| blob | 6305cc4fb0abcf0aeb16af92c10022f37f4f5b89 |
1 /* Build expressions with type checking for C compiler.
2 Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
10 version.
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
20 02111-1307, USA. */
23 /* This file is part of the C front end.
24 It contains routines to build C expressions given their operands,
25 including computing the types of the result, C-specific error checks,
26 and some optimization.
28 There are also routines to build RETURN_STMT nodes and CASE_STMT nodes,
29 and to process initializations in declarations (since they work
30 like a strange sort of assignment). */
49 /* Nonzero if we've already printed a "missing braces around initializer"
50 message within this initializer. */
83 \f
84 /* Do `exp = require_complete_type (exp);' to make sure exp
85 does not have an incomplete type. (That includes void types.) */
87 tree
89 {
95 /* First, detect a valid value with a complete type. */
101 }
103 /* Print an error message for invalid use of an incomplete type.
104 VALUE is the expression that was used (or 0 if that isn't known)
105 and TYPE is the type that was invalid. */
107 void
109 {
112 /* Avoid duplicate error message. */
120 else
121 {
122 retry:
123 /* We must print an error message. Be clever about what it says. */
126 {
145 {
147 {
150 }
153 }
159 }
164 else
165 /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */
168 }
169 }
171 /* Given a type, apply default promotions wrt unnamed function
172 arguments and return the new type. */
174 tree
176 {
181 {
182 /* Preserve unsignedness if not really getting any wider. */
187 }
190 }
192 /* Return a variant of TYPE which has all the type qualifiers of LIKE
193 as well as those of TYPE. */
195 static tree
197 {
200 }
201 \f
202 /* Return the common type of two types.
203 We assume that comptypes has already been done and returned 1;
204 if that isn't so, this may crash. In particular, we assume that qualifiers
205 match.
207 This is the type for the result of most arithmetic operations
208 if the operands have the given two types. */
210 tree
212 {
215 tree attributes;
217 /* Save time if the two types are the same. */
221 /* If one type is nonsense, use the other. */
227 /* Merge the attributes. */
230 /* Treat an enum type as the unsigned integer type of the same width. */
240 /* If one type is complex, form the common type of the non-complex
241 components, then make that complex. Use T1 or T2 if it is the
242 required type. */
244 {
253 else
255 attributes);
256 }
259 {
262 /* If only one is real, use it as the result. */
270 /* Both real or both integers; use the one with greater precision. */
277 /* Same precision. Prefer long longs to longs to ints when the
278 same precision, following the C99 rules on integer type rank
279 (which are equivalent to the C90 rules for C90 types). */
284 attributes);
288 {
291 else
294 }
299 attributes);
303 {
304 /* But preserve unsignedness from the other type,
305 since long cannot hold all the values of an unsigned int. */
308 else
311 }
313 /* Likewise, prefer long double to double even if same size. */
317 attributes);
319 /* Otherwise prefer the unsigned one. */
323 else
327 /* For two pointers, do this recursively on the target type,
328 and combine the qualifiers of the two types' targets. */
329 /* This code was turned off; I don't know why.
330 But ANSI C specifies doing this with the qualifiers.
331 So I turned it on again. */
332 {
342 }
345 {
347 /* Save space: see if the result is identical to one of the args. */
352 /* Merge the element types, and have a size if either arg has one. */
355 }
358 /* Function types: prefer the one that specified arg types.
359 If both do, merge the arg types. Also merge the return types. */
360 {
368 /* Save space: see if the result is identical to one of the args. */
374 /* Simple way if one arg fails to specify argument types. */
376 {
379 }
381 {
384 }
386 /* If both args specify argument types, we must merge the two
387 lists, argument by argument. */
388 /* Tell global_bindings_p to return false so that variable_size
389 doesn't abort on VLAs in parameter types. */
402 {
403 /* A null type means arg type is not specified.
404 Take whatever the other function type has. */
406 {
409 }
411 {
414 }
416 /* Given wait (union {union wait *u; int *i} *)
417 and wait (union wait *),
418 prefer union wait * as type of parm. */
421 {
422 tree memb;
426 COMPARE_STRICT))
427 {
432 }
433 }
436 {
437 tree memb;
441 COMPARE_STRICT))
442 {
447 }
448 }
450 parm_done: ;
451 }
455 /* ... falls through ... */
456 }
460 }
462 }
463 \f
464 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
465 or various other operations. Return 2 if they are compatible
466 but a warning may be needed if you use them together. */
468 int
470 {
475 /* Suppress errors caused by previously reported errors. */
481 /* If either type is the internal version of sizetype, return the
482 language version. */
492 /* Enumerated types are compatible with integer types, but this is
493 not transitive: two enumerated types in the same translation unit
494 are compatible with each other only if they are the same type. */
504 /* Different classes of types can't be compatible. */
508 /* Qualifiers must match. */
513 /* Allow for two different type nodes which have essentially the same
514 definition. Note that we already checked for equality of the type
515 qualifiers (just above). */
520 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
524 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
528 {
530 /* We must give ObjC the first crack at comparing pointers, since
531 protocol qualifiers may be involved. */
543 {
550 /* Target types must match incl. qualifiers. */
553 flags)))
556 /* Sizes must match unless one is missing or variable. */
563 d1_variable = (! d1_zero
566 d2_variable = (! d2_zero
580 }
583 /* We are dealing with two distinct structs. In assorted Objective-C
584 corner cases, however, these can still be deemed equivalent. */
601 }
603 }
605 /* Return 1 if TTL and TTR are pointers to types that are equivalent,
606 ignoring their qualifiers. REFLEXIVE is only used by ObjC - set it
607 to 1 or 0 depending if the check of the pointer types is meant to
608 be reflexive or not (typically, assignments are not reflexive,
609 while comparisons are reflexive).
610 */
612 static int
614 {
617 /* Give objc_comptypes a crack at letting these types through. */
627 }
628 \f
629 /* Subroutines of `comptypes'. */
631 /* Determine whether two trees derive from the same translation unit.
632 If the CONTEXT chain ends in a null, that tree's context is still
633 being parsed, so if two trees have context chains ending in null,
634 they're in the same translation unit. */
635 int
637 {
640 {
645 }
649 {
654 }
657 }
659 /* The C standard says that two structures in different translation
660 units are compatible with each other only if the types of their
661 fields are compatible (among other things). So, consider two copies
662 of this structure: */
666 tree t1;
667 tree t2;
668 };
670 /* Can they be compatible with each other? We choose to break the
671 recursion by allowing those types to be compatible. */
675 /* Return 1 if two 'struct', 'union', or 'enum' types T1 and T2 are
676 compatible. If the two types are not the same (which has been
677 checked earlier), this can only happen when multiple translation
678 units are being compiled. See C99 6.2.7 paragraph 1 for the exact
679 rules. */
681 static int
683 {
687 /* We have to verify that the tags of the types are the same. This
688 is harder than it looks because this may be a typedef, so we have
689 to go look at the original type. It may even be a typedef of a
690 typedef...
691 In the case of compiler-created builtin structs the TYPE_DECL
692 may be a dummy, with no DECL_ORIGINAL_TYPE. Don't fault. */
703 /* C90 didn't have the requirement that the two tags be the same. */
707 /* C90 didn't say what happened if one or both of the types were
708 incomplete; we choose to follow C99 rules here, which is that they
709 are compatible. */
714 {
719 }
722 {
724 {
726 /* Speed up the case where the type values are in the same order. */
734 {
739 }
750 {
755 }
757 }
760 {
765 {
777 {
792 }
796 }
798 }
801 {
812 {
827 }
832 }
836 }
837 }
839 /* Return 1 if two function types F1 and F2 are compatible.
840 If either type specifies no argument types,
841 the other must specify a fixed number of self-promoting arg types.
842 Otherwise, if one type specifies only the number of arguments,
843 the other must specify that number of self-promoting arg types.
844 Otherwise, the argument types must match. */
846 static int
848 {
850 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
858 /* 'volatile' qualifiers on a function's return type mean the function
859 is noreturn. */
875 /* An unspecified parmlist matches any specified parmlist
876 whose argument types don't need default promotions. */
879 {
882 /* If one of these types comes from a non-prototype fn definition,
883 compare that with the other type's arglist.
884 If they don't match, ask for a warning (but no error). */
887 flags))
890 }
892 {
897 flags))
900 }
902 /* Both types have argument lists: compare them and propagate results. */
905 }
907 /* Check two lists of types for compatibility,
908 returning 0 for incompatible, 1 for compatible,
909 or 2 for compatible with warning. */
911 static int
913 {
914 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
919 {
922 /* If one list is shorter than the other,
923 they fail to match. */
926 /* A null pointer instead of a type
927 means there is supposed to be an argument
928 but nothing is specified about what type it has.
929 So match anything that self-promotes. */
931 {
934 }
936 {
939 }
940 /* If one of the lists has an error marker, ignore this arg. */
943 ;
946 flags)))
947 {
948 /* Allow wait (union {union wait *u; int *i} *)
949 and wait (union wait *) to be compatible. */
956 {
957 tree memb;
961 flags))
965 }
972 {
973 tree memb;
977 flags))
981 }
982 else
984 }
986 /* comptypes said ok, but record if it said to warn. */
992 }
993 }
994 \f
995 /* Compute the size to increment a pointer by. */
997 tree
999 {
1006 {
1009 }
1011 /* Convert in case a char is more than one unit. */
1015 }
1016 \f
1017 /* Return either DECL or its known constant value (if it has one). */
1019 tree
1021 {
1023 in a place where a variable is invalid. Note that DECL_INITIAL
1024 isn't valid for a PARM_DECL. */
1031 /* This is invalid if initial value is not constant.
