Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * proclang.c
4 : * PostgreSQL LANGUAGE support code.
5 : *
6 : * Portions Copyright (c) 1996-2026, 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/htup_details.h"
17 : #include "access/table.h"
18 : #include "catalog/catalog.h"
19 : #include "catalog/dependency.h"
20 : #include "catalog/indexing.h"
21 : #include "catalog/objectaccess.h"
22 : #include "catalog/pg_language.h"
23 : #include "catalog/pg_proc.h"
24 : #include "catalog/pg_type.h"
25 : #include "commands/proclang.h"
26 : #include "miscadmin.h"
27 : #include "parser/parse_func.h"
28 : #include "utils/builtins.h"
29 : #include "utils/lsyscache.h"
30 : #include "utils/rel.h"
31 : #include "utils/syscache.h"
32 :
33 :
34 : /*
35 : * CREATE LANGUAGE
36 : */
37 : ObjectAddress
38 72 : CreateProceduralLanguage(CreatePLangStmt *stmt)
39 : {
40 72 : const char *languageName = stmt->plname;
41 72 : Oid languageOwner = GetUserId();
42 : Oid handlerOid,
43 : inlineOid,
44 : valOid;
45 : Oid funcrettype;
46 : Oid funcargtypes[1];
47 : Relation rel;
48 : TupleDesc tupDesc;
49 : Datum values[Natts_pg_language];
50 : bool nulls[Natts_pg_language];
51 : bool replaces[Natts_pg_language];
52 : NameData langname;
53 : HeapTuple oldtup;
54 : HeapTuple tup;
55 : Oid langoid;
56 : bool is_update;
57 : ObjectAddress myself,
58 : referenced;
59 : ObjectAddresses *addrs;
60 :
61 : /*
62 : * Check permission
63 : */
64 72 : if (!superuser())
65 0 : ereport(ERROR,
66 : (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
67 : errmsg("must be superuser to create custom procedural language")));
68 :
69 : /*
70 : * Lookup the PL handler function and check that it is of the expected
71 : * return type
72 : */
73 : Assert(stmt->plhandler);
74 72 : handlerOid = LookupFuncName(stmt->plhandler, 0, NULL, false);
75 72 : funcrettype = get_func_rettype(handlerOid);
76 72 : if (funcrettype != LANGUAGE_HANDLEROID)
77 0 : ereport(ERROR,
78 : (errcode(ERRCODE_WRONG_OBJECT_TYPE),
79 : errmsg("function %s must return type %s",
80 : NameListToString(stmt->plhandler), "language_handler")));
81 :
82 : /* validate the inline function */
83 72 : if (stmt->plinline)
84 : {
85 63 : funcargtypes[0] = INTERNALOID;
86 63 : inlineOid = LookupFuncName(stmt->plinline, 1, funcargtypes, false);
87 : /* return value is ignored, so we don't check the type */
88 : }
89 : else
90 9 : inlineOid = InvalidOid;
91 :
92 : /* validate the validator function */
93 72 : if (stmt->plvalidator)
94 : {
95 63 : funcargtypes[0] = OIDOID;
96 63 : valOid = LookupFuncName(stmt->plvalidator, 1, funcargtypes, false);
97 : /* return value is ignored, so we don't check the type */
98 : }
99 : else
100 9 : valOid = InvalidOid;
101 :
102 : /* ok to create it */
103 72 : rel = table_open(LanguageRelationId, RowExclusiveLock);
104 72 : tupDesc = RelationGetDescr(rel);
105 :
106 : /* Prepare data to be inserted */
107 72 : memset(values, 0, sizeof(values));
108 72 : memset(nulls, false, sizeof(nulls));
109 72 : memset(replaces, true, sizeof(replaces));
110 :
111 72 : namestrcpy(&langname, languageName);
112 72 : values[Anum_pg_language_lanname - 1] = NameGetDatum(&langname);
113 72 : values[Anum_pg_language_lanowner - 1] = ObjectIdGetDatum(languageOwner);
114 72 : values[Anum_pg_language_lanispl - 1] = BoolGetDatum(true);
115 72 : values[Anum_pg_language_lanpltrusted - 1] = BoolGetDatum(stmt->pltrusted);
116 72 : values[Anum_pg_language_lanplcallfoid - 1] = ObjectIdGetDatum(handlerOid);
117 72 : values[Anum_pg_language_laninline - 1] = ObjectIdGetDatum(inlineOid);
118 72 : values[Anum_pg_language_lanvalidator - 1] = ObjectIdGetDatum(valOid);
119 72 : nulls[Anum_pg_language_lanacl - 1] = true;
120 :
121 : /* Check for pre-existing definition */
122 72 : oldtup = SearchSysCache1(LANGNAME, PointerGetDatum(languageName));
123 :
124 72 : if (HeapTupleIsValid(oldtup))
125 : {
126 0 : Form_pg_language oldform = (Form_pg_language) GETSTRUCT(oldtup);
127 :
128 : /* There is one; okay to replace it? */
129 0 : if (!stmt->replace)
130 0 : ereport(ERROR,
131 : (errcode(ERRCODE_DUPLICATE_OBJECT),
132 : errmsg("language \"%s\" already exists", languageName)));
133 :
134 : /* This is currently pointless, since we already checked superuser */
135 : #ifdef NOT_USED
136 : if (!object_ownercheck(LanguageRelationId, oldform->oid, languageOwner))
137 : aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_LANGUAGE,
138 : languageName);
139 : #endif
140 :
141 : /*
142 : * Do not change existing oid, ownership or permissions. Note
143 : * dependency-update code below has to agree with this decision.
