| blob | dd8abdd11f75181e787a39176daa99e72dc901b5 |
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 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 {
153 {
156 }
159 }
165 }
170 else
171 /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */
174 }
175 }
177 /* Return a variant of TYPE which has all the type qualifiers of LIKE
178 as well as those of TYPE. */
180 static tree
183 {
186 }
187 \f
188 /* Return the common type of two types.
189 We assume that comptypes has already been done and returned 1;
190 if that isn't so, this may crash. In particular, we assume that qualifiers
191 match.
193 This is the type for the result of most arithmetic operations
194 if the operands have the given two types. */
196 tree
199 {
202 tree attributes;
204 /* Save time if the two types are the same. */
208 /* If one type is nonsense, use the other. */
214 /* Merge the attributes. */
217 /* Treat an enum type as the unsigned integer type of the same width. */
227 /* If one type is complex, form the common type of the non-complex
228 components, then make that complex. Use T1 or T2 if it is the
229 required type. */
231 {
240 else
242 attributes);
243 }
246 {
249 /* If only one is real, use it as the result. */
257 /* Both real or both integers; use the one with greater precision. */
264 /* Same precision. Prefer longs to ints even when same size. */
269 attributes);
273 {
274 /* But preserve unsignedness from the other type,
275 since long cannot hold all the values of an unsigned int. */
278 else
281 }
283 /* Likewise, prefer long double to double even if same size. */
287 attributes);
289 /* Otherwise prefer the unsigned one. */
293 else
297 /* For two pointers, do this recursively on the target type,
298 and combine the qualifiers of the two types' targets. */
299 /* This code was turned off; I don't know why.
300 But ANSI C specifies doing this with the qualifiers.
301 So I turned it on again. */
302 {
312 }
313 #if 0
316 #endif
319 {
321 /* Save space: see if the result is identical to one of the args. */
326 /* Merge the element types, and have a size if either arg has one. */
329 }
332 /* Function types: prefer the one that specified arg types.
333 If both do, merge the arg types. Also merge the return types. */
334 {
342 /* Save space: see if the result is identical to one of the args. */
348 /* Simple way if one arg fails to specify argument types. */
350 {
353 }
355 {
358 }
360 /* If both args specify argument types, we must merge the two
361 lists, argument by argument. */
376 {
377 /* A null type means arg type is not specified.
378 Take whatever the other function type has. */
380 {
383 }
385 {
388 }
390 /* Given wait (union {union wait *u; int *i} *)
391 and wait (union wait *),
392 prefer union wait * as type of parm. */
395 {
396 tree memb;
400 {
405 }
406 }
409 {
410 tree memb;
414 {
419 }
420 }
422 parm_done: ;
423 }
428 /* ... falls through ... */
429 }
433 }
435 }
436 \f
437 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
438 or various other operations. Return 2 if they are compatible
439 but a warning may be needed if you use them together. */
441 int
444 {
449 /* Suppress errors caused by previously reported errors. */
455 /* If either type is the internal version of sizetype, return the
456 language version. */
465 /* Treat an enum type as the integer type of the same width and
466 signedness. */
476 /* Different classes of types can't be compatible. */
480 /* Qualifiers must match. */
485 /* Allow for two different type nodes which have essentially the same
486 definition. Note that we already checked for equality of the type
487 qualifiers (just above). */
492 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
496 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
500 {
511 {
518 /* Target types must match incl. qualifiers. */
523 /* Sizes must match unless one is missing or variable. */
530 d1_variable = (! d1_zero
533 d2_variable = (! d2_zero
547 }
556 }
558 }
560 /* Return 1 if TTL and TTR are pointers to types that are equivalent,
561 ignoring their qualifiers. */
563 static int
566 {
569 /* Give maybe_objc_comptypes a crack at letting these types through. */
579 }
580 \f
581 /* Subroutines of `comptypes'. */
583 /* Return 1 if two function types F1 and F2 are compatible.
584 If either type specifies no argument types,
585 the other must specify a fixed number of self-promoting arg types.
586 Otherwise, if one type specifies only the number of arguments,
587 the other must specify that number of self-promoting arg types.
588 Otherwise, the argument types must match. */
590 static int
593 {
595 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
606 /* An unspecified parmlist matches any specified parmlist
607 whose argument types don't need default promotions. */
610 {
613 /* If one of these types comes from a non-prototype fn definition,
614 compare that with the other type's arglist.
615 If they don't match, ask for a warning (but no error). */
620 }
622 {
629 }
631 /* Both types have argument lists: compare them and propagate results. */
634 }
636 /* Check two lists of types for compatibility,
637 returning 0 for incompatible, 1 for compatible,
638 or 2 for compatible with warning. */
640 static int
643 {
644 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
649 {
652 /* If one list is shorter than the other,
653 they fail to match. */
656 /* A null pointer instead of a type
657 means there is supposed to be an argument
658 but nothing is specified about what type it has.
659 So match anything that self-promotes. */
661 {
664 }
666 {
669 }
672 {
673 /* Allow wait (union {union wait *u; int *i} *)
674 and wait (union wait *) to be compatible. */
681 {
682 tree memb;
689 }
696 {
697 tree memb;
704 }
705 else
707 }
709 /* comptypes said ok, but record if it said to warn. */
715 }
716 }
717 \f
718 /* Compute the value of the `sizeof' operator. */
720 tree
722 tree type;
723 {
725 tree size;
728 {
732 }
734 {
738 }
742 {
745 }
746 else
747 /* Convert in case a char is more than one unit. */
752 /* SIZE will have an integer type with TYPE_IS_SIZETYPE set.
753 TYPE_IS_SIZETYPE means that certain things (like overflow) will
754 never happen. However, this node should really have type
755 `size_t', which is just a typedef for an ordinary integer type. */
757 }
759 tree
761 tree type;
762 {
764 tree size;
770 else
771 /* Convert in case a char is more than one unit. */
776 /* SIZE will have an integer type with TYPE_IS_SIZETYPE set.
777 TYPE_IS_SIZETYPE means that certain things (like overflow) will
778 never happen. However, this node should really have type
779 `size_t', which is just a typedef for an ordinary integer type. */
781 }
783 /* Compute the size to increment a pointer by. */
785 tree
787 tree type;
788 {
795 {
798 }
800 /* Convert in case a char is more than one unit. */
804 }
805 \f
806 /* Return either DECL or its known constant value (if it has one). */
808 tree
810 tree decl;
811 {
813 in a place where a variable is invalid. */
819 /* This is invalid if initial value is not constant.
820 If it has either a function call, a memory reference,
821 or a variable, then re-evaluating it could give different results. */
823 /* Check for cases where this is sub-optimal, even though valid. */
827 }
829 /* Return either DECL or its known constant value (if it has one), but
830 return DECL if pedantic or DECL has mode BLKmode. This is for
831 bug-compatibility with the old behavior of decl_constant_value
832 (before GCC 3.0); every use of this function is a bug and it should
833 be removed before GCC 3.1. It is not appropriate to use pedantic
834 in a way that affects optimization, and BLKmode is probably not the
835 right test for avoiding misoptimizations either. */
837 static tree
839 tree decl;
840 {
843 else
845 }
848 /* Perform the default conversion of arrays and functions to pointers.
849 Return the result of converting EXP. For any other expression, just
850 return EXP. */
852 static tree
854 tree exp;
855 {
856 tree orig_exp;
861 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
862 an lvalue.
864 Do not use STRIP_NOPS here! It will remove conversions from pointer
865 to integer and cause infinite recursion. */
870 {
874 }
876 /* Preserve the original expression code. */
881 {
883 }
885 {
886 tree adr;
888 tree ptrtype;
894 {
897 }
900 restype
911 {
915 }
919 {
920 /* Before C99, non-lvalue arrays do not decay to pointers.
921 Normally, using such an array would be invalid; but it can
922 be used correctly inside sizeof or as a statement expression.
923 Thus, do not give an error here; an error will result later. */
925 }
930 {
931 /* ??? This is not really quite correct
932 in that the type of the operand of ADDR_EXPR
933 is not the target type of the type of the ADDR_EXPR itself.
934 Question is, can this lossage be avoided? */
941 }
942 /* This way is better for a COMPONENT_REF since it can
943 simplify the offset for a component. */
946 }
948 }
950 /* Perform default promotions for C data used in expressions.
951 Arrays and functions are converted to pointers;
952 enumeral types or short or char, to int.
953 In addition, manifest constants symbols are replaced by their values. */
955 tree
957 tree exp;
958 {
959 tree orig_exp;
966 /* Constants can be used directly unless they're not loadable. */
970 /* Replace a nonvolatile const static variable with its value unless
971 it is an array, in which case we must be sure that taking the
972 address of the array produces consistent results. */
974 {
977 }
979 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
980 an lvalue.
982 Do not use STRIP_NOPS here! It will remove conversions from pointer
983 to integer and cause infinite recursion. */
990 /* Preserve the original expression code. */
994 /* Normally convert enums to int,
995 but convert wide enums to something wider. */
997 {
1000 ((flag_traditional
1006 }
1010 /* If it's thinner than an int, promote it like a
1011 c_promoting_integer_type_p, otherwise leave it alone. */
1016 exp);
1019 {
1020 /* Traditionally, unsignedness is preserved in default promotions.
1021 Also preserve unsignedness if not really getting any wider. */
1023 && (flag_traditional
1028 }
1035 {
1038 }
1040 }
1041 \f
1042 /* Look up COMPONENT in a structure or union DECL.
