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genbki.h
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1 /*-------------------------------------------------------------------------
2  *
3  * genbki.h
4  * Required include file for all POSTGRES catalog header files
5  *
6  * genbki.h defines CATALOG(), BKI_BOOTSTRAP and related macros
7  * so that the catalog header files can be read by the C compiler.
8  * (These same words are recognized by genbki.pl to build the BKI
9  * bootstrap file from these header files.)
10  *
11  *
12  * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
13  * Portions Copyright (c) 1994, Regents of the University of California
14  *
15  * src/include/catalog/genbki.h
16  *
17  *-------------------------------------------------------------------------
18  */
19 #ifndef GENBKI_H
20 #define GENBKI_H
21 
22 /* Introduces a catalog's structure definition */
23 #define CATALOG(name,oid,oidmacro) typedef struct CppConcat(FormData_,name)
24 
25 /* Options that may appear after CATALOG (on the same line) */
26 #define BKI_BOOTSTRAP
27 #define BKI_SHARED_RELATION
28 #define BKI_ROWTYPE_OID(oid,oidmacro)
29 #define BKI_SCHEMA_MACRO
30 
31 /* Options that may appear after an attribute (on the same line) */
32 #define BKI_FORCE_NULL
33 #define BKI_FORCE_NOT_NULL
34 /* Specifies a default value for a catalog field */
35 #define BKI_DEFAULT(value)
36 /* Specifies a default value for auto-generated array types */
37 #define BKI_ARRAY_DEFAULT(value)
38 /*
39  * Indicates that the attribute contains OIDs referencing the named catalog;
40  * can be applied to columns of oid, regproc, oid[], or oidvector type.
41  * genbki.pl uses this to know how to perform name lookups in the initial
42  * data (if any), and it also feeds into regression-test validity checks.
43  * The _OPT suffix indicates that values can be zero instead of
44  * a valid OID reference.
45  */
46 #define BKI_LOOKUP(catalog)
47 #define BKI_LOOKUP_OPT(catalog)
48 
49 /*
50  * These lines are processed by genbki.pl to create the statements
51  * the bootstrap parser will turn into BootstrapToastTable commands.
52  * Each line specifies the system catalog that needs a toast table,
53  * the OID to assign to the toast table, and the OID to assign to the
54  * toast table's index. The reason we hard-wire these OIDs is that we
55  * need stable OIDs for shared relations, and that includes toast tables
56  * of shared relations.
57  *
58  * The macro definition is just to keep the C compiler from spitting up.
59  */
60 #define DECLARE_TOAST(name,toastoid,indexoid) extern int no_such_variable
61 
62 /*
63  * These lines are processed by genbki.pl to create the statements
64  * the bootstrap parser will turn into DefineIndex calls.
65  *
66  * The keyword is DECLARE_INDEX or DECLARE_UNIQUE_INDEX or
67  * DECLARE_UNIQUE_INDEX_PKEY. ("PKEY" marks the index as being the catalog's
68  * primary key; currently this is only cosmetically different from a regular
69  * unique index. By convention, we usually make a catalog's OID column its
70  * pkey, if it has one.) The first two arguments are the index's name and
71  * OID, the rest is much like a standard 'create index' SQL command.
72  *
73  * For each index, we also provide a #define for its OID. References to
74  * the index in the C code should always use these #defines, not the actual
75  * index name (much less the numeric OID).
76  *
77  * The macro definitions are just to keep the C compiler from spitting up.
78  */
79 #define DECLARE_INDEX(name,oid,decl) extern int no_such_variable
80 #define DECLARE_UNIQUE_INDEX(name,oid,decl) extern int no_such_variable
81 #define DECLARE_UNIQUE_INDEX_PKEY(name,oid,decl) extern int no_such_variable
82 
83 /*
84  * These lines are processed by genbki.pl to create a table for use
85  * by the pg_get_catalog_foreign_keys() function. We do not have any
86  * mechanism that actually enforces foreign-key relationships in the
87  * system catalogs, but it is still useful to record the intended
88  * relationships in a machine-readable form.
89  *
90  * The keyword is DECLARE_FOREIGN_KEY[_OPT] or DECLARE_ARRAY_FOREIGN_KEY[_OPT].
91  * The first argument is a parenthesized list of the referencing columns;
92  * the second, the name of the referenced table; the third, a parenthesized
93  * list of the referenced columns. Use of the ARRAY macros means that the
94  * last referencing column is an array, each of whose elements is supposed
95  * to match some entry in the last referenced column. Use of the OPT suffix
96  * indicates that the referencing column(s) can be zero instead of a valid
97  * reference.
98  *
99  * Columns that are marked with a BKI_LOOKUP rule do not need an explicit
100  * DECLARE_FOREIGN_KEY macro, as genbki.pl can infer the FK relationship
101  * from that. Thus, these macros are only needed in special cases.
102  *
103  * The macro definitions are just to keep the C compiler from spitting up.
104  */
105 #define DECLARE_FOREIGN_KEY(cols,reftbl,refcols) extern int no_such_variable
106 #define DECLARE_FOREIGN_KEY_OPT(cols,reftbl,refcols) extern int no_such_variable
107 #define DECLARE_ARRAY_FOREIGN_KEY(cols,reftbl,refcols) extern int no_such_variable
108 #define DECLARE_ARRAY_FOREIGN_KEY_OPT(cols,reftbl,refcols) extern int no_such_variable
109 
110 /* The following are never defined; they are here only for documentation. */
111 
112 /*
113  * Variable-length catalog fields (except possibly the first not nullable one)
114  * should not be visible in C structures, so they are made invisible by #ifdefs
115  * of an undefined symbol. See also the BOOTCOL_NULL_AUTO code in bootstrap.c
116  * for how this is handled.
117  */
118 #undef CATALOG_VARLEN
119 
120 /*
121  * There is code in some catalog headers that needs to be visible to clients,
122  * but we don't want clients to include the full header because of safety
123  * issues with other code in the header. To handle that, surround code that
124  * should be visible to clients with "#ifdef EXPOSE_TO_CLIENT_CODE". That
125  * instructs genbki.pl to copy the section when generating the corresponding
126  * "_d" header, which can be included by both client and backend code.
127  */
128 #undef EXPOSE_TO_CLIENT_CODE
129 
130 #endif /* GENBKI_H */