by the C-based front ends. The structure of gimplified, or
language-independent, trees is dictated by the grammar described in this
file.
- Copyright (C) 2002, 2003 Free Software Foundation, Inc.
+ Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
Lowering of expressions contributed by Sebastian Pop <s.pop@laposte.net>
Re-written to support lowering of whole function trees, documentation
and miscellaneous cleanups by Diego Novillo <dnovillo@redhat.com>
/* Local declarations. */
-static enum gimplify_status gimplify_expr_stmt (tree *);
-static enum gimplify_status gimplify_decl_stmt (tree *);
-static enum gimplify_status gimplify_for_stmt (tree *, tree *);
-static enum gimplify_status gimplify_while_stmt (tree *);
-static enum gimplify_status gimplify_do_stmt (tree *);
-static enum gimplify_status gimplify_if_stmt (tree *);
-static enum gimplify_status gimplify_switch_stmt (tree *);
-static enum gimplify_status gimplify_return_stmt (tree *);
-static enum gimplify_status gimplify_compound_literal_expr (tree *);
-static void gimplify_cleanup_stmts (tree);
-static tree gimplify_c_loop (tree, tree, tree, bool);
-static void push_context (void);
-static void pop_context (void);
-static void add_block_to_enclosing (tree);
-
enum bc_t { bc_break = 0, bc_continue = 1 };
-static tree begin_bc_block (enum bc_t);
-static tree finish_bc_block (tree, tree);
-static tree build_bc_goto (enum bc_t);
static struct c_gimplify_ctx
{
static void
push_context (void)
{
- if (ctxp)
- abort ();
+ gcc_assert (!ctxp);
ctxp = (struct c_gimplify_ctx *) xcalloc (1, sizeof (struct c_gimplify_ctx));
ctxp->bc_id[bc_continue] = get_identifier ("continue");
ctxp->bc_id[bc_break] = get_identifier ("break");
static void
pop_context (void)
{
- if (!ctxp || ctxp->current_bc_label)
- abort ();
+ gcc_assert (ctxp && !ctxp->current_bc_label);
free (ctxp);
ctxp = NULL;
}
/* Go ahead and gimplify for now. */
push_context ();
- gimplify_cleanup_stmts (fndecl);
gimplify_function_tree (fndecl);
pop_context ();
c_genericize (cgn->decl);
}
-/* Genericize a CLEANUP_STMT. This just turns into a TRY_FINALLY or
- TRY_CATCH depending on whether it's EH-only. */
-
-static tree
-gimplify_cleanup_stmt (tree *stmt_p, int *walk_subtrees,
- void *data ATTRIBUTE_UNUSED)
-{
- tree stmt = *stmt_p;
-
- if (DECL_P (stmt) || TYPE_P (stmt))
- *walk_subtrees = 0;
- else if (TREE_CODE (stmt) == CLEANUP_STMT)
- *stmt_p = build (CLEANUP_EH_ONLY (stmt) ? TRY_CATCH_EXPR : TRY_FINALLY_EXPR,
- void_type_node, CLEANUP_BODY (stmt), CLEANUP_EXPR (stmt));
-
- return NULL;
-}
-
-static void
-gimplify_cleanup_stmts (tree fndecl)
-{
- walk_tree (&DECL_SAVED_TREE (fndecl), gimplify_cleanup_stmt, NULL, NULL);
-}
-
-/* Entry point for the tree lowering pass. Recursively scan
- *STMT_P and convert it to a GIMPLE tree. */
-
-int
-c_gimplify_stmt (tree *stmt_p)
-{
- tree stmt = *stmt_p;
- tree pre, post;
- int saved_stmts_are_full_exprs_p;
- location_t stmt_locus;
- enum gimplify_status ret;
