| blob | 0bad8e5a45c751cbb488050a31460d7bf375527d |
1 /* Build expressions with type checking for C compiler.
2 Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
23 /* This file is part of the C front end.
24 It contains routines to build C expressions given their operands,
25 including computing the types of the result, C-specific error checks,
26 and some optimization. */
48 /* Possible cases of implicit bad conversions. Used to select
49 diagnostic messages in convert_for_assignment. */
51 ic_argpass,
52 ic_argpass_nonproto,
53 ic_assign,
54 ic_init,
55 ic_return
56 };
58 /* The level of nesting inside "__alignof__". */
61 /* The level of nesting inside "sizeof". */
64 /* The level of nesting inside "typeof". */
70 /* Nonzero if we've already printed a "missing braces around initializer"
71 message within this initializer. */
109 \f
110 /* Return true if EXP is a null pointer constant, false otherwise. */
112 static bool
114 {
115 /* This should really operate on c_expr structures, but they aren't
116 yet available everywhere required. */
125 }
130 const_tree t1;
131 const_tree t2;
132 /* The return value of tagged_types_tu_compatible_p if we had seen
133 these two types already. */
135 };
140 /* Do `exp = require_complete_type (exp);' to make sure exp
141 does not have an incomplete type. (That includes void types.) */
143 tree
145 {
151 /* First, detect a valid value with a complete type. */
157 }
159 /* Print an error message for invalid use of an incomplete type.
160 VALUE is the expression that was used (or 0 if that isn't known)
161 and TYPE is the type that was invalid. */
163 void
165 {
168 /* Avoid duplicate error message. */
175 else
176 {
177 retry:
178 /* We must print an error message. Be clever about what it says. */
181 {
200 {
202 {
205 }
208 }
214 }
219 else
220 /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */
222 }
223 }
225 /* Given a type, apply default promotions wrt unnamed function
226 arguments and return the new type. */
228 tree
230 {
235 {
236 /* Preserve unsignedness if not really getting any wider. */
241 }
244 }
246 /* Return a variant of TYPE which has all the type qualifiers of LIKE
247 as well as those of TYPE. */
249 static tree
251 {
254 }
256 /* Return true iff the given tree T is a variable length array. */
258 bool
260 {
265 }
266 \f
267 /* Return the composite type of two compatible types.
269 We assume that comptypes has already been done and returned
270 nonzero; if that isn't so, this may crash. In particular, we
271 assume that qualifiers match. */
273 tree
275 {
278 tree attributes;
280 /* Save time if the two types are the same. */
284 /* If one type is nonsense, use the other. */
293 /* Merge the attributes. */
296 /* If one is an enumerated type and the other is the compatible
297 integer type, the composite type might be either of the two
298 (DR#013 question 3). For consistency, use the enumerated type as
299 the composite type. */
309 {
311 /* For two pointers, do this recursively on the target type. */
312 {
319 }
322 {
325 tree unqual_elt;
331 /* We should not have any type quals on arrays at all. */
337 d1_variable = (!d1_zero
340 d2_variable = (!d2_zero
346 /* Save space: see if the result is identical to one of the args. */
359 /* Merge the element types, and have a size if either arg has
360 one. We may have qualifiers on the element types. To set
361 up TYPE_MAIN_VARIANT correctly, we need to form the
362 composite of the unqualified types and add the qualifiers
363 back at the end. */
368 && (d2_variable
369 || d2_zero
371 ? t1
375 }
381 {
382 /* Try harder not to create a new aggregate type. */
387 }
391 /* Function types: prefer the one that specified arg types.
392 If both do, merge the arg types. Also merge the return types. */
393 {
401 /* Save space: see if the result is identical to one of the args. */
407 /* Simple way if one arg fails to specify argument types. */
409 {
413 }
415 {
419 }
421 /* If both args specify argument types, we must merge the two
422 lists, argument by argument. */
423 /* Tell global_bindings_p to return false so that variable_size
424 doesn't die on VLAs in parameter types. */
437 {
438 /* A null type means arg type is not specified.
439 Take whatever the other function type has. */
441 {
444 }
446 {
449 }
451 /* Given wait (union {union wait *u; int *i} *)
452 and wait (union wait *),
453 prefer union wait * as type of parm. */
456 {
457 tree memb;
464 {
470 {
476 }
477 }
478 }
481 {
482 tree memb;
489 {
495 {
501 }
502 }
503 }
505 parm_done: ;
506 }
511 /* ... falls through ... */
512 }
516 }
518 }
520 /* Return the type of a conditional expression between pointers to
521 possibly differently qualified versions of compatible types.
523 We assume that comp_target_types has already been done and returned
524 nonzero; if that isn't so, this may crash. */
526 static tree
528 {
529 tree attributes;
532 tree target;
534 /* Save time if the two types are the same. */
538 /* If one type is nonsense, use the other. */
547 /* Merge the attributes. */
550 /* Find the composite type of the target types, and combine the
551 qualifiers of the two types' targets. Do not lose qualifiers on
552 array element types by taking the TYPE_MAIN_VARIANT. */
565 }
567 /* Return the common type for two arithmetic types under the usual
568 arithmetic conversions. The default conversions have already been
569 applied, and enumerated types converted to their compatible integer
570 types. The resulting type is unqualified and has no attributes.
572 This is the type for the result of most arithmetic operations
573 if the operands have the given two types. */
575 static tree
577 {
581 /* If one type is nonsense, use the other. */
599 /* Save time if the two types are the same. */
613 /* When one operand is a decimal float type, the other operand cannot be
614 a generic float type or a complex type. We also disallow vector types
615 here. */
618 {
620 {
623 }
625 {
628 }
630 {
633 }
634 }
636 /* If one type is a vector type, return that type. (How the usual
637 arithmetic conversions apply to the vector types extension is not
638 precisely specified.) */
645 /* If one type is complex, form the common type of the non-complex
646 components, then make that complex. Use T1 or T2 if it is the
647 required type. */
649 {
658 else
660 }
662 /* If only one is real, use it as the result. */
670 /* If both are real and either are decimal floating point types, use
671 the decimal floating point type with the greater precision. */
674 {
684 }
686 /* Deal with fixed-point types. */
688 {
696 /* If one input type is saturating, the result type is saturating. */
700 /* If both fixed-point types are unsigned, the result type is unsigned.
701 When mixing fixed-point and integer types, follow the sign of the
702 fixed-point type.
703 Otherwise, the result type is signed. */
712 /* The result type is signed. */
714 {
715 /* If the input type is unsigned, we need to convert to the
716 signed type. */
718 {
724 else
727 }
729 {
735 else
738 }
739 }
742 {
745 }
746 else
747 {
749 /* Signed integers need to subtract one sign bit. */
751 }
754 {
757 }
758 else
759 {
761 /* Signed integers need to subtract one sign bit. */
763 }
768 satp);
769 }
771 /* Both real or both integers; use the one with greater precision. */
778 /* Same precision. Prefer long longs to longs to ints when the
779 same precision, following the C99 rules on integer type rank
780 (which are equivalent to the C90 rules for C90 types). */
788 {
791 else
793 }
801 {
802 /* But preserve unsignedness from the other type,
803 since long cannot hold all the values of an unsigned int. */
806 else
808 }
810 /* Likewise, prefer long double to double even if same size. */
815 /* Otherwise prefer the unsigned one. */
819 else
821 }
822 \f
823 /* Wrapper around c_common_type that is used by c-common.c and other
824 front end optimizations that remove promotions. ENUMERAL_TYPEs
825 are allowed here and are converted to their compatible integer types.
826 BOOLEAN_TYPEs are allowed here and return either boolean_type_node or
827 preferably a non-Boolean type as the common type. */
828 tree
830 {
836 /* If both types are BOOLEAN_TYPE, then return boolean_type_node. */
841 /* If either type is BOOLEAN_TYPE, then return the other. */
848 }
850 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
851 or various other operations. Return 2 if they are compatible
852 but a warning may be needed if you use them together. */
854 int
856 {
864 }
865 \f
866 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
867 or various other operations. Return 2 if they are compatible
868 but a warning may be needed if you use them together. This
869 differs from comptypes, in that we don't free the seen types. */
871 static int
873 {
878 /* Suppress errors caused by previously reported errors. */
884 /* If either type is the internal version of sizetype, return the
885 language version. */
895 /* Enumerated types are compatible with integer types, but this is
896 not transitive: two enumerated types in the same translation unit
897 are compatible with each other only if they are the same type. */
907 /* Different classes of types can't be compatible. */
912 /* Qualifiers must match. C99 6.7.3p9 */
917 /* Allow for two different type nodes which have essentially the same
918 definition. Note that we already checked for equality of the type
919 qualifiers (just above). */
925 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
929 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
933 {
935 /* Do not remove mode or aliasing information. */
948 {
955 /* Target types must match incl. qualifiers. */
960 /* Sizes must match unless one is missing or variable. */
967 d1_variable = (!d1_zero
970 d2_variable = (!d2_zero
986 }
992 {
1003 }
1013 }
1015 }
1017 /* Return 1 if TTL and TTR are pointers to types that are equivalent,
1018 ignoring their qualifiers. */
1020 static int
1022 {
1026 /* Do not lose qualifiers on element types of array types that are
1027 pointer targets by taking their TYPE_MAIN_VARIANT. */
1039 }
1040 \f
1041 /* Subroutines of `comptypes'. */
1043 /* Determine whether two trees derive from the same translation unit.
1044 If the CONTEXT chain ends in a null, that tree's context is still
1045 being parsed, so if two trees have context chains ending in null,
1046 they're in the same translation unit. */
1047 int
1049 {
1052 {
1060 }
1064 {
1072 }
1075 }
1077 /* Allocate the seen two types, assuming that they are compatible. */
1081 {
1089 /* The C standard says that two structures in different translation
1090 units are compatible with each other only if the types of their
1091 fields are compatible (among other things). We assume that they
1092 are compatible until proven otherwise when building the cache.
1093 An example where this can occur is:
1094 struct a
1095 {
1096 struct a *next;
1097 };
1098 If we are comparing this against a similar struct in another TU,
1099 and did not assume they were compatible, we end up with an infinite
1100 loop. */
1103 }
1105 /* Free the seen types until we get to TU_TIL. */
1107 static void
1109 {
1112 {
1117 }
1119 }
1121 /* Return 1 if two 'struct', 'union', or 'enum' types T1 and T2 are
1122 compatible. If the two types are not the same (which has been
1123 checked earlier), this can only happen when multiple translation
1124 units are being compiled. See C99 6.2.7 paragraph 1 for the exact
1125 rules. */
1127 static int
1129 {
1133 /* We have to verify that the tags of the types are the same. This
1134 is harder than it looks because this may be a typedef, so we have
1135 to go look at the original type. It may even be a typedef of a
1136 typedef...
1137 In the case of compiler-created builtin structs the TYPE_DECL
1138 may be a dummy, with no DECL_ORIGINAL_TYPE. Don't fault. */
1149 /* C90 didn't have the requirement that the two tags be the same. */
1153 /* C90 didn't say what happened if one or both of the types were
1154 incomplete; we choose to follow C99 rules here, which is that they
1155 are compatible. */
1160 {
1165 }
1168 {
1170 {
1172 /* Speed up the case where the type values are in the same order. */
1177 {
1179 }
1182 {
1186 {
1189 }
1190 }
1193 {
1195 }
1197 {
1200 }
1203 {
1206 }
1209 {
1213 {
1216 }
1217 }
1219 }
1222 {
1225 {
1228 }
1230 /* Speed up the common case where the fields are in the same order. */
1233 {
1242 {
1245 }
1252 {
1255 }
1256 }
1258 {
1261 }
1264 {
1270 {
1274 {
1277 }
1288 }
1290 {
1293 }
1294 }
1297 }
1300 {
1306 {
1321 }
1324 else
1327 }
1331 }
1332 }
1334 /* Return 1 if two function types F1 and F2 are compatible.
