| blob | 0793b6005acc604b68b4d82e86eecb924052afe8 |
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 }
2093 /* Recursive call does not count as usage. */
2095 {
2099 }
2102 {
2109 }
2112 {
2117 }
2123 {
2128 }
2129 /* C99 6.7.4p3: An inline definition of a function with external
2130 linkage ... shall not contain a reference to an identifier with
2131 internal linkage. */
2142 }
2144 /* Record details of decls possibly used inside sizeof or typeof. */
2145 struct maybe_used_decl
2146 {
2147 /* The decl. */
2148 tree decl;
2149 /* The level seen at (in_sizeof + in_typeof). */
2151 /* The next one at this level or above, or NULL. */
2153 };
2157 /* Record that DECL, an undefined static function reference seen
2158 inside sizeof or typeof, might be used if the operand of sizeof is
2159 a VLA type or the operand of typeof is a variably modified
2160 type. */
2162 static void
2164 {
2170 }
2172 /* Pop the stack of decls possibly used inside sizeof or typeof. If
2173 USED is false, just discard them. If it is true, mark them used
2174 (if no longer inside sizeof or typeof) or move them to the next
2175 level up (if still inside sizeof or typeof). */
2177 void
2179 {
2183 {
2185 {
2188 else
2190 }
2192 }
2195 }
2197 /* Return the result of sizeof applied to EXPR. */
2199 struct c_expr
2201 {
2204 {
2208 }
2209 else
2210 {
2214 {
2215 /* sizeof is evaluated when given a vla (C99 6.5.3.4p2). */
2217 }
2219 }
2221 }
2223 /* Return the result of sizeof applied to T, a structure for the type
2224 name passed to sizeof (rather than the type itself). */
2226 struct c_expr
2228 {
2229 tree type;
2237 }
2239 /* Build a function call to function FUNCTION with parameters PARAMS.
2240 PARAMS is a list--a chain of TREE_LIST nodes--in which the
2241 TREE_VALUE of each node is a parameter-expression.
2242 FUNCTION's data type may be a function type or a pointer-to-function. */
2244 tree
2246 {
2249 tree tem;
2254 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2257 /* Convert anything with function type to a pointer-to-function. */
2259 {
2260 /* Implement type-directed function overloading for builtins.
2261 resolve_overloaded_builtin and targetm.resolve_overloaded_builtin
2262 handle all the type checking. The result is a complete expression
2263 that implements this function call. */
2270 }
2274 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2275 expressions, like those used for ObjC messenger dispatches. */
2285 {
2288 }
2293 /* fntype now gets the type of function pointed to. */
2296 /* Check that the function is called through a compatible prototype.
2297 If it is not, replace the call by a trap, wrapped up in a compound
2298 expression if necessary. This has the nice side-effect to prevent
2299 the tree-inliner from generating invalid assignment trees which may
2300 blow up in the RTL expander later. */
2306 {
2309 NULL_TREE);
2311 /* This situation leads to run-time undefined behavior. We can't,
2312 therefore, simply error unless we can prove that all possible
2313 executions of the program must execute the code. */
2316 /* We can, however, treat "undefined" any way we please.
2317 Call abort to encourage the user to fix the program. */
2322 else
2323 {
2324 tree rhs;
2329 else
2333 }
2334 }
2336 /* Convert the parameters to the types declared in the
2337 function prototype, or apply default promotions. */
2346 /* Check that the arguments to the function are valid. */
2352 {
2359 }
2360 else
2367 }
2368 \f
2369 /* Convert the argument expressions in the list VALUES
2370 to the types in the list TYPELIST. The resulting arguments are
2371 stored in the array ARGARRAY which has size NARGS.
2373 If TYPELIST is exhausted, or when an element has NULL as its type,
2374 perform the default conversions.
2376 PARMLIST is the chain of parm decls for the function being called.
2377 It may be 0, if that info is not available.
2378 It is used only for generating error messages.
2380 FUNCTION is a tree for the called function. It is used only for
2381 error messages, where it is formatted with %qE.
2383 This is also where warnings about wrong number of args are generated.
2385 VALUES is a chain of TREE_LIST nodes with the elements of the list
2386 in the TREE_VALUE slots of those nodes.
2388 Returns the actual number of arguments processed (which may be less
2389 than NARGS in some error situations), or -1 on failure. */
2391 static int
2394 {
2397 tree selector;
2399 /* Change pointer to function to the function itself for
2400 diagnostics. */
2405 /* Handle an ObjC selector specially for diagnostics. */
2408 /* Scan the given expressions and types, producing individual
2409 converted arguments and storing them in ARGARRAY. */
2412 valtail;
2414 {
2422 {
2425 }
2428 {
2431 }
2438 {
2439 /* Formal parm type is specified by a function prototype. */
2440 tree parmval;
2443 {
2446 }
2447 else
2448 {
2449 /* Optionally warn about conversions that
2450 differ from the default conversions. */
2452 {
2485 /* ??? At some point, messages should be written about
2486 conversions between complex types, but that's too messy
2487 to do now. */
2490 {
2491 /* Warn if any argument is passed as `float',
2492 since without a prototype it would be `double'. */
2499 /* Warn if mismatch between argument and prototype
2500 for decimal float types. Warn of conversions with
2501 binary float types and of precision narrowing due to
2502 prototype. */
2510 && (formal_prec
2514 != dfloat64_type_node
2524 }
2525 /* Detect integer changing in width or signedness.
2526 These warnings are only activated with
2527 -Wtraditional-conversion, not with -Wtraditional. */
2530 {
2537 /* No warning if function asks for enum
2538 and the actual arg is that enum type. */
2539 ;
2545 ;
2546 /* Don't complain if the formal parameter type
2547 is an enum, because we can't tell now whether
2548 the value was an enum--even the same enum. */
2550 ;
2553 /* Change in signedness doesn't matter
2554 if a constant value is unaffected. */
2555 ;
2556 /* If the value is extended from a narrower
2557 unsigned type, it doesn't matter whether we
2558 pass it as signed or unsigned; the value
2559 certainly is the same either way. */
2562 ;
2567 else
2570 }
2571 }
2581 }
2583 }
2588 /* Convert `float' to `double'. */
2592 {
2595 }
2596 else
2597 /* Convert `short' and `char' to full-size `int'. */
2602 }
2607 {
2610 }
2613 }
2614 \f
2615 /* This is the entry point used by the parser to build unary operators
2616 in the input. CODE, a tree_code, specifies the unary operator, and
2617 ARG is the operand. For unary plus, the C parser currently uses
2618 CONVERT_EXPR for code. */
2620 struct c_expr
2622 {
2632 }
2634 /* This is the entry point used by the parser to build binary operators
2635 in the input. CODE, a tree_code, specifies the binary operator, and
2636 ARG1 and ARG2 are the operands. In addition to constructing the
2637 expression, we check for operands that were written with other binary
2638 operators in a way that is likely to confuse the user. */
2640 struct c_expr
2643 {
2655 /* Check for cases such as x+y<<z which users are likely
2656 to misinterpret. */
2663 /* Warn about comparisons against string literals, with the exception
2664 of testing for equality or inequality of a string literal with NULL. */
2666 {
2670 }
2681 }
2682 \f
2683 /* Return a tree for the difference of pointers OP0 and OP1.
2684 The resulting tree has type int. */
2686 static tree
2688 {
2696 {
2701 }
2703 /* If the conversion to ptrdiff_type does anything like widening or
2704 converting a partial to an integral mode, we get a convert_expression
2705 that is in the way to do any simplifications.
2706 (fold-const.c doesn't know that the extra bits won't be needed.
2707 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2708 different mode in place.)
2709 So first try to find a common term here 'by hand'; we want to cover
2710 at least the cases that occur in legal static initializers. */
2715 else
2721 else
2725 {
2728 }
2729 else
2733 {
2736 }
2737 else
2741 {
2744 }
2747 /* First do the subtraction as integers;
2748 then drop through to build the divide operator.
2749 Do not do default conversions on the minus operator
2750 in case restype is a short type. */
2754 /* This generates an error if op1 is pointer to incomplete type. */
2758 /* This generates an error if op0 is pointer to incomplete type. */
2761 /* Divide by the size, in easiest possible way. */
2763 }
2764 \f
2765 /* Construct and perhaps optimize a tree representation
2766 for a unary operation. CODE, a tree_code, specifies the operation
2767 and XARG is the operand.
2768 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2769 the default promotions (such as from short to int).
