| blob | 64b568cc2185e6de42c0d0a7d23311b5ef391380 |
1 /* Build expressions with type checking for C compiler.
2 Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
10 version.
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
20 02111-1307, USA. */
23 /* This file is part of the C front end.
24 It contains routines to build C expressions given their operands,
25 including computing the types of the result, C-specific error checks,
26 and some optimization.
28 There are also routines to build RETURN_STMT nodes and CASE_STMT nodes,
29 and to process initializations in declarations (since they work
30 like a strange sort of assignment). */
49 /* Nonzero if we've already printed a "missing braces around initializer"
50 message within this initializer. */
83 \f
84 /* Do `exp = require_complete_type (exp);' to make sure exp
85 does not have an incomplete type. (That includes void types.) */
87 tree
89 {
95 /* First, detect a valid value with a complete type. */
101 }
103 /* Print an error message for invalid use of an incomplete type.
104 VALUE is the expression that was used (or 0 if that isn't known)
105 and TYPE is the type that was invalid. */
107 void
109 {
112 /* Avoid duplicate error message. */
120 else
121 {
122 retry:
123 /* We must print an error message. Be clever about what it says. */
126 {
145 {
147 {
150 }
153 }
159 }
164 else
165 /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */
168 }
169 }
171 /* Given a type, apply default promotions wrt unnamed function
172 arguments and return the new type. */
174 tree
176 {
181 {
182 /* Preserve unsignedness if not really getting any wider. */
187 }
190 }
192 /* Return a variant of TYPE which has all the type qualifiers of LIKE
193 as well as those of TYPE. */
195 static tree
197 {
200 }
201 \f
202 /* Return the common type of two types.
203 We assume that comptypes has already been done and returned 1;
204 if that isn't so, this may crash. In particular, we assume that qualifiers
205 match.
207 This is the type for the result of most arithmetic operations
208 if the operands have the given two types. */
210 tree
212 {
215 tree attributes;
217 /* Save time if the two types are the same. */
221 /* If one type is nonsense, use the other. */
227 /* Merge the attributes. */
230 /* Treat an enum type as the unsigned integer type of the same width. */
240 /* If one type is complex, form the common type of the non-complex
241 components, then make that complex. Use T1 or T2 if it is the
242 required type. */
244 {
253 else
255 attributes);
256 }
259 {
262 /* If only one is real, use it as the result. */
270 /* Both real or both integers; use the one with greater precision. */
277 /* Same precision. Prefer longs to ints even when same size. */
282 attributes);
286 {
287 /* But preserve unsignedness from the other type,
288 since long cannot hold all the values of an unsigned int. */
291 else
294 }
296 /* Likewise, prefer long double to double even if same size. */
300 attributes);
302 /* Otherwise prefer the unsigned one. */
306 else
310 /* For two pointers, do this recursively on the target type,
311 and combine the qualifiers of the two types' targets. */
312 /* This code was turned off; I don't know why.
313 But ANSI C specifies doing this with the qualifiers.
314 So I turned it on again. */
315 {
325 }
328 {
330 /* Save space: see if the result is identical to one of the args. */
335 /* Merge the element types, and have a size if either arg has one. */
338 }
341 /* Function types: prefer the one that specified arg types.
342 If both do, merge the arg types. Also merge the return types. */
343 {
351 /* Save space: see if the result is identical to one of the args. */
357 /* Simple way if one arg fails to specify argument types. */
359 {
362 }
364 {
367 }
369 /* If both args specify argument types, we must merge the two
370 lists, argument by argument. */
371 /* Tell global_bindings_p to return false so that variable_size
372 doesn't abort on VLAs in parameter types. */
385 {
386 /* A null type means arg type is not specified.
387 Take whatever the other function type has. */
389 {
392 }
394 {
397 }
399 /* Given wait (union {union wait *u; int *i} *)
400 and wait (union wait *),
401 prefer union wait * as type of parm. */
404 {
405 tree memb;
409 COMPARE_STRICT))
410 {
415 }
416 }
419 {
420 tree memb;
424 COMPARE_STRICT))
425 {
430 }
431 }
433 parm_done: ;
434 }
438 /* ... falls through ... */
439 }
443 }
445 }
446 \f
447 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
448 or various other operations. Return 2 if they are compatible
449 but a warning may be needed if you use them together. */
451 int
453 {
458 /* Suppress errors caused by previously reported errors. */
464 /* If either type is the internal version of sizetype, return the
465 language version. */
475 /* Enumerated types are compatible with integer types, but this is
476 not transitive: two enumerated types in the same translation unit
477 are compatible with each other only if they are the same type. */
487 /* Different classes of types can't be compatible. */
491 /* Qualifiers must match. */
496 /* Allow for two different type nodes which have essentially the same
497 definition. Note that we already checked for equality of the type
498 qualifiers (just above). */
503 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
507 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
511 {
513 /* We must give ObjC the first crack at comparing pointers, since
514 protocol qualifiers may be involved. */
526 {
533 /* Target types must match incl. qualifiers. */
536 flags)))
539 /* Sizes must match unless one is missing or variable. */
546 d1_variable = (! d1_zero
549 d2_variable = (! d2_zero
563 }
566 /* We are dealing with two distinct structs. In assorted Objective-C
567 corner cases, however, these can still be deemed equivalent. */
578 /* 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 trees derive from the same translation unit.
617 If the CONTEXT chain ends in a null, that tree's context is still
618 being parsed, so if two trees have context chains ending in null,
619 they're in the same translation unit. */
620 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... */
686 /* C90 didn't have the requirement that the two tags be the same. */
690 /* C90 didn't say what happened if one or both of the types were
691 incomplete; we choose to follow C99 rules here, which is that they
692 are compatible. */
697 {
702 }
705 {
707 {
709 /* Speed up the case where the type values are in the same order. */
717 {
722 }
733 {
738 }
740 }
743 {
748 {
760 {
775 }
779 }
781 }
784 {
795 {
810 }
815 }
819 }
820 }
822 /* Return 1 if two function types F1 and F2 are compatible.
823 If either type specifies no argument types,
824 the other must specify a fixed number of self-promoting arg types.
825 Otherwise, if one type specifies only the number of arguments,
826 the other must specify that number of self-promoting arg types.
827 Otherwise, the argument types must match. */
829 static int
831 {
833 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
841 /* 'volatile' qualifiers on a function's return type mean the function
842 is noreturn. */
858 /* An unspecified parmlist matches any specified parmlist
859 whose argument types don't need default promotions. */
862 {
865 /* If one of these types comes from a non-prototype fn definition,
866 compare that with the other type's arglist.
867 If they don't match, ask for a warning (but no error). */
870 flags))
873 }
875 {
880 flags))
883 }
885 /* Both types have argument lists: compare them and propagate results. */
888 }
890 /* Check two lists of types for compatibility,
891 returning 0 for incompatible, 1 for compatible,
892 or 2 for compatible with warning. */
894 static int
896 {
897 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
902 {
905 /* If one list is shorter than the other,
906 they fail to match. */
909 /* A null pointer instead of a type
910 means there is supposed to be an argument
911 but nothing is specified about what type it has.
912 So match anything that self-promotes. */
914 {
917 }
919 {
922 }
923 /* If one of the lists has an error marker, ignore this arg. */
926 ;
929 flags)))
930 {
931 /* Allow wait (union {union wait *u; int *i} *)
932 and wait (union wait *) to be compatible. */
939 {
940 tree memb;
944 flags))
948 }
955 {
956 tree memb;
960 flags))
964 }
965 else
967 }
969 /* comptypes said ok, but record if it said to warn. */
975 }
976 }
977 \f
978 /* Compute the size to increment a pointer by. */
980 tree
982 {
989 {
992 }
994 /* Convert in case a char is more than one unit. */
998 }
999 \f
1000 /* Return either DECL or its known constant value (if it has one). */
1002 tree
1004 {
1006 in a place where a variable is invalid. */
1012 /* This is invalid if initial value is not constant.
1013 If it has either a function call, a memory reference,
1014 or a variable, then re-evaluating it could give different results. */
1016 /* Check for cases where this is sub-optimal, even though valid. */
1020 }
1022 /* Return either DECL or its known constant value (if it has one), but
1023 return DECL if pedantic or DECL has mode BLKmode. This is for
1024 bug-compatibility with the old behavior of decl_constant_value
1025 (before GCC 3.0); every use of this function is a bug and it should
1026 be removed before GCC 3.1. It is not appropriate to use pedantic
1027 in a way that affects optimization, and BLKmode is probably not the
1028 right test for avoiding misoptimizations either. */
1030 static tree
1032 {
1035 else
1037 }
1040 /* Perform the default conversion of arrays and functions to pointers.
1041 Return the result of converting EXP. For any other expression, just
1042 return EXP. */
1044 static tree
1046 {
1047 tree orig_exp;
1052 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
1053 an lvalue.
1055 Do not use STRIP_NOPS here! It will remove conversions from pointer
1056 to integer and cause infinite recursion. */
1061 {
1065 }
1067 /* Preserve the original expression code. */
1072 {
1074 }
1076 {
1077 tree adr;
1079 tree ptrtype;
1085 {
1088 }
1091 restype
1102 {
1106 }
1110 {
1111 /* Before C99, non-lvalue arrays do not decay to pointers.
1112 Normally, using such an array would be invalid; but it can
1113 be used correctly inside sizeof or as a statement expression.
