Remove no-longer-required function declarations.

Remove a bunch of "extern Datum foo(PG_FUNCTION_ARGS);" declarations that
are no longer needed now that PG_FUNCTION_INFO_V1(foo) provides that.

Some of these were evidently missed in commit e7128e8dbb305059, but others
were cargo-culted in in code added since then.  Possibly that can be blamed
in part on the fact that we'd not fixed relevant documentation examples,
which I've now done.

37 files changed, 3 insertions, 170 deletions

diff --git a/contrib/hstore_plperl/hstore_plperl.c b/contrib/hstore_plperl/hstore_plperl.c
index dcc74b12e8..fbbb4c8e76 100644
--- a/contrib/hstore_plperl/hstore_plperl.c
+++ b/contrib/hstore_plperl/hstore_plperl.c
@@ -9,7 +9,6 @@ PG_MODULE_MAGIC;
 
 
 PG_FUNCTION_INFO_V1(hstore_to_plperl);
-Datum		hstore_to_plperl(PG_FUNCTION_ARGS);
 
 Datum
 hstore_to_plperl(PG_FUNCTION_ARGS)
@@ -39,7 +38,6 @@ hstore_to_plperl(PG_FUNCTION_ARGS)
 
 
 PG_FUNCTION_INFO_V1(plperl_to_hstore);
-Datum		plperl_to_hstore(PG_FUNCTION_ARGS);
 
 Datum
 plperl_to_hstore(PG_FUNCTION_ARGS)
diff --git a/contrib/hstore_plpython/hstore_plpython.c b/contrib/hstore_plpython/hstore_plpython.c
index 94404a5061..a3316dd9eb 100644
--- a/contrib/hstore_plpython/hstore_plpython.c
+++ b/contrib/hstore_plpython/hstore_plpython.c
@@ -8,7 +8,6 @@ PG_MODULE_MAGIC;
 
 
 PG_FUNCTION_INFO_V1(hstore_to_plpython);
-Datum		hstore_to_plpython(PG_FUNCTION_ARGS);
 
 Datum
 hstore_to_plpython(PG_FUNCTION_ARGS)
@@ -45,7 +44,6 @@ hstore_to_plpython(PG_FUNCTION_ARGS)
 
 
 PG_FUNCTION_INFO_V1(plpython_to_hstore);
-Datum		plpython_to_hstore(PG_FUNCTION_ARGS);
 
 Datum
 plpython_to_hstore(PG_FUNCTION_ARGS)
diff --git a/contrib/ltree_plpython/ltree_plpython.c b/contrib/ltree_plpython/ltree_plpython.c
index af166a720f..26b7b3c275 100644
--- a/contrib/ltree_plpython/ltree_plpython.c
+++ b/contrib/ltree_plpython/ltree_plpython.c
@@ -7,7 +7,6 @@ PG_MODULE_MAGIC;
 
 
 PG_FUNCTION_INFO_V1(ltree_to_plpython);
-Datum		ltree_to_plpython(PG_FUNCTION_ARGS);
 
 Datum
 ltree_to_plpython(PG_FUNCTION_ARGS)
diff --git a/contrib/pg_audit/pg_audit.c b/contrib/pg_audit/pg_audit.c
index a4b05a6df1..a664d0804b 100644
--- a/contrib/pg_audit/pg_audit.c
+++ b/contrib/pg_audit/pg_audit.c
@@ -42,10 +42,6 @@ PG_MODULE_MAGIC;
 
 void		_PG_init(void);
 
-/* Prototypes for functions used with event triggers */
-Datum		pg_audit_ddl_command_end(PG_FUNCTION_ARGS);
-Datum		pg_audit_sql_drop(PG_FUNCTION_ARGS);
-
 PG_FUNCTION_INFO_V1(pg_audit_ddl_command_end);
 PG_FUNCTION_INFO_V1(pg_audit_sql_drop);
 
diff --git a/doc/src/sgml/event-trigger.sgml b/doc/src/sgml/event-trigger.sgml
index 0cb31a478f..b6cbb1bc24 100644
--- a/doc/src/sgml/event-trigger.sgml
+++ b/doc/src/sgml/event-trigger.sgml
@@ -998,8 +998,6 @@ typedef struct EventTriggerData
 
