| blob | 922cda89cf092a16ae60c198e69352103ed90967 |
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. */
84 \f
85 /* Do `exp = require_complete_type (exp);' to make sure exp
86 does not have an incomplete type. (That includes void types.) */
88 tree
90 {
96 /* First, detect a valid value with a complete type. */
102 }
104 /* Print an error message for invalid use of an incomplete type.
105 VALUE is the expression that was used (or 0 if that isn't known)
106 and TYPE is the type that was invalid. */
108 void
110 {
113 /* Avoid duplicate error message. */
121 else
122 {
123 retry:
124 /* We must print an error message. Be clever about what it says. */
127 {
146 {
148 {
151 }
154 }
160 }
165 else
166 /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */
169 }
170 }
172 /* Given a type, apply default promotions wrt unnamed function
173 arguments and return the new type. */
175 tree
177 {
182 {
183 /* Preserve unsignedness if not really getting any wider. */
188 }
191 }
193 /* Return a variant of TYPE which has all the type qualifiers of LIKE
194 as well as those of TYPE. */
196 static tree
198 {
201 }
202 \f
203 /* Return the common type of two types.
204 We assume that comptypes has already been done and returned 1;
205 if that isn't so, this may crash. In particular, we assume that qualifiers
206 match.
208 This is the type for the result of most arithmetic operations
209 if the operands have the given two types. */
211 tree
213 {
216 tree attributes;
218 /* Save time if the two types are the same. */
222 /* If one type is nonsense, use the other. */
228 /* Merge the attributes. */
231 /* Treat an enum type as the unsigned integer type of the same width. */
241 /* If one type is complex, form the common type of the non-complex
242 components, then make that complex. Use T1 or T2 if it is the
243 required type. */
245 {
254 else
256 attributes);
257 }
260 {
263 /* If only one is real, use it as the result. */
271 /* Both real or both integers; use the one with greater precision. */
278 /* Same precision. Prefer longs to ints even when same size. */
283 attributes);
287 {
288 /* But preserve unsignedness from the other type,
289 since long cannot hold all the values of an unsigned int. */
292 else
295 }
297 /* Likewise, prefer long double to double even if same size. */
301 attributes);
303 /* Otherwise prefer the unsigned one. */
307 else
311 /* For two pointers, do this recursively on the target type,
312 and combine the qualifiers of the two types' targets. */
313 /* This code was turned off; I don't know why.
314 But ANSI C specifies doing this with the qualifiers.
315 So I turned it on again. */
316 {
326 }
329 {
331 /* Save space: see if the result is identical to one of the args. */
336 /* Merge the element types, and have a size if either arg has one. */
339 }
342 /* Function types: prefer the one that specified arg types.
343 If both do, merge the arg types. Also merge the return types. */
344 {
352 /* Save space: see if the result is identical to one of the args. */
358 /* Simple way if one arg fails to specify argument types. */
360 {
363 }
365 {
368 }
370 /* If both args specify argument types, we must merge the two
371 lists, argument by argument. */
386 {
387 /* A null type means arg type is not specified.
388 Take whatever the other function type has. */
390 {
393 }
395 {
398 }
400 /* Given wait (union {union wait *u; int *i} *)
401 and wait (union wait *),
402 prefer union wait * as type of parm. */
405 {
406 tree memb;
410 COMPARE_STRICT))
411 {
416 }
417 }
420 {
421 tree memb;
425 COMPARE_STRICT))
426 {
431 }
432 }
434 parm_done: ;
435 }
440 /* ... falls through ... */
441 }
445 }
447 }
448 \f
449 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
450 or various other operations. Return 2 if they are compatible
451 but a warning may be needed if you use them together. */
453 int
455 {
460 /* Suppress errors caused by previously reported errors. */
466 /* If either type is the internal version of sizetype, return the
467 language version. */
476 /* Treat an enum type as the integer type of the same width and
477 signedness. */
487 /* Different classes of types can't be compatible. */
491 /* Qualifiers must match. */
496 /* Allow for two different type nodes which have essentially the same
497 definition. Note that we already checked for equality of the type
498 qualifiers (just above). */
503 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
507 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
511 {
522 {
529 /* Target types must match incl. qualifiers. */
532 flags)))
535 /* Sizes must match unless one is missing or variable. */
542 d1_variable = (! d1_zero
545 d2_variable = (! d2_zero
559 }
572 /* The target might allow certain vector types to be compatible. */
579 }
581 }
583 /* Return 1 if TTL and TTR are pointers to types that are equivalent,
584 ignoring their qualifiers. REFLEXIVE is only used by ObjC - set it
585 to 1 or 0 depending if the check of the pointer types is meant to
586 be reflexive or not (typically, assignments are not reflexive,
587 while comparisons are reflexive).
588 */
590 static int
592 {
595 /* Give objc_comptypes a crack at letting these types through. */
605 }
606 \f
607 /* Subroutines of `comptypes'. */
609 /* The C standard says that two structures in different translation
610 units are compatible with each other only if the types of their
611 fields are compatible (among other things). So, consider two copies
612 of this structure: */
616 tree t1;
617 tree t2;
618 };
620 /* Can they be compatible with each other? We choose to break the
621 recursion by allowing those types to be compatible. */
625 /* Return 1 if two 'struct', 'union', or 'enum' types T1 and T2 are
626 compatible. If the two types are not the same (which has been
627 checked earlier), this can only happen when multiple translation
628 units are being compiled. See C99 6.2.7 paragraph 1 for the exact
629 rules. */
631 static int
633 {
637 /* We have to verify that the tags of the types are the same. This
638 is harder than it looks because this may be a typedef, so we have
639 to go look at the original type. It may even be a typedef of a
640 typedef... */
647 /* C90 didn't have the requirement that the two tags be the same. */
651 /* C90 didn't say what happened if one or both of the types were
652 incomplete; we choose to follow C99 rules here, which is that they
653 are compatible. */
658 {
663 }
666 {
668 {
673 {
678 }
680 }
683 {
688 {
700 {
715 }
719 }
721 }
724 {
735 {
750 }
755 }
759 }
760 }
762 /* Return 1 if two function types F1 and F2 are compatible.
763 If either type specifies no argument types,
764 the other must specify a fixed number of self-promoting arg types.
765 Otherwise, if one type specifies only the number of arguments,
766 the other must specify that number of self-promoting arg types.
767 Otherwise, the argument types must match. */
769 static int
771 {
773 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
781 /* 'volatile' qualifiers on a function's return type mean the function
782 is noreturn. */
798 /* An unspecified parmlist matches any specified parmlist
799 whose argument types don't need default promotions. */
802 {
805 /* If one of these types comes from a non-prototype fn definition,
806 compare that with the other type's arglist.
807 If they don't match, ask for a warning (but no error). */
810 flags))
813 }
815 {
820 flags))
823 }
825 /* Both types have argument lists: compare them and propagate results. */
828 }
830 /* Check two lists of types for compatibility,
831 returning 0 for incompatible, 1 for compatible,
832 or 2 for compatible with warning. */
834 static int
836 {
837 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
842 {
845 /* If one list is shorter than the other,
846 they fail to match. */
849 /* A null pointer instead of a type
850 means there is supposed to be an argument
851 but nothing is specified about what type it has.
852 So match anything that self-promotes. */
854 {
857 }
859 {
862 }
863 /* If one of the lists has an error marker, ignore this arg. */
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 /* Build an external reference to identifier ID. FUN indicates
1535 whether this will be used for a function call. */
1536 tree
1538 {
1539 tree ref;
1544 {
1545 /* Properly declared variable or function reference. */
1549 {
1553 }
1554 else
1556 }
1560 /* Implicit function declaration. */
1563 /* Don't complain about something that's already been
1564 complained about. */
1566 else
1567 {
1570 }
1583 {
1586 }
1592 {
1597 }
1600 }
1602 /* Build a function call to function FUNCTION with parameters PARAMS.
1603 PARAMS is a list--a chain of TREE_LIST nodes--in which the
1604 TREE_VALUE of each node is a parameter-expression.
1605 FUNCTION's data type may be a function type or a pointer-to-function. */
1607 tree
1609 {
1611 tree coerced_params;
1614 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
1617 /* Convert anything with function type to a pointer-to-function. */
1619 {
1622 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
1623 (because calling an inline function does not mean the function
1624 needs to be separately compiled). */
1630 }
1631 else
1641 {
1644 }
1649 /* fntype now gets the type of function pointed to. */
1652 /* Convert the parameters to the types declared in the
1653 function prototype, or apply default promotions. */
1655 coerced_params
1658 /* Check that the arguments to the function are valid. */
1662 /* Recognize certain built-in functions so we can make tree-codes
1663 other than CALL_EXPR. We do this when it enables fold-const.c
1664 to do something useful. */
1669 {
1674 }
1684 }
1685 \f
1686 /* Convert the argument expressions in the list VALUES
1687 to the types in the list TYPELIST. The result is a list of converted
1688 argument expressions.
