On Fri, Jul 13, 2018 at 06:53:30PM +0200, Jakub Jelinek wrote:
> On Fri, Jul 13, 2018 at 12:24:02PM -0400, Nathan Sidwell wrote:
> > On 07/13/2018 09:49 AM, Jakub Jelinek wrote:
> > > Hi!
> > >
> > > I'd like to ping the following C++ patches:
> > >
> > > - PR c++/85515
> > > make range for temporaries unspellable during parsing and only
> > > turn them into spellable for debug info purposes
> > > http://gcc.gnu.org/ml/gcc-patches/2018-07/msg00086.html
> >
> >
> > How hard would it be to add the 6 special identifiers to the C++ global
> > table via initialize_predefined_identifiers (decl.c) and then use them
> > directly in the for range machinery? repeated get_identifier
> > ("string-const") just smells bad.
>
> Probably not too hard, but we have hundreds of other
> get_identifier ("string-const") calls in the middle-end, C++ FE, other FEs.
> Are those 6 more important than say "abi_tag", "gnu", "begin", "end", "get",
> "tuple_size", "tuple_element", and many others?
>
> Is it worth caching those?
Anyway, here is an updated patch that uses the get_identifier caching.
Ok for trunk?
Shall I submit an incremental patch for the "abi_tag", "gnu", "begin", "end",
"get",
"tuple_size", "tuple_element" etc. identifiers?
2018-07-18 Jakub Jelinek <ja...@redhat.com>
PR c++/85515
* cp-tree.h (enum cp_tree_index): Add
CPTI_FOR_{RANGE,BEGIN,END}{,_}_IDENTIFIER.
(for_range__identifier, for_begin__identifier, for_end__identifier,
for_range_identifier, for_begin_identifier, for_end_identifier):
Define.
* decl.c (initialize_predefined_identifiers): Initialize
for_{range,begin,end}{,_}_identifier.
* parser.c (build_range_temp): Use for_range__identifier instead of
get_identifier ("__for_range").
(cp_convert_range_for): Use for_begin__identifier and
for_end__identifier instead of get_identifier ("__for_begin") and
get_identifier ("__for_end").
* semantics.c (finish_for_stmt): Rename "__for_{range,begin,end} "
local symbols to "__for_{range,begin,end}".
* g++.dg/pr85515-2.C: Add expected dg-error.
* g++.dg/cpp0x/range-for36.C: New test.
--- gcc/cp/cp-tree.h.jj 2018-06-29 09:38:17.790306399 +0200
+++ gcc/cp/cp-tree.h 2018-07-18 11:57:55.980529748 +0200
@@ -154,6 +154,12 @@ enum cp_tree_index
CPTI_AUTO_IDENTIFIER,
CPTI_DECLTYPE_AUTO_IDENTIFIER,
CPTI_INIT_LIST_IDENTIFIER,
+ CPTI_FOR_RANGE__IDENTIFIER,
+ CPTI_FOR_BEGIN__IDENTIFIER,
+ CPTI_FOR_END__IDENTIFIER,
+ CPTI_FOR_RANGE_IDENTIFIER,
+ CPTI_FOR_BEGIN_IDENTIFIER,
+ CPTI_FOR_END_IDENTIFIER,
CPTI_LANG_NAME_C,
CPTI_LANG_NAME_CPLUSPLUS,
@@ -274,6 +280,12 @@ extern GTY(()) tree cp_global_trees[CPTI
#define auto_identifier
cp_global_trees[CPTI_AUTO_IDENTIFIER]
#define decltype_auto_identifier
cp_global_trees[CPTI_DECLTYPE_AUTO_IDENTIFIER]
#define init_list_identifier
cp_global_trees[CPTI_INIT_LIST_IDENTIFIER]
+#define for_range__identifier
cp_global_trees[CPTI_FOR_RANGE__IDENTIFIER]
+#define for_begin__identifier
cp_global_trees[CPTI_FOR_BEGIN__IDENTIFIER]
+#define for_end__identifier
cp_global_trees[CPTI_FOR_END__IDENTIFIER]
+#define for_range_identifier
cp_global_trees[CPTI_FOR_RANGE_IDENTIFIER]
+#define for_begin_identifier
cp_global_trees[CPTI_FOR_BEGIN_IDENTIFIER]
+#define for_end_identifier cp_global_trees[CPTI_FOR_END_IDENTIFIER]
#define lang_name_c cp_global_trees[CPTI_LANG_NAME_C]
#define lang_name_cplusplus
cp_global_trees[CPTI_LANG_NAME_CPLUSPLUS]
--- gcc/cp/decl.c.jj 2018-07-12 21:34:44.798598796 +0200
+++ gcc/cp/decl.c 2018-07-18 11:59:06.220595473 +0200
@@ -4044,6 +4044,12 @@ initialize_predefined_identifiers (void)
{"auto", &auto_identifier, cik_normal},
{"decltype(auto)", &decltype_auto_identifier, cik_normal},
{"initializer_list", &init_list_identifier, cik_normal},
+ {"__for_range ", &for_range__identifier, cik_normal},
+ {"__for_begin ", &for_begin__identifier, cik_normal},
+ {"__for_end ", &for_end__identifier, cik_normal},
+ {"__for_range", &for_range_identifier, cik_normal},
+ {"__for_begin", &for_begin_identifier, cik_normal},
+ {"__for_end", &for_end_identifier, cik_normal},
{NULL, NULL, cik_normal}