 PG_MODULE_MAGIC;
 
-Datum noddl(PG_FUNCTION_ARGS);
-
 PG_FUNCTION_INFO_V1(noddl);
 
 Datum
diff --git a/doc/src/sgml/gist.sgml b/doc/src/sgml/gist.sgml
index dd5d6f9fea..2d1a5aa863 100644
--- a/doc/src/sgml/gist.sgml
+++ b/doc/src/sgml/gist.sgml
@@ -327,7 +327,6 @@ LANGUAGE C STRICT;
         And the matching code in the C module could then follow this skeleton:
 
 <programlisting>
-Datum       my_consistent(PG_FUNCTION_ARGS);
 PG_FUNCTION_INFO_V1(my_consistent);
 
 Datum
@@ -390,7 +389,6 @@ LANGUAGE C STRICT;
         And the matching code in the C module could then follow this skeleton:
 
 <programlisting>
-Datum       my_union(PG_FUNCTION_ARGS);
 PG_FUNCTION_INFO_V1(my_union);
 
 Datum
@@ -464,7 +462,6 @@ LANGUAGE C STRICT;
         And the matching code in the C module could then follow this skeleton:
 
 <programlisting>
-Datum       my_compress(PG_FUNCTION_ARGS);
 PG_FUNCTION_INFO_V1(my_compress);
 
 Datum
@@ -525,7 +522,6 @@ LANGUAGE C STRICT;
         And the matching code in the C module could then follow this skeleton:
 
 <programlisting>
-Datum       my_decompress(PG_FUNCTION_ARGS);
 PG_FUNCTION_INFO_V1(my_decompress);
 
 Datum
@@ -565,7 +561,6 @@ LANGUAGE C STRICT;  -- in some cases penalty functions need not be strict
         And the matching code in the C module could then follow this skeleton:
 
 <programlisting>
-Datum       my_penalty(PG_FUNCTION_ARGS);
 PG_FUNCTION_INFO_V1(my_penalty);
 
 Datum
@@ -614,7 +609,6 @@ LANGUAGE C STRICT;
         And the matching code in the C module could then follow this skeleton:
 
 <programlisting>
-Datum       my_picksplit(PG_FUNCTION_ARGS);
 PG_FUNCTION_INFO_V1(my_picksplit);
 
 Datum
@@ -721,7 +715,6 @@ LANGUAGE C STRICT;
         And the matching code in the C module could then follow this skeleton:
 
 <programlisting>
-Datum       my_same(PG_FUNCTION_ARGS);
 PG_FUNCTION_INFO_V1(my_same);
 
 Datum
@@ -772,7 +765,6 @@ LANGUAGE C STRICT;
         And the matching code in the C module could then follow this skeleton:
 
 <programlisting>
-Datum       my_distance(PG_FUNCTION_ARGS);
 PG_FUNCTION_INFO_V1(my_distance);
 
 Datum
@@ -859,7 +851,6 @@ LANGUAGE C STRICT;
         The matching code in the C module could then follow this skeleton:
 
 <programlisting>
-Datum       my_fetch(PG_FUNCTION_ARGS);
 PG_FUNCTION_INFO_V1(my_fetch);
 
 Datum
diff --git a/doc/src/sgml/trigger.sgml b/doc/src/sgml/trigger.sgml
index bd0d71e0d9..52f28bca7a 100644
--- a/doc/src/sgml/trigger.sgml
+++ b/doc/src/sgml/trigger.sgml
@@ -709,11 +709,7 @@ CREATE TABLE ttest (
 #include "commands/trigger.h"   /* ... triggers ... */
 #include "utils/rel.h"          /* ... and relations */
 
-#ifdef PG_MODULE_MAGIC
 PG_MODULE_MAGIC;
-#endif
-
-extern Datum trigf(PG_FUNCTION_ARGS);
 
