On Mon, Aug 20, 2018 at 11:10 PM David Malcolm <dmalc...@redhat.com> wrote:
>
> We often emit logically-related groups of diagnostics.
>
> A relatively simple case is this:
>
> if (warning_at (body_loc, OPT_Wmultistatement_macros,
> "macro expands to multiple statements"))
> inform (guard_loc, "some parts of macro expansion are not guarded by "
> "this %qs clause", guard_tinfo_to_string (keyword));
>
> where the "note" diagnostic issued by the "inform" call
> is guarded by the -Wmultistatement_macros warning.
>
> More complicated examples can be seen in the C++ frontend,
> where e.g. print_z_candidates can lead to numerous "note"
> diagnostics being emitted.
>
> I'm looking at various ways to improve how we handle such related
> diagnostics, but, prior to this patch, there was no explicit
> relationship between these diagnostics: the diagnostics subsystem
> had no way of "knowing" that these were related.
>
> This patch introduces a simple way to group the diagnostics:
> an auto_diagnostic_group class: all diagnostics emitted within
> the lifetime of an auto_diagnostic_group instance are logically
> grouped.
>
> Hence in the above example, the two diagnostics can be grouped
> by simply adding an auto_diagnostic_group instance:
>
> auto_diagnostic_group d;
> if (warning_at (body_loc, OPT_Wmultistatement_macros,
> "macro expands to multiple statements"))
> inform (guard_loc, "some parts of macro expansion are not guarded by "
> "this %qs clause", guard_tinfo_to_string (keyword));
>
> Some more awkard cases are of the form:
>
> if (some_condition
> && warning_at (...)
> && more_conditions)
> inform (...);
>
> which thus need restructuring to:
>
> if (some_condition)
> {
> auto_diagnostic_group d;
> warning_at (...);
> if (more_conditions)
> inform (...);
> }
>
> so that the lifetime of the auto_diagnostic_group groups the
> warning_at and the inform call.
>
> Nesting is handled by simply tracking a nesting depth within the
> diagnostic_context.: all diagnostics are treated as grouped until the
> final auto_diagnostic_group is popped.
>
> diagnostic.c uses this internally, so that all diagnostics are part of
> a group - those that are "by themselves" are treated as being part of
> a group with one element.
>
> The diagnostic_context gains optional callbacks for displaying the
> start of a group (when the first diagnostic is emitted within it), and
> the end of a group (for when the group was non-empty); these callbacks
> are unused by default, but a test plugin demonstrates them (and verifies
> that the machinery is working).
>
> As noted above, I'm looking at various ways to use the grouping to
> improve how we output the diagnostics.
>
> FWIW, I experimented with a more involved implementation, of the form:
>
> diagnostic_group d;
> if (d.warning_at (body_loc, OPT_Wmultistatement_macros,
> "macro expands to multiple statements"))
> d.inform (guard_loc, "some parts of macro expansion are not guarded by "
> "this %qs clause", guard_tinfo_to_string (keyword));
>
> which had the advantage of allowing auto-detection of the places where
> groups were needed (by converting ::warning_at's return type to bool),
> but it was a much more invasive patch, especially when dealing with
> the places in the C++ frontend that can emit numerous notes after
> an error or warning (and thus having to pass the group around)
> Hence I went with this simpler approach.
IMHO a shame because the
auto_diagnostic_group d;
stuff really looks unrelated and it's probably easy enough to not notice
errors with it.
I'd have used
if (diagnostic_group d = warning_at (...))
d.inform (...);
for the common idiom so we'd be able to elide the conditionals. That is
diagnostic_group initializes from a bool, converts to a bool and the
forwarder methods do nothing if it was initialized from false.
Richard.
>
> Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu; adds
> 4 PASS results to gcc.sum.
>
> Committed to trunk as r263675.
>
> gcc/c-family/ChangeLog:
> PR other/84889
> * c-attribs.c (common_handle_aligned_attribute): Add
> auto_diagnostic_group instance.
> * c-indentation.c (warn_for_misleading_indentation): Likewise.
> * c-opts.c (c_common_post_options): Likewise.
> * c-warn.c (warn_logical_not_parentheses): Likewise.
> (warn_duplicated_cond_add_or_warn): Likewise.
> (warn_for_multistatement_macros): Likewise.
>
> gcc/c/ChangeLog:
> PR other/84889
> * c-decl.c (pushtag): Add auto_diagnostic_group instance.
> (diagnose_mismatched_decls): Likewise, in various places.
> (warn_if_shadowing): Likewise.
> (implicit_decl_warning): Likewise.
> (implicitly_declare): Likewise.
> (undeclared_variable): Likewise.
> (declare_label): Likewise.
> (grokdeclarator): Likewise.
> (start_function): Likewise.
> * c-parser.c (c_parser_declaration_or_fndef): Likewise.
> (c_parser_parameter_declaration): Likewise.
> (c_parser_binary_expression): Likewise.
> * c-typeck.c (c_expr_sizeof_expr): Likewise.
> (parser_build_binary_op): Likewise.
> (build_unary_op): Likewise.
> (error_init): Likewise.
> (pedwarn_init): Likewise.
> (warning_init): Likewise.
> (convert_for_assignment): Likewise.
>
> gcc/cp/ChangeLog:
> PR other/84889
> * call.c (build_user_type_conversion_1): Add auto_diagnostic_group
> instance(s).
> (print_error_for_call_failure): Likewise.
> (build_op_call_1): Likewise.
> (build_conditional_expr_1): Likewise.
> (build_new_op_1): Likewise.
> (build_op_delete_call): Likewise.
> (convert_like_real): Likewise.
> (build_over_call): Likewise.
> (build_new_method_call_1): Likewise.
> (joust): Likewise.
> * class.c (check_tag): Likewise.
> (finish_struct_anon_r): Likewise.
> (one_inherited_ctor): Likewise.
> (finalize_literal_type_property): Likewise.
> (explain_non_literal_class): Likewise.
> (find_flexarrays): Likewise.
> (resolve_address_of_overloaded_function): Likewise.
> * constexpr.c (ensure_literal_type_for_constexpr_object): Likewise.
> (is_valid_constexpr_fn): Likewise.
> (cx_check_missing_mem_inits): Likewise.
> * cp-gimplify.c (cp_genericize_r): Likewise.
> * cvt.c (maybe_warn_nodiscard): Likewise.
> * decl.c (warn_extern_redeclared_static): Likewise.
> (check_redeclaration_exception_specification): Likewise.
> (check_no_redeclaration_friend_default_args): Likewise.
> (duplicate_decls): Likewise.
> (redeclaration_error_message): Likewise.
> (warn_misplaced_attr_for_class_type): Likewise.
> * decl2.c (finish_static_data_member_decl): Likewise.
> (no_linkage_error): Likewise.
> (cp_warn_deprecated_use): Likewise.
> * error.c (qualified_name_lookup_error): Likewise.
> * friend.c (make_friend_class): Likewise.