-
- /* PRE and POST are tree chains that contain the side-effects of the
- gimplified tree. For instance, given the expression tree:
-
- c = ++a * 3 + b++;
-
- After gimplification, the tree will be re-written as:
-
- a = a + 1;
- t1 = a * 3; <-- PRE
- c = t1 + b;
- b = b + 1; <-- POST */
-
- /* Set up context appropriately for handling this statement. */
- saved_stmts_are_full_exprs_p = stmts_are_full_exprs_p ();
- prep_stmt (stmt);
- stmt_locus = input_location;
-
- pre = NULL_TREE;
- post = NULL_TREE;
-
- switch (TREE_CODE (stmt))
- {
- case FOR_STMT:
- ret = gimplify_for_stmt (&stmt, &pre);
- break;
-
- case WHILE_STMT:
- ret = gimplify_while_stmt (&stmt);
- break;
-
- case DO_STMT:
- ret = gimplify_do_stmt (&stmt);
- break;
-
- case IF_STMT:
- ret = gimplify_if_stmt (&stmt);
- break;
-
- case SWITCH_STMT:
- ret = gimplify_switch_stmt (&stmt);
- break;
-
- case EXPR_STMT:
- ret = gimplify_expr_stmt (&stmt);
- break;
-
- case RETURN_STMT:
- ret = gimplify_return_stmt (&stmt);
- break;
-
- case DECL_STMT:
- ret = gimplify_decl_stmt (&stmt);
- break;
-
- case CONTINUE_STMT:
- stmt = build_bc_goto (bc_continue);
- ret = GS_OK;
- break;
-
- case BREAK_STMT:
- stmt = build_bc_goto (bc_break);
- ret = GS_OK;
- break;
-
- default:
- if (lang_gimplify_stmt && (*lang_gimplify_stmt) (&stmt))
- {
- ret = GS_OK;
- break;
- }
-
- fprintf (stderr, "unhandled statement node in c_gimplify_stmt:\n");
- debug_tree (stmt);
- abort ();
- break;
- }
-
- switch (ret)
- {
- case GS_ERROR:
- goto cont;
- case GS_OK:
- gimplify_stmt (&stmt);
- break;
- case GS_ALL_DONE:
- break;
- default:
- abort ();
- }
-
- /* PRE and POST now contain a list of statements for all the
- side-effects in STMT. */
-
- append_to_statement_list (stmt, &pre);
- append_to_statement_list (post, &pre);
- annotate_all_with_locus (&pre, stmt_locus);
- cont:
- /* Restore saved state. */
- current_stmt_tree ()->stmts_are_full_exprs_p = saved_stmts_are_full_exprs_p;
- *stmt_p = pre;
-
- return GS_ALL_DONE;
-}
-
static void
add_block_to_enclosing (tree block)
{
body = build_empty_stmt ();
if (decls || block)
{
- bind = build (BIND_EXPR, void_type_node, decls, body, block);
+ bind = build3 (BIND_EXPR, void_type_node, decls, body, block);
TREE_SIDE_EFFECTS (bind) = 1;
}
else
warning ("statement with no effect");
}
else if (warn_unused_value)
- {
- /* Kludge for 20020220-2.c. warn_if_unused_value shouldn't use
- the stmt file location info. */
- set_file_and_line_for_stmt (input_location);
- warn_if_unused_value (stmt);
- }
+ warn_if_unused_value (stmt, input_location);
}
if (stmt == NULL_TREE)
- stmt = build_empty_stmt ();
- else if (stmts_are_full_exprs_p ())
- stmt = build1 (CLEANUP_POINT_EXPR, void_type_node, stmt);
+ stmt = alloc_stmt_list ();
*stmt_p = stmt;
static tree
finish_bc_block (tree label, tree body)
{
- if (label != ctxp->current_bc_label)
- abort ();
+ gcc_assert (label == ctxp->current_bc_label);
if (TREE_USED (label))
{
