On 7/23/21 4:58 AM, Matthias Kretz wrote:
Hi Jason,
Hi, thanks for your patience; I've been out on PTO a lot in the last
month, and will be again this week.
I found a few regressions from the last patch in the meantime. Version 4 of
the patch is attached.
Questions:
1. I simplified the condition for calling dump_template_parms in
dump_function_name. !DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (t) is
equivalent to DECL_USE_TEMPLATE (t) in this context; implying that
dump_template_parms is unconditionally called with `primary = false`. Or am I
missing something?
Ah, good catch. That suggests that
DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION gives false positives;
DECL_USE_TEMPLATE is also 0 for template patterns themselves, which
would be why for
template <class T>
void f() { foo; }
the error refers to 'void f()' rather than 'void f<T>()'
The macro should probably also check DECL_FRIEND_CONTEXT.
And then the use of !DECL_USE_TEMPLATE is intending to check whether t
is a primary template pattern, and pass true in that case. This would
be more correct if it also checked instantiates_primary_template_p.
2. Given a DECL_TI_ARGS tree, can I query whether an argument was deduced or
explicitly specified? I'm asking because I still consider diagnostics of
function templates unfortunate. `template <class T> void f()` is fine, as is
`void f(T) [with T = float]`, but `void f() [with T = float]` could be better.
I.e. if the template parameter appears somewhere in the function parameter
list, dump_template_parms would only produce noise. If, however, the template
parameter was given explicitly, it would be nice if it could show up
accordingly in diagnostics.
NON_DEFAULT_TEMPLATE_ARGS_COUNT has that information, though there are
some issues with it. Attached is my WIP from May to improve it
somewhat, if that's interesting.
3. When parsing tentatively and the parse is rejected, input_location is not
reset, correct? In the attached patch I therefore made
cp_parser_namespace_alias_definition reset input_location on a failed
tentative parse. But it feels wrong. Shouldn't input_location be restored on
cp_parser_parse_definitely?
Makes sense, I guess cp_lexer_rollback_tokens should call
cp_lexer_set_source_position_from_token.
I'll look at the patch soon.
--
This attribute overrides the diagnostics output string for the entity it
appertains to. The motivation is to improve QoI for library TS
implementations, where diagnostics have a very bad signal-to-noise ratio
due to the long namespaces involved.
With the attribute, it is possible to solve PR89370 and make
std::__cxx11::basic_string<_CharT, _Traits, _Alloc> appear as
std::string in diagnostic output without extra hacks to recognize the
type in the C++ frontend.
Signed-off-by: Matthias Kretz <m.kr...@gsi.de>
gcc/ChangeLog:
PR c++/89370
* doc/extend.texi: Document the diagnose_as attribute.
* doc/invoke.texi: Document -fno-diagnostics-use-aliases.
gcc/c-family/ChangeLog:
PR c++/89370
* c.opt (fdiagnostics-use-aliases): New diagnostics flag.
gcc/cp/ChangeLog:
PR c++/89370
* cp-tree.h: Add is_alias_template_p declaration.
* decl2.c (is_alias_template_p): New function. Determines
whether a given TYPE_DECL is actually an alias template that is
still missing its template_info.
(is_late_template_attribute): Decls with diagnose_as attribute
are early attributes only if they are alias templates.
* error.c (dump_scope): When printing the name of a namespace,
look for the diagnose_as attribute. If found, print the
associated string instead of calling dump_decl.
(dump_decl_name_or_diagnose_as): New function to replace
dump_decl (pp, DECL_NAME(t), flags) and inspect the tree for the
diagnose_as attribute before printing the DECL_NAME.
(dump_template_scope): New function. Prints the scope of a
template instance correctly applying diagnose_as attributes and
adjusting the list of template parms accordingly.
(dump_aggr_type): If the type has a diagnose_as attribute, print
the associated string instead of printing the original type
name. Print template parms only if the attribute was not applied
to the instantiation / full specialization. Delay call to
dump_scope until the diagnose_as attribute is found. If the
attribute has a second argument, use it to override the context
passed to dump_scope.
(dump_simple_decl): Call dump_decl_name_or_diagnose_as instead
of dump_decl.
(dump_decl): Ditto.
(lang_decl_name): Ditto.
(dump_function_decl): Walk the functions context list to
determine whether a call to dump_template_scope is required.
Ensure function templates diagnosed with pretty templates set
TFF_TEMPLATE_NAME to skip dump_template_parms.
(dump_function_name): Replace the function's identifier with the
diagnose_as attribute value, if set. Expand
DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION to DECL_USE_TEMPLATE
and consequently call dump_template_parms with primary = false.
(comparable_template_types_p): Consider the types not a template
if one carries a diagnose_as attribute.
(print_template_differences): Replace the identifier with the
diagnose_as attribute value on the most general template, if it
is set.
* name-lookup.c (handle_namespace_attrs): Handle the diagnose_as
attribute on namespaces. Ensure exactly one string argument.
