| blob | ab8df375448c41790ca284ca47c74f59233163be |
1 /* Build expressions with type checking for C compiler.
2 Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
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. */
48 /* Possible cases of implicit bad conversions. Used to select
49 diagnostic messages in convert_for_assignment. */
51 ic_argpass,
52 ic_argpass_nonproto,
53 ic_assign,
54 ic_init,
55 ic_return
56 };
58 /* The level of nesting inside "__alignof__". */
61 /* The level of nesting inside "sizeof". */
64 /* The level of nesting inside "typeof". */
70 /* Nonzero if we've already printed a "missing braces around initializer"
71 message within this initializer. */
109 \f
110 /* Return true if EXP is a null pointer constant, false otherwise. */
112 static bool
114 {
115 /* This should really operate on c_expr structures, but they aren't
116 yet available everywhere required. */
125 }
130 const_tree t1;
131 const_tree t2;
132 /* The return value of tagged_types_tu_compatible_p if we had seen
133 these two types already. */
135 };
140 /* Do `exp = require_complete_type (exp);' to make sure exp
141 does not have an incomplete type. (That includes void types.) */
143 tree
145 {
151 /* First, detect a valid value with a complete type. */
157 }
159 /* Print an error message for invalid use of an incomplete type.
160 VALUE is the expression that was used (or 0 if that isn't known)
161 and TYPE is the type that was invalid. */
163 void
165 {
168 /* Avoid duplicate error message. */
175 else
176 {
177 retry:
178 /* We must print an error message. Be clever about what it says. */
181 {
200 {
202 {
205 }
208 }
214 }
219 else
220 /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */
222 }
223 }
225 /* Given a type, apply default promotions wrt unnamed function
226 arguments and return the new type. */
228 tree
230 {
235 {
236 /* Preserve unsignedness if not really getting any wider. */
241 }
244 }
246 /* Return a variant of TYPE which has all the type qualifiers of LIKE
247 as well as those of TYPE. */
249 static tree
251 {
254 }
256 /* Return true iff the given tree T is a variable length array. */
258 bool
260 {
265 }
266 \f
267 /* Return the composite type of two compatible types.
269 We assume that comptypes has already been done and returned
270 nonzero; if that isn't so, this may crash. In particular, we
271 assume that qualifiers match. */
273 tree
275 {
278 tree attributes;
280 /* Save time if the two types are the same. */
284 /* If one type is nonsense, use the other. */
293 /* Merge the attributes. */
296 /* If one is an enumerated type and the other is the compatible
297 integer type, the composite type might be either of the two
298 (DR#013 question 3). For consistency, use the enumerated type as
299 the composite type. */
309 {
311 /* For two pointers, do this recursively on the target type. */
312 {
319 }
322 {
325 tree unqual_elt;
331 /* We should not have any type quals on arrays at all. */
337 d1_variable = (!d1_zero
340 d2_variable = (!d2_zero
346 /* Save space: see if the result is identical to one of the args. */
359 /* Merge the element types, and have a size if either arg has
360 one. We may have qualifiers on the element types. To set
361 up TYPE_MAIN_VARIANT correctly, we need to form the
362 composite of the unqualified types and add the qualifiers
363 back at the end. */
368 && (d2_variable
369 || d2_zero
371 ? t1
375 }
381 {
382 /* Try harder not to create a new aggregate type. */
387 }
391 /* Function types: prefer the one that specified arg types.
392 If both do, merge the arg types. Also merge the return types. */
393 {
401 /* Save space: see if the result is identical to one of the args. */
407 /* Simple way if one arg fails to specify argument types. */
409 {
413 }
415 {
419 }
421 /* If both args specify argument types, we must merge the two
422 lists, argument by argument. */
423 /* Tell global_bindings_p to return false so that variable_size
424 doesn't die on VLAs in parameter types. */
437 {
438 /* A null type means arg type is not specified.
439 Take whatever the other function type has. */
441 {
444 }
446 {
449 }
451 /* Given wait (union {union wait *u; int *i} *)
452 and wait (union wait *),
453 prefer union wait * as type of parm. */
456 {
457 tree memb;
464 {
470 {
476 }
477 }
478 }
481 {
482 tree memb;
489 {
495 {
501 }
502 }
503 }
505 parm_done: ;
506 }
511 /* ... falls through ... */
512 }
516 }
518 }
520 /* Return the type of a conditional expression between pointers to
521 possibly differently qualified versions of compatible types.
523 We assume that comp_target_types has already been done and returned
524 nonzero; if that isn't so, this may crash. */
526 static tree
528 {
529 tree attributes;
532 tree target;
535 /* Save time if the two types are the same. */
539 /* If one type is nonsense, use the other. */
548 /* Merge the attributes. */
551 /* Find the composite type of the target types, and combine the
552 qualifiers of the two types' targets. Do not lose qualifiers on
553 array element types by taking the TYPE_MAIN_VARIANT. */
562 /* For function types do not merge const qualifiers, but drop them
563 if used inconsistently. The middle-end uses these to mark const
564 and noreturn functions. */
567 else
571 }
573 /* Return the common type for two arithmetic types under the usual
574 arithmetic conversions. The default conversions have already been
575 applied, and enumerated types converted to their compatible integer
576 types. The resulting type is unqualified and has no attributes.
578 This is the type for the result of most arithmetic operations
579 if the operands have the given two types. */
581 static tree
583 {
587 /* If one type is nonsense, use the other. */
605 /* Save time if the two types are the same. */
619 /* When one operand is a decimal float type, the other operand cannot be
620 a generic float type or a complex type. We also disallow vector types
621 here. */
624 {
626 {
629 }
631 {
634 }
636 {
639 }
640 }
642 /* If one type is a vector type, return that type. (How the usual
643 arithmetic conversions apply to the vector types extension is not
644 precisely specified.) */
651 /* If one type is complex, form the common type of the non-complex
652 components, then make that complex. Use T1 or T2 if it is the
653 required type. */
655 {
664 else
666 }
668 /* If only one is real, use it as the result. */
676 /* If both are real and either are decimal floating point types, use
677 the decimal floating point type with the greater precision. */
680 {
690 }
692 /* Deal with fixed-point types. */
694 {
702 /* If one input type is saturating, the result type is saturating. */
706 /* If both fixed-point types are unsigned, the result type is unsigned.
707 When mixing fixed-point and integer types, follow the sign of the
708 fixed-point type.
709 Otherwise, the result type is signed. */
718 /* The result type is signed. */
720 {
721 /* If the input type is unsigned, we need to convert to the
722 signed type. */
724 {
730 else
733 }
735 {
741 else
744 }
745 }
748 {
751 }
752 else
753 {
755 /* Signed integers need to subtract one sign bit. */
757 }
760 {
763 }
764 else
765 {
767 /* Signed integers need to subtract one sign bit. */
769 }
774 satp);
775 }
777 /* Both real or both integers; use the one with greater precision. */
784 /* Same precision. Prefer long longs to longs to ints when the
785 same precision, following the C99 rules on integer type rank
786 (which are equivalent to the C90 rules for C90 types). */
794 {
797 else
799 }
807 {
808 /* But preserve unsignedness from the other type,
809 since long cannot hold all the values of an unsigned int. */
812 else
814 }
816 /* Likewise, prefer long double to double even if same size. */
821 /* Otherwise prefer the unsigned one. */
825 else
827 }
828 \f
829 /* Wrapper around c_common_type that is used by c-common.c and other
830 front end optimizations that remove promotions. ENUMERAL_TYPEs
831 are allowed here and are converted to their compatible integer types.
832 BOOLEAN_TYPEs are allowed here and return either boolean_type_node or
833 preferably a non-Boolean type as the common type. */
834 tree
836 {
842 /* If both types are BOOLEAN_TYPE, then return boolean_type_node. */
847 /* If either type is BOOLEAN_TYPE, then return the other. */
854 }
856 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
857 or various other operations. Return 2 if they are compatible
858 but a warning may be needed if you use them together. */
860 int
862 {
870 }
871 \f
872 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
873 or various other operations. Return 2 if they are compatible
874 but a warning may be needed if you use them together. This
875 differs from comptypes, in that we don't free the seen types. */
877 static int
879 {
884 /* Suppress errors caused by previously reported errors. */
890 /* If either type is the internal version of sizetype, return the
891 language version. */
901 /* Enumerated types are compatible with integer types, but this is
902 not transitive: two enumerated types in the same translation unit
903 are compatible with each other only if they are the same type. */
913 /* Different classes of types can't be compatible. */
918 /* Qualifiers must match. C99 6.7.3p9 */
923 /* Allow for two different type nodes which have essentially the same
924 definition. Note that we already checked for equality of the type
925 qualifiers (just above). */
931 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
935 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
939 {
941 /* Do not remove mode or aliasing information. */
954 {
961 /* Target types must match incl. qualifiers. */
966 /* Sizes must match unless one is missing or variable. */
973 d1_variable = (!d1_zero
976 d2_variable = (!d2_zero
992 }
998 {
1009 }
1019 }
1021 }
1023 /* Return 1 if TTL and TTR are pointers to types that are equivalent,
1024 ignoring their qualifiers. */
1026 static int
1028 {
1032 /* Do not lose qualifiers on element types of array types that are
1033 pointer targets by taking their TYPE_MAIN_VARIANT. */
1045 }
1046 \f
1047 /* Subroutines of `comptypes'. */
1049 /* Determine whether two trees derive from the same translation unit.
1050 If the CONTEXT chain ends in a null, that tree's context is still
1051 being parsed, so if two trees have context chains ending in null,
1052 they're in the same translation unit. */
1053 int
1055 {
1058 {
1066 }
1070 {
1078 }
1081 }
1083 /* Allocate the seen two types, assuming that they are compatible. */
1087 {
1095 /* The C standard says that two structures in different translation
1096 units are compatible with each other only if the types of their
1097 fields are compatible (among other things). We assume that they
1098 are compatible until proven otherwise when building the cache.
1099 An example where this can occur is:
1100 struct a
1101 {
1102 struct a *next;
1103 };
1104 If we are comparing this against a similar struct in another TU,
1105 and did not assume they were compatible, we end up with an infinite
1106 loop. */
1109 }
1111 /* Free the seen types until we get to TU_TIL. */
1113 static void
1115 {
1118 {
1123 }
1125 }
1127 /* Return 1 if two 'struct', 'union', or 'enum' types T1 and T2 are
1128 compatible. If the two types are not the same (which has been
1129 checked earlier), this can only happen when multiple translation
1130 units are being compiled. See C99 6.2.7 paragraph 1 for the exact
1131 rules. */
1133 static int
1135 {
1139 /* We have to verify that the tags of the types are the same. This
1140 is harder than it looks because this may be a typedef, so we have
1141 to go look at the original type. It may even be a typedef of a
1142 typedef...
1143 In the case of compiler-created builtin structs the TYPE_DECL
1144 may be a dummy, with no DECL_ORIGINAL_TYPE. Don't fault. */
1155 /* C90 didn't have the requirement that the two tags be the same. */
1159 /* C90 didn't say what happened if one or both of the types were
1160 incomplete; we choose to follow C99 rules here, which is that they
1161 are compatible. */
1166 {
1171 }
1174 {
1176 {
1178 /* Speed up the case where the type values are in the same order. */
1183 {
1185 }
1188 {
1192 {
1195 }
1196 }
1199 {
1201 }
1203 {
1206 }
1209 {
1212 }
1215 {
1219 {
1222 }
1223 }
1225 }
1228 {
1231 {
1234 }
1236 /* Speed up the common case where the fields are in the same order. */
1239 {
1249 {
1252 }
1259 {
1262 }
1263 }
1265 {
1268 }
1271 {
1276 {
1284 {
1287 }
1298 }
1300 {
1303 }
1304 }
1307 }
1310 {
1316 {
1331 }
1334 else
1337 }
1341 }
1342 }
1344 /* Return 1 if two function types F1 and F2 are compatible.