1032 If it has either a function call, a memory reference,
1033 or a variable, then re-evaluating it could give different results. */
1035 /* Check for cases where this is sub-optimal, even though valid. */
1039 }
1041 /* Return either DECL or its known constant value (if it has one), but
1042 return DECL if pedantic or DECL has mode BLKmode. This is for
1043 bug-compatibility with the old behavior of decl_constant_value
1044 (before GCC 3.0); every use of this function is a bug and it should
1045 be removed before GCC 3.1. It is not appropriate to use pedantic
1046 in a way that affects optimization, and BLKmode is probably not the
1047 right test for avoiding misoptimizations either. */
1049 static tree
1051 {
1054 else
1056 }
1059 /* Perform the default conversion of arrays and functions to pointers.
1060 Return the result of converting EXP. For any other expression, just
1061 return EXP. */
1063 static tree
1065 {
1066 tree orig_exp;
1071 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
1072 an lvalue.
1074 Do not use STRIP_NOPS here! It will remove conversions from pointer
1075 to integer and cause infinite recursion. */
1080 {
1084 }
1086 /* Preserve the original expression code. */
1091 {
1093 }
1095 {
1096 tree adr;
1098 tree ptrtype;
1104 {
1107 }
1110 restype
1121 {
1125 }
1129 {
1130 /* Before C99, non-lvalue arrays do not decay to pointers.
1131 Normally, using such an array would be invalid; but it can
1132 be used correctly inside sizeof or as a statement expression.
1133 Thus, do not give an error here; an error will result later. */
1135 }
1140 {
1141 /* ??? This is not really quite correct
1142 in that the type of the operand of ADDR_EXPR
1143 is not the target type of the type of the ADDR_EXPR itself.
1144 Question is, can this lossage be avoided? */
1150 }
1151 /* This way is better for a COMPONENT_REF since it can
1152 simplify the offset for a component. */
1155 }
1157 }
1159 /* Perform default promotions for C data used in expressions.
1160 Arrays and functions are converted to pointers;
1161 enumeral types or short or char, to int.
1162 In addition, manifest constants symbols are replaced by their values. */
1164 tree
1166 {
1167 tree orig_exp;
1174 /* Constants can be used directly unless they're not loadable. */
1178 /* Replace a nonvolatile const static variable with its value unless
1179 it is an array, in which case we must be sure that taking the
1180 address of the array produces consistent results. */
1182 {
1185 }
1187 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
1188 an lvalue.
1190 Do not use STRIP_NOPS here! It will remove conversions from pointer
1191 to integer and cause infinite recursion. */
1198 /* Preserve the original expression code. */
1202 /* Normally convert enums to int,
1203 but convert wide enums to something wider. */
1205 {
1213 }
1217 /* If it's thinner than an int, promote it like a
1218 c_promoting_integer_type_p, otherwise leave it alone. */
1224 {
1225 /* Preserve unsignedness if not really getting any wider. */
1231 }
1234 {
1237 }
1239 }
1240 \f
1241 /* Look up COMPONENT in a structure or union DECL.
1243 If the component name is not found, returns NULL_TREE. Otherwise,
1244 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL
1245 stepping down the chain to the component, which is in the last
1246 TREE_VALUE of the list. Normally the list is of length one, but if
1247 the component is embedded within (nested) anonymous structures or
1248 unions, the list steps down the chain to the component. */
1250 static tree
1252 {
1254 tree field;
1256 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers
1257 to the field elements. Use a binary search on this array to quickly
1258 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC
1259 will always be set for structures which have many elements. */
1262 {
1270 {
1275 {
1276 /* Step through all anon unions in linear fashion. */
1278 {
1282 {
1287 }
1288 }
1290 /* Entire record is only anon unions. */
1294 /* Restart the binary search, with new lower bound. */
1296 }
1302 else
1304 }
1310 }
1311 else
1312 {
1314 {
1318 {
1323 }
1327 }
1331 }
1334 }
1336 /* Make an expression to refer to the COMPONENT field of
1337 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */
1339 tree
1341 {
1345 tree ref;
1347 /* If DATUM is a COMPOUND_EXPR, move our reference inside it.
1348 Ensure that the arguments are not lvalues; otherwise,
1349 if the component is an array, it would wrongly decay to a pointer in
1350 C89 mode.
1351 We cannot do this with a COND_EXPR, because in a conditional expression
1352 the default promotions are applied to both sides, and this would yield
1353 the wrong type of the result; for example, if the components have
1354 type "char". */
1356 {
1358 {
1362 }
1365 }
1367 /* See if there is a field or component with name COMPONENT. */
1370 {
1372 {
1375 }
1380 {
1385 }
1387 /* Chain the COMPONENT_REFs if necessary down to the FIELD.
1388 This might be better solved in future the way the C++ front
1389 end does it - by giving the anonymous entities each a
1390 separate name and type, and then have build_component_ref
1391 recursively call itself. We can't do that here. */
1392 do
1393 {
1411 }
1415 }
1421 }
1422 \f
1423 /* Given an expression PTR for a pointer, return an expression
1424 for the value pointed to.
1425 ERRORSTRING is the name of the operator to appear in error messages. */
1427 tree
1429 {
1434 {
1439 else
1440 {
1445 {
1448 }
1452 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
1453 so that we get the proper error message if the result is used
1454 to assign to. Also, &* is supposed to be a no-op.
1455 And ANSI C seems to specify that the type of the result
1456 should be the const type. */
1457 /* A de-reference of a pointer to const is not a const. It is valid
1458 to change it via some other pointer. */
1464 }
1465 }
1469 }
1471 /* This handles expressions of the form "a[i]", which denotes
1472 an array reference.
1474 This is logically equivalent in C to *(a+i), but we may do it differently.
1475 If A is a variable or a member, we generate a primitive ARRAY_REF.
1476 This avoids forcing the array out of registers, and can work on
1477 arrays that are not lvalues (for example, members of structures returned
1478 by functions). */
1480 tree
1482 {
1484 {
1487 }
1494 {
1497 /* Subscripting with type char is likely to lose
1498 on a machine where chars are signed.
1499 So warn on any machine, but optionally.
1500 Don't warn for unsigned char since that type is safe.
1501 Don't warn for signed char because anyone who uses that
1502 must have done so deliberately. */
1507 /* Apply default promotions *after* noticing character types. */
1510 /* Require integer *after* promotion, for sake of enums. */
1512 {
1515 }
1517 /* An array that is indexed by a non-constant
1518 cannot be stored in a register; we must be able to do
1519 address arithmetic on its address.
1520 Likewise an array of elements of variable size. */
1524 {
1527 }
1528 /* An array that is indexed by a constant value which is not within
1529 the array bounds cannot be stored in a register either; because we
1530 would get a crash in store_bit_field/extract_bit_field when trying
1531 to access a non-existent part of the register. */
1535 {
1538 }
1541 {
1549 }
1553 /* Array ref is const/volatile if the array elements are
1554 or if the array is. */
1563 /* This was added by rms on 16 Nov 91.
1564 It fixes vol struct foo *a; a->elts[1]
1565 in an inline function.
1566 Hope it doesn't break something else. */
1569 }
1571 {
1575 /* Do the same warning check as above, but only on the part that's
1576 syntactically the index and only if it is also semantically
1577 the index. */
1583 /* Put the integer in IND to simplify error checking. */
1585 {
1589 }
1596 {
1599 }
1601 {
1604 }
1608 }
1609 }
1610 \f
1611 /* Build an external reference to identifier ID. FUN indicates
1612 whether this will be used for a function call. */
1613 tree
1615 {
1616 tree ref;
1621 {
1622 /* Properly declared variable or function reference. */
1626 {
1630 }
1631 else
1633 }
1637 /* Implicit function declaration. */
1640 /* Don't complain about something that's already been
1641 complained about. */
1643 else
1644 {
1647 }
1660 {
1664 }
1670 {
1675 }
1678 }
1680 /* Build a function call to function FUNCTION with parameters PARAMS.
1681 PARAMS is a list--a chain of TREE_LIST nodes--in which the
1682 TREE_VALUE of each node is a parameter-expression.
1683 FUNCTION's data type may be a function type or a pointer-to-function. */
1685 tree
1687 {
1689 tree coerced_params;
1691 tree tem;
1693 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
1696 /* Convert anything with function type to a pointer-to-function. */
1698 {
1701 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
1702 (because calling an inline function does not mean the function
1703 needs to be separately compiled). */
1709 }
1710 else
1720 {
1723 }
1728 /* fntype now gets the type of function pointed to. */
1731 /* Check that the function is called through a compatible prototype.
1732 If it is not, replace the call by a trap, wrapped up in a compound
1733 expression if necessary. This has the nice side-effect to prevent
1734 the tree-inliner from generating invalid assignment trees which may
1735 blow up in the RTL expander later.
1737 ??? This doesn't work for Objective-C because objc_comptypes
1738 refuses to compare function prototypes, yet the compiler appears
1739 to build calls that are flagged as invalid by C's comptypes. */
1745 {
1748 NULL_TREE);
1750 /* This situation leads to run-time undefined behavior. We can't,
1751 therefore, simply error unless we can prove that all possible
1752 executions of the program must execute the code. */
1755 /* We can, however, treat "undefined" any way we please.