1690 If TYPELIST is exhausted, or when an element has NULL as its type,
1691 perform the default conversions.
1693 PARMLIST is the chain of parm decls for the function being called.
1694 It may be 0, if that info is not available.
1695 It is used only for generating error messages.
1697 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
1699 This is also where warnings about wrong number of args are generated.
1701 Both VALUES and the returned value are chains of TREE_LIST nodes
1702 with the elements of the list in the TREE_VALUE slots of those nodes. */
1704 static tree
1706 {
1711 /* Scan the given expressions and types, producing individual
1712 converted arguments and pushing them on RESULT in reverse order. */
1715 valtail;
1717 {
1722 {
1726 else
1729 }
1731 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
1732 /* Do not use STRIP_NOPS here! We do not want an enumerator with value 0
1733 to convert automatically to a pointer. */
1742 {
1743 /* Formal parm type is specified by a function prototype. */
1744 tree parmval;
1747 {
1750 }
1751 else
1752 {
1753 /* Optionally warn about conversions that
1754 differ from the default conversions. */
1756 {
1761 warn_for_assignment ("%s as integer rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1764 warn_for_assignment ("%s as integer rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1767 warn_for_assignment ("%s as complex rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1770 warn_for_assignment ("%s as floating rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1773 warn_for_assignment ("%s as complex rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1776 warn_for_assignment ("%s as floating rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1777 /* ??? At some point, messages should be written about
1778 conversions between complex types, but that's too messy
1779 to do now. */
1782 {
1783 /* Warn if any argument is passed as `float',
1784 since without a prototype it would be `double'. */
1786 warn_for_assignment ("%s as `float' rather than `double' due to prototype", (char *) 0, name, parmnum + 1);
1787 }
1788 /* Detect integer changing in width or signedness.
1789 These warnings are only activated with
1790 -Wconversion, not with -Wtraditional. */
1793 {
1800 /* No warning if function asks for enum
1801 and the actual arg is that enum type. */
1802 ;
1804 warn_for_assignment ("%s with different width due to prototype", (char *) 0, name, parmnum + 1);
1806 ;
1807 /* Don't complain if the formal parameter type
1808 is an enum, because we can't tell now whether
1809 the value was an enum--even the same enum. */
1811 ;
1814 /* Change in signedness doesn't matter
1815 if a constant value is unaffected. */
1816 ;
1817 /* Likewise for a constant in a NOP_EXPR. */
1821 ;
1822 /* If the value is extended from a narrower
1823 unsigned type, it doesn't matter whether we
1824 pass it as signed or unsigned; the value
1825 certainly is the same either way. */
1828 ;
1831 else
1833 }
1834 }
1844 }
1846 }
1850 /* Convert `float' to `double'. */
1852 else
1853 /* Convert `short' and `char' to full-size `int'. */
1858 }
1861 {
1865 else
1867 }
1870 }
1871 \f
1872 /* This is the entry point used by the parser
1873 for binary operators in the input.
1874 In addition to constructing the expression,
1875 we check for operands that were written with other binary operators
1876 in a way that is likely to confuse the user. */
1878 tree
1880 {
1897 /* Check for cases such as x+y<<z which users are likely
1898 to misinterpret. If parens are used, C_EXP_ORIGINAL_CODE
1899 is cleared to prevent these warnings. */
1901 {
1903 {
1907 }
1910 {
1914 }
1917 {
1923 /* Check cases like x|y==z */
1926 }
1929 {
1935 /* Check cases like x^y==z */
1938 }
1941 {
1945 /* Check cases like x&y==z */
1948 }
1949 }
1951 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */
1962 /* Record the code that was specified in the source,
1963 for the sake of warnings about confusing nesting. */
1966 else
1967 {
1969 /* We used to use NOP_EXPR rather than NON_LVALUE_EXPR
1970 so that convert_for_assignment wouldn't strip it.
1971 That way, we got warnings for things like p = (1 - 1).
1972 But it turns out we should not get those warnings. */
1976 }
1979 }
1980 \f
1982 /* Return true if `t' is known to be non-negative. */
1984 int
1986 {
1988 {
1991 /* Find the last statement in the chain, ignoring the final
1992 * scope statement */
1997 }
1999 }
2001 /* Return a tree for the difference of pointers OP0 and OP1.
2002 The resulting tree has type int. */
2004 static tree
2006 {
2015 {
2020 }
2022 /* If the conversion to ptrdiff_type does anything like widening or
2023 converting a partial to an integral mode, we get a convert_expression
2024 that is in the way to do any simplifications.
2025 (fold-const.c doesn't know that the extra bits won't be needed.
2026 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2027 different mode in place.)
2028 So first try to find a common term here 'by hand'; we want to cover
2029 at least the cases that occur in legal static initializers. */
2034 {
2037 }
2038 else
2042 {
2045 }
2046 else
2050 {
2053 }
2056 /* First do the subtraction as integers;
2057 then drop through to build the divide operator.
2058 Do not do default conversions on the minus operator
2059 in case restype is a short type. */
2063 /* This generates an error if op1 is pointer to incomplete type. */
2067 /* This generates an error if op0 is pointer to incomplete type. */
2070 /* Divide by the size, in easiest possible way. */
2078 }
2079 \f
2080 /* Construct and perhaps optimize a tree representation
2081 for a unary operation. CODE, a tree_code, specifies the operation
2082 and XARG is the operand.
2083 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2084 the default promotions (such as from short to int).
2085 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2086 allows non-lvalues; this is only used to handle conversion of non-lvalue
2087 arrays to pointers in C99. */
2089 tree
2091 {
2092 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2096 tree val;
2105 {
2107 /* This is used for unary plus, because a CONVERT_EXPR
2108 is enough to prevent anybody from looking inside for
2109 associativity, but won't generate any code. */
2112 {
2115 }
2125 {
2128 }
2135 {
2138 }
2140 {
2146 }
2147 else
2148 {
2151 }
2157 {
2160 }
2166 /* Conjugating a real value is a no-op, but allow it anyway. */
2169 {
2172 }
2181 /* These will convert to a pointer. */
2183 {
2186 }
2198 else
2206 else
2213 /* Handle complex lvalues (when permitted)
2214 by reduction to simpler cases. */
2220 /* Increment or decrement the real part of the value,
2221 and don't change the imaginary part. */
2223 {
2234 }
2236 /* Report invalid types. */
2240 {
2243 else
2247 }
2249 {
2250 tree inc;
2256 /* Compute the increment. */
2259 {
2260 /* If pointer target is an undefined struct,
2261 we just cannot know how to do the arithmetic. */
2263 {
2266 else
2268 }
2272 {
2275 else
2277 }
2280 }
2281 else
2286 /* Handle incrementing a cast-expression. */
2290 {
2299 /* If the real type has the same machine representation
2300 as the type it is cast to, we can make better output
2301 by adding directly to the inside of the cast. */
2307 else
2308 {
2312 else
2313 {
2317 else
2326 }
2329 }
2334 }
2335 give_up:
2337 /* Complain about anything else that is not a true lvalue. */
2344 /* Report a read-only lvalue. */
2353 else
2360 }
2363 /* Note that this operation never does default_conversion. */
2365 /* Let &* cancel out to simplify resulting code. */
2367 {
2368 /* Don't let this be an lvalue. */
2372 }
2374 /* For &x[y], return x+y */
2376 {
2381 }
2383 /* Handle complex lvalues (when permitted)
2384 by reduction to simpler cases. */
2389 /* Anything not already handled and not a true memory reference
2390 or a non-lvalue array is an error. */
2395 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
2398 /* If the lvalue is const or volatile, merge that into the type
2399 to which the address will point. Note that you can't get a
2400 restricted pointer by taking the address of something, so we
2401 only have to deal with `const' and `volatile' here. */
2413 {
2414 tree addr;
2417 {
2423 {
2427 }
2432 }
2433 else
2436 /* Address of a static or external variable or
2437 file-scope function counts as a constant. */
2443 }
2447 }
2452 }
2454 /* Return nonzero if REF is an lvalue valid for this language.