> (do_friend): Likewise.
> * init.c (perform_member_init): Likewise.
> (build_new_1): Likewise.
> (build_vec_delete_1): Likewise.
> (build_delete): Likewise.
> * lex.c (unqualified_name_lookup_error): Likewise.
> * name-lookup.c (check_extern_c_conflict): Likewise.
> (inform_shadowed): New function.
> (check_local_shadow): Add auto_diagnostic_group instances,
> replacing goto "inform_shadowed" label with call to subroutine.
> (set_local_extern_decl_linkage): Add auto_diagnostic_group
> instance(s).
> * parser.c (cp_parser_diagnose_invalid_type_name): Likewise.
> (cp_parser_namespace_name): Likewise.
> * pt.c (check_specialization_namespace): Likewise.
> (check_template_variable): Likewise.
> (warn_spec_missing_attributes): Likewise.
> (check_explicit_specialization): Likewise.
> (process_partial_specialization): Likewise.
> (lookup_template_class_1): Likewise.
> (finish_template_variable): Likewise.
> (do_auto_deduction): Likewise.
> * search.c (check_final_overrider): Likewise.
> (look_for_overrides_r): Likewise.
> * tree.c (maybe_warn_parm_abi): Likewise.
> * typeck.c (cxx_sizeof_expr): Likewise.
> (cp_build_function_call_vec): Likewise.
> (cp_build_binary_op): Likewise.
> (convert_for_assignment): Likewise.
> (maybe_warn_about_returning_address_of_local): Likewise.
> * typeck2.c (abstract_virtuals_error_sfinae): Likewise.
> (check_narrowing): Likewise.
>
> gcc/ChangeLog:
> PR other/84889
> * attribs.c (diag_attr_exclusions): Add auto_diagnostic_group
> instance.
> (decl_attributes): Likewise.
> * calls.c (maybe_warn_nonstring_arg): Add auto_diagnostic_group
> instance.
> * cgraphunit.c (maybe_diag_incompatible_alias): Likewise.
> * diagnostic-core.h (class auto_diagnostic_group): New class.
> * diagnostic.c (diagnostic_initialize): Initialize the new fields.
> (diagnostic_report_diagnostic): Handle the first diagnostics within
> a group.
> (emit_diagnostic): Add auto_diagnostic_group instance.
> (inform): Likewise.
> (inform_n): Likewise.
> (warning): Likewise.
> (warning_at): Likewise.
> (warning_n): Likewise.
> (pedwarn): Likewise.
> (permerror): Likewise.
> (error): Likewise.
> (error_n): Likewise.
> (error_at): Likewise.
> (sorry): Likewise.
> (fatal_error): Likewise.
> (internal_error): Likewise.
> (internal_error_no_backtrace): Likewise.
> (auto_diagnostic_group::auto_diagnostic_group): New ctor.
> (auto_diagnostic_group::~auto_diagnostic_group): New dtor.
> * diagnostic.h (struct diagnostic_context): Add fields
> "diagnostic_group_nesting_depth",
> "diagnostic_group_emission_count", "begin_group_cb",
> "end_group_cb".
> * gimple-ssa-isolate-paths.c (find_implicit_erroneous_behavior):
> Add auto_diagnostic_group instance(s).
> (find_explicit_erroneous_behavior): Likewise.
> * gimple-ssa-warn-alloca.c (pass_walloca::execute): Likewise.
> * gimple-ssa-warn-restrict.c (maybe_diag_offset_bounds): Likewise.
> * gimplify.c (warn_implicit_fallthrough_r): Likewise.
> (gimplify_va_arg_expr): Likewise.
> * hsa-gen.c (HSA_SORRY_ATV): Likewise.
> (HSA_SORRY_AT): Likewise.
> * ipa-devirt.c (compare_virtual_tables): Likewise.
> (warn_odr): Likewise.
> * multiple_target.c (expand_target_clones): Likewise.
> * opts-common.c (cmdline_handle_error): Likewise.
> * reginfo.c (globalize_reg): Likewise.
> * substring-locations.c (format_warning_n_va): Likewise.
> * tree-inline.c (expand_call_inline): Likewise.
> * tree-ssa-ccp.c (pass_post_ipa_warn::execute): Likewise.
> * tree-ssa-loop-niter.c
> (do_warn_aggressive_loop_optimizations): Likewise.
> * tree-ssa-uninit.c (warn_uninit): Likewise.
> * tree.c (warn_deprecated_use): Likewise.
>
> gcc/testsuite/ChangeLog:
> PR other/84889
> * gcc.dg/plugin/diagnostic-group-test-1.c: New test.
> * gcc.dg/plugin/diagnostic_group_plugin.c: New test.
> * gcc.dg/plugin/plugin.exp (plugin_test_list): Add the new tests.
> ---
> gcc/attribs.c | 3 +-
> gcc/c-family/c-attribs.c | 1 +
> gcc/c-family/c-indentation.c | 1 +
> gcc/c-family/c-opts.c | 1 +
> gcc/c-family/c-warn.c | 3 +
> gcc/c/c-decl.c | 44 +++-
> gcc/c/c-parser.c | 22 +-
> gcc/c/c-typeck.c | 78 ++++---
> gcc/calls.c | 1 +
> gcc/cgraphunit.c | 17 +-
> gcc/cp/call.c | 29 ++-
> gcc/cp/class.c | 75 ++++---
> gcc/cp/constexpr.c | 21 +-
> gcc/cp/cp-gimplify.c | 15 +-
> gcc/cp/cvt.c | 3 +
> gcc/cp/decl.c | 28 ++-
> gcc/cp/decl2.c | 3 +
> gcc/cp/error.c | 2 +
> gcc/cp/friend.c | 4 +
> gcc/cp/init.c | 48 +++--
> gcc/cp/lex.c | 1 +
> gcc/cp/name-lookup.c | 35 +--
> gcc/cp/parser.c | 6 +
> gcc/cp/pt.c | 8 +
> gcc/cp/search.c | 10 +
> gcc/cp/tree.c | 2 +
> gcc/cp/typeck.c | 49 +++--
> gcc/cp/typeck2.c | 2 +
> gcc/diagnostic-core.h | 9 +
> gcc/diagnostic.c | 60 ++++++
> gcc/diagnostic.h | 17 ++
> gcc/gimple-ssa-isolate-paths.c | 26 ++-
> gcc/gimple-ssa-warn-alloca.c | 50 +++--
> gcc/gimple-ssa-warn-restrict.c | 2 +
> gcc/gimplify.c | 2 +
> gcc/hsa-gen.c | 2 +
> gcc/ipa-devirt.c | 39 ++--
> gcc/multiple_target.c | 1 +
> gcc/opts-common.c | 1 +
> gcc/reginfo.c | 1 +
> gcc/substring-locations.c | 1 +
> .../gcc.dg/plugin/diagnostic-group-test-1.c | 26 +++
> .../gcc.dg/plugin/diagnostic_group_plugin.c | 234
> +++++++++++++++++++++
> gcc/testsuite/gcc.dg/plugin/plugin.exp | 2 +
> gcc/tree-inline.c | 1 +
> gcc/tree-ssa-ccp.c | 1 +
> gcc/tree-ssa-loop-niter.c | 1 +
> gcc/tree-ssa-uninit.c | 1 +
> gcc/tree.c | 2 +
> 49 files changed, 797 insertions(+), 194 deletions(-)
> create mode 100644 gcc/testsuite/gcc.dg/plugin/diagnostic-group-test-1.c
> create mode 100644 gcc/testsuite/gcc.dg/plugin/diagnostic_group_plugin.c
>
> diff --git a/gcc/attribs.c b/gcc/attribs.c
> index efc879b..64700b6 100644
> --- a/gcc/attribs.c
> +++ b/gcc/attribs.c