1756 Call abort to encourage the user to fix the program. */
1761 else
1762 {
1763 tree rhs;
1768 NULL_TREE));
1769 else
1773 }
1774 }
1776 /* Convert the parameters to the types declared in the
1777 function prototype, or apply default promotions. */
1779 coerced_params
1782 /* Check that the arguments to the function are valid. */
1786 /* Recognize certain built-in functions so we can make tree-codes
1787 other than CALL_EXPR. We do this when it enables fold-const.c
1788 to do something useful. */
1793 {
1798 }
1808 }
1809 \f
1810 /* Convert the argument expressions in the list VALUES
1811 to the types in the list TYPELIST. The result is a list of converted
1812 argument expressions.
1814 If TYPELIST is exhausted, or when an element has NULL as its type,
1815 perform the default conversions.
1817 PARMLIST is the chain of parm decls for the function being called.
1818 It may be 0, if that info is not available.
1819 It is used only for generating error messages.
1821 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
1823 This is also where warnings about wrong number of args are generated.
1825 Both VALUES and the returned value are chains of TREE_LIST nodes
1826 with the elements of the list in the TREE_VALUE slots of those nodes. */
1828 static tree
1830 {
1835 /* Scan the given expressions and types, producing individual
1836 converted arguments and pushing them on RESULT in reverse order. */
1839 valtail;
1841 {
1846 {
1850 else
1853 }
1855 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
1856 /* Do not use STRIP_NOPS here! We do not want an enumerator with value 0
1857 to convert automatically to a pointer. */
1866 {
1867 /* Formal parm type is specified by a function prototype. */
1868 tree parmval;
1871 {
1874 }
1875 else
1876 {
1877 /* Optionally warn about conversions that
1878 differ from the default conversions. */
1880 {
1885 warn_for_assignment ("%s as integer rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1888 warn_for_assignment ("%s as integer rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1891 warn_for_assignment ("%s as complex rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1894 warn_for_assignment ("%s as floating rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1897 warn_for_assignment ("%s as complex rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1900 warn_for_assignment ("%s as floating rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1901 /* ??? At some point, messages should be written about
1902 conversions between complex types, but that's too messy
1903 to do now. */
1906 {
1907 /* Warn if any argument is passed as `float',
1908 since without a prototype it would be `double'. */
1910 warn_for_assignment ("%s as `float' rather than `double' due to prototype", (char *) 0, name, parmnum + 1);
1911 }
1912 /* Detect integer changing in width or signedness.
1913 These warnings are only activated with
1914 -Wconversion, not with -Wtraditional. */
1917 {
1924 /* No warning if function asks for enum
1925 and the actual arg is that enum type. */
1926 ;
1928 warn_for_assignment ("%s with different width due to prototype", (char *) 0, name, parmnum + 1);
1930 ;
1931 /* Don't complain if the formal parameter type
1932 is an enum, because we can't tell now whether
1933 the value was an enum--even the same enum. */
1935 ;
1938 /* Change in signedness doesn't matter
1939 if a constant value is unaffected. */
1940 ;
1941 /* Likewise for a constant in a NOP_EXPR. */
1945 ;
1946 /* If the value is extended from a narrower
1947 unsigned type, it doesn't matter whether we
1948 pass it as signed or unsigned; the value
1949 certainly is the same either way. */
1952 ;
1955 else
1957 }
1958 }
1968 }
1970 }
1974 /* Convert `float' to `double'. */
1976 else
1977 /* Convert `short' and `char' to full-size `int'. */
1982 }
1985 {
1989 else
1991 }
1994 }
1995 \f
1996 /* This is the entry point used by the parser
1997 for binary operators in the input.
1998 In addition to constructing the expression,
1999 we check for operands that were written with other binary operators
2000 in a way that is likely to confuse the user. */
2002 tree
2004 {
2021 /* Check for cases such as x+y<<z which users are likely
2022 to misinterpret. If parens are used, C_EXP_ORIGINAL_CODE
2023 is cleared to prevent these warnings. */
2025 {
2027 {
2031 }
2034 {
2038 }
2041 {
2047 /* Check cases like x|y==z */
2050 }
2053 {
2059 /* Check cases like x^y==z */
2062 }
2065 {
2069 /* Check cases like x&y==z */
2072 }
2073 }
2075 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */
2086 /* Record the code that was specified in the source,
2087 for the sake of warnings about confusing nesting. */
2090 else
2091 {
2092 /* We used to use NOP_EXPR rather than NON_LVALUE_EXPR
2093 so that convert_for_assignment wouldn't strip it.
2094 That way, we got warnings for things like p = (1 - 1).
2095 But it turns out we should not get those warnings. */
2098 }
2101 }
2102 \f
2104 /* Return true if `t' is known to be non-negative. */
2106 int
2108 {
2110 {
2113 /* Find the last statement in the chain, ignoring the final
2114 * scope statement */
2119 }
2121 }
2123 /* Return a tree for the difference of pointers OP0 and OP1.
2124 The resulting tree has type int. */
2126 static tree
2128 {
2136 {
2141 }
2143 /* If the conversion to ptrdiff_type does anything like widening or
2144 converting a partial to an integral mode, we get a convert_expression
2145 that is in the way to do any simplifications.
2146 (fold-const.c doesn't know that the extra bits won't be needed.
2147 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2148 different mode in place.)
2149 So first try to find a common term here 'by hand'; we want to cover
2150 at least the cases that occur in legal static initializers. */
2155 {
2158 }
2159 else
2163 {
2166 }
2167 else
2171 {
2174 }
2177 /* First do the subtraction as integers;
2178 then drop through to build the divide operator.
2179 Do not do default conversions on the minus operator
2180 in case restype is a short type. */
2184 /* This generates an error if op1 is pointer to incomplete type. */
2188 /* This generates an error if op0 is pointer to incomplete type. */
2191 /* Divide by the size, in easiest possible way. */
2193 }
2194 \f
2195 /* Construct and perhaps optimize a tree representation
2196 for a unary operation. CODE, a tree_code, specifies the operation
2197 and XARG is the operand.
2198 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2199 the default promotions (such as from short to int).
2200 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2201 allows non-lvalues; this is only used to handle conversion of non-lvalue
2202 arrays to pointers in C99. */
2204 tree
2206 {
2207 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2211 tree val;
2220 {
2222 /* This is used for unary plus, because a CONVERT_EXPR
2223 is enough to prevent anybody from looking inside for
2224 associativity, but won't generate any code. */
2227 {
2230 }
2240 {
2243 }
2250 {
2253 }
2255 {
2261 }
2262 else
2263 {
2266 }
2271 {
2274 }
2280 /* Conjugating a real value is a no-op, but allow it anyway. */
2283 {
2286 }
2295 /* These will convert to a pointer. */
2297 {
2300 }
2312 else
2320 else
2328 /* Increment or decrement the real part of the value,
2329 and don't change the imaginary part. */
2331 {
2342 }
2344 /* Report invalid types. */
2348 {
2351 else
2355 }
2357 {
2358 tree inc;
2364 /* Compute the increment. */
2367 {
2368 /* If pointer target is an undefined struct,
2369 we just cannot know how to do the arithmetic. */
2371 {
2374 else
2376 }
2380 {
2383 else
2385 }
2388 }
2389 else
2394 /* Complain about anything else that is not a true lvalue. */
2401 /* Report a read-only lvalue. */
2410 else
2417 }
2420 /* Note that this operation never does default_conversion. */
2422 /* Let &* cancel out to simplify resulting code. */
2424 {
2425 /* Don't let this be an lvalue. */
2429 }
2431 /* For &x[y], return x+y */
2433 {
2438 }
2440 /* Anything not already handled and not a true memory reference
2441 or a non-lvalue array is an error. */
2446 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
2449 /* If the lvalue is const or volatile, merge that into the type
2450 to which the address will point. Note that you can't get a
2451 restricted pointer by taking the address of something, so we
2452 only have to deal with `const' and `volatile' here. */
2464 {
2465 tree addr;
2468 {
2474 {
2478 }
2483 }
2484 else
2488 }
2492 }
2497 }
2499 /* Return nonzero if REF is an lvalue valid for this language.
2500 Lvalues can be assigned, unless their type has TYPE_READONLY.
2501 Lvalues can have their address taken, unless they have C_DECL_REGISTER. */
2503 int
2505 {
2509 {
2534 }
2535 }
2537 /* Return nonzero if REF is an lvalue valid for this language;
2538 otherwise, print an error message and return zero. */
2540 int
2542 {
2549 }
2551 \f
2552 /* Warn about storing in something that is `const'. */
2554 void
2556 {
2558 {
2561 else
2564 }
2568 else
2570 }
2571 \f
2572 /* Mark EXP saying that we need to be able to take the
2573 address of it; it should not be allocated in a register.
2574 Returns true if successful. */
2576 bool
2578 {
2583 {
2586 {
2590 }
2592 /* ... fall through ... */
2612 {
2614 {
2618 }
2621 }
2623 {
2625 {
2629 }
2633 }
2636 /* drops in */
2639 /* drops out */
2642 }
2643 }
2644 \f
2645 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
2647 tree
2649 {
2650 tree type1;
2651 tree type2;
2659 /* Promote both alternatives. */
2676 /* C90 does not permit non-lvalue arrays in conditional expressions.
2677 In C99 they will be pointers by now. */
2679 {
2682 }
2684 /* Quickly detect the usual case where op1 and op2 have the same type
2685 after promotion. */
2687 {
2690 else
2692 }
2697 {
2700 /* If -Wsign-compare, warn here if type1 and type2 have
2701 different signedness. We'll promote the signed to unsigned
2702 and later code won't know it used to be different.
