Go back to returning int from ereport auxiliary functions.

This reverts the parts of commit 17a28b03645e27d73bf69a95d7569b61e58f06eb
that changed ereport's auxiliary functions from returning dummy integer
values to returning void.  It turns out that a minority of compilers
complain (not entirely unreasonably) about constructs such as

	(condition) ? errdetail(...) : 0

if errdetail() returns void rather than int.  We could update those
call sites to say "(void) 0" perhaps, but the expectation for this
patch set was that ereport callers would not have to change anything.
And this aspect of the patch set was already the most invasive and
least compelling part of it, so let's just drop it.

Per buildfarm.

Discussion: https://postgr.es/m/CA+fd4k6N8EjNvZpM8nme+y+05mz-SM8Z_BgkixzkA34R+ej0Kw@mail.gmail.com

7 files changed, 78 insertions, 44 deletions

diff --git a/src/backend/executor/execUtils.c b/src/backend/executor/execUtils.c
index 6deef1c679a..cc5177cc2b9 100644
--- a/src/backend/executor/execUtils.c
+++ b/src/backend/executor/execUtils.c
@@ -832,21 +832,21 @@ UpdateChangedParamSet(PlanState *node, Bitmapset *newchg)
  * normal non-error case: computing character indexes would be much more
  * expensive than storing token offsets.)
  */
-void
+int
 executor_errposition(EState *estate, int location)
 {
 	int			pos;
 
 	/* No-op if location was not provided */
 	if (location < 0)
-		return;
+		return 0;
 	/* Can't do anything if source text is not available */
 	if (estate == NULL || estate->es_sourceText == NULL)
-		return;
+		return 0;
 	/* Convert offset to character number */
 	pos = pg_mbstrlen_with_len(estate->es_sourceText, location) + 1;
 	/* And pass it to the ereport mechanism */
-	errposition(pos);
+	return errposition(pos);
 }
 
 /*
diff --git a/src/backend/parser/parse_coerce.c b/src/backend/parser/parse_coerce.c
index 91d4e99d345..645e4aa4ceb 100644
--- a/src/backend/parser/parse_coerce.c
+++ b/src/backend/parser/parse_coerce.c
@@ -1246,15 +1246,15 @@ coerce_to_specific_type(ParseState *pstate, Node *node,
  * XXX possibly this is more generally useful than coercion errors;
  * if so, should rename and place with parser_errposition.
  */
-void
+int
 parser_coercion_errposition(ParseState *pstate,
 							int coerce_location,
 							Node *input_expr)
 {
 	if (coerce_location >= 0)
-		parser_errposition(pstate, coerce_location);
+		return parser_errposition(pstate, coerce_location);
 	else
-		parser_errposition(pstate, exprLocation(input_expr));
+		return parser_errposition(pstate, exprLocation(input_expr));
 }
 
 
diff --git a/src/backend/parser/parse_node.c b/src/backend/parser/parse_node.c
index 9a2fd924b67..6e98fe55fc4 100644
--- a/src/backend/parser/parse_node.c
+++ b/src/backend/parser/parse_node.c
@@ -106,21 +106,21 @@ free_parsestate(ParseState *pstate)
  * normal non-error case: computing character indexes would be much more
  * expensive than storing token offsets.)
  */
-void
+int
 parser_errposition(ParseState *pstate, int location)
 {
 	int			pos;
 
 	/* No-op if location was not provided */
 	if (location < 0)
-		return;
+		return 0;
 	/* Can't do anything if source text is not available */
 	if (pstate == NULL || pstate->p_sourcetext == NULL)
-		return;
+		return 0;
 	/* Convert offset to character number */
 	pos = pg_mbstrlen_with_len(pstate->p_sourcetext, location) + 1;
 	/* And pass it to the ereport mechanism */
-	errposition(pos);
+	return errposition(pos);
 }
 
 
diff --git a/src/backend/parser/scan.l b/src/backend/parser/scan.l
index 50ba68abd4f..b1ea0cb5384 100644
--- a/src/backend/parser/scan.l
+++ b/src/backend/parser/scan.l
@@ -1076,18 +1076,18 @@ other			.
  * (essentially, scan.l, parser.c, and gram.y), since it requires the
  * yyscanner struct to still be available.
  */
-void
+int
 scanner_errposition(int location, core_yyscan_t yyscanner)
 {
 	int			pos;
 
 	if (location < 0)
-		return;				/* no-op if location is unknown */
+		return 0;				/* no-op if location is unknown */
 
 	/* Convert byte offset to character number */
 	pos = pg_mbstrlen_with_len(yyextra->scanbuf, location) + 1;
 	/* And pass it to the ereport mechanism */
-	errposition(pos);
+	return errposition(pos);
 }
 