1044 If the component name is not found, returns NULL_TREE. Otherwise,
1045 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL
1046 stepping down the chain to the component, which is in the last
1047 TREE_VALUE of the list. Normally the list is of length one, but if
1048 the component is embedded within (nested) anonymous structures or
1049 unions, the list steps down the chain to the component. */
1051 static tree
1054 {
1056 tree field;
1058 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers
1059 to the field elements. Use a binary search on this array to quickly
1060 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC
1061 will always be set for structures which have many elements. */
1064 {
1072 {
1077 {
1078 /* Step through all anon unions in linear fashion. */
1080 {
1084 {
1089 }
1090 }
1092 /* Entire record is only anon unions. */
1096 /* Restart the binary search, with new lower bound. */
1098 }
1104 else
1106 }
1112 }
1113 else
1114 {
1116 {
1120 {
1125 }
1129 }
1133 }
1136 }
1138 /* Make an expression to refer to the COMPONENT field of
1139 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */
1141 tree
1144 {
1148 tree ref;
1150 /* If DATUM is a COMPOUND_EXPR, move our reference inside it.
1151 If pedantic ensure that the arguments are not lvalues; otherwise,
1152 if the component is an array, it would wrongly decay to a pointer in
1153 C89 mode.
1154 We cannot do this with a COND_EXPR, because in a conditional expression
1155 the default promotions are applied to both sides, and this would yield
1156 the wrong type of the result; for example, if the components have
1157 type "char". */
1159 {
1161 {
1165 }
1168 }
1170 /* See if there is a field or component with name COMPONENT. */
1173 {
1175 {
1178 }
1183 {
1188 }
1190 /* Chain the COMPONENT_REFs if necessary down to the FIELD.
1191 This might be better solved in future the way the C++ front
1192 end does it - by giving the anonymous entities each a
1193 separate name and type, and then have build_component_ref
1194 recursively call itself. We can't do that here. */
1196 {
1212 }
1215 }
1221 }
1222 \f
1223 /* Given an expression PTR for a pointer, return an expression
1224 for the value pointed to.
1225 ERRORSTRING is the name of the operator to appear in error messages. */
1227 tree
1229 tree ptr;
1231 {
1236 {
1238 && !flag_volatile
1242 else
1243 {
1248 {
1251 }
1255 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
1256 so that we get the proper error message if the result is used
1257 to assign to. Also, &* is supposed to be a no-op.
1258 And ANSI C seems to specify that the type of the result
1259 should be the const type. */
1260 /* A de-reference of a pointer to const is not a const. It is valid
1261 to change it via some other pointer. */
1267 }
1268 }
1272 }
1274 /* This handles expressions of the form "a[i]", which denotes
1275 an array reference.
1277 This is logically equivalent in C to *(a+i), but we may do it differently.
1278 If A is a variable or a member, we generate a primitive ARRAY_REF.
1279 This avoids forcing the array out of registers, and can work on
1280 arrays that are not lvalues (for example, members of structures returned
1281 by functions). */
1283 tree
1286 {
1288 {
1291 }
1299 {
1302 /* Subscripting with type char is likely to lose
1303 on a machine where chars are signed.
1304 So warn on any machine, but optionally.
1305 Don't warn for unsigned char since that type is safe.
1306 Don't warn for signed char because anyone who uses that
1307 must have done so deliberately. */
1312 /* Apply default promotions *after* noticing character types. */
1315 /* Require integer *after* promotion, for sake of enums. */
1317 {
1320 }
1322 /* An array that is indexed by a non-constant
1323 cannot be stored in a register; we must be able to do
1324 address arithmetic on its address.
1325 Likewise an array of elements of variable size. */
1329 {
1332 }
1333 /* An array that is indexed by a constant value which is not within
1334 the array bounds cannot be stored in a register either; because we
1335 would get a crash in store_bit_field/extract_bit_field when trying
1336 to access a non-existent part of the register. */
1340 {
1343 }
1346 {
1354 }
1358 /* Array ref is const/volatile if the array elements are
1359 or if the array is. */
1368 /* This was added by rms on 16 Nov 91.
1369 It fixes vol struct foo *a; a->elts[1]
1370 in an inline function.
1371 Hope it doesn't break something else. */
1374 }
1376 {
1380 /* Do the same warning check as above, but only on the part that's
1381 syntactically the index and only if it is also semantically
1382 the index. */
1388 /* Put the integer in IND to simplify error checking. */
1390 {
1394 }
1401 {
1404 }
1406 {
1409 }
1413 }
1414 }
1415 \f
1416 /* Build an external reference to identifier ID. FUN indicates
1417 whether this will be used for a function call. */
1418 tree
1420 tree id;
1422 {
1423 tree ref;
1431 {
1435 {
1437 /* Ordinary implicit function declaration. */
1439 else
1440 {
1441 /* Implicit declaration of built-in function. Don't
1442 change the built-in declaration, but don't let this
1443 go by silently, either. */
1446 /* only issue this warning once */
1449 }
1450 }
1451 else
1452 {
1453 /* Reference to undeclared variable, including reference to
1454 builtin outside of function-call context. */
1458 else
1459 {
1462 {
1467 {
1471 }
1472 }
1475 }
1477 }
1478 }
1479 else
1480 {
1481 /* Properly declared variable or function reference. */
1485 {
1489 }
1490 else
1492 }
1501 {
1504 }
1507 }
1509 /* Build a function call to function FUNCTION with parameters PARAMS.
1510 PARAMS is a list--a chain of TREE_LIST nodes--in which the
1511 TREE_VALUE of each node is a parameter-expression.
1512 FUNCTION's data type may be a function type or a pointer-to-function. */
1514 tree
1517 {
1519 tree coerced_params;
1522 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
1525 /* Convert anything with function type to a pointer-to-function. */
1527 {
1531 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
1532 (because calling an inline function does not mean the function
1533 needs to be separately compiled). */
1539 }
1540 else
1550 {
1553 }
1558 /* fntype now gets the type of function pointed to. */
1561 /* Convert the parameters to the types declared in the
1562 function prototype, or apply default promotions. */
1564 coerced_params
1567 /* Check for errors in format strings. */
1572 /* Recognize certain built-in functions so we can make tree-codes
1573 other than CALL_EXPR. We do this when it enables fold-const.c
1574 to do something useful. */
1579 {
1584 }
1594 }
1595 \f
1596 /* Convert the argument expressions in the list VALUES
1597 to the types in the list TYPELIST. The result is a list of converted
1598 argument expressions.
1600 If TYPELIST is exhausted, or when an element has NULL as its type,
1601 perform the default conversions.
1603 PARMLIST is the chain of parm decls for the function being called.
1604 It may be 0, if that info is not available.
1605 It is used only for generating error messages.
1607 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
1609 This is also where warnings about wrong number of args are generated.
1611 Both VALUES and the returned value are chains of TREE_LIST nodes
1612 with the elements of the list in the TREE_VALUE slots of those nodes. */
1614 static tree
1617 {
1622 /* Scan the given expressions and types, producing individual
1623 converted arguments and pushing them on RESULT in reverse order. */
1626 valtail;
1628 {
1633 {
1637 else
1640 }
1642 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
1643 /* Do not use STRIP_NOPS here! We do not want an enumerator with value 0
1644 to convert automatically to a pointer. */
1653 {
1654 /* Formal parm type is specified by a function prototype. */
1655 tree parmval;
1658 {
1661 }
1662 else
1663 {
1664 /* Optionally warn about conversions that
1665 differ from the default conversions. */
1667 {
1672 warn_for_assignment ("%s as integer rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1675 warn_for_assignment ("%s as integer rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1678 warn_for_assignment ("%s as complex rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1681 warn_for_assignment ("%s as floating rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1684 warn_for_assignment ("%s as complex rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1687 warn_for_assignment ("%s as floating rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1688 /* ??? At some point, messages should be written about
1689 conversions between complex types, but that's too messy
1690 to do now. */
1693 {
1694 /* Warn if any argument is passed as `float',
1695 since without a prototype it would be `double'. */
1697 warn_for_assignment ("%s as `float' rather than `double' due to prototype", (char *) 0, name, parmnum + 1);
1698 }
1699 /* Detect integer changing in width or signedness.
1700 These warnings are only activated with
1701 -Wconversion, not with -Wtraditional. */
1704 {
1711 /* No warning if function asks for enum
1712 and the actual arg is that enum type. */
1713 ;
1715 warn_for_assignment ("%s with different width due to prototype", (char *) 0, name, parmnum + 1);
1717 ;
1718 /* Don't complain if the formal parameter type
1719 is an enum, because we can't tell now whether
1720 the value was an enum--even the same enum. */
1722 ;
1725 /* Change in signedness doesn't matter
1726 if a constant value is unaffected. */
1727 ;
1728 /* Likewise for a constant in a NOP_EXPR. */
1732 ;
1737 /* Change in signedness doesn't matter
1738 if an enum value is unaffected. */
1739 ;
1740 #endif
1741 /* If the value is extended from a narrower
1742 unsigned type, it doesn't matter whether we
1743 pass it as signed or unsigned; the value
1744 certainly is the same either way. */
1747 ;
1750 else
1752 }
1753 }
1763 }
1765 }
1769 /* Convert `float' to `double'. */
1771 else
1772 /* Convert `short' and `char' to full-size `int'. */
1777 }
1780 {
1784 else
1786 }
1789 }
1790 \f
1791 /* This is the entry point used by the parser
1792 for binary operators in the input.
