On Wed, Jun 21, 2023 at 04:44:00PM -0400, David Malcolm via Gcc-patches wrote:
> I'd like to ping this C++ FE patch for review:
> https://gcc.gnu.org/pipermail/gcc-patches/2023-June/621779.html
Not an approval, but LGTM, though some nits below:
> On Wed, 2023-06-14 at 20:28 -0400, David Malcolm wrote:
> > PR c++/110164 notes that in cases where we have a forward decl
> > of a std library type such as:
> >
> > std::array<int, 10> x;
> >
> > we omit this diagnostic:
> >
> > error: aggregate ‘std::array<int, 10> x’ has incomplete type and cannot be
> > defined
> >
> > This patch adds this hint to the diagnostic:
> >
> > note: ‘std::array’ is defined in header ‘<array>’; this is probably fixable
> > by adding ‘#include <array>’
> >
> > Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu.
> > OK for trunk?
> >
> > gcc/cp/ChangeLog:
> > PR c++/110164
> > * cp-name-hint.h (maybe_suggest_missing_header): New decl.
> > * decl.cc: Define INCLUDE_MEMORY. Add include of
> > "cp/cp-name-hint.h".
> > (start_decl_1): Call maybe_suggest_missing_header.
> > * name-lookup.cc (maybe_suggest_missing_header): Remove "static".
> >
> > gcc/testsuite/ChangeLog:
> > PR c++/110164
> > * g++.dg/missing-header-pr110164.C: New test.
> > ---
> > gcc/cp/cp-name-hint.h | 3 +++
> > gcc/cp/decl.cc | 10 ++++++++++
> > gcc/cp/name-lookup.cc | 2 +-
> > gcc/testsuite/g++.dg/missing-header-pr110164.C | 10 ++++++++++
> > 4 files changed, 24 insertions(+), 1 deletion(-)
> > create mode 100644 gcc/testsuite/g++.dg/missing-header-pr110164.C
> >
> > diff --git a/gcc/cp/cp-name-hint.h b/gcc/cp/cp-name-hint.h
> > index bfa7c53c8f6..e2387e23d1f 100644
> > --- a/gcc/cp/cp-name-hint.h
> > +++ b/gcc/cp/cp-name-hint.h
> > @@ -32,6 +32,9 @@ along with GCC; see the file COPYING3. If not see
> >
> > extern name_hint suggest_alternatives_for (location_t, tree, bool);
> > extern name_hint suggest_alternatives_in_other_namespaces (location_t,
> > tree);
> > +extern name_hint maybe_suggest_missing_header (location_t location,
> > + tree name,
> > + tree scope);
The enclosing decls omit the parameter names; if you do that, it may
fit on one line.
> > extern name_hint suggest_alternative_in_explicit_scope (location_t, tree,
> > tree);
> > extern name_hint suggest_alternative_in_scoped_enum (tree, tree);
> >
> > diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
> > index a672e4844f1..504b08ec250 100644
> > --- a/gcc/cp/decl.cc
> > +++ b/gcc/cp/decl.cc
> > @@ -27,6 +27,7 @@ along with GCC; see the file COPYING3. If not see
> > line numbers. For example, the CONST_DECLs for enum values. */
> >
> > #include "config.h"
> > +#define INCLUDE_MEMORY
> > #include "system.h"
> > #include "coretypes.h"
> > #include "target.h"
> > @@ -46,6 +47,7 @@ along with GCC; see the file COPYING3. If not see
> > #include "c-family/c-objc.h"
> > #include "c-family/c-pragma.h"
> > #include "c-family/c-ubsan.h"
> > +#include "cp/cp-name-hint.h"
> > #include "debug.h"
> > #include "plugin.h"
> > #include "builtins.h"
> > @@ -5995,7 +5997,11 @@ start_decl_1 (tree decl, bool initialized)
> > ; /* An auto type is ok. */
> > else if (TREE_CODE (type) != ARRAY_TYPE)
> > {
> > + auto_diagnostic_group d;
> > error ("variable %q#D has initializer but incomplete type", decl);
> > + maybe_suggest_missing_header (input_location,
> > + TYPE_IDENTIFIER (type),
> > + TYPE_CONTEXT (type));
Maybe CP_TYPE_CONTEXT?
> > type = TREE_TYPE (decl) = error_mark_node;
> > }
> > else if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (type))))
> > @@ -6011,8 +6017,12 @@ start_decl_1 (tree decl, bool initialized)
> > gcc_assert (CLASS_PLACEHOLDER_TEMPLATE (type));
> > else
> > {
> > + auto_diagnostic_group d;
> > error ("aggregate %q#D has incomplete type and cannot be defined",
> > decl);
> > + maybe_suggest_missing_header (input_location,
> > + TYPE_IDENTIFIER (type),
> > + TYPE_CONTEXT (type));
Here as well.
> > /* Change the type so that assemble_variable will give
> > DECL an rtl we can live with: (mem (const_int 0)). */
> > type = TREE_TYPE (decl) = error_mark_node;
> > diff --git a/gcc/cp/name-lookup.cc b/gcc/cp/name-lookup.cc
> > index 6ac58a35b56..917b481c163 100644
> > --- a/gcc/cp/name-lookup.cc
> > +++ b/gcc/cp/name-lookup.cc
> > @@ -6796,7 +6796,7 @@ maybe_suggest_missing_std_header (location_t
> > location, tree name)
> > for NAME within SCOPE at LOCATION, or an empty name_hint if this isn't
> > applicable. */
> >
> > -static name_hint
> > +name_hint
> > maybe_suggest_missing_header (location_t location, tree name, tree scope)
> > {
> > if (scope == NULL_TREE)
> > diff --git a/gcc/testsuite/g++.dg/missing-header-pr110164.C
> > b/gcc/testsuite/g++.dg/missing-header-pr110164.C
> > new file mode 100644
> > index 00000000000..15980071c38
> > --- /dev/null
> > +++ b/gcc/testsuite/g++.dg/missing-header-pr110164.C
Can we put the new test into g++.dg/diagnostic/?
Thanks,
> > @@ -0,0 +1,10 @@
> > +// { dg-require-effective-target c++11 }
> > +
> > +#include <map>
> > +
> > +std::array<int, 10> a1; /* { dg-error "incomplete type" } */
> > +/* { dg-message "'std::array' is defined in header '<array>'; this is
> > probably fixable by adding '#include <array>'" "hint" { target *-*-* } .-1
> > } */
> > +
> > +std::array<int, 10> a2 {5}; /* { dg-error "incomplete type" } */
> > +/* { dg-message "'std::array' is defined in header '<array>'; this is
> > probably fixable by adding '#include <array>'" "hint" { target *-*-* } .-1
> > } */
> > +
>
Marek
