| blob | b6a5d9ee30e552d6e723f392b00b603b865cac2c |
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, 2004 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. */
83 \f
84 /* Do `exp = require_complete_type (exp);' to make sure exp
85 does not have an incomplete type. (That includes void types.) */
87 tree
89 {
95 /* First, detect a valid value with a complete type. */
101 }
103 /* Print an error message for invalid use of an incomplete type.
104 VALUE is the expression that was used (or 0 if that isn't known)
105 and TYPE is the type that was invalid. */
107 void
109 {
112 /* Avoid duplicate error message. */
120 else
121 {
122 retry:
123 /* We must print an error message. Be clever about what it says. */
126 {
145 {
147 {
150 }
153 }
159 }
164 else
165 /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */
168 }
169 }
171 /* Given a type, apply default promotions wrt unnamed function
172 arguments and return the new type. */
174 tree
176 {
181 {
182 /* Preserve unsignedness if not really getting any wider. */
187 }
190 }
192 /* Return a variant of TYPE which has all the type qualifiers of LIKE
193 as well as those of TYPE. */
195 static tree
197 {
200 }
201 \f
202 /* Return the common type of two types.
203 We assume that comptypes has already been done and returned 1;
204 if that isn't so, this may crash. In particular, we assume that qualifiers
205 match.
207 This is the type for the result of most arithmetic operations
208 if the operands have the given two types. */
210 tree
212 {
215 tree attributes;
217 /* Save time if the two types are the same. */
221 /* If one type is nonsense, use the other. */
227 /* Merge the attributes. */
230 /* Treat an enum type as the unsigned integer type of the same width. */
240 /* If one type is complex, form the common type of the non-complex
241 components, then make that complex. Use T1 or T2 if it is the
242 required type. */
244 {
253 else
255 attributes);
256 }
259 {
262 /* If only one is real, use it as the result. */
270 /* Both real or both integers; use the one with greater precision. */
277 /* Same precision. Prefer longs to ints even when same size. */
282 attributes);
286 {
287 /* But preserve unsignedness from the other type,
288 since long cannot hold all the values of an unsigned int. */
291 else
294 }
296 /* Likewise, prefer long double to double even if same size. */
300 attributes);
302 /* Otherwise prefer the unsigned one. */
306 else
310 /* For two pointers, do this recursively on the target type,
311 and combine the qualifiers of the two types' targets. */
312 /* This code was turned off; I don't know why.
313 But ANSI C specifies doing this with the qualifiers.
314 So I turned it on again. */
315 {
325 }
328 {
330 /* Save space: see if the result is identical to one of the args. */
335 /* Merge the element types, and have a size if either arg has one. */
338 }
341 /* Function types: prefer the one that specified arg types.
342 If both do, merge the arg types. Also merge the return types. */
343 {
351 /* Save space: see if the result is identical to one of the args. */
357 /* Simple way if one arg fails to specify argument types. */
359 {
362 }
364 {
367 }
369 /* If both args specify argument types, we must merge the two
370 lists, argument by argument. */
385 {
386 /* A null type means arg type is not specified.
387 Take whatever the other function type has. */
389 {
392 }
394 {
397 }
399 /* Given wait (union {union wait *u; int *i} *)
400 and wait (union wait *),
401 prefer union wait * as type of parm. */
404 {
405 tree memb;
409 COMPARE_STRICT))
410 {
415 }
416 }
419 {
420 tree memb;
424 COMPARE_STRICT))
425 {
430 }
431 }
433 parm_done: ;
434 }
439 /* ... falls through ... */
440 }
444 }
446 }
447 \f
448 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
449 or various other operations. Return 2 if they are compatible
450 but a warning may be needed if you use them together. */
452 int
454 {
459 /* Suppress errors caused by previously reported errors. */
465 /* If either type is the internal version of sizetype, return the
466 language version. */
475 /* Enumerated types are compatible with integer types, but this is
476 not transitive: two enumerated types in the same translation unit
477 are compatible with each other only if they are the same type. */
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 {
513 /* We must give ObjC the first crack at comparing pointers, since
514 protocol qualifiers may be involved. */
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 }
566 /* We are dealing with two distinct structs. In assorted Objective-C
567 corner cases, however, these can still be deemed equivalent. */
578 /* The target might allow certain vector types to be compatible. */
585 }
587 }
589 /* Return 1 if TTL and TTR are pointers to types that are equivalent,
590 ignoring their qualifiers. REFLEXIVE is only used by ObjC - set it
591 to 1 or 0 depending if the check of the pointer types is meant to
592 be reflexive or not (typically, assignments are not reflexive,
593 while comparisons are reflexive).
594 */
596 static int
598 {
601 /* Give objc_comptypes a crack at letting these types through. */
611 }
612 \f
613 /* Subroutines of `comptypes'. */
615 /* Determine whether two types derive from the same translation unit.
616 If the CONTEXT chain ends in a null, that type's context is still
617 being parsed, so if two types have context chains ending in null,
618 they're in the same translation unit. */
619 static int
621 {
624 {
629 }
633 {
638 }
641 }
643 /* The C standard says that two structures in different translation
644 units are compatible with each other only if the types of their
645 fields are compatible (among other things). So, consider two copies
646 of this structure: */
650 tree t1;
651 tree t2;
652 };
654 /* Can they be compatible with each other? We choose to break the
655 recursion by allowing those types to be compatible. */
659 /* Return 1 if two 'struct', 'union', or 'enum' types T1 and T2 are
660 compatible. If the two types are not the same (which has been
661 checked earlier), this can only happen when multiple translation
662 units are being compiled. See C99 6.2.7 paragraph 1 for the exact
663 rules. */
665 static int
667 {
671 /* We have to verify that the tags of the types are the same. This
672 is harder than it looks because this may be a typedef, so we have
673 to go look at the original type. It may even be a typedef of a
674 typedef... */
681 /* C90 didn't have the requirement that the two tags be the same. */
685 /* C90 didn't say what happened if one or both of the types were
686 incomplete; we choose to follow C99 rules here, which is that they
687 are compatible. */
692 {
697 }
700 {
702 {
707 {
712 }
714 }
717 {
722 {
734 {
749 }
753 }
755 }
758 {
769 {
784 }
789 }
793 }
794 }
796 /* Return 1 if two function types F1 and F2 are compatible.
797 If either type specifies no argument types,
798 the other must specify a fixed number of self-promoting arg types.
799 Otherwise, if one type specifies only the number of arguments,
800 the other must specify that number of self-promoting arg types.
801 Otherwise, the argument types must match. */
803 static int
805 {
807 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
815 /* 'volatile' qualifiers on a function's return type mean the function
816 is noreturn. */
832 /* An unspecified parmlist matches any specified parmlist
833 whose argument types don't need default promotions. */
836 {
839 /* If one of these types comes from a non-prototype fn definition,
840 compare that with the other type's arglist.
841 If they don't match, ask for a warning (but no error). */
844 flags))
847 }
849 {
854 flags))
857 }
859 /* Both types have argument lists: compare them and propagate results. */
862 }
864 /* Check two lists of types for compatibility,
865 returning 0 for incompatible, 1 for compatible,
866 or 2 for compatible with warning. */
868 static int
870 {
871 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
876 {
879 /* If one list is shorter than the other,
880 they fail to match. */
883 /* A null pointer instead of a type
884 means there is supposed to be an argument
885 but nothing is specified about what type it has.
886 So match anything that self-promotes. */
888 {
891 }
893 {
896 }
897 /* If one of the lists has an error marker, ignore this arg. */
900 ;
903 flags)))
904 {
905 /* Allow wait (union {union wait *u; int *i} *)
906 and wait (union wait *) to be compatible. */
913 {
914 tree memb;
918 flags))
922 }
929 {
930 tree memb;
934 flags))
938 }
939 else
941 }
943 /* comptypes said ok, but record if it said to warn. */
949 }
950 }
951 \f
952 /* Compute the size to increment a pointer by. */
954 tree
956 {
963 {
966 }
968 /* Convert in case a char is more than one unit. */
972 }
973 \f
974 /* Return either DECL or its known constant value (if it has one). */
976 tree
978 {
980 in a place where a variable is invalid. */
986 /* This is invalid if initial value is not constant.
987 If it has either a function call, a memory reference,
988 or a variable, then re-evaluating it could give different results. */
990 /* Check for cases where this is sub-optimal, even though valid. */
994 }
996 /* Return either DECL or its known constant value (if it has one), but
997 return DECL if pedantic or DECL has mode BLKmode. This is for
998 bug-compatibility with the old behavior of decl_constant_value
999 (before GCC 3.0); every use of this function is a bug and it should
1000 be removed before GCC 3.1. It is not appropriate to use pedantic
1001 in a way that affects optimization, and BLKmode is probably not the
1002 right test for avoiding misoptimizations either. */
1004 static tree
1006 {
1009 else
1011 }
1014 /* Perform the default conversion of arrays and functions to pointers.
1015 Return the result of converting EXP. For any other expression, just
1016 return EXP. */
1018 static tree
1020 {
1021 tree orig_exp;
1026 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
1027 an lvalue.
1029 Do not use STRIP_NOPS here! It will remove conversions from pointer
1030 to integer and cause infinite recursion. */
1035 {
1039 }
1041 /* Preserve the original expression code. */
1046 {
1048 }
1050 {
1051 tree adr;
1053 tree ptrtype;
1059 {
1062 }
1065 restype
1076 {
1080 }
1084 {
1085 /* Before C99, non-lvalue arrays do not decay to pointers.
