/* GIMPLE lowering pass. Converts High GIMPLE into Low GIMPLE.
- Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
+ Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009
+ Free Software Foundation, Inc.
This file is part of GCC.
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
-#include "rtl.h"
-#include "varray.h"
#include "gimple.h"
#include "tree-iterator.h"
#include "tree-inline.h"
-#include "diagnostic.h"
-#include "langhooks.h"
-#include "langhooks-def.h"
#include "tree-flow.h"
-#include "timevar.h"
-#include "except.h"
-#include "hashtab.h"
#include "flags.h"
#include "function.h"
-#include "expr.h"
#include "toplev.h"
#include "tree-pass.h"
of the function. */
VEC(return_statements_t,heap) *return_statements;
+ /* True if the current statement cannot fall through. */
+ bool cannot_fallthru;
+
/* True if the function calls __builtin_setjmp. */
bool calls_builtin_setjmp;
};
tree disp_label, disp_var, arg;
/* Build 'DISP_LABEL:' and insert. */
- disp_label = create_artificial_label ();
+ disp_label = create_artificial_label (cfun->function_end_locus);
/* This mark will create forward edges from every call site. */
DECL_NONLOCAL (disp_label) = 1;
cfun->has_nonlocal_label = 1;
return 0;
}
-struct gimple_opt_pass pass_lower_cf =
+struct gimple_opt_pass pass_lower_cf =
{
{
GIMPLE_PASS,
NULL, /* sub */
NULL, /* next */
0, /* static_pass_number */
- 0, /* tv_id */
+ TV_NONE, /* tv_id */
PROP_gimple_any, /* properties_required */
PROP_gimple_lcf, /* properties_provided */
0, /* properties_destroyed */
};
+/* Verify if the type of the argument matches that of the function
+ declaration. If we cannot verify this or there is a mismatch,
+ return false. */
+
+bool
+gimple_check_call_args (gimple stmt)
+{
+ tree fndecl, parms, p;
+ unsigned int i, nargs;
+
+ nargs = gimple_call_num_args (stmt);
+
+ /* Get argument types for verification. */
+ fndecl = gimple_call_fndecl (stmt);
+ parms = NULL_TREE;
+ if (fndecl)
+ parms = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
+ else if (POINTER_TYPE_P (TREE_TYPE (gimple_call_fn (stmt))))
+ parms = TYPE_ARG_TYPES (TREE_TYPE (TREE_TYPE (gimple_call_fn (stmt))));
+
+ /* Verify if the type of the argument matches that of the function
+ declaration. If we cannot verify this or there is a mismatch,
+ return false. */
+ if (fndecl && DECL_ARGUMENTS (fndecl))
+ {
+ for (i = 0, p = DECL_ARGUMENTS (fndecl);
+ i < nargs;
+ i++, p = TREE_CHAIN (p))
+ {
+ /* We cannot distinguish a varargs function from the case
+ of excess parameters, still deferring the inlining decision
+ to the callee is possible. */
+ if (!p)
+ break;
+ if (p == error_mark_node
+ || gimple_call_arg (stmt, i) == error_mark_node
+ || !fold_convertible_p (DECL_ARG_TYPE (p),
+ gimple_call_arg (stmt, i)))
+ return false;
+ }
+ }
+ else if (parms)
+ {
+ for (i = 0, p = parms; i < nargs; i++, p = TREE_CHAIN (p))
+ {
+ /* If this is a varargs function defer inlining decision
+ to callee. */
+ if (!p)
+ break;
+ if (TREE_VALUE (p) == error_mark_node
+ || gimple_call_arg (stmt, i) == error_mark_node
+ || TREE_CODE (TREE_VALUE (p)) == VOID_TYPE
+ || !fold_convertible_p (TREE_VALUE (p),
+ gimple_call_arg (stmt, i)))
+ return false;
+ }
+ }
+ else
+ {
+ if (nargs != 0)
+ return false;
+ }
+ return true;
+}
+
+
/* Lower sequence SEQ. Unlike gimplification the statements are not relowered
when they are changed -- if this has to be done, the lowering routine must
do it explicitly. DATA is passed through the recursion. */
lower_omp_directive (gimple_stmt_iterator *gsi, struct lower_data *data)
{
gimple stmt;
-
+
stmt = gsi_stmt (*gsi);
lower_sequence (gimple_omp_body (stmt), data);
}
-/* Lower statement GSI. DATA is passed through the recursion. */
+/* Lower statement GSI. DATA is passed through the recursion. We try to
+ track the fallthruness of statements and get rid of unreachable return
+ statements in order to prevent the EH lowering pass from adding useless
+ edges that can cause bogus warnings to be issued later; this guess need
+ not be 100% accurate, simply be conservative and reset cannot_fallthru
+ to false if we don't know. */
static void
lower_stmt (gimple_stmt_iterator *gsi, struct lower_data *data)
{
case GIMPLE_BIND:
lower_gimple_bind (gsi, data);
