performs name lookup for an identifier and resolves it to a
type/expression/template/etc. in the same step. This scheme is
intended to improve both performance (by reducing the number of
redundant name lookups for a given identifier token) and error
recovery (by giving Sema a chance to correct type names before the
parser has decided that the identifier isn't a type name). For
example, this allows us to properly typo-correct type names at the
beginning of a statement:
t.c:6:3: error: use of undeclared identifier 'integer'; did you mean
'Integer'?
integer *i = 0;
^~~~~~~
Integer
t.c:1:13: note: 'Integer' declared here
typedef int Integer;
^
Previously, we wouldn't give a Fix-It because the typo correction
occurred after the parser had checked whether "integer" was a type
name (via Sema::getTypeName(), which isn't allowed to typo-correct)
and therefore decided to parse "integer * i = 0" as an expression. By
typo-correcting earlier, we typo-correct to the type name Integer and
parse this as a declaration.
Moreover, in this context, we can also typo-correct identifiers to
keywords, e.g.,
t.c:7:3: error: use of undeclared identifier 'vid'; did you mean
'void'?
vid *p = i;
^~~
void
and recover appropriately.
Note that this is very much a work-in-progress. The new
Sema::ClassifyName is only used for expression-or-declaration
disambiguation in C at the statement level. The next steps will be to
make this work for the same disambiguation in C++ (where
functional-style casts make some trouble), then push it
further into the parser to eliminate more redundant name lookups.
Fixes <rdar://problem/7963833> for C and starts us down the path of
<rdar://problem/8172000>.
llvm-svn: 130082
This patch authored by Eric Niebler.
Many methods on the Sema class (e.g. ConvertPropertyForRValue) take Expr
pointers as in/out parameters (Expr *&). This is especially true for the
routines that apply implicit conversions to nodes in-place. This design is
workable only as long as those conversions cannot fail. If they are allowed
to fail, they need a way to report their failures. The typical way of doing
this in clang is to use an ExprResult, which has an extra bit to signal a
valid/invalid state. Returning ExprResult is de riguour elsewhere in the Sema
interface. We suggest changing the Expr *& parameters in the Sema interface
to ExprResult &. This increases interface consistency and maintainability.
This interface change is important for work supporting MS-style C++
properties. For reasons explained here
<http://lists.cs.uiuc.edu/pipermail/cfe-dev/2011-February/013180.html>,
seemingly trivial operations like rvalue/lvalue conversions that formerly
could not fail now can. (The reason is that given the semantics of the
feature, getter/setter method lookup cannot happen until the point of use, at
which point it may be found that the method does not exist, or it may have the
wrong type, or overload resolution may fail, or it may be inaccessible.)
llvm-svn: 129143
to cope with non-type templates by providing appropriate
errors. Previously, we would either assert, crash, or silently build a
dependent type when we shouldn't. Fixes PR9226.
llvm-svn: 127037
DeclContext once we've created it. This mirrors what we do for
function parameters, where the parameters start out with
translation-unit context and then are adopted by the appropriate
DeclContext when it is created. Also give template parameters public
access and make sure that they don't show up for the purposes of name
lookup.
Fixes PR9400, a regression introduced by r126920, which implemented
substitution of default template arguments provided in template
template parameters (C++ core issue 150).
How on earth could the DeclContext of a template parameter affect the
handling of default template arguments?
I'm so glad you asked! The link is
Sema::getTemplateInstantiationArgs(), which determines the outer
template argument lists that correspond to a given declaration. When
we're instantiating a default template argument for a template
template parameter within the body of a template definition (not it's
instantiation, per core issue 150), we weren't getting any outer
template arguments because the context of the template template
parameter was the translation unit. Now that the context of the
template template parameter is its owning template, we get the
template arguments from the injected-class-name of the owning
template, so substitution works as it should.
llvm-svn: 127004
template <class T> void foo();
template <> void foo<int>(); /* Spec 1 */
template <> void foo<int>(); /* Spec 2 */
If we look at the main location of the first explicit specialization (Spec 1) it can be seen that it points to the name of the *second* explicit specialization (Spec 2), which is a redeclaration of Spec1.