1335 If either type specifies no argument types,
1336 the other must specify a fixed number of self-promoting arg types.
1337 Otherwise, if one type specifies only the number of arguments,
1338 the other must specify that number of self-promoting arg types.
1339 Otherwise, the argument types must match. */
1341 static int
1343 {
1345 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
1353 /* 'volatile' qualifiers on a function's return type used to mean
1354 the function is noreturn. */
1370 /* An unspecified parmlist matches any specified parmlist
1371 whose argument types don't need default promotions. */
1374 {
1377 /* If one of these types comes from a non-prototype fn definition,
1378 compare that with the other type's arglist.
1379 If they don't match, ask for a warning (but no error). */
1384 }
1386 {
1393 }
1395 /* Both types have argument lists: compare them and propagate results. */
1398 }
1400 /* Check two lists of types for compatibility,
1401 returning 0 for incompatible, 1 for compatible,
1402 or 2 for compatible with warning. */
1404 static int
1406 {
1407 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
1412 {
1416 /* If one list is shorter than the other,
1417 they fail to match. */
1426 /* A null pointer instead of a type
1427 means there is supposed to be an argument
1428 but nothing is specified about what type it has.
1429 So match anything that self-promotes. */
1431 {
1434 }
1436 {
1439 }
1440 /* If one of the lists has an error marker, ignore this arg. */
1443 ;
1445 {
1446 /* Allow wait (union {union wait *u; int *i} *)
1447 and wait (union wait *) to be compatible. */
1454 {
1455 tree memb;
1458 {
1465 }
1468 }
1475 {
1476 tree memb;
1479 {
1486 }
1489 }
1490 else
1492 }
1494 /* comptypes said ok, but record if it said to warn. */
1500 }
1501 }
1502 \f
1503 /* Compute the size to increment a pointer by. */
1505 static tree
1507 {
1514 {
1517 }
1519 /* Convert in case a char is more than one unit. */
1523 }
1524 \f
1525 /* Return either DECL or its known constant value (if it has one). */
1527 tree
1529 {
1531 in a place where a variable is invalid. Note that DECL_INITIAL
1532 isn't valid for a PARM_DECL. */
1539 /* This is invalid if initial value is not constant.
1540 If it has either a function call, a memory reference,
1541 or a variable, then re-evaluating it could give different results. */
1543 /* Check for cases where this is sub-optimal, even though valid. */
1547 }
1549 /* Return either DECL or its known constant value (if it has one), but
1550 return DECL if pedantic or DECL has mode BLKmode. This is for
1551 bug-compatibility with the old behavior of decl_constant_value
1552 (before GCC 3.0); every use of this function is a bug and it should
1553 be removed before GCC 3.1. It is not appropriate to use pedantic
1554 in a way that affects optimization, and BLKmode is probably not the
1555 right test for avoiding misoptimizations either. */
1557 static tree
1559 {
1560 tree ret;
1566 /* Avoid unwanted tree sharing between the initializer and current
1567 function's body where the tree can be modified e.g. by the
1568 gimplifier. */
1572 }
1574 /* Convert the array expression EXP to a pointer. */
1575 static tree
1577 {
1580 tree adr;
1582 tree ptrtype;
1597 {
1598 /* We are making an ADDR_EXPR of ptrtype. This is a valid
1599 ADDR_EXPR because it's the best way of representing what
1600 happens in C when we take the address of an array and place
1601 it in a pointer to the element type. */
1607 }
1609 /* This way is better for a COMPONENT_REF since it can
1610 simplify the offset for a component. */
1613 }
1615 /* Convert the function expression EXP to a pointer. */
1616 static tree
1618 {
1629 }
1631 /* Perform the default conversion of arrays and functions to pointers.
1632 Return the result of converting EXP. For any other expression, just
1633 return EXP after removing NOPs. */
1635 struct c_expr
1637 {
1643 {
1645 {
1653 {
1657 }
1664 {
1665 /* Before C99, non-lvalue arrays do not decay to pointers.
1666 Normally, using such an array would be invalid; but it can
1667 be used correctly inside sizeof or as a statement expression.
1668 Thus, do not give an error here; an error will result later. */
1670 }
1673 }
1683 }
1686 }
1689 /* EXP is an expression of integer type. Apply the integer promotions
1690 to it and return the promoted value. */
1692 tree
1694 {
1700 /* Normally convert enums to int,
1701 but convert wide enums to something wider. */
1703 {
1711 }
1713 /* ??? This should no longer be needed now bit-fields have their
1714 proper types. */
1717 /* If it's thinner than an int, promote it like a
1718 c_promoting_integer_type_p, otherwise leave it alone. */
1724 {
1725 /* Preserve unsignedness if not really getting any wider. */
1731 }
1734 }
1737 /* Perform default promotions for C data used in expressions.
1738 Enumeral types or short or char are converted to int.
1739 In addition, manifest constants symbols are replaced by their values. */
1741 tree
1743 {
1744 tree orig_exp;
1748 /* Functions and arrays have been converted during parsing. */
1753 /* Constants can be used directly unless they're not loadable. */
1757 /* Replace a nonvolatile const static variable with its value unless
1758 it is an array, in which case we must be sure that taking the
1759 address of the array produces consistent results. */
1761 {
1764 }
1766 /* Strip no-op conversions. */
1774 {
1777 }
1787 }
1788 \f
1789 /* Look up COMPONENT in a structure or union DECL.
1791 If the component name is not found, returns NULL_TREE. Otherwise,
1792 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL
1793 stepping down the chain to the component, which is in the last
1794 TREE_VALUE of the list. Normally the list is of length one, but if
1795 the component is embedded within (nested) anonymous structures or
1796 unions, the list steps down the chain to the component. */
1798 static tree
1800 {
1802 tree field;
1804 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers
1805 to the field elements. Use a binary search on this array to quickly
1806 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC
1807 will always be set for structures which have many elements. */
1810 {
1818 {
1823 {
1824 /* Step through all anon unions in linear fashion. */
1826 {
1830 {
1835 }
1836 }
1838 /* Entire record is only anon unions. */
1842 /* Restart the binary search, with new lower bound. */
1844 }
1850 else
1852 }
1858 }
1859 else
1860 {
1862 {
1866 {
1871 }
1875 }
1879 }
1882 }
1884 /* Make an expression to refer to the COMPONENT field of
1885 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */
1887 tree
1889 {
1893 tree ref;
1898 /* See if there is a field or component with name COMPONENT. */
1901 {
1903 {
1906 }
1911 {
1914 }
1916 /* Chain the COMPONENT_REFs if necessary down to the FIELD.
1917 This might be better solved in future the way the C++ front
1918 end does it - by giving the anonymous entities each a
1919 separate name and type, and then have build_component_ref
1920 recursively call itself. We can't do that here. */
1921 do
1922 {
1925 tree subtype;
1935 NULL_TREE);
1947 }
1951 }
1954 component);
1957 }
1958 \f
1959 /* Given an expression PTR for a pointer, return an expression
1960 for the value pointed to.
1961 ERRORSTRING is the name of the operator to appear in error messages. */
1963 tree
1965 {
1970 {
1974 {
1975 /* If a warning is issued, mark it to avoid duplicates from
1976 the backend. This only needs to be done at
1977 warn_strict_aliasing > 2. */
1982 }
1988 else
1989 {
1991 tree ref;
1996 {
1999 }
2003 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2004 so that we get the proper error message if the result is used
2005 to assign to. Also, &* is supposed to be a no-op.
2006 And ANSI C seems to specify that the type of the result
2007 should be the const type. */
2008 /* A de-reference of a pointer to const is not a const. It is valid
2009 to change it via some other pointer. */
2015 }
2016 }
2020 }
2022 /* This handles expressions of the form "a[i]", which denotes
2023 an array reference.
2025 This is logically equivalent in C to *(a+i), but we may do it differently.
2026 If A is a variable or a member, we generate a primitive ARRAY_REF.
2027 This avoids forcing the array out of registers, and can work on
2028 arrays that are not lvalues (for example, members of structures returned
2029 by functions). */
2031 tree
2033 {
2041 {
2042 tree temp;
2045 {
2048 }
2053 }
2056 {
2059 }
2062 {
2065 }
2067 /* ??? Existing practice has been to warn only when the char
2068 index is syntactically the index, not for char[array]. */
2072 /* Apply default promotions *after* noticing character types. */
2078 {
2081 /* An array that is indexed by a non-constant
2082 cannot be stored in a register; we must be able to do
2083 address arithmetic on its address.
2084 Likewise an array of elements of variable size. */
2088 {
2091 }
2092 /* An array that is indexed by a constant value which is not within
2093 the array bounds cannot be stored in a register either; because we
2094 would get a crash in store_bit_field/extract_bit_field when trying
2095 to access a non-existent part of the register. */
2099 {
2102 }
2105 {
2113 }
2119 /* Array ref is const/volatile if the array elements are
2120 or if the array is. */
2129 /* This was added by rms on 16 Nov 91.
2130 It fixes vol struct foo *a; a->elts[1]
2131 in an inline function.
2132 Hope it doesn't break something else. */
2135 }
2136 else
2137 {
2148 }
2149 }
2150 \f
2151 /* Build an external reference to identifier ID. FUN indicates
2152 whether this will be used for a function call. LOC is the source
2153 location of the identifier. */
2154 tree
2156 {
2157 tree ref;
2160 /* In Objective-C, an instance variable (ivar) may be preferred to
2161 whatever lookup_name() found. */
2167 /* Implicit function declaration. */
2170 /* Don't complain about something that's already been
2171 complained about. */
2173 else
2174 {
2177 }
2185 /* Recursive call does not count as usage. */
2187 {
2191 }
2194 {
2201 }
2204 {
2209 }
2215 {
2220 }
2221 /* C99 6.7.4p3: An inline definition of a function with external
2222 linkage ... shall not contain a reference to an identifier with
2223 internal linkage. */
2234 }
2236 /* Record details of decls possibly used inside sizeof or typeof. */
2237 struct maybe_used_decl
2238 {
2239 /* The decl. */
2240 tree decl;
2241 /* The level seen at (in_sizeof + in_typeof). */
2243 /* The next one at this level or above, or NULL. */
2245 };
2249 /* Record that DECL, an undefined static function reference seen
2250 inside sizeof or typeof, might be used if the operand of sizeof is
2251 a VLA type or the operand of typeof is a variably modified
2252 type. */
2254 static void
2256 {
2262 }
2264 /* Pop the stack of decls possibly used inside sizeof or typeof. If
2265 USED is false, just discard them. If it is true, mark them used
2266 (if no longer inside sizeof or typeof) or move them to the next
2267 level up (if still inside sizeof or typeof). */
2269 void
2271 {
2275 {
2277 {
2280 else
2282 }
2284 }
2287 }
2289 /* Return the result of sizeof applied to EXPR. */
2291 struct c_expr
2293 {
2296 {
2300 }
2301 else
2302 {
2306 {
2307 /* sizeof is evaluated when given a vla (C99 6.5.3.4p2). */
2309 }
2311 }
2313 }
2315 /* Return the result of sizeof applied to T, a structure for the type
2316 name passed to sizeof (rather than the type itself). */
2318 struct c_expr
2320 {
2321 tree type;
2329 }
2331 /* Build a function call to function FUNCTION with parameters PARAMS.
