Reworked syntax for new error context vars, based on feedback from the other devs.

doc/sql.extensions/README.context_variables

@@ -170,20 +170,30 @@ SQLSTATE (FB 2.5)
     1. SQLSTATE always evaluates to NULL outside the exception handling block.
 
 
-EXCEPTION (FB 4.0)
+RDB$ERROR (FB 4.0)
 ------------------
 
   Function:
-    Returns name of the active user-defined exception.
+    Returns specific context of the active exception.
 
   Author:
     Dmitry Yemanov <dimitr@firebirdsql.org>
 
   Syntax rules:
-    EXCEPTION
+    RDB$ERROR ( context )
+    context ::= { GDSCODE | SQLCODE | SQLSTATE | EXCEPTION | MESSAGE }
+
+	GDSCODE, SQLCODE, SQLSTATE - see above
+
+	EXCEPTION : VARCHAR(63) CHARACTER SET UTF8 
+	  Returns name of the active user-defined exception
+	  or NULL if active exception is a system one
+
+	MESSAGE : VARCHAR(1024) CHARACTER SET UTF8
+	  Returns interpreted text for the active exception
 
   Type:
-    VARCHAR(63) CHARACTER SET UTF8
+    Depends on context
 
   Scope:
     PSQL, context of the exception handling block.
@@ -192,41 +202,8 @@ EXCEPTION (FB 4.0)
     BEGIN
       ...
     WHEN ANY DO
-      IF (EXCEPTION IS NOT NULL)
+      EXECUTE PROCEDURE P_LOG_EXCEPTION(RDB$ERROR(MESSAGE));
-        EXECUTE PROCEDURE P_USR_EXCEPTION(EXCEPTION);
-      ELSE
-        EXECUTE PROCEDURE P_SYS_EXCEPTION;
     END
 
   Note(s):
-    1. EXCEPTION always contains NULL outside the exception handling block.
+    RDB$ERROR always contains NULL outside the exception handling block.
-    2. If system exception is thrown, EXCEPTION also contains NULL.
-
-
-ERROR_MESSAGE (FB 4.0)
-----------------------
-
-  Function:
-    Returns interpreted text for the active exception.
-
-  Author:
-    Dmitry Yemanov <dimitr@firebirdsql.org>
-
-  Syntax rules:
-    ERROR_MESSAGE
-
-  Type:
-    VARCHAR(1024) CHARACTER SET UTF8
-
-  Scope:
-    PSQL, context of the exception handling block.
-
-  Example(s):
-    BEGIN
-      ...
-    WHEN ANY DO
-      EXECUTE PROCEDURE P_LOG_EXCEPTION(ERROR_MESSAGE);
-    END
-
-  Note(s):
-    1. ERROR_MESSAGE always contains NULL outside the exception handling block.

src/dsql/ExprNodes.cpp

@@ -6125,7 +6125,9 @@ const InternalInfoNode::InfoAttr InternalInfoNode::INFO_TYPE_ATTRIBUTES[MAX_INFO
 	{"SQLCODE", DsqlCompilerScratch::FLAG_BLOCK},
 	{"ROW_COUNT", DsqlCompilerScratch::FLAG_BLOCK},
 	{"INSERTING/UPDATING/DELETING", DsqlCompilerScratch::FLAG_TRIGGER},
-	{"SQLSTATE", DsqlCompilerScratch::FLAG_BLOCK}
+	{"SQLSTATE", DsqlCompilerScratch::FLAG_BLOCK},
+	{"EXCEPTION", DsqlCompilerScratch::FLAG_BLOCK},
+	{"MESSAGE", DsqlCompilerScratch::FLAG_BLOCK}
 };
 
 InternalInfoNode::InternalInfoNode(MemoryPool& pool, ValueExprNode* aArg)

src/dsql/parse-conflicts.txt

@@ -1 +1 @@
-44 shift/reduce conflicts, 583 reduce/reduce conflicts.
+44 shift/reduce conflicts, 17 reduce/reduce conflicts.

src/dsql/parse.y

@@ -593,7 +593,7 @@ using namespace Firebird;
 
