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c-typeck.c
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c-typeck.c
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/* Build expressions with type checking for C compiler.
Copyright (C) 1987, 88, 91-7, 1998 Free Software Foundation, Inc.
This file is part of GNU CC.
GNU CC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING. If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
/* This file is part of the C front end.
It contains routines to build C expressions given their operands,
including computing the types of the result, C-specific error checks,
and some optimization.
There are also routines to build RETURN_STMT nodes and CASE_STMT nodes,
and to process initializations in declarations (since they work
like a strange sort of assignment). */
#include "config.h"
#include <stdio.h>
#include "tree.h"
#include "c-tree.h"
#include "flags.h"
#include "output.h"
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#else
#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif
#endif
/* Nonzero if we've already printed a "missing braces around initializer"
message within this initializer. */
static int missing_braces_mentioned;
#ifdef NEED_DECLARATION_INDEX
extern char *index ();
#endif
#ifdef NEED_DECLARATION_RINDEX
extern char *rindex ();
#endif
static tree qualify_type PROTO((tree, tree));
static int comp_target_types PROTO((tree, tree));
static int function_types_compatible_p PROTO((tree, tree));
static int type_lists_compatible_p PROTO((tree, tree));
static int self_promoting_type_p PROTO((tree));
static tree decl_constant_value PROTO((tree));
static tree lookup_field PROTO((tree, tree, tree *));
static tree convert_arguments PROTO((tree, tree, tree, tree));
static tree pointer_int_sum PROTO((enum tree_code, tree, tree));
static tree pointer_diff PROTO((tree, tree));
static tree unary_complex_lvalue PROTO((enum tree_code, tree));
static void pedantic_lvalue_warning PROTO((enum tree_code));
static tree internal_build_compound_expr PROTO((tree, int));
static tree convert_for_assignment PROTO((tree, tree, char *, tree,
tree, int));
static void warn_for_assignment PROTO((char *, char *, tree, int));
static tree valid_compound_expr_initializer PROTO((tree, tree));
static void push_string PROTO((char *));
static void push_member_name PROTO((tree));
static void push_array_bounds PROTO((int));
static int spelling_length PROTO((void));
static char *print_spelling PROTO((char *));
static char *get_spelling PROTO((char *));
static void warning_init PROTO((char *, char *,
char *));
static tree digest_init PROTO((tree, tree, int, int));
static void check_init_type_bitfields PROTO((tree));
static void output_init_element PROTO((tree, tree, tree, int));
static void output_pending_init_elements PROTO((int));
/* Do `exp = require_complete_type (exp);' to make sure exp
does not have an incomplete type. (That includes void types.) */
tree
require_complete_type (value)
tree value;
{
tree type = TREE_TYPE (value);
/* First, detect a valid value with a complete type. */
if (TYPE_SIZE (type) != 0
&& type != void_type_node)
return value;
incomplete_type_error (value, type);
return error_mark_node;
}
/* Print an error message for invalid use of an incomplete type.
VALUE is the expression that was used (or 0 if that isn't known)
and TYPE is the type that was invalid. */
void
incomplete_type_error (value, type)
tree value;
tree type;
{
char *errmsg;
/* Avoid duplicate error message. */
if (TREE_CODE (type) == ERROR_MARK)
return;
if (value != 0 && (TREE_CODE (value) == VAR_DECL
|| TREE_CODE (value) == PARM_DECL))
error ("`%s' has an incomplete type",
IDENTIFIER_POINTER (DECL_NAME (value)));
else
{
retry:
/* We must print an error message. Be clever about what it says. */
switch (TREE_CODE (type))
{
case RECORD_TYPE:
errmsg = "invalid use of undefined type `struct %s'";
break;
case UNION_TYPE:
errmsg = "invalid use of undefined type `union %s'";
break;
case ENUMERAL_TYPE:
errmsg = "invalid use of undefined type `enum %s'";
break;
case VOID_TYPE:
error ("invalid use of void expression");
return;
case ARRAY_TYPE:
if (TYPE_DOMAIN (type))
{
type = TREE_TYPE (type);
goto retry;
}
error ("invalid use of array with unspecified bounds");
return;
default:
abort ();
}
if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
error (errmsg, IDENTIFIER_POINTER (TYPE_NAME (type)));
else
/* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */
error ("invalid use of incomplete typedef `%s'",
IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (type))));
}
}
/* Return a variant of TYPE which has all the type qualifiers of LIKE
as well as those of TYPE. */
static tree
qualify_type (type, like)
tree type, like;
{
int constflag = TYPE_READONLY (type) || TYPE_READONLY (like);
int volflag = TYPE_VOLATILE (type) || TYPE_VOLATILE (like);
return c_build_type_variant (type, constflag, volflag);
}
/* Return the common type of two types.
