| blob | ff27c973094005f09d0f5eed1ec4896114257e42 |
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
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 2, 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 COPYING. If not, write to the Free
20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
21 02110-1301, USA. */
24 /* This file is part of the C front end.
25 It contains routines to build C expressions given their operands,
26 including computing the types of the result, C-specific error checks,
27 and some optimization. */
49 /* Possible cases of implicit bad conversions. Used to select
50 diagnostic messages in convert_for_assignment. */
52 ic_argpass,
53 ic_argpass_nonproto,
54 ic_assign,
55 ic_init,
56 ic_return
57 };
59 /* The level of nesting inside "__alignof__". */
62 /* The level of nesting inside "sizeof". */
65 /* The level of nesting inside "typeof". */
71 /* Nonzero if we've already printed a "missing braces around initializer"
72 message within this initializer. */
110 \f
111 /* Return true if EXP is a null pointer constant, false otherwise. */
113 static bool
115 {
116 /* This should really operate on c_expr structures, but they aren't
117 yet available everywhere required. */
126 }
131 tree t1;
132 tree t2;
133 /* The return value of tagged_types_tu_compatible_p if we had seen
134 these two types already. */
136 };
141 /* Do `exp = require_complete_type (exp);' to make sure exp
142 does not have an incomplete type. (That includes void types.) */
144 tree
146 {
152 /* First, detect a valid value with a complete type. */
158 }
160 /* Print an error message for invalid use of an incomplete type.
161 VALUE is the expression that was used (or 0 if that isn't known)
162 and TYPE is the type that was invalid. */
164 void
166 {
169 /* Avoid duplicate error message. */
176 else
177 {
178 retry:
179 /* We must print an error message. Be clever about what it says. */
182 {
201 {
203 {
206 }
209 }
215 }
220 else
221 /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */
223 }
224 }
226 /* Given a type, apply default promotions wrt unnamed function
227 arguments and return the new type. */
229 tree
231 {
236 {
237 /* Preserve unsignedness if not really getting any wider. */
242 }
245 }
247 /* Return a variant of TYPE which has all the type qualifiers of LIKE
248 as well as those of TYPE. */
250 static tree
252 {
255 }
257 /* Return true iff the given tree T is a variable length array. */
259 bool
261 {
266 }
267 \f
268 /* Return the composite type of two compatible types.
270 We assume that comptypes has already been done and returned
271 nonzero; if that isn't so, this may crash. In particular, we
272 assume that qualifiers match. */
274 tree
276 {
279 tree attributes;
281 /* Save time if the two types are the same. */
285 /* If one type is nonsense, use the other. */
294 /* Merge the attributes. */
297 /* If one is an enumerated type and the other is the compatible
298 integer type, the composite type might be either of the two
299 (DR#013 question 3). For consistency, use the enumerated type as
300 the composite type. */
310 {
312 /* For two pointers, do this recursively on the target type. */
313 {
320 }
323 {
326 tree unqual_elt;
332 /* We should not have any type quals on arrays at all. */
338 d1_variable = (!d1_zero
341 d2_variable = (!d2_zero
347 /* Save space: see if the result is identical to one of the args. */
360 /* Merge the element types, and have a size if either arg has
361 one. We may have qualifiers on the element types. To set
362 up TYPE_MAIN_VARIANT correctly, we need to form the
363 composite of the unqualified types and add the qualifiers
364 back at the end. */
369 && (d2_variable
370 || d2_zero
372 ? t1
376 }
379 /* Function types: prefer the one that specified arg types.
380 If both do, merge the arg types. Also merge the return types. */
381 {
389 /* Save space: see if the result is identical to one of the args. */
395 /* Simple way if one arg fails to specify argument types. */
397 {
401 }
403 {
407 }
409 /* If both args specify argument types, we must merge the two
410 lists, argument by argument. */
411 /* Tell global_bindings_p to return false so that variable_size
412 doesn't die on VLAs in parameter types. */
425 {
426 /* A null type means arg type is not specified.
427 Take whatever the other function type has. */
429 {
432 }
434 {
437 }
439 /* Given wait (union {union wait *u; int *i} *)
440 and wait (union wait *),
441 prefer union wait * as type of parm. */
444 {
445 tree memb;
452 {
458 {
464 }
465 }
466 }
469 {
470 tree memb;
477 {
483 {
489 }
490 }
491 }
493 parm_done: ;
494 }
499 /* ... falls through ... */
500 }
504 }
506 }
508 /* Return the type of a conditional expression between pointers to
509 possibly differently qualified versions of compatible types.
511 We assume that comp_target_types has already been done and returned
512 nonzero; if that isn't so, this may crash. */
514 static tree
516 {
517 tree attributes;
520 tree target;
522 /* Save time if the two types are the same. */
526 /* If one type is nonsense, use the other. */
535 /* Merge the attributes. */
538 /* Find the composite type of the target types, and combine the
539 qualifiers of the two types' targets. Do not lose qualifiers on
540 array element types by taking the TYPE_MAIN_VARIANT. */
553 }
555 /* Return the common type for two arithmetic types under the usual
556 arithmetic conversions. The default conversions have already been
557 applied, and enumerated types converted to their compatible integer
558 types. The resulting type is unqualified and has no attributes.
560 This is the type for the result of most arithmetic operations
561 if the operands have the given two types. */
563 static tree
565 {
569 /* If one type is nonsense, use the other. */
587 /* Save time if the two types are the same. */
599 /* When one operand is a decimal float type, the other operand cannot be
600 a generic float type or a complex type. We also disallow vector types
601 here. */
604 {
606 {
609 }
611 {
614 }
616 {
619 }
620 }
622 /* If one type is a vector type, return that type. (How the usual
623 arithmetic conversions apply to the vector types extension is not
624 precisely specified.) */
631 /* If one type is complex, form the common type of the non-complex
632 components, then make that complex. Use T1 or T2 if it is the
633 required type. */
635 {
644 else
646 }
648 /* If only one is real, use it as the result. */
656 /* If both are real and either are decimal floating point types, use
657 the decimal floating point type with the greater precision. */
660 {
670 }
672 /* Both real or both integers; use the one with greater precision. */
679 /* Same precision. Prefer long longs to longs to ints when the
680 same precision, following the C99 rules on integer type rank
681 (which are equivalent to the C90 rules for C90 types). */
689 {
692 else
694 }
702 {
703 /* But preserve unsignedness from the other type,
704 since long cannot hold all the values of an unsigned int. */
707 else
709 }
711 /* Likewise, prefer long double to double even if same size. */
716 /* Otherwise prefer the unsigned one. */
720 else
722 }
723 \f
724 /* Wrapper around c_common_type that is used by c-common.c and other
725 front end optimizations that remove promotions. ENUMERAL_TYPEs
726 are allowed here and are converted to their compatible integer types.
727 BOOLEAN_TYPEs are allowed here and return either boolean_type_node or
728 preferably a non-Boolean type as the common type. */
729 tree
731 {
737 /* If both types are BOOLEAN_TYPE, then return boolean_type_node. */
742 /* If either type is BOOLEAN_TYPE, then return the other. */
749 }
751 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
752 or various other operations. Return 2 if they are compatible
753 but a warning may be needed if you use them together. */
755 int
757 {
765 }
766 \f
767 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
768 or various other operations. Return 2 if they are compatible
769 but a warning may be needed if you use them together. This
770 differs from comptypes, in that we don't free the seen types. */
772 static int
774 {
779 /* Suppress errors caused by previously reported errors. */
785 /* If either type is the internal version of sizetype, return the
786 language version. */
796 /* Enumerated types are compatible with integer types, but this is
797 not transitive: two enumerated types in the same translation unit
798 are compatible with each other only if they are the same type. */
808 /* Different classes of types can't be compatible. */
813 /* Qualifiers must match. C99 6.7.3p9 */
818 /* Allow for two different type nodes which have essentially the same
819 definition. Note that we already checked for equality of the type
820 qualifiers (just above). */
826 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
830 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
834 {
836 /* Do not remove mode or aliasing information. */
849 {
856 /* Target types must match incl. qualifiers. */
861 /* Sizes must match unless one is missing or variable. */
868 d1_variable = (!d1_zero
871 d2_variable = (!d2_zero
887 }
893 {
897 }
907 }
909 }
911 /* Return 1 if TTL and TTR are pointers to types that are equivalent,
912 ignoring their qualifiers. */
914 static int
916 {
920 /* Do not lose qualifiers on element types of array types that are
921 pointer targets by taking their TYPE_MAIN_VARIANT. */
933 }
934 \f
935 /* Subroutines of `comptypes'. */
937 /* Determine whether two trees derive from the same translation unit.
938 If the CONTEXT chain ends in a null, that tree's context is still
939 being parsed, so if two trees have context chains ending in null,
940 they're in the same translation unit. */
941 int
943 {
946 {
954 }
958 {
966 }
969 }
971 /* Allocate the seen two types, assuming that they are compatible. */
975 {
983 /* The C standard says that two structures in different translation
984 units are compatible with each other only if the types of their
985 fields are compatible (among other things). We assume that they
986 are compatible until proven otherwise when building the cache.
987 An example where this can occur is:
988 struct a
989 {
990 struct a *next;
991 };
992 If we are comparing this against a similar struct in another TU,
993 and did not assume they were compatible, we end up with an infinite
994 loop. */
997 }
999 /* Free the seen types until we get to TU_TIL. */
1001 static void
1003 {
1006 {
1010 }
1012 }
1014 /* Return 1 if two 'struct', 'union', or 'enum' types T1 and T2 are
1015 compatible. If the two types are not the same (which has been
1016 checked earlier), this can only happen when multiple translation
1017 units are being compiled. See C99 6.2.7 paragraph 1 for the exact
1018 rules. */
1020 static int
1022 {
1026 /* We have to verify that the tags of the types are the same. This
1027 is harder than it looks because this may be a typedef, so we have
1028 to go look at the original type. It may even be a typedef of a
1029 typedef...
1030 In the case of compiler-created builtin structs the TYPE_DECL
1031 may be a dummy, with no DECL_ORIGINAL_TYPE. Don't fault. */
1042 /* C90 didn't have the requirement that the two tags be the same. */
1046 /* C90 didn't say what happened if one or both of the types were
1047 incomplete; we choose to follow C99 rules here, which is that they
1048 are compatible. */
1053 {
1058 }
1061 {
1063 {
1065 /* Speed up the case where the type values are in the same order. */
1070 {
1072 }
1075 {
1079 {
1082 }
1083 }
1086 {
1088 }
1090 {
1093 }
1096 {
1099 }
1102 {
1106 {
1109 }
1110 }
1112 }
1115 {
1118 {
1121 }
1123 /* Speed up the common case where the fields are in the same order. */
1126 {
1135 {
1138 }
1145 {
1148 }
1149 }
1151 {
1154 }
1157 {
1163 {
1167 {
1170 }
1181 }
1183 {
1186 }
1187 }
1190 }
1193 {
1199 {
1214 }
1217 else
1220 }
1224 }
1225 }
1227 /* Return 1 if two function types F1 and F2 are compatible.
1228 If either type specifies no argument types,
1229 the other must specify a fixed number of self-promoting arg types.
1230 Otherwise, if one type specifies only the number of arguments,
1231 the other must specify that number of self-promoting arg types.
