Add infrastucture for "soft" error handle

src/backend/utils/error/elog.c

@@ -79,6 +79,7 @@
 #include "libpq/pqformat.h"
 #include "libpq/pqsignal.h"
 #include "mb/pg_wchar.h"
+#include "nodes/miscnodes.h"
 #include "miscadmin.h"
 #include "postmaster/postmaster.h"
 #include "postmaster/syslogger.h"
@@ -830,6 +831,30 @@ errfinish_and_return(int dummy __attribute__((unused)),...)
 	return edata_copy;
 }
 
+/*
+ *	errsave_start
+ */
+bool
+errsave_start(struct Node *context, 
+				const char *filename, int lineno,
+		 		const char *funcname, const char *domain)
+{
+	ErrorSaveContext *escontext;
+
+	/*
+	 * Do we have a context for soft error reporting?  If not, just punt to
+	 * errstart().
+	 */
+	if (context == NULL || !IsA(context, ErrorSaveContext))
+		return errstart(ERROR, filename, lineno, funcname, domain);
+
+	/* Report that a soft error was detected */
+	escontext = (ErrorSaveContext *) context;
+	escontext->error_occurred = true;
+
+	return false;
+}
+
 
 /*
  * errcode --- add SQLSTATE error code to the current error

src/backend/utils/fmgr/fmgr.c

@@ -23,6 +23,7 @@
 #include "lib/stringinfo.h"
 #include "miscadmin.h"
 #include "nodes/nodeFuncs.h"
+#include "nodes/miscnodes.h"
 #include "pgstat.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
@@ -1887,6 +1888,41 @@ OidFunctionCall9Coll(Oid functionId, Oid collation, Datum arg1, Datum arg2,
 	return result;
 }
 
+/*
+
+ */
+Datum
+OidFunctionCall3CollSafe(Oid functionId, Oid collation, Datum arg1, Datum arg2,
+					 Datum arg3, fmNodePtr escontext)
+{
+	FmgrInfo	flinfo;
+	FunctionCallInfoData fcinfo;
+	Datum		result;
+
+	fmgr_info(functionId, &flinfo);
+
+	InitFunctionCallInfoData(fcinfo, &flinfo, 3, collation, escontext, NULL);
+
+	fcinfo.arg[0] = arg1;
+	fcinfo.arg[1] = arg2;
+	fcinfo.arg[2] = arg3;
+	fcinfo.argnull[0] = false;
+	fcinfo.argnull[1] = false;
+	fcinfo.argnull[2] = false;
+
+	result = FunctionCallInvoke(&fcinfo);
+
+	/* Result value is garbage, and could be null, if an error was reported */
+	if (SOFT_ERROR_OCCURRED(escontext))
+		return (Datum) 0;
+
+	/* Check for null result, since caller is clearly not expecting one */
+	if (fcinfo.isnull)
+		elog(ERROR, "function %u returned NULL", flinfo.fn_oid);
+
+	return result;
+}
+
 
 /*
  * Special cases for convenient invocation of datatype I/O functions.
@@ -1948,6 +1984,52 @@ InputFunctionCall(FmgrInfo *flinfo, char *str, Oid typioparam, int32 typmod)
 	return result;
 }
 
+Datum
+InputFunctionCallSafe(FmgrInfo *flinfo, char *str, Oid typioparam, int32 typmod, fmNodePtr escontext)
+{
+	FunctionCallInfoData fcinfo;
+	Datum		result;
+	bool		pushed;
+
+	if (str == NULL && flinfo->fn_strict)
+		return (Datum) 0;		/* just return null result */
+
+	pushed = SPI_push_conditional();
+
+	InitFunctionCallInfoData(fcinfo, flinfo, 3, InvalidOid, escontext, NULL);
+
+	fcinfo.arg[0] = CStringGetDatum(str);
+	fcinfo.arg[1] = ObjectIdGetDatum(typioparam);
+	fcinfo.arg[2] = Int32GetDatum(typmod);
+	fcinfo.argnull[0] = (str == NULL);
+	fcinfo.argnull[1] = false;
+	fcinfo.argnull[2] = false;
+
+	result = FunctionCallInvoke(&fcinfo);
+
+	/* Result value is garbage, and could be null, if an error was reported */
+	if (SOFT_ERROR_OCCURRED(escontext))
+		return (Datum) 0;
+
+	/* Should get null result if and only if str is NULL */
+	if (str == NULL)
+	{
+		if (!fcinfo.isnull)
+			elog(ERROR, "input function %u returned non-NULL",
+				 fcinfo.flinfo->fn_oid);
+	}
+	else
+	{
+		if (fcinfo.isnull)
+			elog(ERROR, "input function %u returned NULL",
+				 fcinfo.flinfo->fn_oid);
+	}
+
+	SPI_pop_conditional(pushed);
+
+	return result;
+}
+
 /*
  * Call a previously-looked-up datatype output function.
  *

src/include/fmgr.h

@@ -579,6 +579,11 @@ extern Datum OidFunctionCall9Coll(Oid functionId, Oid collation,
 					 Datum arg6, Datum arg7, Datum arg8,
 					 Datum arg9);
 
