1 /* Expand builtin functions.
2 Copyright (C) 1988-2020 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
20 #ifndef GCC_BUILTINS_H
21 #define GCC_BUILTINS_H
25 /* Target-dependent globals. */
26 struct target_builtins
{
27 /* For each register that may be used for calling a function, this
28 gives a mode used to copy the register's value. VOIDmode indicates
29 the register is not used for calling a function. If the machine
30 has register windows, this gives only the outbound registers.
31 INCOMING_REGNO gives the corresponding inbound register. */
32 fixed_size_mode_pod x_apply_args_mode
[FIRST_PSEUDO_REGISTER
];
34 /* For each register that may be used for returning values, this gives
35 a mode used to copy the register's value. VOIDmode indicates the
36 register is not used for returning values. If the machine has
37 register windows, this gives only the outbound registers.
38 INCOMING_REGNO gives the corresponding inbound register. */
39 fixed_size_mode_pod x_apply_result_mode
[FIRST_PSEUDO_REGISTER
];
42 extern struct target_builtins default_target_builtins
;
44 extern struct target_builtins
*this_target_builtins
;
46 #define this_target_builtins (&default_target_builtins)
49 /* Non-zero if __builtin_constant_p should be folded right away. */
50 extern bool force_folding_builtin_constant_p
;
52 extern bool called_as_built_in (tree
);
53 extern bool get_object_alignment_1 (tree
, unsigned int *,
54 unsigned HOST_WIDE_INT
*);
55 extern unsigned int get_object_alignment (tree
);
56 extern bool get_pointer_alignment_1 (tree
, unsigned int *,
57 unsigned HOST_WIDE_INT
*);
58 extern unsigned int get_pointer_alignment (tree
);
59 extern unsigned string_length (const void*, unsigned, unsigned);
63 /* [MINLEN, MAXBOUND, MAXLEN] is a range describing the length of
64 one or more strings of possibly unknown length. For a single
65 string of known length the range is a constant where
66 MINLEN == MAXBOUND == MAXLEN holds.
67 For other strings, MINLEN is the length of the shortest known
68 string. MAXBOUND is the length of a string that could be stored
69 in the largest array referenced by the expression. MAXLEN is
70 the length of the longest sequence of non-zero bytes
71 in an object referenced by the expression. For such strings,
72 MINLEN <= MAXBOUND <= MAXLEN holds. For example, given:
73 struct A { char a[7], b[]; };
76 the computed range will be [0, 6, ALL_ONES].
77 However, for a conditional expression involving a string
78 of known length and an array of unknown bound such as
79 n = strlen (i ? p->b : "123");
80 the range will be [3, 3, ALL_ONES].
81 MINLEN != 0 && MAXLEN == ALL_ONES indicates that MINLEN is
82 the length of the shortest known string and implies that
83 the shortest possible string referenced by the expression may
84 actually be the empty string. This distinction is useful for
85 diagnostics. get_range_strlen() return value distinguishes
86 between these two cases.
87 As the tighter (and more optimistic) bound, MAXBOUND is suitable
88 for diagnostics but not for optimization.
89 As the more conservative bound, MAXLEN is intended to be used
94 /* When non-null, DECL refers to the declaration known to store
95 an unterminated constant character array, as in:
96 const char s[] = { 'a', 'b', 'c' };
97 It is used to diagnose uses of such arrays in functions such as
98 strlen() that expect a nul-terminated string as an argument. */
100 /* Non-constant offset from the beginning of a string not accounted
101 for in the length range. Used to improve diagnostics. */
105 extern tree
c_strlen (tree
, int, c_strlen_data
* = NULL
, unsigned = 1);
106 extern rtx
c_readstr (const char *, scalar_int_mode
, bool = true);
107 extern void expand_builtin_setjmp_setup (rtx
, rtx
);
108 extern void expand_builtin_setjmp_receiver (rtx
);
109 extern void expand_builtin_update_setjmp_buf (rtx
);
110 extern tree
mathfn_built_in (tree
, enum built_in_function fn
);
111 extern tree
mathfn_built_in (tree
, combined_fn
);
112 extern tree
mathfn_built_in_type (combined_fn
);
113 extern rtx
builtin_strncpy_read_str (void *, HOST_WIDE_INT
, scalar_int_mode
);
114 extern rtx
builtin_memset_read_str (void *, HOST_WIDE_INT
, scalar_int_mode
);
115 extern rtx
expand_builtin_saveregs (void);
116 extern tree
std_build_builtin_va_list (void);
117 extern tree
std_fn_abi_va_list (tree
);
118 extern tree
std_canonical_va_list_type (tree
);
119 extern void std_expand_builtin_va_start (tree
, rtx
);
120 extern void expand_builtin_trap (void);
121 extern void expand_ifn_atomic_bit_test_and (gcall
*);
122 extern void expand_ifn_atomic_compare_exchange (gcall
*);
123 extern rtx
expand_builtin (tree
, rtx
, rtx
, machine_mode
, int);
124 extern enum built_in_function
builtin_mathfn_code (const_tree
);
125 extern tree