location_t stmt_locus;
stmt_locus = input_location;
+ stmt_list = NULL_TREE;
+ entry = NULL_TREE;
+
+ break_block = begin_bc_block (bc_break);
+ cont_block = begin_bc_block (bc_continue);
- /* Detect do { ... } while (0) and don't generate loop construct. */
- if (!cond_is_first && cond && integer_zerop (cond))
- top = cond = NULL;
+ /* If condition is zero don't generate a loop construct. */
+ if (cond && integer_zerop (cond))
+ {
+ top = NULL_TREE;
+ exit = NULL_TREE;
+ if (cond_is_first)
+ {
+ t = build_bc_goto (bc_break);
+ append_to_statement_list (t, &stmt_list);
+ }
+ }
else
{
/* If we use a LOOP_EXPR here, we have to feed the whole thing
have to gimplify the loop body NOW so that we can resolve
break/continue stmts, seems easier to just expand to gotos. */
top = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
- }
-
- break_block = begin_bc_block (bc_break);
- if (top)
- {
/* If we have an exit condition, then we build an IF with gotos either
out of the loop, or to the top of it. If there's no exit condition,
then we just build a jump back to the top. */
exit = build_and_jump (&LABEL_EXPR_LABEL (top));
- if (cond)
+ if (cond && !integer_nonzerop (cond))
{
t = build_bc_goto (bc_break);
- exit = build (COND_EXPR, void_type_node, cond, exit, t);
+ exit = build3 (COND_EXPR, void_type_node, cond, exit, t);
exit = fold (exit);
gimplify_stmt (&exit);
+
+ if (cond_is_first)
+ {
+ if (incr)
+ {
+ entry = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
+ t = build_and_jump (&LABEL_EXPR_LABEL (entry));
+ }
+ else
+ t = build_bc_goto (bc_continue);
+ append_to_statement_list (t, &stmt_list);
+ }
}
}
- else
- exit = NULL_TREE;
-
- cont_block = begin_bc_block (bc_continue);
gimplify_stmt (&body);
- if (incr && stmts_are_full_exprs_p ())
- incr = fold (build1 (CLEANUP_POINT_EXPR, void_type_node, incr));
gimplify_stmt (&incr);
body = finish_bc_block (cont_block, body);
- stmt_list = NULL;
-
- if (cond_is_first && cond)
- {
- entry = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
- t = build_and_jump (&LABEL_EXPR_LABEL (entry));
- append_to_statement_list (t, &stmt_list);
- }
- else
- entry = NULL_TREE;
-
append_to_statement_list (top, &stmt_list);
append_to_statement_list (body, &stmt_list);
append_to_statement_list (incr, &stmt_list);
tree stmt = *stmt_p;
if (FOR_INIT_STMT (stmt))
- {
- gimplify_stmt (&FOR_INIT_STMT (stmt));
- append_to_statement_list (FOR_INIT_STMT (stmt), pre_p);
- }
+ gimplify_and_add (FOR_INIT_STMT (stmt), pre_p);
+
*stmt_p = gimplify_c_loop (FOR_COND (stmt), FOR_BODY (stmt),
FOR_EXPR (stmt), 1);
return GS_ALL_DONE;
}
-/* Genericize an IF_STMT by turning it into a COND_EXPR. */
-
-static enum gimplify_status
-gimplify_if_stmt (tree *stmt_p)
-{
- tree stmt, then_, else_;
-
- stmt = *stmt_p;
- then_ = THEN_CLAUSE (stmt);
- else_ = ELSE_CLAUSE (stmt);
-
- if (!then_)
- then_ = build_empty_stmt ();
- if (!else_)
- else_ = build_empty_stmt ();
-
- stmt = build (COND_EXPR, void_type_node, IF_COND (stmt), then_, else_);