We assume that comptypes has already been done and returned 1;
if that isn't so, this may crash. In particular, we assume that qualifiers
match.
This is the type for the result of most arithmetic operations
if the operands have the given two types. */
tree
common_type (t1, t2)
tree t1, t2;
{
register enum tree_code code1;
register enum tree_code code2;
tree attributes;
/* Save time if the two types are the same. */
if (t1 == t2) return t1;
/* If one type is nonsense, use the other. */
if (t1 == error_mark_node)
return t2;
if (t2 == error_mark_node)
return t1;
/* Merge the attributes */
attributes = merge_attributes (TYPE_ATTRIBUTES (t1), TYPE_ATTRIBUTES (t2));
/* Treat an enum type as the unsigned integer type of the same width. */
if (TREE_CODE (t1) == ENUMERAL_TYPE)
t1 = type_for_size (TYPE_PRECISION (t1), 1);
if (TREE_CODE (t2) == ENUMERAL_TYPE)
t2 = type_for_size (TYPE_PRECISION (t2), 1);
code1 = TREE_CODE (t1);
code2 = TREE_CODE (t2);
/* If one type is complex, form the common type of the non-complex
components, then make that complex. Use T1 or T2 if it is the
required type. */
if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
{
tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
tree subtype = common_type (subtype1, subtype2);
if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
return build_type_attribute_variant (t1, attributes);
else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
return build_type_attribute_variant (t2, attributes);
else
return build_type_attribute_variant (build_complex_type (subtype),
attributes);
}
switch (code1)
{
case INTEGER_TYPE:
case REAL_TYPE:
/* If only one is real, use it as the result. */
if (code1 == REAL_TYPE && code2 != REAL_TYPE)
return build_type_attribute_variant (t1, attributes);
if (code2 == REAL_TYPE && code1 != REAL_TYPE)
return build_type_attribute_variant (t2, attributes);
/* Both real or both integers; use the one with greater precision. */
if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
return build_type_attribute_variant (t1, attributes);
else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
return build_type_attribute_variant (t2, attributes);
/* Same precision. Prefer longs to ints even when same size. */
if (TYPE_MAIN_VARIANT (t1) == long_unsigned_type_node
|| TYPE_MAIN_VARIANT (t2) == long_unsigned_type_node)
return build_type_attribute_variant (long_unsigned_type_node,
attributes);
if (TYPE_MAIN_VARIANT (t1) == long_integer_type_node
|| TYPE_MAIN_VARIANT (t2) == long_integer_type_node)
{
/* But preserve unsignedness from the other type,
since long cannot hold all the values of an unsigned int. */
if (TREE_UNSIGNED (t1) || TREE_UNSIGNED (t2))
t1 = long_unsigned_type_node;
else
t1 = long_integer_type_node;
return build_type_attribute_variant (t1, attributes);
}
/* Likewise, prefer long double to double even if same size. */
if (TYPE_MAIN_VARIANT (t1) == long_double_type_node
|| TYPE_MAIN_VARIANT (t2) == long_double_type_node)
return build_type_attribute_variant (long_double_type_node,
attributes);
/* Otherwise prefer the unsigned one. */
if (TREE_UNSIGNED (t1))
return build_type_attribute_variant (t1, attributes);
else
return build_type_attribute_variant (t2, attributes);
case POINTER_TYPE:
/* For two pointers, do this recursively on the target type,
and combine the qualifiers of the two types' targets. */
/* This code was turned off; I don't know why.
