tree-eh.h File Reference

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Typedefs
typedef struct eh_region_d *	eh_region

Functions
void	using_eh_for_cleanups (void)
void	add_stmt_to_eh_lp (gimple *, int)
bool	remove_stmt_from_eh_lp_fn (struct function *, gimple *)
bool	remove_stmt_from_eh_lp (gimple *)
int	lookup_stmt_eh_lp_fn (struct function *, const gimple *)
int	lookup_stmt_eh_lp (const gimple *)
bool	make_eh_dispatch_edges (geh_dispatch *)
edge	make_eh_edge (gimple *)
edge	redirect_eh_edge (edge, basic_block)
void	redirect_eh_dispatch_edge (geh_dispatch *, edge, basic_block)
bool	operation_could_trap_helper_p (enum tree_code, bool, bool, bool, bool, tree, bool *)
bool	operation_could_trap_p (enum tree_code, bool, bool, tree)
bool	tree_could_trap_p (tree)
tree	rewrite_to_non_trapping_overflow (tree)
bool	stmt_could_throw_p (function *, gimple *)
bool	stmt_unremovable_because_of_non_call_eh_p (function *, gimple *)
bool	tree_could_throw_p (tree)
bool	stmt_can_throw_external (function *, gimple *)
bool	stmt_can_throw_internal (function *, gimple *)
bool	maybe_clean_eh_stmt_fn (struct function *, gimple *)
bool	maybe_clean_eh_stmt (gimple *)
bool	maybe_clean_or_replace_eh_stmt (gimple *, gimple *)
bool	maybe_duplicate_eh_stmt_fn (struct function *, gimple *, struct function *, gimple *, hash_map< void *, void * > *, int)
bool	maybe_duplicate_eh_stmt (gimple *, gimple *)
void	maybe_remove_unreachable_handlers (void)
void	unsplit_eh_edges (void)
bool	verify_eh_edges (gimple *)
bool	verify_eh_dispatch_edge (geh_dispatch *)

Typedef Documentation

eh_region

typedef struct eh_region_d* eh_region

Header file for exception handling.
   Copyright (C) 2013-2024 Free Software Foundation, Inc.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.   

Function Documentation

add_stmt_to_eh_lp()

void add_stmt_to_eh_lp ( gimple * t, int num )

extern

Add statement T in the current function (cfun) to EH landing pad NUM.   

References add_stmt_to_eh_lp_fn(), and cfun.

Referenced by cleanup_empty_eh(), gimple_ic(), gsi_insert_finally_seq_after_call(), input_bb(), maybe_clean_or_replace_eh_stmt(), maybe_duplicate_eh_stmt(), cgraph_edge::redirect_call_stmt_to_callee(), redirect_eh_edge_1(), and vect_finish_stmt_generation_1().

lookup_stmt_eh_lp()

int lookup_stmt_eh_lp ( const gimple * t )

extern

Likewise, but always use the current function.   

References cfun, and lookup_stmt_eh_lp_fn().

Referenced by check_call(), cleanup_empty_eh(), copy_reference_ops_from_call(), expand_call_inline(), expand_gimple_stmt(), gimple_ic(), gsi_insert_finally_seq_after_call(), hashable_expr_equal_p(), lower_resx(), make_eh_edge(), mark_reachable_handlers(), maybe_clean_or_replace_eh_stmt(), maybe_duplicate_eh_stmt(), pp_gimple_stmt_1(), cgraph_edge::redirect_call_stmt_to_callee(), redirect_eh_edge_1(), vect_finish_stmt_generation_1(), verify_eh_edges(), and verify_gimple_in_cfg().

lookup_stmt_eh_lp_fn()

int lookup_stmt_eh_lp_fn ( struct function * ifun, const gimple * t )

extern

Determine if statement T is inside an EH region in function IFUN.
Positive numbers indicate a landing pad index; negative numbers
indicate a MUST_NOT_THROW region index; zero indicates that the
statement is not recorded in the region table.   

References ggc_alloc(), and NULL.

Referenced by ipa_icf_gimple::func_checker::compare_bb(), find_outermost_region_in_block(), lookup_stmt_eh_lp(), maybe_duplicate_eh_stmt_fn(), merge_stmts_p(), output_bb(), stmt_can_throw_external(), and stmt_can_throw_internal().

make_eh_dispatch_edges()

bool make_eh_dispatch_edges ( geh_dispatch * stmt )

extern

Create the multiple edges from an EH_DISPATCH statement to all of
the possible handlers for its EH region.  Return true if there's
no fallthru edge; false if there is.   