 PG_FUNCTION_INFO_V1(trigf);
 
diff --git a/src/backend/snowball/dict_snowball.c b/src/backend/snowball/dict_snowball.c
index bc31839bdd..63b471ea51 100644
--- a/src/backend/snowball/dict_snowball.c
+++ b/src/backend/snowball/dict_snowball.c
@@ -61,10 +61,8 @@
 PG_MODULE_MAGIC;
 
 PG_FUNCTION_INFO_V1(dsnowball_init);
-Datum		dsnowball_init(PG_FUNCTION_ARGS);
 
 PG_FUNCTION_INFO_V1(dsnowball_lexize);
-Datum		dsnowball_lexize(PG_FUNCTION_ARGS);
 
 /* List of supported modules */
 typedef struct stemmer_module
diff --git a/src/backend/utils/mb/conversion_procs/ascii_and_mic/ascii_and_mic.c b/src/backend/utils/mb/conversion_procs/ascii_and_mic/ascii_and_mic.c
index 506cf3a6d0..1d77103edf 100644
--- a/src/backend/utils/mb/conversion_procs/ascii_and_mic/ascii_and_mic.c
+++ b/src/backend/utils/mb/conversion_procs/ascii_and_mic/ascii_and_mic.c
@@ -20,9 +20,6 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(ascii_to_mic);
 PG_FUNCTION_INFO_V1(mic_to_ascii);
 
-extern Datum ascii_to_mic(PG_FUNCTION_ARGS);
-extern Datum mic_to_ascii(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/backend/utils/mb/conversion_procs/cyrillic_and_mic/cyrillic_and_mic.c b/src/backend/utils/mb/conversion_procs/cyrillic_and_mic/cyrillic_and_mic.c
index cb7244085d..5d1c59b842 100644
--- a/src/backend/utils/mb/conversion_procs/cyrillic_and_mic/cyrillic_and_mic.c
+++ b/src/backend/utils/mb/conversion_procs/cyrillic_and_mic/cyrillic_and_mic.c
@@ -40,27 +40,6 @@ PG_FUNCTION_INFO_V1(win1251_to_iso);
 PG_FUNCTION_INFO_V1(iso_to_win866);
 PG_FUNCTION_INFO_V1(win866_to_iso);
 
-extern Datum koi8r_to_mic(PG_FUNCTION_ARGS);
-extern Datum mic_to_koi8r(PG_FUNCTION_ARGS);
-extern Datum iso_to_mic(PG_FUNCTION_ARGS);
-extern Datum mic_to_iso(PG_FUNCTION_ARGS);
-extern Datum win1251_to_mic(PG_FUNCTION_ARGS);
-extern Datum mic_to_win1251(PG_FUNCTION_ARGS);
-extern Datum win866_to_mic(PG_FUNCTION_ARGS);
-extern Datum mic_to_win866(PG_FUNCTION_ARGS);
-extern Datum koi8r_to_win1251(PG_FUNCTION_ARGS);
-extern Datum win1251_to_koi8r(PG_FUNCTION_ARGS);
-extern Datum koi8r_to_win866(PG_FUNCTION_ARGS);
-extern Datum win866_to_koi8r(PG_FUNCTION_ARGS);
-extern Datum win866_to_win1251(PG_FUNCTION_ARGS);
-extern Datum win1251_to_win866(PG_FUNCTION_ARGS);
-extern Datum iso_to_koi8r(PG_FUNCTION_ARGS);
-extern Datum koi8r_to_iso(PG_FUNCTION_ARGS);
-extern Datum iso_to_win1251(PG_FUNCTION_ARGS);
-extern Datum win1251_to_iso(PG_FUNCTION_ARGS);
-extern Datum iso_to_win866(PG_FUNCTION_ARGS);
-extern Datum win866_to_iso(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/backend/utils/mb/conversion_procs/euc2004_sjis2004/euc2004_sjis2004.c b/src/backend/utils/mb/conversion_procs/euc2004_sjis2004/euc2004_sjis2004.c
index 1702ad8aeb..398ceb1ab0 100644
--- a/src/backend/utils/mb/conversion_procs/euc2004_sjis2004/euc2004_sjis2004.c
+++ b/src/backend/utils/mb/conversion_procs/euc2004_sjis2004/euc2004_sjis2004.c
@@ -19,9 +19,6 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(euc_jis_2004_to_shift_jis_2004);
 PG_FUNCTION_INFO_V1(shift_jis_2004_to_euc_jis_2004);
 