1114 Thus, do not give an error here; an error will result later. */
1116 }
1121 {
1122 /* ??? This is not really quite correct
1123 in that the type of the operand of ADDR_EXPR
1124 is not the target type of the type of the ADDR_EXPR itself.
1125 Question is, can this lossage be avoided? */
1132 }
1133 /* This way is better for a COMPONENT_REF since it can
1134 simplify the offset for a component. */
1137 }
1139 }
1141 /* Perform default promotions for C data used in expressions.
1142 Arrays and functions are converted to pointers;
1143 enumeral types or short or char, to int.
1144 In addition, manifest constants symbols are replaced by their values. */
1146 tree
1148 {
1149 tree orig_exp;
1156 /* Constants can be used directly unless they're not loadable. */
1160 /* Replace a nonvolatile const static variable with its value unless
1161 it is an array, in which case we must be sure that taking the
1162 address of the array produces consistent results. */
1164 {
1167 }
1169 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
1170 an lvalue.
1172 Do not use STRIP_NOPS here! It will remove conversions from pointer
1173 to integer and cause infinite recursion. */
1180 /* Preserve the original expression code. */
1184 /* Normally convert enums to int,
1185 but convert wide enums to something wider. */
1187 {
1195 }
1199 /* If it's thinner than an int, promote it like a
1200 c_promoting_integer_type_p, otherwise leave it alone. */
1206 {
1207 /* Preserve unsignedness if not really getting any wider. */
1213 }
1216 {
1219 }
1221 }
1222 \f
1223 /* Look up COMPONENT in a structure or union DECL.
1225 If the component name is not found, returns NULL_TREE. Otherwise,
1226 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL
1227 stepping down the chain to the component, which is in the last
1228 TREE_VALUE of the list. Normally the list is of length one, but if
1229 the component is embedded within (nested) anonymous structures or
1230 unions, the list steps down the chain to the component. */
1232 static tree
1234 {
1236 tree field;
1238 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers
1239 to the field elements. Use a binary search on this array to quickly
1240 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC
1241 will always be set for structures which have many elements. */
1244 {
1252 {
1257 {
1258 /* Step through all anon unions in linear fashion. */
1260 {
1264 {
1269 }
1270 }
1272 /* Entire record is only anon unions. */
1276 /* Restart the binary search, with new lower bound. */
1278 }
1284 else
1286 }
1292 }
1293 else
1294 {
1296 {
1300 {
1305 }
1309 }
1313 }
1316 }
1318 /* Make an expression to refer to the COMPONENT field of
1319 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */
1321 tree
1323 {
1327 tree ref;
1329 /* If DATUM is a COMPOUND_EXPR, move our reference inside it.
1330 Ensure that the arguments are not lvalues; otherwise,
1331 if the component is an array, it would wrongly decay to a pointer in
1332 C89 mode.
1333 We cannot do this with a COND_EXPR, because in a conditional expression
1334 the default promotions are applied to both sides, and this would yield
1335 the wrong type of the result; for example, if the components have
1336 type "char". */
1338 {
1340 {
1344 }
1347 }
1349 /* See if there is a field or component with name COMPONENT. */
1352 {
1354 {
1357 }
1362 {
1367 }
1369 /* Chain the COMPONENT_REFs if necessary down to the FIELD.
1370 This might be better solved in future the way the C++ front
1371 end does it - by giving the anonymous entities each a
1372 separate name and type, and then have build_component_ref
1373 recursively call itself. We can't do that here. */
1374 do
1375 {
1393 }
1397 }
1403 }
1404 \f
1405 /* Given an expression PTR for a pointer, return an expression
1406 for the value pointed to.
1407 ERRORSTRING is the name of the operator to appear in error messages. */
1409 tree
1411 {
1416 {
1421 else
1422 {
1427 {
1430 }
1434 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
1435 so that we get the proper error message if the result is used
1436 to assign to. Also, &* is supposed to be a no-op.
1437 And ANSI C seems to specify that the type of the result
1438 should be the const type. */
1439 /* A de-reference of a pointer to const is not a const. It is valid
1440 to change it via some other pointer. */
1446 }
1447 }
1451 }
1453 /* This handles expressions of the form "a[i]", which denotes
1454 an array reference.
1456 This is logically equivalent in C to *(a+i), but we may do it differently.
1457 If A is a variable or a member, we generate a primitive ARRAY_REF.
1458 This avoids forcing the array out of registers, and can work on
1459 arrays that are not lvalues (for example, members of structures returned
1460 by functions). */
1462 tree
1464 {
1466 {
1469 }
1477 {
1480 /* Subscripting with type char is likely to lose
1481 on a machine where chars are signed.
1482 So warn on any machine, but optionally.
1483 Don't warn for unsigned char since that type is safe.
1484 Don't warn for signed char because anyone who uses that
1485 must have done so deliberately. */
1490 /* Apply default promotions *after* noticing character types. */
1493 /* Require integer *after* promotion, for sake of enums. */
1495 {
1498 }
1500 /* An array that is indexed by a non-constant
1501 cannot be stored in a register; we must be able to do
1502 address arithmetic on its address.
1503 Likewise an array of elements of variable size. */
1507 {
1510 }
1511 /* An array that is indexed by a constant value which is not within
1512 the array bounds cannot be stored in a register either; because we
1513 would get a crash in store_bit_field/extract_bit_field when trying
1514 to access a non-existent part of the register. */
1518 {
1521 }
1524 {
1532 }
1536 /* Array ref is const/volatile if the array elements are
1537 or if the array is. */
1546 /* This was added by rms on 16 Nov 91.
1547 It fixes vol struct foo *a; a->elts[1]
1548 in an inline function.
1549 Hope it doesn't break something else. */
1552 }
1554 {
1558 /* Do the same warning check as above, but only on the part that's
1559 syntactically the index and only if it is also semantically
1560 the index. */
1566 /* Put the integer in IND to simplify error checking. */
1568 {
1572 }
1579 {
1582 }
1584 {
1587 }
1591 }
1592 }
1593 \f
1594 /* Build an external reference to identifier ID. FUN indicates
1595 whether this will be used for a function call. */
1596 tree
1598 {
1599 tree ref;
1604 {
1605 /* Properly declared variable or function reference. */
1609 {
1613 }
1614 else
1616 }
1620 /* Implicit function declaration. */
1623 /* Don't complain about something that's already been
1624 complained about. */
1626 else
1627 {
1630 }
1643 {
1646 }
1652 {
1657 }
1660 }
1662 /* Build a function call to function FUNCTION with parameters PARAMS.
1663 PARAMS is a list--a chain of TREE_LIST nodes--in which the
1664 TREE_VALUE of each node is a parameter-expression.
1665 FUNCTION's data type may be a function type or a pointer-to-function. */
1667 tree
1669 {
1671 tree coerced_params;
1673 tree tem;
1675 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
1678 /* Convert anything with function type to a pointer-to-function. */
1680 {
1683 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
1684 (because calling an inline function does not mean the function
1685 needs to be separately compiled). */
1691 }
1692 else
1702 {
1705 }
1710 /* fntype now gets the type of function pointed to. */
1713 /* Check that the function is called through a compatible prototype.
1714 If it is not, replace the call by a trap, wrapped up in a compound
1715 expression if necessary. This has the nice side-effect to prevent
1716 the tree-inliner from generating invalid assignment trees which may
1717 blow up in the RTL expander later.
1719 ??? This doesn't work for Objective-C because objc_comptypes
1720 refuses to compare function prototypes, yet the compiler appears
1721 to build calls that are flagged as invalid by C's comptypes. */
1727 {
1730 NULL_TREE);
1732 /* This situation leads to run-time undefined behavior. We can't,
1733 therefore, simply error unless we can prove that all possible
1734 executions of the program must execute the code. */
1737 /* We can, however, treat "undefined" any way we please.
1738 Call abort to encourage the user to fix the program. */
1743 else
1744 {
1745 tree rhs;
1750 NULL_TREE));
1751 else
1755 }
1756 }
1758 /* Convert the parameters to the types declared in the
1759 function prototype, or apply default promotions. */
1761 coerced_params
1764 /* Check that the arguments to the function are valid. */
1768 /* Recognize certain built-in functions so we can make tree-codes
1769 other than CALL_EXPR. We do this when it enables fold-const.c
1770 to do something useful. */
1775 {
1780 }
1790 }
1791 \f
1792 /* Convert the argument expressions in the list VALUES
1793 to the types in the list TYPELIST. The result is a list of converted
1794 argument expressions.
1796 If TYPELIST is exhausted, or when an element has NULL as its type,
1797 perform the default conversions.
1799 PARMLIST is the chain of parm decls for the function being called.
1800 It may be 0, if that info is not available.
1801 It is used only for generating error messages.
1803 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
1805 This is also where warnings about wrong number of args are generated.
1807 Both VALUES and the returned value are chains of TREE_LIST nodes
1808 with the elements of the list in the TREE_VALUE slots of those nodes. */
1810 static tree
1812 {
1817 /* Scan the given expressions and types, producing individual
1818 converted arguments and pushing them on RESULT in reverse order. */
1821 valtail;
1823 {
1828 {
1832 else
1835 }
1837 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
1838 /* Do not use STRIP_NOPS here! We do not want an enumerator with value 0
1839 to convert automatically to a pointer. */
1848 {
1849 /* Formal parm type is specified by a function prototype. */
1850 tree parmval;
1853 {
1856 }
1857 else
1858 {
1859 /* Optionally warn about conversions that
1860 differ from the default conversions. */
1862 {
1867 warn_for_assignment ("%s as integer rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1870 warn_for_assignment ("%s as integer rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1873 warn_for_assignment ("%s as complex rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1876 warn_for_assignment ("%s as floating rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1879 warn_for_assignment ("%s as complex rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1882 warn_for_assignment ("%s as floating rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1883 /* ??? At some point, messages should be written about
1884 conversions between complex types, but that's too messy
1885 to do now. */
1888 {
1889 /* Warn if any argument is passed as `float',
1890 since without a prototype it would be `double'. */
1892 warn_for_assignment ("%s as `float' rather than `double' due to prototype", (char *) 0, name, parmnum + 1);
1893 }
1894 /* Detect integer changing in width or signedness.
