gimple-ssa-warn-alloca.cc File Reference

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "backend.h"
#include "tree.h"
#include "gimple.h"
#include "tree-pass.h"
#include "ssa.h"
#include "gimple-pretty-print.h"
#include "diagnostic-core.h"
#include "fold-const.h"
#include "gimple-iterator.h"
#include "tree-ssa.h"
#include "tree-cfg.h"
#include "builtins.h"
#include "calls.h"
#include "cfgloop.h"
#include "intl.h"
#include "gimple-range.h"

Include dependency graph for gimple-ssa-warn-alloca.cc:

Data Structures
class	pass_walloca
class	alloca_type_and_limit

Enumerations
enum	alloca_type {   ALLOCA_OK , ALLOCA_BOUND_DEFINITELY_LARGE , ALLOCA_BOUND_MAYBE_LARGE , ALLOCA_IN_LOOP ,   ALLOCA_ARG_IS_ZERO , ALLOCA_UNBOUNDED }

Functions
static unsigned HOST_WIDE_INT	adjusted_warn_limit (bool)
static bool	warn_limit_specified_p (bool is_vla)
static class alloca_type_and_limit	alloca_call_type (gimple *stmt, bool is_vla)
static bool	in_loop_p (gimple *stmt)
gimple_opt_pass *	make_pass_walloca (gcc::context *ctxt)

Variables
const pass_data	pass_data_walloca

Enumeration Type Documentation

alloca_type

enum alloca_type

Enumerator
ALLOCA_OK
ALLOCA_BOUND_DEFINITELY_LARGE
ALLOCA_BOUND_MAYBE_LARGE
ALLOCA_IN_LOOP
ALLOCA_ARG_IS_ZERO
ALLOCA_UNBOUNDED

Function Documentation

adjusted_warn_limit()

static unsigned HOST_WIDE_INT adjusted_warn_limit ( bool idx )

static

Warn on problematic uses of alloca and variable length arrays.
   Copyright (C) 2016-2025 Free Software Foundation, Inc.
   Contributed by Aldy Hernandez <aldyh@redhat.com>.

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/>.   

Return the value of the argument N to -Walloca-larger-than= or
-Wvla-larger-than= adjusted for the target data model so that
when N == HOST_WIDE_INT_MAX, the adjusted value is set to
PTRDIFF_MAX on the target.  This is done to prevent warnings
for unknown/unbounded allocations in the "permissive mode"
while still diagnosing excessive and necessarily invalid
allocations.   

References HOST_WIDE_INT_MAX, limits, ptrdiff_type_node, tree_to_shwi(), and TYPE_MAX_VALUE.

Referenced by alloca_call_type(), pass_walloca::execute(), and pass_walloca::gate().

alloca_call_type()

static class alloca_type_and_limit alloca_call_type ( gimple * stmt, bool is_vla )

static

References adjusted_warn_limit(), ALLOCA_ARG_IS_ZERO, ALLOCA_BOUND_DEFINITELY_LARGE, ALLOCA_BOUND_MAYBE_LARGE, alloca_call_type(), ALLOCA_OK, alloca_type_and_limit::alloca_type_and_limit(), ALLOCA_UNBOUNDED, cfun, compare_tree_int(), gcc_assert, get_range_query(), gimple_alloca_call_p(), gimple_call_arg(), gimple_call_builtin_p(), integer_zero_node, integer_zerop(), max_object_size(), r, wi::shwi(), size_type_node, wi::to_offset(), wi::to_wide(), TREE_CODE, tree_to_shwi(), tree_to_uhwi(), TREE_TYPE, TYPE_PRECISION, types_compatible_p(), VR_ANTI_RANGE, and warn_limit_specified_p().

Referenced by alloca_call_type(), and pass_walloca::execute().

in_loop_p()

static bool in_loop_p ( gimple * stmt )

static

References cfun, ENTRY_BLOCK_PTR_FOR_FN, gimple_bb(), loop::header, and basic_block_def::loop_father.

Referenced by pass_walloca::execute().

make_pass_walloca()

gimple_opt_pass * make_pass_walloca

(

gcc::context *

ctxt

)

warn_limit_specified_p()

static bool warn_limit_specified_p ( bool is_vla )

static

Return TRUE if the user specified a limit for either VLAs or ALLOCAs.   

References HOST_WIDE_INT_MAX.

Referenced by alloca_call_type().

Variable Documentation

pass_data_walloca

const pass_data pass_data_walloca

Initial value:

= {
  GIMPLE_PASS,
  "walloca",
  OPTGROUP_NONE,
  TV_NONE,
  PROP_cfg, 
  0,        
  0,        
  0,        
  0,        
}

Referenced by pass_walloca::pass_walloca().