diff options
| author | Jason Merrill <jason@redhat.com> | 2020-05-21 10:27:11 -0400 |
|---|---|---|
| committer | Jason Merrill <jason@redhat.com> | 2020-05-21 18:04:22 -0400 |
| commit | beb019d346b903c16b9fd349937de444b6a8b6c0 (patch) | |
| tree | 712206ff4c6993253a99a11b9736f06d069f998a /gcc/cp | |
| parent | 4f602147b6abbe05f862d3feda8290d4cf5c583f (diff) | |
c++: Constant expression parsing and parameters.
The difference between a "potential" constant-expression and a regular
constant-expression is the treatment of parameters; in a constexpr function,
a parameter is potentially constant when evaluating a call to that function,
but it is not constant during parsing of the function.
cp_parser_constant_expression should check the latter rather than the
former.
gcc/cp/ChangeLog:
* cp-tree.h (is_rvalue_constant_expression): Declare.
* constexpr.c (is_rvalue_constant_expression): New.
* parser.c (cp_parser_constant_expression): Use it.
* decl.c (cp_finish_decl): Try to treat a constexpr initializer in a
template as constant.
Diffstat (limited to 'gcc/cp')
| -rw-r--r-- | gcc/cp/constexpr.c | 8 | ||||
| -rw-r--r-- | gcc/cp/cp-tree.h | 1 | ||||
| -rw-r--r-- | gcc/cp/decl.c | 2 | ||||
| -rw-r--r-- | gcc/cp/parser.c | 4 |
4 files changed, 12 insertions, 3 deletions
diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c index c1ab9288f72..98c974e657f 100644 --- a/gcc/cp/constexpr.c +++ b/gcc/cp/constexpr.c @@ -8359,6 +8359,14 @@ is_constant_expression (tree t) return potential_constant_expression_1 (t, false, true, true, tf_none); } +/* As above, but expect an rvalue. */ + +bool +is_rvalue_constant_expression (tree t) +{ + return potential_constant_expression_1 (t, true, true, true, tf_none); +} + /* Like above, but complain about non-constant expressions. */ bool diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h index 07c16144c98..db125a3a1db 100644 --- a/gcc/cp/cp-tree.h +++ b/gcc/cp/cp-tree.h @@ -7939,6 +7939,7 @@ extern tree constexpr_fn_retval (tree); extern tree ensure_literal_type_for_constexpr_object (tree); extern bool potential_constant_expression (tree); extern bool is_constant_expression (tree); +extern bool is_rvalue_constant_expression (tree); extern bool is_nondependent_constant_expression (tree); extern bool is_nondependent_static_init_expression (tree); extern bool is_static_init_expression (tree); diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c index a389579ee52..6d1c08e064a 100644 --- a/gcc/cp/decl.c +++ b/gcc/cp/decl.c @@ -7612,7 +7612,7 @@ cp_finish_decl (tree decl, tree init, bool init_const_expr_p, init = boolean_true_node; } else if (init - && init_const_expr_p + && (init_const_expr_p || DECL_DECLARED_CONSTEXPR_P (decl)) && !TYPE_REF_P (type) && decl_maybe_constant_var_p (decl) && !(dep_init = value_dependent_init_p (init))) diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c index a8082d39aca..6a0ef4d76ee 100644 --- a/gcc/cp/parser.c +++ b/gcc/cp/parser.c @@ -10184,10 +10184,10 @@ cp_parser_constant_expression (cp_parser* parser, if (TREE_TYPE (expression) && TREE_CODE (TREE_TYPE (expression)) == ARRAY_TYPE) decay = build_address (expression); - bool is_const = potential_rvalue_constant_expression (decay); + bool is_const = is_rvalue_constant_expression (decay); parser->non_integral_constant_expression_p = !is_const; if (!is_const && !allow_non_constant_p) - require_potential_rvalue_constant_expression (decay); + require_rvalue_constant_expression (decay); } if (allow_non_constant_p) *non_constant_p = parser->non_integral_constant_expression_p; |