| blob | 7564660cd012094dea9c8e66b949c4079b3b42c3 |
1 /* Build expressions with type checking for C compiler.
2 Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
10 version.
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
20 02111-1307, USA. */
23 /* This file is part of the C front end.
24 It contains routines to build C expressions given their operands,
25 including computing the types of the result, C-specific error checks,
26 and some optimization.
28 There are also routines to build RETURN_STMT nodes and CASE_STMT nodes,
29 and to process initializations in declarations (since they work
30 like a strange sort of assignment). */
48 /* Nonzero if we've already printed a "missing braces around initializer"
49 message within this initializer. */
52 /* 1 if we explained undeclared var errors. */
88 \f
89 /* Do `exp = require_complete_type (exp);' to make sure exp
90 does not have an incomplete type. (That includes void types.) */
92 tree
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 {
117 /* Avoid duplicate error message. */
125 else
126 {
127 retry:
128 /* We must print an error message. Be clever about what it says. */
131 {
150 {
152 {
155 }
158 }
164 }
169 else
170 /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */
173 }
174 }
176 /* Given a type, apply default promotions wrt unnamed function
177 arguments and return the new type. */
179 tree
181 {
186 {
187 /* Preserve unsignedness if not really getting any wider. */
192 }
195 }
197 /* Return a variant of TYPE which has all the type qualifiers of LIKE
198 as well as those of TYPE. */
200 static tree
202 {
205 }
206 \f
207 /* Return the common type of two types.
208 We assume that comptypes has already been done and returned 1;
209 if that isn't so, this may crash. In particular, we assume that qualifiers
210 match.
212 This is the type for the result of most arithmetic operations
213 if the operands have the given two types. */
215 tree
217 {
220 tree attributes;
222 /* Save time if the two types are the same. */
226 /* If one type is nonsense, use the other. */
232 /* Merge the attributes. */
235 /* Treat an enum type as the unsigned integer type of the same width. */
245 /* If one type is complex, form the common type of the non-complex
246 components, then make that complex. Use T1 or T2 if it is the
247 required type. */
249 {
258 else
260 attributes);
261 }
264 {
267 /* If only one is real, use it as the result. */
275 /* Both real or both integers; use the one with greater precision. */
282 /* Same precision. Prefer longs to ints even when same size. */
287 attributes);
291 {
292 /* But preserve unsignedness from the other type,
293 since long cannot hold all the values of an unsigned int. */
296 else
299 }
301 /* Likewise, prefer long double to double even if same size. */
305 attributes);
307 /* Otherwise prefer the unsigned one. */
311 else
315 /* For two pointers, do this recursively on the target type,
316 and combine the qualifiers of the two types' targets. */
317 /* This code was turned off; I don't know why.
318 But ANSI C specifies doing this with the qualifiers.
319 So I turned it on again. */
320 {
330 }
333 {
335 /* Save space: see if the result is identical to one of the args. */
340 /* Merge the element types, and have a size if either arg has one. */
343 }
346 /* Function types: prefer the one that specified arg types.
347 If both do, merge the arg types. Also merge the return types. */
348 {
356 /* Save space: see if the result is identical to one of the args. */
362 /* Simple way if one arg fails to specify argument types. */
364 {
367 }
369 {
372 }
374 /* If both args specify argument types, we must merge the two
375 lists, argument by argument. */
390 {
391 /* A null type means arg type is not specified.
392 Take whatever the other function type has. */
394 {
397 }
399 {
402 }
404 /* Given wait (union {union wait *u; int *i} *)
405 and wait (union wait *),
406 prefer union wait * as type of parm. */
409 {
410 tree memb;
414 COMPARE_STRICT))
415 {
420 }
421 }
424 {
425 tree memb;
429 COMPARE_STRICT))
430 {
435 }
436 }
438 parm_done: ;
439 }
444 /* ... falls through ... */
445 }
449 }
451 }
452 \f
453 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
454 or various other operations. Return 2 if they are compatible
455 but a warning may be needed if you use them together. */
457 int
459 {
464 /* Suppress errors caused by previously reported errors. */
470 /* If either type is the internal version of sizetype, return the
471 language version. */
480 /* Treat an enum type as the integer type of the same width and
481 signedness. */
491 /* Different classes of types can't be compatible. */
495 /* Qualifiers must match. */
500 /* Allow for two different type nodes which have essentially the same
501 definition. Note that we already checked for equality of the type
502 qualifiers (just above). */
507 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
511 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
515 {
526 {
533 /* Target types must match incl. qualifiers. */
536 flags)))
539 /* Sizes must match unless one is missing or variable. */
546 d1_variable = (! d1_zero
549 d2_variable = (! d2_zero
563 }
576 /* The target might allow certain vector types to be compatible. */
583 }
585 }
587 /* Return 1 if TTL and TTR are pointers to types that are equivalent,
588 ignoring their qualifiers. REFLEXIVE is only used by ObjC - set it
589 to 1 or 0 depending if the check of the pointer types is meant to
590 be reflexive or not (typically, assignments are not reflexive,
591 while comparisons are reflexive).
592 */
594 static int
596 {
599 /* Give objc_comptypes a crack at letting these types through. */
609 }
610 \f
611 /* Subroutines of `comptypes'. */
613 /* The C standard says that two structures in different translation
614 units are compatible with each other only if the types of their
615 fields are compatible (among other things). So, consider two copies
616 of this structure: */
620 tree t1;
621 tree t2;
622 };
624 /* Can they be compatible with each other? We choose to break the
625 recursion by allowing those types to be compatible. */
629 /* Return 1 if two 'struct', 'union', or 'enum' types T1 and T2 are
630 compatible. If the two types are not the same (which has been
631 checked earlier), this can only happen when multiple translation
632 units are being compiled. See C99 6.2.7 paragraph 1 for the exact
633 rules. */
635 static int
637 {
641 /* We have to verify that the tags of the types are the same. This
642 is harder than it looks because this may be a typedef, so we have
643 to go look at the original type. It may even be a typedef of a
644 typedef... */
651 /* C90 didn't have the requirement that the two tags be the same. */
655 /* C90 didn't say what happened if one or both of the types were
656 incomplete; we choose to follow C99 rules here, which is that they
657 are compatible. */
662 {
667 }
670 {
672 {
677 {
682 }
684 }
687 {
692 {
704 {
719 }
723 }
725 }
728 {
739 {
754 }
759 }
763 }
764 }
766 /* Return 1 if two function types F1 and F2 are compatible.
767 If either type specifies no argument types,
768 the other must specify a fixed number of self-promoting arg types.
769 Otherwise, if one type specifies only the number of arguments,
770 the other must specify that number of self-promoting arg types.
771 Otherwise, the argument types must match. */
773 static int
775 {
777 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
785 /* 'volatile' qualifiers on a function's return type mean the function
786 is noreturn. */
802 /* An unspecified parmlist matches any specified parmlist
803 whose argument types don't need default promotions. */
806 {
809 /* If one of these types comes from a non-prototype fn definition,
810 compare that with the other type's arglist.
811 If they don't match, ask for a warning (but no error). */
814 flags))
817 }
819 {
824 flags))
827 }
829 /* Both types have argument lists: compare them and propagate results. */
832 }
834 /* Check two lists of types for compatibility,
835 returning 0 for incompatible, 1 for compatible,
836 or 2 for compatible with warning. */
838 static int
840 {
841 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
846 {
849 /* If one list is shorter than the other,
850 they fail to match. */
853 /* A null pointer instead of a type
854 means there is supposed to be an argument
855 but nothing is specified about what type it has.
856 So match anything that self-promotes. */
858 {
861 }
863 {
866 }
869 flags)))
870 {
871 /* Allow wait (union {union wait *u; int *i} *)
872 and wait (union wait *) to be compatible. */
879 {
880 tree memb;
884 flags))
888 }
895 {
896 tree memb;
900 flags))
904 }
905 else
907 }
909 /* comptypes said ok, but record if it said to warn. */
915 }
916 }
917 \f
918 /* Compute the size to increment a pointer by. */
920 tree
922 {
929 {
932 }
934 /* Convert in case a char is more than one unit. */
938 }
939 \f
940 /* Return either DECL or its known constant value (if it has one). */
942 tree
944 {
946 in a place where a variable is invalid. */
952 /* This is invalid if initial value is not constant.
953 If it has either a function call, a memory reference,
954 or a variable, then re-evaluating it could give different results. */
956 /* Check for cases where this is sub-optimal, even though valid. */
960 }
962 /* Return either DECL or its known constant value (if it has one), but
963 return DECL if pedantic or DECL has mode BLKmode. This is for
964 bug-compatibility with the old behavior of decl_constant_value
965 (before GCC 3.0); every use of this function is a bug and it should
966 be removed before GCC 3.1. It is not appropriate to use pedantic
967 in a way that affects optimization, and BLKmode is probably not the
968 right test for avoiding misoptimizations either. */
970 static tree
972 {
975 else
977 }
980 /* Perform the default conversion of arrays and functions to pointers.
981 Return the result of converting EXP. For any other expression, just
982 return EXP. */
984 static tree
986 {
987 tree orig_exp;
992 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
993 an lvalue.
995 Do not use STRIP_NOPS here! It will remove conversions from pointer
996 to integer and cause infinite recursion. */
1001 {
1005 }
1007 /* Preserve the original expression code. */
1012 {
1014 }
1016 {
1017 tree adr;
1019 tree ptrtype;
1025 {
1028 }
1031 restype
1042 {
1046 }
1050 {
1051 /* Before C99, non-lvalue arrays do not decay to pointers.