2770 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2771 allows non-lvalues; this is only used to handle conversion of non-lvalue
2772 arrays to pointers in C99. */
2774 tree
2776 {
2777 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2781 tree val;
2792 {
2795 }
2798 {
2800 /* This is used for unary plus, because a CONVERT_EXPR
2801 is enough to prevent anybody from looking inside for
2802 associativity, but won't generate any code. */
2806 {
2809 }
2819 {
2822 }
2829 {
2832 }
2834 {
2840 }
2841 else
2842 {
2845 }
2850 {
2853 }
2859 /* Conjugating a real value is a no-op, but allow it anyway. */
2862 {
2865 }
2874 {
2877 }
2886 else
2894 else
2902 /* Increment or decrement the real part of the value,
2903 and don't change the imaginary part. */
2905 {
2920 }
2922 /* Report invalid types. */
2926 {
2929 else
2933 }
2935 {
2936 tree inc;
2942 /* Compute the increment. */
2945 {
2946 /* If pointer target is an undefined struct,
2947 we just cannot know how to do the arithmetic. */
2949 {
2952 else
2954 }
2958 {
2961 else
2963 }
2967 }
2968 else
2969 {
2972 }
2974 /* Complain about anything else that is not a true lvalue. */
2977 ? lv_increment
2981 /* Report a read-only lvalue. */
2983 {
2989 }
2993 else
3000 }
3003 /* Note that this operation never does default_conversion. */
3005 /* Let &* cancel out to simplify resulting code. */
3007 {
3008 /* Don't let this be an lvalue. */
3012 }
3014 /* For &x[y], return x+y */
3016 {
3025 }
3027 /* Anything not already handled and not a true memory reference
3028 or a non-lvalue array is an error. */
3033 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
3036 /* If the lvalue is const or volatile, merge that into the type
3037 to which the address will point. Note that you can't get a
3038 restricted pointer by taking the address of something, so we
3039 only have to deal with `const' and `volatile' here. */
3054 /* ??? Cope with user tricks that amount to offsetof. Delete this
3055 when we have proper support for integer constant expressions. */
3059 {
3064 }
3072 }
3078 }
3080 /* Return nonzero if REF is an lvalue valid for this language.
3081 Lvalues can be assigned, unless their type has TYPE_READONLY.
3082 Lvalues can have their address taken, unless they have C_DECL_REGISTER. */
3084 static int
3086 {
3090 {
3114 }
3115 }
3116 \f
3117 /* Give an error for storing in something that is 'const'. */
3119 static void
3121 {
3124 /* Using this macro rather than (for example) arrays of messages
3125 ensures that all the format strings are checked at compile
3126 time. */
3127 #define READONLY_MSG(A, I, D, AS) (use == lv_assign ? (A) \
3128 : (use == lv_increment ? (I) \
3129 : (use == lv_decrement ? (D) : (AS))))
3131 {
3134 else
3140 }
3146 arg);
3147 else
3152 }
3155 /* Return nonzero if REF is an lvalue valid for this language;
3156 otherwise, print an error message and return zero. USE says
3157 how the lvalue is being used and so selects the error message. */
3159 static int
3161 {
3168 }
3169 \f
3170 /* Mark EXP saying that we need to be able to take the
3171 address of it; it should not be allocated in a register.
3172 Returns true if successful. */
3174 bool
3176 {
3181 {
3184 {
3185 error
3188 }
3190 /* ... fall through ... */
3210 {
3212 {
3213 error
3216 }
3218 }
3220 {
3223 else
3226 }
3228 /* drops in */
3231 /* drops out */
3234 }
3235 }
3236 \f
3237 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
3239 tree
3241 {
3242 tree type1;
3243 tree type2;
3249 /* Promote both alternatives. */
3266 /* C90 does not permit non-lvalue arrays in conditional expressions.
3267 In C99 they will be pointers by now. */
3269 {
3272 }
3274 /* Quickly detect the usual case where op1 and op2 have the same type
3275 after promotion. */
3277 {
3280 else
3282 }
3287 {
3290 /* If -Wsign-compare, warn here if type1 and type2 have
3291 different signedness. We'll promote the signed to unsigned
3292 and later code won't know it used to be different.
3293 Do this check on the original types, so that explicit casts
3294 will be considered, but default promotions won't. */
3296 {
3301 {
3304 /* Do not warn if the result type is signed, since the
3305 signed type will only be chosen if it can represent
3306 all the values of the unsigned type. */
3309 /* Do not warn if the signed quantity is an unsuffixed
3310 integer literal (or some static constant expression
3311 involving such literals) and it is non-negative. */
3314 || (unsigned_op1
3317 else
3319 }
3320 }
3321 }
3323 {
3327 }
3329 {
3337 {
3343 }
3345 {
3351 }
3352 else
3353 {
3356 }
3357 }
3359 {
3362 else
3363 {
3365 }
3367 }
3369 {
3372 else
3373 {
3375 }
3377 }
3380 {
3383 else
3384 {
3387 }
3388 }
3390 /* Merge const and volatile flags of the incoming types. */
3391 result_type
3402 }
3403 \f
3404 /* Return a compound expression that performs two expressions and
3405 returns the value of the second of them. */
3407 tree
3409 {
3411 {
3412 /* The left-hand operand of a comma expression is like an expression
3413 statement: with -Wextra or -Wunused, we should warn if it doesn't have
3414 any side-effects, unless it was explicitly cast to (void). */
3416 {
3426 else
3429 }
3430 }
3432 /* With -Wunused, we should also warn if the left-hand operand does have
3433 side-effects, but computes a value which is not used. For example, in
3434 `foo() + bar(), baz()' the result of the `+' operator is not used,
3435 so we should issue a warning. */
3443 }
3445 /* Build an expression representing a cast to type TYPE of expression EXPR. */
3447 tree
3449 {
3455 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
3456 only in <protocol> qualifications. But when constructing cast expressions,
3457 the protocols do matter and must be kept around. */
3464 {
3467 }
3470 {
3473 }
3476 {
3478 {
3482 }
3483 }
3485 {
3486 tree field;
3494 {
3495 tree t;
3505 }
3508 }
3509 else
3510 {
3518 /* Optionally warn about potentially worrisome casts. */
3523 {
3529 /* Check that the qualifiers on IN_TYPE are a superset of
3530 the qualifiers of IN_OTYPE. The outermost level of
3531 POINTER_TYPE nodes is uninteresting and we stop as soon
3532 as we hit a non-POINTER_TYPE node on either type. */
3533 do
3534 {
3538 /* GNU C allows cv-qualified function types. 'const'
3539 means the function is very pure, 'volatile' means it
3540 can't return. We need to warn when such qualifiers
3541 are added, not when they're taken away. */
3545 else
3547 }
3555 /* There are qualifiers present in IN_OTYPE that are not
3556 present in IN_TYPE. */
3558 }
3560 /* Warn about possible alignment problems. */
3566 /* Don't warn about opaque types, where the actual alignment
3567 restriction is unknown. */
3578 /* Unlike conversion of integers to pointers, where the
3579 warning is disabled for converting constants because
3580 of cases such as SIG_*, warn about converting constant
3581 pointers to integers. In some cases it may cause unwanted
3582 sign extension, and a warning is appropriate. */
3594 /* Don't warn about converting any constant. */
3602 /* If pedantic, warn for conversions between function and object
3603 pointer types, except for converting a null pointer constant
3604 to function pointer type. */
3623 /* Ignore any integer overflow caused by the cast. */
3625 {
3627 {
3629 {
3630 /* Avoid clobbering a shared constant. */
3633 }
3634 }
3636 /* Reset VALUE's overflow flags, ensuring constant sharing. */
3640 }
3641 }
3643 /* Don't let a cast be an lvalue. */
3648 }
3650 /* Interpret a cast of expression EXPR to type TYPE. */
3651 tree
3653 {
3654 tree type;
3657 /* This avoids warnings about unprototyped casts on
3658 integers. E.g. "#define SIG_DFL (void(*)())0". */
3665 }
3666 \f
3667 /* Build an assignment expression of lvalue LHS from value RHS.
3668 MODIFYCODE is the code for a binary operator that we use
3669 to combine the old value of LHS with RHS to get the new value.
3670 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3672 tree
3674 {
3675 tree result;
3676 tree newrhs;
3680 /* Types that aren't fully specified cannot be used in assignments. */
3683 /* Avoid duplicate error messages from operands that had errors. */
3694 /* If a binary op has been requested, combine the old LHS value with the RHS
3695 producing the value we should actually store into the LHS. */
3698 {
3701 }
3703 /* Give an error for storing in something that is 'const'. */
3709 {
3712 }
3714 /* If storing into a structure or union member,
3715 it has probably been given type `int'.
3716 Compute the type that would go with
3717 the actual amount of storage the member occupies. */
3726 /* If storing in a field that is in actuality a short or narrower than one,
3727 we must store in the field in its actual type. */
3730 {
3733 }
3735 /* Convert new value to destination type. */
3742 /* Emit ObjC write barrier, if necessary. */
3744 {
3748 }
3750 /* Scan operands. */
3755 /* If we got the LHS in a different type for storing in,
3756 convert the result back to the nominal type of LHS
3757 so that the value we return always has the same type
3758 as the LHS argument. */
3764 }
3765 \f
3766 /* Convert value RHS to type TYPE as preparation for an assignment
3767 to an lvalue of type TYPE.
