| blob | 1cfc8039244fe0cfcc35226da4dd386168b1d65f |
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. */
84 \f
85 /* Do `exp = require_complete_type (exp);' to make sure exp
86 does not have an incomplete type. (That includes void types.) */
88 tree
90 {
96 /* First, detect a valid value with a complete type. */
102 }
104 /* Print an error message for invalid use of an incomplete type.
105 VALUE is the expression that was used (or 0 if that isn't known)
106 and TYPE is the type that was invalid. */
108 void
110 {
113 /* Avoid duplicate error message. */
121 else
122 {
123 retry:
124 /* We must print an error message. Be clever about what it says. */
127 {
146 {
148 {
151 }
154 }
160 }
165 else
166 /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */
169 }
170 }
172 /* Given a type, apply default promotions wrt unnamed function
173 arguments and return the new type. */
175 tree
177 {
182 {
183 /* Preserve unsignedness if not really getting any wider. */
188 }
191 }
193 /* Return a variant of TYPE which has all the type qualifiers of LIKE
194 as well as those of TYPE. */
196 static tree
198 {
201 }
202 \f
203 /* Return the common type of two types.
204 We assume that comptypes has already been done and returned 1;
205 if that isn't so, this may crash. In particular, we assume that qualifiers
206 match.
208 This is the type for the result of most arithmetic operations
209 if the operands have the given two types. */
211 tree
213 {
216 tree attributes;
218 /* Save time if the two types are the same. */
222 /* If one type is nonsense, use the other. */
228 /* Merge the attributes. */
231 /* Treat an enum type as the unsigned integer type of the same width. */
241 /* If one type is complex, form the common type of the non-complex
242 components, then make that complex. Use T1 or T2 if it is the
243 required type. */
245 {
254 else
256 attributes);
257 }
260 {
263 /* If only one is real, use it as the result. */
271 /* Both real or both integers; use the one with greater precision. */
278 /* Same precision. Prefer longs to ints even when same size. */
283 attributes);
287 {
288 /* But preserve unsignedness from the other type,
289 since long cannot hold all the values of an unsigned int. */
292 else
295 }
297 /* Likewise, prefer long double to double even if same size. */
301 attributes);
303 /* Otherwise prefer the unsigned one. */
307 else
311 /* For two pointers, do this recursively on the target type,
312 and combine the qualifiers of the two types' targets. */
313 /* This code was turned off; I don't know why.
314 But ANSI C specifies doing this with the qualifiers.
315 So I turned it on again. */
316 {
326 }
329 {
331 /* Save space: see if the result is identical to one of the args. */
336 /* Merge the element types, and have a size if either arg has one. */
339 }
342 /* Function types: prefer the one that specified arg types.
343 If both do, merge the arg types. Also merge the return types. */
344 {
352 /* Save space: see if the result is identical to one of the args. */
358 /* Simple way if one arg fails to specify argument types. */
360 {
363 }
365 {
368 }
370 /* If both args specify argument types, we must merge the two
371 lists, argument by argument. */
386 {
387 /* A null type means arg type is not specified.
388 Take whatever the other function type has. */
390 {
393 }
395 {
398 }
400 /* Given wait (union {union wait *u; int *i} *)
401 and wait (union wait *),
402 prefer union wait * as type of parm. */
405 {
406 tree memb;
410 COMPARE_STRICT))
411 {
416 }
417 }
420 {
421 tree memb;
425 COMPARE_STRICT))
426 {
431 }
432 }
434 parm_done: ;
435 }
440 /* ... falls through ... */
441 }
445 }
447 }
448 \f
449 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
450 or various other operations. Return 2 if they are compatible
451 but a warning may be needed if you use them together. */
453 int
455 {
460 /* Suppress errors caused by previously reported errors. */
466 /* If either type is the internal version of sizetype, return the
467 language version. */
476 /* Enumerated types are compatible with integer types, but this is
477 not transitive: two enumerated types in the same translation unit
478 are compatible with each other only if they are the same type. */
488 /* Different classes of types can't be compatible. */
492 /* Qualifiers must match. */
497 /* Allow for two different type nodes which have essentially the same
498 definition. Note that we already checked for equality of the type
499 qualifiers (just above). */
504 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
508 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
512 {
514 /* We must give ObjC the first crack at comparing pointers, since
515 protocol qualifiers may be involved. */
527 {
534 /* Target types must match incl. qualifiers. */
537 flags)))
540 /* Sizes must match unless one is missing or variable. */
547 d1_variable = (! d1_zero
550 d2_variable = (! d2_zero
564 }
567 /* We are dealing with two distinct structs. In assorted Objective-C
568 corner cases, however, these can still be deemed equivalent. */
579 /* The target might allow certain vector types to be compatible. */
587 }
589 }
591 /* Return 1 if TTL and TTR are pointers to types that are equivalent,
592 ignoring their qualifiers. REFLEXIVE is only used by ObjC - set it
593 to 1 or 0 depending if the check of the pointer types is meant to
594 be reflexive or not (typically, assignments are not reflexive,
595 while comparisons are reflexive).
596 */
598 static int
600 {
603 /* Give objc_comptypes a crack at letting these types through. */
613 }
614 \f
615 /* Subroutines of `comptypes'. */
617 /* Determine whether two types derive from the same translation unit.
618 If the CONTEXT chain ends in a null, that type's context is still
619 being parsed, so if two types have context chains ending in null,
620 they're in the same translation unit. */
621 static int
623 {
626 {
631 }
635 {
640 }
643 }
645 /* The C standard says that two structures in different translation
646 units are compatible with each other only if the types of their
647 fields are compatible (among other things). So, consider two copies
648 of this structure: */
652 tree t1;
653 tree t2;
654 };
656 /* Can they be compatible with each other? We choose to break the
657 recursion by allowing those types to be compatible. */
661 /* Return 1 if two 'struct', 'union', or 'enum' types T1 and T2 are
662 compatible. If the two types are not the same (which has been
663 checked earlier), this can only happen when multiple translation
664 units are being compiled. See C99 6.2.7 paragraph 1 for the exact
665 rules. */
667 static int
669 {
673 /* We have to verify that the tags of the types are the same. This
674 is harder than it looks because this may be a typedef, so we have
675 to go look at the original type. It may even be a typedef of a
676 typedef... */
687 /* C90 didn't have the requirement that the two tags be the same. */
691 /* C90 didn't say what happened if one or both of the types were
692 incomplete; we choose to follow C99 rules here, which is that they
693 are compatible. */
698 {
703 }
706 {
708 {
710 /* Speed up the case where the type values are in the same order. */
718 {
723 }
734 {
739 }
741 }
744 {
749 {
761 {
776 }
780 }
782 }
785 {
796 {
811 }
816 }
820 }
821 }
823 /* Return 1 if two function types F1 and F2 are compatible.
824 If either type specifies no argument types,
825 the other must specify a fixed number of self-promoting arg types.
826 Otherwise, if one type specifies only the number of arguments,
827 the other must specify that number of self-promoting arg types.
828 Otherwise, the argument types must match. */
830 static int
832 {
834 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
842 /* 'volatile' qualifiers on a function's return type mean the function
843 is noreturn. */
859 /* An unspecified parmlist matches any specified parmlist
860 whose argument types don't need default promotions. */
863 {
866 /* If one of these types comes from a non-prototype fn definition,
867 compare that with the other type's arglist.
868 If they don't match, ask for a warning (but no error). */
871 flags))
874 }
876 {
881 flags))
884 }
886 /* Both types have argument lists: compare them and propagate results. */
889 }
891 /* Check two lists of types for compatibility,
892 returning 0 for incompatible, 1 for compatible,
893 or 2 for compatible with warning. */
895 static int
897 {
898 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
903 {
906 /* If one list is shorter than the other,
907 they fail to match. */
910 /* A null pointer instead of a type
911 means there is supposed to be an argument
912 but nothing is specified about what type it has.
913 So match anything that self-promotes. */
915 {
918 }
920 {
923 }
924 /* If one of the lists has an error marker, ignore this arg. */
927 ;
930 flags)))
931 {
932 /* Allow wait (union {union wait *u; int *i} *)
933 and wait (union wait *) to be compatible. */
940 {
941 tree memb;
945 flags))
949 }
956 {
957 tree memb;
961 flags))
965 }
966 else
968 }
970 /* comptypes said ok, but record if it said to warn. */
976 }
977 }
978 \f
979 /* Compute the size to increment a pointer by. */
981 tree
983 {
990 {
993 }
995 /* Convert in case a char is more than one unit. */
999 }
1000 \f
1001 /* Return either DECL or its known constant value (if it has one). */
1003 tree
1005 {
1007 in a place where a variable is invalid. */
1013 /* This is invalid if initial value is not constant.
1014 If it has either a function call, a memory reference,
1015 or a variable, then re-evaluating it could give different results. */
1017 /* Check for cases where this is sub-optimal, even though valid. */
1021 }
1023 /* Return either DECL or its known constant value (if it has one), but
1024 return DECL if pedantic or DECL has mode BLKmode. This is for
1025 bug-compatibility with the old behavior of decl_constant_value
1026 (before GCC 3.0); every use of this function is a bug and it should
1027 be removed before GCC 3.1. It is not appropriate to use pedantic
1028 in a way that affects optimization, and BLKmode is probably not the
1029 right test for avoiding misoptimizations either. */
1031 static tree
1033 {
1036 else
1038 }
1041 /* Perform the default conversion of arrays and functions to pointers.