1052 Normally, using such an array would be invalid; but it can
1053 be used correctly inside sizeof or as a statement expression.
1054 Thus, do not give an error here; an error will result later. */
1056 }
1061 {
1062 /* ??? This is not really quite correct
1063 in that the type of the operand of ADDR_EXPR
1064 is not the target type of the type of the ADDR_EXPR itself.
1065 Question is, can this lossage be avoided? */
1072 }
1073 /* This way is better for a COMPONENT_REF since it can
1074 simplify the offset for a component. */
1077 }
1079 }
1081 /* Perform default promotions for C data used in expressions.
1082 Arrays and functions are converted to pointers;
1083 enumeral types or short or char, to int.
1084 In addition, manifest constants symbols are replaced by their values. */
1086 tree
1088 {
1089 tree orig_exp;
1096 /* Constants can be used directly unless they're not loadable. */
1100 /* Replace a nonvolatile const static variable with its value unless
1101 it is an array, in which case we must be sure that taking the
1102 address of the array produces consistent results. */
1104 {
1107 }
1109 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
1110 an lvalue.
1112 Do not use STRIP_NOPS here! It will remove conversions from pointer
1113 to integer and cause infinite recursion. */
1120 /* Preserve the original expression code. */
1124 /* Normally convert enums to int,
1125 but convert wide enums to something wider. */
1127 {
1135 }
1139 /* If it's thinner than an int, promote it like a
1140 c_promoting_integer_type_p, otherwise leave it alone. */
1146 {
1147 /* Preserve unsignedness if not really getting any wider. */
1153 }
1156 {
1159 }
1161 }
1162 \f
1163 /* Look up COMPONENT in a structure or union DECL.
1165 If the component name is not found, returns NULL_TREE. Otherwise,
1166 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL
1167 stepping down the chain to the component, which is in the last
1168 TREE_VALUE of the list. Normally the list is of length one, but if
1169 the component is embedded within (nested) anonymous structures or
1170 unions, the list steps down the chain to the component. */
1172 static tree
1174 {
1176 tree field;
1178 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers
1179 to the field elements. Use a binary search on this array to quickly
1180 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC
1181 will always be set for structures which have many elements. */
1184 {
1192 {
1197 {
1198 /* Step through all anon unions in linear fashion. */
1200 {
1204 {
1209 }
1210 }
1212 /* Entire record is only anon unions. */
1216 /* Restart the binary search, with new lower bound. */
1218 }
1224 else
1226 }
1232 }
1233 else
1234 {
1236 {
1240 {
1245 }
1249 }
1253 }
1256 }
1258 /* Make an expression to refer to the COMPONENT field of
1259 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */
1261 tree
1263 {
1267 tree ref;
1269 /* If DATUM is a COMPOUND_EXPR, move our reference inside it.
1270 If pedantic ensure that the arguments are not lvalues; otherwise,
1271 if the component is an array, it would wrongly decay to a pointer in
1272 C89 mode.
1273 We cannot do this with a COND_EXPR, because in a conditional expression
1274 the default promotions are applied to both sides, and this would yield
1275 the wrong type of the result; for example, if the components have
1276 type "char". */
1278 {
1280 {
1284 }
1287 }
1289 /* See if there is a field or component with name COMPONENT. */
1292 {
1294 {
1297 }
1302 {
1307 }
1309 /* Chain the COMPONENT_REFs if necessary down to the FIELD.
1310 This might be better solved in future the way the C++ front
1311 end does it - by giving the anonymous entities each a
1312 separate name and type, and then have build_component_ref
1313 recursively call itself. We can't do that here. */
1314 do
1315 {
1333 }
1337 }
1343 }
1344 \f
1345 /* Given an expression PTR for a pointer, return an expression
1346 for the value pointed to.
1347 ERRORSTRING is the name of the operator to appear in error messages. */
1349 tree
1351 {
1356 {
1361 else
1362 {
1367 {
1370 }
1374 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
1375 so that we get the proper error message if the result is used
1376 to assign to. Also, &* is supposed to be a no-op.
1377 And ANSI C seems to specify that the type of the result
1378 should be the const type. */
1379 /* A de-reference of a pointer to const is not a const. It is valid
1380 to change it via some other pointer. */
1386 }
1387 }
1391 }
1393 /* This handles expressions of the form "a[i]", which denotes
1394 an array reference.
1396 This is logically equivalent in C to *(a+i), but we may do it differently.
1397 If A is a variable or a member, we generate a primitive ARRAY_REF.
1398 This avoids forcing the array out of registers, and can work on
1399 arrays that are not lvalues (for example, members of structures returned
1400 by functions). */
1402 tree
1404 {
1406 {
1409 }
1417 {
1420 /* Subscripting with type char is likely to lose
1421 on a machine where chars are signed.
1422 So warn on any machine, but optionally.
1423 Don't warn for unsigned char since that type is safe.
1424 Don't warn for signed char because anyone who uses that
1425 must have done so deliberately. */
1430 /* Apply default promotions *after* noticing character types. */
1433 /* Require integer *after* promotion, for sake of enums. */
1435 {
1438 }
1440 /* An array that is indexed by a non-constant
1441 cannot be stored in a register; we must be able to do
1442 address arithmetic on its address.
1443 Likewise an array of elements of variable size. */
1447 {
1450 }
1451 /* An array that is indexed by a constant value which is not within
1452 the array bounds cannot be stored in a register either; because we
1453 would get a crash in store_bit_field/extract_bit_field when trying
1454 to access a non-existent part of the register. */
1458 {
1461 }
1464 {
1472 }
1476 /* Array ref is const/volatile if the array elements are
1477 or if the array is. */
1486 /* This was added by rms on 16 Nov 91.
1487 It fixes vol struct foo *a; a->elts[1]
1488 in an inline function.
1489 Hope it doesn't break something else. */
1492 }
1494 {
1498 /* Do the same warning check as above, but only on the part that's
1499 syntactically the index and only if it is also semantically
1500 the index. */
1506 /* Put the integer in IND to simplify error checking. */
1508 {
1512 }
1519 {
1522 }
1524 {
1527 }
1531 }
1532 }
1533 \f
1534 /* Issue an error message for a reference to an undeclared variable ID,
1535 including a reference to a builtin outside of function-call context.
1536 Arrange to suppress further errors for the same identifier. */
1537 static void
1539 {
1541 {
1545 }
1546 else
1547 {
1552 {
1556 }
1558 /* Set IDENTIFIER_SYMBOL_VALUE (id) to error_mark_node
1559 at function scope. This suppresses further warnings
1560 about this undeclared identifier in this function. */
1562 }
1563 }
1565 /* Build an external reference to identifier ID. FUN indicates
1566 whether this will be used for a function call. */
1567 tree
1569 {
1570 tree ref;
1575 {
1576 /* Properly declared variable or function reference. */
1580 {
1584 }
1585 else
1587 }
1591 /* Implicit function declaration. */
1594 /* Don't complain about something that's already been
1595 complained about. */
1597 else
1598 {
1601 }
1614 {
1617 }
1623 {
1628 }
1631 }
1633 /* Build a function call to function FUNCTION with parameters PARAMS.
1634 PARAMS is a list--a chain of TREE_LIST nodes--in which the
1635 TREE_VALUE of each node is a parameter-expression.
1636 FUNCTION's data type may be a function type or a pointer-to-function. */
1638 tree
1640 {
1642 tree coerced_params;
1645 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
1648 /* Convert anything with function type to a pointer-to-function. */
1650 {
1653 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
1654 (because calling an inline function does not mean the function
1655 needs to be separately compiled). */
1661 }
1662 else
1672 {
1675 }
1680 /* fntype now gets the type of function pointed to. */
1683 /* Convert the parameters to the types declared in the
1684 function prototype, or apply default promotions. */
1686 coerced_params
1689 /* Check that the arguments to the function are valid. */
1693 /* Recognize certain built-in functions so we can make tree-codes
1694 other than CALL_EXPR. We do this when it enables fold-const.c
1695 to do something useful. */
1700 {
1705 }
1715 }
1716 \f
1717 /* Convert the argument expressions in the list VALUES
1718 to the types in the list TYPELIST. The result is a list of converted
1719 argument expressions.
1721 If TYPELIST is exhausted, or when an element has NULL as its type,
1722 perform the default conversions.
1724 PARMLIST is the chain of parm decls for the function being called.
1725 It may be 0, if that info is not available.
1726 It is used only for generating error messages.
1728 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
1730 This is also where warnings about wrong number of args are generated.
1732 Both VALUES and the returned value are chains of TREE_LIST nodes
1733 with the elements of the list in the TREE_VALUE slots of those nodes. */
1735 static tree
1737 {
1742 /* Scan the given expressions and types, producing individual
1743 converted arguments and pushing them on RESULT in reverse order. */
1746 valtail;
1748 {
1753 {
1757 else
1760 }
1762 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
1763 /* Do not use STRIP_NOPS here! We do not want an enumerator with value 0
1764 to convert automatically to a pointer. */
1773 {
1774 /* Formal parm type is specified by a function prototype. */
1775 tree parmval;
1778 {
1781 }
1782 else
1783 {
1784 /* Optionally warn about conversions that
1785 differ from the default conversions. */
1787 {
1792 warn_for_assignment ("%s as integer rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1795 warn_for_assignment ("%s as integer rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1798 warn_for_assignment ("%s as complex rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1801 warn_for_assignment ("%s as floating rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1804 warn_for_assignment ("%s as complex rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1807 warn_for_assignment ("%s as floating rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1808 /* ??? At some point, messages should be written about
1809 conversions between complex types, but that's too messy
1810 to do now. */
1813 {
1814 /* Warn if any argument is passed as `float',
1815 since without a prototype it would be `double'. */
1817 warn_for_assignment ("%s as `float' rather than `double' due to prototype", (char *) 0, name, parmnum + 1);
1818 }
1819 /* Detect integer changing in width or signedness.
