Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * proclang.c
4 : * PostgreSQL LANGUAGE support code.
5 : *
6 : * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
7 : * Portions Copyright (c) 1994, Regents of the University of California
8 : *
9 : * IDENTIFICATION
10 : * src/backend/commands/proclang.c
11 : *
12 : *-------------------------------------------------------------------------
13 : */
14 : #include "postgres.h"
15 :
16 : #include "access/table.h"
17 : #include "catalog/catalog.h"
18 : #include "catalog/dependency.h"
19 : #include "catalog/indexing.h"
20 : #include "catalog/objectaccess.h"
21 : #include "catalog/pg_language.h"
22 : #include "catalog/pg_namespace.h"
23 : #include "catalog/pg_proc.h"
24 : #include "catalog/pg_type.h"
25 : #include "commands/defrem.h"
26 : #include "commands/proclang.h"
27 : #include "miscadmin.h"
28 : #include "parser/parse_func.h"
29 : #include "utils/builtins.h"
30 : #include "utils/lsyscache.h"
31 : #include "utils/rel.h"
32 : #include "utils/syscache.h"
33 :
34 :
35 : /*
36 : * CREATE LANGUAGE
37 : */
38 : ObjectAddress
39 648 : CreateProceduralLanguage(CreatePLangStmt *stmt)
40 : {
41 648 : const char *languageName = stmt->plname;
42 648 : Oid languageOwner = GetUserId();
43 : Oid handlerOid,
44 : inlineOid,
45 : valOid;
46 : Oid funcrettype;
47 : Oid funcargtypes[1];
48 : Relation rel;
49 : TupleDesc tupDesc;
50 : Datum values[Natts_pg_language];
51 : bool nulls[Natts_pg_language];
52 : bool replaces[Natts_pg_language];
53 : NameData langname;
54 : HeapTuple oldtup;
55 : HeapTuple tup;
56 : Oid langoid;
57 : bool is_update;
58 : ObjectAddress myself,
59 : referenced;
60 : ObjectAddresses *addrs;
61 :
62 : /*
63 : * Check permission
64 : */
65 648 : if (!superuser())
66 0 : ereport(ERROR,
67 : (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
68 : errmsg("must be superuser to create custom procedural language")));
69 :
70 : /*
71 : * Lookup the PL handler function and check that it is of the expected
72 : * return type
73 : */
74 : Assert(stmt->plhandler);
75 648 : handlerOid = LookupFuncName(stmt->plhandler, 0, NULL, false);
76 648 : funcrettype = get_func_rettype(handlerOid);
77 648 : if (funcrettype != LANGUAGE_HANDLEROID)
78 0 : ereport(ERROR,
79 : (errcode(ERRCODE_WRONG_OBJECT_TYPE),
80 : errmsg("function %s must return type %s",
81 : NameListToString(stmt->plhandler), "language_handler")));
82 :
83 : /* validate the inline function */
84 648 : if (stmt->plinline)
85 : {
86 630 : funcargtypes[0] = INTERNALOID;
87 630 : inlineOid = LookupFuncName(stmt->plinline, 1, funcargtypes, false);
88 : /* return value is ignored, so we don't check the type */
89 : }
90 : else
91 18 : inlineOid = InvalidOid;
92 :
93 : /* validate the validator function */
94 648 : if (stmt->plvalidator)
95 : {
96 630 : funcargtypes[0] = OIDOID;
97 630 : valOid = LookupFuncName(stmt->plvalidator, 1, funcargtypes, false);
98 : /* return value is ignored, so we don't check the type */
99 : }
100 : else
101 18 : valOid = InvalidOid;
102 :
103 : /* ok to create it */
104 648 : rel = table_open(LanguageRelationId, RowExclusiveLock);
105 648 : tupDesc = RelationGetDescr(rel);
106 :
107 : /* Prepare data to be inserted */
108 648 : memset(values, 0, sizeof(values));
109 648 : memset(nulls, false, sizeof(nulls));
110 648 : memset(replaces, true, sizeof(replaces));
111 :
112 648 : namestrcpy(&langname, languageName);
113 648 : values[Anum_pg_language_lanname - 1] = NameGetDatum(&langname);
114 648 : values[Anum_pg_language_lanowner - 1] = ObjectIdGetDatum(languageOwner);
115 648 : values[Anum_pg_language_lanispl - 1] = BoolGetDatum(true);
116 648 : values[Anum_pg_language_lanpltrusted - 1] = BoolGetDatum(stmt->pltrusted);
117 648 : values[Anum_pg_language_lanplcallfoid - 1] = ObjectIdGetDatum(handlerOid);
118 648 : values[Anum_pg_language_laninline - 1] = ObjectIdGetDatum(inlineOid);
119 648 : values[Anum_pg_language_lanvalidator - 1] = ObjectIdGetDatum(valOid);
120 648 : nulls[Anum_pg_language_lanacl - 1] = true;
121 :
122 : /* Check for pre-existing definition */
123 648 : oldtup = SearchSysCache1(LANGNAME, PointerGetDatum(languageName));
124 :
125 648 : if (HeapTupleIsValid(oldtup))
126 : {
127 0 : Form_pg_language oldform = (Form_pg_language) GETSTRUCT(oldtup);
128 :
129 : /* There is one; okay to replace it? */
130 0 : if (!stmt->replace)
131 0 : ereport(ERROR,
132 : (errcode(ERRCODE_DUPLICATE_OBJECT),
133 : errmsg("language \"%s\" already exists", languageName)));
134 :
135 : /* This is currently pointless, since we already checked superuser */
136 : #ifdef NOT_USED
137 : if (!object_ownercheck(LanguageRelationId, oldform->oid, languageOwner))
138 : aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_LANGUAGE,
139 : languageName);
140 : #endif
141 :
142 : /*
143 : * Do not change existing oid, ownership or permissions. Note
144 : * dependency-update code below has to agree with this decision.