Ensure previous diagnose_as attributes used the same name.
'diagnose_as' on namespace aliases are forwarded to the original
namespace. Support no-argument 'diagnose_as' on namespace
aliases.
(do_namespace_alias): Add attributes parameter and call
handle_namespace_attrs.
* name-lookup.h (do_namespace_alias): Add attributes tree
parameter.
* parser.c (cp_parser_declaration): If the next token is
RID_NAMESPACE, tentatively parse a namespace alias definition.
If this fails expect a namespace definition.
(cp_parser_namespace_alias_definition): Allow optional
attributes before and after the identifier. Fast exit, restoring
input_location, if the expected CPP_EQ token is missing. Pass
attributes to do_namespace_alias.
* tree.c (cxx_attribute_table): Add diagnose_as attribute to the
table.
(check_diagnose_as_redeclaration): New function; copied and
adjusted from check_abi_tag_redeclaration.
(handle_diagnose_as_attribute): New function; copied and
adjusted from handle_abi_tag_attribute. If the given *node is a
TYPE_DECL: allow no argument to the attribute, using DECL_NAME
instead; apply the attribute to the type on the RHS in place,
even if the type is complete. Allow 2 arguments when called from
handle_diagnose_as_attribute. For type aliases, append
CP_DECL_CONTEXT as second attribute argument when the RHS type
has a different context. Warn about alias templates without
matching template arguments. Apply the attribute to the primary
template type for alias templates.
gcc/testsuite/ChangeLog:
PR c++/89370
* g++.dg/diagnostic/diagnose-as1.C: New test.
* g++.dg/diagnostic/diagnose-as2.C: New test.
* g++.dg/diagnostic/diagnose-as3.C: New test.
* g++.dg/diagnostic/diagnose-as4.C: New test.
* g++.dg/diagnostic/diagnose-as5.C: New test.
* g++.dg/diagnostic/diagnose-as6.C: New test.
---
gcc/c-family/c.opt | 4 +
gcc/cp/cp-tree.h | 1 +
gcc/cp/decl2.c | 45 ++++
gcc/cp/error.c | 247 ++++++++++++++++--
gcc/cp/name-lookup.c | 52 +++-
gcc/cp/name-lookup.h | 2 +-
gcc/cp/parser.c | 41 +--
gcc/cp/tree.c | 148 +++++++++++
gcc/doc/extend.texi | 45 ++++
gcc/doc/invoke.texi | 9 +-
.../g++.dg/diagnostic/diagnose-as1.C | 213 +++++++++++++++
.../g++.dg/diagnostic/diagnose-as2.C | 144 ++++++++++
.../g++.dg/diagnostic/diagnose-as3.C | 152 +++++++++++
.../g++.dg/diagnostic/diagnose-as4.C | 158 +++++++++++
.../g++.dg/diagnostic/diagnose-as5.C | 21 ++
.../g++.dg/diagnostic/diagnose-as6.C | 45 ++++
16 files changed, 1291 insertions(+), 36 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/diagnostic/diagnose-as1.C
create mode 100644 gcc/testsuite/g++.dg/diagnostic/diagnose-as2.C
create mode 100644 gcc/testsuite/g++.dg/diagnostic/diagnose-as3.C
create mode 100644 gcc/testsuite/g++.dg/diagnostic/diagnose-as4.C
create mode 100644 gcc/testsuite/g++.dg/diagnostic/diagnose-as5.C
create mode 100644 gcc/testsuite/g++.dg/diagnostic/diagnose-as6.C
>From 857e349f43a59c88634664ec8635ae49dd7bd50f Mon Sep 17 00:00:00 2001
From: Jason Merrill <ja...@redhat.com>
Date: Thu, 27 May 2021 14:04:45 -0400
Subject: [PATCH] default
To: gcc-patches@gcc.gnu.org
---
gcc/cp/error.c | 13 +++++++------
gcc/cp/pt.c | 44 +++++++++++++++++++++++++++-----------------
2 files changed, 34 insertions(+), 23 deletions(-)
diff --git a/gcc/cp/error.c b/gcc/cp/error.c
index 9cb8bfc413e..cac4d3e2089 100644
--- a/gcc/cp/error.c
+++ b/gcc/cp/error.c
@@ -87,8 +87,6 @@ static void dump_exception_spec (cxx_pretty_printer *, tree, int);
static void dump_template_argument (cxx_pretty_printer *, tree, int);
static void dump_template_argument_list (cxx_pretty_printer *, tree, int);
static void dump_template_parameter (cxx_pretty_printer *, tree, int);
-static void dump_template_bindings (cxx_pretty_printer *, tree, tree,
- vec<tree, va_gc> *);
static void dump_scope (cxx_pretty_printer *, tree, int);
static void dump_template_parms (cxx_pretty_printer *, tree, int, int);
static int get_non_default_template_args_count (tree, int);
@@ -375,7 +373,7 @@ dump_template_parameter (cxx_pretty_printer *pp, tree parm, int flags)
static void
dump_template_bindings (cxx_pretty_printer *pp, tree parms, tree args,
- vec<tree, va_gc> *typenames)
+ vec<tree, va_gc> *typenames, int flags)
{
/* Print "[with" and ']', conditional on whether anything is printed at all.