1820 These warnings are only activated with
1821 -Wconversion, not with -Wtraditional. */
1824 {
1831 /* No warning if function asks for enum
1832 and the actual arg is that enum type. */
1833 ;
1835 warn_for_assignment ("%s with different width due to prototype", (char *) 0, name, parmnum + 1);
1837 ;
1838 /* Don't complain if the formal parameter type
1839 is an enum, because we can't tell now whether
1840 the value was an enum--even the same enum. */
1842 ;
1845 /* Change in signedness doesn't matter
1846 if a constant value is unaffected. */
1847 ;
1848 /* Likewise for a constant in a NOP_EXPR. */
1852 ;
1853 /* If the value is extended from a narrower
1854 unsigned type, it doesn't matter whether we
1855 pass it as signed or unsigned; the value
1856 certainly is the same either way. */
1859 ;
1862 else
1864 }
1865 }
1875 }
1877 }
1881 /* Convert `float' to `double'. */
1883 else
1884 /* Convert `short' and `char' to full-size `int'. */
1889 }
1892 {
1896 else
1898 }
1901 }
1902 \f
1903 /* This is the entry point used by the parser
1904 for binary operators in the input.
1905 In addition to constructing the expression,
1906 we check for operands that were written with other binary operators
1907 in a way that is likely to confuse the user. */
1909 tree
1911 {
1928 /* Check for cases such as x+y<<z which users are likely
1929 to misinterpret. If parens are used, C_EXP_ORIGINAL_CODE
1930 is cleared to prevent these warnings. */
1932 {
1934 {
1938 }
1941 {
1945 }
1948 {
1954 /* Check cases like x|y==z */
1957 }
1960 {
1966 /* Check cases like x^y==z */
1969 }
1972 {
1976 /* Check cases like x&y==z */
1979 }
1980 }
1982 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */
1993 /* Record the code that was specified in the source,
1994 for the sake of warnings about confusing nesting. */
1997 else
1998 {
2000 /* We used to use NOP_EXPR rather than NON_LVALUE_EXPR
2001 so that convert_for_assignment wouldn't strip it.
2002 That way, we got warnings for things like p = (1 - 1).
2003 But it turns out we should not get those warnings. */
2007 }
2010 }
2012 /* Build a binary-operation expression without default conversions.
2013 CODE is the kind of expression to build.
2014 This function differs from `build' in several ways:
2015 the data type of the result is computed and recorded in it,
2016 warnings are generated if arg data types are invalid,
2017 special handling for addition and subtraction of pointers is known,
2018 and some optimization is done (operations on narrow ints
2019 are done in the narrower type when that gives the same result).
2020 Constant folding is also done before the result is returned.
2022 Note that the operands will never have enumeral types, or function
2023 or array types, because either they will have the default conversions
2024 performed or they have both just been converted to some other type in which
2025 the arithmetic is to be done. */
2027 tree
2030 {
2035 /* Expression code to give to the expression when it is built.
2036 Normally this is CODE, which is what the caller asked for,
2037 but in some special cases we change it. */
2040 /* Data type in which the computation is to be performed.
2041 In the simplest cases this is the common type of the arguments. */
2044 /* Nonzero means operands have already been type-converted
2045 in whatever way is necessary.
2046 Zero means they need to be converted to RESULT_TYPE. */
2049 /* Nonzero means create the expression with this type, rather than
2050 RESULT_TYPE. */
2053 /* Nonzero means after finally constructing the expression
2054 convert it to this type. */
2057 /* Nonzero if this is an operation like MIN or MAX which can
2058 safely be computed in short if both args are promoted shorts.
2059 Also implies COMMON.
2060 -1 indicates a bitwise operation; this makes a difference
2061 in the exact conditions for when it is safe to do the operation
2062 in a narrower mode. */
2065 /* Nonzero if this is a comparison operation;
2066 if both args are promoted shorts, compare the original shorts.
2067 Also implies COMMON. */
2070 /* Nonzero if this is a right-shift operation, which can be computed on the
2071 original short and then promoted if the operand is a promoted short. */
2074 /* Nonzero means set RESULT_TYPE to the common type of the args. */
2078 {
2081 }
2082 else
2083 {
2086 }
2091 /* The expression codes of the data types of the arguments tell us
2092 whether the arguments are integers, floating, pointers, etc. */
2096 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2100 /* If an error was already reported for one of the arguments,
2101 avoid reporting another error. */
2107 {
2109 /* Handle the pointer + int case. */
2114 else
2119 /* Subtraction of two similar pointers.
2120 We must subtract them as integers, then divide by object size. */
2124 /* Handle pointer minus int. Just like pointer plus int. */
2127 else
2140 /* Floating point division by zero is a legitimate way to obtain
2141 infinities and NaNs. */
2149 {
2152 else
2153 /* Although it would be tempting to shorten always here, that
2154 loses on some targets, since the modulo instruction is
2155 undefined if the quotient can't be represented in the
2156 computation mode. We shorten only if unsigned or if
2157 dividing by something we know != -1. */
2162 }
2181 {
2182 /* Although it would be tempting to shorten always here, that loses
2183 on some targets, since the modulo instruction is undefined if the
2184 quotient can't be represented in the computation mode. We shorten
2185 only if unsigned or if dividing by something we know != -1. */
2190 }
2202 {
2203 /* Result of these operations is always an int,
2204 but that does not mean the operands should be
2205 converted to ints! */
2210 }
2213 /* Shift operations: result has same type as first operand;
2214 always convert second operand to int.
2215 Also set SHORT_SHIFT if shifting rightward. */
2219 {
2221 {
2224 else
2225 {
2231 }
2232 }
2234 /* Use the type of the value to be shifted. */
2236 /* Convert the shift-count to an integer, regardless of size
2237 of value being shifted. */
2240 /* Avoid converting op1 to result_type later. */
2242 }
2247 {
2249 {
2255 }
2257 /* Use the type of the value to be shifted. */
2259 /* Convert the shift-count to an integer, regardless of size
2260 of value being shifted. */
2263 /* Avoid converting op1 to result_type later. */
2265 }
2271 {
2273 {
2278 }
2280 /* Use the type of the value to be shifted. */
2282 /* Convert the shift-count to an integer, regardless of size
2283 of value being shifted. */
2286 /* Avoid converting op1 to result_type later. */
2288 }
2295 /* Result of comparison is always int,
2296 but don't convert the args to int! */
2306 {
2309 /* Anything compares with void *. void * compares with anything.
2310 Otherwise, the targets must be compatible
2311 and both must be object or both incomplete. */
2315 {
2316 /* op0 != orig_op0 detects the case of something
2317 whose value is 0 but which isn't a valid null ptr const. */
2321 }
2323 {
2327 }
2328 else
2333 }
2341 {
2344 }
2346 {
2349 }
2358 {
2360 {
2365 }
2366 else
2367 {
2370 }
2371 }
2383 {
2385 {
2393 }
2394 else
2395 {
2398 }
2399 }
2402 {
2406 }
2409 {
2413 }
2415 {
2418 }
2420 {
2423 }
2435 {
2438 }
2444 }
2448 &&
2451 {
2457 /* For certain operations (which identify themselves by shorten != 0)
2458 if both args were extended from the same smaller type,
2459 do the arithmetic in that type and then extend.
2461 shorten !=0 and !=1 indicates a bitwise operation.
2462 For them, this optimization is safe only if
2463 both args are zero-extended or both are sign-extended.
2464 Otherwise, we might change the result.
2465 Eg, (short)-1 | (unsigned short)-1 is (int)-1
2466 but calculated in (unsigned short) it would be (unsigned short)-1. */
2469 {
2473 /* UNS is 1 if the operation to be done is an unsigned one. */
2475 tree type;
2479 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
2480 but it *requires* conversion to FINAL_TYPE. */
2491 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
2493 /* For bitwise operations, signedness of nominal type
2494 does not matter. Consider only how operands were extended. */
2498 /* Note that in all three cases below we refrain from optimizing
2499 an unsigned operation on sign-extended args.
2500 That would not be valid. */
2502 /* Both args variable: if both extended in same way
2503 from same width, do it in that width.
2504 Do it unsigned if args were zero-extended. */
2511 result_type
2512 = c_common_signed_or_unsigned_type
2518 && (type
2527 && (type
2532 }
2534 /* Shifts can be shortened if shifting right. */
2537 {
2547 /* We can shorten only if the shift count is less than the
2548 number of bits in the smaller type size. */
2550 /* We cannot drop an unsigned shift after sign-extension. */
2552 {
2553 /* Do an unsigned shift if the operand was zero-extended. */
2554 result_type
2557 /* Convert value-to-be-shifted to that type. */
2561 }
2562 }
2564 /* Comparison operations are shortened too but differently.
2565 They identify themselves by setting short_compare = 1. */
2568 {
2569 /* Don't write &op0, etc., because that would prevent op0
2570 from being kept in a register.
2571 Instead, make copies of the our local variables and
2572 pass the copies by reference, then copy them back afterward. */
2575 tree val
2586 {
2598 /* Give warnings for comparisons between signed and unsigned
2599 quantities that may fail.
2601 Do the checking based on the original operand trees, so that
2602 casts will be considered, but default promotions won't be.