References cfun, ERT_ALLOWED_EXCEPTIONS, ERT_TRY, gcc_unreachable, get_eh_region_from_number(), gimple_bb(), gimple_eh_dispatch_region(), eh_catch_d::label, label_to_block(), make_edge(), eh_catch_d::next_catch, NULL, r, and eh_catch_d::type_list.

Referenced by copy_edges_for_bb(), and make_edges_bb().

make_eh_edge()

edge make_eh_edge ( gimple * stmt )

extern

Create the single EH edge from STMT to its nearest landing pad,
if there is such a landing pad within the current function.   

References cfun, gcc_assert, get_eh_landing_pad_from_number(), ggc_alloc(), gimple_bb(), label_to_block(), lookup_stmt_eh_lp(), make_edge(), NULL, and eh_landing_pad_d::post_landing_pad.

Referenced by copy_edges_for_bb(), gsi_insert_finally_seq_after_call(), and make_edges_bb().

maybe_clean_eh_stmt()

bool maybe_clean_eh_stmt ( gimple * stmt )

extern

Likewise, but always use the current function.   

References cfun, and maybe_clean_eh_stmt_fn().

Referenced by ipcp_modif_dom_walker::before_dom_children(), execute_fixup_cfg(), expand_complex_comparison(), expand_vector_operations(), instrument_builtin_call(), ipa_simd_modify_function_body(), ipa_param_body_adjustments::modify_cfun_body(), redirect_all_calls(), and sra_modify_function_body().

maybe_clean_eh_stmt_fn()

bool maybe_clean_eh_stmt_fn ( struct function * ifun, gimple * stmt )

extern

Given a statement STMT in IFUN, if STMT can no longer throw, then
remove any entry it might have from the EH table.  Return true if
any change was made.   

References ggc_alloc(), remove_stmt_from_eh_lp_fn(), and stmt_could_throw_p().

Referenced by maybe_clean_eh_stmt(), and update_call_expr().

maybe_clean_or_replace_eh_stmt()

bool maybe_clean_or_replace_eh_stmt ( gimple * old_stmt, gimple * new_stmt )

extern

Given a statement OLD_STMT and a new statement NEW_STMT that has replaced
OLD_STMT in the function, remove OLD_STMT from the EH table and put NEW_STMT
in the table if it should be in there.  Return TRUE if a replacement was
done that my require an EH edge purge.   

References add_stmt_to_eh_lp(), cfun, ggc_alloc(), lookup_stmt_eh_lp(), remove_stmt_from_eh_lp(), and stmt_could_throw_p().

Referenced by substitute_and_fold_dom_walker::before_dom_children(), convert_mult_to_fma_1(), eliminate_dom_walker::eliminate_cleanup(), eliminate_dom_walker::eliminate_stmt(), eliminate_unnecessary_stmts(), expand_call_inline(), fold_marked_statements(), gsi_replace(), strlen_pass::handle_integral_assign(), instrument_builtin_call(), optimize_atomic_bit_test_and(), optimize_atomic_op_fetch_cmp_0(), dom_opt_dom_walker::optimize_stmt(), replace_uses_by(), tidy_after_forward_propagate_addr(), and update_complex_assignment().

maybe_duplicate_eh_stmt()

bool maybe_duplicate_eh_stmt ( gimple * new_stmt, gimple * old_stmt )

extern

Similar, but both OLD_STMT and NEW_STMT are within the current function,
and thus no remapping is required.   

References add_stmt_to_eh_lp(), cfun, ggc_alloc(), lookup_stmt_eh_lp(), and stmt_could_throw_p().

Referenced by gimple_duplicate_bb().

maybe_duplicate_eh_stmt_fn()

bool maybe_duplicate_eh_stmt_fn ( struct function * new_fun, gimple * new_stmt, struct function * old_fun, gimple * old_stmt, hash_map< void *, void * > * map, int default_lp_nr )

extern

Given a statement OLD_STMT in OLD_FUN and a duplicate statement NEW_STMT
in NEW_FUN, copy the EH table data from OLD_STMT to NEW_STMT.  The MAP
operand is the return value of duplicate_eh_regions.   

References add_stmt_to_eh_lp_fn(), ggc_alloc(), lookup_stmt_eh_lp_fn(), map, and stmt_could_throw_p().

