| blob | 9f3d9cbac49d5691d1c5f3a918252179ac56e564 |
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 }
2117 /* Array ref is const/volatile if the array elements are
2118 or if the array is. */
2127 /* This was added by rms on 16 Nov 91.
2128 It fixes vol struct foo *a; a->elts[1]
2129 in an inline function.
2130 Hope it doesn't break something else. */
2133 }
2134 else
2135 {
2146 }
2147 }
2148 \f
2149 /* Build an external reference to identifier ID. FUN indicates
2150 whether this will be used for a function call. LOC is the source
2151 location of the identifier. */
2152 tree
2154 {
2155 tree ref;
2158 /* In Objective-C, an instance variable (ivar) may be preferred to
2159 whatever lookup_name() found. */
2165 /* Implicit function declaration. */
2168 /* Don't complain about something that's already been
2169 complained about. */
2171 else
2172 {
2175 }
2183 /* Recursive call does not count as usage. */
2185 {
2189 }
2192 {
2199 }
2202 {
2207 }
2213 {
2218 }
2219 /* C99 6.7.4p3: An inline definition of a function with external
2220 linkage ... shall not contain a reference to an identifier with
2221 internal linkage. */
2232 }
2234 /* Record details of decls possibly used inside sizeof or typeof. */
2235 struct maybe_used_decl
2236 {
2237 /* The decl. */
2238 tree decl;
2239 /* The level seen at (in_sizeof + in_typeof). */
2241 /* The next one at this level or above, or NULL. */
2243 };
2247 /* Record that DECL, an undefined static function reference seen
2248 inside sizeof or typeof, might be used if the operand of sizeof is
2249 a VLA type or the operand of typeof is a variably modified
2250 type. */
2252 static void
2254 {
2260 }
2262 /* Pop the stack of decls possibly used inside sizeof or typeof. If
2263 USED is false, just discard them. If it is true, mark them used
2264 (if no longer inside sizeof or typeof) or move them to the next
2265 level up (if still inside sizeof or typeof). */
2267 void
2269 {
2273 {
2275 {
2278 else
2280 }
2282 }
2285 }
2287 /* Return the result of sizeof applied to EXPR. */
2289 struct c_expr
2291 {
2294 {
2298 }
2299 else
2300 {
2304 {
2305 /* sizeof is evaluated when given a vla (C99 6.5.3.4p2). */
2307 }
2309 }
2311 }
2313 /* Return the result of sizeof applied to T, a structure for the type
2314 name passed to sizeof (rather than the type itself). */
2316 struct c_expr
2318 {
2319 tree type;
2327 }
2329 /* Build a function call to function FUNCTION with parameters PARAMS.
2330 PARAMS is a list--a chain of TREE_LIST nodes--in which the
2331 TREE_VALUE of each node is a parameter-expression.
2332 FUNCTION's data type may be a function type or a pointer-to-function. */
2334 tree
2336 {
2339 tree tem;
2344 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2347 /* Convert anything with function type to a pointer-to-function. */
2349 {
2350 /* Implement type-directed function overloading for builtins.
2351 resolve_overloaded_builtin and targetm.resolve_overloaded_builtin
2352 handle all the type checking. The result is a complete expression
2353 that implements this function call. */
2360 }
2364 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2365 expressions, like those used for ObjC messenger dispatches. */
2375 {
2378 }
2383 /* fntype now gets the type of function pointed to. */
2386 /* Check that the function is called through a compatible prototype.
2387 If it is not, replace the call by a trap, wrapped up in a compound
2388 expression if necessary. This has the nice side-effect to prevent
2389 the tree-inliner from generating invalid assignment trees which may
2390 blow up in the RTL expander later. */
2396 {
2399 NULL_TREE);
2401 /* This situation leads to run-time undefined behavior. We can't,
2402 therefore, simply error unless we can prove that all possible
2403 executions of the program must execute the code. */
2406 /* We can, however, treat "undefined" any way we please.
2407 Call abort to encourage the user to fix the program. */
2412 else
2413 {
2414 tree rhs;
2419 else
2423 }
2424 }
2426 /* Convert the parameters to the types declared in the
2427 function prototype, or apply default promotions. */
2436 /* Check that the arguments to the function are valid. */
2442 {
2449 }
2450 else
2457 }
2458 \f
2459 /* Convert the argument expressions in the list VALUES
2460 to the types in the list TYPELIST. The resulting arguments are
2461 stored in the array ARGARRAY which has size NARGS.
2463 If TYPELIST is exhausted, or when an element has NULL as its type,
2464 perform the default conversions.
2466 PARMLIST is the chain of parm decls for the function being called.
2467 It may be 0, if that info is not available.
2468 It is used only for generating error messages.
2470 FUNCTION is a tree for the called function. It is used only for
2471 error messages, where it is formatted with %qE.
2473 This is also where warnings about wrong number of args are generated.
2475 VALUES is a chain of TREE_LIST nodes with the elements of the list
2476 in the TREE_VALUE slots of those nodes.
2478 Returns the actual number of arguments processed (which may be less
2479 than NARGS in some error situations), or -1 on failure. */
2481 static int
2484 {
2489 tree selector;
2491 /* Change pointer to function to the function itself for
2492 diagnostics. */
2497 /* Handle an ObjC selector specially for diagnostics. */
2500 /* Scan the given expressions and types, producing individual
2501 converted arguments and storing them in ARGARRAY. */
2504 valtail;
2506 {
2514 {
2517 }
2520 {
2523 }
2530 {
2531 /* Formal parm type is specified by a function prototype. */
2532 tree parmval;
2535 {
2538 }
2539 else
2540 {
2541 /* Optionally warn about conversions that
2542 differ from the default conversions. */
2544 {
2577 /* ??? At some point, messages should be written about
2578 conversions between complex types, but that's too messy
2579 to do now. */
2582 {
2583 /* Warn if any argument is passed as `float',
2584 since without a prototype it would be `double'. */
2591 /* Warn if mismatch between argument and prototype
2592 for decimal float types. Warn of conversions with
2593 binary float types and of precision narrowing due to
2594 prototype. */
2602 && (formal_prec
2606 != dfloat64_type_node
2616 }
2617 /* Detect integer changing in width or signedness.
2618 These warnings are only activated with
2619 -Wtraditional-conversion, not with -Wtraditional. */
2622 {
2629 /* No warning if function asks for enum
2630 and the actual arg is that enum type. */
2631 ;
2637 ;
2638 /* Don't complain if the formal parameter type
2639 is an enum, because we can't tell now whether
2640 the value was an enum--even the same enum. */
2642 ;
2645 /* Change in signedness doesn't matter
2646 if a constant value is unaffected. */
2647 ;
2648 /* If the value is extended from a narrower
2649 unsigned type, it doesn't matter whether we
2650 pass it as signed or unsigned; the value
2651 certainly is the same either way. */
2654 ;
2659 else
2662 }
2663 }
2673 }
2675 }
2680 {
2683 else
2684 /* Convert `float' to `double'. */
2686 }
2689 {
2692 }
2693 else
2694 /* Convert `short' and `char' to full-size `int'. */
2699 }
2704 {
2707 }
2710 }
2711 \f
2712 /* This is the entry point used by the parser to build unary operators
2713 in the input. CODE, a tree_code, specifies the unary operator, and
2714 ARG is the operand. For unary plus, the C parser currently uses
2715 CONVERT_EXPR for code. */
2717 struct c_expr
2719 {
2729 }
2731 /* This is the entry point used by the parser to build binary operators
2732 in the input. CODE, a tree_code, specifies the binary operator, and
2733 ARG1 and ARG2 are the operands. In addition to constructing the
2734 expression, we check for operands that were written with other binary
2735 operators in a way that is likely to confuse the user. */
2737 struct c_expr
2740 {
2752 /* Check for cases such as x+y<<z which users are likely
2753 to misinterpret. */
2760 /* Warn about comparisons against string literals, with the exception
2761 of testing for equality or inequality of a string literal with NULL. */
2763 {
2767 }
2778 }
2779 \f
2780 /* Return a tree for the difference of pointers OP0 and OP1.
2781 The resulting tree has type int. */
2783 static tree
2785 {
2793 {
2798 }
2800 /* If the conversion to ptrdiff_type does anything like widening or
2801 converting a partial to an integral mode, we get a convert_expression
2802 that is in the way to do any simplifications.
2803 (fold-const.c doesn't know that the extra bits won't be needed.
2804 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2805 different mode in place.)
2806 So first try to find a common term here 'by hand'; we want to cover
2807 at least the cases that occur in legal static initializers. */
2812 else
2818 else
2822 {
2825 }
2826 else
2830 {
2833 }
2834 else
2838 {
2841 }
2844 /* First do the subtraction as integers;
2845 then drop through to build the divide operator.
2846 Do not do default conversions on the minus operator
2847 in case restype is a short type. */
2851 /* This generates an error if op1 is pointer to incomplete type. */
2855 /* This generates an error if op0 is pointer to incomplete type. */
2858 /* Divide by the size, in easiest possible way. */
2860 }
2861 \f
2862 /* Construct and perhaps optimize a tree representation
2863 for a unary operation. CODE, a tree_code, specifies the operation
2864 and XARG is the operand.
