| blob | 52105ac84ecef8a6a705bc43bfeec65c5278e51e |
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). */
48 /* Nonzero if we've already printed a "missing braces around initializer"
49 message within this initializer. */
52 /* 1 if we explained undeclared var errors. */
87 \f
88 /* Do `exp = require_complete_type (exp);' to make sure exp
89 does not have an incomplete type. (That includes void types.) */
91 tree
93 tree value;
94 {
100 /* First, detect a valid value with a complete type. */
106 }
108 /* Print an error message for invalid use of an incomplete type.
109 VALUE is the expression that was used (or 0 if that isn't known)
110 and TYPE is the type that was invalid. */
112 void
114 tree value;
115 tree type;
116 {
119 /* Avoid duplicate error message. */
127 else
128 {
129 retry:
130 /* We must print an error message. Be clever about what it says. */
133 {
152 {
154 {
157 }
160 }
166 }
171 else
172 /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */
175 }
176 }
178 /* Given a type, apply default promotions wrt unnamed function
179 arguments and return the new type. */
181 tree
183 tree type;
184 {
189 {
190 /* Preserve unsignedness if not really getting any wider. */
195 }
198 }
200 /* Return a variant of TYPE which has all the type qualifiers of LIKE
201 as well as those of TYPE. */
203 static tree
206 {
209 }
210 \f
211 /* Return the common type of two types.
212 We assume that comptypes has already been done and returned 1;
213 if that isn't so, this may crash. In particular, we assume that qualifiers
214 match.
216 This is the type for the result of most arithmetic operations
217 if the operands have the given two types. */
219 tree
222 {
225 tree attributes;
227 /* Save time if the two types are the same. */
231 /* If one type is nonsense, use the other. */
237 /* Merge the attributes. */
240 /* Treat an enum type as the unsigned integer type of the same width. */
250 /* If one type is complex, form the common type of the non-complex
251 components, then make that complex. Use T1 or T2 if it is the
252 required type. */
254 {
263 else
265 attributes);
266 }
269 {
272 /* If only one is real, use it as the result. */
280 /* Both real or both integers; use the one with greater precision. */
287 /* Same precision. Prefer longs to ints even when same size. */
292 attributes);
296 {
297 /* But preserve unsignedness from the other type,
298 since long cannot hold all the values of an unsigned int. */
301 else
304 }
306 /* Likewise, prefer long double to double even if same size. */
310 attributes);
312 /* Otherwise prefer the unsigned one. */
316 else
320 /* For two pointers, do this recursively on the target type,
321 and combine the qualifiers of the two types' targets. */
322 /* This code was turned off; I don't know why.
323 But ANSI C specifies doing this with the qualifiers.
324 So I turned it on again. */
325 {
335 }
336 #if 0
339 #endif
342 {
344 /* Save space: see if the result is identical to one of the args. */
349 /* Merge the element types, and have a size if either arg has one. */
352 }
355 /* Function types: prefer the one that specified arg types.
356 If both do, merge the arg types. Also merge the return types. */
357 {
365 /* Save space: see if the result is identical to one of the args. */
371 /* Simple way if one arg fails to specify argument types. */
373 {
376 }
378 {
381 }
383 /* If both args specify argument types, we must merge the two
384 lists, argument by argument. */
399 {
400 /* A null type means arg type is not specified.
401 Take whatever the other function type has. */
403 {
406 }
408 {
411 }
413 /* Given wait (union {union wait *u; int *i} *)
414 and wait (union wait *),
415 prefer union wait * as type of parm. */
418 {
419 tree memb;
423 {
428 }
429 }
432 {
433 tree memb;
437 {
442 }
443 }
445 parm_done: ;
446 }
451 /* ... falls through ... */
452 }
456 }
458 }
459 \f
460 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
461 or various other operations. Return 2 if they are compatible
462 but a warning may be needed if you use them together. */
464 int
467 {
472 /* Suppress errors caused by previously reported errors. */
478 /* If either type is the internal version of sizetype, return the
479 language version. */
488 /* Treat an enum type as the integer type of the same width and
489 signedness. */
499 /* Different classes of types can't be compatible. */
503 /* Qualifiers must match. */
508 /* Allow for two different type nodes which have essentially the same
509 definition. Note that we already checked for equality of the type
510 qualifiers (just above). */
515 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
519 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
523 {
534 {
541 /* Target types must match incl. qualifiers. */
546 /* Sizes must match unless one is missing or variable. */
553 d1_variable = (! d1_zero
556 d2_variable = (! d2_zero
570 }
578 /* The target might allow certain vector types to be compatible. */
585 }
587 }
589 /* Return 1 if TTL and TTR are pointers to types that are equivalent,
590 ignoring their qualifiers. REFLEXIVE is only used by ObjC - set it
591 to 1 or 0 depending if the check of the pointer types is meant to
592 be reflexive or not (typically, assignments are not reflexive,
593 while comparisons are reflexive).
594 */
596 static int
600 {
603 /* Give objc_comptypes a crack at letting these types through. */
613 }
614 \f
615 /* Subroutines of `comptypes'. */
617 /* Return 1 if two function types F1 and F2 are compatible.
618 If either type specifies no argument types,
619 the other must specify a fixed number of self-promoting arg types.
620 Otherwise, if one type specifies only the number of arguments,
621 the other must specify that number of self-promoting arg types.
622 Otherwise, the argument types must match. */
624 static int
627 {
629 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
640 /* An unspecified parmlist matches any specified parmlist
641 whose argument types don't need default promotions. */
644 {
647 /* If one of these types comes from a non-prototype fn definition,
648 compare that with the other type's arglist.
649 If they don't match, ask for a warning (but no error). */
654 }
656 {
663 }
665 /* Both types have argument lists: compare them and propagate results. */
668 }
670 /* Check two lists of types for compatibility,
671 returning 0 for incompatible, 1 for compatible,
672 or 2 for compatible with warning. */
674 static int
677 {
678 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
683 {
686 /* If one list is shorter than the other,
687 they fail to match. */
690 /* A null pointer instead of a type
691 means there is supposed to be an argument
692 but nothing is specified about what type it has.
693 So match anything that self-promotes. */
695 {
698 }
700 {
703 }
706 {
707 /* Allow wait (union {union wait *u; int *i} *)
708 and wait (union wait *) to be compatible. */
715 {
716 tree memb;
723 }
730 {
731 tree memb;
738 }
739 else
741 }
743 /* comptypes said ok, but record if it said to warn. */
749 }
750 }
751 \f
752 /* Compute the size to increment a pointer by. */
754 tree
756 tree type;
757 {
764 {
767 }
769 /* Convert in case a char is more than one unit. */
773 }
774 \f
775 /* Return either DECL or its known constant value (if it has one). */
777 tree
779 tree decl;
780 {
782 in a place where a variable is invalid. */
788 /* This is invalid if initial value is not constant.
789 If it has either a function call, a memory reference,
790 or a variable, then re-evaluating it could give different results. */
792 /* Check for cases where this is sub-optimal, even though valid. */
796 }
798 /* Return either DECL or its known constant value (if it has one), but
799 return DECL if pedantic or DECL has mode BLKmode. This is for
800 bug-compatibility with the old behavior of decl_constant_value
801 (before GCC 3.0); every use of this function is a bug and it should
802 be removed before GCC 3.1. It is not appropriate to use pedantic
803 in a way that affects optimization, and BLKmode is probably not the
804 right test for avoiding misoptimizations either. */
806 static tree
808 tree decl;
809 {
812 else
814 }
817 /* Perform the default conversion of arrays and functions to pointers.
818 Return the result of converting EXP. For any other expression, just
819 return EXP. */
821 static tree
823 tree exp;
824 {
825 tree orig_exp;
830 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
831 an lvalue.
833 Do not use STRIP_NOPS here! It will remove conversions from pointer
834 to integer and cause infinite recursion. */
839 {
843 }
845 /* Preserve the original expression code. */
850 {
852 }
854 {
855 tree adr;
857 tree ptrtype;
863 {
866 }
869 restype
880 {
884 }
888 {
889 /* Before C99, non-lvalue arrays do not decay to pointers.
890 Normally, using such an array would be invalid; but it can
891 be used correctly inside sizeof or as a statement expression.
892 Thus, do not give an error here; an error will result later. */
894 }
899 {
900 /* ??? This is not really quite correct
901 in that the type of the operand of ADDR_EXPR
902 is not the target type of the type of the ADDR_EXPR itself.
903 Question is, can this lossage be avoided? */
910 }
911 /* This way is better for a COMPONENT_REF since it can
912 simplify the offset for a component. */
915 }
917 }
919 /* Perform default promotions for C data used in expressions.
920 Arrays and functions are converted to pointers;
921 enumeral types or short or char, to int.
922 In addition, manifest constants symbols are replaced by their values. */
924 tree
926 tree exp;
927 {
928 tree orig_exp;
935 /* Constants can be used directly unless they're not loadable. */
939 /* Replace a nonvolatile const static variable with its value unless
940 it is an array, in which case we must be sure that taking the
941 address of the array produces consistent results. */
943 {
946 }
948 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
949 an lvalue.
951 Do not use STRIP_NOPS here! It will remove conversions from pointer
952 to integer and cause infinite recursion. */
959 /* Preserve the original expression code. */
963 /* Normally convert enums to int,
964 but convert wide enums to something wider. */
966 {
974 }
978 /* If it's thinner than an int, promote it like a
979 c_promoting_integer_type_p, otherwise leave it alone. */
985 {
986 /* Preserve unsignedness if not really getting any wider. */
992 }
995 {
998 }
1000 }
1001 \f
1002 /* Look up COMPONENT in a structure or union DECL.