> @@ -430,7 +430,7 @@ diag_attr_exclusions (tree last_decl, tree node, tree
> attrname,
>
> /* Print a note? */
> bool note = last_decl != NULL_TREE;
> -
> + auto_diagnostic_group d;
> if (TREE_CODE (node) == FUNCTION_DECL
> && DECL_BUILT_IN (node))
> note &= warning (OPT_Wattributes,
> @@ -587,6 +587,7 @@ decl_attributes (tree *node, tree attributes, int flags,
> /* This is a c++11 attribute that appertains to a
> type-specifier, outside of the definition of, a class
> type. Ignore it. */
> + auto_diagnostic_group d;
> if (warning (OPT_Wattributes, "attribute ignored"))
> inform (input_location,
> "an attribute that appertains to a type-specifier "
> diff --git a/gcc/c-family/c-attribs.c b/gcc/c-family/c-attribs.c
> index 9da9c27..5454e09 100644
> --- a/gcc/c-family/c-attribs.c
> +++ b/gcc/c-family/c-attribs.c
> @@ -1881,6 +1881,7 @@ common_handle_aligned_attribute (tree *node, tree name,
> tree args, int flags,
> bitalign /= BITS_PER_UNIT;
>
> bool diagd = true;
> + auto_diagnostic_group d;
> if (DECL_USER_ALIGN (decl) || DECL_USER_ALIGN (last_decl))
> diagd = warning (OPT_Wattributes,
> "ignoring attribute %<%E (%u)%> because it
> conflicts "
> diff --git a/gcc/c-family/c-indentation.c b/gcc/c-family/c-indentation.c
> index 436d61b..cff5aec 100644
> --- a/gcc/c-family/c-indentation.c
> +++ b/gcc/c-family/c-indentation.c
> @@ -609,6 +609,7 @@ warn_for_misleading_indentation (const token_indent_info
> &guard_tinfo,
> body_tinfo,
> next_tinfo))
> {
> + auto_diagnostic_group d;
> if (warning_at (guard_tinfo.location, OPT_Wmisleading_indentation,
> "this %qs clause does not guard...",
> guard_tinfo_to_string (guard_tinfo.keyword)))
> diff --git a/gcc/c-family/c-opts.c b/gcc/c-family/c-opts.c
> index cb69fb3..ec05771 100644
> --- a/gcc/c-family/c-opts.c
> +++ b/gcc/c-family/c-opts.c
> @@ -931,6 +931,7 @@ c_common_post_options (const char **pfilename)
> warn_abi_version = latest_abi_version;
> if (flag_abi_version == latest_abi_version)
> {
> + auto_diagnostic_group d;
> if (warning (OPT_Wabi, "-Wabi won't warn about anything"))
> {
> inform (input_location, "-Wabi warns about differences "
> diff --git a/gcc/c-family/c-warn.c b/gcc/c-family/c-warn.c
> index d34d667..ca259aa 100644
> --- a/gcc/c-family/c-warn.c
> +++ b/gcc/c-family/c-warn.c
> @@ -491,6 +491,7 @@ warn_logical_not_parentheses (location_t location, enum
> tree_code code,
> && integer_zerop (rhs))
> return;
>
> + auto_diagnostic_group d;
> if (warning_at (location, OPT_Wlogical_not_parentheses,
> "logical not is only applied to the left hand side of "
> "comparison")
> @@ -2232,6 +2233,7 @@ warn_duplicated_cond_add_or_warn (location_t loc, tree
> cond, vec<tree> **chain)
> FOR_EACH_VEC_ELT (**chain, ix, t)
> if (operand_equal_p (cond, t, 0))
> {
> + auto_diagnostic_group d;
> if (warning_at (loc, OPT_Wduplicated_cond,
> "duplicated %<if%> condition"))
> inform (EXPR_LOCATION (t), "previously used here");
> @@ -2601,6 +2603,7 @@ warn_for_multistatement_macros (location_t body_loc,
> location_t next_loc,
> return;
> }
>
> + auto_diagnostic_group d;
> if (warning_at (body_loc, OPT_Wmultistatement_macros,
> "macro expands to multiple statements"))
> inform (guard_loc, "some parts of macro expansion are not guarded by "
> diff --git a/gcc/c/c-decl.c b/gcc/c/c-decl.c
> index 1bbccdd..9524977 100644
> --- a/gcc/c/c-decl.c
> +++ b/gcc/c/c-decl.c
> @@ -1571,6 +1571,7 @@ pushtag (location_t loc, tree name, tree type)
> && (TYPE_MAIN_VARIANT (TREE_TYPE (b->decl))
> != TYPE_MAIN_VARIANT (type)))
> {
> + auto_diagnostic_group d;
> if (warning_at (loc, OPT_Wc___compat,
> ("using %qD as both a typedef and a tag is "
> "invalid in C++"), b->decl)
> @@ -1823,8 +1824,6 @@ diagnose_mismatched_decls (tree newdecl, tree olddecl,
> tree *newtypep, tree *oldtypep)
> {
> tree newtype, oldtype;
> - bool pedwarned = false;
> - bool warned = false;
> bool retval = true;
>
> #define DECL_EXTERN_INLINE(DECL) (DECL_DECLARED_INLINE_P (DECL) \
> @@ -1847,6 +1846,7 @@ diagnose_mismatched_decls (tree newdecl, tree olddecl,
> && DECL_BUILT_IN (olddecl)
> && !C_DECL_DECLARED_BUILTIN (olddecl)))
> {
> + auto_diagnostic_group d;
> error ("%q+D redeclared as different kind of symbol", newdecl);
> locate_old_decl (olddecl);
> }
> @@ -1864,11 +1864,16 @@ diagnose_mismatched_decls (tree newdecl, tree olddecl,
> given scope. */
> if (TREE_CODE (olddecl) == CONST_DECL)
> {
> + auto_diagnostic_group d;
> error ("redeclaration of enumerator %q+D", newdecl);
> locate_old_decl (olddecl);
> return false;
> }
>
> + bool pedwarned = false;
> + bool warned = false;
> + auto_diagnostic_group d;
> +
> if (!comptypes (oldtype, newtype))
> {
> if (TREE_CODE (olddecl) == FUNCTION_DECL
> @@ -2052,6 +2057,7 @@ diagnose_mismatched_decls (tree newdecl, tree olddecl,
> )
> && same_translation_unit_p (newdecl, olddecl))
> {
> + auto_diagnostic_group d;
> error ("redefinition of %q+D", newdecl);
> locate_old_decl (olddecl);
> return false;
> @@ -2062,11 +2068,14 @@ diagnose_mismatched_decls (tree newdecl, tree olddecl,
> the argument types must be checked specially. */
> else if (DECL_INITIAL (olddecl)
> && !prototype_p (oldtype) && prototype_p (newtype)
> - && TYPE_ACTUAL_ARG_TYPES (oldtype)
> - && !validate_proto_after_old_defn (newdecl, newtype, oldtype))
> + && TYPE_ACTUAL_ARG_TYPES (oldtype))
> {
> - locate_old_decl (olddecl);
> - return false;
> + auto_diagnostic_group d;
> + if (!validate_proto_after_old_defn (newdecl, newtype, oldtype))
> + {
> + locate_old_decl (olddecl);
> + return false;
> + }
> }
> /* A non-static declaration (even an "extern") followed by a
> static declaration is undefined behavior per C99 6.2.2p3-5,7.