2332 PARAMS is a list--a chain of TREE_LIST nodes--in which the
2333 TREE_VALUE of each node is a parameter-expression.
2334 FUNCTION's data type may be a function type or a pointer-to-function. */
2336 tree
2338 {
2341 tree tem;
2346 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2349 /* Convert anything with function type to a pointer-to-function. */
2351 {
2352 /* Implement type-directed function overloading for builtins.
2353 resolve_overloaded_builtin and targetm.resolve_overloaded_builtin
2354 handle all the type checking. The result is a complete expression
2355 that implements this function call. */
2362 }
2366 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2367 expressions, like those used for ObjC messenger dispatches. */
2377 {
2380 }
2385 /* fntype now gets the type of function pointed to. */
2388 /* Check that the function is called through a compatible prototype.
2389 If it is not, replace the call by a trap, wrapped up in a compound
2390 expression if necessary. This has the nice side-effect to prevent
2391 the tree-inliner from generating invalid assignment trees which may
2392 blow up in the RTL expander later. */
2398 {
2401 NULL_TREE);
2403 /* This situation leads to run-time undefined behavior. We can't,
2404 therefore, simply error unless we can prove that all possible
2405 executions of the program must execute the code. */
2408 /* We can, however, treat "undefined" any way we please.
2409 Call abort to encourage the user to fix the program. */
2414 else
2415 {
2416 tree rhs;
2421 else
2425 }
2426 }
2428 /* Convert the parameters to the types declared in the
2429 function prototype, or apply default promotions. */
2438 /* Check that the arguments to the function are valid. */
2444 {
2451 }
2452 else
2459 }
2460 \f
2461 /* Convert the argument expressions in the list VALUES
2462 to the types in the list TYPELIST. The resulting arguments are
2463 stored in the array ARGARRAY which has size NARGS.
2465 If TYPELIST is exhausted, or when an element has NULL as its type,
2466 perform the default conversions.
2468 PARMLIST is the chain of parm decls for the function being called.
2469 It may be 0, if that info is not available.
2470 It is used only for generating error messages.
2472 FUNCTION is a tree for the called function. It is used only for
2473 error messages, where it is formatted with %qE.
2475 This is also where warnings about wrong number of args are generated.
2477 VALUES is a chain of TREE_LIST nodes with the elements of the list
2478 in the TREE_VALUE slots of those nodes.
2480 Returns the actual number of arguments processed (which may be less
2481 than NARGS in some error situations), or -1 on failure. */
2483 static int
2486 {
2491 tree selector;
2493 /* Change pointer to function to the function itself for
2494 diagnostics. */
2499 /* Handle an ObjC selector specially for diagnostics. */
2502 /* Scan the given expressions and types, producing individual
2503 converted arguments and storing them in ARGARRAY. */
2506 valtail;
2508 {
2516 {
2519 }
2522 {
2525 }
2532 {
2533 /* Formal parm type is specified by a function prototype. */
2534 tree parmval;
2537 {
2540 }
2541 else
2542 {
2543 /* Optionally warn about conversions that
2544 differ from the default conversions. */
2546 {
2579 /* ??? At some point, messages should be written about
2580 conversions between complex types, but that's too messy
2581 to do now. */
2584 {
2585 /* Warn if any argument is passed as `float',
2586 since without a prototype it would be `double'. */
2593 /* Warn if mismatch between argument and prototype
2594 for decimal float types. Warn of conversions with
2595 binary float types and of precision narrowing due to
2596 prototype. */
2604 && (formal_prec
2608 != dfloat64_type_node
2618 }
2619 /* Detect integer changing in width or signedness.
2620 These warnings are only activated with
2621 -Wtraditional-conversion, not with -Wtraditional. */
2624 {
2631 /* No warning if function asks for enum
2632 and the actual arg is that enum type. */
2633 ;
2639 ;
2640 /* Don't complain if the formal parameter type
2641 is an enum, because we can't tell now whether
2642 the value was an enum--even the same enum. */
2644 ;
2647 /* Change in signedness doesn't matter
2648 if a constant value is unaffected. */
2649 ;
2650 /* If the value is extended from a narrower
2651 unsigned type, it doesn't matter whether we
2652 pass it as signed or unsigned; the value
2653 certainly is the same either way. */
2656 ;
2661 else
2664 }
2665 }
2675 }
2677 }
2682 {
2685 else
2686 /* Convert `float' to `double'. */
2688 }
2691 {
2694 }
2695 else
2696 /* Convert `short' and `char' to full-size `int'. */
2701 }
2706 {
2709 }
2712 }
2713 \f
2714 /* This is the entry point used by the parser to build unary operators
2715 in the input. CODE, a tree_code, specifies the unary operator, and
2716 ARG is the operand. For unary plus, the C parser currently uses
2717 CONVERT_EXPR for code. */
2719 struct c_expr
2721 {
2731 }
2733 /* This is the entry point used by the parser to build binary operators
2734 in the input. CODE, a tree_code, specifies the binary operator, and
2735 ARG1 and ARG2 are the operands. In addition to constructing the
2736 expression, we check for operands that were written with other binary
2737 operators in a way that is likely to confuse the user. */
2739 struct c_expr
2742 {
2754 /* Check for cases such as x+y<<z which users are likely
2755 to misinterpret. */
2762 /* Warn about comparisons against string literals, with the exception
2763 of testing for equality or inequality of a string literal with NULL. */
2765 {
2769 }
2780 }
2781 \f
2782 /* Return a tree for the difference of pointers OP0 and OP1.
2783 The resulting tree has type int. */
2785 static tree
2787 {
2795 {
2800 }
2802 /* If the conversion to ptrdiff_type does anything like widening or
2803 converting a partial to an integral mode, we get a convert_expression
2804 that is in the way to do any simplifications.
2805 (fold-const.c doesn't know that the extra bits won't be needed.
2806 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2807 different mode in place.)
2808 So first try to find a common term here 'by hand'; we want to cover
2809 at least the cases that occur in legal static initializers. */
2814 else
2820 else
2824 {
2827 }
2828 else
2832 {
2835 }
2836 else
2840 {
2843 }
2846 /* First do the subtraction as integers;
2847 then drop through to build the divide operator.
2848 Do not do default conversions on the minus operator
2849 in case restype is a short type. */
2853 /* This generates an error if op1 is pointer to incomplete type. */
2857 /* This generates an error if op0 is pointer to incomplete type. */
2860 /* Divide by the size, in easiest possible way. */
2862 }
2863 \f
2864 /* Construct and perhaps optimize a tree representation
2865 for a unary operation. CODE, a tree_code, specifies the operation
2866 and XARG is the operand.
2867 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2868 the default promotions (such as from short to int).
2869 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2870 allows non-lvalues; this is only used to handle conversion of non-lvalue
2871 arrays to pointers in C99. */
2873 tree
2875 {
2876 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2880 tree val;
2895 {
2898 }
2901 {
2903 /* This is used for unary plus, because a CONVERT_EXPR
2904 is enough to prevent anybody from looking inside for
2905 associativity, but won't generate any code. */
2909 {
2912 }
2922 {
2925 }
2931 /* ~ works on integer types and non float vectors. */
2935 {
2938 }
2940 {
2946 }
2947 else
2948 {
2951 }
2956 {
2959 }
2965 /* Conjugating a real value is a no-op, but allow it anyway. */
2968 {
2971 }
2980 {
2983 }
2992 else
3000 else
3008 /* Increment or decrement the real part of the value,
3009 and don't change the imaginary part. */
3011 {
3026 }
3028 /* Report invalid types. */
3032 {
3035 else
3039 }
3041 {
3042 tree inc;
3048 /* Compute the increment. */
3051 {
3052 /* If pointer target is an undefined struct,
3053 we just cannot know how to do the arithmetic. */
3055 {
3058 else
3060 }
3064 {
3067 else
3069 }
3073 }
3075 {
3076 /* For signed fract types, we invert ++ to -- or
3077 -- to ++, and change inc from 1 to -1, because
3078 it is not possible to represent 1 in signed fract constants.
3079 For unsigned fract types, the result always overflows and
3080 we get an undefined (original) or the maximum value. */
3092 }
3093 else
3094 {
3097 }
3099 /* Complain about anything else that is not a true lvalue. */
3102 ? lv_increment
3106 /* Report a read-only lvalue. */
3108 {
3114 }
3118 else
3125 }
3128 /* Note that this operation never does default_conversion. */
3130 /* Let &* cancel out to simplify resulting code. */
3132 {
3133 /* Don't let this be an lvalue. */
3137 }
3139 /* For &x[y], return x+y */
3141 {
3150 }
3152 /* Anything not already handled and not a true memory reference
3153 or a non-lvalue array is an error. */
3158 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
3161 /* If the lvalue is const or volatile, merge that into the type
3162 to which the address will point. Note that you can't get a
3163 restricted pointer by taking the address of something, so we
3164 only have to deal with `const' and `volatile' here. */
3179 /* ??? Cope with user tricks that amount to offsetof. Delete this
3180 when we have proper support for integer constant expressions. */
3184 {
3189 }
3197 }
3203 }
3205 /* Return nonzero if REF is an lvalue valid for this language.
3206 Lvalues can be assigned, unless their type has TYPE_READONLY.
3207 Lvalues can have their address taken, unless they have C_DECL_REGISTER. */
3209 static int
3211 {
3215 {
3239 }
3240 }
3241 \f
3242 /* Give an error for storing in something that is 'const'. */
3244 static void
3246 {
3249 /* Using this macro rather than (for example) arrays of messages
3250 ensures that all the format strings are checked at compile
3251 time. */
3252 #define READONLY_MSG(A, I, D, AS) (use == lv_assign ? (A) \
3253 : (use == lv_increment ? (I) \
3254 : (use == lv_decrement ? (D) : (AS))))
3256 {
3259 else
3265 }
3271 arg);
3272 else
3277 arg);
3278 }
3281 /* Return nonzero if REF is an lvalue valid for this language;
3282 otherwise, print an error message and return zero. USE says
3283 how the lvalue is being used and so selects the error message. */
3285 static int
3287 {
3294 }
3295 \f
3296 /* Mark EXP saying that we need to be able to take the
3297 address of it; it should not be allocated in a register.
3298 Returns true if successful. */
3300 bool
3302 {
3307 {
3310 {
3311 error
3314 }
3316 /* ... fall through ... */
3336 {
3338 {
3339 error
3342 }
3344 }
3346 {
3349 else
3352 }
3354 /* drops in */
3357 /* drops out */
3360 }
3361 }
3362 \f
3363 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
3365 tree
3367 {
3368 tree type1;
3369 tree type2;
3375 /* Promote both alternatives. */
3392 /* C90 does not permit non-lvalue arrays in conditional expressions.
3393 In C99 they will be pointers by now. */
3395 {
3398 }
3400 /* Quickly detect the usual case where op1 and op2 have the same type
3401 after promotion. */
3403 {
3406 else
3408 }
3413 {
3416 /* If -Wsign-compare, warn here if type1 and type2 have
3417 different signedness. We'll promote the signed to unsigned
3418 and later code won't know it used to be different.
