> On Fri, 2023-06-23 at 12:08 -0400, Jason Merrill wrote:
> > On 6/22/23 11:50, Marek Polacek wrote:
> > > 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:
> OK with the tweaks Marek suggests.
Thanks Marek and Jason.
For reference, here's what I pushed (as r14-2055-g13709b518aa976):
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 emit 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>’
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/diagnostic/missing-header-pr110164.C: New test.
---
gcc/cp/cp-name-hint.h | 1 +
gcc/cp/decl.cc | 10 ++++++++++
gcc/cp/name-lookup.cc | 2 +-
.../g++.dg/diagnostic/missing-header-pr110164.C | 10 ++++++++++
4 files changed, 22 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/diagnostic/missing-header-pr110164.C
diff --git a/gcc/cp/cp-name-hint.h b/gcc/cp/cp-name-hint.h
index bfa7c53c8f6..7693980138a 100644
--- a/gcc/cp/cp-name-hint.h
+++ b/gcc/cp/cp-name-hint.h
@@ -32,6 +32,7 @@ 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, tree, tree);
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 c07a4a8d58d..60f107d50c4 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),
+ CP_TYPE_CONTEXT (type));
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),
+ CP_TYPE_CONTEXT (type));
/* 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 53b6870f067..74565184403 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/diagnostic/missing-header-pr110164.C
b/gcc/testsuite/g++.dg/diagnostic/missing-header-pr110164.C
new file mode 100644
index 00000000000..15980071c38
--- /dev/null
+++ b/gcc/testsuite/g++.dg/diagnostic/missing-header-pr110164.C
@@ -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 } */
+
--
2.26.3