1004 If the component name is not found, returns NULL_TREE. Otherwise,
1005 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL
1006 stepping down the chain to the component, which is in the last
1007 TREE_VALUE of the list. Normally the list is of length one, but if
1008 the component is embedded within (nested) anonymous structures or
1009 unions, the list steps down the chain to the component. */
1011 static tree
1014 {
1016 tree field;
1018 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers
1019 to the field elements. Use a binary search on this array to quickly
1020 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC
1021 will always be set for structures which have many elements. */
1024 {
1032 {
1037 {
1038 /* Step through all anon unions in linear fashion. */
1040 {
1044 {
1049 }
1050 }
1052 /* Entire record is only anon unions. */
1056 /* Restart the binary search, with new lower bound. */
1058 }
1064 else
1066 }
1072 }
1073 else
1074 {
1076 {
1080 {
1085 }
1089 }
1093 }
1096 }
1098 /* Make an expression to refer to the COMPONENT field of
1099 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */
1101 tree
1104 {
1108 tree ref;
1110 /* If DATUM is a COMPOUND_EXPR, move our reference inside it.
1111 If pedantic ensure that the arguments are not lvalues; otherwise,
1112 if the component is an array, it would wrongly decay to a pointer in
1113 C89 mode.
1114 We cannot do this with a COND_EXPR, because in a conditional expression
1115 the default promotions are applied to both sides, and this would yield
1116 the wrong type of the result; for example, if the components have
1117 type "char". */
1119 {
1121 {
1125 }
1128 }
1130 /* See if there is a field or component with name COMPONENT. */
1133 {
1135 {
1138 }
1143 {
1148 }
1150 /* Chain the COMPONENT_REFs if necessary down to the FIELD.
1151 This might be better solved in future the way the C++ front
1152 end does it - by giving the anonymous entities each a
1153 separate name and type, and then have build_component_ref
1154 recursively call itself. We can't do that here. */
1156 {
1172 }
1175 }
1181 }
1182 \f
1183 /* Given an expression PTR for a pointer, return an expression
1184 for the value pointed to.
1185 ERRORSTRING is the name of the operator to appear in error messages. */
1187 tree
1189 tree ptr;
1191 {
1196 {
1201 else
1202 {
1207 {
1210 }
1214 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
1215 so that we get the proper error message if the result is used
1216 to assign to. Also, &* is supposed to be a no-op.
1217 And ANSI C seems to specify that the type of the result
1218 should be the const type. */
1219 /* A de-reference of a pointer to const is not a const. It is valid
1220 to change it via some other pointer. */
1226 }
1227 }
1231 }
1233 /* This handles expressions of the form "a[i]", which denotes
1234 an array reference.
1236 This is logically equivalent in C to *(a+i), but we may do it differently.
1237 If A is a variable or a member, we generate a primitive ARRAY_REF.
1238 This avoids forcing the array out of registers, and can work on
1239 arrays that are not lvalues (for example, members of structures returned
1240 by functions). */
1242 tree
1245 {
1247 {
1250 }
1258 {
1261 /* Subscripting with type char is likely to lose
1262 on a machine where chars are signed.
1263 So warn on any machine, but optionally.
1264 Don't warn for unsigned char since that type is safe.
1265 Don't warn for signed char because anyone who uses that
1266 must have done so deliberately. */
1271 /* Apply default promotions *after* noticing character types. */
1274 /* Require integer *after* promotion, for sake of enums. */
1276 {
1279 }
1281 /* An array that is indexed by a non-constant
1282 cannot be stored in a register; we must be able to do
1283 address arithmetic on its address.
1284 Likewise an array of elements of variable size. */
1288 {
1291 }
1292 /* An array that is indexed by a constant value which is not within
1293 the array bounds cannot be stored in a register either; because we
1294 would get a crash in store_bit_field/extract_bit_field when trying
1295 to access a non-existent part of the register. */
1299 {
1302 }
1305 {
1313 }
1317 /* Array ref is const/volatile if the array elements are
1318 or if the array is. */
1327 /* This was added by rms on 16 Nov 91.
1328 It fixes vol struct foo *a; a->elts[1]
1329 in an inline function.
1330 Hope it doesn't break something else. */
1333 }
1335 {
1339 /* Do the same warning check as above, but only on the part that's
1340 syntactically the index and only if it is also semantically
1341 the index. */
1347 /* Put the integer in IND to simplify error checking. */
1349 {
1353 }
1360 {
1363 }
1365 {
1368 }
1372 }
1373 }
1374 \f
1375 /* Build an external reference to identifier ID. FUN indicates
1376 whether this will be used for a function call. */
1377 tree
1379 tree id;
1381 {
1382 tree ref;
1390 {
1394 {
1396 /* Ordinary implicit function declaration. */
1398 else
1399 {
1400 /* Implicit declaration of built-in function. Don't
1401 change the built-in declaration, but don't let this
1402 go by silently, either. */
1405 /* only issue this warning once */
1408 }
1409 }
1410 else
1411 {
1412 /* Reference to undeclared variable, including reference to
1413 builtin outside of function-call context. */
1417 else
1418 {
1421 {
1426 {
1430 }
1431 }
1434 }
1436 }
1437 }
1438 else
1439 {
1440 /* Properly declared variable or function reference. */
1444 {
1448 }
1449 else
1451 }
1461 {
1464 }
1467 }
1469 /* Build a function call to function FUNCTION with parameters PARAMS.
1470 PARAMS is a list--a chain of TREE_LIST nodes--in which the
1471 TREE_VALUE of each node is a parameter-expression.
1472 FUNCTION's data type may be a function type or a pointer-to-function. */
1474 tree
1477 {
1479 tree coerced_params;
1482 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
1485 /* Convert anything with function type to a pointer-to-function. */
1487 {
1490 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
1491 (because calling an inline function does not mean the function
1492 needs to be separately compiled). */
1498 }
1499 else
1509 {
1512 }
1517 /* fntype now gets the type of function pointed to. */
1520 /* Convert the parameters to the types declared in the
1521 function prototype, or apply default promotions. */
1523 coerced_params
1526 /* Check that the arguments to the function are valid. */
1530 /* Recognize certain built-in functions so we can make tree-codes
1531 other than CALL_EXPR. We do this when it enables fold-const.c
1532 to do something useful. */
1537 {
1542 }
1552 }
1553 \f
1554 /* Convert the argument expressions in the list VALUES
1555 to the types in the list TYPELIST. The result is a list of converted
1556 argument expressions.
1558 If TYPELIST is exhausted, or when an element has NULL as its type,
1559 perform the default conversions.
1561 PARMLIST is the chain of parm decls for the function being called.
1562 It may be 0, if that info is not available.
1563 It is used only for generating error messages.
1565 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
1567 This is also where warnings about wrong number of args are generated.
1569 Both VALUES and the returned value are chains of TREE_LIST nodes
1570 with the elements of the list in the TREE_VALUE slots of those nodes. */
1572 static tree
1575 {
1580 /* Scan the given expressions and types, producing individual
1581 converted arguments and pushing them on RESULT in reverse order. */
1584 valtail;
1586 {
1591 {
1595 else
1598 }
1600 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
1601 /* Do not use STRIP_NOPS here! We do not want an enumerator with value 0
1602 to convert automatically to a pointer. */
1611 {
1612 /* Formal parm type is specified by a function prototype. */
1613 tree parmval;
1616 {
1619 }
1620 else
1621 {
1622 /* Optionally warn about conversions that
1623 differ from the default conversions. */
1625 {
1630 warn_for_assignment ("%s as integer rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1633 warn_for_assignment ("%s as integer rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1636 warn_for_assignment ("%s as complex rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1639 warn_for_assignment ("%s as floating rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1642 warn_for_assignment ("%s as complex rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1645 warn_for_assignment ("%s as floating rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1646 /* ??? At some point, messages should be written about
1647 conversions between complex types, but that's too messy
1648 to do now. */
1651 {
1652 /* Warn if any argument is passed as `float',
1653 since without a prototype it would be `double'. */
1655 warn_for_assignment ("%s as `float' rather than `double' due to prototype", (char *) 0, name, parmnum + 1);
1656 }
1657 /* Detect integer changing in width or signedness.
1658 These warnings are only activated with
1659 -Wconversion, not with -Wtraditional. */
1662 {
1669 /* No warning if function asks for enum
1670 and the actual arg is that enum type. */
1671 ;
1673 warn_for_assignment ("%s with different width due to prototype", (char *) 0, name, parmnum + 1);
1675 ;
1676 /* Don't complain if the formal parameter type
1677 is an enum, because we can't tell now whether
1678 the value was an enum--even the same enum. */
1680 ;
1683 /* Change in signedness doesn't matter
1684 if a constant value is unaffected. */
1685 ;
1686 /* Likewise for a constant in a NOP_EXPR. */
1690 ;
1695 /* Change in signedness doesn't matter
1696 if an enum value is unaffected. */
1697 ;
1698 #endif
1699 /* If the value is extended from a narrower
1700 unsigned type, it doesn't matter whether we
1701 pass it as signed or unsigned; the value
1702 certainly is the same either way. */
1705 ;
1708 else
1710 }
1711 }
1721 }
1723 }
1727 /* Convert `float' to `double'. */
1729 else
1730 /* Convert `short' and `char' to full-size `int'. */
1735 }
1738 {
1742 else
1744 }
1747 }
1748 \f
1749 /* This is the entry point used by the parser
1750 for binary operators in the input.