3768 The real work of conversion is done by `convert'.
3769 The purpose of this function is to generate error messages
3770 for assignments that are not allowed in C.
3771 ERRTYPE says whether it is argument passing, assignment,
3772 initialization or return.
3774 FUNCTION is a tree for the function being called.
3775 PARMNUM is the number of the argument, for printing in error messages. */
3777 static tree
3780 {
3782 tree rhstype;
3788 {
3789 tree selector;
3790 /* Change pointer to function to the function itself for
3791 diagnostics. */
3796 /* Handle an ObjC selector specially for diagnostics. */
3800 {
3803 }
3804 }
3806 /* This macro is used to emit diagnostics to ensure that all format
3807 strings are complete sentences, visible to gettext and checked at
3808 compile time. */
3809 #define WARN_FOR_ASSIGNMENT(AR, AS, IN, RE) \
3810 do { \
3811 switch (errtype) \
3812 { \
3813 case ic_argpass: \
3814 pedwarn (AR, parmnum, rname); \
3815 break; \
3816 case ic_argpass_nonproto: \
3817 warning (0, AR, parmnum, rname); \
3818 break; \
3819 case ic_assign: \
3820 pedwarn (AS); \
3821 break; \
3822 case ic_init: \
3823 pedwarn (IN); \
3824 break; \
3825 case ic_return: \
3826 pedwarn (RE); \
3827 break; \
3828 default: \
3829 gcc_unreachable (); \
3830 } \
3831 } while (0)
3846 {
3850 {
3866 }
3869 }
3875 {
3876 /* Except for passing an argument to an unprototyped function,
3877 this is a constraint violation. When passing an argument to
3878 an unprototyped function, it is compile-time undefined;
3879 making it a constraint in that case was rejected in
3880 DR#252. */
3883 }
3884 /* A type converts to a reference to it.
3885 This code doesn't fully support references, it's just for the
3886 special case of va_start and va_copy. */
3889 {
3891 {
3894 }
3899 /* We already know that these two types are compatible, but they
3900 may not be exactly identical. In fact, `TREE_TYPE (type)' is
3901 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
3902 likely to be va_list, a typedef to __builtin_va_list, which
3903 is different enough that it will cause problems later. */
3909 }
3910 /* Some types can interconvert without explicit casts. */
3914 /* Arithmetic types all interconvert, and enum is treated like int. */
3923 /* Aggregates in different TUs might need conversion. */
3929 /* Conversion to a transparent union from its member types.
3930 This applies only to function arguments. */
3933 {
3937 {
3948 {
3952 /* Any non-function converts to a [const][volatile] void *
3953 and vice versa; otherwise, targets must be the same.
3954 Meanwhile, the lhs target must have all the qualifiers of
3955 the rhs. */
3958 {
3959 /* If this type won't generate any warnings, use it. */
3969 /* Keep looking for a better type, but remember this one. */
3972 }
3973 }
3975 /* Can convert integer zero to any pointer type. */
3977 {
3980 }
3981 }
3984 {
3986 {
3987 /* We have only a marginally acceptable member type;
3988 it needs a warning. */
3992 /* Const and volatile mean something different for function
3993 types, so the usual warnings are not appropriate. */
3996 {
3997 /* Because const and volatile on functions are
3998 restrictions that say the function will not do
3999 certain things, it is okay to use a const or volatile
4000 function where an ordinary one is wanted, but not
4001 vice-versa. */
4004 "makes qualified function "
4007 "function pointer from "
4010 "function pointer from "
4014 }
4026 }
4032 }
4033 }
4035 /* Conversions among pointers */
4038 {
4050 /* Opaque pointers are treated like void pointers. */
4056 /* C++ does not allow the implicit conversion void* -> T*. However,
4057 for the purpose of reducing the number of false positives, we
4058 tolerate the special case of
4060 int *p = NULL;
4062 where NULL is typically defined in C to be '(void *) 0'. */
4067 /* Check if the right-hand side has a format attribute but the
4068 left-hand side doesn't. */
4071 {
4073 {
4077 "argument %d of %qE might be "
4083 "assignment left-hand side might be "
4088 "initialization left-hand side might be "
4093 "return type might be "
4098 }
4099 }
4101 /* Any non-function converts to a [const][volatile] void *
4102 and vice versa; otherwise, targets must be the same.
4103 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
4106 || is_opaque_pointer
4109 {
4112 ||
4117 "%qE between function pointer "
4125 /* Const and volatile mean something different for function types,
4126 so the usual warnings are not appropriate. */
4129 {
4131 {
4132 /* Types differing only by the presence of the 'volatile'
4133 qualifier are acceptable if the 'volatile' has been added
4134 in by the Objective-C EH machinery. */
4144 }
4145 /* If this is not a case of ignoring a mismatch in signedness,
4146 no warning. */
4149 ;
4150 /* If there is a mismatch, do warn. */
4160 }
4163 {
4164 /* Because const and volatile on functions are restrictions
4165 that say the function will not do certain things,
4166 it is okay to use a const or volatile function
4167 where an ordinary one is wanted, but not vice-versa. */
4170 "qualified function pointer "
4178 }
4179 }
4180 else
4181 /* Avoid warning about the volatile ObjC EH puts on decls. */
4191 }
4193 {
4194 /* ??? This should not be an error when inlining calls to
4195 unprototyped functions. */
4198 }
4200 {
4201 /* An explicit constant 0 can convert to a pointer,
4202 or one that results from arithmetic, even including
4203 a cast to integer type. */
4215 }
4217 {
4227 }
4232 {
4235 /* ??? This should not be an error when inlining calls to
4236 unprototyped functions. */
4250 }
4253 }
4254 \f
4255 /* If VALUE is a compound expr all of whose expressions are constant, then
4256 return its value. Otherwise, return error_mark_node.
4258 This is for handling COMPOUND_EXPRs as initializer elements
4259 which is allowed with a warning when -pedantic is specified. */
4261 static tree
4263 {
4265 {
4270 endtype);
4271 }
4274 else
4276 }
4277 \f
4278 /* Perform appropriate conversions on the initial value of a variable,
4279 store it in the declaration DECL,
4280 and print any error messages that are appropriate.
4281 If the init is invalid, store an ERROR_MARK. */
4283 void
4285 {
4288 /* If variable's type was invalidly declared, just ignore it. */
4294 /* Digest the specified initializer into an expression. */
4298 /* Store the expression if valid; else report error. */
4307 /* ANSI wants warnings about out-of-range constant initializers. */
4312 /* Check if we need to set array size from compound literal size. */
4316 {
4323 {
4327 {
4328 /* For int foo[] = (int [3]){1}; we need to set array size
4329 now since later on array initializer will be just the
4330 brace enclosed list of the compound literal. */
4336 }
4337 }
4338 }
4339 }
4340 \f
4341 /* Methods for storing and printing names for error messages. */
4343 /* Implement a spelling stack that allows components of a name to be pushed
4344 and popped. Each element on the stack is this structure. */
4346 struct spelling
4347 {
4349 union
4350 {
4354 };
4356 #define SPELLING_STRING 1
4357 #define SPELLING_MEMBER 2
4358 #define SPELLING_BOUNDS 3
4364 /* Macros to save and restore the spelling stack around push_... functions.
4365 Alternative to SAVE_SPELLING_STACK. */
4367 #define SPELLING_DEPTH() (spelling - spelling_base)
4368 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
4370 /* Push an element on the spelling stack with type KIND and assign VALUE
4371 to MEMBER. */
4373 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
4374 { \
4375 int depth = SPELLING_DEPTH (); \
4376 \
4377 if (depth >= spelling_size) \
4378 { \
4379 spelling_size += 10; \
4380 spelling_base = XRESIZEVEC (struct spelling, spelling_base, \
4381 spelling_size); \
4382 RESTORE_SPELLING_DEPTH (depth); \
4383 } \
4384 \
4385 spelling->kind = (KIND); \
4386 spelling->MEMBER = (VALUE); \
4387 spelling++; \
4388 }
4390 /* Push STRING on the stack. Printed literally. */
4392 static void
4394 {
4396 }
4398 /* Push a member name on the stack. Printed as '.' STRING. */
4400 static void
4402 {
4406 }
4408 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
4410 static void
4412 {
4414 }
4416 /* Compute the maximum size in bytes of the printed spelling. */
4418 static int
4420 {
4425 {
4428 else
4430 }
4433 }
4435 /* Print the spelling to BUFFER and return it. */
4439 {
4445 {
4448 }
4449 else
4450 {
4455 ;
4456 }
4459 }
4461 /* Issue an error message for a bad initializer component.
4462 MSGID identifies the message.
4463 The component name is taken from the spelling stack. */
4465 void
4467 {
4474 }
4476 /* Issue a pedantic warning for a bad initializer component.