2604 Do not warn if the comparison is being done in a signed type,
2605 since the signed type will only be chosen if it can represent
2606 all the values of the unsigned type. */
2609 /* Do not warn if both operands are the same signedness. */
2612 else
2613 {
2618 else
2621 /* Do not warn if the signed quantity is an
2622 unsuffixed integer literal (or some static
2623 constant expression involving such literals or a
2624 conditional expression involving such literals)
2625 and it is non-negative. */
2628 /* Do not warn if the comparison is an equality operation,
2629 the unsigned quantity is an integral constant, and it
2630 would fit in the result if the result were signed. */
2633 && int_fits_type_p
2636 /* Do not warn if the unsigned quantity is an enumeration
2637 constant and its maximum value would fit in the result
2638 if the result were signed. */
2641 && int_fits_type_p
2645 else
2647 }
2649 /* Warn if two unsigned values are being compared in a size
2650 larger than their original size, and one (and only one) is the
2651 result of a `~' operator. This comparison will always fail.
2653 Also warn if one operand is a constant, and the constant
2654 does not have all bits set that are set in the ~ operand
2655 when it is extended. */
2659 {
2663 else
2668 {
2669 tree primop;
2674 {
2678 }
2679 else
2680 {
2684 }
2689 {
2693 }
2694 }
2701 }
2702 }
2703 }
2704 }
2706 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
2707 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
2708 Then the expression will be built.
2709 It will be given type FINAL_TYPE if that is nonzero;
2710 otherwise, it will be given type RESULT_TYPE. */
2713 {
2716 }
2719 {
2724 }
2729 {
2731 tree folded;
2739 }
2740 }
2741 \f
2743 /* Return true if `t' is known to be non-negative. */
2745 int
2747 {
2749 {
2752 /* Find the last statement in the chain, ignoring the final
2753 * scope statement */
2758 }
2760 }
2762 /* Return a tree for the difference of pointers OP0 and OP1.
2763 The resulting tree has type int. */
2765 static tree
2767 {
2776 {
2781 }
2783 /* If the conversion to ptrdiff_type does anything like widening or
2784 converting a partial to an integral mode, we get a convert_expression
2785 that is in the way to do any simplifications.
2786 (fold-const.c doesn't know that the extra bits won't be needed.
2787 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2788 different mode in place.)
2789 So first try to find a common term here 'by hand'; we want to cover
2790 at least the cases that occur in legal static initializers. */
2795 {
2798 }
2799 else
2803 {
2806 }
2807 else
2811 {
2814 }
2817 /* First do the subtraction as integers;
2818 then drop through to build the divide operator.
2819 Do not do default conversions on the minus operator
2820 in case restype is a short type. */
2824 /* This generates an error if op1 is pointer to incomplete type. */
2828 /* This generates an error if op0 is pointer to incomplete type. */
2831 /* Divide by the size, in easiest possible way. */
2839 }
2840 \f
2841 /* Construct and perhaps optimize a tree representation
2842 for a unary operation. CODE, a tree_code, specifies the operation
2843 and XARG is the operand.
2844 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2845 the default promotions (such as from short to int).
2846 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2847 allows non-lvalues; this is only used to handle conversion of non-lvalue
2848 arrays to pointers in C99. */
2850 tree
2852 {
2853 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2857 tree val;
2866 {
2868 /* This is used for unary plus, because a CONVERT_EXPR
2869 is enough to prevent anybody from looking inside for
2870 associativity, but won't generate any code. */
2873 {
2876 }
2886 {
2889 }
2896 {
2899 }
2901 {
2907 }
2908 else
2909 {
2912 }
2918 {
2921 }
2927 /* Conjugating a real value is a no-op, but allow it anyway. */
2930 {
2933 }
2942 /* These will convert to a pointer. */
2944 {
2947 }
2959 else
2967 else
2974 /* Handle complex lvalues (when permitted)
2975 by reduction to simpler cases. */
2981 /* Increment or decrement the real part of the value,
2982 and don't change the imaginary part. */
2984 {
2995 }
2997 /* Report invalid types. */
3001 {
3004 else
3008 }
3010 {
3011 tree inc;
3017 /* Compute the increment. */
3020 {
3021 /* If pointer target is an undefined struct,
3022 we just cannot know how to do the arithmetic. */
3024 {
3027 else
3029 }
3033 {
3036 else
3038 }
3041 }
3042 else
3047 /* Handle incrementing a cast-expression. */
3051 {
3060 /* If the real type has the same machine representation
3061 as the type it is cast to, we can make better output
3062 by adding directly to the inside of the cast. */
3068 else
3069 {
3073 else
3074 {
3078 else
3087 }
3090 }
3095 }
3096 give_up:
3098 /* Complain about anything else that is not a true lvalue. */
3105 /* Report a read-only lvalue. */
3114 else
3121 }
3124 /* Note that this operation never does default_conversion. */
3126 /* Let &* cancel out to simplify resulting code. */
3128 {
3129 /* Don't let this be an lvalue. */
3133 }
3135 /* For &x[y], return x+y */
3137 {
3142 }
3144 /* Handle complex lvalues (when permitted)
3145 by reduction to simpler cases. */
3150 /* Anything not already handled and not a true memory reference
3151 or a non-lvalue array is an error. */
3156 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
3159 /* If the lvalue is const or volatile, merge that into the type
3160 to which the address will point. Note that you can't get a
3161 restricted pointer by taking the address of something, so we
3162 only have to deal with `const' and `volatile' here. */
3174 {
3175 tree addr;
3178 {
3184 {
3188 }
3193 }
3194 else
3197 /* Address of a static or external variable or
3198 file-scope function counts as a constant. */
3204 }
3208 }
3213 }
3215 /* Return nonzero if REF is an lvalue valid for this language.
3216 Lvalues can be assigned, unless their type has TYPE_READONLY.
3217 Lvalues can have their address taken, unless they have DECL_REGISTER. */
3219 int
3221 {
3225 {
3250 }
3251 }
3253 /* Return nonzero if REF is an lvalue valid for this language;
3254 otherwise, print an error message and return zero. */
3256 int
3258 {
3265 }
3267 /* Apply unary lvalue-demanding operator CODE to the expression ARG
3268 for certain kinds of expressions which are not really lvalues
3269 but which we can accept as lvalues. If FLAG is nonzero, then
3270 non-lvalues are OK since we may be converting a non-lvalue array to
3271 a pointer in C99.
3273 If ARG is not a kind of expression we can handle, return zero. */
3275 static tree
3277 {
3278 /* Handle (a, b) used as an "lvalue". */
3280 {
3283 /* If this returns a function type, it isn't really being used as
3284 an lvalue, so don't issue a warning about it. */
3290 }
3292 /* Handle (a ? b : c) used as an "lvalue". */
3294 {
3304 }
3307 }
3309 /* If pedantic, warn about improper lvalue. CODE is either COND_EXPR
3310 COMPOUND_EXPR, or CONVERT_EXPR (for casts). */
3312 static void
3314 {
3317 {
3327 }
3328 }
3329 \f
3330 /* Warn about storing in something that is `const'. */
3332 void
3334 {
3336 {
3339 else
3342 }
3346 else
3348 }
3349 \f
3350 /* Mark EXP saying that we need to be able to take the
3351 address of it; it should not be allocated in a register.
3352 Returns true if successful. */
3354 bool
3356 {
3361 {
3364 {
3368 }
3370 /* ... fall through ... */
3390 {
3392 {
3396 }
3399 }
3401 {
3403 {
3407 }
3409 /* If we are making this addressable due to its having
3410 volatile components, give a different error message. Also
3411 handle the case of an unnamed parameter by not trying
3412 to give the name. */
3415 {
3418 }
3422 }
3425 /* drops in */
3428 /* drops out */
3431 }
3432 }
3433 \f
3434 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
3436 tree
3438 {
3439 tree type1;
3440 tree type2;
3448 /* Promote both alternatives. */
3465 /* Quickly detect the usual case where op1 and op2 have the same type
3466 after promotion. */
3468 {
3471 else
3473 }
3478 {
3481 /* If -Wsign-compare, warn here if type1 and type2 have
3482 different signedness. We'll promote the signed to unsigned
3483 and later code won't know it used to be different.