2455 Lvalues can be assigned, unless their type has TYPE_READONLY.
2456 Lvalues can have their address taken, unless they have DECL_REGISTER. */
2458 int
2460 {
2464 {
2489 }
2490 }
2492 /* Return nonzero if REF is an lvalue valid for this language;
2493 otherwise, print an error message and return zero. */
2495 int
2497 {
2504 }
2506 /* Apply unary lvalue-demanding operator CODE to the expression ARG
2507 for certain kinds of expressions which are not really lvalues
2508 but which we can accept as lvalues. If FLAG is nonzero, then
2509 non-lvalues are OK since we may be converting a non-lvalue array to
2510 a pointer in C99.
2512 If ARG is not a kind of expression we can handle, return zero. */
2514 static tree
2516 {
2517 /* Handle (a, b) used as an "lvalue". */
2519 {
2522 /* If this returns a function type, it isn't really being used as
2523 an lvalue, so don't issue a warning about it. */
2529 }
2531 /* Handle (a ? b : c) used as an "lvalue". */
2533 {
2543 }
2546 }
2548 /* If pedantic, warn about improper lvalue. CODE is either COND_EXPR
2549 COMPOUND_EXPR, or CONVERT_EXPR (for casts). */
2551 static void
2553 {
2556 {
2566 }
2567 }
2568 \f
2569 /* Warn about storing in something that is `const'. */
2571 void
2573 {
2575 {
2578 else
2581 }
2585 else
2587 }
2588 \f
2589 /* Mark EXP saying that we need to be able to take the
2590 address of it; it should not be allocated in a register.
2591 Returns true if successful. */
2593 bool
2595 {
2600 {
2603 {
2607 }
2609 /* ... fall through ... */
2629 {
2631 {
2635 }
2638 }
2640 {
2642 {
2646 }
2648 /* If we are making this addressable due to its having
2649 volatile components, give a different error message. Also
2650 handle the case of an unnamed parameter by not trying
2651 to give the name. */
2654 {
2657 }
2661 }
2664 /* drops in */
2667 /* drops out */
2670 }
2671 }
2672 \f
2673 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
2675 tree
2677 {
2678 tree type1;
2679 tree type2;
2687 /* Promote both alternatives. */
2704 /* Quickly detect the usual case where op1 and op2 have the same type
2705 after promotion. */
2707 {
2710 else
2712 }
2717 {
2720 /* If -Wsign-compare, warn here if type1 and type2 have
2721 different signedness. We'll promote the signed to unsigned
2722 and later code won't know it used to be different.
2723 Do this check on the original types, so that explicit casts
2724 will be considered, but default promotions won't. */
2726 {
2731 {
2732 /* Do not warn if the result type is signed, since the
2733 signed type will only be chosen if it can represent
2734 all the values of the unsigned type. */
2737 /* Do not warn if the signed quantity is an unsuffixed
2738 integer literal (or some static constant expression
2739 involving such literals) and it is non-negative. */
2743 else
2745 }
2746 }
2747 }
2749 {
2753 }
2755 {
2765 {
2770 }
2772 {
2777 }
2778 else
2779 {
2782 }
2783 }
2785 {
2788 else
2789 {
2791 }
2793 }
2795 {
2798 else
2799 {
2801 }
2803 }
2806 {
2809 else
2810 {
2813 }
2814 }
2816 /* Merge const and volatile flags of the incoming types. */
2817 result_type
2831 }
2832 \f
2833 /* Given a list of expressions, return a compound expression
2834 that performs them all and returns the value of the last of them. */
2836 tree
2838 {
2840 }
2842 static tree
2844 {
2845 tree rest;
2848 {
2849 /* Convert arrays and functions to pointers when there
2850 really is a comma operator. */
2855 /* Don't let (0, 0) be null pointer constant. */
2859 }
2864 {
2865 /* The left-hand operand of a comma expression is like an expression
2866 statement: with -Wextra or -Wunused, we should warn if it doesn't have
2867 any side-effects, unless it was explicitly cast to (void). */
2873 /* When pedantic, a compound expression can be neither an lvalue
2874 nor an integer constant expression. */
2877 }
2879 /* With -Wunused, we should also warn if the left-hand operand does have
2880 side-effects, but computes a value which is not used. For example, in
2881 `foo() + bar(), baz()' the result of the `+' operator is not used,
2882 so we should issue a warning. */
2887 }
2889 /* Build an expression representing a cast to type TYPE of expression EXPR. */
2891 tree
2893 {
2899 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
2900 only in <protocol> qualifications. But when constructing cast expressions,
2901 the protocols do matter and must be kept around. */
2906 {
2909 }
2912 {
2915 }
2918 {
2920 {
2924 }
2925 }
2927 {
2928 tree field;
2937 {
2938 tree t;
2948 }
2951 }
2952 else
2953 {
2956 /* If casting to void, avoid the error that would come
2957 from default_conversion in the case of a non-lvalue array. */
2961 /* Convert functions and arrays to pointers,
2962 but don't convert any other types. */
2966 /* Optionally warn about potentially worrisome casts. */
2971 {
2977 /* Check that the qualifiers on IN_TYPE are a superset of
2978 the qualifiers of IN_OTYPE. The outermost level of
2979 POINTER_TYPE nodes is uninteresting and we stop as soon
2980 as we hit a non-POINTER_TYPE node on either type. */
2981 do
2982 {
2986 /* GNU C allows cv-qualified function types. 'const'
2987 means the function is very pure, 'volatile' means it
2988 can't return. We need to warn when such qualifiers
2989 are added, not when they're taken away. */
2993 else
2995 }
3003 /* There are qualifiers present in IN_OTYPE that are not
3004 present in IN_TYPE. */
3006 }
3008 /* Warn about possible alignment problems. */
3014 /* Don't warn about opaque types, where the actual alignment
3015 restriction is unknown. */
3036 /* Don't warn about converting any constant. */
3046 {
3047 /* Casting the address of a decl to non void pointer. Warn
3048 if the cast breaks type based aliasing. */
3055 }
3058 /* Replace a nonvolatile const static variable with its value. */
3063 /* Ignore any integer overflow caused by the cast. */
3065 {
3068 }
3069 }
3071 /* Pedantically, don't let (void *) (FOO *) 0 be a null pointer constant. */
3077 /* If pedantic, don't let a cast be an lvalue. */
3082 }
3084 /* Interpret a cast of expression EXPR to type TYPE. */
3085 tree
3087 {
3090 /* This avoids warnings about unprototyped casts on
3091 integers. E.g. "#define SIG_DFL (void(*)())0". */
3098 }
3100 \f
3101 /* Build an assignment expression of lvalue LHS from value RHS.
3102 MODIFYCODE is the code for a binary operator that we use
3103 to combine the old value of LHS with RHS to get the new value.
3104 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3106 tree
3108 {
3109 tree result;
3110 tree newrhs;
3114 /* Types that aren't fully specified cannot be used in assignments. */
3117 /* Avoid duplicate error messages from operands that had errors. */
3121 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3122 /* Do not use STRIP_NOPS here. We do not want an enumerator
3123 whose value is 0 to count as a null pointer constant. */
3129 /* Handle control structure constructs used as "lvalues". */
3132 {
3133 /* Handle (a, b) used as an "lvalue". */
3142 /* Handle (a ? b : c) used as an "lvalue". */
3146 {
3147 /* Produce (a ? (b = rhs) : (c = rhs))
3148 except that the RHS goes through a save-expr
3149 so the code to compute it is only emitted once. */
3150 tree cond
3158 /* Make sure the code to compute the rhs comes out
3159 before the split. */
3161 /* But cast it to void to avoid an "unused" error. */
3163 }
3166 }
3168 /* If a binary op has been requested, combine the old LHS value with the RHS
3169 producing the value we should actually store into the LHS. */
3172 {
3175 }
3177 /* Handle a cast used as an "lvalue".
3178 We have already performed any binary operator using the value as cast.
3179 Now convert the result to the cast type of the lhs,
3180 and then true type of the lhs and store it there;
3181 then convert result back to the cast type to be the value
3182 of the assignment. */
3185 {
3194 {
3196 tree result;
3204 }
3208 }
3210 /* Now we have handled acceptable kinds of LHS that are not truly lvalues.
3211 Reject anything strange now. */
3216 /* Warn about storing in something that is `const'. */
3224 /* If storing into a structure or union member,
3225 it has probably been given type `int'.