But ANSI C specifies doing this with the qualifiers.
So I turned it on again. */
{
tree target = common_type (TYPE_MAIN_VARIANT (TREE_TYPE (t1)),
TYPE_MAIN_VARIANT (TREE_TYPE (t2)));
int constp
= TYPE_READONLY (TREE_TYPE (t1)) || TYPE_READONLY (TREE_TYPE (t2));
int volatilep
= TYPE_VOLATILE (TREE_TYPE (t1)) || TYPE_VOLATILE (TREE_TYPE (t2));
t1 = build_pointer_type (c_build_type_variant (target, constp,
volatilep));
return build_type_attribute_variant (t1, attributes);
}
#if 0
t1 = build_pointer_type (common_type (TREE_TYPE (t1), TREE_TYPE (t2)));
return build_type_attribute_variant (t1, attributes);
#endif
case ARRAY_TYPE:
{
tree elt = common_type (TREE_TYPE (t1), TREE_TYPE (t2));
/* Save space: see if the result is identical to one of the args. */
if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
return build_type_attribute_variant (t1, attributes);
if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
return build_type_attribute_variant (t2, attributes);
/* Merge the element types, and have a size if either arg has one. */
t1 = build_array_type (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
return build_type_attribute_variant (t1, attributes);
}
case FUNCTION_TYPE:
/* Function types: prefer the one that specified arg types.
If both do, merge the arg types. Also merge the return types. */
{
tree valtype = common_type (TREE_TYPE (t1), TREE_TYPE (t2));
tree p1 = TYPE_ARG_TYPES (t1);
tree p2 = TYPE_ARG_TYPES (t2);
int len;
tree newargs, n;
int i;
/* Save space: see if the result is identical to one of the args. */
if (valtype == TREE_TYPE (t1) && ! TYPE_ARG_TYPES (t2))
return build_type_attribute_variant (t1, attributes);
if (valtype == TREE_TYPE (t2) && ! TYPE_ARG_TYPES (t1))
return build_type_attribute_variant (t2, attributes);
/* Simple way if one arg fails to specify argument types. */
if (TYPE_ARG_TYPES (t1) == 0)
{
t1 = build_function_type (valtype, TYPE_ARG_TYPES (t2));
return build_type_attribute_variant (t1, attributes);
}
if (TYPE_ARG_TYPES (t2) == 0)
{
t1 = build_function_type (valtype, TYPE_ARG_TYPES (t1));
return build_type_attribute_variant (t1, attributes);
}
/* If both args specify argument types, we must merge the two
lists, argument by argument. */
len = list_length (p1);
newargs = 0;
for (i = 0; i < len; i++)
newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
n = newargs;
for (; p1;
p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n))
{
/* A null type means arg type is not specified.