> @@ -2087,6 +2096,7 @@ diagnose_mismatched_decls (tree newdecl, tree olddecl,
> if (!DECL_IS_BUILTIN (olddecl)
> && !DECL_EXTERN_INLINE (olddecl))
> {
> + auto_diagnostic_group d;
> error ("static declaration of %q+D follows "
> "non-static declaration", newdecl);
> locate_old_decl (olddecl);
> @@ -2097,6 +2107,7 @@ diagnose_mismatched_decls (tree newdecl, tree olddecl,
> {
> if (DECL_CONTEXT (olddecl))
> {
> + auto_diagnostic_group d;
> error ("non-static declaration of %q+D follows "
> "static declaration", newdecl);
> locate_old_decl (olddecl);
> @@ -2121,6 +2132,7 @@ diagnose_mismatched_decls (tree newdecl, tree olddecl,
> DECL_ATTRIBUTES (olddecl)) != NULL;
> if (newa != olda)
> {
> + auto_diagnostic_group d;
> error_at (input_location, "%<gnu_inline%> attribute present on
> %q+D",
> newa ? newdecl : olddecl);
> error_at (DECL_SOURCE_LOCATION (newa ? olddecl : newdecl),
> @@ -2141,6 +2153,7 @@ diagnose_mismatched_decls (tree newdecl, tree olddecl,
> }
> else if (DECL_THREAD_LOCAL_P (newdecl) != DECL_THREAD_LOCAL_P
> (olddecl))
> {
> + auto_diagnostic_group d;
> if (DECL_THREAD_LOCAL_P (newdecl))
> error ("thread-local declaration of %q+D follows "
> "non-thread-local declaration", newdecl);
> @@ -2155,6 +2168,7 @@ diagnose_mismatched_decls (tree newdecl, tree olddecl,
> /* Multiple initialized definitions are not allowed (6.9p3,5). */
> if (DECL_INITIAL (newdecl) && DECL_INITIAL (olddecl))
> {
> + auto_diagnostic_group d;
> error ("redefinition of %q+D", newdecl);
> locate_old_decl (olddecl);
> return false;
> @@ -2175,6 +2189,7 @@ diagnose_mismatched_decls (tree newdecl, tree olddecl,
> {
> if (!DECL_FILE_SCOPE_P (olddecl))
> {
> + auto_diagnostic_group d;
> error ("extern declaration of %q+D follows "
> "declaration with no linkage", newdecl);
> locate_old_decl (olddecl);
> @@ -2189,6 +2204,7 @@ diagnose_mismatched_decls (tree newdecl, tree olddecl,
> }
> else
> {
> + auto_diagnostic_group d;
> if (TREE_PUBLIC (newdecl))
> error ("non-static declaration of %q+D follows "
> "static declaration", newdecl);
> @@ -2211,12 +2227,14 @@ diagnose_mismatched_decls (tree newdecl, tree olddecl,
> }
> else if (DECL_EXTERNAL (olddecl))
> {
> + auto_diagnostic_group d;
> error ("declaration of %q+D with no linkage follows "
> "extern declaration", newdecl);
> locate_old_decl (olddecl);
> }
> else
> {
> + auto_diagnostic_group d;
> error ("redeclaration of %q+D with no linkage", newdecl);
> locate_old_decl (olddecl);
> }
> @@ -2263,6 +2281,7 @@ diagnose_mismatched_decls (tree newdecl, tree olddecl,
> if (TREE_CODE (newdecl) == PARM_DECL
> && (!TREE_ASM_WRITTEN (olddecl) || TREE_ASM_WRITTEN (newdecl)))
> {
> + auto_diagnostic_group d;
> error ("redefinition of parameter %q+D", newdecl);
> locate_old_decl (olddecl);
> return false;
> @@ -2778,7 +2797,6 @@ warn_if_shadowing (tree new_decl)
> DECL_SOURCE_LOCATION (b->decl))))
> {
> tree old_decl = b->decl;
> - bool warned = false;
>
> if (old_decl == error_mark_node)
> {
> @@ -2786,7 +2804,10 @@ warn_if_shadowing (tree new_decl)
> "non-variable", new_decl);
> break;
> }
> - else if (TREE_CODE (old_decl) == PARM_DECL)
> +
> + bool warned = false;
> + auto_diagnostic_group d;
> + if (TREE_CODE (old_decl) == PARM_DECL)
> {
> enum opt_code warning_code;
>
> @@ -3123,6 +3144,7 @@ implicit_decl_warning (location_t loc, tree id, tree
> olddecl)
> return;
>
> bool warned;
> + auto_diagnostic_group d;
> name_hint hint;
> if (!olddecl)
> hint = lookup_name_fuzzy (id, FUZZY_LOOKUP_FUNCTION_NAME, loc);
> @@ -3435,6 +3457,7 @@ implicitly_declare (location_t loc, tree functionid)
> {
> if (!comptypes (newtype, TREE_TYPE (decl)))
> {
> + auto_diagnostic_group d;
> error_at (loc, "incompatible implicit declaration of "
> "function %qD", decl);
> locate_old_decl (decl);
> @@ -3487,6 +3510,7 @@ undeclared_variable (location_t loc, tree id)
> static bool already = false;
> struct c_scope *scope;
>
> + auto_diagnostic_group d;
> if (current_function_decl == NULL_TREE)
> {
> name_hint guessed_id = lookup_name_fuzzy (id, FUZZY_LOOKUP_NAME, loc);
> @@ -3686,6 +3710,7 @@ declare_label (tree name)
> at this scope */
> if (b && B_IN_CURRENT_SCOPE (b))
> {
> + auto_diagnostic_group d;
> error ("duplicate label declaration %qE", name);
> locate_old_decl (b->decl);
>
> @@ -3784,6 +3809,7 @@ define_label (location_t location, tree name)
> || (DECL_CONTEXT (label) != current_function_decl
> && C_DECLARED_LABEL_FLAG (label))))
> {
> + auto_diagnostic_group d;
> error_at (location, "duplicate label %qD", label);
> locate_old_decl (label);
> return NULL_TREE;
> @@ -6720,6 +6746,7 @@ grokdeclarator (const struct c_declarator *declarator,
> || (current_scope == file_scope && B_IN_EXTERNAL_SCOPE (b)))
> && TYPE_MAIN_VARIANT (b->decl) != TYPE_MAIN_VARIANT (type))
> {
> + auto_diagnostic_group d;
> if (warning_at (declarator->id_loc, OPT_Wc___compat,
> ("using %qD as both a typedef and a tag is "
> "invalid in C++"), decl)
> @@ -8794,6 +8821,7 @@ start_function (struct c_declspecs *declspecs, struct
> c_declarator *declarator,
> {
> if (stdarg_p (TREE_TYPE (old_decl)))