1086 Normally, using such an array would be invalid; but it can
1087 be used correctly inside sizeof or as a statement expression.
1088 Thus, do not give an error here; an error will result later. */
1090 }
1095 {
1096 /* ??? This is not really quite correct
1097 in that the type of the operand of ADDR_EXPR
1098 is not the target type of the type of the ADDR_EXPR itself.
1099 Question is, can this lossage be avoided? */
1106 }
1107 /* This way is better for a COMPONENT_REF since it can
1108 simplify the offset for a component. */
1111 }
1113 }
1115 /* Perform default promotions for C data used in expressions.
1116 Arrays and functions are converted to pointers;
1117 enumeral types or short or char, to int.
1118 In addition, manifest constants symbols are replaced by their values. */
1120 tree
1122 {
1123 tree orig_exp;
1130 /* Constants can be used directly unless they're not loadable. */
1134 /* Replace a nonvolatile const static variable with its value unless
1135 it is an array, in which case we must be sure that taking the
1136 address of the array produces consistent results. */
1138 {
1141 }
1143 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
1144 an lvalue.
1146 Do not use STRIP_NOPS here! It will remove conversions from pointer
1147 to integer and cause infinite recursion. */
1154 /* Preserve the original expression code. */
1158 /* Normally convert enums to int,
1159 but convert wide enums to something wider. */
1161 {
1169 }
1173 /* If it's thinner than an int, promote it like a
1174 c_promoting_integer_type_p, otherwise leave it alone. */
1180 {
1181 /* Preserve unsignedness if not really getting any wider. */
1187 }
1190 {
1193 }
1195 }
1196 \f
1197 /* Look up COMPONENT in a structure or union DECL.
1199 If the component name is not found, returns NULL_TREE. Otherwise,
1200 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL
1201 stepping down the chain to the component, which is in the last
1202 TREE_VALUE of the list. Normally the list is of length one, but if
1203 the component is embedded within (nested) anonymous structures or
1204 unions, the list steps down the chain to the component. */
1206 static tree
1208 {
1210 tree field;
1212 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers
1213 to the field elements. Use a binary search on this array to quickly
1214 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC
1215 will always be set for structures which have many elements. */
1218 {
1226 {
1231 {
1232 /* Step through all anon unions in linear fashion. */
1234 {
1238 {
1243 }
1244 }
1246 /* Entire record is only anon unions. */
1250 /* Restart the binary search, with new lower bound. */
1252 }
1258 else
1260 }
1266 }
1267 else
1268 {
1270 {
1274 {
1279 }
1283 }
1287 }
1290 }
1292 /* Make an expression to refer to the COMPONENT field of
1293 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */
1295 tree
1297 {
1301 tree ref;
1303 /* If DATUM is a COMPOUND_EXPR, move our reference inside it.
1304 Ensure that the arguments are not lvalues; otherwise,
1305 if the component is an array, it would wrongly decay to a pointer in
1306 C89 mode.
1307 We cannot do this with a COND_EXPR, because in a conditional expression
1308 the default promotions are applied to both sides, and this would yield
1309 the wrong type of the result; for example, if the components have
1310 type "char". */
1312 {
1314 {
1318 }
1321 }
1323 /* See if there is a field or component with name COMPONENT. */
1326 {
1328 {
1331 }
1336 {
1341 }
1343 /* Chain the COMPONENT_REFs if necessary down to the FIELD.
1344 This might be better solved in future the way the C++ front
1345 end does it - by giving the anonymous entities each a
1346 separate name and type, and then have build_component_ref
1347 recursively call itself. We can't do that here. */
1348 do
1349 {
1367 }
1371 }
1377 }
1378 \f
1379 /* Given an expression PTR for a pointer, return an expression
1380 for the value pointed to.
1381 ERRORSTRING is the name of the operator to appear in error messages. */
1383 tree
1385 {
1390 {
1395 else
1396 {
1401 {
1404 }
1408 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
1409 so that we get the proper error message if the result is used
1410 to assign to. Also, &* is supposed to be a no-op.
1411 And ANSI C seems to specify that the type of the result
1412 should be the const type. */
1413 /* A de-reference of a pointer to const is not a const. It is valid
1414 to change it via some other pointer. */
1420 }
1421 }
1425 }
1427 /* This handles expressions of the form "a[i]", which denotes
1428 an array reference.
1430 This is logically equivalent in C to *(a+i), but we may do it differently.
1431 If A is a variable or a member, we generate a primitive ARRAY_REF.
1432 This avoids forcing the array out of registers, and can work on
1433 arrays that are not lvalues (for example, members of structures returned
1434 by functions). */
1436 tree
1438 {
1440 {
1443 }
1451 {
1454 /* Subscripting with type char is likely to lose
1455 on a machine where chars are signed.
1456 So warn on any machine, but optionally.
1457 Don't warn for unsigned char since that type is safe.
1458 Don't warn for signed char because anyone who uses that
1459 must have done so deliberately. */
1464 /* Apply default promotions *after* noticing character types. */
1467 /* Require integer *after* promotion, for sake of enums. */
1469 {
1472 }
1474 /* An array that is indexed by a non-constant
1475 cannot be stored in a register; we must be able to do
1476 address arithmetic on its address.
1477 Likewise an array of elements of variable size. */
1481 {
1484 }
1485 /* An array that is indexed by a constant value which is not within
1486 the array bounds cannot be stored in a register either; because we
1487 would get a crash in store_bit_field/extract_bit_field when trying
1488 to access a non-existent part of the register. */
1492 {
1495 }
1498 {
1506 }
1510 /* Array ref is const/volatile if the array elements are
1511 or if the array is. */
1520 /* This was added by rms on 16 Nov 91.
1521 It fixes vol struct foo *a; a->elts[1]
1522 in an inline function.
1523 Hope it doesn't break something else. */
1526 }
1528 {
1532 /* Do the same warning check as above, but only on the part that's
1533 syntactically the index and only if it is also semantically
1534 the index. */
1540 /* Put the integer in IND to simplify error checking. */
1542 {
1546 }
1553 {
1556 }
1558 {
1561 }
1565 }
1566 }
1567 \f
1568 /* Build an external reference to identifier ID. FUN indicates
1569 whether this will be used for a function call. */
1570 tree
1572 {
1573 tree ref;
1578 {
1579 /* Properly declared variable or function reference. */
1583 {
1587 }
1588 else
1590 }
1594 /* Implicit function declaration. */
1597 /* Don't complain about something that's already been
1598 complained about. */
1600 else
1601 {
1604 }
1617 {
1620 }
1626 {
1631 }
1634 }
1636 /* Build a function call to function FUNCTION with parameters PARAMS.
1637 PARAMS is a list--a chain of TREE_LIST nodes--in which the
1638 TREE_VALUE of each node is a parameter-expression.
1639 FUNCTION's data type may be a function type or a pointer-to-function. */
1641 tree
1643 {
1645 tree coerced_params;
1647 tree tem;
1649 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
1652 /* Convert anything with function type to a pointer-to-function. */
1654 {
1657 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
1658 (because calling an inline function does not mean the function
1659 needs to be separately compiled). */
1665 }
1666 else
1676 {
1679 }
1684 /* fntype now gets the type of function pointed to. */
1687 /* Check that the function is called through a compatible prototype.
1688 If it is not, replace the call by a trap, wrapped up in a compound
1689 expression if necessary. This has the nice side-effect to prevent
1690 the tree-inliner from generating invalid assignment trees which may
1691 blow up in the RTL expander later.
1693 ??? This doesn't work for Objective-C because objc_comptypes
1694 refuses to compare function prototypes, yet the compiler appears
1695 to build calls that are flagged as invalid by C's comptypes. */
1701 {
1704 NULL_TREE);
1706 /* This situation leads to run-time undefined behavior. We can't,
1707 therefore, simply error unless we can prove that all possible
1708 executions of the program must execute the code. */
1713 else
1714 {
1715 tree rhs;
1720 NULL_TREE));
1721 else
1725 }
1726 }
1728 /* Convert the parameters to the types declared in the
1729 function prototype, or apply default promotions. */
1731 coerced_params
1734 /* Check that the arguments to the function are valid. */
1738 /* Recognize certain built-in functions so we can make tree-codes
1739 other than CALL_EXPR. We do this when it enables fold-const.c
1740 to do something useful. */
1745 {
1750 }
1760 }
1761 \f
1762 /* Convert the argument expressions in the list VALUES
1763 to the types in the list TYPELIST. The result is a list of converted
1764 argument expressions.
1766 If TYPELIST is exhausted, or when an element has NULL as its type,
1767 perform the default conversions.
