| blob | 6d94cabdf99e4cdb3079f7bfbbc32f2ddef4a9da |
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 {
1243 {
1246 }
1253 {
1256 }
1257 }
1259 {
1262 }
1265 {
1270 {
1278 {
1281 }
1292 }
1294 {
1297 }
1298 }
1301 }
1304 {
1310 {
1325 }
1328 else
1331 }
1335 }
1336 }
1338 /* Return 1 if two function types F1 and F2 are compatible.
1339 If either type specifies no argument types,
1340 the other must specify a fixed number of self-promoting arg types.
1341 Otherwise, if one type specifies only the number of arguments,
1342 the other must specify that number of self-promoting arg types.
1343 Otherwise, the argument types must match. */
1345 static int
1347 {
1349 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
1357 /* 'volatile' qualifiers on a function's return type used to mean
1358 the function is noreturn. */
1374 /* An unspecified parmlist matches any specified parmlist
1375 whose argument types don't need default promotions. */
1378 {
1381 /* If one of these types comes from a non-prototype fn definition,
1382 compare that with the other type's arglist.
1383 If they don't match, ask for a warning (but no error). */
1388 }
1390 {
1397 }
1399 /* Both types have argument lists: compare them and propagate results. */
1402 }
1404 /* Check two lists of types for compatibility,
1405 returning 0 for incompatible, 1 for compatible,
1406 or 2 for compatible with warning. */
1408 static int
1410 {
1411 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
1416 {
1420 /* If one list is shorter than the other,
1421 they fail to match. */
1430 /* A null pointer instead of a type
1431 means there is supposed to be an argument
1432 but nothing is specified about what type it has.
1433 So match anything that self-promotes. */
1435 {
1438 }
1440 {
1443 }
1444 /* If one of the lists has an error marker, ignore this arg. */
1447 ;
1449 {
1450 /* Allow wait (union {union wait *u; int *i} *)
1451 and wait (union wait *) to be compatible. */
1458 {
1459 tree memb;
1462 {
1469 }
1472 }
1479 {
1480 tree memb;
1483 {
1490 }
1493 }
1494 else
1496 }
1498 /* comptypes said ok, but record if it said to warn. */
1504 }
1505 }
1506 \f
1507 /* Compute the size to increment a pointer by. */
1509 static tree
1511 {
1518 {
1521 }
1523 /* Convert in case a char is more than one unit. */
1527 }
1528 \f
1529 /* Return either DECL or its known constant value (if it has one). */
1531 tree
1533 {
1535 in a place where a variable is invalid. Note that DECL_INITIAL
1536 isn't valid for a PARM_DECL. */
1543 /* This is invalid if initial value is not constant.
1544 If it has either a function call, a memory reference,
1545 or a variable, then re-evaluating it could give different results. */
1547 /* Check for cases where this is sub-optimal, even though valid. */
1551 }
1553 /* Return either DECL or its known constant value (if it has one), but
1554 return DECL if pedantic or DECL has mode BLKmode. This is for
1555 bug-compatibility with the old behavior of decl_constant_value
1556 (before GCC 3.0); every use of this function is a bug and it should
1557 be removed before GCC 3.1. It is not appropriate to use pedantic
1558 in a way that affects optimization, and BLKmode is probably not the
1559 right test for avoiding misoptimizations either. */
1561 static tree
1563 {
1564 tree ret;
1570 /* Avoid unwanted tree sharing between the initializer and current
1571 function's body where the tree can be modified e.g. by the
1572 gimplifier. */
1576 }
1578 /* Convert the array expression EXP to a pointer. */
1579 static tree
1581 {
1584 tree adr;
1586 tree ptrtype;
1601 {
1602 /* We are making an ADDR_EXPR of ptrtype. This is a valid
1603 ADDR_EXPR because it's the best way of representing what
1604 happens in C when we take the address of an array and place
1605 it in a pointer to the element type. */
1611 }
1613 /* This way is better for a COMPONENT_REF since it can
1614 simplify the offset for a component. */
1617 }
1619 /* Convert the function expression EXP to a pointer. */
1620 static tree
1622 {
1633 }
1635 /* Perform the default conversion of arrays and functions to pointers.
1636 Return the result of converting EXP. For any other expression, just
1637 return EXP after removing NOPs. */
1639 struct c_expr
1641 {
1647 {
1649 {
1657 {
1661 }
1668 {
1669 /* Before C99, non-lvalue arrays do not decay to pointers.
1670 Normally, using such an array would be invalid; but it can
1671 be used correctly inside sizeof or as a statement expression.
1672 Thus, do not give an error here; an error will result later. */
1674 }
1677 }
1687 }
1690 }
1693 /* EXP is an expression of integer type. Apply the integer promotions
1694 to it and return the promoted value. */
1696 tree
1698 {
1704 /* Normally convert enums to int,
1705 but convert wide enums to something wider. */
1707 {
1715 }
1717 /* ??? This should no longer be needed now bit-fields have their
1718 proper types. */
1721 /* If it's thinner than an int, promote it like a
1722 c_promoting_integer_type_p, otherwise leave it alone. */
1728 {
1729 /* Preserve unsignedness if not really getting any wider. */
1735 }
1738 }
1741 /* Perform default promotions for C data used in expressions.
1742 Enumeral types or short or char are converted to int.
1743 In addition, manifest constants symbols are replaced by their values. */
1745 tree
1747 {
1748 tree orig_exp;
1752 /* Functions and arrays have been converted during parsing. */
1757 /* Constants can be used directly unless they're not loadable. */
1761 /* Replace a nonvolatile const static variable with its value unless
1762 it is an array, in which case we must be sure that taking the
1763 address of the array produces consistent results. */
1765 {
1768 }
1770 /* Strip no-op conversions. */
1778 {
1781 }
1791 }
1792 \f
1793 /* Look up COMPONENT in a structure or union DECL.
1795 If the component name is not found, returns NULL_TREE. Otherwise,
1796 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL
1797 stepping down the chain to the component, which is in the last
1798 TREE_VALUE of the list. Normally the list is of length one, but if
1799 the component is embedded within (nested) anonymous structures or
1800 unions, the list steps down the chain to the component. */
1802 static tree
1804 {
1806 tree field;
1808 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers
1809 to the field elements. Use a binary search on this array to quickly
1810 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC
1811 will always be set for structures which have many elements. */
1814 {
1822 {
1827 {
1828 /* Step through all anon unions in linear fashion. */
1830 {
1834 {
1839 }
1840 }
1842 /* Entire record is only anon unions. */
1846 /* Restart the binary search, with new lower bound. */
1848 }
1854 else
1856 }
1862 }
1863 else
1864 {
1866 {
1870 {
1875 }
1879 }
1883 }
1886 }
1888 /* Make an expression to refer to the COMPONENT field of
1889 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */
1891 tree
1893 {
1897 tree ref;
1902 /* See if there is a field or component with name COMPONENT. */
1905 {
1907 {
1910 }
1915 {
1918 }
1920 /* Chain the COMPONENT_REFs if necessary down to the FIELD.
1921 This might be better solved in future the way the C++ front
1922 end does it - by giving the anonymous entities each a
1923 separate name and type, and then have build_component_ref
1924 recursively call itself. We can't do that here. */
1925 do
1926 {
1929 tree subtype;
1939 NULL_TREE);
1951 }
1955 }
1958 component);
1961 }
1962 \f
1963 /* Given an expression PTR for a pointer, return an expression
1964 for the value pointed to.
1965 ERRORSTRING is the name of the operator to appear in error messages. */
1967 tree
1969 {
1974 {
1978 {
1979 /* If a warning is issued, mark it to avoid duplicates from
1980 the backend. This only needs to be done at
1981 warn_strict_aliasing > 2. */
1986 }
1992 else
1993 {
1995 tree ref;
2000 {
2003 }
2007 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2008 so that we get the proper error message if the result is used
2009 to assign to. Also, &* is supposed to be a no-op.
2010 And ANSI C seems to specify that the type of the result
2011 should be the const type. */
2012 /* A de-reference of a pointer to const is not a const. It is valid
2013 to change it via some other pointer. */
2019 }
2020 }
2024 }
2026 /* This handles expressions of the form "a[i]", which denotes
2027 an array reference.
2029 This is logically equivalent in C to *(a+i), but we may do it differently.
2030 If A is a variable or a member, we generate a primitive ARRAY_REF.
2031 This avoids forcing the array out of registers, and can work on
2032 arrays that are not lvalues (for example, members of structures returned
2033 by functions). */
2035 tree
2037 {
2045 {
2046 tree temp;
2049 {
2052 }
2057 }
2060 {
2063 }
2066 {
2069 }
2071 /* ??? Existing practice has been to warn only when the char
2072 index is syntactically the index, not for char[array]. */
2076 /* Apply default promotions *after* noticing character types. */
2082 {
2085 /* An array that is indexed by a non-constant
2086 cannot be stored in a register; we must be able to do
2087 address arithmetic on its address.
2088 Likewise an array of elements of variable size. */
2092 {
2095 }
2096 /* An array that is indexed by a constant value which is not within
2097 the array bounds cannot be stored in a register either; because we
2098 would get a crash in store_bit_field/extract_bit_field when trying
2099 to access a non-existent part of the register. */
2103 {
2106 }
2109 {
2117 }
2121 /* Array ref is const/volatile if the array elements are
2122 or if the array is. */
2131 /* This was added by rms on 16 Nov 91.
2132 It fixes vol struct foo *a; a->elts[1]
2133 in an inline function.
