| blob | a4eed3fe36964613b275f1f5eebcb0eb50716359 |
1 /* Build expressions with type checking for C compiler.
2 Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 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 }
382 {
383 /* Try harder not to create a new aggregate type. */
388 }
392 /* Function types: prefer the one that specified arg types.
393 If both do, merge the arg types. Also merge the return types. */
394 {
402 /* Save space: see if the result is identical to one of the args. */
408 /* Simple way if one arg fails to specify argument types. */
410 {
414 }
416 {
420 }
422 /* If both args specify argument types, we must merge the two
423 lists, argument by argument. */
424 /* Tell global_bindings_p to return false so that variable_size
425 doesn't die on VLAs in parameter types. */
438 {
439 /* A null type means arg type is not specified.
440 Take whatever the other function type has. */
442 {
445 }
447 {
450 }
452 /* Given wait (union {union wait *u; int *i} *)
453 and wait (union wait *),
454 prefer union wait * as type of parm. */
457 {
458 tree memb;
465 {
471 {
477 }
478 }
479 }
482 {
483 tree memb;
490 {
496 {
502 }
503 }
504 }
506 parm_done: ;
507 }
512 /* ... falls through ... */
513 }
517 }
519 }
521 /* Return the type of a conditional expression between pointers to
522 possibly differently qualified versions of compatible types.
524 We assume that comp_target_types has already been done and returned
525 nonzero; if that isn't so, this may crash. */
527 static tree
529 {
530 tree attributes;
533 tree target;
535 /* Save time if the two types are the same. */
539 /* If one type is nonsense, use the other. */
548 /* Merge the attributes. */
551 /* Find the composite type of the target types, and combine the
552 qualifiers of the two types' targets. Do not lose qualifiers on
553 array element types by taking the TYPE_MAIN_VARIANT. */
566 }
568 /* Return the common type for two arithmetic types under the usual
569 arithmetic conversions. The default conversions have already been
570 applied, and enumerated types converted to their compatible integer
571 types. The resulting type is unqualified and has no attributes.
573 This is the type for the result of most arithmetic operations
574 if the operands have the given two types. */
576 static tree
578 {
582 /* If one type is nonsense, use the other. */
600 /* Save time if the two types are the same. */
612 /* When one operand is a decimal float type, the other operand cannot be
613 a generic float type or a complex type. We also disallow vector types
614 here. */
617 {
619 {
622 }
624 {
627 }
629 {
632 }
633 }
635 /* If one type is a vector type, return that type. (How the usual
636 arithmetic conversions apply to the vector types extension is not
637 precisely specified.) */
644 /* If one type is complex, form the common type of the non-complex
645 components, then make that complex. Use T1 or T2 if it is the
646 required type. */
648 {
657 else
659 }
661 /* If only one is real, use it as the result. */
669 /* If both are real and either are decimal floating point types, use
670 the decimal floating point type with the greater precision. */
673 {
683 }
685 /* Both real or both integers; use the one with greater precision. */
692 /* Same precision. Prefer long longs to longs to ints when the
693 same precision, following the C99 rules on integer type rank
694 (which are equivalent to the C90 rules for C90 types). */
702 {
705 else
707 }
715 {
716 /* But preserve unsignedness from the other type,
717 since long cannot hold all the values of an unsigned int. */
720 else
722 }
724 /* Likewise, prefer long double to double even if same size. */
729 /* Otherwise prefer the unsigned one. */
733 else
735 }
736 \f
737 /* Wrapper around c_common_type that is used by c-common.c and other
738 front end optimizations that remove promotions. ENUMERAL_TYPEs
739 are allowed here and are converted to their compatible integer types.
740 BOOLEAN_TYPEs are allowed here and return either boolean_type_node or
741 preferably a non-Boolean type as the common type. */
742 tree
744 {
750 /* If both types are BOOLEAN_TYPE, then return boolean_type_node. */
755 /* If either type is BOOLEAN_TYPE, then return the other. */
762 }
764 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
765 or various other operations. Return 2 if they are compatible
766 but a warning may be needed if you use them together. */
768 int
770 {
778 }
779 \f
780 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
781 or various other operations. Return 2 if they are compatible
782 but a warning may be needed if you use them together. This
783 differs from comptypes, in that we don't free the seen types. */
785 static int
787 {
792 /* Suppress errors caused by previously reported errors. */
798 /* If either type is the internal version of sizetype, return the
799 language version. */
809 /* Enumerated types are compatible with integer types, but this is
810 not transitive: two enumerated types in the same translation unit
811 are compatible with each other only if they are the same type. */
821 /* Different classes of types can't be compatible. */
826 /* Qualifiers must match. C99 6.7.3p9 */
831 /* Allow for two different type nodes which have essentially the same
832 definition. Note that we already checked for equality of the type
833 qualifiers (just above). */
839 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
843 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
847 {
849 /* Do not remove mode or aliasing information. */
862 {
869 /* Target types must match incl. qualifiers. */
874 /* Sizes must match unless one is missing or variable. */
881 d1_variable = (!d1_zero
884 d2_variable = (!d2_zero
900 }
906 {
917 }
927 }
929 }
931 /* Return 1 if TTL and TTR are pointers to types that are equivalent,
932 ignoring their qualifiers. */
934 static int
936 {
940 /* Do not lose qualifiers on element types of array types that are
941 pointer targets by taking their TYPE_MAIN_VARIANT. */
953 }
954 \f
955 /* Subroutines of `comptypes'. */
957 /* Determine whether two trees derive from the same translation unit.
958 If the CONTEXT chain ends in a null, that tree's context is still
959 being parsed, so if two trees have context chains ending in null,
960 they're in the same translation unit. */
961 int
963 {
966 {
974 }
978 {
986 }
989 }
991 /* Allocate the seen two types, assuming that they are compatible. */
995 {
1003 /* The C standard says that two structures in different translation
1004 units are compatible with each other only if the types of their
1005 fields are compatible (among other things). We assume that they
1006 are compatible until proven otherwise when building the cache.
1007 An example where this can occur is:
1008 struct a
1009 {
1010 struct a *next;
1011 };
1012 If we are comparing this against a similar struct in another TU,
1013 and did not assume they were compatible, we end up with an infinite
1014 loop. */
1017 }
1019 /* Free the seen types until we get to TU_TIL. */
1021 static void
1023 {
1026 {
1030 }
1032 }
1034 /* Return 1 if two 'struct', 'union', or 'enum' types T1 and T2 are
1035 compatible. If the two types are not the same (which has been
1036 checked earlier), this can only happen when multiple translation
1037 units are being compiled. See C99 6.2.7 paragraph 1 for the exact
1038 rules. */
1040 static int
1042 {
1046 /* We have to verify that the tags of the types are the same. This
1047 is harder than it looks because this may be a typedef, so we have
1048 to go look at the original type. It may even be a typedef of a
1049 typedef...
1050 In the case of compiler-created builtin structs the TYPE_DECL
1051 may be a dummy, with no DECL_ORIGINAL_TYPE. Don't fault. */
1062 /* C90 didn't have the requirement that the two tags be the same. */
1066 /* C90 didn't say what happened if one or both of the types were
1067 incomplete; we choose to follow C99 rules here, which is that they
1068 are compatible. */
1073 {
1078 }
1081 {
1083 {
1085 /* Speed up the case where the type values are in the same order. */
1090 {
1092 }
1095 {
1099 {
1102 }
1103 }
1106 {
1108 }
1110 {
1113 }
1116 {
1119 }
1122 {
1126 {
1129 }
1130 }
1132 }
1135 {
1138 {
1141 }
1143 /* Speed up the common case where the fields are in the same order. */
1146 {
1155 {
1158 }
1165 {
1168 }
1169 }
1171 {
1174 }
1177 {
1183 {
1187 {
1190 }
1201 }
1203 {
1206 }
1207 }
1210 }
1213 {
1219 {
1234 }
1237 else
1240 }
1244 }
1245 }
1247 /* Return 1 if two function types F1 and F2 are compatible.
1248 If either type specifies no argument types,
1249 the other must specify a fixed number of self-promoting arg types.
1250 Otherwise, if one type specifies only the number of arguments,
1251 the other must specify that number of self-promoting arg types.
1252 Otherwise, the argument types must match. */
1254 static int
1256 {
1258 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
1266 /* 'volatile' qualifiers on a function's return type used to mean
1267 the function is noreturn. */
1283 /* An unspecified parmlist matches any specified parmlist
1284 whose argument types don't need default promotions. */
1287 {
1290 /* If one of these types comes from a non-prototype fn definition,
1291 compare that with the other type's arglist.
1292 If they don't match, ask for a warning (but no error). */
1297 }
1299 {
1306 }
1308 /* Both types have argument lists: compare them and propagate results. */
1311 }
1313 /* Check two lists of types for compatibility,
1314 returning 0 for incompatible, 1 for compatible,
1315 or 2 for compatible with warning. */
1317 static int
1319 {
1320 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
1325 {
1329 /* If one list is shorter than the other,
1330 they fail to match. */
1339 /* A null pointer instead of a type
1340 means there is supposed to be an argument
1341 but nothing is specified about what type it has.
1342 So match anything that self-promotes. */
1344 {
1347 }
1349 {
1352 }
1353 /* If one of the lists has an error marker, ignore this arg. */
1356 ;
1358 {
1359 /* Allow wait (union {union wait *u; int *i} *)
1360 and wait (union wait *) to be compatible. */
1367 {
1368 tree memb;
1371 {
1378 }
1381 }
1388 {
1389 tree memb;
1392 {
1399 }
1402 }
1403 else
1405 }
1407 /* comptypes said ok, but record if it said to warn. */
1413 }
1414 }
1415 \f
1416 /* Compute the size to increment a pointer by. */
1418 static tree
1420 {
1427 {
1430 }
1432 /* Convert in case a char is more than one unit. */
1436 }
1437 \f
1438 /* Return either DECL or its known constant value (if it has one). */
1440 tree
1442 {
1444 in a place where a variable is invalid. Note that DECL_INITIAL
1445 isn't valid for a PARM_DECL. */
1452 /* This is invalid if initial value is not constant.