Referenced by copy_bb(), and move_block_to_fn().

maybe_remove_unreachable_handlers()

void maybe_remove_unreachable_handlers ( void )

extern

Remove unreachable handlers if any landing pads have been removed after
last ehcleanup pass (due to gimple_purge_dead_eh_edges).   

References cfun, FOR_EACH_VEC_SAFE_ELT, i, label_to_block(), NULL, NULL_TREE, eh_landing_pad_d::post_landing_pad, and remove_unreachable_handlers().

Referenced by execute_cleanup_cfg_post_optimizing(), and unsplit_eh_edges().

operation_could_trap_helper_p()

bool operation_could_trap_helper_p ( enum tree_code op, bool fp_operation, bool honor_trapv, bool honor_nans, bool honor_snans, tree divisor, bool * handled )

extern

Helper function for operation_could_trap_p and stmt_could_throw_p.   

References fixed_zerop(), ggc_alloc(), i, integer_zerop(), TREE_CODE, TREE_CONSTANT, TREE_TYPE, TYPE_VECTOR_SUBPARTS(), vector_cst_elt(), vector_cst_encoded_nelts(), and VECTOR_CST_STEPPED_P.

Referenced by operation_could_trap_p(), stmt_could_throw_1_p(), and vn_nary_may_trap().

operation_could_trap_p()

bool operation_could_trap_p ( enum tree_code op, bool fp_operation, bool honor_trapv, tree divisor )

extern

Return true if operation OP may trap.  FP_OPERATION is true if OP is applied
on floating-point values.  HONOR_TRAPV is true if OP is applied on integer
type operands that may trap.  If OP is a division operator, DIVISOR contains
the value of the divisor.   

References gcc_assert, ggc_alloc(), operation_could_trap_helper_p(), tcc_binary, tcc_comparison, tcc_unary, and TREE_CODE_CLASS.

Referenced by expand_omp_for_init_vars(), fold_binary_op_with_conditional_arg(), gimple_could_trap_p_1(), maybe_resimplify_conditional_op(), replace_stmt_with_simplification(), stmt_could_throw_p(), and tree_could_trap_p().

redirect_eh_dispatch_edge()

void redirect_eh_dispatch_edge ( geh_dispatch * stmt, edge e, basic_block new_bb )

extern

This is a subroutine of gimple_redirect_edge_and_branch.  Update the
labels for redirecting a non-fallthru EH_DISPATCH edge E to NEW_BB.
The actual edge update will happen in the caller.   

References cfun, ERT_ALLOWED_EXCEPTIONS, ERT_TRY, gcc_assert, gcc_unreachable, get_eh_region_from_number(), ggc_alloc(), gimple_block_label(), gimple_eh_dispatch_region(), eh_catch_d::label, label_to_block(), eh_catch_d::next_catch, and r.

Referenced by gimple_redirect_edge_and_branch().

redirect_eh_edge()

edge redirect_eh_edge ( edge edge_in, basic_block new_bb )

extern

Redirect EH edge E to NEW_BB.   

References ggc_alloc(), redirect_eh_edge_1(), and ssa_redirect_edge().

Referenced by gimple_redirect_edge_and_branch().

remove_stmt_from_eh_lp()

bool remove_stmt_from_eh_lp ( gimple * t )

extern

Remove statement T in the current function (cfun) from its
EH landing pad.   

References cfun, and remove_stmt_from_eh_lp_fn().

Referenced by cleanup_empty_eh(), gsi_remove(), maybe_clean_or_replace_eh_stmt(), cgraph_edge::redirect_call_stmt_to_callee(), and redirect_eh_edge_1().

remove_stmt_from_eh_lp_fn()

bool remove_stmt_from_eh_lp_fn ( struct function * ifun, gimple * t )

extern

Remove statement T in function IFUN from its EH landing pad.   

References get_eh_throw_stmt_table(), ggc_alloc(), and hash_map< KeyId, Value, Traits >::remove().

Referenced by maybe_clean_eh_stmt_fn(), move_block_to_fn(), and remove_stmt_from_eh_lp().

rewrite_to_non_trapping_overflow()

tree rewrite_to_non_trapping_overflow ( tree expr )

extern

If any subexpression of EXPR can trap due to -ftrapv, rewrite it
using unsigned arithmetics to avoid traps in it.   