Take whatever the other function type has. */
if (TREE_VALUE (p1) == 0)
{
TREE_VALUE (n) = TREE_VALUE (p2);
goto parm_done;
}
if (TREE_VALUE (p2) == 0)
{
TREE_VALUE (n) = TREE_VALUE (p1);
goto parm_done;
}
/* Given wait (union {union wait *u; int *i} *)
and wait (union wait *),
prefer union wait * as type of parm. */
if (TREE_CODE (TREE_VALUE (p1)) == UNION_TYPE
&& TREE_VALUE (p1) != TREE_VALUE (p2))
{
tree memb;
for (memb = TYPE_FIELDS (TREE_VALUE (p1));
memb; memb = TREE_CHAIN (memb))
if (comptypes (TREE_TYPE (memb), TREE_VALUE (p2)))
{
TREE_VALUE (n) = TREE_VALUE (p2);
if (pedantic)
pedwarn ("function types not truly compatible in ANSI C");
goto parm_done;
}
}
if (TREE_CODE (TREE_VALUE (p2)) == UNION_TYPE
&& TREE_VALUE (p2) != TREE_VALUE (p1))
{
tree memb;
for (memb = TYPE_FIELDS (TREE_VALUE (p2));
memb; memb = TREE_CHAIN (memb))
if (comptypes (TREE_TYPE (memb), TREE_VALUE (p1)))
{
TREE_VALUE (n) = TREE_VALUE (p1);
if (pedantic)
pedwarn ("function types not truly compatible in ANSI C");
goto parm_done;
}
}
TREE_VALUE (n) = common_type (TREE_VALUE (p1), TREE_VALUE (p2));
parm_done: ;
}
t1 = build_function_type (valtype, newargs);
/* ... falls through ... */
}
default:
return build_type_attribute_variant (t1, attributes);
}
}
/* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
or various other operations. Return 2 if they are compatible
but a warning may be needed if you use them together. */
int
comptypes (type1, type2)
tree type1, type2;
{
register tree t1 = type1;
register tree t2 = type2;
int attrval, val;
/* Suppress errors caused by previously reported errors. */
if (t1 == t2 || TREE_CODE (t1) == ERROR_MARK || TREE_CODE (t2) == ERROR_MARK)
return 1;
/* Treat an enum type as the integer type of the same width and
signedness. */
if (TREE_CODE (t1) == ENUMERAL_TYPE)
t1 = type_for_size (TYPE_PRECISION (t1), TREE_UNSIGNED (t1));
if (TREE_CODE (t2) == ENUMERAL_TYPE)
t2 = type_for_size (TYPE_PRECISION (t2), TREE_UNSIGNED (t2));
if (t1 == t2)
return 1;
/* Different classes of types can't be compatible. */
if (TREE_CODE (t1) != TREE_CODE (t2)) return 0;
/* Qualifiers must match. */
if (TYPE_READONLY (t1) != TYPE_READONLY (t2))
return 0;
if (TYPE_VOLATILE (t1) != TYPE_VOLATILE (t2))
return 0;
/* Allow for two different type nodes which have essentially the same
definition. Note that we already checked for equality of the type
type qualifiers (just above). */
if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
return 1;
#ifndef COMP_TYPE_ATTRIBUTES
#define COMP_TYPE_ATTRIBUTES(t1,t2) 1
#endif
/* 1 if no need for warning yet, 2 if warning cause has been seen. */
if (! (attrval = COMP_TYPE_ATTRIBUTES (t1, t2)))
return 0;
/* 1 if no need for warning yet, 2 if warning cause has been seen. */
val = 0;
switch (TREE_CODE (t1))
{
case POINTER_TYPE:
val = (TREE_TYPE (t1) == TREE_TYPE (t2)
? 1 : comptypes (TREE_TYPE (t1), TREE_TYPE (t2)));
break;
case FUNCTION_TYPE:
val = function_types_compatible_p (t1, t2);
break;
case ARRAY_TYPE:
{
tree d1 = TYPE_DOMAIN (t1);
tree d2 = TYPE_DOMAIN (t2);
val = 1;
/* Target types must match incl. qualifiers. */
if (TREE_TYPE (t1) != TREE_TYPE (t2)
&& 0 == (val = comptypes (TREE_TYPE (t1), TREE_TYPE (t2))))
return 0;
/* Sizes must match unless one is missing or variable. */
if (d1 == 0 || d2 == 0 || d1 == d2