Hence, the source range obtained for Spec1 is not only inaccurate, but also invalid (the end location comes before the start location).
llvm-svn: 127002
parameter, save the instantiated default template arguments along with
the explicitly-specified template argument list. That way, we prefer
the default template template arguments corresponding to the template
template parameter rather than those of its template template argument.
This addresses the likely direction of C++ core issue 150, and fixes
PR9353/<rdar://problem/9069136>, bringing us closer to the behavior of
EDG and GCC.
llvm-svn: 126920
template arguments. I believe that this is the last place in the AST
where we were storing a source range for a nested-name-specifier
rather than a proper nested-name-specifier location structure. (Yay!)
There is still a lot of cleanup to do in the TreeTransform, which
doesn't take advantage of nested-name-specifiers with source-location
information everywhere it could.
llvm-svn: 126844
template specialization types. This also required some parser tweaks,
since we were losing track of the nested-name-specifier's source
location information in several places in the parser. Other notable
changes this required:
- Sema::ActOnTagTemplateIdType now type-checks and forms the
appropriate type nodes (+ source-location information) for an
elaborated-type-specifier ending in a template-id. Previously, we
used a combination of ActOnTemplateIdType and
ActOnTagTemplateIdType that resulted in an ElaboratedType wrapped
around a DependentTemplateSpecializationType, which duplicated the
keyword ("class", "struct", etc.) and nested-name-specifier
storage.
- Sema::ActOnTemplateIdType now gets a nested-name-specifier, which
it places into the returned type-source location information.
- Sema::ActOnDependentTag now creates types with source-location
information.
llvm-svn: 126808
template specialization types. There are still a few rough edges to
clean up with some of the parser actions dropping
nested-name-specifiers too early.
llvm-svn: 126776
nested-name-speciciers within elaborated type names, e.g.,
enum clang::NestedNameSpecifier::SpecifierKind
Fixes in this iteration include:
(1) Compute the type-source range properly for a dependent template
specialization type that starts with "template template-id ::", as
in a member access expression
dep->template f<T>::f()
This is a latent bug I triggered with this change (because now we're
checking the computed source ranges for dependent template
specialization types). But the real problem was...
(2) Make sure to set the qualifier range on a dependent template
specialization type appropriately. This will go away once we push
nested-name-specifier locations into dependent template
specialization types, but it was the source of the
valgrind errors on the buildbots.
llvm-svn: 126765
a dependent template name rather than (indirectly and incorrectly)
trying to determine whether we can compute a context for the
nested-name-specifier. Fixes a GCC testsuite regression,
<rdar://problem/9068589>.
llvm-svn: 126749
information for qualifier type names throughout the parser to address
several problems.
The commit message from r126737:
Push nested-name-specifier source location information into elaborated
name types, e.g., "enum clang::NestedNameSpecifier::SpecifierKind".
Aside from the normal changes, this also required some tweaks to the
parser. Essentially, when we're looking at a type name (via
getTypeName()) specifically for the purpose of creating an annotation
token, we pass down the flag that asks for full type-source location
information to be stored within the returned type. That way, we retain
source-location information involving nested-name-specifiers rather
than trying to reconstruct that information later, long after it's
been lost in the parser.
With this change, test/Index/recursive-cxx-member-calls.cpp is showing
much improved results again, since that code has lots of
nested-name-specifiers.
llvm-svn: 126748
name types, e.g., "enum clang::NestedNameSpecifier::SpecifierKind".
Aside from the normal changes, this also required some tweaks to the
parser. Essentially, when we're looking at a type name (via
getTypeName()) specifically for the purpose of creating an annotation
token, we pass down the flag that asks for full type-source location
information to be stored within the returned type. That way, we retain
source-location information involving nested-name-specifiers rather
than trying to reconstruct that information later, long after it's
been lost in the parser.
With this change, test/Index/recursive-cxx-member-calls.cpp is showing
much improved results again, since that code has lots of
nested-name-specifiers.
llvm-svn: 126737
DependentNameTypeLoc. Teach the recursive AST visitor and libclang how to
walk DependentNameTypeLoc nodes.