1793 In addition to constructing the expression,
1794 we check for operands that were written with other binary operators
1795 in a way that is likely to confuse the user. */
1797 tree
1801 {
1818 /* Check for cases such as x+y<<z which users are likely
1819 to misinterpret. If parens are used, C_EXP_ORIGINAL_CODE
1820 is cleared to prevent these warnings. */
1822 {
1824 {
1828 }
1831 {
1835 }
1838 {
1844 /* Check cases like x|y==z */
1847 }
1850 {
1856 /* Check cases like x^y==z */
1859 }
1862 {
1866 /* Check cases like x&y==z */
1869 }
1870 }
1872 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */
1883 /* Record the code that was specified in the source,
1884 for the sake of warnings about confusing nesting. */
1887 else
1888 {
1890 /* We used to use NOP_EXPR rather than NON_LVALUE_EXPR
1891 so that convert_for_assignment wouldn't strip it.
1892 That way, we got warnings for things like p = (1 - 1).
1893 But it turns out we should not get those warnings. */
1897 }
1900 }
1902 /* Build a binary-operation expression without default conversions.
1903 CODE is the kind of expression to build.
1904 This function differs from `build' in several ways:
1905 the data type of the result is computed and recorded in it,
1906 warnings are generated if arg data types are invalid,
1907 special handling for addition and subtraction of pointers is known,
1908 and some optimization is done (operations on narrow ints
1909 are done in the narrower type when that gives the same result).
1910 Constant folding is also done before the result is returned.
1912 Note that the operands will never have enumeral types, or function
1913 or array types, because either they will have the default conversions
1914 performed or they have both just been converted to some other type in which
1915 the arithmetic is to be done. */
1917 tree
1922 {
1927 /* Expression code to give to the expression when it is built.
1928 Normally this is CODE, which is what the caller asked for,
1929 but in some special cases we change it. */
1932 /* Data type in which the computation is to be performed.
1933 In the simplest cases this is the common type of the arguments. */
1936 /* Nonzero means operands have already been type-converted
1937 in whatever way is necessary.
1938 Zero means they need to be converted to RESULT_TYPE. */
1941 /* Nonzero means create the expression with this type, rather than
1942 RESULT_TYPE. */
1945 /* Nonzero means after finally constructing the expression
1946 convert it to this type. */
1949 /* Nonzero if this is an operation like MIN or MAX which can
1950 safely be computed in short if both args are promoted shorts.
1951 Also implies COMMON.
1952 -1 indicates a bitwise operation; this makes a difference
1953 in the exact conditions for when it is safe to do the operation
1954 in a narrower mode. */
1957 /* Nonzero if this is a comparison operation;
1958 if both args are promoted shorts, compare the original shorts.
1959 Also implies COMMON. */
1962 /* Nonzero if this is a right-shift operation, which can be computed on the
1963 original short and then promoted if the operand is a promoted short. */
1966 /* Nonzero means set RESULT_TYPE to the common type of the args. */
1970 {
1973 }
1974 else
1975 {
1978 }
1983 /* The expression codes of the data types of the arguments tell us
1984 whether the arguments are integers, floating, pointers, etc. */
1988 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
1992 /* If an error was already reported for one of the arguments,
1993 avoid reporting another error. */
1999 {
2001 /* Handle the pointer + int case. */
2006 else
2011 /* Subtraction of two similar pointers.
2012 We must subtract them as integers, then divide by object size. */
2016 /* Handle pointer minus int. Just like pointer plus int. */
2019 else
2032 /* Floating point division by zero is a legitimate way to obtain
2033 infinities and NaNs. */
2041 {
2044 else
2045 /* Although it would be tempting to shorten always here, that
2046 loses on some targets, since the modulo instruction is
2047 undefined if the quotient can't be represented in the
2048 computation mode. We shorten only if unsigned or if
2049 dividing by something we know != -1. */
2054 }
2071 {
2072 /* Although it would be tempting to shorten always here, that loses
2073 on some targets, since the modulo instruction is undefined if the
2074 quotient can't be represented in the computation mode. We shorten
2075 only if unsigned or if dividing by something we know != -1. */
2080 }
2092 {
2093 /* Result of these operations is always an int,
2094 but that does not mean the operands should be
2095 converted to ints! */
2100 }
2103 /* Shift operations: result has same type as first operand;
2104 always convert second operand to int.
2105 Also set SHORT_SHIFT if shifting rightward. */
2109 {
2111 {
2114 else
2115 {
2121 }
2122 }
2124 /* Use the type of the value to be shifted.
2125 This is what most traditional C compilers do. */
2127 /* Unless traditional, convert the shift-count to an integer,
2128 regardless of size of value being shifted. */
2130 {
2133 /* Avoid converting op1 to result_type later. */
2135 }
2136 }
2141 {
2143 {
2149 }
2151 /* Use the type of the value to be shifted.
2152 This is what most traditional C compilers do. */
2154 /* Unless traditional, convert the shift-count to an integer,
2155 regardless of size of value being shifted. */
2157 {
2160 /* Avoid converting op1 to result_type later. */
2162 }
2163 }
2169 {
2171 {
2176 }
2178 /* Use the type of the value to be shifted.
2179 This is what most traditional C compilers do. */
2181 /* Unless traditional, convert the shift-count to an integer,
2182 regardless of size of value being shifted. */
2184 {
2187 /* Avoid converting op1 to result_type later. */
2189 }
2190 }
2197 /* Result of comparison is always int,
2198 but don't convert the args to int! */
2206 {
2209 /* Anything compares with void *. void * compares with anything.
2210 Otherwise, the targets must be compatible
2211 and both must be object or both incomplete. */
2215 {
2216 /* op0 != orig_op0 detects the case of something
2217 whose value is 0 but which isn't a valid null ptr const. */
2221 }
2223 {
2227 }
2228 else
2233 }
2241 {
2245 }
2247 {
2251 }
2260 {
2262 {
2267 }
2268 else
2269 {
2272 }
2273 }
2285 {
2287 {
2295 }
2296 else
2297 {
2300 }
2301 }
2304 {
2308 }
2311 {
2315 }
2317 {
2321 }
2323 {
2327 }
2339 {
2342 }
2348 }
2351 &&
2353 {
2359 /* For certain operations (which identify themselves by shorten != 0)
2360 if both args were extended from the same smaller type,
2361 do the arithmetic in that type and then extend.
2363 shorten !=0 and !=1 indicates a bitwise operation.
2364 For them, this optimization is safe only if
2365 both args are zero-extended or both are sign-extended.
2366 Otherwise, we might change the result.
2367 Eg, (short)-1 | (unsigned short)-1 is (int)-1
2368 but calculated in (unsigned short) it would be (unsigned short)-1. */
2371 {
2375 /* UNS is 1 if the operation to be done is an unsigned one. */
2377 tree type;
2381 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
2382 but it *requires* conversion to FINAL_TYPE. */
2393 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
2395 /* For bitwise operations, signedness of nominal type
2396 does not matter. Consider only how operands were extended. */
2400 /* Note that in all three cases below we refrain from optimizing
2401 an unsigned operation on sign-extended args.
2402 That would not be valid. */
2404 /* Both args variable: if both extended in same way
2405 from same width, do it in that width.
2406 Do it unsigned if args were zero-extended. */
2413 result_type
2432 }
2434 /* Shifts can be shortened if shifting right. */
2437 {
2447 /* We can shorten only if the shift count is less than the
2448 number of bits in the smaller type size. */
2450 /* We cannot drop an unsigned shift after sign-extension. */
2452 {
2453 /* Do an unsigned shift if the operand was zero-extended. */
2454 result_type
2456 /* Convert value-to-be-shifted to that type. */
2460 }
2461 }
2463 /* Comparison operations are shortened too but differently.
2464 They identify themselves by setting short_compare = 1. */
2467 {
2468 /* Don't write &op0, etc., because that would prevent op0
2469 from being kept in a register.
2470 Instead, make copies of the our local variables and
2471 pass the copies by reference, then copy them back afterward. */
2474 tree val
2486 {
2498 /* Give warnings for comparisons between signed and unsigned
2499 quantities that may fail.
2501 Do the checking based on the original operand trees, so that
2502 casts will be considered, but default promotions won't be.
2504 Do not warn if the comparison is being done in a signed type,
2505 since the signed type will only be chosen if it can represent
2506 all the values of the unsigned type. */
2509 /* Do not warn if both operands are the same signedness. */
2512 else
2513 {
2518 else
2521 /* Do not warn if the signed quantity is an
2522 unsuffixed integer literal (or some static
2523 constant expression involving such literals or a
2524 conditional expression involving such literals)
2525 and it is non-negative. */
2528 /* Do not warn if the comparison is an equality operation,
2529 the unsigned quantity is an integral constant, and it
2530 would fit in the result if the result were signed. */
2535 /* Do not warn if the unsigned quantity is an enumeration
2536 constant and its maximum value would fit in the result
2537 if the result were signed. */
2543 else
2545 }
2547 /* Warn if two unsigned values are being compared in a size
2548 larger than their original size, and one (and only one) is the
2549 result of a `~' operator. This comparison will always fail.
2551 Also warn if one operand is a constant, and the constant
2552 does not have all bits set that are set in the ~ operand
2553 when it is extended. */
2557 {
2561 else
2566 {
2567 tree primop;
2572 {
2576 }
2577 else
2578 {
2582 }
2587 {
2591 }
2592 }
2599 }
2600 }
2601 }
2602 }
2604 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
2605 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
2606 Then the expression will be built.
2607 It will be given type FINAL_TYPE if that is nonzero;
2608 otherwise, it will be given type RESULT_TYPE. */
2611 {
2614 }
2617 {
2622 }
2627 {
2629 tree folded;
2637 }
2638 }
2639 \f
2640 /* Return a tree for the sum or difference (RESULTCODE says which)
2641 of pointer PTROP and integer INTOP. */
2643 static tree
2647 {
2648 tree size_exp;
2650 tree result;
2651 tree folded;
2653 /* The result is a pointer of the same type that is being added. */
2658 {
2662 }
2664 {
2668 }
2669 else
2672 /* If what we are about to multiply by the size of the elements
2673 contains a constant term, apply distributive law
2674 and multiply that constant term separately.