2703 Do this check on the original types, so that explicit casts
2704 will be considered, but default promotions won't. */
2706 {
2711 {
2712 /* Do not warn if the result type is signed, since the
2713 signed type will only be chosen if it can represent
2714 all the values of the unsigned type. */
2717 /* Do not warn if the signed quantity is an unsuffixed
2718 integer literal (or some static constant expression
2719 involving such literals) and it is non-negative. */
2723 else
2725 }
2726 }
2727 }
2729 {
2733 }
2735 {
2745 {
2750 }
2752 {
2757 }
2758 else
2759 {
2762 }
2763 }
2765 {
2768 else
2769 {
2771 }
2773 }
2775 {
2778 else
2779 {
2781 }
2783 }
2786 {
2789 else
2790 {
2793 }
2794 }
2796 /* Merge const and volatile flags of the incoming types. */
2797 result_type
2811 }
2812 \f
2813 /* Given a list of expressions, return a compound expression
2814 that performs them all and returns the value of the last of them. */
2816 tree
2818 {
2820 }
2822 static tree
2824 {
2825 tree rest;
2828 {
2829 /* Convert arrays and functions to pointers when there
2830 really is a comma operator. */
2835 /* Don't let (0, 0) be null pointer constant. */
2839 }
2844 {
2845 /* The left-hand operand of a comma expression is like an expression
2846 statement: with -Wextra or -Wunused, we should warn if it doesn't have
2847 any side-effects, unless it was explicitly cast to (void). */
2852 }
2854 /* With -Wunused, we should also warn if the left-hand operand does have
2855 side-effects, but computes a value which is not used. For example, in
2856 `foo() + bar(), baz()' the result of the `+' operator is not used,
2857 so we should issue a warning. */
2862 }
2864 /* Build an expression representing a cast to type TYPE of expression EXPR. */
2866 tree
2868 {
2874 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
2875 only in <protocol> qualifications. But when constructing cast expressions,
2876 the protocols do matter and must be kept around. */
2881 {
2884 }
2887 {
2890 }
2893 {
2895 {
2899 }
2900 }
2902 {
2903 tree field;
2912 {
2913 tree t;
2924 }
2927 }
2928 else
2929 {
2932 /* If casting to void, avoid the error that would come
2933 from default_conversion in the case of a non-lvalue array. */
2937 /* Convert functions and arrays to pointers,
2938 but don't convert any other types. */
2942 /* Optionally warn about potentially worrisome casts. */
2947 {
2953 /* Check that the qualifiers on IN_TYPE are a superset of
2954 the qualifiers of IN_OTYPE. The outermost level of
2955 POINTER_TYPE nodes is uninteresting and we stop as soon
2956 as we hit a non-POINTER_TYPE node on either type. */
2957 do
2958 {
2962 /* GNU C allows cv-qualified function types. 'const'
2963 means the function is very pure, 'volatile' means it
2964 can't return. We need to warn when such qualifiers
2965 are added, not when they're taken away. */
2969 else
2971 }
2979 /* There are qualifiers present in IN_OTYPE that are not
2980 present in IN_TYPE. */
2982 }
2984 /* Warn about possible alignment problems. */
2990 /* Don't warn about opaque types, where the actual alignment
2991 restriction is unknown. */
3012 /* Don't warn about converting any constant. */
3022 {
3023 /* Casting the address of a decl to non void pointer. Warn
3024 if the cast breaks type based aliasing. */
3027 else
3028 {
3037 }
3038 }
3040 /* If pedantic, warn for conversions between function and object
3041 pointer types, except for converting a null pointer constant
3042 to function pointer type. */
3060 /* Replace a nonvolatile const static variable with its value. */
3065 /* Ignore any integer overflow caused by the cast. */
3067 {
3072 }
3073 }
3075 /* Don't let (void *) (FOO *) 0 be a null pointer constant. */
3081 /* Don't let a cast be an lvalue. */
3086 }
3088 /* Interpret a cast of expression EXPR to type TYPE. */
3089 tree
3091 {
3094 /* This avoids warnings about unprototyped casts on
3095 integers. E.g. "#define SIG_DFL (void(*)())0". */
3102 }
3104 \f
3105 /* Build an assignment expression of lvalue LHS from value RHS.
3106 MODIFYCODE is the code for a binary operator that we use
3107 to combine the old value of LHS with RHS to get the new value.
3108 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3110 tree
3112 {
3113 tree result;
3114 tree newrhs;
3118 /* Types that aren't fully specified cannot be used in assignments. */
3121 /* Avoid duplicate error messages from operands that had errors. */
3125 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3126 /* Do not use STRIP_NOPS here. We do not want an enumerator
3127 whose value is 0 to count as a null pointer constant. */
3133 /* If a binary op has been requested, combine the old LHS value with the RHS
3134 producing the value we should actually store into the LHS. */
3137 {
3140 }
3145 /* Warn about storing in something that is `const'. */
3153 /* If storing into a structure or union member,
3154 it has probably been given type `int'.
3155 Compute the type that would go with
3156 the actual amount of storage the member occupies. */
3165 /* If storing in a field that is in actuality a short or narrower than one,
3166 we must store in the field in its actual type. */
3169 {
3172 }
3174 /* Convert new value to destination type. */
3181 /* Scan operands */
3186 /* If we got the LHS in a different type for storing in,
3187 convert the result back to the nominal type of LHS
3188 so that the value we return always has the same type
3189 as the LHS argument. */
3195 }
3196 \f
3197 /* Convert value RHS to type TYPE as preparation for an assignment
3198 to an lvalue of type TYPE.
3199 The real work of conversion is done by `convert'.
3200 The purpose of this function is to generate error messages
3201 for assignments that are not allowed in C.
3202 ERRTYPE is a string to use in error messages:
3203 "assignment", "return", etc. If it is null, this is parameter passing
3204 for a function call (and different error messages are output).
3206 FUNNAME is the name of the function being called,
3207 as an IDENTIFIER_NODE, or null.
3208 PARMNUM is the number of the argument, for printing in error messages. */
3210 static tree
3213 {
3215 tree rhstype;
3218 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3219 /* Do not use STRIP_NOPS here. We do not want an enumerator
3220 whose value is 0 to count as a null pointer constant. */
3237 {
3239 /* Check for Objective-C protocols. This will automatically
3240 issue a warning if there are protocol violations. No need to
3241 use the return value. */
3245 }
3248 {
3251 }
3252 /* A type converts to a reference to it.
3253 This code doesn't fully support references, it's just for the
3254 special case of va_start and va_copy. */
3257 {
3259 {
3262 }
3267 /* We already know that these two types are compatible, but they
3268 may not be exactly identical. In fact, `TREE_TYPE (type)' is
3269 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
3270 likely to be va_list, a typedef to __builtin_va_list, which
3271 is different enough that it will cause problems later. */
3277 }
3278 /* Some types can interconvert without explicit casts. */
3282 /* Arithmetic types all interconvert, and enum is treated like int. */
3291 /* Conversion to a transparent union from its member types.
3292 This applies only to function arguments. */
3294 {
3295 tree memb_types;
3300 {
3311 {
3315 /* Any non-function converts to a [const][volatile] void *
3316 and vice versa; otherwise, targets must be the same.
3317 Meanwhile, the lhs target must have all the qualifiers of
3318 the rhs. */
3321 {
3322 /* If this type won't generate any warnings, use it. */
3332 /* Keep looking for a better type, but remember this one. */
3335 }
3336 }
3338 /* Can convert integer zero to any pointer type. */
3342 {
3345 }
3346 }
3349 {
3351 {
3352 /* We have only a marginally acceptable member type;
3353 it needs a warning. */
3357 /* Const and volatile mean something different for function
3358 types, so the usual warnings are not appropriate. */
3361 {
3362 /* Because const and volatile on functions are
3363 restrictions that say the function will not do
3364 certain things, it is okay to use a const or volatile
3365 function where an ordinary one is wanted, but not
3366 vice-versa. */
3370 }
3374 parmnum);
3375 }
3381 }
3382 }
3384 /* Conversions among pointers */
3387 {
3393 /* Opaque pointers are treated like void pointers. */
3399 /* Any non-function converts to a [const][volatile] void *
3400 and vice versa; otherwise, targets must be the same.
3401 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
3404 || is_opaque_pointer
3407 {
3410 ||
3412 /* Check TREE_CODE to catch cases like (void *) (char *) 0
3413 which are not ANSI null ptr constants. */
3418 /* Const and volatile mean something different for function types,
3419 so the usual warnings are not appropriate. */
3422 {
3426 /* If this is not a case of ignoring a mismatch in signedness,
3427 no warning. */
3430 ;
3431 /* If there is a mismatch, do warn. */
3435 }
3438 {
3439 /* Because const and volatile on functions are restrictions
3440 that say the function will not do certain things,
3441 it is okay to use a const or volatile function
3442 where an ordinary one is wanted, but not vice-versa. */
3446 }
3447 }
3448 else
3452 }
3454 {
3457 }
3459 {
3460 /* An explicit constant 0 can convert to a pointer,
3461 or one that results from arithmetic, even including
3462 a cast to integer type. */
3464 &&
3473 }
3475 {
3479 }
3484 {
3486 {
3492 else
3495 }
3496 else
3498 parmnum);
3499 }
3500 else
3504 }
3506 /* Convert VALUE for assignment into inlined parameter PARM. ARGNUM
3507 is used for error and waring reporting and indicates which argument
3508 is being processed. */
3510 tree
3512 {
3515 /* If FN was prototyped, the value has been converted already
3516 in convert_arguments. */
3529 }
3531 /* Print a warning using MSGID.
3532 It gets OPNAME as its one parameter.
3533 if OPNAME is null and ARGNUM is 0, it is replaced by "passing arg of `FUNCTION'".
