c++: Remove CHECK_CONSTR

On Mon, Jul 22, 2024 at 11:48:51AM -0400, Patrick Palka wrote:
> FWIW this tree code seems to be a vestige of the initial Concepts TS
> implementation and is effectively unused, we can remove it outright.

Here is a patch which removes that.

2024-07-23  Jakub Jelinek  <jakub@redhat.com>

	* cp-tree.def (CHECK_CONSTR): Remove.
	* cp-tree.h (CHECK_CONSTR_CONCEPT, CHECK_CONSTR_ARGS): Remove.
	* cp-objcp-common.cc (cp_common_init_ts): Don't handle CHECK_CONSTR.
	* tree.cc (cp_tree_equal): Likewise.
	* error.cc (dump_expr): Likewise.
	* cxx-pretty-print.cc (cxx_pretty_printer::expression): Likewise.
	(pp_cxx_check_constraint): Remove.
	(pp_cxx_constraint): Don't handle CHECK_CONSTR.

6 files changed, 0 insertions, 51 deletions

diff --git a/gcc/cp/cp-objcp-common.cc b/gcc/cp/cp-objcp-common.cc
index 86e0b49..cd37951 100644
--- a/gcc/cp/cp-objcp-common.cc
+++ b/gcc/cp/cp-objcp-common.cc
@@ -701,7 +701,6 @@ cp_common_init_ts (void)
   MARK_TS_EXP (UNARY_RIGHT_FOLD_EXPR);
 
   /* Constraints.  */
-  MARK_TS_EXP (CHECK_CONSTR);
   MARK_TS_EXP (COMPOUND_REQ);
   MARK_TS_EXP (CONJ_CONSTR);
   MARK_TS_EXP (DISJ_CONSTR);
diff --git a/gcc/cp/cp-tree.def b/gcc/cp/cp-tree.def
index a0a47c3..18f7510 100644
--- a/gcc/cp/cp-tree.def
+++ b/gcc/cp/cp-tree.def
@@ -538,14 +538,6 @@ DEFTREECODE (ATOMIC_CONSTR, "atomic_constr", tcc_expression, 1)
 DEFTREECODE (CONJ_CONSTR, "conj_constr", tcc_expression, 2)
 DEFTREECODE (DISJ_CONSTR, "disj_constr", tcc_expression, 2)
 
-/* A check constraint represents the checking of a concept
-   C. It has two operands: the template defining the concept
-   and a sequence of template arguments.
-
-   CHECK_CONSTR_CONCEPT has the concept definition
-   CHECK_CONSTR_ARGS are the template arguments.   */
-DEFTREECODE (CHECK_CONSTR, "check_constr", tcc_expression, 2)
-
 /* The co_await expression is used to support coroutines.
 
   Op 0 is the cast expresssion (potentially modified by the
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 609d894..76ac9c3 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -1723,14 +1723,6 @@ check_constraint_info (tree t)
 #define ATOMIC_CONSTR_EXPR(NODE) \
   CONSTR_EXPR (ATOMIC_CONSTR_CHECK (NODE))
 
-/* The concept of a concept check. */
-#define CHECK_CONSTR_CONCEPT(NODE) \
-  TREE_OPERAND (TREE_CHECK (NODE, CHECK_CONSTR), 0)
-
-/* The template arguments of a concept check. */
-#define CHECK_CONSTR_ARGS(NODE) \
-  TREE_OPERAND (TREE_CHECK (NODE, CHECK_CONSTR), 1)
-
 /* Whether a PARM_DECL represents a local parameter in a
    requires-expression.  */
 #define CONSTRAINT_VAR_P(NODE) \
diff --git a/gcc/cp/cxx-pretty-print.cc b/gcc/cp/cxx-pretty-print.cc
index 806aebf..e690354 100644
--- a/gcc/cp/cxx-pretty-print.cc
+++ b/gcc/cp/cxx-pretty-print.cc
@@ -1257,7 +1257,6 @@ cxx_pretty_printer::expression (tree t)
       break;
 
     case ATOMIC_CONSTR:
-    case CHECK_CONSTR:
     case CONJ_CONSTR:
     case DISJ_CONSTR:
       pp_cxx_constraint (this, t);
@@ -2815,29 +2814,6 @@ pp_cxx_nested_requirement (cxx_pretty_printer *pp, tree t)
   pp_cxx_semicolon (pp);
 }
 
-void
-pp_cxx_check_constraint (cxx_pretty_printer *pp, tree t)
-{
-  tree decl = CHECK_CONSTR_CONCEPT (t);
-  tree tmpl = DECL_TI_TEMPLATE (decl);
-  tree args = CHECK_CONSTR_ARGS (t);
-  tree id = build_nt (TEMPLATE_ID_EXPR, tmpl, args);
-
-  if (TREE_CODE (decl) == CONCEPT_DECL)
-    pp->expression (id);
-  else if (VAR_P (decl))
-    pp->expression (id);
-  else if (TREE_CODE (decl) == FUNCTION_DECL)
-    {
-      tree call = build_vl_exp (CALL_EXPR, 2);
-      TREE_OPERAND (call, 0) = integer_two_node;
-      TREE_OPERAND (call, 1) = id;
-      pp->expression (call);
-    }
-  else
-    gcc_unreachable ();
-}
-
 /* Output the "[with ...]" clause for a parameter mapping of an atomic
    constraint.   */
 
@@ -2917,10 +2893,6 @@ pp_cxx_constraint (cxx_pretty_printer *pp, tree t)
       pp_cxx_atomic_constraint (pp, t);
       break;
 
-    case CHECK_CONSTR:
-      pp_cxx_check_constraint (pp, t);
-      break;
-
     case CONJ_CONSTR:
       pp_cxx_conjunction (pp, t);
       break;
diff --git a/gcc/cp/error.cc b/gcc/cp/error.cc
index 6d99cb2..d80bac8 100644
--- a/gcc/cp/error.cc
+++ b/gcc/cp/error.cc
@@ -3095,7 +3095,6 @@ dump_expr (cxx_pretty_printer *pp, tree t, int flags)
       break;
 
     case ATOMIC_CONSTR:
-    case CHECK_CONSTR:
     case CONJ_CONSTR:
     case DISJ_CONSTR:
       {
diff --git a/gcc/cp/tree.cc b/gcc/cp/tree.cc
index 0e32d90..250239e 100644
--- a/gcc/cp/tree.cc
+++ b/gcc/cp/tree.cc
@@ -4116,11 +4116,6 @@ cp_tree_equal (tree t1, tree t2)
       return cp_tree_equal (CI_ASSOCIATED_CONSTRAINTS (t1),
                             CI_ASSOCIATED_CONSTRAINTS (t2));
 
-    case CHECK_CONSTR:
-      return (CHECK_CONSTR_CONCEPT (t1) == CHECK_CONSTR_CONCEPT (t2)
-              && comp_template_args (CHECK_CONSTR_ARGS (t1),
-				     CHECK_CONSTR_ARGS (t2)));
-
     case TREE_VEC:
       /* These are template args.  Really we should be getting the
 	 caller to do this as it knows it to be true.  */