2865 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2866 the default promotions (such as from short to int).
2867 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2868 allows non-lvalues; this is only used to handle conversion of non-lvalue
2869 arrays to pointers in C99. */
2871 tree
2873 {
2874 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2878 tree val;
2893 {
2896 }
2899 {
2901 /* This is used for unary plus, because a CONVERT_EXPR
2902 is enough to prevent anybody from looking inside for
2903 associativity, but won't generate any code. */
2907 {
2910 }
2920 {
2923 }
2929 /* ~ works on integer types and non float vectors. */
2933 {
2936 }
2938 {
2944 }
2945 else
2946 {
2949 }
2954 {
2957 }
2963 /* Conjugating a real value is a no-op, but allow it anyway. */
2966 {
2969 }
2978 {
2981 }
2990 else
2998 else
3006 /* Increment or decrement the real part of the value,
3007 and don't change the imaginary part. */
3009 {
3024 }
3026 /* Report invalid types. */
3030 {
3033 else
3037 }
3039 {
3040 tree inc;
3046 /* Compute the increment. */
3049 {
3050 /* If pointer target is an undefined struct,
3051 we just cannot know how to do the arithmetic. */
3053 {
3056 else
3058 }
3062 {
3065 else
3067 }
3071 }
3073 {
3074 /* For signed fract types, we invert ++ to -- or
3075 -- to ++, and change inc from 1 to -1, because
3076 it is not possible to represent 1 in signed fract constants.
3077 For unsigned fract types, the result always overflows and
3078 we get an undefined (original) or the maximum value. */
3090 }
3091 else
3092 {
3095 }
3097 /* Complain about anything else that is not a true lvalue. */
3100 ? lv_increment
3104 /* Report a read-only lvalue. */
3106 {
3112 }
3116 else
3123 }
3126 /* Note that this operation never does default_conversion. */
3128 /* Let &* cancel out to simplify resulting code. */
3130 {
3131 /* Don't let this be an lvalue. */
3135 }
3137 /* For &x[y], return x+y */
3139 {
3148 }
3150 /* Anything not already handled and not a true memory reference
3151 or a non-lvalue array is an error. */
3156 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
3159 /* If the lvalue is const or volatile, merge that into the type
3160 to which the address will point. Note that you can't get a
3161 restricted pointer by taking the address of something, so we
3162 only have to deal with `const' and `volatile' here. */
3177 /* ??? Cope with user tricks that amount to offsetof. Delete this
3178 when we have proper support for integer constant expressions. */
3182 {
3187 }
3195 }
3201 }
3203 /* Return nonzero if REF is an lvalue valid for this language.
3204 Lvalues can be assigned, unless their type has TYPE_READONLY.
3205 Lvalues can have their address taken, unless they have C_DECL_REGISTER. */
3207 static int
3209 {
3213 {
3237 }
3238 }
3239 \f
3240 /* Give an error for storing in something that is 'const'. */
3242 static void
3244 {
3247 /* Using this macro rather than (for example) arrays of messages
3248 ensures that all the format strings are checked at compile
3249 time. */
3250 #define READONLY_MSG(A, I, D, AS) (use == lv_assign ? (A) \
3251 : (use == lv_increment ? (I) \
3252 : (use == lv_decrement ? (D) : (AS))))
3254 {
3257 else
3263 }
3269 arg);
3270 else
3275 arg);
3276 }
3279 /* Return nonzero if REF is an lvalue valid for this language;
3280 otherwise, print an error message and return zero. USE says
3281 how the lvalue is being used and so selects the error message. */
3283 static int
3285 {
3292 }
3293 \f
3294 /* Mark EXP saying that we need to be able to take the
3295 address of it; it should not be allocated in a register.
3296 Returns true if successful. */
3298 bool
3300 {
3305 {
3308 {
3309 error
3312 }
3314 /* ... fall through ... */
3334 {
3336 {
3337 error
3340 }
3342 }
3344 {
3347 else
3350 }
3352 /* drops in */
3355 /* drops out */
3358 }
3359 }
3360 \f
3361 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
3363 tree
3365 {
3366 tree type1;
3367 tree type2;
3373 /* Promote both alternatives. */
3390 /* C90 does not permit non-lvalue arrays in conditional expressions.
3391 In C99 they will be pointers by now. */
3393 {
3396 }
3398 /* Quickly detect the usual case where op1 and op2 have the same type
3399 after promotion. */
3401 {
3404 else
3406 }
3411 {
3414 /* If -Wsign-compare, warn here if type1 and type2 have
3415 different signedness. We'll promote the signed to unsigned
3416 and later code won't know it used to be different.
3417 Do this check on the original types, so that explicit casts
3418 will be considered, but default promotions won't. */
3420 {
3425 {
3428 /* Do not warn if the result type is signed, since the
3429 signed type will only be chosen if it can represent
3430 all the values of the unsigned type. */
3433 /* Do not warn if the signed quantity is an unsuffixed
3434 integer literal (or some static constant expression
3435 involving such literals) and it is non-negative. */
3438 || (unsigned_op1
3441 else
3443 }
3444 }
3445 }
3447 {
3451 }
3453 {
3461 {
3467 }
3469 {
3475 }
3476 else
3477 {
3480 }
3481 }
3483 {
3486 else
3487 {
3489 }
3491 }
3493 {
3496 else
3497 {
3499 }
3501 }
3504 {
3507 else
3508 {
3511 }
3512 }
3514 /* Merge const and volatile flags of the incoming types. */
3515 result_type
3526 }
3527 \f
3528 /* Return a compound expression that performs two expressions and
3529 returns the value of the second of them. */
3531 tree
3533 {
3535 {
3536 /* The left-hand operand of a comma expression is like an expression
3537 statement: with -Wunused, we should warn if it doesn't have
3538 any side-effects, unless it was explicitly cast to (void). */
3540 {
3550 else
3553 }
3554 }
3556 /* With -Wunused, we should also warn if the left-hand operand does have
3557 side-effects, but computes a value which is not used. For example, in
3558 `foo() + bar(), baz()' the result of the `+' operator is not used,
3559 so we should issue a warning. */
3567 }
3569 /* Build an expression representing a cast to type TYPE of expression EXPR. */
3571 tree
3573 {
3579 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
3580 only in <protocol> qualifications. But when constructing cast expressions,
3581 the protocols do matter and must be kept around. */
3588 {
3591 }
3594 {
3597 }
3600 {
3604 }
3607 {
3609 {
3613 }
3614 }
3616 {
3617 tree field;
3625 {
3626 tree t;
3636 }
3639 }
3640 else
3641 {
3649 /* Optionally warn about potentially worrisome casts. */
3654 {
3660 /* Check that the qualifiers on IN_TYPE are a superset of
3661 the qualifiers of IN_OTYPE. The outermost level of
3662 POINTER_TYPE nodes is uninteresting and we stop as soon
3663 as we hit a non-POINTER_TYPE node on either type. */
3664 do
3665 {
3669 /* GNU C allows cv-qualified function types. 'const'
3670 means the function is very pure, 'volatile' means it
3671 can't return. We need to warn when such qualifiers
3672 are added, not when they're taken away. */
3676 else
3678 }
3686 /* There are qualifiers present in IN_OTYPE that are not
3687 present in IN_TYPE. */
3689 }
3691 /* Warn about possible alignment problems. */
3697 /* Don't warn about opaque types, where the actual alignment
3698 restriction is unknown. */
3709 /* Unlike conversion of integers to pointers, where the
3710 warning is disabled for converting constants because
3711 of cases such as SIG_*, warn about converting constant
3712 pointers to integers. In some cases it may cause unwanted
3713 sign extension, and a warning is appropriate. */
3725 /* Don't warn about converting any constant. */
3733 /* If pedantic, warn for conversions between function and object
3734 pointer types, except for converting a null pointer constant
3735 to function pointer type. */
3754 /* Ignore any integer overflow caused by the cast. */
3756 {
3758 {
3760 {
3761 /* Avoid clobbering a shared constant. */
3764 }
3765 }
3767 /* Reset VALUE's overflow flags, ensuring constant sharing. */
3771 }
3772 }
3774 /* Don't let a cast be an lvalue. */
3779 }
3781 /* Interpret a cast of expression EXPR to type TYPE. */
3782 tree
3784 {
3785 tree type;
3788 /* This avoids warnings about unprototyped casts on
3789 integers. E.g. "#define SIG_DFL (void(*)())0". */
3796 }
3797 \f
3798 /* Build an assignment expression of lvalue LHS from value RHS.
3799 MODIFYCODE is the code for a binary operator that we use
3800 to combine the old value of LHS with RHS to get the new value.