3226 Compute the type that would go with
3227 the actual amount of storage the member occupies. */
3236 /* If storing in a field that is in actuality a short or narrower than one,
3237 we must store in the field in its actual type. */
3240 {
3243 }
3245 /* Convert new value to destination type. */
3252 /* Scan operands */
3257 /* If we got the LHS in a different type for storing in,
3258 convert the result back to the nominal type of LHS
3259 so that the value we return always has the same type
3260 as the LHS argument. */
3266 }
3267 \f
3268 /* Convert value RHS to type TYPE as preparation for an assignment
3269 to an lvalue of type TYPE.
3270 The real work of conversion is done by `convert'.
3271 The purpose of this function is to generate error messages
3272 for assignments that are not allowed in C.
3273 ERRTYPE is a string to use in error messages:
3274 "assignment", "return", etc. If it is null, this is parameter passing
3275 for a function call (and different error messages are output).
3277 FUNNAME is the name of the function being called,
3278 as an IDENTIFIER_NODE, or null.
3279 PARMNUM is the number of the argument, for printing in error messages. */
3281 static tree
3284 {
3286 tree rhstype;
3289 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3290 /* Do not use STRIP_NOPS here. We do not want an enumerator
3291 whose value is 0 to count as a null pointer constant. */
3308 {
3310 /* Check for Objective-C protocols. This will automatically
3311 issue a warning if there are protocol violations. No need to
3312 use the return value. */
3316 }
3319 {
3322 }
3323 /* A type converts to a reference to it.
3324 This code doesn't fully support references, it's just for the
3325 special case of va_start and va_copy. */
3328 {
3330 {
3333 }
3338 /* We already know that these two types are compatible, but they
3339 may not be exactly identical. In fact, `TREE_TYPE (type)' is
3340 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
3341 likely to be va_list, a typedef to __builtin_va_list, which
3342 is different enough that it will cause problems later. */
3348 }
3349 /* Some types can interconvert without explicit casts. */
3354 /* Arithmetic types all interconvert, and enum is treated like int. */
3363 /* Conversion to a transparent union from its member types.
3364 This applies only to function arguments. */
3366 {
3367 tree memb_types;
3372 {
3383 {
3387 /* Any non-function converts to a [const][volatile] void *
3388 and vice versa; otherwise, targets must be the same.
3389 Meanwhile, the lhs target must have all the qualifiers of
3390 the rhs. */
3393 {
3394 /* If this type won't generate any warnings, use it. */
3404 /* Keep looking for a better type, but remember this one. */
3407 }
3408 }
3410 /* Can convert integer zero to any pointer type. */
3414 {
3417 }
3418 }
3421 {
3423 {
3424 /* We have only a marginally acceptable member type;
3425 it needs a warning. */
3429 /* Const and volatile mean something different for function
3430 types, so the usual warnings are not appropriate. */
3433 {
3434 /* Because const and volatile on functions are
3435 restrictions that say the function will not do
3436 certain things, it is okay to use a const or volatile
3437 function where an ordinary one is wanted, but not
3438 vice-versa. */
3442 }
3446 parmnum);
3447 }
3453 }
3454 }
3456 /* Conversions among pointers */
3459 {
3464 /* Opaque pointers are treated like void pointers. */
3470 /* Any non-function converts to a [const][volatile] void *
3471 and vice versa; otherwise, targets must be the same.
3472 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
3475 || is_opaque_pointer
3478 {
3481 ||
3483 /* Check TREE_CODE to catch cases like (void *) (char *) 0
3484 which are not ANSI null ptr constants. */
3489 /* Const and volatile mean something different for function types,
3490 so the usual warnings are not appropriate. */
3493 {
3497 /* If this is not a case of ignoring a mismatch in signedness,
3498 no warning. */
3501 ;
3502 /* If there is a mismatch, do warn. */
3506 }
3509 {
3510 /* Because const and volatile on functions are restrictions
3511 that say the function will not do certain things,
3512 it is okay to use a const or volatile function
3513 where an ordinary one is wanted, but not vice-versa. */
3517 }
3518 }
3519 else
3523 }
3525 {
3526 /* An explicit constant 0 can convert to a pointer,
3527 or one that results from arithmetic, even including
3528 a cast to integer type. */
3530 &&
3535 {
3539 }
3541 }
3543 {
3547 }
3552 {
3554 {
3560 else
3563 }
3564 else
3566 parmnum);
3567 }
3568 else
3572 }
3574 /* Convert VALUE for assignment into inlined parameter PARM. */
3576 tree
3578 {
3581 /* If FN was prototyped, the value has been converted already
3582 in convert_arguments. */
3595 }
3597 /* Print a warning using MSGID.
3598 It gets OPNAME as its one parameter.
3599 if OPNAME is null and ARGNUM is 0, it is replaced by "passing arg of `FUNCTION'".
3600 Otherwise if OPNAME is null, it is replaced by "passing arg ARGNUM of `FUNCTION'".
3601 FUNCTION and ARGNUM are handled specially if we are building an
3602 Objective-C selector. */
3604 static void
3607 {
3609 {
3614 {
3617 }
3619 {
3621 {
3622 /* Function name is known; supply it. */
3628 }
3629 else
3630 {
3631 /* Function name unknown (call through ptr). */
3635 }
3636 }
3638 {
3639 /* Function name is known; supply it. */
3645 }
3646 else
3647 {
3648 /* Function name unknown (call through ptr); just give arg number. */
3652 }
3654 }
3656 }
3657 \f
3658 /* If VALUE is a compound expr all of whose expressions are constant, then
3659 return its value. Otherwise, return error_mark_node.
3661 This is for handling COMPOUND_EXPRs as initializer elements
3662 which is allowed with a warning when -pedantic is specified. */
3664 static tree
3666 {
3668 {
3673 endtype);
3674 }
3678 else
3680 }
3681 \f
3682 /* Perform appropriate conversions on the initial value of a variable,
3683 store it in the declaration DECL,
3684 and print any error messages that are appropriate.
3685 If the init is invalid, store an ERROR_MARK. */
3687 void
3689 {
3692 /* If variable's type was invalidly declared, just ignore it. */
3698 /* Digest the specified initializer into an expression. */
3702 /* Store the expression if valid; else report error. */
3710 /* ANSI wants warnings about out-of-range constant initializers. */
3714 /* Check if we need to set array size from compound literal size. */
3718 {
3726 {
3730 {
3731 /* For int foo[] = (int [3]){1}; we need to set array size
3732 now since later on array initializer will be just the
3733 brace enclosed list of the compound literal. */
3737 }
3738 }
3739 }
3740 }
3741 \f
3742 /* Methods for storing and printing names for error messages. */
3744 /* Implement a spelling stack that allows components of a name to be pushed
3745 and popped. Each element on the stack is this structure. */
3747 struct spelling
3748 {
3750 union
3751 {
3755 };
3757 #define SPELLING_STRING 1
3758 #define SPELLING_MEMBER 2
3759 #define SPELLING_BOUNDS 3
3765 /* Macros to save and restore the spelling stack around push_... functions.
3766 Alternative to SAVE_SPELLING_STACK. */
3768 #define SPELLING_DEPTH() (spelling - spelling_base)
3769 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
3771 /* Push an element on the spelling stack with type KIND and assign VALUE
3772 to MEMBER. */
3774 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
3775 { \
3776 int depth = SPELLING_DEPTH (); \
3777 \
3778 if (depth >= spelling_size) \
3779 { \
3780 spelling_size += 10; \
3781 if (spelling_base == 0) \
3782 spelling_base = xmalloc (spelling_size * sizeof (struct spelling)); \
3783 else \
3784 spelling_base = xrealloc (spelling_base, \
3785 spelling_size * sizeof (struct spelling)); \
3786 RESTORE_SPELLING_DEPTH (depth); \
3787 } \
3788 \
3789 spelling->kind = (KIND); \
3790 spelling->MEMBER = (VALUE); \
3791 spelling++; \
3792 }
3794 /* Push STRING on the stack. Printed literally. */
3796 static void
3798 {
3800 }
3802 /* Push a member name on the stack. Printed as '.' STRING. */
3804 static void
3806 {
3810 }
3812 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
3814 static void
3816 {
3818 }
3820 /* Compute the maximum size in bytes of the printed spelling. */
3822 static int
3824 {
3829 {
3832 else
3834 }
3837 }
3839 /* Print the spelling to BUFFER and return it. */
3843 {
3849 {
3852 }
3853 else
3854 {
3859 ;
3860 }
3863 }
3865 /* Issue an error message for a bad initializer component.
3866 MSGID identifies the message.
3867 The component name is taken from the spelling stack. */
3869 void
3871 {
3878 }
3880 /* Issue a pedantic warning for a bad initializer component.