 %token <metaNamePtr> CUME_DIST
 %token <metaNamePtr> DEFINER
-%token <metaNamePtr> ERROR_MESSAGE
+%token <metaNamePtr> MESSAGE
 %token <metaNamePtr> EXCLUDE
 %token <metaNamePtr> FOLLOWING
 %token <metaNamePtr> INVOKER
@@ -603,6 +603,7 @@ using namespace Firebird;
 %token <metaNamePtr> PRECEDING
 %token <metaNamePtr> PRIVILEGE
 %token <metaNamePtr> RANGE
+%token <metaNamePtr> RDB_ERROR
 %token <metaNamePtr> RDB_ROLE_IN_USE
 %token <metaNamePtr> RDB_SYSTEM_PRIVILEGE
 %token <metaNamePtr> SECURITY
@@ -6952,12 +6953,25 @@ internal_info
 		{ $$ = newNode<InternalInfoNode>(MAKE_const_slong(INFO_TYPE_SQLSTATE)); }
 	| ROW_COUNT
 		{ $$ = newNode<InternalInfoNode>(MAKE_const_slong(INFO_TYPE_ROWS_AFFECTED)); }
-	| EXCEPTION
+	| RDB_ERROR '(' error_context ')'
-		{ $$ = newNode<InternalInfoNode>(MAKE_const_slong(INFO_TYPE_EXCEPTION)); }
+		{ $$ = newNode<InternalInfoNode>(MAKE_const_slong($3)); }
-	| ERROR_MESSAGE
-		{ $$ = newNode<InternalInfoNode>(MAKE_const_slong(INFO_TYPE_ERROR_MSG)); }
 	;
 
+%type <int32Val> error_context
+error_context
+	: GDSCODE
+		{ $$ = INFO_TYPE_GDSCODE; }
+	| SQLCODE
+		{ $$ = INFO_TYPE_SQLCODE; }
+	| SQLSTATE
+		{ $$ = INFO_TYPE_SQLSTATE; }
+	| EXCEPTION
+		{ $$ = INFO_TYPE_EXCEPTION; }
+	| MESSAGE
+		{ $$ = INFO_TYPE_ERROR_MSG; }
+	;
+
+
 %type <intlStringPtr> sql_string
 sql_string
 	: STRING					// string in current charset
@@ -8088,16 +8102,17 @@ non_reserved_word
 	| TRUSTED
 	| CUME_DIST				// added in FB 4.0
 	| DEFINER
-	| ERROR_MESSAGE
 	| EXCLUDE
 	| FOLLOWING
 	| INVOKER
+	| MESSAGE
 	| NTILE
 	| OTHERS
 	| PERCENT_RANK
 	| PRECEDING
 	| PRIVILEGE
 	| RANGE
+	| RDB_ERROR
 	| RDB_ROLE_IN_USE
 	| RDB_SYSTEM_PRIVILEGE
 	| SECURITY

src/yvalve/keywords.cpp

@@ -182,7 +182,6 @@ static const TOK tokens[] =
 	{TOK_END, "END", false},
 	{TOK_ENGINE, "ENGINE", true},
 	{TOK_ENTRY_POINT, "ENTRY_POINT", false},
-	{TOK_ERROR_MESSAGE, "ERROR_MESSAGE", true},
 	{TOK_ESCAPE, "ESCAPE", false},
 	{TOK_EXCEPTION, "EXCEPTION", false},
 	{TOK_EXCLUDE, "EXCLUDE", false},
@@ -269,6 +268,7 @@ static const TOK tokens[] =
 	{TOK_MAXIMUM, "MAX", false},
 	{TOK_MAXVALUE, "MAXVALUE", false},
 	{TOK_MERGE, "MERGE", false},
+	{TOK_MESSAGE, "MESSAGE", true},
 	{TOK_MILLISECOND, "MILLISECOND", false},
 	{TOK_MIDDLENAME, "MIDDLENAME", false},
 	{TOK_MINIMUM, "MIN", false},
@@ -336,6 +336,7 @@ static const TOK tokens[] =
 	{TOK_RANGE, "RANGE", false},
 	{TOK_RANK, "RANK", false},
 	{TOK_DB_KEY, "RDB$DB_KEY", false},
+	{TOK_RDB_ERROR, "RDB$ERROR", true},
 	{TOK_RDB_GET_CONTEXT, "RDB$GET_CONTEXT", true},
 	{TOK_RDB_RECORD_VERSION, "RDB$RECORD_VERSION", false},
 	{TOK_RDB_ROLE_IN_USE, "RDB$ROLE_IN_USE", true},