fold_builtin_expect (location_t
, tree
, tree
, tree
, tree
);
126 extern bool avoid_folding_inline_builtin (tree
);
127 extern tree
fold_call_expr (location_t
, tree
, bool);
128 extern tree
fold_builtin_call_array (location_t
, tree
, tree
, int, tree
*);
129 extern bool validate_gimple_arglist (const gcall
*, ...);
130 extern rtx
default_expand_builtin (tree
, rtx
, rtx
, machine_mode
, int);
131 extern void maybe_emit_call_builtin___clear_cache (rtx
, rtx
);
132 extern bool fold_builtin_next_arg (tree
, bool);
133 extern tree
do_mpc_arg2 (tree
, tree
, tree
, int, int (*)(mpc_ptr
, mpc_srcptr
, mpc_srcptr
, mpc_rnd_t
));
134 extern tree
fold_call_stmt (gcall
*, bool);
135 extern void set_builtin_user_assembler_name (tree decl
, const char *asmspec
);
136 extern bool is_simple_builtin (tree
);
137 extern bool is_inexpensive_builtin (tree
);
138 extern bool readonly_data_expr (tree exp
);
139 extern bool init_target_chars (void);
140 extern unsigned HOST_WIDE_INT target_newline
;
141 extern unsigned HOST_WIDE_INT target_percent
;
142 extern char target_percent_s
[3];
143 extern char target_percent_c
[3];
144 extern char target_percent_s_newline
[4];
145 extern bool target_char_cst_p (tree t
, char *p
);
147 extern internal_fn
associated_internal_fn (tree
);
148 extern internal_fn
replacement_internal_fn (gcall
*);
150 extern bool check_nul_terminated_array (tree
, tree
, tree
= NULL_TREE
);
151 extern void warn_string_no_nul (location_t
, tree
, const char *, tree
,
152 tree
, tree
= NULL_TREE
, bool = false,
153 const wide_int
[2] = NULL
);
154 extern tree
unterminated_array (tree
, tree
* = NULL
, bool * = NULL
);
155 extern bool builtin_with_linkage_p (tree
);
157 /* Describes recursion limits used by functions that follow use-def
158 chains of SSA_NAMEs. */
160 class ssa_name_limit_t
162 bitmap visited
; /* Bitmap of visited SSA_NAMEs. */
163 unsigned ssa_def_max
; /* Longest chain of SSA_NAMEs to follow. */
165 /* Not copyable or assignable. */
166 DISABLE_COPY_AND_ASSIGN (ssa_name_limit_t
);
172 ssa_def_max (param_ssa_name_def_chain_limit
) { }
174 /* Set a bit for the PHI in VISITED and return true if it wasn't
176 bool visit_phi (tree
);
177 /* Clear a bit for the PHI in VISITED. */
178 void leave_phi (tree
);
179 /* Return false if the SSA_NAME chain length counter has reached
180 the limit, otherwise increment the counter and return true. */
183 /* If the SSA_NAME has already been "seen" return a positive value.
184 Otherwise add it to VISITED. If the SSA_NAME limit has been
185 reached, return a negative value. Otherwise return zero. */
188 ~ssa_name_limit_t ();
193 /* Describes a reference to an object used in an access. */
196 /* Set the bounds of the reference to at most as many bytes
197 as the first argument or unknown when null, and at least
198 one when the second argument is true unless the first one
199 is a constant zero. */
200 access_ref (tree
= NULL_TREE
, bool = false);
202 /* Return the PHI node REF refers to or null if it doesn't. */
205 /* Return the object to which REF refers. */
206 tree
get_ref (vec
<access_ref
> *, access_ref
* = NULL
, int = 1,
207 ssa_name_limit_t
* = NULL
, pointer_query
* = NULL
) const;
209 /* Return true if OFFRNG is the constant zero. */
210 bool offset_zero () const
212 return offrng
[0] == 0 && offrng
[1] == 0;
215 /* Return true if OFFRNG is bounded to a subrange of offset values
216 valid for the largest possible object. */
217 bool offset_bounded () const;
219 /* Return the maximum amount of space remaining and if non-null, set
220 argument to the minimum. */
221 offset_int
size_remaining (offset_int
* = NULL
) const;
223 /* Return true if *THIS is an access to a declared object. */
224 bool ref_declared () const
226 return DECL_P (ref
) && base0
&& deref
< 1;
229 /* Set the size range to the maximum. */
230 void set_max_size_range ()
233 sizrng
[1] = wi::to_offset (max_object_size ());
236 /* Add OFF to the offset range. */
237 void add_offset (const offset_int
&off
)
239 add_offset (off
, off
);
242 /* Add the range [MIN, MAX] to the offset range. */
243 void add_offset (const offset_int
&, const offset_int
&);
245 /* Add the maximum representable offset to the offset range. */
246 void add_max_offset ()
248 offset_int maxoff
= wi::to_offset (TYPE_MAX_VALUE (ptrdiff_type_node
));
249 add_offset (-maxoff
- 1, maxoff
);
252 /* Issue an informational message describing the target of an access
253 with the given mode. */
254 void inform_access (access_mode
) const;
256 /* Reference to the accessed object(s). */
259 /* Range of byte offsets into and sizes of the object(s). */
260 offset_int offrng
[2];
261 offset_int sizrng
[2];
262 /* Range of the bound of the access: denotes that the access
263 is at least BNDRNG[0] bytes but no more than BNDRNG[1].