1042 Return the result of converting EXP. For any other expression, just
1043 return EXP. */
1045 static tree
1047 {
1048 tree orig_exp;
1053 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
1054 an lvalue.
1056 Do not use STRIP_NOPS here! It will remove conversions from pointer
1057 to integer and cause infinite recursion. */
1062 {
1066 }
1068 /* Preserve the original expression code. */
1073 {
1075 }
1077 {
1078 tree adr;
1080 tree ptrtype;
1086 {
1089 }
1092 restype
1103 {
1107 }
1111 {
1112 /* Before C99, non-lvalue arrays do not decay to pointers.
1113 Normally, using such an array would be invalid; but it can
1114 be used correctly inside sizeof or as a statement expression.
1115 Thus, do not give an error here; an error will result later. */
1117 }
1122 {
1123 /* ??? This is not really quite correct
1124 in that the type of the operand of ADDR_EXPR
1125 is not the target type of the type of the ADDR_EXPR itself.
1126 Question is, can this lossage be avoided? */
1133 }
1134 /* This way is better for a COMPONENT_REF since it can
1135 simplify the offset for a component. */
1138 }
1140 }
1142 /* Perform default promotions for C data used in expressions.
1143 Arrays and functions are converted to pointers;
1144 enumeral types or short or char, to int.
1145 In addition, manifest constants symbols are replaced by their values. */
1147 tree
1149 {
1150 tree orig_exp;
1157 /* Constants can be used directly unless they're not loadable. */
1161 /* Replace a nonvolatile const static variable with its value unless
1162 it is an array, in which case we must be sure that taking the
1163 address of the array produces consistent results. */
1165 {
1168 }
1170 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
1171 an lvalue.
1173 Do not use STRIP_NOPS here! It will remove conversions from pointer
1174 to integer and cause infinite recursion. */
1181 /* Preserve the original expression code. */
1185 /* Normally convert enums to int,
1186 but convert wide enums to something wider. */
1188 {
1196 }
1200 /* If it's thinner than an int, promote it like a
1201 c_promoting_integer_type_p, otherwise leave it alone. */
1207 {
1208 /* Preserve unsignedness if not really getting any wider. */
1214 }
1217 {
1220 }
1222 }
1223 \f
1224 /* Look up COMPONENT in a structure or union DECL.
1226 If the component name is not found, returns NULL_TREE. Otherwise,
1227 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL
1228 stepping down the chain to the component, which is in the last
1229 TREE_VALUE of the list. Normally the list is of length one, but if
1230 the component is embedded within (nested) anonymous structures or
1231 unions, the list steps down the chain to the component. */
1233 static tree
1235 {
1237 tree field;
1239 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers
1240 to the field elements. Use a binary search on this array to quickly
1241 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC
1242 will always be set for structures which have many elements. */
1245 {
1253 {
1258 {
1259 /* Step through all anon unions in linear fashion. */
1261 {
1265 {
1270 }
1271 }
1273 /* Entire record is only anon unions. */
1277 /* Restart the binary search, with new lower bound. */
1279 }
1285 else
1287 }
1293 }
1294 else
1295 {
1297 {
1301 {
1306 }
1310 }
1314 }
1317 }
1319 /* Make an expression to refer to the COMPONENT field of
1320 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */
1322 tree
1324 {
1328 tree ref;
1330 /* If DATUM is a COMPOUND_EXPR, move our reference inside it.
1331 Ensure that the arguments are not lvalues; otherwise,
1332 if the component is an array, it would wrongly decay to a pointer in
1333 C89 mode.
1334 We cannot do this with a COND_EXPR, because in a conditional expression
1335 the default promotions are applied to both sides, and this would yield
1336 the wrong type of the result; for example, if the components have
1337 type "char". */
1339 {
1341 {
1345 }
1348 }
1350 /* See if there is a field or component with name COMPONENT. */
1353 {
1355 {
1358 }
1363 {
1368 }
1370 /* Chain the COMPONENT_REFs if necessary down to the FIELD.
1371 This might be better solved in future the way the C++ front
1372 end does it - by giving the anonymous entities each a
1373 separate name and type, and then have build_component_ref
1374 recursively call itself. We can't do that here. */
1375 do
1376 {
1394 }
1398 }
1404 }
1405 \f
1406 /* Given an expression PTR for a pointer, return an expression
1407 for the value pointed to.
1408 ERRORSTRING is the name of the operator to appear in error messages. */
1410 tree
1412 {
1417 {
1422 else
1423 {
1428 {
1431 }
1435 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
1436 so that we get the proper error message if the result is used
1437 to assign to. Also, &* is supposed to be a no-op.
1438 And ANSI C seems to specify that the type of the result
1439 should be the const type. */
1440 /* A de-reference of a pointer to const is not a const. It is valid
1441 to change it via some other pointer. */
1447 }
1448 }
1452 }
1454 /* This handles expressions of the form "a[i]", which denotes
1455 an array reference.
1457 This is logically equivalent in C to *(a+i), but we may do it differently.
1458 If A is a variable or a member, we generate a primitive ARRAY_REF.
1459 This avoids forcing the array out of registers, and can work on
1460 arrays that are not lvalues (for example, members of structures returned
1461 by functions). */
1463 tree
1465 {
1467 {
1470 }
1478 {
1481 /* Subscripting with type char is likely to lose
1482 on a machine where chars are signed.
1483 So warn on any machine, but optionally.
1484 Don't warn for unsigned char since that type is safe.
1485 Don't warn for signed char because anyone who uses that
1486 must have done so deliberately. */
1491 /* Apply default promotions *after* noticing character types. */
1494 /* Require integer *after* promotion, for sake of enums. */
1496 {
1499 }
1501 /* An array that is indexed by a non-constant
1502 cannot be stored in a register; we must be able to do
1503 address arithmetic on its address.
1504 Likewise an array of elements of variable size. */
1508 {
1511 }
1512 /* An array that is indexed by a constant value which is not within
1513 the array bounds cannot be stored in a register either; because we
1514 would get a crash in store_bit_field/extract_bit_field when trying
1515 to access a non-existent part of the register. */
1519 {
1522 }
1525 {
1533 }
1537 /* Array ref is const/volatile if the array elements are
1538 or if the array is. */
1547 /* This was added by rms on 16 Nov 91.
1548 It fixes vol struct foo *a; a->elts[1]
1549 in an inline function.
1550 Hope it doesn't break something else. */
1553 }
1555 {
1559 /* Do the same warning check as above, but only on the part that's
1560 syntactically the index and only if it is also semantically
1561 the index. */
1567 /* Put the integer in IND to simplify error checking. */
1569 {
1573 }
1580 {
1583 }
1585 {
1588 }
1592 }
1593 }
1594 \f
1595 /* Build an external reference to identifier ID. FUN indicates
1596 whether this will be used for a function call. */
1597 tree
1599 {
1600 tree ref;
1605 {
1606 /* Properly declared variable or function reference. */
1610 {
1614 }
1615 else
1617 }
1621 /* Implicit function declaration. */
1624 /* Don't complain about something that's already been
1625 complained about. */
1627 else
1628 {
1631 }
1644 {
1647 }
1653 {
1658 }
1661 }
1663 /* Build a function call to function FUNCTION with parameters PARAMS.
1664 PARAMS is a list--a chain of TREE_LIST nodes--in which the
1665 TREE_VALUE of each node is a parameter-expression.
1666 FUNCTION's data type may be a function type or a pointer-to-function. */
1668 tree
1670 {
1672 tree coerced_params;
1674 tree tem;
1676 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
1679 /* Convert anything with function type to a pointer-to-function. */
1681 {
1684 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
1685 (because calling an inline function does not mean the function
1686 needs to be separately compiled). */
1692 }
1693 else
1703 {
1706 }
1711 /* fntype now gets the type of function pointed to. */
1714 /* Check that the function is called through a compatible prototype.
1715 If it is not, replace the call by a trap, wrapped up in a compound
1716 expression if necessary. This has the nice side-effect to prevent
1717 the tree-inliner from generating invalid assignment trees which may
1718 blow up in the RTL expander later.
1720 ??? This doesn't work for Objective-C because objc_comptypes
1721 refuses to compare function prototypes, yet the compiler appears
1722 to build calls that are flagged as invalid by C's comptypes. */
1728 {
1731 NULL_TREE);
1733 /* This situation leads to run-time undefined behavior. We can't,
1734 therefore, simply error unless we can prove that all possible
1735 executions of the program must execute the code. */
1738 /* We can, however, treat "undefined" any way we please.
1739 Call abort to encourage the user to fix the program. */
1744 else
1745 {
1746 tree rhs;
1751 NULL_TREE));
1752 else
1756 }
1757 }
1759 /* Convert the parameters to the types declared in the
1760 function prototype, or apply default promotions. */
1762 coerced_params
1765 /* Check that the arguments to the function are valid. */
1769 /* Recognize certain built-in functions so we can make tree-codes
1770 other than CALL_EXPR. We do this when it enables fold-const.c
1771 to do something useful. */
1776 {
1781 }
1791 }
1792 \f
1793 /* Convert the argument expressions in the list VALUES
1794 to the types in the list TYPELIST. The result is a list of converted
1795 argument expressions.
1797 If TYPELIST is exhausted, or when an element has NULL as its type,
1798 perform the default conversions.
