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, 2004 Free Software Foundation, Inc.
+ Copyright (C) 2002, 2003, 2004, 2005 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>
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING. If not, write to the Free
-Software Foundation, 59 Temple Place - Suite 330, Boston, MA
-02111-1307, USA. */
+Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301, USA. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
-#include "errors.h"
#include "varray.h"
#include "c-tree.h"
#include "c-common.h"
walk back up, we check that they fit our constraints, and copy them
into temporaries if not. */
-/* Local declarations. */
-
-enum bc_t { bc_break = 0, bc_continue = 1 };
-
-static struct c_gimplify_ctx
-{
- /* For handling break and continue. */
- tree current_bc_label;
- tree bc_id[2];
-} *ctxp;
-
-static void
-push_context (void)
-{
- if (ctxp)
- abort ();
- 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 ();
- free (ctxp);
- ctxp = NULL;
-}
-
/* Gimplification of statement trees. */
/* Convert the tree representation of FNDECL from C frontend trees to
void
c_genericize (tree fndecl)
{
- FILE *dump_file;
+ FILE *dump_orig;
int local_dump_flags;
struct cgraph_node *cgn;
/* Dump the C-specific tree IR. */
- dump_file = dump_begin (TDI_original, &local_dump_flags);
- if (dump_file)
+ dump_orig = dump_begin (TDI_original, &local_dump_flags);
+ if (dump_orig)
{
- fprintf (dump_file, "\n;; Function %s",
+ fprintf (dump_orig, "\n;; Function %s",
lang_hooks.decl_printable_name (fndecl, 2));
- fprintf (dump_file, " (%s)\n",
+ fprintf (dump_orig, " (%s)\n",
IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (fndecl)));
- fprintf (dump_file, ";; enabled by -%s\n", dump_flag_name (TDI_original));
- fprintf (dump_file, "\n");
+ fprintf (dump_orig, ";; enabled by -%s\n", dump_flag_name (TDI_original));
+ fprintf (dump_orig, "\n");
if (local_dump_flags & TDF_RAW)
dump_node (DECL_SAVED_TREE (fndecl),
- TDF_SLIM | local_dump_flags, dump_file);
+ TDF_SLIM | local_dump_flags, dump_orig);
else
- print_c_tree (dump_file, DECL_SAVED_TREE (fndecl));
- fprintf (dump_file, "\n");
+ print_c_tree (dump_orig, DECL_SAVED_TREE (fndecl));
+ fprintf (dump_orig, "\n");
- dump_end (TDI_original, dump_file);
+ dump_end (TDI_original, dump_orig);
}
/* Go ahead and gimplify for now. */
- push_context ();
gimplify_function_tree (fndecl);
- pop_context ();
/* Dump the genericized tree IR. */
dump_function (TDI_generic, fndecl);
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
return bind;
}
-/* Gimplify an EXPR_STMT node.
-
- STMT is the statement node.
-
- PRE_P points to the list where side effects that must happen before
- STMT should be stored.
-
- POST_P points to the list where side effects that must happen after
- STMT should be stored. */
-
-static enum gimplify_status
-gimplify_expr_stmt (tree *stmt_p)
-{
- tree stmt = EXPR_STMT_EXPR (*stmt_p);
-
- if (stmt == error_mark_node)
- stmt = NULL;
-
- /* Gimplification of a statement expression will nullify the
- statement if all its side effects are moved to *PRE_P and *POST_P.
-
- In this case we will not want to emit the gimplified statement.
- However, we may still want to emit a warning, so we do that before
- gimplification. */
- if (stmt && (extra_warnings || warn_unused_value))
- {
- if (!TREE_SIDE_EFFECTS (stmt))
- {
- if (!IS_EMPTY_STMT (stmt)
- && !VOID_TYPE_P (TREE_TYPE (stmt))
- && !TREE_NO_WARNING (stmt))
- warning ("statement with no effect");
- }
- else if (warn_unused_value)
- warn_if_unused_value (stmt, input_location);
- }
-
- if (stmt == NULL_TREE)
- stmt = alloc_stmt_list ();
-
- *stmt_p = stmt;
-
- return GS_OK;
-}
-
-/* Begin a scope which can be exited by a break or continue statement. BC
- indicates which.