References hash_set< KeyId, Lazy, Traits >::empty(), expr, find_trapping_overflow(), ggc_alloc(), replace_trapping_overflow(), unshare_expr(), and walk_tree.

Referenced by add_iv_candidate_for_doloop(), create_waw_or_war_checks(), generate_memcpy_builtin(), generate_memset_builtin(), get_segment_min_max(), and vect_get_loop_niters().

stmt_can_throw_external()

bool stmt_can_throw_external ( function * fun, gimple * stmt )

extern

Return true if STMT can throw an exception that is not caught within its
function FUN.  FUN can be NULL but the function is extra conservative
then.   

References lookup_stmt_eh_lp_fn(), and stmt_could_throw_p().

Referenced by analyze_function(), check_call(), check_stmt(), cleanup_empty_eh(), compute_avail(), symbol_table::create_edge(), find_tail_calls(), cgraph_edge::set_call_stmt(), stmt_can_terminate_bb_p(), stmt_kills_ref_p(), and stmt_may_terminate_function_p().

stmt_can_throw_internal()

bool stmt_can_throw_internal ( function * fun, gimple * stmt )

extern

Return true if STMT can throw an exception that is caught within its
function FUN.   

References gcc_checking_assert, lookup_stmt_eh_lp_fn(), and stmt_could_throw_p().

Referenced by add_autoinc_candidates(), convert_mult_to_fma_1(), convert_to_divmod(), copy_edges_for_bb(), expand_call_tm(), expand_complex_libcall(), expand_complex_multiplication(), fold_builtin_atomic_compare_exchange(), gimple_expand_vec_cond_expr(), gimple_purge_dead_eh_edges(), gimple_regimplify_operands(), handle_builtin_alloca(), predicate::init_from_control_deps(), is_ctrl_altering_stmt(), is_division_by(), is_division_by_square(), mark_aliased_reaching_defs_necessary_1(), maybe_move_debug_stmts_to_successors(), optimize_atomic_bit_test_and(), optimize_atomic_op_fetch_cmp_0(), propagate_with_phi(), sink_common_stores_to_bb(), stmt_kills_ref_p(), vect_build_slp_tree_1(), vect_find_stmt_data_reference(), vectorizable_call(), and vectorizable_simd_clone_call().

stmt_could_throw_p()

bool stmt_could_throw_p ( function * fun, gimple * stmt )

extern

Return true if statement STMT within FUN could throw an exception.   

References function::can_throw_non_call_exceptions, FLOAT_TYPE_P, ggc_alloc(), gimple_asm_volatile_p(), gimple_call_nothrow_p(), gimple_clobber_p(), gimple_cond_code(), gimple_cond_lhs(), NULL_TREE, operation_could_trap_p(), stmt_could_throw_1_p(), and TREE_TYPE.

Referenced by strlen_pass::adjust_last_stmt(), find_candidates_dom_walker::before_dom_children(), substitute_and_fold_dom_walker::before_dom_children(), check_bool_pattern(), check_call(), check_stmt(), compute_avail(), convert_mult_to_fma_1(), copy_reference_ops_from_call(), dse_optimize_call(), dse_optimize_stmt(), expand_call_stmt(), expand_complex_libcall(), find_givs_in_stmt_scev(), find_tail_calls(), gimple_ic(), gimple_stringop_fixed_value(), strlen_pass::handle_store(), hashable_expr_equal_p(), ifcvt_can_hoist(), initialize_ao_ref_for_dse(), linearize_expr_tree(), lower_eh_constructs_2(), mark_stmt_if_obviously_necessary(), maybe_clean_eh_stmt_fn(), maybe_clean_or_replace_eh_stmt(), maybe_duplicate_eh_stmt(), maybe_duplicate_eh_stmt_fn(), maybe_optimize_range_tests(), movement_possibility_1(), oacc_entry_exit_ok_1(), reassociate_bb(), simple_dce_from_worklist(), sink_code_in_bb(), ssa_is_replaceable_p(), stmt_can_throw_external(), stmt_can_throw_internal(), stmt_unremovable_because_of_non_call_eh_p(), suitable_cond_bb(), vect_finish_stmt_generation_1(), verify_eh_edges(), and verify_gimple_in_cfg().

stmt_unremovable_because_of_non_call_eh_p()

bool stmt_unremovable_because_of_non_call_eh_p ( function * fun, gimple * stmt )

extern

Return true if STMT in function FUN must be assumed necessary because of
non-call exceptions.   