- *stmt_p = stmt;
-
- return GS_OK;
-}
-
/* Genericize a SWITCH_STMT by turning it into a SWITCH_EXPR. */
static enum gimplify_status
if (!body)
body = build_empty_stmt ();
- *stmt_p = build (SWITCH_EXPR, SWITCH_TYPE (stmt), SWITCH_COND (stmt),
- body, NULL_TREE);
- annotate_with_locus (*stmt_p, stmt_locus);
+ *stmt_p = build3 (SWITCH_EXPR, SWITCH_TYPE (stmt), SWITCH_COND (stmt),
+ body, NULL_TREE);
+ SET_EXPR_LOCATION (*stmt_p, stmt_locus);
gimplify_stmt (stmt_p);
*stmt_p = finish_bc_block (break_block, *stmt_p);
return GS_ALL_DONE;
}
-/* Genericize a RETURN_STMT by turning it into a RETURN_EXPR. */
-
-static enum gimplify_status
-gimplify_return_stmt (tree *stmt_p)
-{
- tree expr = RETURN_STMT_EXPR (*stmt_p);
- expr = build1 (RETURN_EXPR, void_type_node, expr);
- if (stmts_are_full_exprs_p ())
- expr = build1 (CLEANUP_POINT_EXPR, void_type_node, expr);
- *stmt_p = expr;
- return GS_OK;
-}
-
-/* Gimplifies a DECL_STMT node *STMT_P by making any necessary allocation
- and initialization explicit. */
-
-static enum gimplify_status
-gimplify_decl_stmt (tree *stmt_p)
-{
- tree stmt = *stmt_p;
- tree decl = DECL_STMT_DECL (stmt);
- tree pre = NULL_TREE;
- tree post = NULL_TREE;
-
- if (TREE_TYPE (decl) == error_mark_node)
- {
- *stmt_p = NULL;
- return GS_ERROR;
- }
-
- if (TREE_CODE (decl) == TYPE_DECL)
- {
- tree type = TREE_TYPE (decl);
- if (TYPE_SIZE_UNIT (type)
- && !TREE_CONSTANT (TYPE_SIZE_UNIT (type)))
- {
- /* This is a variable-sized array type. Simplify its size. */
- tree temp = TYPE_SIZE_UNIT (type);
- gimplify_expr (&temp, &pre, &post, is_gimple_val, fb_rvalue);
- }
- }
-
- if (TREE_CODE (decl) == VAR_DECL && !DECL_EXTERNAL (decl))
- {
- tree init = DECL_INITIAL (decl);
-
- if (!TREE_CONSTANT (DECL_SIZE (decl)))
- {
- tree pt_type = build_pointer_type (TREE_TYPE (decl));
- tree alloc, size;
-
- /* This is a variable-sized decl. Simplify its size and mark it
- for deferred expansion. Note that mudflap depends on the format
- of the emitted code: see mx_register_decls(). */
-
- size = get_initialized_tmp_var (DECL_SIZE_UNIT (decl), &pre, &post);
- DECL_DEFER_OUTPUT (decl) = 1;
- alloc = build_function_call_expr
- (implicit_built_in_decls[BUILT_IN_STACK_ALLOC],
- tree_cons (NULL_TREE,
- build1 (ADDR_EXPR, pt_type, decl),
- tree_cons (NULL_TREE, size, NULL_TREE)));
- append_to_compound_expr (alloc, &pre);
- }
-
- if (init && init != error_mark_node)
- {
- if (!TREE_STATIC (decl))
- {
- /* Do not warn about int x = x; as it is a GCC extension
- to turn off this warning but only if warn_init_self
- is zero. */
- if (init == decl && !warn_init_self)
- TREE_NO_WARNING (decl) = 1;
-
- DECL_INITIAL (decl) = NULL_TREE;
- init = build (MODIFY_EXPR, void_type_node, decl, init);
- if (stmts_are_full_exprs_p ())
- init = build1 (CLEANUP_POINT_EXPR, void_type_node, init);
- append_to_compound_expr (init, &pre);
- }
- else
- {
- /* We must still examine initializers for static variables