1453 If it has either a function call, a memory reference,
1454 or a variable, then re-evaluating it could give different results. */
1456 /* Check for cases where this is sub-optimal, even though valid. */
1460 }
1462 /* Return either DECL or its known constant value (if it has one), but
1463 return DECL if pedantic or DECL has mode BLKmode. This is for
1464 bug-compatibility with the old behavior of decl_constant_value
1465 (before GCC 3.0); every use of this function is a bug and it should
1466 be removed before GCC 3.1. It is not appropriate to use pedantic
1467 in a way that affects optimization, and BLKmode is probably not the
1468 right test for avoiding misoptimizations either. */
1470 static tree
1472 {
1473 tree ret;
1479 /* Avoid unwanted tree sharing between the initializer and current
1480 function's body where the tree can be modified e.g. by the
1481 gimplifier. */
1485 }
1487 /* Convert the array expression EXP to a pointer. */
1488 static tree
1490 {
1493 tree adr;
1495 tree ptrtype;
1510 {
1511 /* We are making an ADDR_EXPR of ptrtype. This is a valid
1512 ADDR_EXPR because it's the best way of representing what
1513 happens in C when we take the address of an array and place
1514 it in a pointer to the element type. */
1520 }
1522 /* This way is better for a COMPONENT_REF since it can
1523 simplify the offset for a component. */
1526 }
1528 /* Convert the function expression EXP to a pointer. */
1529 static tree
1531 {
1542 }
1544 /* Perform the default conversion of arrays and functions to pointers.
1545 Return the result of converting EXP. For any other expression, just
1546 return EXP after removing NOPs. */
1548 struct c_expr
1550 {
1556 {
1558 {
1566 {
1570 }
1577 {
1578 /* Before C99, non-lvalue arrays do not decay to pointers.
1579 Normally, using such an array would be invalid; but it can
1580 be used correctly inside sizeof or as a statement expression.
1581 Thus, do not give an error here; an error will result later. */
1583 }
1586 }
1596 }
1599 }
1602 /* EXP is an expression of integer type. Apply the integer promotions
1603 to it and return the promoted value. */
1605 tree
1607 {
1613 /* Normally convert enums to int,
1614 but convert wide enums to something wider. */
1616 {
1624 }
1626 /* ??? This should no longer be needed now bit-fields have their
1627 proper types. */
1630 /* If it's thinner than an int, promote it like a
1631 c_promoting_integer_type_p, otherwise leave it alone. */
1637 {
1638 /* Preserve unsignedness if not really getting any wider. */
1644 }
1647 }
1650 /* Perform default promotions for C data used in expressions.
1651 Enumeral types or short or char are converted to int.
1652 In addition, manifest constants symbols are replaced by their values. */
1654 tree
1656 {
1657 tree orig_exp;
1661 /* Functions and arrays have been converted during parsing. */
1666 /* Constants can be used directly unless they're not loadable. */
1670 /* Replace a nonvolatile const static variable with its value unless
1671 it is an array, in which case we must be sure that taking the
1672 address of the array produces consistent results. */
1674 {
1677 }
1679 /* Strip no-op conversions. */
1690 {
1693 }
1695 }
1696 \f
1697 /* Look up COMPONENT in a structure or union DECL.
1699 If the component name is not found, returns NULL_TREE. Otherwise,
1700 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL
1701 stepping down the chain to the component, which is in the last
1702 TREE_VALUE of the list. Normally the list is of length one, but if
1703 the component is embedded within (nested) anonymous structures or
1704 unions, the list steps down the chain to the component. */
1706 static tree
1708 {
1710 tree field;
1712 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers
1713 to the field elements. Use a binary search on this array to quickly
1714 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC
1715 will always be set for structures which have many elements. */
1718 {
1726 {
1731 {
1732 /* Step through all anon unions in linear fashion. */
1734 {
1738 {
1743 }
1744 }
1746 /* Entire record is only anon unions. */
1750 /* Restart the binary search, with new lower bound. */
1752 }
1758 else
1760 }
1766 }
1767 else
1768 {
1770 {
1774 {
1779 }
1783 }
1787 }
1790 }
1792 /* Make an expression to refer to the COMPONENT field of
1793 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */
1795 tree
1797 {
1801 tree ref;
1806 /* See if there is a field or component with name COMPONENT. */
1809 {
1811 {
1814 }
1819 {
1822 }
1824 /* Chain the COMPONENT_REFs if necessary down to the FIELD.
1825 This might be better solved in future the way the C++ front
1826 end does it - by giving the anonymous entities each a
1827 separate name and type, and then have build_component_ref
1828 recursively call itself. We can't do that here. */
1829 do
1830 {
1833 tree subtype;
1843 NULL_TREE);
1855 }
1859 }
1862 component);
1865 }
1866 \f
1867 /* Given an expression PTR for a pointer, return an expression
1868 for the value pointed to.
1869 ERRORSTRING is the name of the operator to appear in error messages. */
1871 tree
1873 {
1878 {
1882 {
1883 /* If a warning is issued, mark it to avoid duplicates from
1884 the backend. This only needs to be done at
1885 warn_strict_aliasing > 2. */
1890 }
1896 else
1897 {
1899 tree ref;
1904 {
1907 }
1911 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
1912 so that we get the proper error message if the result is used
1913 to assign to. Also, &* is supposed to be a no-op.
1914 And ANSI C seems to specify that the type of the result
1915 should be the const type. */
1916 /* A de-reference of a pointer to const is not a const. It is valid
1917 to change it via some other pointer. */
1923 }
1924 }
1928 }
1930 /* This handles expressions of the form "a[i]", which denotes
1931 an array reference.
1933 This is logically equivalent in C to *(a+i), but we may do it differently.
1934 If A is a variable or a member, we generate a primitive ARRAY_REF.
1935 This avoids forcing the array out of registers, and can work on
1936 arrays that are not lvalues (for example, members of structures returned
1937 by functions). */
1939 tree
1941 {
1949 {
1950 tree temp;
1953 {
1956 }
1961 }
1964 {
1967 }
1970 {
1973 }
1975 /* ??? Existing practice has been to warn only when the char
1976 index is syntactically the index, not for char[array]. */
1980 /* Apply default promotions *after* noticing character types. */
1986 {
1989 /* An array that is indexed by a non-constant
1990 cannot be stored in a register; we must be able to do
1991 address arithmetic on its address.
1992 Likewise an array of elements of variable size. */
1996 {
1999 }
2000 /* An array that is indexed by a constant value which is not within
2001 the array bounds cannot be stored in a register either; because we
2002 would get a crash in store_bit_field/extract_bit_field when trying
2003 to access a non-existent part of the register. */
2007 {
2010 }
2013 {
2021 }
2027 /* Array ref is const/volatile if the array elements are
2028 or if the array is. */
2037 /* This was added by rms on 16 Nov 91.
2038 It fixes vol struct foo *a; a->elts[1]
2039 in an inline function.
2040 Hope it doesn't break something else. */
2043 }
2044 else
2045 {
2056 }
2057 }
2058 \f
2059 /* Build an external reference to identifier ID. FUN indicates
2060 whether this will be used for a function call. LOC is the source
2061 location of the identifier. */
2062 tree
2064 {
2065 tree ref;
2068 /* In Objective-C, an instance variable (ivar) may be preferred to
2069 whatever lookup_name() found. */
2075 /* Implicit function declaration. */
2078 /* Don't complain about something that's already been
2079 complained about. */
2081 else
2082 {
2085 }
2098 {
2105 }
2108 {
2113 }
2119 {
2124 }
2125 /* C99 6.7.4p3: An inline definition of a function with external
2126 linkage ... shall not contain a reference to an identifier with
2127 internal linkage. */
2138 }
2140 /* Record details of decls possibly used inside sizeof or typeof. */
2141 struct maybe_used_decl
2142 {
2143 /* The decl. */
2144 tree decl;
2145 /* The level seen at (in_sizeof + in_typeof). */
2147 /* The next one at this level or above, or NULL. */
2149 };
2153 /* Record that DECL, an undefined static function reference seen
2154 inside sizeof or typeof, might be used if the operand of sizeof is
2155 a VLA type or the operand of typeof is a variably modified
2156 type. */
2158 static void
2160 {
2166 }
2168 /* Pop the stack of decls possibly used inside sizeof or typeof. If
2169 USED is false, just discard them. If it is true, mark them used
2170 (if no longer inside sizeof or typeof) or move them to the next
2171 level up (if still inside sizeof or typeof). */
2173 void
2175 {
2179 {
2181 {
2184 else
2186 }
2188 }
2191 }
2193 /* Return the result of sizeof applied to EXPR. */
2195 struct c_expr
2197 {
2200 {
2204 }
2205 else
2206 {
2210 {
2211 /* sizeof is evaluated when given a vla (C99 6.5.3.4p2). */
2213 }
2215 }
2217 }
2219 /* Return the result of sizeof applied to T, a structure for the type
2220 name passed to sizeof (rather than the type itself). */
2222 struct c_expr
2224 {
2225 tree type;
2233 }
2235 /* Build a function call to function FUNCTION with parameters PARAMS.
2236 PARAMS is a list--a chain of TREE_LIST nodes--in which the
2237 TREE_VALUE of each node is a parameter-expression.
2238 FUNCTION's data type may be a function type or a pointer-to-function. */
2240 tree
2242 {
2245 tree tem;
2250 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2253 /* Convert anything with function type to a pointer-to-function. */
2255 {
2256 /* Implement type-directed function overloading for builtins.
2257 resolve_overloaded_builtin and targetm.resolve_overloaded_builtin
2258 handle all the type checking. The result is a complete expression
2259 that implements this function call. */
2266 }
2270 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2271 expressions, like those used for ObjC messenger dispatches. */
2281 {
2284 }
2289 /* fntype now gets the type of function pointed to. */
2292 /* Check that the function is called through a compatible prototype.
2293 If it is not, replace the call by a trap, wrapped up in a compound
2294 expression if necessary. This has the nice side-effect to prevent
2295 the tree-inliner from generating invalid assignment trees which may
2296 blow up in the RTL expander later. */
2302 {
2305 NULL_TREE);
2307 /* This situation leads to run-time undefined behavior. We can't,
2308 therefore, simply error unless we can prove that all possible
2309 executions of the program must execute the code. */
2312 /* We can, however, treat "undefined" any way we please.
2313 Call abort to encourage the user to fix the program. */
2318 else
2319 {
2320 tree rhs;
2325 else
2329 }
2330 }
2332 /* Convert the parameters to the types declared in the
2333 function prototype, or apply default promotions. */
2342 /* Check that the arguments to the function are valid. */
2348 {
2355 }
2356 else
2363 }
2364 \f
2365 /* Convert the argument expressions in the list VALUES
2366 to the types in the list TYPELIST. The resulting arguments are
2367 stored in the array ARGARRAY which has size NARGS.
2369 If TYPELIST is exhausted, or when an element has NULL as its type,
2370 perform the default conversions.
2372 PARMLIST is the chain of parm decls for the function being called.
2373 It may be 0, if that info is not available.
2374 It is used only for generating error messages.
2376 FUNCTION is a tree for the called function. It is used only for
2377 error messages, where it is formatted with %qE.
