| blob | eee6d5517835fa33d702c0721696b324acb3aa4b |
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 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). */
48 /* Nonzero if we've already printed a "missing braces around initializer"
49 message within this initializer. */
85 \f
86 /* Do `exp = require_complete_type (exp);' to make sure exp
87 does not have an incomplete type. (That includes void types.) */
89 tree
91 {
97 /* First, detect a valid value with a complete type. */
103 }
105 /* Print an error message for invalid use of an incomplete type.
106 VALUE is the expression that was used (or 0 if that isn't known)
107 and TYPE is the type that was invalid. */
109 void
111 {
114 /* Avoid duplicate error message. */
122 else
123 {
124 retry:
125 /* We must print an error message. Be clever about what it says. */
128 {
147 {
149 {
152 }
155 }
161 }
166 else
167 /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */
170 }
171 }
173 /* Given a type, apply default promotions wrt unnamed function
174 arguments and return the new type. */
176 tree
178 {
183 {
184 /* Preserve unsignedness if not really getting any wider. */
189 }
192 }
194 /* Return a variant of TYPE which has all the type qualifiers of LIKE
195 as well as those of TYPE. */
197 static tree
199 {
202 }
203 \f
204 /* Return the common type of two types.
205 We assume that comptypes has already been done and returned 1;
206 if that isn't so, this may crash. In particular, we assume that qualifiers
207 match.
209 This is the type for the result of most arithmetic operations
210 if the operands have the given two types. */
212 tree
214 {
217 tree attributes;
219 /* Save time if the two types are the same. */
223 /* If one type is nonsense, use the other. */
229 /* Merge the attributes. */
232 /* Treat an enum type as the unsigned integer type of the same width. */
242 /* If one type is complex, form the common type of the non-complex
243 components, then make that complex. Use T1 or T2 if it is the
244 required type. */
246 {
255 else
257 attributes);
258 }
261 {
264 /* If only one is real, use it as the result. */
272 /* Both real or both integers; use the one with greater precision. */
279 /* Same precision. Prefer longs to ints even when same size. */
284 attributes);
288 {
289 /* But preserve unsignedness from the other type,
290 since long cannot hold all the values of an unsigned int. */
293 else
296 }
298 /* Likewise, prefer long double to double even if same size. */
302 attributes);
304 /* Otherwise prefer the unsigned one. */
308 else
312 /* For two pointers, do this recursively on the target type,
313 and combine the qualifiers of the two types' targets. */
314 /* This code was turned off; I don't know why.
315 But ANSI C specifies doing this with the qualifiers.
316 So I turned it on again. */
317 {
327 }
330 {
332 /* Save space: see if the result is identical to one of the args. */
337 /* Merge the element types, and have a size if either arg has one. */
340 }
343 /* Function types: prefer the one that specified arg types.
344 If both do, merge the arg types. Also merge the return types. */
345 {
353 /* Save space: see if the result is identical to one of the args. */
359 /* Simple way if one arg fails to specify argument types. */
361 {
364 }
366 {
369 }
371 /* If both args specify argument types, we must merge the two
372 lists, argument by argument. */
387 {
388 /* A null type means arg type is not specified.
389 Take whatever the other function type has. */
391 {
394 }
396 {
399 }
401 /* Given wait (union {union wait *u; int *i} *)
402 and wait (union wait *),
403 prefer union wait * as type of parm. */
406 {
407 tree memb;
411 COMPARE_STRICT))
412 {
417 }
418 }
421 {
422 tree memb;
426 COMPARE_STRICT))
427 {
432 }
433 }
435 parm_done: ;
436 }
441 /* ... falls through ... */
442 }
446 }
448 }
449 \f
450 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
451 or various other operations. Return 2 if they are compatible
452 but a warning may be needed if you use them together. */
454 int
456 {
461 /* Suppress errors caused by previously reported errors. */
467 /* If either type is the internal version of sizetype, return the
468 language version. */
477 /* Treat an enum type as the integer type of the same width and
478 signedness. */
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. */
586 }
588 }
590 /* Return 1 if TTL and TTR are pointers to types that are equivalent,
591 ignoring their qualifiers. REFLEXIVE is only used by ObjC - set it
592 to 1 or 0 depending if the check of the pointer types is meant to
593 be reflexive or not (typically, assignments are not reflexive,
594 while comparisons are reflexive).
595 */
597 static int
599 {
602 /* Give objc_comptypes a crack at letting these types through. */
612 }
613 \f
614 /* Subroutines of `comptypes'. */
616 /* Determine whether two types derive from the same translation unit.
617 If the CONTEXT chain ends in a null, that type's context is still
618 being parsed, so if two types have context chains ending in null,
619 they're in the same translation unit. */
620 static int
622 {
625 {
630 }
634 {
639 }
642 }
644 /* The C standard says that two structures in different translation
645 units are compatible with each other only if the types of their
646 fields are compatible (among other things). So, consider two copies
647 of this structure: */
651 tree t1;
652 tree t2;
653 };
655 /* Can they be compatible with each other? We choose to break the
656 recursion by allowing those types to be compatible. */
660 /* Return 1 if two 'struct', 'union', or 'enum' types T1 and T2 are
661 compatible. If the two types are not the same (which has been
662 checked earlier), this can only happen when multiple translation
663 units are being compiled. See C99 6.2.7 paragraph 1 for the exact
664 rules. */
666 static int
668 {
672 /* We have to verify that the tags of the types are the same. This
673 is harder than it looks because this may be a typedef, so we have
674 to go look at the original type. It may even be a typedef of a
675 typedef... */
682 /* C90 didn't have the requirement that the two tags be the same. */
686 /* C90 didn't say what happened if one or both of the types were
687 incomplete; we choose to follow C99 rules here, which is that they
688 are compatible. */
693 {
698 }
701 {
703 {
708 {
713 }
715 }
718 {
723 {
735 {
750 }
754 }
756 }
759 {
770 {
785 }
790 }
794 }
795 }
797 /* Return 1 if two function types F1 and F2 are compatible.
798 If either type specifies no argument types,
799 the other must specify a fixed number of self-promoting arg types.
800 Otherwise, if one type specifies only the number of arguments,
801 the other must specify that number of self-promoting arg types.
802 Otherwise, the argument types must match. */
804 static int
806 {
808 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
816 /* 'volatile' qualifiers on a function's return type mean the function
817 is noreturn. */
833 /* An unspecified parmlist matches any specified parmlist
834 whose argument types don't need default promotions. */
837 {
840 /* If one of these types comes from a non-prototype fn definition,
841 compare that with the other type's arglist.
842 If they don't match, ask for a warning (but no error). */
845 flags))
848 }
850 {
855 flags))
858 }
860 /* Both types have argument lists: compare them and propagate results. */
863 }
865 /* Check two lists of types for compatibility,
866 returning 0 for incompatible, 1 for compatible,
867 or 2 for compatible with warning. */
869 static int
871 {
872 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
877 {
880 /* If one list is shorter than the other,
881 they fail to match. */
884 /* A null pointer instead of a type
885 means there is supposed to be an argument
886 but nothing is specified about what type it has.
887 So match anything that self-promotes. */
889 {
892 }
894 {
897 }
898 /* If one of the lists has an error marker, ignore this arg. */
901 ;
904 flags)))
905 {
906 /* Allow wait (union {union wait *u; int *i} *)
907 and wait (union wait *) to be compatible. */
914 {
915 tree memb;
919 flags))
923 }
930 {
931 tree memb;
935 flags))
939 }
940 else
942 }
944 /* comptypes said ok, but record if it said to warn. */
950 }
951 }
952 \f
953 /* Compute the size to increment a pointer by. */
955 tree
957 {
964 {
967 }
969 /* Convert in case a char is more than one unit. */
973 }
974 \f
975 /* Return either DECL or its known constant value (if it has one). */
977 tree
979 {
981 in a place where a variable is invalid. */
987 /* This is invalid if initial value is not constant.
988 If it has either a function call, a memory reference,
989 or a variable, then re-evaluating it could give different results. */
991 /* Check for cases where this is sub-optimal, even though valid. */
995 }
997 /* Return either DECL or its known constant value (if it has one), but
998 return DECL if pedantic or DECL has mode BLKmode. This is for
999 bug-compatibility with the old behavior of decl_constant_value
1000 (before GCC 3.0); every use of this function is a bug and it should
1001 be removed before GCC 3.1. It is not appropriate to use pedantic
1002 in a way that affects optimization, and BLKmode is probably not the
1003 right test for avoiding misoptimizations either. */
1005 static tree
1007 {
1010 else
1012 }
1015 /* Perform the default conversion of arrays and functions to pointers.
1016 Return the result of converting EXP. For any other expression, just
1017 return EXP. */
1019 static tree
1021 {
1022 tree orig_exp;
1027 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
1028 an lvalue.
1030 Do not use STRIP_NOPS here! It will remove conversions from pointer
1031 to integer and cause infinite recursion. */
1036 {
1040 }
1042 /* Preserve the original expression code. */
1047 {
1049 }
1051 {
1052 tree adr;
1054 tree ptrtype;
1060 {
1063 }
1066 restype
1077 {
1081 }
1085 {
1086 /* Before C99, non-lvalue arrays do not decay to pointers.
1087 Normally, using such an array would be invalid; but it can
1088 be used correctly inside sizeof or as a statement expression.
1089 Thus, do not give an error here; an error will result later. */
1091 }
1096 {
1097 /* ??? This is not really quite correct
1098 in that the type of the operand of ADDR_EXPR
1099 is not the target type of the type of the ADDR_EXPR itself.