3419 Do this check on the original types, so that explicit casts
3420 will be considered, but default promotions won't. */
3422 {
3427 {
3430 /* Do not warn if the result type is signed, since the
3431 signed type will only be chosen if it can represent
3432 all the values of the unsigned type. */
3435 /* Do not warn if the signed quantity is an unsuffixed
3436 integer literal (or some static constant expression
3437 involving such literals) and it is non-negative. */
3440 || (unsigned_op1
3443 else
3445 }
3446 }
3447 }
3449 {
3453 }
3455 {
3463 {
3469 }
3471 {
3477 }
3478 else
3479 {
3482 }
3483 }
3485 {
3488 else
3489 {
3491 }
3493 }
3495 {
3498 else
3499 {
3501 }
3503 }
3506 {
3509 else
3510 {
3513 }
3514 }
3516 /* Merge const and volatile flags of the incoming types. */
3517 result_type
3528 }
3529 \f
3530 /* Return a compound expression that performs two expressions and
3531 returns the value of the second of them. */
3533 tree
3535 {
3537 {
3538 /* The left-hand operand of a comma expression is like an expression
3539 statement: with -Wextra or -Wunused, we should warn if it doesn't have
3540 any side-effects, unless it was explicitly cast to (void). */
3542 {
3552 else
3555 }
3556 }
3558 /* With -Wunused, we should also warn if the left-hand operand does have
3559 side-effects, but computes a value which is not used. For example, in
3560 `foo() + bar(), baz()' the result of the `+' operator is not used,
3561 so we should issue a warning. */
3569 }
3571 /* Build an expression representing a cast to type TYPE of expression EXPR. */
3573 tree
3575 {
3581 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
3582 only in <protocol> qualifications. But when constructing cast expressions,
3583 the protocols do matter and must be kept around. */
3590 {
3593 }
3596 {
3599 }
3602 {
3606 }
3609 {
3611 {
3615 }
3616 }
3618 {
3619 tree field;
3627 {
3628 tree t;
3638 }
3641 }
3642 else
3643 {
3651 /* Optionally warn about potentially worrisome casts. */
3656 {
3662 /* Check that the qualifiers on IN_TYPE are a superset of
3663 the qualifiers of IN_OTYPE. The outermost level of
3664 POINTER_TYPE nodes is uninteresting and we stop as soon
3665 as we hit a non-POINTER_TYPE node on either type. */
3666 do
3667 {
3671 /* GNU C allows cv-qualified function types. 'const'
3672 means the function is very pure, 'volatile' means it
3673 can't return. We need to warn when such qualifiers
3674 are added, not when they're taken away. */
3678 else
3680 }
3688 /* There are qualifiers present in IN_OTYPE that are not
3689 present in IN_TYPE. */
3691 }
3693 /* Warn about possible alignment problems. */
3699 /* Don't warn about opaque types, where the actual alignment
3700 restriction is unknown. */
3711 /* Unlike conversion of integers to pointers, where the
3712 warning is disabled for converting constants because
3713 of cases such as SIG_*, warn about converting constant
3714 pointers to integers. In some cases it may cause unwanted
3715 sign extension, and a warning is appropriate. */
3727 /* Don't warn about converting any constant. */
3735 /* If pedantic, warn for conversions between function and object
3736 pointer types, except for converting a null pointer constant
3737 to function pointer type. */
3756 /* Ignore any integer overflow caused by the cast. */
3758 {
3760 {
3762 {
3763 /* Avoid clobbering a shared constant. */
3766 }
3767 }
3769 /* Reset VALUE's overflow flags, ensuring constant sharing. */
3773 }
3774 }
3776 /* Don't let a cast be an lvalue. */
3781 }
3783 /* Interpret a cast of expression EXPR to type TYPE. */
3784 tree
3786 {
3787 tree type;
3790 /* This avoids warnings about unprototyped casts on
3791 integers. E.g. "#define SIG_DFL (void(*)())0". */
3798 }
3799 \f
3800 /* Build an assignment expression of lvalue LHS from value RHS.
3801 MODIFYCODE is the code for a binary operator that we use
3802 to combine the old value of LHS with RHS to get the new value.
3803 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3805 tree
3807 {
3808 tree result;
3809 tree newrhs;
3813 /* Types that aren't fully specified cannot be used in assignments. */
3816 /* Avoid duplicate error messages from operands that had errors. */
3827 /* If a binary op has been requested, combine the old LHS value with the RHS
3828 producing the value we should actually store into the LHS. */
3831 {
3834 }
3836 /* Give an error for storing in something that is 'const'. */
3842 {
3845 }
3847 /* If storing into a structure or union member,
3848 it has probably been given type `int'.
3849 Compute the type that would go with
3850 the actual amount of storage the member occupies. */
3859 /* If storing in a field that is in actuality a short or narrower than one,
3860 we must store in the field in its actual type. */
3863 {
3866 }
3868 /* Convert new value to destination type. */
3875 /* Emit ObjC write barrier, if necessary. */
3877 {
3881 }
3883 /* Scan operands. */
3888 /* If we got the LHS in a different type for storing in,
3889 convert the result back to the nominal type of LHS
3890 so that the value we return always has the same type
3891 as the LHS argument. */
3897 }
3898 \f
3899 /* Convert value RHS to type TYPE as preparation for an assignment
3900 to an lvalue of type TYPE.
3901 The real work of conversion is done by `convert'.
3902 The purpose of this function is to generate error messages
3903 for assignments that are not allowed in C.
3904 ERRTYPE says whether it is argument passing, assignment,
3905 initialization or return.
3907 FUNCTION is a tree for the function being called.
3908 PARMNUM is the number of the argument, for printing in error messages. */
3910 static tree
3913 {
3915 tree rhstype;
3921 {
3922 tree selector;
3923 /* Change pointer to function to the function itself for
3924 diagnostics. */
3929 /* Handle an ObjC selector specially for diagnostics. */
3933 {
3936 }
3937 }
3939 /* This macro is used to emit diagnostics to ensure that all format
3940 strings are complete sentences, visible to gettext and checked at
3941 compile time. */
3942 #define WARN_FOR_ASSIGNMENT(AR, AS, IN, RE) \
3943 do { \
3944 switch (errtype) \
3945 { \
3946 case ic_argpass: \
3947 pedwarn (AR, parmnum, rname); \
3948 break; \
3949 case ic_argpass_nonproto: \
3950 warning (0, AR, parmnum, rname); \
3951 break; \
3952 case ic_assign: \
3953 pedwarn (AS); \
3954 break; \
3955 case ic_init: \
3956 pedwarn (IN); \
3957 break; \
3958 case ic_return: \
3959 pedwarn (RE); \
3960 break; \
3961 default: \
3962 gcc_unreachable (); \
3963 } \
3964 } while (0)
3979 {
3983 {
3999 }
4002 }
4008 {
4009 /* Except for passing an argument to an unprototyped function,
4010 this is a constraint violation. When passing an argument to
4011 an unprototyped function, it is compile-time undefined;
4012 making it a constraint in that case was rejected in
4013 DR#252. */
4016 }
4020 /* A type converts to a reference to it.
4021 This code doesn't fully support references, it's just for the
4022 special case of va_start and va_copy. */
4025 {
4027 {
4030 }
4035 /* We already know that these two types are compatible, but they
4036 may not be exactly identical. In fact, `TREE_TYPE (type)' is
4037 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
4038 likely to be va_list, a typedef to __builtin_va_list, which
4039 is different enough that it will cause problems later. */
4045 }
4046 /* Some types can interconvert without explicit casts. */
4050 /* Arithmetic types all interconvert, and enum is treated like int. */
4061 /* Aggregates in different TUs might need conversion. */
4067 /* Conversion to a transparent union from its member types.
4068 This applies only to function arguments. */
4071 {
4075 {
4086 {
4090 /* Any non-function converts to a [const][volatile] void *
4091 and vice versa; otherwise, targets must be the same.
4092 Meanwhile, the lhs target must have all the qualifiers of
4093 the rhs. */
4096 {
4097 /* If this type won't generate any warnings, use it. */
4107 /* Keep looking for a better type, but remember this one. */
4110 }
4111 }
4113 /* Can convert integer zero to any pointer type. */
4115 {
4118 }
4119 }
4122 {
4124 {
4125 /* We have only a marginally acceptable member type;
4126 it needs a warning. */
4130 /* Const and volatile mean something different for function
4131 types, so the usual warnings are not appropriate. */
4134 {
4135 /* Because const and volatile on functions are
4136 restrictions that say the function will not do
4137 certain things, it is okay to use a const or volatile
4138 function where an ordinary one is wanted, but not
4139 vice-versa. */
4142 "makes qualified function "
4145 "function pointer from "
4148 "function pointer from "
4152 }
4164 }
4171 }
4172 }
4174 /* Conversions among pointers */
4177 {
4189 /* Opaque pointers are treated like void pointers. */
4195 /* C++ does not allow the implicit conversion void* -> T*. However,
4196 for the purpose of reducing the number of false positives, we
4197 tolerate the special case of
4199 int *p = NULL;
4201 where NULL is typically defined in C to be '(void *) 0'. */
4206 /* Check if the right-hand side has a format attribute but the
4207 left-hand side doesn't. */
4210 {
4212 {
4216 "argument %d of %qE might be "
4222 "assignment left-hand side might be "
4227 "initialization left-hand side might be "
4232 "return type might be "
4237 }
4238 }
4240 /* Any non-function converts to a [const][volatile] void *
4241 and vice versa; otherwise, targets must be the same.
4242 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
4245 || is_opaque_pointer
4248 {
4251 ||
4256 "%qE between function pointer "
4264 /* Const and volatile mean something different for function types,
4265 so the usual warnings are not appropriate. */
4268 {
4270 {
4271 /* Types differing only by the presence of the 'volatile'
4272 qualifier are acceptable if the 'volatile' has been added
4273 in by the Objective-C EH machinery. */
4283 }
4284 /* If this is not a case of ignoring a mismatch in signedness,
4285 no warning. */
4288 ;
4289 /* If there is a mismatch, do warn. */
4299 }
4302 {
4303 /* Because const and volatile on functions are restrictions
4304 that say the function will not do certain things,
4305 it is okay to use a const or volatile function
4306 where an ordinary one is wanted, but not vice-versa. */
4309 "qualified function pointer "
4317 }
4318 }
4319 else
4320 /* Avoid warning about the volatile ObjC EH puts on decls. */
4330 }
4332 {
4333 /* ??? This should not be an error when inlining calls to
4334 unprototyped functions. */
4337 }
4339 {
4340 /* An explicit constant 0 can convert to a pointer,
4341 or one that results from arithmetic, even including
4342 a cast to integer type. */
4354 }
4356 {
4366 }
4371 {
4374 /* ??? This should not be an error when inlining calls to
4375 unprototyped functions. */
4389 }
4392 }
4393 \f
4394 /* If VALUE is a compound expr all of whose expressions are constant, then
4395 return its value. Otherwise, return error_mark_node.
4397 This is for handling COMPOUND_EXPRs as initializer elements
4398 which is allowed with a warning when -pedantic is specified. */
4400 static tree
4402 {
4404 {
4409 endtype);
4410 }
4413 else
4415 }
4416 \f
4417 /* Perform appropriate conversions on the initial value of a variable,
4418 store it in the declaration DECL,
4419 and print any error messages that are appropriate.