-extern Datum euc_jis_2004_to_shift_jis_2004(PG_FUNCTION_ARGS);
-extern Datum shift_jis_2004_to_euc_jis_2004(PG_FUNCTION_ARGS);
-
 static void euc_jis_20042shift_jis_2004(const unsigned char *euc, unsigned char *p, int len);
 static void shift_jis_20042euc_jis_2004(const unsigned char *sjis, unsigned char *p, int len);
 
diff --git a/src/backend/utils/mb/conversion_procs/euc_cn_and_mic/euc_cn_and_mic.c b/src/backend/utils/mb/conversion_procs/euc_cn_and_mic/euc_cn_and_mic.c
index 3f2e817e5f..534fd69966 100644
--- a/src/backend/utils/mb/conversion_procs/euc_cn_and_mic/euc_cn_and_mic.c
+++ b/src/backend/utils/mb/conversion_procs/euc_cn_and_mic/euc_cn_and_mic.c
@@ -20,9 +20,6 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(euc_cn_to_mic);
 PG_FUNCTION_INFO_V1(mic_to_euc_cn);
 
-extern Datum euc_cn_to_mic(PG_FUNCTION_ARGS);
-extern Datum mic_to_euc_cn(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/backend/utils/mb/conversion_procs/euc_jp_and_sjis/euc_jp_and_sjis.c b/src/backend/utils/mb/conversion_procs/euc_jp_and_sjis/euc_jp_and_sjis.c
index 3fe7e7933b..c56a91951b 100644
--- a/src/backend/utils/mb/conversion_procs/euc_jp_and_sjis/euc_jp_and_sjis.c
+++ b/src/backend/utils/mb/conversion_procs/euc_jp_and_sjis/euc_jp_and_sjis.c
@@ -36,13 +36,6 @@ PG_FUNCTION_INFO_V1(mic_to_euc_jp);
 PG_FUNCTION_INFO_V1(sjis_to_mic);
 PG_FUNCTION_INFO_V1(mic_to_sjis);
 
-extern Datum euc_jp_to_sjis(PG_FUNCTION_ARGS);
-extern Datum sjis_to_euc_jp(PG_FUNCTION_ARGS);
-extern Datum euc_jp_to_mic(PG_FUNCTION_ARGS);
-extern Datum mic_to_euc_jp(PG_FUNCTION_ARGS);
-extern Datum sjis_to_mic(PG_FUNCTION_ARGS);
-extern Datum mic_to_sjis(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/backend/utils/mb/conversion_procs/euc_kr_and_mic/euc_kr_and_mic.c b/src/backend/utils/mb/conversion_procs/euc_kr_and_mic/euc_kr_and_mic.c
index 3ea16e6ee7..db4afd94c8 100644
--- a/src/backend/utils/mb/conversion_procs/euc_kr_and_mic/euc_kr_and_mic.c
+++ b/src/backend/utils/mb/conversion_procs/euc_kr_and_mic/euc_kr_and_mic.c
@@ -20,9 +20,6 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(euc_kr_to_mic);
 PG_FUNCTION_INFO_V1(mic_to_euc_kr);
 
-extern Datum euc_kr_to_mic(PG_FUNCTION_ARGS);
-extern Datum mic_to_euc_kr(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/backend/utils/mb/conversion_procs/euc_tw_and_big5/euc_tw_and_big5.c b/src/backend/utils/mb/conversion_procs/euc_tw_and_big5/euc_tw_and_big5.c
index 2afb3b9b60..795d51cbee 100644
--- a/src/backend/utils/mb/conversion_procs/euc_tw_and_big5/euc_tw_and_big5.c
+++ b/src/backend/utils/mb/conversion_procs/euc_tw_and_big5/euc_tw_and_big5.c
@@ -26,13 +26,6 @@ PG_FUNCTION_INFO_V1(mic_to_euc_tw);
 PG_FUNCTION_INFO_V1(big5_to_mic);
 PG_FUNCTION_INFO_V1(mic_to_big5);
 
