| blob | 23e73e8798253fbc51a3f163d9bb5aa47bb5044c |
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 {
523 {
530 /* Target types must match incl. qualifiers. */
533 flags)))
536 /* Sizes must match unless one is missing or variable. */
543 d1_variable = (! d1_zero
546 d2_variable = (! d2_zero
560 }
573 /* The target might allow certain vector types to be compatible. */
580 }
582 }
584 /* Return 1 if TTL and TTR are pointers to types that are equivalent,
585 ignoring their qualifiers. REFLEXIVE is only used by ObjC - set it
586 to 1 or 0 depending if the check of the pointer types is meant to
587 be reflexive or not (typically, assignments are not reflexive,
588 while comparisons are reflexive).
589 */
591 static int
593 {
596 /* Give objc_comptypes a crack at letting these types through. */
606 }
607 \f
608 /* Subroutines of `comptypes'. */
610 /* Determine whether two types derive from the same translation unit.
611 If the CONTEXT chain ends in a null, that type's context is still
612 being parsed, so if two types have context chains ending in null,
613 they're in the same translation unit. */
614 static int
616 {
619 {
624 }
628 {
633 }
636 }
638 /* The C standard says that two structures in different translation
639 units are compatible with each other only if the types of their
640 fields are compatible (among other things). So, consider two copies
641 of this structure: */
645 tree t1;
646 tree t2;
647 };
649 /* Can they be compatible with each other? We choose to break the
650 recursion by allowing those types to be compatible. */
654 /* Return 1 if two 'struct', 'union', or 'enum' types T1 and T2 are
655 compatible. If the two types are not the same (which has been
656 checked earlier), this can only happen when multiple translation
657 units are being compiled. See C99 6.2.7 paragraph 1 for the exact
658 rules. */
660 static int
662 {
666 /* We have to verify that the tags of the types are the same. This
667 is harder than it looks because this may be a typedef, so we have
668 to go look at the original type. It may even be a typedef of a
669 typedef... */
676 /* C90 didn't have the requirement that the two tags be the same. */
680 /* C90 didn't say what happened if one or both of the types were
681 incomplete; we choose to follow C99 rules here, which is that they
682 are compatible. */
687 {
692 }
695 {
697 {
702 {
707 }
709 }
712 {
717 {
729 {
744 }
748 }
750 }
753 {
764 {
779 }
784 }
788 }
789 }
791 /* Return 1 if two function types F1 and F2 are compatible.
792 If either type specifies no argument types,
793 the other must specify a fixed number of self-promoting arg types.
794 Otherwise, if one type specifies only the number of arguments,
795 the other must specify that number of self-promoting arg types.
796 Otherwise, the argument types must match. */
798 static int
800 {
802 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
810 /* 'volatile' qualifiers on a function's return type mean the function
811 is noreturn. */
827 /* An unspecified parmlist matches any specified parmlist
828 whose argument types don't need default promotions. */
831 {
834 /* If one of these types comes from a non-prototype fn definition,
835 compare that with the other type's arglist.
836 If they don't match, ask for a warning (but no error). */
839 flags))
842 }
844 {
849 flags))
852 }
854 /* Both types have argument lists: compare them and propagate results. */
857 }
859 /* Check two lists of types for compatibility,
860 returning 0 for incompatible, 1 for compatible,
861 or 2 for compatible with warning. */
863 static int
865 {
866 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
871 {
874 /* If one list is shorter than the other,
875 they fail to match. */
878 /* A null pointer instead of a type
879 means there is supposed to be an argument
880 but nothing is specified about what type it has.
881 So match anything that self-promotes. */
883 {
886 }
888 {
891 }
892 /* If one of the lists has an error marker, ignore this arg. */
895 ;
898 flags)))
899 {
900 /* Allow wait (union {union wait *u; int *i} *)
901 and wait (union wait *) to be compatible. */
908 {
909 tree memb;
913 flags))
917 }
924 {
925 tree memb;
929 flags))
933 }
934 else
936 }
938 /* comptypes said ok, but record if it said to warn. */
944 }
945 }
946 \f
947 /* Compute the size to increment a pointer by. */
949 tree
951 {
958 {
961 }
963 /* Convert in case a char is more than one unit. */
967 }
968 \f
969 /* Return either DECL or its known constant value (if it has one). */
971 tree
973 {
975 in a place where a variable is invalid. */
981 /* This is invalid if initial value is not constant.
982 If it has either a function call, a memory reference,
983 or a variable, then re-evaluating it could give different results. */
985 /* Check for cases where this is sub-optimal, even though valid. */
989 }
991 /* Return either DECL or its known constant value (if it has one), but
992 return DECL if pedantic or DECL has mode BLKmode. This is for
993 bug-compatibility with the old behavior of decl_constant_value
994 (before GCC 3.0); every use of this function is a bug and it should
995 be removed before GCC 3.1. It is not appropriate to use pedantic
996 in a way that affects optimization, and BLKmode is probably not the
997 right test for avoiding misoptimizations either. */
999 static tree
1001 {
1004 else
1006 }
1009 /* Perform the default conversion of arrays and functions to pointers.
1010 Return the result of converting EXP. For any other expression, just
1011 return EXP. */
1013 static tree
1015 {
1016 tree orig_exp;
1021 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
1022 an lvalue.
1024 Do not use STRIP_NOPS here! It will remove conversions from pointer
1025 to integer and cause infinite recursion. */
1030 {
1034 }
1036 /* Preserve the original expression code. */
1041 {
1043 }
1045 {
1046 tree adr;
1048 tree ptrtype;
1054 {
1057 }
1060 restype
1071 {
1075 }
1079 {
1080 /* Before C99, non-lvalue arrays do not decay to pointers.
1081 Normally, using such an array would be invalid; but it can
1082 be used correctly inside sizeof or as a statement expression.
1083 Thus, do not give an error here; an error will result later. */
1085 }
1090 {
1091 /* ??? This is not really quite correct
1092 in that the type of the operand of ADDR_EXPR
1093 is not the target type of the type of the ADDR_EXPR itself.
1094 Question is, can this lossage be avoided? */
1101 }
1102 /* This way is better for a COMPONENT_REF since it can
1103 simplify the offset for a component. */
1106 }
1108 }
1110 /* Perform default promotions for C data used in expressions.
1111 Arrays and functions are converted to pointers;
1112 enumeral types or short or char, to int.
1113 In addition, manifest constants symbols are replaced by their values. */
1115 tree
1117 {
1118 tree orig_exp;
1125 /* Constants can be used directly unless they're not loadable. */
1129 /* Replace a nonvolatile const static variable with its value unless
1130 it is an array, in which case we must be sure that taking the
1131 address of the array produces consistent results. */
1133 {
1136 }
1138 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
1139 an lvalue.
1141 Do not use STRIP_NOPS here! It will remove conversions from pointer
1142 to integer and cause infinite recursion. */
1149 /* Preserve the original expression code. */
1153 /* Normally convert enums to int,
1154 but convert wide enums to something wider. */
1156 {
1164 }
1168 /* If it's thinner than an int, promote it like a
1169 c_promoting_integer_type_p, otherwise leave it alone. */
1175 {
1176 /* Preserve unsignedness if not really getting any wider. */
1182 }
1185 {
1188 }
1190 }
1191 \f
1192 /* Look up COMPONENT in a structure or union DECL.
1194 If the component name is not found, returns NULL_TREE. Otherwise,
1195 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL
1196 stepping down the chain to the component, which is in the last
1197 TREE_VALUE of the list. Normally the list is of length one, but if
1198 the component is embedded within (nested) anonymous structures or
1199 unions, the list steps down the chain to the component. */
1201 static tree
1203 {
1205 tree field;
1207 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers
1208 to the field elements. Use a binary search on this array to quickly
1209 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC
1210 will always be set for structures which have many elements. */
1213 {
1221 {
1226 {
1227 /* Step through all anon unions in linear fashion. */
1229 {
1233 {
1238 }
1239 }
1241 /* Entire record is only anon unions. */
1245 /* Restart the binary search, with new lower bound. */
1247 }
1253 else
1255 }
1261 }
1262 else
1263 {
1265 {
1269 {
1274 }
1278 }
1282 }
1285 }
1287 /* Make an expression to refer to the COMPONENT field of
1288 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */
1290 tree
1292 {
1296 tree ref;
1298 /* If DATUM is a COMPOUND_EXPR, move our reference inside it.
1299 If pedantic ensure that the arguments are not lvalues; otherwise,
1300 if the component is an array, it would wrongly decay to a pointer in
1301 C89 mode.
1302 We cannot do this with a COND_EXPR, because in a conditional expression
1303 the default promotions are applied to both sides, and this would yield
1304 the wrong type of the result; for example, if the components have
1305 type "char". */
1307 {
1309 {
1313 }
1316 }
1318 /* See if there is a field or component with name COMPONENT. */
1321 {
1323 {
1326 }
1331 {
1336 }
1338 /* Chain the COMPONENT_REFs if necessary down to the FIELD.
