Go back to returning int from ereport auxiliary functions.

This reverts the parts of commit 17a28b0
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

Author: tglsfdc

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);
 }
 
 /*

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));
 }
 
 

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);
 }
 
 

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);
 }
 
 /*

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();
 }

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);
 }