3881 MSGID identifies the message.
3882 The component name is taken from the spelling stack. */
3884 void
3886 {
3893 }
3895 /* Issue a warning for a bad initializer component.
3896 MSGID identifies the message.
3897 The component name is taken from the spelling stack. */
3899 static void
3901 {
3908 }
3909 \f
3910 /* Digest the parser output INIT as an initializer for type TYPE.
3911 Return a C expression of type TYPE to represent the initial value.
3913 REQUIRE_CONSTANT requests an error if non-constant initializers or
3914 elements are seen. */
3916 static tree
3918 {
3927 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3928 /* Do not use STRIP_NOPS here. We do not want an enumerator
3929 whose value is 0 to count as a null pointer constant. */
3935 /* Initialization of an array of chars from a string constant
3936 optionally enclosed in braces. */
3939 {
3947 {
3955 {
3958 }
3962 {
3965 }
3971 /* Subtract 1 (or sizeof (wchar_t))
3972 because it's ok to ignore the terminating null char
3973 that is counted in the length of the constant. */
3984 }
3985 }
3987 /* Build a VECTOR_CST from a *constant* vector constructor. If the
3988 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
3989 below and handle as a constructor. */
3993 {
3997 COMPARE_STRICT))
3999 else
4001 }
4003 /* Any type can be initialized
4004 from an expression of the same type, optionally with braces. */
4018 {
4024 {
4025 /* As an extension, allow initializing objects with static storage
4026 duration with compound literals (which are then treated just as
4027 the brace enclosed list they contain). */
4030 }
4034 {
4037 }
4042 /* Compound expressions can only occur here if -pedantic or
4043 -pedantic-errors is specified. In the later case, we always want
4044 an error. In the former case, we simply want a warning. */
4047 {
4048 inside_init
4053 else
4057 }
4060 /* This test catches things like `7 / 0' which
4061 result in an expression for which TREE_CONSTANT
4062 is true, but which is not actually something
4063 that is a legal constant. We really should not
4064 be using this function, because it is a part of
4065 the back-end. Instead, the expression should
4066 already have been turned into ERROR_MARK_NODE. */
4069 {
4072 }
4075 }
4077 /* Handle scalar types, including conversions. */
4081 {
4082 /* Note that convert_for_assignment calls default_conversion
4083 for arrays and functions. We must not call it in the
4084 case where inside_init is a null pointer constant. */
4085 inside_init
4090 {
4093 }
4096 {
4099 }
4102 }
4104 /* Come here only for records and arrays. */
4107 {
4110 }
4114 }
4115 \f
4116 /* Handle initializers that use braces. */
4118 /* Type of object we are accumulating a constructor for.
4119 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4122 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4123 left to fill. */
4126 /* For an ARRAY_TYPE, this is the specified index
4127 at which to store the next element we get. */
4130 /* For an ARRAY_TYPE, this is the maximum index. */
4133 /* For a RECORD_TYPE, this is the first field not yet written out. */
4136 /* For an ARRAY_TYPE, this is the index of the first element
4137 not yet written out. */
4140 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4141 This is so we can generate gaps between fields, when appropriate. */
4144 /* If we are saving up the elements rather than allocating them,
4145 this is the list of elements so far (in reverse order,
4146 most recent first). */
4149 /* 1 if constructor should be incrementally stored into a constructor chain,
4150 0 if all the elements should be kept in AVL tree. */
4153 /* 1 if so far this constructor's elements are all compile-time constants. */
4156 /* 1 if so far this constructor's elements are all valid address constants. */
4159 /* 1 if this constructor is erroneous so far. */
4162 /* Structure for managing pending initializer elements, organized as an
4163 AVL tree. */
4165 struct init_node
4166 {
4170 tree purpose;
4171 tree value;
4172 };
4174 /* Tree of pending elements at this constructor level.
4175 These are elements encountered out of order
4176 which belong at places we haven't reached yet in actually
4177 writing the output.
4178 Will never hold tree nodes across GC runs. */
4181 /* The SPELLING_DEPTH of this constructor. */
4184 /* 0 if implicitly pushing constructor levels is allowed. */
4190 /* DECL node for which an initializer is being read.
4191 0 means we are reading a constructor expression
4192 such as (struct foo) {...}. */
4195 /* start_init saves the ASMSPEC arg here for really_start_incremental_init. */
4198 /* Nonzero if this is an initializer for a top-level decl. */
4201 /* Nonzero if there were any member designators in this initializer. */
4204 /* Nesting depth of designator list. */
4207 /* Nonzero if there were diagnosed errors in this designator list. */
4210 \f
4211 /* This stack has a level for each implicit or explicit level of
4212 structuring in the initializer, including the outermost one. It
4213 saves the values of most of the variables above. */
4217 struct constructor_stack
4218 {
4220 tree type;
4221 tree fields;
4222 tree index;
4223 tree max_index;
4224 tree unfilled_index;
4225 tree unfilled_fields;
4226 tree bit_index;
4227 tree elements;
4231 /* If nonzero, this value should replace the entire
4232 constructor at this level. */
4233 tree replacement_value;
4242 };
4246 /* This stack represents designators from some range designator up to
4247 the last designator in the list. */
4249 struct constructor_range_stack
4250 {
4253 tree range_start;
4254 tree index;
4255 tree range_end;
4256 tree fields;
4257 };
4261 /* This stack records separate initializers that are nested.
4262 Nested initializers can't happen in ANSI C, but GNU C allows them
4263 in cases like { ... (struct foo) { ... } ... }. */
4265 struct initializer_stack
4266 {
4268 tree decl;
4272 tree elements;
4279 };
4282 \f
4283 /* Prepare to parse and output the initializer for variable DECL. */
4285 void
4287 {
4315 {
4317 require_constant_elements
4319 /* For a scalar, you can always use any value to initialize,
4320 even within braces. */
4326 }
4327 else
4328 {
4332 }
4345 }
4347 void
4349 {
4352 /* Free the whole constructor stack of this initializer. */
4354 {
4358 }
4363 /* Pop back to the data of the outer initializer (if any). */
4377 }
4378 \f
4379 /* Call here when we see the initializer is surrounded by braces.
4380 This is instead of a call to push_init_level;
4381 it is matched by a call to pop_init_level.
4383 TYPE is the type to initialize, for a constructor expression.
4384 For an initializer for a decl, TYPE is zero. */
4386 void
4388 {
4432 {
4434 /* Skip any nameless bit fields at the beginning. */
4441 }
4443 {
4445 {
4446 constructor_max_index
4449 /* Detect non-empty initializations of zero-length arrays. */
4454 /* constructor_max_index needs to be an INTEGER_CST. Attempts
4455 to initialize VLAs will cause a proper error; avoid tree
4456 checking errors as well by setting a safe value. */
4461 constructor_index
4464 }
4465 else
4469 }
4471 {
4472 /* Vectors are like simple fixed-size arrays. */
4473 constructor_max_index =
4477 }
4478 else
4479 {
4480 /* Handle the case of int x = {5}; */
4483 }
4484 }
4485 \f
4486 /* Push down into a subobject, for initialization.
4487 If this is for an explicit set of braces, IMPLICIT is 0.
4488 If it is because the next element belongs at a lower level,
4489 IMPLICIT is 1 (or 2 if the push is because of designator list). */
4491 void
4493 {
4497 /* If we've exhausted any levels that didn't have braces,
4498 pop them now. */
4500 {
4506 && constructor_max_index
4509 else
4511 }
4513 /* Unless this is an explicit brace, we need to preserve previous
4514 content if any. */
4516 {
4523 }
4556 {
4561 }
4563 /* Don't die if an entire brace-pair level is superfluous
4564 in the containing level. */
4566 ;
4569 {
4570 /* Don't die if there are extra init elts at the end. */
4573 else
4574 {
4577 constructor_depth++;
4578 }
4579 }
4581 {
4584 constructor_depth++;
4585 }
4588 {
4593 }
4596 {
4604 }
4607 {
4610 }
4614 {
4616 /* Skip any nameless bit fields at the beginning. */
4623 }
4625 {
4626 /* Vectors are like simple fixed-size arrays. */
4627 constructor_max_index =
4631 }
4633 {
4635 {
4636 constructor_max_index
4639 /* Detect non-empty initializations of zero-length arrays. */
4644 /* constructor_max_index needs to be an INTEGER_CST. Attempts
4645 to initialize VLAs will cause a proper error; avoid tree
4646 checking errors as well by setting a safe value. */
4651 constructor_index
4654 }
4655 else
4660 {
4661 /* We need to split the char/wchar array into individual
4662 characters, so that we don't have to special case it
4663 everywhere. */
4665 }
4666 }
4667 else
4668 {
4672 }
4673 }
4675 /* At the end of an implicit or explicit brace level,
4676 finish up that level of constructor.