1339 This might be better solved in future the way the C++ front
1340 end does it - by giving the anonymous entities each a
1341 separate name and type, and then have build_component_ref
1342 recursively call itself. We can't do that here. */
1343 do
1344 {
1362 }
1366 }
1372 }
1373 \f
1374 /* Given an expression PTR for a pointer, return an expression
1375 for the value pointed to.
1376 ERRORSTRING is the name of the operator to appear in error messages. */
1378 tree
1380 {
1385 {
1390 else
1391 {
1396 {
1399 }
1403 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
1404 so that we get the proper error message if the result is used
1405 to assign to. Also, &* is supposed to be a no-op.
1406 And ANSI C seems to specify that the type of the result
1407 should be the const type. */
1408 /* A de-reference of a pointer to const is not a const. It is valid
1409 to change it via some other pointer. */
1415 }
1416 }
1420 }
1422 /* This handles expressions of the form "a[i]", which denotes
1423 an array reference.
1425 This is logically equivalent in C to *(a+i), but we may do it differently.
1426 If A is a variable or a member, we generate a primitive ARRAY_REF.
1427 This avoids forcing the array out of registers, and can work on
1428 arrays that are not lvalues (for example, members of structures returned
1429 by functions). */
1431 tree
1433 {
1435 {
1438 }
1446 {
1449 /* Subscripting with type char is likely to lose
1450 on a machine where chars are signed.
1451 So warn on any machine, but optionally.
1452 Don't warn for unsigned char since that type is safe.
1453 Don't warn for signed char because anyone who uses that
1454 must have done so deliberately. */
1459 /* Apply default promotions *after* noticing character types. */
1462 /* Require integer *after* promotion, for sake of enums. */
1464 {
1467 }
1469 /* An array that is indexed by a non-constant
1470 cannot be stored in a register; we must be able to do
1471 address arithmetic on its address.
1472 Likewise an array of elements of variable size. */
1476 {
1479 }
1480 /* An array that is indexed by a constant value which is not within
1481 the array bounds cannot be stored in a register either; because we
1482 would get a crash in store_bit_field/extract_bit_field when trying
1483 to access a non-existent part of the register. */
1487 {
1490 }
1493 {
1501 }
1505 /* Array ref is const/volatile if the array elements are
1506 or if the array is. */
1515 /* This was added by rms on 16 Nov 91.
1516 It fixes vol struct foo *a; a->elts[1]
1517 in an inline function.
1518 Hope it doesn't break something else. */
1521 }
1523 {
1527 /* Do the same warning check as above, but only on the part that's
1528 syntactically the index and only if it is also semantically
1529 the index. */
1535 /* Put the integer in IND to simplify error checking. */
1537 {
1541 }
1548 {
1551 }
1553 {
1556 }
1560 }
1561 }
1562 \f
1563 /* Build an external reference to identifier ID. FUN indicates
1564 whether this will be used for a function call. */
1565 tree
1567 {
1568 tree ref;
1573 {
1574 /* Properly declared variable or function reference. */
1578 {
1582 }
1583 else
1585 }
1589 /* Implicit function declaration. */
1592 /* Don't complain about something that's already been
1593 complained about. */
1595 else
1596 {
1599 }
1612 {
1615 }
1621 {
1626 }
1629 }
1631 /* Build a function call to function FUNCTION with parameters PARAMS.
1632 PARAMS is a list--a chain of TREE_LIST nodes--in which the
1633 TREE_VALUE of each node is a parameter-expression.
1634 FUNCTION's data type may be a function type or a pointer-to-function. */
1636 tree
1638 {
1640 tree coerced_params;
1643 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
1646 /* Convert anything with function type to a pointer-to-function. */
1648 {
1651 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
1652 (because calling an inline function does not mean the function
1653 needs to be separately compiled). */
1659 }
1660 else
1670 {
1673 }
1678 /* fntype now gets the type of function pointed to. */
1681 /* Convert the parameters to the types declared in the
1682 function prototype, or apply default promotions. */
1684 coerced_params
1687 /* Check that the arguments to the function are valid. */
1691 /* Recognize certain built-in functions so we can make tree-codes
1692 other than CALL_EXPR. We do this when it enables fold-const.c
1693 to do something useful. */
1698 {
1703 }
1713 }
1714 \f
1715 /* Convert the argument expressions in the list VALUES
1716 to the types in the list TYPELIST. The result is a list of converted
1717 argument expressions.
1719 If TYPELIST is exhausted, or when an element has NULL as its type,
1720 perform the default conversions.
1722 PARMLIST is the chain of parm decls for the function being called.
1723 It may be 0, if that info is not available.
1724 It is used only for generating error messages.
1726 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
1728 This is also where warnings about wrong number of args are generated.
1730 Both VALUES and the returned value are chains of TREE_LIST nodes
1731 with the elements of the list in the TREE_VALUE slots of those nodes. */
1733 static tree
1735 {
1740 /* Scan the given expressions and types, producing individual
1741 converted arguments and pushing them on RESULT in reverse order. */
1744 valtail;
1746 {
1751 {
1755 else
1758 }
1760 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
1761 /* Do not use STRIP_NOPS here! We do not want an enumerator with value 0
1762 to convert automatically to a pointer. */
1771 {
1772 /* Formal parm type is specified by a function prototype. */
1773 tree parmval;
1776 {
1779 }
1780 else
1781 {
1782 /* Optionally warn about conversions that
1783 differ from the default conversions. */
1785 {
1790 warn_for_assignment ("%s as integer rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1793 warn_for_assignment ("%s as integer rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1796 warn_for_assignment ("%s as complex rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1799 warn_for_assignment ("%s as floating rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1802 warn_for_assignment ("%s as complex rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1805 warn_for_assignment ("%s as floating rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1806 /* ??? At some point, messages should be written about
1807 conversions between complex types, but that's too messy
1808 to do now. */
1811 {
1812 /* Warn if any argument is passed as `float',
1813 since without a prototype it would be `double'. */
1815 warn_for_assignment ("%s as `float' rather than `double' due to prototype", (char *) 0, name, parmnum + 1);
1816 }
1817 /* Detect integer changing in width or signedness.
1818 These warnings are only activated with
1819 -Wconversion, not with -Wtraditional. */
1822 {
1829 /* No warning if function asks for enum
1830 and the actual arg is that enum type. */
1831 ;
1833 warn_for_assignment ("%s with different width due to prototype", (char *) 0, name, parmnum + 1);
1835 ;
1836 /* Don't complain if the formal parameter type
1837 is an enum, because we can't tell now whether
1838 the value was an enum--even the same enum. */
1840 ;
1843 /* Change in signedness doesn't matter
1844 if a constant value is unaffected. */
1845 ;
1846 /* Likewise for a constant in a NOP_EXPR. */
1850 ;
1851 /* If the value is extended from a narrower
1852 unsigned type, it doesn't matter whether we
1853 pass it as signed or unsigned; the value
1854 certainly is the same either way. */
1857 ;
1860 else
1862 }
1863 }
1873 }
1875 }
1879 /* Convert `float' to `double'. */
1881 else
1882 /* Convert `short' and `char' to full-size `int'. */
1887 }
1890 {
1894 else
1896 }
1899 }
1900 \f
1901 /* This is the entry point used by the parser
1902 for binary operators in the input.
1903 In addition to constructing the expression,
1904 we check for operands that were written with other binary operators
1905 in a way that is likely to confuse the user. */
1907 tree
1909 {
1926 /* Check for cases such as x+y<<z which users are likely
1927 to misinterpret. If parens are used, C_EXP_ORIGINAL_CODE
1928 is cleared to prevent these warnings. */
1930 {
1932 {
1936 }
1939 {
1943 }
1946 {
1952 /* Check cases like x|y==z */
1955 }
1958 {
1964 /* Check cases like x^y==z */
1967 }
1970 {
1974 /* Check cases like x&y==z */
1977 }
1978 }
1980 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */
1991 /* Record the code that was specified in the source,
1992 for the sake of warnings about confusing nesting. */
1995 else
1996 {
1998 /* We used to use NOP_EXPR rather than NON_LVALUE_EXPR
1999 so that convert_for_assignment wouldn't strip it.
2000 That way, we got warnings for things like p = (1 - 1).
2001 But it turns out we should not get those warnings. */
2005 }
2008 }
2009 \f
2011 /* Return true if `t' is known to be non-negative. */
2013 int
2015 {
2017 {
2020 /* Find the last statement in the chain, ignoring the final
2021 * scope statement */
2026 }
2028 }
2030 /* Return a tree for the difference of pointers OP0 and OP1.
2031 The resulting tree has type int. */
2033 static tree
2035 {
2044 {
2049 }
2051 /* If the conversion to ptrdiff_type does anything like widening or
2052 converting a partial to an integral mode, we get a convert_expression
2053 that is in the way to do any simplifications.
2054 (fold-const.c doesn't know that the extra bits won't be needed.
2055 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2056 different mode in place.)
2057 So first try to find a common term here 'by hand'; we want to cover
2058 at least the cases that occur in legal static initializers. */
2063 {
2066 }
2067 else
2071 {
2074 }
2075 else
2079 {
2082 }
2085 /* First do the subtraction as integers;
2086 then drop through to build the divide operator.