2675 This helps produce common subexpressions. */
2681 /* If the constant comes from pointer subtraction,
2682 skip this optimization--it would cause an error. */
2684 /* If the constant is unsigned, and smaller than the pointer size,
2685 then we must skip this optimization. This is because it could cause
2686 an overflow error if the constant is negative but INTOP is not. */
2690 {
2695 /* Convert both subexpression types to the type of intop,
2696 because weird cases involving pointer arithmetic
2697 can result in a sum or difference with different type args. */
2701 }
2703 /* Convert the integer argument to a type the same size as sizetype
2704 so the multiply won't overflow spuriously. */
2711 /* Replace the integer argument with a suitable product by the object size.
2712 Do this multiplication as signed, then convert to the appropriate
2713 pointer type (actually unsigned integral). */
2719 /* Create the sum or difference. */
2727 }
2729 /* Return a tree for the difference of pointers OP0 and OP1.
2730 The resulting tree has type int. */
2732 static tree
2735 {
2744 {
2749 }
2751 /* If the conversion to ptrdiff_type does anything like widening or
2752 converting a partial to an integral mode, we get a convert_expression
2753 that is in the way to do any simplifications.
2754 (fold-const.c doesn't know that the extra bits won't be needed.
2755 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2756 different mode in place.)
2757 So first try to find a common term here 'by hand'; we want to cover
2758 at least the cases that occur in legal static initializers. */
2763 {
2766 }
2767 else
2771 {
2774 }
2775 else
2779 {
2782 }
2785 /* First do the subtraction as integers;
2786 then drop through to build the divide operator.
2787 Do not do default conversions on the minus operator
2788 in case restype is a short type. */
2792 /* This generates an error if op1 is pointer to incomplete type. */
2796 /* This generates an error if op0 is pointer to incomplete type. */
2799 /* Divide by the size, in easiest possible way. */
2807 }
2808 \f
2809 /* Construct and perhaps optimize a tree representation
2810 for a unary operation. CODE, a tree_code, specifies the operation
2811 and XARG is the operand.
2812 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2813 the default promotions (such as from short to int).
2814 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2815 allows non-lvalues; this is only used to handle conversion of non-lvalue
2816 arrays to pointers in C99. */
2818 tree
2821 tree xarg;
2823 {
2824 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2828 tree val;
2837 {
2839 /* This is used for unary plus, because a CONVERT_EXPR
2840 is enough to prevent anybody from looking inside for
2841 associativity, but won't generate any code. */
2844 {
2847 }
2855 {
2858 }
2865 {
2871 }
2873 {
2876 }
2884 {
2887 }
2893 /* Conjugating a real value is a no-op, but allow it anyway. */
2896 {
2899 }
2908 /* These will convert to a pointer. */
2910 {
2913 }
2925 else
2933 else
2940 /* Handle complex lvalues (when permitted)
2941 by reduction to simpler cases. */
2947 /* Increment or decrement the real part of the value,
2948 and don't change the imaginary part. */
2950 {
2961 }
2963 /* Report invalid types. */
2967 {
2970 else
2974 }
2976 {
2977 tree inc;
2983 /* Compute the increment. */
2986 {
2987 /* If pointer target is an undefined struct,
2988 we just cannot know how to do the arithmetic. */
2990 {
2993 else
2995 }
2999 {
3002 else
3004 }
3007 }
3008 else
3013 /* Handle incrementing a cast-expression. */
3017 {
3026 /* If the real type has the same machine representation
3027 as the type it is cast to, we can make better output
3028 by adding directly to the inside of the cast. */
3034 else
3035 {
3039 else
3040 {
3044 else
3053 }
3056 }
3061 }
3062 give_up:
3064 /* Complain about anything else that is not a true lvalue. */
3071 /* Report a read-only lvalue. */
3080 else
3087 }
3090 /* Note that this operation never does default_conversion. */
3092 /* Let &* cancel out to simplify resulting code. */
3094 {
3095 /* Don't let this be an lvalue. */
3099 }
3101 /* For &x[y], return x+y */
3103 {
3108 }
3110 /* Handle complex lvalues (when permitted)
3111 by reduction to simpler cases. */
3117 float f; *&(int)f = 3.4 stores in int format
3118 whereas (int)f = 3.4 stores in float format. */
3119 /* Address of a cast is just a cast of the address
3120 of the operand of the cast. */
3122 {
3135 }
3136 #endif
3138 /* Anything not already handled and not a true memory reference
3139 or a non-lvalue array is an error. */
3144 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
3147 /* If the lvalue is const or volatile, merge that into the type
3148 to which the address will point. Note that you can't get a
3149 restricted pointer by taking the address of something, so we
3150 only have to deal with `const' and `volatile' here. */
3162 {
3163 tree addr;
3166 {
3172 {
3176 }
3181 }
3182 else
3185 /* Address of a static or external variable or
3186 file-scope function counts as a constant. */
3192 }
3196 }
3201 }
3203 #if 0
3204 /* If CONVERSIONS is a conversion expression or a nested sequence of such,
3205 convert ARG with the same conversions in the same order
3206 and return the result. */
3208 static tree
3210 tree conversions;
3211 tree arg;
3212 {
3214 {
3224 arg));
3228 }
3229 }
3232 /* Return nonzero if REF is an lvalue valid for this language.
3233 Lvalues can be assigned, unless their type has TYPE_READONLY.
3234 Lvalues can have their address taken, unless they have DECL_REGISTER. */
3236 int
3238 tree ref;
3239 {
3243 {
3268 }
3269 }
3271 /* Return nonzero if REF is an lvalue valid for this language;
3272 otherwise, print an error message and return zero. */
3274 int
3276 tree ref;
3278 {
3285 }
3287 /* Apply unary lvalue-demanding operator CODE to the expression ARG
3288 for certain kinds of expressions which are not really lvalues
3289 but which we can accept as lvalues. If FLAG is nonzero, then
3290 non-lvalues are OK since we may be converting a non-lvalue array to
3291 a pointer in C99.
3293 If ARG is not a kind of expression we can handle, return zero. */
3295 static tree
3298 tree arg;
3300 {
3301 /* Handle (a, b) used as an "lvalue". */
3303 {
3306 /* If this returns a function type, it isn't really being used as
3307 an lvalue, so don't issue a warning about it. */
3313 }
3315 /* Handle (a ? b : c) used as an "lvalue". */
3317 {
3327 }
3330 }
3332 /* If pedantic, warn about improper lvalue. CODE is either COND_EXPR
3333 COMPOUND_EXPR, or CONVERT_EXPR (for casts). */
3335 static void
3338 {
3341 {
3351 }
3352 }
3353 \f
3354 /* Warn about storing in something that is `const'. */
3356 void
3358 tree arg;
3360 {
3362 {
3365 else
3368 }
3372 else
3374 }
3375 \f
3376 /* Mark EXP saying that we need to be able to take the
3377 address of it; it should not be allocated in a register.
3378 Value is 1 if successful. */
3380 int
3382 tree exp;
3383 {
3387 {
3390 {
3394 }
3396 /* ... fall through ... */
3416 {
3418 {
3422 }
3425 }
3427 {
3429 {
3433 }
3435 /* If we are making this addressable due to its having
3436 volatile components, give a different error message. Also
3437 handle the case of an unnamed parameter by not trying
3438 to give the name. */
3441 {
3444 }
3448 }
3451 /* drops in */
3457 #endif
3461 }
3462 }
3463 \f
3464 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
3466 tree
3469 {
3470 tree type1;
3471 tree type2;
3480 /* Don't promote the operands separately if they promote
3481 the same way. Return the unpromoted type and let the combined
3482 value get promoted if necessary. */
3488 {
3493 }
3494 #endif
3496 /* Promote both alternatives. */
3513 /* Quickly detect the usual case where op1 and op2 have the same type
3514 after promotion. */
3516 {
3519 else
3521 }
3526 {
3529 /* If -Wsign-compare, warn here if type1 and type2 have
3530 different signedness. We'll promote the signed to unsigned
3531 and later code won't know it used to be different.