4420 If the init is invalid, store an ERROR_MARK. */
4422 void
4424 {
4427 /* If variable's type was invalidly declared, just ignore it. */
4433 /* Digest the specified initializer into an expression. */
4437 /* Store the expression if valid; else report error. */
4446 /* ANSI wants warnings about out-of-range constant initializers. */
4451 /* Check if we need to set array size from compound literal size. */
4455 {
4462 {
4466 {
4467 /* For int foo[] = (int [3]){1}; we need to set array size
4468 now since later on array initializer will be just the
4469 brace enclosed list of the compound literal. */
4475 }
4476 }
4477 }
4478 }
4479 \f
4480 /* Methods for storing and printing names for error messages. */
4482 /* Implement a spelling stack that allows components of a name to be pushed
4483 and popped. Each element on the stack is this structure. */
4485 struct spelling
4486 {
4488 union
4489 {
4493 };
4495 #define SPELLING_STRING 1
4496 #define SPELLING_MEMBER 2
4497 #define SPELLING_BOUNDS 3
4503 /* Macros to save and restore the spelling stack around push_... functions.
4504 Alternative to SAVE_SPELLING_STACK. */
4506 #define SPELLING_DEPTH() (spelling - spelling_base)
4507 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
4509 /* Push an element on the spelling stack with type KIND and assign VALUE
4510 to MEMBER. */
4512 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
4513 { \
4514 int depth = SPELLING_DEPTH (); \
4515 \
4516 if (depth >= spelling_size) \
4517 { \
4518 spelling_size += 10; \
4519 spelling_base = XRESIZEVEC (struct spelling, spelling_base, \
4520 spelling_size); \
4521 RESTORE_SPELLING_DEPTH (depth); \
4522 } \
4523 \
4524 spelling->kind = (KIND); \
4525 spelling->MEMBER = (VALUE); \
4526 spelling++; \
4527 }
4529 /* Push STRING on the stack. Printed literally. */
4531 static void
4533 {
4535 }
4537 /* Push a member name on the stack. Printed as '.' STRING. */
4539 static void
4541 {
4545 }
4547 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
4549 static void
4551 {
4553 }
4555 /* Compute the maximum size in bytes of the printed spelling. */
4557 static int
4559 {
4564 {
4567 else
4569 }
4572 }
4574 /* Print the spelling to BUFFER and return it. */
4578 {
4584 {
4587 }
4588 else
4589 {
4594 ;
4595 }
4598 }
4600 /* Issue an error message for a bad initializer component.
4601 MSGID identifies the message.
4602 The component name is taken from the spelling stack. */
4604 void
4606 {
4613 }
4615 /* Issue a pedantic warning for a bad initializer component.
4616 MSGID identifies the message.
4617 The component name is taken from the spelling stack. */
4619 void
4621 {
4628 }
4630 /* Issue a warning for a bad initializer component.
4631 MSGID identifies the message.
4632 The component name is taken from the spelling stack. */
4634 static void
4636 {
4643 }
4644 \f
4645 /* If TYPE is an array type and EXPR is a parenthesized string
4646 constant, warn if pedantic that EXPR is being used to initialize an
4647 object of type TYPE. */
4649 void
4651 {
4657 }
4659 /* Digest the parser output INIT as an initializer for type TYPE.
4660 Return a C expression of type TYPE to represent the initial value.
4662 If INIT is a string constant, STRICT_STRING is true if it is
4663 unparenthesized or we should not warn here for it being parenthesized.
4664 For other types of INIT, STRICT_STRING is not used.
4666 REQUIRE_CONSTANT requests an error if non-constant initializers or
4667 elements are seen. */
4669 static tree
4671 {
4676 || !init
4685 /* Initialization of an array of chars from a string constant
4686 optionally enclosed in braces. */
4690 {
4692 /* Note that an array could be both an array of character type
4693 and an array of wchar_t if wchar_t is signed char or unsigned
4694 char. */
4700 {
4707 char_string
4716 {
4719 }
4721 {
4724 }
4730 /* Subtract 1 (or sizeof (wchar_t))
4731 because it's ok to ignore the terminating null char
4732 that is counted in the length of the constant. */
4743 }
4745 {
4749 }
4750 }
4752 /* Build a VECTOR_CST from a *constant* vector constructor. If the
4753 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
4754 below and handle as a constructor. */
4759 {
4766 {
4768 tree value;
4771 /* Iterate through elements and check if all constructor
4772 elements are *_CSTs. */
4775 {
4778 }
4783 }
4784 }
4786 /* Any type can be initialized
4787 from an expression of the same type, optionally with braces. */
4800 {
4802 {
4804 {
4808 else
4809 {
4812 }
4813 }
4814 }
4817 /* Although the types are compatible, we may require a
4818 conversion. */
4824 {
4825 /* As an extension, allow initializing objects with static storage
4826 duration with compound literals (which are then treated just as
4827 the brace enclosed list they contain). Also allow this for
4828 vectors, as we can only assign them with compound literals. */
4831 }
4835 {
4838 }
4843 /* Compound expressions can only occur here if -pedantic or
4844 -pedantic-errors is specified. In the later case, we always want
4845 an error. In the former case, we simply want a warning. */
4848 {
4849 inside_init
4854 else
4858 }
4862 {
4865 }
4867 /* Added to enable additional -Wmissing-format-attribute warnings. */
4872 }
4874 /* Handle scalar types, including conversions. */
4879 {
4884 inside_init
4888 /* Check to see if we have already given an error message. */
4890 ;
4892 {
4895 }
4899 {
4902 }
4905 }
4907 /* Come here only for records and arrays. */
4910 {
4913 }
4917 }
4918 \f
4919 /* Handle initializers that use braces. */
4921 /* Type of object we are accumulating a constructor for.
4922 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4925 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4926 left to fill. */
4929 /* For an ARRAY_TYPE, this is the specified index
4930 at which to store the next element we get. */
4933 /* For an ARRAY_TYPE, this is the maximum index. */
4936 /* For a RECORD_TYPE, this is the first field not yet written out. */
4939 /* For an ARRAY_TYPE, this is the index of the first element
4940 not yet written out. */
4943 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4944 This is so we can generate gaps between fields, when appropriate. */
4947 /* If we are saving up the elements rather than allocating them,
4948 this is the list of elements so far (in reverse order,
4949 most recent first). */
4952 /* 1 if constructor should be incrementally stored into a constructor chain,
4953 0 if all the elements should be kept in AVL tree. */
4956 /* 1 if so far this constructor's elements are all compile-time constants. */
4959 /* 1 if so far this constructor's elements are all valid address constants. */
4962 /* 1 if this constructor is erroneous so far. */
4965 /* Structure for managing pending initializer elements, organized as an
4966 AVL tree. */
4968 struct init_node
4969 {
4973 tree purpose;
4974 tree value;
4975 };
4977 /* Tree of pending elements at this constructor level.
4978 These are elements encountered out of order
4979 which belong at places we haven't reached yet in actually
4980 writing the output.
4981 Will never hold tree nodes across GC runs. */
4984 /* The SPELLING_DEPTH of this constructor. */
4987 /* DECL node for which an initializer is being read.
4988 0 means we are reading a constructor expression
4989 such as (struct foo) {...}. */
4992 /* Nonzero if this is an initializer for a top-level decl. */
4995 /* Nonzero if there were any member designators in this initializer. */
4998 /* Nesting depth of designator list. */
5001 /* Nonzero if there were diagnosed errors in this designator list. */
5004 \f
5005 /* This stack has a level for each implicit or explicit level of
5006 structuring in the initializer, including the outermost one. It
5007 saves the values of most of the variables above. */
5011 struct constructor_stack
5012 {
5014 tree type;
5015 tree fields;
5016 tree index;
5017 tree max_index;
5018 tree unfilled_index;
5019 tree unfilled_fields;
5020 tree bit_index;
5025 /* If value nonzero, this value should replace the entire
5026 constructor at this level. */
5036 };
5040 /* This stack represents designators from some range designator up to
5041 the last designator in the list. */
5043 struct constructor_range_stack
5044 {
5047 tree range_start;
5048 tree index;
5049 tree range_end;
5050 tree fields;
5051 };
5055 /* This stack records separate initializers that are nested.
5056 Nested initializers can't happen in ANSI C, but GNU C allows them
5057 in cases like { ... (struct foo) { ... } ... }. */
5059 struct initializer_stack
5060 {
5062 tree decl;
5072 };
5075 \f
5076 /* Prepare to parse and output the initializer for variable DECL. */
5078 void
5080 {
5102 {
5104 require_constant_elements
5106 /* For a scalar, you can always use any value to initialize,
5107 even within braces. */
5113 }
5114 else
5115 {
5119 }
5132 }
5134 void
5136 {
5139 /* Free the whole constructor stack of this initializer. */
5141 {
5145 }
5149 /* Pop back to the data of the outer initializer (if any). */
5164 }
5165 \f
5166 /* Call here when we see the initializer is surrounded by braces.
5167 This is instead of a call to push_init_level;
5168 it is matched by a call to pop_init_level.
5170 TYPE is the type to initialize, for a constructor expression.
5171 For an initializer for a decl, TYPE is zero. */
5173 void
5175 {
5220 {
5222 /* Skip any nameless bit fields at the beginning. */
5229 }
5231 {
5233 {
5234 constructor_max_index
5237 /* Detect non-empty initializations of zero-length arrays. */
5242 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5243 to initialize VLAs will cause a proper error; avoid tree
5244 checking errors as well by setting a safe value. */
5249 constructor_index
5252 }
5253 else
5254 {
5257 }
5260 }
5262 {
5263 /* Vectors are like simple fixed-size arrays. */
5264 constructor_max_index =
5268 }
5269 else
5270 {
5271 /* Handle the case of int x = {5}; */
5274 }
5275 }
5276 \f
5277 /* Push down into a subobject, for initialization.
5278 If this is for an explicit set of braces, IMPLICIT is 0.
5279 If it is because the next element belongs at a lower level,
5280 IMPLICIT is 1 (or 2 if the push is because of designator list). */
5282 void
5284 {
5288 /* If we've exhausted any levels that didn't have braces,
5289 pop them now. If implicit == 1, this will have been done in
5290 process_init_element; do not repeat it here because in the case
5291 of excess initializers for an empty aggregate this leads to an
5292 infinite cycle of popping a level and immediately recreating
5293 it. */
5295 {
5297 {
5303 && constructor_max_index
5305 constructor_index))
5307 else
5309 }
5310 }
5312 /* Unless this is an explicit brace, we need to preserve previous
5313 content if any. */
5315 {
5322 }
5356 {
5361 }
5363 /* Don't die if an entire brace-pair level is superfluous
5364 in the containing level. */
5366 ;
5369 {
5370 /* Don't die if there are extra init elts at the end. */
5373 else
5374 {
5377 constructor_depth++;
5378 }
5379 }
5381 {
5384 constructor_depth++;
5385 }
5388 {
5393 }
5396 {
5404 }
5407 {
5410 }
5414 {
5416 /* Skip any nameless bit fields at the beginning. */
5423 }
5425 {
5426 /* Vectors are like simple fixed-size arrays. */
5427 constructor_max_index =
5431 }
5433 {
5435 {
5436 constructor_max_index
5439 /* Detect non-empty initializations of zero-length arrays. */
5444 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5445 to initialize VLAs will cause a proper error; avoid tree
5446 checking errors as well by setting a safe value. */
5451 constructor_index
5454 }
5455 else
5460 {
5461 /* We need to split the char/wchar array into individual
5462 characters, so that we don't have to special case it
5463 everywhere. */
5465 }
5466 }
5467 else
5468 {
5473 }
5474 }
5476 /* At the end of an implicit or explicit brace level,
5477 finish up that level of constructor. If a single expression
5478 with redundant braces initialized that level, return the
5479 c_expr structure for that expression. Otherwise, the original_code
5480 element is set to ERROR_MARK.