-extern Datum euc_tw_to_big5(PG_FUNCTION_ARGS);
-extern Datum big5_to_euc_tw(PG_FUNCTION_ARGS);
-extern Datum euc_tw_to_mic(PG_FUNCTION_ARGS);
-extern Datum mic_to_euc_tw(PG_FUNCTION_ARGS);
-extern Datum big5_to_mic(PG_FUNCTION_ARGS);
-extern Datum mic_to_big5(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/backend/utils/mb/conversion_procs/latin2_and_win1250/latin2_and_win1250.c b/src/backend/utils/mb/conversion_procs/latin2_and_win1250/latin2_and_win1250.c
index 58d75be35e..8f831ba1b3 100644
--- a/src/backend/utils/mb/conversion_procs/latin2_and_win1250/latin2_and_win1250.c
+++ b/src/backend/utils/mb/conversion_procs/latin2_and_win1250/latin2_and_win1250.c
@@ -26,13 +26,6 @@ PG_FUNCTION_INFO_V1(mic_to_win1250);
 PG_FUNCTION_INFO_V1(latin2_to_win1250);
 PG_FUNCTION_INFO_V1(win1250_to_latin2);
 
-extern Datum latin2_to_mic(PG_FUNCTION_ARGS);
-extern Datum mic_to_latin2(PG_FUNCTION_ARGS);
-extern Datum win1250_to_mic(PG_FUNCTION_ARGS);
-extern Datum mic_to_win1250(PG_FUNCTION_ARGS);
-extern Datum latin2_to_win1250(PG_FUNCTION_ARGS);
-extern Datum win1250_to_latin2(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/backend/utils/mb/conversion_procs/latin_and_mic/latin_and_mic.c b/src/backend/utils/mb/conversion_procs/latin_and_mic/latin_and_mic.c
index 35ded6b1bb..b727691994 100644
--- a/src/backend/utils/mb/conversion_procs/latin_and_mic/latin_and_mic.c
+++ b/src/backend/utils/mb/conversion_procs/latin_and_mic/latin_and_mic.c
@@ -24,13 +24,6 @@ PG_FUNCTION_INFO_V1(mic_to_latin3);
 PG_FUNCTION_INFO_V1(latin4_to_mic);
 PG_FUNCTION_INFO_V1(mic_to_latin4);
 
-extern Datum latin1_to_mic(PG_FUNCTION_ARGS);
-extern Datum mic_to_latin1(PG_FUNCTION_ARGS);
-extern Datum latin3_to_mic(PG_FUNCTION_ARGS);
-extern Datum mic_to_latin3(PG_FUNCTION_ARGS);
-extern Datum latin4_to_mic(PG_FUNCTION_ARGS);
-extern Datum mic_to_latin4(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_ascii/utf8_and_ascii.c b/src/backend/utils/mb/conversion_procs/utf8_and_ascii/utf8_and_ascii.c
index 96d80477ed..22cb01ab83 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_ascii/utf8_and_ascii.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_ascii/utf8_and_ascii.c
@@ -20,9 +20,6 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(ascii_to_utf8);
 PG_FUNCTION_INFO_V1(utf8_to_ascii);
 
-extern Datum ascii_to_utf8(PG_FUNCTION_ARGS);
-extern Datum utf8_to_ascii(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_big5/utf8_and_big5.c b/src/backend/utils/mb/conversion_procs/utf8_and_big5/utf8_and_big5.c
index a422a26d00..ed2ef1170f 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_big5/utf8_and_big5.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_big5/utf8_and_big5.c
@@ -22,9 +22,6 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(big5_to_utf8);
 PG_FUNCTION_INFO_V1(utf8_to_big5);
 