> {
> + auto_diagnostic_group d;
> warning_at (loc, 0, "%q+D defined as variadic function "
> "without prototype", decl1);
> locate_old_decl (old_decl);
> diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
> index 5ad4f57..0d5dbea 100644
> --- a/gcc/c/c-parser.c
> +++ b/gcc/c/c-parser.c
> @@ -1814,6 +1814,7 @@ c_parser_declaration_or_fndef (c_parser *parser, bool
> fndef_ok,
> }
> else
> {
> + auto_diagnostic_group d;
> name_hint hint = lookup_name_fuzzy (name, FUZZY_LOOKUP_TYPENAME,
> here);
> if (hint)
> @@ -4058,6 +4059,7 @@ c_parser_parameter_declaration (c_parser *parser, tree
> attrs)
> c_parser_set_source_position_from_token (token);
> if (c_parser_next_tokens_start_typename (parser, cla_prefer_type))
> {
> + auto_diagnostic_group d;
> name_hint hint = lookup_name_fuzzy (token->value,
> FUZZY_LOOKUP_TYPENAME,
> token->location);
> @@ -6873,14 +6875,18 @@ c_parser_binary_expression (c_parser *parser, struct
> c_expr *after,
> && !(TREE_CODE (first_arg) == PARM_DECL
> \
> && C_ARRAY_PARAMETER (first_arg)
> \
> && warn_sizeof_array_argument))
> \
> - if (warning_at (stack[sp].loc, OPT_Wsizeof_pointer_div,
> \
> - "division %<sizeof (%T) / sizeof (%T)%> does "
> \
> - "not compute the number of array elements",
> \
> - type0, type1))
> \
> - if (DECL_P (first_arg))
> \
> - inform (DECL_SOURCE_LOCATION (first_arg),
> \
> - "first %<sizeof%> operand was declared here");
> \
> - }
> \
> + { \
> + auto_diagnostic_group d;
> \
> + if (warning_at (stack[sp].loc, OPT_Wsizeof_pointer_div, \
> + "division %<sizeof (%T) / sizeof (%T)%> " \
> + "does not compute the number of array " \
> + "elements", \
> + type0, type1)) \
> + if (DECL_P (first_arg)) \
> + inform (DECL_SOURCE_LOCATION (first_arg), \
> + "first %<sizeof%> operand was declared here"); \
> + } \
> + } \
> break;
> \
> default:
> \
> break;
> \
> diff --git a/gcc/c/c-typeck.c b/gcc/c/c-typeck.c
> index 726ea83..54c7967 100644
> --- a/gcc/c/c-typeck.c
> +++ b/gcc/c/c-typeck.c
> @@ -2906,6 +2906,7 @@ c_expr_sizeof_expr (location_t loc, struct c_expr expr)
> if (TREE_CODE (expr.value) == PARM_DECL
> && C_ARRAY_PARAMETER (expr.value))
> {
> + auto_diagnostic_group d;
> if (warning_at (loc, OPT_Wsizeof_array_argument,
> "%<sizeof%> on array function parameter %qE will "
> "return size of %qT", expr.value,
> @@ -3735,19 +3736,27 @@ parser_build_binary_op (location_t location, enum
> tree_code code,
> "comparison with string literal results in unspecified
> behavior");
> /* Warn for ptr == '\0', it's likely that it should've been ptr[0]. */
> if (POINTER_TYPE_P (type1)
> - && null_pointer_constant_p (arg2.value)
> - && char_type_p (type2)
> - && warning_at (location, OPT_Wpointer_compare,
> - "comparison between pointer and zero character "
> - "constant"))
> - inform (arg1.get_start (), "did you mean to dereference the
> pointer?");
> + && null_pointer_constant_p (arg2.value)
> + && char_type_p (type2))
> + {
> + auto_diagnostic_group d;
> + if (warning_at (location, OPT_Wpointer_compare,
> + "comparison between pointer and zero character "
> + "constant"))
> + inform (arg1.get_start (),
> + "did you mean to dereference the pointer?");
> + }
> else if (POINTER_TYPE_P (type2)
> && null_pointer_constant_p (arg1.value)
> - && char_type_p (type1)
> - && warning_at (location, OPT_Wpointer_compare,
> - "comparison between pointer and zero character "
> - "constant"))
> - inform (arg2.get_start (), "did you mean to dereference the
> pointer?");
> + && char_type_p (type1))
> + {
> + auto_diagnostic_group d;
> + if (warning_at (location, OPT_Wpointer_compare,
> + "comparison between pointer and zero character "
> + "constant"))
> + inform (arg2.get_start (),
> + "did you mean to dereference the pointer?");
> + }
> }
> else if (TREE_CODE_CLASS (code) == tcc_comparison
> && (code1 == STRING_CST || code2 == STRING_CST))
> @@ -4288,13 +4297,16 @@ build_unary_op (location_t location, enum tree_code
> code, tree xarg,
> e = TREE_OPERAND (e, 1);
>
> if ((TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE
> - || truth_value_p (TREE_CODE (e)))
> - && warning_at (location, OPT_Wbool_operation,
> - "%<~%> on a boolean expression"))
> + || truth_value_p (TREE_CODE (e))))
> {
> - gcc_rich_location richloc (location);
> - richloc.add_fixit_insert_before (location, "!");
> - inform (&richloc, "did you mean to use logical not?");
> + auto_diagnostic_group d;
> + if (warning_at (location, OPT_Wbool_operation,
> + "%<~%> on a boolean expression"))
> + {
> + gcc_rich_location richloc (location);
> + richloc.add_fixit_insert_before (location, "!");
> + inform (&richloc, "did you mean to use logical not?");
> + }
> }
> if (!noconvert)
> arg = default_conversion (arg);
> @@ -6197,6 +6209,8 @@ error_init (location_t loc, const char *gmsgid)
> {
> char *ofwhat;
>
> + auto_diagnostic_group d;
> +
> /* The gmsgid may be a format string with %< and %>. */
> error_at (loc, gmsgid);
> ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
> @@ -6216,7 +6230,7 @@ pedwarn_init (location_t loc, int opt, const char
> *gmsgid, ...)