5481 If we were outputting the elements as they are read, return 0 as the value
5482 from inner levels (process_init_element ignores that),
5483 but return error_mark_node as the value from the outermost level
5484 (that's what we want to put in DECL_INITIAL).
5485 Otherwise, return a CONSTRUCTOR expression as the value. */
5487 struct c_expr
5489 {
5496 {
5497 /* When we come to an explicit close brace,
5498 pop any inner levels that didn't have explicit braces. */
5503 }
5505 /* Now output all pending elements. */
5511 /* Error for initializing a flexible array member, or a zero-length
5512 array member in an inappropriate context. */
5517 {
5518 /* Silently discard empty initializations. The parser will
5519 already have pedwarned for empty brackets. */
5522 else
5523 {
5531 /* We have already issued an error message for the existence
5532 of a flexible array member not at the end of the structure.
5533 Discard the initializer so that we do not die later. */
5536 }
5537 }
5539 /* Warn when some struct elements are implicitly initialized to zero. */
5541 && constructor_type
5544 {
5545 /* Do not warn for flexible array members or zero-length arrays. */
5551 /* Do not warn if this level of the initializer uses member
5552 designators; it is likely to be deliberate. */
5554 {
5558 }
5559 }
5561 /* Pad out the end of the structure. */
5563 /* If this closes a superfluous brace pair,
5564 just pass out the element between them. */
5567 ;
5572 {
5573 /* A nonincremental scalar initializer--just return
5574 the element, after verifying there is just one. */
5576 {
5580 }
5582 {
5585 }
5586 else
5588 }
5589 else
5590 {
5593 else
5594 {
5596 constructor_elements);
5601 }
5602 }
5629 }
5631 /* Common handling for both array range and field name designators.
5632 ARRAY argument is nonzero for array ranges. Returns zero for success. */
5634 static int
5636 {
5637 tree subtype;
5640 /* Don't die if an entire brace-pair level is superfluous
5641 in the containing level. */
5645 /* If there were errors in this designator list already, bail out
5646 silently. */
5651 {
5654 /* Designator list starts at the level of closest explicit
5655 braces. */
5660 }
5663 {
5675 }
5679 {
5682 }
5684 {
5687 }
5692 }
5694 /* If there are range designators in designator list, push a new designator
5695 to constructor_range_stack. RANGE_END is end of such stack range or
5696 NULL_TREE if there is no range designator at this level. */
5698 static void
5700 {
5714 }
5716 /* Within an array initializer, specify the next index to be initialized.
5717 FIRST is that index. If LAST is nonzero, then initialize a range
5718 of indices, running from FIRST through LAST. */
5720 void
5722 {
5730 {
5733 }
5746 else
5747 {
5751 {
5755 {
5758 }
5759 else
5760 {
5764 {
5767 }
5768 }
5769 }
5771 designator_depth++;
5775 }
5776 }
5778 /* Within a struct initializer, specify the next field to be initialized. */
5780 void
5782 {
5783 tree tail;
5792 {
5795 }
5799 {
5802 }
5806 else
5807 {
5809 designator_depth++;
5813 }
5814 }
5815 \f
5816 /* Add a new initializer to the tree of pending initializers. PURPOSE
5817 identifies the initializer, either array index or field in a structure.
5818 VALUE is the value of that index or field. */
5820 static void
5822 {
5829 {
5831 {
5837 else
5838 {
5845 }
5846 }
5847 }
5848 else
5849 {
5850 tree bitpos;
5854 {
5860 else
5861 {
5868 }
5869 }
5870 }
5883 {
5887 {
5891 {
5893 {
5894 /* L rotation. */
5907 {
5910 else
5912 }
5913 else
5915 }
5916 else
5917 {
5918 /* LR rotation. */
5940 {
5943 else
5945 }
5946 else
5948 }
5950 }
5951 else
5952 {
5953 /* p->balance == +1; growth of left side balances the node. */
5956 }
5957 }
5959 {
5961 /* Growth propagation from right side. */
5964 {
5966 {
5967 /* R rotation. */
5980 {
5983 else
5985 }
5986 else
5988 }
5990 {
5991 /* RL rotation */
6013 {
6016 else
6018 }
6019 else
6021 }
6023 }
6024 else
6025 {
6026 /* p->balance == -1; growth of right side balances the node. */
6029 }
6030 }
6034 }
6035 }
6037 /* Build AVL tree from a sorted chain. */
6039 static void
6041 {
6053 {
6055 /* Skip any nameless bit fields at the beginning. */
6061 }
6063 {
6065 constructor_unfilled_index
6068 else
6070 }
6072 }
6074 /* Build AVL tree from a string constant. */
6076 static void
6078 {
6089 else
6090 {
6094 }
6103 {
6105 {
6108 }
6109 else
6110 {
6114 {
6117 else
6122 }
6123 }
6126 {
6129 {
6131 {
6134 }
6135 }
6137 {
6140 }
6145 }
6149 }
6152 }
6154 /* Return value of FIELD in pending initializer or zero if the field was
6155 not initialized yet. */
6157 static tree
6159 {
6163 {
6170 {
6175 else
6177 }
6178 }
6180 {
6184 && (!constructor_unfilled_fields
6191 {
6196 else
6198 }
6199 }
6201 {
6206 }
6208 }
6210 /* "Output" the next constructor element.
6211 At top level, really output it to assembler code now.
6212 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
6213 TYPE is the data type that the containing data type wants here.
6214 FIELD is the field (a FIELD_DECL) or the index that this element fills.
6215 If VALUE is a string constant, STRICT_STRING is true if it is
6216 unparenthesized or we should not warn here for it being parenthesized.
6217 For other types of VALUE, STRICT_STRING is not used.
6219 PENDING if non-nil means output pending elements that belong
6220 right after this element. (PENDING is normally 1;
6221 it is 0 while outputting pending elements, to avoid recursion.) */
6223 static void
6226 {
6230 {
6233 }
6246 {
6247 /* As an extension, allow initializing objects with static storage
6248 duration with compound literals (which are then treated just as
6249 the brace enclosed list they contain). */
6252 }
6266 {
6268 {
6271 }
6274 }
6276 /* If this field is empty (and not at the end of structure),
6277 don't do anything other than checking the initializer. */
6288 {
6291 }
6293 /* If this element doesn't come next in sequence,
6294 put it on constructor_pending_elts. */
6296 && (!constructor_incremental
6298 {
6305 }
6307 && (!constructor_incremental
6309 {
6310 /* We do this for records but not for unions. In a union,
6311 no matter which field is specified, it can be initialized
6312 right away since it starts at the beginning of the union. */
6314 {
6317 else
6318 {
6326 }
6327 }
6331 }
6334 {
6341 /* We can have just one union field set. */
6343 }
6345 /* Otherwise, output this element either to
6346 constructor_elements or to the assembler file. */
6352 /* Advance the variable that indicates sequential elements output. */
6354 constructor_unfilled_index
6356 bitsize_one_node);
6358 {
6359 constructor_unfilled_fields
6362 /* Skip any nameless bit fields. */
6366 constructor_unfilled_fields =
6368 }
6372 /* Now output any pending elements which have become next. */
6375 }
6377 /* Output any pending elements which have become next.
6378 As we output elements, constructor_unfilled_{fields,index}
6379 advances, which may cause other elements to become next;
6380 if so, they too are output.
6382 If ALL is 0, we return when there are
6383 no more pending elements to output now.
6385 If ALL is 1, we output space as necessary so that
6386 we can output all the pending elements. */
6388 static void
6390 {
6392 tree next;
6394 retry:
6396 /* Look through the whole pending tree.
6397 If we find an element that should be output now,
6398 output it. Otherwise, set NEXT to the element
6399 that comes first among those still pending. */
6403 {
6405 {
6407 constructor_unfilled_index))
6413 {
6414 /* Advance to the next smaller node. */
6417 else
6418 {
6419 /* We have reached the smallest node bigger than the
6420 current unfilled index. Fill the space first. */
6423 }
6424 }
6425 else
6426 {
6427 /* Advance to the next bigger node. */
6430 else
6431 {
6432 /* We have reached the biggest node in a subtree. Find
6433 the parent of it, which is the next bigger node. */
6439 {
6442 }
6443 }
6444 }
6445 }
6448 {
6451 /* If the current record is complete we are done. */
6457 /* We can't compare fields here because there might be empty
6458 fields in between. */
6460 {
6464 }
6466 {
6467 /* Advance to the next smaller node. */
6470 else
6471 {
6472 /* We have reached the smallest node bigger than the
6473 current unfilled field. Fill the space first. */
6476 }
6477 }
6478 else
6479 {
6480 /* Advance to the next bigger node. */
6483 else
6484 {
6485 /* We have reached the biggest node in a subtree. Find
6486 the parent of it, which is the next bigger node. */
6493 {
6496 }
6497 }
6498 }
6499 }
6500 }
6502 /* Ordinarily return, but not if we want to output all
6503 and there are elements left. */
6507 /* If it's not incremental, just skip over the gap, so that after
6508 jumping to retry we will output the next successive element. */
6515 /* ELT now points to the node in the pending tree with the next
6516 initializer to output. */
6518 }
6519 \f
6520 /* Add one non-braced element to the current constructor level.
6521 This adjusts the current position within the constructor's type.
6522 This may also start or terminate implicit levels
6523 to handle a partly-braced initializer.
6525 Once this has found the correct level for the new element,
6526 it calls output_init_element. */
6528 void
6530 {
6538 /* Handle superfluous braces around string cst as in
6539 char x[] = {"foo"}; */
6541 && constructor_type
6545 {
6550 }
6553 {
6556 }
6558 /* Ignore elements of a brace group if it is entirely superfluous
6559 and has already been diagnosed. */
6563 /* If we've exhausted any levels that didn't have braces,
6564 pop them now. */
6566 {
6574 constructor_index)))
6576 else
6578 }
6580 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
6582 {
6583 /* If value is a compound literal and we'll be just using its
6584 content, don't put it into a SAVE_EXPR. */
6586 || !require_constant_value
6589 }
6592 {
6594 {
6595 tree fieldtype;
6599 {
6602 }
6609 /* Error for non-static initialization of a flexible array member. */
6611 && !require_constant_value
6614 {
6617 }
6619 /* Accept a string constant to initialize a subarray. */
6625 /* Otherwise, if we have come to a subaggregate,
6626 and we don't have an element of its type, push into it. */
6632 {
6635 }
6638 {
6643 }
6644 else
6645 /* Do the bookkeeping for an element that was
6646 directly output as a constructor. */
6647 {
6648 /* For a record, keep track of end position of last field. */
6650 constructor_bit_index
6655 /* If the current field was the first one not yet written out,
6656 it isn't now, so update. */
6658 {
6660 /* Skip any nameless bit fields. */
6664 constructor_unfilled_fields =
6666 }
6667 }
6670 /* Skip any nameless bit fields at the beginning. */
6675 }
6677 {
6678 tree fieldtype;
6682 {
6685 }
6692 /* Warn that traditional C rejects initialization of unions.
6693 We skip the warning if the value is zero. This is done
6694 under the assumption that the zero initializer in user
6695 code appears conditioned on e.g. __STDC__ to avoid
6696 "missing initializer" warnings and relies on default
6697 initialization to zero in the traditional C case.