2379 This is also where warnings about wrong number of args are generated.
2381 VALUES is a chain of TREE_LIST nodes with the elements of the list
2382 in the TREE_VALUE slots of those nodes.
2384 Returns the actual number of arguments processed (which may be less
2385 than NARGS in some error situations), or -1 on failure. */
2387 static int
2390 {
2393 tree selector;
2395 /* Change pointer to function to the function itself for
2396 diagnostics. */
2401 /* Handle an ObjC selector specially for diagnostics. */
2404 /* Scan the given expressions and types, producing individual
2405 converted arguments and storing them in ARGARRAY. */
2408 valtail;
2410 {
2418 {
2421 }
2424 {
2427 }
2434 {
2435 /* Formal parm type is specified by a function prototype. */
2436 tree parmval;
2439 {
2442 }
2443 else
2444 {
2445 /* Optionally warn about conversions that
2446 differ from the default conversions. */
2448 {
2481 /* ??? At some point, messages should be written about
2482 conversions between complex types, but that's too messy
2483 to do now. */
2486 {
2487 /* Warn if any argument is passed as `float',
2488 since without a prototype it would be `double'. */
2495 /* Warn if mismatch between argument and prototype
2496 for decimal float types. Warn of conversions with
2497 binary float types and of precision narrowing due to
2498 prototype. */
2506 && (formal_prec
2510 != dfloat64_type_node
2520 }
2521 /* Detect integer changing in width or signedness.
2522 These warnings are only activated with
2523 -Wtraditional-conversion, not with -Wtraditional. */
2526 {
2533 /* No warning if function asks for enum
2534 and the actual arg is that enum type. */
2535 ;
2541 ;
2542 /* Don't complain if the formal parameter type
2543 is an enum, because we can't tell now whether
2544 the value was an enum--even the same enum. */
2546 ;
2549 /* Change in signedness doesn't matter
2550 if a constant value is unaffected. */
2551 ;
2552 /* If the value is extended from a narrower
2553 unsigned type, it doesn't matter whether we
2554 pass it as signed or unsigned; the value
2555 certainly is the same either way. */
2558 ;
2563 else
2566 }
2567 }
2577 }
2579 }
2584 /* Convert `float' to `double'. */
2588 {
2591 }
2592 else
2593 /* Convert `short' and `char' to full-size `int'. */
2598 }
2603 {
2606 }
2609 }
2610 \f
2611 /* This is the entry point used by the parser to build unary operators
2612 in the input. CODE, a tree_code, specifies the unary operator, and
2613 ARG is the operand. For unary plus, the C parser currently uses
2614 CONVERT_EXPR for code. */
2616 struct c_expr
2618 {
2628 }
2630 /* This is the entry point used by the parser to build binary operators
2631 in the input. CODE, a tree_code, specifies the binary operator, and
2632 ARG1 and ARG2 are the operands. In addition to constructing the
2633 expression, we check for operands that were written with other binary
2634 operators in a way that is likely to confuse the user. */
2636 struct c_expr
2639 {
2651 /* Check for cases such as x+y<<z which users are likely
2652 to misinterpret. */
2659 /* Warn about comparisons against string literals, with the exception
2660 of testing for equality or inequality of a string literal with NULL. */
2662 {
2666 }
2677 }
2678 \f
2679 /* Return a tree for the difference of pointers OP0 and OP1.
2680 The resulting tree has type int. */
2682 static tree
2684 {
2692 {
2697 }
2699 /* If the conversion to ptrdiff_type does anything like widening or
2700 converting a partial to an integral mode, we get a convert_expression
2701 that is in the way to do any simplifications.
2702 (fold-const.c doesn't know that the extra bits won't be needed.
2703 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2704 different mode in place.)
2705 So first try to find a common term here 'by hand'; we want to cover
2706 at least the cases that occur in legal static initializers. */
2711 else
2717 else
2721 {
2724 }
2725 else
2729 {
2732 }
2733 else
2737 {
2740 }
2743 /* First do the subtraction as integers;
2744 then drop through to build the divide operator.
2745 Do not do default conversions on the minus operator
2746 in case restype is a short type. */
2750 /* This generates an error if op1 is pointer to incomplete type. */
2754 /* This generates an error if op0 is pointer to incomplete type. */
2757 /* Divide by the size, in easiest possible way. */
2759 }
2760 \f
2761 /* Construct and perhaps optimize a tree representation
2762 for a unary operation. CODE, a tree_code, specifies the operation
2763 and XARG is the operand.
2764 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2765 the default promotions (such as from short to int).
2766 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2767 allows non-lvalues; this is only used to handle conversion of non-lvalue
2768 arrays to pointers in C99. */
2770 tree
2772 {
2773 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2777 tree val;
2788 {
2791 }
2794 {
2796 /* This is used for unary plus, because a CONVERT_EXPR
2797 is enough to prevent anybody from looking inside for
2798 associativity, but won't generate any code. */
2802 {
2805 }
2815 {
2818 }
2825 {
2828 }
2830 {
2836 }
2837 else
2838 {
2841 }
2846 {
2849 }
2855 /* Conjugating a real value is a no-op, but allow it anyway. */
2858 {
2861 }
2870 {
2873 }
2882 else
2890 else
2898 /* Increment or decrement the real part of the value,
2899 and don't change the imaginary part. */
2901 {
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 {
3298 /* Do not warn if the result type is signed, since the
3299 signed type will only be chosen if it can represent
3300 all the values of the unsigned type. */
3303 /* Do not warn if the signed quantity is an unsuffixed
3304 integer literal (or some static constant expression
3305 involving such literals) and it is non-negative. */
3308 || (unsigned_op1
3311 else
3313 }
3314 }
3315 }
3317 {
3321 }
3323 {
3331 {
3337 }
3339 {
3345 }
3346 else
3347 {
3350 }
3351 }
3353 {
3356 else
3357 {
3359 }
3361 }
3363 {
3366 else
3367 {
3369 }
3371 }
3374 {
3377 else
3378 {
3381 }
3382 }
3384 /* Merge const and volatile flags of the incoming types. */
3385 result_type
3396 }
3397 \f
3398 /* Return a compound expression that performs two expressions and
3399 returns the value of the second of them. */
3401 tree
3403 {
3405 {
3406 /* The left-hand operand of a comma expression is like an expression
3407 statement: with -Wextra or -Wunused, we should warn if it doesn't have
3408 any side-effects, unless it was explicitly cast to (void). */
3410 {
3420 else
3423 }
3424 }
3426 /* With -Wunused, we should also warn if the left-hand operand does have
3427 side-effects, but computes a value which is not used. For example, in
3428 `foo() + bar(), baz()' the result of the `+' operator is not used,
3429 so we should issue a warning. */
3437 }
3439 /* Build an expression representing a cast to type TYPE of expression EXPR. */
3441 tree
3443 {
3449 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
3450 only in <protocol> qualifications. But when constructing cast expressions,
3451 the protocols do matter and must be kept around. */
3458 {
3461 }
3464 {
3467 }
3470 {
3472 {
3476 }
3477 }
3479 {
3480 tree field;
3488 {
3489 tree t;
3499 }
3502 }
3503 else
3504 {
3512 /* Optionally warn about potentially worrisome casts. */
3517 {
3523 /* Check that the qualifiers on IN_TYPE are a superset of
3524 the qualifiers of IN_OTYPE. The outermost level of
3525 POINTER_TYPE nodes is uninteresting and we stop as soon
3526 as we hit a non-POINTER_TYPE node on either type. */
3527 do
3528 {
3532 /* GNU C allows cv-qualified function types. 'const'
3533 means the function is very pure, 'volatile' means it
3534 can't return. We need to warn when such qualifiers
3535 are added, not when they're taken away. */
3539 else
3541 }
3549 /* There are qualifiers present in IN_OTYPE that are not
3550 present in IN_TYPE. */
3552 }
3554 /* Warn about possible alignment problems. */
3560 /* Don't warn about opaque types, where the actual alignment
3561 restriction is unknown. */
3572 /* Unlike conversion of integers to pointers, where the
3573 warning is disabled for converting constants because
3574 of cases such as SIG_*, warn about converting constant
3575 pointers to integers. In some cases it may cause unwanted
3576 sign extension, and a warning is appropriate. */
3588 /* Don't warn about converting any constant. */
3596 /* If pedantic, warn for conversions between function and object
3597 pointer types, except for converting a null pointer constant
3598 to function pointer type. */
3617 /* Ignore any integer overflow caused by the cast. */
3619 {
3621 {
3623 {
3624 /* Avoid clobbering a shared constant. */
3627 }
3628 }
3630 /* Reset VALUE's overflow flags, ensuring constant sharing. */
3634 }
3635 }
3637 /* Don't let a cast be an lvalue. */
3642 }
3644 /* Interpret a cast of expression EXPR to type TYPE. */
3645 tree
3647 {
3648 tree type;
3651 /* This avoids warnings about unprototyped casts on
3652 integers. E.g. "#define SIG_DFL (void(*)())0". */
3659 }
3660 \f
3661 /* Build an assignment expression of lvalue LHS from value RHS.
3662 MODIFYCODE is the code for a binary operator that we use
3663 to combine the old value of LHS with RHS to get the new value.
3664 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3666 tree
3668 {
3669 tree result;
3670 tree newrhs;
3674 /* Types that aren't fully specified cannot be used in assignments. */
3677 /* Avoid duplicate error messages from operands that had errors. */
3688 /* If a binary op has been requested, combine the old LHS value with the RHS
3689 producing the value we should actually store into the LHS. */
3692 {
3695 }
3697 /* Give an error for storing in something that is 'const'. */
3703 {
3706 }
3708 /* If storing into a structure or union member,
3709 it has probably been given type `int'.
3710 Compute the type that would go with
3711 the actual amount of storage the member occupies. */
3720 /* If storing in a field that is in actuality a short or narrower than one,
3721 we must store in the field in its actual type. */
3724 {
3727 }
3729 /* Convert new value to destination type. */
3736 /* Emit ObjC write barrier, if necessary. */
3738 {
3742 }
3744 /* Scan operands. */
3749 /* If we got the LHS in a different type for storing in,
3750 convert the result back to the nominal type of LHS
3751 so that the value we return always has the same type
3752 as the LHS argument. */
3758 }
3759 \f
3760 /* Convert value RHS to type TYPE as preparation for an assignment
3761 to an lvalue of type TYPE.
3762 The real work of conversion is done by `convert'.
3763 The purpose of this function is to generate error messages
3764 for assignments that are not allowed in C.