2134 Hope it doesn't break something else. */
2137 }
2138 else
2139 {
2150 }
2151 }
2152 \f
2153 /* Build an external reference to identifier ID. FUN indicates
2154 whether this will be used for a function call. LOC is the source
2155 location of the identifier. */
2156 tree
2158 {
2159 tree ref;
2162 /* In Objective-C, an instance variable (ivar) may be preferred to
2163 whatever lookup_name() found. */
2169 /* Implicit function declaration. */
2172 /* Don't complain about something that's already been
2173 complained about. */
2175 else
2176 {
2179 }
2187 /* Recursive call does not count as usage. */
2189 {
2193 }
2196 {
2203 }
2206 {
2211 }
2217 {
2222 }
2223 /* C99 6.7.4p3: An inline definition of a function with external
2224 linkage ... shall not contain a reference to an identifier with
2225 internal linkage. */
2236 }
2238 /* Record details of decls possibly used inside sizeof or typeof. */
2239 struct maybe_used_decl
2240 {
2241 /* The decl. */
2242 tree decl;
2243 /* The level seen at (in_sizeof + in_typeof). */
2245 /* The next one at this level or above, or NULL. */
2247 };
2251 /* Record that DECL, an undefined static function reference seen
2252 inside sizeof or typeof, might be used if the operand of sizeof is
2253 a VLA type or the operand of typeof is a variably modified
2254 type. */
2256 static void
2258 {
2264 }
2266 /* Pop the stack of decls possibly used inside sizeof or typeof. If
2267 USED is false, just discard them. If it is true, mark them used
2268 (if no longer inside sizeof or typeof) or move them to the next
2269 level up (if still inside sizeof or typeof). */
2271 void
2273 {
2277 {
2279 {
2282 else
2284 }
2286 }
2289 }
2291 /* Return the result of sizeof applied to EXPR. */
2293 struct c_expr
2295 {
2298 {
2302 }
2303 else
2304 {
2308 {
2309 /* sizeof is evaluated when given a vla (C99 6.5.3.4p2). */
2311 }
2313 }
2315 }
2317 /* Return the result of sizeof applied to T, a structure for the type
2318 name passed to sizeof (rather than the type itself). */
2320 struct c_expr
2322 {
2323 tree type;
2331 }
2333 /* Build a function call to function FUNCTION with parameters PARAMS.
2334 PARAMS is a list--a chain of TREE_LIST nodes--in which the
2335 TREE_VALUE of each node is a parameter-expression.
2336 FUNCTION's data type may be a function type or a pointer-to-function. */
2338 tree
2340 {
2343 tree tem;
2348 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2351 /* Convert anything with function type to a pointer-to-function. */
2353 {
2354 /* Implement type-directed function overloading for builtins.
2355 resolve_overloaded_builtin and targetm.resolve_overloaded_builtin
2356 handle all the type checking. The result is a complete expression
2357 that implements this function call. */
2364 }
2368 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2369 expressions, like those used for ObjC messenger dispatches. */
2379 {
2382 }
2387 /* fntype now gets the type of function pointed to. */
2390 /* Check that the function is called through a compatible prototype.
2391 If it is not, replace the call by a trap, wrapped up in a compound
2392 expression if necessary. This has the nice side-effect to prevent
2393 the tree-inliner from generating invalid assignment trees which may
2394 blow up in the RTL expander later. */
2400 {
2403 NULL_TREE);
2405 /* This situation leads to run-time undefined behavior. We can't,
2406 therefore, simply error unless we can prove that all possible
2407 executions of the program must execute the code. */
2410 /* We can, however, treat "undefined" any way we please.
2411 Call abort to encourage the user to fix the program. */
2416 else
2417 {
2418 tree rhs;
2423 else
2427 }
2428 }
2430 /* Convert the parameters to the types declared in the
2431 function prototype, or apply default promotions. */
2440 /* Check that the arguments to the function are valid. */
2446 {
2453 }
2454 else
2461 }
2462 \f
2463 /* Convert the argument expressions in the list VALUES
2464 to the types in the list TYPELIST. The resulting arguments are
2465 stored in the array ARGARRAY which has size NARGS.
2467 If TYPELIST is exhausted, or when an element has NULL as its type,
2468 perform the default conversions.
2470 PARMLIST is the chain of parm decls for the function being called.
2471 It may be 0, if that info is not available.
2472 It is used only for generating error messages.
2474 FUNCTION is a tree for the called function. It is used only for
2475 error messages, where it is formatted with %qE.
2477 This is also where warnings about wrong number of args are generated.
2479 VALUES is a chain of TREE_LIST nodes with the elements of the list
2480 in the TREE_VALUE slots of those nodes.
2482 Returns the actual number of arguments processed (which may be less
2483 than NARGS in some error situations), or -1 on failure. */
2485 static int
2488 {
2493 tree selector;
2495 /* Change pointer to function to the function itself for
2496 diagnostics. */
2501 /* Handle an ObjC selector specially for diagnostics. */
2504 /* Scan the given expressions and types, producing individual
2505 converted arguments and storing them in ARGARRAY. */
2508 valtail;
2510 {
2518 {
2521 }
2524 {
2527 }
2534 {
2535 /* Formal parm type is specified by a function prototype. */
2536 tree parmval;
2539 {
2542 }
2543 else
2544 {
2545 /* Optionally warn about conversions that
2546 differ from the default conversions. */
2548 {
2581 /* ??? At some point, messages should be written about
2582 conversions between complex types, but that's too messy
2583 to do now. */
2586 {
2587 /* Warn if any argument is passed as `float',
2588 since without a prototype it would be `double'. */
2595 /* Warn if mismatch between argument and prototype
2596 for decimal float types. Warn of conversions with
2597 binary float types and of precision narrowing due to
2598 prototype. */
2606 && (formal_prec
2610 != dfloat64_type_node
2620 }
2621 /* Detect integer changing in width or signedness.
2622 These warnings are only activated with
2623 -Wtraditional-conversion, not with -Wtraditional. */
2626 {
2633 /* No warning if function asks for enum
2634 and the actual arg is that enum type. */
2635 ;
2641 ;
2642 /* Don't complain if the formal parameter type
2643 is an enum, because we can't tell now whether
2644 the value was an enum--even the same enum. */
2646 ;
2649 /* Change in signedness doesn't matter
2650 if a constant value is unaffected. */
2651 ;
2652 /* If the value is extended from a narrower
2653 unsigned type, it doesn't matter whether we
2654 pass it as signed or unsigned; the value
2655 certainly is the same either way. */
2658 ;
2663 else
2666 }
2667 }
2677 }
2679 }
2684 {
2687 else
2688 /* Convert `float' to `double'. */
2690 }
2693 {
2696 }
2697 else
2698 /* Convert `short' and `char' to full-size `int'. */
2703 }
2708 {
2711 }
2714 }
2715 \f
2716 /* This is the entry point used by the parser to build unary operators
2717 in the input. CODE, a tree_code, specifies the unary operator, and
2718 ARG is the operand. For unary plus, the C parser currently uses
2719 CONVERT_EXPR for code. */
2721 struct c_expr
2723 {
2733 }
2735 /* This is the entry point used by the parser to build binary operators
2736 in the input. CODE, a tree_code, specifies the binary operator, and
2737 ARG1 and ARG2 are the operands. In addition to constructing the
2738 expression, we check for operands that were written with other binary
2739 operators in a way that is likely to confuse the user. */
2741 struct c_expr
2744 {
2756 /* Check for cases such as x+y<<z which users are likely
2757 to misinterpret. */
2764 /* Warn about comparisons against string literals, with the exception
2765 of testing for equality or inequality of a string literal with NULL. */
2767 {
2771 }
2782 }
2783 \f
2784 /* Return a tree for the difference of pointers OP0 and OP1.
2785 The resulting tree has type int. */
2787 static tree
2789 {
2797 {
2802 }
2804 /* If the conversion to ptrdiff_type does anything like widening or
2805 converting a partial to an integral mode, we get a convert_expression
2806 that is in the way to do any simplifications.
2807 (fold-const.c doesn't know that the extra bits won't be needed.
2808 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2809 different mode in place.)
2810 So first try to find a common term here 'by hand'; we want to cover
2811 at least the cases that occur in legal static initializers. */
2816 else
2822 else
2826 {
2829 }
2830 else
2834 {
2837 }
2838 else
2842 {
2845 }
2848 /* First do the subtraction as integers;
2849 then drop through to build the divide operator.
2850 Do not do default conversions on the minus operator
2851 in case restype is a short type. */
2855 /* This generates an error if op1 is pointer to incomplete type. */
2859 /* This generates an error if op0 is pointer to incomplete type. */
2862 /* Divide by the size, in easiest possible way. */
2864 }
2865 \f
2866 /* Construct and perhaps optimize a tree representation
2867 for a unary operation. CODE, a tree_code, specifies the operation
2868 and XARG is the operand.
2869 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2870 the default promotions (such as from short to int).
2871 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2872 allows non-lvalues; this is only used to handle conversion of non-lvalue
2873 arrays to pointers in C99. */
2875 tree
2877 {
2878 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2882 tree val;
2897 {
2900 }
2903 {
2905 /* This is used for unary plus, because a CONVERT_EXPR
2906 is enough to prevent anybody from looking inside for
2907 associativity, but won't generate any code. */
2911 {
2914 }
2924 {
2927 }
2933 /* ~ works on integer types and non float vectors. */
2937 {
2940 }
2942 {
2948 }
2949 else
2950 {
2953 }
2958 {
2961 }
2967 /* Conjugating a real value is a no-op, but allow it anyway. */
2970 {
2973 }
2982 {
2985 }
2994 else
3002 else
3010 /* Increment or decrement the real part of the value,
3011 and don't change the imaginary part. */
3013 {
3028 }
3030 /* Report invalid types. */
3034 {
3037 else
3041 }
3043 {
3044 tree inc;
3050 /* Compute the increment. */
3053 {
3054 /* If pointer target is an undefined struct,
3055 we just cannot know how to do the arithmetic. */
3057 {
3060 else
3062 }
3066 {
3069 else
3071 }
3075 }
3077 {
3078 /* For signed fract types, we invert ++ to -- or
3079 -- to ++, and change inc from 1 to -1, because
3080 it is not possible to represent 1 in signed fract constants.
3081 For unsigned fract types, the result always overflows and
3082 we get an undefined (original) or the maximum value. */
3094 }
3095 else
3096 {
3099 }
3101 /* Complain about anything else that is not a true lvalue. */
3104 ? lv_increment
3108 /* Report a read-only lvalue. */
3110 {
3116 }
3120 else
3127 }
3130 /* Note that this operation never does default_conversion. */
3132 /* Let &* cancel out to simplify resulting code. */
3134 {
3135 /* Don't let this be an lvalue. */
3139 }
3141 /* For &x[y], return x+y */
3143 {
3152 }
3154 /* Anything not already handled and not a true memory reference
3155 or a non-lvalue array is an error. */
3160 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
3163 /* If the lvalue is const or volatile, merge that into the type
3164 to which the address will point. Note that you can't get a
3165 restricted pointer by taking the address of something, so we
3166 only have to deal with `const' and `volatile' here. */
3181 /* ??? Cope with user tricks that amount to offsetof. Delete this
3182 when we have proper support for integer constant expressions. */
3186 {
3191 }
3199 }
3205 }
3207 /* Return nonzero if REF is an lvalue valid for this language.
