In type_sanity, check I/O functions of built-in types are not volatile.

We have a project policy that I/O functions must not be volatile, as per
commit aab353a60b, but we weren't doing
anything to enforce that.  In most usage the marking of the function
doesn't matter as long as its behavior is sane --- but I/O casts can
expose the marking as user-visible behavior, as per today's complaint
from Joe Van Dyk about contrib/ltree.

This test as such will only protect us against future errors in built-in
data types.  To catch the same error in contrib or third-party types,
perhaps we should make CREATE TYPE complain?  But that's a separate
issue from enforcing the policy for built-in types.

src/test/regress/expected/type_sanity.out

@@ -155,6 +155,14 @@ ORDER BY 1;
   30 | oidvector  |  54 | oidvectorin
 (2 rows)
 
+-- typinput routines should not be volatile
+SELECT p1.oid, p1.typname, p2.oid, p2.proname
+FROM pg_type AS p1, pg_proc AS p2
+WHERE p1.typinput = p2.oid AND p2.provolatile NOT IN ('i', 's');
+ oid | typname | oid | proname 
+-----+---------+-----+---------
+(0 rows)
+
 -- Composites, domains, enums, ranges should all use the same input routines
 SELECT DISTINCT typtype, typinput
 FROM pg_type AS p1
@@ -192,6 +200,14 @@ WHERE p1.typoutput = p2.oid AND NOT
 -----+---------+-----+---------
 (0 rows)
 
+-- typoutput routines should not be volatile
+SELECT p1.oid, p1.typname, p2.oid, p2.proname
+FROM pg_type AS p1, pg_proc AS p2
+WHERE p1.typoutput = p2.oid AND p2.provolatile NOT IN ('i', 's');
+ oid | typname | oid | proname 
+-----+---------+-----+---------
+(0 rows)
+
 -- Composites, enums, ranges should all use the same output routines
 SELECT DISTINCT typtype, typoutput
 FROM pg_type AS p1
@@ -262,6 +278,14 @@ WHERE p1.typinput = p2.oid AND p1.typreceive = p3.oid AND
 -----+---------+-----+---------+-----+---------
 (0 rows)
 
+-- typreceive routines should not be volatile
+SELECT p1.oid, p1.typname, p2.oid, p2.proname
+FROM pg_type AS p1, pg_proc AS p2
+WHERE p1.typreceive = p2.oid AND p2.provolatile NOT IN ('i', 's');
+ oid | typname | oid | proname 
+-----+---------+-----+---------
+(0 rows)
+
 -- Composites, domains, enums, ranges should all use the same receive routines
 SELECT DISTINCT typtype, typreceive
 FROM pg_type AS p1
@@ -299,6 +323,14 @@ WHERE p1.typsend = p2.oid AND NOT
 -----+---------+-----+---------
 (0 rows)
 
+-- typsend routines should not be volatile
+SELECT p1.oid, p1.typname, p2.oid, p2.proname
+FROM pg_type AS p1, pg_proc AS p2
+WHERE p1.typsend = p2.oid AND p2.provolatile NOT IN ('i', 's');
+ oid | typname | oid | proname 
+-----+---------+-----+---------
+(0 rows)
+
 -- Composites, enums, ranges should all use the same send routines
 SELECT DISTINCT typtype, typsend
 FROM pg_type AS p1
@@ -330,6 +362,14 @@ WHERE p1.typmodin = p2.oid AND NOT
 -----+---------+-----+---------
 (0 rows)
 
+-- typmodin routines should not be volatile
+SELECT p1.oid, p1.typname, p2.oid, p2.proname
+FROM pg_type AS p1, pg_proc AS p2
+WHERE p1.typmodin = p2.oid AND p2.provolatile NOT IN ('i', 's');
+ oid | typname | oid | proname 
+-----+---------+-----+---------
+(0 rows)
+
 -- Check for bogus typmodout routines
 SELECT p1.oid, p1.typname, p2.oid, p2.proname
 FROM pg_type AS p1, pg_proc AS p2
@@ -341,6 +381,14 @@ WHERE p1.typmodout = p2.oid AND NOT
 -----+---------+-----+---------
 (0 rows)
 
+-- typmodout routines should not be volatile
+SELECT p1.oid, p1.typname, p2.oid, p2.proname
+FROM pg_type AS p1, pg_proc AS p2
+WHERE p1.typmodout = p2.oid AND p2.provolatile NOT IN ('i', 's');
+ oid | typname | oid | proname 
+-----+---------+-----+---------
+(0 rows)
+
 -- Array types should have same typmodin/out as their element types
 SELECT p1.oid, p1.typname, p2.oid, p2.typname
 FROM pg_type AS p1, pg_type AS p2
@@ -379,6 +427,7 @@ WHERE p1.typanalyze = p2.oid AND NOT
 -----+---------+-----+---------
 (0 rows)
 