6698 We also skip the warning if the initializer is designated,
6699 again on the assumption that this must be conditional on
6700 __STDC__ anyway (and we've already complained about the
6701 member-designator already). */
6708 /* Accept a string constant to initialize a subarray. */
6714 /* Otherwise, if we have come to a subaggregate,
6715 and we don't have an element of its type, push into it. */
6721 {
6724 }
6727 {
6732 }
6733 else
6734 /* Do the bookkeeping for an element that was
6735 directly output as a constructor. */
6736 {
6739 }
6742 }
6744 {
6748 /* Accept a string constant to initialize a subarray. */
6754 /* Otherwise, if we have come to a subaggregate,
6755 and we don't have an element of its type, push into it. */
6761 {
6764 }
6769 {
6772 }
6774 /* Now output the actual element. */
6776 {
6781 }
6783 constructor_index
6787 /* If we are doing the bookkeeping for an element that was
6788 directly output as a constructor, we must update
6789 constructor_unfilled_index. */
6791 }
6793 {
6796 /* Do a basic check of initializer size. Note that vectors
6797 always have a fixed size derived from their type. */
6799 {
6802 }
6804 /* Now output the actual element. */
6809 constructor_index
6813 /* If we are doing the bookkeeping for an element that was
6814 directly output as a constructor, we must update
6815 constructor_unfilled_index. */
6817 }
6819 /* Handle the sole element allowed in a braced initializer
6820 for a scalar variable. */
6823 {
6826 }
6827 else
6828 {
6833 }
6835 /* Handle range initializers either at this level or anywhere higher
6836 in the designator stack. */
6838 {
6845 {
6848 }
6852 {
6855 }
6862 {
6866 {
6869 }
6877 }
6882 }
6885 }
6888 }
6889 \f
6890 /* Build a complete asm-statement, whose components are a CV_QUALIFIER
6891 (guaranteed to be 'volatile' or null) and ARGS (represented using
6892 an ASM_EXPR node). */
6893 tree
6895 {
6899 }
6901 /* Build an asm-expr, whose components are a STRING, some OUTPUTS,
6902 some INPUTS, and some CLOBBERS. The latter three may be NULL.
6903 SIMPLE indicates whether there was anything at all after the
6904 string in the asm expression -- asm("blah") and asm("blah" : )
6905 are subtly different. We use a ASM_EXPR node to represent this. */
6906 tree
6909 {
6910 tree tail;
6911 tree args;
6924 /* Remove output conversions that change the type but not the mode. */
6926 {
6929 /* ??? Really, this should not be here. Users should be using a
6930 proper lvalue, dammit. But there's a long history of using casts
6931 in the output operands. In cases like longlong.h, this becomes a
6932 primitive form of typechecking -- if the cast can be removed, then
6933 the output operand had a type of the proper width; otherwise we'll
6934 get an error. Gross, but ... */
6953 {
6954 /* If the operand is going to end up in memory,
6955 mark it addressable. */
6958 }
6959 else
6963 }
6966 {
6967 tree input;
6974 {
6975 /* If the operand is going to end up in memory,
6976 mark it addressable. */
6978 {
6979 /* Strip the nops as we allow this case. FIXME, this really
6980 should be rejected or made deprecated. */
6984 }
6985 }
6986 else
6990 }
6994 /* asm statements without outputs, including simple ones, are treated
6995 as volatile. */
7000 }
7001 \f
7002 /* Generate a goto statement to LABEL. */
7004 tree
7006 {
7012 {
7015 }
7018 {
7021 }
7024 {
7025 /* No jump from outside this statement expression context, so
7026 record that there is a jump from within this context. */
7032 }
7035 {
7036 /* No jump from outside this context context of identifiers with
7037 variably modified type, so record that there is a jump from
7038 within this context. */
7044 }
7048 }
7050 /* Generate a computed goto statement to EXPR. */
7052 tree
7054 {
7059 }
7061 /* Generate a C `return' statement. RETVAL is the expression for what
7062 to return, or a null pointer for `return;' with no value. */
7064 tree
7066 {
7074 {
7078 {
7082 }
7083 }
7085 {
7091 }
7092 else
7093 {
7097 tree inner;
7105 /* Strip any conversions, additions, and subtractions, and see if
7106 we are returning the address of a local variable. Warn if so. */
7108 {
7110 {
7117 /* If the second operand of the MINUS_EXPR has a pointer
7118 type (or is converted from it), this may be valid, so
7119 don't give a warning. */
7120 {
7134 }
7152 }
7155 }
7158 }
7163 }
7164 \f
7166 /* The SWITCH_EXPR being built. */
7167 tree switch_expr;
7169 /* The original type of the testing expression, i.e. before the
7170 default conversion is applied. */
7171 tree orig_type;
7173 /* A splay-tree mapping the low element of a case range to the high
7174 element, or NULL_TREE if there is no high element. Used to
7175 determine whether or not a new case label duplicates an old case
7176 label. We need a tree, rather than simply a hash table, because
7177 of the GNU case range extension. */
7178 splay_tree cases;
7180 /* Number of nested statement expressions within this switch
7181 statement; if nonzero, case and default labels may not
7182 appear. */
7185 /* Scope of outermost declarations of identifiers with variably
7186 modified type within this switch statement; if nonzero, case and
7187 default labels may not appear. */
7190 /* The next node on the stack. */
7192 };
7194 /* A stack of the currently active switch statements. The innermost
7195 switch statement is on the top of the stack. There is no need to
7196 mark the stack for garbage collection because it is only active
7197 during the processing of the body of a function, and we never
7198 collect at that point. */
7202 /* Start a C switch statement, testing expression EXP. Return the new
7203 SWITCH_EXPR. */
7205 tree
7207 {
7212 {
7216 {
7218 {
7221 }
7223 }
7224 else
7225 {
7235 }
7236 }
7238 /* Add this new SWITCH_EXPR to the stack. */
7249 }
7251 /* Process a case label. */
7253 tree
7255 {
7260 {
7267 }
7269 {
7273 else
7276 }
7278 {
7282 else
7285 }
7288 else
7292 }
7294 /* Finish the switch statement. */
7296 void
7298 {
7300 location_t switch_location;
7304 /* We must not be within a statement expression nested in the switch
7305 at this point; we might, however, be within the scope of an
7306 identifier with variably modified type nested in the switch. */
7309 /* Emit warnings as needed. */
7312 else
7318 /* Pop the stack. */
7322 }
7323 \f
7324 /* Emit an if statement. IF_LOCUS is the location of the 'if'. COND,
7325 THEN_BLOCK and ELSE_BLOCK are expressions to be used; ELSE_BLOCK
7326 may be null. NESTED_IF is true if THEN_BLOCK contains another IF
7327 statement, and was not surrounded with parenthesis. */
7329 void
7332 {
7333 tree stmt;
7335 /* Diagnose an ambiguous else if if-then-else is nested inside if-then. */
7337 {
7340 /* We know from the grammar productions that there is an IF nested
7341 within THEN_BLOCK. Due to labels and c99 conditional declarations,
7342 it might not be exactly THEN_BLOCK, but should be the last
7343 non-container statement within. */
7346 {
7361 }
7362 found:
7368 }
7375 }
7377 /* Emit a general-purpose loop construct. START_LOCUS is the location of
7378 the beginning of the loop. COND is the loop condition. COND_IS_FIRST
7379 is false for DO loops. INCR is the FOR increment expression. BODY is
7380 the statement controlled by the loop. BLAB is the break label. CLAB is
7381 the continue label. Everything is allowed to be NULL. */
7383 void
7386 {
7389 /* If the condition is zero don't generate a loop construct. */
7391 {
7393 {
7397 }
7398 }
7399 else
7400 {
7403 /* If we have an exit condition, then we build an IF with gotos either
7404 out of the loop, or to the top of it. If there's no exit condition,
7405 then we just build a jump back to the top. */
7409 {
7410 /* Canonicalize the loop condition to the end. This means
7411 generating a branch to the loop condition. Reuse the
7412 continue label, if possible. */
7414 {
7416 {
7419 }
7420 else
7424 }
7430 else
7432 }
7435 }
7449 }
7451 tree
7453 {
7457 /* In switch statements break is sometimes stylistically used after
7458 a return statement. This can lead to spurious warnings about
7459 control reaching the end of a non-void function when it is
7460 inlined. Note that we are calling block_may_fallthru with
7461 language specific tree nodes; this works because
7462 block_may_fallthru returns true when given something it does not
7463 understand. */
7467 {
7470 }
7472 ;
7474 {
7478 else
7489 }
7495 }
7497 /* A helper routine for c_process_expr_stmt and c_finish_stmt_expr. */
7499 static void
7501 {
7503 ;
7505 {
7509 }
7510 else
7512 }
7514 /* Process an expression as if it were a complete statement. Emit
7515 diagnostics, but do not call ADD_STMT. */
7517 tree
7519 {
7531 /* If we're not processing a statement expression, warn about unused values.
7532 Warnings for statement expressions will be emitted later, once we figure
7533 out which is the result. */
7538 /* If the expression is not of a type to which we cannot assign a line
7539 number, wrap the thing in a no-op NOP_EXPR. */
7547 }
7549 /* Emit an expression as a statement. */
7551 tree
7553 {
7556 else
7558 }
7560 /* Do the opposite and emit a statement as an expression. To begin,
7561 create a new binding level and return it. */
7563 tree
7565 {
7566 tree ret;
7570 /* We must force a BLOCK for this level so that, if it is not expanded
7571 later, there is a way to turn off the entire subtree of blocks that
7572 are contained in it. */
7576 {
7579 }
7583 {
7585 }
7592 /* Mark the current statement list as belonging to a statement list. */
7596 }
7598 tree
7600 {
7607 {
7610 }
7611 /* It is no longer possible to jump to labels defined within this
7612 statement expression. */
7616 {
7618 }
7619 /* It is again possible to define labels with a goto just outside
7620 this statement expression. */
7624 {
7627 }
7630 else
7635 /* Locate the last statement in BODY. See c_end_compound_stmt
7636 about always returning a BIND_EXPR. */
7640 continue_searching:
7642 {
7643 tree_stmt_iterator i;
7645 /* This can happen with degenerate cases like ({ }). No value. */
7649 /* If we're supposed to generate side effects warnings, process
7650 all of the statements except the last. */
7652 {
7655 }
7656 else
7660 }
7662 /* If the end of the list is exception related, then the list was split
7663 by a call to push_cleanup. Continue searching. */
7666 {
7670 }
7672 /* In the case that the BIND_EXPR is not necessary, return the
7673 expression out from inside it. */
7677 {
7678 /* Do not warn if the return value of a statement expression is
7679 unused. */
7683 }
7685 /* Extract the type of said expression. */
7688 /* If we're not returning a value at all, then the BIND_EXPR that
7689 we already have is a fine expression to return. */
7693 /* Now that we've located the expression containing the value, it seems
7694 silly to make voidify_wrapper_expr repeat the process. Create a
7695 temporary of the appropriate type and stick it in a TARGET_EXPR. */
7698 /* Unwrap a no-op NOP_EXPR as added by c_finish_expr_stmt. This avoids
7699 tree_expr_nonnegative_p giving up immediately. */
7709 }
7711 /* Begin the scope of an identifier of variably modified type, scope
7712 number SCOPE. Jumping from outside this scope to inside it is not
7713 permitted. */
7715 void
7717 {
7723 /* At file_scope, we don't have to do any processing. */
7732 {
7734 }
7741 }
7743 /* End a scope which may contain identifiers of variably modified
7744 type, scope number SCOPE. */
7746 void
7748 {
7753 /* We may have a number of nested scopes of identifiers with
7754 variably modified type, all at this depth. Pop each in turn. */
7756 {
7759 /* It is no longer possible to jump to labels defined within this
7760 scope. */
7764 {
7766 }
7767 /* It is again possible to define labels with a goto just outside
7768 this scope. */
7772 {
7775 }
7778 else
7782 }
7783 }
7784 \f
7785 /* Begin and end compound statements. This is as simple as pushing
7786 and popping new statement lists from the tree. */
7788 tree
7790 {
7795 }
7797 tree
7799 {
7803 {
7807 }
7812 /* If this compound statement is nested immediately inside a statement
7813 expression, then force a BIND_EXPR to be created. Otherwise we'll
7814 do the wrong thing for ({ { 1; } }) or ({ 1; { } }). In particular,
7815 STATEMENT_LISTs merge, and thus we can lose track of what statement
7816 was really last. */
7820 {
7823 }
7826 }
7828 /* Queue a cleanup. CLEANUP is an expression/statement to be executed
7829 when the current scope is exited. EH_ONLY is true when this is not
7830 meant to apply to normal control flow transfer. */
7832 void
7834 {
7846 }
7847 \f
7848 /* Build a binary-operation expression without default conversions.