1100 Question is, can this lossage be avoided? */
1107 }
1108 /* This way is better for a COMPONENT_REF since it can
1109 simplify the offset for a component. */
1112 }
1114 }
1116 /* Perform default promotions for C data used in expressions.
1117 Arrays and functions are converted to pointers;
1118 enumeral types or short or char, to int.
1119 In addition, manifest constants symbols are replaced by their values. */
1121 tree
1123 {
1124 tree orig_exp;
1131 /* Constants can be used directly unless they're not loadable. */
1135 /* Replace a nonvolatile const static variable with its value unless
1136 it is an array, in which case we must be sure that taking the
1137 address of the array produces consistent results. */
1139 {
1142 }
1144 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
1145 an lvalue.
1147 Do not use STRIP_NOPS here! It will remove conversions from pointer
1148 to integer and cause infinite recursion. */
1155 /* Preserve the original expression code. */
1159 /* Normally convert enums to int,
1160 but convert wide enums to something wider. */
1162 {
1170 }
1174 /* If it's thinner than an int, promote it like a
1175 c_promoting_integer_type_p, otherwise leave it alone. */
1181 {
1182 /* Preserve unsignedness if not really getting any wider. */
1188 }
1191 {
1194 }
1196 }
1197 \f
1198 /* Look up COMPONENT in a structure or union DECL.
1200 If the component name is not found, returns NULL_TREE. Otherwise,
1201 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL
1202 stepping down the chain to the component, which is in the last
1203 TREE_VALUE of the list. Normally the list is of length one, but if
1204 the component is embedded within (nested) anonymous structures or
1205 unions, the list steps down the chain to the component. */
1207 static tree
1209 {
1211 tree field;
1213 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers
1214 to the field elements. Use a binary search on this array to quickly
1215 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC
1216 will always be set for structures which have many elements. */
1219 {
1227 {
1232 {
1233 /* Step through all anon unions in linear fashion. */
1235 {
1239 {
1244 }
1245 }
1247 /* Entire record is only anon unions. */
1251 /* Restart the binary search, with new lower bound. */
1253 }
1259 else
1261 }
1267 }
1268 else
1269 {
1271 {
1275 {
1280 }
1284 }
1288 }
1291 }
1293 /* Make an expression to refer to the COMPONENT field of
1294 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */
1296 tree
1298 {
1302 tree ref;
1304 /* If DATUM is a COMPOUND_EXPR, move our reference inside it.
1305 If pedantic ensure that the arguments are not lvalues; otherwise,
1306 if the component is an array, it would wrongly decay to a pointer in
1307 C89 mode.
1308 We cannot do this with a COND_EXPR, because in a conditional expression
1309 the default promotions are applied to both sides, and this would yield
1310 the wrong type of the result; for example, if the components have
1311 type "char". */
1313 {
1315 {
1319 }
1322 }
1324 /* See if there is a field or component with name COMPONENT. */
1327 {
1329 {
1332 }
1337 {
1342 }
1344 /* Chain the COMPONENT_REFs if necessary down to the FIELD.
1345 This might be better solved in future the way the C++ front
1346 end does it - by giving the anonymous entities each a
1347 separate name and type, and then have build_component_ref
1348 recursively call itself. We can't do that here. */
1349 do
1350 {
1368 }
1372 }
1378 }
1379 \f
1380 /* Given an expression PTR for a pointer, return an expression
1381 for the value pointed to.
1382 ERRORSTRING is the name of the operator to appear in error messages. */
1384 tree
1386 {
1391 {
1396 else
1397 {
1402 {
1405 }
1409 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
1410 so that we get the proper error message if the result is used
1411 to assign to. Also, &* is supposed to be a no-op.
1412 And ANSI C seems to specify that the type of the result
1413 should be the const type. */
1414 /* A de-reference of a pointer to const is not a const. It is valid
1415 to change it via some other pointer. */
1421 }
1422 }
1426 }
1428 /* This handles expressions of the form "a[i]", which denotes
1429 an array reference.
1431 This is logically equivalent in C to *(a+i), but we may do it differently.
1432 If A is a variable or a member, we generate a primitive ARRAY_REF.
1433 This avoids forcing the array out of registers, and can work on
1434 arrays that are not lvalues (for example, members of structures returned
1435 by functions). */
1437 tree
1439 {
1441 {
1444 }
1452 {
1455 /* Subscripting with type char is likely to lose
1456 on a machine where chars are signed.
1457 So warn on any machine, but optionally.
1458 Don't warn for unsigned char since that type is safe.
1459 Don't warn for signed char because anyone who uses that
1460 must have done so deliberately. */
1465 /* Apply default promotions *after* noticing character types. */
1468 /* Require integer *after* promotion, for sake of enums. */
1470 {
1473 }
1475 /* An array that is indexed by a non-constant
1476 cannot be stored in a register; we must be able to do
1477 address arithmetic on its address.
1478 Likewise an array of elements of variable size. */
1482 {
1485 }
1486 /* An array that is indexed by a constant value which is not within
1487 the array bounds cannot be stored in a register either; because we
1488 would get a crash in store_bit_field/extract_bit_field when trying
1489 to access a non-existent part of the register. */
1493 {
1496 }
1499 {
1507 }
1511 /* Array ref is const/volatile if the array elements are
1512 or if the array is. */
1521 /* This was added by rms on 16 Nov 91.
1522 It fixes vol struct foo *a; a->elts[1]
1523 in an inline function.
1524 Hope it doesn't break something else. */
1527 }
1529 {
1533 /* Do the same warning check as above, but only on the part that's
1534 syntactically the index and only if it is also semantically
1535 the index. */
1541 /* Put the integer in IND to simplify error checking. */
1543 {
1547 }
1554 {
1557 }
1559 {
1562 }
1566 }
1567 }
1568 \f
1569 /* Build an external reference to identifier ID. FUN indicates
1570 whether this will be used for a function call. */
1571 tree
1573 {
1574 tree ref;
1579 {
1580 /* Properly declared variable or function reference. */
1584 {
1588 }
1589 else
1591 }
1595 /* Implicit function declaration. */
1598 /* Don't complain about something that's already been
1599 complained about. */
1601 else
1602 {
1605 }
1618 {
1621 }
1627 {
1632 }
1635 }
1637 /* Build a function call to function FUNCTION with parameters PARAMS.
1638 PARAMS is a list--a chain of TREE_LIST nodes--in which the
1639 TREE_VALUE of each node is a parameter-expression.
1640 FUNCTION's data type may be a function type or a pointer-to-function. */
1642 tree
1644 {
1646 tree coerced_params;
1648 tree tem;
1650 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
1653 /* Convert anything with function type to a pointer-to-function. */
1655 {
1658 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
1659 (because calling an inline function does not mean the function
1660 needs to be separately compiled). */
1666 }
1667 else
1677 {
1680 }
1685 /* fntype now gets the type of function pointed to. */
1688 /* Check that the function is called through a compatible prototype.
1689 If it is not, replace the call by a trap, wrapped up in a compound
1690 expression if necessary. This has the nice side-effect to prevent
1691 the tree-inliner from generating invalid assignment trees which may
1692 blow up in the RTL expander later.
1694 ??? This doesn't work for Objective-C because objc_comptypes
1695 refuses to compare function prototypes, yet the compiler appears
1696 to build calls that are flagged as invalid by C's comptypes. */
1702 {
1705 NULL_TREE);
1707 /* This situation leads to run-time undefined behavior. We can't,
1708 therefore, simply error unless we can prove that all possible
1709 executions of the program must execute the code. */
1714 else
1715 {
1716 tree rhs;
1721 NULL_TREE));
1722 else
1726 }
1727 }
1729 /* Convert the parameters to the types declared in the
1730 function prototype, or apply default promotions. */
1732 coerced_params
1735 /* Check that the arguments to the function are valid. */
1739 /* Recognize certain built-in functions so we can make tree-codes
1740 other than CALL_EXPR. We do this when it enables fold-const.c
1741 to do something useful. */
1746 {
1751 }
1761 }
1762 \f
1763 /* Convert the argument expressions in the list VALUES
1764 to the types in the list TYPELIST. The result is a list of converted
1765 argument expressions.
1767 If TYPELIST is exhausted, or when an element has NULL as its type,
1768 perform the default conversions.
1770 PARMLIST is the chain of parm decls for the function being called.
1771 It may be 0, if that info is not available.
1772 It is used only for generating error messages.
1774 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
1776 This is also where warnings about wrong number of args are generated.
1778 Both VALUES and the returned value are chains of TREE_LIST nodes
1779 with the elements of the list in the TREE_VALUE slots of those nodes. */
1781 static tree
1783 {
1788 /* Scan the given expressions and types, producing individual
1789 converted arguments and pushing them on RESULT in reverse order. */
1792 valtail;
1794 {
1799 {
1803 else
1806 }
1808 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
1809 /* Do not use STRIP_NOPS here! We do not want an enumerator with value 0
1810 to convert automatically to a pointer. */
1819 {
1820 /* Formal parm type is specified by a function prototype. */
1821 tree parmval;
1824 {
1827 }
1828 else
1829 {
1830 /* Optionally warn about conversions that
1831 differ from the default conversions. */
1833 {
1838 warn_for_assignment ("%s as integer rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1841 warn_for_assignment ("%s as integer rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1844 warn_for_assignment ("%s as complex rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1847 warn_for_assignment ("%s as floating rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1850 warn_for_assignment ("%s as complex rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1853 warn_for_assignment ("%s as floating rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1854 /* ??? At some point, messages should be written about
1855 conversions between complex types, but that's too messy
1856 to do now. */
1859 {
1860 /* Warn if any argument is passed as `float',
1861 since without a prototype it would be `double'. */
1863 warn_for_assignment ("%s as `float' rather than `double' due to prototype", (char *) 0, name, parmnum + 1);
1864 }
1865 /* Detect integer changing in width or signedness.