-extern Datum big5_to_utf8(PG_FUNCTION_ARGS);
-extern Datum utf8_to_big5(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_cyrillic/utf8_and_cyrillic.c b/src/backend/utils/mb/conversion_procs/utf8_and_cyrillic/utf8_and_cyrillic.c
index f2b01e50a3..65e7616eea 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_cyrillic/utf8_and_cyrillic.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_cyrillic/utf8_and_cyrillic.c
@@ -27,12 +27,6 @@ PG_FUNCTION_INFO_V1(koi8r_to_utf8);
 PG_FUNCTION_INFO_V1(utf8_to_koi8u);
 PG_FUNCTION_INFO_V1(koi8u_to_utf8);
 
-extern Datum utf8_to_koi8r(PG_FUNCTION_ARGS);
-extern Datum koi8r_to_utf8(PG_FUNCTION_ARGS);
-
-extern Datum utf8_to_koi8u(PG_FUNCTION_ARGS);
-extern Datum koi8u_to_utf8(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_euc2004/utf8_and_euc2004.c b/src/backend/utils/mb/conversion_procs/utf8_and_euc2004/utf8_and_euc2004.c
index a49eda8838..cba8958fa3 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_euc2004/utf8_and_euc2004.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_euc2004/utf8_and_euc2004.c
@@ -24,9 +24,6 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(euc_jis_2004_to_utf8);
 PG_FUNCTION_INFO_V1(utf8_to_euc_jis_2004);
 
-extern Datum euc_jis_2004_to_utf8(PG_FUNCTION_ARGS);
-extern Datum utf8_to_euc_jis_2004(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_euc_cn/utf8_and_euc_cn.c b/src/backend/utils/mb/conversion_procs/utf8_and_euc_cn/utf8_and_euc_cn.c
index 8332926317..fcc8659bc6 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_euc_cn/utf8_and_euc_cn.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_euc_cn/utf8_and_euc_cn.c
@@ -22,9 +22,6 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(euc_cn_to_utf8);
 PG_FUNCTION_INFO_V1(utf8_to_euc_cn);
 
-extern Datum euc_cn_to_utf8(PG_FUNCTION_ARGS);
-extern Datum utf8_to_euc_cn(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_euc_jp/utf8_and_euc_jp.c b/src/backend/utils/mb/conversion_procs/utf8_and_euc_jp/utf8_and_euc_jp.c
index 6d9aeb4138..0524ec2497 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_euc_jp/utf8_and_euc_jp.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_euc_jp/utf8_and_euc_jp.c
@@ -22,9 +22,6 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(euc_jp_to_utf8);
 PG_FUNCTION_INFO_V1(utf8_to_euc_jp);
 
-extern Datum euc_jp_to_utf8(PG_FUNCTION_ARGS);
-extern Datum utf8_to_euc_jp(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_euc_kr/utf8_and_euc_kr.c b/src/backend/utils/mb/conversion_procs/utf8_and_euc_kr/utf8_and_euc_kr.c
index 7edd09b115..14b2fefa56 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_euc_kr/utf8_and_euc_kr.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_euc_kr/utf8_and_euc_kr.c
@@ -22,9 +22,6 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(euc_kr_to_utf8);
 PG_FUNCTION_INFO_V1(utf8_to_euc_kr);
 
-extern Datum euc_kr_to_utf8(PG_FUNCTION_ARGS);
-extern Datum utf8_to_euc_kr(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_euc_tw/utf8_and_euc_tw.c b/src/backend/utils/mb/conversion_procs/utf8_and_euc_tw/utf8_and_euc_tw.c
index bc129993ba..a956ebb3e9 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_euc_tw/utf8_and_euc_tw.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_euc_tw/utf8_and_euc_tw.c
@@ -22,9 +22,6 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(euc_tw_to_utf8);
 PG_FUNCTION_INFO_V1(utf8_to_euc_tw);
 
-extern Datum euc_tw_to_utf8(PG_FUNCTION_ARGS);
-extern Datum utf8_to_euc_tw(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_gb18030/utf8_and_gb18030.c b/src/backend/utils/mb/conversion_procs/utf8_and_gb18030/utf8_and_gb18030.c
index 60f0a21925..de2438525e 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_gb18030/utf8_and_gb18030.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_gb18030/utf8_and_gb18030.c
@@ -22,9 +22,6 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(gb18030_to_utf8);
 PG_FUNCTION_INFO_V1(utf8_to_gb18030);
 