3208 Lvalues can be assigned, unless their type has TYPE_READONLY.
3209 Lvalues can have their address taken, unless they have C_DECL_REGISTER. */
3211 static int
3213 {
3217 {
3241 }
3242 }
3243 \f
3244 /* Give an error for storing in something that is 'const'. */
3246 static void
3248 {
3251 /* Using this macro rather than (for example) arrays of messages
3252 ensures that all the format strings are checked at compile
3253 time. */
3254 #define READONLY_MSG(A, I, D, AS) (use == lv_assign ? (A) \
3255 : (use == lv_increment ? (I) \
3256 : (use == lv_decrement ? (D) : (AS))))
3258 {
3261 else
3267 }
3273 arg);
3274 else
3279 arg);
3280 }
3283 /* Return nonzero if REF is an lvalue valid for this language;
3284 otherwise, print an error message and return zero. USE says
3285 how the lvalue is being used and so selects the error message. */
3287 static int
3289 {
3296 }
3297 \f
3298 /* Mark EXP saying that we need to be able to take the
3299 address of it; it should not be allocated in a register.
3300 Returns true if successful. */
3302 bool
3304 {
3309 {
3312 {
3313 error
3316 }
3318 /* ... fall through ... */
3338 {
3340 {
3341 error
3344 }
3346 }
3348 {
3351 else
3354 }
3356 /* drops in */
3359 /* drops out */
3362 }
3363 }
3364 \f
3365 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
3367 tree
3369 {
3370 tree type1;
3371 tree type2;
3377 /* Promote both alternatives. */
3394 /* C90 does not permit non-lvalue arrays in conditional expressions.
3395 In C99 they will be pointers by now. */
3397 {
3400 }
3402 /* Quickly detect the usual case where op1 and op2 have the same type
3403 after promotion. */
3405 {
3408 else
3410 }
3415 {
3418 /* If -Wsign-compare, warn here if type1 and type2 have
3419 different signedness. We'll promote the signed to unsigned
3420 and later code won't know it used to be different.
3421 Do this check on the original types, so that explicit casts
3422 will be considered, but default promotions won't. */
3424 {
3429 {
3432 /* Do not warn if the result type is signed, since the
3433 signed type will only be chosen if it can represent
3434 all the values of the unsigned type. */
3437 /* Do not warn if the signed quantity is an unsuffixed
3438 integer literal (or some static constant expression
3439 involving such literals) and it is non-negative. */
3442 || (unsigned_op1
3445 else
3447 }
3448 }
3449 }
3451 {
3455 }
3457 {
3465 {
3471 }
3473 {
3479 }
3480 else
3481 {
3484 }
3485 }
3487 {
3490 else
3491 {
3493 }
3495 }
3497 {
3500 else
3501 {
3503 }
3505 }
3508 {
3511 else
3512 {
3515 }
3516 }
3518 /* Merge const and volatile flags of the incoming types. */
3519 result_type
3530 }
3531 \f
3532 /* Return a compound expression that performs two expressions and
3533 returns the value of the second of them. */
3535 tree
3537 {
3539 {
3540 /* The left-hand operand of a comma expression is like an expression
3541 statement: with -Wunused, we should warn if it doesn't have
3542 any side-effects, unless it was explicitly cast to (void). */
3544 {
3554 else
3557 }
3558 }
3560 /* With -Wunused, we should also warn if the left-hand operand does have
3561 side-effects, but computes a value which is not used. For example, in
3562 `foo() + bar(), baz()' the result of the `+' operator is not used,
3563 so we should issue a warning. */
3571 }
3573 /* Build an expression representing a cast to type TYPE of expression EXPR. */
3575 tree
3577 {
3583 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
3584 only in <protocol> qualifications. But when constructing cast expressions,
3585 the protocols do matter and must be kept around. */
3592 {
3595 }
3598 {
3601 }
3604 {
3608 }
3611 {
3613 {
3617 }
3618 }
3620 {
3621 tree field;
3629 {
3630 tree t;
3640 }
3643 }
3644 else
3645 {
3653 /* Optionally warn about potentially worrisome casts. */
3658 {
3664 /* Check that the qualifiers on IN_TYPE are a superset of
3665 the qualifiers of IN_OTYPE. The outermost level of
3666 POINTER_TYPE nodes is uninteresting and we stop as soon
3667 as we hit a non-POINTER_TYPE node on either type. */
3668 do
3669 {
3673 /* GNU C allows cv-qualified function types. 'const'
3674 means the function is very pure, 'volatile' means it
3675 can't return. We need to warn when such qualifiers
3676 are added, not when they're taken away. */
3680 else
3682 }
3690 /* There are qualifiers present in IN_OTYPE that are not
3691 present in IN_TYPE. */
3693 }
3695 /* Warn about possible alignment problems. */
3701 /* Don't warn about opaque types, where the actual alignment
3702 restriction is unknown. */
3713 /* Unlike conversion of integers to pointers, where the
3714 warning is disabled for converting constants because
3715 of cases such as SIG_*, warn about converting constant
3716 pointers to integers. In some cases it may cause unwanted
3717 sign extension, and a warning is appropriate. */
3729 /* Don't warn about converting any constant. */
3737 /* If pedantic, warn for conversions between function and object
3738 pointer types, except for converting a null pointer constant
3739 to function pointer type. */
3758 /* Ignore any integer overflow caused by the cast. */
3760 {
3762 {
3764 {
3765 /* Avoid clobbering a shared constant. */
3768 }
3769 }
3771 /* Reset VALUE's overflow flags, ensuring constant sharing. */
3775 }
3776 }
3778 /* Don't let a cast be an lvalue. */
3783 }
3785 /* Interpret a cast of expression EXPR to type TYPE. */
3786 tree
3788 {
3789 tree type;
3792 /* This avoids warnings about unprototyped casts on
3793 integers. E.g. "#define SIG_DFL (void(*)())0". */
3800 }
3801 \f
3802 /* Build an assignment expression of lvalue LHS from value RHS.
3803 MODIFYCODE is the code for a binary operator that we use
3804 to combine the old value of LHS with RHS to get the new value.
3805 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3807 tree
3809 {
3810 tree result;
3811 tree newrhs;
3815 /* Types that aren't fully specified cannot be used in assignments. */
3818 /* Avoid duplicate error messages from operands that had errors. */
3829 /* If a binary op has been requested, combine the old LHS value with the RHS
3830 producing the value we should actually store into the LHS. */
3833 {
3836 }
3838 /* Give an error for storing in something that is 'const'. */
3844 {
3847 }
3849 /* If storing into a structure or union member,
3850 it has probably been given type `int'.
3851 Compute the type that would go with
3852 the actual amount of storage the member occupies. */
3861 /* If storing in a field that is in actuality a short or narrower than one,
3862 we must store in the field in its actual type. */
3865 {
3868 }
3870 /* Convert new value to destination type. */
3877 /* Emit ObjC write barrier, if necessary. */
3879 {
3883 }
3885 /* Scan operands. */
3890 /* If we got the LHS in a different type for storing in,
3891 convert the result back to the nominal type of LHS
3892 so that the value we return always has the same type
3893 as the LHS argument. */
3899 }
3900 \f
3901 /* Convert value RHS to type TYPE as preparation for an assignment
3902 to an lvalue of type TYPE.
3903 The real work of conversion is done by `convert'.
3904 The purpose of this function is to generate error messages
3905 for assignments that are not allowed in C.
3906 ERRTYPE says whether it is argument passing, assignment,
3907 initialization or return.
3909 FUNCTION is a tree for the function being called.
3910 PARMNUM is the number of the argument, for printing in error messages. */
3912 static tree
3915 {
3917 tree rhstype;
3923 {
3924 tree selector;
3925 /* Change pointer to function to the function itself for
3926 diagnostics. */
3931 /* Handle an ObjC selector specially for diagnostics. */
3935 {
3938 }
3939 }
3941 /* This macro is used to emit diagnostics to ensure that all format
3942 strings are complete sentences, visible to gettext and checked at
3943 compile time. */
3944 #define WARN_FOR_ASSIGNMENT(AR, AS, IN, RE) \
3945 do { \
3946 switch (errtype) \
3947 { \
3948 case ic_argpass: \
3949 pedwarn (AR, parmnum, rname); \
3950 break; \
3951 case ic_argpass_nonproto: \
3952 warning (0, AR, parmnum, rname); \
3953 break; \
3954 case ic_assign: \
3955 pedwarn (AS); \
3956 break; \
3957 case ic_init: \
3958 pedwarn (IN); \
3959 break; \
3960 case ic_return: \
3961 pedwarn (RE); \
3962 break; \
3963 default: \
3964 gcc_unreachable (); \
3965 } \
3966 } while (0)
3981 {
3985 {
4001 }
4004 }
4010 {
4011 /* Except for passing an argument to an unprototyped function,
4012 this is a constraint violation. When passing an argument to
4013 an unprototyped function, it is compile-time undefined;
4014 making it a constraint in that case was rejected in
4015 DR#252. */
4018 }
4022 /* A type converts to a reference to it.
4023 This code doesn't fully support references, it's just for the
4024 special case of va_start and va_copy. */
4027 {
4029 {
4032 }
4037 /* We already know that these two types are compatible, but they
4038 may not be exactly identical. In fact, `TREE_TYPE (type)' is
4039 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
4040 likely to be va_list, a typedef to __builtin_va_list, which
4041 is different enough that it will cause problems later. */
4047 }
4048 /* Some types can interconvert without explicit casts. */
4052 /* Arithmetic types all interconvert, and enum is treated like int. */
4063 /* Aggregates in different TUs might need conversion. */
4069 /* Conversion to a transparent union from its member types.