1751 In addition to constructing the expression,
1752 we check for operands that were written with other binary operators
1753 in a way that is likely to confuse the user. */
1755 tree
1759 {
1776 /* Check for cases such as x+y<<z which users are likely
1777 to misinterpret. If parens are used, C_EXP_ORIGINAL_CODE
1778 is cleared to prevent these warnings. */
1780 {
1782 {
1786 }
1789 {
1793 }
1796 {
1802 /* Check cases like x|y==z */
1805 }
1808 {
1814 /* Check cases like x^y==z */
1817 }
1820 {
1824 /* Check cases like x&y==z */
1827 }
1828 }
1830 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */
1841 /* Record the code that was specified in the source,
1842 for the sake of warnings about confusing nesting. */
1845 else
1846 {
1848 /* We used to use NOP_EXPR rather than NON_LVALUE_EXPR
1849 so that convert_for_assignment wouldn't strip it.
1850 That way, we got warnings for things like p = (1 - 1).
1851 But it turns out we should not get those warnings. */
1855 }
1858 }
1860 /* Build a binary-operation expression without default conversions.
1861 CODE is the kind of expression to build.
1862 This function differs from `build' in several ways:
1863 the data type of the result is computed and recorded in it,
1864 warnings are generated if arg data types are invalid,
1865 special handling for addition and subtraction of pointers is known,
1866 and some optimization is done (operations on narrow ints
1867 are done in the narrower type when that gives the same result).
1868 Constant folding is also done before the result is returned.
1870 Note that the operands will never have enumeral types, or function
1871 or array types, because either they will have the default conversions
1872 performed or they have both just been converted to some other type in which
1873 the arithmetic is to be done. */
1875 tree
1880 {
1885 /* Expression code to give to the expression when it is built.
1886 Normally this is CODE, which is what the caller asked for,
1887 but in some special cases we change it. */
1890 /* Data type in which the computation is to be performed.
1891 In the simplest cases this is the common type of the arguments. */
1894 /* Nonzero means operands have already been type-converted
1895 in whatever way is necessary.
1896 Zero means they need to be converted to RESULT_TYPE. */
1899 /* Nonzero means create the expression with this type, rather than
1900 RESULT_TYPE. */
1903 /* Nonzero means after finally constructing the expression
1904 convert it to this type. */
1907 /* Nonzero if this is an operation like MIN or MAX which can
1908 safely be computed in short if both args are promoted shorts.
1909 Also implies COMMON.
1910 -1 indicates a bitwise operation; this makes a difference
1911 in the exact conditions for when it is safe to do the operation
1912 in a narrower mode. */
1915 /* Nonzero if this is a comparison operation;
1916 if both args are promoted shorts, compare the original shorts.
1917 Also implies COMMON. */
1920 /* Nonzero if this is a right-shift operation, which can be computed on the
1921 original short and then promoted if the operand is a promoted short. */
1924 /* Nonzero means set RESULT_TYPE to the common type of the args. */
1928 {
1931 }
1932 else
1933 {
1936 }
1941 /* The expression codes of the data types of the arguments tell us
1942 whether the arguments are integers, floating, pointers, etc. */
1946 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
1950 /* If an error was already reported for one of the arguments,
1951 avoid reporting another error. */
1957 {
1959 /* Handle the pointer + int case. */
1964 else
1969 /* Subtraction of two similar pointers.
1970 We must subtract them as integers, then divide by object size. */
1974 /* Handle pointer minus int. Just like pointer plus int. */
1977 else
1990 /* Floating point division by zero is a legitimate way to obtain
1991 infinities and NaNs. */
1999 {
2002 else
2003 /* Although it would be tempting to shorten always here, that
2004 loses on some targets, since the modulo instruction is
2005 undefined if the quotient can't be represented in the
2006 computation mode. We shorten only if unsigned or if
2007 dividing by something we know != -1. */
2012 }
2031 {
2032 /* Although it would be tempting to shorten always here, that loses
2033 on some targets, since the modulo instruction is undefined if the
2034 quotient can't be represented in the computation mode. We shorten
2035 only if unsigned or if dividing by something we know != -1. */
2040 }
2052 {
2053 /* Result of these operations is always an int,
2054 but that does not mean the operands should be
2055 converted to ints! */
2060 }
2063 /* Shift operations: result has same type as first operand;
2064 always convert second operand to int.
2065 Also set SHORT_SHIFT if shifting rightward. */
2069 {
2071 {
2074 else
2075 {
2081 }
2082 }
2084 /* Use the type of the value to be shifted. */
2086 /* Convert the shift-count to an integer, regardless of size
2087 of value being shifted. */
2090 /* Avoid converting op1 to result_type later. */
2092 }
2097 {
2099 {
2105 }
2107 /* Use the type of the value to be shifted. */
2109 /* Convert the shift-count to an integer, regardless of size
2110 of value being shifted. */
2113 /* Avoid converting op1 to result_type later. */
2115 }
2121 {
2123 {
2128 }
2130 /* Use the type of the value to be shifted. */
2132 /* Convert the shift-count to an integer, regardless of size
2133 of value being shifted. */
2136 /* Avoid converting op1 to result_type later. */
2138 }
2145 /* Result of comparison is always int,
2146 but don't convert the args to int! */
2156 {
2159 /* Anything compares with void *. void * compares with anything.
2160 Otherwise, the targets must be compatible
2161 and both must be object or both incomplete. */
2165 {
2166 /* op0 != orig_op0 detects the case of something
2167 whose value is 0 but which isn't a valid null ptr const. */
2171 }
2173 {
2177 }
2178 else
2183 }
2191 {
2194 }
2196 {
2199 }
2208 {
2210 {
2215 }
2216 else
2217 {
2220 }
2221 }
2233 {
2235 {
2243 }
2244 else
2245 {
2248 }
2249 }
2252 {
2256 }
2259 {
2263 }
2265 {
2268 }
2270 {
2273 }
2285 {
2288 }
2294 }
2298 &&
2301 {
2307 /* For certain operations (which identify themselves by shorten != 0)
2308 if both args were extended from the same smaller type,
2309 do the arithmetic in that type and then extend.
2311 shorten !=0 and !=1 indicates a bitwise operation.
2312 For them, this optimization is safe only if
2313 both args are zero-extended or both are sign-extended.
2314 Otherwise, we might change the result.
2315 Eg, (short)-1 | (unsigned short)-1 is (int)-1
2316 but calculated in (unsigned short) it would be (unsigned short)-1. */
2319 {
2323 /* UNS is 1 if the operation to be done is an unsigned one. */
2325 tree type;
2329 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
2330 but it *requires* conversion to FINAL_TYPE. */
2341 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
2343 /* For bitwise operations, signedness of nominal type
2344 does not matter. Consider only how operands were extended. */
2348 /* Note that in all three cases below we refrain from optimizing
2349 an unsigned operation on sign-extended args.
2350 That would not be valid. */
2352 /* Both args variable: if both extended in same way
2353 from same width, do it in that width.
2354 Do it unsigned if args were zero-extended. */
2361 result_type
2362 = c_common_signed_or_unsigned_type
2368 && (type
2377 && (type
2382 }
2384 /* Shifts can be shortened if shifting right. */
2387 {
2397 /* We can shorten only if the shift count is less than the
2398 number of bits in the smaller type size. */
2400 /* We cannot drop an unsigned shift after sign-extension. */
2402 {
2403 /* Do an unsigned shift if the operand was zero-extended. */
2404 result_type
2407 /* Convert value-to-be-shifted to that type. */
2411 }
2412 }
2414 /* Comparison operations are shortened too but differently.
2415 They identify themselves by setting short_compare = 1. */
2418 {
2419 /* Don't write &op0, etc., because that would prevent op0
2420 from being kept in a register.
2421 Instead, make copies of the our local variables and
2422 pass the copies by reference, then copy them back afterward. */
2425 tree val
2437 {
2449 /* Give warnings for comparisons between signed and unsigned
2450 quantities that may fail.
2452 Do the checking based on the original operand trees, so that
2453 casts will be considered, but default promotions won't be.
2455 Do not warn if the comparison is being done in a signed type,
2456 since the signed type will only be chosen if it can represent
2457 all the values of the unsigned type. */
2460 /* Do not warn if both operands are the same signedness. */
2463 else
2464 {
2469 else
2472 /* Do not warn if the signed quantity is an
2473 unsuffixed integer literal (or some static
2474 constant expression involving such literals or a
2475 conditional expression involving such literals)
2476 and it is non-negative. */
2479 /* Do not warn if the comparison is an equality operation,
2480 the unsigned quantity is an integral constant, and it
2481 would fit in the result if the result were signed. */
2484 && int_fits_type_p
2487 /* Do not warn if the unsigned quantity is an enumeration
2488 constant and its maximum value would fit in the result
2489 if the result were signed. */
2492 && int_fits_type_p
2496 else
2498 }
2500 /* Warn if two unsigned values are being compared in a size
2501 larger than their original size, and one (and only one) is the
2502 result of a `~' operator. This comparison will always fail.
2504 Also warn if one operand is a constant, and the constant
2505 does not have all bits set that are set in the ~ operand
2506 when it is extended. */
2510 {
2514 else
2519 {
2520 tree primop;
2525 {
2529 }
2530 else
2531 {
2535 }
2540 {
2544 }
2545 }
2552 }
2553 }
2554 }
2555 }
2557 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
2558 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
2559 Then the expression will be built.
2560 It will be given type FINAL_TYPE if that is nonzero;
2561 otherwise, it will be given type RESULT_TYPE. */
2564 {
2567 }
2570 {
2575 }
2580 {
2582 tree folded;
2590 }
2591 }
2592 \f
2594 /* Return true if `t' is known to be non-negative. */
2596 int
2598 tree t;
2599 {
2601 {
2604 /* Find the last statement in the chain, ignoring the final
2605 * scope statement */
2610 }
2612 }
2614 /* Return a tree for the difference of pointers OP0 and OP1.