1769 PARMLIST is the chain of parm decls for the function being called.
1770 It may be 0, if that info is not available.
1771 It is used only for generating error messages.
1773 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
1775 This is also where warnings about wrong number of args are generated.
1777 Both VALUES and the returned value are chains of TREE_LIST nodes
1778 with the elements of the list in the TREE_VALUE slots of those nodes. */
1780 static tree
1782 {
1787 /* Scan the given expressions and types, producing individual
1788 converted arguments and pushing them on RESULT in reverse order. */
1791 valtail;
1793 {
1798 {
1802 else
1805 }
1807 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
1808 /* Do not use STRIP_NOPS here! We do not want an enumerator with value 0
1809 to convert automatically to a pointer. */
1818 {
1819 /* Formal parm type is specified by a function prototype. */
1820 tree parmval;
1823 {
1826 }
1827 else
1828 {
1829 /* Optionally warn about conversions that
1830 differ from the default conversions. */
1832 {
1837 warn_for_assignment ("%s as integer rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1840 warn_for_assignment ("%s as integer rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1843 warn_for_assignment ("%s as complex rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1846 warn_for_assignment ("%s as floating rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1849 warn_for_assignment ("%s as complex rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1852 warn_for_assignment ("%s as floating rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1853 /* ??? At some point, messages should be written about
1854 conversions between complex types, but that's too messy
1855 to do now. */
1858 {
1859 /* Warn if any argument is passed as `float',
1860 since without a prototype it would be `double'. */
1862 warn_for_assignment ("%s as `float' rather than `double' due to prototype", (char *) 0, name, parmnum + 1);
1863 }
1864 /* Detect integer changing in width or signedness.
1865 These warnings are only activated with
1866 -Wconversion, not with -Wtraditional. */
1869 {
1876 /* No warning if function asks for enum
1877 and the actual arg is that enum type. */
1878 ;
1880 warn_for_assignment ("%s with different width due to prototype", (char *) 0, name, parmnum + 1);
1882 ;
1883 /* Don't complain if the formal parameter type
1884 is an enum, because we can't tell now whether
1885 the value was an enum--even the same enum. */
1887 ;
1890 /* Change in signedness doesn't matter
1891 if a constant value is unaffected. */
1892 ;
1893 /* Likewise for a constant in a NOP_EXPR. */
1897 ;
1898 /* If the value is extended from a narrower
1899 unsigned type, it doesn't matter whether we
1900 pass it as signed or unsigned; the value
1901 certainly is the same either way. */
1904 ;
1907 else
1909 }
1910 }
1920 }
1922 }
1926 /* Convert `float' to `double'. */
1928 else
1929 /* Convert `short' and `char' to full-size `int'. */
1934 }
1937 {
1941 else
1943 }
1946 }
1947 \f
1948 /* This is the entry point used by the parser
1949 for binary operators in the input.
1950 In addition to constructing the expression,
1951 we check for operands that were written with other binary operators
1952 in a way that is likely to confuse the user. */
1954 tree
1956 {
1973 /* Check for cases such as x+y<<z which users are likely
1974 to misinterpret. If parens are used, C_EXP_ORIGINAL_CODE
1975 is cleared to prevent these warnings. */
1977 {
1979 {
1983 }
1986 {
1990 }
1993 {
1999 /* Check cases like x|y==z */
2002 }
2005 {
2011 /* Check cases like x^y==z */
2014 }
2017 {
2021 /* Check cases like x&y==z */
2024 }
2025 }
2027 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */
2038 /* Record the code that was specified in the source,
2039 for the sake of warnings about confusing nesting. */
2042 else
2043 {
2045 /* We used to use NOP_EXPR rather than NON_LVALUE_EXPR
2046 so that convert_for_assignment wouldn't strip it.
2047 That way, we got warnings for things like p = (1 - 1).
2048 But it turns out we should not get those warnings. */
2052 }
2055 }
2056 \f
2058 /* Return true if `t' is known to be non-negative. */
2060 int
2062 {
2064 {
2067 /* Find the last statement in the chain, ignoring the final
2068 * scope statement */
2073 }
2075 }
2077 /* Return a tree for the difference of pointers OP0 and OP1.
2078 The resulting tree has type int. */
2080 static tree
2082 {
2091 {
2096 }
2098 /* If the conversion to ptrdiff_type does anything like widening or
2099 converting a partial to an integral mode, we get a convert_expression
2100 that is in the way to do any simplifications.
2101 (fold-const.c doesn't know that the extra bits won't be needed.
2102 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2103 different mode in place.)
2104 So first try to find a common term here 'by hand'; we want to cover
2105 at least the cases that occur in legal static initializers. */
2110 {
2113 }
2114 else
2118 {
2121 }
2122 else
2126 {
2129 }
2132 /* First do the subtraction as integers;
2133 then drop through to build the divide operator.
2134 Do not do default conversions on the minus operator
2135 in case restype is a short type. */
2139 /* This generates an error if op1 is pointer to incomplete type. */
2143 /* This generates an error if op0 is pointer to incomplete type. */
2146 /* Divide by the size, in easiest possible way. */
2154 }
2155 \f
2156 /* Construct and perhaps optimize a tree representation
2157 for a unary operation. CODE, a tree_code, specifies the operation
2158 and XARG is the operand.
2159 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2160 the default promotions (such as from short to int).
2161 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2162 allows non-lvalues; this is only used to handle conversion of non-lvalue
2163 arrays to pointers in C99. */
2165 tree
2167 {
2168 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2172 tree val;
2181 {
2183 /* This is used for unary plus, because a CONVERT_EXPR
2184 is enough to prevent anybody from looking inside for
2185 associativity, but won't generate any code. */
2188 {
2191 }
2201 {
2204 }
2211 {
2214 }
2216 {
2222 }
2223 else
2224 {
2227 }
2232 {
2235 }
2241 /* Conjugating a real value is a no-op, but allow it anyway. */
2244 {
2247 }
2256 /* These will convert to a pointer. */
2258 {
2261 }
2273 else
2281 else
2289 /* Increment or decrement the real part of the value,
2290 and don't change the imaginary part. */
2292 {
2303 }
2305 /* Report invalid types. */
2309 {
2312 else
2316 }
2318 {
2319 tree inc;
2325 /* Compute the increment. */
2328 {
2329 /* If pointer target is an undefined struct,
2330 we just cannot know how to do the arithmetic. */
2332 {
2335 else
2337 }
2341 {
2344 else
2346 }
2349 }
2350 else
2355 /* Complain about anything else that is not a true lvalue. */
2362 /* Report a read-only lvalue. */
2371 else
2378 }
2381 /* Note that this operation never does default_conversion. */
2383 /* Let &* cancel out to simplify resulting code. */
2385 {
2386 /* Don't let this be an lvalue. */
2390 }
2392 /* For &x[y], return x+y */
2394 {
2399 }
2401 /* Anything not already handled and not a true memory reference
2402 or a non-lvalue array is an error. */
2407 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
2410 /* If the lvalue is const or volatile, merge that into the type
2411 to which the address will point. Note that you can't get a
2412 restricted pointer by taking the address of something, so we
2413 only have to deal with `const' and `volatile' here. */
2425 {
2426 tree addr;
2429 {
2435 {
2439 }
2444 }
2445 else
2448 /* Address of a static or external variable or
2449 file-scope function counts as a constant. */
2455 }
2459 }
2464 }
2466 /* Return nonzero if REF is an lvalue valid for this language.
2467 Lvalues can be assigned, unless their type has TYPE_READONLY.
2468 Lvalues can have their address taken, unless they have DECL_REGISTER. */
2470 int
2472 {
2476 {
2501 }
2502 }
2504 /* Return nonzero if REF is an lvalue valid for this language;
2505 otherwise, print an error message and return zero. */
2507 int
2509 {
2516 }
2518 \f
2519 /* Warn about storing in something that is `const'. */
2521 void
2523 {
2525 {
2528 else
2531 }
2535 else
2537 }
2538 \f
2539 /* Mark EXP saying that we need to be able to take the
2540 address of it; it should not be allocated in a register.
2541 Returns true if successful. */
2543 bool
2545 {
2550 {
2553 {
2557 }
2559 /* ... fall through ... */
2579 {
2581 {
2585 }
2588 }
2590 {
2592 {
2596 }
2598 /* If we are making this addressable due to its having
2599 volatile components, give a different error message. Also
2600 handle the case of an unnamed parameter by not trying
2601 to give the name. */
2604 {
2607 }
2611 }
2614 /* drops in */
2617 /* drops out */
2620 }
2621 }
2622 \f
2623 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
2625 tree
2627 {
2628 tree type1;
2629 tree type2;
2637 /* Promote both alternatives. */
2654 /* Quickly detect the usual case where op1 and op2 have the same type
2655 after promotion. */
2657 {
2660 else
2662 }
2667 {
2670 /* If -Wsign-compare, warn here if type1 and type2 have
2671 different signedness. We'll promote the signed to unsigned
2672 and later code won't know it used to be different.