1345 If either type specifies no argument types,
1346 the other must specify a fixed number of self-promoting arg types.
1347 Otherwise, if one type specifies only the number of arguments,
1348 the other must specify that number of self-promoting arg types.
1349 Otherwise, the argument types must match. */
1351 static int
1353 {
1355 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
1363 /* 'volatile' qualifiers on a function's return type used to mean
1364 the function is noreturn. */
1380 /* An unspecified parmlist matches any specified parmlist
1381 whose argument types don't need default promotions. */
1384 {
1387 /* If one of these types comes from a non-prototype fn definition,
1388 compare that with the other type's arglist.
1389 If they don't match, ask for a warning (but no error). */
1394 }
1396 {
1403 }
1405 /* Both types have argument lists: compare them and propagate results. */
1408 }
1410 /* Check two lists of types for compatibility,
1411 returning 0 for incompatible, 1 for compatible,
1412 or 2 for compatible with warning. */
1414 static int
1416 {
1417 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
1422 {
1426 /* If one list is shorter than the other,
1427 they fail to match. */
1436 /* A null pointer instead of a type
1437 means there is supposed to be an argument
1438 but nothing is specified about what type it has.
1439 So match anything that self-promotes. */
1441 {
1444 }
1446 {
1449 }
1450 /* If one of the lists has an error marker, ignore this arg. */
1453 ;
1455 {
1456 /* Allow wait (union {union wait *u; int *i} *)
1457 and wait (union wait *) to be compatible. */
1464 {
1465 tree memb;
1468 {
1475 }
1478 }
1485 {
1486 tree memb;
1489 {
1496 }
1499 }
1500 else
1502 }
1504 /* comptypes said ok, but record if it said to warn. */
1510 }
1511 }
1512 \f
1513 /* Compute the size to increment a pointer by. */
1515 static tree
1517 {
1524 {
1527 }
1529 /* Convert in case a char is more than one unit. */
1533 }
1534 \f
1535 /* Return either DECL or its known constant value (if it has one). */
1537 tree
1539 {
1541 in a place where a variable is invalid. Note that DECL_INITIAL
1542 isn't valid for a PARM_DECL. */
1549 /* This is invalid if initial value is not constant.
1550 If it has either a function call, a memory reference,
1551 or a variable, then re-evaluating it could give different results. */
1553 /* Check for cases where this is sub-optimal, even though valid. */
1557 }
1559 /* Return either DECL or its known constant value (if it has one), but
1560 return DECL if pedantic or DECL has mode BLKmode. This is for
1561 bug-compatibility with the old behavior of decl_constant_value
1562 (before GCC 3.0); every use of this function is a bug and it should
1563 be removed before GCC 3.1. It is not appropriate to use pedantic
1564 in a way that affects optimization, and BLKmode is probably not the
1565 right test for avoiding misoptimizations either. */
1567 static tree
1569 {
1570 tree ret;
1576 /* Avoid unwanted tree sharing between the initializer and current
1577 function's body where the tree can be modified e.g. by the
1578 gimplifier. */
1582 }
1584 /* Convert the array expression EXP to a pointer. */
1585 static tree
1587 {
1590 tree adr;
1592 tree ptrtype;
1607 {
1608 /* We are making an ADDR_EXPR of ptrtype. This is a valid
1609 ADDR_EXPR because it's the best way of representing what
1610 happens in C when we take the address of an array and place
1611 it in a pointer to the element type. */
1617 }
1619 /* This way is better for a COMPONENT_REF since it can
1620 simplify the offset for a component. */
1623 }
1625 /* Convert the function expression EXP to a pointer. */
1626 static tree
1628 {
1639 }
1641 /* Perform the default conversion of arrays and functions to pointers.
1642 Return the result of converting EXP. For any other expression, just
1643 return EXP after removing NOPs. */
1645 struct c_expr
1647 {
1653 {
1655 {
1662 {
1666 }
1673 {
1674 /* Before C99, non-lvalue arrays do not decay to pointers.
1675 Normally, using such an array would be invalid; but it can
1676 be used correctly inside sizeof or as a statement expression.
1677 Thus, do not give an error here; an error will result later. */
1679 }
1682 }
1692 }
1695 }
1698 /* EXP is an expression of integer type. Apply the integer promotions
1699 to it and return the promoted value. */
1701 tree
1703 {
1709 /* Normally convert enums to int,
1710 but convert wide enums to something wider. */
1712 {
1720 }
1722 /* ??? This should no longer be needed now bit-fields have their
1723 proper types. */
1726 /* If it's thinner than an int, promote it like a
1727 c_promoting_integer_type_p, otherwise leave it alone. */
1733 {
1734 /* Preserve unsignedness if not really getting any wider. */
1740 }
1743 }
1746 /* Perform default promotions for C data used in expressions.
1747 Enumeral types or short or char are converted to int.
1748 In addition, manifest constants symbols are replaced by their values. */
1750 tree
1752 {
1753 tree orig_exp;
1757 /* Functions and arrays have been converted during parsing. */
1762 /* Constants can be used directly unless they're not loadable. */
1766 /* Replace a nonvolatile const static variable with its value unless
1767 it is an array, in which case we must be sure that taking the
1768 address of the array produces consistent results. */
1770 {
1773 }
1775 /* Strip no-op conversions. */
1783 {
1786 }
1796 }
1797 \f
1798 /* Look up COMPONENT in a structure or union DECL.
1800 If the component name is not found, returns NULL_TREE. Otherwise,
1801 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL
1802 stepping down the chain to the component, which is in the last
1803 TREE_VALUE of the list. Normally the list is of length one, but if
1804 the component is embedded within (nested) anonymous structures or
1805 unions, the list steps down the chain to the component. */
1807 static tree
1809 {
1811 tree field;
1813 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers
1814 to the field elements. Use a binary search on this array to quickly
1815 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC
1816 will always be set for structures which have many elements. */
1819 {
1827 {
1832 {
1833 /* Step through all anon unions in linear fashion. */
1835 {
1839 {
1844 }
1845 }
1847 /* Entire record is only anon unions. */
1851 /* Restart the binary search, with new lower bound. */
1853 }
1859 else
1861 }
1867 }
1868 else
1869 {
1871 {
1875 {
1880 }
1884 }
1888 }
1891 }
1893 /* Make an expression to refer to the COMPONENT field of
1894 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */
1896 tree
1898 {
1902 tree ref;
1907 /* See if there is a field or component with name COMPONENT. */
1910 {
1912 {
1915 }
1920 {
1923 }
1925 /* Chain the COMPONENT_REFs if necessary down to the FIELD.
1926 This might be better solved in future the way the C++ front
1927 end does it - by giving the anonymous entities each a
1928 separate name and type, and then have build_component_ref
1929 recursively call itself. We can't do that here. */
1930 do
1931 {
1934 tree subtype;
1944 NULL_TREE);
1956 }
1960 }
1963 component);
1966 }
1967 \f
1968 /* Given an expression PTR for a pointer, return an expression
1969 for the value pointed to.
1970 ERRORSTRING is the name of the operator to appear in error messages.
1972 LOC is the location to use for the generated tree. */
1974 tree
1976 {
1979 tree ref;
1982 {
1985 {
1986 /* If a warning is issued, mark it to avoid duplicates from
1987 the backend. This only needs to be done at
1988 warn_strict_aliasing > 2. */
1993 }
1998 {
2002 }
2003 else
2004 {
2010 {
2013 }
2017 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2018 so that we get the proper error message if the result is used
2019 to assign to. Also, &* is supposed to be a no-op.
2020 And ANSI C seems to specify that the type of the result
2021 should be the const type. */
2022 /* A de-reference of a pointer to const is not a const. It is valid
2023 to change it via some other pointer. */
2030 }
2031 }
2036 }
2038 /* This handles expressions of the form "a[i]", which denotes
2039 an array reference.
2041 This is logically equivalent in C to *(a+i), but we may do it differently.
2042 If A is a variable or a member, we generate a primitive ARRAY_REF.
2043 This avoids forcing the array out of registers, and can work on
2044 arrays that are not lvalues (for example, members of structures returned
2045 by functions).
2047 LOC is the location to use for the returned expression. */
2049 tree
2051 {
2052 tree ret;
2060 {
2061 tree temp;
2064 {
2067 }
2072 }
2075 {
2078 }
2081 {
2084 }
2086 /* ??? Existing practice has been to warn only when the char
2087 index is syntactically the index, not for char[array]. */
2091 /* Apply default promotions *after* noticing character types. */
2097 {
2100 /* An array that is indexed by a non-constant
2101 cannot be stored in a register; we must be able to do
2102 address arithmetic on its address.
2103 Likewise an array of elements of variable size. */
2107 {
2110 }
2111 /* An array that is indexed by a constant value which is not within
2112 the array bounds cannot be stored in a register either; because we
2113 would get a crash in store_bit_field/extract_bit_field when trying
2114 to access a non-existent part of the register. */
2118 {
2121 }
2124 {
2134 }
2138 /* Array ref is const/volatile if the array elements are
2139 or if the array is. */
2148 /* This was added by rms on 16 Nov 91.
2149 It fixes vol struct foo *a; a->elts[1]
2150 in an inline function.
2151 Hope it doesn't break something else. */
2156 }
2157 else
2158 {
2167 return build_indirect_ref
2170 }
2171 }
2172 \f
2173 /* Build an external reference to identifier ID. FUN indicates
2174 whether this will be used for a function call. LOC is the source
2175 location of the identifier. */
2176 tree
2178 {
2179 tree ref;
2182 /* In Objective-C, an instance variable (ivar) may be preferred to
2183 whatever lookup_name() found. */
2189 /* Implicit function declaration. */
2192 /* Don't complain about something that's already been
2193 complained about. */
2195 else
2196 {
2199 }
2207 /* Recursive call does not count as usage. */
2209 {
2211 }
2214 {
2221 }
2224 {
2228 }
2234 {
2239 }
2240 /* C99 6.7.4p3: An inline definition of a function with external
2241 linkage ... shall not contain a reference to an identifier with
2242 internal linkage. */
2254 }
2256 /* Record details of decls possibly used inside sizeof or typeof. */
2257 struct maybe_used_decl
2258 {
2259 /* The decl. */
2260 tree decl;
2261 /* The level seen at (in_sizeof + in_typeof). */
2263 /* The next one at this level or above, or NULL. */
2265 };
2269 /* Record that DECL, an undefined static function reference seen
2270 inside sizeof or typeof, might be used if the operand of sizeof is
2271 a VLA type or the operand of typeof is a variably modified
2272 type. */
2274 static void
2276 {
2282 }
2284 /* Pop the stack of decls possibly used inside sizeof or typeof. If
2285 USED is false, just discard them. If it is true, mark them used
2286 (if no longer inside sizeof or typeof) or move them to the next
2287 level up (if still inside sizeof or typeof). */
2289 void
2291 {
2295 {
2297 {
2300 else
2302 }
2304 }
2307 }
2309 /* Return the result of sizeof applied to EXPR. */
2311 struct c_expr
2313 {
2316 {
2320 }
2321 else
2322 {
2326 {
2327 /* sizeof is evaluated when given a vla (C99 6.5.3.4p2). */
2329 }
2331 }
2333 }
2335 /* Return the result of sizeof applied to T, a structure for the type
2336 name passed to sizeof (rather than the type itself). */
2338 struct c_expr
2340 {
2341 tree type;
2349 }
2351 /* Build a function call to function FUNCTION with parameters PARAMS.
