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.

30 files changed, 3 insertions, 146 deletions

diff --git a/src/backend/snowball/dict_snowball.c b/src/backend/snowball/dict_snowball.c
index bc31839bdd9..63b471ea51e 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 506cf3a6d04..1d77103edf8 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 cb7244085db..5d1c59b8429 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 1702ad8aeb8..398ceb1ab07 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 3f2e817e5f3..534fd699668 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 3fe7e7933bf..c56a91951b9 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 3ea16e6ee71..db4afd94c83 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 2afb3b9b604..795d51cbeec 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 58d75be35e8..8f831ba1b30 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 35ded6b1bbb..b7276919945 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 96d80477ede..22cb01ab839 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 a422a26d008..ed2ef1170fd 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 f2b01e50a34..65e7616eea4 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 a49eda8838c..cba8958fa35 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 83329263179..fcc8659bc6d 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 6d9aeb4138b..0524ec2497a 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 7edd09b1154..14b2fefa560 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 bc129993ba4..a956ebb3e96 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 60f0a21925b..de2438525ed 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 adc33a68e6b..f48fdd3cef0 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 39e4ce12e5a..7057c6d8894 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 13a62e11a19..3635674a84b 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 15b49f24b1e..2a08f2a3916 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 7a3281b640b..fda2bbdb81b 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 29f4256fe01..1727c685aa4 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 984980935d2..43fe289c960 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 c2a4ec35f7f..2304ea24bae 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 4d614430ce1..026ed55a3c9 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 a263110cd2d..ea7051bdebd 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 abe409b8591..f668d281bb1 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 */