Code review for protransform patches.

Fix loss of previous expression-simplification work when a transform
function fires: we must not simply revert to untransformed input tree.
Instead build a dummy FuncExpr node to pass to the transform function.
This has the additional advantage of providing a simpler, more uniform
API for transform functions.

Move documentation to a somewhat less buried spot, relocate some
poorly-placed code, be more wary of null constants and invalid typmod
values, add an opr_sanity check on protransform function signatures,
and some other minor cosmetic adjustments.

Note: although this patch touches pg_proc.h, no need for catversion
bump, because the changes are cosmetic and don't actually change the
intended catalog contents.

3 files changed, 13 insertions, 13 deletions

diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 2db848903c..49b0754a2c 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -767,7 +767,7 @@ DATA(insert OID = 668 (  bpchar			   PGNSP PGUID 12 1 0 0 0 f f f f t f i 3 0 10
 DESCR("adjust char() to typmod length");
 DATA(insert OID = 3097 ( varchar_transform PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 2281 "2281" _null_ _null_ _null_ _null_ varchar_transform _null_ _null_ _null_ ));
 DESCR("transform a varchar length coercion");
-DATA(insert OID = 669 (  varchar		   PGNSP PGUID 12 1 0 0 3097 f f f f t f i 3 0 1043 "1043 23 16" _null_ _null_ _null_ _null_ varchar _null_ _null_ _null_ ));
+DATA(insert OID = 669 (  varchar		   PGNSP PGUID 12 1 0 0 varchar_transform f f f f t f i 3 0 1043 "1043 23 16" _null_ _null_ _null_ _null_ varchar _null_ _null_ _null_ ));
 DESCR("adjust varchar() to typmod length");
 
 DATA(insert OID = 676 (  mktinterval	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 704 "702 702" _null_ _null_ _null_ _null_ mktinterval _null_ _null_ _null_ ));
@@ -1267,7 +1267,7 @@ DESCR("date difference preserving months and years");
 
 DATA(insert OID = 3918 (  interval_transform PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 2281 "2281" _null_ _null_ _null_ _null_ interval_transform _null_ _null_ _null_ ));
 DESCR("transform an interval length coercion");
-DATA(insert OID = 1200 (  interval			PGNSP PGUID 12 1 0 0 3918 f f f f t f i 2 0 1186 "1186 23" _null_ _null_ _null_ _null_ interval_scale _null_ _null_ _null_ ));
+DATA(insert OID = 1200 (  interval			PGNSP PGUID 12 1 0 0 interval_transform f f f f t f i 2 0 1186 "1186 23" _null_ _null_ _null_ _null_ interval_scale _null_ _null_ _null_ ));
 DESCR("adjust interval precision");
 
 DATA(insert OID = 1215 (  obj_description	PGNSP PGUID 14 100 0 0 0 f f f f t f s 2 0 25 "26 19" _null_ _null_ _null_ _null_ "select description from pg_catalog.pg_description where objoid = $1 and classoid = (select oid from pg_catalog.pg_class where relname = $2 and relnamespace = PGNSP) and objsubid = 0" _null_ _null_ _null_ ));
@@ -2023,7 +2023,7 @@ DATA(insert OID = 1685 (  bit			   PGNSP PGUID 12 1 0 0 0 f f f f t f i 3 0 1560
 DESCR("adjust bit() to typmod length");
 DATA(insert OID = 3158 ( varbit_transform  PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 2281 "2281" _null_ _null_ _null_ _null_ varbit_transform _null_ _null_ _null_ ));
 DESCR("transform a varbit length coercion");
-DATA(insert OID = 1687 (  varbit		   PGNSP PGUID 12 1 0 0 3158 f f f f t f i 3 0 1562 "1562 23 16" _null_ _null_ _null_ _null_ varbit _null_ _null_ _null_ ));
+DATA(insert OID = 1687 (  varbit		   PGNSP PGUID 12 1 0 0 varbit_transform f f f f t f i 3 0 1562 "1562 23 16" _null_ _null_ _null_ _null_ varbit _null_ _null_ _null_ ));
 DESCR("adjust varbit() to typmod length");
 
 DATA(insert OID = 1698 (  position		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 23 "1560 1560" _null_ _null_ _null_ _null_ bitposition _null_ _null_ _null_ ));
@@ -2156,10 +2156,10 @@ DATA(insert OID = 2917 (  numerictypmodin		PGNSP PGUID 12 1 0 0 0 f f f f t f i
 DESCR("I/O typmod");
 DATA(insert OID = 2918 (  numerictypmodout		PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 2275 "23" _null_ _null_ _null_ _null_	numerictypmodout _null_ _null_ _null_ ));
 DESCR("I/O typmod");
-DATA(insert OID = 1703 ( numeric				PGNSP PGUID 12 1 0 0 3157 f f f f t f i 2 0 1700 "1700 23" _null_ _null_ _null_ _null_ numeric _null_ _null_ _null_ ));
-DESCR("adjust numeric to typmod precision/scale");
 DATA(insert OID = 3157 ( numeric_transform		PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 2281 "2281" _null_ _null_ _null_ _null_ numeric_transform _null_ _null_ _null_ ));
 DESCR("transform a numeric length coercion");
+DATA(insert OID = 1703 ( numeric				PGNSP PGUID 12 1 0 0 numeric_transform f f f f t f i 2 0 1700 "1700 23" _null_ _null_ _null_ _null_ numeric _null_ _null_ _null_ ));
+DESCR("adjust numeric to typmod precision/scale");
 DATA(insert OID = 1704 ( numeric_abs			PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1700" _null_ _null_ _null_ _null_ numeric_abs _null_ _null_ _null_ ));
 DATA(insert OID = 1705 ( abs					PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 1700 "1700" _null_ _null_ _null_ _null_ numeric_abs _null_ _null_ _null_ ));
 DESCR("absolute value");
@@ -2746,7 +2746,10 @@ DESCR("less-equal-greater");
 