2352 PARAMS is a list--a chain of TREE_LIST nodes--in which the
2353 TREE_VALUE of each node is a parameter-expression.
2354 FUNCTION's data type may be a function type or a pointer-to-function. */
2356 tree
2358 {
2361 tree tem;
2366 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2369 /* Convert anything with function type to a pointer-to-function. */
2371 {
2372 /* Implement type-directed function overloading for builtins.
2373 resolve_overloaded_builtin and targetm.resolve_overloaded_builtin
2374 handle all the type checking. The result is a complete expression
2375 that implements this function call. */
2382 }
2386 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2387 expressions, like those used for ObjC messenger dispatches. */
2397 {
2400 }
2405 /* fntype now gets the type of function pointed to. */
2408 /* Check that the function is called through a compatible prototype.
2409 If it is not, replace the call by a trap, wrapped up in a compound
2410 expression if necessary. This has the nice side-effect to prevent
2411 the tree-inliner from generating invalid assignment trees which may
2412 blow up in the RTL expander later. */
2417 {
2420 NULL_TREE);
2422 /* This situation leads to run-time undefined behavior. We can't,
2423 therefore, simply error unless we can prove that all possible
2424 executions of the program must execute the code. */
2426 /* We can, however, treat "undefined" any way we please.
2427 Call abort to encourage the user to fix the program. */
2432 else
2433 {
2434 tree rhs;
2439 else
2443 }
2444 }
2446 /* Convert the parameters to the types declared in the
2447 function prototype, or apply default promotions. */
2456 /* Check that arguments to builtin functions match the expectations. */
2463 /* Check that the arguments to the function are valid. */
2468 {
2475 }
2476 else
2483 }
2484 \f
2485 /* Convert the argument expressions in the list VALUES
2486 to the types in the list TYPELIST. The resulting arguments are
2487 stored in the array ARGARRAY which has size NARGS.
2489 If TYPELIST is exhausted, or when an element has NULL as its type,
2490 perform the default conversions.
2492 PARMLIST is the chain of parm decls for the function being called.
2493 It may be 0, if that info is not available.
2494 It is used only for generating error messages.
2496 FUNCTION is a tree for the called function. It is used only for
2497 error messages, where it is formatted with %qE.
2499 This is also where warnings about wrong number of args are generated.
2501 VALUES is a chain of TREE_LIST nodes with the elements of the list
2502 in the TREE_VALUE slots of those nodes.
2504 Returns the actual number of arguments processed (which may be less
2505 than NARGS in some error situations), or -1 on failure. */
2507 static int
2510 {
2515 tree selector;
2517 /* Change pointer to function to the function itself for
2518 diagnostics. */
2523 /* Handle an ObjC selector specially for diagnostics. */
2526 /* Scan the given expressions and types, producing individual
2527 converted arguments and storing them in ARGARRAY. */
2530 valtail;
2532 {
2540 {
2543 }
2546 {
2549 }
2556 {
2557 /* Formal parm type is specified by a function prototype. */
2558 tree parmval;
2561 {
2564 }
2565 else
2566 {
2567 /* Optionally warn about conversions that
2568 differ from the default conversions. */
2570 {
2603 /* ??? At some point, messages should be written about
2604 conversions between complex types, but that's too messy
2605 to do now. */
2608 {
2609 /* Warn if any argument is passed as `float',
2610 since without a prototype it would be `double'. */
2617 /* Warn if mismatch between argument and prototype
2618 for decimal float types. Warn of conversions with
2619 binary float types and of precision narrowing due to
2620 prototype. */
2628 && (formal_prec
2632 != dfloat64_type_node
2642 }
2643 /* Detect integer changing in width or signedness.
2644 These warnings are only activated with
2645 -Wtraditional-conversion, not with -Wtraditional. */
2648 {
2655 /* No warning if function asks for enum
2656 and the actual arg is that enum type. */
2657 ;
2663 ;
2664 /* Don't complain if the formal parameter type
2665 is an enum, because we can't tell now whether
2666 the value was an enum--even the same enum. */
2668 ;
2671 /* Change in signedness doesn't matter
2672 if a constant value is unaffected. */
2673 ;
2674 /* If the value is extended from a narrower
2675 unsigned type, it doesn't matter whether we
2676 pass it as signed or unsigned; the value
2677 certainly is the same either way. */
2680 ;
2685 else
2688 }
2689 }
2699 }
2701 }
2706 {
2709 else
2710 /* Convert `float' to `double'. */
2712 }
2715 {
2718 }
2719 else
2720 /* Convert `short' and `char' to full-size `int'. */
2725 }
2730 {
2733 }
2736 }
2737 \f
2738 /* This is the entry point used by the parser to build unary operators
2739 in the input. CODE, a tree_code, specifies the unary operator, and
2740 ARG is the operand. For unary plus, the C parser currently uses
2741 CONVERT_EXPR for code.
2743 LOC is the location to use for the tree generated.
2744 */
2746 struct c_expr
2748 {
2758 }
2760 /* This is the entry point used by the parser to build binary operators
2761 in the input. CODE, a tree_code, specifies the binary operator, and
2762 ARG1 and ARG2 are the operands. In addition to constructing the
2763 expression, we check for operands that were written with other binary
2764 operators in a way that is likely to confuse the user.
2766 LOCATION is the location of the binary operator. */
2768 struct c_expr
2771 {
2787 /* Check for cases such as x+y<<z which users are likely
2788 to misinterpret. */
2795 /* Warn about comparisons against string literals, with the exception
2796 of testing for equality or inequality of a string literal with NULL. */
2798 {
2802 }
2813 }
2814 \f
2815 /* Return a tree for the difference of pointers OP0 and OP1.
2816 The resulting tree has type int. */
2818 static tree
2820 {
2834 /* If the conversion to ptrdiff_type does anything like widening or
2835 converting a partial to an integral mode, we get a convert_expression
2836 that is in the way to do any simplifications.
2837 (fold-const.c doesn't know that the extra bits won't be needed.
2838 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2839 different mode in place.)
2840 So first try to find a common term here 'by hand'; we want to cover
2841 at least the cases that occur in legal static initializers. */
2846 else
2852 else
2856 {
2859 }
2860 else
2864 {
2867 }
2868 else
2872 {
2875 }
2878 /* First do the subtraction as integers;
2879 then drop through to build the divide operator.
2880 Do not do default conversions on the minus operator
2881 in case restype is a short type. */
2886 /* This generates an error if op1 is pointer to incomplete type. */
2890 /* This generates an error if op0 is pointer to incomplete type. */
2893 /* Divide by the size, in easiest possible way. */
2895 }
2896 \f
2897 /* Construct and perhaps optimize a tree representation
2898 for a unary operation. CODE, a tree_code, specifies the operation
2899 and XARG is the operand.
2900 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2901 the default promotions (such as from short to int).
2902 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2903 allows non-lvalues; this is only used to handle conversion of non-lvalue
2904 arrays to pointers in C99.
2906 LOCATION is the location of the operator. */
2908 tree
2911 {
2912 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2916 tree val;
2932 {
2935 }
2938 {
2940 /* This is used for unary plus, because a CONVERT_EXPR
2941 is enough to prevent anybody from looking inside for
2942 associativity, but won't generate any code. */
2946 {
2949 }
2959 {
2962 }
2968 /* ~ works on integer types and non float vectors. */
2972 {
2975 }
2977 {
2983 }
2984 else
2985 {
2988 }
2993 {
2996 }
3002 /* Conjugating a real value is a no-op, but allow it anyway. */
3005 {
3008 }
3017 {
3021 }
3031 else
3040 else
3049 /* Increment or decrement the real part of the value,
3050 and don't change the imaginary part. */
3052 {
3067 }
3069 /* Report invalid types. */
3073 {
3076 else
3080 }
3082 {
3083 tree inc;
3089 /* Compute the increment. */
3092 {
3093 /* If pointer target is an undefined struct,
3094 we just cannot know how to do the arithmetic. */
3096 {
3100 else
3103 }
3106 {
3110 else
3113 }
3117 }
3119 {
3120 /* For signed fract types, we invert ++ to -- or
3121 -- to ++, and change inc from 1 to -1, because
3122 it is not possible to represent 1 in signed fract constants.
3123 For unsigned fract types, the result always overflows and
3124 we get an undefined (original) or the maximum value. */
3136 }
3137 else
3138 {
3141 }
3143 /* Complain about anything else that is not a true lvalue. */
3146 ? lv_increment
3150 /* Report a read-only lvalue. */
3152 {
3158 }
3162 else
3170 }
3173 /* Note that this operation never does default_conversion. */
3175 /* Let &* cancel out to simplify resulting code. */
3177 {
3178 /* Don't let this be an lvalue. */
3183 }
3185 /* For &x[y], return x+y */
3187 {
3196 }
3198 /* Anything not already handled and not a true memory reference
3199 or a non-lvalue array is an error. */
3204 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
3207 /* If the lvalue is const or volatile, merge that into the type
3208 to which the address will point. Note that you can't get a
3209 restricted pointer by taking the address of something, so we
3210 only have to deal with `const' and `volatile' here. */
3225 /* ??? Cope with user tricks that amount to offsetof. Delete this
3226 when we have proper support for integer constant expressions. */
3230 {
3236 }
3245 }
3251 return_build_unary_op:
3255 }
3257 /* Return nonzero if REF is an lvalue valid for this language.
3258 Lvalues can be assigned, unless their type has TYPE_READONLY.
3259 Lvalues can have their address taken, unless they have C_DECL_REGISTER. */
3261 static int
3263 {
3267 {
3291 }
3292 }
3293 \f
3294 /* Give an error for storing in something that is 'const'. */
3296 static void
3298 {
3301 /* Using this macro rather than (for example) arrays of messages
3302 ensures that all the format strings are checked at compile
3303 time. */
3304 #define READONLY_MSG(A, I, D, AS) (use == lv_assign ? (A) \
3305 : (use == lv_increment ? (I) \
3306 : (use == lv_decrement ? (D) : (AS))))
3308 {
3311 else
3317 }
3323 arg);
3324 else
3329 arg);
3330 }
3333 /* Return nonzero if REF is an lvalue valid for this language;
3334 otherwise, print an error message and return zero. USE says
3335 how the lvalue is being used and so selects the error message. */
3337 static int
3339 {
3346 }
3347 \f
3348 /* Mark EXP saying that we need to be able to take the
3349 address of it; it should not be allocated in a register.
3350 Returns true if successful. */
3352 bool
3354 {
3359 {
3362 {
3363 error
3366 }
3368 /* ... fall through ... */
3388 {
3390 {
3391 error
3394 }
3396 }
3398 {
3401 else
3404 }
3406 /* drops in */
3409 /* drops out */
3412 }
3413 }
3414 \f
3415 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
3417 tree
3419 {
3420 tree type1;
3421 tree type2;
3427 /* Promote both alternatives. */
3444 /* C90 does not permit non-lvalue arrays in conditional expressions.