-extern Datum gb18030_to_utf8(PG_FUNCTION_ARGS);
-extern Datum utf8_to_gb18030(PG_FUNCTION_ARGS);
-
 /*
  * Convert 4-byte GB18030 characters to and from a linear code space
  *
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_gbk/utf8_and_gbk.c b/src/backend/utils/mb/conversion_procs/utf8_and_gbk/utf8_and_gbk.c
index adc33a68e6..f48fdd3cef 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_gbk/utf8_and_gbk.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_gbk/utf8_and_gbk.c
@@ -22,9 +22,6 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(gbk_to_utf8);
 PG_FUNCTION_INFO_V1(utf8_to_gbk);
 
-extern Datum gbk_to_utf8(PG_FUNCTION_ARGS);
-extern Datum utf8_to_gbk(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_iso8859/utf8_and_iso8859.c b/src/backend/utils/mb/conversion_procs/utf8_and_iso8859/utf8_and_iso8859.c
index 39e4ce12e5..7057c6d889 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_iso8859/utf8_and_iso8859.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_iso8859/utf8_and_iso8859.c
@@ -46,9 +46,6 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(iso8859_to_utf8);
 PG_FUNCTION_INFO_V1(utf8_to_iso8859);
 
-extern Datum iso8859_to_utf8(PG_FUNCTION_ARGS);
-extern Datum utf8_to_iso8859(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_iso8859_1/utf8_and_iso8859_1.c b/src/backend/utils/mb/conversion_procs/utf8_and_iso8859_1/utf8_and_iso8859_1.c
index 13a62e11a1..3635674a84 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_iso8859_1/utf8_and_iso8859_1.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_iso8859_1/utf8_and_iso8859_1.c
@@ -20,9 +20,6 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(iso8859_1_to_utf8);
 PG_FUNCTION_INFO_V1(utf8_to_iso8859_1);
 
-extern Datum iso8859_1_to_utf8(PG_FUNCTION_ARGS);
-extern Datum utf8_to_iso8859_1(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_johab/utf8_and_johab.c b/src/backend/utils/mb/conversion_procs/utf8_and_johab/utf8_and_johab.c
index 15b49f24b1..2a08f2a391 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_johab/utf8_and_johab.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_johab/utf8_and_johab.c
@@ -22,9 +22,6 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(johab_to_utf8);
 PG_FUNCTION_INFO_V1(utf8_to_johab);
 
-extern Datum johab_to_utf8(PG_FUNCTION_ARGS);
-extern Datum utf8_to_johab(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_sjis/utf8_and_sjis.c b/src/backend/utils/mb/conversion_procs/utf8_and_sjis/utf8_and_sjis.c
index 7a3281b640..fda2bbdb81 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_sjis/utf8_and_sjis.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_sjis/utf8_and_sjis.c
@@ -22,9 +22,6 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(sjis_to_utf8);
 PG_FUNCTION_INFO_V1(utf8_to_sjis);
 
-extern Datum sjis_to_utf8(PG_FUNCTION_ARGS);
-extern Datum utf8_to_sjis(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_sjis2004/utf8_and_sjis2004.c b/src/backend/utils/mb/conversion_procs/utf8_and_sjis2004/utf8_and_sjis2004.c
index 29f4256fe0..1727c685aa 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_sjis2004/utf8_and_sjis2004.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_sjis2004/utf8_and_sjis2004.c
@@ -24,9 +24,6 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(shift_jis_2004_to_utf8);
 PG_FUNCTION_INFO_V1(utf8_to_shift_jis_2004);
 