4677 If we were outputting the elements as they are read, return 0
4678 from inner levels (process_init_element ignores that),
4679 but return error_mark_node from the outermost level
4680 (that's what we want to put in DECL_INITIAL).
4681 Otherwise, return a CONSTRUCTOR expression. */
4683 tree
4685 {
4690 {
4691 /* When we come to an explicit close brace,
4692 pop any inner levels that didn't have explicit braces. */
4698 }
4702 /* Error for initializing a flexible array member, or a zero-length
4703 array member in an inappropriate context. */
4708 {
4709 /* Silently discard empty initializations. The parser will
4710 already have pedwarned for empty brackets. */
4714 {
4720 /* We have already issued an error message for the existence
4721 of a flexible array member not at the end of the structure.
4722 Discard the initializer so that we do not abort later. */
4725 }
4726 else
4727 /* Zero-length arrays are no longer special, so we should no longer
4728 get here. */
4730 }
4732 /* Warn when some struct elements are implicitly initialized to zero. */
4734 && constructor_type
4737 {
4738 /* Do not warn for flexible array members or zero-length arrays. */
4744 /* Do not warn if this level of the initializer uses member
4745 designators; it is likely to be deliberate. */
4747 {
4751 }
4752 }
4754 /* Now output all pending elements. */
4758 /* Pad out the end of the structure. */
4760 /* If this closes a superfluous brace pair,
4761 just pass out the element between them. */
4764 ;
4769 {
4770 /* A nonincremental scalar initializer--just return
4771 the element, after verifying there is just one. */
4773 {
4777 }
4779 {
4782 }
4783 else
4785 }
4786 else
4787 {
4790 else
4791 {
4798 }
4799 }
4824 {
4828 }
4830 }
4832 /* Common handling for both array range and field name designators.
4833 ARRAY argument is nonzero for array ranges. Returns zero for success. */
4835 static int
4837 {
4838 tree subtype;
4841 /* Don't die if an entire brace-pair level is superfluous
4842 in the containing level. */
4846 /* If there were errors in this designator list already, bail out silently. */
4851 {
4855 /* Designator list starts at the level of closest explicit
4856 braces. */
4861 }
4864 {
4867 }
4871 {
4875 }
4877 {
4879 }
4880 else
4885 {
4888 }
4890 {
4893 }
4898 }
4900 /* If there are range designators in designator list, push a new designator
4901 to constructor_range_stack. RANGE_END is end of such stack range or
4902 NULL_TREE if there is no range designator at this level. */
4904 static void
4906 {
4920 }
4922 /* Within an array initializer, specify the next index to be initialized.
4923 FIRST is that index. If LAST is nonzero, then initialize a range
4924 of indices, running from FIRST through LAST. */
4926 void
4928 {
4958 else
4959 {
4963 {
4967 {
4970 }
4971 else
4972 {
4976 {
4979 }
4980 }
4981 }
4983 designator_depth++;
4987 }
4988 }
4990 /* Within a struct initializer, specify the next field to be initialized. */
4992 void
4994 {
4995 tree tail;
5004 {
5007 }
5011 {
5014 }
5019 else
5020 {
5022 designator_depth++;
5026 }
5027 }
5028 \f
5029 /* Add a new initializer to the tree of pending initializers. PURPOSE
5030 identifies the initializer, either array index or field in a structure.
5031 VALUE is the value of that index or field. */
5033 static void
5035 {
5042 {
5044 {
5050 else
5051 {
5056 }
5057 }
5058 }
5059 else
5060 {
5061 tree bitpos;
5065 {
5071 else
5072 {
5077 }
5078 }
5079 }
5092 {
5096 {
5100 {
5102 {
5103 /* L rotation. */
5116 {
5119 else
5121 }
5122 else
5124 }
5125 else
5126 {
5127 /* LR rotation. */
5149 {
5152 else
5154 }
5155 else
5157 }
5159 }
5160 else
5161 {
5162 /* p->balance == +1; growth of left side balances the node. */
5165 }
5166 }
5168 {
5170 /* Growth propagation from right side. */
5173 {
5175 {
5176 /* R rotation. */
5189 {
5192 else
5194 }
5195 else
5197 }
5199 {
5200 /* RL rotation */
5222 {
5225 else
5227 }
5228 else
5230 }
5232 }
5233 else
5234 {
5235 /* p->balance == -1; growth of right side balances the node. */
5238 }
5239 }
5243 }
5244 }
5246 /* Build AVL tree from a sorted chain. */
5248 static void
5250 {
5251 tree chain;
5261 {
5263 /* Skip any nameless bit fields at the beginning. */
5269 }
5271 {
5273 constructor_unfilled_index
5276 else
5278 }
5280 }
5282 /* Build AVL tree from a string constant. */
5284 static void
5286 {
5301 else
5312 {
5314 {
5317 }
5318 else
5319 {
5323 {
5326 else
5331 }
5332 }
5335 {
5338 {
5340 {
5343 }
5344 }
5346 {
5349 }
5354 }
5359 }
5362 }
5364 /* Return value of FIELD in pending initializer or zero if the field was
5365 not initialized yet. */
5367 static tree
5369 {
5373 {
5380 {
5385 else
5387 }
5388 }
5390 {
5394 && (!constructor_unfilled_fields
5401 {
5406 else
5408 }
5409 }
5411 {
5415 }
5417 }
5419 /* "Output" the next constructor element.
5420 At top level, really output it to assembler code now.
5421 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
5422 TYPE is the data type that the containing data type wants here.
5423 FIELD is the field (a FIELD_DECL) or the index that this element fills.
5425 PENDING if non-nil means output pending elements that belong
5426 right after this element. (PENDING is normally 1;
5427 it is 0 while outputting pending elements, to avoid recursion.) */
5429 static void
5431 {
5433 {
5436 }
5448 {
5449 /* As an extension, allow initializing objects with static storage
5450 duration with compound literals (which are then treated just as
5451 the brace enclosed list they contain). */
5454 }
5468 {
5471 }
5476 /* If this field is empty (and not at the end of structure),
5477 don't do anything other than checking the initializer. */
5488 {
5491 }
5493 /* If this element doesn't come next in sequence,
5494 put it on constructor_pending_elts. */
5496 && (!constructor_incremental
5498 {
5505 }
5507 && (!constructor_incremental
5509 {
5510 /* We do this for records but not for unions. In a union,
5511 no matter which field is specified, it can be initialized
5512 right away since it starts at the beginning of the union. */
5514 {
5517 else
5518 {
5526 }
5527 }
5531 }
5534 {
5538 /* We can have just one union field set. */
5540 }
5542 /* Otherwise, output this element either to
5543 constructor_elements or to the assembler file. */
5547 constructor_elements
5550 /* Advance the variable that indicates sequential elements output. */
5552 constructor_unfilled_index
5554 bitsize_one_node);
5556 {
5557 constructor_unfilled_fields
5560 /* Skip any nameless bit fields. */
5564 constructor_unfilled_fields =
5566 }
5570 /* Now output any pending elements which have become next. */
5573 }
5575 /* Output any pending elements which have become next.
5576 As we output elements, constructor_unfilled_{fields,index}
5577 advances, which may cause other elements to become next;
5578 if so, they too are output.
5580 If ALL is 0, we return when there are
5581 no more pending elements to output now.
5583 If ALL is 1, we output space as necessary so that
5584 we can output all the pending elements. */
5586 static void
5588 {
5590 tree next;
5592 retry:
5594 /* Look thru the whole pending tree.
5595 If we find an element that should be output now,
5596 output it. Otherwise, set NEXT to the element
5597 that comes first among those still pending. */
5601 {
5603 {
5605 constructor_unfilled_index))
5611 {
5612 /* Advance to the next smaller node. */
5615 else
5616 {
5617 /* We have reached the smallest node bigger than the
5618 current unfilled index. Fill the space first. */
5621 }
5622 }
5623 else
5624 {
5625 /* Advance to the next bigger node. */
5628 else
5629 {
5630 /* We have reached the biggest node in a subtree. Find
5631 the parent of it, which is the next bigger node. */
5637 {
5640 }
5641 }
5642 }
5643 }
5646 {
5649 /* If the current record is complete we are done. */
5655 /* We can't compare fields here because there might be empty
5656 fields in between. */
5658 {
5662 }
5664 {
5665 /* Advance to the next smaller node. */
5668 else
5669 {
5670 /* We have reached the smallest node bigger than the
5671 current unfilled field. Fill the space first. */
5674 }
5675 }
5676 else
5677 {
5678 /* Advance to the next bigger node. */
5681 else
5682 {
5683 /* We have reached the biggest node in a subtree. Find
5684 the parent of it, which is the next bigger node. */
5691 {
5694 }
5695 }
5696 }
5697 }
5698 }
5700 /* Ordinarily return, but not if we want to output all
5701 and there are elements left. */
5705 /* If it's not incremental, just skip over the gap, so that after
5706 jumping to retry we will output the next successive element. */
5713 /* ELT now points to the node in the pending tree with the next
5714 initializer to output. */
5716 }
5717 \f
5718 /* Add one non-braced element to the current constructor level.