1866 These warnings are only activated with
1867 -Wconversion, not with -Wtraditional. */
1870 {
1877 /* No warning if function asks for enum
1878 and the actual arg is that enum type. */
1879 ;
1881 warn_for_assignment ("%s with different width due to prototype", (char *) 0, name, parmnum + 1);
1883 ;
1884 /* Don't complain if the formal parameter type
1885 is an enum, because we can't tell now whether
1886 the value was an enum--even the same enum. */
1888 ;
1891 /* Change in signedness doesn't matter
1892 if a constant value is unaffected. */
1893 ;
1894 /* Likewise for a constant in a NOP_EXPR. */
1898 ;
1899 /* If the value is extended from a narrower
1900 unsigned type, it doesn't matter whether we
1901 pass it as signed or unsigned; the value
1902 certainly is the same either way. */
1905 ;
1908 else
1910 }
1911 }
1921 }
1923 }
1927 /* Convert `float' to `double'. */
1929 else
1930 /* Convert `short' and `char' to full-size `int'. */
1935 }
1938 {
1942 else
1944 }
1947 }
1948 \f
1949 /* This is the entry point used by the parser
1950 for binary operators in the input.
1951 In addition to constructing the expression,
1952 we check for operands that were written with other binary operators
1953 in a way that is likely to confuse the user. */
1955 tree
1957 {
1974 /* Check for cases such as x+y<<z which users are likely
1975 to misinterpret. If parens are used, C_EXP_ORIGINAL_CODE
1976 is cleared to prevent these warnings. */
1978 {
1980 {
1984 }
1987 {
1991 }
1994 {
2000 /* Check cases like x|y==z */
2003 }
2006 {
2012 /* Check cases like x^y==z */
2015 }
2018 {
2022 /* Check cases like x&y==z */
2025 }
2026 }
2028 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */
2039 /* Record the code that was specified in the source,
2040 for the sake of warnings about confusing nesting. */
2043 else
2044 {
2046 /* We used to use NOP_EXPR rather than NON_LVALUE_EXPR
2047 so that convert_for_assignment wouldn't strip it.
2048 That way, we got warnings for things like p = (1 - 1).
2049 But it turns out we should not get those warnings. */
2053 }
2056 }
2057 \f
2059 /* Return true if `t' is known to be non-negative. */
2061 int
2063 {
2065 {
2068 /* Find the last statement in the chain, ignoring the final
2069 * scope statement */
2074 }
2076 }
2078 /* Return a tree for the difference of pointers OP0 and OP1.
2079 The resulting tree has type int. */
2081 static tree
2083 {
2092 {
2097 }
2099 /* If the conversion to ptrdiff_type does anything like widening or
2100 converting a partial to an integral mode, we get a convert_expression
2101 that is in the way to do any simplifications.
2102 (fold-const.c doesn't know that the extra bits won't be needed.
2103 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2104 different mode in place.)
2105 So first try to find a common term here 'by hand'; we want to cover
2106 at least the cases that occur in legal static initializers. */
2111 {
2114 }
2115 else
2119 {
2122 }
2123 else
2127 {
2130 }
2133 /* First do the subtraction as integers;
2134 then drop through to build the divide operator.
2135 Do not do default conversions on the minus operator
2136 in case restype is a short type. */
2140 /* This generates an error if op1 is pointer to incomplete type. */
2144 /* This generates an error if op0 is pointer to incomplete type. */
2147 /* Divide by the size, in easiest possible way. */
2155 }
2156 \f
2157 /* Construct and perhaps optimize a tree representation
2158 for a unary operation. CODE, a tree_code, specifies the operation
2159 and XARG is the operand.
2160 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2161 the default promotions (such as from short to int).
2162 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2163 allows non-lvalues; this is only used to handle conversion of non-lvalue
2164 arrays to pointers in C99. */
2166 tree
2168 {
2169 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2173 tree val;
2182 {
2184 /* This is used for unary plus, because a CONVERT_EXPR
2185 is enough to prevent anybody from looking inside for
2186 associativity, but won't generate any code. */
2189 {
2192 }
2202 {
2205 }
2212 {
2215 }
2217 {
2223 }
2224 else
2225 {
2228 }
2233 {
2236 }
2242 /* Conjugating a real value is a no-op, but allow it anyway. */
2245 {
2248 }
2257 /* These will convert to a pointer. */
2259 {
2262 }
2274 else
2282 else
2289 /* Handle complex lvalues (when permitted)
2290 by reduction to simpler cases. */
2296 /* Increment or decrement the real part of the value,
2297 and don't change the imaginary part. */
2299 {
2310 }
2312 /* Report invalid types. */
2316 {
2319 else
2323 }
2325 {
2326 tree inc;
2332 /* Compute the increment. */
2335 {
2336 /* If pointer target is an undefined struct,
2337 we just cannot know how to do the arithmetic. */
2339 {
2342 else
2344 }
2348 {
2351 else
2353 }
2356 }
2357 else
2362 /* Handle incrementing a cast-expression. */
2366 {
2375 /* If the real type has the same machine representation
2376 as the type it is cast to, we can make better output
2377 by adding directly to the inside of the cast. */
2383 else
2384 {
2388 else
2389 {
2393 else
2402 }
2405 }
2410 }
2411 give_up:
2413 /* Complain about anything else that is not a true lvalue. */
2420 /* Report a read-only lvalue. */
2429 else
2436 }
2439 /* Note that this operation never does default_conversion. */
2441 /* Let &* cancel out to simplify resulting code. */
2443 {
2444 /* Don't let this be an lvalue. */
2448 }
2450 /* For &x[y], return x+y */
2452 {
2457 }
2459 /* Handle complex lvalues (when permitted)
2460 by reduction to simpler cases. */
2465 /* Anything not already handled and not a true memory reference
2466 or a non-lvalue array is an error. */
2471 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
2474 /* If the lvalue is const or volatile, merge that into the type
2475 to which the address will point. Note that you can't get a
2476 restricted pointer by taking the address of something, so we
2477 only have to deal with `const' and `volatile' here. */
2489 {
2490 tree addr;
2493 {
2499 {
2503 }
2508 }
2509 else
2512 /* Address of a static or external variable or
2513 file-scope function counts as a constant. */
2519 }
2523 }
2528 }
2530 /* Return nonzero if REF is an lvalue valid for this language.
2531 Lvalues can be assigned, unless their type has TYPE_READONLY.
2532 Lvalues can have their address taken, unless they have DECL_REGISTER. */
2534 int
2536 {
2540 {
2565 }
2566 }
2568 /* Return nonzero if REF is an lvalue valid for this language;
2569 otherwise, print an error message and return zero. */
2571 int
2573 {
2580 }
2582 /* Apply unary lvalue-demanding operator CODE to the expression ARG
2583 for certain kinds of expressions which are not really lvalues
2584 but which we can accept as lvalues. If FLAG is nonzero, then
2585 non-lvalues are OK since we may be converting a non-lvalue array to
2586 a pointer in C99.
2588 If ARG is not a kind of expression we can handle, return zero. */
2590 static tree
2592 {
2593 /* Handle (a, b) used as an "lvalue". */
2595 {
2598 /* If this returns a function type, it isn't really being used as
2599 an lvalue, so don't issue a warning about it. */
2605 }
2607 /* Handle (a ? b : c) used as an "lvalue". */
2609 {
2619 }
2622 }
2624 /* If pedantic, warn about improper lvalue. CODE is either COND_EXPR
2625 COMPOUND_EXPR, or CONVERT_EXPR (for casts). */
2627 static void
2629 {
2631 {
2641 }
2642 }
2643 \f
2644 /* Warn about storing in something that is `const'. */
2646 void
2648 {
2650 {
2653 else
2656 }
2660 else
2662 }
2663 \f
2664 /* Mark EXP saying that we need to be able to take the
2665 address of it; it should not be allocated in a register.
2666 Returns true if successful. */
2668 bool
2670 {
2675 {
2678 {
2682 }
2684 /* ... fall through ... */
2704 {
2706 {
2710 }
2713 }
2715 {
2717 {
2721 }
2723 /* If we are making this addressable due to its having
2724 volatile components, give a different error message. Also
2725 handle the case of an unnamed parameter by not trying
2726 to give the name. */
2729 {
2732 }
2736 }
2739 /* drops in */
2742 /* drops out */
2745 }
2746 }
2747 \f
2748 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
2750 tree
2752 {
2753 tree type1;
2754 tree type2;
2762 /* Promote both alternatives. */
2779 /* Quickly detect the usual case where op1 and op2 have the same type
2780 after promotion. */
2782 {
2785 else
2787 }
2792 {
2795 /* If -Wsign-compare, warn here if type1 and type2 have
2796 different signedness. We'll promote the signed to unsigned
2797 and later code won't know it used to be different.