3801 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3803 tree
3805 {
3806 tree result;
3807 tree newrhs;
3811 /* Types that aren't fully specified cannot be used in assignments. */
3814 /* Avoid duplicate error messages from operands that had errors. */
3825 /* If a binary op has been requested, combine the old LHS value with the RHS
3826 producing the value we should actually store into the LHS. */
3829 {
3832 }
3834 /* Give an error for storing in something that is 'const'. */
3840 {
3843 }
3845 /* If storing into a structure or union member,
3846 it has probably been given type `int'.
3847 Compute the type that would go with
3848 the actual amount of storage the member occupies. */
3857 /* If storing in a field that is in actuality a short or narrower than one,
3858 we must store in the field in its actual type. */
3861 {
3864 }
3866 /* Convert new value to destination type. */
3873 /* Emit ObjC write barrier, if necessary. */
3875 {
3879 }
3881 /* Scan operands. */
3886 /* If we got the LHS in a different type for storing in,
3887 convert the result back to the nominal type of LHS
3888 so that the value we return always has the same type
3889 as the LHS argument. */
3895 }
3896 \f
3897 /* Convert value RHS to type TYPE as preparation for an assignment
3898 to an lvalue of type TYPE.
3899 The real work of conversion is done by `convert'.
3900 The purpose of this function is to generate error messages
3901 for assignments that are not allowed in C.
3902 ERRTYPE says whether it is argument passing, assignment,
3903 initialization or return.
3905 FUNCTION is a tree for the function being called.
3906 PARMNUM is the number of the argument, for printing in error messages. */
3908 static tree
3911 {
3913 tree rhstype;
3919 {
3920 tree selector;
3921 /* Change pointer to function to the function itself for
3922 diagnostics. */
3927 /* Handle an ObjC selector specially for diagnostics. */
3931 {
3934 }
3935 }
3937 /* This macro is used to emit diagnostics to ensure that all format
3938 strings are complete sentences, visible to gettext and checked at
3939 compile time. */
3940 #define WARN_FOR_ASSIGNMENT(AR, AS, IN, RE) \
3941 do { \
3942 switch (errtype) \
3943 { \
3944 case ic_argpass: \
3945 pedwarn (AR, parmnum, rname); \
3946 break; \
3947 case ic_argpass_nonproto: \
3948 warning (0, AR, parmnum, rname); \
3949 break; \
3950 case ic_assign: \
3951 pedwarn (AS); \
3952 break; \
3953 case ic_init: \
3954 pedwarn (IN); \
3955 break; \
3956 case ic_return: \
3957 pedwarn (RE); \
3958 break; \
3959 default: \
3960 gcc_unreachable (); \
3961 } \
3962 } while (0)
3977 {
3981 {
3997 }
4000 }
4006 {
4007 /* Except for passing an argument to an unprototyped function,
4008 this is a constraint violation. When passing an argument to
4009 an unprototyped function, it is compile-time undefined;
4010 making it a constraint in that case was rejected in
4011 DR#252. */
4014 }
4018 /* A type converts to a reference to it.
4019 This code doesn't fully support references, it's just for the
4020 special case of va_start and va_copy. */
4023 {
4025 {
4028 }
4033 /* We already know that these two types are compatible, but they
4034 may not be exactly identical. In fact, `TREE_TYPE (type)' is
4035 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
4036 likely to be va_list, a typedef to __builtin_va_list, which
4037 is different enough that it will cause problems later. */
4043 }
4044 /* Some types can interconvert without explicit casts. */
4048 /* Arithmetic types all interconvert, and enum is treated like int. */
4059 /* Aggregates in different TUs might need conversion. */
4065 /* Conversion to a transparent union from its member types.
4066 This applies only to function arguments. */
4069 {
4073 {
4084 {
4088 /* Any non-function converts to a [const][volatile] void *
4089 and vice versa; otherwise, targets must be the same.
4090 Meanwhile, the lhs target must have all the qualifiers of
4091 the rhs. */
4094 {
4095 /* If this type won't generate any warnings, use it. */
4105 /* Keep looking for a better type, but remember this one. */
4108 }
4109 }
4111 /* Can convert integer zero to any pointer type. */
4113 {
4116 }
4117 }
4120 {
4122 {
4123 /* We have only a marginally acceptable member type;
4124 it needs a warning. */
4128 /* Const and volatile mean something different for function
4129 types, so the usual warnings are not appropriate. */
4132 {
4133 /* Because const and volatile on functions are
4134 restrictions that say the function will not do
4135 certain things, it is okay to use a const or volatile
4136 function where an ordinary one is wanted, but not
4137 vice-versa. */
4140 "makes qualified function "
4143 "function pointer from "
4146 "function pointer from "
4150 }
4162 }
4169 }
4170 }
4172 /* Conversions among pointers */
4175 {
4187 /* Opaque pointers are treated like void pointers. */
4193 /* C++ does not allow the implicit conversion void* -> T*. However,
4194 for the purpose of reducing the number of false positives, we
4195 tolerate the special case of
4197 int *p = NULL;
4199 where NULL is typically defined in C to be '(void *) 0'. */
4204 /* Check if the right-hand side has a format attribute but the
4205 left-hand side doesn't. */
4208 {
4210 {
4214 "argument %d of %qE might be "
4220 "assignment left-hand side might be "
4225 "initialization left-hand side might be "
4230 "return type might be "
4235 }
4236 }
4238 /* Any non-function converts to a [const][volatile] void *
4239 and vice versa; otherwise, targets must be the same.
4240 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
4243 || is_opaque_pointer
4246 {
4249 ||
4254 "%qE between function pointer "
4262 /* Const and volatile mean something different for function types,
4263 so the usual warnings are not appropriate. */
4266 {
4268 {
4269 /* Types differing only by the presence of the 'volatile'
4270 qualifier are acceptable if the 'volatile' has been added
4271 in by the Objective-C EH machinery. */
4281 }
4282 /* If this is not a case of ignoring a mismatch in signedness,
4283 no warning. */
4286 ;
4287 /* If there is a mismatch, do warn. */
4297 }
4300 {
4301 /* Because const and volatile on functions are restrictions
4302 that say the function will not do certain things,
4303 it is okay to use a const or volatile function
4304 where an ordinary one is wanted, but not vice-versa. */
4307 "qualified function pointer "
4315 }
4316 }
4317 else
4318 /* Avoid warning about the volatile ObjC EH puts on decls. */
4328 }
4330 {
4331 /* ??? This should not be an error when inlining calls to
4332 unprototyped functions. */
4335 }
4337 {
4338 /* An explicit constant 0 can convert to a pointer,
4339 or one that results from arithmetic, even including
4340 a cast to integer type. */
4352 }
4354 {
4364 }
4369 {
4372 /* ??? This should not be an error when inlining calls to
4373 unprototyped functions. */
4387 }
4390 }
4391 \f
4392 /* If VALUE is a compound expr all of whose expressions are constant, then
4393 return its value. Otherwise, return error_mark_node.
4395 This is for handling COMPOUND_EXPRs as initializer elements
4396 which is allowed with a warning when -pedantic is specified. */
4398 static tree
4400 {
4402 {
4407 endtype);
4408 }
4411 else
4413 }
4414 \f
4415 /* Perform appropriate conversions on the initial value of a variable,
4416 store it in the declaration DECL,
4417 and print any error messages that are appropriate.
4418 If the init is invalid, store an ERROR_MARK. */
4420 void
4422 {
4425 /* If variable's type was invalidly declared, just ignore it. */
4431 /* Digest the specified initializer into an expression. */
4435 /* Store the expression if valid; else report error. */
4444 /* ANSI wants warnings about out-of-range constant initializers. */
4449 /* Check if we need to set array size from compound literal size. */
4453 {
4460 {
4464 {
4465 /* For int foo[] = (int [3]){1}; we need to set array size
4466 now since later on array initializer will be just the
4467 brace enclosed list of the compound literal. */
4473 }
4474 }
4475 }
4476 }
4477 \f
4478 /* Methods for storing and printing names for error messages. */
4480 /* Implement a spelling stack that allows components of a name to be pushed
4481 and popped. Each element on the stack is this structure. */
4483 struct spelling
4484 {
4486 union
4487 {
4491 };
4493 #define SPELLING_STRING 1
4494 #define SPELLING_MEMBER 2
4495 #define SPELLING_BOUNDS 3
4501 /* Macros to save and restore the spelling stack around push_... functions.
4502 Alternative to SAVE_SPELLING_STACK. */
4504 #define SPELLING_DEPTH() (spelling - spelling_base)
4505 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
4507 /* Push an element on the spelling stack with type KIND and assign VALUE
4508 to MEMBER. */
4510 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
4511 { \
4512 int depth = SPELLING_DEPTH (); \
4513 \
4514 if (depth >= spelling_size) \
4515 { \
4516 spelling_size += 10; \
4517 spelling_base = XRESIZEVEC (struct spelling, spelling_base, \
4518 spelling_size); \
4519 RESTORE_SPELLING_DEPTH (depth); \
4520 } \
4521 \
4522 spelling->kind = (KIND); \
4523 spelling->MEMBER = (VALUE); \
4524 spelling++; \
4525 }
4527 /* Push STRING on the stack. Printed literally. */
4529 static void
4531 {
4533 }
4535 /* Push a member name on the stack. Printed as '.' STRING. */
4537 static void
4539 {
4543 }
4545 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
4547 static void
4549 {
4551 }
4553 /* Compute the maximum size in bytes of the printed spelling. */
4555 static int
4557 {
4562 {
4565 else
4567 }
4570 }
4572 /* Print the spelling to BUFFER and return it. */
4576 {
4582 {
4585 }
4586 else
4587 {
4592 ;
4593 }
4596 }
4598 /* Issue an error message for a bad initializer component.