1800 PARMLIST is the chain of parm decls for the function being called.
1801 It may be 0, if that info is not available.
1802 It is used only for generating error messages.
1804 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
1806 This is also where warnings about wrong number of args are generated.
1808 Both VALUES and the returned value are chains of TREE_LIST nodes
1809 with the elements of the list in the TREE_VALUE slots of those nodes. */
1811 static tree
1813 {
1818 /* Scan the given expressions and types, producing individual
1819 converted arguments and pushing them on RESULT in reverse order. */
1822 valtail;
1824 {
1829 {
1833 else
1836 }
1838 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
1839 /* Do not use STRIP_NOPS here! We do not want an enumerator with value 0
1840 to convert automatically to a pointer. */
1849 {
1850 /* Formal parm type is specified by a function prototype. */
1851 tree parmval;
1854 {
1857 }
1858 else
1859 {
1860 /* Optionally warn about conversions that
1861 differ from the default conversions. */
1863 {
1868 warn_for_assignment ("%s as integer rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1871 warn_for_assignment ("%s as integer rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1874 warn_for_assignment ("%s as complex rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1877 warn_for_assignment ("%s as floating rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1880 warn_for_assignment ("%s as complex rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1883 warn_for_assignment ("%s as floating rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1884 /* ??? At some point, messages should be written about
1885 conversions between complex types, but that's too messy
1886 to do now. */
1889 {
1890 /* Warn if any argument is passed as `float',
1891 since without a prototype it would be `double'. */
1893 warn_for_assignment ("%s as `float' rather than `double' due to prototype", (char *) 0, name, parmnum + 1);
1894 }
1895 /* Detect integer changing in width or signedness.
1896 These warnings are only activated with
1897 -Wconversion, not with -Wtraditional. */
1900 {
1907 /* No warning if function asks for enum
1908 and the actual arg is that enum type. */
1909 ;
1911 warn_for_assignment ("%s with different width due to prototype", (char *) 0, name, parmnum + 1);
1913 ;
1914 /* Don't complain if the formal parameter type
1915 is an enum, because we can't tell now whether
1916 the value was an enum--even the same enum. */
1918 ;
1921 /* Change in signedness doesn't matter
1922 if a constant value is unaffected. */
1923 ;
1924 /* Likewise for a constant in a NOP_EXPR. */
1928 ;
1929 /* If the value is extended from a narrower
1930 unsigned type, it doesn't matter whether we
1931 pass it as signed or unsigned; the value
1932 certainly is the same either way. */
1935 ;
1938 else
1940 }
1941 }
1951 }
1953 }
1957 /* Convert `float' to `double'. */
1959 else
1960 /* Convert `short' and `char' to full-size `int'. */
1965 }
1968 {
1972 else
1974 }
1977 }
1978 \f
1979 /* This is the entry point used by the parser
1980 for binary operators in the input.
1981 In addition to constructing the expression,
1982 we check for operands that were written with other binary operators
1983 in a way that is likely to confuse the user. */
1985 tree
1987 {
2004 /* Check for cases such as x+y<<z which users are likely
2005 to misinterpret. If parens are used, C_EXP_ORIGINAL_CODE
2006 is cleared to prevent these warnings. */
2008 {
2010 {
2014 }
2017 {
2021 }
2024 {
2030 /* Check cases like x|y==z */
2033 }
2036 {
2042 /* Check cases like x^y==z */
2045 }
2048 {
2052 /* Check cases like x&y==z */
2055 }
2056 }
2058 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */
2069 /* Record the code that was specified in the source,
2070 for the sake of warnings about confusing nesting. */
2073 else
2074 {
2076 /* We used to use NOP_EXPR rather than NON_LVALUE_EXPR
2077 so that convert_for_assignment wouldn't strip it.
2078 That way, we got warnings for things like p = (1 - 1).
2079 But it turns out we should not get those warnings. */
2083 }
2086 }
2087 \f
2089 /* Return true if `t' is known to be non-negative. */
2091 int
2093 {
2095 {
2098 /* Find the last statement in the chain, ignoring the final
2099 * scope statement */
2104 }
2106 }
2108 /* Return a tree for the difference of pointers OP0 and OP1.
2109 The resulting tree has type int. */
2111 static tree
2113 {
2122 {
2127 }
2129 /* If the conversion to ptrdiff_type does anything like widening or
2130 converting a partial to an integral mode, we get a convert_expression
2131 that is in the way to do any simplifications.
2132 (fold-const.c doesn't know that the extra bits won't be needed.
2133 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2134 different mode in place.)
2135 So first try to find a common term here 'by hand'; we want to cover
2136 at least the cases that occur in legal static initializers. */
2141 {
2144 }
2145 else
2149 {
2152 }
2153 else
2157 {
2160 }
2163 /* First do the subtraction as integers;
2164 then drop through to build the divide operator.
2165 Do not do default conversions on the minus operator
2166 in case restype is a short type. */
2170 /* This generates an error if op1 is pointer to incomplete type. */
2174 /* This generates an error if op0 is pointer to incomplete type. */
2177 /* Divide by the size, in easiest possible way. */
2185 }
2186 \f
2187 /* Construct and perhaps optimize a tree representation
2188 for a unary operation. CODE, a tree_code, specifies the operation
2189 and XARG is the operand.
2190 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2191 the default promotions (such as from short to int).
2192 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2193 allows non-lvalues; this is only used to handle conversion of non-lvalue
2194 arrays to pointers in C99. */
2196 tree
2198 {
2199 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2203 tree val;
2212 {
2214 /* This is used for unary plus, because a CONVERT_EXPR
2215 is enough to prevent anybody from looking inside for
2216 associativity, but won't generate any code. */
2219 {
2222 }
2232 {
2235 }
2242 {
2245 }
2247 {
2253 }
2254 else
2255 {
2258 }
2263 {
2266 }
2272 /* Conjugating a real value is a no-op, but allow it anyway. */
2275 {
2278 }
2287 /* These will convert to a pointer. */
2289 {
2292 }
2304 else
2312 else
2320 /* Increment or decrement the real part of the value,
2321 and don't change the imaginary part. */
2323 {
2334 }
2336 /* Report invalid types. */
2340 {
2343 else
2347 }
2349 {
2350 tree inc;
2356 /* Compute the increment. */
2359 {
2360 /* If pointer target is an undefined struct,
2361 we just cannot know how to do the arithmetic. */
2363 {
2366 else
2368 }
2372 {
2375 else
2377 }
2380 }
2381 else
2386 /* Complain about anything else that is not a true lvalue. */
2393 /* Report a read-only lvalue. */
2402 else
2409 }
2412 /* Note that this operation never does default_conversion. */
2414 /* Let &* cancel out to simplify resulting code. */
2416 {
2417 /* Don't let this be an lvalue. */
2421 }
2423 /* For &x[y], return x+y */
2425 {
2430 }
2432 /* Anything not already handled and not a true memory reference
2433 or a non-lvalue array is an error. */
2438 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
2441 /* If the lvalue is const or volatile, merge that into the type
2442 to which the address will point. Note that you can't get a
2443 restricted pointer by taking the address of something, so we
2444 only have to deal with `const' and `volatile' here. */
2456 {
2457 tree addr;
2460 {
2466 {
2470 }
2475 }
2476 else
2479 /* Address of a static or external variable or
2480 file-scope function counts as a constant. */
2486 }
2490 }
2495 }
2497 /* Return nonzero if REF is an lvalue valid for this language.
2498 Lvalues can be assigned, unless their type has TYPE_READONLY.
2499 Lvalues can have their address taken, unless they have DECL_REGISTER. */
2501 int
2503 {
2507 {
2532 }
2533 }
2535 /* Return nonzero if REF is an lvalue valid for this language;
2536 otherwise, print an error message and return zero. */
2538 int
2540 {
2547 }
2549 \f
2550 /* Warn about storing in something that is `const'. */
2552 void
2554 {
2556 {
2559 else
2562 }
2566 else
2568 }
2569 \f
2570 /* Mark EXP saying that we need to be able to take the
2571 address of it; it should not be allocated in a register.
2572 Returns true if successful. */
2574 bool
2576 {
2581 {
2584 {
2588 }
2590 /* ... fall through ... */
2610 {
2612 {
2616 }
2619 }
2621 {
2623 {
2627 }
2629 /* If we are making this addressable due to its having
2630 volatile components, give a different error message. Also
2631 handle the case of an unnamed parameter by not trying
2632 to give the name. */
2635 {
2638 }
2642 }
2645 /* drops in */
2648 /* drops out */
2651 }
2652 }
2653 \f
2654 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
2656 tree
2658 {
2659 tree type1;
2660 tree type2;
2668 /* Promote both alternatives. */
2685 /* C90 does not permit non-lvalue arrays in conditional expressions.
2686 In C99 they will be pointers by now. */
2688 {
2691 }
2693 /* Quickly detect the usual case where op1 and op2 have the same type
2694 after promotion. */
2696 {
2699 else
2701 }
2706 {
2709 /* If -Wsign-compare, warn here if type1 and type2 have
2710 different signedness. We'll promote the signed to unsigned
2711 and later code won't know it used to be different.