145 : */
146 0 : replaces[Anum_pg_language_oid - 1] = false;
147 0 : replaces[Anum_pg_language_lanowner - 1] = false;
148 0 : replaces[Anum_pg_language_lanacl - 1] = false;
149 :
150 : /* Okay, do it... */
151 0 : tup = heap_modify_tuple(oldtup, tupDesc, values, nulls, replaces);
152 0 : CatalogTupleUpdate(rel, &tup->t_self, tup);
153 :
154 0 : langoid = oldform->oid;
155 0 : ReleaseSysCache(oldtup);
156 0 : is_update = true;
157 : }
158 : else
159 : {
160 : /* Creating a new language */
161 648 : langoid = GetNewOidWithIndex(rel, LanguageOidIndexId,
162 : Anum_pg_language_oid);
163 648 : values[Anum_pg_language_oid - 1] = ObjectIdGetDatum(langoid);
164 648 : tup = heap_form_tuple(tupDesc, values, nulls);
165 648 : CatalogTupleInsert(rel, tup);
166 648 : is_update = false;
167 : }
168 :
169 : /*
170 : * Create dependencies for the new language. If we are updating an
171 : * existing language, first delete any existing pg_depend entries.
172 : * (However, since we are not changing ownership or permissions, the
173 : * shared dependencies do *not* need to change, and we leave them alone.)
174 : */
175 648 : myself.classId = LanguageRelationId;
176 648 : myself.objectId = langoid;
177 648 : myself.objectSubId = 0;
178 :
179 648 : if (is_update)
180 0 : deleteDependencyRecordsFor(myself.classId, myself.objectId, true);
181 :
182 : /* dependency on owner of language */
183 648 : if (!is_update)
184 648 : recordDependencyOnOwner(myself.classId, myself.objectId,
185 : languageOwner);
186 :
187 : /* dependency on extension */
188 648 : recordDependencyOnCurrentExtension(&myself, is_update);
189 :
190 648 : addrs = new_object_addresses();
191 :
192 : /* dependency on the PL handler function */
193 648 : ObjectAddressSet(referenced, ProcedureRelationId, handlerOid);
194 648 : add_exact_object_address(&referenced, addrs);
195 :
196 : /* dependency on the inline handler function, if any */
197 648 : if (OidIsValid(inlineOid))
198 : {
199 630 : ObjectAddressSet(referenced, ProcedureRelationId, inlineOid);
200 630 : add_exact_object_address(&referenced, addrs);
201 : }
202 :
203 : /* dependency on the validator function, if any */
204 648 : if (OidIsValid(valOid))
205 : {
206 630 : ObjectAddressSet(referenced, ProcedureRelationId, valOid);
207 630 : add_exact_object_address(&referenced, addrs);
208 : }
209 :
210 648 : record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL);
211 648 : free_object_addresses(addrs);
212 :
213 : /* Post creation hook for new procedural language */
214 648 : InvokeObjectPostCreateHook(LanguageRelationId, myself.objectId, 0);
215 :
216 648 : table_close(rel, RowExclusiveLock);
217 :
218 648 : return myself;
219 : }
220 :
221 : /*
222 : * get_language_oid - given a language name, look up the OID
223 : *
224 : * If missing_ok is false, throw an error if language name not found. If
225 : * true, just return InvalidOid.
226 : */
227 : Oid
228 1476 : get_language_oid(const char *langname, bool missing_ok)
229 : {
230 : Oid oid;
231 :
232 1476 : oid = GetSysCacheOid1(LANGNAME, Anum_pg_language_oid,
233 : CStringGetDatum(langname));
234 1476 : if (!OidIsValid(oid) && !missing_ok)
235 16 : ereport(ERROR,
236 : (errcode(ERRCODE_UNDEFINED_OBJECT),
237 : errmsg("language \"%s\" does not exist", langname)));
238 1460 : return oid;
239 : }
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