4477 MSGID identifies the message.
4478 The component name is taken from the spelling stack. */
4480 void
4482 {
4489 }
4491 /* Issue a warning for a bad initializer component.
4492 MSGID identifies the message.
4493 The component name is taken from the spelling stack. */
4495 static void
4497 {
4504 }
4505 \f
4506 /* If TYPE is an array type and EXPR is a parenthesized string
4507 constant, warn if pedantic that EXPR is being used to initialize an
4508 object of type TYPE. */
4510 void
4512 {
4518 }
4520 /* Digest the parser output INIT as an initializer for type TYPE.
4521 Return a C expression of type TYPE to represent the initial value.
4523 If INIT is a string constant, STRICT_STRING is true if it is
4524 unparenthesized or we should not warn here for it being parenthesized.
4525 For other types of INIT, STRICT_STRING is not used.
4527 REQUIRE_CONSTANT requests an error if non-constant initializers or
4528 elements are seen. */
4530 static tree
4532 {
4537 || !init
4546 /* Initialization of an array of chars from a string constant
4547 optionally enclosed in braces. */
4551 {
4553 /* Note that an array could be both an array of character type
4554 and an array of wchar_t if wchar_t is signed char or unsigned
4555 char. */
4561 {
4568 char_string
4577 {
4580 }
4582 {
4585 }
4591 /* Subtract 1 (or sizeof (wchar_t))
4592 because it's ok to ignore the terminating null char
4593 that is counted in the length of the constant. */
4604 }
4606 {
4610 }
4611 }
4613 /* Build a VECTOR_CST from a *constant* vector constructor. If the
4614 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
4615 below and handle as a constructor. */
4620 {
4627 {
4629 tree value;
4632 /* Iterate through elements and check if all constructor
4633 elements are *_CSTs. */
4636 {
4639 }
4644 }
4645 }
4647 /* Any type can be initialized
4648 from an expression of the same type, optionally with braces. */
4661 {
4663 {
4665 {
4669 else
4670 {
4673 }
4674 }
4675 }
4678 /* Although the types are compatible, we may require a
4679 conversion. */
4685 {
4686 /* As an extension, allow initializing objects with static storage
4687 duration with compound literals (which are then treated just as
4688 the brace enclosed list they contain). Also allow this for
4689 vectors, as we can only assign them with compound literals. */
4692 }
4696 {
4699 }
4704 /* Compound expressions can only occur here if -pedantic or
4705 -pedantic-errors is specified. In the later case, we always want
4706 an error. In the former case, we simply want a warning. */
4709 {
4710 inside_init
4715 else
4719 }
4723 {
4726 }
4728 /* Added to enable additional -Wmissing-format-attribute warnings. */
4733 }
4735 /* Handle scalar types, including conversions. */
4740 {
4745 inside_init
4749 /* Check to see if we have already given an error message. */
4751 ;
4753 {
4756 }
4760 {
4763 }
4766 }
4768 /* Come here only for records and arrays. */
4771 {
4774 }
4778 }
4779 \f
4780 /* Handle initializers that use braces. */
4782 /* Type of object we are accumulating a constructor for.
4783 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4786 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4787 left to fill. */
4790 /* For an ARRAY_TYPE, this is the specified index
4791 at which to store the next element we get. */
4794 /* For an ARRAY_TYPE, this is the maximum index. */
4797 /* For a RECORD_TYPE, this is the first field not yet written out. */
4800 /* For an ARRAY_TYPE, this is the index of the first element
4801 not yet written out. */
4804 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4805 This is so we can generate gaps between fields, when appropriate. */
4808 /* If we are saving up the elements rather than allocating them,
4809 this is the list of elements so far (in reverse order,
4810 most recent first). */
4813 /* 1 if constructor should be incrementally stored into a constructor chain,
4814 0 if all the elements should be kept in AVL tree. */
4817 /* 1 if so far this constructor's elements are all compile-time constants. */
4820 /* 1 if so far this constructor's elements are all valid address constants. */
4823 /* 1 if this constructor is erroneous so far. */
4826 /* Structure for managing pending initializer elements, organized as an
4827 AVL tree. */
4829 struct init_node
4830 {
4834 tree purpose;
4835 tree value;
4836 };
4838 /* Tree of pending elements at this constructor level.
4839 These are elements encountered out of order
4840 which belong at places we haven't reached yet in actually
4841 writing the output.
4842 Will never hold tree nodes across GC runs. */
4845 /* The SPELLING_DEPTH of this constructor. */
4848 /* DECL node for which an initializer is being read.
4849 0 means we are reading a constructor expression
4850 such as (struct foo) {...}. */
4853 /* Nonzero if this is an initializer for a top-level decl. */
4856 /* Nonzero if there were any member designators in this initializer. */
4859 /* Nesting depth of designator list. */
4862 /* Nonzero if there were diagnosed errors in this designator list. */
4865 \f
4866 /* This stack has a level for each implicit or explicit level of
4867 structuring in the initializer, including the outermost one. It
4868 saves the values of most of the variables above. */
4872 struct constructor_stack
4873 {
4875 tree type;
4876 tree fields;
4877 tree index;
4878 tree max_index;
4879 tree unfilled_index;
4880 tree unfilled_fields;
4881 tree bit_index;
4886 /* If value nonzero, this value should replace the entire
4887 constructor at this level. */
4897 };
4901 /* This stack represents designators from some range designator up to
4902 the last designator in the list. */
4904 struct constructor_range_stack
4905 {
4908 tree range_start;
4909 tree index;
4910 tree range_end;
4911 tree fields;
4912 };
4916 /* This stack records separate initializers that are nested.
4917 Nested initializers can't happen in ANSI C, but GNU C allows them
4918 in cases like { ... (struct foo) { ... } ... }. */
4920 struct initializer_stack
4921 {
4923 tree decl;
4933 };
4936 \f
4937 /* Prepare to parse and output the initializer for variable DECL. */
4939 void
4941 {
4963 {
4965 require_constant_elements
4967 /* For a scalar, you can always use any value to initialize,
4968 even within braces. */
4974 }
4975 else
4976 {
4980 }
4993 }
4995 void
4997 {
5000 /* Free the whole constructor stack of this initializer. */
5002 {
5006 }
5010 /* Pop back to the data of the outer initializer (if any). */
5025 }
5026 \f
5027 /* Call here when we see the initializer is surrounded by braces.
5028 This is instead of a call to push_init_level;
5029 it is matched by a call to pop_init_level.
5031 TYPE is the type to initialize, for a constructor expression.
5032 For an initializer for a decl, TYPE is zero. */
5034 void
5036 {
5081 {
5083 /* Skip any nameless bit fields at the beginning. */
5090 }
5092 {
5094 {
5095 constructor_max_index
5098 /* Detect non-empty initializations of zero-length arrays. */
5103 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5104 to initialize VLAs will cause a proper error; avoid tree
5105 checking errors as well by setting a safe value. */
5110 constructor_index
5113 }
5114 else
5115 {
5118 }
5121 }
5123 {
5124 /* Vectors are like simple fixed-size arrays. */
5125 constructor_max_index =
5129 }
5130 else
5131 {
5132 /* Handle the case of int x = {5}; */
5135 }
5136 }
5137 \f
5138 /* Push down into a subobject, for initialization.
5139 If this is for an explicit set of braces, IMPLICIT is 0.
5140 If it is because the next element belongs at a lower level,
5141 IMPLICIT is 1 (or 2 if the push is because of designator list). */
5143 void
5145 {
5149 /* If we've exhausted any levels that didn't have braces,
5150 pop them now. If implicit == 1, this will have been done in
5151 process_init_element; do not repeat it here because in the case
5152 of excess initializers for an empty aggregate this leads to an
5153 infinite cycle of popping a level and immediately recreating
5154 it. */
5156 {
5158 {
5164 && constructor_max_index
5166 constructor_index))
5168 else
5170 }
5171 }
5173 /* Unless this is an explicit brace, we need to preserve previous
5174 content if any. */
5176 {
5183 }
5217 {
5222 }
5224 /* Don't die if an entire brace-pair level is superfluous
5225 in the containing level. */
5227 ;
5230 {
5231 /* Don't die if there are extra init elts at the end. */
5234 else
5235 {
5238 constructor_depth++;
5239 }
5240 }
5242 {
5245 constructor_depth++;
5246 }
5249 {
5254 }
5257 {
5265 }
5268 {
5271 }
5275 {
5277 /* Skip any nameless bit fields at the beginning. */
5284 }
5286 {
5287 /* Vectors are like simple fixed-size arrays. */
5288 constructor_max_index =
5292 }
5294 {
5296 {
5297 constructor_max_index
5300 /* Detect non-empty initializations of zero-length arrays. */
5305 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5306 to initialize VLAs will cause a proper error; avoid tree
5307 checking errors as well by setting a safe value. */
5312 constructor_index
5315 }
5316 else
5321 {
5322 /* We need to split the char/wchar array into individual
5323 characters, so that we don't have to special case it
5324 everywhere. */
5326 }
5327 }
5328 else
5329 {
5334 }
5335 }
5337 /* At the end of an implicit or explicit brace level,
5338 finish up that level of constructor. If a single expression
5339 with redundant braces initialized that level, return the
5340 c_expr structure for that expression. Otherwise, the original_code
5341 element is set to ERROR_MARK.