2087 Do not do default conversions on the minus operator
2088 in case restype is a short type. */
2092 /* This generates an error if op1 is pointer to incomplete type. */
2096 /* This generates an error if op0 is pointer to incomplete type. */
2099 /* Divide by the size, in easiest possible way. */
2107 }
2108 \f
2109 /* Construct and perhaps optimize a tree representation
2110 for a unary operation. CODE, a tree_code, specifies the operation
2111 and XARG is the operand.
2112 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2113 the default promotions (such as from short to int).
2114 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2115 allows non-lvalues; this is only used to handle conversion of non-lvalue
2116 arrays to pointers in C99. */
2118 tree
2120 {
2121 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2125 tree val;
2134 {
2136 /* This is used for unary plus, because a CONVERT_EXPR
2137 is enough to prevent anybody from looking inside for
2138 associativity, but won't generate any code. */
2141 {
2144 }
2154 {
2157 }
2164 {
2167 }
2169 {
2175 }
2176 else
2177 {
2180 }
2185 {
2188 }
2194 /* Conjugating a real value is a no-op, but allow it anyway. */
2197 {
2200 }
2209 /* These will convert to a pointer. */
2211 {
2214 }
2226 else
2234 else
2241 /* Handle complex lvalues (when permitted)
2242 by reduction to simpler cases. */
2248 /* Increment or decrement the real part of the value,
2249 and don't change the imaginary part. */
2251 {
2262 }
2264 /* Report invalid types. */
2268 {
2271 else
2275 }
2277 {
2278 tree inc;
2284 /* Compute the increment. */
2287 {
2288 /* If pointer target is an undefined struct,
2289 we just cannot know how to do the arithmetic. */
2291 {
2294 else
2296 }
2300 {
2303 else
2305 }
2308 }
2309 else
2314 /* Handle incrementing a cast-expression. */
2318 {
2327 /* If the real type has the same machine representation
2328 as the type it is cast to, we can make better output
2329 by adding directly to the inside of the cast. */
2335 else
2336 {
2340 else
2341 {
2345 else
2354 }
2357 }
2362 }
2363 give_up:
2365 /* Complain about anything else that is not a true lvalue. */
2372 /* Report a read-only lvalue. */
2381 else
2388 }
2391 /* Note that this operation never does default_conversion. */
2393 /* Let &* cancel out to simplify resulting code. */
2395 {
2396 /* Don't let this be an lvalue. */
2400 }
2402 /* For &x[y], return x+y */
2404 {
2409 }
2411 /* Handle complex lvalues (when permitted)
2412 by reduction to simpler cases. */
2417 /* Anything not already handled and not a true memory reference
2418 or a non-lvalue array is an error. */
2423 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
2426 /* If the lvalue is const or volatile, merge that into the type
2427 to which the address will point. Note that you can't get a
2428 restricted pointer by taking the address of something, so we
2429 only have to deal with `const' and `volatile' here. */
2441 {
2442 tree addr;
2445 {
2451 {
2455 }
2460 }
2461 else
2464 /* Address of a static or external variable or
2465 file-scope function counts as a constant. */
2471 }
2475 }
2480 }
2482 /* Return nonzero if REF is an lvalue valid for this language.
2483 Lvalues can be assigned, unless their type has TYPE_READONLY.
2484 Lvalues can have their address taken, unless they have DECL_REGISTER. */
2486 int
2488 {
2492 {
2517 }
2518 }
2520 /* Return nonzero if REF is an lvalue valid for this language;
2521 otherwise, print an error message and return zero. */
2523 int
2525 {
2532 }
2534 /* Apply unary lvalue-demanding operator CODE to the expression ARG
2535 for certain kinds of expressions which are not really lvalues
2536 but which we can accept as lvalues. If FLAG is nonzero, then
2537 non-lvalues are OK since we may be converting a non-lvalue array to
2538 a pointer in C99.
2540 If ARG is not a kind of expression we can handle, return zero. */
2542 static tree
2544 {
2545 /* Handle (a, b) used as an "lvalue". */
2547 {
2550 /* If this returns a function type, it isn't really being used as
2551 an lvalue, so don't issue a warning about it. */
2557 }
2559 /* Handle (a ? b : c) used as an "lvalue". */
2561 {
2571 }
2574 }
2576 /* If pedantic, warn about improper lvalue. CODE is either COND_EXPR
2577 COMPOUND_EXPR, or CONVERT_EXPR (for casts). */
2579 static void
2581 {
2584 {
2594 }
2595 }
2596 \f
2597 /* Warn about storing in something that is `const'. */
2599 void
2601 {
2603 {
2606 else
2609 }
2613 else
2615 }
2616 \f
2617 /* Mark EXP saying that we need to be able to take the
2618 address of it; it should not be allocated in a register.
2619 Returns true if successful. */
2621 bool
2623 {
2628 {
2631 {
2635 }
2637 /* ... fall through ... */
2657 {
2659 {
2663 }
2666 }
2668 {
2670 {
2674 }
2676 /* If we are making this addressable due to its having
2677 volatile components, give a different error message. Also
2678 handle the case of an unnamed parameter by not trying
2679 to give the name. */
2682 {
2685 }
2689 }
2692 /* drops in */
2695 /* drops out */
2698 }
2699 }
2700 \f
2701 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
2703 tree
2705 {
2706 tree type1;
2707 tree type2;
2715 /* Promote both alternatives. */
2732 /* Quickly detect the usual case where op1 and op2 have the same type
2733 after promotion. */
2735 {
2738 else
2740 }
2745 {
2748 /* If -Wsign-compare, warn here if type1 and type2 have
2749 different signedness. We'll promote the signed to unsigned
2750 and later code won't know it used to be different.
2751 Do this check on the original types, so that explicit casts
2752 will be considered, but default promotions won't. */
2754 {
2759 {
2760 /* Do not warn if the result type is signed, since the
2761 signed type will only be chosen if it can represent
2762 all the values of the unsigned type. */
2765 /* Do not warn if the signed quantity is an unsuffixed
2766 integer literal (or some static constant expression
2767 involving such literals) and it is non-negative. */
2771 else
2773 }
2774 }
2775 }
2777 {
2781 }
2783 {
2793 {
2798 }
2800 {
2805 }
2806 else
2807 {
2810 }
2811 }
2813 {
2816 else
2817 {
2819 }
2821 }
2823 {
2826 else
2827 {
2829 }
2831 }
2834 {
2837 else
2838 {
2841 }
2842 }
2844 /* Merge const and volatile flags of the incoming types. */
2845 result_type
2859 }
2860 \f
2861 /* Given a list of expressions, return a compound expression
2862 that performs them all and returns the value of the last of them. */
2864 tree
2866 {
2868 }
2870 static tree
2872 {
2873 tree rest;
2876 {
2877 /* Convert arrays and functions to pointers when there
2878 really is a comma operator. */
2883 /* Don't let (0, 0) be null pointer constant. */
2887 }
2892 {
2893 /* The left-hand operand of a comma expression is like an expression
2894 statement: with -Wextra or -Wunused, we should warn if it doesn't have
2895 any side-effects, unless it was explicitly cast to (void). */
2901 /* When pedantic, a compound expression can be neither an lvalue
2902 nor an integer constant expression. */
2905 }
2907 /* With -Wunused, we should also warn if the left-hand operand does have
2908 side-effects, but computes a value which is not used. For example, in
2909 `foo() + bar(), baz()' the result of the `+' operator is not used,
2910 so we should issue a warning. */
2915 }
2917 /* Build an expression representing a cast to type TYPE of expression EXPR. */
2919 tree
2921 {
2927 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
2928 only in <protocol> qualifications. But when constructing cast expressions,
2929 the protocols do matter and must be kept around. */
2934 {
2937 }
2940 {
2943 }
2946 {
2948 {
2952 }
2953 }
2955 {
2956 tree field;
2965 {
2966 tree t;
2976 }
2979 }
2980 else
2981 {
2984 /* If casting to void, avoid the error that would come
2985 from default_conversion in the case of a non-lvalue array. */
2989 /* Convert functions and arrays to pointers,
2990 but don't convert any other types. */
2994 /* Optionally warn about potentially worrisome casts. */
2999 {
3005 /* Check that the qualifiers on IN_TYPE are a superset of
3006 the qualifiers of IN_OTYPE. The outermost level of
3007 POINTER_TYPE nodes is uninteresting and we stop as soon
3008 as we hit a non-POINTER_TYPE node on either type. */
3009 do
3010 {
3014 /* GNU C allows cv-qualified function types. 'const'
3015 means the function is very pure, 'volatile' means it
3016 can't return. We need to warn when such qualifiers
3017 are added, not when they're taken away. */
3021 else
3023 }
3031 /* There are qualifiers present in IN_OTYPE that are not
3032 present in IN_TYPE. */
3034 }
3036 /* Warn about possible alignment problems. */
3042 /* Don't warn about opaque types, where the actual alignment
3043 restriction is unknown. */
3064 /* Don't warn about converting any constant. */
3074 {
3075 /* Casting the address of a decl to non void pointer. Warn
3076 if the cast breaks type based aliasing. */
3083 }
3086 /* Replace a nonvolatile const static variable with its value. */
3091 /* Ignore any integer overflow caused by the cast. */
3093 {
3096 }
3097 }
3099 /* Pedantically, don't let (void *) (FOO *) 0 be a null pointer constant. */
3105 /* If pedantic, don't let a cast be an lvalue. */
3110 }
3112 /* Interpret a cast of expression EXPR to type TYPE. */
3113 tree
3115 {
3118 /* This avoids warnings about unprototyped casts on
3119 integers. E.g. "#define SIG_DFL (void(*)())0". */
3126 }
3128 \f
3129 /* Build an assignment expression of lvalue LHS from value RHS.
