C++17 permits using 'typename' or 'class' for a template template
parameter, but the error message in the parser only refers to 'class'.
This patch, in C++17 or newer modes, adds "or 'template'" to the
diagnostic.
No other compiler accepts this as an extension, not even in permissive
mode. We're not doing anyone any favors by allowing this, and it's
unlikely to be at all common, even in Clang-only code, in the wild.
- add more tests (the test added in 2f448467e4 is weak);
- improve the `MyTemplate<type_typo, int>();` case, with this patch, typo correction
suggests the type decl, and no regressions found.
Differential Revision: https://reviews.llvm.org/D83025
The DependentNameType must have a non-null NSS. This property could be
violated during typo correction.
Differential Revision: https://reviews.llvm.org/D82738
in the token stream.
Previously we deleted all template-id annotations at the end of each
top-level declaration. That doesn't work: we can do some lookahead and
form a template-id annotation, and then roll back that lookahead, parse,
and decide that we're missing a semicolon at the end of a top-level
declaration, before we reach the annotation token. In that situation,
we'd end up parsing the annotation token after deleting its associated
data, leading to various forms of badness.
We now only delete template-id annotations if the preprocessor can
assure us that there are no annotation tokens left in the token stream
(or if we're already at EOF). This lets us delete the annotation tokens
earlier in a lot of cases; we now clean them up at the end of each
statement and class member, not just after each top-level declaration.
This also permitted some simplification of the delay-parsed templates
cleanup code.
Instead of bailing out of parsing when we encounter an invalid
template-name or template arguments in a template-id, produce an
annotation token describing the invalid construct.
This avoids duplicate errors and generally allows us to recover better.
In principle we should be able to extend this to store some kinds of
invalid template-id in the AST for tooling use, but that isn't handled
as part of this change.
classification.
We were accidentally treating invalid scope specs as being empty,
resulting in our trying to form an ADL-only call with a qualified
callee, which tripped up an assert later on.
template name is not visible to unqualified lookup.
In order to support this without a severe degradation in our ability to
diagnose typos in template names, this change significantly restructures
the way we handle template-id-shaped syntax for which lookup of the
template name finds nothing.
Instead of eagerly diagnosing an undeclared template name, we now form a
placeholder template-name representing a name that is known to not find
any templates. When the parser sees such a name, it attempts to
disambiguate whether we have a less-than comparison or a template-id.
Any diagnostics or typo-correction for the name are delayed until its
point of use.
The upshot should be a small improvement of our diagostic quality
overall: we now take more syntactic context into account when trying to
resolve an undeclared identifier on the left hand side of a '<'. In
fact, this works well enough that the backwards-compatible portion (for
an undeclared identifier rather than a lookup that finds functions but
no function templates) is enabled in all language modes.
llvm-svn: 360308
The parser can only be tricked into parsing a function template
definition by inserting a typename keyword before the function template
declaration. This used to make us crash, and now it's fixed.
While here, remove an unneeded boolean parameter from ParseDeclGroup.
This boolean always corresponded to non-typedef declarators at file
scope. ParseDeclGroup already has precise diagnostics for the function
definition typedef case, so we can let that through.
Fixes PR21839.
llvm-svn: 224287
In delayed template parsing mode, adjust the template depth counter for each template parameter list associated with an out of line member template specialization.
llvm-svn: 196351
Specifically, using a an integer outside [0, 1] as a boolean constant seems to
be an easy mistake to make with things like "x == a || b" where the author
intended "x == a || x == b".
The bug caused by calling SkipUntil with three token kinds was also identified
by a VC diagnostic & reported by Francois Pichet as review feedback for my
commit r154163. I've included test cases to verify the error recovery that was
broken/poorly implemented due to this bug.
The other fix (lib/Sema/SemaExpr.cpp) seems like that code was never actually
reached in any of Clang's tests & is related to Objective C features I'm not
familiar with, so I've not been able to construct a test case for it. Perhaps
someone else can.
llvm-svn: 154325
In a few cases clang emitted a rather content-free diagnostic: 'parse error'.