2673 Do this check on the original types, so that explicit casts
2674 will be considered, but default promotions won't. */
2676 {
2681 {
2682 /* Do not warn if the result type is signed, since the
2683 signed type will only be chosen if it can represent
2684 all the values of the unsigned type. */
2687 /* Do not warn if the signed quantity is an unsuffixed
2688 integer literal (or some static constant expression
2689 involving such literals) and it is non-negative. */
2693 else
2695 }
2696 }
2697 }
2699 {
2703 }
2705 {
2715 {
2720 }
2722 {
2727 }
2728 else
2729 {
2732 }
2733 }
2735 {
2738 else
2739 {
2741 }
2743 }
2745 {
2748 else
2749 {
2751 }
2753 }
2756 {
2759 else
2760 {
2763 }
2764 }
2766 /* Merge const and volatile flags of the incoming types. */
2767 result_type
2781 }
2782 \f
2783 /* Given a list of expressions, return a compound expression
2784 that performs them all and returns the value of the last of them. */
2786 tree
2788 {
2790 }
2792 static tree
2794 {
2795 tree rest;
2798 {
2799 /* Convert arrays and functions to pointers when there
2800 really is a comma operator. */
2805 /* Don't let (0, 0) be null pointer constant. */
2809 }
2814 {
2815 /* The left-hand operand of a comma expression is like an expression
2816 statement: with -Wextra or -Wunused, we should warn if it doesn't have
2817 any side-effects, unless it was explicitly cast to (void). */
2822 }
2824 /* With -Wunused, we should also warn if the left-hand operand does have
2825 side-effects, but computes a value which is not used. For example, in
2826 `foo() + bar(), baz()' the result of the `+' operator is not used,
2827 so we should issue a warning. */
2832 }
2834 /* Build an expression representing a cast to type TYPE of expression EXPR. */
2836 tree
2838 {
2844 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
2845 only in <protocol> qualifications. But when constructing cast expressions,
2846 the protocols do matter and must be kept around. */
2851 {
2854 }
2857 {
2860 }
2863 {
2865 {
2869 }
2870 }
2872 {
2873 tree field;
2882 {
2883 tree t;
2893 }
2896 }
2897 else
2898 {
2901 /* If casting to void, avoid the error that would come
2902 from default_conversion in the case of a non-lvalue array. */
2906 /* Convert functions and arrays to pointers,
2907 but don't convert any other types. */
2911 /* Optionally warn about potentially worrisome casts. */
2916 {
2922 /* Check that the qualifiers on IN_TYPE are a superset of
2923 the qualifiers of IN_OTYPE. The outermost level of
2924 POINTER_TYPE nodes is uninteresting and we stop as soon
2925 as we hit a non-POINTER_TYPE node on either type. */
2926 do
2927 {
2931 /* GNU C allows cv-qualified function types. 'const'
2932 means the function is very pure, 'volatile' means it
2933 can't return. We need to warn when such qualifiers
2934 are added, not when they're taken away. */
2938 else
2940 }
2948 /* There are qualifiers present in IN_OTYPE that are not
2949 present in IN_TYPE. */
2951 }
2953 /* Warn about possible alignment problems. */
2959 /* Don't warn about opaque types, where the actual alignment
2960 restriction is unknown. */
2981 /* Don't warn about converting any constant. */
2991 {
2992 /* Casting the address of a decl to non void pointer. Warn
2993 if the cast breaks type based aliasing. */
3000 }
3002 /* If pedantic, warn for conversions between function and object
3003 pointer types, except for converting a null pointer constant
3004 to function pointer type. */
3022 /* Replace a nonvolatile const static variable with its value. */
3027 /* Ignore any integer overflow caused by the cast. */
3029 {
3032 }
3033 }
3035 /* Don't let (void *) (FOO *) 0 be a null pointer constant. */
3041 /* Don't let a cast be an lvalue. */
3046 }
3048 /* Interpret a cast of expression EXPR to type TYPE. */
3049 tree
3051 {
3054 /* This avoids warnings about unprototyped casts on
3055 integers. E.g. "#define SIG_DFL (void(*)())0". */
3062 }
3064 \f
3065 /* Build an assignment expression of lvalue LHS from value RHS.
3066 MODIFYCODE is the code for a binary operator that we use
3067 to combine the old value of LHS with RHS to get the new value.
3068 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3070 tree
3072 {
3073 tree result;
3074 tree newrhs;
3078 /* Types that aren't fully specified cannot be used in assignments. */
3081 /* Avoid duplicate error messages from operands that had errors. */
3085 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3086 /* Do not use STRIP_NOPS here. We do not want an enumerator
3087 whose value is 0 to count as a null pointer constant. */
3093 /* If a binary op has been requested, combine the old LHS value with the RHS
3094 producing the value we should actually store into the LHS. */
3097 {
3100 }
3105 /* Warn about storing in something that is `const'. */
3113 /* If storing into a structure or union member,
3114 it has probably been given type `int'.
3115 Compute the type that would go with
3116 the actual amount of storage the member occupies. */
3125 /* If storing in a field that is in actuality a short or narrower than one,
3126 we must store in the field in its actual type. */
3129 {
3132 }
3134 /* Convert new value to destination type. */
3141 /* Scan operands */
3146 /* If we got the LHS in a different type for storing in,
3147 convert the result back to the nominal type of LHS
3148 so that the value we return always has the same type
3149 as the LHS argument. */
3155 }
3156 \f
3157 /* Convert value RHS to type TYPE as preparation for an assignment
3158 to an lvalue of type TYPE.
3159 The real work of conversion is done by `convert'.
3160 The purpose of this function is to generate error messages
3161 for assignments that are not allowed in C.
3162 ERRTYPE is a string to use in error messages:
3163 "assignment", "return", etc. If it is null, this is parameter passing
3164 for a function call (and different error messages are output).
3166 FUNNAME is the name of the function being called,
3167 as an IDENTIFIER_NODE, or null.
3168 PARMNUM is the number of the argument, for printing in error messages. */
3170 static tree
3173 {
3175 tree rhstype;
3178 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3179 /* Do not use STRIP_NOPS here. We do not want an enumerator
3180 whose value is 0 to count as a null pointer constant. */
3197 {
3199 /* Check for Objective-C protocols. This will automatically
3200 issue a warning if there are protocol violations. No need to
3201 use the return value. */
3205 }
3208 {
3211 }
3212 /* A type converts to a reference to it.
3213 This code doesn't fully support references, it's just for the
3214 special case of va_start and va_copy. */
3217 {
3219 {
3222 }
3227 /* We already know that these two types are compatible, but they
3228 may not be exactly identical. In fact, `TREE_TYPE (type)' is
3229 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
3230 likely to be va_list, a typedef to __builtin_va_list, which
3231 is different enough that it will cause problems later. */
3237 }
3238 /* Some types can interconvert without explicit casts. */
3243 /* Arithmetic types all interconvert, and enum is treated like int. */
3252 /* Conversion to a transparent union from its member types.
3253 This applies only to function arguments. */
3255 {
3256 tree memb_types;
3261 {
3272 {
3276 /* Any non-function converts to a [const][volatile] void *
3277 and vice versa; otherwise, targets must be the same.
3278 Meanwhile, the lhs target must have all the qualifiers of
3279 the rhs. */
3282 {
3283 /* If this type won't generate any warnings, use it. */
3293 /* Keep looking for a better type, but remember this one. */
3296 }
3297 }
3299 /* Can convert integer zero to any pointer type. */
3303 {
3306 }
3307 }
3310 {
3312 {
3313 /* We have only a marginally acceptable member type;
3314 it needs a warning. */
3318 /* Const and volatile mean something different for function
3319 types, so the usual warnings are not appropriate. */
3322 {
3323 /* Because const and volatile on functions are
3324 restrictions that say the function will not do
3325 certain things, it is okay to use a const or volatile
3326 function where an ordinary one is wanted, but not
3327 vice-versa. */
3331 }
3335 parmnum);
3336 }
3342 }
3343 }
3345 /* Conversions among pointers */
3348 {
3354 /* Opaque pointers are treated like void pointers. */
3360 /* Any non-function converts to a [const][volatile] void *
3361 and vice versa; otherwise, targets must be the same.
3362 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
3365 || is_opaque_pointer
3368 {
3371 ||
3373 /* Check TREE_CODE to catch cases like (void *) (char *) 0
3374 which are not ANSI null ptr constants. */
3379 /* Const and volatile mean something different for function types,
3380 so the usual warnings are not appropriate. */
3383 {
3387 /* If this is not a case of ignoring a mismatch in signedness,
3388 no warning. */
3391 ;
3392 /* If there is a mismatch, do warn. */
3396 }
3399 {
3400 /* Because const and volatile on functions are restrictions
3401 that say the function will not do certain things,
3402 it is okay to use a const or volatile function
3403 where an ordinary one is wanted, but not vice-versa. */
3407 }
3408 }
3409 else
3413 }
3415 {
3418 }
3420 {
3421 /* An explicit constant 0 can convert to a pointer,
3422 or one that results from arithmetic, even including
3423 a cast to integer type. */
3425 &&
3434 }
3436 {
3440 }
3445 {
3447 {
3453 else
3456 }
3457 else
3459 parmnum);
3460 }
3461 else
3465 }
3467 /* Convert VALUE for assignment into inlined parameter PARM. ARGNUM
3468 is used for error and waring reporting and indicates which argument
3469 is being processed. */
3471 tree
3473 {
3476 /* If FN was prototyped, the value has been converted already
3477 in convert_arguments. */
3490 }
3492 /* Print a warning using MSGID.
3493 It gets OPNAME as its one parameter.
3494 if OPNAME is null and ARGNUM is 0, it is replaced by "passing arg of `FUNCTION'".
3495 Otherwise if OPNAME is null, it is replaced by "passing arg ARGNUM of `FUNCTION'".
3496 FUNCTION and ARGNUM are handled specially if we are building an
3497 Objective-C selector. */
3499 static void
3502 {
3504 {
3509 {
3512 }
3514 {
3516 {
3517 /* Function name is known; supply it. */
3523 }
3524 else
3525 {
3526 /* Function name unknown (call through ptr). */
3530 }
3531 }
3533 {
3534 /* Function name is known; supply it. */
3540 }
3541 else
3542 {
3543 /* Function name unknown (call through ptr); just give arg number. */
3547 }
3549 }
3551 }
3552 \f
3553 /* If VALUE is a compound expr all of whose expressions are constant, then
3554 return its value. Otherwise, return error_mark_node.