1895 These warnings are only activated with
1896 -Wconversion, not with -Wtraditional. */
1899 {
1906 /* No warning if function asks for enum
1907 and the actual arg is that enum type. */
1908 ;
1910 warn_for_assignment ("%s with different width due to prototype", (char *) 0, name, parmnum + 1);
1912 ;
1913 /* Don't complain if the formal parameter type
1914 is an enum, because we can't tell now whether
1915 the value was an enum--even the same enum. */
1917 ;
1920 /* Change in signedness doesn't matter
1921 if a constant value is unaffected. */
1922 ;
1923 /* Likewise for a constant in a NOP_EXPR. */
1927 ;
1928 /* If the value is extended from a narrower
1929 unsigned type, it doesn't matter whether we
1930 pass it as signed or unsigned; the value
1931 certainly is the same either way. */
1934 ;
1937 else
1939 }
1940 }
1950 }
1952 }
1956 /* Convert `float' to `double'. */
1958 else
1959 /* Convert `short' and `char' to full-size `int'. */
1964 }
1967 {
1971 else
1973 }
1976 }
1977 \f
1978 /* This is the entry point used by the parser
1979 for binary operators in the input.
1980 In addition to constructing the expression,
1981 we check for operands that were written with other binary operators
1982 in a way that is likely to confuse the user. */
1984 tree
1986 {
2003 /* Check for cases such as x+y<<z which users are likely
2004 to misinterpret. If parens are used, C_EXP_ORIGINAL_CODE
2005 is cleared to prevent these warnings. */
2007 {
2009 {
2013 }
2016 {
2020 }
2023 {
2029 /* Check cases like x|y==z */
2032 }
2035 {
2041 /* Check cases like x^y==z */
2044 }
2047 {
2051 /* Check cases like x&y==z */
2054 }
2055 }
2057 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */
2068 /* Record the code that was specified in the source,
2069 for the sake of warnings about confusing nesting. */
2072 else
2073 {
2075 /* We used to use NOP_EXPR rather than NON_LVALUE_EXPR
2076 so that convert_for_assignment wouldn't strip it.
2077 That way, we got warnings for things like p = (1 - 1).
2078 But it turns out we should not get those warnings. */
2082 }
2085 }
2086 \f
2088 /* Return true if `t' is known to be non-negative. */
2090 int
2092 {
2094 {
2097 /* Find the last statement in the chain, ignoring the final
2098 * scope statement */
2103 }
2105 }
2107 /* Return a tree for the difference of pointers OP0 and OP1.
2108 The resulting tree has type int. */
2110 static tree
2112 {
2121 {
2126 }
2128 /* If the conversion to ptrdiff_type does anything like widening or
2129 converting a partial to an integral mode, we get a convert_expression
2130 that is in the way to do any simplifications.
2131 (fold-const.c doesn't know that the extra bits won't be needed.
2132 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2133 different mode in place.)
2134 So first try to find a common term here 'by hand'; we want to cover
2135 at least the cases that occur in legal static initializers. */
2140 {
2143 }
2144 else
2148 {
2151 }
2152 else
2156 {
2159 }
2162 /* First do the subtraction as integers;
2163 then drop through to build the divide operator.
2164 Do not do default conversions on the minus operator
2165 in case restype is a short type. */
2169 /* This generates an error if op1 is pointer to incomplete type. */
2173 /* This generates an error if op0 is pointer to incomplete type. */
2176 /* Divide by the size, in easiest possible way. */
2184 }
2185 \f
2186 /* Construct and perhaps optimize a tree representation
2187 for a unary operation. CODE, a tree_code, specifies the operation
2188 and XARG is the operand.
2189 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2190 the default promotions (such as from short to int).
2191 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2192 allows non-lvalues; this is only used to handle conversion of non-lvalue
2193 arrays to pointers in C99. */
2195 tree
2197 {
2198 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2202 tree val;
2211 {
2213 /* This is used for unary plus, because a CONVERT_EXPR
2214 is enough to prevent anybody from looking inside for
2215 associativity, but won't generate any code. */
2218 {
2221 }
2231 {
2234 }
2241 {
2244 }
2246 {
2252 }
2253 else
2254 {
2257 }
2262 {
2265 }
2271 /* Conjugating a real value is a no-op, but allow it anyway. */
2274 {
2277 }
2286 /* These will convert to a pointer. */
2288 {
2291 }
2303 else
2311 else
2319 /* Increment or decrement the real part of the value,
2320 and don't change the imaginary part. */
2322 {
2333 }
2335 /* Report invalid types. */
2339 {
2342 else
2346 }
2348 {
2349 tree inc;
2355 /* Compute the increment. */
2358 {
2359 /* If pointer target is an undefined struct,
2360 we just cannot know how to do the arithmetic. */
2362 {
2365 else
2367 }
2371 {
2374 else
2376 }
2379 }
2380 else
2385 /* Complain about anything else that is not a true lvalue. */
2392 /* Report a read-only lvalue. */
2401 else
2408 }
2411 /* Note that this operation never does default_conversion. */
2413 /* Let &* cancel out to simplify resulting code. */
2415 {
2416 /* Don't let this be an lvalue. */
2420 }
2422 /* For &x[y], return x+y */
2424 {
2429 }
2431 /* Anything not already handled and not a true memory reference
2432 or a non-lvalue array is an error. */
2437 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
2440 /* If the lvalue is const or volatile, merge that into the type
2441 to which the address will point. Note that you can't get a
2442 restricted pointer by taking the address of something, so we
2443 only have to deal with `const' and `volatile' here. */
2455 {
2456 tree addr;
2459 {
2465 {
2469 }
2474 }
2475 else
2478 /* Address of a static or external variable or
2479 file-scope function counts as a constant. */
2485 }
2489 }
2494 }
2496 /* Return nonzero if REF is an lvalue valid for this language.
2497 Lvalues can be assigned, unless their type has TYPE_READONLY.
2498 Lvalues can have their address taken, unless they have C_DECL_REGISTER. */
2500 int
2502 {
2506 {
2531 }
2532 }
2534 /* Return nonzero if REF is an lvalue valid for this language;
2535 otherwise, print an error message and return zero. */
2537 int
2539 {
2546 }
2548 \f
2549 /* Warn about storing in something that is `const'. */
2551 void
2553 {
2555 {
2558 else
2561 }
2565 else
2567 }
2568 \f
2569 /* Mark EXP saying that we need to be able to take the
2570 address of it; it should not be allocated in a register.
2571 Returns true if successful. */
2573 bool
2575 {
2580 {
2583 {
2587 }
2589 /* ... fall through ... */
2609 {
2611 {
2615 }
2618 }
2620 {
2622 {
2626 }
2630 }
2633 /* drops in */
2636 /* drops out */
2639 }
2640 }
2641 \f
2642 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
2644 tree
2646 {
2647 tree type1;
2648 tree type2;
2656 /* Promote both alternatives. */
2673 /* C90 does not permit non-lvalue arrays in conditional expressions.
2674 In C99 they will be pointers by now. */
2676 {
2679 }
2681 /* Quickly detect the usual case where op1 and op2 have the same type
2682 after promotion. */
2684 {
2687 else
2689 }
2694 {
2697 /* If -Wsign-compare, warn here if type1 and type2 have
2698 different signedness. We'll promote the signed to unsigned
2699 and later code won't know it used to be different.