3534 Otherwise if OPNAME is null, it is replaced by "passing arg ARGNUM of `FUNCTION'".
3535 FUNCTION and ARGNUM are handled specially if we are building an
3536 Objective-C selector. */
3538 static void
3541 {
3543 {
3548 {
3551 }
3553 {
3555 {
3556 /* Function name is known; supply it. */
3562 }
3563 else
3564 {
3565 /* Function name unknown (call through ptr). */
3569 }
3570 }
3572 {
3573 /* Function name is known; supply it. */
3579 }
3580 else
3581 {
3582 /* Function name unknown (call through ptr); just give arg number. */
3586 }
3588 }
3590 }
3591 \f
3592 /* If VALUE is a compound expr all of whose expressions are constant, then
3593 return its value. Otherwise, return error_mark_node.
3595 This is for handling COMPOUND_EXPRs as initializer elements
3596 which is allowed with a warning when -pedantic is specified. */
3598 static tree
3600 {
3602 {
3607 endtype);
3608 }
3612 else
3614 }
3615 \f
3616 /* Perform appropriate conversions on the initial value of a variable,
3617 store it in the declaration DECL,
3618 and print any error messages that are appropriate.
3619 If the init is invalid, store an ERROR_MARK. */
3621 void
3623 {
3626 /* If variable's type was invalidly declared, just ignore it. */
3632 /* Digest the specified initializer into an expression. */
3636 /* Store the expression if valid; else report error. */
3644 /* ANSI wants warnings about out-of-range constant initializers. */
3648 /* Check if we need to set array size from compound literal size. */
3652 {
3660 {
3664 {
3665 /* For int foo[] = (int [3]){1}; we need to set array size
3666 now since later on array initializer will be just the
3667 brace enclosed list of the compound literal. */
3671 }
3672 }
3673 }
3674 }
3675 \f
3676 /* Methods for storing and printing names for error messages. */
3678 /* Implement a spelling stack that allows components of a name to be pushed
3679 and popped. Each element on the stack is this structure. */
3681 struct spelling
3682 {
3684 union
3685 {
3689 };
3691 #define SPELLING_STRING 1
3692 #define SPELLING_MEMBER 2
3693 #define SPELLING_BOUNDS 3
3699 /* Macros to save and restore the spelling stack around push_... functions.
3700 Alternative to SAVE_SPELLING_STACK. */
3702 #define SPELLING_DEPTH() (spelling - spelling_base)
3703 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
3705 /* Push an element on the spelling stack with type KIND and assign VALUE
3706 to MEMBER. */
3708 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
3709 { \
3710 int depth = SPELLING_DEPTH (); \
3711 \
3712 if (depth >= spelling_size) \
3713 { \
3714 spelling_size += 10; \
3715 if (spelling_base == 0) \
3716 spelling_base = xmalloc (spelling_size * sizeof (struct spelling)); \
3717 else \
3718 spelling_base = xrealloc (spelling_base, \
3719 spelling_size * sizeof (struct spelling)); \
3720 RESTORE_SPELLING_DEPTH (depth); \
3721 } \
3722 \
3723 spelling->kind = (KIND); \
3724 spelling->MEMBER = (VALUE); \
3725 spelling++; \
3726 }
3728 /* Push STRING on the stack. Printed literally. */
3730 static void
3732 {
3734 }
3736 /* Push a member name on the stack. Printed as '.' STRING. */
3738 static void
3740 {
3744 }
3746 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
3748 static void
3750 {
3752 }
3754 /* Compute the maximum size in bytes of the printed spelling. */
3756 static int
3758 {
3763 {
3766 else
3768 }
3771 }
3773 /* Print the spelling to BUFFER and return it. */
3777 {
3783 {
3786 }
3787 else
3788 {
3793 ;
3794 }
3797 }
3799 /* Issue an error message for a bad initializer component.
3800 MSGID identifies the message.
3801 The component name is taken from the spelling stack. */
3803 void
3805 {
3812 }
3814 /* Issue a pedantic warning for a bad initializer component.
3815 MSGID identifies the message.
3816 The component name is taken from the spelling stack. */
3818 void
3820 {
3827 }
3829 /* Issue a warning for a bad initializer component.
3830 MSGID identifies the message.
3831 The component name is taken from the spelling stack. */
3833 static void
3835 {
3842 }
3843 \f
3844 /* Digest the parser output INIT as an initializer for type TYPE.
3845 Return a C expression of type TYPE to represent the initial value.
3847 REQUIRE_CONSTANT requests an error if non-constant initializers or
3848 elements are seen. */
3850 static tree
3852 {
3861 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3862 /* Do not use STRIP_NOPS here. We do not want an enumerator
3863 whose value is 0 to count as a null pointer constant. */
3869 /* Initialization of an array of chars from a string constant
3870 optionally enclosed in braces. */
3873 {
3881 {
3889 {
3892 }
3896 {
3899 }
3905 /* Subtract 1 (or sizeof (wchar_t))
3906 because it's ok to ignore the terminating null char
3907 that is counted in the length of the constant. */
3918 }
3919 }
3921 /* Build a VECTOR_CST from a *constant* vector constructor. If the
3922 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
3923 below and handle as a constructor. */
3927 {
3931 COMPARE_STRICT))
3933 else
3935 }
3937 /* Any type can be initialized
3938 from an expression of the same type, optionally with braces. */
3955 {
3957 {
3961 {
3964 }
3965 }
3968 /* Although the types are compatible, we may require a
3969 conversion. */
3974 {
3975 /* As an extension, allow initializing objects with static storage
3976 duration with compound literals (which are then treated just as
3977 the brace enclosed list they contain). */
3980 }
3984 {
3987 }
3992 /* Compound expressions can only occur here if -pedantic or
3993 -pedantic-errors is specified. In the later case, we always want
3994 an error. In the former case, we simply want a warning. */
3997 {
3998 inside_init
4003 else
4007 }
4010 /* This test catches things like `7 / 0' which
4011 result in an expression for which TREE_CONSTANT
4012 is true, but which is not actually something
4013 that is a legal constant. We really should not
4014 be using this function, because it is a part of
4015 the back-end. Instead, the expression should
4016 already have been turned into ERROR_MARK_NODE. */
4019 {
4022 }
4025 }
4027 /* Handle scalar types, including conversions. */
4032 {
4033 /* Note that convert_for_assignment calls default_conversion
4034 for arrays and functions. We must not call it in the
4035 case where inside_init is a null pointer constant. */
4036 inside_init
4041 {
4044 }
4047 {
4050 }
4053 }
4055 /* Come here only for records and arrays. */
4058 {
4061 }
4065 }
4066 \f
4067 /* Handle initializers that use braces. */
4069 /* Type of object we are accumulating a constructor for.
4070 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4073 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4074 left to fill. */
4077 /* For an ARRAY_TYPE, this is the specified index
4078 at which to store the next element we get. */
4081 /* For an ARRAY_TYPE, this is the maximum index. */
4084 /* For a RECORD_TYPE, this is the first field not yet written out. */
4087 /* For an ARRAY_TYPE, this is the index of the first element
4088 not yet written out. */
4091 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4092 This is so we can generate gaps between fields, when appropriate. */
4095 /* If we are saving up the elements rather than allocating them,
4096 this is the list of elements so far (in reverse order,
4097 most recent first). */
4100 /* 1 if constructor should be incrementally stored into a constructor chain,
4101 0 if all the elements should be kept in AVL tree. */
4104 /* 1 if so far this constructor's elements are all compile-time constants. */
4107 /* 1 if so far this constructor's elements are all valid address constants. */
4110 /* 1 if this constructor is erroneous so far. */
4113 /* Structure for managing pending initializer elements, organized as an
4114 AVL tree. */
4116 struct init_node
4117 {
4121 tree purpose;
4122 tree value;
4123 };
4125 /* Tree of pending elements at this constructor level.
4126 These are elements encountered out of order
4127 which belong at places we haven't reached yet in actually
4128 writing the output.
4129 Will never hold tree nodes across GC runs. */
4132 /* The SPELLING_DEPTH of this constructor. */
4135 /* 0 if implicitly pushing constructor levels is allowed. */
4141 /* DECL node for which an initializer is being read.
4142 0 means we are reading a constructor expression
4143 such as (struct foo) {...}. */
4146 /* start_init saves the ASMSPEC arg here for really_start_incremental_init. */
4149 /* Nonzero if this is an initializer for a top-level decl. */
4152 /* Nonzero if there were any member designators in this initializer. */
4155 /* Nesting depth of designator list. */
4158 /* Nonzero if there were diagnosed errors in this designator list. */
4161 \f
4162 /* This stack has a level for each implicit or explicit level of
4163 structuring in the initializer, including the outermost one. It
4164 saves the values of most of the variables above. */
4168 struct constructor_stack
4169 {
4171 tree type;
4172 tree fields;
4173 tree index;
4174 tree max_index;
4175 tree unfilled_index;
4176 tree unfilled_fields;
4177 tree bit_index;
4178 tree elements;
4182 /* If nonzero, this value should replace the entire
4183 constructor at this level. */
4184 tree replacement_value;
4193 };
4197 /* This stack represents designators from some range designator up to
4198 the last designator in the list. */
4200 struct constructor_range_stack
4201 {
4204 tree range_start;
4205 tree index;
4206 tree range_end;
4207 tree fields;
4208 };
4212 /* This stack records separate initializers that are nested.
4213 Nested initializers can't happen in ANSI C, but GNU C allows them
4214 in cases like { ... (struct foo) { ... } ... }. */
4216 struct initializer_stack
4217 {
4219 tree decl;
4223 tree elements;
4230 };
4233 \f
4234 /* Prepare to parse and output the initializer for variable DECL. */
4236 void
4238 {
4266 {
4268 require_constant_elements
4270 /* For a scalar, you can always use any value to initialize,
4271 even within braces. */
4277 }
4278 else
4279 {
4283 }
4296 }
4298 void
4300 {
4303 /* Free the whole constructor stack of this initializer. */
4305 {
4309 }
4314 /* Pop back to the data of the outer initializer (if any). */
4330 }
4331 \f
4332 /* Call here when we see the initializer is surrounded by braces.