144 : */
145 0 : replaces[Anum_pg_language_oid - 1] = false;
146 0 : replaces[Anum_pg_language_lanowner - 1] = false;
147 0 : replaces[Anum_pg_language_lanacl - 1] = false;
148 :
149 : /* Okay, do it... */
150 0 : tup = heap_modify_tuple(oldtup, tupDesc, values, nulls, replaces);
151 0 : CatalogTupleUpdate(rel, &tup->t_self, tup);
152 :
153 0 : langoid = oldform->oid;
154 0 : ReleaseSysCache(oldtup);
155 0 : is_update = true;
156 : }
157 : else
158 : {
159 : /* Creating a new language */
160 72 : langoid = GetNewOidWithIndex(rel, LanguageOidIndexId,
161 : Anum_pg_language_oid);
162 72 : values[Anum_pg_language_oid - 1] = ObjectIdGetDatum(langoid);
163 72 : tup = heap_form_tuple(tupDesc, values, nulls);
164 72 : CatalogTupleInsert(rel, tup);
165 72 : is_update = false;
166 : }
167 :
168 : /*
169 : * Create dependencies for the new language. If we are updating an
170 : * existing language, first delete any existing pg_depend entries.
171 : * (However, since we are not changing ownership or permissions, the
172 : * shared dependencies do *not* need to change, and we leave them alone.)
173 : */
174 72 : myself.classId = LanguageRelationId;
175 72 : myself.objectId = langoid;
176 72 : myself.objectSubId = 0;
177 :
178 72 : if (is_update)
179 0 : deleteDependencyRecordsFor(myself.classId, myself.objectId, true);
180 :
181 : /* dependency on owner of language */
182 72 : if (!is_update)
183 72 : recordDependencyOnOwner(myself.classId, myself.objectId,
184 : languageOwner);
185 :
186 : /* dependency on extension */
187 72 : recordDependencyOnCurrentExtension(&myself, is_update);
188 :
189 72 : addrs = new_object_addresses();
190 :
191 : /* dependency on the PL handler function */
192 72 : ObjectAddressSet(referenced, ProcedureRelationId, handlerOid);
193 72 : add_exact_object_address(&referenced, addrs);
194 :
195 : /* dependency on the inline handler function, if any */
196 72 : if (OidIsValid(inlineOid))
197 : {
198 63 : ObjectAddressSet(referenced, ProcedureRelationId, inlineOid);
199 63 : add_exact_object_address(&referenced, addrs);
200 : }
201 :
202 : /* dependency on the validator function, if any */
203 72 : if (OidIsValid(valOid))
204 : {
205 63 : ObjectAddressSet(referenced, ProcedureRelationId, valOid);
206 63 : add_exact_object_address(&referenced, addrs);
207 : }
208 :
209 72 : record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL);
210 72 : free_object_addresses(addrs);
211 :
212 : /* Post creation hook for new procedural language */
213 72 : InvokeObjectPostCreateHook(LanguageRelationId, myself.objectId, 0);
214 :
215 72 : table_close(rel, RowExclusiveLock);
216 :
217 72 : return myself;
218 : }
219 :
220 : /*
221 : * get_language_oid - given a language name, look up the OID
222 : *
223 : * If missing_ok is false, throw an error if language name not found. If
224 : * true, just return InvalidOid.
225 : */
226 : Oid
227 240 : get_language_oid(const char *langname, bool missing_ok)
228 : {
229 : Oid oid;
230 :
231 240 : oid = GetSysCacheOid1(LANGNAME, Anum_pg_language_oid,
232 : CStringGetDatum(langname));
233 240 : if (!OidIsValid(oid) && !missing_ok)
234 8 : ereport(ERROR,
235 : (errcode(ERRCODE_UNDEFINED_OBJECT),
236 : errmsg("language \"%s\" does not exist", langname)));
237 232 : return oid;
238 : }
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