3765 ERRTYPE says whether it is argument passing, assignment,
3766 initialization or return.
3768 FUNCTION is a tree for the function being called.
3769 PARMNUM is the number of the argument, for printing in error messages. */
3771 static tree
3774 {
3776 tree rhstype;
3782 {
3783 tree selector;
3784 /* Change pointer to function to the function itself for
3785 diagnostics. */
3790 /* Handle an ObjC selector specially for diagnostics. */
3794 {
3797 }
3798 }
3800 /* This macro is used to emit diagnostics to ensure that all format
3801 strings are complete sentences, visible to gettext and checked at
3802 compile time. */
3803 #define WARN_FOR_ASSIGNMENT(AR, AS, IN, RE) \
3804 do { \
3805 switch (errtype) \
3806 { \
3807 case ic_argpass: \
3808 pedwarn (AR, parmnum, rname); \
3809 break; \
3810 case ic_argpass_nonproto: \
3811 warning (0, AR, parmnum, rname); \
3812 break; \
3813 case ic_assign: \
3814 pedwarn (AS); \
3815 break; \
3816 case ic_init: \
3817 pedwarn (IN); \
3818 break; \
3819 case ic_return: \
3820 pedwarn (RE); \
3821 break; \
3822 default: \
3823 gcc_unreachable (); \
3824 } \
3825 } while (0)
3840 {
3844 {
3860 }
3863 }
3869 {
3870 /* Except for passing an argument to an unprototyped function,
3871 this is a constraint violation. When passing an argument to
3872 an unprototyped function, it is compile-time undefined;
3873 making it a constraint in that case was rejected in
3874 DR#252. */
3877 }
3878 /* A type converts to a reference to it.
3879 This code doesn't fully support references, it's just for the
3880 special case of va_start and va_copy. */
3883 {
3885 {
3888 }
3893 /* We already know that these two types are compatible, but they
3894 may not be exactly identical. In fact, `TREE_TYPE (type)' is
3895 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
3896 likely to be va_list, a typedef to __builtin_va_list, which
3897 is different enough that it will cause problems later. */
3903 }
3904 /* Some types can interconvert without explicit casts. */
3908 /* Arithmetic types all interconvert, and enum is treated like int. */
3917 /* Aggregates in different TUs might need conversion. */
3923 /* Conversion to a transparent union from its member types.
3924 This applies only to function arguments. */
3927 {
3931 {
3942 {
3946 /* Any non-function converts to a [const][volatile] void *
3947 and vice versa; otherwise, targets must be the same.
3948 Meanwhile, the lhs target must have all the qualifiers of
3949 the rhs. */
3952 {
3953 /* If this type won't generate any warnings, use it. */
3963 /* Keep looking for a better type, but remember this one. */
3966 }
3967 }
3969 /* Can convert integer zero to any pointer type. */
3971 {
3974 }
3975 }
3978 {
3980 {
3981 /* We have only a marginally acceptable member type;
3982 it needs a warning. */
3986 /* Const and volatile mean something different for function
3987 types, so the usual warnings are not appropriate. */
3990 {
3991 /* Because const and volatile on functions are
3992 restrictions that say the function will not do
3993 certain things, it is okay to use a const or volatile
3994 function where an ordinary one is wanted, but not
3995 vice-versa. */
3998 "makes qualified function "
4001 "function pointer from "
4004 "function pointer from "
4008 }
4020 }
4026 }
4027 }
4029 /* Conversions among pointers */
4032 {
4044 /* Opaque pointers are treated like void pointers. */
4050 /* C++ does not allow the implicit conversion void* -> T*. However,
4051 for the purpose of reducing the number of false positives, we
4052 tolerate the special case of
4054 int *p = NULL;
4056 where NULL is typically defined in C to be '(void *) 0'. */
4061 /* Check if the right-hand side has a format attribute but the
4062 left-hand side doesn't. */
4065 {
4067 {
4071 "argument %d of %qE might be "
4077 "assignment left-hand side might be "
4082 "initialization left-hand side might be "
4087 "return type might be "
4092 }
4093 }
4095 /* Any non-function converts to a [const][volatile] void *
4096 and vice versa; otherwise, targets must be the same.
4097 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
4100 || is_opaque_pointer
4103 {
4106 ||
4111 "%qE between function pointer "
4119 /* Const and volatile mean something different for function types,
4120 so the usual warnings are not appropriate. */
4123 {
4125 {
4126 /* Types differing only by the presence of the 'volatile'
4127 qualifier are acceptable if the 'volatile' has been added
4128 in by the Objective-C EH machinery. */
4138 }
4139 /* If this is not a case of ignoring a mismatch in signedness,
4140 no warning. */
4143 ;
4144 /* If there is a mismatch, do warn. */
4154 }
4157 {
4158 /* Because const and volatile on functions are restrictions
4159 that say the function will not do certain things,
4160 it is okay to use a const or volatile function
4161 where an ordinary one is wanted, but not vice-versa. */
4164 "qualified function pointer "
4172 }
4173 }
4174 else
4175 /* Avoid warning about the volatile ObjC EH puts on decls. */
4185 }
4187 {
4188 /* ??? This should not be an error when inlining calls to
4189 unprototyped functions. */
4192 }
4194 {
4195 /* An explicit constant 0 can convert to a pointer,
4196 or one that results from arithmetic, even including
4197 a cast to integer type. */
4209 }
4211 {
4221 }
4226 {
4229 /* ??? This should not be an error when inlining calls to
4230 unprototyped functions. */
4244 }
4247 }
4249 /* Convert VALUE for assignment into inlined parameter PARM. ARGNUM
4250 is used for error and warning reporting and indicates which argument
4251 is being processed. */
4253 tree
4255 {
4258 /* If FN was prototyped at the call site, the value has been converted
4259 already in convert_arguments.
4260 However, we might see a prototype now that was not in place when
4261 the function call was seen, so check that the VALUE actually matches
4262 PARM before taking an early exit. */
4278 }
4279 \f
4280 /* If VALUE is a compound expr all of whose expressions are constant, then
4281 return its value. Otherwise, return error_mark_node.
4283 This is for handling COMPOUND_EXPRs as initializer elements
4284 which is allowed with a warning when -pedantic is specified. */
4286 static tree
4288 {
4290 {
4295 endtype);
4296 }
4299 else
4301 }
4302 \f
4303 /* Perform appropriate conversions on the initial value of a variable,
4304 store it in the declaration DECL,
4305 and print any error messages that are appropriate.
4306 If the init is invalid, store an ERROR_MARK. */
4308 void
4310 {
4313 /* If variable's type was invalidly declared, just ignore it. */
4319 /* Digest the specified initializer into an expression. */
4323 /* Store the expression if valid; else report error. */
4332 /* ANSI wants warnings about out-of-range constant initializers. */
4337 /* Check if we need to set array size from compound literal size. */
4341 {
4348 {
4352 {
4353 /* For int foo[] = (int [3]){1}; we need to set array size
4354 now since later on array initializer will be just the
4355 brace enclosed list of the compound literal. */
4361 }
4362 }
4363 }
4364 }
4365 \f
4366 /* Methods for storing and printing names for error messages. */
4368 /* Implement a spelling stack that allows components of a name to be pushed
4369 and popped. Each element on the stack is this structure. */
4371 struct spelling
4372 {
4374 union
4375 {
4379 };
4381 #define SPELLING_STRING 1
4382 #define SPELLING_MEMBER 2
4383 #define SPELLING_BOUNDS 3
4389 /* Macros to save and restore the spelling stack around push_... functions.
4390 Alternative to SAVE_SPELLING_STACK. */
4392 #define SPELLING_DEPTH() (spelling - spelling_base)
4393 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
4395 /* Push an element on the spelling stack with type KIND and assign VALUE
4396 to MEMBER. */
4398 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
4399 { \
4400 int depth = SPELLING_DEPTH (); \
4401 \
4402 if (depth >= spelling_size) \
4403 { \
4404 spelling_size += 10; \
4405 spelling_base = XRESIZEVEC (struct spelling, spelling_base, \
4406 spelling_size); \
4407 RESTORE_SPELLING_DEPTH (depth); \
4408 } \
4409 \
4410 spelling->kind = (KIND); \
4411 spelling->MEMBER = (VALUE); \
4412 spelling++; \
4413 }
4415 /* Push STRING on the stack. Printed literally. */
4417 static void
4419 {
4421 }
4423 /* Push a member name on the stack. Printed as '.' STRING. */
4425 static void
4427 {
4431 }
4433 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
4435 static void
4437 {
4439 }
4441 /* Compute the maximum size in bytes of the printed spelling. */
4443 static int
4445 {
4450 {
4453 else
4455 }
4458 }
4460 /* Print the spelling to BUFFER and return it. */
4464 {
4470 {
4473 }
4474 else
4475 {
4480 ;
4481 }
4484 }
4486 /* Issue an error message for a bad initializer component.
4487 MSGID identifies the message.
4488 The component name is taken from the spelling stack. */
4490 void
4492 {
4499 }
4501 /* Issue a pedantic warning for a bad initializer component.
4502 MSGID identifies the message.
4503 The component name is taken from the spelling stack. */
4505 void
4507 {
4514 }
4516 /* Issue a warning for a bad initializer component.
4517 MSGID identifies the message.
4518 The component name is taken from the spelling stack. */
4520 static void
4522 {
4529 }
4530 \f
4531 /* If TYPE is an array type and EXPR is a parenthesized string
4532 constant, warn if pedantic that EXPR is being used to initialize an
4533 object of type TYPE. */
4535 void
4537 {
4543 }
4545 /* Digest the parser output INIT as an initializer for type TYPE.
4546 Return a C expression of type TYPE to represent the initial value.
4548 If INIT is a string constant, STRICT_STRING is true if it is
4549 unparenthesized or we should not warn here for it being parenthesized.