3130 MODIFYCODE is the code for a binary operator that we use
3131 to combine the old value of LHS with RHS to get the new value.
3132 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3134 tree
3136 {
3137 tree result;
3138 tree newrhs;
3142 /* Types that aren't fully specified cannot be used in assignments. */
3145 /* Avoid duplicate error messages from operands that had errors. */
3149 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3150 /* Do not use STRIP_NOPS here. We do not want an enumerator
3151 whose value is 0 to count as a null pointer constant. */
3157 /* Handle control structure constructs used as "lvalues". */
3160 {
3161 /* Handle (a, b) used as an "lvalue". */
3170 /* Handle (a ? b : c) used as an "lvalue". */
3174 {
3175 /* Produce (a ? (b = rhs) : (c = rhs))
3176 except that the RHS goes through a save-expr
3177 so the code to compute it is only emitted once. */
3178 tree cond
3186 /* Make sure the code to compute the rhs comes out
3187 before the split. */
3189 /* But cast it to void to avoid an "unused" error. */
3191 }
3194 }
3196 /* If a binary op has been requested, combine the old LHS value with the RHS
3197 producing the value we should actually store into the LHS. */
3200 {
3203 }
3205 /* Handle a cast used as an "lvalue".
3206 We have already performed any binary operator using the value as cast.
3207 Now convert the result to the cast type of the lhs,
3208 and then true type of the lhs and store it there;
3209 then convert result back to the cast type to be the value
3210 of the assignment. */
3213 {
3222 {
3224 tree result;
3232 }
3236 }
3238 /* Now we have handled acceptable kinds of LHS that are not truly lvalues.
3239 Reject anything strange now. */
3244 /* Warn about storing in something that is `const'. */
3252 /* If storing into a structure or union member,
3253 it has probably been given type `int'.
3254 Compute the type that would go with
3255 the actual amount of storage the member occupies. */
3264 /* If storing in a field that is in actuality a short or narrower than one,
3265 we must store in the field in its actual type. */
3268 {
3271 }
3273 /* Convert new value to destination type. */
3280 /* Scan operands */
3285 /* If we got the LHS in a different type for storing in,
3286 convert the result back to the nominal type of LHS
3287 so that the value we return always has the same type
3288 as the LHS argument. */
3294 }
3295 \f
3296 /* Convert value RHS to type TYPE as preparation for an assignment
3297 to an lvalue of type TYPE.
3298 The real work of conversion is done by `convert'.
3299 The purpose of this function is to generate error messages
3300 for assignments that are not allowed in C.
3301 ERRTYPE is a string to use in error messages:
3302 "assignment", "return", etc. If it is null, this is parameter passing
3303 for a function call (and different error messages are output).
3305 FUNNAME is the name of the function being called,
3306 as an IDENTIFIER_NODE, or null.
3307 PARMNUM is the number of the argument, for printing in error messages. */
3309 static tree
3312 {
3314 tree rhstype;
3317 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3318 /* Do not use STRIP_NOPS here. We do not want an enumerator
3319 whose value is 0 to count as a null pointer constant. */
3336 {
3338 /* Check for Objective-C protocols. This will automatically
3339 issue a warning if there are protocol violations. No need to
3340 use the return value. */
3344 }
3347 {
3350 }
3351 /* A type converts to a reference to it.
3352 This code doesn't fully support references, it's just for the
3353 special case of va_start and va_copy. */
3356 {
3358 {
3361 }
3366 /* We already know that these two types are compatible, but they
3367 may not be exactly identical. In fact, `TREE_TYPE (type)' is
3368 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
3369 likely to be va_list, a typedef to __builtin_va_list, which
3370 is different enough that it will cause problems later. */
3376 }
3377 /* Some types can interconvert without explicit casts. */
3382 /* Arithmetic types all interconvert, and enum is treated like int. */
3391 /* Conversion to a transparent union from its member types.
3392 This applies only to function arguments. */
3394 {
3395 tree memb_types;
3400 {
3411 {
3415 /* Any non-function converts to a [const][volatile] void *
3416 and vice versa; otherwise, targets must be the same.
3417 Meanwhile, the lhs target must have all the qualifiers of
3418 the rhs. */
3421 {
3422 /* If this type won't generate any warnings, use it. */
3432 /* Keep looking for a better type, but remember this one. */
3435 }
3436 }
3438 /* Can convert integer zero to any pointer type. */
3442 {
3445 }
3446 }
3449 {
3451 {
3452 /* We have only a marginally acceptable member type;
3453 it needs a warning. */
3457 /* Const and volatile mean something different for function
3458 types, so the usual warnings are not appropriate. */
3461 {
3462 /* Because const and volatile on functions are
3463 restrictions that say the function will not do
3464 certain things, it is okay to use a const or volatile
3465 function where an ordinary one is wanted, but not
3466 vice-versa. */
3470 }
3474 parmnum);
3475 }
3481 }
3482 }
3484 /* Conversions among pointers */
3487 {
3492 /* Opaque pointers are treated like void pointers. */
3498 /* Any non-function converts to a [const][volatile] void *
3499 and vice versa; otherwise, targets must be the same.
3500 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
3503 || is_opaque_pointer
3506 {
3509 ||
3511 /* Check TREE_CODE to catch cases like (void *) (char *) 0
3512 which are not ANSI null ptr constants. */
3517 /* Const and volatile mean something different for function types,
3518 so the usual warnings are not appropriate. */
3521 {
3525 /* If this is not a case of ignoring a mismatch in signedness,
3526 no warning. */
3529 ;
3530 /* If there is a mismatch, do warn. */
3534 }
3537 {
3538 /* Because const and volatile on functions are restrictions
3539 that say the function will not do certain things,
3540 it is okay to use a const or volatile function
3541 where an ordinary one is wanted, but not vice-versa. */
3545 }
3546 }
3547 else
3551 }
3553 {
3554 /* An explicit constant 0 can convert to a pointer,
3555 or one that results from arithmetic, even including
3556 a cast to integer type. */
3558 &&
3563 {
3567 }
3569 }
3571 {
3575 }
3580 {
3582 {
3588 else
3591 }
3592 else
3594 parmnum);
3595 }
3596 else
3600 }
3602 /* Convert VALUE for assignment into inlined parameter PARM. */
3604 tree
3606 {
3609 /* If FN was prototyped, the value has been converted already
3610 in convert_arguments. */
3623 }
3625 /* Print a warning using MSGID.
3626 It gets OPNAME as its one parameter.
3627 if OPNAME is null and ARGNUM is 0, it is replaced by "passing arg of `FUNCTION'".
3628 Otherwise if OPNAME is null, it is replaced by "passing arg ARGNUM of `FUNCTION'".
3629 FUNCTION and ARGNUM are handled specially if we are building an
3630 Objective-C selector. */
3632 static void
3635 {
3637 {
3642 {
3645 }
3647 {
3649 {
3650 /* Function name is known; supply it. */
3656 }
3657 else
3658 {
3659 /* Function name unknown (call through ptr). */
3663 }
3664 }
3666 {
3667 /* Function name is known; supply it. */
3673 }
3674 else
3675 {
3676 /* Function name unknown (call through ptr); just give arg number. */
3680 }
3682 }
3684 }
3685 \f
3686 /* If VALUE is a compound expr all of whose expressions are constant, then
3687 return its value. Otherwise, return error_mark_node.
3689 This is for handling COMPOUND_EXPRs as initializer elements
3690 which is allowed with a warning when -pedantic is specified. */
3692 static tree
3694 {
3696 {
3701 endtype);
3702 }
3706 else
3708 }
3709 \f
3710 /* Perform appropriate conversions on the initial value of a variable,
3711 store it in the declaration DECL,
3712 and print any error messages that are appropriate.
3713 If the init is invalid, store an ERROR_MARK. */
3715 void
3717 {
3720 /* If variable's type was invalidly declared, just ignore it. */
3726 /* Digest the specified initializer into an expression. */
3730 /* Store the expression if valid; else report error. */
3738 /* ANSI wants warnings about out-of-range constant initializers. */
3742 /* Check if we need to set array size from compound literal size. */
3746 {
3754 {
3758 {
3759 /* For int foo[] = (int [3]){1}; we need to set array size
3760 now since later on array initializer will be just the
3761 brace enclosed list of the compound literal. */
3765 }
3766 }
3767 }
3768 }
3769 \f
3770 /* Methods for storing and printing names for error messages. */
3772 /* Implement a spelling stack that allows components of a name to be pushed
3773 and popped. Each element on the stack is this structure. */
3775 struct spelling
3776 {
3778 union
3779 {
3783 };
3785 #define SPELLING_STRING 1
3786 #define SPELLING_MEMBER 2
3787 #define SPELLING_BOUNDS 3
3793 /* Macros to save and restore the spelling stack around push_... functions.