3556 This is for handling COMPOUND_EXPRs as initializer elements
3557 which is allowed with a warning when -pedantic is specified. */
3559 static tree
3561 {
3563 {
3568 endtype);
3569 }
3573 else
3575 }
3576 \f
3577 /* Perform appropriate conversions on the initial value of a variable,
3578 store it in the declaration DECL,
3579 and print any error messages that are appropriate.
3580 If the init is invalid, store an ERROR_MARK. */
3582 void
3584 {
3587 /* If variable's type was invalidly declared, just ignore it. */
3593 /* Digest the specified initializer into an expression. */
3597 /* Store the expression if valid; else report error. */
3605 /* ANSI wants warnings about out-of-range constant initializers. */
3609 /* Check if we need to set array size from compound literal size. */
3613 {
3621 {
3625 {
3626 /* For int foo[] = (int [3]){1}; we need to set array size
3627 now since later on array initializer will be just the
3628 brace enclosed list of the compound literal. */
3632 }
3633 }
3634 }
3635 }
3636 \f
3637 /* Methods for storing and printing names for error messages. */
3639 /* Implement a spelling stack that allows components of a name to be pushed
3640 and popped. Each element on the stack is this structure. */
3642 struct spelling
3643 {
3645 union
3646 {
3650 };
3652 #define SPELLING_STRING 1
3653 #define SPELLING_MEMBER 2
3654 #define SPELLING_BOUNDS 3
3660 /* Macros to save and restore the spelling stack around push_... functions.
3661 Alternative to SAVE_SPELLING_STACK. */
3663 #define SPELLING_DEPTH() (spelling - spelling_base)
3664 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
3666 /* Push an element on the spelling stack with type KIND and assign VALUE
3667 to MEMBER. */
3669 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
3670 { \
3671 int depth = SPELLING_DEPTH (); \
3672 \
3673 if (depth >= spelling_size) \
3674 { \
3675 spelling_size += 10; \
3676 if (spelling_base == 0) \
3677 spelling_base = xmalloc (spelling_size * sizeof (struct spelling)); \
3678 else \
3679 spelling_base = xrealloc (spelling_base, \
3680 spelling_size * sizeof (struct spelling)); \
3681 RESTORE_SPELLING_DEPTH (depth); \
3682 } \
3683 \
3684 spelling->kind = (KIND); \
3685 spelling->MEMBER = (VALUE); \
3686 spelling++; \
3687 }
3689 /* Push STRING on the stack. Printed literally. */
3691 static void
3693 {
3695 }
3697 /* Push a member name on the stack. Printed as '.' STRING. */
3699 static void
3701 {
3705 }
3707 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
3709 static void
3711 {
3713 }
3715 /* Compute the maximum size in bytes of the printed spelling. */
3717 static int
3719 {
3724 {
3727 else
3729 }
3732 }
3734 /* Print the spelling to BUFFER and return it. */
3738 {
3744 {
3747 }
3748 else
3749 {
3754 ;
3755 }
3758 }
3760 /* Issue an error message for a bad initializer component.
3761 MSGID identifies the message.
3762 The component name is taken from the spelling stack. */
3764 void
3766 {
3773 }
3775 /* Issue a pedantic warning for a bad initializer component.
3776 MSGID identifies the message.
3777 The component name is taken from the spelling stack. */
3779 void
3781 {
3788 }
3790 /* Issue a warning for a bad initializer component.
3791 MSGID identifies the message.
3792 The component name is taken from the spelling stack. */
3794 static void
3796 {
3803 }
3804 \f
3805 /* Digest the parser output INIT as an initializer for type TYPE.
3806 Return a C expression of type TYPE to represent the initial value.
3808 REQUIRE_CONSTANT requests an error if non-constant initializers or
3809 elements are seen. */
3811 static tree
3813 {
3822 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3823 /* Do not use STRIP_NOPS here. We do not want an enumerator
3824 whose value is 0 to count as a null pointer constant. */
3830 /* Initialization of an array of chars from a string constant
3831 optionally enclosed in braces. */
3834 {
3842 {
3850 {
3853 }
3857 {
3860 }
3866 /* Subtract 1 (or sizeof (wchar_t))
3867 because it's ok to ignore the terminating null char
3868 that is counted in the length of the constant. */
3879 }
3880 }
3882 /* Build a VECTOR_CST from a *constant* vector constructor. If the
3883 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
3884 below and handle as a constructor. */
3888 {
3892 COMPARE_STRICT))
3894 else
3896 }
3898 /* Any type can be initialized
3899 from an expression of the same type, optionally with braces. */
3916 {
3918 {
3922 {
3925 }
3926 }
3929 /* Although the types are compatible, we may require a
3930 conversion. */
3935 {
3936 /* As an extension, allow initializing objects with static storage
3937 duration with compound literals (which are then treated just as
3938 the brace enclosed list they contain). */
3941 }
3945 {
3948 }
3953 /* Compound expressions can only occur here if -pedantic or
3954 -pedantic-errors is specified. In the later case, we always want
3955 an error. In the former case, we simply want a warning. */
3958 {
3959 inside_init
3964 else
3968 }
3971 /* This test catches things like `7 / 0' which
3972 result in an expression for which TREE_CONSTANT
3973 is true, but which is not actually something
3974 that is a legal constant. We really should not
3975 be using this function, because it is a part of
3976 the back-end. Instead, the expression should
3977 already have been turned into ERROR_MARK_NODE. */
3980 {
3983 }
3986 }
3988 /* Handle scalar types, including conversions. */
3992 {
3993 /* Note that convert_for_assignment calls default_conversion
3994 for arrays and functions. We must not call it in the
3995 case where inside_init is a null pointer constant. */
3996 inside_init
4001 {
4004 }
4007 {
4010 }
4013 }
4015 /* Come here only for records and arrays. */
4018 {
4021 }
4025 }
4026 \f
4027 /* Handle initializers that use braces. */
4029 /* Type of object we are accumulating a constructor for.
4030 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4033 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4034 left to fill. */
4037 /* For an ARRAY_TYPE, this is the specified index
4038 at which to store the next element we get. */
4041 /* For an ARRAY_TYPE, this is the maximum index. */
4044 /* For a RECORD_TYPE, this is the first field not yet written out. */
4047 /* For an ARRAY_TYPE, this is the index of the first element
4048 not yet written out. */
4051 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4052 This is so we can generate gaps between fields, when appropriate. */
4055 /* If we are saving up the elements rather than allocating them,
4056 this is the list of elements so far (in reverse order,
4057 most recent first). */
4060 /* 1 if constructor should be incrementally stored into a constructor chain,
4061 0 if all the elements should be kept in AVL tree. */
4064 /* 1 if so far this constructor's elements are all compile-time constants. */
4067 /* 1 if so far this constructor's elements are all valid address constants. */
4070 /* 1 if this constructor is erroneous so far. */
4073 /* Structure for managing pending initializer elements, organized as an
4074 AVL tree. */
4076 struct init_node
4077 {
4081 tree purpose;
4082 tree value;
4083 };
4085 /* Tree of pending elements at this constructor level.
4086 These are elements encountered out of order
4087 which belong at places we haven't reached yet in actually
4088 writing the output.
4089 Will never hold tree nodes across GC runs. */
4092 /* The SPELLING_DEPTH of this constructor. */
4095 /* 0 if implicitly pushing constructor levels is allowed. */
4101 /* DECL node for which an initializer is being read.
4102 0 means we are reading a constructor expression
4103 such as (struct foo) {...}. */
4106 /* Nonzero if this is an initializer for a top-level decl. */
4109 /* Nonzero if there were any member designators in this initializer. */
4112 /* Nesting depth of designator list. */
4115 /* Nonzero if there were diagnosed errors in this designator list. */
4118 \f
4119 /* This stack has a level for each implicit or explicit level of
4120 structuring in the initializer, including the outermost one. It
4121 saves the values of most of the variables above. */
4125 struct constructor_stack
4126 {
4128 tree type;
4129 tree fields;
4130 tree index;
4131 tree max_index;
4132 tree unfilled_index;
4133 tree unfilled_fields;
4134 tree bit_index;
4135 tree elements;
4139 /* If nonzero, this value should replace the entire
4140 constructor at this level. */
4141 tree replacement_value;
4150 };
4154 /* This stack represents designators from some range designator up to
4155 the last designator in the list. */
4157 struct constructor_range_stack
4158 {
4161 tree range_start;
4162 tree index;
4163 tree range_end;
4164 tree fields;
4165 };
4169 /* This stack records separate initializers that are nested.
4170 Nested initializers can't happen in ANSI C, but GNU C allows them
4171 in cases like { ... (struct foo) { ... } ... }. */
4173 struct initializer_stack
4174 {
4176 tree decl;
4179 tree elements;
4186 };
4189 \f
4190 /* Prepare to parse and output the initializer for variable DECL. */
4192 void
4194 {
4216 {
4218 require_constant_elements
4220 /* For a scalar, you can always use any value to initialize,
4221 even within braces. */
4227 }
4228 else
4229 {
4233 }
4246 }
4248 void
4250 {
4253 /* Free the whole constructor stack of this initializer. */
4255 {
4259 }
4264 /* Pop back to the data of the outer initializer (if any). */
4279 }
4280 \f
4281 /* Call here when we see the initializer is surrounded by braces.