> it was defined to make sure macros defined in system headers
> but used incorrectly elsewhere are diagnosed. */
> source_location exploc = expansion_point_location_if_in_system_header
> (loc);
> -
> + auto_diagnostic_group d;
> va_list ap;
> va_start (ap, gmsgid);
> bool warned = emit_diagnostic_valist (DK_PEDWARN, exploc, opt, gmsgid,
> &ap);
> @@ -6238,6 +6252,8 @@ warning_init (location_t loc, int opt, const char
> *gmsgid)
> char *ofwhat;
> bool warned;
>
> + auto_diagnostic_group d;
> +
> /* Use the location where a macro was expanded rather than where
> it was defined to make sure macros defined in system headers
> but used incorrectly elsewhere are diagnosed. */
> @@ -6379,8 +6395,11 @@ convert_for_assignment (location_t location,
> location_t expr_loc, tree type,
> switch (errtype) \
> { \
> case ic_argpass: \
> - if (pedwarn (PLOC, OPT, AR, parmnum, rname)) \
> - inform_for_arg (fundecl, (PLOC), parmnum, type, rhstype); \
> + { \
> + auto_diagnostic_group d;
> \
> + if (pedwarn (PLOC, OPT, AR, parmnum, rname)) \
> + inform_for_arg (fundecl, (PLOC), parmnum, type, rhstype); \
> + } \
> break; \
> case ic_assign: \
> pedwarn (LOCATION, OPT, AS); \
> @@ -6405,8 +6424,11 @@ convert_for_assignment (location_t location,
> location_t expr_loc, tree type,
> switch (errtype) \
> { \
> case ic_argpass: \
> - if (pedwarn (PLOC, OPT, AR, parmnum, rname, QUALS)) \
> - inform_for_arg (fundecl, (PLOC), parmnum, type, rhstype); \
> + { \
> + auto_diagnostic_group d;
> \
> + if (pedwarn (PLOC, OPT, AR, parmnum, rname, QUALS)) \
> + inform_for_arg (fundecl, (PLOC), parmnum, type, rhstype); \
> + } \
> break; \
> case ic_assign: \
> pedwarn (LOCATION, OPT, AS, QUALS); \
> @@ -6431,8 +6453,11 @@ convert_for_assignment (location_t location,
> location_t expr_loc, tree type,
> switch (errtype) \
> { \
> case ic_argpass: \
> - if (warning_at (PLOC, OPT, AR, parmnum, rname, QUALS)) \
> - inform_for_arg (fundecl, (PLOC), parmnum, type, rhstype); \
> + { \
> + auto_diagnostic_group d;
> \
> + if (warning_at (PLOC, OPT, AR, parmnum, rname, QUALS)) \
> + inform_for_arg (fundecl, (PLOC), parmnum, type, rhstype); \
> + } \
> break; \
> case ic_assign: \
> warning_at (LOCATION, OPT, AS, QUALS); \
> @@ -6925,6 +6950,7 @@ convert_for_assignment (location_t location, location_t
> expr_loc, tree type,
> {
> case ic_argpass:
> {
> + auto_diagnostic_group d;
> range_label_for_type_mismatch rhs_label (rhstype, type);
> gcc_rich_location richloc (expr_loc, &rhs_label);
> if (pedwarn (&richloc, OPT_Wpointer_sign,
> @@ -6984,6 +7010,7 @@ convert_for_assignment (location_t location, location_t
> expr_loc, tree type,
> {
> case ic_argpass:
> {
> + auto_diagnostic_group d;
> range_label_for_type_mismatch rhs_label (rhstype, type);
> gcc_rich_location richloc (expr_loc, &rhs_label);
> if (pedwarn (&richloc, OPT_Wincompatible_pointer_types,
> @@ -7031,6 +7058,7 @@ convert_for_assignment (location_t location, location_t
> expr_loc, tree type,
> {
> case ic_argpass:
> {
> + auto_diagnostic_group d;
> range_label_for_type_mismatch rhs_label (rhstype, type);
> gcc_rich_location richloc (expr_loc, &rhs_label);
> if (pedwarn (&richloc, OPT_Wint_conversion,
> @@ -7066,6 +7094,7 @@ convert_for_assignment (location_t location, location_t
> expr_loc, tree type,
> {
> case ic_argpass:
> {
> + auto_diagnostic_group d;
> range_label_for_type_mismatch rhs_label (rhstype, type);
> gcc_rich_location richloc (expr_loc, &rhs_label);
> if (pedwarn (&richloc, OPT_Wint_conversion,
> @@ -7109,6 +7138,7 @@ convert_for_assignment (location_t location, location_t
> expr_loc, tree type,
> {
> case ic_argpass:
> {
> + auto_diagnostic_group d;
> range_label_for_type_mismatch rhs_label (rhstype, type);
> gcc_rich_location richloc (expr_loc, &rhs_label);
> error_at (&richloc, "incompatible type for argument %d of %qE",
> parmnum,
> diff --git a/gcc/calls.c b/gcc/calls.c
> index 384c023..0fb10b1 100644
> --- a/gcc/calls.c
> +++ b/gcc/calls.c
> @@ -1773,6 +1773,7 @@ maybe_warn_nonstring_arg (tree fndecl, tree exp)
>
> bool warned = false;
>
> + auto_diagnostic_group d;
> if (wi::ltu_p (asize, wibnd))
> {
> if (bndrng[0] == bndrng[1])
> diff --git a/gcc/cgraphunit.c b/gcc/cgraphunit.c
> index 462e247..208798f 100644
> --- a/gcc/cgraphunit.c
> +++ b/gcc/cgraphunit.c
> @@ -1358,6 +1358,7 @@ maybe_diag_incompatible_alias (tree alias, tree target)
> {
> funcptr = build_pointer_type (funcptr);
>
> + auto_diagnostic_group d;
> if (warning_at (DECL_SOURCE_LOCATION (target),
> OPT_Wattribute_alias,
> "%<ifunc%> resolver for %qD should return %qT",
> @@ -1365,12 +1366,16 @@ maybe_diag_incompatible_alias (tree alias, tree
> target)
> inform (DECL_SOURCE_LOCATION (alias),
> "resolver indirect function declared here");
> }
> - else if (warning_at (DECL_SOURCE_LOCATION (alias),
> - OPT_Wattribute_alias,
> - "%qD alias between functions of incompatible "
> - "types %qT and %qT", alias, altype, targtype))
> - inform (DECL_SOURCE_LOCATION (target),
> - "aliased declaration here");
> + else
> + {
> + auto_diagnostic_group d;
> + if (warning_at (DECL_SOURCE_LOCATION (alias),
> + OPT_Wattribute_alias,
> + "%qD alias between functions of incompatible "
> + "types %qT and %qT", alias, altype, targtype))
> + inform (DECL_SOURCE_LOCATION (target),