+-- there does not seem to be a reason to care about volatility of typanalyze
 -- domains inherit their base type's typanalyze
 SELECT d.oid, d.typname, d.typanalyze, t.oid, t.typname, t.typanalyze
 FROM pg_type d JOIN pg_type t ON d.typbasetype = t.oid

src/test/regress/sql/type_sanity.sql

@@ -122,6 +122,11 @@ WHERE p1.typinput = p2.oid AND
     (p2.oid = 'array_in'::regproc)
 ORDER BY 1;
 
+-- typinput routines should not be volatile
+SELECT p1.oid, p1.typname, p2.oid, p2.proname
+FROM pg_type AS p1, pg_proc AS p2
+WHERE p1.typinput = p2.oid AND p2.provolatile NOT IN ('i', 's');
+
 -- Composites, domains, enums, ranges should all use the same input routines
 SELECT DISTINCT typtype, typinput
 FROM pg_type AS p1
@@ -146,6 +151,11 @@ FROM pg_type AS p1, pg_proc AS p2
 WHERE p1.typoutput = p2.oid AND NOT
     (p2.prorettype = 'cstring'::regtype AND NOT p2.proretset);
 
+-- typoutput routines should not be volatile
+SELECT p1.oid, p1.typname, p2.oid, p2.proname
+FROM pg_type AS p1, pg_proc AS p2
+WHERE p1.typoutput = p2.oid AND p2.provolatile NOT IN ('i', 's');
+
 -- Composites, enums, ranges should all use the same output routines
 SELECT DISTINCT typtype, typoutput
 FROM pg_type AS p1
@@ -193,6 +203,11 @@ FROM pg_type AS p1, pg_proc AS p2, pg_proc AS p3
 WHERE p1.typinput = p2.oid AND p1.typreceive = p3.oid AND
     p2.pronargs != p3.pronargs;
 
+-- typreceive routines should not be volatile
+SELECT p1.oid, p1.typname, p2.oid, p2.proname
+FROM pg_type AS p1, pg_proc AS p2
+WHERE p1.typreceive = p2.oid AND p2.provolatile NOT IN ('i', 's');
+
 -- Composites, domains, enums, ranges should all use the same receive routines
 SELECT DISTINCT typtype, typreceive
 FROM pg_type AS p1
@@ -217,6 +232,11 @@ FROM pg_type AS p1, pg_proc AS p2
 WHERE p1.typsend = p2.oid AND NOT
     (p2.prorettype = 'bytea'::regtype AND NOT p2.proretset);
 
+-- typsend routines should not be volatile
+SELECT p1.oid, p1.typname, p2.oid, p2.proname
+FROM pg_type AS p1, pg_proc AS p2
+WHERE p1.typsend = p2.oid AND p2.provolatile NOT IN ('i', 's');
+
 -- Composites, enums, ranges should all use the same send routines
 SELECT DISTINCT typtype, typsend
 FROM pg_type AS p1
@@ -237,6 +257,11 @@ WHERE p1.typmodin = p2.oid AND NOT
      p2.proargtypes[0] = 'cstring[]'::regtype AND
      p2.prorettype = 'int4'::regtype AND NOT p2.proretset);
 
+-- typmodin routines should not be volatile
+SELECT p1.oid, p1.typname, p2.oid, p2.proname
+FROM pg_type AS p1, pg_proc AS p2
+WHERE p1.typmodin = p2.oid AND p2.provolatile NOT IN ('i', 's');
+
 -- Check for bogus typmodout routines
 
 SELECT p1.oid, p1.typname, p2.oid, p2.proname
@@ -246,6 +271,11 @@ WHERE p1.typmodout = p2.oid AND NOT
      p2.proargtypes[0] = 'int4'::regtype AND
      p2.prorettype = 'cstring'::regtype AND NOT p2.proretset);
 
+-- typmodout routines should not be volatile
+SELECT p1.oid, p1.typname, p2.oid, p2.proname
+FROM pg_type AS p1, pg_proc AS p2
+WHERE p1.typmodout = p2.oid AND p2.provolatile NOT IN ('i', 's');
+
 -- Array types should have same typmodin/out as their element types
 
 SELECT p1.oid, p1.typname, p2.oid, p2.typname
@@ -276,6 +306,8 @@ WHERE p1.typanalyze = p2.oid AND NOT
      p2.proargtypes[0] = 'internal'::regtype AND
      p2.prorettype = 'bool'::regtype AND NOT p2.proretset);
 
+-- there does not seem to be a reason to care about volatility of typanalyze
+
 -- domains inherit their base type's typanalyze
 
 SELECT d.oid, d.typname, d.typanalyze, t.oid, t.typname, t.typanalyze