3484 Do this check on the original types, so that explicit casts
3485 will be considered, but default promotions won't. */
3487 {
3492 {
3493 /* Do not warn if the result type is signed, since the
3494 signed type will only be chosen if it can represent
3495 all the values of the unsigned type. */
3498 /* Do not warn if the signed quantity is an unsuffixed
3499 integer literal (or some static constant expression
3500 involving such literals) and it is non-negative. */
3504 else
3506 }
3507 }
3508 }
3510 {
3514 }
3516 {
3526 {
3531 }
3533 {
3538 }
3539 else
3540 {
3543 }
3544 }
3546 {
3549 else
3550 {
3552 }
3554 }
3556 {
3559 else
3560 {
3562 }
3564 }
3567 {
3570 else
3571 {
3574 }
3575 }
3577 /* Merge const and volatile flags of the incoming types. */
3578 result_type
3592 }
3593 \f
3594 /* Given a list of expressions, return a compound expression
3595 that performs them all and returns the value of the last of them. */
3597 tree
3599 {
3601 }
3603 static tree
3605 {
3606 tree rest;
3609 {
3610 /* Convert arrays and functions to pointers when there
3611 really is a comma operator. */
3616 /* Don't let (0, 0) be null pointer constant. */
3620 }
3625 {
3626 /* The left-hand operand of a comma expression is like an expression
3627 statement: with -Wextra or -Wunused, we should warn if it doesn't have
3628 any side-effects, unless it was explicitly cast to (void). */
3634 /* When pedantic, a compound expression can be neither an lvalue
3635 nor an integer constant expression. */
3638 }
3640 /* With -Wunused, we should also warn if the left-hand operand does have
3641 side-effects, but computes a value which is not used. For example, in
3642 `foo() + bar(), baz()' the result of the `+' operator is not used,
3643 so we should issue a warning. */
3648 }
3650 /* Build an expression representing a cast to type TYPE of expression EXPR. */
3652 tree
3654 {
3660 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
3661 only in <protocol> qualifications. But when constructing cast expressions,
3662 the protocols do matter and must be kept around. */
3667 {
3670 }
3673 {
3676 }
3679 {
3681 {
3685 }
3686 }
3688 {
3689 tree field;
3698 {
3699 tree t;
3709 }
3712 }
3713 else
3714 {
3717 /* If casting to void, avoid the error that would come
3718 from default_conversion in the case of a non-lvalue array. */
3722 /* Convert functions and arrays to pointers,
3723 but don't convert any other types. */
3727 /* Optionally warn about potentially worrisome casts. */
3732 {
3738 /* Check that the qualifiers on IN_TYPE are a superset of
3739 the qualifiers of IN_OTYPE. The outermost level of
3740 POINTER_TYPE nodes is uninteresting and we stop as soon
3741 as we hit a non-POINTER_TYPE node on either type. */
3742 do
3743 {
3747 /* GNU C allows cv-qualified function types. 'const'
3748 means the function is very pure, 'volatile' means it
3749 can't return. We need to warn when such qualifiers
3750 are added, not when they're taken away. */
3754 else
3756 }
3764 /* There are qualifiers present in IN_OTYPE that are not
3765 present in IN_TYPE. */
3767 }
3769 /* Warn about possible alignment problems. */
3775 /* Don't warn about opaque types, where the actual alignment
3776 restriction is unknown. */
3797 /* Don't warn about converting any constant. */
3807 {
3808 /* Casting the address of a decl to non void pointer. Warn
3809 if the cast breaks type based aliasing. */
3816 }
3819 /* Replace a nonvolatile const static variable with its value. */
3824 /* Ignore any integer overflow caused by the cast. */
3826 {
3829 }
3830 }
3832 /* Pedantically, don't let (void *) (FOO *) 0 be a null pointer constant. */
3838 /* If pedantic, don't let a cast be an lvalue. */
3843 }
3845 /* Interpret a cast of expression EXPR to type TYPE. */
3846 tree
3848 {
3851 /* This avoids warnings about unprototyped casts on
3852 integers. E.g. "#define SIG_DFL (void(*)())0". */
3859 }
3861 \f
3862 /* Build an assignment expression of lvalue LHS from value RHS.
3863 MODIFYCODE is the code for a binary operator that we use
3864 to combine the old value of LHS with RHS to get the new value.
3865 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3867 tree
3869 {
3870 tree result;
3871 tree newrhs;
3875 /* Types that aren't fully specified cannot be used in assignments. */
3878 /* Avoid duplicate error messages from operands that had errors. */
3882 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3883 /* Do not use STRIP_NOPS here. We do not want an enumerator
3884 whose value is 0 to count as a null pointer constant. */
3890 /* Handle control structure constructs used as "lvalues". */
3893 {
3894 /* Handle (a, b) used as an "lvalue". */
3903 /* Handle (a ? b : c) used as an "lvalue". */
3907 {
3908 /* Produce (a ? (b = rhs) : (c = rhs))
3909 except that the RHS goes through a save-expr
3910 so the code to compute it is only emitted once. */
3911 tree cond
3919 /* Make sure the code to compute the rhs comes out
3920 before the split. */
3922 /* But cast it to void to avoid an "unused" error. */
3924 }
3927 }
3929 /* If a binary op has been requested, combine the old LHS value with the RHS
3930 producing the value we should actually store into the LHS. */
3933 {
3936 }
3938 /* Handle a cast used as an "lvalue".
3939 We have already performed any binary operator using the value as cast.
3940 Now convert the result to the cast type of the lhs,
3941 and then true type of the lhs and store it there;
3942 then convert result back to the cast type to be the value
3943 of the assignment. */
3946 {
3955 {
3957 tree result;
3965 }
3969 }
3971 /* Now we have handled acceptable kinds of LHS that are not truly lvalues.
3972 Reject anything strange now. */
3977 /* Warn about storing in something that is `const'. */
3985 /* If storing into a structure or union member,
3986 it has probably been given type `int'.
3987 Compute the type that would go with
3988 the actual amount of storage the member occupies. */
3997 /* If storing in a field that is in actuality a short or narrower than one,
3998 we must store in the field in its actual type. */
4001 {
4004 }
4006 /* Convert new value to destination type. */
4013 /* Scan operands */
4018 /* If we got the LHS in a different type for storing in,
4019 convert the result back to the nominal type of LHS
4020 so that the value we return always has the same type
4021 as the LHS argument. */
4027 }
4028 \f
4029 /* Convert value RHS to type TYPE as preparation for an assignment
4030 to an lvalue of type TYPE.
4031 The real work of conversion is done by `convert'.
4032 The purpose of this function is to generate error messages
4033 for assignments that are not allowed in C.
4034 ERRTYPE is a string to use in error messages:
4035 "assignment", "return", etc. If it is null, this is parameter passing
4036 for a function call (and different error messages are output).
4038 FUNNAME is the name of the function being called,
4039 as an IDENTIFIER_NODE, or null.
4040 PARMNUM is the number of the argument, for printing in error messages. */
4042 static tree
4045 {
4047 tree rhstype;
4050 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
4051 /* Do not use STRIP_NOPS here. We do not want an enumerator
4052 whose value is 0 to count as a null pointer constant. */
4069 {
4071 /* Check for Objective-C protocols. This will automatically
4072 issue a warning if there are protocol violations. No need to
4073 use the return value. */
4077 }
4080 {
4083 }
4084 /* A type converts to a reference to it.
4085 This code doesn't fully support references, it's just for the
4086 special case of va_start and va_copy. */
4089 {
4091 {
4094 }
4099 /* We already know that these two types are compatible, but they
4100 may not be exactly identical. In fact, `TREE_TYPE (type)' is
4101 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
4102 likely to be va_list, a typedef to __builtin_va_list, which
4103 is different enough that it will cause problems later. */
4109 }
4110 /* Some types can interconvert without explicit casts. */
4115 /* Arithmetic types all interconvert, and enum is treated like int. */
4124 /* Conversion to a transparent union from its member types.
4125 This applies only to function arguments. */
4127 {
4128 tree memb_types;
4133 {
4144 {
4148 /* Any non-function converts to a [const][volatile] void *
4149 and vice versa; otherwise, targets must be the same.
4150 Meanwhile, the lhs target must have all the qualifiers of
4151 the rhs. */
4154 {
4155 /* If this type won't generate any warnings, use it. */
4165 /* Keep looking for a better type, but remember this one. */
4168 }
4169 }
4171 /* Can convert integer zero to any pointer type. */
4175 {
4178 }
4179 }
4182 {
4184 {
4185 /* We have only a marginally acceptable member type;
4186 it needs a warning. */
4190 /* Const and volatile mean something different for function
4191 types, so the usual warnings are not appropriate. */
4194 {
4195 /* Because const and volatile on functions are
4196 restrictions that say the function will not do
4197 certain things, it is okay to use a const or volatile
4198 function where an ordinary one is wanted, but not
4199 vice-versa. */
4203 }
4207 parmnum);
4208 }
4214 }
4215 }
4217 /* Conversions among pointers */
4220 {
4225 /* Opaque pointers are treated like void pointers. */
4231 /* Any non-function converts to a [const][volatile] void *
4232 and vice versa; otherwise, targets must be the same.
4233 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
4236 || is_opaque_pointer
4239 {
4242 ||
4244 /* Check TREE_CODE to catch cases like (void *) (char *) 0
4245 which are not ANSI null ptr constants. */
4250 /* Const and volatile mean something different for function types,
4251 so the usual warnings are not appropriate. */
4254 {
4258 /* If this is not a case of ignoring a mismatch in signedness,
4259 no warning. */
4262 ;
4263 /* If there is a mismatch, do warn. */
4267 }
4270 {
4271 /* Because const and volatile on functions are restrictions
4272 that say the function will not do certain things,
4273 it is okay to use a const or volatile function
4274 where an ordinary one is wanted, but not vice-versa. */
4278 }
4279 }
4280 else
4284 }
4286 {
4287 /* An explicit constant 0 can convert to a pointer,
4288 or one that results from arithmetic, even including
4289 a cast to integer type. */
4291 &&
4296 {
4300 }
4302 }
4304 {
4308 }
4313 {
4315 {
4321 else
4324 }
4325 else
4327 parmnum);
4328 }
4329 else
4333 }
4335 /* Convert VALUE for assignment into inlined parameter PARM. */
4337 tree
4339 {
4342 /* If FN was prototyped, the value has been converted already
4343 in convert_arguments. */
4356 }
4358 /* Print a warning using MSGID.
4359 It gets OPNAME as its one parameter.
4360 if OPNAME is null and ARGNUM is 0, it is replaced by "passing arg of `FUNCTION'".
4361 Otherwise if OPNAME is null, it is replaced by "passing arg ARGNUM of `FUNCTION'".
4362 FUNCTION and ARGNUM are handled specially if we are building an
4363 Objective-C selector. */
4365 static void
4368 {
4370 {
4375 {
4378 }
4380 {
4382 {
4383 /* Function name is known; supply it. */
4390 }
4391 else
4392 {
4393 /* Function name unknown (call through ptr). */
4397 }
4398 }
4400 {
4401 /* Function name is known; supply it. */
4408 }
4409 else
4410 {
4411 /* Function name unknown (call through ptr); just give arg number. */
4415 }
4417 }
4419 }
4420 \f
4421 /* If VALUE is a compound expr all of whose expressions are constant, then
4422 return its value. Otherwise, return error_mark_node.