Also, teach libclang about TypedefDecl source ranges, so that we get
those. The massive churn in test/Index/recursive-cxx-member-calls.cpp
is a good thing: we're annotating a lot more of this test correctly
now.
llvm-svn: 126729
source-location information. We don't actually preserve this
information in any of the resulting TypeLocs (yet), so it doesn't
matter.
llvm-svn: 126693
UnresolvedLookupExpr and UnresolvedMemberExpr.
Also, improve the computation that checks whether the base of a member
expression (either unresolved or dependent-scoped) is implicit. The
previous check didn't cover all of the cases we use in our
representation, which threw off source-location information for these
expressions (which, in turn, caused some breakage in libclang's token
annotation).
llvm-svn: 126681
CXXDependentScopeMemberExpr, and clean up instantiation of
nested-name-specifiers with dependent template specialization types in
the process.
llvm-svn: 126663
dependent template names. There is still a lot of redundant code in
TreeTransform to cope with TemplateSpecializationTypes, which I'll
remove in stages.
llvm-svn: 126656
specifiers such as
typename T::template apply<U>
Previously, we would turn T::template apply<U> into a
TemplateSpecializationType. Then, we'd reprocess that
TemplateSpecializationType and turn it into either a
TemplateSpecializationType wrapped in an ElaboratedType (when we could
resolve "apply" to a template declaration) or a
DependentTemplateSpecializationType. We now produce the same ASTs but
without generating the intermediate TemplateSpecializationType.
The end goal here is to avoid generating TemplateSpecializationTypes
with dependent template-names, ever. We're not there yet.
llvm-svn: 126589
UnresolvedUsingValueDecl to use NestedNameSpecifierLoc rather than the
extremely-lossy NestedNameSpecifier/SourceRange pair it used to use,
improving source-location information.
Various infrastructure updates to support NestedNameSpecifierLoc:
- AST/PCH (de-)serialization
- Recursive AST visitor
- libclang traversal (including the first tests of this
functionality)
llvm-svn: 126459
nested-name-specifiers throughout the parser, and provide a new class
(NestedNameSpecifierLoc) that contains a nested-name-specifier along
with its type-source information.
Right now, this information is completely useless, because we don't
actually store the source-location information anywhere in the
AST. Call this Step 1/N.
llvm-svn: 126391
way it keeps track of namespaces. Previously, we would map from the
namespace alias to its underlying namespace when building a
nested-name-specifier, losing source information in the process.
llvm-svn: 126358
includes explicitly-specified template arguments) to a function
template specialization in cases where no deduction is performed or
deduction fails. Patch by Faisal Vali, fixes PR7505!
llvm-svn: 126048
enumeration type, we were generating an integer literal implicitly
casted to the appropriate enumeration type. However, later checks on
that expression would strip the implicit cast.
This commit tweaks the lame hack, by creating an explicit cast instead
of an implicit cast. The right answer is to introduce a
SubstNonTypeTemplateParmExpr expression that acts like the substituted
result. I'll investigate that soon.
llvm-svn: 125818
it's okay for the following template parameters to not have default
arguments (since those template parameters can still be
deduced). Also, downgrade the error about default template arguments
in function templates to an extension warning, since this is a
harmless C++0x extension.
llvm-svn: 124855
argument but doesn't (because previous template parameters had default
arguments), clear out all of the default arguments so that we maintain
the invariant that a template parameter has a default argument only if
subsequence template parameters also have default arguments.
Fixes a crash-on-invalid <rdar://problem/8913649>.
llvm-svn: 124345
derived-to-base cast that also casts away constness (one of the cases
for static_cast followed by const_cast) would be treated as a bit-cast
rather than a derived-to-base class, causing miscompiles and
heartburn.
Fixes <rdar://problem/8913298>.
llvm-svn: 124340
generate meaningful [*] template argument location information.
[*] Well, as meaningful as possible, given that this entire code path
is a hack for when we've lost type-source information.
llvm-svn: 124211