2615 The resulting tree has type int. */
2617 static tree
2620 {
2629 {
2634 }
2636 /* If the conversion to ptrdiff_type does anything like widening or
2637 converting a partial to an integral mode, we get a convert_expression
2638 that is in the way to do any simplifications.
2639 (fold-const.c doesn't know that the extra bits won't be needed.
2640 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2641 different mode in place.)
2642 So first try to find a common term here 'by hand'; we want to cover
2643 at least the cases that occur in legal static initializers. */
2648 {
2651 }
2652 else
2656 {
2659 }
2660 else
2664 {
2667 }
2670 /* First do the subtraction as integers;
2671 then drop through to build the divide operator.
2672 Do not do default conversions on the minus operator
2673 in case restype is a short type. */
2677 /* This generates an error if op1 is pointer to incomplete type. */
2681 /* This generates an error if op0 is pointer to incomplete type. */
2684 /* Divide by the size, in easiest possible way. */
2692 }
2693 \f
2694 /* Construct and perhaps optimize a tree representation
2695 for a unary operation. CODE, a tree_code, specifies the operation
2696 and XARG is the operand.
2697 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2698 the default promotions (such as from short to int).
2699 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2700 allows non-lvalues; this is only used to handle conversion of non-lvalue
2701 arrays to pointers in C99. */
2703 tree
2706 tree xarg;
2708 {
2709 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2713 tree val;
2722 {
2724 /* This is used for unary plus, because a CONVERT_EXPR
2725 is enough to prevent anybody from looking inside for
2726 associativity, but won't generate any code. */
2729 {
2732 }
2742 {
2745 }
2752 {
2755 }
2757 {
2763 }
2764 else
2765 {
2768 }
2774 {
2777 }
2783 /* Conjugating a real value is a no-op, but allow it anyway. */
2786 {
2789 }
2798 /* These will convert to a pointer. */
2800 {
2803 }
2815 else
2823 else
2830 /* Handle complex lvalues (when permitted)
2831 by reduction to simpler cases. */
2837 /* Increment or decrement the real part of the value,
2838 and don't change the imaginary part. */
2840 {
2851 }
2853 /* Report invalid types. */
2857 {
2860 else
2864 }
2866 {
2867 tree inc;
2873 /* Compute the increment. */
2876 {
2877 /* If pointer target is an undefined struct,
2878 we just cannot know how to do the arithmetic. */
2880 {
2883 else
2885 }
2889 {
2892 else
2894 }
2897 }
2898 else
2903 /* Handle incrementing a cast-expression. */
2907 {
2916 /* If the real type has the same machine representation
2917 as the type it is cast to, we can make better output
2918 by adding directly to the inside of the cast. */
2924 else
2925 {
2929 else
2930 {
2934 else
2943 }
2946 }
2951 }
2952 give_up:
2954 /* Complain about anything else that is not a true lvalue. */
2961 /* Report a read-only lvalue. */
2970 else
2977 }
2980 /* Note that this operation never does default_conversion. */
2982 /* Let &* cancel out to simplify resulting code. */
2984 {
2985 /* Don't let this be an lvalue. */
2989 }
2991 /* For &x[y], return x+y */
2993 {
2998 }
3000 /* Handle complex lvalues (when permitted)
3001 by reduction to simpler cases. */
3007 float f; *&(int)f = 3.4 stores in int format
3008 whereas (int)f = 3.4 stores in float format. */
3009 /* Address of a cast is just a cast of the address
3010 of the operand of the cast. */
3012 {
3025 }
3026 #endif
3028 /* Anything not already handled and not a true memory reference
3029 or a non-lvalue array is an error. */
3034 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
3037 /* If the lvalue is const or volatile, merge that into the type
3038 to which the address will point. Note that you can't get a
3039 restricted pointer by taking the address of something, so we
3040 only have to deal with `const' and `volatile' here. */
3052 {
3053 tree addr;
3056 {
3062 {
3066 }
3071 }
3072 else
3075 /* Address of a static or external variable or
3076 file-scope function counts as a constant. */
3082 }
3086 }
3091 }
3093 #if 0
3094 /* If CONVERSIONS is a conversion expression or a nested sequence of such,
3095 convert ARG with the same conversions in the same order
3096 and return the result. */
3098 static tree
3100 tree conversions;
3101 tree arg;
3102 {
3104 {
3114 arg));
3118 }
3119 }
3122 /* Return nonzero if REF is an lvalue valid for this language.
3123 Lvalues can be assigned, unless their type has TYPE_READONLY.
3124 Lvalues can have their address taken, unless they have DECL_REGISTER. */
3126 int
3128 tree ref;
3129 {
3133 {
3158 }
3159 }
3161 /* Return nonzero if REF is an lvalue valid for this language;
3162 otherwise, print an error message and return zero. */
3164 int
3166 tree ref;
3168 {
3175 }
3177 /* Apply unary lvalue-demanding operator CODE to the expression ARG
3178 for certain kinds of expressions which are not really lvalues
3179 but which we can accept as lvalues. If FLAG is nonzero, then
3180 non-lvalues are OK since we may be converting a non-lvalue array to
3181 a pointer in C99.
3183 If ARG is not a kind of expression we can handle, return zero. */
3185 static tree
3188 tree arg;
3190 {
3191 /* Handle (a, b) used as an "lvalue". */
3193 {
3196 /* If this returns a function type, it isn't really being used as
3197 an lvalue, so don't issue a warning about it. */
3203 }
3205 /* Handle (a ? b : c) used as an "lvalue". */
3207 {
3217 }
3220 }
3222 /* If pedantic, warn about improper lvalue. CODE is either COND_EXPR
3223 COMPOUND_EXPR, or CONVERT_EXPR (for casts). */
3225 static void
3228 {
3231 {
3241 }
3242 }
3243 \f
3244 /* Warn about storing in something that is `const'. */
3246 void
3248 tree arg;
3250 {
3252 {
3255 else
3258 }
3262 else
3264 }
3265 \f
3266 /* Mark EXP saying that we need to be able to take the
3267 address of it; it should not be allocated in a register.
3268 Returns true if successful. */
3270 bool
3272 tree exp;
3273 {
3278 {
3281 {
3285 }
3287 /* ... fall through ... */
3307 {
3309 {
3313 }
3316 }
3318 {
3320 {
3324 }
3326 /* If we are making this addressable due to its having
3327 volatile components, give a different error message. Also
3328 handle the case of an unnamed parameter by not trying
3329 to give the name. */
3332 {
3335 }
3339 }
3342 /* drops in */
3348 #endif
3352 }
3353 }
3354 \f
3355 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
3357 tree
3360 {
3361 tree type1;
3362 tree type2;
3371 /* Don't promote the operands separately if they promote
3372 the same way. Return the unpromoted type and let the combined
3373 value get promoted if necessary. */
3379 {
3384 }
3385 #endif
3387 /* Promote both alternatives. */
3404 /* Quickly detect the usual case where op1 and op2 have the same type
3405 after promotion. */
3407 {
3410 else
3412 }
3417 {
3420 /* If -Wsign-compare, warn here if type1 and type2 have
3421 different signedness. We'll promote the signed to unsigned
3422 and later code won't know it used to be different.
3423 Do this check on the original types, so that explicit casts
3424 will be considered, but default promotions won't. */
3427 {
3432 {
3433 /* Do not warn if the result type is signed, since the
3434 signed type will only be chosen if it can represent
3435 all the values of the unsigned type. */
3438 /* Do not warn if the signed quantity is an unsuffixed
3439 integer literal (or some static constant expression
3440 involving such literals) and it is non-negative. */
3444 else
3446 }
3447 }
3448 }
3450 {
3454 }
3456 {
3466 {
3471 }
3473 {
3478 }
3479 else
3480 {
3483 }
3484 }
3486 {
3489 else
3490 {
3492 }
3494 }
3496 {
3499 else
3500 {
3502 }
3504 }
3507 {
3510 else
3511 {
3514 }
3515 }
3517 /* Merge const and volatile flags of the incoming types. */
3518 result_type
3532 }
3533 \f
3534 /* Given a list of expressions, return a compound expression
3535 that performs them all and returns the value of the last of them. */
3537 tree
3539 tree list;
3540 {
3542 }
3544 static tree
3546 tree list;
3548 {
3549 tree rest;
3552 {
3553 /* Convert arrays and functions to pointers when there
3554 really is a comma operator. */
3560 /* Consider (x, y+0), which is not an lvalue since y+0 is not. */
3562 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3565 #endif
3567 /* Don't let (0, 0) be null pointer constant. */
3571 }
3576 {
3577 /* The left-hand operand of a comma expression is like an expression
3578 statement: with -Wextra or -Wunused, we should warn if it doesn't have
3579 any side-effects, unless it was explicitly cast to (void). */
3585 /* When pedantic, a compound expression can be neither an lvalue
3586 nor an integer constant expression. */
3589 }
3591 /* With -Wunused, we should also warn if the left-hand operand does have
3592 side-effects, but computes a value which is not used. For example, in
3593 `foo() + bar(), baz()' the result of the `+' operator is not used,
3594 so we should issue a warning. */
3599 }
3601 /* Build an expression representing a cast to type TYPE of expression EXPR. */
3603 tree
3605 tree type;
3606 tree expr;
3607 {
3613 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
3614 only in <protocol> qualifications. But when constructing cast expressions,
3615 the protocols do matter and must be kept around. */
3619 #if 0
3620 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3623 #endif
3626 {
3629 }
3632 {
3635 }
3638 {
3640 {
3644 }
3645 }
3647 {
3648 tree field;
3657 {
3658 tree t;
3666 }
3669 }
3670 else
3671 {
3674 /* If casting to void, avoid the error that would come
3675 from default_conversion in the case of a non-lvalue array. */
3679 /* Convert functions and arrays to pointers,
3680 but don't convert any other types. */
3684 /* Optionally warn about potentially worrisome casts. */
3689 {
3695 /* Check that the qualifiers on IN_TYPE are a superset of
3696 the qualifiers of IN_OTYPE. The outermost level of
3697 POINTER_TYPE nodes is uninteresting and we stop as soon
3698 as we hit a non-POINTER_TYPE node on either type. */
3699 do
3700 {
3704 /* GNU C allows cv-qualified function types. 'const'
3705 means the function is very pure, 'volatile' means it
3706 can't return. We need to warn when such qualifiers
3707 are added, not when they're taken away. */
3711 else
3713 }
3721 /* There are qualifiers present in IN_OTYPE that are not
3722 present in IN_TYPE. */
3724 }
3726 /* Warn about possible alignment problems. */
3732 /* Don't warn about opaque types, where the actual alignment
3733 restriction is unknown. */
3754 /* Don't warn about converting any constant. */
3764 {
3765 /* Casting the address of a decl to non void pointer. Warn
3766 if the cast breaks type based aliasing. */
3773 }
3776 /* Replace a nonvolatile const static variable with its value. */
3781 /* Ignore any integer overflow caused by the cast. */
3783 {
3786 }
3787 }
3789 /* Pedantically, don't let (void *) (FOO *) 0 be a null pointer constant. */
3795 /* If pedantic, don't let a cast be an lvalue. */
3800 }
3802 /* Interpret a cast of expression EXPR to type TYPE. */
3803 tree
3806 {
3809 /* This avoids warnings about unprototyped casts on
3810 integers. E.g. "#define SIG_DFL (void(*)())0". */
3817 }
3819 \f
3820 /* Build an assignment expression of lvalue LHS from value RHS.