4550 For other types of INIT, STRICT_STRING is not used.
4552 REQUIRE_CONSTANT requests an error if non-constant initializers or
4553 elements are seen. */
4555 static tree
4557 {
4562 || !init
4571 /* Initialization of an array of chars from a string constant
4572 optionally enclosed in braces. */
4576 {
4578 /* Note that an array could be both an array of character type
4579 and an array of wchar_t if wchar_t is signed char or unsigned
4580 char. */
4586 {
4593 char_string
4602 {
4605 }
4607 {
4610 }
4616 /* Subtract 1 (or sizeof (wchar_t))
4617 because it's ok to ignore the terminating null char
4618 that is counted in the length of the constant. */
4629 }
4631 {
4635 }
4636 }
4638 /* Build a VECTOR_CST from a *constant* vector constructor. If the
4639 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
4640 below and handle as a constructor. */
4645 {
4652 {
4654 tree value;
4657 /* Iterate through elements and check if all constructor
4658 elements are *_CSTs. */
4661 {
4664 }
4669 }
4670 }
4672 /* Any type can be initialized
4673 from an expression of the same type, optionally with braces. */
4686 {
4688 {
4690 {
4694 else
4695 {
4698 }
4699 }
4700 }
4703 /* Although the types are compatible, we may require a
4704 conversion. */
4710 {
4711 /* As an extension, allow initializing objects with static storage
4712 duration with compound literals (which are then treated just as
4713 the brace enclosed list they contain). Also allow this for
4714 vectors, as we can only assign them with compound literals. */
4717 }
4721 {
4724 }
4729 /* Compound expressions can only occur here if -pedantic or
4730 -pedantic-errors is specified. In the later case, we always want
4731 an error. In the former case, we simply want a warning. */
4734 {
4735 inside_init
4740 else
4744 }
4748 {
4751 }
4753 /* Added to enable additional -Wmissing-format-attribute warnings. */
4758 }
4760 /* Handle scalar types, including conversions. */
4765 {
4770 inside_init
4774 /* Check to see if we have already given an error message. */
4776 ;
4778 {
4781 }
4785 {
4788 }
4791 }
4793 /* Come here only for records and arrays. */
4796 {
4799 }
4803 }
4804 \f
4805 /* Handle initializers that use braces. */
4807 /* Type of object we are accumulating a constructor for.
4808 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4811 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4812 left to fill. */
4815 /* For an ARRAY_TYPE, this is the specified index
4816 at which to store the next element we get. */
4819 /* For an ARRAY_TYPE, this is the maximum index. */
4822 /* For a RECORD_TYPE, this is the first field not yet written out. */
4825 /* For an ARRAY_TYPE, this is the index of the first element
4826 not yet written out. */
4829 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4830 This is so we can generate gaps between fields, when appropriate. */
4833 /* If we are saving up the elements rather than allocating them,
4834 this is the list of elements so far (in reverse order,
4835 most recent first). */
4838 /* 1 if constructor should be incrementally stored into a constructor chain,
4839 0 if all the elements should be kept in AVL tree. */
4842 /* 1 if so far this constructor's elements are all compile-time constants. */
4845 /* 1 if so far this constructor's elements are all valid address constants. */
4848 /* 1 if this constructor is erroneous so far. */
4851 /* Structure for managing pending initializer elements, organized as an
4852 AVL tree. */
4854 struct init_node
4855 {
4859 tree purpose;
4860 tree value;
4861 };
4863 /* Tree of pending elements at this constructor level.
4864 These are elements encountered out of order
4865 which belong at places we haven't reached yet in actually
4866 writing the output.
4867 Will never hold tree nodes across GC runs. */
4870 /* The SPELLING_DEPTH of this constructor. */
4873 /* DECL node for which an initializer is being read.
4874 0 means we are reading a constructor expression
4875 such as (struct foo) {...}. */
4878 /* Nonzero if this is an initializer for a top-level decl. */
4881 /* Nonzero if there were any member designators in this initializer. */
4884 /* Nesting depth of designator list. */
4887 /* Nonzero if there were diagnosed errors in this designator list. */
4890 \f
4891 /* This stack has a level for each implicit or explicit level of
4892 structuring in the initializer, including the outermost one. It
4893 saves the values of most of the variables above. */
4897 struct constructor_stack
4898 {
4900 tree type;
4901 tree fields;
4902 tree index;
4903 tree max_index;
4904 tree unfilled_index;
4905 tree unfilled_fields;
4906 tree bit_index;
4911 /* If value nonzero, this value should replace the entire
4912 constructor at this level. */
4922 };
4926 /* This stack represents designators from some range designator up to
4927 the last designator in the list. */
4929 struct constructor_range_stack
4930 {
4933 tree range_start;
4934 tree index;
4935 tree range_end;
4936 tree fields;
4937 };
4941 /* This stack records separate initializers that are nested.
4942 Nested initializers can't happen in ANSI C, but GNU C allows them
4943 in cases like { ... (struct foo) { ... } ... }. */
4945 struct initializer_stack
4946 {
4948 tree decl;
4958 };
4961 \f
4962 /* Prepare to parse and output the initializer for variable DECL. */
4964 void
4966 {
4988 {
4990 require_constant_elements
4992 /* For a scalar, you can always use any value to initialize,
4993 even within braces. */
4999 }
5000 else
5001 {
5005 }
5018 }
5020 void
5022 {
5025 /* Free the whole constructor stack of this initializer. */
5027 {
5031 }
5035 /* Pop back to the data of the outer initializer (if any). */
5050 }
5051 \f
5052 /* Call here when we see the initializer is surrounded by braces.
5053 This is instead of a call to push_init_level;
5054 it is matched by a call to pop_init_level.
5056 TYPE is the type to initialize, for a constructor expression.
5057 For an initializer for a decl, TYPE is zero. */
5059 void
5061 {
5106 {
5108 /* Skip any nameless bit fields at the beginning. */
5115 }
5117 {
5119 {
5120 constructor_max_index
5123 /* Detect non-empty initializations of zero-length arrays. */
5128 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5129 to initialize VLAs will cause a proper error; avoid tree
5130 checking errors as well by setting a safe value. */
5135 constructor_index
5138 }
5139 else
5140 {
5143 }
5146 }
5148 {
5149 /* Vectors are like simple fixed-size arrays. */
5150 constructor_max_index =
5154 }
5155 else
5156 {
5157 /* Handle the case of int x = {5}; */
5160 }
5161 }
5162 \f
5163 /* Push down into a subobject, for initialization.
5164 If this is for an explicit set of braces, IMPLICIT is 0.
5165 If it is because the next element belongs at a lower level,
5166 IMPLICIT is 1 (or 2 if the push is because of designator list). */
5168 void
5170 {
5174 /* If we've exhausted any levels that didn't have braces,
5175 pop them now. If implicit == 1, this will have been done in
5176 process_init_element; do not repeat it here because in the case
5177 of excess initializers for an empty aggregate this leads to an
5178 infinite cycle of popping a level and immediately recreating
5179 it. */
5181 {
5183 {
5189 && constructor_max_index
5191 constructor_index))
5193 else
5195 }
5196 }
5198 /* Unless this is an explicit brace, we need to preserve previous
5199 content if any. */
5201 {
5208 }
5242 {
5247 }
5249 /* Don't die if an entire brace-pair level is superfluous
5250 in the containing level. */
5252 ;
5255 {
5256 /* Don't die if there are extra init elts at the end. */
5259 else
5260 {
5263 constructor_depth++;
5264 }
5265 }
5267 {
5270 constructor_depth++;
5271 }
5274 {
5279 }
5282 {
5290 }
5293 {
5296 }
5300 {
5302 /* Skip any nameless bit fields at the beginning. */
5309 }
5311 {
5312 /* Vectors are like simple fixed-size arrays. */
5313 constructor_max_index =
5317 }
5319 {
5321 {
5322 constructor_max_index
5325 /* Detect non-empty initializations of zero-length arrays. */
5330 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5331 to initialize VLAs will cause a proper error; avoid tree
5332 checking errors as well by setting a safe value. */
5337 constructor_index
5340 }
5341 else
5346 {
5347 /* We need to split the char/wchar array into individual
5348 characters, so that we don't have to special case it
5349 everywhere. */
5351 }
5352 }
5353 else
5354 {
5359 }
5360 }
5362 /* At the end of an implicit or explicit brace level,
5363 finish up that level of constructor. If a single expression
5364 with redundant braces initialized that level, return the
5365 c_expr structure for that expression. Otherwise, the original_code
5366 element is set to ERROR_MARK.
5367 If we were outputting the elements as they are read, return 0 as the value
5368 from inner levels (process_init_element ignores that),
5369 but return error_mark_node as the value from the outermost level
5370 (that's what we want to put in DECL_INITIAL).
5371 Otherwise, return a CONSTRUCTOR expression as the value. */
5373 struct c_expr
5375 {
5382 {
5383 /* When we come to an explicit close brace,
5384 pop any inner levels that didn't have explicit braces. */
5389 }
5391 /* Now output all pending elements. */
5397 /* Error for initializing a flexible array member, or a zero-length
5398 array member in an inappropriate context. */
5403 {
5404 /* Silently discard empty initializations. The parser will
5405 already have pedwarned for empty brackets. */
5408 else
5409 {
5417 /* We have already issued an error message for the existence
5418 of a flexible array member not at the end of the structure.
5419 Discard the initializer so that we do not die later. */
5422 }
5423 }
5425 /* Warn when some struct elements are implicitly initialized to zero. */
5427 && constructor_type
5430 {
5431 /* Do not warn for flexible array members or zero-length arrays. */
5437 /* Do not warn if this level of the initializer uses member
5438 designators; it is likely to be deliberate. */
5440 {
5444 }
5445 }
5447 /* Pad out the end of the structure. */
5449 /* If this closes a superfluous brace pair,
5450 just pass out the element between them. */
5453 ;
5458 {
5459 /* A nonincremental scalar initializer--just return
5460 the element, after verifying there is just one. */
5462 {
5466 }
5468 {
5471 }
5472 else
5474 }
5475 else
5476 {
5479 else
5480 {
5482 constructor_elements);
5487 }
5488 }
5515 }
5517 /* Common handling for both array range and field name designators.
5518 ARRAY argument is nonzero for array ranges. Returns zero for success. */
5520 static int
5522 {
5523 tree subtype;
5526 /* Don't die if an entire brace-pair level is superfluous
5527 in the containing level. */
5531 /* If there were errors in this designator list already, bail out
5532 silently. */
5537 {
5540 /* Designator list starts at the level of closest explicit
5541 braces. */
5546 }
5549 {
5561 }
5565 {
5568 }
5570 {
5573 }
5578 }
5580 /* If there are range designators in designator list, push a new designator
5581 to constructor_range_stack. RANGE_END is end of such stack range or
5582 NULL_TREE if there is no range designator at this level. */
5584 static void
5586 {
5600 }
5602 /* Within an array initializer, specify the next index to be initialized.
5603 FIRST is that index. If LAST is nonzero, then initialize a range
5604 of indices, running from FIRST through LAST. */
5606 void
5608 {
5616 {
5619 }
5632 else
5633 {
5637 {
5641 {
5644 }
5645 else
5646 {
5650 {
5653 }
5654 }
5655 }
5657 designator_depth++;
5661 }
5662 }
5664 /* Within a struct initializer, specify the next field to be initialized. */
5666 void
5668 {
5669 tree tail;
5678 {
5681 }
5685 {
5688 }
5692 else
5693 {
5695 designator_depth++;
5699 }
5700 }
5701 \f
5702 /* Add a new initializer to the tree of pending initializers. PURPOSE
5703 identifies the initializer, either array index or field in a structure.