};
--- gcc/cp/parser.c.jj 2018-07-18 10:09:10.655030931 +0200
+++ gcc/cp/parser.c 2018-07-18 12:00:22.907667232 +0200
@@ -11952,8 +11952,8 @@ build_range_temp (tree range_expr)
type_uses_auto (range_type));
/* Create the __range variable. */
- range_temp = build_decl (input_location, VAR_DECL,
- get_identifier ("__for_range"), range_type);
+ range_temp = build_decl (input_location, VAR_DECL, for_range__identifier,
+ range_type);
TREE_USED (range_temp) = 1;
DECL_ARTIFICIAL (range_temp) = 1;
@@ -12060,8 +12060,8 @@ cp_convert_range_for (tree statement, tr
}
/* The new for initialization statement. */
- begin = build_decl (input_location, VAR_DECL,
- get_identifier ("__for_begin"), iter_type);
+ begin = build_decl (input_location, VAR_DECL, for_begin__identifier,
+ iter_type);
TREE_USED (begin) = 1;
DECL_ARTIFICIAL (begin) = 1;
pushdecl (begin);
@@ -12071,8 +12071,7 @@ cp_convert_range_for (tree statement, tr
if (cxx_dialect >= cxx17)
iter_type = cv_unqualified (TREE_TYPE (end_expr));
- end = build_decl (input_location, VAR_DECL,
- get_identifier ("__for_end"), iter_type);
+ end = build_decl (input_location, VAR_DECL, for_end__identifier, iter_type);
TREE_USED (end) = 1;
DECL_ARTIFICIAL (end) = 1;
pushdecl (end);
--- gcc/cp/semantics.c.jj 2018-07-10 09:11:24.254062152 +0200
+++ gcc/cp/semantics.c 2018-07-18 12:03:24.482837137 +0200
@@ -1060,7 +1060,35 @@ finish_for_stmt (tree for_stmt)
: &FOR_SCOPE (for_stmt));
tree scope = *scope_ptr;
*scope_ptr = NULL;
+
+ /* During parsing of the body, range for uses "__for_{range,begin,end} "
+ decl names to make those unaccessible by code in the body.
+ Change it to ones with underscore instead of space, so that it can
+ be inspected in the debugger. */
+ tree range_for_decl[3] = { NULL_TREE, NULL_TREE, NULL_TREE };
+ gcc_assert (CPTI_FOR_BEGIN__IDENTIFIER == CPTI_FOR_RANGE__IDENTIFIER + 1
+ && CPTI_FOR_END__IDENTIFIER == CPTI_FOR_RANGE__IDENTIFIER + 2
+ && CPTI_FOR_RANGE_IDENTIFIER == CPTI_FOR_RANGE__IDENTIFIER + 3
+ && CPTI_FOR_BEGIN_IDENTIFIER == CPTI_FOR_BEGIN__IDENTIFIER + 3
+ && CPTI_FOR_END_IDENTIFIER == CPTI_FOR_END__IDENTIFIER + 3);
+ for (int i = 0; i < 3; i++)
+ {
+ tree id = cp_global_trees[CPTI_FOR_RANGE__IDENTIFIER + i];
+ if (IDENTIFIER_BINDING (id)
+ && IDENTIFIER_BINDING (id)->scope == current_binding_level)
+ {
+ range_for_decl[i] = IDENTIFIER_BINDING (id)->value;
+ gcc_assert (VAR_P (range_for_decl[i])
+ && DECL_ARTIFICIAL (range_for_decl[i]));
+ }
+ }
+
add_stmt (do_poplevel (scope));
+
+ for (int i = 0; i < 3; i++)
+ if (range_for_decl[i])
+ DECL_NAME (range_for_decl[i])
+ = cp_global_trees[CPTI_FOR_RANGE_IDENTIFIER + i];
}
/* Begin a range-for-statement. Returns a new RANGE_FOR_STMT.
--- gcc/testsuite/g++.dg/pr85515-2.C.jj 2018-07-05 11:41:51.439718304 +0200
+++ gcc/testsuite/g++.dg/pr85515-2.C 2018-07-18 11:27:36.452850086 +0200
@@ -15,8 +15,7 @@ int test_2 ()
int sum = 0;
for (const auto v: arr) {
sum += v;
- // TODO: should we issue an error for the following assignment?
- __for_begin = __for_end;
+ __for_begin = __for_end; // { dg-error "was not declared in this scope" }
}
return sum;
}
--- gcc/testsuite/g++.dg/cpp0x/range-for36.C.jj 2018-07-18 11:27:36.452850086
+0200
+++ gcc/testsuite/g++.dg/cpp0x/range-for36.C 2018-07-18 11:27:36.452850086
+0200
@@ -0,0 +1,32 @@
+// PR c++/85515
+// { dg-do compile { target c++11 } }
+
+int a[10];
+
+void
+foo ()
+{
+ for (auto &i : a)
+ if (i != *__for_begin // { dg-error "was not declared in this
scope" }
+ || &i == __for_end // { dg-error "was not declared in this
scope" }
+ || &__for_range[0] != &a[0]) // { dg-error "was not declared in this
scope" }
+ __builtin_abort ();
+}
+
+template <int N>
+void
+bar ()
+{
+ for (auto &i : a)
+ if (i != *__for_begin // { dg-error "was not declared in this
scope" }
+ || &i == __for_end // { dg-error "was not declared in this
scope" }
+ || &__for_range[0] != &a[0]) // { dg-error "was not declared in this
scope" }
+ __builtin_abort ();
+}
+
+void
+baz ()
+{
+ foo ();
+ bar <0> ();
+}
Jakub