3794 Alternative to SAVE_SPELLING_STACK. */
3796 #define SPELLING_DEPTH() (spelling - spelling_base)
3797 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
3799 /* Push an element on the spelling stack with type KIND and assign VALUE
3800 to MEMBER. */
3802 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
3803 { \
3804 int depth = SPELLING_DEPTH (); \
3805 \
3806 if (depth >= spelling_size) \
3807 { \
3808 spelling_size += 10; \
3809 if (spelling_base == 0) \
3810 spelling_base = xmalloc (spelling_size * sizeof (struct spelling)); \
3811 else \
3812 spelling_base = xrealloc (spelling_base, \
3813 spelling_size * sizeof (struct spelling)); \
3814 RESTORE_SPELLING_DEPTH (depth); \
3815 } \
3816 \
3817 spelling->kind = (KIND); \
3818 spelling->MEMBER = (VALUE); \
3819 spelling++; \
3820 }
3822 /* Push STRING on the stack. Printed literally. */
3824 static void
3826 {
3828 }
3830 /* Push a member name on the stack. Printed as '.' STRING. */
3832 static void
3834 {
3838 }
3840 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
3842 static void
3844 {
3846 }
3848 /* Compute the maximum size in bytes of the printed spelling. */
3850 static int
3852 {
3857 {
3860 else
3862 }
3865 }
3867 /* Print the spelling to BUFFER and return it. */
3871 {
3877 {
3880 }
3881 else
3882 {
3887 ;
3888 }
3891 }
3893 /* Issue an error message for a bad initializer component.
3894 MSGID identifies the message.
3895 The component name is taken from the spelling stack. */
3897 void
3899 {
3906 }
3908 /* Issue a pedantic warning for a bad initializer component.
3909 MSGID identifies the message.
3910 The component name is taken from the spelling stack. */
3912 void
3914 {
3921 }
3923 /* Issue a warning for a bad initializer component.
3924 MSGID identifies the message.
3925 The component name is taken from the spelling stack. */
3927 static void
3929 {
3936 }
3937 \f
3938 /* Digest the parser output INIT as an initializer for type TYPE.
3939 Return a C expression of type TYPE to represent the initial value.
3941 REQUIRE_CONSTANT requests an error if non-constant initializers or
3942 elements are seen. */
3944 static tree
3946 {
3955 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3956 /* Do not use STRIP_NOPS here. We do not want an enumerator
3957 whose value is 0 to count as a null pointer constant. */
3963 /* Initialization of an array of chars from a string constant
3964 optionally enclosed in braces. */
3967 {
3975 {
3983 {
3986 }
3990 {
3993 }
3999 /* Subtract 1 (or sizeof (wchar_t))
4000 because it's ok to ignore the terminating null char
4001 that is counted in the length of the constant. */
4012 }
4013 }
4015 /* Build a VECTOR_CST from a *constant* vector constructor. If the
4016 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
4017 below and handle as a constructor. */
4021 {
4025 COMPARE_STRICT))
4027 else
4029 }
4031 /* Any type can be initialized
4032 from an expression of the same type, optionally with braces. */
4046 {
4051 /* Although the types are compatible, we may require a
4052 conversion. */
4057 {
4058 /* As an extension, allow initializing objects with static storage
4059 duration with compound literals (which are then treated just as
4060 the brace enclosed list they contain). */
4063 }
4067 {
4070 }
4075 /* Compound expressions can only occur here if -pedantic or
4076 -pedantic-errors is specified. In the later case, we always want
4077 an error. In the former case, we simply want a warning. */
4080 {
4081 inside_init
4086 else
4090 }
4093 /* This test catches things like `7 / 0' which
4094 result in an expression for which TREE_CONSTANT
4095 is true, but which is not actually something
4096 that is a legal constant. We really should not
4097 be using this function, because it is a part of
4098 the back-end. Instead, the expression should
4099 already have been turned into ERROR_MARK_NODE. */
4102 {
4105 }
4108 }
4110 /* Handle scalar types, including conversions. */
4114 {
4115 /* Note that convert_for_assignment calls default_conversion
4116 for arrays and functions. We must not call it in the
4117 case where inside_init is a null pointer constant. */
4118 inside_init
4123 {
4126 }
4129 {
4132 }
4135 }
4137 /* Come here only for records and arrays. */
4140 {
4143 }
4147 }
4148 \f
4149 /* Handle initializers that use braces. */
4151 /* Type of object we are accumulating a constructor for.
4152 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4155 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4156 left to fill. */
4159 /* For an ARRAY_TYPE, this is the specified index
4160 at which to store the next element we get. */
4163 /* For an ARRAY_TYPE, this is the maximum index. */
4166 /* For a RECORD_TYPE, this is the first field not yet written out. */
4169 /* For an ARRAY_TYPE, this is the index of the first element
4170 not yet written out. */
4173 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4174 This is so we can generate gaps between fields, when appropriate. */
4177 /* If we are saving up the elements rather than allocating them,
4178 this is the list of elements so far (in reverse order,
4179 most recent first). */
4182 /* 1 if constructor should be incrementally stored into a constructor chain,
4183 0 if all the elements should be kept in AVL tree. */
4186 /* 1 if so far this constructor's elements are all compile-time constants. */
4189 /* 1 if so far this constructor's elements are all valid address constants. */
4192 /* 1 if this constructor is erroneous so far. */
4195 /* Structure for managing pending initializer elements, organized as an
4196 AVL tree. */
4198 struct init_node
4199 {
4203 tree purpose;
4204 tree value;
4205 };
4207 /* Tree of pending elements at this constructor level.
4208 These are elements encountered out of order
4209 which belong at places we haven't reached yet in actually
4210 writing the output.
4211 Will never hold tree nodes across GC runs. */
4214 /* The SPELLING_DEPTH of this constructor. */
4217 /* 0 if implicitly pushing constructor levels is allowed. */
4223 /* DECL node for which an initializer is being read.
4224 0 means we are reading a constructor expression
4225 such as (struct foo) {...}. */
4228 /* start_init saves the ASMSPEC arg here for really_start_incremental_init. */
4231 /* Nonzero if this is an initializer for a top-level decl. */
4234 /* Nonzero if there were any member designators in this initializer. */
4237 /* Nesting depth of designator list. */
4240 /* Nonzero if there were diagnosed errors in this designator list. */
4243 \f
4244 /* This stack has a level for each implicit or explicit level of
4245 structuring in the initializer, including the outermost one. It
4246 saves the values of most of the variables above. */
4250 struct constructor_stack
4251 {
4253 tree type;
4254 tree fields;
4255 tree index;
4256 tree max_index;
4257 tree unfilled_index;
4258 tree unfilled_fields;
4259 tree bit_index;
4260 tree elements;
4264 /* If nonzero, this value should replace the entire
4265 constructor at this level. */
4266 tree replacement_value;
4275 };
4279 /* This stack represents designators from some range designator up to
4280 the last designator in the list. */
4282 struct constructor_range_stack
4283 {
4286 tree range_start;
4287 tree index;
4288 tree range_end;
4289 tree fields;
4290 };
4294 /* This stack records separate initializers that are nested.
4295 Nested initializers can't happen in ANSI C, but GNU C allows them
4296 in cases like { ... (struct foo) { ... } ... }. */
4298 struct initializer_stack
4299 {
4301 tree decl;
4305 tree elements;
4312 };
4315 \f
4316 /* Prepare to parse and output the initializer for variable DECL. */
4318 void
4320 {
4348 {
4350 require_constant_elements
4352 /* For a scalar, you can always use any value to initialize,
4353 even within braces. */
4359 }
4360 else
4361 {
4365 }
4378 }
4380 void
4382 {
4385 /* Free the whole constructor stack of this initializer. */
4387 {
4391 }
4396 /* Pop back to the data of the outer initializer (if any). */
4410 }
4411 \f
4412 /* Call here when we see the initializer is surrounded by braces.
4413 This is instead of a call to push_init_level;
4414 it is matched by a call to pop_init_level.
4416 TYPE is the type to initialize, for a constructor expression.
4417 For an initializer for a decl, TYPE is zero. */
4419 void
4421 {
4465 {
4467 /* Skip any nameless bit fields at the beginning. */
4474 }
4476 {
4478 {
4479 constructor_max_index
4482 /* Detect non-empty initializations of zero-length arrays. */
4487 /* constructor_max_index needs to be an INTEGER_CST. Attempts
4488 to initialize VLAs will cause a proper error; avoid tree
4489 checking errors as well by setting a safe value. */
4494 constructor_index
4497 }
4498 else
4502 }
4504 {
4505 /* Vectors are like simple fixed-size arrays. */
4506 constructor_max_index =
4510 }
4511 else
4512 {
4513 /* Handle the case of int x = {5}; */
4516 }
4517 }
4518 \f
4519 /* Push down into a subobject, for initialization.