4070 This applies only to function arguments. */
4073 {
4077 {
4088 {
4092 /* Any non-function converts to a [const][volatile] void *
4093 and vice versa; otherwise, targets must be the same.
4094 Meanwhile, the lhs target must have all the qualifiers of
4095 the rhs. */
4098 {
4099 /* If this type won't generate any warnings, use it. */
4109 /* Keep looking for a better type, but remember this one. */
4112 }
4113 }
4115 /* Can convert integer zero to any pointer type. */
4117 {
4120 }
4121 }
4124 {
4126 {
4127 /* We have only a marginally acceptable member type;
4128 it needs a warning. */
4132 /* Const and volatile mean something different for function
4133 types, so the usual warnings are not appropriate. */
4136 {
4137 /* Because const and volatile on functions are
4138 restrictions that say the function will not do
4139 certain things, it is okay to use a const or volatile
4140 function where an ordinary one is wanted, but not
4141 vice-versa. */
4144 "makes qualified function "
4147 "function pointer from "
4150 "function pointer from "
4154 }
4166 }
4173 }
4174 }
4176 /* Conversions among pointers */
4179 {
4191 /* Opaque pointers are treated like void pointers. */
4197 /* C++ does not allow the implicit conversion void* -> T*. However,
4198 for the purpose of reducing the number of false positives, we
4199 tolerate the special case of
4201 int *p = NULL;
4203 where NULL is typically defined in C to be '(void *) 0'. */
4208 /* Check if the right-hand side has a format attribute but the
4209 left-hand side doesn't. */
4212 {
4214 {
4218 "argument %d of %qE might be "
4224 "assignment left-hand side might be "
4229 "initialization left-hand side might be "
4234 "return type might be "
4239 }
4240 }
4242 /* Any non-function converts to a [const][volatile] void *
4243 and vice versa; otherwise, targets must be the same.
4244 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
4247 || is_opaque_pointer
4250 {
4253 ||
4258 "%qE between function pointer "
4266 /* Const and volatile mean something different for function types,
4267 so the usual warnings are not appropriate. */
4270 {
4272 {
4273 /* Types differing only by the presence of the 'volatile'
4274 qualifier are acceptable if the 'volatile' has been added
4275 in by the Objective-C EH machinery. */
4285 }
4286 /* If this is not a case of ignoring a mismatch in signedness,
4287 no warning. */
4290 ;
4291 /* If there is a mismatch, do warn. */
4301 }
4304 {
4305 /* Because const and volatile on functions are restrictions
4306 that say the function will not do certain things,
4307 it is okay to use a const or volatile function
4308 where an ordinary one is wanted, but not vice-versa. */
4311 "qualified function pointer "
4319 }
4320 }
4321 else
4322 /* Avoid warning about the volatile ObjC EH puts on decls. */
4332 }
4334 {
4335 /* ??? This should not be an error when inlining calls to
4336 unprototyped functions. */
4339 }
4341 {
4342 /* An explicit constant 0 can convert to a pointer,
4343 or one that results from arithmetic, even including
4344 a cast to integer type. */
4356 }
4358 {
4368 }
4373 {
4376 /* ??? This should not be an error when inlining calls to
4377 unprototyped functions. */
4391 }
4394 }
4395 \f
4396 /* If VALUE is a compound expr all of whose expressions are constant, then
4397 return its value. Otherwise, return error_mark_node.
4399 This is for handling COMPOUND_EXPRs as initializer elements
4400 which is allowed with a warning when -pedantic is specified. */
4402 static tree
4404 {
4406 {
4411 endtype);
4412 }
4415 else
4417 }
4418 \f
4419 /* Perform appropriate conversions on the initial value of a variable,
4420 store it in the declaration DECL,
4421 and print any error messages that are appropriate.
4422 If the init is invalid, store an ERROR_MARK. */
4424 void
4426 {
4429 /* If variable's type was invalidly declared, just ignore it. */
4435 /* Digest the specified initializer into an expression. */
4439 /* Store the expression if valid; else report error. */
4448 /* ANSI wants warnings about out-of-range constant initializers. */
4453 /* Check if we need to set array size from compound literal size. */
4457 {
4464 {
4468 {
4469 /* For int foo[] = (int [3]){1}; we need to set array size
4470 now since later on array initializer will be just the
4471 brace enclosed list of the compound literal. */
4477 }
4478 }
4479 }
4480 }
4481 \f
4482 /* Methods for storing and printing names for error messages. */
4484 /* Implement a spelling stack that allows components of a name to be pushed
4485 and popped. Each element on the stack is this structure. */
4487 struct spelling
4488 {
4490 union
4491 {
4495 };
4497 #define SPELLING_STRING 1
4498 #define SPELLING_MEMBER 2
4499 #define SPELLING_BOUNDS 3
4505 /* Macros to save and restore the spelling stack around push_... functions.
4506 Alternative to SAVE_SPELLING_STACK. */
4508 #define SPELLING_DEPTH() (spelling - spelling_base)
4509 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
4511 /* Push an element on the spelling stack with type KIND and assign VALUE
4512 to MEMBER. */
4514 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
4515 { \
4516 int depth = SPELLING_DEPTH (); \
4517 \
4518 if (depth >= spelling_size) \
4519 { \
4520 spelling_size += 10; \
4521 spelling_base = XRESIZEVEC (struct spelling, spelling_base, \
4522 spelling_size); \
4523 RESTORE_SPELLING_DEPTH (depth); \
4524 } \
4525 \
4526 spelling->kind = (KIND); \
4527 spelling->MEMBER = (VALUE); \
4528 spelling++; \
4529 }
4531 /* Push STRING on the stack. Printed literally. */
4533 static void
4535 {
4537 }
4539 /* Push a member name on the stack. Printed as '.' STRING. */
4541 static void
4543 {
4547 }
4549 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
4551 static void
4553 {
4555 }
4557 /* Compute the maximum size in bytes of the printed spelling. */
4559 static int
4561 {
4566 {
4569 else
4571 }
4574 }
4576 /* Print the spelling to BUFFER and return it. */
4580 {
4586 {
4589 }
4590 else
4591 {
4596 ;
4597 }
4600 }
4602 /* Issue an error message for a bad initializer component.
4603 MSGID identifies the message.
4604 The component name is taken from the spelling stack. */
4606 void
4608 {
4615 }
4617 /* Issue a pedantic warning for a bad initializer component.
4618 MSGID identifies the message.
4619 The component name is taken from the spelling stack. */
4621 void
4623 {
4630 }
4632 /* Issue a warning for a bad initializer component.
4633 MSGID identifies the message.
4634 The component name is taken from the spelling stack. */
4636 static void
4638 {
4645 }
4646 \f
4647 /* If TYPE is an array type and EXPR is a parenthesized string
4648 constant, warn if pedantic that EXPR is being used to initialize an
4649 object of type TYPE. */
4651 void
4653 {
4659 }
4661 /* Digest the parser output INIT as an initializer for type TYPE.
4662 Return a C expression of type TYPE to represent the initial value.
4664 If INIT is a string constant, STRICT_STRING is true if it is
4665 unparenthesized or we should not warn here for it being parenthesized.
4666 For other types of INIT, STRICT_STRING is not used.
4668 REQUIRE_CONSTANT requests an error if non-constant initializers or
4669 elements are seen. */
4671 static tree
4673 {
4678 || !init
4687 /* Initialization of an array of chars from a string constant
4688 optionally enclosed in braces. */
4692 {
4694 /* Note that an array could be both an array of character type
4695 and an array of wchar_t if wchar_t is signed char or unsigned
4696 char. */
4702 {
4709 char_string
4718 {
4721 }
4723 {
4726 }
4732 /* Subtract 1 (or sizeof (wchar_t))
4733 because it's ok to ignore the terminating null char
4734 that is counted in the length of the constant. */
4745 }
4747 {
4751 }
4752 }
4754 /* Build a VECTOR_CST from a *constant* vector constructor. If the
4755 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
4756 below and handle as a constructor. */
4761 {
4768 {
4770 tree value;
4773 /* Iterate through elements and check if all constructor
4774 elements are *_CSTs. */
4777 {
4780 }
4785 }
4786 }
4788 /* Any type can be initialized
4789 from an expression of the same type, optionally with braces. */
4802 {
4804 {
4806 {
4810 else
4811 {
4814 }
4815 }
4816 }
4819 /* Although the types are compatible, we may require a
4820 conversion. */
4826 {
4827 /* As an extension, allow initializing objects with static storage
4828 duration with compound literals (which are then treated just as
4829 the brace enclosed list they contain). Also allow this for
4830 vectors, as we can only assign them with compound literals. */
4833 }
4837 {
4840 }
4845 /* Compound expressions can only occur here if -pedantic or
4846 -pedantic-errors is specified. In the later case, we always want
4847 an error. In the former case, we simply want a warning. */
4850 {
4851 inside_init
4856 else
4860 }
4864 {
4867 }
4869 /* Added to enable additional -Wmissing-format-attribute warnings. */
4874 }
4876 /* Handle scalar types, including conversions. */
4881 {
4886 inside_init
4890 /* Check to see if we have already given an error message. */
4892 ;
4894 {
4897 }
4901 {
4904 }
4907 }
4909 /* Come here only for records and arrays. */
4912 {
4915 }
4919 }
4920 \f
4921 /* Handle initializers that use braces. */
4923 /* Type of object we are accumulating a constructor for.
4924 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4927 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4928 left to fill. */
4931 /* For an ARRAY_TYPE, this is the specified index
4932 at which to store the next element we get. */
4935 /* For an ARRAY_TYPE, this is the maximum index. */
4938 /* For a RECORD_TYPE, this is the first field not yet written out. */
4941 /* For an ARRAY_TYPE, this is the index of the first element
4942 not yet written out. */
4945 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4946 This is so we can generate gaps between fields, when appropriate. */
4949 /* If we are saving up the elements rather than allocating them,
4950 this is the list of elements so far (in reverse order,
4951 most recent first). */
4954 /* 1 if constructor should be incrementally stored into a constructor chain,
4955 0 if all the elements should be kept in AVL tree. */
4958 /* 1 if so far this constructor's elements are all compile-time constants. */
4961 /* 1 if so far this constructor's elements are all valid address constants. */
4964 /* 1 if this constructor is erroneous so far. */
4967 /* Structure for managing pending initializer elements, organized as an
4968 AVL tree. */
4970 struct init_node
4971 {
4975 tree purpose;
4976 tree value;
4977 };
4979 /* Tree of pending elements at this constructor level.