3532 Do this check on the original types, so that explicit casts
3533 will be considered, but default promotions won't. */
3536 {
3541 {
3542 /* Do not warn if the result type is signed, since the
3543 signed type will only be chosen if it can represent
3544 all the values of the unsigned type. */
3547 /* Do not warn if the signed quantity is an unsuffixed
3548 integer literal (or some static constant expression
3549 involving such literals) and it is non-negative. */
3553 else
3555 }
3556 }
3557 }
3559 {
3563 }
3565 {
3575 {
3580 }
3582 {
3587 }
3588 else
3589 {
3592 }
3593 }
3595 {
3598 else
3599 {
3601 }
3603 }
3605 {
3608 else
3609 {
3611 }
3613 }
3616 {
3619 else
3620 {
3623 }
3624 }
3626 /* Merge const and volatile flags of the incoming types. */
3627 result_type
3641 }
3642 \f
3643 /* Given a list of expressions, return a compound expression
3644 that performs them all and returns the value of the last of them. */
3646 tree
3648 tree list;
3649 {
3651 }
3653 static tree
3655 tree list;
3657 {
3658 tree rest;
3661 {
3662 /* Convert arrays and functions to pointers when there
3663 really is a comma operator. */
3669 /* Consider (x, y+0), which is not an lvalue since y+0 is not. */
3671 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3674 #endif
3676 /* Don't let (0, 0) be null pointer constant. */
3680 }
3685 {
3686 /* The left-hand operand of a comma expression is like an expression
3687 statement: with -W or -Wunused, we should warn if it doesn't have
3688 any side-effects, unless it was explicitly cast to (void). */
3694 /* When pedantic, a compound expression can be neither an lvalue
3695 nor an integer constant expression. */
3698 }
3700 /* With -Wunused, we should also warn if the left-hand operand does have
3701 side-effects, but computes a value which is not used. For example, in
3702 `foo() + bar(), baz()' the result of the `+' operator is not used,
3703 so we should issue a warning. */
3708 }
3710 /* Build an expression representing a cast to type TYPE of expression EXPR. */
3712 tree
3714 tree type;
3715 tree expr;
3716 {
3723 #if 0
3724 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3727 #endif
3730 {
3733 }
3736 {
3739 }
3742 {
3744 {
3748 }
3749 }
3751 {
3752 tree field;
3761 {
3763 tree t;
3768 {
3771 else
3773 }
3774 else
3781 }
3784 }
3785 else
3786 {
3789 /* If casting to void, avoid the error that would come
3790 from default_conversion in the case of a non-lvalue array. */
3794 /* Convert functions and arrays to pointers,
3795 but don't convert any other types. */
3799 /* Optionally warn about potentially worrisome casts. */
3804 {
3810 /* Check that the qualifiers on IN_TYPE are a superset of
3811 the qualifiers of IN_OTYPE. The outermost level of
3812 POINTER_TYPE nodes is uninteresting and we stop as soon
3813 as we hit a non-POINTER_TYPE node on either type. */
3814 do
3815 {
3819 /* GNU C allows cv-qualified function types. 'const'
3820 means the function is very pure, 'volatile' means it
3821 can't return. We need to warn when such qualifiers
3822 are added, not when they're taken away. */
3826 else
3828 }
3836 /* There are qualifiers present in IN_OTYPE that are not
3837 present in IN_TYPE. */
3839 }
3841 /* Warn about possible alignment problems. */
3847 /* Don't warn about opaque types, where the actual alignment
3848 restriction is unknown. */
3869 /* Don't warn about converting any constant. */
3876 /* Ignore any integer overflow caused by the cast. */
3878 {
3881 }
3882 }
3884 /* Pedantically, don't let (void *) (FOO *) 0 be a null pointer constant. */
3890 /* If pedantic, don't let a cast be an lvalue. */
3895 }
3897 /* Interpret a cast of expression EXPR to type TYPE. */
3898 tree
3901 {
3904 /* This avoids warnings about unprototyped casts on
3905 integers. E.g. "#define SIG_DFL (void(*)())0". */
3912 }
3914 \f
3915 /* Build an assignment expression of lvalue LHS from value RHS.
3916 MODIFYCODE is the code for a binary operator that we use
3917 to combine the old value of LHS with RHS to get the new value.
3918 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3920 tree
3924 {
3925 tree result;
3926 tree newrhs;
3930 /* Types that aren't fully specified cannot be used in assignments. */
3933 /* Avoid duplicate error messages from operands that had errors. */
3937 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3938 /* Do not use STRIP_NOPS here. We do not want an enumerator
3939 whose value is 0 to count as a null pointer constant. */
3945 /* Handle control structure constructs used as "lvalues". */
3948 {
3949 /* Handle (a, b) used as an "lvalue". */
3958 /* Handle (a ? b : c) used as an "lvalue". */
3962 {
3963 /* Produce (a ? (b = rhs) : (c = rhs))
3964 except that the RHS goes through a save-expr
3965 so the code to compute it is only emitted once. */
3966 tree cond
3974 /* Make sure the code to compute the rhs comes out
3975 before the split. */
3977 /* But cast it to void to avoid an "unused" error. */
3979 }
3982 }
3984 /* If a binary op has been requested, combine the old LHS value with the RHS
3985 producing the value we should actually store into the LHS. */
3988 {
3991 }
3993 /* Handle a cast used as an "lvalue".
3994 We have already performed any binary operator using the value as cast.
3995 Now convert the result to the cast type of the lhs,
3996 and then true type of the lhs and store it there;
3997 then convert result back to the cast type to be the value
3998 of the assignment. */
4001 {
4010 {
4012 tree result;
4020 }
4024 }
4026 /* Now we have handled acceptable kinds of LHS that are not truly lvalues.
4027 Reject anything strange now. */
4032 /* Warn about storing in something that is `const'. */
4040 /* If storing into a structure or union member,
4041 it has probably been given type `int'.
4042 Compute the type that would go with
4043 the actual amount of storage the member occupies. */
4052 /* If storing in a field that is in actuality a short or narrower than one,
4053 we must store in the field in its actual type. */
4056 {
4059 }
4061 /* Convert new value to destination type. */
4068 /* Scan operands */
4073 /* If we got the LHS in a different type for storing in,
4074 convert the result back to the nominal type of LHS
4075 so that the value we return always has the same type
4076 as the LHS argument. */
4082 }
4083 \f
4084 /* Convert value RHS to type TYPE as preparation for an assignment
4085 to an lvalue of type TYPE.
4086 The real work of conversion is done by `convert'.
4087 The purpose of this function is to generate error messages
4088 for assignments that are not allowed in C.
4089 ERRTYPE is a string to use in error messages:
4090 "assignment", "return", etc. If it is null, this is parameter passing
4091 for a function call (and different error messages are output).
4093 FUNNAME is the name of the function being called,
4094 as an IDENTIFIER_NODE, or null.
4095 PARMNUM is the number of the argument, for printing in error messages. */
4097 static tree
4103 {
4105 tree rhstype;
4108 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
4109 /* Do not use STRIP_NOPS here. We do not want an enumerator
4110 whose value is 0 to count as a null pointer constant. */
4127 {
4129 /* Check for Objective-C protocols. This will issue a warning if
4130 there are protocol violations. No need to use the return value. */
4133 }
4136 {
4139 }
4140 /* A type converts to a reference to it.
4141 This code doesn't fully support references, it's just for the
4142 special case of va_start and va_copy. */
4145 {
4150 /* We already know that these two types are compatible, but they
4151 may not be exactly identical. In fact, `TREE_TYPE (type)' is
4152 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
4153 likely to be va_list, a typedef to __builtin_va_list, which
4154 is different enough that it will cause problems later. */
4160 }
4161 /* Arithmetic types all interconvert, and enum is treated like int. */
4170 /* Conversion to a transparent union from its member types.
4171 This applies only to function arguments. */
4173 {
4174 tree memb_types;
4179 {
4190 {
4194 /* Any non-function converts to a [const][volatile] void *
4195 and vice versa; otherwise, targets must be the same.
4196 Meanwhile, the lhs target must have all the qualifiers of
4197 the rhs. */
4200 {
4201 /* If this type won't generate any warnings, use it. */
4211 /* Keep looking for a better type, but remember this one. */
4214 }
4215 }
4217 /* Can convert integer zero to any pointer type. */
4221 {
4224 }
4225 }
4228 {
4230 {
4231 /* We have only a marginally acceptable member type;
4232 it needs a warning. */
4236 /* Const and volatile mean something different for function
4237 types, so the usual warnings are not appropriate. */
4240 {
4241 /* Because const and volatile on functions are
4242 restrictions that say the function will not do
4243 certain things, it is okay to use a const or volatile
4244 function where an ordinary one is wanted, but not
4245 vice-versa. */
4249 }
4253 parmnum);
4254 }
4260 }
4261 }
4263 /* Conversions among pointers */
4266 {
4270 /* Any non-function converts to a [const][volatile] void *
4271 and vice versa; otherwise, targets must be the same.
4272 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
4277 {
4280 ||
4282 /* Check TREE_CODE to catch cases like (void *) (char *) 0
4283 which are not ANSI null ptr constants. */
4288 /* Const and volatile mean something different for function types,
4289 so the usual warnings are not appropriate. */
4292 {
4296 /* If this is not a case of ignoring a mismatch in signedness,
4297 no warning. */
4300 ;
4301 /* If there is a mismatch, do warn. */
4305 }
4308 {
4309 /* Because const and volatile on functions are restrictions
4310 that say the function will not do certain things,
4311 it is okay to use a const or volatile function
4312 where an ordinary one is wanted, but not vice-versa. */
4316 }
4317 }
4318 else
4322 }
4324 {
4325 /* An explicit constant 0 can convert to a pointer,
4326 or one that results from arithmetic, even including
4327 a cast to integer type. */
4329 &&
4334 {
4338 }
4340 }
4342 {
4346 }
4351 {
4353 {
4359 else
4362 }
4363 else
4365 parmnum);
4366 }
4367 else
4371 }
4373 /* Print a warning using MSGID.
4374 It gets OPNAME as its one parameter.
4375 If OPNAME is null, it is replaced by "passing arg ARGNUM of `FUNCTION'".
4376 FUNCTION and ARGNUM are handled specially if we are building an
4377 Objective-C selector. */
4379 static void
4383 tree function;
4385 {
4387 {
4392 {
4395 }
4397 {
4398 /* Function name is known; supply it. */
4405 }
4406 else
4407 {
4408 /* Function name unknown (call through ptr); just give arg number. */
4412 }
4414 }
4416 }
4417 \f
4418 /* If VALUE is a compound expr all of whose expressions are constant, then
4419 return its value. Otherwise, return error_mark_node.
4421 This is for handling COMPOUND_EXPRs as initializer elements
4422 which is allowed with a warning when -pedantic is specified. */
4424 static tree
4426 tree value;
4427 tree endtype;
4428 {
4430 {
4435 endtype);
4436 }
4440 else
4442 }
4443 \f
4444 /* Perform appropriate conversions on the initial value of a variable,
4445 store it in the declaration DECL,
4446 and print any error messages that are appropriate.