2798 Do this check on the original types, so that explicit casts
2799 will be considered, but default promotions won't. */
2801 {
2806 {
2807 /* Do not warn if the result type is signed, since the
2808 signed type will only be chosen if it can represent
2809 all the values of the unsigned type. */
2812 /* Do not warn if the signed quantity is an unsuffixed
2813 integer literal (or some static constant expression
2814 involving such literals) and it is non-negative. */
2818 else
2820 }
2821 }
2822 }
2824 {
2828 }
2830 {
2840 {
2845 }
2847 {
2852 }
2853 else
2854 {
2857 }
2858 }
2860 {
2863 else
2864 {
2866 }
2868 }
2870 {
2873 else
2874 {
2876 }
2878 }
2881 {
2884 else
2885 {
2888 }
2889 }
2891 /* Merge const and volatile flags of the incoming types. */
2892 result_type
2906 }
2907 \f
2908 /* Given a list of expressions, return a compound expression
2909 that performs them all and returns the value of the last of them. */
2911 tree
2913 {
2915 }
2917 static tree
2919 {
2920 tree rest;
2923 {
2924 /* Convert arrays and functions to pointers when there
2925 really is a comma operator. */
2930 /* Don't let (0, 0) be null pointer constant. */
2934 }
2939 {
2940 /* The left-hand operand of a comma expression is like an expression
2941 statement: with -Wextra or -Wunused, we should warn if it doesn't have
2942 any side-effects, unless it was explicitly cast to (void). */
2947 }
2949 /* With -Wunused, we should also warn if the left-hand operand does have
2950 side-effects, but computes a value which is not used. For example, in
2951 `foo() + bar(), baz()' the result of the `+' operator is not used,
2952 so we should issue a warning. */
2957 }
2959 /* Build an expression representing a cast to type TYPE of expression EXPR. */
2961 tree
2963 {
2969 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
2970 only in <protocol> qualifications. But when constructing cast expressions,
2971 the protocols do matter and must be kept around. */
2976 {
2979 }
2982 {
2985 }
2988 {
2990 {
2994 }
2995 }
2997 {
2998 tree field;
3007 {
3008 tree t;
3018 }
3021 }
3022 else
3023 {
3026 /* If casting to void, avoid the error that would come
3027 from default_conversion in the case of a non-lvalue array. */
3031 /* Convert functions and arrays to pointers,
3032 but don't convert any other types. */
3036 /* Optionally warn about potentially worrisome casts. */
3041 {
3047 /* Check that the qualifiers on IN_TYPE are a superset of
3048 the qualifiers of IN_OTYPE. The outermost level of
3049 POINTER_TYPE nodes is uninteresting and we stop as soon
3050 as we hit a non-POINTER_TYPE node on either type. */
3051 do
3052 {
3056 /* GNU C allows cv-qualified function types. 'const'
3057 means the function is very pure, 'volatile' means it
3058 can't return. We need to warn when such qualifiers
3059 are added, not when they're taken away. */
3063 else
3065 }
3073 /* There are qualifiers present in IN_OTYPE that are not
3074 present in IN_TYPE. */
3076 }
3078 /* Warn about possible alignment problems. */
3084 /* Don't warn about opaque types, where the actual alignment
3085 restriction is unknown. */
3106 /* Don't warn about converting any constant. */
3116 {
3117 /* Casting the address of a decl to non void pointer. Warn
3118 if the cast breaks type based aliasing. */
3125 }
3128 /* Replace a nonvolatile const static variable with its value. */
3133 /* Ignore any integer overflow caused by the cast. */
3135 {
3138 }
3139 }
3141 /* Pedantically, don't let (void *) (FOO *) 0 be a null pointer constant. */
3147 /* If pedantic, don't let a cast be an lvalue. */
3152 }
3154 /* Interpret a cast of expression EXPR to type TYPE. */
3155 tree
3157 {
3160 /* This avoids warnings about unprototyped casts on
3161 integers. E.g. "#define SIG_DFL (void(*)())0". */
3168 }
3170 \f
3171 /* Build an assignment expression of lvalue LHS from value RHS.
3172 MODIFYCODE is the code for a binary operator that we use
3173 to combine the old value of LHS with RHS to get the new value.
3174 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3176 tree
3178 {
3179 tree result;
3180 tree newrhs;
3184 /* Types that aren't fully specified cannot be used in assignments. */
3187 /* Avoid duplicate error messages from operands that had errors. */
3191 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3192 /* Do not use STRIP_NOPS here. We do not want an enumerator
3193 whose value is 0 to count as a null pointer constant. */
3199 /* Handle control structure constructs used as "lvalues". */
3202 {
3203 /* Handle (a, b) used as an "lvalue". */
3212 /* Handle (a ? b : c) used as an "lvalue". */
3216 {
3217 /* Produce (a ? (b = rhs) : (c = rhs))
3218 except that the RHS goes through a save-expr
3219 so the code to compute it is only emitted once. */
3220 tree cond
3228 /* Make sure the code to compute the rhs comes out
3229 before the split. */
3231 /* But cast it to void to avoid an "unused" error. */
3233 }
3236 }
3238 /* If a binary op has been requested, combine the old LHS value with the RHS
3239 producing the value we should actually store into the LHS. */
3242 {
3245 }
3247 /* Handle a cast used as an "lvalue".
3248 We have already performed any binary operator using the value as cast.
3249 Now convert the result to the cast type of the lhs,
3250 and then true type of the lhs and store it there;
3251 then convert result back to the cast type to be the value
3252 of the assignment. */
3255 {
3264 {
3266 tree result;
3274 }
3278 }
3280 /* Now we have handled acceptable kinds of LHS that are not truly lvalues.
3281 Reject anything strange now. */
3286 /* Warn about storing in something that is `const'. */
3294 /* If storing into a structure or union member,
3295 it has probably been given type `int'.
3296 Compute the type that would go with
3297 the actual amount of storage the member occupies. */
3306 /* If storing in a field that is in actuality a short or narrower than one,
3307 we must store in the field in its actual type. */
3310 {
3313 }
3315 /* Convert new value to destination type. */
3322 /* Scan operands */
3327 /* If we got the LHS in a different type for storing in,
3328 convert the result back to the nominal type of LHS
3329 so that the value we return always has the same type
3330 as the LHS argument. */
3336 }
3337 \f
3338 /* Convert value RHS to type TYPE as preparation for an assignment
3339 to an lvalue of type TYPE.
3340 The real work of conversion is done by `convert'.
3341 The purpose of this function is to generate error messages
3342 for assignments that are not allowed in C.
3343 ERRTYPE is a string to use in error messages:
3344 "assignment", "return", etc. If it is null, this is parameter passing
3345 for a function call (and different error messages are output).
3347 FUNNAME is the name of the function being called,
3348 as an IDENTIFIER_NODE, or null.
3349 PARMNUM is the number of the argument, for printing in error messages. */
3351 static tree
3354 {
3356 tree rhstype;
3359 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3360 /* Do not use STRIP_NOPS here. We do not want an enumerator
3361 whose value is 0 to count as a null pointer constant. */
3378 {
3380 /* Check for Objective-C protocols. This will automatically
3381 issue a warning if there are protocol violations. No need to
3382 use the return value. */
3386 }
3389 {
3392 }
3393 /* A type converts to a reference to it.
3394 This code doesn't fully support references, it's just for the
3395 special case of va_start and va_copy. */
3398 {
3400 {
3403 }
3408 /* We already know that these two types are compatible, but they
3409 may not be exactly identical. In fact, `TREE_TYPE (type)' is
3410 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
3411 likely to be va_list, a typedef to __builtin_va_list, which
3412 is different enough that it will cause problems later. */
3418 }
3419 /* Some types can interconvert without explicit casts. */
3424 /* Arithmetic types all interconvert, and enum is treated like int. */
3433 /* Conversion to a transparent union from its member types.
3434 This applies only to function arguments. */
3436 {
3437 tree memb_types;
3442 {
3453 {
3457 /* Any non-function converts to a [const][volatile] void *
3458 and vice versa; otherwise, targets must be the same.
3459 Meanwhile, the lhs target must have all the qualifiers of
3460 the rhs. */
3463 {
3464 /* If this type won't generate any warnings, use it. */
3474 /* Keep looking for a better type, but remember this one. */
3477 }
3478 }
3480 /* Can convert integer zero to any pointer type. */
3484 {
3487 }
3488 }
3491 {
3493 {
3494 /* We have only a marginally acceptable member type;
3495 it needs a warning. */
3499 /* Const and volatile mean something different for function
3500 types, so the usual warnings are not appropriate. */
3503 {
3504 /* Because const and volatile on functions are
3505 restrictions that say the function will not do
3506 certain things, it is okay to use a const or volatile
3507 function where an ordinary one is wanted, but not
3508 vice-versa. */
3512 }
3516 parmnum);
3517 }
3523 }
3524 }
3526 /* Conversions among pointers */
3529 {
3535 /* Opaque pointers are treated like void pointers. */
3541 /* Any non-function converts to a [const][volatile] void *
3542 and vice versa; otherwise, targets must be the same.
3543 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
3546 || is_opaque_pointer
3549 {
3552 ||
3554 /* Check TREE_CODE to catch cases like (void *) (char *) 0
3555 which are not ANSI null ptr constants. */
3560 /* Const and volatile mean something different for function types,
3561 so the usual warnings are not appropriate. */
3564 {
3568 /* If this is not a case of ignoring a mismatch in signedness,
3569 no warning. */
3572 ;
3573 /* If there is a mismatch, do warn. */
3577 }
3580 {
3581 /* Because const and volatile on functions are restrictions
3582 that say the function will not do certain things,
3583 it is okay to use a const or volatile function
3584 where an ordinary one is wanted, but not vice-versa. */
3588 }
3589 }
3590 else
3594 }
3596 {
3599 }
3601 {
3602 /* An explicit constant 0 can convert to a pointer,
3603 or one that results from arithmetic, even including
3604 a cast to integer type. */
3606 &&
3611 {
3615 }
3617 }
3619 {
3623 }
3628 {
3630 {
3636 else
3639 }
3640 else
3642 parmnum);
3643 }
3644 else
3648 }
3650 /* Convert VALUE for assignment into inlined parameter PARM. ARGNUM
3651 is used for error and waring reporting and indicates which argument
3652 is being processed. */
3654 tree
3656 {
3659 /* If FN was prototyped, the value has been converted already
3660 in convert_arguments. */
3673 }
3675 /* Print a warning using MSGID.