4424 This is for handling COMPOUND_EXPRs as initializer elements
4425 which is allowed with a warning when -pedantic is specified. */
4427 static tree
4429 {
4431 {
4436 endtype);
4437 }
4441 else
4443 }
4444 \f
4445 /* Perform appropriate conversions on the initial value of a variable,
4446 store it in the declaration DECL,
4447 and print any error messages that are appropriate.
4448 If the init is invalid, store an ERROR_MARK. */
4450 void
4452 {
4455 /* If variable's type was invalidly declared, just ignore it. */
4461 /* Digest the specified initializer into an expression. */
4465 /* Store the expression if valid; else report error. */
4473 /* ANSI wants warnings about out-of-range constant initializers. */
4477 /* Check if we need to set array size from compound literal size. */
4481 {
4489 {
4493 {
4494 /* For int foo[] = (int [3]){1}; we need to set array size
4495 now since later on array initializer will be just the
4496 brace enclosed list of the compound literal. */
4500 }
4501 }
4502 }
4503 }
4504 \f
4505 /* Methods for storing and printing names for error messages. */
4507 /* Implement a spelling stack that allows components of a name to be pushed
4508 and popped. Each element on the stack is this structure. */
4510 struct spelling
4511 {
4513 union
4514 {
4518 };
4520 #define SPELLING_STRING 1
4521 #define SPELLING_MEMBER 2
4522 #define SPELLING_BOUNDS 3
4528 /* Macros to save and restore the spelling stack around push_... functions.
4529 Alternative to SAVE_SPELLING_STACK. */
4531 #define SPELLING_DEPTH() (spelling - spelling_base)
4532 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
4534 /* Push an element on the spelling stack with type KIND and assign VALUE
4535 to MEMBER. */
4537 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
4538 { \
4539 int depth = SPELLING_DEPTH (); \
4540 \
4541 if (depth >= spelling_size) \
4542 { \
4543 spelling_size += 10; \
4544 if (spelling_base == 0) \
4545 spelling_base \
4546 = (struct spelling *) xmalloc (spelling_size * sizeof (struct spelling)); \
4547 else \
4548 spelling_base \
4549 = (struct spelling *) xrealloc (spelling_base, \
4550 spelling_size * sizeof (struct spelling)); \
4551 RESTORE_SPELLING_DEPTH (depth); \
4552 } \
4553 \
4554 spelling->kind = (KIND); \
4555 spelling->MEMBER = (VALUE); \
4556 spelling++; \
4557 }
4559 /* Push STRING on the stack. Printed literally. */
4561 static void
4563 {
4565 }
4567 /* Push a member name on the stack. Printed as '.' STRING. */
4569 static void
4571 {
4575 }
4577 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
4579 static void
4581 {
4583 }
4585 /* Compute the maximum size in bytes of the printed spelling. */
4587 static int
4589 {
4594 {
4597 else
4599 }
4602 }
4604 /* Print the spelling to BUFFER and return it. */
4608 {
4614 {
4617 }
4618 else
4619 {
4624 ;
4625 }
4628 }
4630 /* Issue an error message for a bad initializer component.
4631 MSGID identifies the message.
4632 The component name is taken from the spelling stack. */
4634 void
4636 {
4643 }
4645 /* Issue a pedantic warning for a bad initializer component.
4646 MSGID identifies the message.
4647 The component name is taken from the spelling stack. */
4649 void
4651 {
4658 }
4660 /* Issue a warning for a bad initializer component.
4661 MSGID identifies the message.
4662 The component name is taken from the spelling stack. */
4664 static void
4666 {
4673 }
4674 \f
4675 /* Digest the parser output INIT as an initializer for type TYPE.
4676 Return a C expression of type TYPE to represent the initial value.
4678 REQUIRE_CONSTANT requests an error if non-constant initializers or
4679 elements are seen. */
4681 static tree
4683 {
4692 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
4693 /* Do not use STRIP_NOPS here. We do not want an enumerator
4694 whose value is 0 to count as a null pointer constant. */
4700 /* Initialization of an array of chars from a string constant
4701 optionally enclosed in braces. */
4704 {
4712 {
4720 {
4723 }
4727 {
4730 }
4736 /* Subtract 1 (or sizeof (wchar_t))
4737 because it's ok to ignore the terminating null char
4738 that is counted in the length of the constant. */
4749 }
4750 }
4752 /* Build a VECTOR_CST from a *constant* vector constructor. If the
4753 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
4754 below and handle as a constructor. */
4758 {
4762 COMPARE_STRICT))
4764 else
4766 }
4768 /* Any type can be initialized
4769 from an expression of the same type, optionally with braces. */
4783 {
4789 {
4790 /* As an extension, allow initializing objects with static storage
4791 duration with compound literals (which are then treated just as
4792 the brace enclosed list they contain). */
4795 }
4799 {
4802 }
4807 /* Compound expressions can only occur here if -pedantic or
4808 -pedantic-errors is specified. In the later case, we always want
4809 an error. In the former case, we simply want a warning. */
4812 {
4813 inside_init
4818 else
4822 }
4825 /* This test catches things like `7 / 0' which
4826 result in an expression for which TREE_CONSTANT
4827 is true, but which is not actually something
4828 that is a legal constant. We really should not
4829 be using this function, because it is a part of
4830 the back-end. Instead, the expression should
4831 already have been turned into ERROR_MARK_NODE. */
4834 {
4837 }
4840 }
4842 /* Handle scalar types, including conversions. */
4846 {
4847 /* Note that convert_for_assignment calls default_conversion
4848 for arrays and functions. We must not call it in the
4849 case where inside_init is a null pointer constant. */
4850 inside_init
4855 {
4858 }
4861 {
4864 }
4867 }
4869 /* Come here only for records and arrays. */
4872 {
4875 }
4879 }
4880 \f
4881 /* Handle initializers that use braces. */
4883 /* Type of object we are accumulating a constructor for.
4884 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4887 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4888 left to fill. */
4891 /* For an ARRAY_TYPE, this is the specified index
4892 at which to store the next element we get. */
4895 /* For an ARRAY_TYPE, this is the maximum index. */
4898 /* For a RECORD_TYPE, this is the first field not yet written out. */
4901 /* For an ARRAY_TYPE, this is the index of the first element
4902 not yet written out. */
4905 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4906 This is so we can generate gaps between fields, when appropriate. */
4909 /* If we are saving up the elements rather than allocating them,
4910 this is the list of elements so far (in reverse order,
4911 most recent first). */
4914 /* 1 if constructor should be incrementally stored into a constructor chain,
4915 0 if all the elements should be kept in AVL tree. */
4918 /* 1 if so far this constructor's elements are all compile-time constants. */
4921 /* 1 if so far this constructor's elements are all valid address constants. */
4924 /* 1 if this constructor is erroneous so far. */
4927 /* Structure for managing pending initializer elements, organized as an
4928 AVL tree. */
4930 struct init_node
4931 {
4935 tree purpose;
4936 tree value;
4937 };
4939 /* Tree of pending elements at this constructor level.
4940 These are elements encountered out of order
4941 which belong at places we haven't reached yet in actually
4942 writing the output.
4943 Will never hold tree nodes across GC runs. */
4946 /* The SPELLING_DEPTH of this constructor. */
4949 /* 0 if implicitly pushing constructor levels is allowed. */
4955 /* DECL node for which an initializer is being read.
4956 0 means we are reading a constructor expression
4957 such as (struct foo) {...}. */
4960 /* start_init saves the ASMSPEC arg here for really_start_incremental_init. */
4963 /* Nonzero if this is an initializer for a top-level decl. */
4966 /* Nonzero if there were any member designators in this initializer. */
4969 /* Nesting depth of designator list. */
4972 /* Nonzero if there were diagnosed errors in this designator list. */
4975 \f
4976 /* This stack has a level for each implicit or explicit level of
4977 structuring in the initializer, including the outermost one. It
4978 saves the values of most of the variables above. */
4982 struct constructor_stack
4983 {
4985 tree type;
4986 tree fields;
4987 tree index;
4988 tree max_index;
4989 tree unfilled_index;
4990 tree unfilled_fields;
4991 tree bit_index;
4992 tree elements;
4996 /* If nonzero, this value should replace the entire
4997 constructor at this level. */
4998 tree replacement_value;
5007 };
5011 /* This stack represents designators from some range designator up to
5012 the last designator in the list. */
5014 struct constructor_range_stack
5015 {
5018 tree range_start;
5019 tree index;
5020 tree range_end;
5021 tree fields;
5022 };
5026 /* This stack records separate initializers that are nested.
5027 Nested initializers can't happen in ANSI C, but GNU C allows them
5028 in cases like { ... (struct foo) { ... } ... }. */
5030 struct initializer_stack
5031 {
5033 tree decl;
5037 tree elements;
5044 };
5047 \f
5048 /* Prepare to parse and output the initializer for variable DECL. */
5050 void
5052 {
5081 {
5083 require_constant_elements
5085 /* For a scalar, you can always use any value to initialize,
5086 even within braces. */
5092 }
5093 else
5094 {
5098 }
5111 }
5113 void
5115 {
5118 /* Free the whole constructor stack of this initializer. */
5120 {
5124 }
5129 /* Pop back to the data of the outer initializer (if any). */
5143 }
5144 \f
5145 /* Call here when we see the initializer is surrounded by braces.
5146 This is instead of a call to push_init_level;
5147 it is matched by a call to pop_init_level.