This is tied to whether a semicolon is needed to separate multiple template
@@ -425,7 +423,8 @@ dump_template_bindings (cxx_pretty_printer *pp, tree parms, tree args,
if (TMPL_ARGS_DEPTH (args) >= lvl)
lvl_args = TMPL_ARGS_LEVEL (args, lvl);
- for (i = 0; i < TREE_VEC_LENGTH (p); ++i)
+ int len = get_non_default_template_args_count (lvl_args, flags);
+ for (i = 0; i < len; ++i)
{
tree arg = NULL_TREE;
@@ -1663,7 +1662,8 @@ dump_substitution (cxx_pretty_printer *pp,
&& !(flags & TFF_NO_TEMPLATE_BINDINGS))
{
vec<tree, va_gc> *typenames = t ? find_typenames (t) : NULL;
- dump_template_bindings (pp, template_parms, template_args, typenames);
+ dump_template_bindings (pp, template_parms, template_args, typenames,
+ flags);
}
}
@@ -3449,7 +3449,8 @@ subst_to_string (tree p)
return "";
dump_template_decl (cxx_pp, TREE_PURPOSE (p), flags);
- dump_substitution (cxx_pp, NULL, tparms, targs, /*flags=*/0);
+ dump_substitution (cxx_pp, NULL, tparms, targs,
+ /*TFF_NO_OMIT_DEFAULT_TEMPLATE_ARGUMENTS*/0);
return pp_ggc_formatted_text (cxx_pp);
}
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 0870ccdc9f6..691f1b82535 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -2518,7 +2518,7 @@ determine_specialization (tree template_id,
if (candidates)
{
tree fn = TREE_VALUE (candidates);
- *targs_out = copy_node (DECL_TI_ARGS (fn));
+ *targs_out = copy_template_args (DECL_TI_ARGS (fn));
/* Propagate the candidate's constraints to the declaration. */
if (tsk != tsk_template)
@@ -4816,11 +4816,16 @@ template_parms_level_to_args (tree parms)
{
tree a = copy_node (parms);
TREE_TYPE (a) = NULL_TREE;
+ int nondefault = 0;
for (int i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
- TREE_VEC_ELT (a, i) = template_parm_to_arg (TREE_VEC_ELT (a, i));
+ {
+ tree elt = TREE_VEC_ELT (a, i);
+ TREE_VEC_ELT (a, i) = template_parm_to_arg (elt);
+ if (!elt || elt == error_mark_node || !TREE_PURPOSE (elt))
+ ++nondefault;
+ }
- if (CHECKING_P)
- SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (a, TREE_VEC_LENGTH (a));
+ SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (a, nondefault);
return a;
}
@@ -13276,8 +13281,9 @@ copy_template_args (tree t)
TREE_VEC_ELT (new_vec, i) = elt;
}
- NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_vec)
- = NON_DEFAULT_TEMPLATE_ARGS_COUNT (t);
+ if (!TMPL_ARGS_HAVE_MULTIPLE_LEVELS (t))
+ NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_vec)
+ = NON_DEFAULT_TEMPLATE_ARGS_COUNT (t);
return new_vec;
}
@@ -22339,9 +22345,17 @@ type_unification_real (tree tparms,
be NULL_TREE or ERROR_MARK_NODE, so we do not need
to explicitly check cxx_dialect here. */
if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)))
- /* OK, there is a default argument. Wait until after the
- conversion check to do substitution. */
- continue;
+ {
+ /* The position of the first default template argument,
+ is also the number of non-defaulted arguments in TARGS.
+ Record that. */
+ if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
+ SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, i);
+
+ /* OK, there is a default argument. Wait until after the
+ conversion check to do substitution. */
+ continue;
+ }
/* If the type parameter is a parameter pack, then it will
be deduced to an empty parameter pack. */
@@ -22444,14 +22458,7 @@ type_unification_real (tree tparms,
if (arg == error_mark_node)
return 1;
else if (arg)
- {
- TREE_VEC_ELT (targs, i) = arg;
- /* The position of the first default template argument,
- is also the number of non-defaulted arguments in TARGS.
- Record that. */
- if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
- SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, i);
- }
+ TREE_VEC_ELT (targs, i) = arg;
}
if (saw_undeduced++ == 1)
@@ -24821,6 +24828,9 @@ get_partial_spec_bindings (tree tmpl, tree spec_tmpl, tree args)
if (!template_template_parm_bindings_ok_p (tparms, deduced_args))
return NULL_TREE;
+ if (CHECKING_P)
+ SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (deduced_args, ntparms);
+
return deduced_args;
}
--
2.27.0