2712 Do this check on the original types, so that explicit casts
2713 will be considered, but default promotions won't. */
2715 {
2720 {
2721 /* Do not warn if the result type is signed, since the
2722 signed type will only be chosen if it can represent
2723 all the values of the unsigned type. */
2726 /* Do not warn if the signed quantity is an unsuffixed
2727 integer literal (or some static constant expression
2728 involving such literals) and it is non-negative. */
2732 else
2734 }
2735 }
2736 }
2738 {
2742 }
2744 {
2754 {
2759 }
2761 {
2766 }
2767 else
2768 {
2771 }
2772 }
2774 {
2777 else
2778 {
2780 }
2782 }
2784 {
2787 else
2788 {
2790 }
2792 }
2795 {
2798 else
2799 {
2802 }
2803 }
2805 /* Merge const and volatile flags of the incoming types. */
2806 result_type
2820 }
2821 \f
2822 /* Given a list of expressions, return a compound expression
2823 that performs them all and returns the value of the last of them. */
2825 tree
2827 {
2829 }
2831 static tree
2833 {
2834 tree rest;
2837 {
2838 /* Convert arrays and functions to pointers when there
2839 really is a comma operator. */
2844 /* Don't let (0, 0) be null pointer constant. */
2848 }
2853 {
2854 /* The left-hand operand of a comma expression is like an expression
2855 statement: with -Wextra or -Wunused, we should warn if it doesn't have
2856 any side-effects, unless it was explicitly cast to (void). */
2861 }
2863 /* With -Wunused, we should also warn if the left-hand operand does have
2864 side-effects, but computes a value which is not used. For example, in
2865 `foo() + bar(), baz()' the result of the `+' operator is not used,
2866 so we should issue a warning. */
2871 }
2873 /* Build an expression representing a cast to type TYPE of expression EXPR. */
2875 tree
2877 {
2883 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
2884 only in <protocol> qualifications. But when constructing cast expressions,
2885 the protocols do matter and must be kept around. */
2890 {
2893 }
2896 {
2899 }
2902 {
2904 {
2908 }
2909 }
2911 {
2912 tree field;
2921 {
2922 tree t;
2932 }
2935 }
2936 else
2937 {
2940 /* If casting to void, avoid the error that would come
2941 from default_conversion in the case of a non-lvalue array. */
2945 /* Convert functions and arrays to pointers,
2946 but don't convert any other types. */
2950 /* Optionally warn about potentially worrisome casts. */
2955 {
2961 /* Check that the qualifiers on IN_TYPE are a superset of
2962 the qualifiers of IN_OTYPE. The outermost level of
2963 POINTER_TYPE nodes is uninteresting and we stop as soon
2964 as we hit a non-POINTER_TYPE node on either type. */
2965 do
2966 {
2970 /* GNU C allows cv-qualified function types. 'const'
2971 means the function is very pure, 'volatile' means it
2972 can't return. We need to warn when such qualifiers
2973 are added, not when they're taken away. */
2977 else
2979 }
2987 /* There are qualifiers present in IN_OTYPE that are not
2988 present in IN_TYPE. */
2990 }
2992 /* Warn about possible alignment problems. */
2998 /* Don't warn about opaque types, where the actual alignment
2999 restriction is unknown. */
3020 /* Don't warn about converting any constant. */
3030 {
3031 /* Casting the address of a decl to non void pointer. Warn
3032 if the cast breaks type based aliasing. */
3035 else
3036 {
3045 }
3046 }
3048 /* If pedantic, warn for conversions between function and object
3049 pointer types, except for converting a null pointer constant
3050 to function pointer type. */
3068 /* Replace a nonvolatile const static variable with its value. */
3073 /* Ignore any integer overflow caused by the cast. */
3075 {
3078 }
3079 }
3081 /* Don't let (void *) (FOO *) 0 be a null pointer constant. */
3087 /* Don't let a cast be an lvalue. */
3092 }
3094 /* Interpret a cast of expression EXPR to type TYPE. */
3095 tree
3097 {
3100 /* This avoids warnings about unprototyped casts on
3101 integers. E.g. "#define SIG_DFL (void(*)())0". */
3108 }
3110 \f
3111 /* Build an assignment expression of lvalue LHS from value RHS.
3112 MODIFYCODE is the code for a binary operator that we use
3113 to combine the old value of LHS with RHS to get the new value.
3114 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3116 tree
3118 {
3119 tree result;
3120 tree newrhs;
3124 /* Types that aren't fully specified cannot be used in assignments. */
3127 /* Avoid duplicate error messages from operands that had errors. */
3131 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3132 /* Do not use STRIP_NOPS here. We do not want an enumerator
3133 whose value is 0 to count as a null pointer constant. */
3139 /* If a binary op has been requested, combine the old LHS value with the RHS
3140 producing the value we should actually store into the LHS. */
3143 {
3146 }
3151 /* Warn about storing in something that is `const'. */
3159 /* If storing into a structure or union member,
3160 it has probably been given type `int'.
3161 Compute the type that would go with
3162 the actual amount of storage the member occupies. */
3171 /* If storing in a field that is in actuality a short or narrower than one,
3172 we must store in the field in its actual type. */
3175 {
3178 }
3180 /* Convert new value to destination type. */
3187 /* Scan operands */
3192 /* If we got the LHS in a different type for storing in,
3193 convert the result back to the nominal type of LHS
3194 so that the value we return always has the same type
3195 as the LHS argument. */
3201 }
3202 \f
3203 /* Convert value RHS to type TYPE as preparation for an assignment
3204 to an lvalue of type TYPE.
3205 The real work of conversion is done by `convert'.
3206 The purpose of this function is to generate error messages
3207 for assignments that are not allowed in C.
3208 ERRTYPE is a string to use in error messages:
3209 "assignment", "return", etc. If it is null, this is parameter passing
3210 for a function call (and different error messages are output).
3212 FUNNAME is the name of the function being called,
3213 as an IDENTIFIER_NODE, or null.
3214 PARMNUM is the number of the argument, for printing in error messages. */
3216 static tree
3219 {
3221 tree rhstype;
3224 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3225 /* Do not use STRIP_NOPS here. We do not want an enumerator
3226 whose value is 0 to count as a null pointer constant. */
3243 {
3245 /* Check for Objective-C protocols. This will automatically
3246 issue a warning if there are protocol violations. No need to
3247 use the return value. */
3251 }
3254 {
3257 }
3258 /* A type converts to a reference to it.
3259 This code doesn't fully support references, it's just for the
3260 special case of va_start and va_copy. */
3263 {
3265 {
3268 }
3273 /* We already know that these two types are compatible, but they
3274 may not be exactly identical. In fact, `TREE_TYPE (type)' is
3275 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
3276 likely to be va_list, a typedef to __builtin_va_list, which
3277 is different enough that it will cause problems later. */
3283 }
3284 /* Some types can interconvert without explicit casts. */
3288 /* Arithmetic types all interconvert, and enum is treated like int. */
3297 /* Conversion to a transparent union from its member types.
3298 This applies only to function arguments. */
3300 {
3301 tree memb_types;
3306 {
3317 {
3321 /* Any non-function converts to a [const][volatile] void *
3322 and vice versa; otherwise, targets must be the same.
3323 Meanwhile, the lhs target must have all the qualifiers of
3324 the rhs. */
3327 {
3328 /* If this type won't generate any warnings, use it. */
3338 /* Keep looking for a better type, but remember this one. */
3341 }
3342 }
3344 /* Can convert integer zero to any pointer type. */
3348 {
3351 }
3352 }
3355 {
3357 {
3358 /* We have only a marginally acceptable member type;
3359 it needs a warning. */
3363 /* Const and volatile mean something different for function
3364 types, so the usual warnings are not appropriate. */
3367 {
3368 /* Because const and volatile on functions are
3369 restrictions that say the function will not do
3370 certain things, it is okay to use a const or volatile
3371 function where an ordinary one is wanted, but not
3372 vice-versa. */
3376 }
3380 parmnum);
3381 }
3387 }
3388 }
3390 /* Conversions among pointers */
3393 {
3399 /* Opaque pointers are treated like void pointers. */
3405 /* Any non-function converts to a [const][volatile] void *
3406 and vice versa; otherwise, targets must be the same.
3407 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
3410 || is_opaque_pointer
3413 {
3416 ||
3418 /* Check TREE_CODE to catch cases like (void *) (char *) 0
3419 which are not ANSI null ptr constants. */
3424 /* Const and volatile mean something different for function types,
3425 so the usual warnings are not appropriate. */
3428 {
3432 /* If this is not a case of ignoring a mismatch in signedness,
3433 no warning. */
3436 ;
3437 /* If there is a mismatch, do warn. */
3441 }
3444 {
3445 /* Because const and volatile on functions are restrictions
3446 that say the function will not do certain things,
3447 it is okay to use a const or volatile function
3448 where an ordinary one is wanted, but not vice-versa. */
3452 }
3453 }
3454 else
3458 }
3460 {
3463 }
3465 {
3466 /* An explicit constant 0 can convert to a pointer,
3467 or one that results from arithmetic, even including
3468 a cast to integer type. */
3470 &&
3479 }
3481 {
3485 }
3490 {
3492 {
3498 else
3501 }
3502 else
3504 parmnum);
3505 }
3506 else
3510 }
3512 /* Convert VALUE for assignment into inlined parameter PARM. ARGNUM
3513 is used for error and waring reporting and indicates which argument
3514 is being processed. */
3516 tree
3518 {
3521 /* If FN was prototyped, the value has been converted already
3522 in convert_arguments. */
3535 }
3537 /* Print a warning using MSGID.
3538 It gets OPNAME as its one parameter.
3539 if OPNAME is null and ARGNUM is 0, it is replaced by "passing arg of `FUNCTION'".
3540 Otherwise if OPNAME is null, it is replaced by "passing arg ARGNUM of `FUNCTION'".
3541 FUNCTION and ARGNUM are handled specially if we are building an
3542 Objective-C selector. */
3544 static void
3547 {
3549 {
3554 {
3557 }
3559 {
3561 {
3562 /* Function name is known; supply it. */
3568 }
3569 else
3570 {
3571 /* Function name unknown (call through ptr). */
3575 }
3576 }
3578 {
3579 /* Function name is known; supply it. */
3585 }
3586 else
3587 {
3588 /* Function name unknown (call through ptr); just give arg number. */
3592 }
3594 }
3596 }
3597 \f
3598 /* If VALUE is a compound expr all of whose expressions are constant, then
3599 return its value. Otherwise, return error_mark_node.