1232 Otherwise, the argument types must match. */
1234 static int
1236 {
1238 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
1246 /* 'volatile' qualifiers on a function's return type used to mean
1247 the function is noreturn. */
1263 /* An unspecified parmlist matches any specified parmlist
1264 whose argument types don't need default promotions. */
1267 {
1270 /* If one of these types comes from a non-prototype fn definition,
1271 compare that with the other type's arglist.
1272 If they don't match, ask for a warning (but no error). */
1277 }
1279 {
1286 }
1288 /* Both types have argument lists: compare them and propagate results. */
1291 }
1293 /* Check two lists of types for compatibility,
1294 returning 0 for incompatible, 1 for compatible,
1295 or 2 for compatible with warning. */
1297 static int
1299 {
1300 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
1305 {
1309 /* If one list is shorter than the other,
1310 they fail to match. */
1319 /* A null pointer instead of a type
1320 means there is supposed to be an argument
1321 but nothing is specified about what type it has.
1322 So match anything that self-promotes. */
1324 {
1327 }
1329 {
1332 }
1333 /* If one of the lists has an error marker, ignore this arg. */
1336 ;
1338 {
1339 /* Allow wait (union {union wait *u; int *i} *)
1340 and wait (union wait *) to be compatible. */
1347 {
1348 tree memb;
1351 {
1358 }
1361 }
1368 {
1369 tree memb;
1372 {
1379 }
1382 }
1383 else
1385 }
1387 /* comptypes said ok, but record if it said to warn. */
1393 }
1394 }
1395 \f
1396 /* Compute the size to increment a pointer by. */
1398 static tree
1400 {
1407 {
1410 }
1412 /* Convert in case a char is more than one unit. */
1416 }
1417 \f
1418 /* Return either DECL or its known constant value (if it has one). */
1420 tree
1422 {
1424 in a place where a variable is invalid. Note that DECL_INITIAL
1425 isn't valid for a PARM_DECL. */
1432 /* This is invalid if initial value is not constant.
1433 If it has either a function call, a memory reference,
1434 or a variable, then re-evaluating it could give different results. */
1436 /* Check for cases where this is sub-optimal, even though valid. */
1440 }
1442 /* Return either DECL or its known constant value (if it has one), but
1443 return DECL if pedantic or DECL has mode BLKmode. This is for
1444 bug-compatibility with the old behavior of decl_constant_value
1445 (before GCC 3.0); every use of this function is a bug and it should
1446 be removed before GCC 3.1. It is not appropriate to use pedantic
1447 in a way that affects optimization, and BLKmode is probably not the
1448 right test for avoiding misoptimizations either. */
1450 static tree
1452 {
1453 tree ret;
1459 /* Avoid unwanted tree sharing between the initializer and current
1460 function's body where the tree can be modified e.g. by the
1461 gimplifier. */
1465 }
1467 /* Convert the array expression EXP to a pointer. */
1468 static tree
1470 {
1473 tree adr;
1475 tree ptrtype;
1490 {
1491 /* We are making an ADDR_EXPR of ptrtype. This is a valid
1492 ADDR_EXPR because it's the best way of representing what
1493 happens in C when we take the address of an array and place
1494 it in a pointer to the element type. */
1500 }
1502 /* This way is better for a COMPONENT_REF since it can
1503 simplify the offset for a component. */
1506 }
1508 /* Convert the function expression EXP to a pointer. */
1509 static tree
1511 {
1522 }
1524 /* Perform the default conversion of arrays and functions to pointers.
1525 Return the result of converting EXP. For any other expression, just
1526 return EXP after removing NOPs. */
1528 struct c_expr
1530 {
1536 {
1538 {
1546 {
1550 }
1557 {
1558 /* Before C99, non-lvalue arrays do not decay to pointers.
1559 Normally, using such an array would be invalid; but it can
1560 be used correctly inside sizeof or as a statement expression.
1561 Thus, do not give an error here; an error will result later. */
1563 }
1566 }
1576 }
1579 }
1582 /* EXP is an expression of integer type. Apply the integer promotions
1583 to it and return the promoted value. */
1585 tree
1587 {
1593 /* Normally convert enums to int,
1594 but convert wide enums to something wider. */
1596 {
1604 }
1606 /* ??? This should no longer be needed now bit-fields have their
1607 proper types. */
1610 /* If it's thinner than an int, promote it like a
1611 c_promoting_integer_type_p, otherwise leave it alone. */
1617 {
1618 /* Preserve unsignedness if not really getting any wider. */
1624 }
1627 }
1630 /* Perform default promotions for C data used in expressions.
1631 Enumeral types or short or char are converted to int.
1632 In addition, manifest constants symbols are replaced by their values. */
1634 tree
1636 {
1637 tree orig_exp;
1641 /* Functions and arrays have been converted during parsing. */
1646 /* Constants can be used directly unless they're not loadable. */
1650 /* Replace a nonvolatile const static variable with its value unless
1651 it is an array, in which case we must be sure that taking the
1652 address of the array produces consistent results. */
1654 {
1657 }
1659 /* Strip no-op conversions. */
1670 {
1673 }
1675 }
1676 \f
1677 /* Look up COMPONENT in a structure or union DECL.
1679 If the component name is not found, returns NULL_TREE. Otherwise,
1680 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL
1681 stepping down the chain to the component, which is in the last
1682 TREE_VALUE of the list. Normally the list is of length one, but if
1683 the component is embedded within (nested) anonymous structures or
1684 unions, the list steps down the chain to the component. */
1686 static tree
1688 {
1690 tree field;
1692 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers
1693 to the field elements. Use a binary search on this array to quickly
1694 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC
1695 will always be set for structures which have many elements. */
1698 {
1706 {
1711 {
1712 /* Step through all anon unions in linear fashion. */
1714 {
1718 {
1723 }
1724 }
1726 /* Entire record is only anon unions. */
1730 /* Restart the binary search, with new lower bound. */
1732 }
1738 else
1740 }
1746 }
1747 else
1748 {
1750 {
1754 {
1759 }
1763 }
1767 }
1770 }
1772 /* Make an expression to refer to the COMPONENT field of
1773 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */
1775 tree
1777 {
1781 tree ref;
1786 /* See if there is a field or component with name COMPONENT. */
1789 {
1791 {
1794 }
1799 {
1802 }
1804 /* Chain the COMPONENT_REFs if necessary down to the FIELD.
1805 This might be better solved in future the way the C++ front
1806 end does it - by giving the anonymous entities each a
1807 separate name and type, and then have build_component_ref
1808 recursively call itself. We can't do that here. */
1809 do
1810 {
1817 NULL_TREE);
1829 }
1833 }
1836 component);
1839 }
1840 \f
1841 /* Given an expression PTR for a pointer, return an expression
1842 for the value pointed to.
1843 ERRORSTRING is the name of the operator to appear in error messages. */
1845 tree
1847 {
1852 {
1857 else
1858 {
1860 tree ref;
1865 {
1868 }
1872 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
1873 so that we get the proper error message if the result is used
1874 to assign to. Also, &* is supposed to be a no-op.
1875 And ANSI C seems to specify that the type of the result
1876 should be the const type. */
1877 /* A de-reference of a pointer to const is not a const. It is valid
1878 to change it via some other pointer. */
1884 }
1885 }
1889 }
1891 /* This handles expressions of the form "a[i]", which denotes
1892 an array reference.
1894 This is logically equivalent in C to *(a+i), but we may do it differently.
1895 If A is a variable or a member, we generate a primitive ARRAY_REF.
1896 This avoids forcing the array out of registers, and can work on
1897 arrays that are not lvalues (for example, members of structures returned
1898 by functions). */
1900 tree
1902 {
1910 {
1911 tree temp;
1914 {
1917 }
1922 }
1925 {
1928 }
1931 {
1934 }
1936 /* ??? Existing practice has been to warn only when the char
1937 index is syntactically the index, not for char[array]. */
1941 /* Apply default promotions *after* noticing character types. */
1947 {
1950 /* An array that is indexed by a non-constant
1951 cannot be stored in a register; we must be able to do
1952 address arithmetic on its address.
1953 Likewise an array of elements of variable size. */
1957 {
1960 }
1961 /* An array that is indexed by a constant value which is not within
1962 the array bounds cannot be stored in a register either; because we
1963 would get a crash in store_bit_field/extract_bit_field when trying
1964 to access a non-existent part of the register. */
1968 {
1971 }
1974 {
1982 }
1988 /* Array ref is const/volatile if the array elements are
1989 or if the array is. */
1998 /* This was added by rms on 16 Nov 91.
1999 It fixes vol struct foo *a; a->elts[1]
2000 in an inline function.
2001 Hope it doesn't break something else. */
2004 }
2005 else
2006 {
2017 }
2018 }
2019 \f
2020 /* Build an external reference to identifier ID. FUN indicates
2021 whether this will be used for a function call. LOC is the source
2022 location of the identifier. */
2023 tree
2025 {
2026 tree ref;
2029 /* In Objective-C, an instance variable (ivar) may be preferred to
2030 whatever lookup_name() found. */
2036 /* Implicit function declaration. */
2039 /* Don't complain about something that's already been
2040 complained about. */
2042 else
2043 {
2046 }
2059 {
2066 }
2069 {
2074 }
2080 {
2085 }
2088 }
2090 /* Record details of decls possibly used inside sizeof or typeof. */
2091 struct maybe_used_decl
2092 {
2093 /* The decl. */
2094 tree decl;
2095 /* The level seen at (in_sizeof + in_typeof). */
2097 /* The next one at this level or above, or NULL. */
2099 };
2103 /* Record that DECL, an undefined static function reference seen
2104 inside sizeof or typeof, might be used if the operand of sizeof is
2105 a VLA type or the operand of typeof is a variably modified
2106 type. */
2108 static void
2110 {
2116 }
2118 /* Pop the stack of decls possibly used inside sizeof or typeof. If
2119 USED is false, just discard them. If it is true, mark them used
2120 (if no longer inside sizeof or typeof) or move them to the next
2121 level up (if still inside sizeof or typeof). */
2123 void
2125 {
2129 {
2131 {
2134 else
2136 }
2138 }
2141 }
2143 /* Return the result of sizeof applied to EXPR. */
2145 struct c_expr
2147 {
2150 {
2154 }
2155 else
2156 {
2160 {
2161 /* sizeof is evaluated when given a vla (C99 6.5.3.4p2). */
2163 }
2165 }
2167 }
2169 /* Return the result of sizeof applied to T, a structure for the type
2170 name passed to sizeof (rather than the type itself). */
2172 struct c_expr
2174 {
2175 tree type;
2183 }
2185 /* Build a function call to function FUNCTION with parameters PARAMS.
2186 PARAMS is a list--a chain of TREE_LIST nodes--in which the
2187 TREE_VALUE of each node is a parameter-expression.
2188 FUNCTION's data type may be a function type or a pointer-to-function. */
2190 tree
2192 {
2194 tree coerced_params;
2196 tree tem;
2198 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2201 /* Convert anything with function type to a pointer-to-function. */
2203 {
2204 /* Implement type-directed function overloading for builtins.
2205 resolve_overloaded_builtin and targetm.resolve_overloaded_builtin
2206 handle all the type checking. The result is a complete expression
2207 that implements this function call. */
2214 }
2218 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2219 expressions, like those used for ObjC messenger dispatches. */
2229 {
2232 }
2237 /* fntype now gets the type of function pointed to. */
2240 /* Check that the function is called through a compatible prototype.