5342 If we were outputting the elements as they are read, return 0 as the value
5343 from inner levels (process_init_element ignores that),
5344 but return error_mark_node as the value from the outermost level
5345 (that's what we want to put in DECL_INITIAL).
5346 Otherwise, return a CONSTRUCTOR expression as the value. */
5348 struct c_expr
5350 {
5357 {
5358 /* When we come to an explicit close brace,
5359 pop any inner levels that didn't have explicit braces. */
5364 }
5366 /* Now output all pending elements. */
5372 /* Error for initializing a flexible array member, or a zero-length
5373 array member in an inappropriate context. */
5378 {
5379 /* Silently discard empty initializations. The parser will
5380 already have pedwarned for empty brackets. */
5383 else
5384 {
5392 /* We have already issued an error message for the existence
5393 of a flexible array member not at the end of the structure.
5394 Discard the initializer so that we do not die later. */
5397 }
5398 }
5400 /* Warn when some struct elements are implicitly initialized to zero. */
5402 && constructor_type
5405 {
5406 /* Do not warn for flexible array members or zero-length arrays. */
5412 /* Do not warn if this level of the initializer uses member
5413 designators; it is likely to be deliberate. */
5415 {
5419 }
5420 }
5422 /* Pad out the end of the structure. */
5424 /* If this closes a superfluous brace pair,
5425 just pass out the element between them. */
5428 ;
5433 {
5434 /* A nonincremental scalar initializer--just return
5435 the element, after verifying there is just one. */
5437 {
5441 }
5443 {
5446 }
5447 else
5449 }
5450 else
5451 {
5454 else
5455 {
5457 constructor_elements);
5462 }
5463 }
5490 }
5492 /* Common handling for both array range and field name designators.
5493 ARRAY argument is nonzero for array ranges. Returns zero for success. */
5495 static int
5497 {
5498 tree subtype;
5501 /* Don't die if an entire brace-pair level is superfluous
5502 in the containing level. */
5506 /* If there were errors in this designator list already, bail out
5507 silently. */
5512 {
5515 /* Designator list starts at the level of closest explicit
5516 braces. */
5521 }
5524 {
5536 }
5540 {
5543 }
5545 {
5548 }
5553 }
5555 /* If there are range designators in designator list, push a new designator
5556 to constructor_range_stack. RANGE_END is end of such stack range or
5557 NULL_TREE if there is no range designator at this level. */
5559 static void
5561 {
5575 }
5577 /* Within an array initializer, specify the next index to be initialized.
5578 FIRST is that index. If LAST is nonzero, then initialize a range
5579 of indices, running from FIRST through LAST. */
5581 void
5583 {
5591 {
5594 }
5607 else
5608 {
5612 {
5616 {
5619 }
5620 else
5621 {
5625 {
5628 }
5629 }
5630 }
5632 designator_depth++;
5636 }
5637 }
5639 /* Within a struct initializer, specify the next field to be initialized. */
5641 void
5643 {
5644 tree tail;
5653 {
5656 }
5660 {
5663 }
5667 else
5668 {
5670 designator_depth++;
5674 }
5675 }
5676 \f
5677 /* Add a new initializer to the tree of pending initializers. PURPOSE
5678 identifies the initializer, either array index or field in a structure.
5679 VALUE is the value of that index or field. */
5681 static void
5683 {
5690 {
5692 {
5698 else
5699 {
5706 }
5707 }
5708 }
5709 else
5710 {
5711 tree bitpos;
5715 {
5721 else
5722 {
5729 }
5730 }
5731 }
5744 {
5748 {
5752 {
5754 {
5755 /* L rotation. */
5768 {
5771 else
5773 }
5774 else
5776 }
5777 else
5778 {
5779 /* LR rotation. */
5801 {
5804 else
5806 }
5807 else
5809 }
5811 }
5812 else
5813 {
5814 /* p->balance == +1; growth of left side balances the node. */
5817 }
5818 }
5820 {
5822 /* Growth propagation from right side. */
5825 {
5827 {
5828 /* R rotation. */
5841 {
5844 else
5846 }
5847 else
5849 }
5851 {
5852 /* RL rotation */
5874 {
5877 else
5879 }
5880 else
5882 }
5884 }
5885 else
5886 {
5887 /* p->balance == -1; growth of right side balances the node. */
5890 }
5891 }
5895 }
5896 }
5898 /* Build AVL tree from a sorted chain. */
5900 static void
5902 {
5914 {
5916 /* Skip any nameless bit fields at the beginning. */
5922 }
5924 {
5926 constructor_unfilled_index
5929 else
5931 }
5933 }
5935 /* Build AVL tree from a string constant. */
5937 static void
5939 {
5950 else
5951 {
5955 }
5964 {
5966 {
5969 }
5970 else
5971 {
5975 {
5978 else
5983 }
5984 }
5987 {
5990 {
5992 {
5995 }
5996 }
5998 {
6001 }
6006 }
6010 }
6013 }
6015 /* Return value of FIELD in pending initializer or zero if the field was
6016 not initialized yet. */
6018 static tree
6020 {
6024 {
6031 {
6036 else
6038 }
6039 }
6041 {
6045 && (!constructor_unfilled_fields
6052 {
6057 else
6059 }
6060 }
6062 {
6067 }
6069 }
6071 /* "Output" the next constructor element.
6072 At top level, really output it to assembler code now.
6073 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
6074 TYPE is the data type that the containing data type wants here.
6075 FIELD is the field (a FIELD_DECL) or the index that this element fills.
6076 If VALUE is a string constant, STRICT_STRING is true if it is
6077 unparenthesized or we should not warn here for it being parenthesized.
6078 For other types of VALUE, STRICT_STRING is not used.
6080 PENDING if non-nil means output pending elements that belong
6081 right after this element. (PENDING is normally 1;
6082 it is 0 while outputting pending elements, to avoid recursion.) */
6084 static void
6087 {
6091 {
6094 }
6107 {
6108 /* As an extension, allow initializing objects with static storage
6109 duration with compound literals (which are then treated just as
6110 the brace enclosed list they contain). */
6113 }
6127 {
6129 {
6132 }
6135 }
6137 /* If this field is empty (and not at the end of structure),
6138 don't do anything other than checking the initializer. */
6149 {
6152 }
6154 /* If this element doesn't come next in sequence,
6155 put it on constructor_pending_elts. */
6157 && (!constructor_incremental
6159 {
6166 }
6168 && (!constructor_incremental
6170 {
6171 /* We do this for records but not for unions. In a union,
6172 no matter which field is specified, it can be initialized
6173 right away since it starts at the beginning of the union. */
6175 {
6178 else
6179 {
6187 }
6188 }
6192 }
6195 {
6202 /* We can have just one union field set. */
6204 }
6206 /* Otherwise, output this element either to
6207 constructor_elements or to the assembler file. */
6213 /* Advance the variable that indicates sequential elements output. */
6215 constructor_unfilled_index
6217 bitsize_one_node);
6219 {
6220 constructor_unfilled_fields
6223 /* Skip any nameless bit fields. */
6227 constructor_unfilled_fields =
6229 }
6233 /* Now output any pending elements which have become next. */
6236 }
6238 /* Output any pending elements which have become next.
6239 As we output elements, constructor_unfilled_{fields,index}
6240 advances, which may cause other elements to become next;
6241 if so, they too are output.
6243 If ALL is 0, we return when there are
6244 no more pending elements to output now.
6246 If ALL is 1, we output space as necessary so that
6247 we can output all the pending elements. */
6249 static void
6251 {
6253 tree next;
6255 retry:
6257 /* Look through the whole pending tree.