References function::can_delete_dead_exceptions, function::can_throw_non_call_exceptions, and stmt_could_throw_p().

Referenced by simple_dce_from_worklist().

tree_could_throw_p()

bool tree_could_throw_p ( tree t )

extern

Return true if expression T could throw an exception.   

References call_expr_flags(), cfun, ECF_NOTHROW, ggc_alloc(), TREE_CODE, tree_could_trap_p(), and TREE_OPERAND.

Referenced by can_sm_ref_p(), check_call(), expand_call(), gimple_cond_get_ops_from_tree(), is_gimple_condexpr_1(), lower_eh_constructs_2(), and suitable_reference_p().

tree_could_trap_p()

bool tree_could_trap_p ( tree expr )

extern

Return true if EXPR can trap, as in dereferencing an invalid pointer
location or floating point arithmetic.  C.f. the rtl version, may_trap_p.
This routine expects only GIMPLE lhs or rhs input.   

References CALL_EXPR_FN, COMPARISON_CLASS_P, DECL_COMDAT, DECL_EXTERNAL, DECL_P, DECL_SIZE_UNIT, DECL_WEAK, FLOAT_TYPE_P, cgraph_node::function_symbol(), cgraph_node::get(), varpool_node::get(), get_callee_fndecl(), ggc_alloc(), in_array_bounds_p(), symtab_node::in_other_partition, INTEGRAL_TYPE_P, mem_ref_offset(), NULL_TREE, operation_could_trap_p(), poly_int_tree_p(), range_in_array_bounds_p(), tcc_binary, TMR_INDEX, TMR_INDEX2, wi::to_poly_offset(), TREE_CODE, TREE_CODE_CLASS, tree_could_trap_p(), TREE_OPERAND, TREE_STRING_LENGTH, TREE_THIS_NOTRAP, TREE_THIS_VOLATILE, TREE_TYPE, TYPE_OVERFLOW_TRAPS, and varpool_node::ultimate_alias_target().

Referenced by can_sm_ref_p(), cond_store_replacement(), generic_expr_could_trap_p(), gimple_could_trap_p_1(), pcom_worker::prepare_initializers_chain(), set_mem_attributes_minus_bitpos(), stmt_could_throw_1_p(), tree_could_throw_p(), tree_could_trap_p(), vn_nary_may_trap(), and vn_reference_may_trap().

unsplit_eh_edges()

void unsplit_eh_edges ( void )

extern

Wrapper around unsplit_all_eh that makes it usable everywhere.   

References CDI_DOMINATORS, CDI_POST_DOMINATORS, changed, delete_unreachable_blocks(), free_dominance_info(), maybe_remove_unreachable_handlers(), and unsplit_all_eh().

using_eh_for_cleanups()

void using_eh_for_cleanups ( void )

extern

This routine is called from front ends to indicate eh should be used for
cleanups.   

References using_eh_for_cleanups_flag.

verify_eh_dispatch_edge()

bool verify_eh_dispatch_edge ( geh_dispatch * stmt )

extern

Similarly, but handle GIMPLE_EH_DISPATCH specifically.   

References cfun, error(), ERT_ALLOWED_EXCEPTIONS, ERT_TRY, find_edge(), FOR_EACH_EDGE, gcc_assert, gcc_unreachable, get_eh_region_from_number(), ggc_alloc(), gimple_bb(), gimple_eh_dispatch_region(), basic_block_def::index, eh_catch_d::label, label_to_block(), eh_catch_d::next_catch, NULL, r, basic_block_def::succs, and eh_catch_d::type_list.

Referenced by gimple_verify_flow_info().

verify_eh_edges()

bool verify_eh_edges ( gimple * stmt )

extern

Disable warnings about missing quoting in GCC diagnostics for
the verification errors.  Their format strings don't follow GCC
diagnostic conventions but are only used for debugging.   

Verify that BB containing STMT as the last statement, has precisely the
edge that make_eh_edge would create.   

References cfun, error(), FOR_EACH_EDGE, get_eh_landing_pad_from_number(), ggc_alloc(), gimple_bb(), basic_block_def::index, label_to_block(), lookup_stmt_eh_lp(), NULL, eh_landing_pad_d::post_landing_pad, stmt_could_throw_p(), and basic_block_def::succs.

Referenced by gimple_verify_flow_info().