This change replaces two actual cases (template parameter parsing and K&R
parameter declaration parsing) with more specific diagnostics and removes a
third dead case of this in the BalancedDelimiterTracker (the ctor already
checked the invariant necessary to ensure that the diag::parse_error was never
actually used).
llvm-svn: 154224
Based on Doug's feedback to r153887 this omits the FixIt if the following token
isn't syntactically valid for the context. (not a comma, '...', identifier,
'>', or '>>')
There's a bunch of work to handle the '>>' case, but it makes for a much more
pleasant diagnostic in this case.
llvm-svn: 154163
The diagnostic message correctly informs the user that they have omitted the
'class' keyword, but neither suggests this insertion as a fixit, nor attempts
to recover as if they had provided the keyword.
This fixes the recovery, adds the fixit, and adds a separate diagnostic and
corresponding replacement fixit for cases where the user wrote 'struct' or
'typename' instead of 'class' (suggested by Richard Smith as a possible common
mistake).
I'm not sure the diagnostic message for either the original or new cases feel
very Clang-esque, so I'm open to suggestions there. The fixit hints make it
fairly easy to see what's required, though.
llvm-svn: 153887
context. This happens fairly rarely (which is why we got away with
this bug). Fixes PR6184, where we skipped over the template parameter
scope while tentatively parsing.
llvm-svn: 95376
- This is designed to make it obvious that %clang_cc1 is a "test variable"
which is substituted. It is '%clang_cc1' instead of '%clang -cc1' because it
can be useful to redefine what gets run as 'clang -cc1' (for example, to set
a default target).
llvm-svn: 91446
templates, and keep track of how those member classes were
instantiated or specialized.
Make sure that we don't try to instantiate an explicitly-specialized
member class of a class template, when that explicit specialization
was a declaration rather than a definition.
llvm-svn: 83547
member functions of class template specializations, and static data
members. The mechanics are (mostly) present, but the semantic analysis
is very weak.
llvm-svn: 82789
templates, e.g.,
template<typename T>
struct Outer {
struct Inner;
};
template<typename T>
struct Outer<T>::Inner {
// ...
};
Implementing this feature required some extensions to ActOnTag, which
now takes a set of template parameter lists, and is the precursor to
removing the ActOnClassTemplate function from the parser Action
interface. The reason for this approach is simple: the parser cannot
tell the difference between a class template definition and the
definition of a member of a class template; both have template
parameter lists, and semantic analysis determines what that template
parameter list means.
There is still some cleanup to do with ActOnTag and
ActOnClassTemplate. This commit provides the basic functionality we
need, however.
llvm-svn: 76820
templates.
For example, this now type-checks (but does not instantiate the body
of deref<int>):
template<typename T> T& deref(T* t) { return *t; }
void test(int *ip) {
int &ir = deref(ip);
}
Specific changes/additions:
* Template argument deduction from a call to a function template.
* Instantiation of a function template specializations (just the
declarations) from the template arguments deduced from a call.
* FunctionTemplateDecls are stored directly in declaration contexts
and found via name lookup (all forms), rather than finding the
FunctionDecl and then realizing it is a template. This is
responsible for most of the churn, since some of the core
declaration matching and lookup code assumes that all functions are
FunctionDecls.
llvm-svn: 74213
<rdar://problem/6952203>.
To do this, we actually remove a not-quite-correct optimization in the
C++ name lookup routines. We'll revisit this optimization for the
general case once more C++ is working.
llvm-svn: 73659
-Makes typeof consistent with sizeof/alignof
-Fixes a bug when '>' is in a typeof expression, inside a template type param:
A<typeof(x>1)> a;
llvm-svn: 72255
parse just a single declaration and provide a reasonable diagnostic
when the "only one declarator per template declaration" rule is
violated. This eliminates some ugly, ugly hackery where we used to
require thatn the layout of a DeclGroup of a single element be the
same as the layout of a single declaration.
llvm-svn: 71596
arguments. This commit covers checking and merging default template
arguments from previous declarations, but it does not cover the actual
use of default template arguments when naming class template
specializations.
llvm-svn: 64229
Erich Keane