+
+extern Datum OidFunctionCall3CollSafe(Oid functionId, Oid collation,
+					 Datum arg1, Datum arg2,
+					 Datum arg3, fmNodePtr escontext);
+
 /* These macros allow the collation argument to be omitted (with a default of
  * InvalidOid, ie, no collation).  They exist mostly for backwards
  * compatibility of source code.
@@ -641,9 +646,15 @@ extern Datum OidFunctionCall9Coll(Oid functionId, Oid collation,
 	OidFunctionCall9Coll(functionId, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9)
 
 
+#define OidFunctionCall3Safe(functionId, arg1, arg2, arg3, escontext) \
+	OidFunctionCall3CollSafe(functionId, InvalidOid, arg1, arg2, arg3, escontext)
+
+
 /* Special cases for convenient invocation of datatype I/O functions. */
 extern Datum InputFunctionCall(FmgrInfo *flinfo, char *str,
 				  Oid typioparam, int32 typmod);
+extern Datum InputFunctionCallSafe(FmgrInfo *flinfo, char *str,
+				  Oid typioparam, int32 typmod, fmNodePtr escontext);
 extern Datum OidInputFunctionCall(Oid functionId, char *str,
 					 Oid typioparam, int32 typmod);
 extern char *OutputFunctionCall(FmgrInfo *flinfo, Datum val);

src/include/nodes/miscnodes.h

@@ -0,0 +1,26 @@
+/*-------------------------------------------------------------------------
+ *
+ * miscnodes.h
+ *	  Definitions for hard-to-classify node types.
+ *
+ * src/include/nodes/miscnodes.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef MISCNODES_H
+#define MISCNODES_H
+#include "nodes/nodes.h"
+
+typedef struct ErrorSaveContext
+{
+	NodeTag		type;
+	bool		error_occurred; /* set to true if we detect a soft error */
+} ErrorSaveContext;
+
+/* Often-useful macro for checking if a soft error was reported */
+#define SOFT_ERROR_OCCURRED(escontext) \
+	((escontext) != NULL && IsA(escontext, ErrorSaveContext) && \
+	 ((ErrorSaveContext *) (escontext))->error_occurred)
+
+#endif	

src/include/nodes/nodes.h

@@ -571,6 +571,8 @@ typedef enum NodeTag
 	T_GpPolicy,	/* in catalog/gp_policy.h */
 	T_RetrieveStmt,
 
+	T_ErrorSaveContext,
+
 } NodeTag;
 
 /*

src/include/utils/elog.h

@@ -20,6 +20,9 @@
 #include <sys/time.h>
 #include <setjmp.h>
 
+/* We cannot include nodes.h yet, so forward-declare struct Node */
+struct Node;
+
 /* Error level codes */
 #define DEBUG5		10			/* Debugging messages, in categories of
 								 * decreasing detail. */
@@ -204,6 +207,26 @@ extern bool errstart(int elevel, const char *filename, int lineno,
 		 const char *funcname, const char *domain);
 extern void errfinish(int dummy,...);
 
+#define errsave_domain(context, domain, rest)	\
+	do { \
+		struct Node *context_ = (context); \
+		if (errsave_start(context_, __FILE__, __LINE__, __func__, domain)) \
+			errfinish rest; \
+	} while(0)
+#define errsave(context, rest)	\
+	errsave_domain(context, TEXTDOMAIN, rest)
+
+#define ereturn_domain(context, dummy_value, domain, rest)	\
+	do { \
+		errsave_domain(context, domain, rest); \
+		return dummy_value; \
+	} while(0)
+#define ereturn(context, dummy_value, rest)	\
+	ereturn_domain(context, dummy_value, TEXTDOMAIN, rest)
+
+extern bool errsave_start(struct Node* context, const char *filename, int lineno,
+		 const char *funcname, const char *domain);
+
 extern int	errcode(int sqlerrcode);
 
 extern int	errcode_for_file_access(void);