4980 These are elements encountered out of order
4981 which belong at places we haven't reached yet in actually
4982 writing the output.
4983 Will never hold tree nodes across GC runs. */
4986 /* The SPELLING_DEPTH of this constructor. */
4989 /* DECL node for which an initializer is being read.
4990 0 means we are reading a constructor expression
4991 such as (struct foo) {...}. */
4994 /* Nonzero if this is an initializer for a top-level decl. */
4997 /* Nonzero if there were any member designators in this initializer. */
5000 /* Nesting depth of designator list. */
5003 /* Nonzero if there were diagnosed errors in this designator list. */
5006 \f
5007 /* This stack has a level for each implicit or explicit level of
5008 structuring in the initializer, including the outermost one. It
5009 saves the values of most of the variables above. */
5013 struct constructor_stack
5014 {
5016 tree type;
5017 tree fields;
5018 tree index;
5019 tree max_index;
5020 tree unfilled_index;
5021 tree unfilled_fields;
5022 tree bit_index;
5027 /* If value nonzero, this value should replace the entire
5028 constructor at this level. */
5038 };
5042 /* This stack represents designators from some range designator up to
5043 the last designator in the list. */
5045 struct constructor_range_stack
5046 {
5049 tree range_start;
5050 tree index;
5051 tree range_end;
5052 tree fields;
5053 };
5057 /* This stack records separate initializers that are nested.
5058 Nested initializers can't happen in ANSI C, but GNU C allows them
5059 in cases like { ... (struct foo) { ... } ... }. */
5061 struct initializer_stack
5062 {
5064 tree decl;
5074 };
5077 \f
5078 /* Prepare to parse and output the initializer for variable DECL. */
5080 void
5082 {
5104 {
5106 require_constant_elements
5108 /* For a scalar, you can always use any value to initialize,
5109 even within braces. */
5115 }
5116 else
5117 {
5121 }
5134 }
5136 void
5138 {
5141 /* Free the whole constructor stack of this initializer. */
5143 {
5147 }
5151 /* Pop back to the data of the outer initializer (if any). */
5166 }
5167 \f
5168 /* Call here when we see the initializer is surrounded by braces.
5169 This is instead of a call to push_init_level;
5170 it is matched by a call to pop_init_level.
5172 TYPE is the type to initialize, for a constructor expression.
5173 For an initializer for a decl, TYPE is zero. */
5175 void
5177 {
5222 {
5224 /* Skip any nameless bit fields at the beginning. */
5231 }
5233 {
5235 {
5236 constructor_max_index
5239 /* Detect non-empty initializations of zero-length arrays. */
5244 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5245 to initialize VLAs will cause a proper error; avoid tree
5246 checking errors as well by setting a safe value. */
5251 constructor_index
5254 }
5255 else
5256 {
5259 }
5262 }
5264 {
5265 /* Vectors are like simple fixed-size arrays. */
5266 constructor_max_index =
5270 }
5271 else
5272 {
5273 /* Handle the case of int x = {5}; */
5276 }
5277 }
5278 \f
5279 /* Push down into a subobject, for initialization.
5280 If this is for an explicit set of braces, IMPLICIT is 0.
5281 If it is because the next element belongs at a lower level,
5282 IMPLICIT is 1 (or 2 if the push is because of designator list). */
5284 void
5286 {
5290 /* If we've exhausted any levels that didn't have braces,
5291 pop them now. If implicit == 1, this will have been done in
5292 process_init_element; do not repeat it here because in the case
5293 of excess initializers for an empty aggregate this leads to an
5294 infinite cycle of popping a level and immediately recreating
5295 it. */
5297 {
5299 {
5305 && constructor_max_index
5307 constructor_index))
5309 else
5311 }
5312 }
5314 /* Unless this is an explicit brace, we need to preserve previous
5315 content if any. */
5317 {
5324 }
5358 {
5363 }
5365 /* Don't die if an entire brace-pair level is superfluous
5366 in the containing level. */
5368 ;
5371 {
5372 /* Don't die if there are extra init elts at the end. */
5375 else
5376 {
5379 constructor_depth++;
5380 }
5381 }
5383 {
5386 constructor_depth++;
5387 }
5390 {
5395 }
5398 {
5406 }
5409 {
5412 }
5416 {
5418 /* Skip any nameless bit fields at the beginning. */
5425 }
5427 {
5428 /* Vectors are like simple fixed-size arrays. */
5429 constructor_max_index =
5433 }
5435 {
5437 {
5438 constructor_max_index
5441 /* Detect non-empty initializations of zero-length arrays. */
5446 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5447 to initialize VLAs will cause a proper error; avoid tree
5448 checking errors as well by setting a safe value. */
5453 constructor_index
5456 }
5457 else
5462 {
5463 /* We need to split the char/wchar array into individual
5464 characters, so that we don't have to special case it
5465 everywhere. */
5467 }
5468 }
5469 else
5470 {
5475 }
5476 }
5478 /* At the end of an implicit or explicit brace level,
5479 finish up that level of constructor. If a single expression
5480 with redundant braces initialized that level, return the
5481 c_expr structure for that expression. Otherwise, the original_code
5482 element is set to ERROR_MARK.
5483 If we were outputting the elements as they are read, return 0 as the value
5484 from inner levels (process_init_element ignores that),
5485 but return error_mark_node as the value from the outermost level
5486 (that's what we want to put in DECL_INITIAL).
5487 Otherwise, return a CONSTRUCTOR expression as the value. */
5489 struct c_expr
5491 {
5498 {
5499 /* When we come to an explicit close brace,
5500 pop any inner levels that didn't have explicit braces. */
5505 }
5507 /* Now output all pending elements. */
5513 /* Error for initializing a flexible array member, or a zero-length
5514 array member in an inappropriate context. */
5519 {
5520 /* Silently discard empty initializations. The parser will
5521 already have pedwarned for empty brackets. */
5524 else
5525 {
5533 /* We have already issued an error message for the existence
5534 of a flexible array member not at the end of the structure.
5535 Discard the initializer so that we do not die later. */
5538 }
5539 }
5541 /* Warn when some struct elements are implicitly initialized to zero. */
5543 && constructor_type
5546 {
5547 /* Do not warn for flexible array members or zero-length arrays. */
5553 /* Do not warn if this level of the initializer uses member
5554 designators; it is likely to be deliberate. */
5556 {
5560 }
5561 }
5563 /* Pad out the end of the structure. */
5565 /* If this closes a superfluous brace pair,
5566 just pass out the element between them. */
5569 ;
5574 {
5575 /* A nonincremental scalar initializer--just return
5576 the element, after verifying there is just one. */
5578 {
5582 }
5584 {
5587 }
5588 else
5590 }
5591 else
5592 {
5595 else
5596 {
5598 constructor_elements);
5603 }
5604 }
5631 }
5633 /* Common handling for both array range and field name designators.
5634 ARRAY argument is nonzero for array ranges. Returns zero for success. */
5636 static int
5638 {
5639 tree subtype;
5642 /* Don't die if an entire brace-pair level is superfluous
5643 in the containing level. */
5647 /* If there were errors in this designator list already, bail out
5648 silently. */
5653 {
5656 /* Designator list starts at the level of closest explicit
5657 braces. */
5662 }
5665 {
5677 }
5681 {
5684 }
5686 {
5689 }
5694 }
5696 /* If there are range designators in designator list, push a new designator
5697 to constructor_range_stack. RANGE_END is end of such stack range or
5698 NULL_TREE if there is no range designator at this level. */
5700 static void
5702 {
5716 }
5718 /* Within an array initializer, specify the next index to be initialized.
5719 FIRST is that index. If LAST is nonzero, then initialize a range
5720 of indices, running from FIRST through LAST. */
5722 void
5724 {
5732 {
5735 }
5748 else
5749 {
5753 {
5757 {
5760 }
5761 else
5762 {
5766 {
5769 }
5770 }
5771 }
5773 designator_depth++;
5777 }
5778 }
5780 /* Within a struct initializer, specify the next field to be initialized. */
5782 void
5784 {
5785 tree tail;
5794 {
5797 }
5801 {
5804 }
5808 else
5809 {
5811 designator_depth++;
5815 }
5816 }
5817 \f
5818 /* Add a new initializer to the tree of pending initializers. PURPOSE
5819 identifies the initializer, either array index or field in a structure.
5820 VALUE is the value of that index or field. */
5822 static void
5824 {
5831 {
5833 {
5839 else
5840 {
5847 }
5848 }
5849 }
5850 else
5851 {
5852 tree bitpos;
5856 {
5862 else
5863 {
5870 }
5871 }
5872 }
5885 {
5889 {
5893 {
5895 {
5896 /* L rotation. */
5909 {
5912 else
5914 }
5915 else
5917 }
5918 else
5919 {
5920 /* LR rotation. */
5942 {
5945 else
5947 }
5948 else
5950 }
5952 }
5953 else
5954 {
5955 /* p->balance == +1; growth of left side balances the node. */
5958 }
5959 }
5961 {
5963 /* Growth propagation from right side. */
5966 {
5968 {
5969 /* R rotation. */
5982 {
5985 else
5987 }
5988 else
5990 }
5992 {
5993 /* RL rotation */
6015 {
6018 else
6020 }
6021 else
6023 }
6025 }
6026 else
6027 {
6028 /* p->balance == -1; growth of right side balances the node. */
6031 }
6032 }
6036 }
6037 }
6039 /* Build AVL tree from a sorted chain. */
6041 static void
6043 {
6055 {
6057 /* Skip any nameless bit fields at the beginning. */
6063 }
6065 {
6067 constructor_unfilled_index
6070 else
6072 }
6074 }
6076 /* Build AVL tree from a string constant. */
6078 static void
6080 {
6091 else
6092 {
6096 }
6105 {
6107 {
6110 }
6111 else
6112 {
6116 {
6119 else
6124 }
6125 }
6128 {
6131 {
6133 {
6136 }
6137 }
6139 {
6142 }
6147 }
6151 }
6154 }
6156 /* Return value of FIELD in pending initializer or zero if the field was
6157 not initialized yet. */
6159 static tree
6161 {
6165 {
6172 {
6177 else
6179 }
6180 }
6182 {
6186 && (!constructor_unfilled_fields
6193 {
6198 else
6200 }
6201 }
6203 {
6208 }
6210 }
6212 /* "Output" the next constructor element.