2241 If it is not, replace the call by a trap, wrapped up in a compound
2242 expression if necessary. This has the nice side-effect to prevent
2243 the tree-inliner from generating invalid assignment trees which may
2244 blow up in the RTL expander later. */
2250 {
2253 NULL_TREE);
2255 /* This situation leads to run-time undefined behavior. We can't,
2256 therefore, simply error unless we can prove that all possible
2257 executions of the program must execute the code. */
2260 /* We can, however, treat "undefined" any way we please.
2261 Call abort to encourage the user to fix the program. */
2266 else
2267 {
2268 tree rhs;
2273 else
2277 }
2278 }
2280 /* Convert the parameters to the types declared in the
2281 function prototype, or apply default promotions. */
2283 coerced_params
2289 /* Check that the arguments to the function are valid. */
2295 {
2303 }
2304 else
2311 }
2312 \f
2313 /* Convert the argument expressions in the list VALUES
2314 to the types in the list TYPELIST. The result is a list of converted
2315 argument expressions, unless there are too few arguments in which
2316 case it is error_mark_node.
2318 If TYPELIST is exhausted, or when an element has NULL as its type,
2319 perform the default conversions.
2321 PARMLIST is the chain of parm decls for the function being called.
2322 It may be 0, if that info is not available.
2323 It is used only for generating error messages.
2325 FUNCTION is a tree for the called function. It is used only for
2326 error messages, where it is formatted with %qE.
2328 This is also where warnings about wrong number of args are generated.
2330 Both VALUES and the returned value are chains of TREE_LIST nodes
2331 with the elements of the list in the TREE_VALUE slots of those nodes. */
2333 static tree
2335 {
2339 tree selector;
2341 /* Change pointer to function to the function itself for
2342 diagnostics. */
2347 /* Handle an ObjC selector specially for diagnostics. */
2350 /* Scan the given expressions and types, producing individual
2351 converted arguments and pushing them on RESULT in reverse order. */
2354 valtail;
2356 {
2364 {
2367 }
2370 {
2373 }
2380 {
2381 /* Formal parm type is specified by a function prototype. */
2382 tree parmval;
2385 {
2388 }
2389 else
2390 {
2391 /* Optionally warn about conversions that
2392 differ from the default conversions. */
2394 {
2427 /* ??? At some point, messages should be written about
2428 conversions between complex types, but that's too messy
2429 to do now. */
2432 {
2433 /* Warn if any argument is passed as `float',
2434 since without a prototype it would be `double'. */
2441 /* Warn if mismatch between argument and prototype
2442 for decimal float types. Warn of conversions with
2443 binary float types and of precision narrowing due to
2444 prototype. */
2452 && (formal_prec
2456 != dfloat64_type_node
2466 }
2467 /* Detect integer changing in width or signedness.
2468 These warnings are only activated with
2469 -Wconversion, not with -Wtraditional. */
2472 {
2479 /* No warning if function asks for enum
2480 and the actual arg is that enum type. */
2481 ;
2487 ;
2488 /* Don't complain if the formal parameter type
2489 is an enum, because we can't tell now whether
2490 the value was an enum--even the same enum. */
2492 ;
2495 /* Change in signedness doesn't matter
2496 if a constant value is unaffected. */
2497 ;
2498 /* If the value is extended from a narrower
2499 unsigned type, it doesn't matter whether we
2500 pass it as signed or unsigned; the value
2501 certainly is the same either way. */
2504 ;
2509 else
2512 }
2513 }
2523 }
2525 }
2530 /* Convert `float' to `double'. */
2534 {
2537 }
2538 else
2539 /* Convert `short' and `char' to full-size `int'. */
2544 }
2547 {
2550 }
2553 }
2554 \f
2555 /* This is the entry point used by the parser to build unary operators
2556 in the input. CODE, a tree_code, specifies the unary operator, and
2557 ARG is the operand. For unary plus, the C parser currently uses
2558 CONVERT_EXPR for code. */
2560 struct c_expr
2562 {
2569 }
2571 /* This is the entry point used by the parser to build binary operators
2572 in the input. CODE, a tree_code, specifies the binary operator, and
2573 ARG1 and ARG2 are the operands. In addition to constructing the
2574 expression, we check for operands that were written with other binary
2575 operators in a way that is likely to confuse the user. */
2577 struct c_expr
2580 {
2592 /* Check for cases such as x+y<<z which users are likely
2593 to misinterpret. */
2595 {
2597 {
2602 }
2605 {
2610 }
2613 {
2620 /* Check cases like x|y==z */
2625 }
2628 {
2635 /* Check cases like x^y==z */
2640 }
2643 {
2648 /* Check cases like x&y==z */
2653 }
2654 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */
2661 }
2663 /* Warn about comparisons against string literals, with the exception
2664 of testing for equality or inequality of a string literal with NULL. */
2666 {
2671 }
2680 }
2681 \f
2682 /* Return a tree for the difference of pointers OP0 and OP1.
2683 The resulting tree has type int. */
2685 static tree
2687 {
2695 {
2700 }
2702 /* If the conversion to ptrdiff_type does anything like widening or
2703 converting a partial to an integral mode, we get a convert_expression
2704 that is in the way to do any simplifications.
2705 (fold-const.c doesn't know that the extra bits won't be needed.
2706 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2707 different mode in place.)
2708 So first try to find a common term here 'by hand'; we want to cover
2709 at least the cases that occur in legal static initializers. */
2714 else
2720 else
2724 {
2727 }
2728 else
2732 {
2735 }
2736 else
2740 {
2743 }
2746 /* First do the subtraction as integers;
2747 then drop through to build the divide operator.
2748 Do not do default conversions on the minus operator
2749 in case restype is a short type. */
2753 /* This generates an error if op1 is pointer to incomplete type. */
2757 /* This generates an error if op0 is pointer to incomplete type. */
2760 /* Divide by the size, in easiest possible way. */
2762 }
2763 \f
2764 /* Construct and perhaps optimize a tree representation
2765 for a unary operation. CODE, a tree_code, specifies the operation
2766 and XARG is the operand.
2767 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2768 the default promotions (such as from short to int).
2769 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2770 allows non-lvalues; this is only used to handle conversion of non-lvalue
2771 arrays to pointers in C99. */
2773 tree
2775 {
2776 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2780 tree val;
2791 {
2794 }
2797 {
2799 /* This is used for unary plus, because a CONVERT_EXPR
2800 is enough to prevent anybody from looking inside for
2801 associativity, but won't generate any code. */
2805 {
2808 }
2818 {
2821 }
2828 {
2831 }
2833 {
2839 }
2840 else
2841 {
2844 }
2849 {
2852 }
2858 /* Conjugating a real value is a no-op, but allow it anyway. */
2861 {
2864 }
2873 {
2876 }
2885 else
2893 else
2901 /* Increment or decrement the real part of the value,
2902 and don't change the imaginary part. */
2904 {
2916 }
2918 /* Report invalid types. */
2922 {
2925 else
2929 }
2931 {
2932 tree inc;
2938 /* Compute the increment. */
2941 {
2942 /* If pointer target is an undefined struct,
2943 we just cannot know how to do the arithmetic. */
2945 {
2948 else
2950 }
2954 {
2957 else
2959 }
2962 }
2963 else
2968 /* Complain about anything else that is not a true lvalue. */
2971 ? lv_increment
2975 /* Report a read-only lvalue. */
2977 {
2983 }
2987 else
2994 }
2997 /* Note that this operation never does default_conversion. */
2999 /* Let &* cancel out to simplify resulting code. */
3001 {
3002 /* Don't let this be an lvalue. */
3006 }
3008 /* For &x[y], return x+y */
3010 {
3019 }
3021 /* Anything not already handled and not a true memory reference
3022 or a non-lvalue array is an error. */
3027 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
3030 /* If the lvalue is const or volatile, merge that into the type
3031 to which the address will point. Note that you can't get a
3032 restricted pointer by taking the address of something, so we
3033 only have to deal with `const' and `volatile' here. */
3048 /* ??? Cope with user tricks that amount to offsetof. Delete this
3049 when we have proper support for integer constant expressions. */
3053 {
3058 }
3066 }
3072 }
3074 /* Return nonzero if REF is an lvalue valid for this language.
3075 Lvalues can be assigned, unless their type has TYPE_READONLY.
3076 Lvalues can have their address taken, unless they have C_DECL_REGISTER. */
3078 static int
3080 {
3084 {
3108 }
3109 }
3110 \f
3111 /* Give an error for storing in something that is 'const'. */
3113 static void
3115 {
3118 /* Using this macro rather than (for example) arrays of messages
3119 ensures that all the format strings are checked at compile
3120 time. */
3121 #define READONLY_MSG(A, I, D, AS) (use == lv_assign ? (A) \
3122 : (use == lv_increment ? (I) \
3123 : (use == lv_decrement ? (D) : (AS))))
3125 {
3128 else
3134 }
3140 arg);
3141 else
3146 }
3149 /* Return nonzero if REF is an lvalue valid for this language;
3150 otherwise, print an error message and return zero. USE says
3151 how the lvalue is being used and so selects the error message. */
3153 static int
3155 {
3162 }
3163 \f
3164 /* Mark EXP saying that we need to be able to take the
3165 address of it; it should not be allocated in a register.
3166 Returns true if successful. */
3168 bool
3170 {
3175 {
3178 {
3179 error
3182 }
3184 /* ... fall through ... */
3204 {
3206 {
3207 error
3210 }
3212 }
3214 {
3217 else
3220 }
3222 /* drops in */
3225 /* drops out */
3228 }
3229 }
3230 \f
3231 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
3233 tree
3235 {
3236 tree type1;
3237 tree type2;
3243 /* Promote both alternatives. */
3260 /* C90 does not permit non-lvalue arrays in conditional expressions.
3261 In C99 they will be pointers by now. */
3263 {
3266 }
3268 /* Quickly detect the usual case where op1 and op2 have the same type
3269 after promotion. */
3271 {
3274 else
3276 }
3281 {
3284 /* If -Wsign-compare, warn here if type1 and type2 have
3285 different signedness. We'll promote the signed to unsigned
3286 and later code won't know it used to be different.