3676 It gets OPNAME as its one parameter.
3677 if OPNAME is null and ARGNUM is 0, it is replaced by "passing arg of `FUNCTION'".
3678 Otherwise if OPNAME is null, it is replaced by "passing arg ARGNUM of `FUNCTION'".
3679 FUNCTION and ARGNUM are handled specially if we are building an
3680 Objective-C selector. */
3682 static void
3685 {
3687 {
3692 {
3695 }
3697 {
3699 {
3700 /* Function name is known; supply it. */
3706 }
3707 else
3708 {
3709 /* Function name unknown (call through ptr). */
3713 }
3714 }
3716 {
3717 /* Function name is known; supply it. */
3723 }
3724 else
3725 {
3726 /* Function name unknown (call through ptr); just give arg number. */
3730 }
3732 }
3734 }
3735 \f
3736 /* If VALUE is a compound expr all of whose expressions are constant, then
3737 return its value. Otherwise, return error_mark_node.
3739 This is for handling COMPOUND_EXPRs as initializer elements
3740 which is allowed with a warning when -pedantic is specified. */
3742 static tree
3744 {
3746 {
3751 endtype);
3752 }
3756 else
3758 }
3759 \f
3760 /* Perform appropriate conversions on the initial value of a variable,
3761 store it in the declaration DECL,
3762 and print any error messages that are appropriate.
3763 If the init is invalid, store an ERROR_MARK. */
3765 void
3767 {
3770 /* If variable's type was invalidly declared, just ignore it. */
3776 /* Digest the specified initializer into an expression. */
3780 /* Store the expression if valid; else report error. */
3788 /* ANSI wants warnings about out-of-range constant initializers. */
3792 /* Check if we need to set array size from compound literal size. */
3796 {
3804 {
3808 {
3809 /* For int foo[] = (int [3]){1}; we need to set array size
3810 now since later on array initializer will be just the
3811 brace enclosed list of the compound literal. */
3815 }
3816 }
3817 }
3818 }
3819 \f
3820 /* Methods for storing and printing names for error messages. */
3822 /* Implement a spelling stack that allows components of a name to be pushed
3823 and popped. Each element on the stack is this structure. */
3825 struct spelling
3826 {
3828 union
3829 {
3833 };
3835 #define SPELLING_STRING 1
3836 #define SPELLING_MEMBER 2
3837 #define SPELLING_BOUNDS 3
3843 /* Macros to save and restore the spelling stack around push_... functions.
3844 Alternative to SAVE_SPELLING_STACK. */
3846 #define SPELLING_DEPTH() (spelling - spelling_base)
3847 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
3849 /* Push an element on the spelling stack with type KIND and assign VALUE
3850 to MEMBER. */
3852 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
3853 { \
3854 int depth = SPELLING_DEPTH (); \
3855 \
3856 if (depth >= spelling_size) \
3857 { \
3858 spelling_size += 10; \
3859 if (spelling_base == 0) \
3860 spelling_base = xmalloc (spelling_size * sizeof (struct spelling)); \
3861 else \
3862 spelling_base = xrealloc (spelling_base, \
3863 spelling_size * sizeof (struct spelling)); \
3864 RESTORE_SPELLING_DEPTH (depth); \
3865 } \
3866 \
3867 spelling->kind = (KIND); \
3868 spelling->MEMBER = (VALUE); \
3869 spelling++; \
3870 }
3872 /* Push STRING on the stack. Printed literally. */
3874 static void
3876 {
3878 }
3880 /* Push a member name on the stack. Printed as '.' STRING. */
3882 static void
3884 {
3888 }
3890 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
3892 static void
3894 {
3896 }
3898 /* Compute the maximum size in bytes of the printed spelling. */
3900 static int
3902 {
3907 {
3910 else
3912 }
3915 }
3917 /* Print the spelling to BUFFER and return it. */
3921 {
3927 {
3930 }
3931 else
3932 {
3937 ;
3938 }
3941 }
3943 /* Issue an error message for a bad initializer component.
3944 MSGID identifies the message.
3945 The component name is taken from the spelling stack. */
3947 void
3949 {
3956 }
3958 /* Issue a pedantic warning for a bad initializer component.
3959 MSGID identifies the message.
3960 The component name is taken from the spelling stack. */
3962 void
3964 {
3971 }
3973 /* Issue a warning for a bad initializer component.
3974 MSGID identifies the message.
3975 The component name is taken from the spelling stack. */
3977 static void
3979 {
3986 }
3987 \f
3988 /* Digest the parser output INIT as an initializer for type TYPE.
3989 Return a C expression of type TYPE to represent the initial value.
3991 REQUIRE_CONSTANT requests an error if non-constant initializers or
3992 elements are seen. */
3994 static tree
3996 {
4005 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
4006 /* Do not use STRIP_NOPS here. We do not want an enumerator
4007 whose value is 0 to count as a null pointer constant. */
4013 /* Initialization of an array of chars from a string constant
4014 optionally enclosed in braces. */
4017 {
4025 {
4033 {
4036 }
4040 {
4043 }
4049 /* Subtract 1 (or sizeof (wchar_t))
4050 because it's ok to ignore the terminating null char
4051 that is counted in the length of the constant. */
4062 }
4063 }
4065 /* Build a VECTOR_CST from a *constant* vector constructor. If the
4066 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
4067 below and handle as a constructor. */
4071 {
4075 COMPARE_STRICT))
4077 else
4079 }
4081 /* Any type can be initialized
4082 from an expression of the same type, optionally with braces. */
4096 {
4098 {
4102 {
4105 }
4106 }
4109 /* Although the types are compatible, we may require a
4110 conversion. */
4115 {
4116 /* As an extension, allow initializing objects with static storage
4117 duration with compound literals (which are then treated just as
4118 the brace enclosed list they contain). */
4121 }
4125 {
4128 }
4133 /* Compound expressions can only occur here if -pedantic or
4134 -pedantic-errors is specified. In the later case, we always want
4135 an error. In the former case, we simply want a warning. */
4138 {
4139 inside_init
4144 else
4148 }
4151 /* This test catches things like `7 / 0' which
4152 result in an expression for which TREE_CONSTANT
4153 is true, but which is not actually something
4154 that is a legal constant. We really should not
4155 be using this function, because it is a part of
4156 the back-end. Instead, the expression should
4157 already have been turned into ERROR_MARK_NODE. */
4160 {
4163 }
4166 }
4168 /* Handle scalar types, including conversions. */
4172 {
4173 /* Note that convert_for_assignment calls default_conversion
4174 for arrays and functions. We must not call it in the
4175 case where inside_init is a null pointer constant. */
4176 inside_init
4181 {
4184 }
4187 {
4190 }
4193 }
4195 /* Come here only for records and arrays. */
4198 {
4201 }
4205 }
4206 \f
4207 /* Handle initializers that use braces. */
4209 /* Type of object we are accumulating a constructor for.
4210 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4213 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4214 left to fill. */
4217 /* For an ARRAY_TYPE, this is the specified index
4218 at which to store the next element we get. */
4221 /* For an ARRAY_TYPE, this is the maximum index. */
4224 /* For a RECORD_TYPE, this is the first field not yet written out. */
4227 /* For an ARRAY_TYPE, this is the index of the first element
4228 not yet written out. */
4231 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4232 This is so we can generate gaps between fields, when appropriate. */
4235 /* If we are saving up the elements rather than allocating them,
4236 this is the list of elements so far (in reverse order,
4237 most recent first). */
4240 /* 1 if constructor should be incrementally stored into a constructor chain,
4241 0 if all the elements should be kept in AVL tree. */
4244 /* 1 if so far this constructor's elements are all compile-time constants. */
4247 /* 1 if so far this constructor's elements are all valid address constants. */
4250 /* 1 if this constructor is erroneous so far. */
4253 /* Structure for managing pending initializer elements, organized as an
4254 AVL tree. */
4256 struct init_node
4257 {
4261 tree purpose;
4262 tree value;
4263 };
4265 /* Tree of pending elements at this constructor level.
4266 These are elements encountered out of order
4267 which belong at places we haven't reached yet in actually
4268 writing the output.
4269 Will never hold tree nodes across GC runs. */
4272 /* The SPELLING_DEPTH of this constructor. */
4275 /* 0 if implicitly pushing constructor levels is allowed. */
4281 /* DECL node for which an initializer is being read.
4282 0 means we are reading a constructor expression
4283 such as (struct foo) {...}. */
4286 /* start_init saves the ASMSPEC arg here for really_start_incremental_init. */
4289 /* Nonzero if this is an initializer for a top-level decl. */
4292 /* Nonzero if there were any member designators in this initializer. */
4295 /* Nesting depth of designator list. */
4298 /* Nonzero if there were diagnosed errors in this designator list. */
4301 \f
4302 /* This stack has a level for each implicit or explicit level of
4303 structuring in the initializer, including the outermost one. It
4304 saves the values of most of the variables above. */
4308 struct constructor_stack
4309 {
4311 tree type;
4312 tree fields;
4313 tree index;
4314 tree max_index;
4315 tree unfilled_index;
4316 tree unfilled_fields;
4317 tree bit_index;
4318 tree elements;
4322 /* If nonzero, this value should replace the entire
4323 constructor at this level. */
4324 tree replacement_value;
4333 };
4337 /* This stack represents designators from some range designator up to
4338 the last designator in the list. */
4340 struct constructor_range_stack
4341 {
4344 tree range_start;
4345 tree index;
4346 tree range_end;
4347 tree fields;
4348 };
4352 /* This stack records separate initializers that are nested.