3821 MODIFYCODE is the code for a binary operator that we use
3822 to combine the old value of LHS with RHS to get the new value.
3823 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3825 tree
3829 {
3830 tree result;
3831 tree newrhs;
3835 /* Types that aren't fully specified cannot be used in assignments. */
3838 /* Avoid duplicate error messages from operands that had errors. */
3842 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3843 /* Do not use STRIP_NOPS here. We do not want an enumerator
3844 whose value is 0 to count as a null pointer constant. */
3850 /* Handle control structure constructs used as "lvalues". */
3853 {
3854 /* Handle (a, b) used as an "lvalue". */
3863 /* Handle (a ? b : c) used as an "lvalue". */
3867 {
3868 /* Produce (a ? (b = rhs) : (c = rhs))
3869 except that the RHS goes through a save-expr
3870 so the code to compute it is only emitted once. */
3871 tree cond
3879 /* Make sure the code to compute the rhs comes out
3880 before the split. */
3882 /* But cast it to void to avoid an "unused" error. */
3884 }
3887 }
3889 /* If a binary op has been requested, combine the old LHS value with the RHS
3890 producing the value we should actually store into the LHS. */
3893 {
3896 }
3898 /* Handle a cast used as an "lvalue".
3899 We have already performed any binary operator using the value as cast.
3900 Now convert the result to the cast type of the lhs,
3901 and then true type of the lhs and store it there;
3902 then convert result back to the cast type to be the value
3903 of the assignment. */
3906 {
3915 {
3917 tree result;
3925 }
3929 }
3931 /* Now we have handled acceptable kinds of LHS that are not truly lvalues.
3932 Reject anything strange now. */
3937 /* Warn about storing in something that is `const'. */
3945 /* If storing into a structure or union member,
3946 it has probably been given type `int'.
3947 Compute the type that would go with
3948 the actual amount of storage the member occupies. */
3957 /* If storing in a field that is in actuality a short or narrower than one,
3958 we must store in the field in its actual type. */
3961 {
3964 }
3966 /* Convert new value to destination type. */
3973 /* Scan operands */
3978 /* If we got the LHS in a different type for storing in,
3979 convert the result back to the nominal type of LHS
3980 so that the value we return always has the same type
3981 as the LHS argument. */
3987 }
3988 \f
3989 /* Convert value RHS to type TYPE as preparation for an assignment
3990 to an lvalue of type TYPE.
3991 The real work of conversion is done by `convert'.
3992 The purpose of this function is to generate error messages
3993 for assignments that are not allowed in C.
3994 ERRTYPE is a string to use in error messages:
3995 "assignment", "return", etc. If it is null, this is parameter passing
3996 for a function call (and different error messages are output).
3998 FUNNAME is the name of the function being called,
3999 as an IDENTIFIER_NODE, or null.
4000 PARMNUM is the number of the argument, for printing in error messages. */
4002 static tree
4008 {
4010 tree rhstype;
4013 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
4014 /* Do not use STRIP_NOPS here. We do not want an enumerator
4015 whose value is 0 to count as a null pointer constant. */
4032 {
4034 /* Check for Objective-C protocols. This will automatically
4035 issue a warning if there are protocol violations. No need to
4036 use the return value. */
4040 }
4043 {
4046 }
4047 /* A type converts to a reference to it.
4048 This code doesn't fully support references, it's just for the
4049 special case of va_start and va_copy. */
4052 {
4054 {
4057 }
4062 /* We already know that these two types are compatible, but they
4063 may not be exactly identical. In fact, `TREE_TYPE (type)' is
4064 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
4065 likely to be va_list, a typedef to __builtin_va_list, which
4066 is different enough that it will cause problems later. */
4072 }
4073 /* Some types can interconvert without explicit casts. */
4078 /* Arithmetic types all interconvert, and enum is treated like int. */
4087 /* Conversion to a transparent union from its member types.
4088 This applies only to function arguments. */
4090 {
4091 tree memb_types;
4096 {
4107 {
4111 /* Any non-function converts to a [const][volatile] void *
4112 and vice versa; otherwise, targets must be the same.
4113 Meanwhile, the lhs target must have all the qualifiers of
4114 the rhs. */
4117 {
4118 /* If this type won't generate any warnings, use it. */
4128 /* Keep looking for a better type, but remember this one. */
4131 }
4132 }
4134 /* Can convert integer zero to any pointer type. */
4138 {
4141 }
4142 }
4145 {
4147 {
4148 /* We have only a marginally acceptable member type;
4149 it needs a warning. */
4153 /* Const and volatile mean something different for function
4154 types, so the usual warnings are not appropriate. */
4157 {
4158 /* Because const and volatile on functions are
4159 restrictions that say the function will not do
4160 certain things, it is okay to use a const or volatile
4161 function where an ordinary one is wanted, but not
4162 vice-versa. */
4166 }
4170 parmnum);
4171 }
4177 }
4178 }
4180 /* Conversions among pointers */
4183 {
4187 /* Any non-function converts to a [const][volatile] void *
4188 and vice versa; otherwise, targets must be the same.
4189 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
4194 {
4197 ||
4199 /* Check TREE_CODE to catch cases like (void *) (char *) 0
4200 which are not ANSI null ptr constants. */
4205 /* Const and volatile mean something different for function types,
4206 so the usual warnings are not appropriate. */
4209 {
4213 /* If this is not a case of ignoring a mismatch in signedness,
4214 no warning. */
4217 ;
4218 /* If there is a mismatch, do warn. */
4222 }
4225 {
4226 /* Because const and volatile on functions are restrictions
4227 that say the function will not do certain things,
4228 it is okay to use a const or volatile function
4229 where an ordinary one is wanted, but not vice-versa. */
4233 }
4234 }
4235 else
4239 }
4241 {
4242 /* An explicit constant 0 can convert to a pointer,
4243 or one that results from arithmetic, even including
4244 a cast to integer type. */
4246 &&
4251 {
4255 }
4257 }
4259 {
4263 }
4268 {
4270 {
4276 else
4279 }
4280 else
4282 parmnum);
4283 }
4284 else
4288 }
4290 /* Convert VALUE for assignment into inlined parameter PARM. */
4292 tree
4295 {
4298 /* If FN was prototyped, the value has been converted already
4299 in convert_arguments. */
4312 }
4314 /* Print a warning using MSGID.
4315 It gets OPNAME as its one parameter.
4316 if OPNAME is null and ARGNUM is 0, it is replaced by "passing arg of `FUNCTION'".
4317 Otherwise if OPNAME is null, it is replaced by "passing arg ARGNUM of `FUNCTION'".
4318 FUNCTION and ARGNUM are handled specially if we are building an
4319 Objective-C selector. */
4321 static void
4325 tree function;
4327 {
4329 {
4334 {
4337 }
4339 {
4341 {
4342 /* Function name is known; supply it. */
4349 }
4350 else
4351 {
4352 /* Function name unknown (call through ptr). */
4356 }
4357 }
4359 {
4360 /* Function name is known; supply it. */
4367 }
4368 else
4369 {
4370 /* Function name unknown (call through ptr); just give arg number. */
4374 }
4376 }
4378 }
4379 \f
4380 /* If VALUE is a compound expr all of whose expressions are constant, then
4381 return its value. Otherwise, return error_mark_node.
4383 This is for handling COMPOUND_EXPRs as initializer elements
4384 which is allowed with a warning when -pedantic is specified. */
4386 static tree
4388 tree value;
4389 tree endtype;
4390 {
4392 {
4397 endtype);
4398 }
4402 else
4404 }
4405 \f
4406 /* Perform appropriate conversions on the initial value of a variable,
4407 store it in the declaration DECL,
4408 and print any error messages that are appropriate.