5704 VALUE is the value of that index or field. */
5706 static void
5708 {
5715 {
5717 {
5723 else
5724 {
5731 }
5732 }
5733 }
5734 else
5735 {
5736 tree bitpos;
5740 {
5746 else
5747 {
5754 }
5755 }
5756 }
5769 {
5773 {
5777 {
5779 {
5780 /* L rotation. */
5793 {
5796 else
5798 }
5799 else
5801 }
5802 else
5803 {
5804 /* LR rotation. */
5826 {
5829 else
5831 }
5832 else
5834 }
5836 }
5837 else
5838 {
5839 /* p->balance == +1; growth of left side balances the node. */
5842 }
5843 }
5845 {
5847 /* Growth propagation from right side. */
5850 {
5852 {
5853 /* R rotation. */
5866 {
5869 else
5871 }
5872 else
5874 }
5876 {
5877 /* RL rotation */
5899 {
5902 else
5904 }
5905 else
5907 }
5909 }
5910 else
5911 {
5912 /* p->balance == -1; growth of right side balances the node. */
5915 }
5916 }
5920 }
5921 }
5923 /* Build AVL tree from a sorted chain. */
5925 static void
5927 {
5939 {
5941 /* Skip any nameless bit fields at the beginning. */
5947 }
5949 {
5951 constructor_unfilled_index
5954 else
5956 }
5958 }
5960 /* Build AVL tree from a string constant. */
5962 static void
5964 {
5975 else
5976 {
5980 }
5989 {
5991 {
5994 }
5995 else
5996 {
6000 {
6003 else
6008 }
6009 }
6012 {
6015 {
6017 {
6020 }
6021 }
6023 {
6026 }
6031 }
6035 }
6038 }
6040 /* Return value of FIELD in pending initializer or zero if the field was
6041 not initialized yet. */
6043 static tree
6045 {
6049 {
6056 {
6061 else
6063 }
6064 }
6066 {
6070 && (!constructor_unfilled_fields
6077 {
6082 else
6084 }
6085 }
6087 {
6092 }
6094 }
6096 /* "Output" the next constructor element.
6097 At top level, really output it to assembler code now.
6098 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
6099 TYPE is the data type that the containing data type wants here.
6100 FIELD is the field (a FIELD_DECL) or the index that this element fills.
6101 If VALUE is a string constant, STRICT_STRING is true if it is
6102 unparenthesized or we should not warn here for it being parenthesized.
6103 For other types of VALUE, STRICT_STRING is not used.
6105 PENDING if non-nil means output pending elements that belong
6106 right after this element. (PENDING is normally 1;
6107 it is 0 while outputting pending elements, to avoid recursion.) */
6109 static void
6112 {
6116 {
6119 }
6132 {
6133 /* As an extension, allow initializing objects with static storage
6134 duration with compound literals (which are then treated just as
6135 the brace enclosed list they contain). */
6138 }
6152 {
6154 {
6157 }
6160 }
6162 /* If this field is empty (and not at the end of structure),
6163 don't do anything other than checking the initializer. */
6174 {
6177 }
6179 /* If this element doesn't come next in sequence,
6180 put it on constructor_pending_elts. */
6182 && (!constructor_incremental
6184 {
6191 }
6193 && (!constructor_incremental
6195 {
6196 /* We do this for records but not for unions. In a union,
6197 no matter which field is specified, it can be initialized
6198 right away since it starts at the beginning of the union. */
6200 {
6203 else
6204 {
6212 }
6213 }
6217 }
6220 {
6227 /* We can have just one union field set. */
6229 }
6231 /* Otherwise, output this element either to
6232 constructor_elements or to the assembler file. */
6238 /* Advance the variable that indicates sequential elements output. */
6240 constructor_unfilled_index
6242 bitsize_one_node);
6244 {
6245 constructor_unfilled_fields
6248 /* Skip any nameless bit fields. */
6252 constructor_unfilled_fields =
6254 }
6258 /* Now output any pending elements which have become next. */
6261 }
6263 /* Output any pending elements which have become next.
6264 As we output elements, constructor_unfilled_{fields,index}
6265 advances, which may cause other elements to become next;
6266 if so, they too are output.
6268 If ALL is 0, we return when there are
6269 no more pending elements to output now.
6271 If ALL is 1, we output space as necessary so that
6272 we can output all the pending elements. */
6274 static void
6276 {
6278 tree next;
6280 retry:
6282 /* Look through the whole pending tree.
6283 If we find an element that should be output now,
6284 output it. Otherwise, set NEXT to the element
6285 that comes first among those still pending. */
6289 {
6291 {
6293 constructor_unfilled_index))
6299 {
6300 /* Advance to the next smaller node. */
6303 else
6304 {
6305 /* We have reached the smallest node bigger than the
6306 current unfilled index. Fill the space first. */
6309 }
6310 }
6311 else
6312 {
6313 /* Advance to the next bigger node. */
6316 else
6317 {
6318 /* We have reached the biggest node in a subtree. Find
6319 the parent of it, which is the next bigger node. */
6325 {
6328 }
6329 }
6330 }
6331 }
6334 {
6337 /* If the current record is complete we are done. */
6343 /* We can't compare fields here because there might be empty
6344 fields in between. */
6346 {
6350 }
6352 {
6353 /* Advance to the next smaller node. */
6356 else
6357 {
6358 /* We have reached the smallest node bigger than the
6359 current unfilled field. Fill the space first. */
6362 }
6363 }
6364 else
6365 {
6366 /* Advance to the next bigger node. */
6369 else
6370 {
6371 /* We have reached the biggest node in a subtree. Find
6372 the parent of it, which is the next bigger node. */
6379 {
6382 }
6383 }
6384 }
6385 }
6386 }
6388 /* Ordinarily return, but not if we want to output all
6389 and there are elements left. */
6393 /* If it's not incremental, just skip over the gap, so that after
6394 jumping to retry we will output the next successive element. */
6401 /* ELT now points to the node in the pending tree with the next
6402 initializer to output. */
6404 }
6405 \f
6406 /* Add one non-braced element to the current constructor level.
6407 This adjusts the current position within the constructor's type.
6408 This may also start or terminate implicit levels
6409 to handle a partly-braced initializer.
6411 Once this has found the correct level for the new element,
6412 it calls output_init_element. */
6414 void
6416 {
6424 /* Handle superfluous braces around string cst as in
6425 char x[] = {"foo"}; */
6427 && constructor_type
6431 {
6436 }
6439 {
6442 }
6444 /* Ignore elements of a brace group if it is entirely superfluous
6445 and has already been diagnosed. */
6449 /* If we've exhausted any levels that didn't have braces,
6450 pop them now. */
6452 {
6460 constructor_index)))
6462 else
6464 }
6466 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
6468 {
6469 /* If value is a compound literal and we'll be just using its
6470 content, don't put it into a SAVE_EXPR. */
6472 || !require_constant_value
6475 }
6478 {
6480 {
6481 tree fieldtype;
6485 {
6488 }
6495 /* Error for non-static initialization of a flexible array member. */
6497 && !require_constant_value
6500 {
6503 }
6505 /* Accept a string constant to initialize a subarray. */
6511 /* Otherwise, if we have come to a subaggregate,
6512 and we don't have an element of its type, push into it. */
6518 {
6521 }
6524 {
6529 }
6530 else
6531 /* Do the bookkeeping for an element that was
6532 directly output as a constructor. */
6533 {
6534 /* For a record, keep track of end position of last field. */
6536 constructor_bit_index
6541 /* If the current field was the first one not yet written out,
6542 it isn't now, so update. */
6544 {
6546 /* Skip any nameless bit fields. */
6550 constructor_unfilled_fields =
6552 }
6553 }
6556 /* Skip any nameless bit fields at the beginning. */
6561 }
6563 {
6564 tree fieldtype;
6568 {
6571 }
6578 /* Warn that traditional C rejects initialization of unions.
6579 We skip the warning if the value is zero. This is done
6580 under the assumption that the zero initializer in user
6581 code appears conditioned on e.g. __STDC__ to avoid
6582 "missing initializer" warnings and relies on default
6583 initialization to zero in the traditional C case.
6584 We also skip the warning if the initializer is designated,
6585 again on the assumption that this must be conditional on
6586 __STDC__ anyway (and we've already complained about the
6587 member-designator already). */
6594 /* Accept a string constant to initialize a subarray. */
6600 /* Otherwise, if we have come to a subaggregate,
6601 and we don't have an element of its type, push into it. */
6607 {
6610 }
6613 {
6618 }
6619 else
6620 /* Do the bookkeeping for an element that was
6621 directly output as a constructor. */
6622 {
6625 }
6628 }
6630 {
6634 /* Accept a string constant to initialize a subarray. */
6640 /* Otherwise, if we have come to a subaggregate,
6641 and we don't have an element of its type, push into it. */
6647 {
6650 }
6655 {
6658 }
6660 /* Now output the actual element. */
6662 {
6667 }
6669 constructor_index
6673 /* If we are doing the bookkeeping for an element that was
6674 directly output as a constructor, we must update
6675 constructor_unfilled_index. */
6677 }
6679 {
6682 /* Do a basic check of initializer size. Note that vectors
6683 always have a fixed size derived from their type. */
6685 {
6688 }
6690 /* Now output the actual element. */
6695 constructor_index
6699 /* If we are doing the bookkeeping for an element that was
6700 directly output as a constructor, we must update
6701 constructor_unfilled_index. */
6703 }
6705 /* Handle the sole element allowed in a braced initializer
6706 for a scalar variable. */
6709 {
6712 }
6713 else
6714 {
6719 }
6721 /* Handle range initializers either at this level or anywhere higher
6722 in the designator stack. */
6724 {
6731 {
6734 }
6738 {
6741 }
6748 {
6752 {
6755 }
6763 }
6768 }
6771 }
6774 }
6775 \f
6776 /* Build a complete asm-statement, whose components are a CV_QUALIFIER
6777 (guaranteed to be 'volatile' or null) and ARGS (represented using
6778 an ASM_EXPR node). */
6779 tree
6781 {
6785 }
6787 /* Build an asm-expr, whose components are a STRING, some OUTPUTS,
6788 some INPUTS, and some CLOBBERS. The latter three may be NULL.