3287 Do this check on the original types, so that explicit casts
3288 will be considered, but default promotions won't. */
3290 {
3295 {
3296 /* Do not warn if the result type is signed, since the
3297 signed type will only be chosen if it can represent
3298 all the values of the unsigned type. */
3301 /* Do not warn if the signed quantity is an unsuffixed
3302 integer literal (or some static constant expression
3303 involving such literals) and it is non-negative. */
3307 else
3309 }
3310 }
3311 }
3313 {
3317 }
3319 {
3327 {
3333 }
3335 {
3341 }
3342 else
3343 {
3346 }
3347 }
3349 {
3352 else
3353 {
3355 }
3357 }
3359 {
3362 else
3363 {
3365 }
3367 }
3370 {
3373 else
3374 {
3377 }
3378 }
3380 /* Merge const and volatile flags of the incoming types. */
3381 result_type
3392 }
3393 \f
3394 /* Return a compound expression that performs two expressions and
3395 returns the value of the second of them. */
3397 tree
3399 {
3401 {
3402 /* The left-hand operand of a comma expression is like an expression
3403 statement: with -Wextra or -Wunused, we should warn if it doesn't have
3404 any side-effects, unless it was explicitly cast to (void). */
3406 {
3416 else
3418 }
3419 }
3421 /* With -Wunused, we should also warn if the left-hand operand does have
3422 side-effects, but computes a value which is not used. For example, in
3423 `foo() + bar(), baz()' the result of the `+' operator is not used,
3424 so we should issue a warning. */
3429 }
3431 /* Build an expression representing a cast to type TYPE of expression EXPR. */
3433 tree
3435 {
3441 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
3442 only in <protocol> qualifications. But when constructing cast expressions,
3443 the protocols do matter and must be kept around. */
3450 {
3453 }
3456 {
3459 }
3462 {
3464 {
3468 }
3469 }
3471 {
3472 tree field;
3480 {
3481 tree t;
3491 }
3494 }
3495 else
3496 {
3504 /* Optionally warn about potentially worrisome casts. */
3509 {
3515 /* Check that the qualifiers on IN_TYPE are a superset of
3516 the qualifiers of IN_OTYPE. The outermost level of
3517 POINTER_TYPE nodes is uninteresting and we stop as soon
3518 as we hit a non-POINTER_TYPE node on either type. */
3519 do
3520 {
3524 /* GNU C allows cv-qualified function types. 'const'
3525 means the function is very pure, 'volatile' means it
3526 can't return. We need to warn when such qualifiers
3527 are added, not when they're taken away. */
3531 else
3533 }
3541 /* There are qualifiers present in IN_OTYPE that are not
3542 present in IN_TYPE. */
3544 }
3546 /* Warn about possible alignment problems. */
3552 /* Don't warn about opaque types, where the actual alignment
3553 restriction is unknown. */
3564 /* Unlike conversion of integers to pointers, where the
3565 warning is disabled for converting constants because
3566 of cases such as SIG_*, warn about converting constant
3567 pointers to integers. In some cases it may cause unwanted
3568 sign extension, and a warning is appropriate. */
3580 /* Don't warn about converting any constant. */
3587 /* If pedantic, warn for conversions between function and object
3588 pointer types, except for converting a null pointer constant
3589 to function pointer type. */
3608 /* Ignore any integer overflow caused by the cast. */
3610 {
3613 {
3614 /* Avoid clobbering a shared constant. */
3618 }
3620 /* Reset VALUE's overflow flags, ensuring constant sharing. */
3624 }
3625 }
3627 /* Don't let a cast be an lvalue. */
3632 }
3634 /* Interpret a cast of expression EXPR to type TYPE. */
3635 tree
3637 {
3638 tree type;
3641 /* This avoids warnings about unprototyped casts on
3642 integers. E.g. "#define SIG_DFL (void(*)())0". */
3649 }
3650 \f
3651 /* Build an assignment expression of lvalue LHS from value RHS.
3652 MODIFYCODE is the code for a binary operator that we use
3653 to combine the old value of LHS with RHS to get the new value.
3654 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3656 tree
3658 {
3659 tree result;
3660 tree newrhs;
3664 /* Types that aren't fully specified cannot be used in assignments. */
3667 /* Avoid duplicate error messages from operands that had errors. */
3678 /* If a binary op has been requested, combine the old LHS value with the RHS
3679 producing the value we should actually store into the LHS. */
3682 {
3685 }
3687 /* Give an error for storing in something that is 'const'. */
3693 {
3696 }
3698 /* If storing into a structure or union member,
3699 it has probably been given type `int'.
3700 Compute the type that would go with
3701 the actual amount of storage the member occupies. */
3710 /* If storing in a field that is in actuality a short or narrower than one,
3711 we must store in the field in its actual type. */
3714 {
3717 }
3719 /* Convert new value to destination type. */
3726 /* Emit ObjC write barrier, if necessary. */
3728 {
3732 }
3734 /* Scan operands. */
3739 /* If we got the LHS in a different type for storing in,
3740 convert the result back to the nominal type of LHS
3741 so that the value we return always has the same type
3742 as the LHS argument. */
3748 }
3749 \f
3750 /* Convert value RHS to type TYPE as preparation for an assignment
3751 to an lvalue of type TYPE.
3752 The real work of conversion is done by `convert'.
3753 The purpose of this function is to generate error messages
3754 for assignments that are not allowed in C.
3755 ERRTYPE says whether it is argument passing, assignment,
3756 initialization or return.
3758 FUNCTION is a tree for the function being called.
3759 PARMNUM is the number of the argument, for printing in error messages. */
3761 static tree
3764 {
3766 tree rhstype;
3772 {
3773 tree selector;
3774 /* Change pointer to function to the function itself for
3775 diagnostics. */
3780 /* Handle an ObjC selector specially for diagnostics. */
3784 {
3787 }
3788 }
3790 /* This macro is used to emit diagnostics to ensure that all format
3791 strings are complete sentences, visible to gettext and checked at
3792 compile time. */
3793 #define WARN_FOR_ASSIGNMENT(AR, AS, IN, RE) \
3794 do { \
3795 switch (errtype) \
3796 { \
3797 case ic_argpass: \
3798 pedwarn (AR, parmnum, rname); \
3799 break; \
3800 case ic_argpass_nonproto: \
3801 warning (0, AR, parmnum, rname); \
3802 break; \
3803 case ic_assign: \
3804 pedwarn (AS); \
3805 break; \
3806 case ic_init: \
3807 pedwarn (IN); \
3808 break; \
3809 case ic_return: \
3810 pedwarn (RE); \
3811 break; \
3812 default: \
3813 gcc_unreachable (); \
3814 } \
3815 } while (0)
3830 {
3834 {
3850 }
3853 }
3856 {
3859 }
3862 {
3863 /* Except for passing an argument to an unprototyped function,
3864 this is a constraint violation. When passing an argument to
3865 an unprototyped function, it is compile-time undefined;
3866 making it a constraint in that case was rejected in
3867 DR#252. */
3870 }
3871 /* A type converts to a reference to it.
3872 This code doesn't fully support references, it's just for the
3873 special case of va_start and va_copy. */
3876 {
3878 {
3881 }
3886 /* We already know that these two types are compatible, but they
3887 may not be exactly identical. In fact, `TREE_TYPE (type)' is
3888 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
3889 likely to be va_list, a typedef to __builtin_va_list, which
3890 is different enough that it will cause problems later. */
3896 }
3897 /* Some types can interconvert without explicit casts. */
3901 /* Arithmetic types all interconvert, and enum is treated like int. */
3910 /* Conversion to a transparent union from its member types.
3911 This applies only to function arguments. */
3914 {
3918 {
3929 {
3933 /* Any non-function converts to a [const][volatile] void *
3934 and vice versa; otherwise, targets must be the same.
3935 Meanwhile, the lhs target must have all the qualifiers of
3936 the rhs. */
3939 {
3940 /* If this type won't generate any warnings, use it. */
3950 /* Keep looking for a better type, but remember this one. */
3953 }
3954 }
3956 /* Can convert integer zero to any pointer type. */
3958 {
3961 }
3962 }
3965 {
3967 {
3968 /* We have only a marginally acceptable member type;
3969 it needs a warning. */
3973 /* Const and volatile mean something different for function
3974 types, so the usual warnings are not appropriate. */
3977 {
3978 /* Because const and volatile on functions are
3979 restrictions that say the function will not do
3980 certain things, it is okay to use a const or volatile
3981 function where an ordinary one is wanted, but not
3982 vice-versa. */
3985 "makes qualified function "
3988 "function pointer from "
3991 "function pointer from "
3995 }
4007 }
4013 }
4014 }
4016 /* Conversions among pointers */
4019 {
4031 /* Opaque pointers are treated like void pointers. */
4037 /* C++ does not allow the implicit conversion void* -> T*. However,
4038 for the purpose of reducing the number of false positives, we
4039 tolerate the special case of
4041 int *p = NULL;
4043 where NULL is typically defined in C to be '(void *) 0'. */
4048 /* Check if the right-hand side has a format attribute but the
4049 left-hand side doesn't. */
4052 {
4054 {
4058 "argument %d of %qE might be "
4064 "assignment left-hand side might be "
4069 "initialization left-hand side might be "
4074 "return type might be "
4079 }
4080 }
4082 /* Any non-function converts to a [const][volatile] void *
4083 and vice versa; otherwise, targets must be the same.
4084 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
4087 || is_opaque_pointer
4090 {
4093 ||
4098 "%qE between function pointer "
4106 /* Const and volatile mean something different for function types,
4107 so the usual warnings are not appropriate. */
4110 {
4112 {
4113 /* Types differing only by the presence of the 'volatile'
4114 qualifier are acceptable if the 'volatile' has been added
4115 in by the Objective-C EH machinery. */
4125 }
4126 /* If this is not a case of ignoring a mismatch in signedness,
4127 no warning. */
4130 ;
4131 /* If there is a mismatch, do warn. */
4141 }
4144 {
4145 /* Because const and volatile on functions are restrictions
4146 that say the function will not do certain things,
4147 it is okay to use a const or volatile function
4148 where an ordinary one is wanted, but not vice-versa. */
4151 "qualified function pointer "
4159 }
4160 }
4161 else
4162 /* Avoid warning about the volatile ObjC EH puts on decls. */
4172 }
4174 {
4175 /* ??? This should not be an error when inlining calls to
4176 unprototyped functions. */
4179 }
4181 {
4182 /* An explicit constant 0 can convert to a pointer,
4183 or one that results from arithmetic, even including
4184 a cast to integer type. */
4196 }
4198 {
4208 }
4213 {
4216 /* ??? This should not be an error when inlining calls to
4217 unprototyped functions. */
4231 }
4234 }
4236 /* Convert VALUE for assignment into inlined parameter PARM. ARGNUM
4237 is used for error and waring reporting and indicates which argument
4238 is being processed. */
4240 tree
4242 {
4245 /* If FN was prototyped, the value has been converted already
4246 in convert_arguments. */
4259 }
4260 \f
4261 /* If VALUE is a compound expr all of whose expressions are constant, then
4262 return its value. Otherwise, return error_mark_node.
4264 This is for handling COMPOUND_EXPRs as initializer elements
4265 which is allowed with a warning when -pedantic is specified. */
4267 static tree
4269 {
4271 {
4276 endtype);
4277 }
4280 else
4282 }
4283 \f
4284 /* Perform appropriate conversions on the initial value of a variable,
4285 store it in the declaration DECL,
4286 and print any error messages that are appropriate.
4287 If the init is invalid, store an ERROR_MARK. */
4289 void
4291 {
4294 /* If variable's type was invalidly declared, just ignore it. */
4300 /* Digest the specified initializer into an expression. */
4304 /* Store the expression if valid; else report error. */
4313 /* ANSI wants warnings about out-of-range constant initializers. */
4317 /* Check if we need to set array size from compound literal size. */
4321 {
4328 {
4332 {
4333 /* For int foo[] = (int [3]){1}; we need to set array size
4334 now since later on array initializer will be just the
4335 brace enclosed list of the compound literal. */
4339 }
4340 }
4341 }
4342 }
4343 \f
4344 /* Methods for storing and printing names for error messages. */
4346 /* Implement a spelling stack that allows components of a name to be pushed
4347 and popped. Each element on the stack is this structure. */
4349 struct spelling
4350 {
4352 union
4353 {
4357 };
4359 #define SPELLING_STRING 1
4360 #define SPELLING_MEMBER 2
4361 #define SPELLING_BOUNDS 3
4367 /* Macros to save and restore the spelling stack around push_... functions.