4409 If the init is invalid, store an ERROR_MARK. */
4411 void
4414 {
4417 /* If variable's type was invalidly declared, just ignore it. */
4423 /* Digest the specified initializer into an expression. */
4427 /* Store the expression if valid; else report error. */
4429 #if 0
4430 /* Note that this is the only place we can detect the error
4431 in a case such as struct foo bar = (struct foo) { x, y };
4432 where there is one initial value which is a constructor expression. */
4434 ;
4436 {
4439 }
4442 {
4445 }
4446 else
4447 {
4449 {
4454 }
4455 }
4456 #endif
4464 /* ANSI wants warnings about out-of-range constant initializers. */
4468 /* Check if we need to set array size from compound literal size. */
4472 {
4480 {
4484 {
4485 /* For int foo[] = (int [3]){1}; we need to set array size
4486 now since later on array initializer will be just the
4487 brace enclosed list of the compound literal. */
4491 }
4492 }
4493 }
4494 }
4495 \f
4496 /* Methods for storing and printing names for error messages. */
4498 /* Implement a spelling stack that allows components of a name to be pushed
4499 and popped. Each element on the stack is this structure. */
4501 struct spelling
4502 {
4504 union
4505 {
4509 };
4511 #define SPELLING_STRING 1
4512 #define SPELLING_MEMBER 2
4513 #define SPELLING_BOUNDS 3
4519 /* Macros to save and restore the spelling stack around push_... functions.
4520 Alternative to SAVE_SPELLING_STACK. */
4522 #define SPELLING_DEPTH() (spelling - spelling_base)
4523 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
4525 /* Push an element on the spelling stack with type KIND and assign VALUE
4526 to MEMBER. */
4528 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
4529 { \
4530 int depth = SPELLING_DEPTH (); \
4531 \
4532 if (depth >= spelling_size) \
4533 { \
4534 spelling_size += 10; \
4535 if (spelling_base == 0) \
4536 spelling_base \
4537 = (struct spelling *) xmalloc (spelling_size * sizeof (struct spelling)); \
4538 else \
4539 spelling_base \
4540 = (struct spelling *) xrealloc (spelling_base, \
4541 spelling_size * sizeof (struct spelling)); \
4542 RESTORE_SPELLING_DEPTH (depth); \
4543 } \
4544 \
4545 spelling->kind = (KIND); \
4546 spelling->MEMBER = (VALUE); \
4547 spelling++; \
4548 }
4550 /* Push STRING on the stack. Printed literally. */
4552 static void
4555 {
4557 }
4559 /* Push a member name on the stack. Printed as '.' STRING. */
4561 static void
4563 tree decl;
4565 {
4569 }
4571 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
4573 static void
4576 {
4578 }
4580 /* Compute the maximum size in bytes of the printed spelling. */
4582 static int
4584 {
4589 {
4592 else
4594 }
4597 }
4599 /* Print the spelling to BUFFER and return it. */
4604 {
4610 {
4613 }
4614 else
4615 {
4620 ;
4621 }
4624 }
4626 /* Issue an error message for a bad initializer component.
4627 MSGID identifies the message.
4628 The component name is taken from the spelling stack. */
4630 void
4633 {
4640 }
4642 /* Issue a pedantic warning 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 warning for a bad initializer component.
4659 MSGID identifies the message.
4660 The component name is taken from the spelling stack. */
4662 static void
4665 {
4672 }
4673 \f
4674 /* Digest the parser output INIT as an initializer for type TYPE.
4675 Return a C expression of type TYPE to represent the initial value.
4677 REQUIRE_CONSTANT requests an error if non-constant initializers or
4678 elements are seen. */
4680 static tree
4684 {
4693 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
4694 /* Do not use STRIP_NOPS here. We do not want an enumerator
4695 whose value is 0 to count as a null pointer constant. */
4701 /* Initialization of an array of chars from a string constant
4702 optionally enclosed in braces. */
4705 {
4713 {
4721 {
4724 }
4728 {
4731 }
4737 /* Subtract 1 (or sizeof (wchar_t))
4738 because it's ok to ignore the terminating null char
4739 that is counted in the length of the constant. */
4750 }
4751 }
4753 /* Any type can be initialized
4754 from an expression of the same type, optionally with braces. */
4768 {
4774 {
4775 /* As an extension, allow initializing objects with static storage
4776 duration with compound literals (which are then treated just as
4777 the brace enclosed list they contain). */
4780 }
4784 {
4787 }
4792 /* Compound expressions can only occur here if -pedantic or
4793 -pedantic-errors is specified. In the later case, we always want
4794 an error. In the former case, we simply want a warning. */
4797 {
4798 inside_init
4803 else
4807 }
4810 /* This test catches things like `7 / 0' which
4811 result in an expression for which TREE_CONSTANT
4812 is true, but which is not actually something
4813 that is a legal constant. We really should not
4814 be using this function, because it is a part of
4815 the back-end. Instead, the expression should
4816 already have been turned into ERROR_MARK_NODE. */
4819 {
4822 }
4825 }
4827 /* Handle scalar types, including conversions. */
4831 {
4832 /* Note that convert_for_assignment calls default_conversion
4833 for arrays and functions. We must not call it in the
4834 case where inside_init is a null pointer constant. */
4835 inside_init
4840 {
4843 }
4846 {
4849 }
4852 }
4854 /* Come here only for records and arrays. */
4857 {
4860 }
4864 }
4865 \f
4866 /* Handle initializers that use braces. */
4868 /* Type of object we are accumulating a constructor for.
4869 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4872 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4873 left to fill. */
4876 /* For an ARRAY_TYPE, this is the specified index
4877 at which to store the next element we get. */
4880 /* For an ARRAY_TYPE, this is the maximum index. */
4883 /* For a RECORD_TYPE, this is the first field not yet written out. */
4886 /* For an ARRAY_TYPE, this is the index of the first element
4887 not yet written out. */
4890 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4891 This is so we can generate gaps between fields, when appropriate. */
4894 /* If we are saving up the elements rather than allocating them,
4895 this is the list of elements so far (in reverse order,
4896 most recent first). */
4899 /* 1 if constructor should be incrementally stored into a constructor chain,
4900 0 if all the elements should be kept in AVL tree. */
4903 /* 1 if so far this constructor's elements are all compile-time constants. */
4906 /* 1 if so far this constructor's elements are all valid address constants. */
4909 /* 1 if this constructor is erroneous so far. */
4912 /* 1 if have called defer_addressed_constants. */
4915 /* Structure for managing pending initializer elements, organized as an
4916 AVL tree. */
4918 struct init_node
4919 {
4923 tree purpose;
4924 tree value;
4925 };
4927 /* Tree of pending elements at this constructor level.
4928 These are elements encountered out of order
4929 which belong at places we haven't reached yet in actually
4930 writing the output.
4931 Will never hold tree nodes across GC runs. */
4934 /* The SPELLING_DEPTH of this constructor. */
4937 /* 0 if implicitly pushing constructor levels is allowed. */
4943 /* DECL node for which an initializer is being read.
4944 0 means we are reading a constructor expression
4945 such as (struct foo) {...}. */
4948 /* start_init saves the ASMSPEC arg here for really_start_incremental_init. */
4951 /* Nonzero if this is an initializer for a top-level decl. */
4954 /* Nonzero if there were any member designators in this initializer. */
4957 /* Nesting depth of designator list. */
4960 /* Nonzero if there were diagnosed errors in this designator list. */
4963 \f
4964 /* This stack has a level for each implicit or explicit level of
4965 structuring in the initializer, including the outermost one. It
4966 saves the values of most of the variables above. */
4970 struct constructor_stack
4971 {
4973 tree type;
4974 tree fields;
4975 tree index;
4976 tree max_index;
4977 tree unfilled_index;
4978 tree unfilled_fields;
4979 tree bit_index;
4980 tree elements;
4984 /* If nonzero, this value should replace the entire
4985 constructor at this level. */
4986 tree replacement_value;
4995 };
4999 /* This stack represents designators from some range designator up to
5000 the last designator in the list. */
5002 struct constructor_range_stack
5003 {
5006 tree range_start;
5007 tree index;
5008 tree range_end;
5009 tree fields;
5010 };
5014 /* This stack records separate initializers that are nested.
5015 Nested initializers can't happen in ANSI C, but GNU C allows them
5016 in cases like { ... (struct foo) { ... } ... }. */
5018 struct initializer_stack
5019 {
5021 tree decl;
5025 tree elements;
5033 };
5036 \f
5037 /* Prepare to parse and output the initializer for variable DECL. */
5039 void
5041 tree decl;
5042 tree asmspec_tree;
5044 {
5075 {
5077 require_constant_elements
5079 /* For a scalar, you can always use any value to initialize,
5080 even within braces. */
5086 }
5087 else
5088 {
5092 }
5105 }
5107 void
5109 {
5112 /* Output subconstants (string constants, usually)
5113 that were referenced within this initializer and saved up.
5114 Must do this if and only if we called defer_addressed_constants. */
5118 /* Free the whole constructor stack of this initializer. */
5120 {
5124 }
5129 /* Pop back to the data of the outer initializer (if any). */
5144 }
5145 \f
5146 /* Call here when we see the initializer is surrounded by braces.
5147 This is instead of a call to push_init_level;
5148 it is matched by a call to pop_init_level.