+ /* Propagate fallthruness. */
return;
case GIMPLE_COND:
- /* The gimplifier has already lowered this into gotos. */
- break;
+ case GIMPLE_GOTO:
+ case GIMPLE_SWITCH:
+ data->cannot_fallthru = true;
+ gsi_next (gsi);
+ return;
case GIMPLE_RETURN:
- lower_gimple_return (gsi, data);
+ if (data->cannot_fallthru)
+ {
+ gsi_remove (gsi, false);
+ /* Propagate fallthruness. */
+ }
+ else
+ {
+ lower_gimple_return (gsi, data);
+ data->cannot_fallthru = true;
+ }
return;
case GIMPLE_TRY:
- lower_sequence (gimple_try_eval (stmt), data);
- lower_sequence (gimple_try_cleanup (stmt), data);
+ {
+ bool try_cannot_fallthru;
+ lower_sequence (gimple_try_eval (stmt), data);
+ try_cannot_fallthru = data->cannot_fallthru;
+ data->cannot_fallthru = false;
+ lower_sequence (gimple_try_cleanup (stmt), data);
+ /* See gimple_stmt_may_fallthru for the rationale. */
+ if (gimple_try_kind (stmt) == GIMPLE_TRY_FINALLY)
+ {
+ data->cannot_fallthru |= try_cannot_fallthru;
+ gsi_next (gsi);
+ return;
+ }
+ }
break;
case GIMPLE_CATCH:
+ data->cannot_fallthru = false;
lower_sequence (gimple_catch_handler (stmt), data);
break;
case GIMPLE_EH_FILTER:
+ data->cannot_fallthru = false;
lower_sequence (gimple_eh_filter_failure (stmt), data);
break;
case GIMPLE_NOP:
case GIMPLE_ASM:
case GIMPLE_ASSIGN:
- case GIMPLE_GOTO:
case GIMPLE_PREDICT:
case GIMPLE_LABEL:
- case GIMPLE_SWITCH:
- case GIMPLE_CHANGE_DYNAMIC_TYPE:
+ case GIMPLE_EH_MUST_NOT_THROW:
case GIMPLE_OMP_FOR:
case GIMPLE_OMP_SECTIONS:
case GIMPLE_OMP_SECTIONS_SWITCH:
&& DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
&& DECL_FUNCTION_CODE (decl) == BUILT_IN_SETJMP)
{
- data->calls_builtin_setjmp = true;
lower_builtin_setjmp (gsi);
+ data->cannot_fallthru = false;
+ data->calls_builtin_setjmp = true;
+ return;
+ }
+
+ if (decl && (flags_from_decl_or_type (decl) & ECF_NORETURN))
+ {
+ data->cannot_fallthru = true;
+ gsi_next (gsi);
return;
}
}
case GIMPLE_OMP_PARALLEL:
case GIMPLE_OMP_TASK:
+ data->cannot_fallthru = false;
lower_omp_directive (gsi, data);
+ data->cannot_fallthru = false;
return;
default:
gcc_unreachable ();
}
+ data->cannot_fallthru = false;
gsi_next (gsi);
}
default:
/* This case represents statements to be executed when an
exception occurs. Those statements are implicitly followed
- by a RESX_EXPR to resume execution after the exception. So
- in this case the TRY_CATCH never falls through. */
+ by a RESX statement to resume execution after the exception.
+ So in this case the TRY_CATCH never falls through. */
return false;
}
}
{
case GOTO_EXPR:
case RETURN_EXPR:
- case RESX_EXPR:
- /* Easy cases. If the last statement of the block implies
+ /* Easy cases. If the last statement of the block implies
control transfer, then we can't fall through. */
return false;
case CALL_EXPR:
/* Functions that do not return do not fall through. */
return (call_expr_flags (stmt) & ECF_NORETURN) == 0;
-
+
case CLEANUP_POINT_EXPR:
return block_may_fallthru (TREE_OPERAND (stmt, 0));
case GIMPLE_GOTO:
case GIMPLE_RETURN:
case GIMPLE_RESX:
- /* Easy cases. If the last statement of the seq implies
+ /* Easy cases. If the last statement of the seq implies
control transfer, then we can't fall through. */
return false;
case GIMPLE_SWITCH:
- /* Switch has already been lowered and represents a
- branch to a selected label and hence can not fall through. */
- return true;
+ /* Switch has already been lowered and represents a branch
+ to a selected label and hence can't fall through. */
+ return false;
case GIMPLE_COND:
/* GIMPLE_COND's are already lowered into a two-way branch. They
return (gimple_seq_may_fallthru (gimple_try_eval (stmt))
&& gimple_seq_may_fallthru (gimple_try_cleanup (stmt)));
- case GIMPLE_ASSIGN:
- return true;
-
case GIMPLE_CALL:
/* Functions that do not return do not fall through. */
return (gimple_call_flags (stmt) & ECF_NORETURN) == 0;
-
+
default:
return true;
}
}
/* Not found. Create a new label and record the return statement. */
- tmp_rs.label = create_artificial_label ();
+ tmp_rs.label = create_artificial_label (cfun->function_end_locus);
tmp_rs.stmt = stmt;
VEC_safe_push (return_statements_t, heap, data->return_statements, &tmp_rs);
gsi_remove (gsi, false);
}
-/* Lower a __builtin_setjmp TSI.