3445 In C99 they will be pointers by now. */
3447 {
3450 }
3452 /* Quickly detect the usual case where op1 and op2 have the same type
3453 after promotion. */
3455 {
3458 else
3460 }
3465 {
3468 /* If -Wsign-compare, warn here if type1 and type2 have
3469 different signedness. We'll promote the signed to unsigned
3470 and later code won't know it used to be different.
3471 Do this check on the original types, so that explicit casts
3472 will be considered, but default promotions won't. */
3474 {
3479 {
3482 /* Do not warn if the result type is signed, since the
3483 signed type will only be chosen if it can represent
3484 all the values of the unsigned type. */
3487 /* Do not warn if the signed quantity is an unsuffixed
3488 integer literal (or some static constant expression
3489 involving such literals) and it is non-negative. */
3492 || (unsigned_op1
3495 else
3497 }
3498 }
3499 }
3501 {
3506 }
3508 {
3516 {
3519 "ISO C forbids conditional expr between "
3523 }
3525 {
3528 "ISO C forbids conditional expr between "
3532 }
3533 else
3534 {
3538 }
3539 }
3541 {
3545 else
3546 {
3548 }
3550 }
3552 {
3556 else
3557 {
3559 }
3561 }
3564 {
3567 else
3568 {
3571 }
3572 }
3574 /* Merge const and volatile flags of the incoming types. */
3575 result_type
3586 }
3587 \f
3588 /* Return a compound expression that performs two expressions and
3589 returns the value of the second of them. */
3591 tree
3593 {
3595 {
3596 /* The left-hand operand of a comma expression is like an expression
3597 statement: with -Wunused, we should warn if it doesn't have
3598 any side-effects, unless it was explicitly cast to (void). */
3600 {
3608 else
3611 }
3612 }
3614 /* With -Wunused, we should also warn if the left-hand operand does have
3615 side-effects, but computes a value which is not used. For example, in
3616 `foo() + bar(), baz()' the result of the `+' operator is not used,
3617 so we should issue a warning. */
3625 }
3627 /* Build an expression representing a cast to type TYPE of expression EXPR. */
3629 tree
3631 {
3637 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
3638 only in <protocol> qualifications. But when constructing cast expressions,
3639 the protocols do matter and must be kept around. */
3646 {
3649 }
3652 {
3655 }
3658 {
3662 }
3665 {
3670 }
3672 {
3673 tree field;
3682 {
3683 tree t;
3692 }
3695 }
3696 else
3697 {
3705 /* Optionally warn about potentially worrisome casts. */
3710 {
3716 /* Check that the qualifiers on IN_TYPE are a superset of
3717 the qualifiers of IN_OTYPE. The outermost level of
3718 POINTER_TYPE nodes is uninteresting and we stop as soon
3719 as we hit a non-POINTER_TYPE node on either type. */
3720 do
3721 {
3725 /* GNU C allows cv-qualified function types. 'const'
3726 means the function is very pure, 'volatile' means it
3727 can't return. We need to warn when such qualifiers
3728 are added, not when they're taken away. */
3732 else
3734 }
3742 /* There are qualifiers present in IN_OTYPE that are not
3743 present in IN_TYPE. */
3745 }
3747 /* Warn about possible alignment problems. */
3753 /* Don't warn about opaque types, where the actual alignment
3754 restriction is unknown. */
3765 /* Unlike conversion of integers to pointers, where the
3766 warning is disabled for converting constants because
3767 of cases such as SIG_*, warn about converting constant
3768 pointers to integers. In some cases it may cause unwanted
3769 sign extension, and a warning is appropriate. */
3781 /* Don't warn about converting any constant. */
3789 /* If pedantic, warn for conversions between function and object
3790 pointer types, except for converting a null pointer constant
3791 to function pointer type. */
3812 /* Ignore any integer overflow caused by the cast. */
3814 {
3816 {
3818 {
3819 /* Avoid clobbering a shared constant. */
3822 }
3823 }
3825 /* Reset VALUE's overflow flags, ensuring constant sharing. */
3829 }
3830 }
3832 /* Don't let a cast be an lvalue. */
3837 }
3839 /* Interpret a cast of expression EXPR to type TYPE. */
3840 tree
3842 {
3843 tree type;
3846 /* This avoids warnings about unprototyped casts on
3847 integers. E.g. "#define SIG_DFL (void(*)())0". */
3854 }
3855 \f
3856 /* Build an assignment expression of lvalue LHS from value RHS.
3857 MODIFYCODE is the code for a binary operator that we use
3858 to combine the old value of LHS with RHS to get the new value.
3859 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
3861 LOCATION is the location of the MODIFYCODE operator. */
3863 tree
3866 {
3867 tree result;
3868 tree newrhs;
3872 /* Types that aren't fully specified cannot be used in assignments. */
3875 /* Avoid duplicate error messages from operands that had errors. */
3886 /* If a binary op has been requested, combine the old LHS value with the RHS
3887 producing the value we should actually store into the LHS. */
3890 {
3894 }
3896 /* Give an error for storing in something that is 'const'. */
3902 {
3905 }
3907 /* If storing into a structure or union member,
3908 it has probably been given type `int'.
3909 Compute the type that would go with
3910 the actual amount of storage the member occupies. */
3919 /* If storing in a field that is in actuality a short or narrower than one,
3920 we must store in the field in its actual type. */
3923 {
3926 }
3928 /* Convert new value to destination type. */
3935 /* Emit ObjC write barrier, if necessary. */
3937 {
3940 {
3943 }
3944 }
3946 /* Scan operands. */
3952 /* If we got the LHS in a different type for storing in,
3953 convert the result back to the nominal type of LHS
3954 so that the value we return always has the same type
3955 as the LHS argument. */
3964 }
3965 \f
3966 /* Convert value RHS to type TYPE as preparation for an assignment
3967 to an lvalue of type TYPE.
3968 The real work of conversion is done by `convert'.
3969 The purpose of this function is to generate error messages
3970 for assignments that are not allowed in C.
3971 ERRTYPE says whether it is argument passing, assignment,
3972 initialization or return.
3974 FUNCTION is a tree for the function being called.
3975 PARMNUM is the number of the argument, for printing in error messages. */
3977 static tree
3980 {
3982 tree rhstype;
3988 {
3989 tree selector;
3990 /* Change pointer to function to the function itself for
3991 diagnostics. */
3996 /* Handle an ObjC selector specially for diagnostics. */
4000 {
4003 }
4004 }
4006 /* This macro is used to emit diagnostics to ensure that all format
4007 strings are complete sentences, visible to gettext and checked at
4008 compile time. */
4009 #define WARN_FOR_ASSIGNMENT(LOCATION, OPT, AR, AS, IN, RE) \
4010 do { \
4011 switch (errtype) \
4012 { \
4013 case ic_argpass: \
4014 if (pedwarn (LOCATION, OPT, AR, parmnum, rname)) \
4015 inform (fundecl ? DECL_SOURCE_LOCATION (fundecl) : LOCATION, \
4017 type, rhstype); \
4018 break; \
4019 case ic_argpass_nonproto: \
4020 warning (OPT, AR, parmnum, rname); \
4021 break; \
4022 case ic_assign: \
4023 pedwarn (LOCATION, OPT, AS); \
4024 break; \
4025 case ic_init: \
4026 pedwarn (LOCATION, OPT, IN); \
4027 break; \
4028 case ic_return: \
4029 pedwarn (LOCATION, OPT, RE); \
4030 break; \
4031 default: \
4032 gcc_unreachable (); \
4033 } \
4034 } while (0)
4049 {
4053 {
4069 }
4072 }
4078 {
4079 /* Except for passing an argument to an unprototyped function,
4080 this is a constraint violation. When passing an argument to
4081 an unprototyped function, it is compile-time undefined;
4082 making it a constraint in that case was rejected in
4083 DR#252. */
4086 }
4090 /* A type converts to a reference to it.
4091 This code doesn't fully support references, it's just for the
4092 special case of va_start and va_copy. */
4095 {
4097 {
4100 }
4105 /* We already know that these two types are compatible, but they
4106 may not be exactly identical. In fact, `TREE_TYPE (type)' is
4107 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
4108 likely to be va_list, a typedef to __builtin_va_list, which
4109 is different enough that it will cause problems later. */
4115 }
4116 /* Some types can interconvert without explicit casts. */
4120 /* Arithmetic types all interconvert, and enum is treated like int. */
4131 /* Aggregates in different TUs might need conversion. */
4137 /* Conversion to a transparent union from its member types.
4138 This applies only to function arguments. */
4141 {
4145 {
4156 {
4160 /* Any non-function converts to a [const][volatile] void *
4161 and vice versa; otherwise, targets must be the same.
4162 Meanwhile, the lhs target must have all the qualifiers of
4163 the rhs. */
4166 {
4167 /* If this type won't generate any warnings, use it. */
4177 /* Keep looking for a better type, but remember this one. */
4180 }
4181 }
4183 /* Can convert integer zero to any pointer type. */
4185 {
4188 }
4189 }
4192 {
4194 {
4195 /* We have only a marginally acceptable member type;
4196 it needs a warning. */
4200 /* Const and volatile mean something different for function
4201 types, so the usual warnings are not appropriate. */
4204 {
4205 /* Because const and volatile on functions are
4206 restrictions that say the function will not do
4207 certain things, it is okay to use a const or volatile
4208 function where an ordinary one is wanted, but not
4209 vice-versa. */
4213 "makes qualified function "
4216 "function pointer from "
4219 "function pointer from "
4223 }
4236 }
4244 }
4245 }
4247 /* Conversions among pointers */
4250 {
4262 /* Opaque pointers are treated like void pointers. */
4265 /* C++ does not allow the implicit conversion void* -> T*. However,
4266 for the purpose of reducing the number of false positives, we
4267 tolerate the special case of
4269 int *p = NULL;
4271 where NULL is typically defined in C to be '(void *) 0'. */
4276 /* Check if the right-hand side has a format attribute but the
4277 left-hand side doesn't. */
4280 {
4282 {
4286 "argument %d of %qE might be "
4292 "assignment left-hand side might be "
4297 "initialization left-hand side might be "
4302 "return type might be "
4307 }
4308 }
4310 /* Any non-function converts to a [const][volatile] void *
4311 and vice versa; otherwise, targets must be the same.
4312 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
4315 || is_opaque_pointer
4318 {
4321 ||
4327 "%qE between function pointer "
4335 /* Const and volatile mean something different for function types,
4336 so the usual warnings are not appropriate. */
4339 {
4341 {
4342 /* Types differing only by the presence of the 'volatile'
4343 qualifier are acceptable if the 'volatile' has been added
4344 in by the Objective-C EH machinery. */
4355 }
4356 /* If this is not a case of ignoring a mismatch in signedness,
4357 no warning. */
4360 ;
4361 /* If there is a mismatch, do warn. */
4372 }
4375 {
4376 /* Because const and volatile on functions are restrictions
4377 that say the function will not do certain things,
4378 it is okay to use a const or volatile function
4379 where an ordinary one is wanted, but not vice-versa. */
4383 "qualified function pointer "
4391 }
4392 }
4393 else
4394 /* Avoid warning about the volatile ObjC EH puts on decls. */
4405 }
4407 {
4408 /* ??? This should not be an error when inlining calls to
4409 unprototyped functions. */
4412 }
4414 {
4415 /* An explicit constant 0 can convert to a pointer,
4416 or one that results from arithmetic, even including
4417 a cast to integer type. */
4430 }
4432 {
4443 }
4448 {
4451 /* ??? This should not be an error when inlining calls to
4452 unprototyped functions. */
4466 }
4469 }
4470 \f
4471 /* If VALUE is a compound expr all of whose expressions are constant, then
4472 return its value. Otherwise, return error_mark_node.