7849 CODE is the kind of expression to build.
7850 This function differs from `build' in several ways:
7851 the data type of the result is computed and recorded in it,
7852 warnings are generated if arg data types are invalid,
7853 special handling for addition and subtraction of pointers is known,
7854 and some optimization is done (operations on narrow ints
7855 are done in the narrower type when that gives the same result).
7856 Constant folding is also done before the result is returned.
7858 Note that the operands will never have enumeral types, or function
7859 or array types, because either they will have the default conversions
7860 performed or they have both just been converted to some other type in which
7861 the arithmetic is to be done. */
7863 tree
7866 {
7872 /* Expression code to give to the expression when it is built.
7873 Normally this is CODE, which is what the caller asked for,
7874 but in some special cases we change it. */
7877 /* Data type in which the computation is to be performed.
7878 In the simplest cases this is the common type of the arguments. */
7881 /* Nonzero means operands have already been type-converted
7882 in whatever way is necessary.
7883 Zero means they need to be converted to RESULT_TYPE. */
7886 /* Nonzero means create the expression with this type, rather than
7887 RESULT_TYPE. */
7890 /* Nonzero means after finally constructing the expression
7891 convert it to this type. */
7894 /* Nonzero if this is an operation like MIN or MAX which can
7895 safely be computed in short if both args are promoted shorts.
7896 Also implies COMMON.
7897 -1 indicates a bitwise operation; this makes a difference
7898 in the exact conditions for when it is safe to do the operation
7899 in a narrower mode. */
7902 /* Nonzero if this is a comparison operation;
7903 if both args are promoted shorts, compare the original shorts.
7904 Also implies COMMON. */
7907 /* Nonzero if this is a right-shift operation, which can be computed on the
7908 original short and then promoted if the operand is a promoted short. */
7911 /* Nonzero means set RESULT_TYPE to the common type of the args. */
7914 /* True means types are compatible as far as ObjC is concerned. */
7918 {
7921 }
7922 else
7923 {
7926 }
7931 /* The expression codes of the data types of the arguments tell us
7932 whether the arguments are integers, floating, pointers, etc. */
7936 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
7940 /* If an error was already reported for one of the arguments,
7941 avoid reporting another error. */
7948 {
7951 }
7956 {
7958 /* Handle the pointer + int case. */
7963 else
7968 /* Subtraction of two similar pointers.
7969 We must subtract them as integers, then divide by object size. */
7973 /* Handle pointer minus int. Just like pointer plus int. */
7976 else
7997 {
8008 else
8009 /* Although it would be tempting to shorten always here, that
8010 loses on some targets, since the modulo instruction is
8011 undefined if the quotient can't be represented in the
8012 computation mode. We shorten only if unsigned or if
8013 dividing by something we know != -1. */
8018 }
8026 /* Allow vector types which are not floating point types. */
8039 {
8040 /* Although it would be tempting to shorten always here, that loses
8041 on some targets, since the modulo instruction is undefined if the
8042 quotient can't be represented in the computation mode. We shorten
8043 only if unsigned or if dividing by something we know != -1. */
8048 }
8062 {
8063 /* Result of these operations is always an int,
8064 but that does not mean the operands should be
8065 converted to ints! */
8070 }
8073 /* Shift operations: result has same type as first operand;
8074 always convert second operand to int.
8075 Also set SHORT_SHIFT if shifting rightward. */
8080 {
8082 {
8085 else
8086 {
8092 }
8093 }
8095 /* Use the type of the value to be shifted. */
8097 /* Convert the shift-count to an integer, regardless of size
8098 of value being shifted. */
8101 /* Avoid converting op1 to result_type later. */
8103 }
8109 {
8111 {
8117 }
8119 /* Use the type of the value to be shifted. */
8121 /* Convert the shift-count to an integer, regardless of size
8122 of value being shifted. */
8125 /* Avoid converting op1 to result_type later. */
8127 }
8135 /* Result of comparison is always int,
8136 but don't convert the args to int! */
8144 {
8147 /* Anything compares with void *. void * compares with anything.
8148 Otherwise, the targets must be compatible
8149 and both must be object or both incomplete. */
8153 {
8154 /* op0 != orig_op0 detects the case of something
8155 whose value is 0 but which isn't a valid null ptr const. */
8160 }
8162 {
8167 }
8168 else
8169 /* Avoid warning about the volatile ObjC EH puts on decls. */
8175 }
8177 {
8183 }
8185 {
8191 }
8193 {
8196 }
8198 {
8201 }
8215 {
8217 {
8225 }
8226 else
8227 {
8230 }
8231 }
8233 {
8237 }
8239 {
8243 }
8245 {
8248 }
8250 {
8253 }
8258 }
8267 {
8270 }
8274 &&
8277 {
8281 {
8285 }
8287 /* For certain operations (which identify themselves by shorten != 0)
8288 if both args were extended from the same smaller type,
8289 do the arithmetic in that type and then extend.
8291 shorten !=0 and !=1 indicates a bitwise operation.
8292 For them, this optimization is safe only if
8293 both args are zero-extended or both are sign-extended.
8294 Otherwise, we might change the result.
8295 Eg, (short)-1 | (unsigned short)-1 is (int)-1
8296 but calculated in (unsigned short) it would be (unsigned short)-1. */
8299 {
8303 tree type;
8305 /* Cast OP0 and OP1 to RESULT_TYPE. Doing so prevents
8306 excessive narrowing when we call get_narrower below. For
8307 example, suppose that OP0 is of unsigned int extended
8308 from signed char and that RESULT_TYPE is long long int.
8309 If we explicitly cast OP0 to RESULT_TYPE, OP0 would look
8310 like
8312 (long long int) (unsigned int) signed_char
8314 which get_narrower would narrow down to
8316 (unsigned int) signed char
8318 If we do not cast OP0 first, get_narrower would return
8319 signed_char, which is inconsistent with the case of the
8320 explicit cast. */
8327 /* UNS is 1 if the operation to be done is an unsigned one. */
8332 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
8333 but it *requires* conversion to FINAL_TYPE. */
8344 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
8346 /* For bitwise operations, signedness of nominal type
8347 does not matter. Consider only how operands were extended. */
8351 /* Note that in all three cases below we refrain from optimizing
8352 an unsigned operation on sign-extended args.
8353 That would not be valid. */
8355 /* Both args variable: if both extended in same way
8356 from same width, do it in that width.
8357 Do it unsigned if args were zero-extended. */
8364 result_type
8365 = c_common_signed_or_unsigned_type
8371 && (type
8381 && (type
8387 }
8389 /* Shifts can be shortened if shifting right. */
8392 {
8402 /* We can shorten only if the shift count is less than the
8403 number of bits in the smaller type size. */
8405 /* We cannot drop an unsigned shift after sign-extension. */
8407 {
8408 /* Do an unsigned shift if the operand was zero-extended. */
8409 result_type
8412 /* Convert value-to-be-shifted to that type. */
8416 }
8417 }
8419 /* Comparison operations are shortened too but differently.
8420 They identify themselves by setting short_compare = 1. */
8423 {
8424 /* Don't write &op0, etc., because that would prevent op0
8425 from being kept in a register.
8426 Instead, make copies of the our local variables and
8427 pass the copies by reference, then copy them back afterward. */
8430 tree val
8441 {
8453 /* Give warnings for comparisons between signed and unsigned
8454 quantities that may fail.
8456 Do the checking based on the original operand trees, so that
8457 casts will be considered, but default promotions won't be.
8459 Do not warn if the comparison is being done in a signed type,
8460 since the signed type will only be chosen if it can represent
8461 all the values of the unsigned type. */
8464 /* Do not warn if both operands are the same signedness. */
8467 else
8468 {
8474 else
8477 /* Do not warn if the signed quantity is an
8478 unsuffixed integer literal (or some static
8479 constant expression involving such literals or a
8480 conditional expression involving such literals)
8481 and it is non-negative. */
8484 /* Do not warn if the comparison is an equality operation,
8485 the unsigned quantity is an integral constant, and it
8486 would fit in the result if the result were signed. */
8489 && int_fits_type_p
8492 /* Do not warn if the unsigned quantity is an enumeration
8493 constant and its maximum value would fit in the result
8494 if the result were signed. */
8497 && int_fits_type_p
8501 else
8503 }
8505 /* Warn if two unsigned values are being compared in a size
8506 larger than their original size, and one (and only one) is the
8507 result of a `~' operator. This comparison will always fail.
8509 Also warn if one operand is a constant, and the constant
8510 does not have all bits set that are set in the ~ operand
8511 when it is extended. */
8515 {
8519 else
8524 {
8525 tree primop;
8530 {
8534 }
8535 else
8536 {
8540 }
8545 {
8549 }
8550 }
8557 }
8558 }
8559 }
8560 }
8562 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
8563 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
8564 Then the expression will be built.
8565 It will be given type FINAL_TYPE if that is nonzero;
8566 otherwise, it will be given type RESULT_TYPE. */
8569 {
8572 }
8575 {
8581 /* This can happen if one operand has a vector type, and the other
8582 has a different type. */
8585 }
8590 {
8591 /* Treat expressions in initializers specially as they can't trap. */
8593 build_type,
8601 }
8602 }
8605 /* Convert EXPR to be a truth-value, validating its type for this
8606 purpose. */
8608 tree
8610 {
8612 {
8630 }
8632 /* ??? Should we also give an error for void and vectors rather than
8633 leaving those to give errors later? */
8635 }
8636 \f
8638 /* Convert EXPR to a contained DECL, updating *TC, *TI and *SE as
8639 required. */
8641 tree
8644 {
8646 {
8648 /* Executing a compound literal inside a function reinitializes
8649 it. */
8653 }
8654 else
8656 }
8657 \f
8658 /* Like c_begin_compound_stmt, except force the retention of the BLOCK. */
8660 tree
8662 {
8663 tree block;
8669 }
8671 tree
8673 {
8674 tree stmt;
8684 }
8686 /* For all elements of CLAUSES, validate them vs OpenMP constraints.
8687 Remove any elements from the list that are invalid. */
8689 tree
8691 {
8702 {
8708 {
8726 {
8729 }
8731 {
8736 {
8758 }
8760 {
8764 }
8765 }
8776 {
8779 }
8782 check_dup_generic:
8785 {
8788 }
8792 {
8795 }
8796 else
8806 {
8809 }
8812 {
8815 }
8816 else
8826 {
8829 }
8832 {
8835 }
8836 else
8851 }
8854 {
8858 {
8862 }
8865 {
8871 {
8882 }
8884 {
8888 }
8889 }
8890 }
8894 else
8896 }
8900 }