264 For string functions the size of the actual access is
265 further constrained by the length of the string. */
266 offset_int bndrng
[2];
268 /* Used to fold integer expressions when called from front ends. */
270 /* Positive when REF is dereferenced, negative when its address is
273 /* Set if trailing one-element arrays should be treated as flexible
276 /* Set if valid offsets must start at zero (for declared and allocated
277 objects but not for others referenced by pointers). */
279 /* Set if REF refers to a function array parameter not declared
286 /* Queries and caches compute_objsize results. */
289 DISABLE_COPY_AND_ASSIGN (pointer_query
);
292 /* Type of the two-level cache object defined by clients of the class
293 to have pointer SSA_NAMEs cached for speedy access. */
296 /* 1-based indices into cache. */
297 vec
<unsigned> indices
;
298 /* The cache itself. */
299 vec
<access_ref
> access_refs
;
302 /* Construct an object with the given Ranger instance and cache. */
303 explicit pointer_query (range_query
* = NULL
, cache_type
* = NULL
);
305 /* Retrieve the access_ref for a variable from cache if it's there. */
306 const access_ref
* get_ref (tree
, int = 1) const;
308 /* Retrieve the access_ref for a variable from cache or compute it. */
309 bool get_ref (tree
, access_ref
*, int = 1);
311 /* Add an access_ref for the SSA_NAME to the cache. */
312 void put_ref (tree
, const access_ref
&, int = 1);
314 /* Flush the cache. */
317 /* A Ranger instance. May be null to use global ranges. */
319 /* Cache of SSA_NAMEs. May be null to disable caching. */
320 cache_type
*var_cache
;
322 /* Cache performance counters. */
323 mutable unsigned hits
;
324 mutable unsigned misses
;
325 mutable unsigned failures
;
326 mutable unsigned depth
;
327 mutable unsigned max_depth
;
330 /* Describes a pair of references used in an access by built-in
331 functions like memcpy. */
334 /* Set the access to at most MAXWRITE and MAXREAD bytes, and
335 at least 1 when MINWRITE or MINREAD, respectively, is set. */
336 access_data (tree expr
, access_mode mode
,
337 tree maxwrite
= NULL_TREE
, bool minwrite
= false,
338 tree maxread
= NULL_TREE
, bool minread
= false)
340 dst (maxwrite
, minwrite
), src (maxread
, minread
), mode (mode
) { }
342 /* Built-in function call. */
344 /* Destination and source of the access. */
346 /* Read-only for functions like memcmp or strlen, write-only
347 for memset, read-write for memcpy or strcat. */
351 extern tree
gimple_call_alloc_size (gimple
*, wide_int
[2] = NULL
,
352 range_query
* = NULL
);
353 extern tree
gimple_parm_array_size (tree
, wide_int
[2], bool * = NULL
);
355 extern tree
compute_objsize (tree
, int, access_ref
*, range_query
* = NULL
);
356 /* Legacy/transitional API. Should not be used in new code. */
357 extern tree
compute_objsize (tree
, int, access_ref
*, pointer_query
*);
358 extern tree
compute_objsize (tree
, int, tree
* = NULL
, tree
* = NULL
,
359 range_query
* = NULL
);
360 extern bool check_access (tree
, tree
, tree
, tree
, tree
,
361 access_mode
, const access_data
* = NULL
);
362 extern void maybe_emit_free_warning (tree
);
364 #endif /* GCC_BUILTINS_H */