4520 If this is for an explicit set of braces, IMPLICIT is 0.
4521 If it is because the next element belongs at a lower level,
4522 IMPLICIT is 1 (or 2 if the push is because of designator list). */
4524 void
4526 {
4530 /* If we've exhausted any levels that didn't have braces,
4531 pop them now. */
4533 {
4539 && constructor_max_index
4542 else
4544 }
4546 /* Unless this is an explicit brace, we need to preserve previous
4547 content if any. */
4549 {
4556 }
4589 {
4594 }
4596 /* Don't die if an entire brace-pair level is superfluous
4597 in the containing level. */
4599 ;
4602 {
4603 /* Don't die if there are extra init elts at the end. */
4606 else
4607 {
4610 constructor_depth++;
4611 }
4612 }
4614 {
4617 constructor_depth++;
4618 }
4621 {
4626 }
4629 {
4637 }
4640 {
4643 }
4647 {
4649 /* Skip any nameless bit fields at the beginning. */
4656 }
4658 {
4659 /* Vectors are like simple fixed-size arrays. */
4660 constructor_max_index =
4664 }
4666 {
4668 {
4669 constructor_max_index
4672 /* Detect non-empty initializations of zero-length arrays. */
4677 /* constructor_max_index needs to be an INTEGER_CST. Attempts
4678 to initialize VLAs will cause a proper error; avoid tree
4679 checking errors as well by setting a safe value. */
4684 constructor_index
4687 }
4688 else
4693 {
4694 /* We need to split the char/wchar array into individual
4695 characters, so that we don't have to special case it
4696 everywhere. */
4698 }
4699 }
4700 else
4701 {
4705 }
4706 }
4708 /* At the end of an implicit or explicit brace level,
4709 finish up that level of constructor.
4710 If we were outputting the elements as they are read, return 0
4711 from inner levels (process_init_element ignores that),
4712 but return error_mark_node from the outermost level
4713 (that's what we want to put in DECL_INITIAL).
4714 Otherwise, return a CONSTRUCTOR expression. */
4716 tree
4718 {
4723 {
4724 /* When we come to an explicit close brace,
4725 pop any inner levels that didn't have explicit braces. */
4731 }
4735 /* Error for initializing a flexible array member, or a zero-length
4736 array member in an inappropriate context. */
4741 {
4742 /* Silently discard empty initializations. The parser will
4743 already have pedwarned for empty brackets. */
4747 {
4753 /* We have already issued an error message for the existence
4754 of a flexible array member not at the end of the structure.
4755 Discard the initializer so that we do not abort later. */
4758 }
4759 else
4760 /* Zero-length arrays are no longer special, so we should no longer
4761 get here. */
4763 }
4765 /* Warn when some struct elements are implicitly initialized to zero. */
4767 && constructor_type
4770 {
4771 /* Do not warn for flexible array members or zero-length arrays. */
4777 /* Do not warn if this level of the initializer uses member
4778 designators; it is likely to be deliberate. */
4780 {
4784 }
4785 }
4787 /* Now output all pending elements. */
4791 /* Pad out the end of the structure. */
4793 /* If this closes a superfluous brace pair,
4794 just pass out the element between them. */
4797 ;
4802 {
4803 /* A nonincremental scalar initializer--just return
4804 the element, after verifying there is just one. */
4806 {
4810 }
4812 {
4815 }
4816 else
4818 }
4819 else
4820 {
4823 else
4824 {
4831 }
4832 }
4857 {
4861 }
4863 }
4865 /* Common handling for both array range and field name designators.
4866 ARRAY argument is nonzero for array ranges. Returns zero for success. */
4868 static int
4870 {
4871 tree subtype;
4874 /* Don't die if an entire brace-pair level is superfluous
4875 in the containing level. */
4879 /* If there were errors in this designator list already, bail out silently. */
4884 {
4888 /* Designator list starts at the level of closest explicit
4889 braces. */
4894 }
4897 {
4900 }
4904 {
4908 }
4910 {
4912 }
4913 else
4918 {
4921 }
4923 {
4926 }
4931 }
4933 /* If there are range designators in designator list, push a new designator
4934 to constructor_range_stack. RANGE_END is end of such stack range or
4935 NULL_TREE if there is no range designator at this level. */
4937 static void
4939 {
4953 }
4955 /* Within an array initializer, specify the next index to be initialized.
4956 FIRST is that index. If LAST is nonzero, then initialize a range
4957 of indices, running from FIRST through LAST. */
4959 void
4961 {
4993 else
4994 {
4998 {
5002 {
5005 }
5006 else
5007 {
5011 {
5014 }
5015 }
5016 }
5018 designator_depth++;
5022 }
5023 }
5025 /* Within a struct initializer, specify the next field to be initialized. */
5027 void
5029 {
5030 tree tail;
5039 {
5042 }
5046 {
5049 }
5054 else
5055 {
5057 designator_depth++;
5061 }
5062 }
5063 \f
5064 /* Add a new initializer to the tree of pending initializers. PURPOSE
5065 identifies the initializer, either array index or field in a structure.
5066 VALUE is the value of that index or field. */
5068 static void
5070 {
5077 {
5079 {
5085 else
5086 {
5091 }
5092 }
5093 }
5094 else
5095 {
5096 tree bitpos;
5100 {
5106 else
5107 {
5112 }
5113 }
5114 }
5127 {
5131 {
5135 {
5137 {
5138 /* L rotation. */
5151 {
5154 else
5156 }
5157 else
5159 }
5160 else
5161 {
5162 /* LR rotation. */
5184 {
5187 else
5189 }
5190 else
5192 }
5194 }
5195 else
5196 {
5197 /* p->balance == +1; growth of left side balances the node. */
5200 }
5201 }
5203 {
5205 /* Growth propagation from right side. */
5208 {
5210 {
5211 /* R rotation. */
5224 {
5227 else
5229 }
5230 else
5232 }
5234 {
5235 /* RL rotation */
5257 {
5260 else
5262 }
5263 else
5265 }
5267 }
5268 else
5269 {
5270 /* p->balance == -1; growth of right side balances the node. */
5273 }
5274 }
5278 }
5279 }
5281 /* Build AVL tree from a sorted chain. */
5283 static void
5285 {
5286 tree chain;
5296 {
5298 /* Skip any nameless bit fields at the beginning. */
5304 }
5306 {
5308 constructor_unfilled_index
5311 else
5313 }
5315 }
5317 /* Build AVL tree from a string constant. */
5319 static void
5321 {
5336 else
5347 {
5349 {
5352 }
5353 else
5354 {
5358 {
5361 else
5366 }
5367 }
5370 {
5373 {
5375 {
5378 }
5379 }
5381 {
5384 }
5389 }
5394 }
5397 }
5399 /* Return value of FIELD in pending initializer or zero if the field was
5400 not initialized yet. */
5402 static tree
5404 {
5408 {
5415 {
5420 else
5422 }
5423 }
5425 {
5429 && (!constructor_unfilled_fields
5436 {
5441 else
5443 }
5444 }
5446 {
5450 }
5452 }
5454 /* "Output" the next constructor element.
5455 At top level, really output it to assembler code now.
5456 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
5457 TYPE is the data type that the containing data type wants here.
5458 FIELD is the field (a FIELD_DECL) or the index that this element fills.
5460 PENDING if non-nil means output pending elements that belong
5461 right after this element. (PENDING is normally 1;
5462 it is 0 while outputting pending elements, to avoid recursion.) */
5464 static void
5466 {
5468 {
5471 }
5483 {
5484 /* As an extension, allow initializing objects with static storage
5485 duration with compound literals (which are then treated just as
5486 the brace enclosed list they contain). */
5489 }
5503 {
5506 }
5511 /* If this field is empty (and not at the end of structure),
5512 don't do anything other than checking the initializer. */
5523 {
5526 }
5528 /* If this element doesn't come next in sequence,
5529 put it on constructor_pending_elts. */
5531 && (!constructor_incremental
5533 {
5540 }
5542 && (!constructor_incremental
5544 {
5545 /* We do this for records but not for unions. In a union,
5546 no matter which field is specified, it can be initialized
5547 right away since it starts at the beginning of the union. */
5549 {
5552 else
5553 {
5561 }
5562 }
5566 }
5569 {
5573 /* We can have just one union field set. */
5575 }
5577 /* Otherwise, output this element either to
5578 constructor_elements or to the assembler file. */
5582 constructor_elements
5585 /* Advance the variable that indicates sequential elements output. */
5587 constructor_unfilled_index
5589 bitsize_one_node);
5591 {
5592 constructor_unfilled_fields
5595 /* Skip any nameless bit fields. */
5599 constructor_unfilled_fields =
5601 }
5605 /* Now output any pending elements which have become next. */
5608 }
5610 /* Output any pending elements which have become next.
5611 As we output elements, constructor_unfilled_{fields,index}
5612 advances, which may cause other elements to become next;
5613 if so, they too are output.
5615 If ALL is 0, we return when there are
5616 no more pending elements to output now.