4333 This is instead of a call to push_init_level;
4334 it is matched by a call to pop_init_level.
4336 TYPE is the type to initialize, for a constructor expression.
4337 For an initializer for a decl, TYPE is zero. */
4339 void
4341 {
4385 {
4387 /* Skip any nameless bit fields at the beginning. */
4394 }
4396 {
4398 {
4399 constructor_max_index
4402 /* Detect non-empty initializations of zero-length arrays. */
4407 /* constructor_max_index needs to be an INTEGER_CST. Attempts
4408 to initialize VLAs will cause a proper error; avoid tree
4409 checking errors as well by setting a safe value. */
4414 constructor_index
4417 }
4418 else
4422 }
4424 {
4425 /* Vectors are like simple fixed-size arrays. */
4426 constructor_max_index =
4430 }
4431 else
4432 {
4433 /* Handle the case of int x = {5}; */
4436 }
4437 }
4438 \f
4439 /* Push down into a subobject, for initialization.
4440 If this is for an explicit set of braces, IMPLICIT is 0.
4441 If it is because the next element belongs at a lower level,
4442 IMPLICIT is 1 (or 2 if the push is because of designator list). */
4444 void
4446 {
4450 /* If we've exhausted any levels that didn't have braces,
4451 pop them now. */
4453 {
4459 && constructor_max_index
4462 else
4464 }
4466 /* Unless this is an explicit brace, we need to preserve previous
4467 content if any. */
4469 {
4476 }
4509 {
4514 }
4516 /* Don't die if an entire brace-pair level is superfluous
4517 in the containing level. */
4519 ;
4522 {
4523 /* Don't die if there are extra init elts at the end. */
4526 else
4527 {
4530 constructor_depth++;
4531 }
4532 }
4534 {
4537 constructor_depth++;
4538 }
4541 {
4546 }
4549 {
4557 }
4560 {
4563 }
4567 {
4569 /* Skip any nameless bit fields at the beginning. */
4576 }
4578 {
4579 /* Vectors are like simple fixed-size arrays. */
4580 constructor_max_index =
4584 }
4586 {
4588 {
4589 constructor_max_index
4592 /* Detect non-empty initializations of zero-length arrays. */
4597 /* constructor_max_index needs to be an INTEGER_CST. Attempts
4598 to initialize VLAs will cause a proper error; avoid tree
4599 checking errors as well by setting a safe value. */
4604 constructor_index
4607 }
4608 else
4613 {
4614 /* We need to split the char/wchar array into individual
4615 characters, so that we don't have to special case it
4616 everywhere. */
4618 }
4619 }
4620 else
4621 {
4625 }
4626 }
4628 /* At the end of an implicit or explicit brace level,
4629 finish up that level of constructor.
4630 If we were outputting the elements as they are read, return 0
4631 from inner levels (process_init_element ignores that),
4632 but return error_mark_node from the outermost level
4633 (that's what we want to put in DECL_INITIAL).
4634 Otherwise, return a CONSTRUCTOR expression. */
4636 tree
4638 {
4643 {
4644 /* When we come to an explicit close brace,
4645 pop any inner levels that didn't have explicit braces. */
4651 }
4653 /* Now output all pending elements. */
4659 /* Error for initializing a flexible array member, or a zero-length
4660 array member in an inappropriate context. */
4665 {
4666 /* Silently discard empty initializations. The parser will
4667 already have pedwarned for empty brackets. */
4671 {
4677 /* We have already issued an error message for the existence
4678 of a flexible array member not at the end of the structure.
4679 Discard the initializer so that we do not abort later. */
4682 }
4683 else
4684 /* Zero-length arrays are no longer special, so we should no longer
4685 get here. */
4687 }
4689 /* Warn when some struct elements are implicitly initialized to zero. */
4691 && constructor_type
4694 {
4695 /* Do not warn for flexible array members or zero-length arrays. */
4701 /* Do not warn if this level of the initializer uses member
4702 designators; it is likely to be deliberate. */
4704 {
4708 }
4709 }
4711 /* Pad out the end of the structure. */
4713 /* If this closes a superfluous brace pair,
4714 just pass out the element between them. */
4717 ;
4722 {
4723 /* A nonincremental scalar initializer--just return
4724 the element, after verifying there is just one. */
4726 {
4730 }
4732 {
4735 }
4736 else
4738 }
4739 else
4740 {
4743 else
4744 {
4751 }
4752 }
4777 {
4781 }
4783 }
4785 /* Common handling for both array range and field name designators.
4786 ARRAY argument is nonzero for array ranges. Returns zero for success. */
4788 static int
4790 {
4791 tree subtype;
4794 /* Don't die if an entire brace-pair level is superfluous
4795 in the containing level. */
4799 /* If there were errors in this designator list already, bail out silently. */
4804 {
4808 /* Designator list starts at the level of closest explicit
4809 braces. */
4814 }
4817 {
4820 }
4824 {
4828 }
4830 {
4832 }
4833 else
4838 {
4841 }
4843 {
4846 }
4851 }
4853 /* If there are range designators in designator list, push a new designator
4854 to constructor_range_stack. RANGE_END is end of such stack range or
4855 NULL_TREE if there is no range designator at this level. */
4857 static void
4859 {
4873 }
4875 /* Within an array initializer, specify the next index to be initialized.
4876 FIRST is that index. If LAST is nonzero, then initialize a range
4877 of indices, running from FIRST through LAST. */
4879 void
4881 {
4913 else
4914 {
4918 {
4922 {
4925 }
4926 else
4927 {
4931 {
4934 }
4935 }
4936 }
4938 designator_depth++;
4942 }
4943 }
4945 /* Within a struct initializer, specify the next field to be initialized. */
4947 void
4949 {
4950 tree tail;
4959 {
4962 }
4966 {
4969 }
4974 else
4975 {
4977 designator_depth++;
4981 }
4982 }
4983 \f
4984 /* Add a new initializer to the tree of pending initializers. PURPOSE
4985 identifies the initializer, either array index or field in a structure.
4986 VALUE is the value of that index or field. */
4988 static void
4990 {
4997 {
4999 {
5005 else
5006 {
5011 }
5012 }
5013 }
5014 else
5015 {
5016 tree bitpos;
5020 {
5026 else
5027 {
5032 }
5033 }
5034 }
5047 {
5051 {
5055 {
5057 {
5058 /* L rotation. */
5071 {
5074 else
5076 }
5077 else
5079 }
5080 else
5081 {
5082 /* LR rotation. */
5104 {
5107 else
5109 }
5110 else
5112 }
5114 }
5115 else
5116 {
5117 /* p->balance == +1; growth of left side balances the node. */
5120 }
5121 }
5123 {
5125 /* Growth propagation from right side. */
5128 {
5130 {
5131 /* R rotation. */
5144 {
5147 else
5149 }
5150 else
5152 }
5154 {
5155 /* RL rotation */
5177 {
5180 else
5182 }
5183 else
5185 }
5187 }
5188 else
5189 {
5190 /* p->balance == -1; growth of right side balances the node. */
5193 }
5194 }
5198 }
5199 }
5201 /* Build AVL tree from a sorted chain. */
5203 static void
5205 {
5206 tree chain;
5216 {
5218 /* Skip any nameless bit fields at the beginning. */
5224 }
5226 {
5228 constructor_unfilled_index
5231 else
5233 }
5235 }
5237 /* Build AVL tree from a string constant. */
5239 static void
5241 {
5256 else
5267 {
5269 {
5272 }
5273 else
5274 {
5278 {
5281 else
5286 }
5287 }
5290 {
5293 {
5295 {
5298 }
5299 }
5301 {
5304 }
5309 }
5314 }
5317 }
5319 /* Return value of FIELD in pending initializer or zero if the field was
5320 not initialized yet. */
5322 static tree
5324 {
5328 {
5335 {
5340 else
5342 }
5343 }
5345 {
5349 && (!constructor_unfilled_fields
5356 {
5361 else
5363 }
5364 }
5366 {
5370 }
5372 }
5374 /* "Output" the next constructor element.
5375 At top level, really output it to assembler code now.
5376 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
5377 TYPE is the data type that the containing data type wants here.
5378 FIELD is the field (a FIELD_DECL) or the index that this element fills.
5380 PENDING if non-nil means output pending elements that belong
5381 right after this element. (PENDING is normally 1;
5382 it is 0 while outputting pending elements, to avoid recursion.) */
5384 static void
5386 {
5388 {
5391 }
5403 {
5404 /* As an extension, allow initializing objects with static storage
5405 duration with compound literals (which are then treated just as
5406 the brace enclosed list they contain). */
5409 }
5423 {
5426 }
5431 /* If this field is empty (and not at the end of structure),
5432 don't do anything other than checking the initializer. */
5443 {
5446 }
5448 /* If this element doesn't come next in sequence,
5449 put it on constructor_pending_elts. */
5451 && (!constructor_incremental
5453 {
5460 }
5462 && (!constructor_incremental
5464 {
5465 /* We do this for records but not for unions. In a union,
5466 no matter which field is specified, it can be initialized
5467 right away since it starts at the beginning of the union. */
5469 {
5472 else
5473 {
5481 }
5482 }
5486 }
5489 {
5493 /* We can have just one union field set. */
5495 }
5497 /* Otherwise, output this element either to
5498 constructor_elements or to the assembler file. */
5502 constructor_elements
5505 /* Advance the variable that indicates sequential elements output. */
5507 constructor_unfilled_index
5509 bitsize_one_node);
5511 {
5512 constructor_unfilled_fields
5515 /* Skip any nameless bit fields. */
5519 constructor_unfilled_fields =
5521 }
5525 /* Now output any pending elements which have become next. */
5528 }
5530 /* Output any pending elements which have become next.