3601 This is for handling COMPOUND_EXPRs as initializer elements
3602 which is allowed with a warning when -pedantic is specified. */
3604 static tree
3606 {
3608 {
3613 endtype);
3614 }
3618 else
3620 }
3621 \f
3622 /* Perform appropriate conversions on the initial value of a variable,
3623 store it in the declaration DECL,
3624 and print any error messages that are appropriate.
3625 If the init is invalid, store an ERROR_MARK. */
3627 void
3629 {
3632 /* If variable's type was invalidly declared, just ignore it. */
3638 /* Digest the specified initializer into an expression. */
3642 /* Store the expression if valid; else report error. */
3650 /* ANSI wants warnings about out-of-range constant initializers. */
3654 /* Check if we need to set array size from compound literal size. */
3658 {
3666 {
3670 {
3671 /* For int foo[] = (int [3]){1}; we need to set array size
3672 now since later on array initializer will be just the
3673 brace enclosed list of the compound literal. */
3677 }
3678 }
3679 }
3680 }
3681 \f
3682 /* Methods for storing and printing names for error messages. */
3684 /* Implement a spelling stack that allows components of a name to be pushed
3685 and popped. Each element on the stack is this structure. */
3687 struct spelling
3688 {
3690 union
3691 {
3695 };
3697 #define SPELLING_STRING 1
3698 #define SPELLING_MEMBER 2
3699 #define SPELLING_BOUNDS 3
3705 /* Macros to save and restore the spelling stack around push_... functions.
3706 Alternative to SAVE_SPELLING_STACK. */
3708 #define SPELLING_DEPTH() (spelling - spelling_base)
3709 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
3711 /* Push an element on the spelling stack with type KIND and assign VALUE
3712 to MEMBER. */
3714 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
3715 { \
3716 int depth = SPELLING_DEPTH (); \
3717 \
3718 if (depth >= spelling_size) \
3719 { \
3720 spelling_size += 10; \
3721 if (spelling_base == 0) \
3722 spelling_base = xmalloc (spelling_size * sizeof (struct spelling)); \
3723 else \
3724 spelling_base = xrealloc (spelling_base, \
3725 spelling_size * sizeof (struct spelling)); \
3726 RESTORE_SPELLING_DEPTH (depth); \
3727 } \
3728 \
3729 spelling->kind = (KIND); \
3730 spelling->MEMBER = (VALUE); \
3731 spelling++; \
3732 }
3734 /* Push STRING on the stack. Printed literally. */
3736 static void
3738 {
3740 }
3742 /* Push a member name on the stack. Printed as '.' STRING. */
3744 static void
3746 {
3750 }
3752 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
3754 static void
3756 {
3758 }
3760 /* Compute the maximum size in bytes of the printed spelling. */
3762 static int
3764 {
3769 {
3772 else
3774 }
3777 }
3779 /* Print the spelling to BUFFER and return it. */
3783 {
3789 {
3792 }
3793 else
3794 {
3799 ;
3800 }
3803 }
3805 /* Issue an error message for a bad initializer component.
3806 MSGID identifies the message.
3807 The component name is taken from the spelling stack. */
3809 void
3811 {
3818 }
3820 /* Issue a pedantic warning for a bad initializer component.
3821 MSGID identifies the message.
3822 The component name is taken from the spelling stack. */
3824 void
3826 {
3833 }
3835 /* Issue a warning for a bad initializer component.
3836 MSGID identifies the message.
3837 The component name is taken from the spelling stack. */
3839 static void
3841 {
3848 }
3849 \f
3850 /* Digest the parser output INIT as an initializer for type TYPE.
3851 Return a C expression of type TYPE to represent the initial value.
3853 REQUIRE_CONSTANT requests an error if non-constant initializers or
3854 elements are seen. */
3856 static tree
3858 {
3867 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3868 /* Do not use STRIP_NOPS here. We do not want an enumerator
3869 whose value is 0 to count as a null pointer constant. */
3875 /* Initialization of an array of chars from a string constant
3876 optionally enclosed in braces. */
3879 {
3887 {
3895 {
3898 }
3902 {
3905 }
3911 /* Subtract 1 (or sizeof (wchar_t))
3912 because it's ok to ignore the terminating null char
3913 that is counted in the length of the constant. */
3924 }
3925 }
3927 /* Build a VECTOR_CST from a *constant* vector constructor. If the
3928 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
3929 below and handle as a constructor. */
3933 {
3937 COMPARE_STRICT))
3939 else
3941 }
3943 /* Any type can be initialized
3944 from an expression of the same type, optionally with braces. */
3961 {
3963 {
3967 {
3970 }
3971 }
3974 /* Although the types are compatible, we may require a
3975 conversion. */
3980 {
3981 /* As an extension, allow initializing objects with static storage
3982 duration with compound literals (which are then treated just as
3983 the brace enclosed list they contain). */
3986 }
3990 {
3993 }
3998 /* Compound expressions can only occur here if -pedantic or
3999 -pedantic-errors is specified. In the later case, we always want
4000 an error. In the former case, we simply want a warning. */
4003 {
4004 inside_init
4009 else
4013 }
4016 /* This test catches things like `7 / 0' which
4017 result in an expression for which TREE_CONSTANT
4018 is true, but which is not actually something
4019 that is a legal constant. We really should not
4020 be using this function, because it is a part of
4021 the back-end. Instead, the expression should
4022 already have been turned into ERROR_MARK_NODE. */
4025 {
4028 }
4031 }
4033 /* Handle scalar types, including conversions. */
4037 {
4038 /* Note that convert_for_assignment calls default_conversion
4039 for arrays and functions. We must not call it in the
4040 case where inside_init is a null pointer constant. */
4041 inside_init
4046 {
4049 }
4052 {
4055 }
4058 }
4060 /* Come here only for records and arrays. */
4063 {
4066 }
4070 }
4071 \f
4072 /* Handle initializers that use braces. */
4074 /* Type of object we are accumulating a constructor for.
4075 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4078 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4079 left to fill. */
4082 /* For an ARRAY_TYPE, this is the specified index
4083 at which to store the next element we get. */
4086 /* For an ARRAY_TYPE, this is the maximum index. */
4089 /* For a RECORD_TYPE, this is the first field not yet written out. */
4092 /* For an ARRAY_TYPE, this is the index of the first element
4093 not yet written out. */
4096 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4097 This is so we can generate gaps between fields, when appropriate. */
4100 /* If we are saving up the elements rather than allocating them,
4101 this is the list of elements so far (in reverse order,
4102 most recent first). */
4105 /* 1 if constructor should be incrementally stored into a constructor chain,
4106 0 if all the elements should be kept in AVL tree. */
4109 /* 1 if so far this constructor's elements are all compile-time constants. */
4112 /* 1 if so far this constructor's elements are all valid address constants. */
4115 /* 1 if this constructor is erroneous so far. */
4118 /* Structure for managing pending initializer elements, organized as an
4119 AVL tree. */
4121 struct init_node
4122 {
4126 tree purpose;
4127 tree value;
4128 };
4130 /* Tree of pending elements at this constructor level.
4131 These are elements encountered out of order
4132 which belong at places we haven't reached yet in actually
4133 writing the output.
4134 Will never hold tree nodes across GC runs. */
4137 /* The SPELLING_DEPTH of this constructor. */
4140 /* 0 if implicitly pushing constructor levels is allowed. */
4146 /* DECL node for which an initializer is being read.
4147 0 means we are reading a constructor expression
4148 such as (struct foo) {...}. */
4151 /* start_init saves the ASMSPEC arg here for really_start_incremental_init. */
4154 /* Nonzero if this is an initializer for a top-level decl. */
4157 /* Nonzero if there were any member designators in this initializer. */
4160 /* Nesting depth of designator list. */
4163 /* Nonzero if there were diagnosed errors in this designator list. */
4166 \f
4167 /* This stack has a level for each implicit or explicit level of
4168 structuring in the initializer, including the outermost one. It
4169 saves the values of most of the variables above. */
4173 struct constructor_stack
4174 {
4176 tree type;
4177 tree fields;
4178 tree index;
4179 tree max_index;
4180 tree unfilled_index;
4181 tree unfilled_fields;
4182 tree bit_index;
4183 tree elements;
4187 /* If nonzero, this value should replace the entire
4188 constructor at this level. */
4189 tree replacement_value;
4198 };
4202 /* This stack represents designators from some range designator up to
4203 the last designator in the list. */
4205 struct constructor_range_stack
4206 {
4209 tree range_start;
4210 tree index;
4211 tree range_end;
4212 tree fields;
4213 };
4217 /* This stack records separate initializers that are nested.
4218 Nested initializers can't happen in ANSI C, but GNU C allows them
4219 in cases like { ... (struct foo) { ... } ... }. */
4221 struct initializer_stack
4222 {
4224 tree decl;
4228 tree elements;
4235 };
4238 \f
4239 /* Prepare to parse and output the initializer for variable DECL. */
4241 void
4243 {
4271 {
4273 require_constant_elements
4275 /* For a scalar, you can always use any value to initialize,
4276 even within braces. */
4282 }
4283 else
4284 {
4288 }
4301 }
4303 void
4305 {
4308 /* Free the whole constructor stack of this initializer. */
4310 {
4314 }
4319 /* Pop back to the data of the outer initializer (if any). */
4335 }
4336 \f
4337 /* Call here when we see the initializer is surrounded by braces.