> + "aliased declaration here");
> + }
> }
> }
>
> diff --git a/gcc/cp/call.c b/gcc/cp/call.c
> index 16bb6bf..1f72ac8 100644
> --- a/gcc/cp/call.c
> +++ b/gcc/cp/call.c
> @@ -3968,6 +3968,7 @@ build_user_type_conversion_1 (tree totype, tree expr,
> int flags,
> {
> if (complain & tf_error)
> {
> + auto_diagnostic_group d;
> error ("conversion from %qH to %qI is ambiguous",
> fromtype, totype);
> print_z_candidates (location_of (expr), candidates);
> @@ -4280,6 +4281,7 @@ print_error_for_call_failure (tree fn, vec<tree, va_gc>
> *args,
> if (targs)
> name = lookup_template_function (name, targs);
>
> + auto_diagnostic_group d;
> if (!any_strictly_viable (candidates))
> error_at (loc, "no matching function for call to %<%D(%A)%>",
> name, build_tree_list_vec (args));
> @@ -4590,6 +4592,7 @@ build_op_call_1 (tree obj, vec<tree, va_gc> **args,
> tsubst_flags_t complain)
> {
> if (complain & tf_error)
> {
> + auto_diagnostic_group d;
> error ("no match for call to %<(%T) (%A)%>", TREE_TYPE (obj),
> build_tree_list_vec (*args));
> print_z_candidates (location_of (TREE_TYPE (obj)), candidates);
> @@ -4603,6 +4606,7 @@ build_op_call_1 (tree obj, vec<tree, va_gc> **args,
> tsubst_flags_t complain)
> {
> if (complain & tf_error)
> {
> + auto_diagnostic_group d;
> error ("call of %<(%T) (%A)%> is ambiguous",
> TREE_TYPE (obj), build_tree_list_vec (*args));
> print_z_candidates (location_of (TREE_TYPE (obj)), candidates);
> @@ -5229,6 +5233,7 @@ build_conditional_expr_1 (location_t loc, tree arg1,
> tree arg2, tree arg3,
> {
> if (complain & tf_error)
> {
> + auto_diagnostic_group d;
> op_error (loc, COND_EXPR, NOP_EXPR, arg1, arg2, arg3, FALSE);
> print_z_candidates (loc, candidates);
> }
> @@ -5860,6 +5865,7 @@ build_new_op_1 (location_t loc, enum tree_code code,
> int flags, tree arg1,
> {
> /* ... Otherwise, report the more generic
> "no matching operator found" error */
> + auto_diagnostic_group d;
> op_error (loc, code, code2, arg1, arg2, arg3, FALSE);
> print_z_candidates (loc, candidates);
> }
> @@ -5875,6 +5881,7 @@ build_new_op_1 (location_t loc, enum tree_code code,
> int flags, tree arg1,
> {
> if (complain & tf_error)
> {
> + auto_diagnostic_group d;
> op_error (loc, code, code2, arg1, arg2, arg3, TRUE);
> print_z_candidates (loc, candidates);
> }
> @@ -6311,14 +6318,18 @@ build_op_delete_call (enum tree_code code, tree addr,
> tree size,
> -Wc++14-compat. */
> else if (!flag_sized_deallocation)
> {
> - if ((complain & tf_warning)
> - && warning (OPT_Wc__14_compat, msg1))
> - inform (DECL_SOURCE_LOCATION (fn), msg2, fn);
> + if (complain & tf_warning)
> + {
> + auto_diagnostic_group d;
> + if (warning (OPT_Wc__14_compat, msg1))
> + inform (DECL_SOURCE_LOCATION (fn), msg2, fn);
> + }
> goto ok;
> }
>
> if (complain & tf_warning_or_error)
> {
> + auto_diagnostic_group d;
> if (permerror (input_location, msg1))
> {
> /* Only mention C++14 for namespace-scope delete. */
> @@ -6712,6 +6723,7 @@ convert_like_real (conversion *convs, tree expr, tree
> fn, int argnum,
> {
> if (t->kind == ck_user && t->cand->reason)
> {
> + auto_diagnostic_group d;
> complained = permerror (loc, "invalid user-defined conversion "
> "from %qH to %qI", TREE_TYPE (expr),
> totype);
> @@ -6795,6 +6807,7 @@ convert_like_real (conversion *convs, tree expr, tree
> fn, int argnum,
> if (CONSTRUCTOR_NELTS (expr) == 0
> && FUNCTION_FIRST_USER_PARMTYPE (convfn) != void_list_node)
> {
> + auto_diagnostic_group d;
> if (pedwarn (loc, 0, "converting to %qT from initializer list
> "
> "would use explicit constructor %qD",
> totype, convfn))
> @@ -6973,6 +6986,7 @@ convert_like_real (conversion *convs, tree expr, tree
> fn, int argnum,
> {
> if (complain & tf_error)
> {
> + auto_diagnostic_group d;
> maybe_print_user_conv_context (convs);
> if (fn)
> inform (DECL_SOURCE_LOCATION (fn),
> @@ -7025,6 +7039,7 @@ convert_like_real (conversion *convs, tree expr, tree
> fn, int argnum,
> expr = build_temp (expr, totype, flags, &diag_kind, complain);
> if (diag_kind && complain)
> {
> + auto_diagnostic_group d;
> maybe_print_user_conv_context (convs);
> if (fn)
> inform (DECL_SOURCE_LOCATION (fn),
> @@ -7040,6 +7055,7 @@ convert_like_real (conversion *convs, tree expr, tree
> fn, int argnum,
> if (convs->bad_p && !next_conversion (convs)->bad_p)
> {
> tree extype = TREE_TYPE (expr);
> + auto_diagnostic_group d;
> if (TYPE_REF_IS_RVALUE (ref_type)
> && lvalue_p (expr))
> error_at (loc, "cannot bind rvalue reference of type %qH to "
> @@ -7931,6 +7947,7 @@ build_over_call (struct z_candidate *cand, int flags,
> tsubst_flags_t complain)
> {
> if (complain & tf_error)
> {
> + auto_diagnostic_group d;
> if (permerror (input_location, "passing %qT as %<this%> "
> "argument discards qualifiers",
> TREE_TYPE (argtype)))
> @@ -9212,6 +9229,7 @@ build_new_method_call_1 (tree instance, tree fns,
> vec<tree, va_gc> **args,
>
> basetype = DECL_CONTEXT (fn);
> name = constructor_name (basetype);
> + auto_diagnostic_group d;
> if (permerror (input_location,
> "cannot call constructor %<%T::%D%> directly",
> basetype, name))
> @@ -9350,6 +9368,7 @@ build_new_method_call_1 (tree instance, tree fns,
> vec<tree, va_gc> **args,
> {
> if (complain & tf_error)
> {
> + auto_diagnostic_group d;
> if (!COMPLETE_OR_OPEN_TYPE_P (basetype))