|| TREE_CODE (TYPE_MIN_VALUE (d1)) != INTEGER_CST
|| TREE_CODE (TYPE_MIN_VALUE (d2)) != INTEGER_CST
|| TREE_CODE (TYPE_MAX_VALUE (d1)) != INTEGER_CST
|| TREE_CODE (TYPE_MAX_VALUE (d2)) != INTEGER_CST)
break;
if (! ((TREE_INT_CST_LOW (TYPE_MIN_VALUE (d1))
== TREE_INT_CST_LOW (TYPE_MIN_VALUE (d2)))
&& (TREE_INT_CST_HIGH (TYPE_MIN_VALUE (d1))
== TREE_INT_CST_HIGH (TYPE_MIN_VALUE (d2)))
&& (TREE_INT_CST_LOW (TYPE_MAX_VALUE (d1))
== TREE_INT_CST_LOW (TYPE_MAX_VALUE (d2)))
&& (TREE_INT_CST_HIGH (TYPE_MAX_VALUE (d1))
== TREE_INT_CST_HIGH (TYPE_MAX_VALUE (d2)))))
val = 0;
break;
}
case RECORD_TYPE:
if (maybe_objc_comptypes (t1, t2, 0) == 1)
val = 1;
break;
default:
break;
}
return attrval == 2 && val == 1 ? 2 : val;
}
/* Return 1 if TTL and TTR are pointers to types that are equivalent,
ignoring their qualifiers. */
static int
comp_target_types (ttl, ttr)
tree ttl, ttr;
{
int val;
/* Give maybe_objc_comptypes a crack at letting these types through. */
if (val = maybe_objc_comptypes (ttl, ttr, 1) >= 0)
return val;
val = comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (ttl)),
TYPE_MAIN_VARIANT (TREE_TYPE (ttr)));
if (val == 2 && pedantic)
pedwarn ("types are not quite compatible");
return val;
}
/* Subroutines of `comptypes'. */
/* Return 1 if two function types F1 and F2 are compatible.
If either type specifies no argument types,
the other must specify a fixed number of self-promoting arg types.
Otherwise, if one type specifies only the number of arguments,
the other must specify that number of self-promoting arg types.
Otherwise, the argument types must match. */
static int
function_types_compatible_p (f1, f2)
tree f1, f2;
{
tree args1, args2;
/* 1 if no need for warning yet, 2 if warning cause has been seen. */
int val = 1;
int val1;
if (!(TREE_TYPE (f1) == TREE_TYPE (f2)
|| (val = comptypes (TREE_TYPE (f1), TREE_TYPE (f2)))))
return 0;
args1 = TYPE_ARG_TYPES (f1);
args2 = TYPE_ARG_TYPES (f2);
/* An unspecified parmlist matches any specified parmlist
whose argument types don't need default promotions. */
if (args1 == 0)
{
if (!self_promoting_args_p (args2))
return 0;
/* If one of these types comes from a non-prototype fn definition,
compare that with the other type's arglist.
If they don't match, ask for a warning (but no error). */
if (TYPE_ACTUAL_ARG_TYPES (f1)
&& 1 != type_lists_compatible_p (args2, TYPE_ACTUAL_ARG_TYPES (f1)))
val = 2;
return val;
}
if (args2 == 0)
{
if (!self_promoting_args_p (args1))
return 0;
if (TYPE_ACTUAL_ARG_TYPES (f2)
&& 1 != type_lists_compatible_p (args1, TYPE_ACTUAL_ARG_TYPES (f2)))
val = 2;
return val;
}
/* Both types have argument lists: compare them and propagate results. */
val1 = type_lists_compatible_p (args1, args2);
return val1 != 1 ? val1 : val;
}
/* Check two lists of types for compatibility,
returning 0 for incompatible, 1 for compatible,
or 2 for compatible with warning. */
static int
type_lists_compatible_p (args1, args2)
tree args1, args2;
{
/* 1 if no need for warning yet, 2 if warning cause has been seen. */
int val = 1;
int newval = 0;
while (1)
{
if (args1 == 0 && args2 == 0)
return val;
/* If one list is shorter than the other,
they fail to match. */
if (args1 == 0 || args2 == 0)
return 0;
/* A null pointer instead of a type
means there is supposed to be an argument
but nothing is specified about what type it has.