4353 Nested initializers can't happen in ANSI C, but GNU C allows them
4354 in cases like { ... (struct foo) { ... } ... }. */
4356 struct initializer_stack
4357 {
4359 tree decl;
4363 tree elements;
4370 };
4373 \f
4374 /* Prepare to parse and output the initializer for variable DECL. */
4376 void
4378 {
4406 {
4408 require_constant_elements
4410 /* For a scalar, you can always use any value to initialize,
4411 even within braces. */
4417 }
4418 else
4419 {
4423 }
4436 }
4438 void
4440 {
4443 /* Free the whole constructor stack of this initializer. */
4445 {
4449 }
4454 /* Pop back to the data of the outer initializer (if any). */
4468 }
4469 \f
4470 /* Call here when we see the initializer is surrounded by braces.
4471 This is instead of a call to push_init_level;
4472 it is matched by a call to pop_init_level.
4474 TYPE is the type to initialize, for a constructor expression.
4475 For an initializer for a decl, TYPE is zero. */
4477 void
4479 {
4523 {
4525 /* Skip any nameless bit fields at the beginning. */
4532 }
4534 {
4536 {
4537 constructor_max_index
4540 /* Detect non-empty initializations of zero-length arrays. */
4545 /* constructor_max_index needs to be an INTEGER_CST. Attempts
4546 to initialize VLAs will cause a proper error; avoid tree
4547 checking errors as well by setting a safe value. */
4552 constructor_index
4555 }
4556 else
4560 }
4562 {
4563 /* Vectors are like simple fixed-size arrays. */
4564 constructor_max_index =
4568 }
4569 else
4570 {
4571 /* Handle the case of int x = {5}; */
4574 }
4575 }
4576 \f
4577 /* Push down into a subobject, for initialization.
4578 If this is for an explicit set of braces, IMPLICIT is 0.
4579 If it is because the next element belongs at a lower level,
4580 IMPLICIT is 1 (or 2 if the push is because of designator list). */
4582 void
4584 {
4588 /* If we've exhausted any levels that didn't have braces,
4589 pop them now. */
4591 {
4597 && constructor_max_index
4600 else
4602 }
4604 /* Unless this is an explicit brace, we need to preserve previous
4605 content if any. */
4607 {
4614 }
4647 {
4652 }
4654 /* Don't die if an entire brace-pair level is superfluous
4655 in the containing level. */
4657 ;
4660 {
4661 /* Don't die if there are extra init elts at the end. */
4664 else
4665 {
4668 constructor_depth++;
4669 }
4670 }
4672 {
4675 constructor_depth++;
4676 }
4679 {
4684 }
4687 {
4695 }
4698 {
4701 }
4705 {
4707 /* Skip any nameless bit fields at the beginning. */
4714 }
4716 {
4717 /* Vectors are like simple fixed-size arrays. */
4718 constructor_max_index =
4722 }
4724 {
4726 {
4727 constructor_max_index
4730 /* Detect non-empty initializations of zero-length arrays. */
4735 /* constructor_max_index needs to be an INTEGER_CST. Attempts
4736 to initialize VLAs will cause a proper error; avoid tree
4737 checking errors as well by setting a safe value. */
4742 constructor_index
4745 }
4746 else
4751 {
4752 /* We need to split the char/wchar array into individual
4753 characters, so that we don't have to special case it
4754 everywhere. */
4756 }
4757 }
4758 else
4759 {
4763 }
4764 }
4766 /* At the end of an implicit or explicit brace level,
4767 finish up that level of constructor.
4768 If we were outputting the elements as they are read, return 0
4769 from inner levels (process_init_element ignores that),
4770 but return error_mark_node from the outermost level
4771 (that's what we want to put in DECL_INITIAL).
4772 Otherwise, return a CONSTRUCTOR expression. */
4774 tree
4776 {
4781 {
4782 /* When we come to an explicit close brace,
4783 pop any inner levels that didn't have explicit braces. */
4789 }
4793 /* Error for initializing a flexible array member, or a zero-length
4794 array member in an inappropriate context. */
4799 {
4800 /* Silently discard empty initializations. The parser will
4801 already have pedwarned for empty brackets. */
4805 {
4811 /* We have already issued an error message for the existence
4812 of a flexible array member not at the end of the structure.
4813 Discard the initializer so that we do not abort later. */
4816 }
4817 else
4818 /* Zero-length arrays are no longer special, so we should no longer
4819 get here. */
4821 }
4823 /* Warn when some struct elements are implicitly initialized to zero. */
4825 && constructor_type
4828 {
4829 /* Do not warn for flexible array members or zero-length arrays. */
4835 /* Do not warn if this level of the initializer uses member
4836 designators; it is likely to be deliberate. */
4838 {
4842 }
4843 }
4845 /* Now output all pending elements. */
4849 /* Pad out the end of the structure. */
4851 /* If this closes a superfluous brace pair,
4852 just pass out the element between them. */
4855 ;
4860 {
4861 /* A nonincremental scalar initializer--just return
4862 the element, after verifying there is just one. */
4864 {
4868 }
4870 {
4873 }
4874 else
4876 }
4877 else
4878 {
4881 else
4882 {
4889 }
4890 }
4915 {
4919 }
4921 }
4923 /* Common handling for both array range and field name designators.
4924 ARRAY argument is nonzero for array ranges. Returns zero for success. */
4926 static int
4928 {
4929 tree subtype;
4932 /* Don't die if an entire brace-pair level is superfluous
4933 in the containing level. */
4937 /* If there were errors in this designator list already, bail out silently. */
4942 {
4946 /* Designator list starts at the level of closest explicit
4947 braces. */
4952 }
4955 {
4958 }
4962 {
4966 }
4968 {
4970 }
4971 else
4976 {
4979 }
4981 {
4984 }
4989 }
4991 /* If there are range designators in designator list, push a new designator
4992 to constructor_range_stack. RANGE_END is end of such stack range or
4993 NULL_TREE if there is no range designator at this level. */
4995 static void
4997 {
5011 }
5013 /* Within an array initializer, specify the next index to be initialized.
5014 FIRST is that index. If LAST is nonzero, then initialize a range
5015 of indices, running from FIRST through LAST. */
5017 void
5019 {
5051 else
5052 {
5056 {
5060 {
5063 }
5064 else
5065 {
5069 {
5072 }
5073 }
5074 }
5076 designator_depth++;
5080 }
5081 }
5083 /* Within a struct initializer, specify the next field to be initialized. */
5085 void
5087 {
5088 tree tail;
5097 {
5100 }
5104 {
5107 }
5112 else
5113 {
5115 designator_depth++;
5119 }
5120 }
5121 \f
5122 /* Add a new initializer to the tree of pending initializers. PURPOSE
5123 identifies the initializer, either array index or field in a structure.
5124 VALUE is the value of that index or field. */
5126 static void
5128 {
5135 {
5137 {
5143 else
5144 {
5149 }
5150 }
5151 }
5152 else
5153 {
5154 tree bitpos;
5158 {
5164 else
5165 {
5170 }
5171 }
5172 }
5185 {
5189 {
5193 {
5195 {
5196 /* L rotation. */
5209 {
5212 else
5214 }
5215 else
5217 }
5218 else
5219 {
5220 /* LR rotation. */
5242 {
5245 else
5247 }
5248 else
5250 }
5252 }
5253 else
5254 {
5255 /* p->balance == +1; growth of left side balances the node. */
5258 }
5259 }
5261 {
5263 /* Growth propagation from right side. */
5266 {
5268 {
5269 /* R rotation. */
5282 {
5285 else
5287 }
5288 else
5290 }
5292 {
5293 /* RL rotation */
5315 {
5318 else
5320 }
5321 else
5323 }
5325 }
5326 else
5327 {
5328 /* p->balance == -1; growth of right side balances the node. */
5331 }
5332 }
5336 }
5337 }
5339 /* Build AVL tree from a sorted chain. */
5341 static void
5343 {
5344 tree chain;
5354 {
5356 /* Skip any nameless bit fields at the beginning. */
5362 }
5364 {
5366 constructor_unfilled_index
5369 else
5371 }
5373 }
5375 /* Build AVL tree from a string constant. */
5377 static void
5379 {
5394 else
5405 {
5407 {
5410 }
5411 else
5412 {
5416 {
5419 else
5424 }
5425 }
5428 {
5431 {
5433 {
5436 }
5437 }
5439 {
5442 }
5447 }
5452 }
5455 }
5457 /* Return value of FIELD in pending initializer or zero if the field was
5458 not initialized yet. */
5460 static tree
5462 {
5466 {
5473 {
5478 else
5480 }
5481 }
5483 {
5487 && (!constructor_unfilled_fields
5494 {
5499 else
5501 }
5502 }
5504 {
5508 }
5510 }
5512 /* "Output" the next constructor element.