> cxx_incomplete_type_error (instance, basetype);
> else if (optype)
> @@ -9393,6 +9412,7 @@ build_new_method_call_1 (tree instance, tree fns,
> vec<tree, va_gc> **args,
> arglist = build_tree_list_vec (user_args);
> if (skip_first_for_error)
> arglist = TREE_CHAIN (arglist);
> + auto_diagnostic_group d;
> if (!any_strictly_viable (candidates))
> error ("no matching function for call to %<%s(%A)%>",
> pretty_name, arglist);
> @@ -10299,6 +10319,7 @@ joust (struct z_candidate *cand1, struct z_candidate
> *cand2, bool warn,
> tree source = source_type (w->convs[0]);
> if (INDIRECT_TYPE_P (source))
> source = TREE_TYPE (source);
> + auto_diagnostic_group d;
> if (warning (OPT_Wconversion, "choosing %qD over %qD", w->fn, l->fn)
> && warning (OPT_Wconversion, " for conversion from %qH to %qI",
> source, w->second_conv->type))
> @@ -10526,6 +10547,7 @@ joust (struct z_candidate *cand1, struct z_candidate
> *cand2, bool warn,
> {
> if (complain & tf_error)
> {
> + auto_diagnostic_group d;
> if (permerror (input_location,
> "default argument mismatch in "
> "overload resolution"))
> @@ -10577,6 +10599,7 @@ tweak:
> return 0;
> if (warn)
> {
> + auto_diagnostic_group d;
> pedwarn (input_location, 0,
> "ISO C++ says that these are ambiguous, even "
> "though the worst conversion for the first is better than "
> diff --git a/gcc/cp/class.c b/gcc/cp/class.c
> index 7b10b20..e11173d 100644
> --- a/gcc/cp/class.c
> +++ b/gcc/cp/class.c
> @@ -1331,6 +1331,7 @@ check_tag (tree tag, tree id, tree *tp, abi_tag_data *p)
> /* Otherwise we're diagnosing missing tags. */
> if (TREE_CODE (p->t) == FUNCTION_DECL)
> {
> + auto_diagnostic_group d;
> if (warning (OPT_Wabi_tag, "%qD inherits the %E ABI tag "
> "that %qT (used in its return type) has",
> p->t, tag, *tp))
> @@ -1338,12 +1339,14 @@ check_tag (tree tag, tree id, tree *tp, abi_tag_data
> *p)
> }
> else if (VAR_P (p->t))
> {
> + auto_diagnostic_group d;
> if (warning (OPT_Wabi_tag, "%qD inherits the %E ABI tag "
> "that %qT (used in its type) has", p->t, tag, *tp))
> inform (location_of (*tp), "%qT declared here", *tp);
> }
> else if (TYPE_P (p->subob))
> {
> + auto_diagnostic_group d;
> if (warning (OPT_Wabi_tag, "%qT does not have the %E ABI tag "
> "that base %qT has", p->t, tag, p->subob))
> inform (location_of (p->subob), "%qT declared here",
> @@ -1351,6 +1354,7 @@ check_tag (tree tag, tree id, tree *tp, abi_tag_data *p)
> }
> else
> {
> + auto_diagnostic_group d;
> if (warning (OPT_Wabi_tag, "%qT does not have the %E ABI tag "
> "that %qT (used in the type of %qD) has",
> p->t, tag, *tp, p->subob))
> @@ -2904,20 +2908,24 @@ finish_struct_anon_r (tree field, bool complain)
> {
> /* We already complained about static data members in
> finish_static_data_member_decl. */
> - if (!VAR_P (elt)
> - && permerror (DECL_SOURCE_LOCATION (elt),
> - TREE_CODE (TREE_TYPE (field)) == UNION_TYPE
> - ? "%q#D invalid; an anonymous union may "
> - "only have public non-static data members"
> - : "%q#D invalid; an anonymous struct may "
> - "only have public non-static data members", elt))
> + if (!VAR_P (elt))
> {
> - static bool hint;
> - if (flag_permissive && !hint)
> + auto_diagnostic_group d;
> + if (permerror (DECL_SOURCE_LOCATION (elt),
> + TREE_CODE (TREE_TYPE (field)) == UNION_TYPE
> + ? "%q#D invalid; an anonymous union may "
> + "only have public non-static data members"
> + : "%q#D invalid; an anonymous struct may "
> + "only have public non-static data members", elt))
> {
> - hint = true;
> - inform (DECL_SOURCE_LOCATION (elt),
> - "this flexibility is deprecated and will be
> removed");
> + static bool hint;
> + if (flag_permissive && !hint)
> + {
> + hint = true;
> + inform (DECL_SOURCE_LOCATION (elt),
> + "this flexibility is deprecated and will be "
> + "removed");
> + }
> }
> }
> }
> @@ -3107,6 +3115,7 @@ one_inherited_ctor (tree ctor, tree t, tree using_decl)
> one_inheriting_sig (t, ctor, new_parms, i);
> if (parms == NULL_TREE)
> {
> + auto_diagnostic_group d;
> if (warning (OPT_Winherited_variadic_ctor,
> "the ellipsis in %qD is not inherited", ctor))
> inform (DECL_SOURCE_LOCATION (ctor), "%qD declared here", ctor);
> @@ -5399,11 +5408,14 @@ finalize_literal_type_property (tree t)
> && !DECL_CONSTRUCTOR_P (fn))
> {
> DECL_DECLARED_CONSTEXPR_P (fn) = false;
> - if (!DECL_GENERATED_P (fn)
> - && pedwarn (DECL_SOURCE_LOCATION (fn), OPT_Wpedantic,
> - "enclosing class of %<constexpr%> non-static member
> "
> - "function %q+#D is not a literal type", fn))
> - explain_non_literal_class (t);
> + if (!DECL_GENERATED_P (fn))
> + {
> + auto_diagnostic_group d;
> + if (pedwarn (DECL_SOURCE_LOCATION (fn), OPT_Wpedantic,
> + "enclosing class of %<constexpr%> non-static "
> + "member function %q+#D is not a literal type",
> fn))
> + explain_non_literal_class (t);
> + }
> }
> }
>
> @@ -5425,6 +5437,7 @@ explain_non_literal_class (tree t)
> /* Already explained. */
> return;
>
> + auto_diagnostic_group d;
> inform (UNKNOWN_LOCATION, "%q+T is not literal because:", t);
> if (cxx_dialect < cxx17 && LAMBDA_TYPE_P (t))
> inform (UNKNOWN_LOCATION,
> @@ -6626,17 +6639,20 @@ find_flexarrays (tree t, flexmems_t *fmem, bool
> base_p,
> static void
> diagnose_invalid_flexarray (const flexmems_t *fmem)
> {
> - if (fmem->array && fmem->enclosing
> - && pedwarn (l