6213 At top level, really output it to assembler code now.
6214 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
6215 TYPE is the data type that the containing data type wants here.
6216 FIELD is the field (a FIELD_DECL) or the index that this element fills.
6217 If VALUE is a string constant, STRICT_STRING is true if it is
6218 unparenthesized or we should not warn here for it being parenthesized.
6219 For other types of VALUE, STRICT_STRING is not used.
6221 PENDING if non-nil means output pending elements that belong
6222 right after this element. (PENDING is normally 1;
6223 it is 0 while outputting pending elements, to avoid recursion.) */
6225 static void
6228 {
6232 {
6235 }
6248 {
6249 /* As an extension, allow initializing objects with static storage
6250 duration with compound literals (which are then treated just as
6251 the brace enclosed list they contain). */
6254 }
6268 {
6270 {
6273 }
6276 }
6278 /* If this field is empty (and not at the end of structure),
6279 don't do anything other than checking the initializer. */
6290 {
6293 }
6295 /* If this element doesn't come next in sequence,
6296 put it on constructor_pending_elts. */
6298 && (!constructor_incremental
6300 {
6307 }
6309 && (!constructor_incremental
6311 {
6312 /* We do this for records but not for unions. In a union,
6313 no matter which field is specified, it can be initialized
6314 right away since it starts at the beginning of the union. */
6316 {
6319 else
6320 {
6328 }
6329 }
6333 }
6336 {
6343 /* We can have just one union field set. */
6345 }
6347 /* Otherwise, output this element either to
6348 constructor_elements or to the assembler file. */
6354 /* Advance the variable that indicates sequential elements output. */
6356 constructor_unfilled_index
6358 bitsize_one_node);
6360 {
6361 constructor_unfilled_fields
6364 /* Skip any nameless bit fields. */
6368 constructor_unfilled_fields =
6370 }
6374 /* Now output any pending elements which have become next. */
6377 }
6379 /* Output any pending elements which have become next.
6380 As we output elements, constructor_unfilled_{fields,index}
6381 advances, which may cause other elements to become next;
6382 if so, they too are output.
6384 If ALL is 0, we return when there are
6385 no more pending elements to output now.
6387 If ALL is 1, we output space as necessary so that
6388 we can output all the pending elements. */
6390 static void
6392 {
6394 tree next;
6396 retry:
6398 /* Look through the whole pending tree.
6399 If we find an element that should be output now,
6400 output it. Otherwise, set NEXT to the element
6401 that comes first among those still pending. */
6405 {
6407 {
6409 constructor_unfilled_index))
6415 {
6416 /* Advance to the next smaller node. */
6419 else
6420 {
6421 /* We have reached the smallest node bigger than the
6422 current unfilled index. Fill the space first. */
6425 }
6426 }
6427 else
6428 {
6429 /* Advance to the next bigger node. */
6432 else
6433 {
6434 /* We have reached the biggest node in a subtree. Find
6435 the parent of it, which is the next bigger node. */
6441 {
6444 }
6445 }
6446 }
6447 }
6450 {
6453 /* If the current record is complete we are done. */
6459 /* We can't compare fields here because there might be empty
6460 fields in between. */
6462 {
6466 }
6468 {
6469 /* Advance to the next smaller node. */
6472 else
6473 {
6474 /* We have reached the smallest node bigger than the
6475 current unfilled field. Fill the space first. */
6478 }
6479 }
6480 else
6481 {
6482 /* Advance to the next bigger node. */
6485 else
6486 {
6487 /* We have reached the biggest node in a subtree. Find
6488 the parent of it, which is the next bigger node. */
6495 {
6498 }
6499 }
6500 }
6501 }
6502 }
6504 /* Ordinarily return, but not if we want to output all
6505 and there are elements left. */
6509 /* If it's not incremental, just skip over the gap, so that after
6510 jumping to retry we will output the next successive element. */
6517 /* ELT now points to the node in the pending tree with the next
6518 initializer to output. */
6520 }
6521 \f
6522 /* Add one non-braced element to the current constructor level.
6523 This adjusts the current position within the constructor's type.
6524 This may also start or terminate implicit levels
6525 to handle a partly-braced initializer.
6527 Once this has found the correct level for the new element,
6528 it calls output_init_element. */
6530 void
6532 {
6540 /* Handle superfluous braces around string cst as in
6541 char x[] = {"foo"}; */
6543 && constructor_type
6547 {
6552 }
6555 {
6558 }
6560 /* Ignore elements of a brace group if it is entirely superfluous
6561 and has already been diagnosed. */
6565 /* If we've exhausted any levels that didn't have braces,
6566 pop them now. */
6568 {
6576 constructor_index)))
6578 else
6580 }
6582 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
6584 {
6585 /* If value is a compound literal and we'll be just using its
6586 content, don't put it into a SAVE_EXPR. */
6588 || !require_constant_value
6591 }
6594 {
6596 {
6597 tree fieldtype;
6601 {
6604 }
6611 /* Error for non-static initialization of a flexible array member. */
6613 && !require_constant_value
6616 {
6619 }
6621 /* Accept a string constant to initialize a subarray. */
6627 /* Otherwise, if we have come to a subaggregate,
6628 and we don't have an element of its type, push into it. */
6634 {
6637 }
6640 {
6645 }
6646 else
6647 /* Do the bookkeeping for an element that was
6648 directly output as a constructor. */
6649 {
6650 /* For a record, keep track of end position of last field. */
6652 constructor_bit_index
6657 /* If the current field was the first one not yet written out,
6658 it isn't now, so update. */
6660 {
6662 /* Skip any nameless bit fields. */
6666 constructor_unfilled_fields =
6668 }
6669 }
6672 /* Skip any nameless bit fields at the beginning. */
6677 }
6679 {
6680 tree fieldtype;
6684 {
6687 }
6694 /* Warn that traditional C rejects initialization of unions.
6695 We skip the warning if the value is zero. This is done
6696 under the assumption that the zero initializer in user
6697 code appears conditioned on e.g. __STDC__ to avoid
6698 "missing initializer" warnings and relies on default
6699 initialization to zero in the traditional C case.
6700 We also skip the warning if the initializer is designated,
6701 again on the assumption that this must be conditional on
6702 __STDC__ anyway (and we've already complained about the
6703 member-designator already). */
6710 /* Accept a string constant to initialize a subarray. */
6716 /* Otherwise, if we have come to a subaggregate,
6717 and we don't have an element of its type, push into it. */
6723 {
6726 }
6729 {
6734 }
6735 else
6736 /* Do the bookkeeping for an element that was
6737 directly output as a constructor. */
6738 {
6741 }
6744 }
6746 {
6750 /* Accept a string constant to initialize a subarray. */
6756 /* Otherwise, if we have come to a subaggregate,
6757 and we don't have an element of its type, push into it. */
6763 {
6766 }
6771 {
6774 }
6776 /* Now output the actual element. */
6778 {
6783 }
6785 constructor_index
6789 /* If we are doing the bookkeeping for an element that was
6790 directly output as a constructor, we must update
6791 constructor_unfilled_index. */
6793 }
6795 {
6798 /* Do a basic check of initializer size. Note that vectors
6799 always have a fixed size derived from their type. */
6801 {
6804 }
6806 /* Now output the actual element. */
6811 constructor_index
6815 /* If we are doing the bookkeeping for an element that was
6816 directly output as a constructor, we must update
6817 constructor_unfilled_index. */
6819 }
6821 /* Handle the sole element allowed in a braced initializer
6822 for a scalar variable. */
6825 {
6828 }
6829 else
6830 {
6835 }
6837 /* Handle range initializers either at this level or anywhere higher
6838 in the designator stack. */
6840 {
6847 {
6850 }
6854 {
6857 }
6864 {
6868 {
6871 }
6879 }
6884 }
6887 }
6890 }
6891 \f
6892 /* Build a complete asm-statement, whose components are a CV_QUALIFIER
6893 (guaranteed to be 'volatile' or null) and ARGS (represented using
6894 an ASM_EXPR node). */
6895 tree
6897 {
6901 }
6903 /* Build an asm-expr, whose components are a STRING, some OUTPUTS,
6904 some INPUTS, and some CLOBBERS. The latter three may be NULL.