-extern Datum shift_jis_2004_to_utf8(PG_FUNCTION_ARGS);
-extern Datum utf8_to_shift_jis_2004(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_uhc/utf8_and_uhc.c b/src/backend/utils/mb/conversion_procs/utf8_and_uhc/utf8_and_uhc.c
index 984980935d..43fe289c96 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_uhc/utf8_and_uhc.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_uhc/utf8_and_uhc.c
@@ -22,9 +22,6 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(uhc_to_utf8);
 PG_FUNCTION_INFO_V1(utf8_to_uhc);
 
-extern Datum uhc_to_utf8(PG_FUNCTION_ARGS);
-extern Datum utf8_to_uhc(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_win/utf8_and_win.c b/src/backend/utils/mb/conversion_procs/utf8_and_win/utf8_and_win.c
index c2a4ec35f7..2304ea24ba 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_win/utf8_and_win.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_win/utf8_and_win.c
@@ -42,9 +42,6 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(win_to_utf8);
 PG_FUNCTION_INFO_V1(utf8_to_win);
 
-extern Datum win_to_utf8(PG_FUNCTION_ARGS);
-extern Datum utf8_to_win(PG_FUNCTION_ARGS);
-
 /* ----------
  * conv_proc(
  *		INTEGER,	-- source encoding id
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 4d614430ce..026ed55a3c 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -401,9 +401,9 @@ extern Datum jsonb_pretty(PG_FUNCTION_ARGS);
 extern Datum jsonb_concat(PG_FUNCTION_ARGS);
 
 /* deletion */
-Datum		jsonb_delete(PG_FUNCTION_ARGS);
-Datum		jsonb_delete_idx(PG_FUNCTION_ARGS);
-Datum		jsonb_delete_path(PG_FUNCTION_ARGS);
+extern Datum jsonb_delete(PG_FUNCTION_ARGS);
+extern Datum jsonb_delete_idx(PG_FUNCTION_ARGS);
+extern Datum jsonb_delete_path(PG_FUNCTION_ARGS);
 
 /* replacement */
 extern Datum jsonb_replace(PG_FUNCTION_ARGS);
diff --git a/src/tutorial/complex.c b/src/tutorial/complex.c
index a263110cd2..ea7051bdeb 100644
--- a/src/tutorial/complex.c
+++ b/src/tutorial/complex.c
@@ -20,23 +20,6 @@ typedef struct Complex
 	double		y;
 }	Complex;
 
-/*
- * Since we use V1 function calling convention, all these functions have
- * the same signature as far as C is concerned.  We provide these prototypes
- * just to forestall warnings when compiled with gcc -Wmissing-prototypes.
- */
-Datum		complex_in(PG_FUNCTION_ARGS);
-Datum		complex_out(PG_FUNCTION_ARGS);
-Datum		complex_recv(PG_FUNCTION_ARGS);
-Datum		complex_send(PG_FUNCTION_ARGS);
-Datum		complex_add(PG_FUNCTION_ARGS);
-Datum		complex_abs_lt(PG_FUNCTION_ARGS);
-Datum		complex_abs_le(PG_FUNCTION_ARGS);
-Datum		complex_abs_eq(PG_FUNCTION_ARGS);
-Datum		complex_abs_ge(PG_FUNCTION_ARGS);
-Datum		complex_abs_gt(PG_FUNCTION_ARGS);
-Datum		complex_abs_cmp(PG_FUNCTION_ARGS);
-
 
 /*****************************************************************************
  * Input/Output functions
diff --git a/src/tutorial/funcs_new.c b/src/tutorial/funcs_new.c
index abe409b859..f668d281bb 100644
--- a/src/tutorial/funcs_new.c
+++ b/src/tutorial/funcs_new.c
@@ -18,15 +18,6 @@
 
 PG_MODULE_MAGIC;
 
-/* These prototypes just prevent possible warnings from gcc. */
-
-Datum		add_one(PG_FUNCTION_ARGS);
-Datum		add_one_float8(PG_FUNCTION_ARGS);
-Datum		makepoint(PG_FUNCTION_ARGS);
-Datum		copytext(PG_FUNCTION_ARGS);
-Datum		concat_text(PG_FUNCTION_ARGS);
-Datum		c_overpaid(PG_FUNCTION_ARGS);
-
 
 /* By Value */