So match anything that self-promotes. */
if (TREE_VALUE (args1) == 0)
{
if (! self_promoting_type_p (TREE_VALUE (args2)))
return 0;
}
else if (TREE_VALUE (args2) == 0)
{
if (! self_promoting_type_p (TREE_VALUE (args1)))
return 0;
}
else if (! (newval = comptypes (TREE_VALUE (args1), TREE_VALUE (args2))))
{
/* Allow wait (union {union wait *u; int *i} *)
and wait (union wait *) to be compatible. */
if (TREE_CODE (TREE_VALUE (args1)) == UNION_TYPE
&& (TYPE_NAME (TREE_VALUE (args1)) == 0
|| TYPE_TRANSPARENT_UNION (TREE_VALUE (args1)))
&& TREE_CODE (TYPE_SIZE (TREE_VALUE (args1))) == INTEGER_CST
&& tree_int_cst_equal (TYPE_SIZE (TREE_VALUE (args1)),
TYPE_SIZE (TREE_VALUE (args2))))
{
tree memb;
for (memb = TYPE_FIELDS (TREE_VALUE (args1));
memb; memb = TREE_CHAIN (memb))
if (comptypes (TREE_TYPE (memb), TREE_VALUE (args2)))
break;
if (memb == 0)
return 0;
}
else if (TREE_CODE (TREE_VALUE (args2)) == UNION_TYPE
&& (TYPE_NAME (TREE_VALUE (args2)) == 0
|| TYPE_TRANSPARENT_UNION (TREE_VALUE (args2)))
&& TREE_CODE (TYPE_SIZE (TREE_VALUE (args2))) == INTEGER_CST
&& tree_int_cst_equal (TYPE_SIZE (TREE_VALUE (args2)),
TYPE_SIZE (TREE_VALUE (args1))))
{
tree memb;
for (memb = TYPE_FIELDS (TREE_VALUE (args2));
memb; memb = TREE_CHAIN (memb))
if (comptypes (TREE_TYPE (memb), TREE_VALUE (args1)))
break;
if (memb == 0)
return 0;
}
else
return 0;
}
/* comptypes said ok, but record if it said to warn. */
if (newval > val)
val = newval;
args1 = TREE_CHAIN (args1);
args2 = TREE_CHAIN (args2);
}
}
/* Return 1 if PARMS specifies a fixed number of parameters
and none of their types is affected by default promotions. */
int
self_promoting_args_p (parms)
tree parms;
{
register tree t;
for (t = parms; t; t = TREE_CHAIN (t))
{
register tree type = TREE_VALUE (t);
if (TREE_CHAIN (t) == 0 && type != void_type_node)
return 0;
if (type == 0)
return 0;
if (TYPE_MAIN_VARIANT (type) == float_type_node)
return 0;
if (C_PROMOTING_INTEGER_TYPE_P (type))
return 0;
}
return 1;
}
/* Return 1 if TYPE is not affected by default promotions. */
static int
self_promoting_type_p (type)
tree type;
{
if (TYPE_MAIN_VARIANT (type) == float_type_node)
return 0;
if (C_PROMOTING_INTEGER_TYPE_P (type))
return 0;
return 1;
}
/* Return an unsigned type the same as TYPE in other respects. */
tree
unsigned_type (type)
tree type;
{
tree type1 = TYPE_MAIN_VARIANT (type);
if (type1 == signed_char_type_node || type1 == char_type_node)
return unsigned_char_type_node;
if (type1 == integer_type_node)
return unsigned_type_node;
if (type1 == short_integer_type_node)
return short_unsigned_type_node;
if (type1 == long_integer_type_node)
return long_unsigned_type_node;
if (type1 == long_long_integer_type_node)
return long_long_unsigned_type_node;
if (type1 == intDI_type_node)
return unsigned_intDI_type_node;
if (type1 == intSI_type_node)
return unsigned_intSI_type_node;
if (type1 == intHI_type_node)
return unsigned_intHI_type_node;
if (type1 == intQI_type_node)
return unsigned_intQI_type_node;
return signed_or_unsigned_type (1, type);
}
/* Return a signed type the same as TYPE in other respects. */
tree
