Move loop and switch tree data structures from cp/ to c-family/.

This patch moves the definitions for DO_STMT, FOR_STMT, WHILE_STMT,
SWITCH_STMT, BREAK_STMT, and CONTINUE_STMT from the C++ front end to
c-family.  This includes the genericizers, pretty-printers, and dump
support as well as the tree definitions and accessors.  Some related
code for OMP_FOR and similar OMP constructs is also moved.

2020-08-12  Sandra Loosemore  <sandra@codesourcery.com>

	gcc/c-family/
	* c-common.c (c_block_may_fallthrough): New, split from
	cxx_block_may_fallthrough in the cp front end.
	(c_common_init_ts): Move handling of loop and switch-related
	statements here from the cp front end.
	* c-common.def (FOR_STMT, WHILE_STMT, DO_STMT): Move here from
	cp front end.
	(BREAK_STMT, CONTINUE_STMT, SWITCH_STMT): Likewise.
	* c-common.h (c_block_may_fallthru): Declare.
	(bc_state_t): Move here from cp front end.
	(save_bc_state, restore_bc_state): Declare.
	(c_genericize_control_stmt): Declare.
	(WHILE_COND, WHILE_BODY): Likewise.
	(DO_COND, DO_BODY): Likewise.
	(FOR_INIT_STMT, FOR_COND, FOR_EXPR, FOR_BODY, FOR_SCOPE): Likewise.
	(SWITCH_STMT_COND, SWITCH_STMT_BODY): Likewise.
	(SWITCH_STMT_TYPE, SWITCH_STMT_SCOPE): Likewise.
	(SWITCH_STMT_ALL_CASES_P, SWITCH_STMT_NO_BREAK_P): Likewise.
	(LABEL_DECL_BREAK, LABEL_DECL_CONTINUE): Likewise.
	* c-dump.c (dump_stmt): Copy from cp front end.
	(c_dump_tree): Move code to handle structured loop and switch
	tree nodes here from cp front end.
	* c-gimplify.c: Adjust includes.
	(enum bc_t, bc_label, begin_bc_block, finish_bc_block): Move from
	cp front end.
	(save_bc_state, restore_bc_state): New functions using old code
	from cp front end.
	(get_bc_label, expr_loc_or_loc): Move from cp front end.
	(genericize_c_loop): Move from cp front end.
	(genericize_for_stmt, genericize_while_stmt): Likewise.
	(genericize_do_stmt, genericize_switch_stmt): Likewise.
	(genericize_continue_stmt, genericize_break_stmt): Likewise.
	(genericize_omp_for_stmt): Likewise.
	(c_genericize_control_stmt): New function using code split from
	cp front end.
	(c_genericize_control_r): New.
	(c_genericize): Call walk_tree with c_genericize_control_r.
	* c-pretty-print.c (c_pretty_printer::statement): Move code to handle
	structured loop and switch tree nodes here from cp front end.

	gcc/cp/
	* cp-gimplify.c (enum bc_t, bc_label): Move to c-family.
	(begin_bc_block, finish_bc_block, get_bc_label): Likewise.
	(genericize_cp_loop): Likewise.
	(genericize_for_stmt, genericize_while_stmt): Likewise.
	(genericize_do_stmt, genericize_switch_stmt): Likewise.
	(genericize_continue_stmt, genericize_break_stmt): Likewise.
	(genericize_omp_for_stmt): Likewise.
	(cp_genericize_r): Call c_genericize_control_stmt instead of
	above functions directly.
	(cp_genericize): Call save_bc_state and restore_bc_state instead
	of manipulating bc_label directly.
	* cp-objcp-common.c (cxx_block_may_fallthru): Defer to
	c_block_may_fallthru instead of handling SWITCH_STMT here.
	(cp_common_init_ts): Move handling of loop and switch-related
	statements to c-family.
	* cp-tree.def (FOR_STMT, WHILE_STMT, DO_STMT): Move to c-family.
	(BREAK_STMT, CONTINUE_STMT, SWITCH_STMT): Likewise.
	* cp-tree.h (LABEL_DECL_BREAK, LABEL_DECL_CONTINUE): Likewise.
	(WHILE_COND, WHILE_BODY): Likewise.
	(DO_COND, DO_BODY): Likewise.
	(FOR_INIT_STMT, FOR_COND, FOR_EXPR, FOR_BODY, FOR_SCOPE): Likewise.
	(SWITCH_STMT_COND, SWITCH_STMT_BODY): Likewise.
	(SWITCH_STMT_TYPE, SWITCH_STMT_SCOPE): Likewise.
	(SWITCH_STMT_ALL_CASES_P, SWITCH_STMT_NO_BREAK_P): Likewise.
	* cxx-pretty-print.c (cxx_pretty_printer::statement): Move code
	to handle structured loop and switch tree nodes to c-family.
	* dump.c (cp_dump_tree): Likewise.

	gcc/
	* doc/generic.texi (Basic Statements): Document SWITCH_EXPR here,
	not SWITCH_STMT.
	(Statements for C and C++): Rename node to reflect what
	the introduction already says about sharing between C and C++
	front ends.  Copy-edit and correct documentation for structured
	loops and switch.