4447 If the init is invalid, store an ERROR_MARK. */
4449 void
4452 {
4455 /* If variable's type was invalidly declared, just ignore it. */
4461 /* Digest the specified initializer into an expression. */
4466 /* Store the expression if valid; else report error. */
4468 #if 0
4469 /* Note that this is the only place we can detect the error
4470 in a case such as struct foo bar = (struct foo) { x, y };
4471 where there is one initial value which is a constructor expression. */
4473 ;
4475 {
4478 }
4481 {
4484 }
4485 else
4486 {
4488 {
4493 }
4494 }
4495 #endif
4503 /* ANSI wants warnings about out-of-range constant initializers. */
4507 /* Check if we need to set array size from compound literal size. */
4511 {
4519 {
4523 {
4524 /* For int foo[] = (int [3]){1}; we need to set array size
4525 now since later on array initializer will be just the
4526 brace enclosed list of the compound literal. */
4530 }
4531 }
4532 }
4533 }
4534 \f
4535 /* Methods for storing and printing names for error messages. */
4537 /* Implement a spelling stack that allows components of a name to be pushed
4538 and popped. Each element on the stack is this structure. */
4540 struct spelling
4541 {
4543 union
4544 {
4548 };
4550 #define SPELLING_STRING 1
4551 #define SPELLING_MEMBER 2
4552 #define SPELLING_BOUNDS 3
4558 /* Macros to save and restore the spelling stack around push_... functions.
4559 Alternative to SAVE_SPELLING_STACK. */
4561 #define SPELLING_DEPTH() (spelling - spelling_base)
4562 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
4564 /* Save and restore the spelling stack around arbitrary C code. */
4566 #define SAVE_SPELLING_DEPTH(code) \
4567 { \
4568 int __depth = SPELLING_DEPTH (); \
4569 code; \
4570 RESTORE_SPELLING_DEPTH (__depth); \
4571 }
4573 /* Push an element on the spelling stack with type KIND and assign VALUE
4574 to MEMBER. */
4576 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
4577 { \
4578 int depth = SPELLING_DEPTH (); \
4579 \
4580 if (depth >= spelling_size) \
4581 { \
4582 spelling_size += 10; \
4583 if (spelling_base == 0) \
4584 spelling_base \
4585 = (struct spelling *) xmalloc (spelling_size * sizeof (struct spelling)); \
4586 else \
4587 spelling_base \
4588 = (struct spelling *) xrealloc (spelling_base, \
4589 spelling_size * sizeof (struct spelling)); \
4590 RESTORE_SPELLING_DEPTH (depth); \
4591 } \
4592 \
4593 spelling->kind = (KIND); \
4594 spelling->MEMBER = (VALUE); \
4595 spelling++; \
4596 }
4598 /* Push STRING on the stack. Printed literally. */
4600 static void
4603 {
4605 }
4607 /* Push a member name on the stack. Printed as '.' STRING. */
4609 static void
4611 tree decl;
4613 {
4617 }
4619 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
4621 static void
4624 {
4626 }
4628 /* Compute the maximum size in bytes of the printed spelling. */
4630 static int
4632 {
4637 {
4640 else
4642 }
4645 }
4647 /* Print the spelling to BUFFER and return it. */
4652 {
4658 {
4661 }
4662 else
4663 {
4668 ;
4669 }
4672 }
4674 /* Issue an error message for a bad initializer component.
4675 MSGID identifies the message.
4676 The component name is taken from the spelling stack. */
4678 void
4681 {
4688 }
4690 /* Issue a pedantic warning for a bad initializer component.
4691 MSGID identifies the message.
4692 The component name is taken from the spelling stack. */
4694 void
4697 {
4704 }
4706 /* Issue a warning for a bad initializer component.
4707 MSGID identifies the message.
4708 The component name is taken from the spelling stack. */
4710 static void
4713 {
4720 }
4721 \f
4722 /* Digest the parser output INIT as an initializer for type TYPE.
4723 Return a C expression of type TYPE to represent the initial value.
4725 The arguments REQUIRE_CONSTANT and CONSTRUCTOR_CONSTANT request errors
4726 if non-constant initializers or elements are seen. CONSTRUCTOR_CONSTANT
4727 applies only to elements of constructors. */
4729 static tree
4733 {
4742 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
4743 /* Do not use STRIP_NOPS here. We do not want an enumerator
4744 whose value is 0 to count as a null pointer constant. */
4750 /* Initialization of an array of chars from a string constant
4751 optionally enclosed in braces. */
4754 {
4762 {
4770 {
4773 }
4777 {
4780 }
4786 /* Subtract 1 (or sizeof (wchar_t))
4787 because it's ok to ignore the terminating null char
4788 that is counted in the length of the constant. */
4799 }
4800 }
4802 /* Any type can be initialized
4803 from an expression of the same type, optionally with braces. */
4817 {
4823 {
4824 /* As an extension, allow initializing objects with static storage
4825 duration with compound literals (which are then treated just as
4826 the brace enclosed list they contain). */
4829 }
4833 {
4836 }
4841 /* Compound expressions can only occur here if -pedantic or
4842 -pedantic-errors is specified. In the later case, we always want
4843 an error. In the former case, we simply want a warning. */
4846 {
4847 inside_init
4852 else
4856 }
4859 /* This test catches things like `7 / 0' which
4860 result in an expression for which TREE_CONSTANT
4861 is true, but which is not actually something
4862 that is a legal constant. We really should not
4863 be using this function, because it is a part of
4864 the back-end. Instead, the expression should
4865 already have been turned into ERROR_MARK_NODE. */
4868 {
4871 }
4874 }
4876 /* Handle scalar types, including conversions. */
4880 {
4881 /* Note that convert_for_assignment calls default_conversion
4882 for arrays and functions. We must not call it in the
4883 case where inside_init is a null pointer constant. */
4884 inside_init
4889 {
4892 }
4895 {
4898 }
4901 }
4903 /* Come here only for records and arrays. */
4906 {
4909 }
4911 /* Traditionally, you can write struct foo x = 0;
4912 and it initializes the first element of x to 0. */
4914 {
4920 {
4924 else
4931 else
4932 {
4935 }
4936 }
4939 {
4943 constructor_constant));
4945 }
4946 else
4948 }
4951 }
4952 \f
4953 /* Handle initializers that use braces. */
4955 /* Type of object we are accumulating a constructor for.
4956 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4959 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4960 left to fill. */
4963 /* For an ARRAY_TYPE, this is the specified index
4964 at which to store the next element we get. */
4967 /* For an ARRAY_TYPE, this is the maximum index. */
4970 /* For a RECORD_TYPE, this is the first field not yet written out. */
4973 /* For an ARRAY_TYPE, this is the index of the first element
4974 not yet written out. */
4977 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4978 This is so we can generate gaps between fields, when appropriate. */
4981 /* If we are saving up the elements rather than allocating them,
4982 this is the list of elements so far (in reverse order,
4983 most recent first). */
4986 /* 1 if constructor should be incrementally stored into a constructor chain,
4987 0 if all the elements should be kept in AVL tree. */
4990 /* 1 if so far this constructor's elements are all compile-time constants. */
4993 /* 1 if so far this constructor's elements are all valid address constants. */
4996 /* 1 if this constructor is erroneous so far. */
4999 /* 1 if have called defer_addressed_constants. */
5002 /* Structure for managing pending initializer elements, organized as an
5003 AVL tree. */
5005 struct init_node
5006 {
5010 tree purpose;
5011 tree value;
5012 };
5014 /* Tree of pending elements at this constructor level.
5015 These are elements encountered out of order
5016 which belong at places we haven't reached yet in actually
5017 writing the output.
5018 Will never hold tree nodes across GC runs. */
5021 /* The SPELLING_DEPTH of this constructor. */
5024 /* 0 if implicitly pushing constructor levels is allowed. */
5030 /* DECL node for which an initializer is being read.
5031 0 means we are reading a constructor expression
5032 such as (struct foo) {...}. */
5035 /* start_init saves the ASMSPEC arg here for really_start_incremental_init. */
5038 /* Nonzero if this is an initializer for a top-level decl. */
5041 /* Nonzero if there were any member designators in this initializer. */
5044 /* Nesting depth of designator list. */
5047 /* Nonzero if there were diagnosed errors in this designator list. */
5050 \f
5051 /* This stack has a level for each implicit or explicit level of
5052 structuring in the initializer, including the outermost one. It
5053 saves the values of most of the variables above. */
5057 struct constructor_stack
5058 {
5060 tree type;
5061 tree fields;
5062 tree index;
5063 tree max_index;
5064 tree unfilled_index;
5065 tree unfilled_fields;
5066 tree bit_index;
5067 tree elements;
5071 /* If nonzero, this value should replace the entire
5072 constructor at this level. */
5073 tree replacement_value;
5082 };
5086 /* This stack represents designators from some range designator up to
5087 the last designator in the list. */
5089 struct constructor_range_stack
5090 {
5093 tree range_start;
5094 tree index;
5095 tree range_end;
5096 tree fields;
5097 };
5101 /* This stack records separate initializers that are nested.
5102 Nested initializers can't happen in ANSI C, but GNU C allows them
5103 in cases like { ... (struct foo) { ... } ... }. */
5105 struct initializer_stack
5106 {
5108 tree decl;
5112 tree elements;
5120 };
5123 \f
5124 /* Prepare to parse and output the initializer for variable DECL. */
5126 void
5128 tree decl;
5129 tree asmspec_tree;
5131 {
5162 {
5164 require_constant_elements
5166 /* For a scalar, you can always use any value to initialize,
5167 even within braces. */
5173 }
5174 else
5175 {
5179 }
5192 }
5194 void
5196 {
5199 /* Output subconstants (string constants, usually)
5200 that were referenced within this initializer and saved up.