-
- Just creates a label and pushes it into the current context. */
-
-static tree
-begin_bc_block (enum bc_t bc)
-{
- tree label = create_artificial_label ();
- DECL_NAME (label) = ctxp->bc_id[bc];
- TREE_CHAIN (label) = ctxp->current_bc_label;
- ctxp->current_bc_label = label;
- return label;
-}
-
-/* Finish a scope which can be exited by a break or continue statement.
- LABEL was returned from the most recent call to begin_bc_block. BODY is
- an expression for the contents of the scope.
-
- If we saw a break (or continue) in the scope, append a LABEL_EXPR to
- body. Otherwise, just forget the label. */
-
-static tree
-finish_bc_block (tree label, tree body)
-{
- if (label != ctxp->current_bc_label)
- abort ();
-
- if (TREE_USED (label))
- {
- tree t, sl = NULL;
-
- /* Clear the name so flow can delete the label. */
- DECL_NAME (label) = NULL_TREE;
- t = build1 (LABEL_EXPR, void_type_node, label);
-
- append_to_statement_list (body, &sl);
- append_to_statement_list (t, &sl);
- body = sl;
- }
-
- ctxp->current_bc_label = TREE_CHAIN (label);
- TREE_CHAIN (label) = NULL_TREE;
- return body;
-}
-
-/* Build a GOTO_EXPR to represent a break or continue statement. BC
- indicates which. */
-
-static tree
-build_bc_goto (enum bc_t bc)
-{
- tree label;
- tree target_name = ctxp->bc_id[bc];
-
- /* Look for the appropriate type of label. */
- for (label = ctxp->current_bc_label;
- label;
- label = TREE_CHAIN (label))
- if (DECL_NAME (label) == target_name)
- break;
-
- if (label == NULL_TREE)
- {
- if (bc == bc_break)
- error ("break statement not within loop or switch");
- else
- error ("continue statement not within loop or switch");
-
- return NULL_TREE;
- }
-
- /* Mark the label used for finish_bc_block. */
- TREE_USED (label) = 1;
- return build1 (GOTO_EXPR, void_type_node, label);
-}
-
-/* Build a generic representation of one of the C loop forms. COND is the
- loop condition or NULL_TREE. BODY is the (possibly compound) statement
- controlled by the loop. INCR is the increment expression of a for-loop,
- or NULL_TREE. COND_IS_FIRST indicates whether the condition is
- evaluated before the loop body as in while and for loops, or after the
- loop body as in do-while loops. */
-
-static tree
-gimplify_c_loop (tree cond, tree body, tree incr, bool cond_is_first)
-{
- tree top, entry, exit, cont_block, break_block, stmt_list, t;
- location_t stmt_locus;
-
- stmt_locus = input_location;
-
- /* Detect do { ... } while (0) and don't generate loop construct. */
- if (!cond_is_first && cond && integer_zerop (cond))
- top = cond = NULL;
- else
- {
- /* If we use a LOOP_EXPR here, we have to feed the whole thing
- back through the main gimplifier to lower it. Given that we
- 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)
- {
- t = build_bc_goto (bc_break);
- exit = build (COND_EXPR, void_type_node, cond, exit, t);
- exit = fold (exit);
- gimplify_stmt (&exit);
- }
- }
- else
- exit = NULL_TREE;
-
- cont_block = begin_bc_block (bc_continue);
-
- gimplify_stmt (&body);
- 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);
- append_to_statement_list (entry, &stmt_list);
- append_to_statement_list (exit, &stmt_list);
-
- annotate_all_with_locus (&stmt_list, stmt_locus);
-