4599 MSGID identifies the message.
4600 The component name is taken from the spelling stack. */
4602 void
4604 {
4611 }
4613 /* Issue a pedantic warning for a bad initializer component.
4614 MSGID identifies the message.
4615 The component name is taken from the spelling stack. */
4617 void
4619 {
4626 }
4628 /* Issue a warning for a bad initializer component.
4629 MSGID identifies the message.
4630 The component name is taken from the spelling stack. */
4632 static void
4634 {
4641 }
4642 \f
4643 /* If TYPE is an array type and EXPR is a parenthesized string
4644 constant, warn if pedantic that EXPR is being used to initialize an
4645 object of type TYPE. */
4647 void
4649 {
4655 }
4657 /* Digest the parser output INIT as an initializer for type TYPE.
4658 Return a C expression of type TYPE to represent the initial value.
4660 If INIT is a string constant, STRICT_STRING is true if it is
4661 unparenthesized or we should not warn here for it being parenthesized.
4662 For other types of INIT, STRICT_STRING is not used.
4664 REQUIRE_CONSTANT requests an error if non-constant initializers or
4665 elements are seen. */
4667 static tree
4669 {
4674 || !init
4683 /* Initialization of an array of chars from a string constant
4684 optionally enclosed in braces. */
4688 {
4690 /* Note that an array could be both an array of character type
4691 and an array of wchar_t if wchar_t is signed char or unsigned
4692 char. */
4698 {
4705 char_string
4714 {
4717 }
4719 {
4722 }
4728 /* Subtract 1 (or sizeof (wchar_t))
4729 because it's ok to ignore the terminating null char
4730 that is counted in the length of the constant. */
4741 }
4743 {
4747 }
4748 }
4750 /* Build a VECTOR_CST from a *constant* vector constructor. If the
4751 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
4752 below and handle as a constructor. */
4757 {
4764 {
4766 tree value;
4769 /* Iterate through elements and check if all constructor
4770 elements are *_CSTs. */
4773 {
4776 }
4781 }
4782 }
4784 /* Any type can be initialized
4785 from an expression of the same type, optionally with braces. */
4798 {
4800 {
4802 {
4806 else
4807 {
4810 }
4811 }
4812 }
4815 /* Although the types are compatible, we may require a
4816 conversion. */
4822 {
4823 /* As an extension, allow initializing objects with static storage
4824 duration with compound literals (which are then treated just as
4825 the brace enclosed list they contain). Also allow this for
4826 vectors, as we can only assign them with compound literals. */
4829 }
4833 {
4836 }
4841 /* Compound expressions can only occur here if -pedantic or
4842 -pedantic-errors is specified. In the later case, we always want
4843 an error. In the former case, we simply want a warning. */
4846 {
4847 inside_init
4852 else
4856 }
4860 {
4863 }
4865 /* Added to enable additional -Wmissing-format-attribute warnings. */
4870 }
4872 /* Handle scalar types, including conversions. */
4877 {
4882 inside_init
4886 /* Check to see if we have already given an error message. */
4888 ;
4890 {
4893 }
4897 {
4900 }
4903 }
4905 /* Come here only for records and arrays. */
4908 {
4911 }
4915 }
4916 \f
4917 /* Handle initializers that use braces. */
4919 /* Type of object we are accumulating a constructor for.
4920 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4923 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4924 left to fill. */
4927 /* For an ARRAY_TYPE, this is the specified index
4928 at which to store the next element we get. */
4931 /* For an ARRAY_TYPE, this is the maximum index. */
4934 /* For a RECORD_TYPE, this is the first field not yet written out. */
4937 /* For an ARRAY_TYPE, this is the index of the first element
4938 not yet written out. */
4941 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4942 This is so we can generate gaps between fields, when appropriate. */
4945 /* If we are saving up the elements rather than allocating them,
4946 this is the list of elements so far (in reverse order,
4947 most recent first). */
4950 /* 1 if constructor should be incrementally stored into a constructor chain,
4951 0 if all the elements should be kept in AVL tree. */
4954 /* 1 if so far this constructor's elements are all compile-time constants. */
4957 /* 1 if so far this constructor's elements are all valid address constants. */
4960 /* 1 if this constructor is erroneous so far. */
4963 /* Structure for managing pending initializer elements, organized as an
4964 AVL tree. */
4966 struct init_node
4967 {
4971 tree purpose;
4972 tree value;
4973 };
4975 /* Tree of pending elements at this constructor level.
4976 These are elements encountered out of order
4977 which belong at places we haven't reached yet in actually
4978 writing the output.
4979 Will never hold tree nodes across GC runs. */
4982 /* The SPELLING_DEPTH of this constructor. */
4985 /* DECL node for which an initializer is being read.
4986 0 means we are reading a constructor expression
4987 such as (struct foo) {...}. */
4990 /* Nonzero if this is an initializer for a top-level decl. */
4993 /* Nonzero if there were any member designators in this initializer. */
4996 /* Nesting depth of designator list. */
4999 /* Nonzero if there were diagnosed errors in this designator list. */
5002 \f
5003 /* This stack has a level for each implicit or explicit level of
5004 structuring in the initializer, including the outermost one. It
5005 saves the values of most of the variables above. */
5009 struct constructor_stack
5010 {
5012 tree type;
5013 tree fields;
5014 tree index;
5015 tree max_index;
5016 tree unfilled_index;
5017 tree unfilled_fields;
5018 tree bit_index;
5023 /* If value nonzero, this value should replace the entire
5024 constructor at this level. */
5034 };
5038 /* This stack represents designators from some range designator up to
5039 the last designator in the list. */
5041 struct constructor_range_stack
5042 {
5045 tree range_start;
5046 tree index;
5047 tree range_end;
5048 tree fields;
5049 };
5053 /* This stack records separate initializers that are nested.
5054 Nested initializers can't happen in ANSI C, but GNU C allows them
5055 in cases like { ... (struct foo) { ... } ... }. */
5057 struct initializer_stack
5058 {
5060 tree decl;
5070 };
5073 \f
5074 /* Prepare to parse and output the initializer for variable DECL. */
5076 void
5078 {
5100 {
5102 require_constant_elements
5104 /* For a scalar, you can always use any value to initialize,
5105 even within braces. */
5111 }
5112 else
5113 {
5117 }
5130 }
5132 void
5134 {
5137 /* Free the whole constructor stack of this initializer. */
5139 {
5143 }
5147 /* Pop back to the data of the outer initializer (if any). */
5162 }
5163 \f
5164 /* Call here when we see the initializer is surrounded by braces.
5165 This is instead of a call to push_init_level;
5166 it is matched by a call to pop_init_level.
5168 TYPE is the type to initialize, for a constructor expression.
5169 For an initializer for a decl, TYPE is zero. */
5171 void
5173 {
5218 {
5220 /* Skip any nameless bit fields at the beginning. */
5227 }
5229 {
5231 {
5232 constructor_max_index
5235 /* Detect non-empty initializations of zero-length arrays. */
5240 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5241 to initialize VLAs will cause a proper error; avoid tree
5242 checking errors as well by setting a safe value. */
5247 constructor_index
5250 }
5251 else
5252 {
5255 }
5258 }
5260 {
5261 /* Vectors are like simple fixed-size arrays. */
5262 constructor_max_index =
5266 }
5267 else
5268 {
5269 /* Handle the case of int x = {5}; */
5272 }
5273 }
5274 \f
5275 /* Push down into a subobject, for initialization.