4338 This is instead of a call to push_init_level;
4339 it is matched by a call to pop_init_level.
4341 TYPE is the type to initialize, for a constructor expression.
4342 For an initializer for a decl, TYPE is zero. */
4344 void
4346 {
4390 {
4392 /* Skip any nameless bit fields at the beginning. */
4399 }
4401 {
4403 {
4404 constructor_max_index
4407 /* Detect non-empty initializations of zero-length arrays. */
4412 /* constructor_max_index needs to be an INTEGER_CST. Attempts
4413 to initialize VLAs will cause a proper error; avoid tree
4414 checking errors as well by setting a safe value. */
4419 constructor_index
4422 }
4423 else
4427 }
4429 {
4430 /* Vectors are like simple fixed-size arrays. */
4431 constructor_max_index =
4435 }
4436 else
4437 {
4438 /* Handle the case of int x = {5}; */
4441 }
4442 }
4443 \f
4444 /* Push down into a subobject, for initialization.
4445 If this is for an explicit set of braces, IMPLICIT is 0.
4446 If it is because the next element belongs at a lower level,
4447 IMPLICIT is 1 (or 2 if the push is because of designator list). */
4449 void
4451 {
4455 /* If we've exhausted any levels that didn't have braces,
4456 pop them now. */
4458 {
4464 && constructor_max_index
4467 else
4469 }
4471 /* Unless this is an explicit brace, we need to preserve previous
4472 content if any. */
4474 {
4481 }
4514 {
4519 }
4521 /* Don't die if an entire brace-pair level is superfluous
4522 in the containing level. */
4524 ;
4527 {
4528 /* Don't die if there are extra init elts at the end. */
4531 else
4532 {
4535 constructor_depth++;
4536 }
4537 }
4539 {
4542 constructor_depth++;
4543 }
4546 {
4551 }
4554 {
4562 }
4565 {
4568 }
4572 {
4574 /* Skip any nameless bit fields at the beginning. */
4581 }
4583 {
4584 /* Vectors are like simple fixed-size arrays. */
4585 constructor_max_index =
4589 }
4591 {
4593 {
4594 constructor_max_index
4597 /* Detect non-empty initializations of zero-length arrays. */
4602 /* constructor_max_index needs to be an INTEGER_CST. Attempts
4603 to initialize VLAs will cause a proper error; avoid tree
4604 checking errors as well by setting a safe value. */
4609 constructor_index
4612 }
4613 else
4618 {
4619 /* We need to split the char/wchar array into individual
4620 characters, so that we don't have to special case it
4621 everywhere. */
4623 }
4624 }
4625 else
4626 {
4630 }
4631 }
4633 /* At the end of an implicit or explicit brace level,
4634 finish up that level of constructor.
4635 If we were outputting the elements as they are read, return 0
4636 from inner levels (process_init_element ignores that),
4637 but return error_mark_node from the outermost level
4638 (that's what we want to put in DECL_INITIAL).
4639 Otherwise, return a CONSTRUCTOR expression. */
4641 tree
4643 {
4648 {
4649 /* When we come to an explicit close brace,
4650 pop any inner levels that didn't have explicit braces. */
4656 }
4660 /* Error for initializing a flexible array member, or a zero-length
4661 array member in an inappropriate context. */
4666 {
4667 /* Silently discard empty initializations. The parser will
4668 already have pedwarned for empty brackets. */
4672 {
4678 /* We have already issued an error message for the existence
4679 of a flexible array member not at the end of the structure.
4680 Discard the initializer so that we do not abort later. */
4683 }
4684 else
4685 /* Zero-length arrays are no longer special, so we should no longer
4686 get here. */
4688 }
4690 /* Warn when some struct elements are implicitly initialized to zero. */
4692 && constructor_type
4695 {
4696 /* Do not warn for flexible array members or zero-length arrays. */
4702 /* Do not warn if this level of the initializer uses member
4703 designators; it is likely to be deliberate. */
4705 {
4709 }
4710 }
4712 /* Now output all pending elements. */
4716 /* Pad out the end of the structure. */
4718 /* If this closes a superfluous brace pair,
4719 just pass out the element between them. */
4722 ;
4727 {
4728 /* A nonincremental scalar initializer--just return
4729 the element, after verifying there is just one. */
4731 {
4735 }
4737 {
4740 }
4741 else
4743 }
4744 else
4745 {
4748 else
4749 {
4756 }
4757 }
4782 {
4786 }
4788 }
4790 /* Common handling for both array range and field name designators.
4791 ARRAY argument is nonzero for array ranges. Returns zero for success. */
4793 static int
4795 {
4796 tree subtype;
4799 /* Don't die if an entire brace-pair level is superfluous
4800 in the containing level. */
4804 /* If there were errors in this designator list already, bail out silently. */
4809 {
4813 /* Designator list starts at the level of closest explicit
4814 braces. */
4819 }
4822 {
4825 }
4829 {
4833 }
4835 {
4837 }
4838 else
4843 {
4846 }
4848 {
4851 }
4856 }
4858 /* If there are range designators in designator list, push a new designator
4859 to constructor_range_stack. RANGE_END is end of such stack range or
4860 NULL_TREE if there is no range designator at this level. */
4862 static void
4864 {
4878 }
4880 /* Within an array initializer, specify the next index to be initialized.
4881 FIRST is that index. If LAST is nonzero, then initialize a range
4882 of indices, running from FIRST through LAST. */
4884 void
4886 {
4918 else
4919 {
4923 {
4927 {
4930 }
4931 else
4932 {
4936 {
4939 }
4940 }
4941 }
4943 designator_depth++;
4947 }
4948 }
4950 /* Within a struct initializer, specify the next field to be initialized. */
4952 void
4954 {
4955 tree tail;
4964 {
4967 }
4971 {
4974 }
4979 else
4980 {
4982 designator_depth++;
4986 }
4987 }
4988 \f
4989 /* Add a new initializer to the tree of pending initializers. PURPOSE
4990 identifies the initializer, either array index or field in a structure.
4991 VALUE is the value of that index or field. */
4993 static void
4995 {
5002 {
5004 {
5010 else
5011 {
5016 }
5017 }
5018 }
5019 else
5020 {
5021 tree bitpos;
5025 {
5031 else
5032 {
5037 }
5038 }
5039 }
5052 {
5056 {
5060 {
5062 {
5063 /* L rotation. */
5076 {
5079 else
5081 }
5082 else
5084 }
5085 else
5086 {
5087 /* LR rotation. */
5109 {
5112 else
5114 }
5115 else
5117 }
5119 }
5120 else
5121 {
5122 /* p->balance == +1; growth of left side balances the node. */
5125 }
5126 }
5128 {
5130 /* Growth propagation from right side. */
5133 {
5135 {
5136 /* R rotation. */
5149 {
5152 else
5154 }
5155 else
5157 }
5159 {
5160 /* RL rotation */
5182 {
5185 else
5187 }
5188 else
5190 }
5192 }
5193 else
5194 {
5195 /* p->balance == -1; growth of right side balances the node. */
5198 }
5199 }
5203 }
5204 }
5206 /* Build AVL tree from a sorted chain. */
5208 static void
5210 {
5211 tree chain;
5221 {
5223 /* Skip any nameless bit fields at the beginning. */
5229 }
5231 {
5233 constructor_unfilled_index
5236 else
5238 }
5240 }
5242 /* Build AVL tree from a string constant. */
5244 static void
5246 {
5261 else
5272 {
5274 {
5277 }
5278 else
5279 {
5283 {
5286 else
5291 }
5292 }
5295 {
5298 {
5300 {
5303 }
5304 }
5306 {
5309 }
5314 }
5319 }
5322 }
5324 /* Return value of FIELD in pending initializer or zero if the field was
5325 not initialized yet. */
5327 static tree
5329 {
5333 {
5340 {
5345 else
5347 }
5348 }
5350 {
5354 && (!constructor_unfilled_fields
5361 {
5366 else
5368 }
5369 }
5371 {
5375 }
5377 }
5379 /* "Output" the next constructor element.
5380 At top level, really output it to assembler code now.
5381 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
5382 TYPE is the data type that the containing data type wants here.
5383 FIELD is the field (a FIELD_DECL) or the index that this element fills.
5385 PENDING if non-nil means output pending elements that belong
5386 right after this element. (PENDING is normally 1;
5387 it is 0 while outputting pending elements, to avoid recursion.) */
5389 static void
5391 {
5393 {
5396 }
5408 {
5409 /* As an extension, allow initializing objects with static storage
5410 duration with compound literals (which are then treated just as
5411 the brace enclosed list they contain). */
5414 }
5428 {
5431 }
5436 /* If this field is empty (and not at the end of structure),
5437 don't do anything other than checking the initializer. */
5448 {
5451 }
5453 /* If this element doesn't come next in sequence,
5454 put it on constructor_pending_elts. */
5456 && (!constructor_incremental
5458 {
5465 }
5467 && (!constructor_incremental
5469 {
5470 /* We do this for records but not for unions. In a union,
5471 no matter which field is specified, it can be initialized
5472 right away since it starts at the beginning of the union. */
5474 {
5477 else
5478 {
5486 }
5487 }
5491 }
5494 {
5498 /* We can have just one union field set. */
5500 }
5502 /* Otherwise, output this element either to
5503 constructor_elements or to the assembler file. */
5507 constructor_elements
5510 /* Advance the variable that indicates sequential elements output. */
5512 constructor_unfilled_index
5514 bitsize_one_node);
5516 {
5517 constructor_unfilled_fields
5520 /* Skip any nameless bit fields. */
5524 constructor_unfilled_fields =
5526 }
5530 /* Now output any pending elements which have become next. */
5533 }
5535 /* Output any pending elements which have become next.
