12564 and a
fairly embarassing oversight in our C++98/03 support.
llvm-svn: 154844
in the declaration of a non-static member function after the
(optional) cv-qualifier-seq, which in practice means in the exception
specification and late-specified return type.
The new scheme here used to manage 'this' outside of a member function
scope is more general than the Scope-based mechanism previously used
for non-static data member initializers and late-parsesd attributes,
because it can also handle the cv-qualifiers on the member
function. Note, however, that a separate pass is required for static
member functions to determine whether 'this' was used, because we
might not know that we have a static function until after declaration
matching.
Finally, this introduces name mangling for 'this' and for the implicit
'this', which is intended to match GCC's mangling. Independent
verification for the new mangling test case would be appreciated.
Fixes PR10036 and PR12450.
llvm-svn: 154799
base-class subojects.
Incidentally, thinking about virtual bases makes it clear to me that
we're not appropriately computing the access to the virtual base's
member because we're not computing the best possible access to the
virtual base at all; in fact, we're basically assuming it's public.
I'll file a separate PR about that.
llvm-svn: 154346
to define a special member function as deleted so that it properly
establishes an object context for the accesses to the base subobject
members.
llvm-svn: 154343
- The [class.protected] restriction is non-trivial for any instance
member, even if the access lacks an object (for example, if it's
a pointer-to-member constant). In this case, it is equivalent to
requiring the naming class to equal the context class.
- The [class.protected] restriction applies to accesses to constructors
and destructors. A protected constructor or destructor can only be
used to create or destroy a base subobject, as a direct result.
- Several places were dropping or misapplying object information.
The standard could really be much clearer about what the object type is
supposed to be in some of these accesses. Usually it's easy enough to
find a reasonable answer, but still, the standard makes a very confident
statement about accesses to instance members only being possible in
either pointer-to-member literals or member access expressions, which
just completely ignores concepts like constructor and destructor
calls, using declarations, unevaluated field references, etc.
llvm-svn: 154248
move constructor/move assignment operator are not declared, rather than being
defined as deleted, so move operations on the derived class fall back to
copying rather than moving.
If a move operation on the derived class is explicitly defaulted, the
unmovable subobject will be copied instead of being moved.
llvm-svn: 153883
concerning qualified declarator-ids. We now diagnose extraneous
qualification at namespace scope (which we had previously missed) and
diagnose these qualification errors for all kinds of declarations; it
was rather uneven before. Fixes <rdar://problem/11135644>.
llvm-svn: 153577
The deferred lookup table building step couldn't accurately tell which Decls
should be included in the lookup table, and consequently built different tables
in some cases.
Fix this by removing lazy building of DeclContext name lookup tables. In
practice, the laziness was frequently not worthwhile in C++, because we
performed lookup into most DeclContexts. In C, it had a bit more value,
since there is no qualified lookup.
In the place of lazy lookup table building, we simply don't build lookup tables
for function DeclContexts at all. Such name lookup tables are not useful, since
they don't capture the scoping information required to correctly perform name
lookup in a function scope.
The resulting performance delta is within the noise on my testing, but appears
to be a very slight win for C++ and a very slight loss for C. The C performance
can probably be recovered (if it is a measurable problem) by avoiding building
the lookup table for the translation unit.
llvm-svn: 152608
track whether the referenced declaration comes from an enclosing
local context. I'm amenable to suggestions about the exact meaning
of this bit.
llvm-svn: 152491
- getSourceRange().getBegin() is about as awesome a pattern as .copy().size().
I already killed the hot paths so this doesn't seem to impact performance on my
tests-of-the-day, but it is a much more sensible (and shorter) pattern.
llvm-svn: 152419
starting with an underscore is ill-formed.
Since this rule rejects programs that were using <inttypes.h>'s macros, recover
from this error by treating the ud-suffix as a separate preprocessing-token,
with a DefaultError ExtWarn. The approach of treating such cases as two tokens
is under discussion for standardization, but is in any case a conforming
extension and allows existing codebases to keep building while the committee
makes up its mind.
Reword the warning on the definition of literal operators not starting with
underscores (which are, strangely, legal) to more explicitly state that such
operators can't be called by literals. Remove the special-case diagnostic for
hexfloats, since it was both triggering in the wrong cases and incorrect.
llvm-svn: 152287
Note that this transformation has a substantial semantic effect outside of ARC: it gives the converted lambda lifetime semantics similar to a block literal. With ARC, the effect is much less obvious because the lifetime of blocks is already managed.
llvm-svn: 151797
- variant members with nontrivial destructors make the containing class's
destructor deleted
- check for a virtual destructor after checking for overridden methods in the
base class(es)
- check for an inaccessible operator delete for a class with a virtual
destructor.
Do not try to call an anonymous union field's destructor from the destructor of
the containing class.
llvm-svn: 151483
trivial if the implicit declaration would be. Don't forget to set the Trivial
flag on the special member as well as on the class. It doesn't seem ideal that
we have two separate mechanisms for storing this information, but this patch
does not attempt to address that.