6258 If we find an element that should be output now,
6259 output it. Otherwise, set NEXT to the element
6260 that comes first among those still pending. */
6264 {
6266 {
6268 constructor_unfilled_index))
6274 {
6275 /* Advance to the next smaller node. */
6278 else
6279 {
6280 /* We have reached the smallest node bigger than the
6281 current unfilled index. Fill the space first. */
6284 }
6285 }
6286 else
6287 {
6288 /* Advance to the next bigger node. */
6291 else
6292 {
6293 /* We have reached the biggest node in a subtree. Find
6294 the parent of it, which is the next bigger node. */
6300 {
6303 }
6304 }
6305 }
6306 }
6309 {
6312 /* If the current record is complete we are done. */
6318 /* We can't compare fields here because there might be empty
6319 fields in between. */
6321 {
6325 }
6327 {
6328 /* Advance to the next smaller node. */
6331 else
6332 {
6333 /* We have reached the smallest node bigger than the
6334 current unfilled field. Fill the space first. */
6337 }
6338 }
6339 else
6340 {
6341 /* Advance to the next bigger node. */
6344 else
6345 {
6346 /* We have reached the biggest node in a subtree. Find
6347 the parent of it, which is the next bigger node. */
6354 {
6357 }
6358 }
6359 }
6360 }
6361 }
6363 /* Ordinarily return, but not if we want to output all
6364 and there are elements left. */
6368 /* If it's not incremental, just skip over the gap, so that after
6369 jumping to retry we will output the next successive element. */
6376 /* ELT now points to the node in the pending tree with the next
6377 initializer to output. */
6379 }
6380 \f
6381 /* Add one non-braced element to the current constructor level.
6382 This adjusts the current position within the constructor's type.
6383 This may also start or terminate implicit levels
6384 to handle a partly-braced initializer.
6386 Once this has found the correct level for the new element,
6387 it calls output_init_element. */
6389 void
6391 {
6399 /* Handle superfluous braces around string cst as in
6400 char x[] = {"foo"}; */
6402 && constructor_type
6406 {
6411 }
6414 {
6417 }
6419 /* Ignore elements of a brace group if it is entirely superfluous
6420 and has already been diagnosed. */
6424 /* If we've exhausted any levels that didn't have braces,
6425 pop them now. */
6427 {
6435 constructor_index)))
6437 else
6439 }
6441 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
6443 {
6444 /* If value is a compound literal and we'll be just using its
6445 content, don't put it into a SAVE_EXPR. */
6447 || !require_constant_value
6450 }
6453 {
6455 {
6456 tree fieldtype;
6460 {
6463 }
6470 /* Error for non-static initialization of a flexible array member. */
6472 && !require_constant_value
6475 {
6478 }
6480 /* Accept a string constant to initialize a subarray. */
6486 /* Otherwise, if we have come to a subaggregate,
6487 and we don't have an element of its type, push into it. */
6493 {
6496 }
6499 {
6504 }
6505 else
6506 /* Do the bookkeeping for an element that was
6507 directly output as a constructor. */
6508 {
6509 /* For a record, keep track of end position of last field. */
6511 constructor_bit_index
6516 /* If the current field was the first one not yet written out,
6517 it isn't now, so update. */
6519 {
6521 /* Skip any nameless bit fields. */
6525 constructor_unfilled_fields =
6527 }
6528 }
6531 /* Skip any nameless bit fields at the beginning. */
6536 }
6538 {
6539 tree fieldtype;
6543 {
6546 }
6553 /* Warn that traditional C rejects initialization of unions.
6554 We skip the warning if the value is zero. This is done
6555 under the assumption that the zero initializer in user
6556 code appears conditioned on e.g. __STDC__ to avoid
6557 "missing initializer" warnings and relies on default
6558 initialization to zero in the traditional C case.
6559 We also skip the warning if the initializer is designated,
6560 again on the assumption that this must be conditional on
6561 __STDC__ anyway (and we've already complained about the
6562 member-designator already). */
6569 /* Accept a string constant to initialize a subarray. */
6575 /* Otherwise, if we have come to a subaggregate,
6576 and we don't have an element of its type, push into it. */
6582 {
6585 }
6588 {
6593 }
6594 else
6595 /* Do the bookkeeping for an element that was
6596 directly output as a constructor. */
6597 {
6600 }
6603 }
6605 {
6609 /* Accept a string constant to initialize a subarray. */
6615 /* Otherwise, if we have come to a subaggregate,
6616 and we don't have an element of its type, push into it. */
6622 {
6625 }
6630 {
6633 }
6635 /* Now output the actual element. */
6637 {
6642 }
6644 constructor_index
6648 /* If we are doing the bookkeeping for an element that was
6649 directly output as a constructor, we must update
6650 constructor_unfilled_index. */
6652 }
6654 {
6657 /* Do a basic check of initializer size. Note that vectors
6658 always have a fixed size derived from their type. */
6660 {
6663 }
6665 /* Now output the actual element. */
6670 constructor_index
6674 /* If we are doing the bookkeeping for an element that was
6675 directly output as a constructor, we must update
6676 constructor_unfilled_index. */
6678 }
6680 /* Handle the sole element allowed in a braced initializer
6681 for a scalar variable. */
6684 {
6687 }
6688 else
6689 {
6694 }
6696 /* Handle range initializers either at this level or anywhere higher
6697 in the designator stack. */
6699 {
6706 {
6709 }
6713 {
6716 }
6723 {
6727 {
6730 }
6738 }
6743 }
6746 }
6749 }
6750 \f
6751 /* Build a complete asm-statement, whose components are a CV_QUALIFIER
6752 (guaranteed to be 'volatile' or null) and ARGS (represented using
6753 an ASM_EXPR node). */
6754 tree
6756 {
6760 }
6762 /* Build an asm-expr, whose components are a STRING, some OUTPUTS,
6763 some INPUTS, and some CLOBBERS. The latter three may be NULL.
6764 SIMPLE indicates whether there was anything at all after the
6765 string in the asm expression -- asm("blah") and asm("blah" : )
6766 are subtly different. We use a ASM_EXPR node to represent this. */
6767 tree
6770 {
6771 tree tail;
6772 tree args;
6785 /* Remove output conversions that change the type but not the mode. */
6787 {
6790 /* ??? Really, this should not be here. Users should be using a
6791 proper lvalue, dammit. But there's a long history of using casts
6792 in the output operands. In cases like longlong.h, this becomes a
6793 primitive form of typechecking -- if the cast can be removed, then
6794 the output operand had a type of the proper width; otherwise we'll
6795 get an error. Gross, but ... */
6814 {
6815 /* If the operand is going to end up in memory,
6816 mark it addressable. */
6819 }
6820 else
6824 }
6827 {
6828 tree input;
6835 {
6836 /* If the operand is going to end up in memory,
6837 mark it addressable. */
6839 {
6840 /* Strip the nops as we allow this case. FIXME, this really
6841 should be rejected or made deprecated. */
6845 }
6846 }
6847 else
6851 }
6855 /* asm statements without outputs, including simple ones, are treated
6856 as volatile. */
6861 }
6862 \f
6863 /* Generate a goto statement to LABEL. */
6865 tree
6867 {
6873 {
6876 }
6879 {
6882 }
6885 {
6886 /* No jump from outside this statement expression context, so
6887 record that there is a jump from within this context. */
6893 }
6896 {
6897 /* No jump from outside this context context of identifiers with
6898 variably modified type, so record that there is a jump from
6899 within this context. */
6905 }
6909 }
6911 /* Generate a computed goto statement to EXPR. */
6913 tree
6915 {
6920 }
6922 /* Generate a C `return' statement. RETVAL is the expression for what
6923 to return, or a null pointer for `return;' with no value. */
6925 tree
6927 {
6935 {
6939 {
6943 }
6944 }
6946 {
6952 }
6953 else
6954 {
6958 tree inner;
6966 /* Strip any conversions, additions, and subtractions, and see if
6967 we are returning the address of a local variable. Warn if so. */
6969 {
6971 {
6978 /* If the second operand of the MINUS_EXPR has a pointer
6979 type (or is converted from it), this may be valid, so
6980 don't give a warning. */
6981 {
6995 }
7013 }
7016 }
7019 }
7024 }
7025 \f
7027 /* The SWITCH_EXPR being built. */
7028 tree switch_expr;
7030 /* The original type of the testing expression, i.e. before the
7031 default conversion is applied. */
7032 tree orig_type;
7034 /* A splay-tree mapping the low element of a case range to the high
7035 element, or NULL_TREE if there is no high element. Used to
7036 determine whether or not a new case label duplicates an old case
7037 label. We need a tree, rather than simply a hash table, because
7038 of the GNU case range extension. */
7039 splay_tree cases;
7041 /* Number of nested statement expressions within this switch
7042 statement; if nonzero, case and default labels may not
7043 appear. */
7046 /* Scope of outermost declarations of identifiers with variably
7047 modified type within this switch statement; if nonzero, case and
7048 default labels may not appear. */
7051 /* The next node on the stack. */
7053 };
7055 /* A stack of the currently active switch statements. The innermost
7056 switch statement is on the top of the stack. There is no need to