5276 If this is for an explicit set of braces, IMPLICIT is 0.
5277 If it is because the next element belongs at a lower level,
5278 IMPLICIT is 1 (or 2 if the push is because of designator list). */
5280 void
5282 {
5286 /* If we've exhausted any levels that didn't have braces,
5287 pop them now. If implicit == 1, this will have been done in
5288 process_init_element; do not repeat it here because in the case
5289 of excess initializers for an empty aggregate this leads to an
5290 infinite cycle of popping a level and immediately recreating
5291 it. */
5293 {
5295 {
5301 && constructor_max_index
5303 constructor_index))
5305 else
5307 }
5308 }
5310 /* Unless this is an explicit brace, we need to preserve previous
5311 content if any. */
5313 {
5320 }
5354 {
5359 }
5361 /* Don't die if an entire brace-pair level is superfluous
5362 in the containing level. */
5364 ;
5367 {
5368 /* Don't die if there are extra init elts at the end. */
5371 else
5372 {
5375 constructor_depth++;
5376 }
5377 }
5379 {
5382 constructor_depth++;
5383 }
5386 {
5391 }
5394 {
5402 }
5405 {
5408 }
5412 {
5414 /* Skip any nameless bit fields at the beginning. */
5421 }
5423 {
5424 /* Vectors are like simple fixed-size arrays. */
5425 constructor_max_index =
5429 }
5431 {
5433 {
5434 constructor_max_index
5437 /* Detect non-empty initializations of zero-length arrays. */
5442 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5443 to initialize VLAs will cause a proper error; avoid tree
5444 checking errors as well by setting a safe value. */
5449 constructor_index
5452 }
5453 else
5458 {
5459 /* We need to split the char/wchar array into individual
5460 characters, so that we don't have to special case it
5461 everywhere. */
5463 }
5464 }
5465 else
5466 {
5471 }
5472 }
5474 /* At the end of an implicit or explicit brace level,
5475 finish up that level of constructor. If a single expression
5476 with redundant braces initialized that level, return the
5477 c_expr structure for that expression. Otherwise, the original_code
5478 element is set to ERROR_MARK.
5479 If we were outputting the elements as they are read, return 0 as the value
5480 from inner levels (process_init_element ignores that),
5481 but return error_mark_node as the value from the outermost level
5482 (that's what we want to put in DECL_INITIAL).
5483 Otherwise, return a CONSTRUCTOR expression as the value. */
5485 struct c_expr
5487 {
5494 {
5495 /* When we come to an explicit close brace,
5496 pop any inner levels that didn't have explicit braces. */
5501 }
5503 /* Now output all pending elements. */
5509 /* Error for initializing a flexible array member, or a zero-length
5510 array member in an inappropriate context. */
5515 {
5516 /* Silently discard empty initializations. The parser will
5517 already have pedwarned for empty brackets. */
5520 else
5521 {
5529 /* We have already issued an error message for the existence
5530 of a flexible array member not at the end of the structure.
5531 Discard the initializer so that we do not die later. */
5534 }
5535 }
5537 /* Warn when some struct elements are implicitly initialized to zero. */
5539 && constructor_type
5542 {
5543 /* Do not warn for flexible array members or zero-length arrays. */
5549 /* Do not warn if this level of the initializer uses member
5550 designators; it is likely to be deliberate. */
5552 {
5556 }
5557 }
5559 /* Pad out the end of the structure. */
5561 /* If this closes a superfluous brace pair,
5562 just pass out the element between them. */
5565 ;
5570 {
5571 /* A nonincremental scalar initializer--just return
5572 the element, after verifying there is just one. */
5574 {
5578 }
5580 {
5583 }
5584 else
5586 }
5587 else
5588 {
5591 else
5592 {
5594 constructor_elements);
5599 }
5600 }
5627 }
5629 /* Common handling for both array range and field name designators.
5630 ARRAY argument is nonzero for array ranges. Returns zero for success. */
5632 static int
5634 {
5635 tree subtype;
5638 /* Don't die if an entire brace-pair level is superfluous
5639 in the containing level. */
5643 /* If there were errors in this designator list already, bail out
5644 silently. */
5649 {
5652 /* Designator list starts at the level of closest explicit
5653 braces. */
5658 }
5661 {
5673 }
5677 {
5680 }
5682 {
5685 }
5690 }
5692 /* If there are range designators in designator list, push a new designator
5693 to constructor_range_stack. RANGE_END is end of such stack range or
5694 NULL_TREE if there is no range designator at this level. */
5696 static void
5698 {
5712 }
5714 /* Within an array initializer, specify the next index to be initialized.
5715 FIRST is that index. If LAST is nonzero, then initialize a range
5716 of indices, running from FIRST through LAST. */
5718 void
5720 {
5728 {
5731 }
5744 else
5745 {
5749 {
5753 {
5756 }
5757 else
5758 {
5762 {
5765 }
5766 }
5767 }
5769 designator_depth++;
5773 }
5774 }
5776 /* Within a struct initializer, specify the next field to be initialized. */
5778 void
5780 {
5781 tree tail;
5790 {
5793 }
5797 {
5800 }
5804 else
5805 {
5807 designator_depth++;
5811 }
5812 }
5813 \f
5814 /* Add a new initializer to the tree of pending initializers. PURPOSE
5815 identifies the initializer, either array index or field in a structure.
5816 VALUE is the value of that index or field. */
5818 static void
5820 {
5827 {
5829 {
5835 else
5836 {
5843 }
5844 }
5845 }
5846 else
5847 {
5848 tree bitpos;
5852 {
5858 else
5859 {
5866 }
5867 }
5868 }
5881 {
5885 {
5889 {
5891 {
5892 /* L rotation. */
5905 {
5908 else
5910 }
5911 else
5913 }
5914 else
5915 {
5916 /* LR rotation. */
5938 {
5941 else
5943 }
5944 else
5946 }
5948 }
5949 else
5950 {
5951 /* p->balance == +1; growth of left side balances the node. */
5954 }
5955 }
5957 {
5959 /* Growth propagation from right side. */
5962 {
5964 {
5965 /* R rotation. */
5978 {
5981 else
5983 }
5984 else
5986 }
5988 {
5989 /* RL rotation */
6011 {
6014 else
6016 }
6017 else
6019 }
6021 }
6022 else
6023 {
6024 /* p->balance == -1; growth of right side balances the node. */
6027 }
6028 }
6032 }
6033 }
6035 /* Build AVL tree from a sorted chain. */
6037 static void
6039 {
6051 {
6053 /* Skip any nameless bit fields at the beginning. */
6059 }
6061 {
6063 constructor_unfilled_index
6066 else
6068 }
6070 }
6072 /* Build AVL tree from a string constant. */
6074 static void
6076 {
6087 else
6088 {
6092 }
6101 {
6103 {
6106 }
6107 else
6108 {
6112 {
6115 else
6120 }
6121 }
6124 {
6127 {
6129 {
6132 }
6133 }
6135 {
6138 }
6143 }
6147 }
6150 }
6152 /* Return value of FIELD in pending initializer or zero if the field was
6153 not initialized yet. */
6155 static tree
6157 {
6161 {
6168 {
6173 else
6175 }
6176 }
6178 {
6182 && (!constructor_unfilled_fields
6189 {
6194 else
6196 }
6197 }
6199 {
6204 }
6206 }
6208 /* "Output" the next constructor element.
6209 At top level, really output it to assembler code now.
6210 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
6211 TYPE is the data type that the containing data type wants here.
6212 FIELD is the field (a FIELD_DECL) or the index that this element fills.
6213 If VALUE is a string constant, STRICT_STRING is true if it is
6214 unparenthesized or we should not warn here for it being parenthesized.
6215 For other types of VALUE, STRICT_STRING is not used.
6217 PENDING if non-nil means output pending elements that belong
6218 right after this element. (PENDING is normally 1;
6219 it is 0 while outputting pending elements, to avoid recursion.) */
6221 static void
6224 {
6228 {
6231 }
6244 {
6245 /* As an extension, allow initializing objects with static storage
6246 duration with compound literals (which are then treated just as
6247 the brace enclosed list they contain). */
6250 }
6264 {
6266 {
6269 }
6272 }
6274 /* If this field is empty (and not at the end of structure),
6275 don't do anything other than checking the initializer. */
6286 {
6289 }
6291 /* If this element doesn't come next in sequence,
6292 put it on constructor_pending_elts. */
6294 && (!constructor_incremental
6296 {
6303 }
6305 && (!constructor_incremental
6307 {
6308 /* We do this for records but not for unions. In a union,
6309 no matter which field is specified, it can be initialized
6310 right away since it starts at the beginning of the union. */
6312 {
6315 else
6316 {
6324 }
6325 }
6329 }
6332 {
6339 /* We can have just one union field set. */
6341 }
6343 /* Otherwise, output this element either to
6344 constructor_elements or to the assembler file. */
6350 /* Advance the variable that indicates sequential elements output. */
6352 constructor_unfilled_index
6354 bitsize_one_node);
6356 {
6357 constructor_unfilled_fields
6360 /* Skip any nameless bit fields. */
6364 constructor_unfilled_fields =
6366 }
6370 /* Now output any pending elements which have become next. */
6373 }
6375 /* Output any pending elements which have become next.
6376 As we output elements, constructor_unfilled_{fields,index}
6377 advances, which may cause other elements to become next;
6378 if so, they too are output.
6380 If ALL is 0, we return when there are
6381 no more pending elements to output now.
6383 If ALL is 1, we output space as necessary so that
6384 we can output all the pending elements. */
6386 static void
6388 {
6390 tree next;
6392 retry:
6394 /* Look through the whole pending tree.