5201 Must do this if and only if we called defer_addressed_constants. */
5205 /* Free the whole constructor stack of this initializer. */
5207 {
5211 }
5216 /* Pop back to the data of the outer initializer (if any). */
5231 }
5232 \f
5233 /* Call here when we see the initializer is surrounded by braces.
5234 This is instead of a call to push_init_level;
5235 it is matched by a call to pop_init_level.
5237 TYPE is the type to initialize, for a constructor expression.
5238 For an initializer for a decl, TYPE is zero. */
5240 void
5242 tree type;
5243 {
5285 {
5287 /* Skip any nameless bit fields at the beginning. */
5294 }
5296 {
5298 {
5299 constructor_max_index
5302 /* Detect non-empty initializations of zero-length arrays. */
5307 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5308 to initialize VLAs will cause an proper error; avoid tree
5309 checking errors as well by setting a safe value. */
5314 constructor_index
5317 }
5318 else
5322 }
5324 {
5325 /* Vectors are like simple fixed-size arrays. */
5326 constructor_max_index =
5330 }
5331 else
5332 {
5333 /* Handle the case of int x = {5}; */
5336 }
5337 }
5338 \f
5339 /* Push down into a subobject, for initialization.
5340 If this is for an explicit set of braces, IMPLICIT is 0.
5341 If it is because the next element belongs at a lower level,
5342 IMPLICIT is 1 (or 2 if the push is because of designator list). */
5344 void
5347 {
5351 /* If we've exhausted any levels that didn't have braces,
5352 pop them now. */
5354 {
5362 else
5364 }
5366 /* Unless this is an explicit brace, we need to preserve previous
5367 content if any. */
5369 {
5376 }
5409 {
5414 }
5416 /* Don't die if an entire brace-pair level is superfluous
5417 in the containing level. */
5419 ;
5422 {
5423 /* Don't die if there are extra init elts at the end. */
5426 else
5427 {
5430 constructor_depth++;
5431 }
5432 }
5434 {
5437 constructor_depth++;
5438 }
5441 {
5446 }
5449 {
5457 }
5460 {
5463 }
5467 {
5469 /* Skip any nameless bit fields at the beginning. */
5476 }
5478 {
5480 {
5481 constructor_max_index
5484 /* Detect non-empty initializations of zero-length arrays. */
5489 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5490 to initialize VLAs will cause an proper error; avoid tree
5491 checking errors as well by setting a safe value. */
5496 constructor_index
5499 }
5500 else
5505 {
5506 /* We need to split the char/wchar array into individual
5507 characters, so that we don't have to special case it
5508 everywhere. */
5510 }
5511 }
5512 else
5513 {
5517 }
5518 }
5520 /* At the end of an implicit or explicit brace level,
5521 finish up that level of constructor.
5522 If we were outputting the elements as they are read, return 0
5523 from inner levels (process_init_element ignores that),
5524 but return error_mark_node from the outermost level
5525 (that's what we want to put in DECL_INITIAL).
5526 Otherwise, return a CONSTRUCTOR expression. */
5528 tree
5531 {
5536 {
5537 /* When we come to an explicit close brace,
5538 pop any inner levels that didn't have explicit braces. */
5544 }
5548 /* Error for initializing a flexible array member, or a zero-length
5549 array member in an inappropriate context. */
5554 {
5555 /* Silently discard empty initializations. The parser will
5556 already have pedwarned for empty brackets. */
5560 {
5566 /* We have already issued an error message for the existence
5567 of a flexible array member not at the end of the structure.
5568 Discard the initializer so that we do not abort later. */
5571 }
5572 else
5573 /* Zero-length arrays are no longer special, so we should no longer
5574 get here. */
5576 }
5578 /* Warn when some struct elements are implicitly initialized to zero. */
5580 && constructor_type
5583 {
5584 /* Do not warn for flexible array members or zero-length arrays. */
5590 /* Do not warn if this level of the initializer uses member
5591 designators; it is likely to be deliberate. */
5593 {
5597 }
5598 }
5600 /* Now output all pending elements. */
5604 /* Pad out the end of the structure. */
5606 /* If this closes a superfluous brace pair,
5607 just pass out the element between them. */
5610 ;
5615 {
5616 /* A nonincremental scalar initializer--just return
5617 the element, after verifying there is just one. */
5619 {
5623 }
5625 {
5628 }
5629 else
5631 }
5632 else
5633 {
5636 else
5637 {
5644 }
5645 }
5670 {
5674 }
5676 }
5678 /* Common handling for both array range and field name designators.
5679 ARRAY argument is non-zero for array ranges. Returns zero for success. */
5681 static int
5684 {
5685 tree subtype;
5688 /* Don't die if an entire brace-pair level is superfluous
5689 in the containing level. */
5693 /* If there were errors in this designator list already, bail out silently. */
5698 {
5702 /* Designator list starts at the level of closest explicit
5703 braces. */
5708 }
5711 {
5714 }
5718 {
5722 }
5724 {
5726 }
5727 else
5732 {
5735 }
5737 {
5740 }
5745 }
5747 /* If there are range designators in designator list, push a new designator
5748 to constructor_range_stack. RANGE_END is end of such stack range or
5749 NULL_TREE if there is no range designator at this level. */
5751 static void
5753 tree range_end;
5754 {
5769 }
5771 /* Within an array initializer, specify the next index to be initialized.
5772 FIRST is that index. If LAST is nonzero, then initialize a range
5773 of indices, running from FIRST through LAST. */
5775 void
5778 {
5808 else
5809 {
5813 {
5817 {
5820 }
5821 else
5822 {
5826 {
5829 }
5830 }
5831 }
5833 designator_depth++;
5837 }
5838 }
5840 /* Within a struct initializer, specify the next field to be initialized. */
5842 void
5844 tree fieldname;
5845 {
5846 tree tail;
5855 {
5858 }
5862 {
5865 }
5870 else
5871 {
5873 designator_depth++;
5877 }
5878 }
5879 \f
5880 /* Add a new initializer to the tree of pending initializers. PURPOSE
5881 identifies the initializer, either array index or field in a structure.
5882 VALUE is the value of that index or field. */
5884 static void
5887 {
5894 {
5896 {
5902 else
5903 {
5908 }
5909 }
5910 }
5911 else
5912 {
5913 tree bitpos;
5917 {
5923 else
5924 {
5929 }
5930 }
5931 }
5944 {
5948 {
5952 {
5954 {
5955 /* L rotation. */
5968 {
5971 else
5973 }
5974 else
5976 }
5977 else
5978 {
5979 /* LR rotation. */
6001 {
6004 else
6006 }
6007 else
6009 }
6011 }
6012 else
6013 {
6014 /* p->balance == +1; growth of left side balances the node. */
6017 }
6018 }
6020 {
6022 /* Growth propagation from right side. */
6025 {
6027 {
6028 /* R rotation. */
6041 {
6044 else
6046 }
6047 else
6049 }
6051 {
6052 /* RL rotation */
6074 {
6077 else
6079 }
6080 else
6082 }
6084 }
6085 else
6086 {
6087 /* p->balance == -1; growth of right side balances the node. */
6090 }
6091 }
6095 }
6096 }
6098 /* Build AVL tree from a sorted chain. */
6100 static void
6102 {
6103 tree chain;
6113 {
6115 /* Skip any nameless bit fields at the beginning. */
6121 }
6123 {
6125 constructor_unfilled_index
6128 else
6130 }
6132 }
6134 /* Build AVL tree from a string constant. */
6136 static void
6138 tree str;
6139 {
6154 else
6165 {
6167 {
6170 }
6171 else
6172 {
6176 {
6179 else
6184 }
6185 }
6188 {
6191 {
6193 {
6196 }
6197 }
6199 {
6202 }
6207 }
6212 }
6215 }
6217 /* Return value of FIELD in pending initializer or zero if the field was
6218 not initialized yet. */
6220 static tree
6222 tree field;
6223 {
6227 {
6234 {
6239 else
6241 }
6242 }
6244 {
6248 && (!constructor_unfilled_fields
6255 {
6260 else
6262 }
6263 }
6265 {
6269 }
6271 }
6273 /* "Output" the next constructor element.
6274 At top level, really output it to assembler code now.
6275 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
6276 TYPE is the data type that the containing data type wants here.
6277 FIELD is the field (a FIELD_DECL) or the index that this element fills.
6279 PENDING if non-nil means output pending elements that belong
6280 right after this element. (PENDING is normally 1;
6281 it is 0 while outputting pending elements, to avoid recursion.) */
6283 static void
6287 {
6299 {
6300 /* As an extension, allow initializing objects with static storage
6301 duration with compound literals (which are then treated just as
6302 the brace enclosed list they contain). */
6305 }
6319 {
6322 }
6327 /* If this field is empty (and not at the end of structure),
6328 don't do anything other than checking the initializer. */
6338 require_constant_elements);
6340 {
6343 }
6345 /* If this element doesn't come next in sequence,
6346 put it on constructor_pending_elts. */
6348 && (!constructor_incremental
6350 {
6357 }
6359 && (!constructor_incremental
6361 {
6362 /* We do this for records but not for unions. In a union,
6363 no matter which field is specified, it can be initialized
6364 right away since it starts at the beginning of the union. */
6366 {
6369 else
6370 {
6378 }
6379 }
6383 }
6386 {
6390 /* We can have just one union field set. */
6392 }
6394 /* Otherwise, output this element either to
6395 constructor_elements or to the assembler file. */
6399 constructor_elements
6402 /* Advance the variable that indicates sequential elements output. */
6404 constructor_unfilled_index
6406 bitsize_one_node);
6408 {
6409 constructor_unfilled_fields
6412 /* Skip any nameless bit fields. */
6416 constructor_unfilled_fields =
6418 }
6422 /* Now output any pending elements which have become next. */
6425 }
6427 /* Output any pending elements which have become next.
