Home | History | Annotate | Line # | Download | only in lint1
gcc_attribute.c revision 1.9 
      1  1.9  rillig /*	$NetBSD: gcc_attribute.c,v 1.9 2021/07/09 18:55:28 rillig Exp $	*/
      2  1.1  rillig # 3 "gcc_attribute.c"
      3  1.1  rillig 
      4  1.1  rillig /*
      5  1.1  rillig  * Tests for the various attributes for functions, types, statements that are
      6  1.1  rillig  * provided by GCC.
      7  1.1  rillig  *
      8  1.1  rillig  * https://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html
      9  1.1  rillig  */
     10  1.1  rillig 
     11  1.1  rillig void __attribute__((noinline))
     12  1.1  rillig do_not_inline(void)
     13  1.1  rillig {
     14  1.1  rillig }
     15  1.1  rillig 
     16  1.2  rillig /* All pointer arguments must be nonnull. */
     17  1.2  rillig void __attribute__((nonnull))
     18  1.2  rillig function_nonnull(void *, const void *, int);
     19  1.2  rillig 
     20  1.3  rillig /*
     21  1.3  rillig  * The documentation suggests that the argument list of nonnull be nonempty,
     22  1.3  rillig  * but GCC 9.3.0 accepts an empty list as well, treating all parameters as
     23  1.3  rillig  * nonnull.
     24  1.3  rillig  */
     25  1.3  rillig void __attribute__((nonnull()))
     26  1.3  rillig function_nonnull_list(void *, const void *, int);
     27  1.3  rillig 
     28  1.2  rillig /* Arguments 1 and 2 must be nonnull. */
     29  1.1  rillig void __attribute__((nonnull(1, 2)))
     30  1.2  rillig function_nonnull_list(void *, const void *, int);
     31  1.1  rillig 
     32  1.1  rillig /* expect+1: syntax error 'unknown_attribute' */
     33  1.1  rillig void __attribute__((unknown_attribute))
     34  1.1  rillig function_with_unknown_attribute(void);
     35  1.4  rillig 
     36  1.4  rillig /*
     37  1.4  rillig  * There is an attribute called 'pcs', but that attribute must not prevent an
     38  1.5  rillig  * ordinary variable from being named the same.  Starting with scan.l 1.77
     39  1.5  rillig  * from 2017-01-07, that variable name generated a syntax error.  Fixed in
     40  1.5  rillig  * lex.c 1.33 from 2021-05-03.
     41  1.4  rillig  *
     42  1.4  rillig  * Seen in yds.c, function yds_allocate_slots.
     43  1.4  rillig  */
     44  1.5  rillig int
     45  1.4  rillig local_variable_pcs(void)
     46  1.4  rillig {
     47  1.5  rillig 	int pcs = 3;
     48  1.4  rillig 	return pcs;
     49  1.4  rillig }
     50  1.6  rillig 
     51  1.6  rillig /*
     52  1.6  rillig  * FIXME: The attributes are handled by different grammar rules even though
     53  1.6  rillig  *  they occur in the same syntactical position.
     54  1.6  rillig  *
     55  1.6  rillig  * Grammar rule abstract_decl_param_list handles the first attribute.
     56  1.6  rillig  *
     57  1.6  rillig  * Grammar rule direct_abstract_declarator handles all remaining attributes.
     58  1.6  rillig  *
     59  1.6  rillig  * Since abstract_decl_param_list contains type_attribute_opt, this could be
     60  1.6  rillig  * the source of the many shift/reduce conflicts in the grammar.
     61  1.6  rillig  */
     62  1.6  rillig int
     63  1.6  rillig func(
     64  1.6  rillig     int(int)
     65  1.6  rillig     __attribute__((__noreturn__))
     66  1.6  rillig     __attribute__((__noreturn__))
     67  1.6  rillig );
     68  1.8  rillig 
     69  1.8  rillig /*
     70  1.8  rillig  * https://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html says that the
     71  1.8  rillig  * attribute-list is a "possibly empty comma-separated sequence of
     72  1.8  rillig  * attributes".
     73  1.8  rillig  *
     74  1.8  rillig  * No matter whether this particular example is interpreted as an empty list
     75  1.8  rillig  * or a list containing a single empty attribute, the result is the same in
     76  1.8  rillig  * both cases.
     77  1.8  rillig  */
     78  1.8  rillig void one_empty_attribute(void)
     79  1.8  rillig     __attribute__((/* none */));
     80  1.8  rillig 
     81  1.8  rillig /*
     82  1.8  rillig  * https://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html further says that
     83  1.8  rillig  * each individual attribute may be "Empty. Empty attributes are ignored".
     84  1.8  rillig  */
     85  1.8  rillig void two_empty_attributes(void)
     86  1.8  rillig     __attribute__((/* none */, /* still none */));
     87  1.9  rillig 
     88  1.9  rillig /*
     89  1.9  rillig  * Ensure that __attribute__ can be specified everywhere in a declaration.
     90  1.9  rillig  * This is the simplest possible requirement that covers all valid code.
     91  1.9  rillig  * It accepts invalid code as well, but these cases are covered by GCC and
     92  1.9  rillig  * Clang already.
     93  1.9  rillig  *
     94  1.9  rillig  * Since lint only parses the attributes but doesn't really relate them to
     95  1.9  rillig  * identifiers or other entities, ensuring that valid code can be parsed is
     96  1.9  rillig  * enough for now.
     97  1.9  rillig  *
     98  1.9  rillig  * To really associate __attribute__ with the corresponding entity, the
     99  1.9  rillig  * grammar needs to be rewritten, see the example with __noreturn__ above.
    100  1.9  rillig  */
    101  1.9  rillig __attribute__((deprecated("d1")))
    102  1.9  rillig const
    103  1.9  rillig __attribute__((deprecated("d2")))
    104  1.9  rillig int
    105  1.9  rillig __attribute__((deprecated("d3")))
    106  1.9  rillig *
    107  1.9  rillig // The below line would produce a syntax error.
    108  1.9  rillig // __attribute__((deprecated("d3")))
    109  1.9  rillig const
    110  1.9  rillig __attribute__((deprecated("d4")))
    111  1.9  rillig identifier
    112  1.9  rillig __attribute__((deprecated("d5")))
    113  1.9  rillig (
    114  1.9  rillig     __attribute__((deprecated("d6")))
    115  1.9  rillig     void
    116  1.9  rillig     __attribute__((deprecated("d7")))
    117  1.9  rillig     )
    118  1.9  rillig     __attribute__((deprecated("d8")))
    119  1.9  rillig ;
    120