+/* Lower a __builtin_setjmp GSI.
__builtin_setjmp is passed a pointer to an array of five words (not
all will be used on all machines). It operates similarly to the C
lower_builtin_setjmp (gimple_stmt_iterator *gsi)
{
gimple stmt = gsi_stmt (*gsi);
- tree cont_label = create_artificial_label ();
- tree next_label = create_artificial_label ();
+ location_t loc = gimple_location (stmt);
+ tree cont_label = create_artificial_label (loc);
+ tree next_label = create_artificial_label (loc);
tree dest, t, arg;
gimple g;
arg = build_addr (next_label, current_function_decl);
t = implicit_built_in_decls[BUILT_IN_SETJMP_SETUP];
g = gimple_build_call (t, 2, gimple_call_arg (stmt, 0), arg);
- gimple_set_location (g, gimple_location (stmt));
+ gimple_set_location (g, loc);
gimple_set_block (g, gimple_block (stmt));
gsi_insert_before (gsi, g, GSI_SAME_STMT);
/* Build 'DEST = 0' and insert. */
if (dest)
{
- g = gimple_build_assign (dest, fold_convert (TREE_TYPE (dest),
- integer_zero_node));
- gimple_set_location (g, gimple_location (stmt));
+ g = gimple_build_assign (dest, fold_convert_loc (loc, TREE_TYPE (dest),
+ integer_zero_node));
+ gimple_set_location (g, loc);
gimple_set_block (g, gimple_block (stmt));
gsi_insert_before (gsi, g, GSI_SAME_STMT);
}
/* Build 'goto CONT_LABEL' and insert. */
g = gimple_build_goto (cont_label);
- gsi_insert_before (gsi, g, TSI_SAME_STMT);
+ gsi_insert_before (gsi, g, GSI_SAME_STMT);
/* Build 'NEXT_LABEL:' and insert. */
g = gimple_build_label (next_label);
arg = build_addr (next_label, current_function_decl);
t = implicit_built_in_decls[BUILT_IN_SETJMP_RECEIVER];
g = gimple_build_call (t, 1, arg);
- gimple_set_location (g, gimple_location (stmt));
+ gimple_set_location (g, loc);
gimple_set_block (g, gimple_block (stmt));
gsi_insert_before (gsi, g, GSI_SAME_STMT);
/* Build 'DEST = 1' and insert. */
if (dest)
{
- g = gimple_build_assign (dest, fold_convert (TREE_TYPE (dest),
- integer_one_node));
- gimple_set_location (g, gimple_location (stmt));
+ g = gimple_build_assign (dest, fold_convert_loc (loc, TREE_TYPE (dest),
+ integer_one_node));
+ gimple_set_location (g, loc);
gimple_set_block (g, gimple_block (stmt));
gsi_insert_before (gsi, g, GSI_SAME_STMT);
}
{
record_vars_into (vars, current_function_decl);
}
-
-
-/* Mark BLOCK used if it has a used variable in it, then recurse over its
- subblocks. */
-
-static void
-mark_blocks_with_used_vars (tree block)
-{
- tree var;
- tree subblock;
-
- if (!TREE_USED (block))
- {
- for (var = BLOCK_VARS (block);
- var;
- var = TREE_CHAIN (var))
- {
- if (TREE_USED (var))
- {
- TREE_USED (block) = true;
- break;
- }
- }
- }
- for (subblock = BLOCK_SUBBLOCKS (block);
- subblock;
- subblock = BLOCK_CHAIN (subblock))
- mark_blocks_with_used_vars (subblock);
-}
-
-/* Mark the used attribute on blocks correctly. */
-
-static unsigned int
-mark_used_blocks (void)
-{
- mark_blocks_with_used_vars (DECL_INITIAL (current_function_decl));
- return 0;
-}
-
-
-struct gimple_opt_pass pass_mark_used_blocks =
-{
- {
- GIMPLE_PASS,
- "blocks", /* name */
- NULL, /* gate */
- mark_used_blocks, /* execute */
- NULL, /* sub */
- NULL, /* next */
- 0, /* static_pass_number */
- 0, /* tv_id */
- 0, /* properties_required */
- 0, /* properties_provided */
- 0, /* properties_destroyed */
- 0, /* todo_flags_start */
- TODO_dump_func /* todo_flags_finish */
- }
-};
OSDN Git Service