2700 Do this check on the original types, so that explicit casts
2701 will be considered, but default promotions won't. */
2703 {
2708 {
2709 /* Do not warn if the result type is signed, since the
2710 signed type will only be chosen if it can represent
2711 all the values of the unsigned type. */
2714 /* Do not warn if the signed quantity is an unsuffixed
2715 integer literal (or some static constant expression
2716 involving such literals) and it is non-negative. */
2720 else
2722 }
2723 }
2724 }
2726 {
2730 }
2732 {
2742 {
2747 }
2749 {
2754 }
2755 else
2756 {
2759 }
2760 }
2762 {
2765 else
2766 {
2768 }
2770 }
2772 {
2775 else
2776 {
2778 }
2780 }
2783 {
2786 else
2787 {
2790 }
2791 }
2793 /* Merge const and volatile flags of the incoming types. */
2794 result_type
2808 }
2809 \f
2810 /* Given a list of expressions, return a compound expression
2811 that performs them all and returns the value of the last of them. */
2813 tree
2815 {
2817 }
2819 static tree
2821 {
2822 tree rest;
2825 {
2826 /* Convert arrays and functions to pointers when there
2827 really is a comma operator. */
2832 /* Don't let (0, 0) be null pointer constant. */
2836 }
2841 {
2842 /* The left-hand operand of a comma expression is like an expression
2843 statement: with -Wextra or -Wunused, we should warn if it doesn't have
2844 any side-effects, unless it was explicitly cast to (void). */
2849 }
2851 /* With -Wunused, we should also warn if the left-hand operand does have
2852 side-effects, but computes a value which is not used. For example, in
2853 `foo() + bar(), baz()' the result of the `+' operator is not used,
2854 so we should issue a warning. */
2859 }
2861 /* Build an expression representing a cast to type TYPE of expression EXPR. */
2863 tree
2865 {
2871 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
2872 only in <protocol> qualifications. But when constructing cast expressions,
2873 the protocols do matter and must be kept around. */
2878 {
2881 }
2884 {
2887 }
2890 {
2892 {
2896 }
2897 }
2899 {
2900 tree field;
2909 {
2910 tree t;
2920 }
2923 }
2924 else
2925 {
2928 /* If casting to void, avoid the error that would come
2929 from default_conversion in the case of a non-lvalue array. */
2933 /* Convert functions and arrays to pointers,
2934 but don't convert any other types. */
2938 /* Optionally warn about potentially worrisome casts. */
2943 {
2949 /* Check that the qualifiers on IN_TYPE are a superset of
2950 the qualifiers of IN_OTYPE. The outermost level of
2951 POINTER_TYPE nodes is uninteresting and we stop as soon
2952 as we hit a non-POINTER_TYPE node on either type. */
2953 do
2954 {
2958 /* GNU C allows cv-qualified function types. 'const'
2959 means the function is very pure, 'volatile' means it
2960 can't return. We need to warn when such qualifiers
2961 are added, not when they're taken away. */
2965 else
2967 }
2975 /* There are qualifiers present in IN_OTYPE that are not
2976 present in IN_TYPE. */
2978 }
2980 /* Warn about possible alignment problems. */
2986 /* Don't warn about opaque types, where the actual alignment
2987 restriction is unknown. */
3008 /* Don't warn about converting any constant. */
3018 {
3019 /* Casting the address of a decl to non void pointer. Warn
3020 if the cast breaks type based aliasing. */
3023 else
3024 {
3033 }
3034 }
3036 /* If pedantic, warn for conversions between function and object
3037 pointer types, except for converting a null pointer constant
3038 to function pointer type. */
3056 /* Replace a nonvolatile const static variable with its value. */
3061 /* Ignore any integer overflow caused by the cast. */
3063 {
3068 }
3069 }
3071 /* Don't let (void *) (FOO *) 0 be a null pointer constant. */
3077 /* Don't let a cast be an lvalue. */
3082 }
3084 /* Interpret a cast of expression EXPR to type TYPE. */
3085 tree
3087 {
3090 /* This avoids warnings about unprototyped casts on
3091 integers. E.g. "#define SIG_DFL (void(*)())0". */
3098 }
3100 \f
3101 /* Build an assignment expression of lvalue LHS from value RHS.
3102 MODIFYCODE is the code for a binary operator that we use
3103 to combine the old value of LHS with RHS to get the new value.
3104 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3106 tree
3108 {
3109 tree result;
3110 tree newrhs;
3114 /* Types that aren't fully specified cannot be used in assignments. */
3117 /* Avoid duplicate error messages from operands that had errors. */
3121 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3122 /* Do not use STRIP_NOPS here. We do not want an enumerator
3123 whose value is 0 to count as a null pointer constant. */
3129 /* If a binary op has been requested, combine the old LHS value with the RHS
3130 producing the value we should actually store into the LHS. */
3133 {
3136 }
3141 /* Warn about storing in something that is `const'. */
3149 /* If storing into a structure or union member,
3150 it has probably been given type `int'.
3151 Compute the type that would go with
3152 the actual amount of storage the member occupies. */
3161 /* If storing in a field that is in actuality a short or narrower than one,
3162 we must store in the field in its actual type. */
3165 {
3168 }
3170 /* Convert new value to destination type. */
3177 /* Scan operands */
3182 /* If we got the LHS in a different type for storing in,
3183 convert the result back to the nominal type of LHS
3184 so that the value we return always has the same type
3185 as the LHS argument. */
3191 }
3192 \f
3193 /* Convert value RHS to type TYPE as preparation for an assignment
3194 to an lvalue of type TYPE.
3195 The real work of conversion is done by `convert'.
3196 The purpose of this function is to generate error messages
3197 for assignments that are not allowed in C.
3198 ERRTYPE is a string to use in error messages:
3199 "assignment", "return", etc. If it is null, this is parameter passing
3200 for a function call (and different error messages are output).
3202 FUNNAME is the name of the function being called,
3203 as an IDENTIFIER_NODE, or null.
3204 PARMNUM is the number of the argument, for printing in error messages. */
3206 static tree
3209 {
3211 tree rhstype;
3214 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3215 /* Do not use STRIP_NOPS here. We do not want an enumerator
3216 whose value is 0 to count as a null pointer constant. */
3233 {
3235 /* Check for Objective-C protocols. This will automatically
3236 issue a warning if there are protocol violations. No need to
3237 use the return value. */
3241 }
3244 {
3247 }
3248 /* A type converts to a reference to it.
3249 This code doesn't fully support references, it's just for the
3250 special case of va_start and va_copy. */
3253 {
3255 {
3258 }
3263 /* We already know that these two types are compatible, but they
3264 may not be exactly identical. In fact, `TREE_TYPE (type)' is
3265 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
3266 likely to be va_list, a typedef to __builtin_va_list, which
3267 is different enough that it will cause problems later. */
3273 }
3274 /* Some types can interconvert without explicit casts. */
3278 /* Arithmetic types all interconvert, and enum is treated like int. */
3287 /* Conversion to a transparent union from its member types.
3288 This applies only to function arguments. */
3290 {
3291 tree memb_types;
3296 {
3307 {
3311 /* Any non-function converts to a [const][volatile] void *
3312 and vice versa; otherwise, targets must be the same.
3313 Meanwhile, the lhs target must have all the qualifiers of
3314 the rhs. */
3317 {
3318 /* If this type won't generate any warnings, use it. */
3328 /* Keep looking for a better type, but remember this one. */
3331 }
3332 }
3334 /* Can convert integer zero to any pointer type. */
3338 {
3341 }
3342 }
3345 {
3347 {
3348 /* We have only a marginally acceptable member type;
3349 it needs a warning. */
3353 /* Const and volatile mean something different for function
3354 types, so the usual warnings are not appropriate. */
3357 {
3358 /* Because const and volatile on functions are
3359 restrictions that say the function will not do
3360 certain things, it is okay to use a const or volatile
3361 function where an ordinary one is wanted, but not
3362 vice-versa. */
3366 }
3370 parmnum);
3371 }
3377 }
3378 }
3380 /* Conversions among pointers */
3383 {
3389 /* Opaque pointers are treated like void pointers. */
3395 /* Any non-function converts to a [const][volatile] void *
3396 and vice versa; otherwise, targets must be the same.
3397 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
3400 || is_opaque_pointer
3403 {
3406 ||
3408 /* Check TREE_CODE to catch cases like (void *) (char *) 0
3409 which are not ANSI null ptr constants. */
3414 /* Const and volatile mean something different for function types,
3415 so the usual warnings are not appropriate. */
3418 {
3422 /* If this is not a case of ignoring a mismatch in signedness,
3423 no warning. */
3426 ;
3427 /* If there is a mismatch, do warn. */
3431 }
3434 {
3435 /* Because const and volatile on functions are restrictions
3436 that say the function will not do certain things,
3437 it is okay to use a const or volatile function
3438 where an ordinary one is wanted, but not vice-versa. */
3442 }
3443 }
3444 else
3448 }
3450 {
3453 }
3455 {
3456 /* An explicit constant 0 can convert to a pointer,
3457 or one that results from arithmetic, even including
3458 a cast to integer type. */
3460 &&
3469 }
3471 {
3475 }
3480 {
3482 {
3488 else
3491 }
3492 else
3494 parmnum);
3495 }
3496 else
3500 }
3502 /* Convert VALUE for assignment into inlined parameter PARM. ARGNUM
3503 is used for error and waring reporting and indicates which argument
3504 is being processed. */
3506 tree
3508 {
3511 /* If FN was prototyped, the value has been converted already
3512 in convert_arguments. */
3525 }
3527 /* Print a warning using MSGID.
3528 It gets OPNAME as its one parameter.
3529 if OPNAME is null and ARGNUM is 0, it is replaced by "passing arg of `FUNCTION'".
3530 Otherwise if OPNAME is null, it is replaced by "passing arg ARGNUM of `FUNCTION'".
3531 FUNCTION and ARGNUM are handled specially if we are building an
3532 Objective-C selector. */
3534 static void
3537 {
3539 {
3544 {
3547 }
3549 {
3551 {
3552 /* Function name is known; supply it. */
3558 }
3559 else
3560 {
3561 /* Function name unknown (call through ptr). */
3565 }
3566 }
3568 {
3569 /* Function name is known; supply it. */
3575 }
3576 else
3577 {
3578 /* Function name unknown (call through ptr); just give arg number. */
3582 }
3584 }
3586 }
3587 \f
3588 /* If VALUE is a compound expr all of whose expressions are constant, then
3589 return its value. Otherwise, return error_mark_node.
3591 This is for handling COMPOUND_EXPRs as initializer elements
3592 which is allowed with a warning when -pedantic is specified. */
3594 static tree
3596 {
3598 {
3603 endtype);
3604 }
3608 else
3610 }
3611 \f
3612 /* Perform appropriate conversions on the initial value of a variable,
3613 store it in the declaration DECL,
3614 and print any error messages that are appropriate.
3615 If the init is invalid, store an ERROR_MARK. */
3617 void
3619 {
3622 /* If variable's type was invalidly declared, just ignore it. */
3628 /* Digest the specified initializer into an expression. */
3632 /* Store the expression if valid; else report error. */
3640 /* ANSI wants warnings about out-of-range constant initializers. */
3644 /* Check if we need to set array size from compound literal size. */
3648 {
3656 {
3660 {
3661 /* For int foo[] = (int [3]){1}; we need to set array size
3662 now since later on array initializer will be just the
3663 brace enclosed list of the compound literal. */
3667 }
3668 }
3669 }
3670 }
3671 \f
3672 /* Methods for storing and printing names for error messages. */
3674 /* Implement a spelling stack that allows components of a name to be pushed
3675 and popped. Each element on the stack is this structure. */
3677 struct spelling
3678 {
3680 union
3681 {
3685 };
3687 #define SPELLING_STRING 1
3688 #define SPELLING_MEMBER 2
3689 #define SPELLING_BOUNDS 3
3695 /* Macros to save and restore the spelling stack around push_... functions.
3696 Alternative to SAVE_SPELLING_STACK. */
3698 #define SPELLING_DEPTH() (spelling - spelling_base)
3699 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
3701 /* Push an element on the spelling stack with type KIND and assign VALUE
3702 to MEMBER. */
3704 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
3705 { \
3706 int depth = SPELLING_DEPTH (); \
3707 \
3708 if (depth >= spelling_size) \
3709 { \
3710 spelling_size += 10; \
3711 if (spelling_base == 0) \
3712 spelling_base = xmalloc (spelling_size * sizeof (struct spelling)); \
3713 else \
3714 spelling_base = xrealloc (spelling_base, \
3715 spelling_size * sizeof (struct spelling)); \
3716 RESTORE_SPELLING_DEPTH (depth); \
3717 } \
3718 \
3719 spelling->kind = (KIND); \
3720 spelling->MEMBER = (VALUE); \
3721 spelling++; \
3722 }
3724 /* Push STRING on the stack. Printed literally. */
3726 static void
3728 {
3730 }
3732 /* Push a member name on the stack. Printed as '.' STRING. */
3734 static void
3736 {
3740 }
3742 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
3744 static void
3746 {
3748 }
3750 /* Compute the maximum size in bytes of the printed spelling. */
3752 static int
3754 {
3759 {
3762 else
3764 }
3767 }
3769 /* Print the spelling to BUFFER and return it. */
3773 {
3779 {
3782 }
3783 else
3784 {
3789 ;
3790 }
3793 }
3795 /* Issue an error message for a bad initializer component.
3796 MSGID identifies the message.
3797 The component name is taken from the spelling stack. */
3799 void
3801 {
3808 }
3810 /* Issue a pedantic warning for a bad initializer component.
3811 MSGID identifies the message.
3812 The component name is taken from the spelling stack. */
3814 void
3816 {
3823 }
3825 /* Issue a warning for a bad initializer component.
3826 MSGID identifies the message.
3827 The component name is taken from the spelling stack. */
3829 static void
3831 {
3838 }
3839 \f
3840 /* Digest the parser output INIT as an initializer for type TYPE.
3841 Return a C expression of type TYPE to represent the initial value.
3843 REQUIRE_CONSTANT requests an error if non-constant initializers or
3844 elements are seen. */
3846 static tree
3848 {
3857 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3858 /* Do not use STRIP_NOPS here. We do not want an enumerator
3859 whose value is 0 to count as a null pointer constant. */
3865 /* Initialization of an array of chars from a string constant
3866 optionally enclosed in braces. */
3869 {
3877 {
3885 {
3888 }
3892 {
3895 }
3901 /* Subtract 1 (or sizeof (wchar_t))
3902 because it's ok to ignore the terminating null char
3903 that is counted in the length of the constant. */
3914 }
3915 }
3917 /* Build a VECTOR_CST from a *constant* vector constructor. If the
3918 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
3919 below and handle as a constructor. */
3923 {
3927 COMPARE_STRICT))
3929 else
3931 }
3933 /* Any type can be initialized
3934 from an expression of the same type, optionally with braces. */
3951 {
3953 {
3957 {
3960 }
3961 }
3964 /* Although the types are compatible, we may require a
3965 conversion. */
3970 {
3971 /* As an extension, allow initializing objects with static storage
3972 duration with compound literals (which are then treated just as
3973 the brace enclosed list they contain). */
3976 }
3980 {
3983 }
3988 /* Compound expressions can only occur here if -pedantic or
3989 -pedantic-errors is specified. In the later case, we always want
3990 an error. In the former case, we simply want a warning. */
3993 {
3994 inside_init
3999 else
4003 }
4006 /* This test catches things like `7 / 0' which
4007 result in an expression for which TREE_CONSTANT
4008 is true, but which is not actually something
4009 that is a legal constant. We really should not
4010 be using this function, because it is a part of
4011 the back-end. Instead, the expression should
4012 already have been turned into ERROR_MARK_NODE. */
4015 {
4018 }
4021 }
4023 /* Handle scalar types, including conversions. */
4027 {
4028 /* Note that convert_for_assignment calls default_conversion
4029 for arrays and functions. We must not call it in the
4030 case where inside_init is a null pointer constant. */
4031 inside_init
4036 {
4039 }
4042 {
4045 }
4048 }
4050 /* Come here only for records and arrays. */
4053 {
4056 }
4060 }
4061 \f
4062 /* Handle initializers that use braces. */
4064 /* Type of object we are accumulating a constructor for.
4065 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4068 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4069 left to fill. */
4072 /* For an ARRAY_TYPE, this is the specified index
4073 at which to store the next element we get. */
4076 /* For an ARRAY_TYPE, this is the maximum index. */
4079 /* For a RECORD_TYPE, this is the first field not yet written out. */
4082 /* For an ARRAY_TYPE, this is the index of the first element
4083 not yet written out. */
4086 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4087 This is so we can generate gaps between fields, when appropriate. */
4090 /* If we are saving up the elements rather than allocating them,
4091 this is the list of elements so far (in reverse order,
4092 most recent first). */
4095 /* 1 if constructor should be incrementally stored into a constructor chain,
4096 0 if all the elements should be kept in AVL tree. */
4099 /* 1 if so far this constructor's elements are all compile-time constants. */
4102 /* 1 if so far this constructor's elements are all valid address constants. */
4105 /* 1 if this constructor is erroneous so far. */
4108 /* Structure for managing pending initializer elements, organized as an
4109 AVL tree. */
4111 struct init_node
4112 {
4116 tree purpose;
4117 tree value;
4118 };
4120 /* Tree of pending elements at this constructor level.
4121 These are elements encountered out of order
4122 which belong at places we haven't reached yet in actually
4123 writing the output.
4124 Will never hold tree nodes across GC runs. */
4127 /* The SPELLING_DEPTH of this constructor. */
4130 /* 0 if implicitly pushing constructor levels is allowed. */
4136 /* DECL node for which an initializer is being read.
4137 0 means we are reading a constructor expression
4138 such as (struct foo) {...}. */
4141 /* start_init saves the ASMSPEC arg here for really_start_incremental_init. */
4144 /* Nonzero if this is an initializer for a top-level decl. */
4147 /* Nonzero if there were any member designators in this initializer. */
4150 /* Nesting depth of designator list. */
4153 /* Nonzero if there were diagnosed errors in this designator list. */
4156 \f
4157 /* This stack has a level for each implicit or explicit level of
4158 structuring in the initializer, including the outermost one. It
4159 saves the values of most of the variables above. */
4163 struct constructor_stack
4164 {
4166 tree type;
4167 tree fields;
4168 tree index;
4169 tree max_index;
4170 tree unfilled_index;
4171 tree unfilled_fields;
4172 tree bit_index;
4173 tree elements;
4177 /* If nonzero, this value should replace the entire
4178 constructor at this level. */
4179 tree replacement_value;
4188 };
4192 /* This stack represents designators from some range designator up to
4193 the last designator in the list. */
4195 struct constructor_range_stack
4196 {
4199 tree range_start;
4200 tree index;
4201 tree range_end;
4202 tree fields;
4203 };
4207 /* This stack records separate initializers that are nested.
4208 Nested initializers can't happen in ANSI C, but GNU C allows them
4209 in cases like { ... (struct foo) { ... } ... }. */
4211 struct initializer_stack
4212 {
4214 tree decl;
4218 tree elements;
4225 };
4228 \f
4229 /* Prepare to parse and output the initializer for variable DECL. */
4231 void
4233 {
4261 {
4263 require_constant_elements
4265 /* For a scalar, you can always use any value to initialize,
4266 even within braces. */
4272 }
4273 else
4274 {
4278 }
4291 }
4293 void
4295 {
4298 /* Free the whole constructor stack of this initializer. */
4300 {
4304 }
4309 /* Pop back to the data of the outer initializer (if any). */
4325 }
4326 \f
4327 /* Call here when we see the initializer is surrounded by braces.
4328 This is instead of a call to push_init_level;
4329 it is matched by a call to pop_init_level.
4331 TYPE is the type to initialize, for a constructor expression.
4332 For an initializer for a decl, TYPE is zero. */
4334 void
4336 {
4380 {
4382 /* Skip any nameless bit fields at the beginning. */
4389 }
4391 {
4393 {
4394 constructor_max_index
4397 /* Detect non-empty initializations of zero-length arrays. */
4402 /* constructor_max_index needs to be an INTEGER_CST. Attempts
4403 to initialize VLAs will cause a proper error; avoid tree
4404 checking errors as well by setting a safe value. */
4409 constructor_index
4412 }
4413 else
4417 }
4419 {
4420 /* Vectors are like simple fixed-size arrays. */
4421 constructor_max_index =
4425 }
4426 else
4427 {
4428 /* Handle the case of int x = {5}; */
4431 }
4432 }
4433 \f
4434 /* Push down into a subobject, for initialization.
4435 If this is for an explicit set of braces, IMPLICIT is 0.
4436 If it is because the next element belongs at a lower level,
4437 IMPLICIT is 1 (or 2 if the push is because of designator list). */
4439 void
4441 {
4445 /* If we've exhausted any levels that didn't have braces,
4446 pop them now. */
4448 {
4454 && constructor_max_index
4457 else
4459 }
4461 /* Unless this is an explicit brace, we need to preserve previous
4462 content if any. */
4464 {
4471 }
4504 {
4509 }
4511 /* Don't die if an entire brace-pair level is superfluous
4512 in the containing level. */
4514 ;
4517 {
4518 /* Don't die if there are extra init elts at the end. */
4521 else
4522 {
4525 constructor_depth++;
4526 }
4527 }
4529 {
4532 constructor_depth++;
4533 }
4536 {
4541 }
4544 {
4552 }
4555 {
4558 }
4562 {
4564 /* Skip any nameless bit fields at the beginning. */
4571 }
4573 {
4574 /* Vectors are like simple fixed-size arrays. */
4575 constructor_max_index =
4579 }
4581 {
4583 {
4584 constructor_max_index
4587 /* Detect non-empty initializations of zero-length arrays. */
4592 /* constructor_max_index needs to be an INTEGER_CST. Attempts
4593 to initialize VLAs will cause a proper error; avoid tree
4594 checking errors as well by setting a safe value. */
4599 constructor_index
4602 }
4603 else
4608 {
4609 /* We need to split the char/wchar array into individual
4610 characters, so that we don't have to special case it
4611 everywhere. */
4613 }
4614 }
4615 else
4616 {
4620 }
4621 }
4623 /* At the end of an implicit or explicit brace level,
4624 finish up that level of constructor.
4625 If we were outputting the elements as they are read, return 0
4626 from inner levels (process_init_element ignores that),
4627 but return error_mark_node from the outermost level
4628 (that's what we want to put in DECL_INITIAL).
4629 Otherwise, return a CONSTRUCTOR expression. */
4631 tree
4633 {
4638 {
4639 /* When we come to an explicit close brace,
4640 pop any inner levels that didn't have explicit braces. */
4646 }
4648 /* Now output all pending elements. */
4654 /* Error for initializing a flexible array member, or a zero-length
4655 array member in an inappropriate context. */
4660 {
4661 /* Silently discard empty initializations. The parser will
4662 already have pedwarned for empty brackets. */
4666 {
4672 /* We have already issued an error message for the existence
4673 of a flexible array member not at the end of the structure.
4674 Discard the initializer so that we do not abort later. */
4677 }
4678 else
4679 /* Zero-length arrays are no longer special, so we should no longer
4680 get here. */
4682 }
4684 /* Warn when some struct elements are implicitly initialized to zero. */
4686 && constructor_type
4689 {
4690 /* Do not warn for flexible array members or zero-length arrays. */
4696 /* Do not warn if this level of the initializer uses member
4697 designators; it is likely to be deliberate. */
4699 {
4703 }
4704 }
4706 /* Pad out the end of the structure. */
4708 /* If this closes a superfluous brace pair,
4709 just pass out the element between them. */
4712 ;
4717 {
4718 /* A nonincremental scalar initializer--just return
4719 the element, after verifying there is just one. */
4721 {
4725 }
4727 {
4730 }
4731 else
4733 }
4734 else
4735 {
4738 else
4739 {
4746 }
4747 }
4772 {
4776 }
4778 }
4780 /* Common handling for both array range and field name designators.
4781 ARRAY argument is nonzero for array ranges. Returns zero for success. */
4783 static int
4785 {
4786 tree subtype;
4789 /* Don't die if an entire brace-pair level is superfluous
4790 in the containing level. */
4794 /* If there were errors in this designator list already, bail out silently. */
4799 {
4803 /* Designator list starts at the level of closest explicit
4804 braces. */
4809 }
4812 {
4815 }
4819 {
4823 }
4825 {
4827 }
4828 else
4833 {
4836 }
4838 {
4841 }
4846 }
4848 /* If there are range designators in designator list, push a new designator
4849 to constructor_range_stack. RANGE_END is end of such stack range or
4850 NULL_TREE if there is no range designator at this level. */
4852 static void
4854 {
4868 }
4870 /* Within an array initializer, specify the next index to be initialized.
4871 FIRST is that index. If LAST is nonzero, then initialize a range
4872 of indices, running from FIRST through LAST. */
4874 void
4876 {
4908 else
4909 {
4913 {
4917 {
4920 }
4921 else
4922 {
4926 {
4929 }
4930 }
4931 }
4933 designator_depth++;
4937 }
4938 }
4940 /* Within a struct initializer, specify the next field to be initialized. */
4942 void
4944 {
4945 tree tail;
4954 {
4957 }
4961 {
4964 }
4969 else
4970 {
4972 designator_depth++;
4976 }
4977 }
4978 \f
4979 /* Add a new initializer to the tree of pending initializers. PURPOSE
4980 identifies the initializer, either array index or field in a structure.
4981 VALUE is the value of that index or field. */
4983 static void
4985 {
4992 {
4994 {
5000 else
5001 {
5006 }
5007 }
5008 }
5009 else
5010 {
5011 tree bitpos;
5015 {
5021 else
5022 {
5027 }
5028 }
5029 }
5042 {
5046 {
5050 {
5052 {
5053 /* L rotation. */
5066 {
5069 else
5071 }
5072 else
5074 }
5075 else
5076 {
5077 /* LR rotation. */
5099 {
5102 else
5104 }
5105 else
5107 }
5109 }
5110 else
5111 {
5112 /* p->balance == +1; growth of left side balances the node. */
5115 }
5116 }
5118 {
5120 /* Growth propagation from right side. */
5123 {
5125 {
5126 /* R rotation. */
5139 {
5142 else
5144 }
5145 else
5147 }
5149 {
5150 /* RL rotation */
5172 {
5175 else
5177 }
5178 else
5180 }
5182 }
5183 else
5184 {
5185 /* p->balance == -1; growth of right side balances the node. */
5188 }
5189 }
5193 }
5194 }
5196 /* Build AVL tree from a sorted chain. */
5198 static void
5200 {
5201 tree chain;
5211 {
5213 /* Skip any nameless bit fields at the beginning. */
5219 }
5221 {
5223 constructor_unfilled_index
5226 else
5228 }
5230 }
5232 /* Build AVL tree from a string constant. */
5234 static void
5236 {
5251 else
5262 {
5264 {
5267 }
5268 else
5269 {
5273 {
5276 else
5281 }
5282 }
5285 {
5288 {
5290 {
5293 }
5294 }
5296 {
5299 }
5304 }
5309 }
5312 }
5314 /* Return value of FIELD in pending initializer or zero if the field was
5315 not initialized yet. */
5317 static tree
5319 {
5323 {
5330 {
5335 else
5337 }
5338 }
5340 {
5344 && (!constructor_unfilled_fields
5351 {
5356 else
5358 }
5359 }
5361 {
5365 }
5367 }
5369 /* "Output" the next constructor element.
5370 At top level, really output it to assembler code now.
5371 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
5372 TYPE is the data type that the containing data type wants here.
5373 FIELD is the field (a FIELD_DECL) or the index that this element fills.
5375 PENDING if non-nil means output pending elements that belong
5376 right after this element. (PENDING is normally 1;
5377 it is 0 while outputting pending elements, to avoid recursion.) */
5379 static void
5381 {
5383 {
5386 }
5398 {
5399 /* As an extension, allow initializing objects with static storage
5400 duration with compound literals (which are then treated just as
5401 the brace enclosed list they contain). */
5404 }
5418 {
5421 }
5426 /* If this field is empty (and not at the end of structure),
5427 don't do anything other than checking the initializer. */
5438 {
5441 }
5443 /* If this element doesn't come next in sequence,
5444 put it on constructor_pending_elts. */
5446 && (!constructor_incremental
5448 {
5455 }
5457 && (!constructor_incremental
5459 {
5460 /* We do this for records but not for unions. In a union,
5461 no matter which field is specified, it can be initialized
5462 right away since it starts at the beginning of the union. */
5464 {
5467 else
5468 {
5476 }
5477 }
5481 }
5484 {
5488 /* We can have just one union field set. */
5490 }
5492 /* Otherwise, output this element either to
5493 constructor_elements or to the assembler file. */
5497 constructor_elements
5500 /* Advance the variable that indicates sequential elements output. */
5502 constructor_unfilled_index
5504 bitsize_one_node);
5506 {
5507 constructor_unfilled_fields
5510 /* Skip any nameless bit fields. */
5514 constructor_unfilled_fields =
5516 }
5520 /* Now output any pending elements which have become next. */
5523 }
5525 /* Output any pending elements which have become next.
5526 As we output elements, constructor_unfilled_{fields,index}
5527 advances, which may cause other elements to become next;
5528 if so, they too are output.
5530 If ALL is 0, we return when there are
5531 no more pending elements to output now.
5533 If ALL is 1, we output space as necessary so that
5534 we can output all the pending elements. */
5536 static void
5538 {
5540 tree next;
5542 retry:
5544 /* Look through the whole pending tree.
5545 If we find an element that should be output now,
5546 output it. Otherwise, set NEXT to the element
5547 that comes first among those still pending. */
5551 {
5553 {
5555 constructor_unfilled_index))
5561 {
5562 /* Advance to the next smaller node. */
5565 else
5566 {
5567 /* We have reached the smallest node bigger than the
5568 current unfilled index. Fill the space first. */
5571 }
5572 }
5573 else
5574 {
5575 /* Advance to the next bigger node. */
5578 else
5579 {
5580 /* We have reached the biggest node in a subtree. Find
5581 the parent of it, which is the next bigger node. */
5587 {
5590 }
5591 }
5592 }
5593 }
5596 {
5599 /* If the current record is complete we are done. */
5605 /* We can't compare fields here because there might be empty
5606 fields in between. */
5608 {
5612 }
5614 {
5615 /* Advance to the next smaller node. */
5618 else
5619 {
5620 /* We have reached the smallest node bigger than the
5621 current unfilled field. Fill the space first. */
5624 }
5625 }
5626 else
5627 {
5628 /* Advance to the next bigger node. */
5631 else
5632 {
5633 /* We have reached the biggest node in a subtree. Find
5634 the parent of it, which is the next bigger node. */
5641 {
5644 }
5645 }
5646 }
5647 }
5648 }
5650 /* Ordinarily return, but not if we want to output all
5651 and there are elements left. */
5655 /* If it's not incremental, just skip over the gap, so that after
5656 jumping to retry we will output the next successive element. */
5663 /* ELT now points to the node in the pending tree with the next
5664 initializer to output. */
5666 }
5667 \f
5668 /* Add one non-braced element to the current constructor level.
5669 This adjusts the current position within the constructor's type.
5670 This may also start or terminate implicit levels
5671 to handle a partly-braced initializer.
5673 Once this has found the correct level for the new element,
5674 it calls output_init_element. */
5676 void
5678 {
5685 /* Handle superfluous braces around string cst as in
5686 char x[] = {"foo"}; */
5688 && constructor_type
5692 {
5697 }
5700 {
5703 }
5705 /* Ignore elements of a brace group if it is entirely superfluous
5706 and has already been diagnosed. */
5710 /* If we've exhausted any levels that didn't have braces,
5711 pop them now. */
5713 {
5721 constructor_index)))
5723 else
5725 }
5727 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
5729 {
5730 /* If value is a compound literal and we'll be just using its
5731 content, don't put it into a SAVE_EXPR. */
5733 || !require_constant_value
5736 }
5739 {
5741 {
5742 tree fieldtype;
5746 {
5749 }
5756 /* Error for non-static initialization of a flexible array member. */
5758 && !require_constant_value
5761 {
5764 }
5766 /* Accept a string constant to initialize a subarray. */
5772 /* Otherwise, if we have come to a subaggregate,
5773 and we don't have an element of its type, push into it. */
5779 {
5782 }
5785 {
5789 }
5790 else
5791 /* Do the bookkeeping for an element that was
5792 directly output as a constructor. */
5793 {
5794 /* For a record, keep track of end position of last field. */
5796 constructor_bit_index
5801 /* If the current field was the first one not yet written out,
5802 it isn't now, so update. */
5804 {
5806 /* Skip any nameless bit fields. */
5810 constructor_unfilled_fields =
5812 }
5813 }
5816 /* Skip any nameless bit fields at the beginning. */
5821 }
5823 {
5824 tree fieldtype;
5828 {
5831 }
5838 /* Warn that traditional C rejects initialization of unions.
5839 We skip the warning if the value is zero. This is done
5840 under the assumption that the zero initializer in user
5841 code appears conditioned on e.g. __STDC__ to avoid
5842 "missing initializer" warnings and relies on default
5843 initialization to zero in the traditional C case.
5844 We also skip the warning if the initializer is designated,
5845 again on the assumption that this must be conditional on
5846 __STDC__ anyway (and we've already complained about the
5847 member-designator already). */
5852 /* Accept a string constant to initialize a subarray. */
5858 /* Otherwise, if we have come to a subaggregate,
5859 and we don't have an element of its type, push into it. */
5865 {
5868 }
5871 {
5875 }
5876 else
5877 /* Do the bookkeeping for an element that was
5878 directly output as a constructor. */
5879 {
5882 }
5885 }
5887 {
5891 /* Accept a string constant to initialize a subarray. */
5897 /* Otherwise, if we have come to a subaggregate,
5898 and we don't have an element of its type, push into it. */
5904 {
5907 }
5912 {
5915 }
5917 /* Now output the actual element. */
5919 {
5923 }
5925 constructor_index
5929 /* If we are doing the bookkeeping for an element that was
5930 directly output as a constructor, we must update
5931 constructor_unfilled_index. */
5933 }
5935 {
5938 /* Do a basic check of initializer size. Note that vectors
5939 always have a fixed size derived from their type. */
5941 {
5944 }
5946 /* Now output the actual element. */
5950 constructor_index
5954 /* If we are doing the bookkeeping for an element that was
5955 directly output as a constructor, we must update
5956 constructor_unfilled_index. */
5958 }
5960 /* Handle the sole element allowed in a braced initializer
5961 for a scalar variable. */
5963 {
5966 }
5967 else
5968 {
5972 }
5974 /* Handle range initializers either at this level or anywhere higher
5975 in the designator stack. */
5977 {
5984 {
5988 }
5992 {
5996 }
6003 {
6007 {
6010 }
6018 }
6023 }
6026 }
6029 }
6030 \f
6031 /* Build a complete asm-statement, whose components are a CV_QUALIFIER
6032 (guaranteed to be 'volatile' or null) and ARGS (represented using
6033 an ASM_STMT node). */
6034 tree
6036 {
6040 }
6042 /* Build an asm-expr, whose components are a STRING, some OUTPUTS,
6043 some INPUTS, and some CLOBBERS. The latter three may be NULL.
6044 SIMPLE indicates whether there was anything at all after the
6045 string in the asm expression -- asm("blah") and asm("blah" : )
6046 are subtly different. We use a ASM_STMT node to represent this. */
6047 tree
6050 {
6051 tree tail;
6052 tree args;
6054 /* We can remove output conversions that change the type,
6055 but not the mode. */
6057 {
6063 /* Allow conversions as LHS here. build_modify_expr as called below
6064 will do the right thing with them. */
6075 }
6077 /* Remove output conversions that change the type but not the mode. */
6079 {
6083 }
6085 /* Perform default conversions on array and function inputs.
6086 Don't do this for other types as it would screw up operands
6087 expected to be in memory. */
6093 /* Simple asm statements are treated as volatile. */
6095 {
6098 }
6100 }
6102 /* Expand an ASM statement with operands, handling output operands
6103 that are not variables or INDIRECT_REFS by transforming such
6104 cases into cases that expand_asm_operands can handle.
6106 Arguments are same as for expand_asm_operands. */
6108 void
6111 {
6114 /* o[I] is the place that output number I should be written. */
6116 tree tail;
6118 /* Record the contents of OUTPUTS before it is modified. */
6120 {
6124 }
6126 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
6127 OUTPUTS some trees for where the values were actually stored. */
6130 /* Copy all the intermediate outputs into the specified outputs. */
6132 {
6134 {
6139 /* Restore the original value so that it's correct the next
6140 time we expand this function. */
6142 }
6143 /* Detect modification of read-only values.
6144 (Otherwise done by build_modify_expr.) */
6145 else
6146 {
6154 }
6155 }
6157 /* Those MODIFY_EXPRs could do autoincrements. */
6159 }
6160 \f
6161 /* Expand a C `return' statement.
6162 RETVAL is the expression for what to return,
6163 or a null pointer for `return;' with no value. */
6165 tree
6167 {
6174 {
6179 }
6181 {
6185 }
6186 else
6187 {
6191 tree inner;
6199 /* Strip any conversions, additions, and subtractions, and see if
6200 we are returning the address of a local variable. Warn if so. */
6202 {
6204 {
6211 /* If the second operand of the MINUS_EXPR has a pointer
6212 type (or is converted from it), this may be valid, so
6213 don't give a warning. */
6214 {
6228 }
6245 }
6248 }
6251 }
6254 }
6255 \f
6257 /* The SWITCH_STMT being built. */
6258 tree switch_stmt;
6259 /* A splay-tree mapping the low element of a case range to the high
6260 element, or NULL_TREE if there is no high element. Used to
6261 determine whether or not a new case label duplicates an old case
6262 label. We need a tree, rather than simply a hash table, because
6263 of the GNU case range extension. */
6264 splay_tree cases;
6265 /* The next node on the stack. */
6267 };
6269 /* A stack of the currently active switch statements. The innermost
6270 switch statement is on the top of the stack. There is no need to
6271 mark the stack for garbage collection because it is only active
6272 during the processing of the body of a function, and we never
6273 collect at that point. */
6277 /* Start a C switch statement, testing expression EXP. Return the new
6278 SWITCH_STMT. */
6280 tree
6282 {
6288 {
6294 {
6297 }
6298 else
6299 {
6309 }
6310 }
6312 /* Add this new SWITCH_STMT to the stack. */
6320 }
6322 /* Process a case label. */
6324 tree
6326 {
6330 {
6339 {
6340 /* Attach the first case label to the SWITCH_BODY. */
6343 }
6344 }
6347 else
6351 }
6353 /* Finish the switch statement. */
6355 void
6357 {
6360 /* Rechain the next statements to the SWITCH_STMT. */
6363 /* Pop the stack. */
6367 }
6369 /* Build a binary-operation expression without default conversions.