- return finish_bc_block (break_block, stmt_list);
-}
-
-/* Gimplify a FOR_STMT node. Move the stuff in the for-init-stmt into the
- prequeue and hand off to gimplify_c_loop. */
-
-static enum gimplify_status
-gimplify_for_stmt (tree *stmt_p, tree *pre_p)
-{
- 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);
- }
- *stmt_p = gimplify_c_loop (FOR_COND (stmt), FOR_BODY (stmt),
- FOR_EXPR (stmt), 1);
-
- return GS_ALL_DONE;
-}
-
-/* Gimplify a WHILE_STMT node. */
-
-static enum gimplify_status
-gimplify_while_stmt (tree *stmt_p)
-{
- tree stmt = *stmt_p;
- *stmt_p = gimplify_c_loop (WHILE_COND (stmt), WHILE_BODY (stmt),
- NULL_TREE, 1);
- return GS_ALL_DONE;
-}
-
-/* Gimplify a DO_STMT node. */
-
-static enum gimplify_status
-gimplify_do_stmt (tree *stmt_p)
-{
- tree stmt = *stmt_p;
- *stmt_p = gimplify_c_loop (DO_COND (stmt), DO_BODY (stmt),
- NULL_TREE, 0);
- return GS_ALL_DONE;
-}
-
-/* Genericize a SWITCH_STMT by turning it into a SWITCH_EXPR. */
-
-static enum gimplify_status
-gimplify_switch_stmt (tree *stmt_p)
-{
- tree stmt = *stmt_p;
- tree break_block, body;
- location_t stmt_locus = input_location;
-
- break_block = begin_bc_block (bc_break);
-
- body = SWITCH_BODY (stmt);
- 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);
- gimplify_stmt (stmt_p);
-
- *stmt_p = finish_bc_block (break_block, *stmt_p);
- return GS_ALL_DONE;
-}
-
-/* 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);
-
- *stmt_p = NULL_TREE;
-
- if (TREE_TYPE (decl) == error_mark_node)
- return GS_ERROR;
-
- if (TREE_CODE (decl) == TYPE_DECL)
- gimplify_type_sizes (TREE_TYPE (decl), stmt_p);
-
- else if (TREE_CODE (decl) == VAR_DECL && !DECL_EXTERNAL (decl))
- {
- tree init = DECL_INITIAL (decl);
-
- gimplify_one_sizepos (&DECL_SIZE (decl), stmt_p);
- gimplify_one_sizepos (&DECL_SIZE_UNIT (decl), stmt_p);
-
- if (!TREE_CONSTANT (DECL_SIZE (decl)))
- {
- /* 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(). */
-
- tree pt_type = build_pointer_type (TREE_TYPE (decl));
- tree alloc_stmt
- = (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, DECL_SIZE_UNIT (decl),
- NULL_TREE))));
-
- gimplify_and_add (alloc_stmt, stmt_p);
- DECL_DEFER_OUTPUT (decl) = 1;
- }
-
- 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);
- gimplify_and_add (init, stmt_p);
- }
- 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);
- }
-
- return GS_ALL_DONE;
-}
-
/* 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
- instead. */
+/* Gimplify a C99 compound literal expression. This just means adding
+ the DECL_EXPR before the current statement and using its anonymous
+ decl instead. */
static enum gimplify_status
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
anonymous artificial vars aren't pushed, but everything else is. */
- if (DECL_NAME (decl) == NULL_TREE)
+ if (DECL_NAME (decl) == NULL_TREE && !DECL_SEEN_IN_BIND_EXPR_P (decl))
gimple_add_tmp_var (decl);
- gimplify_decl_stmt (&decl_s);
- append_to_statement_list (decl_s, pre_p);
+ gimplify_and_add (decl_s, pre_p);
*expr_p = decl;
return GS_OK;
}
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, 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 DECL_STMT:
- return gimplify_decl_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;
}