6428 As we output elements, constructor_unfilled_{fields,index}
6429 advances, which may cause other elements to become next;
6430 if so, they too are output.
6432 If ALL is 0, we return when there are
6433 no more pending elements to output now.
6435 If ALL is 1, we output space as necessary so that
6436 we can output all the pending elements. */
6438 static void
6441 {
6443 tree next;
6445 retry:
6447 /* Look thru the whole pending tree.
6448 If we find an element that should be output now,
6449 output it. Otherwise, set NEXT to the element
6450 that comes first among those still pending. */
6454 {
6456 {
6458 constructor_unfilled_index))
6464 {
6465 /* Advance to the next smaller node. */
6468 else
6469 {
6470 /* We have reached the smallest node bigger than the
6471 current unfilled index. Fill the space first. */
6474 }
6475 }
6476 else
6477 {
6478 /* Advance to the next bigger node. */
6481 else
6482 {
6483 /* We have reached the biggest node in a subtree. Find
6484 the parent of it, which is the next bigger node. */
6490 {
6493 }
6494 }
6495 }
6496 }
6499 {
6502 /* If the current record is complete we are done. */
6508 /* We can't compare fields here because there might be empty
6509 fields in between. */
6511 {
6515 }
6517 {
6518 /* Advance to the next smaller node. */
6521 else
6522 {
6523 /* We have reached the smallest node bigger than the
6524 current unfilled field. Fill the space first. */
6527 }
6528 }
6529 else
6530 {
6531 /* Advance to the next bigger node. */
6534 else
6535 {
6536 /* We have reached the biggest node in a subtree. Find
6537 the parent of it, which is the next bigger node. */
6544 {
6547 }
6548 }
6549 }
6550 }
6551 }
6553 /* Ordinarily return, but not if we want to output all
6554 and there are elements left. */
6558 /* If it's not incremental, just skip over the gap, so that after
6559 jumping to retry we will output the next successive element. */
6566 /* ELT now points to the node in the pending tree with the next
6567 initializer to output. */
6569 }
6570 \f
6571 /* Add one non-braced element to the current constructor level.
6572 This adjusts the current position within the constructor's type.
6573 This may also start or terminate implicit levels
6574 to handle a partly-braced initializer.
6576 Once this has found the correct level for the new element,
6577 it calls output_init_element. */
6579 void
6581 tree value;
6582 {
6589 /* Handle superfluous braces around string cst as in
6590 char x[] = {"foo"}; */
6592 && constructor_type
6596 {
6601 }
6604 {
6607 }
6609 /* Ignore elements of a brace group if it is entirely superfluous
6610 and has already been diagnosed. */
6614 /* If we've exhausted any levels that didn't have braces,
6615 pop them now. */
6617 {
6625 constructor_index)))
6627 else
6629 }
6631 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
6633 {
6634 /* If value is a compound literal and we'll be just using its
6635 content, don't put it into a SAVE_EXPR. */
6637 || !require_constant_value
6640 }
6643 {
6645 {
6646 tree fieldtype;
6650 {
6653 }
6660 /* Accept a string constant to initialize a subarray. */
6666 /* Otherwise, if we have come to a subaggregate,
6667 and we don't have an element of its type, push into it. */
6673 {
6676 }
6679 {
6683 }
6684 else
6685 /* Do the bookkeeping for an element that was
6686 directly output as a constructor. */
6687 {
6688 /* For a record, keep track of end position of last field. */
6690 constructor_bit_index
6696 /* Skip any nameless bit fields. */
6700 constructor_unfilled_fields =
6702 }
6705 /* Skip any nameless bit fields at the beginning. */
6710 }
6712 {
6713 tree fieldtype;
6717 {
6720 }
6727 /* Warn that traditional C rejects initialization of unions.
6728 We skip the warning if the value is zero. This is done
6729 under the assumption that the zero initializer in user
6730 code appears conditioned on e.g. __STDC__ to avoid
6731 "missing initializer" warnings and relies on default
6732 initialization to zero in the traditional C case.
6733 We also skip the warning if the initializer is designated,
6734 again on the assumption that this must be conditional on
6735 __STDC__ anyway (and we've already complained about the
6736 member-designator already). */
6741 /* Accept a string constant to initialize a subarray. */
6747 /* Otherwise, if we have come to a subaggregate,
6748 and we don't have an element of its type, push into it. */
6754 {
6757 }
6760 {
6764 }
6765 else
6766 /* Do the bookkeeping for an element that was
6767 directly output as a constructor. */
6768 {
6771 }
6774 }
6776 {
6780 /* Accept a string constant to initialize a subarray. */
6786 /* Otherwise, if we have come to a subaggregate,
6787 and we don't have an element of its type, push into it. */
6793 {
6796 }
6801 {
6804 }
6806 /* Now output the actual element. */
6808 {
6812 }
6814 constructor_index
6818 /* If we are doing the bookkeeping for an element that was
6819 directly output as a constructor, we must update
6820 constructor_unfilled_index. */
6822 }
6824 {
6827 /* Do a basic check of initializer size. Note that vectors
6828 always have a fixed size derived from their type. */
6830 {
6833 }
6835 /* Now output the actual element. */
6839 constructor_index
6843 /* If we are doing the bookkeeping for an element that was
6844 directly output as a constructor, we must update
6845 constructor_unfilled_index. */
6847 }
6849 /* Handle the sole element allowed in a braced initializer
6850 for a scalar variable. */
6852 {
6855 }
6856 else
6857 {
6861 }
6863 /* Handle range initializers either at this level or anywhere higher
6864 in the designator stack. */
6866 {
6873 {
6877 }
6881 {
6885 }
6892 {
6896 {
6899 }
6907 }
6912 }
6915 }
6918 }
6919 \f
6920 /* Build a simple asm-statement, from one string literal. */
6921 tree
6923 tree expr;
6924 {
6931 {
6932 tree stmt;
6938 NULL_TREE));
6941 }
6945 }
6947 /* Build an asm-statement, whose components are a CV_QUALIFIER, a
6948 STRING, some OUTPUTS, some INPUTS, and some CLOBBERS. */
6950 tree
6952 tree cv_qualifier;
6953 tree string;
6954 tree outputs;
6955 tree inputs;
6956 tree clobbers;
6957 {
6958 tree tail;
6963 {
6966 }
6970 {
6974 }
6976 /* We can remove output conversions that change the type,
6977 but not the mode. */
6979 {
6985 /* Allow conversions as LHS here. build_modify_expr as called below
6986 will do the right thing with them. */
6997 }
6999 /* Remove output conversions that change the type but not the mode. */
7001 {
7005 }
7007 /* Perform default conversions on array and function inputs.
7008 Don't do this for other types as it would screw up operands
7009 expected to be in memory. */
7015 }
7017 /* Expand an ASM statement with operands, handling output operands
7018 that are not variables or INDIRECT_REFS by transforming such
7019 cases into cases that expand_asm_operands can handle.
7021 Arguments are same as for expand_asm_operands. */
7023 void
7029 {
7032 /* o[I] is the place that output number I should be written. */
7034 tree tail;
7036 /* Record the contents of OUTPUTS before it is modified. */
7040 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
7041 OUTPUTS some trees for where the values were actually stored. */
7044 /* Copy all the intermediate outputs into the specified outputs. */
7046 {
7048 {
7053 /* Restore the original value so that it's correct the next
7054 time we expand this function. */
7056 }
7057 /* Detect modification of read-only values.
7058 (Otherwise done by build_modify_expr.) */
7059 else
7060 {
7068 }
7069 }
7071 /* Those MODIFY_EXPRs could do autoincrements. */
7073 }
7074 \f
7075 /* Expand a C `return' statement.
7076 RETVAL is the expression for what to return,
7077 or a null pointer for `return;' with no value. */
7079 tree
7081 tree retval;
7082 {
7089 {
7094 }
7096 {
7100 }
7101 else
7102 {
7106 tree inner;
7114 /* Strip any conversions, additions, and subtractions, and see if
7115 we are returning the address of a local variable. Warn if so. */
7117 {
7119 {
7126 /* If the second operand of the MINUS_EXPR has a pointer
7127 type (or is converted from it), this may be valid, so
7128 don't give a warning. */
7129 {
7143 }
7160 }
7163 }
7166 }
7169 }
7170 \f
7172 /* The SWITCH_STMT being built. */
7173 tree switch_stmt;
7174 /* A splay-tree mapping the low element of a case range to the high
7175 element, or NULL_TREE if there is no high element. Used to
7176 determine whether or not a new case label duplicates an old case
7177 label. We need a tree, rather than simply a hash table, because
7178 of the GNU case range extension. */
7179 splay_tree cases;
7180 /* The next node on the stack. */
7182 };
7184 /* A stack of the currently active switch statements. The innermost
7185 switch statement is on the top of the stack. There is no need to
7186 mark the stack for garbage collection because it is only active
7187 during the processing of the body of a function, and we never
7188 collect at that point. */
7192 /* Start a C switch statement, testing expression EXP. Return the new
7193 SWITCH_STMT. */
7195 tree
7197 tree exp;
7198 {
7204 {
7210 {
7213 }
7214 else
7215 {
7225 }
7226 }
7228 /* Add this new SWITCH_STMT to the stack. */
7236 }
7238 /* Process a case label. */
7240 tree
7242 tree low_value;
7243 tree high_value;
7244 {
7248 {
7254 }
7257 else
7261 }
7263 /* Finish the switch statement. */
7265 void
7267 {
7272 /* Pop the stack. */
7276 }