4368 Alternative to SAVE_SPELLING_STACK. */
4370 #define SPELLING_DEPTH() (spelling - spelling_base)
4371 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
4373 /* Push an element on the spelling stack with type KIND and assign VALUE
4374 to MEMBER. */
4376 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
4377 { \
4378 int depth = SPELLING_DEPTH (); \
4379 \
4380 if (depth >= spelling_size) \
4381 { \
4382 spelling_size += 10; \
4383 spelling_base = XRESIZEVEC (struct spelling, spelling_base, \
4384 spelling_size); \
4385 RESTORE_SPELLING_DEPTH (depth); \
4386 } \
4387 \
4388 spelling->kind = (KIND); \
4389 spelling->MEMBER = (VALUE); \
4390 spelling++; \
4391 }
4393 /* Push STRING on the stack. Printed literally. */
4395 static void
4397 {
4399 }
4401 /* Push a member name on the stack. Printed as '.' STRING. */
4403 static void
4405 {
4409 }
4411 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
4413 static void
4415 {
4417 }
4419 /* Compute the maximum size in bytes of the printed spelling. */
4421 static int
4423 {
4428 {
4431 else
4433 }
4436 }
4438 /* Print the spelling to BUFFER and return it. */
4442 {
4448 {
4451 }
4452 else
4453 {
4458 ;
4459 }
4462 }
4464 /* Issue an error message for a bad initializer component.
4465 MSGID identifies the message.
4466 The component name is taken from the spelling stack. */
4468 void
4470 {
4477 }
4479 /* Issue a pedantic warning for a bad initializer component.
4480 MSGID identifies the message.
4481 The component name is taken from the spelling stack. */
4483 void
4485 {
4492 }
4494 /* Issue a warning for a bad initializer component.
4495 MSGID identifies the message.
4496 The component name is taken from the spelling stack. */
4498 static void
4500 {
4507 }
4508 \f
4509 /* If TYPE is an array type and EXPR is a parenthesized string
4510 constant, warn if pedantic that EXPR is being used to initialize an
4511 object of type TYPE. */
4513 void
4515 {
4521 }
4523 /* Digest the parser output INIT as an initializer for type TYPE.
4524 Return a C expression of type TYPE to represent the initial value.
4526 If INIT is a string constant, STRICT_STRING is true if it is
4527 unparenthesized or we should not warn here for it being parenthesized.
4528 For other types of INIT, STRICT_STRING is not used.
4530 REQUIRE_CONSTANT requests an error if non-constant initializers or
4531 elements are seen. */
4533 static tree
4535 {
4540 || !init
4549 /* Initialization of an array of chars from a string constant
4550 optionally enclosed in braces. */
4554 {
4556 /* Note that an array could be both an array of character type
4557 and an array of wchar_t if wchar_t is signed char or unsigned
4558 char. */
4564 {
4571 char_string
4580 {
4583 }
4585 {
4588 }
4594 /* Subtract 1 (or sizeof (wchar_t))
4595 because it's ok to ignore the terminating null char
4596 that is counted in the length of the constant. */
4607 }
4609 {
4613 }
4614 }
4616 /* Build a VECTOR_CST from a *constant* vector constructor. If the
4617 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
4618 below and handle as a constructor. */
4623 {
4630 {
4632 tree value;
4635 /* Iterate through elements and check if all constructor
4636 elements are *_CSTs. */
4639 {
4642 }
4647 }
4648 }
4650 /* Any type can be initialized
4651 from an expression of the same type, optionally with braces. */
4664 {
4666 {
4668 {
4672 else
4673 {
4676 }
4677 }
4678 }
4681 /* Although the types are compatible, we may require a
4682 conversion. */
4687 {
4688 /* As an extension, allow initializing objects with static storage
4689 duration with compound literals (which are then treated just as
4690 the brace enclosed list they contain). */
4693 }
4697 {
4700 }
4705 /* Compound expressions can only occur here if -pedantic or
4706 -pedantic-errors is specified. In the later case, we always want
4707 an error. In the former case, we simply want a warning. */
4710 {
4711 inside_init
4716 else
4720 }
4724 {
4727 }
4729 /* Added to enable additional -Wmissing-format-attribute warnings. */
4734 }
4736 /* Handle scalar types, including conversions. */
4741 {
4746 inside_init
4750 /* Check to see if we have already given an error message. */
4752 ;
4754 {
4757 }
4761 {
4764 }
4767 }
4769 /* Come here only for records and arrays. */
4772 {
4775 }
4779 }
4780 \f
4781 /* Handle initializers that use braces. */
4783 /* Type of object we are accumulating a constructor for.
4784 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4787 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4788 left to fill. */
4791 /* For an ARRAY_TYPE, this is the specified index
4792 at which to store the next element we get. */
4795 /* For an ARRAY_TYPE, this is the maximum index. */
4798 /* For a RECORD_TYPE, this is the first field not yet written out. */
4801 /* For an ARRAY_TYPE, this is the index of the first element
4802 not yet written out. */
4805 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4806 This is so we can generate gaps between fields, when appropriate. */
4809 /* If we are saving up the elements rather than allocating them,
4810 this is the list of elements so far (in reverse order,
4811 most recent first). */
4814 /* 1 if constructor should be incrementally stored into a constructor chain,
4815 0 if all the elements should be kept in AVL tree. */
4818 /* 1 if so far this constructor's elements are all compile-time constants. */
4821 /* 1 if so far this constructor's elements are all valid address constants. */
4824 /* 1 if this constructor is erroneous so far. */
4827 /* Structure for managing pending initializer elements, organized as an
4828 AVL tree. */
4830 struct init_node
4831 {
4835 tree purpose;
4836 tree value;
4837 };
4839 /* Tree of pending elements at this constructor level.
4840 These are elements encountered out of order
4841 which belong at places we haven't reached yet in actually
4842 writing the output.
4843 Will never hold tree nodes across GC runs. */
4846 /* The SPELLING_DEPTH of this constructor. */
4849 /* DECL node for which an initializer is being read.
4850 0 means we are reading a constructor expression
4851 such as (struct foo) {...}. */
4854 /* Nonzero if this is an initializer for a top-level decl. */
4857 /* Nonzero if there were any member designators in this initializer. */
4860 /* Nesting depth of designator list. */
4863 /* Nonzero if there were diagnosed errors in this designator list. */
4866 \f
4867 /* This stack has a level for each implicit or explicit level of
4868 structuring in the initializer, including the outermost one. It
4869 saves the values of most of the variables above. */
4873 struct constructor_stack
4874 {
4876 tree type;
4877 tree fields;
4878 tree index;
4879 tree max_index;
4880 tree unfilled_index;
4881 tree unfilled_fields;
4882 tree bit_index;
4887 /* If value nonzero, this value should replace the entire
4888 constructor at this level. */
4898 };
4902 /* This stack represents designators from some range designator up to
4903 the last designator in the list. */
4905 struct constructor_range_stack
4906 {
4909 tree range_start;
4910 tree index;
4911 tree range_end;
4912 tree fields;
4913 };
4917 /* This stack records separate initializers that are nested.
4918 Nested initializers can't happen in ANSI C, but GNU C allows them
4919 in cases like { ... (struct foo) { ... } ... }. */
4921 struct initializer_stack
4922 {
4924 tree decl;
4934 };
4937 \f
4938 /* Prepare to parse and output the initializer for variable DECL. */
4940 void
4942 {
4964 {
4966 require_constant_elements
4968 /* For a scalar, you can always use any value to initialize,
4969 even within braces. */
4975 }
4976 else
4977 {
4981 }
4994 }
4996 void
4998 {
5001 /* Free the whole constructor stack of this initializer. */
5003 {
5007 }
5011 /* Pop back to the data of the outer initializer (if any). */
5026 }
5027 \f
5028 /* Call here when we see the initializer is surrounded by braces.
5029 This is instead of a call to push_init_level;
5030 it is matched by a call to pop_init_level.
5032 TYPE is the type to initialize, for a constructor expression.
5033 For an initializer for a decl, TYPE is zero. */
5035 void
5037 {
5082 {
5084 /* Skip any nameless bit fields at the beginning. */
5091 }
5093 {
5095 {
5096 constructor_max_index
5099 /* Detect non-empty initializations of zero-length arrays. */
5104 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5105 to initialize VLAs will cause a proper error; avoid tree
5106 checking errors as well by setting a safe value. */
5111 constructor_index
5114 }
5115 else
5116 {
5119 }
5122 }
5124 {
5125 /* Vectors are like simple fixed-size arrays. */
5126 constructor_max_index =
5130 }
5131 else
5132 {
5133 /* Handle the case of int x = {5}; */
5136 }
5137 }
5138 \f
5139 /* Push down into a subobject, for initialization.
5140 If this is for an explicit set of braces, IMPLICIT is 0.
5141 If it is because the next element belongs at a lower level,
5142 IMPLICIT is 1 (or 2 if the push is because of designator list). */
5144 void
5146 {
5150 /* If we've exhausted any levels that didn't have braces,
5151 pop them now. If implicit == 1, this will have been done in
5152 process_init_element; do not repeat it here because in the case
5153 of excess initializers for an empty aggregate this leads to an
5154 infinite cycle of popping a level and immediately recreating
5155 it. */
5157 {
5159 {
5165 && constructor_max_index
5167 constructor_index))
5169 else
5171 }
5172 }
5174 /* Unless this is an explicit brace, we need to preserve previous
5175 content if any. */
5177 {
5184 }
5218 {
5223 }
5225 /* Don't die if an entire brace-pair level is superfluous
5226 in the containing level. */
5228 ;
5231 {
5232 /* Don't die if there are extra init elts at the end. */
5235 else
5236 {
5239 constructor_depth++;
5240 }
5241 }
5243 {
5246 constructor_depth++;
5247 }
5250 {
5255 }
5258 {
5266 }
5269 {
5272 }
5276 {
5278 /* Skip any nameless bit fields at the beginning. */
5285 }
5287 {
5288 /* Vectors are like simple fixed-size arrays. */
5289 constructor_max_index =
5293 }
5295 {
5297 {
5298 constructor_max_index
5301 /* Detect non-empty initializations of zero-length arrays. */
5306 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5307 to initialize VLAs will cause a proper error; avoid tree
5308 checking errors as well by setting a safe value. */
5313 constructor_index
5316 }
5317 else
5322 {
5323 /* We need to split the char/wchar array into individual
5324 characters, so that we don't have to special case it
5325 everywhere. */
5327 }
5328 }
5329 else
5330 {
5335 }
5336 }
5338 /* At the end of an implicit or explicit brace level,
5339 finish up that level of constructor. If a single expression
5340 with redundant braces initialized that level, return the
5341 c_expr structure for that expression. Otherwise, the original_code
5342 element is set to ERROR_MARK.
5343 If we were outputting the elements as they are read, return 0 as the value
5344 from inner levels (process_init_element ignores that),
5345 but return error_mark_node as the value from the outermost level
5346 (that's what we want to put in DECL_INITIAL).
5347 Otherwise, return a CONSTRUCTOR expression as the value. */
5349 struct c_expr
5351 {
5358 {
5359 /* When we come to an explicit close brace,
5360 pop any inner levels that didn't have explicit braces. */
5365 }
5367 /* Now output all pending elements. */
5373 /* Error for initializing a flexible array member, or a zero-length
5374 array member in an inappropriate context. */
5379 {
5380 /* Silently discard empty initializations. The parser will
5381 already have pedwarned for empty brackets. */
5384 else
5385 {
5393 /* We have already issued an error message for the existence
5394 of a flexible array member not at the end of the structure.