4474 This is for handling COMPOUND_EXPRs as initializer elements
4475 which is allowed with a warning when -pedantic is specified. */
4477 static tree
4479 {
4481 {
4486 endtype);
4487 }
4490 else
4492 }
4493 \f
4494 /* Perform appropriate conversions on the initial value of a variable,
4495 store it in the declaration DECL,
4496 and print any error messages that are appropriate.
4497 If the init is invalid, store an ERROR_MARK. */
4499 void
4501 {
4504 /* If variable's type was invalidly declared, just ignore it. */
4510 /* Digest the specified initializer into an expression. */
4514 /* Store the expression if valid; else report error. */
4523 /* ANSI wants warnings about out-of-range constant initializers. */
4528 /* Check if we need to set array size from compound literal size. */
4532 {
4539 {
4543 {
4544 /* For int foo[] = (int [3]){1}; we need to set array size
4545 now since later on array initializer will be just the
4546 brace enclosed list of the compound literal. */
4552 }
4553 }
4554 }
4555 }
4556 \f
4557 /* Methods for storing and printing names for error messages. */
4559 /* Implement a spelling stack that allows components of a name to be pushed
4560 and popped. Each element on the stack is this structure. */
4562 struct spelling
4563 {
4565 union
4566 {
4570 };
4572 #define SPELLING_STRING 1
4573 #define SPELLING_MEMBER 2
4574 #define SPELLING_BOUNDS 3
4580 /* Macros to save and restore the spelling stack around push_... functions.
4581 Alternative to SAVE_SPELLING_STACK. */
4583 #define SPELLING_DEPTH() (spelling - spelling_base)
4584 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
4586 /* Push an element on the spelling stack with type KIND and assign VALUE
4587 to MEMBER. */
4589 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
4590 { \
4591 int depth = SPELLING_DEPTH (); \
4592 \
4593 if (depth >= spelling_size) \
4594 { \
4595 spelling_size += 10; \
4596 spelling_base = XRESIZEVEC (struct spelling, spelling_base, \
4597 spelling_size); \
4598 RESTORE_SPELLING_DEPTH (depth); \
4599 } \
4600 \
4601 spelling->kind = (KIND); \
4602 spelling->MEMBER = (VALUE); \
4603 spelling++; \
4604 }
4606 /* Push STRING on the stack. Printed literally. */
4608 static void
4610 {
4612 }
4614 /* Push a member name on the stack. Printed as '.' STRING. */
4616 static void
4618 {
4622 }
4624 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
4626 static void
4628 {
4630 }
4632 /* Compute the maximum size in bytes of the printed spelling. */
4634 static int
4636 {
4641 {
4644 else
4646 }
4649 }
4651 /* Print the spelling to BUFFER and return it. */
4655 {
4661 {
4664 }
4665 else
4666 {
4671 ;
4672 }
4675 }
4677 /* Issue an error message for a bad initializer component.
4678 MSGID identifies the message.
4679 The component name is taken from the spelling stack. */
4681 void
4683 {
4690 }
4692 /* Issue a pedantic warning for a bad initializer component. OPT is
4693 the option OPT_* (from options.h) controlling this warning or 0 if
4694 it is unconditionally given. MSGID identifies the message. The
4695 component name is taken from the spelling stack. */
4697 void
4699 {
4706 }
4708 /* Issue a warning for a bad initializer component.
4710 OPT is the OPT_W* value corresponding to the warning option that
4711 controls this warning. MSGID identifies the message. The
4712 component name is taken from the spelling stack. */
4714 static void
4716 {
4723 }
4724 \f
4725 /* If TYPE is an array type and EXPR is a parenthesized string
4726 constant, warn if pedantic that EXPR is being used to initialize an
4727 object of type TYPE. */
4729 void
4731 {
4738 }
4740 /* Digest the parser output INIT as an initializer for type TYPE.
4741 Return a C expression of type TYPE to represent the initial value.
4743 If INIT is a string constant, STRICT_STRING is true if it is
4744 unparenthesized or we should not warn here for it being parenthesized.
4745 For other types of INIT, STRICT_STRING is not used.
4747 REQUIRE_CONSTANT requests an error if non-constant initializers or
4748 elements are seen. */
4750 static tree
4752 {
4757 || !init
4766 /* Initialization of an array of chars from a string constant
4767 optionally enclosed in braces. */
4771 {
4773 /* Note that an array could be both an array of character type
4774 and an array of wchar_t if wchar_t is signed char or unsigned
4775 char. */
4784 {
4796 {
4798 {
4801 }
4802 }
4803 else
4804 {
4806 {
4810 }
4812 {
4816 }
4817 }
4823 /* Subtract the size of a single (possibly wide) character
4824 because it's ok to ignore the terminating null char
4825 that is counted in the length of the constant. */
4834 }
4836 {
4840 }
4841 }
4843 /* Build a VECTOR_CST from a *constant* vector constructor. If the
4844 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
4845 below and handle as a constructor. */
4850 {
4857 {
4859 tree value;
4862 /* Iterate through elements and check if all constructor
4863 elements are *_CSTs. */
4866 {
4869 }
4874 }
4875 }
4880 /* Any type can be initialized
4881 from an expression of the same type, optionally with braces. */
4894 {
4896 {
4898 {
4902 else
4903 {
4906 }
4907 }
4908 }
4911 /* Although the types are compatible, we may require a
4912 conversion. */
4918 {
4919 /* As an extension, allow initializing objects with static storage
4920 duration with compound literals (which are then treated just as
4921 the brace enclosed list they contain). Also allow this for
4922 vectors, as we can only assign them with compound literals. */
4925 }
4929 {
4932 }
4937 /* Compound expressions can only occur here if -pedantic or
4938 -pedantic-errors is specified. In the later case, we always want
4939 an error. In the former case, we simply want a warning. */
4942 {
4943 inside_init
4948 else
4953 }
4957 {
4960 }
4962 /* Added to enable additional -Wmissing-format-attribute warnings. */
4967 }
4969 /* Handle scalar types, including conversions. */
4974 {
4979 inside_init
4983 /* Check to see if we have already given an error message. */
4985 ;
4987 {
4990 }
4994 {
4997 }
5000 }
5002 /* Come here only for records and arrays. */
5005 {
5008 }
5012 }
5013 \f
5014 /* Handle initializers that use braces. */
5016 /* Type of object we are accumulating a constructor for.
5017 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
5020 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
5021 left to fill. */
5024 /* For an ARRAY_TYPE, this is the specified index
5025 at which to store the next element we get. */
5028 /* For an ARRAY_TYPE, this is the maximum index. */
5031 /* For a RECORD_TYPE, this is the first field not yet written out. */
5034 /* For an ARRAY_TYPE, this is the index of the first element
5035 not yet written out. */
5038 /* In a RECORD_TYPE, the byte index of the next consecutive field.
5039 This is so we can generate gaps between fields, when appropriate. */
5042 /* If we are saving up the elements rather than allocating them,
5043 this is the list of elements so far (in reverse order,
5044 most recent first). */
5047 /* 1 if constructor should be incrementally stored into a constructor chain,
5048 0 if all the elements should be kept in AVL tree. */
5051 /* 1 if so far this constructor's elements are all compile-time constants. */
5054 /* 1 if so far this constructor's elements are all valid address constants. */
5057 /* 1 if this constructor is erroneous so far. */
5060 /* Structure for managing pending initializer elements, organized as an
5061 AVL tree. */
5063 struct init_node
5064 {
5068 tree purpose;
5069 tree value;
5070 };
5072 /* Tree of pending elements at this constructor level.
5073 These are elements encountered out of order
5074 which belong at places we haven't reached yet in actually
5075 writing the output.
5076 Will never hold tree nodes across GC runs. */
5079 /* The SPELLING_DEPTH of this constructor. */
5082 /* DECL node for which an initializer is being read.
5083 0 means we are reading a constructor expression
5084 such as (struct foo) {...}. */
5087 /* Nonzero if this is an initializer for a top-level decl. */
5090 /* Nonzero if there were any member designators in this initializer. */
5093 /* Nesting depth of designator list. */
5096 /* Nonzero if there were diagnosed errors in this designator list. */
5099 \f
5100 /* This stack has a level for each implicit or explicit level of
5101 structuring in the initializer, including the outermost one. It
5102 saves the values of most of the variables above. */
5106 struct constructor_stack
5107 {
5109 tree type;
5110 tree fields;
5111 tree index;
5112 tree max_index;
5113 tree unfilled_index;
5114 tree unfilled_fields;
5115 tree bit_index;
5120 /* If value nonzero, this value should replace the entire
5121 constructor at this level. */
5131 };
5135 /* This stack represents designators from some range designator up to
5136 the last designator in the list. */
5138 struct constructor_range_stack
5139 {
5142 tree range_start;
5143 tree index;
5144 tree range_end;
5145 tree fields;
5146 };
5150 /* This stack records separate initializers that are nested.
5151 Nested initializers can't happen in ANSI C, but GNU C allows them
5152 in cases like { ... (struct foo) { ... } ... }. */
5154 struct initializer_stack
5155 {
5157 tree decl;
5167 };
5170 \f
5171 /* Prepare to parse and output the initializer for variable DECL. */
5173 void
5175 {
5197 {
5199 require_constant_elements
5201 /* For a scalar, you can always use any value to initialize,
5202 even within braces. */
5208 }
5209 else
5210 {
5214 }
5227 }
5229 void
5231 {
5234 /* Free the whole constructor stack of this initializer. */
5236 {
5240 }
5244 /* Pop back to the data of the outer initializer (if any). */
5259 }
5260 \f
5261 /* Call here when we see the initializer is surrounded by braces.
5262 This is instead of a call to push_init_level;
5263 it is matched by a call to pop_init_level.
5265 TYPE is the type to initialize, for a constructor expression.
5266 For an initializer for a decl, TYPE is zero. */
5268 void
5270 {
5315 {
5317 /* Skip any nameless bit fields at the beginning. */
5324 }
5326 {
5328 {
5329 constructor_max_index
5332 /* Detect non-empty initializations of zero-length arrays. */
5337 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5338 to initialize VLAs will cause a proper error; avoid tree
5339 checking errors as well by setting a safe value. */
5344 constructor_index
5347 }
5348 else
5349 {
5352 }
5355 }
5357 {
5358 /* Vectors are like simple fixed-size arrays. */
5359 constructor_max_index =
5363 }
5364 else
5365 {
5366 /* Handle the case of int x = {5}; */
5369 }
5370 }
5371 \f
5372 /* Push down into a subobject, for initialization.
