Refactor error messages to reduce duplication

I also took the liberty of changing

	errmsg("COPY DEFAULT only available using COPY FROM")
to
	errmsg("COPY %s cannot be used with %s", "DEFAULT", "COPY TO")

because the original wording is unlike all other messages that indicate
option incompatibility.  This message was added by commit 9f8377f7a279
(16-era), in whose development thread there was no discussion on this
point.

Backpatch to 17.

4 files changed, 66 insertions, 29 deletions

diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index df7a4a21c94..3bb579a3a44 100644
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -397,7 +397,9 @@ defGetCopyOnErrorChoice(DefElem *def, ParseState *pstate, bool is_from)
 	if (!is_from)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("COPY ON_ERROR cannot be used with COPY TO"),
+		/*- translator: first %s is the name of a COPY option, e.g. ON_ERROR,
+		 second %s is a COPY with direction, e.g. COPY TO */
+				 errmsg("COPY %s cannot be used with %s", "ON_ERROR", "COPY TO"),
 				 parser_errposition(pstate, def->location)));
 
 	/*
@@ -410,7 +412,8 @@ defGetCopyOnErrorChoice(DefElem *def, ParseState *pstate, bool is_from)
 
 	ereport(ERROR,
 			(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-			 errmsg("COPY ON_ERROR \"%s\" not recognized", sval),
+	/*- translator: first %s is the name of a COPY option, e.g. ON_ERROR */
+			 errmsg("COPY %s \"%s\" not recognized", "ON_ERROR", sval),
 			 parser_errposition(pstate, def->location)));
 	return COPY_ON_ERROR_STOP;	/* keep compiler quiet */
 }
@@ -434,7 +437,8 @@ defGetCopyLogVerbosityChoice(DefElem *def, ParseState *pstate)
 
 	ereport(ERROR,
 			(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-			 errmsg("COPY LOG_VERBOSITY \"%s\" not recognized", sval),
+	/*- translator: first %s is the name of a COPY option, e.g. ON_ERROR */
+			 errmsg("COPY %s \"%s\" not recognized", "LOG_VERBOSITY", sval),
 			 parser_errposition(pstate, def->location)));
 	return COPY_LOG_VERBOSITY_DEFAULT;	/* keep compiler quiet */
 }
@@ -647,17 +651,18 @@ ProcessCopyOptions(ParseState *pstate,
 	if (opts_out->binary && opts_out->delim)
 		ereport(ERROR,
 				(errcode(ERRCODE_SYNTAX_ERROR),
-				 errmsg("cannot specify DELIMITER in BINARY mode")));
+		/*- translator: %s is the name of a COPY option, e.g. ON_ERROR */
+				 errmsg("cannot specify %s in BINARY mode", "DELIMITER")));
 
 	if (opts_out->binary && opts_out->null_print)
 		ereport(ERROR,
 				(errcode(ERRCODE_SYNTAX_ERROR),
-				 errmsg("cannot specify NULL in BINARY mode")));
+				 errmsg("cannot specify %s in BINARY mode", "NULL")));
 
 	if (opts_out->binary && opts_out->default_print)
 		ereport(ERROR,
 				(errcode(ERRCODE_SYNTAX_ERROR),
-				 errmsg("cannot specify DEFAULT in BINARY mode")));
+				 errmsg("cannot specify %s in BINARY mode", "DEFAULT")));
 
 	if (opts_out->binary && opts_out->on_error != COPY_ON_ERROR_STOP)
 		ereport(ERROR,
@@ -731,13 +736,15 @@ ProcessCopyOptions(ParseState *pstate,
 	if (opts_out->binary && opts_out->header_line)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("cannot specify HEADER in BINARY mode")));
+		/*- translator: %s is the name of a COPY option, e.g. ON_ERROR */
+				 errmsg("cannot specify %s in BINARY mode", "HEADER")));
 