5395 Discard the initializer so that we do not die later. */
5398 }
5399 }
5401 /* Warn when some struct elements are implicitly initialized to zero. */
5403 && constructor_type
5406 {
5407 /* Do not warn for flexible array members or zero-length arrays. */
5413 /* Do not warn if this level of the initializer uses member
5414 designators; it is likely to be deliberate. */
5416 {
5420 }
5421 }
5423 /* Pad out the end of the structure. */
5425 /* If this closes a superfluous brace pair,
5426 just pass out the element between them. */
5429 ;
5434 {
5435 /* A nonincremental scalar initializer--just return
5436 the element, after verifying there is just one. */
5438 {
5442 }
5444 {
5447 }
5448 else
5450 }
5451 else
5452 {
5455 else
5456 {
5458 constructor_elements);
5463 }
5464 }
5491 }
5493 /* Common handling for both array range and field name designators.
5494 ARRAY argument is nonzero for array ranges. Returns zero for success. */
5496 static int
5498 {
5499 tree subtype;
5502 /* Don't die if an entire brace-pair level is superfluous
5503 in the containing level. */
5507 /* If there were errors in this designator list already, bail out
5508 silently. */
5513 {
5516 /* Designator list starts at the level of closest explicit
5517 braces. */
5522 }
5525 {
5537 }
5541 {
5544 }
5546 {
5549 }
5554 }
5556 /* If there are range designators in designator list, push a new designator
5557 to constructor_range_stack. RANGE_END is end of such stack range or
5558 NULL_TREE if there is no range designator at this level. */
5560 static void
5562 {
5576 }
5578 /* Within an array initializer, specify the next index to be initialized.
5579 FIRST is that index. If LAST is nonzero, then initialize a range
5580 of indices, running from FIRST through LAST. */
5582 void
5584 {
5592 {
5595 }
5608 else
5609 {
5613 {
5617 {
5620 }
5621 else
5622 {
5626 {
5629 }
5630 }
5631 }
5633 designator_depth++;
5637 }
5638 }
5640 /* Within a struct initializer, specify the next field to be initialized. */
5642 void
5644 {
5645 tree tail;
5654 {
5657 }
5661 {
5664 }
5668 else
5669 {
5671 designator_depth++;
5675 }
5676 }
5677 \f
5678 /* Add a new initializer to the tree of pending initializers. PURPOSE
5679 identifies the initializer, either array index or field in a structure.
5680 VALUE is the value of that index or field. */
5682 static void
5684 {
5691 {
5693 {
5699 else
5700 {
5705 }
5706 }
5707 }
5708 else
5709 {
5710 tree bitpos;
5714 {
5720 else
5721 {
5726 }
5727 }
5728 }
5741 {
5745 {
5749 {
5751 {
5752 /* L rotation. */
5765 {
5768 else
5770 }
5771 else
5773 }
5774 else
5775 {
5776 /* LR rotation. */
5798 {
5801 else
5803 }
5804 else
5806 }
5808 }
5809 else
5810 {
5811 /* p->balance == +1; growth of left side balances the node. */
5814 }
5815 }
5817 {
5819 /* Growth propagation from right side. */
5822 {
5824 {
5825 /* R rotation. */
5838 {
5841 else
5843 }
5844 else
5846 }
5848 {
5849 /* RL rotation */
5871 {
5874 else
5876 }
5877 else
5879 }
5881 }
5882 else
5883 {
5884 /* p->balance == -1; growth of right side balances the node. */
5887 }
5888 }
5892 }
5893 }
5895 /* Build AVL tree from a sorted chain. */
5897 static void
5899 {
5911 {
5913 /* Skip any nameless bit fields at the beginning. */
5919 }
5921 {
5923 constructor_unfilled_index
5926 else
5928 }
5930 }
5932 /* Build AVL tree from a string constant. */
5934 static void
5936 {
5947 else
5948 {
5952 }
5961 {
5963 {
5966 }
5967 else
5968 {
5972 {
5975 else
5980 }
5981 }
5984 {
5987 {
5989 {
5992 }
5993 }
5995 {
5998 }
6003 }
6007 }
6010 }
6012 /* Return value of FIELD in pending initializer or zero if the field was
6013 not initialized yet. */
6015 static tree
6017 {
6021 {
6028 {
6033 else
6035 }
6036 }
6038 {
6042 && (!constructor_unfilled_fields
6049 {
6054 else
6056 }
6057 }
6059 {
6064 }
6066 }
6068 /* "Output" the next constructor element.
6069 At top level, really output it to assembler code now.
6070 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
6071 TYPE is the data type that the containing data type wants here.
6072 FIELD is the field (a FIELD_DECL) or the index that this element fills.
6073 If VALUE is a string constant, STRICT_STRING is true if it is
6074 unparenthesized or we should not warn here for it being parenthesized.
6075 For other types of VALUE, STRICT_STRING is not used.
6077 PENDING if non-nil means output pending elements that belong
6078 right after this element. (PENDING is normally 1;
6079 it is 0 while outputting pending elements, to avoid recursion.) */
6081 static void
6084 {
6088 {
6091 }
6104 {
6105 /* As an extension, allow initializing objects with static storage
6106 duration with compound literals (which are then treated just as
6107 the brace enclosed list they contain). */
6110 }
6124 {
6126 {
6129 }
6132 }
6134 /* If this field is empty (and not at the end of structure),
6135 don't do anything other than checking the initializer. */
6146 {
6149 }
6151 /* If this element doesn't come next in sequence,
6152 put it on constructor_pending_elts. */
6154 && (!constructor_incremental
6156 {
6163 }
6165 && (!constructor_incremental
6167 {
6168 /* We do this for records but not for unions. In a union,
6169 no matter which field is specified, it can be initialized
6170 right away since it starts at the beginning of the union. */
6172 {
6175 else
6176 {
6184 }
6185 }
6189 }
6192 {
6197 /* We can have just one union field set. */
6199 }
6201 /* Otherwise, output this element either to
6202 constructor_elements or to the assembler file. */
6208 /* Advance the variable that indicates sequential elements output. */
6210 constructor_unfilled_index
6212 bitsize_one_node);
6214 {
6215 constructor_unfilled_fields
6218 /* Skip any nameless bit fields. */
6222 constructor_unfilled_fields =
6224 }
6228 /* Now output any pending elements which have become next. */
6231 }
6233 /* Output any pending elements which have become next.
6234 As we output elements, constructor_unfilled_{fields,index}
6235 advances, which may cause other elements to become next;
6236 if so, they too are output.
6238 If ALL is 0, we return when there are
6239 no more pending elements to output now.
6241 If ALL is 1, we output space as necessary so that
6242 we can output all the pending elements. */
6244 static void
6246 {
6248 tree next;
6250 retry:
6252 /* Look through the whole pending tree.
6253 If we find an element that should be output now,
6254 output it. Otherwise, set NEXT to the element
6255 that comes first among those still pending. */
6259 {
6261 {
6263 constructor_unfilled_index))
6269 {
6270 /* Advance to the next smaller node. */
6273 else
6274 {
6275 /* We have reached the smallest node bigger than the
6276 current unfilled index. Fill the space first. */
6279 }
6280 }
6281 else
6282 {
6283 /* Advance to the next bigger node. */
6286 else
6287 {
6288 /* We have reached the biggest node in a subtree. Find
6289 the parent of it, which is the next bigger node. */
6295 {
6298 }
6299 }
6300 }
6301 }
6304 {
6307 /* If the current record is complete we are done. */
6313 /* We can't compare fields here because there might be empty
6314 fields in between. */
6316 {
6320 }
6322 {
6323 /* Advance to the next smaller node. */
6326 else
6327 {
6328 /* We have reached the smallest node bigger than the
6329 current unfilled field. Fill the space first. */
6332 }
6333 }
6334 else
6335 {
6336 /* Advance to the next bigger node. */
6339 else
6340 {
6341 /* We have reached the biggest node in a subtree. Find
6342 the parent of it, which is the next bigger node. */
6349 {
6352 }
6353 }
6354 }
6355 }
6356 }
6358 /* Ordinarily return, but not if we want to output all
6359 and there are elements left. */
6363 /* If it's not incremental, just skip over the gap, so that after
6364 jumping to retry we will output the next successive element. */
6371 /* ELT now points to the node in the pending tree with the next
6372 initializer to output. */
6374 }
6375 \f
6376 /* Add one non-braced element to the current constructor level.
6377 This adjusts the current position within the constructor's type.
6378 This may also start or terminate implicit levels
6379 to handle a partly-braced initializer.
6381 Once this has found the correct level for the new element,
6382 it calls output_init_element. */
6384 void
6386 {
6394 /* Handle superfluous braces around string cst as in
6395 char x[] = {"foo"}; */
6397 && constructor_type
6401 {
6406 }
6409 {
6412 }
6414 /* Ignore elements of a brace group if it is entirely superfluous
6415 and has already been diagnosed. */
6419 /* If we've exhausted any levels that didn't have braces,
6420 pop them now. */
6422 {
6430 constructor_index)))
6432 else
6434 }
6436 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
6438 {
6439 /* If value is a compound literal and we'll be just using its
6440 content, don't put it into a SAVE_EXPR. */
6442 || !require_constant_value
6445 }
6448 {
6450 {
6451 tree fieldtype;
6455 {
6458 }
6465 /* Error for non-static initialization of a flexible array member. */
6467 && !require_constant_value
6470 {
6473 }
6475 /* Accept a string constant to initialize a subarray. */
6481 /* Otherwise, if we have come to a subaggregate,
6482 and we don't have an element of its type, push into it. */
6488 {
6491 }
6494 {
6499 }
6500 else
6501 /* Do the bookkeeping for an element that was
6502 directly output as a constructor. */
6503 {
6504 /* For a record, keep track of end position of last field. */
6506 constructor_bit_index
6511 /* If the current field was the first one not yet written out,
6512 it isn't now, so update. */
6514 {
6516 /* Skip any nameless bit fields. */
6520 constructor_unfilled_fields =
6522 }
6523 }
6526 /* Skip any nameless bit fields at the beginning. */
6531 }
6533 {
6534 tree fieldtype;
6538 {
6541 }
6548 /* Warn that traditional C rejects initialization of unions.
6549 We skip the warning if the value is zero. This is done
6550 under the assumption that the zero initializer in user
6551 code appears conditioned on e.g. __STDC__ to avoid
6552 "missing initializer" warnings and relies on default
6553 initialization to zero in the traditional C case.