7057 mark the stack for garbage collection because it is only active
7058 during the processing of the body of a function, and we never
7059 collect at that point. */
7063 /* Start a C switch statement, testing expression EXP. Return the new
7064 SWITCH_EXPR. */
7066 tree
7068 {
7073 {
7077 {
7079 {
7082 }
7084 }
7085 else
7086 {
7096 }
7097 }
7099 /* Add this new SWITCH_EXPR to the stack. */
7110 }
7112 /* Process a case label. */
7114 tree
7116 {
7121 {
7128 }
7130 {
7134 else
7137 }
7139 {
7143 else
7146 }
7149 else
7153 }
7155 /* Finish the switch statement. */
7157 void
7159 {
7161 location_t switch_location;
7165 /* We must not be within a statement expression nested in the switch
7166 at this point; we might, however, be within the scope of an
7167 identifier with variably modified type nested in the switch. */
7170 /* Emit warnings as needed. */
7173 else
7179 /* Pop the stack. */
7183 }
7184 \f
7185 /* Emit an if statement. IF_LOCUS is the location of the 'if'. COND,
7186 THEN_BLOCK and ELSE_BLOCK are expressions to be used; ELSE_BLOCK
7187 may be null. NESTED_IF is true if THEN_BLOCK contains another IF
7188 statement, and was not surrounded with parenthesis. */
7190 void
7193 {
7194 tree stmt;
7196 /* Diagnose an ambiguous else if if-then-else is nested inside if-then. */
7198 {
7201 /* We know from the grammar productions that there is an IF nested
7202 within THEN_BLOCK. Due to labels and c99 conditional declarations,
7203 it might not be exactly THEN_BLOCK, but should be the last
7204 non-container statement within. */
7207 {
7222 }
7223 found:
7229 }
7236 }
7238 /* Emit a general-purpose loop construct. START_LOCUS is the location of
7239 the beginning of the loop. COND is the loop condition. COND_IS_FIRST
7240 is false for DO loops. INCR is the FOR increment expression. BODY is
7241 the statement controlled by the loop. BLAB is the break label. CLAB is
7242 the continue label. Everything is allowed to be NULL. */
7244 void
7247 {
7250 /* If the condition is zero don't generate a loop construct. */
7252 {
7254 {
7258 }
7259 }
7260 else
7261 {
7264 /* If we have an exit condition, then we build an IF with gotos either
7265 out of the loop, or to the top of it. If there's no exit condition,
7266 then we just build a jump back to the top. */
7270 {
7271 /* Canonicalize the loop condition to the end. This means
7272 generating a branch to the loop condition. Reuse the
7273 continue label, if possible. */
7275 {
7277 {
7280 }
7281 else
7285 }
7291 else
7293 }
7296 }
7310 }
7312 tree
7314 {
7318 /* In switch statements break is sometimes stylistically used after
7319 a return statement. This can lead to spurious warnings about
7320 control reaching the end of a non-void function when it is
7321 inlined. Note that we are calling block_may_fallthru with
7322 language specific tree nodes; this works because
7323 block_may_fallthru returns true when given something it does not
7324 understand. */
7328 {
7331 }
7333 ;
7335 {
7339 else
7350 }
7356 }
7358 /* A helper routine for c_process_expr_stmt and c_finish_stmt_expr. */
7360 static void
7362 {
7364 ;
7366 {
7370 }
7371 else
7373 }
7375 /* Process an expression as if it were a complete statement. Emit
7376 diagnostics, but do not call ADD_STMT. */
7378 tree
7380 {
7392 /* If we're not processing a statement expression, warn about unused values.
7393 Warnings for statement expressions will be emitted later, once we figure
7394 out which is the result. */
7399 /* If the expression is not of a type to which we cannot assign a line
7400 number, wrap the thing in a no-op NOP_EXPR. */
7408 }
7410 /* Emit an expression as a statement. */
7412 tree
7414 {
7417 else
7419 }
7421 /* Do the opposite and emit a statement as an expression. To begin,
7422 create a new binding level and return it. */
7424 tree
7426 {
7427 tree ret;
7431 /* We must force a BLOCK for this level so that, if it is not expanded
7432 later, there is a way to turn off the entire subtree of blocks that
7433 are contained in it. */
7437 {
7440 }
7444 {
7446 }
7453 /* Mark the current statement list as belonging to a statement list. */
7457 }
7459 tree
7461 {
7468 {
7471 }
7472 /* It is no longer possible to jump to labels defined within this
7473 statement expression. */
7477 {
7479 }
7480 /* It is again possible to define labels with a goto just outside
7481 this statement expression. */
7485 {
7488 }
7491 else
7496 /* Locate the last statement in BODY. See c_end_compound_stmt
7497 about always returning a BIND_EXPR. */
7501 continue_searching:
7503 {
7504 tree_stmt_iterator i;
7506 /* This can happen with degenerate cases like ({ }). No value. */
7510 /* If we're supposed to generate side effects warnings, process
7511 all of the statements except the last. */
7513 {
7516 }
7517 else
7521 }
7523 /* If the end of the list is exception related, then the list was split
7524 by a call to push_cleanup. Continue searching. */
7527 {
7531 }
7533 /* In the case that the BIND_EXPR is not necessary, return the
7534 expression out from inside it. */
7538 {
7539 /* Do not warn if the return value of a statement expression is
7540 unused. */
7544 }
7546 /* Extract the type of said expression. */
7549 /* If we're not returning a value at all, then the BIND_EXPR that
7550 we already have is a fine expression to return. */
7554 /* Now that we've located the expression containing the value, it seems
7555 silly to make voidify_wrapper_expr repeat the process. Create a
7556 temporary of the appropriate type and stick it in a TARGET_EXPR. */
7559 /* Unwrap a no-op NOP_EXPR as added by c_finish_expr_stmt. This avoids
7560 tree_expr_nonnegative_p giving up immediately. */
7570 }
7572 /* Begin the scope of an identifier of variably modified type, scope
7573 number SCOPE. Jumping from outside this scope to inside it is not
7574 permitted. */
7576 void
7578 {
7584 /* At file_scope, we don't have to do any processing. */
7593 {
7595 }
7602 }
7604 /* End a scope which may contain identifiers of variably modified
7605 type, scope number SCOPE. */
7607 void
7609 {
7614 /* We may have a number of nested scopes of identifiers with
7615 variably modified type, all at this depth. Pop each in turn. */
7617 {
7620 /* It is no longer possible to jump to labels defined within this
7621 scope. */
7625 {
7627 }
7628 /* It is again possible to define labels with a goto just outside
7629 this scope. */
7633 {
7636 }
7639 else
7643 }
7644 }
7645 \f
7646 /* Begin and end compound statements. This is as simple as pushing
7647 and popping new statement lists from the tree. */
7649 tree
7651 {
7656 }
7658 tree
7660 {
7664 {
7668 }
7673 /* If this compound statement is nested immediately inside a statement
7674 expression, then force a BIND_EXPR to be created. Otherwise we'll
7675 do the wrong thing for ({ { 1; } }) or ({ 1; { } }). In particular,
7676 STATEMENT_LISTs merge, and thus we can lose track of what statement
7677 was really last. */
7681 {
7684 }
7687 }
7689 /* Queue a cleanup. CLEANUP is an expression/statement to be executed
7690 when the current scope is exited. EH_ONLY is true when this is not
7691 meant to apply to normal control flow transfer. */
7693 void
7695 {
7707 }
7708 \f
7709 /* Build a binary-operation expression without default conversions.
7710 CODE is the kind of expression to build.
7711 This function differs from `build' in several ways:
7712 the data type of the result is computed and recorded in it,
7713 warnings are generated if arg data types are invalid,
7714 special handling for addition and subtraction of pointers is known,
7715 and some optimization is done (operations on narrow ints
7716 are done in the narrower type when that gives the same result).
7717 Constant folding is also done before the result is returned.
7719 Note that the operands will never have enumeral types, or function
7720 or array types, because either they will have the default conversions
7721 performed or they have both just been converted to some other type in which
7722 the arithmetic is to be done. */
7724 tree
7727 {
7733 /* Expression code to give to the expression when it is built.
7734 Normally this is CODE, which is what the caller asked for,
7735 but in some special cases we change it. */
7738 /* Data type in which the computation is to be performed.
7739 In the simplest cases this is the common type of the arguments. */
7742 /* Nonzero means operands have already been type-converted
7743 in whatever way is necessary.
7744 Zero means they need to be converted to RESULT_TYPE. */
7747 /* Nonzero means create the expression with this type, rather than
7748 RESULT_TYPE. */
7751 /* Nonzero means after finally constructing the expression
7752 convert it to this type. */
7755 /* Nonzero if this is an operation like MIN or MAX which can
7756 safely be computed in short if both args are promoted shorts.
7757 Also implies COMMON.
7758 -1 indicates a bitwise operation; this makes a difference
7759 in the exact conditions for when it is safe to do the operation
7760 in a narrower mode. */
7763 /* Nonzero if this is a comparison operation;
7764 if both args are promoted shorts, compare the original shorts.