5719 This adjusts the current position within the constructor's type.
5720 This may also start or terminate implicit levels
5721 to handle a partly-braced initializer.
5723 Once this has found the correct level for the new element,
5724 it calls output_init_element. */
5726 void
5728 {
5735 /* Handle superfluous braces around string cst as in
5736 char x[] = {"foo"}; */
5738 && constructor_type
5742 {
5747 }
5750 {
5753 }
5755 /* Ignore elements of a brace group if it is entirely superfluous
5756 and has already been diagnosed. */
5760 /* If we've exhausted any levels that didn't have braces,
5761 pop them now. */
5763 {
5771 constructor_index)))
5773 else
5775 }
5777 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
5779 {
5780 /* If value is a compound literal and we'll be just using its
5781 content, don't put it into a SAVE_EXPR. */
5783 || !require_constant_value
5786 }
5789 {
5791 {
5792 tree fieldtype;
5796 {
5799 }
5806 /* Error for non-static initialization of a flexible array member. */
5808 && !require_constant_value
5811 {
5814 }
5816 /* Accept a string constant to initialize a subarray. */
5822 /* Otherwise, if we have come to a subaggregate,
5823 and we don't have an element of its type, push into it. */
5829 {
5832 }
5835 {
5839 }
5840 else
5841 /* Do the bookkeeping for an element that was
5842 directly output as a constructor. */
5843 {
5844 /* For a record, keep track of end position of last field. */
5846 constructor_bit_index
5851 /* If the current field was the first one not yet written out,
5852 it isn't now, so update. */
5854 {
5856 /* Skip any nameless bit fields. */
5860 constructor_unfilled_fields =
5862 }
5863 }
5866 /* Skip any nameless bit fields at the beginning. */
5871 }
5873 {
5874 tree fieldtype;
5878 {
5881 }
5888 /* Warn that traditional C rejects initialization of unions.
5889 We skip the warning if the value is zero. This is done
5890 under the assumption that the zero initializer in user
5891 code appears conditioned on e.g. __STDC__ to avoid
5892 "missing initializer" warnings and relies on default
5893 initialization to zero in the traditional C case.
5894 We also skip the warning if the initializer is designated,
5895 again on the assumption that this must be conditional on
5896 __STDC__ anyway (and we've already complained about the
5897 member-designator already). */
5902 /* Accept a string constant to initialize a subarray. */
5908 /* Otherwise, if we have come to a subaggregate,
5909 and we don't have an element of its type, push into it. */
5915 {
5918 }
5921 {
5925 }
5926 else
5927 /* Do the bookkeeping for an element that was
5928 directly output as a constructor. */
5929 {
5932 }
5935 }
5937 {
5941 /* Accept a string constant to initialize a subarray. */
5947 /* Otherwise, if we have come to a subaggregate,
5948 and we don't have an element of its type, push into it. */
5954 {
5957 }
5962 {
5965 }
5967 /* Now output the actual element. */
5969 {
5973 }
5975 constructor_index
5979 /* If we are doing the bookkeeping for an element that was
5980 directly output as a constructor, we must update
5981 constructor_unfilled_index. */
5983 }
5985 {
5988 /* Do a basic check of initializer size. Note that vectors
5989 always have a fixed size derived from their type. */
5991 {
5994 }
5996 /* Now output the actual element. */
6000 constructor_index
6004 /* If we are doing the bookkeeping for an element that was
6005 directly output as a constructor, we must update
6006 constructor_unfilled_index. */
6008 }
6010 /* Handle the sole element allowed in a braced initializer
6011 for a scalar variable. */
6013 {
6016 }
6017 else
6018 {
6022 }
6024 /* Handle range initializers either at this level or anywhere higher
6025 in the designator stack. */
6027 {
6034 {
6038 }
6042 {
6046 }
6053 {
6057 {
6060 }
6068 }
6073 }
6076 }
6079 }
6080 \f
6081 /* Build a simple asm-statement, from one string literal. */
6082 tree
6084 {
6091 {
6092 tree stmt;
6094 /* Simple asm statements are treated as volatile. */
6099 }
6103 }
6105 /* Build an asm-statement, whose components are a CV_QUALIFIER, a
6106 STRING, some OUTPUTS, some INPUTS, and some CLOBBERS. */
6108 tree
6110 tree clobbers)
6111 {
6112 tree tail;
6115 {
6118 }
6122 {
6126 }
6128 /* We can remove output conversions that change the type,
6129 but not the mode. */
6131 {
6137 /* Allow conversions as LHS here. build_modify_expr as called below
6138 will do the right thing with them. */
6149 }
6151 /* Remove output conversions that change the type but not the mode. */
6153 {
6157 }
6159 /* Perform default conversions on array and function inputs.
6160 Don't do this for other types as it would screw up operands
6161 expected to be in memory. */
6167 }
6169 /* Expand an ASM statement with operands, handling output operands
6170 that are not variables or INDIRECT_REFS by transforming such
6171 cases into cases that expand_asm_operands can handle.
6173 Arguments are same as for expand_asm_operands. */
6175 void
6179 {
6182 /* o[I] is the place that output number I should be written. */
6184 tree tail;
6186 /* Record the contents of OUTPUTS before it is modified. */
6188 {
6192 }
6194 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
6195 OUTPUTS some trees for where the values were actually stored. */
6198 /* Copy all the intermediate outputs into the specified outputs. */
6200 {
6202 {
6207 /* Restore the original value so that it's correct the next
6208 time we expand this function. */
6210 }
6211 /* Detect modification of read-only values.
6212 (Otherwise done by build_modify_expr.) */
6213 else
6214 {
6222 }
6223 }
6225 /* Those MODIFY_EXPRs could do autoincrements. */
6227 }
6228 \f
6229 /* Expand a C `return' statement.
6230 RETVAL is the expression for what to return,
6231 or a null pointer for `return;' with no value. */
6233 tree
6235 {
6242 {
6247 }
6249 {
6253 }
6254 else
6255 {
6259 tree inner;
6267 /* Strip any conversions, additions, and subtractions, and see if
6268 we are returning the address of a local variable. Warn if so. */
6270 {
6272 {
6279 /* If the second operand of the MINUS_EXPR has a pointer
6280 type (or is converted from it), this may be valid, so
6281 don't give a warning. */
6282 {
6296 }
6313 }
6316 }
6319 }
6322 }
6323 \f
6325 /* The SWITCH_STMT being built. */
6326 tree switch_stmt;
6327 /* A splay-tree mapping the low element of a case range to the high
6328 element, or NULL_TREE if there is no high element. Used to
6329 determine whether or not a new case label duplicates an old case
6330 label. We need a tree, rather than simply a hash table, because
6331 of the GNU case range extension. */
6332 splay_tree cases;
6333 /* The next node on the stack. */
6335 };
6337 /* A stack of the currently active switch statements. The innermost
6338 switch statement is on the top of the stack. There is no need to
6339 mark the stack for garbage collection because it is only active
6340 during the processing of the body of a function, and we never
6341 collect at that point. */
6345 /* Start a C switch statement, testing expression EXP. Return the new
6346 SWITCH_STMT. */
6348 tree
6350 {
6356 {
6362 {
6365 }
6366 else
6367 {
6377 }
6378 }
6380 /* Add this new SWITCH_STMT to the stack. */
6388 }
6390 /* Process a case label. */
6392 tree
6394 {
6398 {
6407 {
6408 /* Attach the first case label to the SWITCH_BODY. */
6411 }
6412 }
6415 else
6419 }
6421 /* Finish the switch statement. */
6423 void
6425 {
6428 /* Rechain the next statements to the SWITCH_STMT. */
6431 /* Pop the stack. */
6435 }
6437 /* Build a binary-operation expression without default conversions.
