Question

我正在使用 ANTLR4 为 PL / SQL 代码生成抽象语法树（AST）。对于某些查询，它工作正常，但对于某些代码，它生成一个只有一个节点的AST，这是不对的。

例如：

DECLARE
   a   RAW;            -- migrate to BLOB
   b   LONG RAW;       -- migrate to BLOB
   c   LONG VARCHAR;   -- migrate to LOB
   d   LONG;           -- migrate to LOB
   x   VARCHAR;
   CURSOR mycur RETURN LONG;     -- should flag
   FUNCTION myfunc RETURN LONG RAW    -- should flag
   IS
      z  LONG RAW;    -- should flag
   BEGIN 
      RETURN z;
   END;  
BEGIN
   SELECT mycol, CAST(col2 AS RAW)      -- should flag
     INTO a 
     FROM mytab 
    WHERE (b IS OF TYPE(LONG RAW, RAW, VARCHAR)); -- should flag
END;
CREATE TABLE tab (
   a   RAW,            -- should flag
   b   LONG RAW,       -- should flag
   c   LONG VARCHAR,   -- should flag
   d   LONG,           -- should flag
   x   VARCHAR
);

对于此代码，它会生成此AST：

(compilation_unit DECLARE a RAW ; b LONG RAW ; c LONG VARCHAR ; d LONG ; x VARCHAR ; CURSOR mycur RETURN LONG ; FUNCTION myfunc RETURN LONG RAW IS z LONG RAW ; BEGIN RETURN z ; END ; BEGIN SELECT mycol , CAST ( col2 AS RAW ) INTO a FROM mytab WHERE ( b IS OF TYPE ( LONG RAW , RAW , VARCHAR ) ) ; END ; CREATE TABLE tab ( a RAW , b LONG RAW , c LONG VARCHAR , d LONG , x VARCHAR ) ;)

这只是compilation_unit节点中的给定代码。

但是如果我在没有声明部分的情况下给出相同的代码，它会提供良好的AST。

对于此代码：

FUNCTION myfunc RETURN LONG RAW    -- should flag
   IS
      z  LONG RAW;    -- should flag
   BEGIN 
      RETURN z;
   END;  
BEGIN
   SELECT mycol, CAST(col2 AS RAW)      -- should flag
     INTO a 
     FROM mytab 
    WHERE (b IS OF TYPE(LONG RAW, RAW, VARCHAR)); -- should flag
END;
CREATE TABLE tab (
   a   RAW,            -- should flag
   b   LONG RAW,       -- should flag
   c   LONG VARCHAR,   -- should flag
   d   LONG,           -- should flag
   x   VARCHAR
);

它给出了这个AST：

(compilation_unit (unit_statement (create_function_body FUNCTION (function_name (id (id_expression (regular_id myfunc)))) RETURN (type_spec (datatype (native_datatype_element LONG RAW))) IS (declare_spec (variable_declaration (variable_name (id_expression (regular_id z))) (type_spec (datatype (native_datatype_element LONG RAW))) ;)) (body BEGIN (seq_of_statements (statement (return_statement RETURN (condition (expression (logical_and_expression (negated_expression (equality_expression (multiset_expression (relational_expression (compound_expression (concatenation (additive_expression (multiply_expression (datetime_expression (model_expression (unary_expression (atom (general_element (general_element_part (id_expression (regular_id z))))))))))))))))))))) ;) END) ;)) BEGIN (unit_statement (data_manipulation_language_statements (select_statement (subquery (subquery_basic_elements (query_block SELECT (selected_element (select_list_elements (expression (logical_and_expression (negated_expression (equality_expression (multiset_expression (relational_expression (compound_expression (concatenation (additive_expression (multiply_expression (datetime_expression (model_expression (unary_expression (atom (general_element (general_element_part (id_expression (regular_id mycol)))))))))))))))))))) , (selected_element (select_list_elements (expression (logical_and_expression (negated_expression (equality_expression (multiset_expression (relational_expression (compound_expression (concatenation (additive_expression (multiply_expression (datetime_expression (model_expression (unary_expression (standard_function CAST ( (concatenation_wrapper (concatenation (additive_expression (multiply_expression (datetime_expression (model_expression (unary_expression (atom (general_element (general_element_part (id_expression (regular_id col2)))))))))))) AS (type_spec (datatype (native_datatype_element RAW))) ))))))))))))))))) (into_clause INTO (variable_name (id_expression (regular_id a)))) (from_clause FROM (table_ref_list (table_ref (table_ref_aux (dml_table_expression_clause (tableview_name (id (id_expression (regular_id mytab))))))))) (where_clause WHERE (condition_wrapper (expression (logical_and_expression (negated_expression (equality_expression (multiset_expression (relational_expression (compound_expression (concatenation (additive_expression (multiply_expression (datetime_expression (model_expression (unary_expression (atom ( (expression_or_vector (expression (logical_and_expression (negated_expression (equality_expression (multiset_expression (relational_expression (compound_expression (concatenation (additive_expression (multiply_expression (datetime_expression (model_expression (unary_expression (atom (general_element (general_element_part (id_expression (regular_id b)))))))))))))) IS OF TYPE ( (type_spec (datatype (native_datatype_element LONG RAW))) , (type_spec (datatype (native_datatype_element RAW))) , (type_spec (datatype (native_datatype_element VARCHAR))) )))))) ))))) ; END ;)))))))))))))))))) unit_statement (unit_statement CREATE TABLE tab) (unit_statement (data_manipulation_language_statements (select_statement (subquery (subquery_basic_elements ( (subquery (subquery_basic_elements a RAW , b LONG RAW , c LONG VARCHAR , d LONG , x VARCHAR)) )) ;)))) <EOF>)

因此，似乎在 PL / SQL语法文件中缺少一些像declare这样的关键字（规则）。我在Antlr站点的Antlr中使用了这个plsql.g4文件。

有什么方法可以找到更新的 plsql.g4文件，还是我需要自己添加这些规则？

Answer 1

问题似乎实际上是 plsql antlr-grammar 不支持 LONG VARCHAR 数据类型，在这一部分：“c LONG VARCHAR;”

这会导致声明被误解为过程调用弄乱了解析的其余部分。

我在语法github中打开了一个问题：https://github.com/antlr/grammars-v4/issues/2158

某些PL / SQL文件的PL / SQL ANTLR语法失败了吗？

1 个答案: