| blob | 64f0f07d89ad6e34e657cf79d3fa9c8768c8336a |
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 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). */
46 /* Nonzero if we've already printed a "missing braces around initializer"
47 message within this initializer. */
50 /* 1 if we explained undeclared var errors. */
86 \f
87 /* Do `exp = require_complete_type (exp);' to make sure exp
88 does not have an incomplete type. (That includes void types.) */
90 tree
92 tree value;
93 {
99 /* First, detect a valid value with a complete type. */
105 }
107 /* Print an error message for invalid use of an incomplete type.
108 VALUE is the expression that was used (or 0 if that isn't known)
109 and TYPE is the type that was invalid. */
111 void
113 tree value;
114 tree type;
115 {
118 /* Avoid duplicate error message. */
126 else
127 {
128 retry:
129 /* We must print an error message. Be clever about what it says. */
132 {
151 {
154 }
160 }
165 else
166 /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */
169 }
170 }
172 /* Return a variant of TYPE which has all the type qualifiers of LIKE
173 as well as those of TYPE. */
175 static tree
178 {
181 }
182 \f
183 /* Return the common type of two types.
184 We assume that comptypes has already been done and returned 1;
185 if that isn't so, this may crash. In particular, we assume that qualifiers
186 match.
188 This is the type for the result of most arithmetic operations
189 if the operands have the given two types. */
191 tree
194 {
197 tree attributes;
199 /* Save time if the two types are the same. */
203 /* If one type is nonsense, use the other. */
209 /* Merge the attributes. */
212 /* Treat an enum type as the unsigned integer type of the same width. */
222 /* If one type is complex, form the common type of the non-complex
223 components, then make that complex. Use T1 or T2 if it is the
224 required type. */
226 {
235 else
237 attributes);
238 }
241 {
244 /* If only one is real, use it as the result. */
252 /* Both real or both integers; use the one with greater precision. */
259 /* Same precision. Prefer longs to ints even when same size. */
264 attributes);
268 {
269 /* But preserve unsignedness from the other type,
270 since long cannot hold all the values of an unsigned int. */
273 else
276 }
278 /* Likewise, prefer long double to double even if same size. */
282 attributes);
284 /* Otherwise prefer the unsigned one. */
288 else
292 /* For two pointers, do this recursively on the target type,
293 and combine the qualifiers of the two types' targets. */
294 /* This code was turned off; I don't know why.
295 But ANSI C specifies doing this with the qualifiers.
296 So I turned it on again. */
297 {
307 }
308 #if 0
311 #endif
314 {
316 /* Save space: see if the result is identical to one of the args. */
321 /* Merge the element types, and have a size if either arg has one. */
324 }
327 /* Function types: prefer the one that specified arg types.
328 If both do, merge the arg types. Also merge the return types. */
329 {
337 /* Save space: see if the result is identical to one of the args. */
343 /* Simple way if one arg fails to specify argument types. */
345 {
348 }
350 {
353 }
355 /* If both args specify argument types, we must merge the two
356 lists, argument by argument. */
371 {
372 /* A null type means arg type is not specified.
373 Take whatever the other function type has. */
375 {
378 }
380 {
383 }
385 /* Given wait (union {union wait *u; int *i} *)
386 and wait (union wait *),
387 prefer union wait * as type of parm. */
390 {
391 tree memb;
395 {
400 }
401 }
404 {
405 tree memb;
409 {
414 }
415 }
417 parm_done: ;
418 }
423 /* ... falls through ... */
424 }
428 }
430 }
431 \f
432 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
433 or various other operations. Return 2 if they are compatible
434 but a warning may be needed if you use them together. */
436 int
439 {
444 /* Suppress errors caused by previously reported errors. */
450 /* If either type is the internal version of sizetype, return the
451 language version. */
460 /* Treat an enum type as the integer type of the same width and
461 signedness. */
471 /* Different classes of types can't be compatible. */
475 /* Qualifiers must match. */
480 /* Allow for two different type nodes which have essentially the same
481 definition. Note that we already checked for equality of the type
482 qualifiers (just above). */
487 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
491 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
495 {
506 {
513 /* Target types must match incl. qualifiers. */
518 /* Sizes must match unless one is missing or variable. */
525 d1_variable = (! d1_zero
528 d2_variable = (! d2_zero
542 }
551 }
553 }
555 /* Return 1 if TTL and TTR are pointers to types that are equivalent,
556 ignoring their qualifiers. */
558 static int
561 {
564 /* Give maybe_objc_comptypes a crack at letting these types through. */
574 }
575 \f
576 /* Subroutines of `comptypes'. */
578 /* Return 1 if two function types F1 and F2 are compatible.
579 If either type specifies no argument types,
580 the other must specify a fixed number of self-promoting arg types.
581 Otherwise, if one type specifies only the number of arguments,
582 the other must specify that number of self-promoting arg types.
583 Otherwise, the argument types must match. */
585 static int
588 {
590 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
601 /* An unspecified parmlist matches any specified parmlist
602 whose argument types don't need default promotions. */
605 {
608 /* If one of these types comes from a non-prototype fn definition,
609 compare that with the other type's arglist.
610 If they don't match, ask for a warning (but no error). */
615 }
617 {
624 }
626 /* Both types have argument lists: compare them and propagate results. */
629 }
631 /* Check two lists of types for compatibility,
632 returning 0 for incompatible, 1 for compatible,
633 or 2 for compatible with warning. */
635 static int
638 {
639 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
644 {
647 /* If one list is shorter than the other,
648 they fail to match. */
651 /* A null pointer instead of a type
652 means there is supposed to be an argument
653 but nothing is specified about what type it has.
654 So match anything that self-promotes. */
656 {
659 }
661 {
664 }
667 {
668 /* Allow wait (union {union wait *u; int *i} *)
669 and wait (union wait *) to be compatible. */
676 {
677 tree memb;
684 }
691 {
692 tree memb;
699 }
700 else
702 }
704 /* comptypes said ok, but record if it said to warn. */
710 }
711 }
712 \f
713 /* Compute the value of the `sizeof' operator. */
715 tree
717 tree type;
718 {
720 tree size;
723 {
727 }
729 {
733 }
737 {
740 }
741 else
742 /* Convert in case a char is more than one unit. */
747 /* SIZE will have an integer type with TYPE_IS_SIZETYPE set.
748 TYPE_IS_SIZETYPE means that certain things (like overflow) will
749 never happen. However, this node should really have type
750 `size_t', which is just a typedef for an ordinary integer type. */
752 }
754 tree
756 tree type;
757 {
759 tree size;
765 else
766 /* Convert in case a char is more than one unit. */
771 /* SIZE will have an integer type with TYPE_IS_SIZETYPE set.
772 TYPE_IS_SIZETYPE means that certain things (like overflow) will
773 never happen. However, this node should really have type
774 `size_t', which is just a typedef for an ordinary integer type. */
776 }
778 /* Compute the size to increment a pointer by. */
780 tree
782 tree type;
783 {
790 {
793 }
795 /* Convert in case a char is more than one unit. */
799 }
800 \f
801 /* Return either DECL or its known constant value (if it has one). */
803 tree
805 tree decl;
806 {
808 in a place where a variable is invalid. */
814 /* This is invalid if initial value is not constant.
815 If it has either a function call, a memory reference,
816 or a variable, then re-evaluating it could give different results. */
818 /* Check for cases where this is sub-optimal, even though valid. */
822 }
824 /* Return either DECL or its known constant value (if it has one), but
825 return DECL if pedantic or DECL has mode BLKmode. This is for
826 bug-compatibility with the old behavior of decl_constant_value
827 (before GCC 3.0); every use of this function is a bug and it should
828 be removed before GCC 3.1. It is not appropriate to use pedantic
829 in a way that affects optimization, and BLKmode is probably not the
830 right test for avoiding misoptimizations either. */
832 static tree
834 tree decl;
835 {
838 else
840 }
843 /* Perform the default conversion of arrays and functions to pointers.
844 Return the result of converting EXP. For any other expression, just
845 return EXP. */
847 static tree
849 tree exp;
850 {
851 tree orig_exp;
856 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
857 an lvalue.
859 Do not use STRIP_NOPS here! It will remove conversions from pointer
860 to integer and cause infinite recursion. */
865 {
869 }
871 /* Preserve the original expression code. */
876 {
878 }
880 {
881 tree adr;
883 tree ptrtype;
889 {
892 }
895 restype
906 {
910 }
915 {
916 /* Before C99, non-lvalue arrays do not decay to pointers.
917 Normally, using such an array would be invalid; but it can
918 be used correctly inside sizeof or as a statement expression.
919 Thus, do not give an error here; an error will result later. */
921 }
926 {
927 /* ??? This is not really quite correct
928 in that the type of the operand of ADDR_EXPR
929 is not the target type of the type of the ADDR_EXPR itself.
930 Question is, can this lossage be avoided? */
937 }
938 /* This way is better for a COMPONENT_REF since it can
939 simplify the offset for a component. */
942 }
944 }
946 /* Perform default promotions for C data used in expressions.
947 Arrays and functions are converted to pointers;
948 enumeral types or short or char, to int.
949 In addition, manifest constants symbols are replaced by their values. */
951 tree
953 tree exp;
954 {
955 tree orig_exp;
962 /* Constants can be used directly unless they're not loadable. */
966 /* Replace a nonvolatile const static variable with its value unless
967 it is an array, in which case we must be sure that taking the
968 address of the array produces consistent results. */
970 {
973 }
975 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
976 an lvalue.
978 Do not use STRIP_NOPS here! It will remove conversions from pointer
979 to integer and cause infinite recursion. */
986 /* Preserve the original expression code. */
990 /* Normally convert enums to int,
991 but convert wide enums to something wider. */
993 {
996 ((flag_traditional
1002 }
1006 /* If it's thinner than an int, promote it like a
1007 c_promoting_integer_type_p, otherwise leave it alone. */
1012 exp);
1015 {
1016 /* Traditionally, unsignedness is preserved in default promotions.
1017 Also preserve unsignedness if not really getting any wider. */
1019 && (flag_traditional
1024 }
1031 {
1034 }
1036 }
1037 \f
1038 /* Look up COMPONENT in a structure or union DECL.
1040 If the component name is not found, returns NULL_TREE. Otherwise,
1041 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL
1042 stepping down the chain to the component, which is in the last
1043 TREE_VALUE of the list. Normally the list is of length one, but if
1044 the component is embedded within (nested) anonymous structures or
1045 unions, the list steps down the chain to the component. */
1047 static tree
1050 {
1052 tree field;
1054 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers
1055 to the field elements. Use a binary search on this array to quickly
1056 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC
1057 will always be set for structures which have many elements. */
1060 {
1068 {
1073 {
1074 /* Step through all anon unions in linear fashion. */
1076 {
1080 {
1085 }
1086 }
1088 /* Entire record is only anon unions. */
1092 /* Restart the binary search, with new lower bound. */
1094 }
1100 else
1102 }
1108 }
1109 else
1110 {
1112 {
1116 {
1121 }
1125 }
1129 }
1132 }
1134 /* Make an expression to refer to the COMPONENT field of
1135 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */
1137 tree
1140 {
1144 tree ref;
1146 /* If DATUM is a COMPOUND_EXPR, move our reference inside it.
1147 If pedantic ensure that the arguments are not lvalues; otherwise,
1148 if the component is an array, it would wrongly decay to a pointer in
1149 C89 mode.
1150 We cannot do this with a COND_EXPR, because in a conditional expression
1151 the default promotions are applied to both sides, and this would yield
1152 the wrong type of the result; for example, if the components have
1153 type "char". */
1155 {
1157 {
1161 }
1164 }
1166 /* See if there is a field or component with name COMPONENT. */
1169 {
1171 {
1174 }
1179 {
1184 }
1186 /* Chain the COMPONENT_REFs if necessary down to the FIELD.
1187 This might be better solved in future the way the C++ front
1188 end does it - by giving the anonymous entities each a
1189 separate name and type, and then have build_component_ref
1190 recursively call itself. We can't do that here. */
1192 {
1204 }
1207 }
1213 }
1214 \f
1215 /* Given an expression PTR for a pointer, return an expression
1216 for the value pointed to.
1217 ERRORSTRING is the name of the operator to appear in error messages. */
1219 tree
1221 tree ptr;
1223 {
1228 {
1230 && !flag_volatile
1234 else
1235 {
1240 {
1243 }
1247 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
1248 so that we get the proper error message if the result is used
1249 to assign to. Also, &* is supposed to be a no-op.
1250 And ANSI C seems to specify that the type of the result
1251 should be the const type. */
1252 /* A de-reference of a pointer to const is not a const. It is valid
1253 to change it via some other pointer. */
1259 }
1260 }
1264 }
1266 /* This handles expressions of the form "a[i]", which denotes
1267 an array reference.
1269 This is logically equivalent in C to *(a+i), but we may do it differently.
1270 If A is a variable or a member, we generate a primitive ARRAY_REF.
1271 This avoids forcing the array out of registers, and can work on
1272 arrays that are not lvalues (for example, members of structures returned
1273 by functions). */
1275 tree
1278 {
1280 {
1283 }
1291 {
1294 /* Subscripting with type char is likely to lose
1295 on a machine where chars are signed.
1296 So warn on any machine, but optionally.
1297 Don't warn for unsigned char since that type is safe.
1298 Don't warn for signed char because anyone who uses that
1299 must have done so deliberately. */
1304 /* Apply default promotions *after* noticing character types. */
1307 /* Require integer *after* promotion, for sake of enums. */
1309 {
1312 }
1314 /* An array that is indexed by a non-constant
1315 cannot be stored in a register; we must be able to do
1316 address arithmetic on its address.
1317 Likewise an array of elements of variable size. */
1321 {
1324 }
1325 /* An array that is indexed by a constant value which is not within
1326 the array bounds cannot be stored in a register either; because we
1327 would get a crash in store_bit_field/extract_bit_field when trying
1328 to access a non-existent part of the register. */
1332 {
1335 }
1338 {
1346 }
1350 /* Array ref is const/volatile if the array elements are
1351 or if the array is. */
1360 /* This was added by rms on 16 Nov 91.
1361 It fixes vol struct foo *a; a->elts[1]
1362 in an inline function.
1363 Hope it doesn't break something else. */
1366 }
1368 {
1372 /* Do the same warning check as above, but only on the part that's
1373 syntactically the index and only if it is also semantically
1374 the index. */
1380 /* Put the integer in IND to simplify error checking. */
1382 {
1386 }
1393 {
1396 }
1398 {
1401 }
1405 }
1406 }
1407 \f
1408 /* Build an external reference to identifier ID. FUN indicates
1409 whether this will be used for a function call. */
1410 tree
1412 tree id;
1414 {
1415 tree ref;
1420 {
1424 {
1426 /* Ordinary implicit function declaration. */
1428 else
1429 {
1430 /* Implicit declaration of built-in function. Don't
1431 change the built-in declaration, but don't let this
1432 go by silently, either. */
1435 /* only issue this warning once */
1438 }
1439 }
1440 else
1441 {
1442 /* Reference to undeclared variable, including reference to
1443 builtin outside of function-call context. */
1447 else
1448 {
1451 {
1456 {
1460 }
1461 }
1464 }
1466 }
1467 }
1468 else
1469 {
1470 /* Properly declared variable or function reference. */
1474 {
1478 }
1479 else
1481 }
1490 {
1493 }
1496 }
1498 /* Build a function call to function FUNCTION with parameters PARAMS.
1499 PARAMS is a list--a chain of TREE_LIST nodes--in which the
1500 TREE_VALUE of each node is a parameter-expression.
1501 FUNCTION's data type may be a function type or a pointer-to-function. */
1503 tree
1506 {
1508 tree coerced_params;
1511 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
1514 /* Convert anything with function type to a pointer-to-function. */
1516 {
1520 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
1521 (because calling an inline function does not mean the function
1522 needs to be separately compiled). */
1528 }
1529 else
1539 {
1542 }
1544 /* fntype now gets the type of function pointed to. */
1547 /* Convert the parameters to the types declared in the
1548 function prototype, or apply default promotions. */
1550 coerced_params
1553 /* Check for errors in format strings. */
1558 /* Recognize certain built-in functions so we can make tree-codes
1559 other than CALL_EXPR. We do this when it enables fold-const.c
1560 to do something useful. */
1565 {
1570 }
1580 }
1581 \f
1582 /* Convert the argument expressions in the list VALUES
1583 to the types in the list TYPELIST. The result is a list of converted
1584 argument expressions.
1586 If TYPELIST is exhausted, or when an element has NULL as its type,
1587 perform the default conversions.
1589 PARMLIST is the chain of parm decls for the function being called.
1590 It may be 0, if that info is not available.
1591 It is used only for generating error messages.
1593 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
1595 This is also where warnings about wrong number of args are generated.
1597 Both VALUES and the returned value are chains of TREE_LIST nodes
1598 with the elements of the list in the TREE_VALUE slots of those nodes. */
1600 static tree
1603 {
1608 /* Scan the given expressions and types, producing individual
1609 converted arguments and pushing them on RESULT in reverse order. */
1612 valtail;
1614 {
1619 {
1623 else
1626 }
1628 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
1629 /* Do not use STRIP_NOPS here! We do not want an enumerator with value 0
1630 to convert automatically to a pointer. */
1639 {
1640 /* Formal parm type is specified by a function prototype. */
1641 tree parmval;
1644 {
1647 }
1648 else
1649 {
1650 /* Optionally warn about conversions that
1651 differ from the default conversions. */
1653 {
1658 warn_for_assignment ("%s as integer rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1661 warn_for_assignment ("%s as integer rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1664 warn_for_assignment ("%s as complex rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1667 warn_for_assignment ("%s as floating rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1670 warn_for_assignment ("%s as complex rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1673 warn_for_assignment ("%s as floating rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1674 /* ??? At some point, messages should be written about
1675 conversions between complex types, but that's too messy
1676 to do now. */
1679 {
1680 /* Warn if any argument is passed as `float',
1681 since without a prototype it would be `double'. */
1683 warn_for_assignment ("%s as `float' rather than `double' due to prototype", (char *) 0, name, parmnum + 1);
1684 }
1685 /* Detect integer changing in width or signedness.
1686 These warnings are only activated with
1687 -Wconversion, not with -Wtraditional. */
1690 {
1697 /* No warning if function asks for enum
1698 and the actual arg is that enum type. */
1699 ;
1701 warn_for_assignment ("%s with different width due to prototype", (char *) 0, name, parmnum + 1);
1703 ;
1704 /* Don't complain if the formal parameter type
1705 is an enum, because we can't tell now whether
1706 the value was an enum--even the same enum. */
1708 ;
1711 /* Change in signedness doesn't matter
1712 if a constant value is unaffected. */
1713 ;
1714 /* Likewise for a constant in a NOP_EXPR. */
1718 ;
1723 /* Change in signedness doesn't matter
1724 if an enum value is unaffected. */
1725 ;
1726 #endif
1727 /* If the value is extended from a narrower
1728 unsigned type, it doesn't matter whether we
1729 pass it as signed or unsigned; the value
1730 certainly is the same either way. */
1733 ;
1736 else
1738 }
1739 }
1749 }
1751 }
1755 /* Convert `float' to `double'. */
1757 else
1758 /* Convert `short' and `char' to full-size `int'. */
1763 }
1766 {
1770 else
1772 }
1775 }
1776 \f
1777 /* This is the entry point used by the parser
1778 for binary operators in the input.
1779 In addition to constructing the expression,
1780 we check for operands that were written with other binary operators
1781 in a way that is likely to confuse the user. */
1783 tree
1787 {
1801 /* Check for cases such as x+y<<z which users are likely
1802 to misinterpret. If parens are used, C_EXP_ORIGINAL_CODE
1803 is cleared to prevent these warnings. */
1805 {
1807 {
1811 }
1814 {
1818 }
1821 {
1827 /* Check cases like x|y==z */
1830 }
1833 {
1839 /* Check cases like x^y==z */
1842 }
1845 {
1849 /* Check cases like x&y==z */
1852 }
1853 }
1855 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */
1866 /* Record the code that was specified in the source,
1867 for the sake of warnings about confusing nesting. */
1870 else
1871 {
1873 /* We used to use NOP_EXPR rather than NON_LVALUE_EXPR
1874 so that convert_for_assignment wouldn't strip it.
1875 That way, we got warnings for things like p = (1 - 1).
1876 But it turns out we should not get those warnings. */
1880 }
1883 }
1885 /* Build a binary-operation expression without default conversions.
1886 CODE is the kind of expression to build.
1887 This function differs from `build' in several ways:
1888 the data type of the result is computed and recorded in it,
1889 warnings are generated if arg data types are invalid,
1890 special handling for addition and subtraction of pointers is known,
1891 and some optimization is done (operations on narrow ints
1892 are done in the narrower type when that gives the same result).
1893 Constant folding is also done before the result is returned.
1895 Note that the operands will never have enumeral types, or function
1896 or array types, because either they will have the default conversions
1897 performed or they have both just been converted to some other type in which
1898 the arithmetic is to be done. */
1900 tree
1905 {
1910 /* Expression code to give to the expression when it is built.
1911 Normally this is CODE, which is what the caller asked for,
1912 but in some special cases we change it. */
1915 /* Data type in which the computation is to be performed.
1916 In the simplest cases this is the common type of the arguments. */
1919 /* Nonzero means operands have already been type-converted
1920 in whatever way is necessary.
1921 Zero means they need to be converted to RESULT_TYPE. */
1924 /* Nonzero means create the expression with this type, rather than
1925 RESULT_TYPE. */
1928 /* Nonzero means after finally constructing the expression
1929 convert it to this type. */
1932 /* Nonzero if this is an operation like MIN or MAX which can
1933 safely be computed in short if both args are promoted shorts.
1934 Also implies COMMON.
1935 -1 indicates a bitwise operation; this makes a difference
1936 in the exact conditions for when it is safe to do the operation
1937 in a narrower mode. */
1940 /* Nonzero if this is a comparison operation;
1941 if both args are promoted shorts, compare the original shorts.
1942 Also implies COMMON. */
1945 /* Nonzero if this is a right-shift operation, which can be computed on the
1946 original short and then promoted if the operand is a promoted short. */
1949 /* Nonzero means set RESULT_TYPE to the common type of the args. */
1953 {
1956 }
1957 else
1958 {
1961 }
1966 /* The expression codes of the data types of the arguments tell us
1967 whether the arguments are integers, floating, pointers, etc. */
1971 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
1975 /* If an error was already reported for one of the arguments,
1976 avoid reporting another error. */
1982 {
1984 /* Handle the pointer + int case. */
1989 else
1994 /* Subtraction of two similar pointers.
1995 We must subtract them as integers, then divide by object size. */
1999 /* Handle pointer minus int. Just like pointer plus int. */
2002 else
2015 /* Floating point division by zero is a legitimate way to obtain
2016 infinities and NaNs. */
2024 {
2027 else
2028 /* Although it would be tempting to shorten always here, that
2029 loses on some targets, since the modulo instruction is
2030 undefined if the quotient can't be represented in the
2031 computation mode. We shorten only if unsigned or if
2032 dividing by something we know != -1. */
2037 }
2046 /* If one operand is a constant, and the other is a short type
2047 that has been converted to an int,
2048 really do the work in the short type and then convert the
2049 result to int. If we are lucky, the constant will be 0 or 1
2050 in the short type, making the entire operation go away. */
2055 {
2059 }
2064 {
2068 }
2077 {
2078 /* Although it would be tempting to shorten always here, that loses
2079 on some targets, since the modulo instruction is undefined if the
2080 quotient can't be represented in the computation mode. We shorten
2081 only if unsigned or if dividing by something we know != -1. */
2086 }
2098 {
2099 /* Result of these operations is always an int,
2100 but that does not mean the operands should be
2101 converted to ints! */
2106 }
2109 /* Shift operations: result has same type as first operand;
2110 always convert second operand to int.
2111 Also set SHORT_SHIFT if shifting rightward. */
2115 {
2117 {
2120 else
2121 {
2127 }
2128 }
2130 /* Use the type of the value to be shifted.
2131 This is what most traditional C compilers do. */
2133 /* Unless traditional, convert the shift-count to an integer,
2134 regardless of size of value being shifted. */
2136 {
2139 /* Avoid converting op1 to result_type later. */
2141 }
2142 }
2147 {
2149 {
2155 }
2157 /* Use the type of the value to be shifted.
2158 This is what most traditional C compilers do. */
2160 /* Unless traditional, convert the shift-count to an integer,
2161 regardless of size of value being shifted. */
2163 {
2166 /* Avoid converting op1 to result_type later. */
2168 }
2169 }
2175 {
2177 {
2182 }
2184 /* Use the type of the value to be shifted.
2185 This is what most traditional C compilers do. */
2187 /* Unless traditional, convert the shift-count to an integer,
2188 regardless of size of value being shifted. */
2190 {
2193 /* Avoid converting op1 to result_type later. */
2195 }
2196 }
2203 /* Result of comparison is always int,
2204 but don't convert the args to int! */
2212 {
2215 /* Anything compares with void *. void * compares with anything.
2216 Otherwise, the targets must be compatible
2217 and both must be object or both incomplete. */
2221 {
2222 /* op0 != orig_op0 detects the case of something
2223 whose value is 0 but which isn't a valid null ptr const. */
2227 }
2229 {
2233 }
2234 else
2239 }
2247 {
2251 }
2253 {
2257 }
2266 {
2268 {
2273 }
2274 else
2275 {
2278 }
2279 }
2291 {
2293 {
2301 }
2302 else
2303 {
2306 }
2307 }
2310 {
2314 }
2317 {
2321 }
2323 {
2327 }
2329 {
2333 }
2345 {
2348 }
2354 }
2357 &&
2359 {
2365 /* For certain operations (which identify themselves by shorten != 0)
2366 if both args were extended from the same smaller type,
2367 do the arithmetic in that type and then extend.
2369 shorten !=0 and !=1 indicates a bitwise operation.
2370 For them, this optimization is safe only if
2371 both args are zero-extended or both are sign-extended.
2372 Otherwise, we might change the result.
2373 Eg, (short)-1 | (unsigned short)-1 is (int)-1
2374 but calculated in (unsigned short) it would be (unsigned short)-1. */
2377 {
2381 /* UNS is 1 if the operation to be done is an unsigned one. */
2383 tree type;
2387 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
2388 but it *requires* conversion to FINAL_TYPE. */
2399 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
2401 /* For bitwise operations, signedness of nominal type
2402 does not matter. Consider only how operands were extended. */
2406 /* Note that in all three cases below we refrain from optimizing
2407 an unsigned operation on sign-extended args.
2408 That would not be valid. */
2410 /* Both args variable: if both extended in same way
2411 from same width, do it in that width.
2412 Do it unsigned if args were zero-extended. */
2419 result_type
2438 }
2440 /* Shifts can be shortened if shifting right. */
2443 {
2453 /* We can shorten only if the shift count is less than the
2454 number of bits in the smaller type size. */
2456 /* We cannot drop an unsigned shift after sign-extension. */
2458 {
2459 /* Do an unsigned shift if the operand was zero-extended. */
2460 result_type
2462 /* Convert value-to-be-shifted to that type. */
2466 }
2467 }
2469 /* Comparison operations are shortened too but differently.
2470 They identify themselves by setting short_compare = 1. */
2473 {
2474 /* Don't write &op0, etc., because that would prevent op0
2475 from being kept in a register.
2476 Instead, make copies of the our local variables and
2477 pass the copies by reference, then copy them back afterward. */
2480 tree val
2492 {
2504 /* Give warnings for comparisons between signed and unsigned
2505 quantities that may fail.
2507 Do the checking based on the original operand trees, so that
2508 casts will be considered, but default promotions won't be.
2510 Do not warn if the comparison is being done in a signed type,
2511 since the signed type will only be chosen if it can represent
2512 all the values of the unsigned type. */
2515 /* Do not warn if both operands are the same signedness. */
2518 else
2519 {
2524 else
2527 /* Do not warn if the signed quantity is an
2528 unsuffixed integer literal (or some static
2529 constant expression involving such literals or a
2530 conditional expression involving such literals)
2531 and it is non-negative. */
2534 /* Do not warn if the comparison is an equality operation,
2535 the unsigned quantity is an integral constant, and it
2536 would fit in the result if the result were signed. */
2541 /* Do not warn if the unsigned quantity is an enumeration
2542 constant and its maximum value would fit in the result
2543 if the result were signed. */
2549 else
2551 }
2553 /* Warn if two unsigned values are being compared in a size
2554 larger than their original size, and one (and only one) is the
2555 result of a `~' operator. This comparison will always fail.
2557 Also warn if one operand is a constant, and the constant
2558 does not have all bits set that are set in the ~ operand
2559 when it is extended. */
2563 {
2567 else
2572 {
2573 tree primop;
2578 {
2582 }
2583 else
2584 {
2588 }
2593 {
2597 }
2598 }
2605 }
2606 }
2607 }
2608 }
2610 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
2611 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
2612 Then the expression will be built.
2613 It will be given type FINAL_TYPE if that is nonzero;
2614 otherwise, it will be given type RESULT_TYPE. */
2617 {
2620 }
2623 {
2628 }
2633 {
2635 tree folded;
2643 }
2644 }
2645 \f
2646 /* Return a tree for the sum or difference (RESULTCODE says which)
2647 of pointer PTROP and integer INTOP. */
2649 static tree
2653 {
2654 tree size_exp;
2656 tree result;
2657 tree folded;
2659 /* The result is a pointer of the same type that is being added. */
2664 {
2668 }
2670 {
2674 }
2675 else
2678 /* If what we are about to multiply by the size of the elements
2679 contains a constant term, apply distributive law
2680 and multiply that constant term separately.
2681 This helps produce common subexpressions. */
2687 /* If the constant comes from pointer subtraction,
2688 skip this optimization--it would cause an error. */
2690 /* If the constant is unsigned, and smaller than the pointer size,
2691 then we must skip this optimization. This is because it could cause
2692 an overflow error if the constant is negative but INTOP is not. */
2696 {
2701 /* Convert both subexpression types to the type of intop,
2702 because weird cases involving pointer arithmetic
2703 can result in a sum or difference with different type args. */
2707 }
2709 /* Convert the integer argument to a type the same size as sizetype
2710 so the multiply won't overflow spuriously. */
2717 /* Replace the integer argument with a suitable product by the object size.
2718 Do this multiplication as signed, then convert to the appropriate
2719 pointer type (actually unsigned integral). */
2725 /* Create the sum or difference. */
2733 }
2735 /* Return a tree for the difference of pointers OP0 and OP1.
2736 The resulting tree has type int. */
2738 static tree
2741 {
2750 {
2755 }
2757 /* If the conversion to ptrdiff_type does anything like widening or
2758 converting a partial to an integral mode, we get a convert_expression
2759 that is in the way to do any simplifications.
2760 (fold-const.c doesn't know that the extra bits won't be needed.
2761 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2762 different mode in place.)
2763 So first try to find a common term here 'by hand'; we want to cover
2764 at least the cases that occur in legal static initializers. */
2769 {
2772 }
2773 else
2777 {
2780 }
2781 else
2785 {
2788 }
2791 /* First do the subtraction as integers;
2792 then drop through to build the divide operator.
2793 Do not do default conversions on the minus operator
2794 in case restype is a short type. */
2798 /* This generates an error if op1 is pointer to incomplete type. */
2802 /* This generates an error if op0 is pointer to incomplete type. */
2805 /* Divide by the size, in easiest possible way. */
2813 }
2814 \f
2815 /* Construct and perhaps optimize a tree representation
2816 for a unary operation. CODE, a tree_code, specifies the operation
2817 and XARG is the operand.
2818 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2819 the default promotions (such as from short to int).
2820 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2821 allows non-lvalues; this is only used to handle conversion of non-lvalue
2822 arrays to pointers in C99. */
2824 tree
2827 tree xarg;
2829 {
2830 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2834 tree val;
2843 {
2845 /* This is used for unary plus, because a CONVERT_EXPR
2846 is enough to prevent anybody from looking inside for
2847 associativity, but won't generate any code. */
2850 {
2853 }
2861 {
2864 }
2871 {
2877 }
2879 {
2882 }
2890 {
2893 }
2899 /* Conjugating a real value is a no-op, but allow it anyway. */
2902 {
2905 }
2914 /* These will convert to a pointer. */
2916 {
2919 }
2931 else
2939 else
2946 /* Handle complex lvalues (when permitted)
2947 by reduction to simpler cases. */
2953 /* Increment or decrement the real part of the value,
2954 and don't change the imaginary part. */
2956 {
2967 }
2969 /* Report invalid types. */
2973 {
2976 else
2980 }
2982 {
2983 tree inc;
2989 /* Compute the increment. */
2992 {
2993 /* If pointer target is an undefined struct,
2994 we just cannot know how to do the arithmetic. */
2996 {
2999 else
3001 }
3005 {
3008 else
3010 }
3013 }
3014 else
3019 /* Handle incrementing a cast-expression. */
3023 {
3032 /* If the real type has the same machine representation
3033 as the type it is cast to, we can make better output
3034 by adding directly to the inside of the cast. */
3040 else
3041 {
3045 else
3046 {
3050 else
3059 }
3062 }
3067 }
3068 give_up:
3070 /* Complain about anything else that is not a true lvalue. */
3077 /* Report a read-only lvalue. */
3086 else
3093 }
3096 /* Note that this operation never does default_conversion. */
3098 /* Let &* cancel out to simplify resulting code. */
3100 {
3101 /* Don't let this be an lvalue. */
3105 }
3107 /* For &x[y], return x+y */
3109 {
3114 }
3116 /* Handle complex lvalues (when permitted)
3117 by reduction to simpler cases. */
3123 float f; *&(int)f = 3.4 stores in int format
3124 whereas (int)f = 3.4 stores in float format. */
3125 /* Address of a cast is just a cast of the address
3126 of the operand of the cast. */
3128 {
3141 }
3142 #endif
3144 /* Allow the address of a constructor if all the elements
3145 are constant. */
3147 ;
3148 /* Anything not already handled and not a true memory reference
3149 or a non-lvalue array is an error. */
3154 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
3157 /* If the lvalue is const or volatile, merge that into the type
3158 to which the address will point. Note that you can't get a
3159 restricted pointer by taking the address of something, so we
3160 only have to deal with `const' and `volatile' here. */
3172 {
3173 tree addr;
3176 {
3182 {
3186 }
3191 }
3192 else
3195 /* Address of a static or external variable or
3196 file-scope function counts as a constant. */
3202 }
3206 }
3211 }
3213 #if 0
3214 /* If CONVERSIONS is a conversion expression or a nested sequence of such,
3215 convert ARG with the same conversions in the same order
3216 and return the result. */
3218 static tree
3220 tree conversions;
3221 tree arg;
3222 {
3224 {
3234 arg));
3238 }
3239 }
3242 /* Return nonzero if REF is an lvalue valid for this language.
3243 Lvalues can be assigned, unless their type has TYPE_READONLY.
3244 Lvalues can have their address taken, unless they have DECL_REGISTER. */
3246 int
3248 tree ref;
3249 {
3253 {
3277 }
3278 }
3280 /* Return nonzero if REF is an lvalue valid for this language;
3281 otherwise, print an error message and return zero. */
3283 int
3285 tree ref;
3287 {
3294 }
3296 /* Apply unary lvalue-demanding operator CODE to the expression ARG
3297 for certain kinds of expressions which are not really lvalues
3298 but which we can accept as lvalues. If FLAG is nonzero, then
3299 non-lvalues are OK since we may be converting a non-lvalue array to
3300 a pointer in C99.
3302 If ARG is not a kind of expression we can handle, return zero. */
3304 static tree
3307 tree arg;
3309 {
3310 /* Handle (a, b) used as an "lvalue". */
3312 {
3315 /* If this returns a function type, it isn't really being used as
3316 an lvalue, so don't issue a warning about it. */
3322 }
3324 /* Handle (a ? b : c) used as an "lvalue". */
3326 {
3336 }
3339 }
3341 /* If pedantic, warn about improper lvalue. CODE is either COND_EXPR
3342 COMPOUND_EXPR, or CONVERT_EXPR (for casts). */
3344 static void
3347 {
3350 {
3360 }
3361 }
3362 \f
3363 /* Warn about storing in something that is `const'. */
3365 void
3367 tree arg;
3369 {
3371 {
3374 else
3377 }
3381 else
3383 }
3384 \f
3385 /* Mark EXP saying that we need to be able to take the
3386 address of it; it should not be allocated in a register.
3387 Value is 1 if successful. */
3389 int
3391 tree exp;
3392 {
3396 {
3399 {
3403 }
3405 /* ... fall through ... */
3424 {
3426 {
3430 }
3433 }
3435 {
3437 {
3441 }
3443 /* If we are making this addressable due to its having
3444 volatile components, give a different error message. Also
3445 handle the case of an unnamed parameter by not trying
3446 to give the name. */
3449 {
3452 }
3456 }
3459 /* drops in */
3465 #endif
3469 }
3470 }
3471 \f
3472 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
3474 tree
3477 {
3478 tree type1;
3479 tree type2;
3488 /* Don't promote the operands separately if they promote
3489 the same way. Return the unpromoted type and let the combined
3490 value get promoted if necessary. */
3496 {
3501 }
3502 #endif
3504 /* Promote both alternatives. */
3521 /* Quickly detect the usual case where op1 and op2 have the same type
3522 after promotion. */
3524 {
3527 else
3529 }
3534 {
3537 /* If -Wsign-compare, warn here if type1 and type2 have
3538 different signedness. We'll promote the signed to unsigned
3539 and later code won't know it used to be different.
3540 Do this check on the original types, so that explicit casts
3541 will be considered, but default promotions won't. */
3544 {
3549 {
3550 /* Do not warn if the result type is signed, since the
3551 signed type will only be chosen if it can represent
3552 all the values of the unsigned type. */
3555 /* Do not warn if the signed quantity is an unsuffixed
3556 integer literal (or some static constant expression
3557 involving such literals) and it is non-negative. */
3561 else
3563 }
3564 }
3565 }
3567 {
3571 }
3573 {
3583 {
3588 }
3590 {
3595 }
3596 else
3597 {
3600 }
3601 }
3603 {
3606 else
3607 {
3609 }
3611 }
3613 {
3616 else
3617 {
3619 }
3621 }
3624 {
3627 else
3628 {
3631 }
3632 }
3634 /* Merge const and volatile flags of the incoming types. */
3635 result_type
3649 }
3650 \f
3651 /* Given a list of expressions, return a compound expression
3652 that performs them all and returns the value of the last of them. */
3654 tree
3656 tree list;
3657 {
3659 }
3661 static tree
3663 tree list;
3665 {
3666 tree rest;
3669 {
3670 /* Convert arrays and functions to pointers when there
3671 really is a comma operator. */
3677 /* Consider (x, y+0), which is not an lvalue since y+0 is not. */
3679 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3682 #endif
3684 /* Don't let (0, 0) be null pointer constant. */
3688 }
3693 {
3694 /* The left-hand operand of a comma expression is like an expression
3695 statement: with -W or -Wunused, we should warn if it doesn't have
3696 any side-effects, unless it was explicitly cast to (void). */
3702 /* When pedantic, a compound expression can be neither an lvalue
3703 nor an integer constant expression. */
3706 }
3708 /* With -Wunused, we should also warn if the left-hand operand does have
3709 side-effects, but computes a value which is not used. For example, in
3710 `foo() + bar(), baz()' the result of the `+' operator is not used,
3711 so we should issue a warning. */
3716 }
3718 /* Build an expression representing a cast to type TYPE of expression EXPR. */
3720 tree
3722 tree type;
3723 tree expr;
3724 {
3731 #if 0
3732 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3735 #endif
3738 {
3741 }
3744 {
3747 }
3750 {
3752 {
3756 }
3757 }
3759 {
3760 tree field;
3769 {
3771 tree t;
3776 {
3779 else
3781 }
3782 else
3789 }
3792 }
3793 else
3794 {
3797 /* If casting to void, avoid the error that would come
3798 from default_conversion in the case of a non-lvalue array. */
3802 /* Convert functions and arrays to pointers,
3803 but don't convert any other types. */
3807 /* Optionally warn about potentially worrisome casts. */
3812 {
3817 /* Check that the qualifiers on IN_TYPE are a superset of
3818 the qualifiers of IN_OTYPE. The outermost level of
3819 POINTER_TYPE nodes is uninteresting and we stop as soon
3820 as we hit a non-POINTER_TYPE node on either type. */
3821 do
3822 {
3826 }
3831 /* There are qualifiers present in IN_OTYPE that are not
3832 present in IN_TYPE. */
3834 }
3836 /* Warn about possible alignment problems. */
3842 /* Don't warn about opaque types, where the actual alignment
3843 restriction is unknown. */
3864 /* Don't warn about converting any constant. */
3871 /* Ignore any integer overflow caused by the cast. */
3873 {
3876 }
3877 }
3879 /* Pedantically, don't let (void *) (FOO *) 0 be a null pointer constant. */
3885 /* If pedantic, don't let a cast be an lvalue. */
3890 }
3892 /* Interpret a cast of expression EXPR to type TYPE. */
3893 tree
3896 {
3899 /* This avoids warnings about unprototyped casts on
3900 integers. E.g. "#define SIG_DFL (void(*)())0". */
3907 }
3909 \f
3910 /* Build an assignment expression of lvalue LHS from value RHS.
3911 MODIFYCODE is the code for a binary operator that we use
3912 to combine the old value of LHS with RHS to get the new value.
3913 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3915 tree
3919 {
3920 tree result;
3921 tree newrhs;
3925 /* Types that aren't fully specified cannot be used in assignments. */
3928 /* Avoid duplicate error messages from operands that had errors. */
3932 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3933 /* Do not use STRIP_NOPS here. We do not want an enumerator
3934 whose value is 0 to count as a null pointer constant. */
3940 /* Handle control structure constructs used as "lvalues". */
3943 {
3944 /* Handle (a, b) used as an "lvalue". */
3953 /* Handle (a ? b : c) used as an "lvalue". */
3957 {
3958 /* Produce (a ? (b = rhs) : (c = rhs))
3959 except that the RHS goes through a save-expr
3960 so the code to compute it is only emitted once. */
3961 tree cond
3969 /* Make sure the code to compute the rhs comes out
3970 before the split. */
3972 /* But cast it to void to avoid an "unused" error. */
3974 }
3977 }
3979 /* If a binary op has been requested, combine the old LHS value with the RHS
3980 producing the value we should actually store into the LHS. */
3983 {
3986 }
3988 /* Handle a cast used as an "lvalue".
3989 We have already performed any binary operator using the value as cast.
3990 Now convert the result to the cast type of the lhs,
3991 and then true type of the lhs and store it there;
3992 then convert result back to the cast type to be the value
3993 of the assignment. */
3996 {
4005 {
4007 tree result;
4015 }
4019 }
4021 /* Now we have handled acceptable kinds of LHS that are not truly lvalues.
4022 Reject anything strange now. */
4027 /* Warn about storing in something that is `const'. */
4035 /* If storing into a structure or union member,
4036 it has probably been given type `int'.
4037 Compute the type that would go with
4038 the actual amount of storage the member occupies. */
4047 /* If storing in a field that is in actuality a short or narrower than one,
4048 we must store in the field in its actual type. */
4051 {
4054 }
4056 /* Convert new value to destination type. */
4063 /* Scan operands */
4068 /* If we got the LHS in a different type for storing in,
4069 convert the result back to the nominal type of LHS
4070 so that the value we return always has the same type
4071 as the LHS argument. */
4077 }
4078 \f
4079 /* Convert value RHS to type TYPE as preparation for an assignment
4080 to an lvalue of type TYPE.
4081 The real work of conversion is done by `convert'.
4082 The purpose of this function is to generate error messages
4083 for assignments that are not allowed in C.
4084 ERRTYPE is a string to use in error messages:
4085 "assignment", "return", etc. If it is null, this is parameter passing
4086 for a function call (and different error messages are output).
4088 FUNNAME is the name of the function being called,
4089 as an IDENTIFIER_NODE, or null.
4090 PARMNUM is the number of the argument, for printing in error messages. */
4092 static tree
4098 {
4100 tree rhstype;
4103 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
4104 /* Do not use STRIP_NOPS here. We do not want an enumerator
4105 whose value is 0 to count as a null pointer constant. */
4122 {
4124 /* Check for Objective-C protocols. This will issue a warning if
4125 there are protocol violations. No need to use the return value. */
4128 }
4131 {
4134 }
4135 /* A type converts to a reference to it.
4136 This code doesn't fully support references, it's just for the
4137 special case of va_start and va_copy. */
4140 {
4145 /* We already know that these two types are compatible, but they
4146 may not be exactly identical. In fact, `TREE_TYPE (type)' is
4147 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
4148 likely to be va_list, a typedef to __builtin_va_list, which
4149 is different enough that it will cause problems later. */
4155 }
4156 /* Arithmetic types all interconvert, and enum is treated like int. */
4165 /* Conversion to a transparent union from its member types.
4166 This applies only to function arguments. */
4168 {
4169 tree memb_types;
4174 {
4185 {
4189 /* Any non-function converts to a [const][volatile] void *
4190 and vice versa; otherwise, targets must be the same.
4191 Meanwhile, the lhs target must have all the qualifiers of
4192 the rhs. */
4195 {
4196 /* If this type won't generate any warnings, use it. */
4206 /* Keep looking for a better type, but remember this one. */
4209 }
4210 }
4212 /* Can convert integer zero to any pointer type. */
4216 {
4219 }
4220 }
4223 {
4225 {
4226 /* We have only a marginally acceptable member type;
4227 it needs a warning. */
4231 /* Const and volatile mean something different for function
4232 types, so the usual warnings are not appropriate. */
4235 {
4236 /* Because const and volatile on functions are
4237 restrictions that say the function will not do
4238 certain things, it is okay to use a const or volatile
4239 function where an ordinary one is wanted, but not
4240 vice-versa. */
4244 }
4248 parmnum);
4249 }
4255 }
4256 }
4258 /* Conversions among pointers */
4261 {
4265 /* Any non-function converts to a [const][volatile] void *
4266 and vice versa; otherwise, targets must be the same.
4267 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
4272 {
4275 ||
4277 /* Check TREE_CODE to catch cases like (void *) (char *) 0
4278 which are not ANSI null ptr constants. */
4283 /* Const and volatile mean something different for function types,
4284 so the usual warnings are not appropriate. */
4287 {
4291 /* If this is not a case of ignoring a mismatch in signedness,
4292 no warning. */
4295 ;
4296 /* If there is a mismatch, do warn. */
4300 }
4303 {
4304 /* Because const and volatile on functions are restrictions
4305 that say the function will not do certain things,
4306 it is okay to use a const or volatile function
4307 where an ordinary one is wanted, but not vice-versa. */
4311 }
4312 }
4313 else
4317 }
4319 {
4320 /* An explicit constant 0 can convert to a pointer,
4321 or one that results from arithmetic, even including
4322 a cast to integer type. */
4324 &&
4329 {
4333 }
4335 }
4337 {
4341 }
4346 {
4348 {
4354 else
4357 }
4358 else
4360 parmnum);
4361 }
4362 else
4366 }
4368 /* Print a warning using MSGID.
4369 It gets OPNAME as its one parameter.
4370 If OPNAME is null, it is replaced by "passing arg ARGNUM of `FUNCTION'".
4371 FUNCTION and ARGNUM are handled specially if we are building an
4372 Objective-C selector. */
4374 static void
4378 tree function;
4380 {
4382 {
4387 {
4390 }
4392 {
4393 /* Function name is known; supply it. */
4400 }
4401 else
4402 {
4403 /* Function name unknown (call through ptr); just give arg number.*/
4407 }
4409 }
4411 }
4412 \f
4413 /* If VALUE is a compound expr all of whose expressions are constant, then
4414 return its value. Otherwise, return error_mark_node.
4416 This is for handling COMPOUND_EXPRs as initializer elements
4417 which is allowed with a warning when -pedantic is specified. */
4419 static tree
4421 tree value;
4422 tree endtype;
4423 {
4425 {
4430 endtype);
4431 }
4435 else
4437 }
4438 \f
4439 /* Perform appropriate conversions on the initial value of a variable,
4440 store it in the declaration DECL,
4441 and print any error messages that are appropriate.
4442 If the init is invalid, store an ERROR_MARK. */
4444 void
4447 {
4450 /* If variable's type was invalidly declared, just ignore it. */
4456 /* Digest the specified initializer into an expression. */
4461 /* Store the expression if valid; else report error. */
4463 #if 0
4464 /* Note that this is the only place we can detect the error
4465 in a case such as struct foo bar = (struct foo) { x, y };
4466 where there is one initial value which is a constructor expression. */
4468 ;
4470 {
4473 }
4476 {
4479 }
4480 else
4481 {
4483 {
4488 }
4489 }
4490 #endif
4498 /* ANSI wants warnings about out-of-range constant initializers. */
4501 }
4502 \f
4503 /* Methods for storing and printing names for error messages. */
4505 /* Implement a spelling stack that allows components of a name to be pushed
4506 and popped. Each element on the stack is this structure. */
4508 struct spelling
4509 {
4511 union
4512 {
4516 };
4518 #define SPELLING_STRING 1
4519 #define SPELLING_MEMBER 2
4520 #define SPELLING_BOUNDS 3
4526 /* Macros to save and restore the spelling stack around push_... functions.
4527 Alternative to SAVE_SPELLING_STACK. */
4529 #define SPELLING_DEPTH() (spelling - spelling_base)
4530 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
4532 /* Save and restore the spelling stack around arbitrary C code. */
4534 #define SAVE_SPELLING_DEPTH(code) \
4535 { \
4536 int __depth = SPELLING_DEPTH (); \
4537 code; \
4538 RESTORE_SPELLING_DEPTH (__depth); \
4539 }
4541 /* Push an element on the spelling stack with type KIND and assign VALUE
4542 to MEMBER. */
4544 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
4545 { \
4546 int depth = SPELLING_DEPTH (); \
4547 \
4548 if (depth >= spelling_size) \
4549 { \
4550 spelling_size += 10; \
4551 if (spelling_base == 0) \
4552 spelling_base \
4553 = (struct spelling *) xmalloc (spelling_size * sizeof (struct spelling)); \
4554 else \
4555 spelling_base \
4556 = (struct spelling *) xrealloc (spelling_base, \
4557 spelling_size * sizeof (struct spelling)); \
4558 RESTORE_SPELLING_DEPTH (depth); \
4559 } \
4560 \
4561 spelling->kind = (KIND); \
4562 spelling->MEMBER = (VALUE); \
4563 spelling++; \
4564 }
4566 /* Push STRING on the stack. Printed literally. */
4568 static void
4571 {
4573 }
4575 /* Push a member name on the stack. Printed as '.' STRING. */
4577 static void
4579 tree decl;
4581 {
4585 }
4587 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
4589 static void
4592 {
4594 }
4596 /* Compute the maximum size in bytes of the printed spelling. */
4598 static int
4600 {
4605 {
4608 else
4610 }
4613 }
4615 /* Print the spelling to BUFFER and return it. */
4620 {
4626 {
4629 }
4630 else
4631 {
4636 ;
4637 }
4640 }
4642 /* Issue an error message for a bad initializer component.
4643 MSGID identifies the message.
4644 The component name is taken from the spelling stack. */
4646 void
4649 {
4656 }
4658 /* Issue a pedantic warning for a bad initializer component.
4659 MSGID identifies the message.
4660 The component name is taken from the spelling stack. */
4662 void
4665 {
4672 }
4674 /* Issue a warning for a bad initializer component.
4675 MSGID identifies the message.
4676 The component name is taken from the spelling stack. */
4678 static void
4681 {
4688 }
4689 \f
4690 /* Digest the parser output INIT as an initializer for type TYPE.
4691 Return a C expression of type TYPE to represent the initial value.
4693 The arguments REQUIRE_CONSTANT and CONSTRUCTOR_CONSTANT request errors
4694 if non-constant initializers or elements are seen. CONSTRUCTOR_CONSTANT
4695 applies only to elements of constructors. */
4697 static tree
4701 {
4710 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
4711 /* Do not use STRIP_NOPS here. We do not want an enumerator
4712 whose value is 0 to count as a null pointer constant. */
4718 /* Initialization of an array of chars from a string constant
4719 optionally enclosed in braces. */
4722 {
4730 {
4738 {
4741 }
4745 {
4748 }
4754 /* Subtract 1 (or sizeof (wchar_t))
4755 because it's ok to ignore the terminating null char
4756 that is counted in the length of the constant. */
4767 }
4768 }
4770 /* Any type can be initialized
4771 from an expression of the same type, optionally with braces. */
4783 {
4788 {
4791 }
4796 /* Compound expressions can only occur here if -pedantic or
4797 -pedantic-errors is specified. In the later case, we always want
4798 an error. In the former case, we simply want a warning. */
4801 {
4802 inside_init
4807 else
4811 }
4814 /* This test catches things like `7 / 0' which
4815 result in an expression for which TREE_CONSTANT
4816 is true, but which is not actually something
4817 that is a legal constant. We really should not
4818 be using this function, because it is a part of
4819 the back-end. Instead, the expression should
4820 already have been turned into ERROR_MARK_NODE. */
4823 {
4826 }
4829 }
4831 /* Handle scalar types, including conversions. */
4835 {
4836 /* Note that convert_for_assignment calls default_conversion
4837 for arrays and functions. We must not call it in the
4838 case where inside_init is a null pointer constant. */
4839 inside_init
4844 {
4847 }
4850 {
4853 }
4856 }
4858 /* Come here only for records and arrays. */
4861 {
4864 }
4866 /* Traditionally, you can write struct foo x = 0;
4867 and it initializes the first element of x to 0. */
4869 {
4875 {
4879 else
4886 else
4887 {
4890 }
4891 }
4894 {
4898 constructor_constant));
4900 }
4901 else
4903 }
4906 }
4907 \f
4908 /* Handle initializers that use braces. */
4910 /* Type of object we are accumulating a constructor for.
4911 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4914 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4915 left to fill. */
4918 /* For an ARRAY_TYPE, this is the specified index
4919 at which to store the next element we get. */
4922 /* For an ARRAY_TYPE, this is the maximum index. */
4925 /* For a RECORD_TYPE, this is the first field not yet written out. */
4928 /* For an ARRAY_TYPE, this is the index of the first element
4929 not yet written out. */
4932 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4933 This is so we can generate gaps between fields, when appropriate. */
4936 /* If we are saving up the elements rather than allocating them,
4937 this is the list of elements so far (in reverse order,
4938 most recent first). */
4941 /* 1 if constructor should be incrementally stored into a constructor chain,
4942 0 if all the elements should be kept in AVL tree. */
4945 /* 1 if so far this constructor's elements are all compile-time constants. */
4948 /* 1 if so far this constructor's elements are all valid address constants. */
4951 /* 1 if this constructor is erroneous so far. */
4954 /* 1 if have called defer_addressed_constants. */
4957 /* Structure for managing pending initializer elements, organized as an
4958 AVL tree. */
4960 struct init_node
4961 {
4965 tree purpose;
4966 tree value;
4967 };
4969 /* Tree of pending elements at this constructor level.
4970 These are elements encountered out of order
4971 which belong at places we haven't reached yet in actually
4972 writing the output.
4973 Will never hold tree nodes across GC runs. */
4976 /* The SPELLING_DEPTH of this constructor. */
4979 /* 0 if implicitly pushing constructor levels is allowed. */
4985 /* DECL node for which an initializer is being read.
4986 0 means we are reading a constructor expression
4987 such as (struct foo) {...}. */
4990 /* start_init saves the ASMSPEC arg here for really_start_incremental_init. */
4993 /* Nonzero if this is an initializer for a top-level decl. */
4996 /* Nonzero if there were any member designators in this initializer. */
4999 /* Nesting depth of designator list. */
5002 /* Nonzero if there were diagnosed errors in this designator list. */
5005 \f
5006 /* This stack has a level for each implicit or explicit level of
5007 structuring in the initializer, including the outermost one. It
5008 saves the values of most of the variables above. */
5012 struct constructor_stack
5013 {
5015 tree type;
5016 tree fields;
5017 tree index;
5018 tree max_index;
5019 tree unfilled_index;
5020 tree unfilled_fields;
5021 tree bit_index;
5022 tree elements;
5026 /* If nonzero, this value should replace the entire
5027 constructor at this level. */
5028 tree replacement_value;
5037 };
5041 /* This stack represents designators from some range designator up to
5042 the last designator in the list. */
5044 struct constructor_range_stack
5045 {
5048 tree range_start;
5049 tree index;
5050 tree range_end;
5051 tree fields;
5052 };
5056 /* This stack records separate initializers that are nested.
5057 Nested initializers can't happen in ANSI C, but GNU C allows them
5058 in cases like { ... (struct foo) { ... } ... }. */
5060 struct initializer_stack
5061 {
5063 tree decl;
5067 tree elements;
5075 };
5078 \f
5079 /* Prepare to parse and output the initializer for variable DECL. */
5081 void
5083 tree decl;
5084 tree asmspec_tree;
5086 {
5117 {
5119 require_constant_elements
5121 /* For a scalar, you can always use any value to initialize,
5122 even within braces. */
5128 }
5129 else
5130 {
5134 }
5147 }
5149 void
5151 {
5154 /* Output subconstants (string constants, usually)
5155 that were referenced within this initializer and saved up.
5156 Must do this if and only if we called defer_addressed_constants. */
5160 /* Free the whole constructor stack of this initializer. */
5162 {
5166 }
5171 /* Pop back to the data of the outer initializer (if any). */
5186 }
5187 \f
5188 /* Call here when we see the initializer is surrounded by braces.
5189 This is instead of a call to push_init_level;
5190 it is matched by a call to pop_init_level.
5192 TYPE is the type to initialize, for a constructor expression.
5193 For an initializer for a decl, TYPE is zero. */
5195 void
5197 tree type;
5198 {
5240 {
5242 /* Skip any nameless bit fields at the beginning. */
5249 }
5251 {
5253 {
5254 constructor_max_index
5257 /* Detect non-empty initializations of zero-length arrays. */
5262 constructor_index
5265 }
5266 else
5270 }
5271 else
5272 {
5273 /* Handle the case of int x = {5}; */
5276 }
5277 }
5278 \f
5279 /* Push down into a subobject, for initialization.
5280 If this is for an explicit set of braces, IMPLICIT is 0.
5281 If it is because the next element belongs at a lower level,
5282 IMPLICIT is 1 (or 2 if the push is because of designator list). */
5284 void
5287 {
5291 /* If we've exhausted any levels that didn't have braces,
5292 pop them now. */
5294 {
5302 else
5304 }
5306 /* Unless this is an explicit brace, we need to preserve previous
5307 content if any. */
5309 {
5316 }
5349 {
5354 }
5356 /* Don't die if an entire brace-pair level is superfluous
5357 in the containing level. */
5359 ;
5362 {
5363 /* Don't die if there are extra init elts at the end. */
5366 else
5367 {
5370 constructor_depth++;
5371 }
5372 }
5374 {
5377 constructor_depth++;
5378 }
5381 {
5386 }
5389 {
5397 }
5400 {
5403 }
5407 {
5409 /* Skip any nameless bit fields at the beginning. */
5416 }
5418 {
5420 {
5421 constructor_max_index
5424 /* Detect non-empty initializations of zero-length arrays. */
5429 constructor_index
5432 }
5433 else
5438 {
5439 /* We need to split the char/wchar array into individual
5440 characters, so that we don't have to special case it
5441 everywhere. */
5443 }
5444 }
5445 else
5446 {
5450 }
5451 }
5453 /* At the end of an implicit or explicit brace level,
5454 finish up that level of constructor.
5455 If we were outputting the elements as they are read, return 0
5456 from inner levels (process_init_element ignores that),
5457 but return error_mark_node from the outermost level
5458 (that's what we want to put in DECL_INITIAL).
5459 Otherwise, return a CONSTRUCTOR expression. */
5461 tree
5464 {
5469 {
5470 /* When we come to an explicit close brace,
5471 pop any inner levels that didn't have explicit braces. */
5477 }
5481 /* Error for initializing a flexible array member, or a zero-length
5482 array member in an inappropriate context. */
5487 {
5488 /* Silently discard empty initializations. The parser will
5489 already have pedwarned for empty brackets. */
5493 {
5499 /* We have already issued an error message for the existence
5500 of a flexible array member not at the end of the structure.
5501 Discard the initializer so that we do not abort later. */
5504 }
5505 else
5506 /* Zero-length arrays are no longer special, so we should no longer
5507 get here. */
5509 }
5511 /* Warn when some struct elements are implicitly initialized to zero. */
5513 && constructor_type
5516 {
5517 /* Do not warn for flexible array members or zero-length arrays. */
5523 /* Do not warn if this level of the initializer uses member
5524 designators; it is likely to be deliberate. */
5526 {
5530 }
5531 }
5533 /* Now output all pending elements. */
5537 /* Pad out the end of the structure. */
5539 /* If this closes a superfluous brace pair,
5540 just pass out the element between them. */
5543 ;
5547 {
5548 /* A nonincremental scalar initializer--just return
5549 the element, after verifying there is just one. */
5551 {
5555 }
5557 {
5560 }
5561 else
5563 }
5564 else
5565 {
5568 else
5569 {
5576 }
5577 }
5602 {
5606 }
5608 }
5610 /* Common handling for both array range and field name designators.
5611 ARRAY argument is non-zero for array ranges. Returns zero for success. */
5613 static int
5616 {
5617 tree subtype;
5620 /* Don't die if an entire brace-pair level is superfluous
5621 in the containing level. */
5625 /* If there were errors in this designator list already, bail out silently. */
5630 {
5634 /* Designator list starts at the level of closest explicit
5635 braces. */
5640 }
5643 {
5646 }
5650 {
5654 }
5656 {
5658 }
5659 else
5664 {
5667 }
5669 {
5672 }
5677 }
5679 /* If there are range designators in designator list, push a new designator
5680 to constructor_range_stack. RANGE_END is end of such stack range or
5681 NULL_TREE if there is no range designator at this level. */
5683 static void
5685 tree range_end;
5686 {
5701 }
5703 /* Within an array initializer, specify the next index to be initialized.
5704 FIRST is that index. If LAST is nonzero, then initialize a range
5705 of indices, running from FIRST through LAST. */
5707 void
5710 {
5740 else
5741 {
5745 {
5749 {
5752 }
5753 else
5754 {
5758 {
5761 }
5762 }
5763 }
5765 designator_depth++;
5769 }
5770 }
5772 /* Within a struct initializer, specify the next field to be initialized. */
5774 void
5776 tree fieldname;
5777 {
5778 tree tail;
5787 {
5790 }
5794 {
5797 }
5802 else
5803 {
5805 designator_depth++;
5809 }
5810 }
5811 \f
5812 /* Add a new initializer to the tree of pending initializers. PURPOSE
5813 identifies the initializer, either array index or field in a structure.
5814 VALUE is the value of that index or field. */
5816 static void
5819 {
5826 {
5828 {
5834 else
5835 {
5840 }
5841 }
5842 }
5843 else
5844 {
5845 tree bitpos;
5849 {
5855 else
5856 {
5861 }
5862 }
5863 }
5876 {
5880 {
5884 {
5886 {
5887 /* L rotation. */
5900 {
5903 else
5905 }
5906 else
5908 }
5909 else
5910 {
5911 /* LR rotation. */
5933 {
5936 else
5938 }
5939 else
5941 }
5943 }
5944 else
5945 {
5946 /* p->balance == +1; growth of left side balances the node. */
5949 }
5950 }
5952 {
5954 /* Growth propagation from right side. */
5957 {
5959 {
5960 /* R rotation. */
5973 {
5976 else
5978 }
5979 else
5981 }
5983 {
5984 /* RL rotation */
6006 {
6009 else
6011 }
6012 else
6014 }
6016 }
6017 else
6018 {
6019 /* p->balance == -1; growth of right side balances the node. */
6022 }
6023 }
6027 }
6028 }
6030 /* Build AVL tree from a sorted chain. */
6032 static void
6034 {
6035 tree chain;
6045 {
6047 /* Skip any nameless bit fields at the beginning. */
6053 }
6055 {
6057 constructor_unfilled_index
6060 else
6062 }
6064 }
6066 /* Build AVL tree from a string constant. */
6068 static void
6070 tree str;
6071 {
6086 else
6097 {
6099 {
6102 }
6103 else
6104 {
6108 {
6111 else
6116 }
6117 }
6120 {
6123 {
6125 {
6128 }
6129 }
6131 {
6134 }
6139 }
6144 }
6147 }
6149 /* Return value of FIELD in pending initializer or zero if the field was
6150 not initialized yet. */
6152 static tree
6154 tree field;
6155 {
6159 {
6166 {
6171 else
6173 }
6174 }
6176 {
6180 && (!constructor_unfilled_fields
6187 {
6192 else
6194 }
6195 }
6197 {
6201 }
6203 }
6205 /* "Output" the next constructor element.
6206 At top level, really output it to assembler code now.
6207 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
6208 TYPE is the data type that the containing data type wants here.
6209 FIELD is the field (a FIELD_DECL) or the index that this element fills.
6211 PENDING if non-nil means output pending elements that belong
6212 right after this element. (PENDING is normally 1;
6213 it is 0 while outputting pending elements, to avoid recursion.) */
6215 static void
6219 {
6241 {
6244 }
6249 /* If this field is empty (and not at the end of structure),
6250 don't do anything other than checking the initializer. */
6260 {
6263 }
6265 /* If this element doesn't come next in sequence,
6266 put it on constructor_pending_elts. */
6268 && (!constructor_incremental
6270 {
6277 require_constant_elements));
6279 }
6281 && (!constructor_incremental
6283 {
6284 /* We do this for records but not for unions. In a union,
6285 no matter which field is specified, it can be initialized
6286 right away since it starts at the beginning of the union. */
6288 {
6291 else
6292 {
6300 }
6301 }
6305 require_constant_elements));
6307 }
6310 {
6314 /* We can have just one union field set. */
6316 }
6318 /* Otherwise, output this element either to
6319 constructor_elements or to the assembler file. */
6323 constructor_elements
6325 require_constant_value,
6326 require_constant_elements),
6327 constructor_elements);
6329 /* Advance the variable that indicates sequential elements output. */
6331 constructor_unfilled_index
6333 bitsize_one_node);
6335 {
6336 constructor_unfilled_fields
6339 /* Skip any nameless bit fields. */
6343 constructor_unfilled_fields =
6345 }
6349 /* Now output any pending elements which have become next. */
6352 }
6354 /* Output any pending elements which have become next.
6355 As we output elements, constructor_unfilled_{fields,index}
6356 advances, which may cause other elements to become next;
6357 if so, they too are output.
6359 If ALL is 0, we return when there are
6360 no more pending elements to output now.
6362 If ALL is 1, we output space as necessary so that
6363 we can output all the pending elements. */
6365 static void
6368 {
6370 tree next;
6372 retry:
6374 /* Look thru the whole pending tree.
6375 If we find an element that should be output now,
6376 output it. Otherwise, set NEXT to the element
6377 that comes first among those still pending. */
6381 {
6383 {
6385 constructor_unfilled_index))
6391 {
6392 /* Advance to the next smaller node. */
6395 else
6396 {
6397 /* We have reached the smallest node bigger than the
6398 current unfilled index. Fill the space first. */
6401 }
6402 }
6403 else
6404 {
6405 /* Advance to the next bigger node. */
6408 else
6409 {
6410 /* We have reached the biggest node in a subtree. Find
6411 the parent of it, which is the next bigger node. */
6417 {
6420 }
6421 }
6422 }
6423 }
6426 {
6429 /* If the current record is complete we are done. */
6435 /* We can't compare fields here because there might be empty
6436 fields in between. */
6438 {
6442 }
6444 {
6445 /* Advance to the next smaller node. */
6448 else
6449 {
6450 /* We have reached the smallest node bigger than the
6451 current unfilled field. Fill the space first. */
6454 }
6455 }
6456 else
6457 {
6458 /* Advance to the next bigger node. */
6461 else
6462 {
6463 /* We have reached the biggest node in a subtree. Find
6464 the parent of it, which is the next bigger node. */
6471 {
6474 }
6475 }
6476 }
6477 }
6478 }
6480 /* Ordinarily return, but not if we want to output all
6481 and there are elements left. */
6485 /* If it's not incremental, just skip over the gap, so that after
6486 jumping to retry we will output the next successive element. */
6493 /* ELT now points to the node in the pending tree with the next
6494 initializer to output. */
6496 }
6497 \f
6498 /* Add one non-braced element to the current constructor level.
6499 This adjusts the current position within the constructor's type.
6500 This may also start or terminate implicit levels
6501 to handle a partly-braced initializer.
6503 Once this has found the correct level for the new element,
6504 it calls output_init_element. */
6506 void
6508 tree value;
6509 {
6516 /* Handle superfluous braces around string cst as in
6517 char x[] = {"foo"}; */
6519 && constructor_type
6523 {
6528 }
6531 {
6534 }
6536 /* Ignore elements of a brace group if it is entirely superfluous
6537 and has already been diagnosed. */
6541 /* If we've exhausted any levels that didn't have braces,
6542 pop them now. */
6544 {
6552 constructor_index)))
6554 else
6556 }
6558 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
6563 {
6565 {
6566 tree fieldtype;
6570 {
6573 }
6580 /* Accept a string constant to initialize a subarray. */
6586 /* Otherwise, if we have come to a subaggregate,
6587 and we don't have an element of its type, push into it. */
6593 {
6596 }
6599 {
6603 }
6604 else
6605 /* Do the bookkeeping for an element that was
6606 directly output as a constructor. */
6607 {
6608 /* For a record, keep track of end position of last field. */
6610 constructor_bit_index
6616 /* Skip any nameless bit fields. */
6620 constructor_unfilled_fields =
6622 }
6625 /* Skip any nameless bit fields at the beginning. */
6630 }
6632 {
6633 tree fieldtype;
6637 {
6640 }
6647 /* Warn that traditional C rejects initialization of unions.
6648 We skip the warning if the value is zero. This is done
6649 under the assumption that the zero initializer in user
6650 code appears conditioned on e.g. __STDC__ to avoid
6651 "missing initializer" warnings and relies on default
6652 initialization to zero in the traditional C case.
6653 We also skip the warning if the initializer is designated,
6654 again on the assumption that this must be conditional on
6655 __STDC__ anyway (and we've already complained about the
6656 member-designator already). */
6661 /* Accept a string constant to initialize a subarray. */
6667 /* Otherwise, if we have come to a subaggregate,
6668 and we don't have an element of its type, push into it. */
6674 {
6677 }
6680 {
6684 }
6685 else
6686 /* Do the bookkeeping for an element that was
6687 directly output as a constructor. */
6688 {
6691 }
6694 }
6696 {
6700 /* Accept a string constant to initialize a subarray. */
6706 /* Otherwise, if we have come to a subaggregate,
6707 and we don't have an element of its type, push into it. */
6713 {
6716 }
6721 {
6724 }
6726 /* Now output the actual element. */
6728 {
6732 }
6734 constructor_index
6738 /* If we are doing the bookkeeping for an element that was
6739 directly output as a constructor, we must update
6740 constructor_unfilled_index. */
6742 }
6744 /* Handle the sole element allowed in a braced initializer
6745 for a scalar variable. */
6747 {
6750 }
6751 else
6752 {
6756 }
6758 /* Handle range initializers either at this level or anywhere higher
6759 in the designator stack. */
6761 {
6768 {
6772 }
6776 {
6780 }
6787 {
6791 {
6794 }
6802 }
6807 }
6810 }
6813 }
6814 \f
6815 /* Build a simple asm-statement, from one string literal. */
6816 tree
6818 tree expr;
6819 {
6826 {
6827 tree stmt;
6833 NULL_TREE));
6836 }
6840 }
6842 /* Build an asm-statement, whose components are a CV_QUALIFIER, a
6843 STRING, some OUTPUTS, some INPUTS, and some CLOBBERS. */
6845 tree
6847 tree cv_qualifier;
6848 tree string;
6849 tree outputs;
6850 tree inputs;
6851 tree clobbers;
6852 {
6853 tree tail;
6858 {
6861 }
6865 {
6869 }
6871 /* We can remove output conversions that change the type,
6872 but not the mode. */
6874 {
6880 /* Allow conversions as LHS here. build_modify_expr as called below
6881 will do the right thing with them. */
6892 }
6894 /* Remove output conversions that change the type but not the mode. */
6896 {
6900 }
6902 /* Perform default conversions on array and function inputs.
6903 Don't do this for other types as it would screw up operands
6904 expected to be in memory. */
6910 }
6912 /* Expand an ASM statement with operands, handling output operands
6913 that are not variables or INDIRECT_REFS by transforming such
6914 cases into cases that expand_asm_operands can handle.
6916 Arguments are same as for expand_asm_operands. */
6918 void
6924 {
6927 /* o[I] is the place that output number I should be written. */
6929 tree tail;
6931 /* Record the contents of OUTPUTS before it is modified. */
6935 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
6936 OUTPUTS some trees for where the values were actually stored. */
6939 /* Copy all the intermediate outputs into the specified outputs. */
6941 {
6943 {
6948 /* Restore the original value so that it's correct the next
6949 time we expand this function. */
6951 }
6952 /* Detect modification of read-only values.
6953 (Otherwise done by build_modify_expr.) */
6954 else
6955 {
6963 }
6964 }
6966 /* Those MODIFY_EXPRs could do autoincrements. */
6968 }
6969 \f
6970 /* Expand a C `return' statement.
6971 RETVAL is the expression for what to return,
6972 or a null pointer for `return;' with no value. */
6974 tree
6976 tree retval;
6977 {
6984 {
6989 }
6991 {
6995 }
6996 else
6997 {
7001 tree inner;
7008 /* Strip any conversions, additions, and subtractions, and see if
7009 we are returning the address of a local variable. Warn if so. */
7011 {
7013 {
7020 /* If the second operand of the MINUS_EXPR has a pointer
7021 type (or is converted from it), this may be valid, so
7022 don't give a warning. */
7023 {
7037 }
7054 }
7057 }
7061 }
7064 }
7065 \f
7067 /* The SWITCH_STMT being built. */
7068 tree switch_stmt;
7069 /* A splay-tree mapping the low element of a case range to the high
7070 element, or NULL_TREE if there is no high element. Used to
7071 determine whether or not a new case label duplicates an old case
7072 label. We need a tree, rather than simply a hash table, because
7073 of the GNU case range extension. */
7074 splay_tree cases;
7075 /* The next node on the stack. */
7077 };
7079 /* A stack of the currently active switch statements. The innermost
7080 switch statement is on the top of the stack. There is no need to
7081 mark the stack for garbage collection because it is only active
7082 during the processing of the body of a function, and we never
7083 collect at that point. */
7087 /* Start a C switch statement, testing expression EXP. Return the new
7088 SWITCH_STMT. */
7090 tree
7092 tree exp;
7093 {
7095 tree type;
7099 {
7105 {
7108 }
7109 else
7110 {
7111 tree index;
7122 /* We can't strip a conversion from a signed type to an
7123 unsigned, because if we did, int_fits_type_p would do the
7124 wrong thing when checking case values for being in range,
7125 and it's too hard to do the right thing. */
7129 }
7130 }
7132 /* Add this new SWITCH_STMT to the stack. */
7140 }
7142 /* Process a case label. */
7144 tree
7146 tree low_value;
7147 tree high_value;
7148 {
7152 {
7158 }
7161 else
7165 }
7167 /* Finish the switch statement. */
7169 void
7171 {
7176 /* Pop the stack. */
7180 }