 DATA(insert OID = 3917 (  timestamp_transform PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 2281 "2281" _null_ _null_ _null_ _null_ timestamp_transform _null_ _null_ _null_ ));
 DESCR("transform a timestamp length coercion");
-DATA(insert OID = 1961 (  timestamp		   PGNSP PGUID 12 1 0 0 3917 f f f f t f i 2 0 1114 "1114 23" _null_ _null_ _null_ _null_ timestamp_scale _null_ _null_ _null_ ));
+DATA(insert OID = 3944 (  time_transform   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 2281 "2281" _null_ _null_ _null_ _null_ time_transform _null_ _null_ _null_ ));
+DESCR("transform a time length coercion");
+
+DATA(insert OID = 1961 (  timestamp		   PGNSP PGUID 12 1 0 0 timestamp_transform f f f f t f i 2 0 1114 "1114 23" _null_ _null_ _null_ _null_ timestamp_scale _null_ _null_ _null_ ));
 DESCR("adjust timestamp precision");
 
 DATA(insert OID = 1965 (  oidlarger		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 26 "26 26" _null_ _null_ _null_ _null_ oidlarger _null_ _null_ _null_ ));
@@ -2754,13 +2757,11 @@ DESCR("larger of two");
 DATA(insert OID = 1966 (  oidsmaller	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 26 "26 26" _null_ _null_ _null_ _null_ oidsmaller _null_ _null_ _null_ ));
 DESCR("smaller of two");
 
-DATA(insert OID = 1967 (  timestamptz	   PGNSP PGUID 12 1 0 0 3917 f f f f t f i 2 0 1184 "1184 23" _null_ _null_ _null_ _null_ timestamptz_scale _null_ _null_ _null_ ));
+DATA(insert OID = 1967 (  timestamptz	   PGNSP PGUID 12 1 0 0 timestamp_transform f f f f t f i 2 0 1184 "1184 23" _null_ _null_ _null_ _null_ timestamptz_scale _null_ _null_ _null_ ));
 DESCR("adjust timestamptz precision");
-DATA(insert OID = 3944 (  time_transform   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 2281 "2281" _null_ _null_ _null_ _null_ time_transform _null_ _null_ _null_ ));
-DESCR("transform a time length coercion");
-DATA(insert OID = 1968 (  time			   PGNSP PGUID 12 1 0 0 3944 f f f f t f i 2 0 1083 "1083 23" _null_ _null_ _null_ _null_ time_scale _null_ _null_ _null_ ));
+DATA(insert OID = 1968 (  time			   PGNSP PGUID 12 1 0 0 time_transform f f f f t f i 2 0 1083 "1083 23" _null_ _null_ _null_ _null_ time_scale _null_ _null_ _null_ ));
 DESCR("adjust time precision");
-DATA(insert OID = 1969 (  timetz		   PGNSP PGUID 12 1 0 0 3944 f f f f t f i 2 0 1266 "1266 23" _null_ _null_ _null_ _null_ timetz_scale _null_ _null_ _null_ ));
+DATA(insert OID = 1969 (  timetz		   PGNSP PGUID 12 1 0 0 time_transform f f f f t f i 2 0 1266 "1266 23" _null_ _null_ _null_ _null_ timetz_scale _null_ _null_ _null_ ));
 DESCR("adjust time with time zone precision");
 
 DATA(insert OID = 2003 (  textanycat	   PGNSP PGUID 14 1 0 0 0 f f f f t f s 2 0 25 "25 2776" _null_ _null_ _null_ _null_ "select $1 || $2::pg_catalog.text" _null_ _null_ _null_ ));
diff --git a/src/include/nodes/nodeFuncs.h b/src/include/nodes/nodeFuncs.h
index def4f313ab..e609e4bae2 100644
--- a/src/include/nodes/nodeFuncs.h
+++ b/src/include/nodes/nodeFuncs.h
@@ -29,6 +29,7 @@
 extern Oid	exprType(const Node *expr);
 extern int32 exprTypmod(const Node *expr);
 extern bool exprIsLengthCoercion(const Node *expr, int32 *coercedTypmod);
+extern Node *relabel_to_typmod(Node *expr, int32 typmod);
 extern bool expression_returns_set(Node *clause);
 
 extern Oid	exprCollation(const Node *expr);
diff --git a/src/include/parser/parse_clause.h b/src/include/parser/parse_clause.h
index f8eb41aad4..fd3fc8f570 100644
--- a/src/include/parser/parse_clause.h
+++ b/src/include/parser/parse_clause.h
@@ -44,6 +44,4 @@ extern List *transformDistinctOnClause(ParseState *pstate, List *distinctlist,
 extern Index assignSortGroupRef(TargetEntry *tle, List *tlist);
 extern bool targetIsInSortList(TargetEntry *tle, Oid sortop, List *sortList);
 
-extern Node *relabel_to_typmod(Node *expr, int32 typmod);
-
 #endif   /* PARSE_CLAUSE_H */