5513 At top level, really output it to assembler code now.
5514 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
5515 TYPE is the data type that the containing data type wants here.
5516 FIELD is the field (a FIELD_DECL) or the index that this element fills.
5518 PENDING if non-nil means output pending elements that belong
5519 right after this element. (PENDING is normally 1;
5520 it is 0 while outputting pending elements, to avoid recursion.) */
5522 static void
5524 {
5526 {
5529 }
5541 {
5542 /* As an extension, allow initializing objects with static storage
5543 duration with compound literals (which are then treated just as
5544 the brace enclosed list they contain). */
5547 }
5561 {
5564 }
5569 /* If this field is empty (and not at the end of structure),
5570 don't do anything other than checking the initializer. */
5581 {
5584 }
5586 /* If this element doesn't come next in sequence,
5587 put it on constructor_pending_elts. */
5589 && (!constructor_incremental
5591 {
5598 }
5600 && (!constructor_incremental
5602 {
5603 /* We do this for records but not for unions. In a union,
5604 no matter which field is specified, it can be initialized
5605 right away since it starts at the beginning of the union. */
5607 {
5610 else
5611 {
5619 }
5620 }
5624 }
5627 {
5631 /* We can have just one union field set. */
5633 }
5635 /* Otherwise, output this element either to
5636 constructor_elements or to the assembler file. */
5640 constructor_elements
5643 /* Advance the variable that indicates sequential elements output. */
5645 constructor_unfilled_index
5647 bitsize_one_node);
5649 {
5650 constructor_unfilled_fields
5653 /* Skip any nameless bit fields. */
5657 constructor_unfilled_fields =
5659 }
5663 /* Now output any pending elements which have become next. */
5666 }
5668 /* Output any pending elements which have become next.
5669 As we output elements, constructor_unfilled_{fields,index}
5670 advances, which may cause other elements to become next;
5671 if so, they too are output.
5673 If ALL is 0, we return when there are
5674 no more pending elements to output now.
5676 If ALL is 1, we output space as necessary so that
5677 we can output all the pending elements. */
5679 static void
5681 {
5683 tree next;
5685 retry:
5687 /* Look through the whole pending tree.
5688 If we find an element that should be output now,
5689 output it. Otherwise, set NEXT to the element
5690 that comes first among those still pending. */
5694 {
5696 {
5698 constructor_unfilled_index))
5704 {
5705 /* Advance to the next smaller node. */
5708 else
5709 {
5710 /* We have reached the smallest node bigger than the
5711 current unfilled index. Fill the space first. */
5714 }
5715 }
5716 else
5717 {
5718 /* Advance to the next bigger node. */
5721 else
5722 {
5723 /* We have reached the biggest node in a subtree. Find
5724 the parent of it, which is the next bigger node. */
5730 {
5733 }
5734 }
5735 }
5736 }
5739 {
5742 /* If the current record is complete we are done. */
5748 /* We can't compare fields here because there might be empty
5749 fields in between. */
5751 {
5755 }
5757 {
5758 /* Advance to the next smaller node. */
5761 else
5762 {
5763 /* We have reached the smallest node bigger than the
5764 current unfilled field. Fill the space first. */
5767 }
5768 }
5769 else
5770 {
5771 /* Advance to the next bigger node. */
5774 else
5775 {
5776 /* We have reached the biggest node in a subtree. Find
5777 the parent of it, which is the next bigger node. */
5784 {
5787 }
5788 }
5789 }
5790 }
5791 }
5793 /* Ordinarily return, but not if we want to output all
5794 and there are elements left. */
5798 /* If it's not incremental, just skip over the gap, so that after
5799 jumping to retry we will output the next successive element. */
5806 /* ELT now points to the node in the pending tree with the next
5807 initializer to output. */
5809 }
5810 \f
5811 /* Add one non-braced element to the current constructor level.
5812 This adjusts the current position within the constructor's type.
5813 This may also start or terminate implicit levels
5814 to handle a partly-braced initializer.
5816 Once this has found the correct level for the new element,
5817 it calls output_init_element. */
5819 void
5821 {
5828 /* Handle superfluous braces around string cst as in
5829 char x[] = {"foo"}; */
5831 && constructor_type
5835 {
5840 }
5843 {
5846 }
5848 /* Ignore elements of a brace group if it is entirely superfluous
5849 and has already been diagnosed. */
5853 /* If we've exhausted any levels that didn't have braces,
5854 pop them now. */
5856 {
5864 constructor_index)))
5866 else
5868 }
5870 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
5872 {
5873 /* If value is a compound literal and we'll be just using its
5874 content, don't put it into a SAVE_EXPR. */
5876 || !require_constant_value
5879 }
5882 {
5884 {
5885 tree fieldtype;
5889 {
5892 }
5899 /* Error for non-static initialization of a flexible array member. */
5901 && !require_constant_value
5904 {
5907 }
5909 /* Accept a string constant to initialize a subarray. */
5915 /* Otherwise, if we have come to a subaggregate,
5916 and we don't have an element of its type, push into it. */
5922 {
5925 }
5928 {
5932 }
5933 else
5934 /* Do the bookkeeping for an element that was
5935 directly output as a constructor. */
5936 {
5937 /* For a record, keep track of end position of last field. */
5939 constructor_bit_index
5944 /* If the current field was the first one not yet written out,
5945 it isn't now, so update. */
5947 {
5949 /* Skip any nameless bit fields. */
5953 constructor_unfilled_fields =
5955 }
5956 }
5959 /* Skip any nameless bit fields at the beginning. */
5964 }
5966 {
5967 tree fieldtype;
5971 {
5974 }
5981 /* Warn that traditional C rejects initialization of unions.
5982 We skip the warning if the value is zero. This is done
5983 under the assumption that the zero initializer in user
5984 code appears conditioned on e.g. __STDC__ to avoid
5985 "missing initializer" warnings and relies on default
5986 initialization to zero in the traditional C case.
5987 We also skip the warning if the initializer is designated,
5988 again on the assumption that this must be conditional on
5989 __STDC__ anyway (and we've already complained about the
5990 member-designator already). */
5995 /* Accept a string constant to initialize a subarray. */
6001 /* Otherwise, if we have come to a subaggregate,
6002 and we don't have an element of its type, push into it. */
6008 {
6011 }
6014 {
6018 }
6019 else
6020 /* Do the bookkeeping for an element that was
6021 directly output as a constructor. */
6022 {
6025 }
6028 }
6030 {
6034 /* Accept a string constant to initialize a subarray. */
6040 /* Otherwise, if we have come to a subaggregate,
6041 and we don't have an element of its type, push into it. */
6047 {
6050 }
6055 {
6058 }
6060 /* Now output the actual element. */
6062 {
6066 }
6068 constructor_index
6072 /* If we are doing the bookkeeping for an element that was
6073 directly output as a constructor, we must update
6074 constructor_unfilled_index. */
6076 }
6078 {
6081 /* Do a basic check of initializer size. Note that vectors
6082 always have a fixed size derived from their type. */
6084 {
6087 }
6089 /* Now output the actual element. */
6093 constructor_index
6097 /* If we are doing the bookkeeping for an element that was
6098 directly output as a constructor, we must update
6099 constructor_unfilled_index. */
6101 }
6103 /* Handle the sole element allowed in a braced initializer
6104 for a scalar variable. */
6106 {
6109 }
6110 else
6111 {
6115 }
6117 /* Handle range initializers either at this level or anywhere higher
6118 in the designator stack. */
6120 {
6127 {
6131 }
6135 {
6139 }
6146 {
6150 {
6153 }
6161 }
6166 }
6169 }
6172 }
6173 \f
6174 /* Build a simple asm-statement, from one string literal. */
6175 tree
6177 {
6184 {
6185 tree stmt;
6187 /* Simple asm statements are treated as volatile. */
6192 }
6196 }
6198 /* Build an asm-statement, whose components are a CV_QUALIFIER, a
6199 STRING, some OUTPUTS, some INPUTS, and some CLOBBERS. */
6201 tree
6203 tree clobbers)
6204 {
6205 tree tail;
6208 {
6211 }
6215 {
6219 }
6221 /* We can remove output conversions that change the type,
6222 but not the mode. */
6224 {
6230 /* Allow conversions as LHS here. build_modify_expr as called below
6231 will do the right thing with them. */
6242 }
6244 /* Remove output conversions that change the type but not the mode. */
6246 {
6250 }
6252 /* Perform default conversions on array and function inputs.
6253 Don't do this for other types as it would screw up operands
6254 expected to be in memory. */
6260 }
6262 /* Expand an ASM statement with operands, handling output operands
6263 that are not variables or INDIRECT_REFS by transforming such
6264 cases into cases that expand_asm_operands can handle.
6266 Arguments are same as for expand_asm_operands. */
6268 void
6271 {
6274 /* o[I] is the place that output number I should be written. */
6276 tree tail;
6278 /* Record the contents of OUTPUTS before it is modified. */
6280 {
6284 }
6286 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
6287 OUTPUTS some trees for where the values were actually stored. */
6290 /* Copy all the intermediate outputs into the specified outputs. */
6292 {
6294 {
6299 /* Restore the original value so that it's correct the next
6300 time we expand this function. */
6302 }
6303 /* Detect modification of read-only values.
6304 (Otherwise done by build_modify_expr.) */
6305 else
6306 {
6314 }
6315 }
6317 /* Those MODIFY_EXPRs could do autoincrements. */
6319 }
6320 \f
6321 /* Expand a C `return' statement.