6554 We also skip the warning if the initializer is designated,
6555 again on the assumption that this must be conditional on
6556 __STDC__ anyway (and we've already complained about the
6557 member-designator already). */
6564 /* Accept a string constant to initialize a subarray. */
6570 /* Otherwise, if we have come to a subaggregate,
6571 and we don't have an element of its type, push into it. */
6577 {
6580 }
6583 {
6588 }
6589 else
6590 /* Do the bookkeeping for an element that was
6591 directly output as a constructor. */
6592 {
6595 }
6598 }
6600 {
6604 /* Accept a string constant to initialize a subarray. */
6610 /* Otherwise, if we have come to a subaggregate,
6611 and we don't have an element of its type, push into it. */
6617 {
6620 }
6625 {
6628 }
6630 /* Now output the actual element. */
6632 {
6637 }
6639 constructor_index
6643 /* If we are doing the bookkeeping for an element that was
6644 directly output as a constructor, we must update
6645 constructor_unfilled_index. */
6647 }
6649 {
6652 /* Do a basic check of initializer size. Note that vectors
6653 always have a fixed size derived from their type. */
6655 {
6658 }
6660 /* Now output the actual element. */
6665 constructor_index
6669 /* If we are doing the bookkeeping for an element that was
6670 directly output as a constructor, we must update
6671 constructor_unfilled_index. */
6673 }
6675 /* Handle the sole element allowed in a braced initializer
6676 for a scalar variable. */
6679 {
6682 }
6683 else
6684 {
6689 }
6691 /* Handle range initializers either at this level or anywhere higher
6692 in the designator stack. */
6694 {
6701 {
6704 }
6708 {
6711 }
6718 {
6722 {
6725 }
6733 }
6738 }
6741 }
6744 }
6745 \f
6746 /* Build a complete asm-statement, whose components are a CV_QUALIFIER
6747 (guaranteed to be 'volatile' or null) and ARGS (represented using
6748 an ASM_EXPR node). */
6749 tree
6751 {
6755 }
6757 /* Build an asm-expr, whose components are a STRING, some OUTPUTS,
6758 some INPUTS, and some CLOBBERS. The latter three may be NULL.
6759 SIMPLE indicates whether there was anything at all after the
6760 string in the asm expression -- asm("blah") and asm("blah" : )
6761 are subtly different. We use a ASM_EXPR node to represent this. */
6762 tree
6765 {
6766 tree tail;
6767 tree args;
6780 /* Remove output conversions that change the type but not the mode. */
6782 {
6785 /* ??? Really, this should not be here. Users should be using a
6786 proper lvalue, dammit. But there's a long history of using casts
6787 in the output operands. In cases like longlong.h, this becomes a
6788 primitive form of typechecking -- if the cast can be removed, then
6789 the output operand had a type of the proper width; otherwise we'll
6790 get an error. Gross, but ... */
6809 {
6810 /* If the operand is going to end up in memory,
6811 mark it addressable. */
6814 }
6815 else
6819 }
6822 {
6823 tree input;
6830 {
6831 /* If the operand is going to end up in memory,
6832 mark it addressable. */
6834 {
6835 /* Strip the nops as we allow this case. FIXME, this really
6836 should be rejected or made deprecated. */
6840 }
6841 }
6842 else
6846 }
6850 /* asm statements without outputs, including simple ones, are treated
6851 as volatile. */
6856 }
6857 \f
6858 /* Generate a goto statement to LABEL. */
6860 tree
6862 {
6868 {
6871 }
6874 {
6877 }
6880 {
6881 /* No jump from outside this statement expression context, so
6882 record that there is a jump from within this context. */
6888 }
6891 {
6892 /* No jump from outside this context context of identifiers with
6893 variably modified type, so record that there is a jump from
6894 within this context. */
6900 }
6904 }
6906 /* Generate a computed goto statement to EXPR. */
6908 tree
6910 {
6915 }
6917 /* Generate a C `return' statement. RETVAL is the expression for what
6918 to return, or a null pointer for `return;' with no value. */
6920 tree
6922 {
6930 {
6934 {
6938 }
6939 }
6941 {
6945 }
6946 else
6947 {
6951 tree inner;
6959 /* Strip any conversions, additions, and subtractions, and see if
6960 we are returning the address of a local variable. Warn if so. */
6962 {
6964 {
6971 /* If the second operand of the MINUS_EXPR has a pointer
6972 type (or is converted from it), this may be valid, so
6973 don't give a warning. */
6974 {
6988 }
7006 }
7009 }
7012 }
7017 }
7018 \f
7020 /* The SWITCH_EXPR being built. */
7021 tree switch_expr;
7023 /* The original type of the testing expression, i.e. before the
7024 default conversion is applied. */
7025 tree orig_type;
7027 /* A splay-tree mapping the low element of a case range to the high
7028 element, or NULL_TREE if there is no high element. Used to
7029 determine whether or not a new case label duplicates an old case
7030 label. We need a tree, rather than simply a hash table, because
7031 of the GNU case range extension. */
7032 splay_tree cases;
7034 /* Number of nested statement expressions within this switch
7035 statement; if nonzero, case and default labels may not
7036 appear. */
7039 /* Scope of outermost declarations of identifiers with variably
7040 modified type within this switch statement; if nonzero, case and
7041 default labels may not appear. */
7044 /* The next node on the stack. */
7046 };
7048 /* A stack of the currently active switch statements. The innermost
7049 switch statement is on the top of the stack. There is no need to
7050 mark the stack for garbage collection because it is only active
7051 during the processing of the body of a function, and we never
7052 collect at that point. */
7056 /* Start a C switch statement, testing expression EXP. Return the new
7057 SWITCH_EXPR. */
7059 tree
7061 {
7067 {
7073 {
7077 }
7078 else
7079 {
7090 }
7091 }
7093 /* Add this new SWITCH_EXPR to the stack. */
7104 }
7106 /* Process a case label. */
7108 tree
7110 {
7115 {
7122 }
7124 {
7128 else
7131 }
7133 {
7137 else
7140 }
7143 else
7147 }
7149 /* Finish the switch statement. */
7151 void
7153 {
7155 location_t switch_location;
7159 /* We must not be within a statement expression nested in the switch
7160 at this point; we might, however, be within the scope of an
7161 identifier with variably modified type nested in the switch. */
7164 /* Emit warnings as needed. */
7167 else
7173 /* Pop the stack. */
7177 }
7178 \f
7179 /* Emit an if statement. IF_LOCUS is the location of the 'if'. COND,
7180 THEN_BLOCK and ELSE_BLOCK are expressions to be used; ELSE_BLOCK
7181 may be null. NESTED_IF is true if THEN_BLOCK contains another IF
7182 statement, and was not surrounded with parenthesis. */
7184 void
7187 {
7188 tree stmt;
7190 /* Diagnose an ambiguous else if if-then-else is nested inside if-then. */
7192 {
7195 /* We know from the grammar productions that there is an IF nested
7196 within THEN_BLOCK. Due to labels and c99 conditional declarations,
7197 it might not be exactly THEN_BLOCK, but should be the last
7198 non-container statement within. */
7201 {
7216 }
7217 found:
7223 }
7230 }
7232 /* Emit a general-purpose loop construct. START_LOCUS is the location of
7233 the beginning of the loop. COND is the loop condition. COND_IS_FIRST
7234 is false for DO loops. INCR is the FOR increment expression. BODY is
7235 the statement controlled by the loop. BLAB is the break label. CLAB is
7236 the continue label. Everything is allowed to be NULL. */
7238 void
7241 {
7244 /* If the condition is zero don't generate a loop construct. */
7246 {
7248 {
7252 }
7253 }
7254 else
7255 {
7258 /* If we have an exit condition, then we build an IF with gotos either
7259 out of the loop, or to the top of it. If there's no exit condition,
7260 then we just build a jump back to the top. */
7264 {
7265 /* Canonicalize the loop condition to the end. This means
7266 generating a branch to the loop condition. Reuse the
7267 continue label, if possible. */
7269 {
7271 {
7274 }
7275 else
7279 }
7285 else
7287 }
7290 }
7304 }
7306 tree
7308 {
7312 /* In switch statements break is sometimes stylistically used after
7313 a return statement. This can lead to spurious warnings about
7314 control reaching the end of a non-void function when it is
7315 inlined. Note that we are calling block_may_fallthru with
7316 language specific tree nodes; this works because
7317 block_may_fallthru returns true when given something it does not
7318 understand. */
7322 {
7325 }
7327 ;
7329 {
7333 else
7344 }
7350 }
7352 /* A helper routine for c_process_expr_stmt and c_finish_stmt_expr. */
7354 static void
7356 {
7358 ;
7360 {
7364 }
7367 }
7369 /* Process an expression as if it were a complete statement. Emit
7370 diagnostics, but do not call ADD_STMT. */
7372 tree
7374 {
7386 /* If we're not processing a statement expression, warn about unused values.
7387 Warnings for statement expressions will be emitted later, once we figure
7388 out which is the result. */
7393 /* If the expression is not of a type to which we cannot assign a line
7394 number, wrap the thing in a no-op NOP_EXPR. */
7402 }
7404 /* Emit an expression as a statement. */
7406 tree
7408 {
7411 else
7413 }
7415 /* Do the opposite and emit a statement as an expression. To begin,
7416 create a new binding level and return it. */
7418 tree
7420 {
7421 tree ret;
7425 /* We must force a BLOCK for this level so that, if it is not expanded
7426 later, there is a way to turn off the entire subtree of blocks that
7427 are contained in it. */
7431 {
7434 }
7438 {
7440 }
7447 /* Mark the current statement list as belonging to a statement list. */
7451 }
7453 tree
7455 {
7462 {
7465 }
7466 /* It is no longer possible to jump to labels defined within this
7467 statement expression. */
7471 {
7473 }
7474 /* It is again possible to define labels with a goto just outside
7475 this statement expression. */
7479 {
7482 }
7485 else
7490 /* Locate the last statement in BODY. See c_end_compound_stmt
7491 about always returning a BIND_EXPR. */
7495 continue_searching:
7497 {
7498 tree_stmt_iterator i;
7500 /* This can happen with degenerate cases like ({ }). No value. */
7504 /* If we're supposed to generate side effects warnings, process
7505 all of the statements except the last. */
7507 {
7510 }
7511 else
7515 }
7517 /* If the end of the list is exception related, then the list was split
7518 by a call to push_cleanup. Continue searching. */
7521 {
7525 }
7527 /* In the case that the BIND_EXPR is not necessary, return the
7528 expression out from inside it. */
7532 {
7533 /* Do not warn if the return value of a statement expression is
7534 unused. */
7538 }
7540 /* Extract the type of said expression. */
7543 /* If we're not returning a value at all, then the BIND_EXPR that
7544 we already have is a fine expression to return. */
7548 /* Now that we've located the expression containing the value, it seems
7549 silly to make voidify_wrapper_expr repeat the process. Create a
7550 temporary of the appropriate type and stick it in a TARGET_EXPR. */
7553 /* Unwrap a no-op NOP_EXPR as added by c_finish_expr_stmt. This avoids
7554 tree_expr_nonnegative_p giving up immediately. */
7564 }
7566 /* Begin the scope of an identifier of variably modified type, scope
7567 number SCOPE. Jumping from outside this scope to inside it is not
7568 permitted. */
7570 void
7572 {
7578 /* At file_scope, we don't have to do any processing. */
7587 {
7589 }
7596 }
7598 /* End a scope which may contain identifiers of variably modified
7599 type, scope number SCOPE. */
7601 void
7603 {
7608 /* We may have a number of nested scopes of identifiers with
7609 variably modified type, all at this depth. Pop each in turn. */
7611 {
7614 /* It is no longer possible to jump to labels defined within this
7615 scope. */
7619 {
7621 }
7622 /* It is again possible to define labels with a goto just outside
7623 this scope. */
7627 {
7630 }
7633 else
7637 }
7638 }
7639 \f
7640 /* Begin and end compound statements. This is as simple as pushing
7641 and popping new statement lists from the tree. */
7643 tree
7645 {
7650 }
7652 tree
7654 {
7658 {
7662 }
7667 /* If this compound statement is nested immediately inside a statement
7668 expression, then force a BIND_EXPR to be created. Otherwise we'll
7669 do the wrong thing for ({ { 1; } }) or ({ 1; { } }). In particular,
7670 STATEMENT_LISTs merge, and thus we can lose track of what statement
7671 was really last. */
7675 {
7678 }
7681 }
7683 /* Queue a cleanup. CLEANUP is an expression/statement to be executed
7684 when the current scope is exited. EH_ONLY is true when this is not
7685 meant to apply to normal control flow transfer. */
7687 void
7689 {
7701 }
7702 \f
7703 /* Build a binary-operation expression without default conversions.