5373 If this is for an explicit set of braces, IMPLICIT is 0.
5374 If it is because the next element belongs at a lower level,
5375 IMPLICIT is 1 (or 2 if the push is because of designator list). */
5377 void
5379 {
5383 /* If we've exhausted any levels that didn't have braces,
5384 pop them now. If implicit == 1, this will have been done in
5385 process_init_element; do not repeat it here because in the case
5386 of excess initializers for an empty aggregate this leads to an
5387 infinite cycle of popping a level and immediately recreating
5388 it. */
5390 {
5392 {
5398 && constructor_max_index
5400 constructor_index))
5402 else
5404 }
5405 }
5407 /* Unless this is an explicit brace, we need to preserve previous
5408 content if any. */
5410 {
5417 }
5451 {
5456 }
5458 /* Don't die if an entire brace-pair level is superfluous
5459 in the containing level. */
5461 ;
5464 {
5465 /* Don't die if there are extra init elts at the end. */
5468 else
5469 {
5472 constructor_depth++;
5473 }
5474 }
5476 {
5479 constructor_depth++;
5480 }
5483 {
5488 }
5491 {
5499 }
5502 {
5505 }
5509 {
5511 /* Skip any nameless bit fields at the beginning. */
5518 }
5520 {
5521 /* Vectors are like simple fixed-size arrays. */
5522 constructor_max_index =
5526 }
5528 {
5530 {
5531 constructor_max_index
5534 /* Detect non-empty initializations of zero-length arrays. */
5539 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5540 to initialize VLAs will cause a proper error; avoid tree
5541 checking errors as well by setting a safe value. */
5546 constructor_index
5549 }
5550 else
5555 {
5556 /* We need to split the char/wchar array into individual
5557 characters, so that we don't have to special case it
5558 everywhere. */
5560 }
5561 }
5562 else
5563 {
5568 }
5569 }
5571 /* At the end of an implicit or explicit brace level,
5572 finish up that level of constructor. If a single expression
5573 with redundant braces initialized that level, return the
5574 c_expr structure for that expression. Otherwise, the original_code
5575 element is set to ERROR_MARK.
5576 If we were outputting the elements as they are read, return 0 as the value
5577 from inner levels (process_init_element ignores that),
5578 but return error_mark_node as the value from the outermost level
5579 (that's what we want to put in DECL_INITIAL).
5580 Otherwise, return a CONSTRUCTOR expression as the value. */
5582 struct c_expr
5584 {
5591 {
5592 /* When we come to an explicit close brace,
5593 pop any inner levels that didn't have explicit braces. */
5598 }
5600 /* Now output all pending elements. */
5606 /* Error for initializing a flexible array member, or a zero-length
5607 array member in an inappropriate context. */
5612 {
5613 /* Silently discard empty initializations. The parser will
5614 already have pedwarned for empty brackets. */
5617 else
5618 {
5623 else
5627 /* We have already issued an error message for the existence
5628 of a flexible array member not at the end of the structure.
5629 Discard the initializer so that we do not die later. */
5632 }
5633 }
5635 /* Warn when some struct elements are implicitly initialized to zero. */
5637 && constructor_type
5640 {
5641 /* Do not warn for flexible array members or zero-length arrays. */
5647 /* Do not warn if this level of the initializer uses member
5648 designators; it is likely to be deliberate. */
5650 {
5655 }
5656 }
5658 /* Pad out the end of the structure. */
5660 /* If this closes a superfluous brace pair,
5661 just pass out the element between them. */
5664 ;
5669 {
5670 /* A nonincremental scalar initializer--just return
5671 the element, after verifying there is just one. */
5673 {
5677 }
5679 {
5682 }
5683 else
5685 }
5686 else
5687 {
5690 else
5691 {
5693 constructor_elements);
5698 }
5699 }
5726 }
5728 /* Common handling for both array range and field name designators.
5729 ARRAY argument is nonzero for array ranges. Returns zero for success. */
5731 static int
5733 {
5734 tree subtype;
5737 /* Don't die if an entire brace-pair level is superfluous
5738 in the containing level. */
5742 /* If there were errors in this designator list already, bail out
5743 silently. */
5748 {
5751 /* Designator list starts at the level of closest explicit
5752 braces. */
5757 }
5760 {
5772 }
5776 {
5779 }
5781 {
5784 }
5789 }
5791 /* If there are range designators in designator list, push a new designator
5792 to constructor_range_stack. RANGE_END is end of such stack range or
5793 NULL_TREE if there is no range designator at this level. */
5795 static void
5797 {
5811 }
5813 /* Within an array initializer, specify the next index to be initialized.
5814 FIRST is that index. If LAST is nonzero, then initialize a range
5815 of indices, running from FIRST through LAST. */
5817 void
5819 {
5827 {
5830 }
5843 else
5844 {
5848 {
5852 {
5855 }
5856 else
5857 {
5861 {
5864 }
5865 }
5866 }
5868 designator_depth++;
5872 }
5873 }
5875 /* Within a struct initializer, specify the next field to be initialized. */
5877 void
5879 {
5880 tree tail;
5889 {
5892 }
5896 {
5899 }
5903 else
5904 {
5906 designator_depth++;
5910 }
5911 }
5912 \f
5913 /* Add a new initializer to the tree of pending initializers. PURPOSE
5914 identifies the initializer, either array index or field in a structure.
5915 VALUE is the value of that index or field. */
5917 static void
5919 {
5926 {
5928 {
5934 else
5935 {
5942 }
5943 }
5944 }
5945 else
5946 {
5947 tree bitpos;
5951 {
5957 else
5958 {
5965 }
5966 }
5967 }
5980 {
5984 {
5988 {
5990 {
5991 /* L rotation. */
6004 {
6007 else
6009 }
6010 else
6012 }
6013 else
6014 {
6015 /* LR rotation. */
6037 {
6040 else
6042 }
6043 else
6045 }
6047 }
6048 else
6049 {
6050 /* p->balance == +1; growth of left side balances the node. */
6053 }
6054 }
6056 {
6058 /* Growth propagation from right side. */
6061 {
6063 {
6064 /* R rotation. */
6077 {
6080 else
6082 }
6083 else
6085 }
6087 {
6088 /* RL rotation */
6110 {
6113 else
6115 }
6116 else
6118 }
6120 }
6121 else
6122 {
6123 /* p->balance == -1; growth of right side balances the node. */
6126 }
6127 }
6131 }
6132 }
6134 /* Build AVL tree from a sorted chain. */
6136 static void
6138 {
6150 {
6152 /* Skip any nameless bit fields at the beginning. */
6158 }
6160 {
6162 constructor_unfilled_index
6165 else
6167 }
6169 }
6171 /* Build AVL tree from a string constant. */
6173 static void
6175 {
6192 {
6194 {
6197 }
6198 else
6199 {
6203 {
6206 else
6211 }
6212 }
6215 {
6218 {
6220 {
6223 }
6224 }
6226 {
6229 }
6234 }
6238 }
6241 }
6243 /* Return value of FIELD in pending initializer or zero if the field was
6244 not initialized yet. */
6246 static tree
6248 {
6252 {
6259 {
6264 else
6266 }
6267 }
6269 {
6273 && (!constructor_unfilled_fields
6280 {
6285 else
6287 }
6288 }
6290 {
6295 }
6297 }
6299 /* "Output" the next constructor element.
6300 At top level, really output it to assembler code now.
6301 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
6302 TYPE is the data type that the containing data type wants here.
6303 FIELD is the field (a FIELD_DECL) or the index that this element fills.
6304 If VALUE is a string constant, STRICT_STRING is true if it is
6305 unparenthesized or we should not warn here for it being parenthesized.
6306 For other types of VALUE, STRICT_STRING is not used.
6308 PENDING if non-nil means output pending elements that belong
6309 right after this element. (PENDING is normally 1;
6310 it is 0 while outputting pending elements, to avoid recursion.) */
6312 static void
6315 {
6319 {
6322 }
6335 {
6336 /* As an extension, allow initializing objects with static storage
6337 duration with compound literals (which are then treated just as
6338 the brace enclosed list they contain). */
6341 }
6355 {
6357 {
6360 }
6364 }
6366 /* If this field is empty (and not at the end of structure),
6367 don't do anything other than checking the initializer. */
6378 {
6381 }
6383 /* If this element doesn't come next in sequence,
6384 put it on constructor_pending_elts. */
6386 && (!constructor_incremental
6388 {
6395 }
6397 && (!constructor_incremental
6399 {
6400 /* We do this for records but not for unions. In a union,
6401 no matter which field is specified, it can be initialized
6402 right away since it starts at the beginning of the union. */
6404 {
6407 else
6408 {
6416 }
6417 }
6421 }
6424 {
6431 /* We can have just one union field set. */
6433 }
6435 /* Otherwise, output this element either to
6436 constructor_elements or to the assembler file. */
6442 /* Advance the variable that indicates sequential elements output. */
6444 constructor_unfilled_index
6446 bitsize_one_node);
6448 {
6449 constructor_unfilled_fields
6452 /* Skip any nameless bit fields. */
6456 constructor_unfilled_fields =
6458 }
6462 /* Now output any pending elements which have become next. */
6465 }
6467 /* Output any pending elements which have become next.
6468 As we output elements, constructor_unfilled_{fields,index}
6469 advances, which may cause other elements to become next;
6470 if so, they too are output.
6472 If ALL is 0, we return when there are
6473 no more pending elements to output now.
6475 If ALL is 1, we output space as necessary so that
6476 we can output all the pending elements. */
6478 static void
6480 {
6482 tree next;
6484 retry:
6486 /* Look through the whole pending tree.
6487 If we find an element that should be output now,
6488 output it. Otherwise, set NEXT to the element
6489 that comes first among those still pending. */
6493 {
6495 {
6497 constructor_unfilled_index))
6503 {
6504 /* Advance to the next smaller node. */
6507 else
6508 {
6509 /* We have reached the smallest node bigger than the
6510 current unfilled index. Fill the space first. */
6513 }
6514 }
6515 else
6516 {
6517 /* Advance to the next bigger node. */
6520 else
6521 {
6522 /* We have reached the biggest node in a subtree. Find
6523 the parent of it, which is the next bigger node. */
6529 {
6532 }
6533 }
6534 }
6535 }
6538 {
6541 /* If the current record is complete we are done. */
6547 /* We can't compare fields here because there might be empty
6548 fields in between. */
6550 {
6554 }
6556 {
6557 /* Advance to the next smaller node. */
6560 else
6561 {
6562 /* We have reached the smallest node bigger than the
6563 current unfilled field. Fill the space first. */
6566 }
6567 }
6568 else
6569 {
6570 /* Advance to the next bigger node. */
6573 else
6574 {
6575 /* We have reached the biggest node in a subtree. Find
6576 the parent of it, which is the next bigger node. */
6583 {
6586 }
6587 }
6588 }
6589 }
6590 }
6592 /* Ordinarily return, but not if we want to output all
6593 and there are elements left. */
6597 /* If it's not incremental, just skip over the gap, so that after
6598 jumping to retry we will output the next successive element. */
6605 /* ELT now points to the node in the pending tree with the next
6606 initializer to output. */
6608 }
6609 \f
6610 /* Add one non-braced element to the current constructor level.
6611 This adjusts the current position within the constructor's type.
6612 This may also start or terminate implicit levels
6613 to handle a partly-braced initializer.
6615 Once this has found the correct level for the new element,
6616 it calls output_init_element. */
6618 void
6620 {
6628 /* Handle superfluous braces around string cst as in
6629 char x[] = {"foo"}; */
6631 && constructor_type
6635 {
6640 }
6643 {
6646 }
6648 /* Ignore elements of a brace group if it is entirely superfluous
6649 and has already been diagnosed. */
6653 /* If we've exhausted any levels that didn't have braces,
6654 pop them now. */
6656 {
6664 constructor_index)))
6666 else
6668 }
6670 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
6672 {
6673 /* If value is a compound literal and we'll be just using its
6674 content, don't put it into a SAVE_EXPR. */
6676 || !require_constant_value
6679 }
6682 {
6684 {
6685 tree fieldtype;
6689 {
6693 }
6700 /* Error for non-static initialization of a flexible array member. */
6702 && !require_constant_value
6705 {
6708 }
6710 /* Accept a string constant to initialize a subarray. */
6716 /* Otherwise, if we have come to a subaggregate,
6717 and we don't have an element of its type, push into it. */
6723 {
6726 }
6729 {
6734 }
6735 else
6736 /* Do the bookkeeping for an element that was
6737 directly output as a constructor. */
6738 {
6739 /* For a record, keep track of end position of last field. */
6741 constructor_bit_index
6746 /* If the current field was the first one not yet written out,
6747 it isn't now, so update. */
6749 {
6751 /* Skip any nameless bit fields. */
6755 constructor_unfilled_fields =
6757 }
6758 }
6761 /* Skip any nameless bit fields at the beginning. */
6766 }
6768 {
6769 tree fieldtype;
6773 {
6777 }
6784 /* Warn that traditional C rejects initialization of unions.