6322 RETVAL is the expression for what to return,
6323 or a null pointer for `return;' with no value. */
6325 tree
6327 {
6334 {
6339 }
6341 {
6345 }
6346 else
6347 {
6351 tree inner;
6359 /* Strip any conversions, additions, and subtractions, and see if
6360 we are returning the address of a local variable. Warn if so. */
6362 {
6364 {
6371 /* If the second operand of the MINUS_EXPR has a pointer
6372 type (or is converted from it), this may be valid, so
6373 don't give a warning. */
6374 {
6388 }
6405 }
6408 }
6411 }
6414 }
6415 \f
6417 /* The SWITCH_STMT being built. */
6418 tree switch_stmt;
6419 /* A splay-tree mapping the low element of a case range to the high
6420 element, or NULL_TREE if there is no high element. Used to
6421 determine whether or not a new case label duplicates an old case
6422 label. We need a tree, rather than simply a hash table, because
6423 of the GNU case range extension. */
6424 splay_tree cases;
6425 /* The next node on the stack. */
6427 };
6429 /* A stack of the currently active switch statements. The innermost
6430 switch statement is on the top of the stack. There is no need to
6431 mark the stack for garbage collection because it is only active
6432 during the processing of the body of a function, and we never
6433 collect at that point. */
6437 /* Start a C switch statement, testing expression EXP. Return the new
6438 SWITCH_STMT. */
6440 tree
6442 {
6448 {
6454 {
6457 }
6458 else
6459 {
6469 }
6470 }
6472 /* Add this new SWITCH_STMT to the stack. */
6480 }
6482 /* Process a case label. */
6484 tree
6486 {
6490 {
6499 {
6500 /* Attach the first case label to the SWITCH_BODY. */
6503 }
6504 }
6507 else
6511 }
6513 /* Finish the switch statement. */
6515 void
6517 {
6520 /* Rechain the next statements to the SWITCH_STMT. */
6523 /* Pop the stack. */
6527 }
6529 /* Build a binary-operation expression without default conversions.
6530 CODE is the kind of expression to build.
6531 This function differs from `build' in several ways:
6532 the data type of the result is computed and recorded in it,
6533 warnings are generated if arg data types are invalid,
6534 special handling for addition and subtraction of pointers is known,
6535 and some optimization is done (operations on narrow ints
6536 are done in the narrower type when that gives the same result).
6537 Constant folding is also done before the result is returned.
6539 Note that the operands will never have enumeral types, or function
6540 or array types, because either they will have the default conversions
6541 performed or they have both just been converted to some other type in which
6542 the arithmetic is to be done. */
6544 tree
6547 {
6552 /* Expression code to give to the expression when it is built.
6553 Normally this is CODE, which is what the caller asked for,
6554 but in some special cases we change it. */
6557 /* Data type in which the computation is to be performed.
6558 In the simplest cases this is the common type of the arguments. */
6561 /* Nonzero means operands have already been type-converted
6562 in whatever way is necessary.
6563 Zero means they need to be converted to RESULT_TYPE. */
6566 /* Nonzero means create the expression with this type, rather than
6567 RESULT_TYPE. */
6570 /* Nonzero means after finally constructing the expression
6571 convert it to this type. */
6574 /* Nonzero if this is an operation like MIN or MAX which can
6575 safely be computed in short if both args are promoted shorts.
6576 Also implies COMMON.
6577 -1 indicates a bitwise operation; this makes a difference
6578 in the exact conditions for when it is safe to do the operation
6579 in a narrower mode. */
6582 /* Nonzero if this is a comparison operation;
6583 if both args are promoted shorts, compare the original shorts.
6584 Also implies COMMON. */
6587 /* Nonzero if this is a right-shift operation, which can be computed on the
6588 original short and then promoted if the operand is a promoted short. */
6591 /* Nonzero means set RESULT_TYPE to the common type of the args. */
6595 {
6598 }
6599 else
6600 {
6603 }
6608 /* The expression codes of the data types of the arguments tell us
6609 whether the arguments are integers, floating, pointers, etc. */
6613 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
6617 /* If an error was already reported for one of the arguments,
6618 avoid reporting another error. */
6624 {
6626 /* Handle the pointer + int case. */
6631 else
6636 /* Subtraction of two similar pointers.
6637 We must subtract them as integers, then divide by object size. */
6641 /* Handle pointer minus int. Just like pointer plus int. */
6644 else
6657 /* Floating point division by zero is a legitimate way to obtain
6658 infinities and NaNs. */
6666 {
6669 else
6670 /* Although it would be tempting to shorten always here, that
6671 loses on some targets, since the modulo instruction is
6672 undefined if the quotient can't be represented in the
6673 computation mode. We shorten only if unsigned or if
6674 dividing by something we know != -1. */
6679 }
6697 {
6698 /* Although it would be tempting to shorten always here, that loses
6699 on some targets, since the modulo instruction is undefined if the
6700 quotient can't be represented in the computation mode. We shorten
6701 only if unsigned or if dividing by something we know != -1. */
6706 }
6718 {
6719 /* Result of these operations is always an int,
6720 but that does not mean the operands should be
6721 converted to ints! */
6726 }
6729 /* Shift operations: result has same type as first operand;
6730 always convert second operand to int.
6731 Also set SHORT_SHIFT if shifting rightward. */
6735 {
6737 {
6740 else
6741 {
6747 }
6748 }
6750 /* Use the type of the value to be shifted. */
6752 /* Convert the shift-count to an integer, regardless of size
6753 of value being shifted. */
6756 /* Avoid converting op1 to result_type later. */
6758 }
6763 {
6765 {
6771 }
6773 /* Use the type of the value to be shifted. */
6775 /* Convert the shift-count to an integer, regardless of size
6776 of value being shifted. */
6779 /* Avoid converting op1 to result_type later. */
6781 }
6787 {
6789 {
6794 }
6796 /* Use the type of the value to be shifted. */
6798 /* Convert the shift-count to an integer, regardless of size
6799 of value being shifted. */
6802 /* Avoid converting op1 to result_type later. */
6804 }
6811 /* Result of comparison is always int,
6812 but don't convert the args to int! */
6822 {
6825 /* Anything compares with void *. void * compares with anything.
6826 Otherwise, the targets must be compatible
6827 and both must be object or both incomplete. */
6831 {
6832 /* op0 != orig_op0 detects the case of something
6833 whose value is 0 but which isn't a valid null ptr const. */
6837 }
6839 {
6843 }
6844 else
6849 }
6857 {
6860 }
6862 {
6865 }
6874 {
6876 {
6881 }
6882 else
6883 {
6886 }
6887 }
6899 {
6901 {
6909 }
6910 else
6911 {
6914 }
6915 }
6918 {
6922 }
6925 {
6929 }
6931 {
6934 }
6936 {
6939 }
6951 {
6954 }
6960 }
6964 &&
6967 {
6973 /* For certain operations (which identify themselves by shorten != 0)
6974 if both args were extended from the same smaller type,
6975 do the arithmetic in that type and then extend.
6977 shorten !=0 and !=1 indicates a bitwise operation.
6978 For them, this optimization is safe only if
6979 both args are zero-extended or both are sign-extended.
6980 Otherwise, we might change the result.
6981 Eg, (short)-1 | (unsigned short)-1 is (int)-1
6982 but calculated in (unsigned short) it would be (unsigned short)-1. */
6985 {
6989 /* UNS is 1 if the operation to be done is an unsigned one. */
6991 tree type;
6995 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
6996 but it *requires* conversion to FINAL_TYPE. */
7007 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
7009 /* For bitwise operations, signedness of nominal type
7010 does not matter. Consider only how operands were extended. */
7014 /* Note that in all three cases below we refrain from optimizing
7015 an unsigned operation on sign-extended args.
7016 That would not be valid. */
7018 /* Both args variable: if both extended in same way
7019 from same width, do it in that width.
7020 Do it unsigned if args were zero-extended. */
7027 result_type
7028 = c_common_signed_or_unsigned_type
7034 && (type
7043 && (type
7048 }
7050 /* Shifts can be shortened if shifting right. */
7053 {
7063 /* We can shorten only if the shift count is less than the
7064 number of bits in the smaller type size. */
7066 /* We cannot drop an unsigned shift after sign-extension. */
7068 {
7069 /* Do an unsigned shift if the operand was zero-extended. */
7070 result_type
7073 /* Convert value-to-be-shifted to that type. */
7077 }
7078 }
7080 /* Comparison operations are shortened too but differently.
7081 They identify themselves by setting short_compare = 1. */
7084 {
7085 /* Don't write &op0, etc., because that would prevent op0
7086 from being kept in a register.
7087 Instead, make copies of the our local variables and
7088 pass the copies by reference, then copy them back afterward. */
7091 tree val
7102 {
7114 /* Give warnings for comparisons between signed and unsigned
7115 quantities that may fail.
7117 Do the checking based on the original operand trees, so that
7118 casts will be considered, but default promotions won't be.
7120 Do not warn if the comparison is being done in a signed type,
7121 since the signed type will only be chosen if it can represent
7122 all the values of the unsigned type. */
7125 /* Do not warn if both operands are the same signedness. */
7128 else
7129 {
7134 else
7137 /* Do not warn if the signed quantity is an
7138 unsuffixed integer literal (or some static
7139 constant expression involving such literals or a
7140 conditional expression involving such literals)
7141 and it is non-negative. */
7144 /* Do not warn if the comparison is an equality operation,
7145 the unsigned quantity is an integral constant, and it
7146 would fit in the result if the result were signed. */
7149 && int_fits_type_p
7152 /* Do not warn if the unsigned quantity is an enumeration
7153 constant and its maximum value would fit in the result
7154 if the result were signed. */
7157 && int_fits_type_p
7161 else
7163 }
7165 /* Warn if two unsigned values are being compared in a size
7166 larger than their original size, and one (and only one) is the
7167 result of a `~' operator. This comparison will always fail.
7169 Also warn if one operand is a constant, and the constant
7170 does not have all bits set that are set in the ~ operand
7171 when it is extended. */
7175 {
7179 else
7184 {
7185 tree primop;
7190 {
7194 }
7195 else
7196 {
7200 }
7205 {
7209 }
7210 }
7217 }
7218 }
7219 }
7220 }
7222 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
7223 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
7224 Then the expression will be built.
7225 It will be given type FINAL_TYPE if that is nonzero;
7226 otherwise, it will be given type RESULT_TYPE. */
7229 {
7232 }
7235 {
7240 }
7245 {
7247 tree folded;
7249 /* Treat expressions in initializers specially as they can't trap. */
7257 }
7258 }