4282 This is instead of a call to push_init_level;
4283 it is matched by a call to pop_init_level.
4285 TYPE is the type to initialize, for a constructor expression.
4286 For an initializer for a decl, TYPE is zero. */
4288 void
4290 {
4334 {
4336 /* Skip any nameless bit fields at the beginning. */
4343 }
4345 {
4347 {
4348 constructor_max_index
4351 /* Detect non-empty initializations of zero-length arrays. */
4356 /* constructor_max_index needs to be an INTEGER_CST. Attempts
4357 to initialize VLAs will cause a proper error; avoid tree
4358 checking errors as well by setting a safe value. */
4363 constructor_index
4366 }
4367 else
4371 }
4373 {
4374 /* Vectors are like simple fixed-size arrays. */
4375 constructor_max_index =
4379 }
4380 else
4381 {
4382 /* Handle the case of int x = {5}; */
4385 }
4386 }
4387 \f
4388 /* Push down into a subobject, for initialization.
4389 If this is for an explicit set of braces, IMPLICIT is 0.
4390 If it is because the next element belongs at a lower level,
4391 IMPLICIT is 1 (or 2 if the push is because of designator list). */
4393 void
4395 {
4399 /* If we've exhausted any levels that didn't have braces,
4400 pop them now. */
4402 {
4408 && constructor_max_index
4411 else
4413 }
4415 /* Unless this is an explicit brace, we need to preserve previous
4416 content if any. */
4418 {
4425 }
4458 {
4463 }
4465 /* Don't die if an entire brace-pair level is superfluous
4466 in the containing level. */
4468 ;
4471 {
4472 /* Don't die if there are extra init elts at the end. */
4475 else
4476 {
4479 constructor_depth++;
4480 }
4481 }
4483 {
4486 constructor_depth++;
4487 }
4490 {
4495 }
4498 {
4506 }
4509 {
4512 }
4516 {
4518 /* Skip any nameless bit fields at the beginning. */
4525 }
4527 {
4528 /* Vectors are like simple fixed-size arrays. */
4529 constructor_max_index =
4533 }
4535 {
4537 {
4538 constructor_max_index
4541 /* Detect non-empty initializations of zero-length arrays. */
4546 /* constructor_max_index needs to be an INTEGER_CST. Attempts
4547 to initialize VLAs will cause a proper error; avoid tree
4548 checking errors as well by setting a safe value. */
4553 constructor_index
4556 }
4557 else
4562 {
4563 /* We need to split the char/wchar array into individual
4564 characters, so that we don't have to special case it
4565 everywhere. */
4567 }
4568 }
4569 else
4570 {
4574 }
4575 }
4577 /* At the end of an implicit or explicit brace level,
4578 finish up that level of constructor.
4579 If we were outputting the elements as they are read, return 0
4580 from inner levels (process_init_element ignores that),
4581 but return error_mark_node from the outermost level
4582 (that's what we want to put in DECL_INITIAL).
4583 Otherwise, return a CONSTRUCTOR expression. */
4585 tree
4587 {
4592 {
4593 /* When we come to an explicit close brace,
4594 pop any inner levels that didn't have explicit braces. */
4600 }
4604 /* Error for initializing a flexible array member, or a zero-length
4605 array member in an inappropriate context. */
4610 {
4611 /* Silently discard empty initializations. The parser will
4612 already have pedwarned for empty brackets. */
4616 {
4622 /* We have already issued an error message for the existence
4623 of a flexible array member not at the end of the structure.
4624 Discard the initializer so that we do not abort later. */
4627 }
4628 else
4629 /* Zero-length arrays are no longer special, so we should no longer
4630 get here. */
4632 }
4634 /* Warn when some struct elements are implicitly initialized to zero. */
4636 && constructor_type
4639 {
4640 /* Do not warn for flexible array members or zero-length arrays. */
4646 /* Do not warn if this level of the initializer uses member
4647 designators; it is likely to be deliberate. */
4649 {
4653 }
4654 }
4656 /* Now output all pending elements. */
4660 /* Pad out the end of the structure. */
4662 /* If this closes a superfluous brace pair,
4663 just pass out the element between them. */
4666 ;
4671 {
4672 /* A nonincremental scalar initializer--just return
4673 the element, after verifying there is just one. */
4675 {
4679 }
4681 {
4684 }
4685 else
4687 }
4688 else
4689 {
4692 else
4693 {
4700 }
4701 }
4726 {
4730 }
4732 }
4734 /* Common handling for both array range and field name designators.
4735 ARRAY argument is nonzero for array ranges. Returns zero for success. */
4737 static int
4739 {
4740 tree subtype;
4743 /* Don't die if an entire brace-pair level is superfluous
4744 in the containing level. */
4748 /* If there were errors in this designator list already, bail out silently. */
4753 {
4757 /* Designator list starts at the level of closest explicit
4758 braces. */
4763 }
4766 {
4769 }
4773 {
4777 }
4779 {
4781 }
4782 else
4787 {
4790 }
4792 {
4795 }
4800 }
4802 /* If there are range designators in designator list, push a new designator
4803 to constructor_range_stack. RANGE_END is end of such stack range or
4804 NULL_TREE if there is no range designator at this level. */
4806 static void
4808 {
4822 }
4824 /* Within an array initializer, specify the next index to be initialized.
4825 FIRST is that index. If LAST is nonzero, then initialize a range
4826 of indices, running from FIRST through LAST. */
4828 void
4830 {
4862 else
4863 {
4867 {
4871 {
4874 }
4875 else
4876 {
4880 {
4883 }
4884 }
4885 }
4887 designator_depth++;
4891 }
4892 }
4894 /* Within a struct initializer, specify the next field to be initialized. */
4896 void
4898 {
4899 tree tail;
4908 {
4911 }
4915 {
4918 }
4923 else
4924 {
4926 designator_depth++;
4930 }
4931 }
4932 \f
4933 /* Add a new initializer to the tree of pending initializers. PURPOSE
4934 identifies the initializer, either array index or field in a structure.
4935 VALUE is the value of that index or field. */
4937 static void
4939 {
4946 {
4948 {
4954 else
4955 {
4960 }
4961 }
4962 }
4963 else
4964 {
4965 tree bitpos;
4969 {
4975 else
4976 {
4981 }
4982 }
4983 }
4996 {
5000 {
5004 {
5006 {
5007 /* L rotation. */
5020 {
5023 else
5025 }
5026 else
5028 }
5029 else
5030 {
5031 /* LR rotation. */
5053 {
5056 else
5058 }
5059 else
5061 }
5063 }
5064 else
5065 {
5066 /* p->balance == +1; growth of left side balances the node. */
5069 }
5070 }
5072 {
5074 /* Growth propagation from right side. */
5077 {
5079 {
5080 /* R rotation. */
5093 {
5096 else
5098 }
5099 else
5101 }
5103 {
5104 /* RL rotation */
5126 {
5129 else
5131 }
5132 else
5134 }
5136 }
5137 else
5138 {
5139 /* p->balance == -1; growth of right side balances the node. */
5142 }
5143 }
5147 }
5148 }
5150 /* Build AVL tree from a sorted chain. */
5152 static void
5154 {
5155 tree chain;
5165 {
5167 /* Skip any nameless bit fields at the beginning. */
5173 }
5175 {
5177 constructor_unfilled_index
5180 else
5182 }
5184 }
5186 /* Build AVL tree from a string constant. */
5188 static void
5190 {
5205 else
5216 {
5218 {
5221 }
5222 else
5223 {
5227 {
5230 else
5235 }
5236 }
5239 {
5242 {
5244 {
5247 }
5248 }
5250 {
5253 }
5258 }
5263 }
5266 }
5268 /* Return value of FIELD in pending initializer or zero if the field was
5269 not initialized yet. */
5271 static tree
5273 {
5277 {
5284 {
5289 else
5291 }
5292 }
5294 {
5298 && (!constructor_unfilled_fields
5305 {
5310 else
5312 }
5313 }
5315 {
5319 }
5321 }
5323 /* "Output" the next constructor element.
5324 At top level, really output it to assembler code now.
5325 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
5326 TYPE is the data type that the containing data type wants here.
5327 FIELD is the field (a FIELD_DECL) or the index that this element fills.
5329 PENDING if non-nil means output pending elements that belong
5330 right after this element. (PENDING is normally 1;
5331 it is 0 while outputting pending elements, to avoid recursion.) */
5333 static void
5335 {
5337 {
5340 }
5352 {
5353 /* As an extension, allow initializing objects with static storage
5354 duration with compound literals (which are then treated just as
5355 the brace enclosed list they contain). */
5358 }
5372 {
5375 }
5380 /* If this field is empty (and not at the end of structure),
5381 don't do anything other than checking the initializer. */
5392 {
5395 }
5397 /* If this element doesn't come next in sequence,
5398 put it on constructor_pending_elts. */
5400 && (!constructor_incremental
5402 {
5409 }
5411 && (!constructor_incremental
5413 {
5414 /* We do this for records but not for unions. In a union,
5415 no matter which field is specified, it can be initialized
5416 right away since it starts at the beginning of the union. */
5418 {
5421 else
5422 {
5430 }
5431 }
5435 }
5438 {
5442 /* We can have just one union field set. */
5444 }
5446 /* Otherwise, output this element either to
5447 constructor_elements or to the assembler file. */
5451 constructor_elements
5454 /* Advance the variable that indicates sequential elements output. */
5456 constructor_unfilled_index
5458 bitsize_one_node);
5460 {
5461 constructor_unfilled_fields
5464 /* Skip any nameless bit fields. */
5468 constructor_unfilled_fields =
5470 }
5474 /* Now output any pending elements which have become next. */
5477 }
5479 /* Output any pending elements which have become next.
