From e16925e7a5f9d2e05592da374bc18c1d65ae04c9 Mon Sep 17 00:00:00 2001
From: Pedro Flemming <pedroflemming@gmail.com>
Date: Fri, 7 Apr 2017 16:16:25 +0200
Subject: [PATCH] add parseSQLString method with output parameter instead of
 return value

---
 src/SQLParser.cpp         | 40 +++++++++++++++++++++++++--------------
 src/SQLParser.h           | 10 ++++++++++
 test/sql_grammar_test.cpp |  9 ++++-----
 3 files changed, 40 insertions(+), 19 deletions(-)

diff --git a/src/SQLParser.cpp b/src/SQLParser.cpp
index 5f89911..9f6ee5b 100644
--- a/src/SQLParser.cpp
+++ b/src/SQLParser.cpp
@@ -12,37 +12,49 @@ namespace hsql {
     fprintf(stderr, "SQLParser only has static methods atm! Do not initialize!\n");
   }
 
-  SQLParserResult* SQLParser::parseSQLString(const char* text) {
-    SQLParserResult* result = new SQLParserResult();
+  // static
+  bool SQLParser::parseSQLString(const char* text, SQLParserResult* result) {
     yyscan_t scanner;
     YY_BUFFER_STATE state;
 
     if (hsql_lex_init(&scanner)) {
       // Couldn't initialize the lexer.
       fprintf(stderr, "[Error] SQLParser: Error when initializing lexer!\n");
-      delete result;
-      return NULL;
+      return false;
     }
 
     state = hsql__scan_string(text, scanner);
 
-    // Parser and return early if it failed.
-    if (hsql_parse(result, scanner)) {
-      // Returns an error stmt object.
-      hsql__delete_buffer(state, scanner);
-      hsql_lex_destroy(scanner);
-      return result;
-    }
+    // Parse the tokens.
+    // If parsing fails, the result will contain an error object.
+    hsql_parse(result, scanner);
 
     hsql__delete_buffer(state, scanner);
     hsql_lex_destroy(scanner);
+
+    return true;
+  }
+
+  // static
+  bool SQLParser::parseSQLString(const std::string& text, SQLParserResult* result) {
+    return parseSQLString(text.c_str(), result);
+  }
+
+  // static
+  SQLParserResult* SQLParser::parseSQLString(const char* text) {
+    SQLParserResult* result = new SQLParserResult();
+
+    if (!SQLParser::parseSQLString(text, result)) {
+      delete result;
+      return NULL;
+    }
+
     return result;
   }
 
-
+  // static
   SQLParserResult* SQLParser::parseSQLString(const std::string& text) {
     return parseSQLString(text.c_str());
   }
 
-
-} // namespace hsql
\ No newline at end of file
+} // namespace hsql
diff --git a/src/SQLParser.h b/src/SQLParser.h
index 7ee774e..dffdcea 100644
--- a/src/SQLParser.h
+++ b/src/SQLParser.h
@@ -9,10 +9,20 @@ namespace hsql {
   // Static methods used to parse SQL strings.
   class SQLParser {
    public:
+    // Parses a given constant character SQL string into the result object.
+    static bool parseSQLString(const char* sql, SQLParserResult* result);
+
+    // Parses a given SQL string into the result object.
+    static bool parseSQLString(const std::string& sql, SQLParserResult* result);
+
     // Parses a given constant character SQL string.
+    // Note: This is kept for legacy reasons. It is recommended to use
+    //       the (const char*, SQLParserResult*) implementation.
     static SQLParserResult* parseSQLString(const char* sql);
 
     // Parses an SQL std::string.
+    // Note: This is kept for legacy reasons. It is recommended to use
+    //       the (const std::string&, SQLParserResult*) implementation.
     static SQLParserResult* parseSQLString(const std::string& sql);
 
    private:
diff --git a/test/sql_grammar_test.cpp b/test/sql_grammar_test.cpp
index 3bfecc8..0daf0c0 100644
--- a/test/sql_grammar_test.cpp
+++ b/test/sql_grammar_test.cpp
@@ -79,23 +79,22 @@ TEST(AutoGrammarTest) {
     start = std::chrono::system_clock::now();
 
     // Parsing
-    SQLParserResult* result = SQLParser::parseSQLString(sql.c_str());
+    SQLParserResult result;
+    SQLParser::parseSQLString(sql.c_str(), &result);
 
     end = std::chrono::system_clock::now();
     std::chrono::duration<double> elapsed_seconds = end - start;
     double us = elapsed_seconds.count() * 1000 * 1000;
 
-    if (expectFalse == result->isValid()) {
+    if (expectFalse == result.isValid()) {
       printf("\033[0;31m{  failed}\033[0m\n");
-      printf("\t\033[0;31m%s (L%d:%d)\n\033[0m", result->errorMsg(), result->errorLine(), result->errorColumn());
+      printf("\t\033[0;31m%s (L%d:%d)\n\033[0m", result.errorMsg(), result.errorLine(), result.errorColumn());
       printf("\t%s\n", sql.c_str());
       numFailed++;
     } else {
       // TODO: indicate whether expectFalse was set
       printf("\033[0;32m{      ok} (%.1fus)\033[0m %s\n", us, sql.c_str());
     }
-
-    delete result;
   }
 
   if (numFailed == 0) {