6370 CODE is the kind of expression to build.
6371 This function differs from `build' in several ways:
6372 the data type of the result is computed and recorded in it,
6373 warnings are generated if arg data types are invalid,
6374 special handling for addition and subtraction of pointers is known,
6375 and some optimization is done (operations on narrow ints
6376 are done in the narrower type when that gives the same result).
6377 Constant folding is also done before the result is returned.
6379 Note that the operands will never have enumeral types, or function
6380 or array types, because either they will have the default conversions
6381 performed or they have both just been converted to some other type in which
6382 the arithmetic is to be done. */
6384 tree
6387 {
6392 /* Expression code to give to the expression when it is built.
6393 Normally this is CODE, which is what the caller asked for,
6394 but in some special cases we change it. */
6397 /* Data type in which the computation is to be performed.
6398 In the simplest cases this is the common type of the arguments. */
6401 /* Nonzero means operands have already been type-converted
6402 in whatever way is necessary.
6403 Zero means they need to be converted to RESULT_TYPE. */
6406 /* Nonzero means create the expression with this type, rather than
6407 RESULT_TYPE. */
6410 /* Nonzero means after finally constructing the expression
6411 convert it to this type. */
6414 /* Nonzero if this is an operation like MIN or MAX which can
6415 safely be computed in short if both args are promoted shorts.
6416 Also implies COMMON.
6417 -1 indicates a bitwise operation; this makes a difference
6418 in the exact conditions for when it is safe to do the operation
6419 in a narrower mode. */
6422 /* Nonzero if this is a comparison operation;
6423 if both args are promoted shorts, compare the original shorts.
6424 Also implies COMMON. */
6427 /* Nonzero if this is a right-shift operation, which can be computed on the
6428 original short and then promoted if the operand is a promoted short. */
6431 /* Nonzero means set RESULT_TYPE to the common type of the args. */
6435 {
6438 }
6439 else
6440 {
6443 }
6448 /* The expression codes of the data types of the arguments tell us
6449 whether the arguments are integers, floating, pointers, etc. */
6453 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
6457 /* If an error was already reported for one of the arguments,
6458 avoid reporting another error. */
6464 {
6466 /* Handle the pointer + int case. */
6471 else
6476 /* Subtraction of two similar pointers.
6477 We must subtract them as integers, then divide by object size. */
6481 /* Handle pointer minus int. Just like pointer plus int. */
6484 else
6497 /* Floating point division by zero is a legitimate way to obtain
6498 infinities and NaNs. */
6506 {
6509 else
6510 /* Although it would be tempting to shorten always here, that
6511 loses on some targets, since the modulo instruction is
6512 undefined if the quotient can't be represented in the
6513 computation mode. We shorten only if unsigned or if
6514 dividing by something we know != -1. */
6519 }
6537 {
6538 /* Although it would be tempting to shorten always here, that loses
6539 on some targets, since the modulo instruction is undefined if the
6540 quotient can't be represented in the computation mode. We shorten
6541 only if unsigned or if dividing by something we know != -1. */
6546 }
6558 {
6559 /* Result of these operations is always an int,
6560 but that does not mean the operands should be
6561 converted to ints! */
6566 }
6569 /* Shift operations: result has same type as first operand;
6570 always convert second operand to int.
6571 Also set SHORT_SHIFT if shifting rightward. */
6575 {
6577 {
6580 else
6581 {
6587 }
6588 }
6590 /* Use the type of the value to be shifted. */
6592 /* Convert the shift-count to an integer, regardless of size
6593 of value being shifted. */
6596 /* Avoid converting op1 to result_type later. */
6598 }
6603 {
6605 {
6611 }
6613 /* Use the type of the value to be shifted. */
6615 /* Convert the shift-count to an integer, regardless of size
6616 of value being shifted. */
6619 /* Avoid converting op1 to result_type later. */
6621 }
6627 {
6629 {
6634 }
6636 /* Use the type of the value to be shifted. */
6638 /* Convert the shift-count to an integer, regardless of size
6639 of value being shifted. */
6642 /* Avoid converting op1 to result_type later. */
6644 }
6651 /* Result of comparison is always int,
6652 but don't convert the args to int! */
6660 {
6663 /* Anything compares with void *. void * compares with anything.
6664 Otherwise, the targets must be compatible
6665 and both must be object or both incomplete. */
6669 {
6670 /* op0 != orig_op0 detects the case of something
6671 whose value is 0 but which isn't a valid null ptr const. */
6675 }
6677 {
6681 }
6682 else
6687 }
6695 {
6698 }
6700 {
6703 }
6712 {
6714 {
6719 }
6720 else
6721 {
6724 }
6725 }
6737 {
6739 {
6747 }
6748 else
6749 {
6752 }
6753 }
6756 {
6760 }
6763 {
6767 }
6769 {
6772 }
6774 {
6777 }
6789 {
6792 }
6798 }
6805 &&
6808 {
6814 /* For certain operations (which identify themselves by shorten != 0)
6815 if both args were extended from the same smaller type,
6816 do the arithmetic in that type and then extend.
6818 shorten !=0 and !=1 indicates a bitwise operation.
6819 For them, this optimization is safe only if
6820 both args are zero-extended or both are sign-extended.
6821 Otherwise, we might change the result.
6822 Eg, (short)-1 | (unsigned short)-1 is (int)-1
6823 but calculated in (unsigned short) it would be (unsigned short)-1. */
6826 {
6830 /* UNS is 1 if the operation to be done is an unsigned one. */
6832 tree type;
6836 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
6837 but it *requires* conversion to FINAL_TYPE. */
6848 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
6850 /* For bitwise operations, signedness of nominal type
6851 does not matter. Consider only how operands were extended. */
6855 /* Note that in all three cases below we refrain from optimizing
6856 an unsigned operation on sign-extended args.
6857 That would not be valid. */
6859 /* Both args variable: if both extended in same way
6860 from same width, do it in that width.
6861 Do it unsigned if args were zero-extended. */
6868 result_type
6869 = c_common_signed_or_unsigned_type
6875 && (type
6884 && (type
6889 }
6891 /* Shifts can be shortened if shifting right. */
6894 {
6904 /* We can shorten only if the shift count is less than the
6905 number of bits in the smaller type size. */
6907 /* We cannot drop an unsigned shift after sign-extension. */
6909 {
6910 /* Do an unsigned shift if the operand was zero-extended. */
6911 result_type
6914 /* Convert value-to-be-shifted to that type. */
6918 }
6919 }
6921 /* Comparison operations are shortened too but differently.
6922 They identify themselves by setting short_compare = 1. */
6925 {
6926 /* Don't write &op0, etc., because that would prevent op0
6927 from being kept in a register.
6928 Instead, make copies of the our local variables and
6929 pass the copies by reference, then copy them back afterward. */
6932 tree val
6943 {
6955 /* Give warnings for comparisons between signed and unsigned
6956 quantities that may fail.
6958 Do the checking based on the original operand trees, so that
6959 casts will be considered, but default promotions won't be.
6961 Do not warn if the comparison is being done in a signed type,
6962 since the signed type will only be chosen if it can represent
6963 all the values of the unsigned type. */
6966 /* Do not warn if both operands are the same signedness. */
6969 else
6970 {
6975 else
6978 /* Do not warn if the signed quantity is an
6979 unsuffixed integer literal (or some static
6980 constant expression involving such literals or a
6981 conditional expression involving such literals)
6982 and it is non-negative. */
6985 /* Do not warn if the comparison is an equality operation,
6986 the unsigned quantity is an integral constant, and it
6987 would fit in the result if the result were signed. */
6990 && int_fits_type_p
6993 /* Do not warn if the unsigned quantity is an enumeration
6994 constant and its maximum value would fit in the result
6995 if the result were signed. */
6998 && int_fits_type_p
7002 else
7004 }
7006 /* Warn if two unsigned values are being compared in a size
7007 larger than their original size, and one (and only one) is the
7008 result of a `~' operator. This comparison will always fail.
7010 Also warn if one operand is a constant, and the constant
7011 does not have all bits set that are set in the ~ operand
7012 when it is extended. */
7016 {
7020 else
7025 {
7026 tree primop;
7031 {
7035 }
7036 else
7037 {
7041 }
7046 {
7050 }
7051 }
7058 }
7059 }
7060 }
7061 }
7063 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
7064 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
7065 Then the expression will be built.
7066 It will be given type FINAL_TYPE if that is nonzero;
7067 otherwise, it will be given type RESULT_TYPE. */
7070 {
7073 }
7076 {
7081 }
7086 {
7088 tree folded;
7090 /* Treat expressions in initializers specially as they can't trap. */
7098 }
7099 }