7765 Also implies COMMON. */
7768 /* Nonzero if this is a right-shift operation, which can be computed on the
7769 original short and then promoted if the operand is a promoted short. */
7772 /* Nonzero means set RESULT_TYPE to the common type of the args. */
7775 /* True means types are compatible as far as ObjC is concerned. */
7779 {
7782 }
7783 else
7784 {
7787 }
7792 /* The expression codes of the data types of the arguments tell us
7793 whether the arguments are integers, floating, pointers, etc. */
7797 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
7801 /* If an error was already reported for one of the arguments,
7802 avoid reporting another error. */
7809 {
7812 }
7817 {
7819 /* Handle the pointer + int case. */
7824 else
7829 /* Subtraction of two similar pointers.
7830 We must subtract them as integers, then divide by object size. */
7834 /* Handle pointer minus int. Just like pointer plus int. */
7837 else
7856 {
7866 else
7867 /* Although it would be tempting to shorten always here, that
7868 loses on some targets, since the modulo instruction is
7869 undefined if the quotient can't be represented in the
7870 computation mode. We shorten only if unsigned or if
7871 dividing by something we know != -1. */
7876 }
7893 {
7894 /* Although it would be tempting to shorten always here, that loses
7895 on some targets, since the modulo instruction is undefined if the
7896 quotient can't be represented in the computation mode. We shorten
7897 only if unsigned or if dividing by something we know != -1. */
7902 }
7914 {
7915 /* Result of these operations is always an int,
7916 but that does not mean the operands should be
7917 converted to ints! */
7922 }
7925 /* Shift operations: result has same type as first operand;
7926 always convert second operand to int.
7927 Also set SHORT_SHIFT if shifting rightward. */
7931 {
7933 {
7936 else
7937 {
7943 }
7944 }
7946 /* Use the type of the value to be shifted. */
7948 /* Convert the shift-count to an integer, regardless of size
7949 of value being shifted. */
7952 /* Avoid converting op1 to result_type later. */
7954 }
7959 {
7961 {
7967 }
7969 /* Use the type of the value to be shifted. */
7971 /* Convert the shift-count to an integer, regardless of size
7972 of value being shifted. */
7975 /* Avoid converting op1 to result_type later. */
7977 }
7985 /* Result of comparison is always int,
7986 but don't convert the args to int! */
7994 {
7997 /* Anything compares with void *. void * compares with anything.
7998 Otherwise, the targets must be compatible
7999 and both must be object or both incomplete. */
8003 {
8004 /* op0 != orig_op0 detects the case of something
8005 whose value is 0 but which isn't a valid null ptr const. */
8010 }
8012 {
8017 }
8018 else
8019 /* Avoid warning about the volatile ObjC EH puts on decls. */
8025 }
8027 {
8033 }
8035 {
8041 }
8043 {
8046 }
8048 {
8051 }
8063 {
8065 {
8073 }
8074 else
8075 {
8078 }
8079 }
8081 {
8085 }
8087 {
8091 }
8093 {
8096 }
8098 {
8101 }
8106 }
8115 {
8118 }
8122 &&
8125 {
8129 {
8133 }
8135 /* For certain operations (which identify themselves by shorten != 0)
8136 if both args were extended from the same smaller type,
8137 do the arithmetic in that type and then extend.
8139 shorten !=0 and !=1 indicates a bitwise operation.
8140 For them, this optimization is safe only if
8141 both args are zero-extended or both are sign-extended.
8142 Otherwise, we might change the result.
8143 Eg, (short)-1 | (unsigned short)-1 is (int)-1
8144 but calculated in (unsigned short) it would be (unsigned short)-1. */
8147 {
8151 tree type;
8153 /* Cast OP0 and OP1 to RESULT_TYPE. Doing so prevents
8154 excessive narrowing when we call get_narrower below. For
8155 example, suppose that OP0 is of unsigned int extended
8156 from signed char and that RESULT_TYPE is long long int.
8157 If we explicitly cast OP0 to RESULT_TYPE, OP0 would look
8158 like
8160 (long long int) (unsigned int) signed_char
8162 which get_narrower would narrow down to
8164 (unsigned int) signed char
8166 If we do not cast OP0 first, get_narrower would return
8167 signed_char, which is inconsistent with the case of the
8168 explicit cast. */
8175 /* UNS is 1 if the operation to be done is an unsigned one. */
8180 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
8181 but it *requires* conversion to FINAL_TYPE. */
8192 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
8194 /* For bitwise operations, signedness of nominal type
8195 does not matter. Consider only how operands were extended. */
8199 /* Note that in all three cases below we refrain from optimizing
8200 an unsigned operation on sign-extended args.
8201 That would not be valid. */
8203 /* Both args variable: if both extended in same way
8204 from same width, do it in that width.
8205 Do it unsigned if args were zero-extended. */
8212 result_type
8213 = c_common_signed_or_unsigned_type
8219 && (type
8228 && (type
8233 }
8235 /* Shifts can be shortened if shifting right. */
8238 {
8248 /* We can shorten only if the shift count is less than the
8249 number of bits in the smaller type size. */
8251 /* We cannot drop an unsigned shift after sign-extension. */
8253 {
8254 /* Do an unsigned shift if the operand was zero-extended. */
8255 result_type
8258 /* Convert value-to-be-shifted to that type. */
8262 }
8263 }
8265 /* Comparison operations are shortened too but differently.
8266 They identify themselves by setting short_compare = 1. */
8269 {
8270 /* Don't write &op0, etc., because that would prevent op0
8271 from being kept in a register.
8272 Instead, make copies of the our local variables and
8273 pass the copies by reference, then copy them back afterward. */
8276 tree val
8287 {
8299 /* Give warnings for comparisons between signed and unsigned
8300 quantities that may fail.
8302 Do the checking based on the original operand trees, so that
8303 casts will be considered, but default promotions won't be.
8305 Do not warn if the comparison is being done in a signed type,
8306 since the signed type will only be chosen if it can represent
8307 all the values of the unsigned type. */
8310 /* Do not warn if both operands are the same signedness. */
8313 else
8314 {
8320 else
8323 /* Do not warn if the signed quantity is an
8324 unsuffixed integer literal (or some static
8325 constant expression involving such literals or a
8326 conditional expression involving such literals)
8327 and it is non-negative. */
8330 /* Do not warn if the comparison is an equality operation,
8331 the unsigned quantity is an integral constant, and it
8332 would fit in the result if the result were signed. */
8335 && int_fits_type_p
8338 /* Do not warn if the unsigned quantity is an enumeration
8339 constant and its maximum value would fit in the result
8340 if the result were signed. */
8343 && int_fits_type_p
8347 else
8349 }
8351 /* Warn if two unsigned values are being compared in a size
8352 larger than their original size, and one (and only one) is the
8353 result of a `~' operator. This comparison will always fail.
8355 Also warn if one operand is a constant, and the constant
8356 does not have all bits set that are set in the ~ operand
8357 when it is extended. */
8361 {
8365 else
8370 {
8371 tree primop;
8376 {
8380 }
8381 else
8382 {
8386 }
8391 {
8395 }
8396 }
8403 }
8404 }
8405 }
8406 }
8408 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
8409 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
8410 Then the expression will be built.
8411 It will be given type FINAL_TYPE if that is nonzero;
8412 otherwise, it will be given type RESULT_TYPE. */
8415 {
8418 }
8421 {
8427 /* This can happen if one operand has a vector type, and the other
8428 has a different type. */
8431 }
8436 {
8437 /* Treat expressions in initializers specially as they can't trap. */
8439 build_type,
8447 }
8448 }
8451 /* Convert EXPR to be a truth-value, validating its type for this
8452 purpose. */
8454 tree
8456 {
8458 {
8476 }
8478 /* ??? Should we also give an error for void and vectors rather than
8479 leaving those to give errors later? */
8481 }
8482 \f
8484 /* Convert EXPR to a contained DECL, updating *TC, *TI and *SE as
8485 required. */
8487 tree
8490 {
8492 {
8494 /* Executing a compound literal inside a function reinitializes
8495 it. */
8499 }
8500 else
8502 }
8503 \f
8504 /* Like c_begin_compound_stmt, except force the retention of the BLOCK. */
8506 tree
8508 {
8509 tree block;
8515 }
8517 tree
8519 {
8520 tree stmt;
8530 }
8532 /* For all elements of CLAUSES, validate them vs OpenMP constraints.
8533 Remove any elements from the list that are invalid. */
8535 tree
8537 {
8548 {
8554 {
8572 {
8575 }
8577 {
8582 {
8604 }
8606 {
8610 }
8611 }
8622 {
8625 }
8628 check_dup_generic:
8631 {
8634 }
8638 {
8641 }
8642 else
8652 {
8655 }
8658 {
8661 }
8662 else
8672 {
8675 }
8678 {
8681 }
8682 else
8697 }
8700 {
8704 {
8708 }
8711 {
8717 {
8728 }
8730 {
8734 }
8735 }
8736 }
8740 else
8742 }
8746 }