6789 SIMPLE indicates whether there was anything at all after the
6790 string in the asm expression -- asm("blah") and asm("blah" : )
6791 are subtly different. We use a ASM_EXPR node to represent this. */
6792 tree
6795 {
6796 tree tail;
6797 tree args;
6810 /* Remove output conversions that change the type but not the mode. */
6812 {
6815 /* ??? Really, this should not be here. Users should be using a
6816 proper lvalue, dammit. But there's a long history of using casts
6817 in the output operands. In cases like longlong.h, this becomes a
6818 primitive form of typechecking -- if the cast can be removed, then
6819 the output operand had a type of the proper width; otherwise we'll
6820 get an error. Gross, but ... */
6839 {
6840 /* If the operand is going to end up in memory,
6841 mark it addressable. */
6844 }
6845 else
6849 }
6852 {
6853 tree input;
6860 {
6861 /* If the operand is going to end up in memory,
6862 mark it addressable. */
6864 {
6865 /* Strip the nops as we allow this case. FIXME, this really
6866 should be rejected or made deprecated. */
6870 }
6871 }
6872 else
6876 }
6880 /* asm statements without outputs, including simple ones, are treated
6881 as volatile. */
6886 }
6887 \f
6888 /* Generate a goto statement to LABEL. */
6890 tree
6892 {
6898 {
6901 }
6904 {
6907 }
6910 {
6911 /* No jump from outside this statement expression context, so
6912 record that there is a jump from within this context. */
6918 }
6921 {
6922 /* No jump from outside this context context of identifiers with
6923 variably modified type, so record that there is a jump from
6924 within this context. */
6930 }
6934 }
6936 /* Generate a computed goto statement to EXPR. */
6938 tree
6940 {
6945 }
6947 /* Generate a C `return' statement. RETVAL is the expression for what
6948 to return, or a null pointer for `return;' with no value. */
6950 tree
6952 {
6960 {
6964 {
6968 }
6969 }
6971 {
6977 }
6978 else
6979 {
6983 tree inner;
6991 /* Strip any conversions, additions, and subtractions, and see if
6992 we are returning the address of a local variable. Warn if so. */
6994 {
6996 {
7003 /* If the second operand of the MINUS_EXPR has a pointer
7004 type (or is converted from it), this may be valid, so
7005 don't give a warning. */
7006 {
7020 }
7038 }
7041 }
7044 }
7049 }
7050 \f
7052 /* The SWITCH_EXPR being built. */
7053 tree switch_expr;
7055 /* The original type of the testing expression, i.e. before the
7056 default conversion is applied. */
7057 tree orig_type;
7059 /* A splay-tree mapping the low element of a case range to the high
7060 element, or NULL_TREE if there is no high element. Used to
7061 determine whether or not a new case label duplicates an old case
7062 label. We need a tree, rather than simply a hash table, because
7063 of the GNU case range extension. */
7064 splay_tree cases;
7066 /* Number of nested statement expressions within this switch
7067 statement; if nonzero, case and default labels may not
7068 appear. */
7071 /* Scope of outermost declarations of identifiers with variably
7072 modified type within this switch statement; if nonzero, case and
7073 default labels may not appear. */
7076 /* The next node on the stack. */
7078 };
7080 /* A stack of the currently active switch statements. The innermost
7081 switch statement is on the top of the stack. There is no need to
7082 mark the stack for garbage collection because it is only active
7083 during the processing of the body of a function, and we never
7084 collect at that point. */
7088 /* Start a C switch statement, testing expression EXP. Return the new
7089 SWITCH_EXPR. */
7091 tree
7093 {
7098 {
7102 {
7104 {
7107 }
7109 }
7110 else
7111 {
7121 }
7122 }
7124 /* Add this new SWITCH_EXPR to the stack. */
7135 }
7137 /* Process a case label. */
7139 tree
7141 {
7146 {
7153 }
7155 {
7159 else
7162 }
7164 {
7168 else
7171 }
7174 else
7178 }
7180 /* Finish the switch statement. */
7182 void
7184 {
7186 location_t switch_location;
7190 /* We must not be within a statement expression nested in the switch
7191 at this point; we might, however, be within the scope of an
7192 identifier with variably modified type nested in the switch. */
7195 /* Emit warnings as needed. */
7198 else
7204 /* Pop the stack. */
7208 }
7209 \f
7210 /* Emit an if statement. IF_LOCUS is the location of the 'if'. COND,
7211 THEN_BLOCK and ELSE_BLOCK are expressions to be used; ELSE_BLOCK
7212 may be null. NESTED_IF is true if THEN_BLOCK contains another IF
7213 statement, and was not surrounded with parenthesis. */
7215 void
7218 {
7219 tree stmt;
7221 /* Diagnose an ambiguous else if if-then-else is nested inside if-then. */
7223 {
7226 /* We know from the grammar productions that there is an IF nested
7227 within THEN_BLOCK. Due to labels and c99 conditional declarations,
7228 it might not be exactly THEN_BLOCK, but should be the last
7229 non-container statement within. */
7232 {
7247 }
7248 found:
7254 }
7261 }
7263 /* Emit a general-purpose loop construct. START_LOCUS is the location of
7264 the beginning of the loop. COND is the loop condition. COND_IS_FIRST
7265 is false for DO loops. INCR is the FOR increment expression. BODY is
7266 the statement controlled by the loop. BLAB is the break label. CLAB is
7267 the continue label. Everything is allowed to be NULL. */
7269 void
7272 {
7275 /* If the condition is zero don't generate a loop construct. */
7277 {
7279 {
7283 }
7284 }
7285 else
7286 {
7289 /* If we have an exit condition, then we build an IF with gotos either
7290 out of the loop, or to the top of it. If there's no exit condition,
7291 then we just build a jump back to the top. */
7295 {
7296 /* Canonicalize the loop condition to the end. This means
7297 generating a branch to the loop condition. Reuse the
7298 continue label, if possible. */
7300 {
7302 {
7305 }
7306 else
7310 }
7316 else
7318 }
7321 }
7335 }
7337 tree
7339 {
7343 /* In switch statements break is sometimes stylistically used after
7344 a return statement. This can lead to spurious warnings about
7345 control reaching the end of a non-void function when it is
7346 inlined. Note that we are calling block_may_fallthru with
7347 language specific tree nodes; this works because
7348 block_may_fallthru returns true when given something it does not
7349 understand. */
7353 {
7356 }
7358 ;
7360 {
7364 else
7375 }
7381 }
7383 /* A helper routine for c_process_expr_stmt and c_finish_stmt_expr. */
7385 static void
7387 {
7389 ;
7391 {
7395 }
7396 else
7398 }
7400 /* Process an expression as if it were a complete statement. Emit
7401 diagnostics, but do not call ADD_STMT. */
7403 tree
7405 {
7417 /* If we're not processing a statement expression, warn about unused values.
7418 Warnings for statement expressions will be emitted later, once we figure
7419 out which is the result. */
7424 /* If the expression is not of a type to which we cannot assign a line
7425 number, wrap the thing in a no-op NOP_EXPR. */
7433 }
7435 /* Emit an expression as a statement. */
7437 tree
7439 {
7442 else
7444 }
7446 /* Do the opposite and emit a statement as an expression. To begin,
7447 create a new binding level and return it. */
7449 tree
7451 {
7452 tree ret;
7456 /* We must force a BLOCK for this level so that, if it is not expanded
7457 later, there is a way to turn off the entire subtree of blocks that
7458 are contained in it. */
7462 {
7465 }
7469 {
7471 }
7478 /* Mark the current statement list as belonging to a statement list. */
7482 }
7484 tree
7486 {
7493 {
7496 }
7497 /* It is no longer possible to jump to labels defined within this
7498 statement expression. */
7502 {
7504 }
7505 /* It is again possible to define labels with a goto just outside
7506 this statement expression. */
7510 {
7513 }
7516 else
7521 /* Locate the last statement in BODY. See c_end_compound_stmt
7522 about always returning a BIND_EXPR. */
7526 continue_searching:
7528 {
7529 tree_stmt_iterator i;
7531 /* This can happen with degenerate cases like ({ }). No value. */
7535 /* If we're supposed to generate side effects warnings, process
7536 all of the statements except the last. */
7538 {
7541 }
7542 else
7546 }
7548 /* If the end of the list is exception related, then the list was split
7549 by a call to push_cleanup. Continue searching. */
7552 {
7556 }
7558 /* In the case that the BIND_EXPR is not necessary, return the
7559 expression out from inside it. */
7563 {
7564 /* Do not warn if the return value of a statement expression is
7565 unused. */
7569 }
7571 /* Extract the type of said expression. */
7574 /* If we're not returning a value at all, then the BIND_EXPR that
7575 we already have is a fine expression to return. */
7579 /* Now that we've located the expression containing the value, it seems
7580 silly to make voidify_wrapper_expr repeat the process. Create a
7581 temporary of the appropriate type and stick it in a TARGET_EXPR. */
7584 /* Unwrap a no-op NOP_EXPR as added by c_finish_expr_stmt. This avoids
7585 tree_expr_nonnegative_p giving up immediately. */
7595 }
7597 /* Begin the scope of an identifier of variably modified type, scope
7598 number SCOPE. Jumping from outside this scope to inside it is not
7599 permitted. */
7601 void
7603 {
7609 /* At file_scope, we don't have to do any processing. */
7618 {
7620 }
7627 }
7629 /* End a scope which may contain identifiers of variably modified
7630 type, scope number SCOPE. */
7632 void
7634 {
7639 /* We may have a number of nested scopes of identifiers with
7640 variably modified type, all at this depth. Pop each in turn. */
7642 {
7645 /* It is no longer possible to jump to labels defined within this
7646 scope. */
7650 {
7652 }
7653 /* It is again possible to define labels with a goto just outside
7654 this scope. */
7658 {
7661 }
7664 else
7668 }
7669 }
7670 \f
7671 /* Begin and end compound statements. This is as simple as pushing
7672 and popping new statement lists from the tree. */
7674 tree
7676 {
7681 }
7683 tree
7685 {
7689 {
7693 }
7698 /* If this compound statement is nested immediately inside a statement
7699 expression, then force a BIND_EXPR to be created. Otherwise we'll
7700 do the wrong thing for ({ { 1; } }) or ({ 1; { } }). In particular,
7701 STATEMENT_LISTs merge, and thus we can lose track of what statement
7702 was really last. */
7706 {
7709 }
7712 }
7714 /* Queue a cleanup. CLEANUP is an expression/statement to be executed
7715 when the current scope is exited. EH_ONLY is true when this is not
7716 meant to apply to normal control flow transfer. */
7718 void
7720 {
7732 }
7733 \f
7734 /* Build a binary-operation expression without default conversions.