 	/* Check quote */
 	if (!opts_out->csv_mode && opts_out->quote != NULL)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("COPY QUOTE requires CSV mode")));
+		/*- translator: %s is the name of a COPY option, e.g. ON_ERROR */
+				 errmsg("COPY %s requires CSV mode", "QUOTE")));
 
 	if (opts_out->csv_mode && strlen(opts_out->quote) != 1)
 		ereport(ERROR,
@@ -753,7 +760,8 @@ ProcessCopyOptions(ParseState *pstate,
 	if (!opts_out->csv_mode && opts_out->escape != NULL)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("COPY ESCAPE requires CSV mode")));
+		/*- translator: %s is the name of a COPY option, e.g. ON_ERROR */
+				 errmsg("COPY %s requires CSV mode", "ESCAPE")));
 
 	if (opts_out->csv_mode && strlen(opts_out->escape) != 1)
 		ereport(ERROR,
@@ -764,71 +772,97 @@ ProcessCopyOptions(ParseState *pstate,
 	if (!opts_out->csv_mode && (opts_out->force_quote || opts_out->force_quote_all))
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("COPY FORCE_QUOTE requires CSV mode")));
+		/*- translator: %s is the name of a COPY option, e.g. ON_ERROR */
+				 errmsg("COPY %s requires CSV mode", "FORCE_QUOTE")));
 	if ((opts_out->force_quote || opts_out->force_quote_all) && is_from)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("COPY FORCE_QUOTE cannot be used with COPY FROM")));
+		/*- translator: first %s is the name of a COPY option, e.g. ON_ERROR,
+		 second %s is a COPY with direction, e.g. COPY TO */
+				 errmsg("COPY %s cannot be used with %s", "FORCE_QUOTE",
+						"COPY FROM")));
 
 	/* Check force_notnull */
 	if (!opts_out->csv_mode && opts_out->force_notnull != NIL)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("COPY FORCE_NOT_NULL requires CSV mode")));
+		/*- translator: %s is the name of a COPY option, e.g. ON_ERROR */
+				 errmsg("COPY %s requires CSV mode", "FORCE_NOT_NULL")));
 	if (opts_out->force_notnull != NIL && !is_from)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("COPY FORCE_NOT_NULL cannot be used with COPY TO")));
+		/*- translator: first %s is the name of a COPY option, e.g. ON_ERROR,
+		 second %s is a COPY with direction, e.g. COPY TO */
+				 errmsg("COPY %s cannot be used with %s", "FORCE_NOT_NULL",
+						"COPY TO")));
 
 	/* Check force_null */
 	if (!opts_out->csv_mode && opts_out->force_null != NIL)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("COPY FORCE_NULL requires CSV mode")));
+		/*- translator: %s is the name of a COPY option, e.g. ON_ERROR */
+				 errmsg("COPY %s requires CSV mode", "FORCE_NULL")));
 
 	if (opts_out->force_null != NIL && !is_from)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("COPY FORCE_NULL cannot be used with COPY TO")));
+		/*- translator: first %s is the name of a COPY option, e.g. ON_ERROR,
+		 second %s is a COPY with direction, e.g. COPY TO */
+				 errmsg("COPY %s cannot be used with %s", "FORCE_NULL",
+						"COPY TO")));
 
 	/* Don't allow the delimiter to appear in the null string. */
 	if (strchr(opts_out->null_print, opts_out->delim[0]) != NULL)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("COPY delimiter character must not appear in the NULL specification")));
+		/*- translator: %s is the name of a COPY option, e.g. NULL */
+				 errmsg("COPY delimiter character must not appear in the %s specification",
+						"NULL")));
 
 	/* Don't allow the CSV quote char to appear in the null string. */
 	if (opts_out->csv_mode &&
 		strchr(opts_out->null_print, opts_out->quote[0]) != NULL)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("CSV quote character must not appear in the NULL specification")));
+		/*- translator: %s is the name of a COPY option, e.g. NULL */
+				 errmsg("CSV quote character must not appear in the %s specification",
+						"NULL")));
 
 	/* Check freeze */
 	if (opts_out->freeze && !is_from)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("COPY FREEZE cannot be used with COPY TO")));
+		/*- translator: first %s is the name of a COPY option, e.g. ON_ERROR,
+		 second %s is a COPY with direction, e.g. COPY TO */
+				 errmsg("COPY %s cannot be used with %s", "FREEZE",
+						"COPY TO")));
 
 	if (opts_out->default_print)
 	{
 		if (!is_from)
 			ereport(ERROR,
 					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-					 errmsg("COPY DEFAULT only available using COPY FROM")));
+			/*- translator: first %s is the name of a COPY option, e.g. ON_ERROR,
+			 second %s is a COPY with direction, e.g. COPY TO */
+					 errmsg("COPY %s cannot be used with %s", "DEFAULT",
+							"COPY TO")));
 
 		/* Don't allow the delimiter to appear in the default string. */
 		if (strchr(opts_out->default_print, opts_out->delim[0]) != NULL)
 			ereport(ERROR,
 					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-					 errmsg("COPY delimiter must not appear in the DEFAULT specification")));
+			/*- translator: %s is the name of a COPY option, e.g. NULL */
+					 errmsg("COPY delimiter character must not appear in the %s specification",
+							"DEFAULT")));
 