6905 SIMPLE indicates whether there was anything at all after the
6906 string in the asm expression -- asm("blah") and asm("blah" : )
6907 are subtly different. We use a ASM_EXPR node to represent this. */
6908 tree
6911 {
6912 tree tail;
6913 tree args;
6926 /* Remove output conversions that change the type but not the mode. */
6928 {
6931 /* ??? Really, this should not be here. Users should be using a
6932 proper lvalue, dammit. But there's a long history of using casts
6933 in the output operands. In cases like longlong.h, this becomes a
6934 primitive form of typechecking -- if the cast can be removed, then
6935 the output operand had a type of the proper width; otherwise we'll
6936 get an error. Gross, but ... */
6955 {
6956 /* If the operand is going to end up in memory,
6957 mark it addressable. */
6960 }
6961 else
6965 }
6968 {
6969 tree input;
6976 {
6977 /* If the operand is going to end up in memory,
6978 mark it addressable. */
6980 {
6981 /* Strip the nops as we allow this case. FIXME, this really
6982 should be rejected or made deprecated. */
6986 }
6987 }
6988 else
6992 }
6996 /* asm statements without outputs, including simple ones, are treated
6997 as volatile. */
7002 }
7003 \f
7004 /* Generate a goto statement to LABEL. */
7006 tree
7008 {
7014 {
7017 }
7020 {
7023 }
7026 {
7027 /* No jump from outside this statement expression context, so
7028 record that there is a jump from within this context. */
7034 }
7037 {
7038 /* No jump from outside this context context of identifiers with
7039 variably modified type, so record that there is a jump from
7040 within this context. */
7046 }
7050 }
7052 /* Generate a computed goto statement to EXPR. */
7054 tree
7056 {
7061 }
7063 /* Generate a C `return' statement. RETVAL is the expression for what
7064 to return, or a null pointer for `return;' with no value. */
7066 tree
7068 {
7076 {
7080 {
7084 }
7085 }
7087 {
7093 }
7094 else
7095 {
7099 tree inner;
7107 /* Strip any conversions, additions, and subtractions, and see if
7108 we are returning the address of a local variable. Warn if so. */
7110 {
7112 {
7119 /* If the second operand of the MINUS_EXPR has a pointer
7120 type (or is converted from it), this may be valid, so
7121 don't give a warning. */
7122 {
7136 }
7154 }
7157 }
7160 }
7165 }
7166 \f
7168 /* The SWITCH_EXPR being built. */
7169 tree switch_expr;
7171 /* The original type of the testing expression, i.e. before the
7172 default conversion is applied. */
7173 tree orig_type;
7175 /* A splay-tree mapping the low element of a case range to the high
7176 element, or NULL_TREE if there is no high element. Used to
7177 determine whether or not a new case label duplicates an old case
7178 label. We need a tree, rather than simply a hash table, because
7179 of the GNU case range extension. */
7180 splay_tree cases;
7182 /* Number of nested statement expressions within this switch
7183 statement; if nonzero, case and default labels may not
7184 appear. */
7187 /* Scope of outermost declarations of identifiers with variably
7188 modified type within this switch statement; if nonzero, case and
7189 default labels may not appear. */
7192 /* The next node on the stack. */
7194 };
7196 /* A stack of the currently active switch statements. The innermost
7197 switch statement is on the top of the stack. There is no need to
7198 mark the stack for garbage collection because it is only active
7199 during the processing of the body of a function, and we never
7200 collect at that point. */
7204 /* Start a C switch statement, testing expression EXP. Return the new
7205 SWITCH_EXPR. */
7207 tree
7209 {
7214 {
7218 {
7220 {
7223 }
7225 }
7226 else
7227 {
7237 }
7238 }
7240 /* Add this new SWITCH_EXPR to the stack. */
7251 }
7253 /* Process a case label. */
7255 tree
7257 {
7262 {
7269 }
7271 {
7275 else
7278 }
7280 {
7284 else
7287 }
7290 else
7294 }
7296 /* Finish the switch statement. */
7298 void
7300 {
7302 location_t switch_location;
7306 /* We must not be within a statement expression nested in the switch
7307 at this point; we might, however, be within the scope of an
7308 identifier with variably modified type nested in the switch. */
7311 /* Emit warnings as needed. */
7314 else
7320 /* Pop the stack. */
7324 }
7325 \f
7326 /* Emit an if statement. IF_LOCUS is the location of the 'if'. COND,
7327 THEN_BLOCK and ELSE_BLOCK are expressions to be used; ELSE_BLOCK
7328 may be null. NESTED_IF is true if THEN_BLOCK contains another IF
7329 statement, and was not surrounded with parenthesis. */
7331 void
7334 {
7335 tree stmt;
7337 /* Diagnose an ambiguous else if if-then-else is nested inside if-then. */
7339 {
7342 /* We know from the grammar productions that there is an IF nested
7343 within THEN_BLOCK. Due to labels and c99 conditional declarations,
7344 it might not be exactly THEN_BLOCK, but should be the last
7345 non-container statement within. */
7348 {
7363 }
7364 found:
7370 }
7377 }
7379 /* Emit a general-purpose loop construct. START_LOCUS is the location of
7380 the beginning of the loop. COND is the loop condition. COND_IS_FIRST
7381 is false for DO loops. INCR is the FOR increment expression. BODY is
7382 the statement controlled by the loop. BLAB is the break label. CLAB is
7383 the continue label. Everything is allowed to be NULL. */
7385 void
7388 {
7391 /* If the condition is zero don't generate a loop construct. */
7393 {
7395 {
7399 }
7400 }
7401 else
7402 {
7405 /* If we have an exit condition, then we build an IF with gotos either
7406 out of the loop, or to the top of it. If there's no exit condition,
7407 then we just build a jump back to the top. */
7411 {
7412 /* Canonicalize the loop condition to the end. This means
7413 generating a branch to the loop condition. Reuse the
7414 continue label, if possible. */
7416 {
7418 {
7421 }
7422 else
7426 }
7432 else
7434 }
7437 }
7451 }
7453 tree
7455 {
7459 /* In switch statements break is sometimes stylistically used after
7460 a return statement. This can lead to spurious warnings about
7461 control reaching the end of a non-void function when it is
7462 inlined. Note that we are calling block_may_fallthru with
7463 language specific tree nodes; this works because
7464 block_may_fallthru returns true when given something it does not
7465 understand. */
7469 {
7472 }
7474 ;
7476 {
7480 else
7491 }
7497 }
7499 /* A helper routine for c_process_expr_stmt and c_finish_stmt_expr. */
7501 static void
7503 {
7505 ;
7507 {
7511 }
7512 else
7514 }
7516 /* Process an expression as if it were a complete statement. Emit
7517 diagnostics, but do not call ADD_STMT. */
7519 tree
7521 {
7533 /* If we're not processing a statement expression, warn about unused values.
7534 Warnings for statement expressions will be emitted later, once we figure
7535 out which is the result. */
7540 /* If the expression is not of a type to which we cannot assign a line
7541 number, wrap the thing in a no-op NOP_EXPR. */
7549 }
7551 /* Emit an expression as a statement. */
7553 tree
7555 {
7558 else
7560 }
7562 /* Do the opposite and emit a statement as an expression. To begin,
7563 create a new binding level and return it. */
7565 tree
7567 {
7568 tree ret;
7572 /* We must force a BLOCK for this level so that, if it is not expanded
7573 later, there is a way to turn off the entire subtree of blocks that
7574 are contained in it. */
7578 {
7581 }
7585 {
7587 }
7594 /* Mark the current statement list as belonging to a statement list. */
7598 }
7600 tree
7602 {
7609 {
7612 }
7613 /* It is no longer possible to jump to labels defined within this
7614 statement expression. */
7618 {
7620 }
7621 /* It is again possible to define labels with a goto just outside
7622 this statement expression. */
7626 {
7629 }
7632 else
7637 /* Locate the last statement in BODY. See c_end_compound_stmt
7638 about always returning a BIND_EXPR. */
7642 continue_searching:
7644 {
7645 tree_stmt_iterator i;
7647 /* This can happen with degenerate cases like ({ }). No value. */
7651 /* If we're supposed to generate side effects warnings, process
7652 all of the statements except the last. */
7654 {
7657 }
7658 else
7662 }
7664 /* If the end of the list is exception related, then the list was split
7665 by a call to push_cleanup. Continue searching. */
7668 {
7672 }
7674 /* In the case that the BIND_EXPR is not necessary, return the
7675 expression out from inside it. */
7679 {
7680 /* Do not warn if the return value of a statement expression is
7681 unused. */
7685 }
7687 /* Extract the type of said expression. */
7690 /* If we're not returning a value at all, then the BIND_EXPR that
7691 we already have is a fine expression to return. */
7695 /* Now that we've located the expression containing the value, it seems
7696 silly to make voidify_wrapper_expr repeat the process. Create a
7697 temporary of the appropriate type and stick it in a TARGET_EXPR. */
7700 /* Unwrap a no-op NOP_EXPR as added by c_finish_expr_stmt. This avoids
7701 tree_expr_nonnegative_p giving up immediately. */
7711 }
7713 /* Begin the scope of an identifier of variably modified type, scope
7714 number SCOPE. Jumping from outside this scope to inside it is not
7715 permitted. */
7717 void
7719 {
7725 /* At file_scope, we don't have to do any processing. */
7734 {
7736 }
7743 }
7745 /* End a scope which may contain identifiers of variably modified
7746 type, scope number SCOPE. */
7748 void
7750 {
7755 /* We may have a number of nested scopes of identifiers with
7756 variably modified type, all at this depth. Pop each in turn. */
7758 {
7761 /* It is no longer possible to jump to labels defined within this
7762 scope. */
7766 {
7768 }
7769 /* It is again possible to define labels with a goto just outside
7770 this scope. */
7774 {
7777 }
7780 else
7784 }
7785 }
7786 \f
7787 /* Begin and end compound statements. This is as simple as pushing
7788 and popping new statement lists from the tree. */
7790 tree
7792 {
7797 }
7799 tree
7801 {
7805 {
7809 }
7814 /* If this compound statement is nested immediately inside a statement
7815 expression, then force a BIND_EXPR to be created. Otherwise we'll
7816 do the wrong thing for ({ { 1; } }) or ({ 1; { } }). In particular,
7817 STATEMENT_LISTs merge, and thus we can lose track of what statement
7818 was really last. */
7822 {
7825 }
7828 }
7830 /* Queue a cleanup. CLEANUP is an expression/statement to be executed
7831 when the current scope is exited. EH_ONLY is true when this is not
7832 meant to apply to normal control flow transfer. */
7834 void
7836 {
7848 }
7849 \f
7850 /* Build a binary-operation expression without default conversions.
7851 CODE is the kind of expression to build.
7852 This function differs from `build' in several ways:
7853 the data type of the result is computed and recorded in it,
7854 warnings are generated if arg data types are invalid,
7855 special handling for addition and subtraction of pointers is known,
7856 and some optimization is done (operations on narrow ints
7857 are done in the narrower type when that gives the same result).
7858 Constant folding is also done before the result is returned.
7860 Note that the operands will never have enumeral types, or function
7861 or array types, because either they will have the default conversions
7862 performed or they have both just been converted to some other type in which
7863 the arithmetic is to be done. */
7865 tree
7868 {
7874 /* Expression code to give to the expression when it is built.
7875 Normally this is CODE, which is what the caller asked for,
7876 but in some special cases we change it. */
7879 /* Data type in which the computation is to be performed.
7880 In the simplest cases this is the common type of the arguments. */
7883 /* Nonzero means operands have already been type-converted
7884 in whatever way is necessary.