5149 TYPE is the type to initialize, for a constructor expression.
5150 For an initializer for a decl, TYPE is zero. */
5152 void
5154 {
5199 {
5201 /* Skip any nameless bit fields at the beginning. */
5208 }
5210 {
5212 {
5213 constructor_max_index
5216 /* Detect non-empty initializations of zero-length arrays. */
5221 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5222 to initialize VLAs will cause a proper error; avoid tree
5223 checking errors as well by setting a safe value. */
5228 constructor_index
5231 }
5232 else
5236 }
5238 {
5239 /* Vectors are like simple fixed-size arrays. */
5240 constructor_max_index =
5244 }
5245 else
5246 {
5247 /* Handle the case of int x = {5}; */
5250 }
5251 }
5252 \f
5253 /* Push down into a subobject, for initialization.
5254 If this is for an explicit set of braces, IMPLICIT is 0.
5255 If it is because the next element belongs at a lower level,
5256 IMPLICIT is 1 (or 2 if the push is because of designator list). */
5258 void
5260 {
5264 /* If we've exhausted any levels that didn't have braces,
5265 pop them now. */
5267 {
5273 && constructor_max_index
5276 else
5278 }
5280 /* Unless this is an explicit brace, we need to preserve previous
5281 content if any. */
5283 {
5290 }
5323 {
5328 }
5330 /* Don't die if an entire brace-pair level is superfluous
5331 in the containing level. */
5333 ;
5336 {
5337 /* Don't die if there are extra init elts at the end. */
5340 else
5341 {
5344 constructor_depth++;
5345 }
5346 }
5348 {
5351 constructor_depth++;
5352 }
5355 {
5360 }
5363 {
5371 }
5374 {
5377 }
5381 {
5383 /* Skip any nameless bit fields at the beginning. */
5390 }
5392 {
5393 /* Vectors are like simple fixed-size arrays. */
5394 constructor_max_index =
5398 }
5400 {
5402 {
5403 constructor_max_index
5406 /* Detect non-empty initializations of zero-length arrays. */
5411 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5412 to initialize VLAs will cause a proper error; avoid tree
5413 checking errors as well by setting a safe value. */
5418 constructor_index
5421 }
5422 else
5427 {
5428 /* We need to split the char/wchar array into individual
5429 characters, so that we don't have to special case it
5430 everywhere. */
5432 }
5433 }
5434 else
5435 {
5439 }
5440 }
5442 /* At the end of an implicit or explicit brace level,
5443 finish up that level of constructor.
5444 If we were outputting the elements as they are read, return 0
5445 from inner levels (process_init_element ignores that),
5446 but return error_mark_node from the outermost level
5447 (that's what we want to put in DECL_INITIAL).
5448 Otherwise, return a CONSTRUCTOR expression. */
5450 tree
5452 {
5457 {
5458 /* When we come to an explicit close brace,
5459 pop any inner levels that didn't have explicit braces. */
5465 }
5469 /* Error for initializing a flexible array member, or a zero-length
5470 array member in an inappropriate context. */
5475 {
5476 /* Silently discard empty initializations. The parser will
5477 already have pedwarned for empty brackets. */
5481 {
5487 /* We have already issued an error message for the existence
5488 of a flexible array member not at the end of the structure.
5489 Discard the initializer so that we do not abort later. */
5492 }
5493 else
5494 /* Zero-length arrays are no longer special, so we should no longer
5495 get here. */
5497 }
5499 /* Warn when some struct elements are implicitly initialized to zero. */
5501 && constructor_type
5504 {
5505 /* Do not warn for flexible array members or zero-length arrays. */
5511 /* Do not warn if this level of the initializer uses member
5512 designators; it is likely to be deliberate. */
5514 {
5518 }
5519 }
5521 /* Now output all pending elements. */
5525 /* Pad out the end of the structure. */
5527 /* If this closes a superfluous brace pair,
5528 just pass out the element between them. */
5531 ;
5536 {
5537 /* A nonincremental scalar initializer--just return
5538 the element, after verifying there is just one. */
5540 {
5544 }
5546 {
5549 }
5550 else
5552 }
5553 else
5554 {
5557 else
5558 {
5565 }
5566 }
5591 {
5595 }
5597 }
5599 /* Common handling for both array range and field name designators.
5600 ARRAY argument is nonzero for array ranges. Returns zero for success. */
5602 static int
5604 {
5605 tree subtype;
5608 /* Don't die if an entire brace-pair level is superfluous
5609 in the containing level. */
5613 /* If there were errors in this designator list already, bail out silently. */
5618 {
5622 /* Designator list starts at the level of closest explicit
5623 braces. */
5628 }
5631 {
5634 }
5638 {
5642 }
5644 {
5646 }
5647 else
5652 {
5655 }
5657 {
5660 }
5665 }
5667 /* If there are range designators in designator list, push a new designator
5668 to constructor_range_stack. RANGE_END is end of such stack range or
5669 NULL_TREE if there is no range designator at this level. */
5671 static void
5673 {
5688 }
5690 /* Within an array initializer, specify the next index to be initialized.
5691 FIRST is that index. If LAST is nonzero, then initialize a range
5692 of indices, running from FIRST through LAST. */
5694 void
5696 {
5726 else
5727 {
5731 {
5735 {
5738 }
5739 else
5740 {
5744 {
5747 }
5748 }
5749 }
5751 designator_depth++;
5755 }
5756 }
5758 /* Within a struct initializer, specify the next field to be initialized. */
5760 void
5762 {
5763 tree tail;
5772 {
5775 }
5779 {
5782 }
5787 else
5788 {
5790 designator_depth++;
5794 }
5795 }
5796 \f
5797 /* Add a new initializer to the tree of pending initializers. PURPOSE
5798 identifies the initializer, either array index or field in a structure.
5799 VALUE is the value of that index or field. */
5801 static void
5803 {
5810 {
5812 {
5818 else
5819 {
5824 }
5825 }
5826 }
5827 else
5828 {
5829 tree bitpos;
5833 {
5839 else
5840 {
5845 }
5846 }
5847 }
5860 {
5864 {
5868 {
5870 {
5871 /* L rotation. */
5884 {
5887 else
5889 }
5890 else
5892 }
5893 else
5894 {
5895 /* LR rotation. */
5917 {
5920 else
5922 }
5923 else
5925 }
5927 }
5928 else
5929 {
5930 /* p->balance == +1; growth of left side balances the node. */
5933 }
5934 }
5936 {
5938 /* Growth propagation from right side. */
5941 {
5943 {
5944 /* R rotation. */
5957 {
5960 else
5962 }
5963 else
5965 }
5967 {
5968 /* RL rotation */
5990 {
5993 else
5995 }
5996 else
5998 }
6000 }
6001 else
6002 {
6003 /* p->balance == -1; growth of right side balances the node. */
6006 }
6007 }
6011 }
6012 }
6014 /* Build AVL tree from a sorted chain. */
6016 static void
6018 {
6019 tree chain;
6029 {
6031 /* Skip any nameless bit fields at the beginning. */
6037 }
6039 {
6041 constructor_unfilled_index
6044 else
6046 }
6048 }
6050 /* Build AVL tree from a string constant. */
6052 static void
6054 {
6069 else
6080 {
6082 {
6085 }
6086 else
6087 {
6091 {
6094 else
6099 }
6100 }
6103 {
6106 {
6108 {
6111 }
6112 }
6114 {
6117 }
6122 }
6127 }
6130 }
6132 /* Return value of FIELD in pending initializer or zero if the field was
6133 not initialized yet. */
6135 static tree
6137 {
6141 {
6148 {
6153 else
6155 }
6156 }
6158 {
6162 && (!constructor_unfilled_fields
6169 {
6174 else
6176 }
6177 }
6179 {
6183 }
6185 }
6187 /* "Output" the next constructor element.
6188 At top level, really output it to assembler code now.
6189 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
6190 TYPE is the data type that the containing data type wants here.
6191 FIELD is the field (a FIELD_DECL) or the index that this element fills.
6193 PENDING if non-nil means output pending elements that belong
6194 right after this element. (PENDING is normally 1;
6195 it is 0 while outputting pending elements, to avoid recursion.) */
6197 static void
6199 {
6201 {
6204 }
6216 {
6217 /* As an extension, allow initializing objects with static storage
6218 duration with compound literals (which are then treated just as
6219 the brace enclosed list they contain). */
6222 }
6236 {
6239 }
6244 /* If this field is empty (and not at the end of structure),
6245 don't do anything other than checking the initializer. */
6256 {
6259 }
6261 /* If this element doesn't come next in sequence,
6262 put it on constructor_pending_elts. */
6264 && (!constructor_incremental
6266 {
6273 }
6275 && (!constructor_incremental
6277 {
6278 /* We do this for records but not for unions. In a union,
6279 no matter which field is specified, it can be initialized
6280 right away since it starts at the beginning of the union. */
6282 {
6285 else
6286 {
6294 }
6295 }
6299 }
6302 {
6306 /* We can have just one union field set. */
6308 }
6310 /* Otherwise, output this element either to
6311 constructor_elements or to the assembler file. */
6315 constructor_elements
6318 /* Advance the variable that indicates sequential elements output. */
6320 constructor_unfilled_index
6322 bitsize_one_node);
6324 {
6325 constructor_unfilled_fields
6328 /* Skip any nameless bit fields. */
6332 constructor_unfilled_fields =
6334 }
6338 /* Now output any pending elements which have become next. */
6341 }
6343 /* Output any pending elements which have become next.
6344 As we output elements, constructor_unfilled_{fields,index}
6345 advances, which may cause other elements to become next;
6346 if so, they too are output.