5480 As we output elements, constructor_unfilled_{fields,index}
5481 advances, which may cause other elements to become next;
5482 if so, they too are output.
5484 If ALL is 0, we return when there are
5485 no more pending elements to output now.
5487 If ALL is 1, we output space as necessary so that
5488 we can output all the pending elements. */
5490 static void
5492 {
5494 tree next;
5496 retry:
5498 /* Look through the whole pending tree.
5499 If we find an element that should be output now,
5500 output it. Otherwise, set NEXT to the element
5501 that comes first among those still pending. */
5505 {
5507 {
5509 constructor_unfilled_index))
5515 {
5516 /* Advance to the next smaller node. */
5519 else
5520 {
5521 /* We have reached the smallest node bigger than the
5522 current unfilled index. Fill the space first. */
5525 }
5526 }
5527 else
5528 {
5529 /* Advance to the next bigger node. */
5532 else
5533 {
5534 /* We have reached the biggest node in a subtree. Find
5535 the parent of it, which is the next bigger node. */
5541 {
5544 }
5545 }
5546 }
5547 }
5550 {
5553 /* If the current record is complete we are done. */
5559 /* We can't compare fields here because there might be empty
5560 fields in between. */
5562 {
5566 }
5568 {
5569 /* Advance to the next smaller node. */
5572 else
5573 {
5574 /* We have reached the smallest node bigger than the
5575 current unfilled field. Fill the space first. */
5578 }
5579 }
5580 else
5581 {
5582 /* Advance to the next bigger node. */
5585 else
5586 {
5587 /* We have reached the biggest node in a subtree. Find
5588 the parent of it, which is the next bigger node. */
5595 {
5598 }
5599 }
5600 }
5601 }
5602 }
5604 /* Ordinarily return, but not if we want to output all
5605 and there are elements left. */
5609 /* If it's not incremental, just skip over the gap, so that after
5610 jumping to retry we will output the next successive element. */
5617 /* ELT now points to the node in the pending tree with the next
5618 initializer to output. */
5620 }
5621 \f
5622 /* Add one non-braced element to the current constructor level.
5623 This adjusts the current position within the constructor's type.
5624 This may also start or terminate implicit levels
5625 to handle a partly-braced initializer.
5627 Once this has found the correct level for the new element,
5628 it calls output_init_element. */
5630 void
5632 {
5639 /* Handle superfluous braces around string cst as in
5640 char x[] = {"foo"}; */
5642 && constructor_type
5646 {
5651 }
5654 {
5657 }
5659 /* Ignore elements of a brace group if it is entirely superfluous
5660 and has already been diagnosed. */
5664 /* If we've exhausted any levels that didn't have braces,
5665 pop them now. */
5667 {
5675 constructor_index)))
5677 else
5679 }
5681 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
5683 {
5684 /* If value is a compound literal and we'll be just using its
5685 content, don't put it into a SAVE_EXPR. */
5687 || !require_constant_value
5690 }
5693 {
5695 {
5696 tree fieldtype;
5700 {
5703 }
5710 /* Error for non-static initialization of a flexible array member. */
5712 && !require_constant_value
5715 {
5718 }
5720 /* Accept a string constant to initialize a subarray. */
5726 /* Otherwise, if we have come to a subaggregate,
5727 and we don't have an element of its type, push into it. */
5733 {
5736 }
5739 {
5743 }
5744 else
5745 /* Do the bookkeeping for an element that was
5746 directly output as a constructor. */
5747 {
5748 /* For a record, keep track of end position of last field. */
5750 constructor_bit_index
5755 /* If the current field was the first one not yet written out,
5756 it isn't now, so update. */
5758 {
5760 /* Skip any nameless bit fields. */
5764 constructor_unfilled_fields =
5766 }
5767 }
5770 /* Skip any nameless bit fields at the beginning. */
5775 }
5777 {
5778 tree fieldtype;
5782 {
5785 }
5792 /* Warn that traditional C rejects initialization of unions.
5793 We skip the warning if the value is zero. This is done
5794 under the assumption that the zero initializer in user
5795 code appears conditioned on e.g. __STDC__ to avoid
5796 "missing initializer" warnings and relies on default
5797 initialization to zero in the traditional C case.
5798 We also skip the warning if the initializer is designated,
5799 again on the assumption that this must be conditional on
5800 __STDC__ anyway (and we've already complained about the
5801 member-designator already). */
5806 /* Accept a string constant to initialize a subarray. */
5812 /* Otherwise, if we have come to a subaggregate,
5813 and we don't have an element of its type, push into it. */
5819 {
5822 }
5825 {
5829 }
5830 else
5831 /* Do the bookkeeping for an element that was
5832 directly output as a constructor. */
5833 {
5836 }
5839 }
5841 {
5845 /* Accept a string constant to initialize a subarray. */
5851 /* Otherwise, if we have come to a subaggregate,
5852 and we don't have an element of its type, push into it. */
5858 {
5861 }
5866 {
5869 }
5871 /* Now output the actual element. */
5873 {
5877 }
5879 constructor_index
5883 /* If we are doing the bookkeeping for an element that was
5884 directly output as a constructor, we must update
5885 constructor_unfilled_index. */
5887 }
5889 {
5892 /* Do a basic check of initializer size. Note that vectors
5893 always have a fixed size derived from their type. */
5895 {
5898 }
5900 /* Now output the actual element. */
5904 constructor_index
5908 /* If we are doing the bookkeeping for an element that was
5909 directly output as a constructor, we must update
5910 constructor_unfilled_index. */
5912 }
5914 /* Handle the sole element allowed in a braced initializer
5915 for a scalar variable. */
5917 {
5920 }
5921 else
5922 {
5926 }
5928 /* Handle range initializers either at this level or anywhere higher
5929 in the designator stack. */
5931 {
5938 {
5942 }
5946 {
5950 }
5957 {
5961 {
5964 }
5972 }
5977 }
5980 }
5983 }
5984 \f
5985 /* Build a simple asm-statement, from one string literal. */
5986 tree
5988 {
5995 {
5996 tree stmt;
5998 /* Simple asm statements are treated as volatile. */
6003 }
6007 }
6009 /* Build an asm-statement, whose components are a CV_QUALIFIER, a
6010 STRING, some OUTPUTS, some INPUTS, and some CLOBBERS. */
6012 tree
6014 tree clobbers)
6015 {
6016 tree tail;
6019 {
6022 }
6026 {
6030 }
6032 /* We can remove output conversions that change the type,
6033 but not the mode. */
6035 {
6041 /* Allow conversions as LHS here. build_modify_expr as called below
6042 will do the right thing with them. */
6053 }
6055 /* Remove output conversions that change the type but not the mode. */
6057 {
6061 }
6063 /* Perform default conversions on array and function inputs.
6064 Don't do this for other types as it would screw up operands
6065 expected to be in memory. */
6071 }
6073 /* Expand an ASM statement with operands, handling output operands
6074 that are not variables or INDIRECT_REFS by transforming such
6075 cases into cases that expand_asm_operands can handle.
6077 Arguments are same as for expand_asm_operands. */
6079 void
6082 {
6085 /* o[I] is the place that output number I should be written. */
6087 tree tail;
6089 /* Record the contents of OUTPUTS before it is modified. */
6091 {
6095 }
6097 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
6098 OUTPUTS some trees for where the values were actually stored. */
6101 /* Copy all the intermediate outputs into the specified outputs. */
6103 {
6105 {
6110 /* Restore the original value so that it's correct the next
6111 time we expand this function. */
6113 }
6114 /* Detect modification of read-only values.
6115 (Otherwise done by build_modify_expr.) */
6116 else
6117 {
6125 }
6126 }
6128 /* Those MODIFY_EXPRs could do autoincrements. */
6130 }
6131 \f
6132 /* Expand a C `return' statement.
6133 RETVAL is the expression for what to return,
6134 or a null pointer for `return;' with no value. */
6136 tree
6138 {
6145 {
6150 }
6152 {
6156 }
6157 else
6158 {
6162 tree inner;
6170 /* Strip any conversions, additions, and subtractions, and see if
6171 we are returning the address of a local variable. Warn if so. */
6173 {
6175 {
6182 /* If the second operand of the MINUS_EXPR has a pointer
6183 type (or is converted from it), this may be valid, so
6184 don't give a warning. */
6185 {
6199 }
6216 }
6219 }
6222 }
6225 }
6226 \f
6228 /* The SWITCH_STMT being built. */
6229 tree switch_stmt;
6230 /* A splay-tree mapping the low element of a case range to the high
6231 element, or NULL_TREE if there is no high element. Used to
6232 determine whether or not a new case label duplicates an old case
6233 label. We need a tree, rather than simply a hash table, because
6234 of the GNU case range extension. */
6235 splay_tree cases;
6236 /* The next node on the stack. */
6238 };
6240 /* A stack of the currently active switch statements. The innermost
6241 switch statement is on the top of the stack. There is no need to
6242 mark the stack for garbage collection because it is only active
6243 during the processing of the body of a function, and we never
6244 collect at that point. */
6248 /* Start a C switch statement, testing expression EXP. Return the new
6249 SWITCH_STMT. */
6251 tree
6253 {
6259 {
6265 {
6268 }
6269 else
6270 {
6280 }
6281 }
6283 /* Add this new SWITCH_STMT to the stack. */
6291 }
6293 /* Process a case label. */
6295 tree
6297 {
6301 {
6310 {
6311 /* Attach the first case label to the SWITCH_BODY. */
6314 }
6315 }
6318 else
6322 }
6324 /* Finish the switch statement. */
6326 void
6328 {
6331 /* Rechain the next statements to the SWITCH_STMT. */
6334 /* Pop the stack. */
6338 }
6340 /* Build a binary-operation expression without default conversions.