 		/* Don't allow the CSV quote char to appear in the default string. */
 		if (opts_out->csv_mode &&
 			strchr(opts_out->default_print, opts_out->quote[0]) != NULL)
 			ereport(ERROR,
 					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-					 errmsg("CSV quote character must not appear in the DEFAULT specification")));
+			/*- translator: %s is the name of a COPY option, e.g. NULL */
+					 errmsg("CSV quote character must not appear in the %s specification",
+							"DEFAULT")));
 
 		/* Don't allow the NULL and DEFAULT string to be the same */
 		if (opts_out->null_print_len == opts_out->default_print_len &&
diff --git a/src/backend/commands/copyfrom.c b/src/backend/commands/copyfrom.c
index c42a5621d5a..ca85270be6d 100644
--- a/src/backend/commands/copyfrom.c
+++ b/src/backend/commands/copyfrom.c
@@ -1454,8 +1454,9 @@ BeginCopyFrom(ParseState *pstate,
 			if (!list_member_int(cstate->attnumlist, attnum))
 				ereport(ERROR,
 						(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
-						 errmsg("FORCE_NOT_NULL column \"%s\" not referenced by COPY",
-								NameStr(attr->attname))));
+				/*- translator: first %s is the name of a COPY option, e.g. FORCE_NOT_NULL */
+						 errmsg("%s column \"%s\" not referenced by COPY",
+								"FORCE_NOT_NULL", NameStr(attr->attname))));
 			cstate->opts.force_notnull_flags[attnum - 1] = true;
 		}
 	}
@@ -1496,8 +1497,9 @@ BeginCopyFrom(ParseState *pstate,
 			if (!list_member_int(cstate->attnumlist, attnum))
 				ereport(ERROR,
 						(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
-						 errmsg("FORCE_NULL column \"%s\" not referenced by COPY",
-								NameStr(attr->attname))));
+				/*- translator: first %s is the name of a COPY option, e.g. FORCE_NOT_NULL */
+						 errmsg("%s column \"%s\" not referenced by COPY",
+								"FORCE_NULL", NameStr(attr->attname))));
 			cstate->opts.force_null_flags[attnum - 1] = true;
 		}
 	}
diff --git a/src/backend/commands/copyto.c b/src/backend/commands/copyto.c
index ae8b2e36d72..eb1d3d8fbb5 100644
--- a/src/backend/commands/copyto.c
+++ b/src/backend/commands/copyto.c
@@ -593,8 +593,9 @@ BeginCopyTo(ParseState *pstate,
 			if (!list_member_int(cstate->attnumlist, attnum))
 				ereport(ERROR,
 						(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
-						 errmsg("FORCE_QUOTE column \"%s\" not referenced by COPY",
-								NameStr(attr->attname))));
+				/*- translator: %s is the name of a COPY option, e.g. FORCE_NOT_NULL */
+						 errmsg("%s column \"%s\" not referenced by COPY",
+								"FORCE_QUOTE", NameStr(attr->attname))));
 			cstate->opts.force_quote_flags[attnum - 1] = true;
 		}
 	}
diff --git a/src/test/regress/expected/copy2.out b/src/test/regress/expected/copy2.out
index 931542f2689..e913f683a68 100644
--- a/src/test/regress/expected/copy2.out
+++ b/src/test/regress/expected/copy2.out
@@ -844,7 +844,7 @@ copy copy_default from stdin with (default E'\r');
 ERROR:  COPY default representation cannot use newline or carriage return
 -- DELIMITER cannot appear in DEFAULT spec
 copy copy_default from stdin with (delimiter ';', default 'test;test');
-ERROR:  COPY delimiter must not appear in the DEFAULT specification
+ERROR:  COPY delimiter character must not appear in the DEFAULT specification
 -- CSV quote cannot appear in DEFAULT spec
 copy copy_default from stdin with (format csv, quote '"', default 'test"test');
 ERROR:  CSV quote character must not appear in the DEFAULT specification
@@ -904,4 +904,4 @@ select id, text_value, ts_value from copy_default;
 truncate copy_default;
 -- DEFAULT cannot be used in COPY TO
 copy (select 1 as test) TO stdout with (default '\D');
-ERROR:  COPY DEFAULT only available using COPY FROM
+ERROR:  COPY DEFAULT cannot be used with COPY TO