signed_type (type)
tree type;
{
tree type1 = TYPE_MAIN_VARIANT (type);
if (type1 == unsigned_char_type_node || type1 == char_type_node)
return signed_char_type_node;
if (type1 == unsigned_type_node)
return integer_type_node;
if (type1 == short_unsigned_type_node)
return short_integer_type_node;
if (type1 == long_unsigned_type_node)
return long_integer_type_node;
if (type1 == long_long_unsigned_type_node)
return long_long_integer_type_node;
if (type1 == unsigned_intDI_type_node)
return intDI_type_node;
if (type1 == unsigned_intSI_type_node)
return intSI_type_node;
if (type1 == unsigned_intHI_type_node)
return intHI_type_node;
if (type1 == unsigned_intQI_type_node)
return intQI_type_node;
return signed_or_unsigned_type (0, type);
}
/* Return a type the same as TYPE except unsigned or
signed according to UNSIGNEDP. */
tree
signed_or_unsigned_type (unsignedp, type)
int unsignedp;
tree type;
{
if ((! INTEGRAL_TYPE_P (type) && ! POINTER_TYPE_P (type))
|| TREE_UNSIGNED (type) == unsignedp)
return type;
if (TYPE_PRECISION (type) == TYPE_PRECISION (signed_char_type_node))
return unsignedp ? unsigned_char_type_node : signed_char_type_node;
if (TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node))
return unsignedp ? unsigned_type_node : integer_type_node;
if (TYPE_PRECISION (type) == TYPE_PRECISION (short_integer_type_node))
return unsignedp ? short_unsigned_type_node : short_integer_type_node;
if (TYPE_PRECISION (type) == TYPE_PRECISION (long_integer_type_node))
return unsignedp ? long_unsigned_type_node : long_integer_type_node;
if (TYPE_PRECISION (type) == TYPE_PRECISION (long_long_integer_type_node))
return (unsignedp ? long_long_unsigned_type_node
: long_long_integer_type_node);
return type;
}
/* Compute the value of the `sizeof' operator. */
tree
c_sizeof (type)
tree type;
{
enum tree_code code = TREE_CODE (type);
tree t;
if (code == FUNCTION_TYPE)
{
if (pedantic || warn_pointer_arith)
pedwarn ("sizeof applied to a function type");
return size_int (1);
}
if (code == VOID_TYPE)
{
if (pedantic || warn_pointer_arith)
pedwarn ("sizeof applied to a void type");
return size_int (1);
}
if (code == ERROR_MARK)
return size_int (1);
if (TYPE_SIZE (type) == 0)
{
error ("sizeof applied to an incomplete type");
return size_int (0);
}
/* Convert in case a char is more than one unit. */
t = size_binop (CEIL_DIV_EXPR, TYPE_SIZE (type),
size_int (TYPE_PRECISION (char_type_node)));
/* size_binop does not put the constant in range, so do it now. */
if (TREE_CODE (t) == INTEGER_CST && force_fit_type (t, 0))
TREE_CONSTANT_OVERFLOW (t) = TREE_OVERFLOW (t) = 1;
return t;
}
tree
c_sizeof_nowarn (type)
tree type;
{
enum tree_code code = TREE_CODE (type);
tree t;
if (code == FUNCTION_TYPE
|| code == VOID_TYPE
|| code == ERROR_MARK)
return size_int (1);
if (TYPE_SIZE (type) == 0)
return size_int (0);
/* Convert in case a char is more than one unit. */
t = size_binop (CEIL_DIV_EXPR, TYPE_SIZE (type),
size_int (TYPE_PRECISION (char_type_node)));
force_fit_type (t, 0);
return t;
}
/* Compute the size to increment a pointer by. */
tree
c_size_in_bytes (type)
tree type;