6395 If we find an element that should be output now,
6396 output it. Otherwise, set NEXT to the element
6397 that comes first among those still pending. */
6401 {
6403 {
6405 constructor_unfilled_index))
6411 {
6412 /* Advance to the next smaller node. */
6415 else
6416 {
6417 /* We have reached the smallest node bigger than the
6418 current unfilled index. Fill the space first. */
6421 }
6422 }
6423 else
6424 {
6425 /* Advance to the next bigger node. */
6428 else
6429 {
6430 /* We have reached the biggest node in a subtree. Find
6431 the parent of it, which is the next bigger node. */
6437 {
6440 }
6441 }
6442 }
6443 }
6446 {
6449 /* If the current record is complete we are done. */
6455 /* We can't compare fields here because there might be empty
6456 fields in between. */
6458 {
6462 }
6464 {
6465 /* Advance to the next smaller node. */
6468 else
6469 {
6470 /* We have reached the smallest node bigger than the
6471 current unfilled field. Fill the space first. */
6474 }
6475 }
6476 else
6477 {
6478 /* Advance to the next bigger node. */
6481 else
6482 {
6483 /* We have reached the biggest node in a subtree. Find
6484 the parent of it, which is the next bigger node. */
6491 {
6494 }
6495 }
6496 }
6497 }
6498 }
6500 /* Ordinarily return, but not if we want to output all
6501 and there are elements left. */
6505 /* If it's not incremental, just skip over the gap, so that after
6506 jumping to retry we will output the next successive element. */
6513 /* ELT now points to the node in the pending tree with the next
6514 initializer to output. */
6516 }
6517 \f
6518 /* Add one non-braced element to the current constructor level.
6519 This adjusts the current position within the constructor's type.
6520 This may also start or terminate implicit levels
6521 to handle a partly-braced initializer.
6523 Once this has found the correct level for the new element,
6524 it calls output_init_element. */
6526 void
6528 {
6536 /* Handle superfluous braces around string cst as in
6537 char x[] = {"foo"}; */
6539 && constructor_type
6543 {
6548 }
6551 {
6554 }
6556 /* Ignore elements of a brace group if it is entirely superfluous
6557 and has already been diagnosed. */
6561 /* If we've exhausted any levels that didn't have braces,
6562 pop them now. */
6564 {
6572 constructor_index)))
6574 else
6576 }
6578 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
6580 {
6581 /* If value is a compound literal and we'll be just using its
6582 content, don't put it into a SAVE_EXPR. */
6584 || !require_constant_value
6587 }
6590 {
6592 {
6593 tree fieldtype;
6597 {
6600 }
6607 /* Error for non-static initialization of a flexible array member. */
6609 && !require_constant_value
6612 {
6615 }
6617 /* Accept a string constant to initialize a subarray. */
6623 /* Otherwise, if we have come to a subaggregate,
6624 and we don't have an element of its type, push into it. */
6630 {
6633 }
6636 {
6641 }
6642 else
6643 /* Do the bookkeeping for an element that was
6644 directly output as a constructor. */
6645 {
6646 /* For a record, keep track of end position of last field. */
6648 constructor_bit_index
6653 /* If the current field was the first one not yet written out,
6654 it isn't now, so update. */
6656 {
6658 /* Skip any nameless bit fields. */
6662 constructor_unfilled_fields =
6664 }
6665 }
6668 /* Skip any nameless bit fields at the beginning. */
6673 }
6675 {
6676 tree fieldtype;
6680 {
6683 }
6690 /* Warn that traditional C rejects initialization of unions.
6691 We skip the warning if the value is zero. This is done
6692 under the assumption that the zero initializer in user
6693 code appears conditioned on e.g. __STDC__ to avoid
6694 "missing initializer" warnings and relies on default
6695 initialization to zero in the traditional C case.
6696 We also skip the warning if the initializer is designated,
6697 again on the assumption that this must be conditional on
6698 __STDC__ anyway (and we've already complained about the
6699 member-designator already). */
6706 /* Accept a string constant to initialize a subarray. */
6712 /* Otherwise, if we have come to a subaggregate,
6713 and we don't have an element of its type, push into it. */
6719 {
6722 }
6725 {
6730 }
6731 else
6732 /* Do the bookkeeping for an element that was
6733 directly output as a constructor. */
6734 {
6737 }
6740 }
6742 {
6746 /* Accept a string constant to initialize a subarray. */
6752 /* Otherwise, if we have come to a subaggregate,
6753 and we don't have an element of its type, push into it. */
6759 {
6762 }
6767 {
6770 }
6772 /* Now output the actual element. */
6774 {
6779 }
6781 constructor_index
6785 /* If we are doing the bookkeeping for an element that was
6786 directly output as a constructor, we must update
6787 constructor_unfilled_index. */
6789 }
6791 {
6794 /* Do a basic check of initializer size. Note that vectors
6795 always have a fixed size derived from their type. */
6797 {
6800 }
6802 /* Now output the actual element. */
6807 constructor_index
6811 /* If we are doing the bookkeeping for an element that was
6812 directly output as a constructor, we must update
6813 constructor_unfilled_index. */
6815 }
6817 /* Handle the sole element allowed in a braced initializer
6818 for a scalar variable. */
6821 {
6824 }
6825 else
6826 {
6831 }
6833 /* Handle range initializers either at this level or anywhere higher
6834 in the designator stack. */
6836 {
6843 {
6846 }
6850 {
6853 }
6860 {
6864 {
6867 }
6875 }
6880 }
6883 }
6886 }
6887 \f
6888 /* Build a complete asm-statement, whose components are a CV_QUALIFIER
6889 (guaranteed to be 'volatile' or null) and ARGS (represented using
6890 an ASM_EXPR node). */
6891 tree
6893 {
6897 }
6899 /* Build an asm-expr, whose components are a STRING, some OUTPUTS,
6900 some INPUTS, and some CLOBBERS. The latter three may be NULL.
6901 SIMPLE indicates whether there was anything at all after the
6902 string in the asm expression -- asm("blah") and asm("blah" : )
6903 are subtly different. We use a ASM_EXPR node to represent this. */
6904 tree
6907 {
6908 tree tail;
6909 tree args;
6922 /* Remove output conversions that change the type but not the mode. */
6924 {
6927 /* ??? Really, this should not be here. Users should be using a
6928 proper lvalue, dammit. But there's a long history of using casts
6929 in the output operands. In cases like longlong.h, this becomes a
6930 primitive form of typechecking -- if the cast can be removed, then
6931 the output operand had a type of the proper width; otherwise we'll
6932 get an error. Gross, but ... */
6951 {
6952 /* If the operand is going to end up in memory,
6953 mark it addressable. */
6956 }
6957 else
6961 }
6964 {
6965 tree input;
6972 {
6973 /* If the operand is going to end up in memory,
6974 mark it addressable. */
6976 {
6977 /* Strip the nops as we allow this case. FIXME, this really
6978 should be rejected or made deprecated. */
6982 }
6983 }
6984 else
6988 }
6992 /* asm statements without outputs, including simple ones, are treated
6993 as volatile. */
6998 }
6999 \f
7000 /* Generate a goto statement to LABEL. */
7002 tree
7004 {
7010 {
7013 }
7016 {
7019 }
7022 {
7023 /* No jump from outside this statement expression context, so
7024 record that there is a jump from within this context. */
7030 }
7033 {
7034 /* No jump from outside this context context of identifiers with
7035 variably modified type, so record that there is a jump from
7036 within this context. */
7042 }
7046 }
7048 /* Generate a computed goto statement to EXPR. */
7050 tree
7052 {
7057 }
7059 /* Generate a C `return' statement. RETVAL is the expression for what
7060 to return, or a null pointer for `return;' with no value. */
7062 tree
7064 {
7072 {
7076 {
7080 }
7081 }
7083 {
7089 }
7090 else
7091 {
7095 tree inner;
7103 /* Strip any conversions, additions, and subtractions, and see if
7104 we are returning the address of a local variable. Warn if so. */
7106 {
7108 {
7115 /* If the second operand of the MINUS_EXPR has a pointer
7116 type (or is converted from it), this may be valid, so
7117 don't give a warning. */
7118 {
7132 }
7150 }
7153 }
7156 }
7161 }
7162 \f
7164 /* The SWITCH_EXPR being built. */
7165 tree switch_expr;
7167 /* The original type of the testing expression, i.e. before the
7168 default conversion is applied. */
7169 tree orig_type;
7171 /* A splay-tree mapping the low element of a case range to the high
7172 element, or NULL_TREE if there is no high element. Used to
7173 determine whether or not a new case label duplicates an old case
7174 label. We need a tree, rather than simply a hash table, because
7175 of the GNU case range extension. */
7176 splay_tree cases;
7178 /* Number of nested statement expressions within this switch
7179 statement; if nonzero, case and default labels may not
7180 appear. */
7183 /* Scope of outermost declarations of identifiers with variably
7184 modified type within this switch statement; if nonzero, case and
7185 default labels may not appear. */
7188 /* The next node on the stack. */
7190 };
7192 /* A stack of the currently active switch statements. The innermost
7193 switch statement is on the top of the stack. There is no need to