6438 CODE is the kind of expression to build.
6439 This function differs from `build' in several ways:
6440 the data type of the result is computed and recorded in it,
6441 warnings are generated if arg data types are invalid,
6442 special handling for addition and subtraction of pointers is known,
6443 and some optimization is done (operations on narrow ints
6444 are done in the narrower type when that gives the same result).
6445 Constant folding is also done before the result is returned.
6447 Note that the operands will never have enumeral types, or function
6448 or array types, because either they will have the default conversions
6449 performed or they have both just been converted to some other type in which
6450 the arithmetic is to be done. */
6452 tree
6455 {
6460 /* Expression code to give to the expression when it is built.
6461 Normally this is CODE, which is what the caller asked for,
6462 but in some special cases we change it. */
6465 /* Data type in which the computation is to be performed.
6466 In the simplest cases this is the common type of the arguments. */
6469 /* Nonzero means operands have already been type-converted
6470 in whatever way is necessary.
6471 Zero means they need to be converted to RESULT_TYPE. */
6474 /* Nonzero means create the expression with this type, rather than
6475 RESULT_TYPE. */
6478 /* Nonzero means after finally constructing the expression
6479 convert it to this type. */
6482 /* Nonzero if this is an operation like MIN or MAX which can
6483 safely be computed in short if both args are promoted shorts.
6484 Also implies COMMON.
6485 -1 indicates a bitwise operation; this makes a difference
6486 in the exact conditions for when it is safe to do the operation
6487 in a narrower mode. */
6490 /* Nonzero if this is a comparison operation;
6491 if both args are promoted shorts, compare the original shorts.
6492 Also implies COMMON. */
6495 /* Nonzero if this is a right-shift operation, which can be computed on the
6496 original short and then promoted if the operand is a promoted short. */
6499 /* Nonzero means set RESULT_TYPE to the common type of the args. */
6503 {
6506 }
6507 else
6508 {
6511 }
6516 /* The expression codes of the data types of the arguments tell us
6517 whether the arguments are integers, floating, pointers, etc. */
6521 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
6525 /* If an error was already reported for one of the arguments,
6526 avoid reporting another error. */
6532 {
6534 /* Handle the pointer + int case. */
6539 else
6544 /* Subtraction of two similar pointers.
6545 We must subtract them as integers, then divide by object size. */
6549 /* Handle pointer minus int. Just like pointer plus int. */
6552 else
6565 /* Floating point division by zero is a legitimate way to obtain
6566 infinities and NaNs. */
6574 {
6577 else
6578 /* Although it would be tempting to shorten always here, that
6579 loses on some targets, since the modulo instruction is
6580 undefined if the quotient can't be represented in the
6581 computation mode. We shorten only if unsigned or if
6582 dividing by something we know != -1. */
6587 }
6606 {
6607 /* Although it would be tempting to shorten always here, that loses
6608 on some targets, since the modulo instruction is undefined if the
6609 quotient can't be represented in the computation mode. We shorten
6610 only if unsigned or if dividing by something we know != -1. */
6615 }
6627 {
6628 /* Result of these operations is always an int,
6629 but that does not mean the operands should be
6630 converted to ints! */
6635 }
6638 /* Shift operations: result has same type as first operand;
6639 always convert second operand to int.
6640 Also set SHORT_SHIFT if shifting rightward. */
6644 {
6646 {
6649 else
6650 {
6656 }
6657 }
6659 /* Use the type of the value to be shifted. */
6661 /* Convert the shift-count to an integer, regardless of size
6662 of value being shifted. */
6665 /* Avoid converting op1 to result_type later. */
6667 }
6672 {
6674 {
6680 }
6682 /* Use the type of the value to be shifted. */
6684 /* Convert the shift-count to an integer, regardless of size
6685 of value being shifted. */
6688 /* Avoid converting op1 to result_type later. */
6690 }
6696 {
6698 {
6703 }
6705 /* Use the type of the value to be shifted. */
6707 /* Convert the shift-count to an integer, regardless of size
6708 of value being shifted. */
6711 /* Avoid converting op1 to result_type later. */
6713 }
6720 /* Result of comparison is always int,
6721 but don't convert the args to int! */
6731 {
6734 /* Anything compares with void *. void * compares with anything.
6735 Otherwise, the targets must be compatible
6736 and both must be object or both incomplete. */
6740 {
6741 /* op0 != orig_op0 detects the case of something
6742 whose value is 0 but which isn't a valid null ptr const. */
6746 }
6748 {
6752 }
6753 else
6758 }
6766 {
6769 }
6771 {
6774 }
6783 {
6785 {
6790 }
6791 else
6792 {
6795 }
6796 }
6808 {
6810 {
6818 }
6819 else
6820 {
6823 }
6824 }
6827 {
6831 }
6834 {
6838 }
6840 {
6843 }
6845 {
6848 }
6860 {
6863 }
6869 }
6873 &&
6876 {
6882 /* For certain operations (which identify themselves by shorten != 0)
6883 if both args were extended from the same smaller type,
6884 do the arithmetic in that type and then extend.
6886 shorten !=0 and !=1 indicates a bitwise operation.
6887 For them, this optimization is safe only if
6888 both args are zero-extended or both are sign-extended.
6889 Otherwise, we might change the result.
6890 Eg, (short)-1 | (unsigned short)-1 is (int)-1
6891 but calculated in (unsigned short) it would be (unsigned short)-1. */
6894 {
6898 /* UNS is 1 if the operation to be done is an unsigned one. */
6900 tree type;
6904 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
6905 but it *requires* conversion to FINAL_TYPE. */
6916 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
6918 /* For bitwise operations, signedness of nominal type
6919 does not matter. Consider only how operands were extended. */
6923 /* Note that in all three cases below we refrain from optimizing
6924 an unsigned operation on sign-extended args.
6925 That would not be valid. */
6927 /* Both args variable: if both extended in same way
6928 from same width, do it in that width.
6929 Do it unsigned if args were zero-extended. */
6936 result_type
6937 = c_common_signed_or_unsigned_type
6943 && (type
6952 && (type
6957 }
6959 /* Shifts can be shortened if shifting right. */
6962 {
6972 /* We can shorten only if the shift count is less than the
6973 number of bits in the smaller type size. */
6975 /* We cannot drop an unsigned shift after sign-extension. */
6977 {
6978 /* Do an unsigned shift if the operand was zero-extended. */
6979 result_type
6982 /* Convert value-to-be-shifted to that type. */
6986 }
6987 }
6989 /* Comparison operations are shortened too but differently.
6990 They identify themselves by setting short_compare = 1. */
6993 {
6994 /* Don't write &op0, etc., because that would prevent op0
6995 from being kept in a register.
6996 Instead, make copies of the our local variables and
6997 pass the copies by reference, then copy them back afterward. */
7000 tree val
7011 {
7023 /* Give warnings for comparisons between signed and unsigned
7024 quantities that may fail.
7026 Do the checking based on the original operand trees, so that
7027 casts will be considered, but default promotions won't be.
7029 Do not warn if the comparison is being done in a signed type,
7030 since the signed type will only be chosen if it can represent
7031 all the values of the unsigned type. */
7034 /* Do not warn if both operands are the same signedness. */
7037 else
7038 {
7043 else
7046 /* Do not warn if the signed quantity is an
7047 unsuffixed integer literal (or some static
7048 constant expression involving such literals or a
7049 conditional expression involving such literals)
7050 and it is non-negative. */
7053 /* Do not warn if the comparison is an equality operation,
7054 the unsigned quantity is an integral constant, and it
7055 would fit in the result if the result were signed. */
7058 && int_fits_type_p
7061 /* Do not warn if the unsigned quantity is an enumeration
7062 constant and its maximum value would fit in the result
7063 if the result were signed. */
7066 && int_fits_type_p
7070 else
7072 }
7074 /* Warn if two unsigned values are being compared in a size
7075 larger than their original size, and one (and only one) is the
7076 result of a `~' operator. This comparison will always fail.
7078 Also warn if one operand is a constant, and the constant
7079 does not have all bits set that are set in the ~ operand
7080 when it is extended. */
7084 {
7088 else
7093 {
7094 tree primop;
7099 {
7103 }
7104 else
7105 {
7109 }
7114 {
7118 }
7119 }
7126 }
7127 }
7128 }
7129 }
7131 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
7132 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
7133 Then the expression will be built.
7134 It will be given type FINAL_TYPE if that is nonzero;
7135 otherwise, it will be given type RESULT_TYPE. */
7138 {
7141 }
7144 {
7149 }
7154 {
7156 tree folded;
7158 /* Treat expressions in initializers specially as they can't trap. */
7166 }
7167 }