{
enum tree_code code = TREE_CODE (type);
tree t;
if (code == FUNCTION_TYPE)
return size_int (1);
if (code == VOID_TYPE)
return size_int (1);
if (code == ERROR_MARK)
return size_int (1);
if (TYPE_SIZE (type) == 0)
{
error ("arithmetic on pointer to an incomplete type");
return size_int (1);
}
/* Convert in case a char is more than one unit. */
t = size_binop (CEIL_DIV_EXPR, TYPE_SIZE (type),
size_int (BITS_PER_UNIT));
force_fit_type (t, 0);
return t;
}
/* Implement the __alignof keyword: Return the minimum required
alignment of TYPE, measured in bytes. */
tree
c_alignof (type)
tree type;
{
enum tree_code code = TREE_CODE (type);
if (code == FUNCTION_TYPE)
return size_int (FUNCTION_BOUNDARY / BITS_PER_UNIT);
if (code == VOID_TYPE || code == ERROR_MARK)
return size_int (1);
return size_int (TYPE_ALIGN (type) / BITS_PER_UNIT);
}
/* Implement the __alignof keyword: Return the minimum required
alignment of EXPR, measured in bytes. For VAR_DECL's and
FIELD_DECL's return DECL_ALIGN (which can be set from an
"aligned" __attribute__ specification). */
tree
c_alignof_expr (expr)
tree expr;
{
if (TREE_CODE (expr) == VAR_DECL)
return size_int (DECL_ALIGN (expr) / BITS_PER_UNIT);
if (TREE_CODE (expr) == COMPONENT_REF
&& DECL_C_BIT_FIELD (TREE_OPERAND (expr, 1)))
{
error ("`__alignof' applied to a bit-field");
return size_int (1);
}
else if (TREE_CODE (expr) == COMPONENT_REF
&& TREE_CODE (TREE_OPERAND (expr, 1)) == FIELD_DECL)
return size_int (DECL_ALIGN (TREE_OPERAND (expr, 1)) / BITS_PER_UNIT);
if (TREE_CODE (expr) == INDIRECT_REF)
{
tree t = TREE_OPERAND (expr, 0);
tree best = t;
int bestalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
while (TREE_CODE (t) == NOP_EXPR
&& TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) == POINTER_TYPE)
{
int thisalign;
t = TREE_OPERAND (t, 0);
thisalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
if (thisalign > bestalign)
best = t, bestalign = thisalign;
}
return c_alignof (TREE_TYPE (TREE_TYPE (best)));
}
else
return c_alignof (TREE_TYPE (expr));
}
/* Return either DECL or its known constant value (if it has one). */
static tree
decl_constant_value (decl)
tree decl;
{
if (/* Don't change a variable array bound or initial value to a constant
in a place where a variable is invalid. */
current_function_decl != 0
&& ! pedantic
&& ! TREE_THIS_VOLATILE (decl)
&& TREE_READONLY (decl) && ! ITERATOR_P (decl)
&& DECL_INITIAL (decl) != 0
&& TREE_CODE (DECL_INITIAL (decl)) != ERROR_MARK
/* This is invalid if initial value is not constant.
If it has either a function call, a memory reference,
or a variable, then re-evaluating it could give different results. */
&& TREE_CONSTANT (DECL_INITIAL (decl))
/* Check for cases where this is sub-optimal, even though valid. */
&& TREE_CODE (DECL_INITIAL (decl)) != CONSTRUCTOR
&& DECL_MODE (decl) != BLKmode)
return DECL_INITIAL (decl);
return decl;
}
/* Perform default promotions for C data used in expressions.
Arrays and functions are converted to pointers;
enumeral types or short or char, to int.
In addition, manifest constants symbols are replaced by their values. */