5150 TYPE is the type to initialize, for a constructor expression.
5151 For an initializer for a decl, TYPE is zero. */
5153 void
5155 tree type;
5156 {
5201 {
5203 /* Skip any nameless bit fields at the beginning. */
5210 }
5212 {
5214 {
5215 constructor_max_index
5218 /* Detect non-empty initializations of zero-length arrays. */
5223 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5224 to initialize VLAs will cause a proper error; avoid tree
5225 checking errors as well by setting a safe value. */
5230 constructor_index
5233 }
5234 else
5238 }
5240 {
5241 /* Vectors are like simple fixed-size arrays. */
5242 constructor_max_index =
5246 }
5247 else
5248 {
5249 /* Handle the case of int x = {5}; */
5252 }
5253 }
5254 \f
5255 /* Push down into a subobject, for initialization.
5256 If this is for an explicit set of braces, IMPLICIT is 0.
5257 If it is because the next element belongs at a lower level,
5258 IMPLICIT is 1 (or 2 if the push is because of designator list). */
5260 void
5263 {
5267 /* If we've exhausted any levels that didn't have braces,
5268 pop them now. */
5270 {
5276 && constructor_max_index
5279 else
5281 }
5283 /* Unless this is an explicit brace, we need to preserve previous
5284 content if any. */
5286 {
5293 }
5326 {
5331 }
5333 /* Don't die if an entire brace-pair level is superfluous
5334 in the containing level. */
5336 ;
5339 {
5340 /* Don't die if there are extra init elts at the end. */
5343 else
5344 {
5347 constructor_depth++;
5348 }
5349 }
5351 {
5354 constructor_depth++;
5355 }
5358 {
5363 }
5366 {
5374 }
5377 {
5380 }
5384 {
5386 /* Skip any nameless bit fields at the beginning. */
5393 }
5395 {
5396 /* Vectors are like simple fixed-size arrays. */
5397 constructor_max_index =
5401 }
5403 {
5405 {
5406 constructor_max_index
5409 /* Detect non-empty initializations of zero-length arrays. */
5414 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5415 to initialize VLAs will cause a proper error; avoid tree
5416 checking errors as well by setting a safe value. */
5421 constructor_index
5424 }
5425 else
5430 {
5431 /* We need to split the char/wchar array into individual
5432 characters, so that we don't have to special case it
5433 everywhere. */
5435 }
5436 }
5437 else
5438 {
5442 }
5443 }
5445 /* At the end of an implicit or explicit brace level,
5446 finish up that level of constructor.
5447 If we were outputting the elements as they are read, return 0
5448 from inner levels (process_init_element ignores that),
5449 but return error_mark_node from the outermost level
5450 (that's what we want to put in DECL_INITIAL).
5451 Otherwise, return a CONSTRUCTOR expression. */
5453 tree
5456 {
5461 {
5462 /* When we come to an explicit close brace,
5463 pop any inner levels that didn't have explicit braces. */
5469 }
5473 /* Error for initializing a flexible array member, or a zero-length
5474 array member in an inappropriate context. */
5479 {
5480 /* Silently discard empty initializations. The parser will
5481 already have pedwarned for empty brackets. */
5485 {
5491 /* We have already issued an error message for the existence
5492 of a flexible array member not at the end of the structure.
5493 Discard the initializer so that we do not abort later. */
5496 }
5497 else
5498 /* Zero-length arrays are no longer special, so we should no longer
5499 get here. */
5501 }
5503 /* Warn when some struct elements are implicitly initialized to zero. */
5505 && constructor_type
5508 {
5509 /* Do not warn for flexible array members or zero-length arrays. */
5515 /* Do not warn if this level of the initializer uses member
5516 designators; it is likely to be deliberate. */
5518 {
5522 }
5523 }
5525 /* Now output all pending elements. */
5529 /* Pad out the end of the structure. */
5531 /* If this closes a superfluous brace pair,
5532 just pass out the element between them. */
5535 ;
5540 {
5541 /* A nonincremental scalar initializer--just return
5542 the element, after verifying there is just one. */
5544 {
5548 }
5550 {
5553 }
5554 else
5556 }
5557 else
5558 {
5561 else
5562 {
5569 }
5570 }
5595 {
5599 }
5601 }
5603 /* Common handling for both array range and field name designators.
5604 ARRAY argument is nonzero for array ranges. Returns zero for success. */
5606 static int
5609 {
5610 tree subtype;
5613 /* Don't die if an entire brace-pair level is superfluous
5614 in the containing level. */
5618 /* If there were errors in this designator list already, bail out silently. */
5623 {
5627 /* Designator list starts at the level of closest explicit
5628 braces. */
5633 }
5636 {
5639 }
5643 {
5647 }
5649 {
5651 }
5652 else
5657 {
5660 }
5662 {
5665 }
5670 }
5672 /* If there are range designators in designator list, push a new designator
5673 to constructor_range_stack. RANGE_END is end of such stack range or
5674 NULL_TREE if there is no range designator at this level. */
5676 static void
5678 tree range_end;
5679 {
5694 }
5696 /* Within an array initializer, specify the next index to be initialized.
5697 FIRST is that index. If LAST is nonzero, then initialize a range
5698 of indices, running from FIRST through LAST. */
5700 void
5703 {
5733 else
5734 {
5738 {
5742 {
5745 }
5746 else
5747 {
5751 {
5754 }
5755 }
5756 }
5758 designator_depth++;
5762 }
5763 }
5765 /* Within a struct initializer, specify the next field to be initialized. */
5767 void
5769 tree fieldname;
5770 {
5771 tree tail;
5780 {
5783 }
5787 {
5790 }
5795 else
5796 {
5798 designator_depth++;
5802 }
5803 }
5804 \f
5805 /* Add a new initializer to the tree of pending initializers. PURPOSE
5806 identifies the initializer, either array index or field in a structure.
5807 VALUE is the value of that index or field. */
5809 static void
5812 {
5819 {
5821 {
5827 else
5828 {
5833 }
5834 }
5835 }
5836 else
5837 {
5838 tree bitpos;
5842 {
5848 else
5849 {
5854 }
5855 }
5856 }
5869 {
5873 {
5877 {
5879 {
5880 /* L rotation. */
5893 {
5896 else
5898 }
5899 else
5901 }
5902 else
5903 {
5904 /* LR rotation. */
5926 {
5929 else
5931 }
5932 else
5934 }
5936 }
5937 else
5938 {
5939 /* p->balance == +1; growth of left side balances the node. */
5942 }
5943 }
5945 {
5947 /* Growth propagation from right side. */
5950 {
5952 {
5953 /* R rotation. */
5966 {
5969 else
5971 }
5972 else
5974 }
5976 {
5977 /* RL rotation */
5999 {
6002 else
6004 }
6005 else
6007 }
6009 }
6010 else
6011 {
6012 /* p->balance == -1; growth of right side balances the node. */
6015 }
6016 }
6020 }
6021 }
6023 /* Build AVL tree from a sorted chain. */
6025 static void
6027 {
6028 tree chain;
6038 {
6040 /* Skip any nameless bit fields at the beginning. */
6046 }
6048 {
6050 constructor_unfilled_index
6053 else
6055 }
6057 }
6059 /* Build AVL tree from a string constant. */
6061 static void
6063 tree str;
6064 {
6079 else
6090 {
6092 {
6095 }
6096 else
6097 {
6101 {
6104 else
6109 }
6110 }
6113 {
6116 {
6118 {
6121 }
6122 }
6124 {
6127 }
6132 }
6137 }
6140 }
6142 /* Return value of FIELD in pending initializer or zero if the field was
6143 not initialized yet. */
6145 static tree
6147 tree field;
6148 {
6152 {
6159 {
6164 else
6166 }
6167 }
6169 {
6173 && (!constructor_unfilled_fields
6180 {
6185 else
6187 }
6188 }
6190 {
6194 }
6196 }
6198 /* "Output" the next constructor element.
6199 At top level, really output it to assembler code now.
6200 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
6201 TYPE is the data type that the containing data type wants here.
6202 FIELD is the field (a FIELD_DECL) or the index that this element fills.
6204 PENDING if non-nil means output pending elements that belong
6205 right after this element. (PENDING is normally 1;
6206 it is 0 while outputting pending elements, to avoid recursion.) */
6208 static void
6212 {
6224 {
6225 /* As an extension, allow initializing objects with static storage
6226 duration with compound literals (which are then treated just as
6227 the brace enclosed list they contain). */
6230 }
6244 {
6247 }
6252 /* If this field is empty (and not at the end of structure),
6253 don't do anything other than checking the initializer. */
6264 {
6267 }
6269 /* If this element doesn't come next in sequence,
6270 put it on constructor_pending_elts. */
6272 && (!constructor_incremental
6274 {
6281 }
6283 && (!constructor_incremental
6285 {
6286 /* We do this for records but not for unions. In a union,
6287 no matter which field is specified, it can be initialized
6288 right away since it starts at the beginning of the union. */
6290 {
6293 else
6294 {
6302 }
6303 }
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
6326 /* Advance the variable that indicates sequential elements output. */
6328 constructor_unfilled_index
6330 bitsize_one_node);
6332 {
6333 constructor_unfilled_fields
6336 /* Skip any nameless bit fields. */
6340 constructor_unfilled_fields =
6342 }
6346 /* Now output any pending elements which have become next. */
6349 }
6351 /* Output any pending elements which have become next.
6352 As we output elements, constructor_unfilled_{fields,index}
6353 advances, which may cause other elements to become next;
6354 if so, they too are output.
6356 If ALL is 0, we return when there are
6357 no more pending elements to output now.
6359 If ALL is 1, we output space as necessary so that
6360 we can output all the pending elements. */
6362 static void
6365 {
6367 tree next;
6369 retry:
6371 /* Look thru the whole pending tree.