 /*
diff --git a/src/backend/storage/ipc/dsm_impl.c b/src/backend/storage/ipc/dsm_impl.c
index 8dc9c0b5cdf..1972aecbedc 100644
--- a/src/backend/storage/ipc/dsm_impl.c
+++ b/src/backend/storage/ipc/dsm_impl.c
@@ -92,7 +92,7 @@ static bool dsm_impl_mmap(dsm_op op, dsm_handle handle, Size request_size,
 						  void **impl_private, void **mapped_address,
 						  Size *mapped_size, int elevel);
 #endif
-static void errcode_for_dynamic_shared_memory(void);
+static int	errcode_for_dynamic_shared_memory(void);
 
 const struct config_enum_entry dynamic_shared_memory_options[] = {
 #ifdef USE_DSM_POSIX
@@ -1030,11 +1030,11 @@ dsm_impl_unpin_segment(dsm_handle handle, void **impl_private)
 	}
 }
 
-static void
+static int
 errcode_for_dynamic_shared_memory(void)
 {
 	if (errno == EFBIG || errno == ENOMEM)
-		errcode(ERRCODE_OUT_OF_MEMORY);
+		return errcode(ERRCODE_OUT_OF_MEMORY);
 	else
-		errcode_for_file_access();
+		return errcode_for_file_access();
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 321ab9a0db9..4b5007e0d6f 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -329,7 +329,7 @@ typedef struct JsObject
 			hash_destroy((jso)->val.json_hash); \
 	} while (0)
 
-static void report_json_context(JsonLexContext *lex);
+static int	report_json_context(JsonLexContext *lex);
 
 /* semantic action functions for json_object_keys */
 static void okeys_object_field_start(void *state, char *fname, bool isnull);
@@ -631,7 +631,7 @@ json_ereport_error(JsonParseErrorType error, JsonLexContext *lex)
  * The return value isn't meaningful, but we make it non-void so that this
  * can be invoked inside ereport().
  */
-static void
+static int
 report_json_context(JsonLexContext *lex)
 {
 	const char *context_start;
@@ -689,8 +689,8 @@ report_json_context(JsonLexContext *lex)
 	prefix = (context_start > line_start) ? "..." : "";
 	suffix = (lex->token_type != JSON_TOKEN_END && context_end - lex->input < lex->input_length && *context_end != '\n' && *context_end != '\r') ? "..." : "";
 
-	errcontext("JSON data, line %d: %s%s%s",
-			   line_number, prefix, ctxt, suffix);
+	return errcontext("JSON data, line %d: %s%s%s",
+					  line_number, prefix, ctxt, suffix);
 }
 
 
diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index 6ac2152ddfe..b8858b132b8 100644
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -606,7 +606,7 @@ errfinish(const char *filename, int lineno, const char *funcname)
  *
  * The code is expected to be represented as per MAKE_SQLSTATE().
  */
-void
+int
 errcode(int sqlerrcode)
 {
 	ErrorData  *edata = &errordata[errordata_stack_depth];
@@ -615,6 +615,8 @@ errcode(int sqlerrcode)
 	CHECK_STACK_DEPTH();
 
 	edata->sqlerrcode = sqlerrcode;
+
+	return 0;					/* return value does not matter */
 }
 
 
@@ -627,7 +629,7 @@ errcode(int sqlerrcode)
  * NOTE: the primary error message string should generally include %m
  * when this is used.
  */
-void
+int
 errcode_for_file_access(void)
 {
 	ErrorData  *edata = &errordata[errordata_stack_depth];
@@ -685,6 +687,8 @@ errcode_for_file_access(void)
 			edata->sqlerrcode = ERRCODE_INTERNAL_ERROR;
 			break;
 	}
+
+	return 0;					/* return value does not matter */
 }
 
 /*
@@ -696,7 +700,7 @@ errcode_for_file_access(void)
  * NOTE: the primary error message string should generally include %m
  * when this is used.
  */
-void
+int
 errcode_for_socket_access(void)
 {
 	ErrorData  *edata = &errordata[errordata_stack_depth];
@@ -719,6 +723,8 @@ errcode_for_socket_access(void)
 			edata->sqlerrcode = ERRCODE_INTERNAL_ERROR;
 			break;
 	}
+
+	return 0;					/* return value does not matter */
 }
 
 
@@ -814,7 +820,7 @@ errcode_for_socket_access(void)
  * Note: no newline is needed at the end of the fmt string, since
  * ereport will provide one for the output methods that need it.
  */
-void
+int
 errmsg(const char *fmt,...)
 {
 	ErrorData  *edata = &errordata[errordata_stack_depth];
@@ -829,13 +835,14 @@ errmsg(const char *fmt,...)
 