This leaves us in an interesting position where the has_trivial_X trait for a
class says 'yes' for a deleted but trivial X, but is_trivially_Xable says 'no'.
This seems to be what the standard requires.
llvm-svn: 151465
explicit conversion functions to initialize the argument to a
copy/move constructor that itself is the subject of direct
initialization. Since we don't have that much context in overload
resolution, we end up threading more flags :(.
Fixes <rdar://problem/10903741> / PR10456.
llvm-svn: 151409
A defaulted default constructor for a class X is defined as deleted if [...]
- X is a union and all of its variant members are of const-qualified type.
A pedantic reading therefore says that
union X { };
has a deleted default constructor, which is both silly and almost
certainly unintended. Pretend as if this this read
- X is a union with one or more variant members, and all of its
variant members are of const-qualified type.
llvm-svn: 151394
block pointer that returns a block literal which captures (by copy)
the lambda closure itself. Some aspects of the block literal are left
unspecified, namely the capture variable (which doesn't actually
exist) and the body (which will be filled in by IRgen because it can't
be written as an AST).
Because we're switching to this model, this patch also eliminates
tracking the copy-initialization expression for the block capture of
the conversion function, since that information is now embedded in the
synthesized block literal. -1 side tables FTW.
llvm-svn: 151131
explicit specialization of a function template, mark the instantiation as
constexpr if the specialization is, rather than requiring them to match.
llvm-svn: 151001
We had two separate issues here: firstly, varions functions were assuming that
they did not need to perform semantic checks on trivial destructors (this is
not true in C++11, where a trivial destructor can nonetheless be private or
deleted), and a bunch of DiagnoseUseOfDecl calls were missing for uses of
destructors.
llvm-svn: 150866
decent diagnostics. Finish the work of combining all the 'ShouldDelete'
functions into one. In unifying the code, fix a minor bug where an anonymous
union with a deleted default constructor as a member of a union wasn't being
considered as making the outer union's default constructor deleted.
llvm-svn: 150862
conversion to function pointer. Rather than having IRgen synthesize
the body of this function, we instead introduce a static member
function "__invoke" with the same signature as the lambda's
operator() in the AST. Sema then generates a body for the conversion
to function pointer which simply returns the address of __invoke. This
approach makes it easier to evaluate a call to the conversion function
as a constant, makes the linkage of the __invoke function follow the
normal rules for member functions, and may make life easier down the
road if we ever want to constexpr'ify some of lambdas.
Note that IR generation is responsible for filling in the body of
__invoke (Sema just adds a dummy body), because the body can't
generally be expressed in C++.
Eli, please review!
llvm-svn: 150783
pointers and block pointers). We use dummy definitions to keep the
invariant that an implicit, used definition has a body; IR generation
will substitute the actual contents, since they can't be represented
as C++.
For the block pointer case, compute the copy-initialization needed to
capture the lambda object in the block, which IR generation will need
later.
llvm-svn: 150645
function, provide a specialized diagnostic that indicates the kind of
special member function (default constructor, copy assignment
operator, etc.) and that it was implicitly deleted. Add a hook where
we can provide more detailed information later.
llvm-svn: 150611
lambda expressions. Because these issue was pulled back from Ready
status at the Kona meeting, we still emit an ExtWarn when using
default arguments for lambda expressions.
llvm-svn: 150519
* if, switch, range-based for: warn if semicolon is on the same line.
* for, while: warn if semicolon is on the same line and either next
statement is compound statement or next statement has more
indentation.
Replacing the semicolon with {} or moving the semicolon to the next
line will always silence the warning.
Tests from SemaCXX/if-empty-body.cpp merged into SemaCXX/warn-empty-body.cpp.
llvm-svn: 150515
the instantiation of a constexpr function temploid is now always constexpr, a
defaulted constexpr function temploid is often ill-formed by the rule in
[dcl.fct.def.default]p2 that an explicitly-defaulted constexpr function must
have a constexpr implicit definition. To avoid making loads of completely
reasonable code ill-formed, do not apply that rule to templates.
llvm-svn: 150453
1358, 1360, 1452 and 1453.
- Instantiations of constexpr functions are always constexpr. This removes the
need for separate declaration/definition checking, which is now gone.
- This makes it possible for a constexpr function to be virtual, if they are
only dependently virtual. Virtual calls to such functions are not constant
expressions.
- Likewise, it's now possible for a literal type to have virtual base classes.
A constexpr constructor for such a type cannot actually produce a constant
expression, though, so add a special-case diagnostic for a constructor call
to such a type rather than trying to evaluate it.
- Classes with trivial default constructors (for which value initialization can
produce a fully-initialized value) are considered literal types.
- Classes with volatile members are not literal types.
- constexpr constructors can be members of non-literal types. We do not yet use
static initialization for global objects constructed in this way.
llvm-svn: 150359
instead of having a special-purpose function.