5618 If ALL is 1, we output space as necessary so that
5619 we can output all the pending elements. */
5621 static void
5623 {
5625 tree next;
5627 retry:
5629 /* Look thru the whole pending tree.
5630 If we find an element that should be output now,
5631 output it. Otherwise, set NEXT to the element
5632 that comes first among those still pending. */
5636 {
5638 {
5640 constructor_unfilled_index))
5646 {
5647 /* Advance to the next smaller node. */
5650 else
5651 {
5652 /* We have reached the smallest node bigger than the
5653 current unfilled index. Fill the space first. */
5656 }
5657 }
5658 else
5659 {
5660 /* Advance to the next bigger node. */
5663 else
5664 {
5665 /* We have reached the biggest node in a subtree. Find
5666 the parent of it, which is the next bigger node. */
5672 {
5675 }
5676 }
5677 }
5678 }
5681 {
5684 /* If the current record is complete we are done. */
5690 /* We can't compare fields here because there might be empty
5691 fields in between. */
5693 {
5697 }
5699 {
5700 /* Advance to the next smaller node. */
5703 else
5704 {
5705 /* We have reached the smallest node bigger than the
5706 current unfilled field. Fill the space first. */
5709 }
5710 }
5711 else
5712 {
5713 /* Advance to the next bigger node. */
5716 else
5717 {
5718 /* We have reached the biggest node in a subtree. Find
5719 the parent of it, which is the next bigger node. */
5726 {
5729 }
5730 }
5731 }
5732 }
5733 }
5735 /* Ordinarily return, but not if we want to output all
5736 and there are elements left. */
5740 /* If it's not incremental, just skip over the gap, so that after
5741 jumping to retry we will output the next successive element. */
5748 /* ELT now points to the node in the pending tree with the next
5749 initializer to output. */
5751 }
5752 \f
5753 /* Add one non-braced element to the current constructor level.
5754 This adjusts the current position within the constructor's type.
5755 This may also start or terminate implicit levels
5756 to handle a partly-braced initializer.
5758 Once this has found the correct level for the new element,
5759 it calls output_init_element. */
5761 void
5763 {
5770 /* Handle superfluous braces around string cst as in
5771 char x[] = {"foo"}; */
5773 && constructor_type
5777 {
5782 }
5785 {
5788 }
5790 /* Ignore elements of a brace group if it is entirely superfluous
5791 and has already been diagnosed. */
5795 /* If we've exhausted any levels that didn't have braces,
5796 pop them now. */
5798 {
5806 constructor_index)))
5808 else
5810 }
5812 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
5814 {
5815 /* If value is a compound literal and we'll be just using its
5816 content, don't put it into a SAVE_EXPR. */
5818 || !require_constant_value
5821 }
5824 {
5826 {
5827 tree fieldtype;
5831 {
5834 }
5841 /* Error for non-static initialization of a flexible array member. */
5843 && !require_constant_value
5846 {
5849 }
5851 /* Accept a string constant to initialize a subarray. */
5857 /* Otherwise, if we have come to a subaggregate,
5858 and we don't have an element of its type, push into it. */
5864 {
5867 }
5870 {
5874 }
5875 else
5876 /* Do the bookkeeping for an element that was
5877 directly output as a constructor. */
5878 {
5879 /* For a record, keep track of end position of last field. */
5881 constructor_bit_index
5886 /* If the current field was the first one not yet written out,
5887 it isn't now, so update. */
5889 {
5891 /* Skip any nameless bit fields. */
5895 constructor_unfilled_fields =
5897 }
5898 }
5901 /* Skip any nameless bit fields at the beginning. */
5906 }
5908 {
5909 tree fieldtype;
5913 {
5916 }
5923 /* Warn that traditional C rejects initialization of unions.
5924 We skip the warning if the value is zero. This is done
5925 under the assumption that the zero initializer in user
5926 code appears conditioned on e.g. __STDC__ to avoid
5927 "missing initializer" warnings and relies on default
5928 initialization to zero in the traditional C case.
5929 We also skip the warning if the initializer is designated,
5930 again on the assumption that this must be conditional on
5931 __STDC__ anyway (and we've already complained about the
5932 member-designator already). */
5937 /* Accept a string constant to initialize a subarray. */
5943 /* Otherwise, if we have come to a subaggregate,
5944 and we don't have an element of its type, push into it. */
5950 {
5953 }
5956 {
5960 }
5961 else
5962 /* Do the bookkeeping for an element that was
5963 directly output as a constructor. */
5964 {
5967 }
5970 }
5972 {
5976 /* Accept a string constant to initialize a subarray. */
5982 /* Otherwise, if we have come to a subaggregate,
5983 and we don't have an element of its type, push into it. */
5989 {
5992 }
5997 {
6000 }
6002 /* Now output the actual element. */
6004 {
6008 }
6010 constructor_index
6014 /* If we are doing the bookkeeping for an element that was
6015 directly output as a constructor, we must update
6016 constructor_unfilled_index. */
6018 }
6020 {
6023 /* Do a basic check of initializer size. Note that vectors
6024 always have a fixed size derived from their type. */
6026 {
6029 }
6031 /* Now output the actual element. */
6035 constructor_index
6039 /* If we are doing the bookkeeping for an element that was
6040 directly output as a constructor, we must update
6041 constructor_unfilled_index. */
6043 }
6045 /* Handle the sole element allowed in a braced initializer
6046 for a scalar variable. */
6048 {
6051 }
6052 else
6053 {
6057 }
6059 /* Handle range initializers either at this level or anywhere higher
6060 in the designator stack. */
6062 {
6069 {
6073 }
6077 {
6081 }
6088 {
6092 {
6095 }
6103 }
6108 }
6111 }
6114 }
6115 \f
6116 /* Build a simple asm-statement, from one string literal. */
6117 tree
6119 {
6126 {
6127 tree stmt;
6129 /* Simple asm statements are treated as volatile. */
6134 }
6138 }
6140 /* Build an asm-statement, whose components are a CV_QUALIFIER, a
6141 STRING, some OUTPUTS, some INPUTS, and some CLOBBERS. */
6143 tree
6145 tree clobbers)
6146 {
6147 tree tail;
6150 {
6153 }
6157 {
6161 }
6163 /* We can remove output conversions that change the type,
6164 but not the mode. */
6166 {
6172 /* Allow conversions as LHS here. build_modify_expr as called below
6173 will do the right thing with them. */
6184 }
6186 /* Remove output conversions that change the type but not the mode. */
6188 {
6192 }
6194 /* Perform default conversions on array and function inputs.
6195 Don't do this for other types as it would screw up operands
6196 expected to be in memory. */
6202 }
6204 /* Expand an ASM statement with operands, handling output operands
6205 that are not variables or INDIRECT_REFS by transforming such
6206 cases into cases that expand_asm_operands can handle.
6208 Arguments are same as for expand_asm_operands. */
6210 void
6214 {
6217 /* o[I] is the place that output number I should be written. */
6219 tree tail;
6221 /* Record the contents of OUTPUTS before it is modified. */
6223 {
6227 }
6229 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
6230 OUTPUTS some trees for where the values were actually stored. */
6233 /* Copy all the intermediate outputs into the specified outputs. */
6235 {
6237 {
6242 /* Restore the original value so that it's correct the next
6243 time we expand this function. */
6245 }
6246 /* Detect modification of read-only values.
6247 (Otherwise done by build_modify_expr.) */
6248 else
6249 {
6257 }
6258 }
6260 /* Those MODIFY_EXPRs could do autoincrements. */
6262 }
6263 \f
6264 /* Expand a C `return' statement.
6265 RETVAL is the expression for what to return,
6266 or a null pointer for `return;' with no value. */
6268 tree
6270 {
6277 {
6282 }
6284 {
6288 }
6289 else
6290 {
6294 tree inner;
6302 /* Strip any conversions, additions, and subtractions, and see if
6303 we are returning the address of a local variable. Warn if so. */
6305 {
6307 {
6314 /* If the second operand of the MINUS_EXPR has a pointer
6315 type (or is converted from it), this may be valid, so
6316 don't give a warning. */
6317 {
6331 }
6348 }
6351 }
6354 }
6357 }
6358 \f
6360 /* The SWITCH_STMT being built. */
6361 tree switch_stmt;
6362 /* A splay-tree mapping the low element of a case range to the high
6363 element, or NULL_TREE if there is no high element. Used to
6364 determine whether or not a new case label duplicates an old case
6365 label. We need a tree, rather than simply a hash table, because
6366 of the GNU case range extension. */
6367 splay_tree cases;
6368 /* The next node on the stack. */
6370 };
6372 /* A stack of the currently active switch statements. The innermost
6373 switch statement is on the top of the stack. There is no need to
6374 mark the stack for garbage collection because it is only active
6375 during the processing of the body of a function, and we never
6376 collect at that point. */
6380 /* Start a C switch statement, testing expression EXP. Return the new
6381 SWITCH_STMT. */
6383 tree
6385 {
6391 {
6397 {
6400 }
6401 else
6402 {
6412 }
6413 }
6415 /* Add this new SWITCH_STMT to the stack. */
6423 }
6425 /* Process a case label. */
6427 tree
6429 {
6433 {
6442 {
6443 /* Attach the first case label to the SWITCH_BODY. */
6446 }
6447 }
6450 else
6454 }
6456 /* Finish the switch statement. */
6458 void
6460 {
6463 /* Rechain the next statements to the SWITCH_STMT. */
6466 /* Pop the stack. */
6470 }
6472 /* Build a binary-operation expression without default conversions.