6348 If ALL is 0, we return when there are
6349 no more pending elements to output now.
6351 If ALL is 1, we output space as necessary so that
6352 we can output all the pending elements. */
6354 static void
6356 {
6358 tree next;
6360 retry:
6362 /* Look thru the whole pending tree.
6363 If we find an element that should be output now,
6364 output it. Otherwise, set NEXT to the element
6365 that comes first among those still pending. */
6369 {
6371 {
6373 constructor_unfilled_index))
6379 {
6380 /* Advance to the next smaller node. */
6383 else
6384 {
6385 /* We have reached the smallest node bigger than the
6386 current unfilled index. Fill the space first. */
6389 }
6390 }
6391 else
6392 {
6393 /* Advance to the next bigger node. */
6396 else
6397 {
6398 /* We have reached the biggest node in a subtree. Find
6399 the parent of it, which is the next bigger node. */
6405 {
6408 }
6409 }
6410 }
6411 }
6414 {
6417 /* If the current record is complete we are done. */
6423 /* We can't compare fields here because there might be empty
6424 fields in between. */
6426 {
6430 }
6432 {
6433 /* Advance to the next smaller node. */
6436 else
6437 {
6438 /* We have reached the smallest node bigger than the
6439 current unfilled field. Fill the space first. */
6442 }
6443 }
6444 else
6445 {
6446 /* Advance to the next bigger node. */
6449 else
6450 {
6451 /* We have reached the biggest node in a subtree. Find
6452 the parent of it, which is the next bigger node. */
6459 {
6462 }
6463 }
6464 }
6465 }
6466 }
6468 /* Ordinarily return, but not if we want to output all
6469 and there are elements left. */
6473 /* If it's not incremental, just skip over the gap, so that after
6474 jumping to retry we will output the next successive element. */
6481 /* ELT now points to the node in the pending tree with the next
6482 initializer to output. */
6484 }
6485 \f
6486 /* Add one non-braced element to the current constructor level.
6487 This adjusts the current position within the constructor's type.
6488 This may also start or terminate implicit levels
6489 to handle a partly-braced initializer.
6491 Once this has found the correct level for the new element,
6492 it calls output_init_element. */
6494 void
6496 {
6503 /* Handle superfluous braces around string cst as in
6504 char x[] = {"foo"}; */
6506 && constructor_type
6510 {
6515 }
6518 {
6521 }
6523 /* Ignore elements of a brace group if it is entirely superfluous
6524 and has already been diagnosed. */
6528 /* If we've exhausted any levels that didn't have braces,
6529 pop them now. */
6531 {
6539 constructor_index)))
6541 else
6543 }
6545 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
6547 {
6548 /* If value is a compound literal and we'll be just using its
6549 content, don't put it into a SAVE_EXPR. */
6551 || !require_constant_value
6554 }
6557 {
6559 {
6560 tree fieldtype;
6564 {
6567 }
6574 /* Error for non-static initialization of a flexible array member. */
6576 && !require_constant_value
6579 {
6582 }
6584 /* Accept a string constant to initialize a subarray. */
6590 /* Otherwise, if we have come to a subaggregate,
6591 and we don't have an element of its type, push into it. */
6597 {
6600 }
6603 {
6607 }
6608 else
6609 /* Do the bookkeeping for an element that was
6610 directly output as a constructor. */
6611 {
6612 /* For a record, keep track of end position of last field. */
6614 constructor_bit_index
6619 /* If the current field was the first one not yet written out,
6620 it isn't now, so update. */
6622 {
6624 /* Skip any nameless bit fields. */
6628 constructor_unfilled_fields =
6630 }
6631 }
6634 /* Skip any nameless bit fields at the beginning. */
6639 }
6641 {
6642 tree fieldtype;
6646 {
6649 }
6656 /* Warn that traditional C rejects initialization of unions.
6657 We skip the warning if the value is zero. This is done
6658 under the assumption that the zero initializer in user
6659 code appears conditioned on e.g. __STDC__ to avoid
6660 "missing initializer" warnings and relies on default
6661 initialization to zero in the traditional C case.
6662 We also skip the warning if the initializer is designated,
6663 again on the assumption that this must be conditional on
6664 __STDC__ anyway (and we've already complained about the
6665 member-designator already). */
6670 /* Accept a string constant to initialize a subarray. */
6676 /* Otherwise, if we have come to a subaggregate,
6677 and we don't have an element of its type, push into it. */
6683 {
6686 }
6689 {
6693 }
6694 else
6695 /* Do the bookkeeping for an element that was
6696 directly output as a constructor. */
6697 {
6700 }
6703 }
6705 {
6709 /* Accept a string constant to initialize a subarray. */
6715 /* Otherwise, if we have come to a subaggregate,
6716 and we don't have an element of its type, push into it. */
6722 {
6725 }
6730 {
6733 }
6735 /* Now output the actual element. */
6737 {
6741 }
6743 constructor_index
6747 /* If we are doing the bookkeeping for an element that was
6748 directly output as a constructor, we must update
6749 constructor_unfilled_index. */
6751 }
6753 {
6756 /* Do a basic check of initializer size. Note that vectors
6757 always have a fixed size derived from their type. */
6759 {
6762 }
6764 /* Now output the actual element. */
6768 constructor_index
6772 /* If we are doing the bookkeeping for an element that was
6773 directly output as a constructor, we must update
6774 constructor_unfilled_index. */
6776 }
6778 /* Handle the sole element allowed in a braced initializer
6779 for a scalar variable. */
6781 {
6784 }
6785 else
6786 {
6790 }
6792 /* Handle range initializers either at this level or anywhere higher
6793 in the designator stack. */
6795 {
6802 {
6806 }
6810 {
6814 }
6821 {
6825 {
6828 }
6836 }
6841 }
6844 }
6847 }
6848 \f
6849 /* Build a simple asm-statement, from one string literal. */
6850 tree
6852 {
6859 {
6860 tree stmt;
6862 /* Simple asm statements are treated as volatile. */
6867 }
6871 }
6873 /* Build an asm-statement, whose components are a CV_QUALIFIER, a
6874 STRING, some OUTPUTS, some INPUTS, and some CLOBBERS. */
6876 tree
6878 tree clobbers)
6879 {
6880 tree tail;
6883 {
6886 }
6890 {
6894 }
6896 /* We can remove output conversions that change the type,
6897 but not the mode. */
6899 {
6905 /* Allow conversions as LHS here. build_modify_expr as called below
6906 will do the right thing with them. */
6917 }
6919 /* Remove output conversions that change the type but not the mode. */
6921 {
6925 }
6927 /* Perform default conversions on array and function inputs.
6928 Don't do this for other types as it would screw up operands
6929 expected to be in memory. */
6935 }
6937 /* Expand an ASM statement with operands, handling output operands
6938 that are not variables or INDIRECT_REFS by transforming such
6939 cases into cases that expand_asm_operands can handle.
6941 Arguments are same as for expand_asm_operands. */
6943 void
6947 {
6950 /* o[I] is the place that output number I should be written. */
6952 tree tail;
6954 /* Record the contents of OUTPUTS before it is modified. */
6956 {
6960 }
6962 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
6963 OUTPUTS some trees for where the values were actually stored. */
6966 /* Copy all the intermediate outputs into the specified outputs. */
6968 {
6970 {
6975 /* Restore the original value so that it's correct the next
6976 time we expand this function. */
6978 }
6979 /* Detect modification of read-only values.
6980 (Otherwise done by build_modify_expr.) */
6981 else
6982 {
6990 }
6991 }
6993 /* Those MODIFY_EXPRs could do autoincrements. */
6995 }
6996 \f
6997 /* Expand a C `return' statement.
6998 RETVAL is the expression for what to return,
6999 or a null pointer for `return;' with no value. */
7001 tree
7003 {
7010 {
7015 }
7017 {
7021 }
7022 else
7023 {
7027 tree inner;
7035 /* Strip any conversions, additions, and subtractions, and see if
7036 we are returning the address of a local variable. Warn if so. */
7038 {
7040 {
7047 /* If the second operand of the MINUS_EXPR has a pointer
7048 type (or is converted from it), this may be valid, so
7049 don't give a warning. */
7050 {
7064 }
7081 }
7084 }
7087 }
7090 }
7091 \f
7093 /* The SWITCH_STMT being built. */
7094 tree switch_stmt;
7095 /* A splay-tree mapping the low element of a case range to the high
7096 element, or NULL_TREE if there is no high element. Used to
7097 determine whether or not a new case label duplicates an old case
7098 label. We need a tree, rather than simply a hash table, because
7099 of the GNU case range extension. */
7100 splay_tree cases;
7101 /* The next node on the stack. */
7103 };
7105 /* A stack of the currently active switch statements. The innermost
7106 switch statement is on the top of the stack. There is no need to
7107 mark the stack for garbage collection because it is only active
7108 during the processing of the body of a function, and we never
7109 collect at that point. */
7113 /* Start a C switch statement, testing expression EXP. Return the new
7114 SWITCH_STMT. */
7116 tree
7118 {
7124 {
7130 {
7133 }
7134 else
7135 {
7145 }
7146 }
7148 /* Add this new SWITCH_STMT to the stack. */
7156 }
7158 /* Process a case label. */
7160 tree
7162 {
7166 {
7175 {
7176 /* Attach the first case label to the SWITCH_BODY. */
7179 }
7180 }
7183 else
7187 }
7189 /* Finish the switch statement. */
7191 void
7193 {
7196 /* Rechain the next statements to the SWITCH_STMT. */
7199 /* Pop the stack. */
7203 }