- ActOnCXXDirectInitializer, which was mostly duplication of
AddInitializerToDecl (leading e.g. to PR10620, which Eli fixed a few days
ago), is dropped completely.
- MultiInitializer, which was an ugly hack I added, is dropped again.
- We now have the infrastructure in place to distinguish between
int x = {1};
int x({1});
int x{1};
-- VarDecl now has getInitStyle(), which indicates which of the above was used.
-- CXXConstructExpr now has a flag to indicate that it represents list-
initialization, although this is not yet used.
- InstantiateInitializer was renamed to SubstInitializer and simplified.
- ActOnParenOrParenListExpr has been replaced by ActOnParenListExpr, which
always produces a ParenListExpr. Placed that so far failed to convert that
back to a ParenExpr containing comma operators have been fixed. I'm pretty
sure I could have made a crashing test case before this.
The end result is a (I hope) considerably cleaner design of initializers.
More importantly, the fact that I can now distinguish between the various
initialization kinds means that I can get the tricky generalized initializer
test cases Johannes Schaub supplied to work. (This is not yet done.)
This commit passed self-host, with the resulting compiler passing the tests. I
hope it doesn't break more complicated code. It's a pretty big change, but one
that I feel is necessary.
llvm-svn: 150318
empty union. This still rejects anonymous member structs or unions which only
contain such empty class types, pending standard wording defining exactly what
an empty class type is.
llvm-svn: 150157
the sign bit doesn't have undefined behavior, but a signed left shift of a 1 bit
out of the sign bit still does. As promised to Howard :)
The suppression of the potential constant expression checking in system headers
is also removed, since the problem it was working around is gone.
llvm-svn: 150059
can't produce a constant expression is not ill-formed (so long as some
instantiation of that function can produce a constant expression).
llvm-svn: 149802
value of class type, look for a unique conversion operator converting to
integral or unscoped enumeration type and use that. Implements [expr.const]p5.
Sema::VerifyIntegerConstantExpression now performs the conversion and returns
the converted result. Some important callers of Expr::isIntegralConstantExpr
have been switched over to using it (including all of those required for C++11
conformance); this switch brings a side-benefit of improved diagnostics and, in
several cases, simpler code. However, some language extensions and attributes
have not been moved across and will not perform implicit conversions on
constant expressions of literal class type where an ICE is required.
In passing, fix static_assert to perform a contextual conversion to bool on its
argument.
llvm-svn: 149776
The recent support for potential constant expressions exposed a bug in the
implementation of libstdc++4.6, where numeric_limits<int>::min() is defined
as (int)1 << 31, which isn't a constant expression. Disable the 'constexpr
function never produces a constant expression' error inside system headers
to compensate.
llvm-svn: 149729
function definition can produce a constant expression. This also provides the
last few checks for [dcl.constexpr]p3 and [dcl.constexpr]p4.
llvm-svn: 149108
pointer to incomplete type from an ExtWarn to an error. We put the
ExtWarn in place as part of a workaround for Boost (PR6527), but it
(1) doesn't actually match a GCC extension and (2) has been fixed for
two years in Boost, and (3) causes us to emit code that fails badly at
run time, so it's a bad idea to keep it. Fixes PR11803.
llvm-svn: 148838
This is the last piece of N3031 (decltype in weird places) - supporting
the use of decltype in a class ctor's member-initializer-list to
specify the base classes to initialize.
Reviewed by Richard Smith.
llvm-svn: 148789
Fix some review comments.
Add a test for deduction when std::initializer_list isn't available yet.
Fix redundant error messages. This fixes and outstanding FIXME too.
llvm-svn: 148735
MSVC2010's pair class has a move assignment operator but no explicit copy
constructor, which makes it unusable without this change.
For symmetry, let move copy constructors not mark the default assignment
operator as deleted either. Both changes match cl.exe's behavior. Fixes
pr11826.
Also update the standard excerpt to point to the right paragraph.
llvm-svn: 148675
we have a redeclarable type, and only use the new virtual versions
(getPreviousDeclImpl() and getMostRecentDeclImpl()) when we don't have
that type information. This keeps us from penalizing users with strict
type information (and is the moral equivalent of a "final" method).
Plus, settle on the names getPreviousDecl() and getMostRecentDecl()
throughout.
llvm-svn: 148187
are still added if the cached correction fails validation.
Also fix a copy-and-paste error in a comment from my previous commit.
Finally, add an example of the benefit the typo correction callback adds
to TryNamespaceTypoCorrection--which happens to also tickle the above
caching problem, as the only way a non-namespace Decl would be added to
the possible corrections is if it was cached as the correction for a
previous instance of the same typo where the typo was corrected to a
non-namespace via a different code path.
llvm-svn: 147968
Also includes two examples of the callback: a wrapper/replacement for
the CorrectTypoContext enum, and a conversion of the two calls to
CorrectTypo in SemaDeclCXX.cpp (one of which provides verifiable
improvement to the typo correction, as demonstrated in the added test).
llvm-svn: 147962
Benjamin Kramer