 	MemoryContextSwitchTo(oldcontext);
 	recursion_depth--;
+	return 0;					/* return value does not matter */
 }
 
 /*
  * Add a backtrace to the containing ereport() call.  This is intended to be
  * added temporarily during debugging.
  */
-void
+int
 errbacktrace(void)
 {
 	ErrorData   *edata = &errordata[errordata_stack_depth];
@@ -849,6 +856,8 @@ errbacktrace(void)
 
 	MemoryContextSwitchTo(oldcontext);
 	recursion_depth--;
+
+	return 0;
 }
 
 /*
@@ -898,7 +907,7 @@ set_backtrace(ErrorData *edata, int num_skip)
  * the message because the translation would fail and result in infinite
  * error recursion.
  */
-void
+int
 errmsg_internal(const char *fmt,...)
 {
 	ErrorData  *edata = &errordata[errordata_stack_depth];
@@ -913,6 +922,7 @@ errmsg_internal(const char *fmt,...)
 
 	MemoryContextSwitchTo(oldcontext);
 	recursion_depth--;
+	return 0;					/* return value does not matter */
 }
 
 
@@ -920,7 +930,7 @@ errmsg_internal(const char *fmt,...)
  * errmsg_plural --- add a primary error message text to the current error,
  * with support for pluralization of the message text
  */
-void
+int
 errmsg_plural(const char *fmt_singular, const char *fmt_plural,
 			  unsigned long n,...)
 {
@@ -936,13 +946,14 @@ errmsg_plural(const char *fmt_singular, const char *fmt_plural,
 
 	MemoryContextSwitchTo(oldcontext);
 	recursion_depth--;
+	return 0;					/* return value does not matter */
 }
 
 
 /*
  * errdetail --- add a detail error message text to the current error
  */
-void
+int
 errdetail(const char *fmt,...)
 {
 	ErrorData  *edata = &errordata[errordata_stack_depth];
@@ -956,6 +967,7 @@ errdetail(const char *fmt,...)
 
 	MemoryContextSwitchTo(oldcontext);
 	recursion_depth--;
+	return 0;					/* return value does not matter */
 }
 
 
@@ -968,7 +980,7 @@ errdetail(const char *fmt,...)
  * messages that seem not worth translating for one reason or another
  * (typically, that they don't seem to be useful to average users).
  */
-void
+int
 errdetail_internal(const char *fmt,...)
 {
 	ErrorData  *edata = &errordata[errordata_stack_depth];
@@ -982,13 +994,14 @@ errdetail_internal(const char *fmt,...)
 
 	MemoryContextSwitchTo(oldcontext);
 	recursion_depth--;
+	return 0;					/* return value does not matter */
 }
 
 
 /*
  * errdetail_log --- add a detail_log error message text to the current error
  */
-void
+int
 errdetail_log(const char *fmt,...)
 {
 	ErrorData  *edata = &errordata[errordata_stack_depth];
@@ -1002,13 +1015,14 @@ errdetail_log(const char *fmt,...)
 
 	MemoryContextSwitchTo(oldcontext);
 	recursion_depth--;
+	return 0;					/* return value does not matter */
 }
 
 /*
  * errdetail_log_plural --- add a detail_log error message text to the current error
  * with support for pluralization of the message text
  */
-void
+int
 errdetail_log_plural(const char *fmt_singular, const char *fmt_plural,
 					 unsigned long n,...)
 {
@@ -1023,6 +1037,7 @@ errdetail_log_plural(const char *fmt_singular, const char *fmt_plural,
 
 	MemoryContextSwitchTo(oldcontext);
 	recursion_depth--;
+	return 0;					/* return value does not matter */
 }
 
 
@@ -1030,7 +1045,7 @@ errdetail_log_plural(const char *fmt_singular, const char *fmt_plural,
  * errdetail_plural --- add a detail error message text to the current error,
  * with support for pluralization of the message text
  */
-void
+int
 errdetail_plural(const char *fmt_singular, const char *fmt_plural,
 				 unsigned long n,...)
 {
@@ -1045,13 +1060,14 @@ errdetail_plural(const char *fmt_singular, const char *fmt_plural,
 
 	MemoryContextSwitchTo(oldcontext);
 	recursion_depth--;
+	return 0;					/* return value does not matter */
 }
 
 
 /*
  * errhint --- add a hint error message text to the current error
  */
-void
+int
 errhint(const char *fmt,...)
 {
 	ErrorData  *edata = &errordata[errordata_stack_depth];
@@ -1065,6 +1081,7 @@ errhint(const char *fmt,...)
 
 	MemoryContextSwitchTo(oldcontext);
 	recursion_depth--;
+	return 0;					/* return value does not matter */
 }
 
 
@@ -1075,7 +1092,7 @@ errhint(const char *fmt,...)
  * context information.  We assume earlier calls represent more-closely-nested
  * states.
  */
-void
+int
 errcontext_msg(const char *fmt,...)
 {
 	ErrorData  *edata = &errordata[errordata_stack_depth];
@@ -1089,6 +1106,7 @@ errcontext_msg(const char *fmt,...)
 