1 files changed, 52 insertions, 1 deletions

diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index 4fc64bc..6abfe4b 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -1008,6 +1008,7 @@ extern int case_compare (splay_tree_key, splay_tree_key);
 
 extern tree c_add_case_label (location_t, splay_tree, tree, tree, tree);
 extern bool c_switch_covers_all_cases_p (splay_tree, tree);
+extern bool c_block_may_fallthru (const_tree);
 
 extern tree build_function_call (location_t, tree, tree);
 
@@ -1115,7 +1116,15 @@ class substring_loc;
 extern const char *c_get_substring_location (const substring_loc &substr_loc,
 					     location_t *out_loc);
 
-/* In c-gimplify.c  */
+/* In c-gimplify.c.  */
+typedef struct bc_state
+{
+  tree bc_label[2];
+} bc_state_t;
+extern void save_bc_state (bc_state_t *);
+extern void restore_bc_state (bc_state_t *);
+extern tree c_genericize_control_stmt (tree *, int *, void *,
+				       walk_tree_fn, walk_tree_lh);
 extern void c_genericize (tree);
 extern int c_gimplify_expr (tree *, gimple_seq *, gimple_seq *);
 extern tree c_build_bind_expr (location_t, tree, tree);
@@ -1279,6 +1288,48 @@ extern tree build_userdef_literal (tree suffix_id, tree value,
 				   enum overflow_type overflow,
 				   tree num_string);
 
+
+/* WHILE_STMT accessors. These give access to the condition of the
+   while statement and the body of the while statement, respectively.  */
+#define WHILE_COND(NODE)	TREE_OPERAND (WHILE_STMT_CHECK (NODE), 0)
+#define WHILE_BODY(NODE)	TREE_OPERAND (WHILE_STMT_CHECK (NODE), 1)
+
+/* DO_STMT accessors. These give access to the condition of the do
+   statement and the body of the do statement, respectively.  */
+#define DO_COND(NODE)		TREE_OPERAND (DO_STMT_CHECK (NODE), 0)
+#define DO_BODY(NODE)		TREE_OPERAND (DO_STMT_CHECK (NODE), 1)
+
+/* FOR_STMT accessors. These give access to the init statement,
+   condition, update expression, and body of the for statement,
+   respectively.  */
+#define FOR_INIT_STMT(NODE)	TREE_OPERAND (FOR_STMT_CHECK (NODE), 0)
+#define FOR_COND(NODE)		TREE_OPERAND (FOR_STMT_CHECK (NODE), 1)
+#define FOR_EXPR(NODE)		TREE_OPERAND (FOR_STMT_CHECK (NODE), 2)
+#define FOR_BODY(NODE)		TREE_OPERAND (FOR_STMT_CHECK (NODE), 3)
+#define FOR_SCOPE(NODE)		TREE_OPERAND (FOR_STMT_CHECK (NODE), 4)
+
+#define SWITCH_STMT_COND(NODE)	TREE_OPERAND (SWITCH_STMT_CHECK (NODE), 0)
+#define SWITCH_STMT_BODY(NODE)	TREE_OPERAND (SWITCH_STMT_CHECK (NODE), 1)
+#define SWITCH_STMT_TYPE(NODE)	TREE_OPERAND (SWITCH_STMT_CHECK (NODE), 2)
+#define SWITCH_STMT_SCOPE(NODE)	TREE_OPERAND (SWITCH_STMT_CHECK (NODE), 3)
+/* True if there are case labels for all possible values of switch cond, either
+   because there is a default: case label or because the case label ranges cover
+   all values.  */
+#define SWITCH_STMT_ALL_CASES_P(NODE) \
+  TREE_LANG_FLAG_0 (SWITCH_STMT_CHECK (NODE))
+/* True if the body of a switch stmt contains no BREAK_STMTs.  */
+#define SWITCH_STMT_NO_BREAK_P(NODE) \
+  TREE_LANG_FLAG_2 (SWITCH_STMT_CHECK (NODE))
+
+
+/* Nonzero if NODE is the target for genericization of 'break' stmts.  */
+#define LABEL_DECL_BREAK(NODE) \
+  DECL_LANG_FLAG_0 (LABEL_DECL_CHECK (NODE))
+
+/* Nonzero if NODE is the target for genericization of 'continue' stmts.  */
+#define LABEL_DECL_CONTINUE(NODE) \
+  DECL_LANG_FLAG_1 (LABEL_DECL_CHECK (NODE))
+
 extern bool convert_vector_to_array_for_subscript (location_t, tree *, tree);
 
 /* Possibe cases of scalar_to_vector conversion.  */