7885 Zero means they need to be converted to RESULT_TYPE. */
7888 /* Nonzero means create the expression with this type, rather than
7889 RESULT_TYPE. */
7892 /* Nonzero means after finally constructing the expression
7893 convert it to this type. */
7896 /* Nonzero if this is an operation like MIN or MAX which can
7897 safely be computed in short if both args are promoted shorts.
7898 Also implies COMMON.
7899 -1 indicates a bitwise operation; this makes a difference
7900 in the exact conditions for when it is safe to do the operation
7901 in a narrower mode. */
7904 /* Nonzero if this is a comparison operation;
7905 if both args are promoted shorts, compare the original shorts.
7906 Also implies COMMON. */
7909 /* Nonzero if this is a right-shift operation, which can be computed on the
7910 original short and then promoted if the operand is a promoted short. */
7913 /* Nonzero means set RESULT_TYPE to the common type of the args. */
7916 /* True means types are compatible as far as ObjC is concerned. */
7920 {
7923 }
7924 else
7925 {
7928 }
7933 /* The expression codes of the data types of the arguments tell us
7934 whether the arguments are integers, floating, pointers, etc. */
7938 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
7942 /* If an error was already reported for one of the arguments,
7943 avoid reporting another error. */
7950 {
7953 }
7958 {
7960 /* Handle the pointer + int case. */
7965 else
7970 /* Subtraction of two similar pointers.
7971 We must subtract them as integers, then divide by object size. */
7975 /* Handle pointer minus int. Just like pointer plus int. */
7978 else
7999 {
8010 else
8011 /* Although it would be tempting to shorten always here, that
8012 loses on some targets, since the modulo instruction is
8013 undefined if the quotient can't be represented in the
8014 computation mode. We shorten only if unsigned or if
8015 dividing by something we know != -1. */
8020 }
8028 /* Allow vector types which are not floating point types. */
8041 {
8042 /* Although it would be tempting to shorten always here, that loses
8043 on some targets, since the modulo instruction is undefined if the
8044 quotient can't be represented in the computation mode. We shorten
8045 only if unsigned or if dividing by something we know != -1. */
8050 }
8064 {
8065 /* Result of these operations is always an int,
8066 but that does not mean the operands should be
8067 converted to ints! */
8072 }
8075 /* Shift operations: result has same type as first operand;
8076 always convert second operand to int.
8077 Also set SHORT_SHIFT if shifting rightward. */
8082 {
8084 {
8087 else
8088 {
8094 }
8095 }
8097 /* Use the type of the value to be shifted. */
8099 /* Convert the shift-count to an integer, regardless of size
8100 of value being shifted. */
8103 /* Avoid converting op1 to result_type later. */
8105 }
8111 {
8113 {
8119 }
8121 /* Use the type of the value to be shifted. */
8123 /* Convert the shift-count to an integer, regardless of size
8124 of value being shifted. */
8127 /* Avoid converting op1 to result_type later. */
8129 }
8137 /* Result of comparison is always int,
8138 but don't convert the args to int! */
8146 {
8149 /* Anything compares with void *. void * compares with anything.
8150 Otherwise, the targets must be compatible
8151 and both must be object or both incomplete. */
8155 {
8156 /* op0 != orig_op0 detects the case of something
8157 whose value is 0 but which isn't a valid null ptr const. */
8162 }
8164 {
8169 }
8170 else
8171 /* Avoid warning about the volatile ObjC EH puts on decls. */
8177 }
8179 {
8185 }
8187 {
8193 }
8195 {
8198 }
8200 {
8203 }
8217 {
8219 {
8227 }
8228 else
8229 {
8232 }
8233 }
8235 {
8239 }
8241 {
8245 }
8247 {
8250 }
8252 {
8255 }
8260 }
8269 {
8272 }
8276 &&
8279 {
8283 {
8287 }
8289 /* For certain operations (which identify themselves by shorten != 0)
8290 if both args were extended from the same smaller type,
8291 do the arithmetic in that type and then extend.
8293 shorten !=0 and !=1 indicates a bitwise operation.
8294 For them, this optimization is safe only if
8295 both args are zero-extended or both are sign-extended.
8296 Otherwise, we might change the result.
8297 Eg, (short)-1 | (unsigned short)-1 is (int)-1
8298 but calculated in (unsigned short) it would be (unsigned short)-1. */
8301 {
8305 tree type;
8307 /* Cast OP0 and OP1 to RESULT_TYPE. Doing so prevents
8308 excessive narrowing when we call get_narrower below. For
8309 example, suppose that OP0 is of unsigned int extended
8310 from signed char and that RESULT_TYPE is long long int.
8311 If we explicitly cast OP0 to RESULT_TYPE, OP0 would look
8312 like
8314 (long long int) (unsigned int) signed_char
8316 which get_narrower would narrow down to
8318 (unsigned int) signed char
8320 If we do not cast OP0 first, get_narrower would return
8321 signed_char, which is inconsistent with the case of the
8322 explicit cast. */
8329 /* UNS is 1 if the operation to be done is an unsigned one. */
8334 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
8335 but it *requires* conversion to FINAL_TYPE. */
8346 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
8348 /* For bitwise operations, signedness of nominal type
8349 does not matter. Consider only how operands were extended. */
8353 /* Note that in all three cases below we refrain from optimizing
8354 an unsigned operation on sign-extended args.
8355 That would not be valid. */
8357 /* Both args variable: if both extended in same way
8358 from same width, do it in that width.
8359 Do it unsigned if args were zero-extended. */
8366 result_type
8367 = c_common_signed_or_unsigned_type
8373 && (type
8383 && (type
8389 }
8391 /* Shifts can be shortened if shifting right. */
8394 {
8404 /* We can shorten only if the shift count is less than the
8405 number of bits in the smaller type size. */
8407 /* We cannot drop an unsigned shift after sign-extension. */
8409 {
8410 /* Do an unsigned shift if the operand was zero-extended. */
8411 result_type
8414 /* Convert value-to-be-shifted to that type. */
8418 }
8419 }
8421 /* Comparison operations are shortened too but differently.
8422 They identify themselves by setting short_compare = 1. */
8425 {
8426 /* Don't write &op0, etc., because that would prevent op0
8427 from being kept in a register.
8428 Instead, make copies of the our local variables and
8429 pass the copies by reference, then copy them back afterward. */
8432 tree val
8443 {
8455 /* Give warnings for comparisons between signed and unsigned
8456 quantities that may fail.
8458 Do the checking based on the original operand trees, so that
8459 casts will be considered, but default promotions won't be.
8461 Do not warn if the comparison is being done in a signed type,
8462 since the signed type will only be chosen if it can represent
8463 all the values of the unsigned type. */
8466 /* Do not warn if both operands are the same signedness. */
8469 else
8470 {
8476 else
8479 /* Do not warn if the signed quantity is an
8480 unsuffixed integer literal (or some static
8481 constant expression involving such literals or a
8482 conditional expression involving such literals)
8483 and it is non-negative. */
8486 /* Do not warn if the comparison is an equality operation,
8487 the unsigned quantity is an integral constant, and it
8488 would fit in the result if the result were signed. */
8491 && int_fits_type_p
8494 /* Do not warn if the unsigned quantity is an enumeration
8495 constant and its maximum value would fit in the result
8496 if the result were signed. */
8499 && int_fits_type_p
8503 else
8505 }
8507 /* Warn if two unsigned values are being compared in a size
8508 larger than their original size, and one (and only one) is the
8509 result of a `~' operator. This comparison will always fail.
8511 Also warn if one operand is a constant, and the constant
8512 does not have all bits set that are set in the ~ operand
8513 when it is extended. */
8517 {
8521 else
8526 {
8527 tree primop;
8532 {
8536 }
8537 else
8538 {
8542 }
8547 {
8551 }
8552 }
8559 }
8560 }
8561 }
8562 }
8564 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
8565 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
8566 Then the expression will be built.
8567 It will be given type FINAL_TYPE if that is nonzero;
8568 otherwise, it will be given type RESULT_TYPE. */
8571 {
8574 }
8577 {
8583 /* This can happen if one operand has a vector type, and the other
8584 has a different type. */
8587 }
8592 {
8593 /* Treat expressions in initializers specially as they can't trap. */
8595 build_type,
8603 }
8604 }
8607 /* Convert EXPR to be a truth-value, validating its type for this
8608 purpose. */
8610 tree
8612 {
8614 {
8632 }
8634 /* ??? Should we also give an error for void and vectors rather than
8635 leaving those to give errors later? */
8637 }
8638 \f
8640 /* Convert EXPR to a contained DECL, updating *TC, *TI and *SE as
8641 required. */
8643 tree
8646 {
8648 {
8650 /* Executing a compound literal inside a function reinitializes
8651 it. */
8655 }
8656 else
8658 }
8659 \f
8660 /* Like c_begin_compound_stmt, except force the retention of the BLOCK. */
8662 tree
8664 {
8665 tree block;
8671 }
8673 tree
8675 {
8676 tree stmt;
8686 }
8688 /* For all elements of CLAUSES, validate them vs OpenMP constraints.
8689 Remove any elements from the list that are invalid. */
8691 tree
8693 {
8704 {
8710 {
8728 {
8731 }
8733 {
8738 {
8760 }
8762 {
8766 }
8767 }
8778 {
8781 }
8784 check_dup_generic:
8787 {
8790 }
8794 {
8797 }
8798 else
8808 {
8811 }
8814 {
8817 }
8818 else
8828 {
8831 }
8834 {
8837 }
8838 else
8853 }
8856 {
8860 {
8864 }
8867 {
8873 {
8884 }
8886 {
8890 }
8891 }
8892 }
8896 else
8898 }
8902 }
8904 /* Make a variant type in the proper way for C/C++, propagating qualifiers
8905 down to the element type of an array. */
8907 tree
8909 {
8914 {
8915 tree t;
8917 type_quals);
8919 /* See if we already have an identically qualified type. */
8921 {
8928 }
8930 {
8941 {
8942 tree unqualified_canon
8948 }
8949 else
8951 }
8953 }
8955 /* A restrict-qualified pointer type must be a pointer to object or
8956 incomplete type. Note that the use of POINTER_TYPE_P also allows
8957 REFERENCE_TYPEs, which is appropriate for C++. */
8961 {
8964 }
8967 }