 	MemoryContextSwitchTo(oldcontext);
 	recursion_depth--;
+	return 0;					/* return value does not matter */
 }
 
 /*
@@ -1100,7 +1118,7 @@ errcontext_msg(const char *fmt,...)
  * a set_errcontext_domain() call to specify the domain.  This is usually
  * done transparently by the errcontext() macro.
  */
-void
+int
 set_errcontext_domain(const char *domain)
 {
 	ErrorData  *edata = &errordata[errordata_stack_depth];
@@ -1110,6 +1128,8 @@ set_errcontext_domain(const char *domain)
 
 	/* the default text domain is the backend's */
 	edata->context_domain = domain ? domain : PG_TEXTDOMAIN("postgres");
+
+	return 0;					/* return value does not matter */
 }
 
 
@@ -1118,7 +1138,7 @@ set_errcontext_domain(const char *domain)
  *
  * This should be called if the message text already includes the statement.
  */
-void
+int
 errhidestmt(bool hide_stmt)
 {
 	ErrorData  *edata = &errordata[errordata_stack_depth];
@@ -1127,6 +1147,8 @@ errhidestmt(bool hide_stmt)
 	CHECK_STACK_DEPTH();
 
 	edata->hide_stmt = hide_stmt;
+
+	return 0;					/* return value does not matter */
 }
 
 /*
@@ -1135,7 +1157,7 @@ errhidestmt(bool hide_stmt)
  * This should only be used for verbose debugging messages where the repeated
  * inclusion of context would bloat the log volume too much.
  */
-void
+int
 errhidecontext(bool hide_ctx)
 {
 	ErrorData  *edata = &errordata[errordata_stack_depth];
@@ -1144,6 +1166,8 @@ errhidecontext(bool hide_ctx)
 	CHECK_STACK_DEPTH();
 
 	edata->hide_ctx = hide_ctx;
+
+	return 0;					/* return value does not matter */
 }
 
 
@@ -1154,7 +1178,7 @@ errhidecontext(bool hide_ctx)
  * name appear in messages sent to old-protocol clients.  Note that the
  * passed string is expected to be a non-freeable constant string.
  */
-void
+int
 errfunction(const char *funcname)
 {
 	ErrorData  *edata = &errordata[errordata_stack_depth];
@@ -1164,12 +1188,14 @@ errfunction(const char *funcname)
 
 	edata->funcname = funcname;
 	edata->show_funcname = true;
+
+	return 0;					/* return value does not matter */
 }
 
 /*
  * errposition --- add cursor position to the current error
  */
-void
+int
 errposition(int cursorpos)
 {
 	ErrorData  *edata = &errordata[errordata_stack_depth];
@@ -1178,12 +1204,14 @@ errposition(int cursorpos)
 	CHECK_STACK_DEPTH();
 
 	edata->cursorpos = cursorpos;
+
+	return 0;					/* return value does not matter */
 }
 
 /*
  * internalerrposition --- add internal cursor position to the current error
  */
-void
+int
 internalerrposition(int cursorpos)
 {
 	ErrorData  *edata = &errordata[errordata_stack_depth];
@@ -1192,6 +1220,8 @@ internalerrposition(int cursorpos)
 	CHECK_STACK_DEPTH();
 
 	edata->internalpos = cursorpos;
+
+	return 0;					/* return value does not matter */
 }
 
 /*
@@ -1201,7 +1231,7 @@ internalerrposition(int cursorpos)
  * is intended for use in error callback subroutines that are editorializing
  * on the layout of the error report.
  */
-void
+int
 internalerrquery(const char *query)
 {
 	ErrorData  *edata = &errordata[errordata_stack_depth];
@@ -1217,6 +1247,8 @@ internalerrquery(const char *query)
 
 	if (query)
 		edata->internalquery = MemoryContextStrdup(edata->assoc_context, query);
+
+	return 0;					/* return value does not matter */
 }
 
 /*
@@ -1229,7 +1261,7 @@ internalerrquery(const char *query)
  * Most potential callers should not use this directly, but instead prefer
  * higher-level abstractions, such as errtablecol() (see relcache.c).
  */
-void
+int
 err_generic_string(int field, const char *str)
 {
 	ErrorData  *edata = &errordata[errordata_stack_depth];
@@ -1258,6 +1290,8 @@ err_generic_string(int field, const char *str)
 			elog(ERROR, "unsupported ErrorData field id: %d", field);
 			break;
 	}
+
+	return 0;					/* return value does not matter */
 }
 
 /*