5531 As we output elements, constructor_unfilled_{fields,index}
5532 advances, which may cause other elements to become next;
5533 if so, they too are output.
5535 If ALL is 0, we return when there are
5536 no more pending elements to output now.
5538 If ALL is 1, we output space as necessary so that
5539 we can output all the pending elements. */
5541 static void
5543 {
5545 tree next;
5547 retry:
5549 /* Look through the whole pending tree.
5550 If we find an element that should be output now,
5551 output it. Otherwise, set NEXT to the element
5552 that comes first among those still pending. */
5556 {
5558 {
5560 constructor_unfilled_index))
5566 {
5567 /* Advance to the next smaller node. */
5570 else
5571 {
5572 /* We have reached the smallest node bigger than the
5573 current unfilled index. Fill the space first. */
5576 }
5577 }
5578 else
5579 {
5580 /* Advance to the next bigger node. */
5583 else
5584 {
5585 /* We have reached the biggest node in a subtree. Find
5586 the parent of it, which is the next bigger node. */
5592 {
5595 }
5596 }
5597 }
5598 }
5601 {
5604 /* If the current record is complete we are done. */
5610 /* We can't compare fields here because there might be empty
5611 fields in between. */
5613 {
5617 }
5619 {
5620 /* Advance to the next smaller node. */
5623 else
5624 {
5625 /* We have reached the smallest node bigger than the
5626 current unfilled field. Fill the space first. */
5629 }
5630 }
5631 else
5632 {
5633 /* Advance to the next bigger node. */
5636 else
5637 {
5638 /* We have reached the biggest node in a subtree. Find
5639 the parent of it, which is the next bigger node. */
5646 {
5649 }
5650 }
5651 }
5652 }
5653 }
5655 /* Ordinarily return, but not if we want to output all
5656 and there are elements left. */
5660 /* If it's not incremental, just skip over the gap, so that after
5661 jumping to retry we will output the next successive element. */
5668 /* ELT now points to the node in the pending tree with the next
5669 initializer to output. */
5671 }
5672 \f
5673 /* Add one non-braced element to the current constructor level.
5674 This adjusts the current position within the constructor's type.
5675 This may also start or terminate implicit levels
5676 to handle a partly-braced initializer.
5678 Once this has found the correct level for the new element,
5679 it calls output_init_element. */
5681 void
5683 {
5690 /* Handle superfluous braces around string cst as in
5691 char x[] = {"foo"}; */
5693 && constructor_type
5697 {
5702 }
5705 {
5708 }
5710 /* Ignore elements of a brace group if it is entirely superfluous
5711 and has already been diagnosed. */
5715 /* If we've exhausted any levels that didn't have braces,
5716 pop them now. */
5718 {
5726 constructor_index)))
5728 else
5730 }
5732 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
5734 {
5735 /* If value is a compound literal and we'll be just using its
5736 content, don't put it into a SAVE_EXPR. */
5738 || !require_constant_value
5741 }
5744 {
5746 {
5747 tree fieldtype;
5751 {
5754 }
5761 /* Error for non-static initialization of a flexible array member. */
5763 && !require_constant_value
5766 {
5769 }
5771 /* Accept a string constant to initialize a subarray. */
5777 /* Otherwise, if we have come to a subaggregate,
5778 and we don't have an element of its type, push into it. */
5784 {
5787 }
5790 {
5794 }
5795 else
5796 /* Do the bookkeeping for an element that was
5797 directly output as a constructor. */
5798 {
5799 /* For a record, keep track of end position of last field. */
5801 constructor_bit_index
5806 /* If the current field was the first one not yet written out,
5807 it isn't now, so update. */
5809 {
5811 /* Skip any nameless bit fields. */
5815 constructor_unfilled_fields =
5817 }
5818 }
5821 /* Skip any nameless bit fields at the beginning. */
5826 }
5828 {
5829 tree fieldtype;
5833 {
5836 }
5843 /* Warn that traditional C rejects initialization of unions.
5844 We skip the warning if the value is zero. This is done
5845 under the assumption that the zero initializer in user
5846 code appears conditioned on e.g. __STDC__ to avoid
5847 "missing initializer" warnings and relies on default
5848 initialization to zero in the traditional C case.
5849 We also skip the warning if the initializer is designated,
5850 again on the assumption that this must be conditional on
5851 __STDC__ anyway (and we've already complained about the
5852 member-designator already). */
5857 /* Accept a string constant to initialize a subarray. */
5863 /* Otherwise, if we have come to a subaggregate,
5864 and we don't have an element of its type, push into it. */
5870 {
5873 }
5876 {
5880 }
5881 else
5882 /* Do the bookkeeping for an element that was
5883 directly output as a constructor. */
5884 {
5887 }
5890 }
5892 {
5896 /* Accept a string constant to initialize a subarray. */
5902 /* Otherwise, if we have come to a subaggregate,
5903 and we don't have an element of its type, push into it. */
5909 {
5912 }
5917 {
5920 }
5922 /* Now output the actual element. */
5924 {
5928 }
5930 constructor_index
5934 /* If we are doing the bookkeeping for an element that was
5935 directly output as a constructor, we must update
5936 constructor_unfilled_index. */
5938 }
5940 {
5943 /* Do a basic check of initializer size. Note that vectors
5944 always have a fixed size derived from their type. */
5946 {
5949 }
5951 /* Now output the actual element. */
5955 constructor_index
5959 /* If we are doing the bookkeeping for an element that was
5960 directly output as a constructor, we must update
5961 constructor_unfilled_index. */
5963 }
5965 /* Handle the sole element allowed in a braced initializer
5966 for a scalar variable. */
5968 {
5971 }
5972 else
5973 {
5977 }
5979 /* Handle range initializers either at this level or anywhere higher
5980 in the designator stack. */
5982 {
5989 {
5993 }
5997 {
6001 }
6008 {
6012 {
6015 }
6023 }
6028 }
6031 }
6034 }
6035 \f
6036 /* Build a complete asm-statement, whose components are a CV_QUALIFIER
6037 (guaranteed to be 'volatile' or null) and ARGS (represented using
6038 an ASM_STMT node). */
6039 tree
6041 {
6045 }
6047 /* Build an asm-expr, whose components are a STRING, some OUTPUTS,
6048 some INPUTS, and some CLOBBERS. The latter three may be NULL.
6049 SIMPLE indicates whether there was anything at all after the
6050 string in the asm expression -- asm("blah") and asm("blah" : )
6051 are subtly different. We use a ASM_STMT node to represent this. */
6052 tree
6055 {
6056 tree tail;
6057 tree args;
6067 /* Remove output conversions that change the type but not the mode. */
6069 {
6079 {
6080 /* By marking this operand as erroneous, we will not try
6081 to process this operand again in expand_asm_operands. */
6084 }
6086 /* If the operand is a DECL that is going to end up in
6087 memory, assume it is addressable. This is a bit more
6088 conservative than it would ideally be; the exact test is
6089 buried deep in expand_asm_operands and depends on the
6090 DECL_RTL for the OPERAND -- which we don't have at this
6091 point. */
6094 }
6096 /* Perform default conversions on array and function inputs.
6097 Don't do this for other types as it would screw up operands
6098 expected to be in memory. */
6104 /* Simple asm statements are treated as volatile. */
6106 {
6109 }
6111 }
6113 /* Expand an ASM statement with operands, handling output operands
6114 that are not variables or INDIRECT_REFS by transforming such
6115 cases into cases that expand_asm_operands can handle.
6117 Arguments are same as for expand_asm_operands. */
6119 void
6122 {
6125 /* o[I] is the place that output number I should be written. */
6127 tree tail;
6129 /* Record the contents of OUTPUTS before it is modified. */
6131 {
6135 }
6137 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
6138 OUTPUTS some trees for where the values were actually stored. */
6141 /* Copy all the intermediate outputs into the specified outputs. */
6143 {
6145 {
6150 /* Restore the original value so that it's correct the next
6151 time we expand this function. */
6153 }
6154 /* Detect modification of read-only values.
6155 (Otherwise done by build_modify_expr.) */
6156 else
6157 {
6165 }
6166 }
6168 /* Those MODIFY_EXPRs could do autoincrements. */
6170 }
6171 \f
6172 /* Expand a C `return' statement.
