Convert domain_in to report errors softly.

This is straightforward as far as it goes.  However, it does not
attempt to trap errors occurring during the execution of domain
CHECK constraints.  Since those are general user-defined
expressions, the only way to do that would involve starting up a
subtransaction for each check.  Of course the entire point of
the soft-errors feature is to not need subtransactions, so that
would be self-defeating.  For now, we'll rely on the assumption
that domain checks are written to avoid throwing errors.

Discussion: https://postgr.es/m/1181028.1670635727@sss.pgh.pa.us

1 files changed, 26 insertions, 10 deletions

diff --git a/src/backend/utils/adt/domains.c b/src/backend/utils/adt/domains.c
index 3de0cb01a2c..99aeaddb5d2 100644
--- a/src/backend/utils/adt/domains.c
+++ b/src/backend/utils/adt/domains.c
@@ -126,9 +126,14 @@ domain_state_setup(Oid domainType, bool binary, MemoryContext mcxt)
  * This is roughly similar to the handling of CoerceToDomain nodes in
  * execExpr*.c, but we execute each constraint separately, rather than
  * compiling them in-line within a larger expression.
+ *
+ * If escontext points to an ErrorStateContext, any failures are reported
+ * there, otherwise they are ereport'ed.  Note that we do not attempt to do
+ * soft reporting of errors raised during execution of CHECK constraints.
  */
 static void
-domain_check_input(Datum value, bool isnull, DomainIOData *my_extra)
+domain_check_input(Datum value, bool isnull, DomainIOData *my_extra,
+				   Node *escontext)
 {
 	ExprContext *econtext = my_extra->econtext;
 	ListCell   *l;
@@ -144,11 +149,14 @@ domain_check_input(Datum value, bool isnull, DomainIOData *my_extra)
 		{
 			case DOM_CONSTRAINT_NOTNULL:
 				if (isnull)
-					ereport(ERROR,
+				{
+					errsave(escontext,
 							(errcode(ERRCODE_NOT_NULL_VIOLATION),
 							 errmsg("domain %s does not allow null values",
 									format_type_be(my_extra->domain_type)),
 							 errdatatype(my_extra->domain_type)));
+					goto fail;
+				}
 				break;
 			case DOM_CONSTRAINT_CHECK:
 				{
@@ -179,13 +187,16 @@ domain_check_input(Datum value, bool isnull, DomainIOData *my_extra)
 					econtext->domainValue_isNull = isnull;
 
 					if (!ExecCheck(con->check_exprstate, econtext))
-						ereport(ERROR,
+					{
+						errsave(escontext,
 								(errcode(ERRCODE_CHECK_VIOLATION),
 								 errmsg("value for domain %s violates check constraint \"%s\"",
 										format_type_be(my_extra->domain_type),
 										con->name),
 								 errdomainconstraint(my_extra->domain_type,
 													 con->name)));
+						goto fail;
+					}
 					break;
 				}
 			default:
@@ -200,6 +211,7 @@ domain_check_input(Datum value, bool isnull, DomainIOData *my_extra)
 	 * per-tuple memory.  This avoids leaking non-memory resources, if
 	 * anything in the expression(s) has any.
 	 */
+fail:
 	if (econtext)
 		ReScanExprContext(econtext);
 }
@@ -213,6 +225,7 @@ domain_in(PG_FUNCTION_ARGS)
 {
 	char	   *string;
 	Oid			domainType;
+	Node	   *escontext = fcinfo->context;
 	DomainIOData *my_extra;
 	Datum		value;
 
@@ -245,15 +258,18 @@ domain_in(PG_FUNCTION_ARGS)
 	/*
 	 * Invoke the base type's typinput procedure to convert the data.
 	 */
-	value = InputFunctionCall(&my_extra->proc,
-							  string,
-							  my_extra->typioparam,
-							  my_extra->typtypmod);
+	if (!InputFunctionCallSafe(&my_extra->proc,
+							   string,
+							   my_extra->typioparam,
+							   my_extra->typtypmod,
+							   escontext,
+							   &value))
+		PG_RETURN_NULL();
 
 	/*
 	 * Do the necessary checks to ensure it's a valid domain value.
 	 */
-	domain_check_input(value, (string == NULL), my_extra);
+	domain_check_input(value, (string == NULL), my_extra, escontext);
 
 	if (string == NULL)
 		PG_RETURN_NULL();
@@ -309,7 +325,7 @@ domain_recv(PG_FUNCTION_ARGS)
 	/*
 	 * Do the necessary checks to ensure it's a valid domain value.
 	 */
-	domain_check_input(value, (buf == NULL), my_extra);
+	domain_check_input(value, (buf == NULL), my_extra, NULL);
 
 	if (buf == NULL)
 		PG_RETURN_NULL();
@@ -349,7 +365,7 @@ domain_check(Datum value, bool isnull, Oid domainType,
 	/*
 	 * Do the necessary checks to ensure it's a valid domain value.
 	 */
-	domain_check_input(value, isnull, my_extra);
+	domain_check_input(value, isnull, my_extra, NULL);
 }
 
 /*