7194 mark the stack for garbage collection because it is only active
7195 during the processing of the body of a function, and we never
7196 collect at that point. */
7200 /* Start a C switch statement, testing expression EXP. Return the new
7201 SWITCH_EXPR. */
7203 tree
7205 {
7210 {
7214 {
7216 {
7219 }
7221 }
7222 else
7223 {
7233 }
7234 }
7236 /* Add this new SWITCH_EXPR to the stack. */
7247 }
7249 /* Process a case label. */
7251 tree
7253 {
7258 {
7265 }
7267 {
7271 else
7274 }
7276 {
7280 else
7283 }
7286 else
7290 }
7292 /* Finish the switch statement. */
7294 void
7296 {
7298 location_t switch_location;
7302 /* We must not be within a statement expression nested in the switch
7303 at this point; we might, however, be within the scope of an
7304 identifier with variably modified type nested in the switch. */
7307 /* Emit warnings as needed. */
7310 else
7316 /* Pop the stack. */
7320 }
7321 \f
7322 /* Emit an if statement. IF_LOCUS is the location of the 'if'. COND,
7323 THEN_BLOCK and ELSE_BLOCK are expressions to be used; ELSE_BLOCK
7324 may be null. NESTED_IF is true if THEN_BLOCK contains another IF
7325 statement, and was not surrounded with parenthesis. */
7327 void
7330 {
7331 tree stmt;
7333 /* Diagnose an ambiguous else if if-then-else is nested inside if-then. */
7335 {
7338 /* We know from the grammar productions that there is an IF nested
7339 within THEN_BLOCK. Due to labels and c99 conditional declarations,
7340 it might not be exactly THEN_BLOCK, but should be the last
7341 non-container statement within. */
7344 {
7359 }
7360 found:
7366 }
7373 }
7375 /* Emit a general-purpose loop construct. START_LOCUS is the location of
7376 the beginning of the loop. COND is the loop condition. COND_IS_FIRST
7377 is false for DO loops. INCR is the FOR increment expression. BODY is
7378 the statement controlled by the loop. BLAB is the break label. CLAB is
7379 the continue label. Everything is allowed to be NULL. */
7381 void
7384 {
7387 /* If the condition is zero don't generate a loop construct. */
7389 {
7391 {
7395 }
7396 }
7397 else
7398 {
7401 /* If we have an exit condition, then we build an IF with gotos either
7402 out of the loop, or to the top of it. If there's no exit condition,
7403 then we just build a jump back to the top. */
7407 {
7408 /* Canonicalize the loop condition to the end. This means
7409 generating a branch to the loop condition. Reuse the
7410 continue label, if possible. */
7412 {
7414 {
7417 }
7418 else
7422 }
7428 else
7430 }
7433 }
7447 }
7449 tree
7451 {
7455 /* In switch statements break is sometimes stylistically used after
7456 a return statement. This can lead to spurious warnings about
7457 control reaching the end of a non-void function when it is
7458 inlined. Note that we are calling block_may_fallthru with
7459 language specific tree nodes; this works because
7460 block_may_fallthru returns true when given something it does not
7461 understand. */
7465 {
7468 }
7470 ;
7472 {
7476 else
7487 }
7493 }
7495 /* A helper routine for c_process_expr_stmt and c_finish_stmt_expr. */
7497 static void
7499 {
7501 ;
7503 {
7507 }
7508 else
7510 }
7512 /* Process an expression as if it were a complete statement. Emit
7513 diagnostics, but do not call ADD_STMT. */
7515 tree
7517 {
7529 /* If we're not processing a statement expression, warn about unused values.
7530 Warnings for statement expressions will be emitted later, once we figure
7531 out which is the result. */
7536 /* If the expression is not of a type to which we cannot assign a line
7537 number, wrap the thing in a no-op NOP_EXPR. */
7545 }
7547 /* Emit an expression as a statement. */
7549 tree
7551 {
7554 else
7556 }
7558 /* Do the opposite and emit a statement as an expression. To begin,
7559 create a new binding level and return it. */
7561 tree
7563 {
7564 tree ret;
7568 /* We must force a BLOCK for this level so that, if it is not expanded
7569 later, there is a way to turn off the entire subtree of blocks that
7570 are contained in it. */
7574 {
7577 }
7581 {
7583 }
7590 /* Mark the current statement list as belonging to a statement list. */
7594 }
7596 tree
7598 {
7605 {
7608 }
7609 /* It is no longer possible to jump to labels defined within this
7610 statement expression. */
7614 {
7616 }
7617 /* It is again possible to define labels with a goto just outside
7618 this statement expression. */
7622 {
7625 }
7628 else
7633 /* Locate the last statement in BODY. See c_end_compound_stmt
7634 about always returning a BIND_EXPR. */
7638 continue_searching:
7640 {
7641 tree_stmt_iterator i;
7643 /* This can happen with degenerate cases like ({ }). No value. */
7647 /* If we're supposed to generate side effects warnings, process
7648 all of the statements except the last. */
7650 {
7653 }
7654 else
7658 }
7660 /* If the end of the list is exception related, then the list was split
7661 by a call to push_cleanup. Continue searching. */
7664 {
7668 }
7670 /* In the case that the BIND_EXPR is not necessary, return the
7671 expression out from inside it. */
7675 {
7676 /* Do not warn if the return value of a statement expression is
7677 unused. */
7681 }
7683 /* Extract the type of said expression. */
7686 /* If we're not returning a value at all, then the BIND_EXPR that
7687 we already have is a fine expression to return. */
7691 /* Now that we've located the expression containing the value, it seems
7692 silly to make voidify_wrapper_expr repeat the process. Create a
7693 temporary of the appropriate type and stick it in a TARGET_EXPR. */
7696 /* Unwrap a no-op NOP_EXPR as added by c_finish_expr_stmt. This avoids
7697 tree_expr_nonnegative_p giving up immediately. */
7707 }
7709 /* Begin the scope of an identifier of variably modified type, scope
7710 number SCOPE. Jumping from outside this scope to inside it is not
7711 permitted. */
7713 void
7715 {
7721 /* At file_scope, we don't have to do any processing. */
7730 {
7732 }
7739 }
7741 /* End a scope which may contain identifiers of variably modified
7742 type, scope number SCOPE. */
7744 void
7746 {
7751 /* We may have a number of nested scopes of identifiers with
7752 variably modified type, all at this depth. Pop each in turn. */
7754 {
7757 /* It is no longer possible to jump to labels defined within this
7758 scope. */
7762 {
7764 }
7765 /* It is again possible to define labels with a goto just outside
7766 this scope. */
7770 {
7773 }
7776 else
7780 }
7781 }
7782 \f
7783 /* Begin and end compound statements. This is as simple as pushing
7784 and popping new statement lists from the tree. */
7786 tree
7788 {
7793 }
7795 tree
7797 {
7801 {
7805 }
7810 /* If this compound statement is nested immediately inside a statement
7811 expression, then force a BIND_EXPR to be created. Otherwise we'll
7812 do the wrong thing for ({ { 1; } }) or ({ 1; { } }). In particular,
7813 STATEMENT_LISTs merge, and thus we can lose track of what statement
7814 was really last. */
7818 {
7821 }
7824 }
7826 /* Queue a cleanup. CLEANUP is an expression/statement to be executed
7827 when the current scope is exited. EH_ONLY is true when this is not
7828 meant to apply to normal control flow transfer. */
7830 void
7832 {
7844 }
7845 \f
7846 /* Build a binary-operation expression without default conversions.
7847 CODE is the kind of expression to build.
7848 This function differs from `build' in several ways:
7849 the data type of the result is computed and recorded in it,
7850 warnings are generated if arg data types are invalid,
7851 special handling for addition and subtraction of pointers is known,
7852 and some optimization is done (operations on narrow ints
7853 are done in the narrower type when that gives the same result).
7854 Constant folding is also done before the result is returned.
7856 Note that the operands will never have enumeral types, or function
7857 or array types, because either they will have the default conversions
7858 performed or they have both just been converted to some other type in which
7859 the arithmetic is to be done. */
7861 tree
7864 {
7870 /* Expression code to give to the expression when it is built.
7871 Normally this is CODE, which is what the caller asked for,
7872 but in some special cases we change it. */
7875 /* Data type in which the computation is to be performed.
7876 In the simplest cases this is the common type of the arguments. */
7879 /* Nonzero means operands have already been type-converted
7880 in whatever way is necessary.
7881 Zero means they need to be converted to RESULT_TYPE. */
7884 /* Nonzero means create the expression with this type, rather than
7885 RESULT_TYPE. */
7888 /* Nonzero means after finally constructing the expression
7889 convert it to this type. */
7892 /* Nonzero if this is an operation like MIN or MAX which can
7893 safely be computed in short if both args are promoted shorts.
7894 Also implies COMMON.
7895 -1 indicates a bitwise operation; this makes a difference
7896 in the exact conditions for when it is safe to do the operation
7897 in a narrower mode. */
7900 /* Nonzero if this is a comparison operation;
7901 if both args are promoted shorts, compare the original shorts.