6785 We skip the warning if the value is zero. This is done
6786 under the assumption that the zero initializer in user
6787 code appears conditioned on e.g. __STDC__ to avoid
6788 "missing initializer" warnings and relies on default
6789 initialization to zero in the traditional C case.
6790 We also skip the warning if the initializer is designated,
6791 again on the assumption that this must be conditional on
6792 __STDC__ anyway (and we've already complained about the
6793 member-designator already). */
6800 /* Accept a string constant to initialize a subarray. */
6806 /* Otherwise, if we have come to a subaggregate,
6807 and we don't have an element of its type, push into it. */
6813 {
6816 }
6819 {
6824 }
6825 else
6826 /* Do the bookkeeping for an element that was
6827 directly output as a constructor. */
6828 {
6831 }
6834 }
6836 {
6840 /* Accept a string constant to initialize a subarray. */
6846 /* Otherwise, if we have come to a subaggregate,
6847 and we don't have an element of its type, push into it. */
6853 {
6856 }
6861 {
6865 }
6867 /* Now output the actual element. */
6869 {
6874 }
6876 constructor_index
6880 /* If we are doing the bookkeeping for an element that was
6881 directly output as a constructor, we must update
6882 constructor_unfilled_index. */
6884 }
6886 {
6889 /* Do a basic check of initializer size. Note that vectors
6890 always have a fixed size derived from their type. */
6892 {
6896 }
6898 /* Now output the actual element. */
6903 constructor_index
6907 /* If we are doing the bookkeeping for an element that was
6908 directly output as a constructor, we must update
6909 constructor_unfilled_index. */
6911 }
6913 /* Handle the sole element allowed in a braced initializer
6914 for a scalar variable. */
6917 {
6921 }
6922 else
6923 {
6928 }
6930 /* Handle range initializers either at this level or anywhere higher
6931 in the designator stack. */
6933 {
6940 {
6943 }
6947 {
6950 }
6957 {
6961 {
6964 }
6972 }
6977 }
6980 }
6983 }
6984 \f
6985 /* Build a complete asm-statement, whose components are a CV_QUALIFIER
6986 (guaranteed to be 'volatile' or null) and ARGS (represented using
6987 an ASM_EXPR node). */
6988 tree
6990 {
6994 }
6996 /* Build an asm-expr, whose components are a STRING, some OUTPUTS,
6997 some INPUTS, and some CLOBBERS. The latter three may be NULL.
6998 SIMPLE indicates whether there was anything at all after the
6999 string in the asm expression -- asm("blah") and asm("blah" : )
7000 are subtly different. We use a ASM_EXPR node to represent this. */
7001 tree
7004 {
7005 tree tail;
7006 tree args;
7019 /* Remove output conversions that change the type but not the mode. */
7021 {
7024 /* ??? Really, this should not be here. Users should be using a
7025 proper lvalue, dammit. But there's a long history of using casts
7026 in the output operands. In cases like longlong.h, this becomes a
7027 primitive form of typechecking -- if the cast can be removed, then
7028 the output operand had a type of the proper width; otherwise we'll
7029 get an error. Gross, but ... */
7048 {
7049 /* If the operand is going to end up in memory,
7050 mark it addressable. */
7053 }
7054 else
7058 }
7061 {
7062 tree input;
7069 {
7070 /* If the operand is going to end up in memory,
7071 mark it addressable. */
7073 {
7074 /* Strip the nops as we allow this case. FIXME, this really
7075 should be rejected or made deprecated. */
7079 }
7080 }
7081 else
7085 }
7089 /* asm statements without outputs, including simple ones, are treated
7090 as volatile. */
7095 }
7096 \f
7097 /* Generate a goto statement to LABEL. */
7099 tree
7101 {
7107 {
7110 }
7113 {
7116 }
7119 {
7120 /* No jump from outside this statement expression context, so
7121 record that there is a jump from within this context. */
7127 }
7130 {
7131 /* No jump from outside this context context of identifiers with
7132 variably modified type, so record that there is a jump from
7133 within this context. */
7139 }
7143 }
7145 /* Generate a computed goto statement to EXPR. */
7147 tree
7149 {
7153 }
7155 /* Generate a C `return' statement. RETVAL is the expression for what
7156 to return, or a null pointer for `return;' with no value. */
7158 tree
7160 {
7168 {
7172 {
7174 "%<return%> with no value, in "
7177 }
7178 }
7180 {
7185 else
7188 }
7189 else
7190 {
7194 tree inner;
7202 /* Strip any conversions, additions, and subtractions, and see if
7203 we are returning the address of a local variable. Warn if so. */
7205 {
7207 {
7214 /* If the second operand of the MINUS_EXPR has a pointer
7215 type (or is converted from it), this may be valid, so
7216 don't give a warning. */
7217 {
7230 }
7248 }
7251 }
7257 }
7262 }
7263 \f
7265 /* The SWITCH_EXPR being built. */
7266 tree switch_expr;
7268 /* The original type of the testing expression, i.e. before the
7269 default conversion is applied. */
7270 tree orig_type;
7272 /* A splay-tree mapping the low element of a case range to the high
7273 element, or NULL_TREE if there is no high element. Used to
7274 determine whether or not a new case label duplicates an old case
7275 label. We need a tree, rather than simply a hash table, because
7276 of the GNU case range extension. */
7277 splay_tree cases;
7279 /* Number of nested statement expressions within this switch
7280 statement; if nonzero, case and default labels may not
7281 appear. */
7284 /* Scope of outermost declarations of identifiers with variably
7285 modified type within this switch statement; if nonzero, case and
7286 default labels may not appear. */
7289 /* The next node on the stack. */
7291 };
7293 /* A stack of the currently active switch statements. The innermost
7294 switch statement is on the top of the stack. There is no need to
7295 mark the stack for garbage collection because it is only active
7296 during the processing of the body of a function, and we never
7297 collect at that point. */
7301 /* Start a C switch statement, testing expression EXP. Return the new
7302 SWITCH_EXPR. */
7304 tree
7306 {
7311 {
7315 {
7317 {
7320 }
7322 }
7323 else
7324 {
7337 }
7338 }
7340 /* Add this new SWITCH_EXPR to the stack. */
7351 }
7353 /* Process a case label. */
7355 tree
7357 {
7362 {
7369 }
7371 {
7375 else
7378 }
7380 {
7384 else
7387 }
7390 else
7394 }
7396 /* Finish the switch statement. */
7398 void
7400 {
7402 location_t switch_location;
7406 /* We must not be within a statement expression nested in the switch
7407 at this point; we might, however, be within the scope of an
7408 identifier with variably modified type nested in the switch. */
7411 /* Emit warnings as needed. */
7414 else
7420 /* Pop the stack. */
7424 }
7425 \f
7426 /* Emit an if statement. IF_LOCUS is the location of the 'if'. COND,
7427 THEN_BLOCK and ELSE_BLOCK are expressions to be used; ELSE_BLOCK
7428 may be null. NESTED_IF is true if THEN_BLOCK contains another IF
7429 statement, and was not surrounded with parenthesis. */
7431 void
7434 {
7435 tree stmt;
7437 /* Diagnose an ambiguous else if if-then-else is nested inside if-then. */
7439 {
7442 /* We know from the grammar productions that there is an IF nested
7443 within THEN_BLOCK. Due to labels and c99 conditional declarations,
7444 it might not be exactly THEN_BLOCK, but should be the last
7445 non-container statement within. */
7448 {
7463 }
7464 found:
7470 }
7475 }
7477 /* Emit a general-purpose loop construct. START_LOCUS is the location of
7478 the beginning of the loop. COND is the loop condition. COND_IS_FIRST
7479 is false for DO loops. INCR is the FOR increment expression. BODY is
7480 the statement controlled by the loop. BLAB is the break label. CLAB is
7481 the continue label. Everything is allowed to be NULL. */
7483 void
7486 {
7489 /* If the condition is zero don't generate a loop construct. */
7491 {
7493 {
7497 }
7498 }
7499 else
7500 {
7503 /* If we have an exit condition, then we build an IF with gotos either
7504 out of the loop, or to the top of it. If there's no exit condition,
7505 then we just build a jump back to the top. */
7509 {
7510 /* Canonicalize the loop condition to the end. This means
7511 generating a branch to the loop condition. Reuse the
7512 continue label, if possible. */
7514 {
7516 {
7519 }
7520 else
7524 }
7530 else
7532 }
7535 }
7549 }
7551 tree
7553 {
7557 /* In switch statements break is sometimes stylistically used after
7558 a return statement. This can lead to spurious warnings about
7559 control reaching the end of a non-void function when it is
7560 inlined. Note that we are calling block_may_fallthru with
7561 language specific tree nodes; this works because
7562 block_may_fallthru returns true when given something it does not
7563 understand. */
7567 {
7570 }
7572 ;
7574 {
7578 else
7589 }
7598 }
7600 /* A helper routine for c_process_expr_stmt and c_finish_stmt_expr. */
7602 static void
7604 {
7606 ;
7608 {
7612 }
7613 else
7615 }
7617 /* Process an expression as if it were a complete statement. Emit
7618 diagnostics, but do not call ADD_STMT. */
7620 tree
7622 {
7634 /* If we're not processing a statement expression, warn about unused values.