5536 As we output elements, constructor_unfilled_{fields,index}
5537 advances, which may cause other elements to become next;
5538 if so, they too are output.
5540 If ALL is 0, we return when there are
5541 no more pending elements to output now.
5543 If ALL is 1, we output space as necessary so that
5544 we can output all the pending elements. */
5546 static void
5548 {
5550 tree next;
5552 retry:
5554 /* Look through the whole pending tree.
5555 If we find an element that should be output now,
5556 output it. Otherwise, set NEXT to the element
5557 that comes first among those still pending. */
5561 {
5563 {
5565 constructor_unfilled_index))
5571 {
5572 /* Advance to the next smaller node. */
5575 else
5576 {
5577 /* We have reached the smallest node bigger than the
5578 current unfilled index. Fill the space first. */
5581 }
5582 }
5583 else
5584 {
5585 /* Advance to the next bigger node. */
5588 else
5589 {
5590 /* We have reached the biggest node in a subtree. Find
5591 the parent of it, which is the next bigger node. */
5597 {
5600 }
5601 }
5602 }
5603 }
5606 {
5609 /* If the current record is complete we are done. */
5615 /* We can't compare fields here because there might be empty
5616 fields in between. */
5618 {
5622 }
5624 {
5625 /* Advance to the next smaller node. */
5628 else
5629 {
5630 /* We have reached the smallest node bigger than the
5631 current unfilled field. Fill the space first. */
5634 }
5635 }
5636 else
5637 {
5638 /* Advance to the next bigger node. */
5641 else
5642 {
5643 /* We have reached the biggest node in a subtree. Find
5644 the parent of it, which is the next bigger node. */
5651 {
5654 }
5655 }
5656 }
5657 }
5658 }
5660 /* Ordinarily return, but not if we want to output all
5661 and there are elements left. */
5665 /* If it's not incremental, just skip over the gap, so that after
5666 jumping to retry we will output the next successive element. */
5673 /* ELT now points to the node in the pending tree with the next
5674 initializer to output. */
5676 }
5677 \f
5678 /* Add one non-braced element to the current constructor level.
5679 This adjusts the current position within the constructor's type.
5680 This may also start or terminate implicit levels
5681 to handle a partly-braced initializer.
5683 Once this has found the correct level for the new element,
5684 it calls output_init_element. */
5686 void
5688 {
5695 /* Handle superfluous braces around string cst as in
5696 char x[] = {"foo"}; */
5698 && constructor_type
5702 {
5707 }
5710 {
5713 }
5715 /* Ignore elements of a brace group if it is entirely superfluous
5716 and has already been diagnosed. */
5720 /* If we've exhausted any levels that didn't have braces,
5721 pop them now. */
5723 {
5731 constructor_index)))
5733 else
5735 }
5737 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
5739 {
5740 /* If value is a compound literal and we'll be just using its
5741 content, don't put it into a SAVE_EXPR. */
5743 || !require_constant_value
5746 }
5749 {
5751 {
5752 tree fieldtype;
5756 {
5759 }
5766 /* Error for non-static initialization of a flexible array member. */
5768 && !require_constant_value
5771 {
5774 }
5776 /* Accept a string constant to initialize a subarray. */
5782 /* Otherwise, if we have come to a subaggregate,
5783 and we don't have an element of its type, push into it. */
5789 {
5792 }
5795 {
5799 }
5800 else
5801 /* Do the bookkeeping for an element that was
5802 directly output as a constructor. */
5803 {
5804 /* For a record, keep track of end position of last field. */
5806 constructor_bit_index
5811 /* If the current field was the first one not yet written out,
5812 it isn't now, so update. */
5814 {
5816 /* Skip any nameless bit fields. */
5820 constructor_unfilled_fields =
5822 }
5823 }
5826 /* Skip any nameless bit fields at the beginning. */
5831 }
5833 {
5834 tree fieldtype;
5838 {
5841 }
5848 /* Warn that traditional C rejects initialization of unions.
5849 We skip the warning if the value is zero. This is done
5850 under the assumption that the zero initializer in user
5851 code appears conditioned on e.g. __STDC__ to avoid
5852 "missing initializer" warnings and relies on default
5853 initialization to zero in the traditional C case.
5854 We also skip the warning if the initializer is designated,
5855 again on the assumption that this must be conditional on
5856 __STDC__ anyway (and we've already complained about the
5857 member-designator already). */
5862 /* Accept a string constant to initialize a subarray. */
5868 /* Otherwise, if we have come to a subaggregate,
5869 and we don't have an element of its type, push into it. */
5875 {
5878 }
5881 {
5885 }
5886 else
5887 /* Do the bookkeeping for an element that was
5888 directly output as a constructor. */
5889 {
5892 }
5895 }
5897 {
5901 /* Accept a string constant to initialize a subarray. */
5907 /* Otherwise, if we have come to a subaggregate,
5908 and we don't have an element of its type, push into it. */
5914 {
5917 }
5922 {
5925 }
5927 /* Now output the actual element. */
5929 {
5933 }
5935 constructor_index
5939 /* If we are doing the bookkeeping for an element that was
5940 directly output as a constructor, we must update
5941 constructor_unfilled_index. */
5943 }
5945 {
5948 /* Do a basic check of initializer size. Note that vectors
5949 always have a fixed size derived from their type. */
5951 {
5954 }
5956 /* Now output the actual element. */
5960 constructor_index
5964 /* If we are doing the bookkeeping for an element that was
5965 directly output as a constructor, we must update
5966 constructor_unfilled_index. */
5968 }
5970 /* Handle the sole element allowed in a braced initializer
5971 for a scalar variable. */
5973 {
5976 }
5977 else
5978 {
5982 }
5984 /* Handle range initializers either at this level or anywhere higher
5985 in the designator stack. */
5987 {
5994 {
5998 }
6002 {
6006 }
6013 {
6017 {
6020 }
6028 }
6033 }
6036 }
6039 }
6040 \f
6041 /* Build a complete asm-statement, whose components are a CV_QUALIFIER
6042 (guaranteed to be 'volatile' or null) and ARGS (represented using
6043 an ASM_STMT node). */
6044 tree
6046 {
6050 }
6052 /* Build an asm-expr, whose components are a STRING, some OUTPUTS,
6053 some INPUTS, and some CLOBBERS. The latter three may be NULL.
6054 SIMPLE indicates whether there was anything at all after the
6055 string in the asm expression -- asm("blah") and asm("blah" : )
6056 are subtly different. We use a ASM_STMT node to represent this. */
6057 tree
6060 {
6061 tree tail;
6062 tree args;
6064 /* We can remove output conversions that change the type,
6065 but not the mode. */
6067 {
6073 /* Allow conversions as LHS here. build_modify_expr as called below
6074 will do the right thing with them. */
6085 }
6087 /* Remove output conversions that change the type but not the mode. */
6089 {
6093 }
6095 /* Perform default conversions on array and function inputs.
6096 Don't do this for other types as it would screw up operands
6097 expected to be in memory. */
6103 /* Simple asm statements are treated as volatile. */
6105 {
6108 }
6110 }
6112 /* Expand an ASM statement with operands, handling output operands
6113 that are not variables or INDIRECT_REFS by transforming such
6114 cases into cases that expand_asm_operands can handle.
6116 Arguments are same as for expand_asm_operands. */
6118 void
6121 {
6124 /* o[I] is the place that output number I should be written. */
6126 tree tail;
6128 /* Record the contents of OUTPUTS before it is modified. */
6130 {
6134 }
6136 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
6137 OUTPUTS some trees for where the values were actually stored. */
6140 /* Copy all the intermediate outputs into the specified outputs. */
6142 {
6144 {
6149 /* Restore the original value so that it's correct the next
6150 time we expand this function. */
6152 }
6153 /* Detect modification of read-only values.
6154 (Otherwise done by build_modify_expr.) */
6155 else
6156 {
6164 }
6165 }
6167 /* Those MODIFY_EXPRs could do autoincrements. */
6169 }
6170 \f
6171 /* Expand a C `return' statement.
6172 RETVAL is the expression for what to return,
6173 or a null pointer for `return;' with no value. */
6175 tree
6177 {
6184 {
6189 }
6191 {
6195 }
6196 else
6197 {
6201 tree inner;
6209 /* Strip any conversions, additions, and subtractions, and see if
6210 we are returning the address of a local variable. Warn if so. */
6212 {
6214 {
6221 /* If the second operand of the MINUS_EXPR has a pointer
6222 type (or is converted from it), this may be valid, so
6223 don't give a warning. */
6224 {
6238 }
6255 }
6258 }
6261 }
6264 }
6265 \f
6267 /* The SWITCH_STMT being built. */
6268 tree switch_stmt;
6269 /* A splay-tree mapping the low element of a case range to the high
6270 element, or NULL_TREE if there is no high element. Used to
6271 determine whether or not a new case label duplicates an old case
6272 label. We need a tree, rather than simply a hash table, because
6273 of the GNU case range extension. */
6274 splay_tree cases;
6275 /* The next node on the stack. */
6277 };
6279 /* A stack of the currently active switch statements. The innermost
6280 switch statement is on the top of the stack. There is no need to
6281 mark the stack for garbage collection because it is only active
6282 during the processing of the body of a function, and we never
6283 collect at that point. */
6287 /* Start a C switch statement, testing expression EXP. Return the new
6288 SWITCH_STMT. */
6290 tree
6292 {
6298 {
6304 {
6307 }
6308 else
6309 {
6319 }
6320 }
6322 /* Add this new SWITCH_STMT to the stack. */
6330 }
6332 /* Process a case label. */
6334 tree
6336 {
6340 {
6349 {
6350 /* Attach the first case label to the SWITCH_BODY. */
6353 }
6354 }
6357 else
6361 }
6363 /* Finish the switch statement. */
6365 void
6367 {
6370 /* Rechain the next statements to the SWITCH_STMT. */
6373 /* Pop the stack. */
6377 }
6379 /* Build a binary-operation expression without default conversions.