7902 Also implies COMMON. */
7905 /* Nonzero if this is a right-shift operation, which can be computed on the
7906 original short and then promoted if the operand is a promoted short. */
7909 /* Nonzero means set RESULT_TYPE to the common type of the args. */
7912 /* True means types are compatible as far as ObjC is concerned. */
7916 {
7919 }
7920 else
7921 {
7924 }
7929 /* The expression codes of the data types of the arguments tell us
7930 whether the arguments are integers, floating, pointers, etc. */
7934 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
7938 /* If an error was already reported for one of the arguments,
7939 avoid reporting another error. */
7946 {
7949 }
7954 {
7956 /* Handle the pointer + int case. */
7961 else
7966 /* Subtraction of two similar pointers.
7967 We must subtract them as integers, then divide by object size. */
7971 /* Handle pointer minus int. Just like pointer plus int. */
7974 else
7995 {
8006 else
8007 /* Although it would be tempting to shorten always here, that
8008 loses on some targets, since the modulo instruction is
8009 undefined if the quotient can't be represented in the
8010 computation mode. We shorten only if unsigned or if
8011 dividing by something we know != -1. */
8016 }
8024 /* Allow vector types which are not floating point types. */
8037 {
8038 /* Although it would be tempting to shorten always here, that loses
8039 on some targets, since the modulo instruction is undefined if the
8040 quotient can't be represented in the computation mode. We shorten
8041 only if unsigned or if dividing by something we know != -1. */
8046 }
8060 {
8061 /* Result of these operations is always an int,
8062 but that does not mean the operands should be
8063 converted to ints! */
8068 }
8071 /* Shift operations: result has same type as first operand;
8072 always convert second operand to int.
8073 Also set SHORT_SHIFT if shifting rightward. */
8078 {
8080 {
8083 else
8084 {
8090 }
8091 }
8093 /* Use the type of the value to be shifted. */
8095 /* Convert the shift-count to an integer, regardless of size
8096 of value being shifted. */
8099 /* Avoid converting op1 to result_type later. */
8101 }
8107 {
8109 {
8115 }
8117 /* Use the type of the value to be shifted. */
8119 /* Convert the shift-count to an integer, regardless of size
8120 of value being shifted. */
8123 /* Avoid converting op1 to result_type later. */
8125 }
8133 /* Result of comparison is always int,
8134 but don't convert the args to int! */
8142 {
8145 /* Anything compares with void *. void * compares with anything.
8146 Otherwise, the targets must be compatible
8147 and both must be object or both incomplete. */
8151 {
8152 /* op0 != orig_op0 detects the case of something
8153 whose value is 0 but which isn't a valid null ptr const. */
8158 }
8160 {
8165 }
8166 else
8167 /* Avoid warning about the volatile ObjC EH puts on decls. */
8173 }
8175 {
8181 }
8183 {
8189 }
8191 {
8194 }
8196 {
8199 }
8213 {
8215 {
8223 }
8224 else
8225 {
8228 }
8229 }
8231 {
8235 }
8237 {
8241 }
8243 {
8246 }
8248 {
8251 }
8256 }
8265 {
8268 }
8272 &&
8275 {
8279 {
8283 }
8285 /* For certain operations (which identify themselves by shorten != 0)
8286 if both args were extended from the same smaller type,
8287 do the arithmetic in that type and then extend.
8289 shorten !=0 and !=1 indicates a bitwise operation.
8290 For them, this optimization is safe only if
8291 both args are zero-extended or both are sign-extended.
8292 Otherwise, we might change the result.
8293 Eg, (short)-1 | (unsigned short)-1 is (int)-1
8294 but calculated in (unsigned short) it would be (unsigned short)-1. */
8297 {
8301 tree type;
8303 /* Cast OP0 and OP1 to RESULT_TYPE. Doing so prevents
8304 excessive narrowing when we call get_narrower below. For
8305 example, suppose that OP0 is of unsigned int extended
8306 from signed char and that RESULT_TYPE is long long int.
8307 If we explicitly cast OP0 to RESULT_TYPE, OP0 would look
8308 like
8310 (long long int) (unsigned int) signed_char
8312 which get_narrower would narrow down to
8314 (unsigned int) signed char
8316 If we do not cast OP0 first, get_narrower would return
8317 signed_char, which is inconsistent with the case of the
8318 explicit cast. */
8325 /* UNS is 1 if the operation to be done is an unsigned one. */
8330 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
8331 but it *requires* conversion to FINAL_TYPE. */
8342 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
8344 /* For bitwise operations, signedness of nominal type
8345 does not matter. Consider only how operands were extended. */
8349 /* Note that in all three cases below we refrain from optimizing
8350 an unsigned operation on sign-extended args.
8351 That would not be valid. */
8353 /* Both args variable: if both extended in same way
8354 from same width, do it in that width.
8355 Do it unsigned if args were zero-extended. */
8362 result_type
8363 = c_common_signed_or_unsigned_type
8369 && (type
8379 && (type
8385 }
8387 /* Shifts can be shortened if shifting right. */
8390 {
8400 /* We can shorten only if the shift count is less than the
8401 number of bits in the smaller type size. */
8403 /* We cannot drop an unsigned shift after sign-extension. */
8405 {
8406 /* Do an unsigned shift if the operand was zero-extended. */
8407 result_type
8410 /* Convert value-to-be-shifted to that type. */
8414 }
8415 }
8417 /* Comparison operations are shortened too but differently.
8418 They identify themselves by setting short_compare = 1. */
8421 {
8422 /* Don't write &op0, etc., because that would prevent op0
8423 from being kept in a register.
8424 Instead, make copies of the our local variables and
8425 pass the copies by reference, then copy them back afterward. */
8428 tree val
8439 {
8451 /* Give warnings for comparisons between signed and unsigned
8452 quantities that may fail.
8454 Do the checking based on the original operand trees, so that
8455 casts will be considered, but default promotions won't be.
8457 Do not warn if the comparison is being done in a signed type,
8458 since the signed type will only be chosen if it can represent
8459 all the values of the unsigned type. */
8462 /* Do not warn if both operands are the same signedness. */
8465 else
8466 {
8472 else
8475 /* Do not warn if the signed quantity is an
8476 unsuffixed integer literal (or some static
8477 constant expression involving such literals or a
8478 conditional expression involving such literals)
8479 and it is non-negative. */
8482 /* Do not warn if the comparison is an equality operation,
8483 the unsigned quantity is an integral constant, and it
8484 would fit in the result if the result were signed. */
8487 && int_fits_type_p
8490 /* Do not warn if the unsigned quantity is an enumeration
8491 constant and its maximum value would fit in the result
8492 if the result were signed. */
8495 && int_fits_type_p
8499 else
8501 }
8503 /* Warn if two unsigned values are being compared in a size
8504 larger than their original size, and one (and only one) is the
8505 result of a `~' operator. This comparison will always fail.
8507 Also warn if one operand is a constant, and the constant
8508 does not have all bits set that are set in the ~ operand
8509 when it is extended. */
8513 {
8517 else
8522 {
8523 tree primop;
8528 {
8532 }
8533 else
8534 {
8538 }
8543 {
8547 }
8548 }
8555 }
8556 }
8557 }
8558 }
8560 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
8561 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
8562 Then the expression will be built.
8563 It will be given type FINAL_TYPE if that is nonzero;
8564 otherwise, it will be given type RESULT_TYPE. */
8567 {
8570 }
8573 {
8579 /* This can happen if one operand has a vector type, and the other
8580 has a different type. */
8583 }
8588 {
8589 /* Treat expressions in initializers specially as they can't trap. */
8591 build_type,
8599 }
8600 }
8603 /* Convert EXPR to be a truth-value, validating its type for this
8604 purpose. */
8606 tree
8608 {
8610 {
8628 }
8630 /* ??? Should we also give an error for void and vectors rather than
8631 leaving those to give errors later? */
8633 }
8634 \f
8636 /* Convert EXPR to a contained DECL, updating *TC, *TI and *SE as
8637 required. */
8639 tree
8642 {
8644 {
8646 /* Executing a compound literal inside a function reinitializes
8647 it. */
8651 }
8652 else
8654 }
8655 \f
8656 /* Like c_begin_compound_stmt, except force the retention of the BLOCK. */
8658 tree
8660 {
8661 tree block;
8667 }
8669 tree
8671 {
8672 tree stmt;
8682 }
8684 /* For all elements of CLAUSES, validate them vs OpenMP constraints.
8685 Remove any elements from the list that are invalid. */
8687 tree
8689 {
8700 {
8706 {
8724 {
8727 }
8729 {
8734 {
8756 }
8758 {
8762 }
8763 }
8774 {
8777 }
8780 check_dup_generic:
8783 {
8786 }
8790 {
8793 }
8794 else
8804 {
8807 }
8810 {
8813 }
8814 else
8824 {
8827 }
8830 {
8833 }
8834 else
8849 }
8852 {
8856 {
8860 }
8863 {
8869 {
8880 }
8882 {
8886 }
8887 }
8888 }
8892 else
8894 }
8898 }