7635 Warnings for statement expressions will be emitted later, once we figure
7636 out which is the result. */
7641 /* If the expression is not of a type to which we cannot assign a line
7642 number, wrap the thing in a no-op NOP_EXPR. */
7650 }
7652 /* Emit an expression as a statement. */
7654 tree
7656 {
7659 else
7661 }
7663 /* Do the opposite and emit a statement as an expression. To begin,
7664 create a new binding level and return it. */
7666 tree
7668 {
7669 tree ret;
7673 /* We must force a BLOCK for this level so that, if it is not expanded
7674 later, there is a way to turn off the entire subtree of blocks that
7675 are contained in it. */
7679 {
7682 }
7686 {
7688 }
7695 /* Mark the current statement list as belonging to a statement list. */
7699 }
7701 tree
7703 {
7710 {
7713 }
7714 /* It is no longer possible to jump to labels defined within this
7715 statement expression. */
7719 {
7721 }
7722 /* It is again possible to define labels with a goto just outside
7723 this statement expression. */
7727 {
7730 }
7733 else
7738 /* Locate the last statement in BODY. See c_end_compound_stmt
7739 about always returning a BIND_EXPR. */
7743 continue_searching:
7745 {
7746 tree_stmt_iterator i;
7748 /* This can happen with degenerate cases like ({ }). No value. */
7752 /* If we're supposed to generate side effects warnings, process
7753 all of the statements except the last. */
7755 {
7758 }
7759 else
7763 }
7765 /* If the end of the list is exception related, then the list was split
7766 by a call to push_cleanup. Continue searching. */
7769 {
7773 }
7775 /* In the case that the BIND_EXPR is not necessary, return the
7776 expression out from inside it. */
7780 {
7781 /* Do not warn if the return value of a statement expression is
7782 unused. */
7786 }
7788 /* Extract the type of said expression. */
7791 /* If we're not returning a value at all, then the BIND_EXPR that
7792 we already have is a fine expression to return. */
7796 /* Now that we've located the expression containing the value, it seems
7797 silly to make voidify_wrapper_expr repeat the process. Create a
7798 temporary of the appropriate type and stick it in a TARGET_EXPR. */
7801 /* Unwrap a no-op NOP_EXPR as added by c_finish_expr_stmt. This avoids
7802 tree_expr_nonnegative_p giving up immediately. */
7812 }
7814 /* Begin the scope of an identifier of variably modified type, scope
7815 number SCOPE. Jumping from outside this scope to inside it is not
7816 permitted. */
7818 void
7820 {
7826 /* At file_scope, we don't have to do any processing. */
7835 {
7837 }
7844 }
7846 /* End a scope which may contain identifiers of variably modified
7847 type, scope number SCOPE. */
7849 void
7851 {
7856 /* We may have a number of nested scopes of identifiers with
7857 variably modified type, all at this depth. Pop each in turn. */
7859 {
7862 /* It is no longer possible to jump to labels defined within this
7863 scope. */
7867 {
7869 }
7870 /* It is again possible to define labels with a goto just outside
7871 this scope. */
7875 {
7878 }
7881 else
7885 }
7886 }
7887 \f
7888 /* Begin and end compound statements. This is as simple as pushing
7889 and popping new statement lists from the tree. */
7891 tree
7893 {
7898 }
7900 tree
7902 {
7906 {
7910 }
7915 /* If this compound statement is nested immediately inside a statement
7916 expression, then force a BIND_EXPR to be created. Otherwise we'll
7917 do the wrong thing for ({ { 1; } }) or ({ 1; { } }). In particular,
7918 STATEMENT_LISTs merge, and thus we can lose track of what statement
7919 was really last. */
7923 {
7926 }
7929 }
7931 /* Queue a cleanup. CLEANUP is an expression/statement to be executed
7932 when the current scope is exited. EH_ONLY is true when this is not
7933 meant to apply to normal control flow transfer. */
7935 void
7937 {
7949 }
7950 \f
7951 /* Build a binary-operation expression without default conversions.
7952 CODE is the kind of expression to build.
7953 LOCATION is the operator's location.
7954 This function differs from `build' in several ways:
7955 the data type of the result is computed and recorded in it,
7956 warnings are generated if arg data types are invalid,
7957 special handling for addition and subtraction of pointers is known,
7958 and some optimization is done (operations on narrow ints
7959 are done in the narrower type when that gives the same result).
7960 Constant folding is also done before the result is returned.
7962 Note that the operands will never have enumeral types, or function
7963 or array types, because either they will have the default conversions
7964 performed or they have both just been converted to some other type in which
7965 the arithmetic is to be done. */
7967 tree
7970 {
7977 /* Expression code to give to the expression when it is built.
7978 Normally this is CODE, which is what the caller asked for,
7979 but in some special cases we change it. */
7982 /* Data type in which the computation is to be performed.
7983 In the simplest cases this is the common type of the arguments. */
7986 /* Nonzero means operands have already been type-converted
7987 in whatever way is necessary.
7988 Zero means they need to be converted to RESULT_TYPE. */
7991 /* Nonzero means create the expression with this type, rather than
7992 RESULT_TYPE. */
7995 /* Nonzero means after finally constructing the expression
7996 convert it to this type. */
7999 /* Nonzero if this is an operation like MIN or MAX which can
8000 safely be computed in short if both args are promoted shorts.
8001 Also implies COMMON.
8002 -1 indicates a bitwise operation; this makes a difference
8003 in the exact conditions for when it is safe to do the operation
8004 in a narrower mode. */
8007 /* Nonzero if this is a comparison operation;
8008 if both args are promoted shorts, compare the original shorts.
8009 Also implies COMMON. */
8012 /* Nonzero if this is a right-shift operation, which can be computed on the
8013 original short and then promoted if the operand is a promoted short. */
8016 /* Nonzero means set RESULT_TYPE to the common type of the args. */
8019 /* True means types are compatible as far as ObjC is concerned. */
8026 {
8029 }
8030 else
8031 {
8034 }
8039 /* The expression codes of the data types of the arguments tell us
8040 whether the arguments are integers, floating, pointers, etc. */
8044 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
8048 /* If an error was already reported for one of the arguments,
8049 avoid reporting another error. */
8056 {
8059 }
8064 {
8066 /* Handle the pointer + int case. */
8068 {
8071 }
8073 {
8076 }
8077 else
8082 /* Subtraction of two similar pointers.
8083 We must subtract them as integers, then divide by object size. */
8086 {
8089 }
8090 /* Handle pointer minus int. Just like pointer plus int. */
8092 {
8095 }
8096 else
8117 {
8128 else
8129 /* Although it would be tempting to shorten always here, that
8130 loses on some targets, since the modulo instruction is
8131 undefined if the quotient can't be represented in the
8132 computation mode. We shorten only if unsigned or if
8133 dividing by something we know != -1. */
8138 }
8146 /* Allow vector types which are not floating point types. */
8159 {
8160 /* Although it would be tempting to shorten always here, that loses
8161 on some targets, since the modulo instruction is undefined if the
8162 quotient can't be represented in the computation mode. We shorten
8163 only if unsigned or if dividing by something we know != -1. */
8168 }
8182 {
8183 /* Result of these operations is always an int,
8184 but that does not mean the operands should be
8185 converted to ints! */
8190 }
8193 /* Shift operations: result has same type as first operand;
8194 always convert second operand to int.
8195 Also set SHORT_SHIFT if shifting rightward. */
8200 {
8202 {
8205 else
8206 {
8212 }
8213 }
8215 /* Use the type of the value to be shifted. */
8217 /* Convert the shift-count to an integer, regardless of size
8218 of value being shifted. */
8221 /* Avoid converting op1 to result_type later. */
8223 }
8229 {
8231 {
8237 }
8239 /* Use the type of the value to be shifted. */
8241 /* Convert the shift-count to an integer, regardless of size
8242 of value being shifted. */
8245 /* Avoid converting op1 to result_type later. */
8247 }
8254 OPT_Wfloat_equal,
8256 /* Result of comparison is always int,
8257 but don't convert the args to int! */
8265 {
8268 /* Anything compares with void *. void * compares with anything.
8269 Otherwise, the targets must be compatible
8270 and both must be object or both incomplete. */
8274 {
8275 /* op0 != orig_op0 detects the case of something
8276 whose value is 0 but which isn't a valid null ptr const. */
8281 }
8283 {
8288 }
8289 else
8290 /* Avoid warning about the volatile ObjC EH puts on decls. */
8297 }
8299 {
8306 }
8308 {
8315 }
8317 {
8320 }
8322 {
8325 }
8339 {
8341 {
8350 }
8351 else
8352 {
8356 }
8357 }
8359 {
8367 }
8369 {
8373 }
8375 {
8378 }
8380 {
8383 }
8388 }
8397 {
8400 }
8404 &&
8407 {
8411 {
8415 }
8417 /* For certain operations (which identify themselves by shorten != 0)
8418 if both args were extended from the same smaller type,
8419 do the arithmetic in that type and then extend.
8421 shorten !=0 and !=1 indicates a bitwise operation.
8422 For them, this optimization is safe only if
8423 both args are zero-extended or both are sign-extended.
8424 Otherwise, we might change the result.
8425 Eg, (short)-1 | (unsigned short)-1 is (int)-1
8426 but calculated in (unsigned short) it would be (unsigned short)-1. */
8429 {
8433 }
8435 /* Shifts can be shortened if shifting right. */
8438 {
8448 /* We can shorten only if the shift count is less than the
8449 number of bits in the smaller type size. */
8451 /* We cannot drop an unsigned shift after sign-extension. */
8453 {
8454 /* Do an unsigned shift if the operand was zero-extended. */
8455 result_type
8458 /* Convert value-to-be-shifted to that type. */
8462 }
8463 }
8465 /* Comparison operations are shortened too but differently.
8466 They identify themselves by setting short_compare = 1. */
8469 {
8470 /* Don't write &op0, etc., because that would prevent op0
8471 from being kept in a register.
8472 Instead, make copies of the our local variables and
8473 pass the copies by reference, then copy them back afterward. */
8476 tree val
8480 {
8483 }
8490 {
8493 }
8494 }
8495 }
8497 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
8498 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
8499 Then the expression will be built.
8500 It will be given type FINAL_TYPE if that is nonzero;
8501 otherwise, it will be given type RESULT_TYPE. */
8504 {
8507 }
8510 {
8516 /* This can happen if one operand has a vector type, and the other
8517 has a different type. */
8520 }
8525 /* Treat expressions in initializers specially as they can't trap. */
8527 build_type,
8534 return_build_binary_op:
8538 }
8541 /* Convert EXPR to be a truth-value, validating its type for this
8542 purpose. LOCATION is the source location for the expression. */
8544 tree
8546 {
8548 {
8550 error_at (location, "used array that cannot be converted to pointer where scalar is required");
8566 }
8568 /* ??? Should we also give an error for void and vectors rather than
8569 leaving those to give errors later? */
8571 }
8572 \f
8574 /* Convert EXPR to a contained DECL, updating *TC, *TI and *SE as
8575 required. */
8577 tree
8579 {
8581 {
8583 /* Executing a compound literal inside a function reinitializes
8584 it. */
8588 }
8589 else
8591 }
8592 \f
8593 /* Like c_begin_compound_stmt, except force the retention of the BLOCK. */
8595 tree
8597 {
8598 tree block;
8604 }
8606 /* Generate OMP_PARALLEL, with CLAUSES and BLOCK as its compound statement. */
8608 tree
8610 {
8611 tree stmt;
8621 }
8623 /* Like c_begin_compound_stmt, except force the retention of the BLOCK. */
8625 tree
8627 {
8628 tree block;
8634 }
8636 /* Generate OMP_TASK, with CLAUSES and BLOCK as its compound statement. */
8638 tree
8640 {
8641 tree stmt;
8651 }
8653 /* For all elements of CLAUSES, validate them vs OpenMP constraints.
8654 Remove any elements from the list that are invalid. */
8656 tree
8658 {
8669 {
8675 {
8693 {
8696 }
8698 {
8703 {
8725 }
8727 {
8731 }
8732 }
8743 {
8746 }
8749 check_dup_generic:
8752 {
8755 }
8759 {
8762 }
8763 else
8773 {
8776 }
8779 {
8782 }
8783 else
8793 {
8796 }
8799 {
8802 }
8803 else
8820 }
8823 {
8827 {
8831 }
8834 {
8840 {
8851 }
8853 {
8857 }
8858 }
8859 }
8863 else
8865 }
8869 }
8871 /* Make a variant type in the proper way for C/C++, propagating qualifiers
8872 down to the element type of an array. */
8874 tree
8876 {
8881 {
8882 tree t;
8884 type_quals);
8886 /* See if we already have an identically qualified type. */
8888 {
8895 }
8897 {
8908 {
8909 tree unqualified_canon
8915 }
8916 else
8918 }
8920 }
8922 /* A restrict-qualified pointer type must be a pointer to object or
8923 incomplete type. Note that the use of POINTER_TYPE_P also allows
8924 REFERENCE_TYPEs, which is appropriate for C++. */
8928 {
8931 }
8934 }