6341 CODE is the kind of expression to build.
6342 This function differs from `build' in several ways:
6343 the data type of the result is computed and recorded in it,
6344 warnings are generated if arg data types are invalid,
6345 special handling for addition and subtraction of pointers is known,
6346 and some optimization is done (operations on narrow ints
6347 are done in the narrower type when that gives the same result).
6348 Constant folding is also done before the result is returned.
6350 Note that the operands will never have enumeral types, or function
6351 or array types, because either they will have the default conversions
6352 performed or they have both just been converted to some other type in which
6353 the arithmetic is to be done. */
6355 tree
6358 {
6363 /* Expression code to give to the expression when it is built.
6364 Normally this is CODE, which is what the caller asked for,
6365 but in some special cases we change it. */
6368 /* Data type in which the computation is to be performed.
6369 In the simplest cases this is the common type of the arguments. */
6372 /* Nonzero means operands have already been type-converted
6373 in whatever way is necessary.
6374 Zero means they need to be converted to RESULT_TYPE. */
6377 /* Nonzero means create the expression with this type, rather than
6378 RESULT_TYPE. */
6381 /* Nonzero means after finally constructing the expression
6382 convert it to this type. */
6385 /* Nonzero if this is an operation like MIN or MAX which can
6386 safely be computed in short if both args are promoted shorts.
6387 Also implies COMMON.
6388 -1 indicates a bitwise operation; this makes a difference
6389 in the exact conditions for when it is safe to do the operation
6390 in a narrower mode. */
6393 /* Nonzero if this is a comparison operation;
6394 if both args are promoted shorts, compare the original shorts.
6395 Also implies COMMON. */
6398 /* Nonzero if this is a right-shift operation, which can be computed on the
6399 original short and then promoted if the operand is a promoted short. */
6402 /* Nonzero means set RESULT_TYPE to the common type of the args. */
6406 {
6409 }
6410 else
6411 {
6414 }
6419 /* The expression codes of the data types of the arguments tell us
6420 whether the arguments are integers, floating, pointers, etc. */
6424 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
6428 /* If an error was already reported for one of the arguments,
6429 avoid reporting another error. */
6435 {
6437 /* Handle the pointer + int case. */
6442 else
6447 /* Subtraction of two similar pointers.
6448 We must subtract them as integers, then divide by object size. */
6452 /* Handle pointer minus int. Just like pointer plus int. */
6455 else
6468 /* Floating point division by zero is a legitimate way to obtain
6469 infinities and NaNs. */
6477 {
6480 else
6481 /* Although it would be tempting to shorten always here, that
6482 loses on some targets, since the modulo instruction is
6483 undefined if the quotient can't be represented in the
6484 computation mode. We shorten only if unsigned or if
6485 dividing by something we know != -1. */
6490 }
6508 {
6509 /* Although it would be tempting to shorten always here, that loses
6510 on some targets, since the modulo instruction is undefined if the
6511 quotient can't be represented in the computation mode. We shorten
6512 only if unsigned or if dividing by something we know != -1. */
6517 }
6529 {
6530 /* Result of these operations is always an int,
6531 but that does not mean the operands should be
6532 converted to ints! */
6537 }
6540 /* Shift operations: result has same type as first operand;
6541 always convert second operand to int.
6542 Also set SHORT_SHIFT if shifting rightward. */
6546 {
6548 {
6551 else
6552 {
6558 }
6559 }
6561 /* Use the type of the value to be shifted. */
6563 /* Convert the shift-count to an integer, regardless of size
6564 of value being shifted. */
6567 /* Avoid converting op1 to result_type later. */
6569 }
6574 {
6576 {
6582 }
6584 /* Use the type of the value to be shifted. */
6586 /* Convert the shift-count to an integer, regardless of size
6587 of value being shifted. */
6590 /* Avoid converting op1 to result_type later. */
6592 }
6598 {
6600 {
6605 }
6607 /* Use the type of the value to be shifted. */
6609 /* Convert the shift-count to an integer, regardless of size
6610 of value being shifted. */
6613 /* Avoid converting op1 to result_type later. */
6615 }
6622 /* Result of comparison is always int,
6623 but don't convert the args to int! */
6633 {
6636 /* Anything compares with void *. void * compares with anything.
6637 Otherwise, the targets must be compatible
6638 and both must be object or both incomplete. */
6642 {
6643 /* op0 != orig_op0 detects the case of something
6644 whose value is 0 but which isn't a valid null ptr const. */
6648 }
6650 {
6654 }
6655 else
6660 }
6668 {
6671 }
6673 {
6676 }
6685 {
6687 {
6692 }
6693 else
6694 {
6697 }
6698 }
6710 {
6712 {
6720 }
6721 else
6722 {
6725 }
6726 }
6729 {
6733 }
6736 {
6740 }
6742 {
6745 }
6747 {
6750 }
6762 {
6765 }
6771 }
6775 &&
6778 {
6784 /* For certain operations (which identify themselves by shorten != 0)
6785 if both args were extended from the same smaller type,
6786 do the arithmetic in that type and then extend.
6788 shorten !=0 and !=1 indicates a bitwise operation.
6789 For them, this optimization is safe only if
6790 both args are zero-extended or both are sign-extended.
6791 Otherwise, we might change the result.
6792 Eg, (short)-1 | (unsigned short)-1 is (int)-1
6793 but calculated in (unsigned short) it would be (unsigned short)-1. */
6796 {
6800 /* UNS is 1 if the operation to be done is an unsigned one. */
6802 tree type;
6806 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
6807 but it *requires* conversion to FINAL_TYPE. */
6818 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
6820 /* For bitwise operations, signedness of nominal type
6821 does not matter. Consider only how operands were extended. */
6825 /* Note that in all three cases below we refrain from optimizing
6826 an unsigned operation on sign-extended args.
6827 That would not be valid. */
6829 /* Both args variable: if both extended in same way
6830 from same width, do it in that width.
6831 Do it unsigned if args were zero-extended. */
6838 result_type
6839 = c_common_signed_or_unsigned_type
6845 && (type
6854 && (type
6859 }
6861 /* Shifts can be shortened if shifting right. */
6864 {
6874 /* We can shorten only if the shift count is less than the
6875 number of bits in the smaller type size. */
6877 /* We cannot drop an unsigned shift after sign-extension. */
6879 {
6880 /* Do an unsigned shift if the operand was zero-extended. */
6881 result_type
6884 /* Convert value-to-be-shifted to that type. */
6888 }
6889 }
6891 /* Comparison operations are shortened too but differently.
6892 They identify themselves by setting short_compare = 1. */
6895 {
6896 /* Don't write &op0, etc., because that would prevent op0
6897 from being kept in a register.
6898 Instead, make copies of the our local variables and
6899 pass the copies by reference, then copy them back afterward. */
6902 tree val
6913 {
6925 /* Give warnings for comparisons between signed and unsigned
6926 quantities that may fail.
6928 Do the checking based on the original operand trees, so that
6929 casts will be considered, but default promotions won't be.
6931 Do not warn if the comparison is being done in a signed type,
6932 since the signed type will only be chosen if it can represent
6933 all the values of the unsigned type. */
6936 /* Do not warn if both operands are the same signedness. */
6939 else
6940 {
6945 else
6948 /* Do not warn if the signed quantity is an
6949 unsuffixed integer literal (or some static
6950 constant expression involving such literals or a
6951 conditional expression involving such literals)
6952 and it is non-negative. */
6955 /* Do not warn if the comparison is an equality operation,
6956 the unsigned quantity is an integral constant, and it
6957 would fit in the result if the result were signed. */
6960 && int_fits_type_p
6963 /* Do not warn if the unsigned quantity is an enumeration
6964 constant and its maximum value would fit in the result
6965 if the result were signed. */
6968 && int_fits_type_p
6972 else
6974 }
6976 /* Warn if two unsigned values are being compared in a size
6977 larger than their original size, and one (and only one) is the
6978 result of a `~' operator. This comparison will always fail.
6980 Also warn if one operand is a constant, and the constant
6981 does not have all bits set that are set in the ~ operand
6982 when it is extended. */
6986 {
6990 else
6995 {
6996 tree primop;
7001 {
7005 }
7006 else
7007 {
7011 }
7016 {
7020 }
7021 }
7028 }
7029 }
7030 }
7031 }
7033 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
7034 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
7035 Then the expression will be built.
7036 It will be given type FINAL_TYPE if that is nonzero;
7037 otherwise, it will be given type RESULT_TYPE. */
7040 {
7043 }
7046 {
7051 }
7056 {
7058 tree folded;
7060 /* Treat expressions in initializers specially as they can't trap. */
7068 }
7069 }