- as they may contain a label address. */
- walk_tree (&init, force_labels_r, NULL, NULL);
- }
- }
-
- /* This decl isn't mentioned in the enclosing block, so add it to the
- list of temps. FIXME it seems a bit of a kludge to say that
- anonymous artificial vars aren't pushed, but everything else is. */
- if (DECL_ARTIFICIAL (decl) && DECL_NAME (decl) == NULL_TREE)
- gimple_add_tmp_var (decl);
- }
-
- append_to_compound_expr (post, &pre);
- *stmt_p = pre;
- return GS_OK;
-}
-
/* Gimplification of expression trees. */
/* Gimplify a C99 compound literal expression. This just means adding the
- DECL_STMT before the current EXPR_STMT and using its anonymous decl
+ DECL_EXPR before the current EXPR_STMT and using its anonymous decl
instead. */
static enum gimplify_status
-gimplify_compound_literal_expr (tree *expr_p)
+gimplify_compound_literal_expr (tree *expr_p, tree *pre_p)
{
tree decl_s = COMPOUND_LITERAL_EXPR_DECL_STMT (*expr_p);
- tree decl = DECL_STMT_DECL (decl_s);
+ tree decl = DECL_EXPR_DECL (decl_s);
/* This decl isn't mentioned in the enclosing block, so add it to the
list of temps. FIXME it seems a bit of a kludge to say that
if (DECL_NAME (decl) == NULL_TREE)
gimple_add_tmp_var (decl);
- gimplify_decl_stmt (&decl_s);
- *expr_p = decl_s ? decl_s : decl;
+ gimplify_and_add (decl_s, pre_p);
+ *expr_p = decl;
return GS_OK;
}
/* Do C-specific gimplification. Args are as for gimplify_expr. */
int
-c_gimplify_expr (tree *expr_p, tree *pre_p ATTRIBUTE_UNUSED,
- tree *post_p ATTRIBUTE_UNUSED)
+c_gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p ATTRIBUTE_UNUSED)
{
enum tree_code code = TREE_CODE (*expr_p);
- if (STATEMENT_CODE_P (code))
- return c_gimplify_stmt (expr_p);
-
switch (code)
{
+ case DECL_EXPR:
+ /* This is handled mostly by gimplify.c, but we have to deal with
+ not warning about int x = x; as it is a GCC extension to turn off
+ this warning but only if warn_init_self is zero. */
+ if (TREE_CODE (DECL_EXPR_DECL (*expr_p)) == VAR_DECL
+ && !DECL_EXTERNAL (DECL_EXPR_DECL (*expr_p))
+ && !TREE_STATIC (DECL_EXPR_DECL (*expr_p))
+ && (DECL_INITIAL (DECL_EXPR_DECL (*expr_p))
+ == DECL_EXPR_DECL (*expr_p))
+ && !warn_init_self)
+ TREE_NO_WARNING (DECL_EXPR_DECL (*expr_p)) = 1;
+ return GS_UNHANDLED;
+
case COMPOUND_LITERAL_EXPR:
- return gimplify_compound_literal_expr (expr_p);
+ return gimplify_compound_literal_expr (expr_p, pre_p);
+
+ case FOR_STMT:
+ return gimplify_for_stmt (expr_p, pre_p);
+
+ case WHILE_STMT:
+ return gimplify_while_stmt (expr_p);
+
+ case DO_STMT:
+ return gimplify_do_stmt (expr_p);
+
+ case SWITCH_STMT:
+ return gimplify_switch_stmt (expr_p);
+
+ case EXPR_STMT:
+ return gimplify_expr_stmt (expr_p);
+
+ case CONTINUE_STMT:
+ *expr_p = build_bc_goto (bc_continue);
+ return GS_ALL_DONE;
+
+ case BREAK_STMT:
+ *expr_p = build_bc_goto (bc_break);
+ return GS_ALL_DONE;
default:
return GS_UNHANDLED;
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