6173 RETVAL is the expression for what to return,
6174 or a null pointer for `return;' with no value. */
6176 tree
6178 {
6185 {
6190 }
6192 {
6196 }
6197 else
6198 {
6202 tree inner;
6210 /* Strip any conversions, additions, and subtractions, and see if
6211 we are returning the address of a local variable. Warn if so. */
6213 {
6215 {
6222 /* If the second operand of the MINUS_EXPR has a pointer
6223 type (or is converted from it), this may be valid, so
6224 don't give a warning. */
6225 {
6239 }
6256 }
6259 }
6262 }
6265 }
6266 \f
6268 /* The SWITCH_STMT being built. */
6269 tree switch_stmt;
6270 /* A splay-tree mapping the low element of a case range to the high
6271 element, or NULL_TREE if there is no high element. Used to
6272 determine whether or not a new case label duplicates an old case
6273 label. We need a tree, rather than simply a hash table, because
6274 of the GNU case range extension. */
6275 splay_tree cases;
6276 /* The next node on the stack. */
6278 };
6280 /* A stack of the currently active switch statements. The innermost
6281 switch statement is on the top of the stack. There is no need to
6282 mark the stack for garbage collection because it is only active
6283 during the processing of the body of a function, and we never
6284 collect at that point. */
6288 /* Start a C switch statement, testing expression EXP. Return the new
6289 SWITCH_STMT. */
6291 tree
6293 {
6299 {
6305 {
6308 }
6309 else
6310 {
6320 }
6321 }
6323 /* Add this new SWITCH_STMT to the stack. */
6331 }
6333 /* Process a case label. */
6335 tree
6337 {
6341 {
6350 {
6351 /* Attach the first case label to the SWITCH_BODY. */
6354 }
6355 }
6358 else
6362 }
6364 /* Finish the switch statement. */
6366 void
6368 {
6371 /* Emit warnings as needed. */
6374 /* Rechain the next statements to the SWITCH_STMT. */
6377 /* Pop the stack. */
6381 }
6383 /* Build a binary-operation expression without default conversions.
6384 CODE is the kind of expression to build.
6385 This function differs from `build' in several ways:
6386 the data type of the result is computed and recorded in it,
6387 warnings are generated if arg data types are invalid,
6388 special handling for addition and subtraction of pointers is known,
6389 and some optimization is done (operations on narrow ints
6390 are done in the narrower type when that gives the same result).
6391 Constant folding is also done before the result is returned.
6393 Note that the operands will never have enumeral types, or function
6394 or array types, because either they will have the default conversions
6395 performed or they have both just been converted to some other type in which
6396 the arithmetic is to be done. */
6398 tree
6401 {
6406 /* Expression code to give to the expression when it is built.
6407 Normally this is CODE, which is what the caller asked for,
6408 but in some special cases we change it. */
6411 /* Data type in which the computation is to be performed.
6412 In the simplest cases this is the common type of the arguments. */
6415 /* Nonzero means operands have already been type-converted
6416 in whatever way is necessary.
6417 Zero means they need to be converted to RESULT_TYPE. */
6420 /* Nonzero means create the expression with this type, rather than
6421 RESULT_TYPE. */
6424 /* Nonzero means after finally constructing the expression
6425 convert it to this type. */
6428 /* Nonzero if this is an operation like MIN or MAX which can
6429 safely be computed in short if both args are promoted shorts.
6430 Also implies COMMON.
6431 -1 indicates a bitwise operation; this makes a difference
6432 in the exact conditions for when it is safe to do the operation
6433 in a narrower mode. */
6436 /* Nonzero if this is a comparison operation;
6437 if both args are promoted shorts, compare the original shorts.
6438 Also implies COMMON. */
6441 /* Nonzero if this is a right-shift operation, which can be computed on the
6442 original short and then promoted if the operand is a promoted short. */
6445 /* Nonzero means set RESULT_TYPE to the common type of the args. */
6449 {
6452 }
6453 else
6454 {
6457 }
6462 /* The expression codes of the data types of the arguments tell us
6463 whether the arguments are integers, floating, pointers, etc. */
6467 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
6471 /* If an error was already reported for one of the arguments,
6472 avoid reporting another error. */
6478 {
6480 /* Handle the pointer + int case. */
6485 else
6490 /* Subtraction of two similar pointers.
6491 We must subtract them as integers, then divide by object size. */
6495 /* Handle pointer minus int. Just like pointer plus int. */
6498 else
6511 /* Floating point division by zero is a legitimate way to obtain
6512 infinities and NaNs. */
6520 {
6523 else
6524 /* Although it would be tempting to shorten always here, that
6525 loses on some targets, since the modulo instruction is
6526 undefined if the quotient can't be represented in the
6527 computation mode. We shorten only if unsigned or if
6528 dividing by something we know != -1. */
6533 }
6551 {
6552 /* Although it would be tempting to shorten always here, that loses
6553 on some targets, since the modulo instruction is undefined if the
6554 quotient can't be represented in the computation mode. We shorten
6555 only if unsigned or if dividing by something we know != -1. */
6560 }
6572 {
6573 /* Result of these operations is always an int,
6574 but that does not mean the operands should be
6575 converted to ints! */
6580 }
6583 /* Shift operations: result has same type as first operand;
6584 always convert second operand to int.
6585 Also set SHORT_SHIFT if shifting rightward. */
6589 {
6591 {
6594 else
6595 {
6601 }
6602 }
6604 /* Use the type of the value to be shifted. */
6606 /* Convert the shift-count to an integer, regardless of size
6607 of value being shifted. */
6610 /* Avoid converting op1 to result_type later. */
6612 }
6617 {
6619 {
6625 }
6627 /* Use the type of the value to be shifted. */
6629 /* Convert the shift-count to an integer, regardless of size
6630 of value being shifted. */
6633 /* Avoid converting op1 to result_type later. */
6635 }
6641 {
6643 {
6648 }
6650 /* Use the type of the value to be shifted. */
6652 /* Convert the shift-count to an integer, regardless of size
6653 of value being shifted. */
6656 /* Avoid converting op1 to result_type later. */
6658 }
6665 /* Result of comparison is always int,
6666 but don't convert the args to int! */
6674 {
6677 /* Anything compares with void *. void * compares with anything.
6678 Otherwise, the targets must be compatible
6679 and both must be object or both incomplete. */
6683 {
6684 /* op0 != orig_op0 detects the case of something
6685 whose value is 0 but which isn't a valid null ptr const. */
6689 }
6691 {
6695 }
6696 else
6701 }
6709 {
6712 }
6714 {
6717 }
6726 {
6728 {
6733 }
6734 else
6735 {
6738 }
6739 }
6751 {
6753 {
6761 }
6762 else
6763 {
6766 }
6767 }
6770 {
6774 }
6777 {
6781 }
6783 {
6786 }
6788 {
6791 }
6803 {
6806 }
6812 }
6819 &&
6822 {
6828 /* For certain operations (which identify themselves by shorten != 0)
6829 if both args were extended from the same smaller type,
6830 do the arithmetic in that type and then extend.
6832 shorten !=0 and !=1 indicates a bitwise operation.
6833 For them, this optimization is safe only if
6834 both args are zero-extended or both are sign-extended.
6835 Otherwise, we might change the result.
6836 Eg, (short)-1 | (unsigned short)-1 is (int)-1
6837 but calculated in (unsigned short) it would be (unsigned short)-1. */
6840 {
6844 /* UNS is 1 if the operation to be done is an unsigned one. */
6846 tree type;
6850 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
6851 but it *requires* conversion to FINAL_TYPE. */
6862 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
6864 /* For bitwise operations, signedness of nominal type
6865 does not matter. Consider only how operands were extended. */
6869 /* Note that in all three cases below we refrain from optimizing
6870 an unsigned operation on sign-extended args.
6871 That would not be valid. */
6873 /* Both args variable: if both extended in same way
6874 from same width, do it in that width.
6875 Do it unsigned if args were zero-extended. */
6882 result_type
6883 = c_common_signed_or_unsigned_type
6889 && (type
6898 && (type
6903 }
6905 /* Shifts can be shortened if shifting right. */
6908 {
6918 /* We can shorten only if the shift count is less than the
6919 number of bits in the smaller type size. */
6921 /* We cannot drop an unsigned shift after sign-extension. */
6923 {
6924 /* Do an unsigned shift if the operand was zero-extended. */
6925 result_type
6928 /* Convert value-to-be-shifted to that type. */
6932 }
6933 }
6935 /* Comparison operations are shortened too but differently.
6936 They identify themselves by setting short_compare = 1. */
6939 {
6940 /* Don't write &op0, etc., because that would prevent op0
6941 from being kept in a register.
6942 Instead, make copies of the our local variables and
6943 pass the copies by reference, then copy them back afterward. */
6946 tree val
6957 {
6969 /* Give warnings for comparisons between signed and unsigned
6970 quantities that may fail.
6972 Do the checking based on the original operand trees, so that
6973 casts will be considered, but default promotions won't be.
6975 Do not warn if the comparison is being done in a signed type,
6976 since the signed type will only be chosen if it can represent
6977 all the values of the unsigned type. */
6980 /* Do not warn if both operands are the same signedness. */
6983 else
6984 {
6989 else
6992 /* Do not warn if the signed quantity is an
6993 unsuffixed integer literal (or some static
6994 constant expression involving such literals or a
6995 conditional expression involving such literals)
6996 and it is non-negative. */
6999 /* Do not warn if the comparison is an equality operation,
7000 the unsigned quantity is an integral constant, and it
7001 would fit in the result if the result were signed. */
7004 && int_fits_type_p
7007 /* Do not warn if the unsigned quantity is an enumeration
7008 constant and its maximum value would fit in the result
7009 if the result were signed. */
7012 && int_fits_type_p
7016 else
7018 }
7020 /* Warn if two unsigned values are being compared in a size
7021 larger than their original size, and one (and only one) is the
7022 result of a `~' operator. This comparison will always fail.
7024 Also warn if one operand is a constant, and the constant
7025 does not have all bits set that are set in the ~ operand
7026 when it is extended. */
7030 {
7034 else
7039 {
7040 tree primop;
7045 {
7049 }
7050 else
7051 {
7055 }
7060 {
7064 }
7065 }
7072 }
7073 }
7074 }
7075 }
7077 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
7078 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
7079 Then the expression will be built.
7080 It will be given type FINAL_TYPE if that is nonzero;
7081 otherwise, it will be given type RESULT_TYPE. */
7084 {
7087 }
7090 {
7095 }
7100 {
7103 /* Treat expressions in initializers specially as they can't trap. */
7110 }
7111 }