6372 If we find an element that should be output now,
6373 output it. Otherwise, set NEXT to the element
6374 that comes first among those still pending. */
6378 {
6380 {
6382 constructor_unfilled_index))
6388 {
6389 /* Advance to the next smaller node. */
6392 else
6393 {
6394 /* We have reached the smallest node bigger than the
6395 current unfilled index. Fill the space first. */
6398 }
6399 }
6400 else
6401 {
6402 /* Advance to the next bigger node. */
6405 else
6406 {
6407 /* We have reached the biggest node in a subtree. Find
6408 the parent of it, which is the next bigger node. */
6414 {
6417 }
6418 }
6419 }
6420 }
6423 {
6426 /* If the current record is complete we are done. */
6432 /* We can't compare fields here because there might be empty
6433 fields in between. */
6435 {
6439 }
6441 {
6442 /* Advance to the next smaller node. */
6445 else
6446 {
6447 /* We have reached the smallest node bigger than the
6448 current unfilled field. Fill the space first. */
6451 }
6452 }
6453 else
6454 {
6455 /* Advance to the next bigger node. */
6458 else
6459 {
6460 /* We have reached the biggest node in a subtree. Find
6461 the parent of it, which is the next bigger node. */
6468 {
6471 }
6472 }
6473 }
6474 }
6475 }
6477 /* Ordinarily return, but not if we want to output all
6478 and there are elements left. */
6482 /* If it's not incremental, just skip over the gap, so that after
6483 jumping to retry we will output the next successive element. */
6490 /* ELT now points to the node in the pending tree with the next
6491 initializer to output. */
6493 }
6494 \f
6495 /* Add one non-braced element to the current constructor level.
6496 This adjusts the current position within the constructor's type.
6497 This may also start or terminate implicit levels
6498 to handle a partly-braced initializer.
6500 Once this has found the correct level for the new element,
6501 it calls output_init_element. */
6503 void
6505 tree value;
6506 {
6513 /* Handle superfluous braces around string cst as in
6514 char x[] = {"foo"}; */
6516 && constructor_type
6520 {
6525 }
6528 {
6531 }
6533 /* Ignore elements of a brace group if it is entirely superfluous
6534 and has already been diagnosed. */
6538 /* If we've exhausted any levels that didn't have braces,
6539 pop them now. */
6541 {
6549 constructor_index)))
6551 else
6553 }
6555 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
6557 {
6558 /* If value is a compound literal and we'll be just using its
6559 content, don't put it into a SAVE_EXPR. */
6561 || !require_constant_value
6564 }
6567 {
6569 {
6570 tree fieldtype;
6574 {
6577 }
6584 /* Error for non-static initialization of a flexible array member. */
6586 && !require_constant_value
6589 {
6592 }
6594 /* Accept a string constant to initialize a subarray. */
6600 /* Otherwise, if we have come to a subaggregate,
6601 and we don't have an element of its type, push into it. */
6607 {
6610 }
6613 {
6617 }
6618 else
6619 /* Do the bookkeeping for an element that was
6620 directly output as a constructor. */
6621 {
6622 /* For a record, keep track of end position of last field. */
6624 constructor_bit_index
6629 /* If the current field was the first one not yet written out,
6630 it isn't now, so update. */
6632 {
6634 /* Skip any nameless bit fields. */
6638 constructor_unfilled_fields =
6640 }
6641 }
6644 /* Skip any nameless bit fields at the beginning. */
6649 }
6651 {
6652 tree fieldtype;
6656 {
6659 }
6666 /* Warn that traditional C rejects initialization of unions.
6667 We skip the warning if the value is zero. This is done
6668 under the assumption that the zero initializer in user
6669 code appears conditioned on e.g. __STDC__ to avoid
6670 "missing initializer" warnings and relies on default
6671 initialization to zero in the traditional C case.
6672 We also skip the warning if the initializer is designated,
6673 again on the assumption that this must be conditional on
6674 __STDC__ anyway (and we've already complained about the
6675 member-designator already). */
6680 /* Accept a string constant to initialize a subarray. */
6686 /* Otherwise, if we have come to a subaggregate,
6687 and we don't have an element of its type, push into it. */
6693 {
6696 }
6699 {
6703 }
6704 else
6705 /* Do the bookkeeping for an element that was
6706 directly output as a constructor. */
6707 {
6710 }
6713 }
6715 {
6719 /* Accept a string constant to initialize a subarray. */
6725 /* Otherwise, if we have come to a subaggregate,
6726 and we don't have an element of its type, push into it. */
6732 {
6735 }
6740 {
6743 }
6745 /* Now output the actual element. */
6747 {
6751 }
6753 constructor_index
6757 /* If we are doing the bookkeeping for an element that was
6758 directly output as a constructor, we must update
6759 constructor_unfilled_index. */
6761 }
6763 {
6766 /* Do a basic check of initializer size. Note that vectors
6767 always have a fixed size derived from their type. */
6769 {
6772 }
6774 /* Now output the actual element. */
6778 constructor_index
6782 /* If we are doing the bookkeeping for an element that was
6783 directly output as a constructor, we must update
6784 constructor_unfilled_index. */
6786 }
6788 /* Handle the sole element allowed in a braced initializer
6789 for a scalar variable. */
6791 {
6794 }
6795 else
6796 {
6800 }
6802 /* Handle range initializers either at this level or anywhere higher
6803 in the designator stack. */
6805 {
6812 {
6816 }
6820 {
6824 }
6831 {
6835 {
6838 }
6846 }
6851 }
6854 }
6857 }
6858 \f
6859 /* Build a simple asm-statement, from one string literal. */
6860 tree
6862 tree expr;
6863 {
6870 {
6871 tree stmt;
6873 /* Simple asm statements are treated as volatile. */
6878 }
6882 }
6884 /* Build an asm-statement, whose components are a CV_QUALIFIER, a
6885 STRING, some OUTPUTS, some INPUTS, and some CLOBBERS. */
6887 tree
6889 tree cv_qualifier;
6890 tree string;
6891 tree outputs;
6892 tree inputs;
6893 tree clobbers;
6894 {
6895 tree tail;
6898 {
6901 }
6905 {
6909 }
6911 /* We can remove output conversions that change the type,
6912 but not the mode. */
6914 {
6920 /* Allow conversions as LHS here. build_modify_expr as called below
6921 will do the right thing with them. */
6932 }
6934 /* Remove output conversions that change the type but not the mode. */
6936 {
6940 }
6942 /* Perform default conversions on array and function inputs.
6943 Don't do this for other types as it would screw up operands
6944 expected to be in memory. */
6950 }
6952 /* Expand an ASM statement with operands, handling output operands
6953 that are not variables or INDIRECT_REFS by transforming such
6954 cases into cases that expand_asm_operands can handle.
6956 Arguments are same as for expand_asm_operands. */
6958 void
6964 {
6967 /* o[I] is the place that output number I should be written. */
6969 tree tail;
6971 /* Record the contents of OUTPUTS before it is modified. */
6973 {
6977 }
6979 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
6980 OUTPUTS some trees for where the values were actually stored. */
6983 /* Copy all the intermediate outputs into the specified outputs. */
6985 {
6987 {
6992 /* Restore the original value so that it's correct the next
6993 time we expand this function. */
6995 }
6996 /* Detect modification of read-only values.
6997 (Otherwise done by build_modify_expr.) */
6998 else
6999 {
7007 }
7008 }
7010 /* Those MODIFY_EXPRs could do autoincrements. */
7012 }
7013 \f
7014 /* Expand a C `return' statement.
7015 RETVAL is the expression for what to return,
7016 or a null pointer for `return;' with no value. */
7018 tree
7020 tree retval;
7021 {
7028 {
7033 }
7035 {
7039 }
7040 else
7041 {
7045 tree inner;
7053 /* Strip any conversions, additions, and subtractions, and see if
7054 we are returning the address of a local variable. Warn if so. */
7056 {
7058 {
7065 /* If the second operand of the MINUS_EXPR has a pointer
7066 type (or is converted from it), this may be valid, so
7067 don't give a warning. */
7068 {
7082 }
7099 }
7102 }
7105 }
7108 }
7109 \f
7111 /* The SWITCH_STMT being built. */
7112 tree switch_stmt;
7113 /* A splay-tree mapping the low element of a case range to the high
7114 element, or NULL_TREE if there is no high element. Used to
7115 determine whether or not a new case label duplicates an old case
7116 label. We need a tree, rather than simply a hash table, because
7117 of the GNU case range extension. */
7118 splay_tree cases;
7119 /* The next node on the stack. */
7121 };
7123 /* A stack of the currently active switch statements. The innermost
7124 switch statement is on the top of the stack. There is no need to
7125 mark the stack for garbage collection because it is only active
7126 during the processing of the body of a function, and we never
7127 collect at that point. */
7131 /* Start a C switch statement, testing expression EXP. Return the new
7132 SWITCH_STMT. */
7134 tree
7136 tree exp;
7137 {
7143 {
7149 {
7152 }
7153 else
7154 {
7164 }
7165 }
7167 /* Add this new SWITCH_STMT to the stack. */
7175 }
7177 /* Process a case label. */
7179 tree
7181 tree low_value;
7182 tree high_value;
7183 {
7187 {
7196 {
7197 /* Attach the first case label to the SWITCH_BODY. */
7200 }
7201 }
7204 else
7208 }
7210 /* Finish the switch statement. */
7212 void
7214 {
7217 /* Rechain the next statements to the SWITCH_STMT. */
7220 /* Pop the stack. */
7224 }