7704 CODE is the kind of expression to build.
7705 This function differs from `build' in several ways:
7706 the data type of the result is computed and recorded in it,
7707 warnings are generated if arg data types are invalid,
7708 special handling for addition and subtraction of pointers is known,
7709 and some optimization is done (operations on narrow ints
7710 are done in the narrower type when that gives the same result).
7711 Constant folding is also done before the result is returned.
7713 Note that the operands will never have enumeral types, or function
7714 or array types, because either they will have the default conversions
7715 performed or they have both just been converted to some other type in which
7716 the arithmetic is to be done. */
7718 tree
7721 {
7727 /* Expression code to give to the expression when it is built.
7728 Normally this is CODE, which is what the caller asked for,
7729 but in some special cases we change it. */
7732 /* Data type in which the computation is to be performed.
7733 In the simplest cases this is the common type of the arguments. */
7736 /* Nonzero means operands have already been type-converted
7737 in whatever way is necessary.
7738 Zero means they need to be converted to RESULT_TYPE. */
7741 /* Nonzero means create the expression with this type, rather than
7742 RESULT_TYPE. */
7745 /* Nonzero means after finally constructing the expression
7746 convert it to this type. */
7749 /* Nonzero if this is an operation like MIN or MAX which can
7750 safely be computed in short if both args are promoted shorts.
7751 Also implies COMMON.
7752 -1 indicates a bitwise operation; this makes a difference
7753 in the exact conditions for when it is safe to do the operation
7754 in a narrower mode. */
7757 /* Nonzero if this is a comparison operation;
7758 if both args are promoted shorts, compare the original shorts.
7759 Also implies COMMON. */
7762 /* Nonzero if this is a right-shift operation, which can be computed on the
7763 original short and then promoted if the operand is a promoted short. */
7766 /* Nonzero means set RESULT_TYPE to the common type of the args. */
7769 /* True means types are compatible as far as ObjC is concerned. */
7773 {
7776 }
7777 else
7778 {
7781 }
7786 /* The expression codes of the data types of the arguments tell us
7787 whether the arguments are integers, floating, pointers, etc. */
7791 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
7795 /* If an error was already reported for one of the arguments,
7796 avoid reporting another error. */
7803 {
7806 }
7811 {
7813 /* Handle the pointer + int case. */
7818 else
7823 /* Subtraction of two similar pointers.
7824 We must subtract them as integers, then divide by object size. */
7828 /* Handle pointer minus int. Just like pointer plus int. */
7831 else
7844 /* Floating point division by zero is a legitimate way to obtain
7845 infinities and NaNs. */
7853 {
7863 else
7864 /* Although it would be tempting to shorten always here, that
7865 loses on some targets, since the modulo instruction is
7866 undefined if the quotient can't be represented in the
7867 computation mode. We shorten only if unsigned or if
7868 dividing by something we know != -1. */
7873 }
7891 {
7892 /* Although it would be tempting to shorten always here, that loses
7893 on some targets, since the modulo instruction is undefined if the
7894 quotient can't be represented in the computation mode. We shorten
7895 only if unsigned or if dividing by something we know != -1. */
7900 }
7912 {
7913 /* Result of these operations is always an int,
7914 but that does not mean the operands should be
7915 converted to ints! */
7920 }
7923 /* Shift operations: result has same type as first operand;
7924 always convert second operand to int.
7925 Also set SHORT_SHIFT if shifting rightward. */
7929 {
7931 {
7934 else
7935 {
7941 }
7942 }
7944 /* Use the type of the value to be shifted. */
7946 /* Convert the shift-count to an integer, regardless of size
7947 of value being shifted. */
7950 /* Avoid converting op1 to result_type later. */
7952 }
7957 {
7959 {
7965 }
7967 /* Use the type of the value to be shifted. */
7969 /* Convert the shift-count to an integer, regardless of size
7970 of value being shifted. */
7973 /* Avoid converting op1 to result_type later. */
7975 }
7983 /* Result of comparison is always int,
7984 but don't convert the args to int! */
7992 {
7995 /* Anything compares with void *. void * compares with anything.
7996 Otherwise, the targets must be compatible
7997 and both must be object or both incomplete. */
8001 {
8002 /* op0 != orig_op0 detects the case of something
8003 whose value is 0 but which isn't a valid null ptr const. */
8008 }
8010 {
8015 }
8016 else
8017 /* Avoid warning about the volatile ObjC EH puts on decls. */
8023 }
8025 {
8034 }
8036 {
8045 }
8047 {
8050 }
8052 {
8055 }
8067 {
8069 {
8077 }
8078 else
8079 {
8082 }
8083 }
8085 {
8089 }
8091 {
8095 }
8097 {
8100 }
8102 {
8105 }
8110 }
8119 {
8122 }
8126 &&
8129 {
8135 /* For certain operations (which identify themselves by shorten != 0)
8136 if both args were extended from the same smaller type,
8137 do the arithmetic in that type and then extend.
8139 shorten !=0 and !=1 indicates a bitwise operation.
8140 For them, this optimization is safe only if
8141 both args are zero-extended or both are sign-extended.
8142 Otherwise, we might change the result.
8143 Eg, (short)-1 | (unsigned short)-1 is (int)-1
8144 but calculated in (unsigned short) it would be (unsigned short)-1. */
8147 {
8151 tree type;
8153 /* Cast OP0 and OP1 to RESULT_TYPE. Doing so prevents
8154 excessive narrowing when we call get_narrower below. For
8155 example, suppose that OP0 is of unsigned int extended
8156 from signed char and that RESULT_TYPE is long long int.
8157 If we explicitly cast OP0 to RESULT_TYPE, OP0 would look
8158 like
8160 (long long int) (unsigned int) signed_char
8162 which get_narrower would narrow down to
8164 (unsigned int) signed char
8166 If we do not cast OP0 first, get_narrower would return
8167 signed_char, which is inconsistent with the case of the
8168 explicit cast. */
8175 /* UNS is 1 if the operation to be done is an unsigned one. */
8180 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
8181 but it *requires* conversion to FINAL_TYPE. */
8192 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
8194 /* For bitwise operations, signedness of nominal type
8195 does not matter. Consider only how operands were extended. */
8199 /* Note that in all three cases below we refrain from optimizing
8200 an unsigned operation on sign-extended args.
8201 That would not be valid. */
8203 /* Both args variable: if both extended in same way
8204 from same width, do it in that width.
8205 Do it unsigned if args were zero-extended. */
8212 result_type
8213 = c_common_signed_or_unsigned_type
8219 && (type
8228 && (type
8233 }
8235 /* Shifts can be shortened if shifting right. */
8238 {
8248 /* We can shorten only if the shift count is less than the
8249 number of bits in the smaller type size. */
8251 /* We cannot drop an unsigned shift after sign-extension. */
8253 {
8254 /* Do an unsigned shift if the operand was zero-extended. */
8255 result_type
8258 /* Convert value-to-be-shifted to that type. */
8262 }
8263 }
8265 /* Comparison operations are shortened too but differently.
8266 They identify themselves by setting short_compare = 1. */
8269 {
8270 /* Don't write &op0, etc., because that would prevent op0
8271 from being kept in a register.
8272 Instead, make copies of the our local variables and
8273 pass the copies by reference, then copy them back afterward. */
8276 tree val
8287 {
8299 /* Give warnings for comparisons between signed and unsigned
8300 quantities that may fail.
8302 Do the checking based on the original operand trees, so that
8303 casts will be considered, but default promotions won't be.
8305 Do not warn if the comparison is being done in a signed type,
8306 since the signed type will only be chosen if it can represent
8307 all the values of the unsigned type. */
8310 /* Do not warn if both operands are the same signedness. */
8313 else
8314 {
8319 else
8322 /* Do not warn if the signed quantity is an
8323 unsuffixed integer literal (or some static
8324 constant expression involving such literals or a
8325 conditional expression involving such literals)
8326 and it is non-negative. */
8329 /* Do not warn if the comparison is an equality operation,
8330 the unsigned quantity is an integral constant, and it
8331 would fit in the result if the result were signed. */
8334 && int_fits_type_p
8337 /* Do not warn if the unsigned quantity is an enumeration
8338 constant and its maximum value would fit in the result
8339 if the result were signed. */
8342 && int_fits_type_p
8346 else
8348 }
8350 /* Warn if two unsigned values are being compared in a size
8351 larger than their original size, and one (and only one) is the
8352 result of a `~' operator. This comparison will always fail.
8354 Also warn if one operand is a constant, and the constant
8355 does not have all bits set that are set in the ~ operand
8356 when it is extended. */
8360 {
8364 else
8369 {
8370 tree primop;
8375 {
8379 }
8380 else
8381 {
8385 }
8390 {
8394 }
8395 }
8402 }
8403 }
8404 }
8405 }
8407 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
8408 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
8409 Then the expression will be built.
8410 It will be given type FINAL_TYPE if that is nonzero;
8411 otherwise, it will be given type RESULT_TYPE. */
8414 {
8417 }
8420 {
8426 /* This can happen if one operand has a vector type, and the other
8427 has a different type. */
8430 }
8435 {
8436 /* Treat expressions in initializers specially as they can't trap. */
8438 build_type,
8446 }
8447 }
8450 /* Convert EXPR to be a truth-value, validating its type for this
8451 purpose. */
8453 tree
8455 {
8457 {
8475 }
8477 /* ??? Should we also give an error for void and vectors rather than
8478 leaving those to give errors later? */
8480 }
8481 \f
8483 /* Convert EXPR to a contained DECL, updating *TC, *TI and *SE as
8484 required. */
8486 tree
8489 {
8491 {
8493 /* Executing a compound literal inside a function reinitializes
8494 it. */
8498 }
8499 else
8501 }
8502 \f
8503 /* Like c_begin_compound_stmt, except force the retention of the BLOCK. */
8505 tree
8507 {
8508 tree block;
8514 }
8516 tree
8518 {
8519 tree stmt;
8529 }
8531 /* For all elements of CLAUSES, validate them vs OpenMP constraints.
8532 Remove any elements from the list that are invalid. */
8534 tree
8536 {
8547 {
8553 {
8571 {
8574 }
8576 {
8581 {
8603 }
8605 {
8609 }
8610 }
8621 {
8624 }
8627 check_dup_generic:
8630 {
8633 }
8637 {
8640 }
8641 else
8651 {
8654 }
8657 {
8660 }
8661 else
8671 {
8674 }
8677 {
8680 }
8681 else
8696 }
8699 {
8703 {
8707 }
8710 {
8716 {
8727 }
8729 {
8733 }
8734 }
8735 }
8739 else
8741 }
8745 }