6380 CODE is the kind of expression to build.
6381 This function differs from `build' in several ways:
6382 the data type of the result is computed and recorded in it,
6383 warnings are generated if arg data types are invalid,
6384 special handling for addition and subtraction of pointers is known,
6385 and some optimization is done (operations on narrow ints
6386 are done in the narrower type when that gives the same result).
6387 Constant folding is also done before the result is returned.
6389 Note that the operands will never have enumeral types, or function
6390 or array types, because either they will have the default conversions
6391 performed or they have both just been converted to some other type in which
6392 the arithmetic is to be done. */
6394 tree
6397 {
6402 /* Expression code to give to the expression when it is built.
6403 Normally this is CODE, which is what the caller asked for,
6404 but in some special cases we change it. */
6407 /* Data type in which the computation is to be performed.
6408 In the simplest cases this is the common type of the arguments. */
6411 /* Nonzero means operands have already been type-converted
6412 in whatever way is necessary.
6413 Zero means they need to be converted to RESULT_TYPE. */
6416 /* Nonzero means create the expression with this type, rather than
6417 RESULT_TYPE. */
6420 /* Nonzero means after finally constructing the expression
6421 convert it to this type. */
6424 /* Nonzero if this is an operation like MIN or MAX which can
6425 safely be computed in short if both args are promoted shorts.
6426 Also implies COMMON.
6427 -1 indicates a bitwise operation; this makes a difference
6428 in the exact conditions for when it is safe to do the operation
6429 in a narrower mode. */
6432 /* Nonzero if this is a comparison operation;
6433 if both args are promoted shorts, compare the original shorts.
6434 Also implies COMMON. */
6437 /* Nonzero if this is a right-shift operation, which can be computed on the
6438 original short and then promoted if the operand is a promoted short. */
6441 /* Nonzero means set RESULT_TYPE to the common type of the args. */
6445 {
6448 }
6449 else
6450 {
6453 }
6458 /* The expression codes of the data types of the arguments tell us
6459 whether the arguments are integers, floating, pointers, etc. */
6463 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
6467 /* If an error was already reported for one of the arguments,
6468 avoid reporting another error. */
6474 {
6476 /* Handle the pointer + int case. */
6481 else
6486 /* Subtraction of two similar pointers.
6487 We must subtract them as integers, then divide by object size. */
6491 /* Handle pointer minus int. Just like pointer plus int. */
6494 else
6507 /* Floating point division by zero is a legitimate way to obtain
6508 infinities and NaNs. */
6516 {
6519 else
6520 /* Although it would be tempting to shorten always here, that
6521 loses on some targets, since the modulo instruction is
6522 undefined if the quotient can't be represented in the
6523 computation mode. We shorten only if unsigned or if
6524 dividing by something we know != -1. */
6529 }
6547 {
6548 /* Although it would be tempting to shorten always here, that loses
6549 on some targets, since the modulo instruction is undefined if the
6550 quotient can't be represented in the computation mode. We shorten
6551 only if unsigned or if dividing by something we know != -1. */
6556 }
6568 {
6569 /* Result of these operations is always an int,
6570 but that does not mean the operands should be
6571 converted to ints! */
6576 }
6579 /* Shift operations: result has same type as first operand;
6580 always convert second operand to int.
6581 Also set SHORT_SHIFT if shifting rightward. */
6585 {
6587 {
6590 else
6591 {
6597 }
6598 }
6600 /* Use the type of the value to be shifted. */
6602 /* Convert the shift-count to an integer, regardless of size
6603 of value being shifted. */
6606 /* Avoid converting op1 to result_type later. */
6608 }
6613 {
6615 {
6621 }
6623 /* Use the type of the value to be shifted. */
6625 /* Convert the shift-count to an integer, regardless of size
6626 of value being shifted. */
6629 /* Avoid converting op1 to result_type later. */
6631 }
6637 {
6639 {
6644 }
6646 /* Use the type of the value to be shifted. */
6648 /* Convert the shift-count to an integer, regardless of size
6649 of value being shifted. */
6652 /* Avoid converting op1 to result_type later. */
6654 }
6661 /* Result of comparison is always int,
6662 but don't convert the args to int! */
6672 {
6675 /* Anything compares with void *. void * compares with anything.
6676 Otherwise, the targets must be compatible
6677 and both must be object or both incomplete. */
6681 {
6682 /* op0 != orig_op0 detects the case of something
6683 whose value is 0 but which isn't a valid null ptr const. */
6687 }
6689 {
6693 }
6694 else
6699 }
6707 {
6710 }
6712 {
6715 }
6724 {
6726 {
6731 }
6732 else
6733 {
6736 }
6737 }
6749 {
6751 {
6759 }
6760 else
6761 {
6764 }
6765 }
6768 {
6772 }
6775 {
6779 }
6781 {
6784 }
6786 {
6789 }
6801 {
6804 }
6810 }
6817 &&
6820 {
6826 /* For certain operations (which identify themselves by shorten != 0)
6827 if both args were extended from the same smaller type,
6828 do the arithmetic in that type and then extend.
6830 shorten !=0 and !=1 indicates a bitwise operation.
6831 For them, this optimization is safe only if
6832 both args are zero-extended or both are sign-extended.
6833 Otherwise, we might change the result.
6834 Eg, (short)-1 | (unsigned short)-1 is (int)-1
6835 but calculated in (unsigned short) it would be (unsigned short)-1. */
6838 {
6842 /* UNS is 1 if the operation to be done is an unsigned one. */
6844 tree type;
6848 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
6849 but it *requires* conversion to FINAL_TYPE. */
6860 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
6862 /* For bitwise operations, signedness of nominal type
6863 does not matter. Consider only how operands were extended. */
6867 /* Note that in all three cases below we refrain from optimizing
6868 an unsigned operation on sign-extended args.
6869 That would not be valid. */
6871 /* Both args variable: if both extended in same way
6872 from same width, do it in that width.
6873 Do it unsigned if args were zero-extended. */
6880 result_type
6881 = c_common_signed_or_unsigned_type
6887 && (type
6896 && (type
6901 }
6903 /* Shifts can be shortened if shifting right. */
6906 {
6916 /* We can shorten only if the shift count is less than the
6917 number of bits in the smaller type size. */
6919 /* We cannot drop an unsigned shift after sign-extension. */
6921 {
6922 /* Do an unsigned shift if the operand was zero-extended. */
6923 result_type
6926 /* Convert value-to-be-shifted to that type. */
6930 }
6931 }
6933 /* Comparison operations are shortened too but differently.
6934 They identify themselves by setting short_compare = 1. */
6937 {
6938 /* Don't write &op0, etc., because that would prevent op0
6939 from being kept in a register.
6940 Instead, make copies of the our local variables and
6941 pass the copies by reference, then copy them back afterward. */
6944 tree val
6955 {
6967 /* Give warnings for comparisons between signed and unsigned
6968 quantities that may fail.
6970 Do the checking based on the original operand trees, so that
6971 casts will be considered, but default promotions won't be.
6973 Do not warn if the comparison is being done in a signed type,
6974 since the signed type will only be chosen if it can represent
6975 all the values of the unsigned type. */
6978 /* Do not warn if both operands are the same signedness. */
6981 else
6982 {
6987 else
6990 /* Do not warn if the signed quantity is an
6991 unsuffixed integer literal (or some static
6992 constant expression involving such literals or a
6993 conditional expression involving such literals)
6994 and it is non-negative. */
6997 /* Do not warn if the comparison is an equality operation,
6998 the unsigned quantity is an integral constant, and it
6999 would fit in the result if the result were signed. */
7002 && int_fits_type_p
7005 /* Do not warn if the unsigned quantity is an enumeration
7006 constant and its maximum value would fit in the result
7007 if the result were signed. */
7010 && int_fits_type_p
7014 else
7016 }
7018 /* Warn if two unsigned values are being compared in a size
7019 larger than their original size, and one (and only one) is the
7020 result of a `~' operator. This comparison will always fail.
7022 Also warn if one operand is a constant, and the constant
7023 does not have all bits set that are set in the ~ operand
7024 when it is extended. */
7028 {
7032 else
7037 {
7038 tree primop;
7043 {
7047 }
7048 else
7049 {
7053 }
7058 {
7062 }
7063 }
7070 }
7071 }
7072 }
7073 }
7075 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
7076 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
7077 Then the expression will be built.
7078 It will be given type FINAL_TYPE if that is nonzero;
7079 otherwise, it will be given type RESULT_TYPE. */
7082 {
7085 }
7088 {
7093 }
7098 {
7100 tree folded;
7102 /* Treat expressions in initializers specially as they can't trap. */
7110 }
7111 }