6473 CODE is the kind of expression to build.
6474 This function differs from `build' in several ways:
6475 the data type of the result is computed and recorded in it,
6476 warnings are generated if arg data types are invalid,
6477 special handling for addition and subtraction of pointers is known,
6478 and some optimization is done (operations on narrow ints
6479 are done in the narrower type when that gives the same result).
6480 Constant folding is also done before the result is returned.
6482 Note that the operands will never have enumeral types, or function
6483 or array types, because either they will have the default conversions
6484 performed or they have both just been converted to some other type in which
6485 the arithmetic is to be done. */
6487 tree
6490 {
6495 /* Expression code to give to the expression when it is built.
6496 Normally this is CODE, which is what the caller asked for,
6497 but in some special cases we change it. */
6500 /* Data type in which the computation is to be performed.
6501 In the simplest cases this is the common type of the arguments. */
6504 /* Nonzero means operands have already been type-converted
6505 in whatever way is necessary.
6506 Zero means they need to be converted to RESULT_TYPE. */
6509 /* Nonzero means create the expression with this type, rather than
6510 RESULT_TYPE. */
6513 /* Nonzero means after finally constructing the expression
6514 convert it to this type. */
6517 /* Nonzero if this is an operation like MIN or MAX which can
6518 safely be computed in short if both args are promoted shorts.
6519 Also implies COMMON.
6520 -1 indicates a bitwise operation; this makes a difference
6521 in the exact conditions for when it is safe to do the operation
6522 in a narrower mode. */
6525 /* Nonzero if this is a comparison operation;
6526 if both args are promoted shorts, compare the original shorts.
6527 Also implies COMMON. */
6530 /* Nonzero if this is a right-shift operation, which can be computed on the
6531 original short and then promoted if the operand is a promoted short. */
6534 /* Nonzero means set RESULT_TYPE to the common type of the args. */
6538 {
6541 }
6542 else
6543 {
6546 }
6551 /* The expression codes of the data types of the arguments tell us
6552 whether the arguments are integers, floating, pointers, etc. */
6556 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
6560 /* If an error was already reported for one of the arguments,
6561 avoid reporting another error. */
6567 {
6569 /* Handle the pointer + int case. */
6574 else
6579 /* Subtraction of two similar pointers.
6580 We must subtract them as integers, then divide by object size. */
6584 /* Handle pointer minus int. Just like pointer plus int. */
6587 else
6600 /* Floating point division by zero is a legitimate way to obtain
6601 infinities and NaNs. */
6609 {
6612 else
6613 /* Although it would be tempting to shorten always here, that
6614 loses on some targets, since the modulo instruction is
6615 undefined if the quotient can't be represented in the
6616 computation mode. We shorten only if unsigned or if
6617 dividing by something we know != -1. */
6622 }
6640 {
6641 /* Although it would be tempting to shorten always here, that loses
6642 on some targets, since the modulo instruction is undefined if the
6643 quotient can't be represented in the computation mode. We shorten
6644 only if unsigned or if dividing by something we know != -1. */
6649 }
6661 {
6662 /* Result of these operations is always an int,
6663 but that does not mean the operands should be
6664 converted to ints! */
6669 }
6672 /* Shift operations: result has same type as first operand;
6673 always convert second operand to int.
6674 Also set SHORT_SHIFT if shifting rightward. */
6678 {
6680 {
6683 else
6684 {
6690 }
6691 }
6693 /* Use the type of the value to be shifted. */
6695 /* Convert the shift-count to an integer, regardless of size
6696 of value being shifted. */
6699 /* Avoid converting op1 to result_type later. */
6701 }
6706 {
6708 {
6714 }
6716 /* Use the type of the value to be shifted. */
6718 /* Convert the shift-count to an integer, regardless of size
6719 of value being shifted. */
6722 /* Avoid converting op1 to result_type later. */
6724 }
6730 {
6732 {
6737 }
6739 /* Use the type of the value to be shifted. */
6741 /* Convert the shift-count to an integer, regardless of size
6742 of value being shifted. */
6745 /* Avoid converting op1 to result_type later. */
6747 }
6754 /* Result of comparison is always int,
6755 but don't convert the args to int! */
6765 {
6768 /* Anything compares with void *. void * compares with anything.
6769 Otherwise, the targets must be compatible
6770 and both must be object or both incomplete. */
6774 {
6775 /* op0 != orig_op0 detects the case of something
6776 whose value is 0 but which isn't a valid null ptr const. */
6780 }
6782 {
6786 }
6787 else
6792 }
6800 {
6803 }
6805 {
6808 }
6817 {
6819 {
6824 }
6825 else
6826 {
6829 }
6830 }
6842 {
6844 {
6852 }
6853 else
6854 {
6857 }
6858 }
6861 {
6865 }
6868 {
6872 }
6874 {
6877 }
6879 {
6882 }
6894 {
6897 }
6903 }
6907 &&
6910 {
6916 /* For certain operations (which identify themselves by shorten != 0)
6917 if both args were extended from the same smaller type,
6918 do the arithmetic in that type and then extend.
6920 shorten !=0 and !=1 indicates a bitwise operation.
6921 For them, this optimization is safe only if
6922 both args are zero-extended or both are sign-extended.
6923 Otherwise, we might change the result.
6924 Eg, (short)-1 | (unsigned short)-1 is (int)-1
6925 but calculated in (unsigned short) it would be (unsigned short)-1. */
6928 {
6932 /* UNS is 1 if the operation to be done is an unsigned one. */
6934 tree type;
6938 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
6939 but it *requires* conversion to FINAL_TYPE. */
6950 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
6952 /* For bitwise operations, signedness of nominal type
6953 does not matter. Consider only how operands were extended. */
6957 /* Note that in all three cases below we refrain from optimizing
6958 an unsigned operation on sign-extended args.
6959 That would not be valid. */
6961 /* Both args variable: if both extended in same way
6962 from same width, do it in that width.
6963 Do it unsigned if args were zero-extended. */
6970 result_type
6971 = c_common_signed_or_unsigned_type
6977 && (type
6986 && (type
6991 }
6993 /* Shifts can be shortened if shifting right. */
6996 {
7006 /* We can shorten only if the shift count is less than the
7007 number of bits in the smaller type size. */
7009 /* We cannot drop an unsigned shift after sign-extension. */
7011 {
7012 /* Do an unsigned shift if the operand was zero-extended. */
7013 result_type
7016 /* Convert value-to-be-shifted to that type. */
7020 }
7021 }
7023 /* Comparison operations are shortened too but differently.
7024 They identify themselves by setting short_compare = 1. */
7027 {
7028 /* Don't write &op0, etc., because that would prevent op0
7029 from being kept in a register.
7030 Instead, make copies of the our local variables and
7031 pass the copies by reference, then copy them back afterward. */
7034 tree val
7045 {
7057 /* Give warnings for comparisons between signed and unsigned
7058 quantities that may fail.
7060 Do the checking based on the original operand trees, so that
7061 casts will be considered, but default promotions won't be.
7063 Do not warn if the comparison is being done in a signed type,
7064 since the signed type will only be chosen if it can represent
7065 all the values of the unsigned type. */
7068 /* Do not warn if both operands are the same signedness. */
7071 else
7072 {
7077 else
7080 /* Do not warn if the signed quantity is an
7081 unsuffixed integer literal (or some static
7082 constant expression involving such literals or a
7083 conditional expression involving such literals)
7084 and it is non-negative. */
7087 /* Do not warn if the comparison is an equality operation,
7088 the unsigned quantity is an integral constant, and it
7089 would fit in the result if the result were signed. */
7092 && int_fits_type_p
7095 /* Do not warn if the unsigned quantity is an enumeration
7096 constant and its maximum value would fit in the result
7097 if the result were signed. */
7100 && int_fits_type_p
7104 else
7106 }
7108 /* Warn if two unsigned values are being compared in a size
7109 larger than their original size, and one (and only one) is the
7110 result of a `~' operator. This comparison will always fail.
7112 Also warn if one operand is a constant, and the constant
7113 does not have all bits set that are set in the ~ operand
7114 when it is extended. */
7118 {
7122 else
7127 {
7128 tree primop;
7133 {
7137 }
7138 else
7139 {
7143 }
7148 {
7152 }
7153 }
7160 }
7161 }
7162 }
7163 }
7165 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
7166 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
7167 Then the expression will be built.
7168 It will be given type FINAL_TYPE if that is nonzero;
7169 otherwise, it will be given type RESULT_TYPE. */
7172 {
7175 }
7178 {
7183 }
7188 {
7190 tree folded;
7192 /* Treat expressions in initializers specially as they can't trap. */
7200 }
7201 }