7735 CODE is the kind of expression to build.
7736 This function differs from `build' in several ways:
7737 the data type of the result is computed and recorded in it,
7738 warnings are generated if arg data types are invalid,
7739 special handling for addition and subtraction of pointers is known,
7740 and some optimization is done (operations on narrow ints
7741 are done in the narrower type when that gives the same result).
7742 Constant folding is also done before the result is returned.
7744 Note that the operands will never have enumeral types, or function
7745 or array types, because either they will have the default conversions
7746 performed or they have both just been converted to some other type in which
7747 the arithmetic is to be done. */
7749 tree
7752 {
7758 /* Expression code to give to the expression when it is built.
7759 Normally this is CODE, which is what the caller asked for,
7760 but in some special cases we change it. */
7763 /* Data type in which the computation is to be performed.
7764 In the simplest cases this is the common type of the arguments. */
7767 /* Nonzero means operands have already been type-converted
7768 in whatever way is necessary.
7769 Zero means they need to be converted to RESULT_TYPE. */
7772 /* Nonzero means create the expression with this type, rather than
7773 RESULT_TYPE. */
7776 /* Nonzero means after finally constructing the expression
7777 convert it to this type. */
7780 /* Nonzero if this is an operation like MIN or MAX which can
7781 safely be computed in short if both args are promoted shorts.
7782 Also implies COMMON.
7783 -1 indicates a bitwise operation; this makes a difference
7784 in the exact conditions for when it is safe to do the operation
7785 in a narrower mode. */
7788 /* Nonzero if this is a comparison operation;
7789 if both args are promoted shorts, compare the original shorts.
7790 Also implies COMMON. */
7793 /* Nonzero if this is a right-shift operation, which can be computed on the
7794 original short and then promoted if the operand is a promoted short. */
7797 /* Nonzero means set RESULT_TYPE to the common type of the args. */
7800 /* True means types are compatible as far as ObjC is concerned. */
7804 {
7807 }
7808 else
7809 {
7812 }
7817 /* The expression codes of the data types of the arguments tell us
7818 whether the arguments are integers, floating, pointers, etc. */
7822 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
7826 /* If an error was already reported for one of the arguments,
7827 avoid reporting another error. */
7834 {
7837 }
7842 {
7844 /* Handle the pointer + int case. */
7849 else
7854 /* Subtraction of two similar pointers.
7855 We must subtract them as integers, then divide by object size. */
7859 /* Handle pointer minus int. Just like pointer plus int. */
7862 else
7881 {
7891 else
7892 /* Although it would be tempting to shorten always here, that
7893 loses on some targets, since the modulo instruction is
7894 undefined if the quotient can't be represented in the
7895 computation mode. We shorten only if unsigned or if
7896 dividing by something we know != -1. */
7901 }
7918 {
7919 /* Although it would be tempting to shorten always here, that loses
7920 on some targets, since the modulo instruction is undefined if the
7921 quotient can't be represented in the computation mode. We shorten
7922 only if unsigned or if dividing by something we know != -1. */
7927 }
7939 {
7940 /* Result of these operations is always an int,
7941 but that does not mean the operands should be
7942 converted to ints! */
7947 }
7950 /* Shift operations: result has same type as first operand;
7951 always convert second operand to int.
7952 Also set SHORT_SHIFT if shifting rightward. */
7956 {
7958 {
7961 else
7962 {
7968 }
7969 }
7971 /* Use the type of the value to be shifted. */
7973 /* Convert the shift-count to an integer, regardless of size
7974 of value being shifted. */
7977 /* Avoid converting op1 to result_type later. */
7979 }
7984 {
7986 {
7992 }
7994 /* Use the type of the value to be shifted. */
7996 /* Convert the shift-count to an integer, regardless of size
7997 of value being shifted. */
8000 /* Avoid converting op1 to result_type later. */
8002 }
8010 /* Result of comparison is always int,
8011 but don't convert the args to int! */
8019 {
8022 /* Anything compares with void *. void * compares with anything.
8023 Otherwise, the targets must be compatible
8024 and both must be object or both incomplete. */
8028 {
8029 /* op0 != orig_op0 detects the case of something
8030 whose value is 0 but which isn't a valid null ptr const. */
8035 }
8037 {
8042 }
8043 else
8044 /* Avoid warning about the volatile ObjC EH puts on decls. */
8050 }
8052 {
8058 }
8060 {
8066 }
8068 {
8071 }
8073 {
8076 }
8088 {
8090 {
8098 }
8099 else
8100 {
8103 }
8104 }
8106 {
8110 }
8112 {
8116 }
8118 {
8121 }
8123 {
8126 }
8131 }
8140 {
8143 }
8147 &&
8150 {
8154 {
8158 }
8160 /* For certain operations (which identify themselves by shorten != 0)
8161 if both args were extended from the same smaller type,
8162 do the arithmetic in that type and then extend.
8164 shorten !=0 and !=1 indicates a bitwise operation.
8165 For them, this optimization is safe only if
8166 both args are zero-extended or both are sign-extended.
8167 Otherwise, we might change the result.
8168 Eg, (short)-1 | (unsigned short)-1 is (int)-1
8169 but calculated in (unsigned short) it would be (unsigned short)-1. */
8172 {
8176 tree type;
8178 /* Cast OP0 and OP1 to RESULT_TYPE. Doing so prevents
8179 excessive narrowing when we call get_narrower below. For
8180 example, suppose that OP0 is of unsigned int extended
8181 from signed char and that RESULT_TYPE is long long int.
8182 If we explicitly cast OP0 to RESULT_TYPE, OP0 would look
8183 like
8185 (long long int) (unsigned int) signed_char
8187 which get_narrower would narrow down to
8189 (unsigned int) signed char
8191 If we do not cast OP0 first, get_narrower would return
8192 signed_char, which is inconsistent with the case of the
8193 explicit cast. */
8200 /* UNS is 1 if the operation to be done is an unsigned one. */
8205 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
8206 but it *requires* conversion to FINAL_TYPE. */
8217 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
8219 /* For bitwise operations, signedness of nominal type
8220 does not matter. Consider only how operands were extended. */
8224 /* Note that in all three cases below we refrain from optimizing
8225 an unsigned operation on sign-extended args.
8226 That would not be valid. */
8228 /* Both args variable: if both extended in same way
8229 from same width, do it in that width.
8230 Do it unsigned if args were zero-extended. */
8237 result_type
8238 = c_common_signed_or_unsigned_type
8244 && (type
8253 && (type
8258 }
8260 /* Shifts can be shortened if shifting right. */
8263 {
8273 /* We can shorten only if the shift count is less than the
8274 number of bits in the smaller type size. */
8276 /* We cannot drop an unsigned shift after sign-extension. */
8278 {
8279 /* Do an unsigned shift if the operand was zero-extended. */
8280 result_type
8283 /* Convert value-to-be-shifted to that type. */
8287 }
8288 }
8290 /* Comparison operations are shortened too but differently.
8291 They identify themselves by setting short_compare = 1. */
8294 {
8295 /* Don't write &op0, etc., because that would prevent op0
8296 from being kept in a register.
8297 Instead, make copies of the our local variables and
8298 pass the copies by reference, then copy them back afterward. */
8301 tree val
8312 {
8324 /* Give warnings for comparisons between signed and unsigned
8325 quantities that may fail.
8327 Do the checking based on the original operand trees, so that
8328 casts will be considered, but default promotions won't be.
8330 Do not warn if the comparison is being done in a signed type,
8331 since the signed type will only be chosen if it can represent
8332 all the values of the unsigned type. */
8335 /* Do not warn if both operands are the same signedness. */
8338 else
8339 {
8345 else
8348 /* Do not warn if the signed quantity is an
8349 unsuffixed integer literal (or some static
8350 constant expression involving such literals or a
8351 conditional expression involving such literals)
8352 and it is non-negative. */
8355 /* Do not warn if the comparison is an equality operation,
8356 the unsigned quantity is an integral constant, and it
8357 would fit in the result if the result were signed. */
8360 && int_fits_type_p
8363 /* Do not warn if the unsigned quantity is an enumeration
8364 constant and its maximum value would fit in the result
8365 if the result were signed. */
8368 && int_fits_type_p
8372 else
8374 }
8376 /* Warn if two unsigned values are being compared in a size
8377 larger than their original size, and one (and only one) is the
8378 result of a `~' operator. This comparison will always fail.
8380 Also warn if one operand is a constant, and the constant
8381 does not have all bits set that are set in the ~ operand
8382 when it is extended. */
8386 {
8390 else
8395 {
8396 tree primop;
8401 {
8405 }
8406 else
8407 {
8411 }
8416 {
8420 }
8421 }
8428 }
8429 }
8430 }
8431 }
8433 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
8434 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
8435 Then the expression will be built.
8436 It will be given type FINAL_TYPE if that is nonzero;
8437 otherwise, it will be given type RESULT_TYPE. */
8440 {
8443 }
8446 {
8452 /* This can happen if one operand has a vector type, and the other
8453 has a different type. */
8456 }
8461 {
8462 /* Treat expressions in initializers specially as they can't trap. */
8464 build_type,
8472 }
8473 }
8476 /* Convert EXPR to be a truth-value, validating its type for this
8477 purpose. */
8479 tree
8481 {
8483 {
8501 }
8503 /* ??? Should we also give an error for void and vectors rather than
8504 leaving those to give errors later? */
8506 }
8507 \f
8509 /* Convert EXPR to a contained DECL, updating *TC, *TI and *SE as
8510 required. */
8512 tree
8515 {
8517 {
8519 /* Executing a compound literal inside a function reinitializes
8520 it. */
8524 }
8525 else
8527 }
8528 \f
8529 /* Like c_begin_compound_stmt, except force the retention of the BLOCK. */
8531 tree
8533 {
8534 tree block;
8540 }
8542 tree
8544 {
8545 tree stmt;
8555 }
8557 /* For all elements of CLAUSES, validate them vs OpenMP constraints.
8558 Remove any elements from the list that are invalid. */
8560 tree
8562 {
8573 {
8579 {
8597 {
8600 }
8602 {
8607 {
8629 }
8631 {
8635 }
8636 }
8647 {
8650 }
8653 check_dup_generic:
8656 {
8659 }
8663 {
8666 }
8667 else
8677 {
8680 }
8683 {
8686 }
8687 else
8697 {
8700 }
8703 {
8706 }
8707 else
8722 }
8725 {
8729 {
8733 }
8736 {
8742 {
8753 }
8755 {
8759 }
8760 }
8761 }
8765 else
8767 }
8771 }