Fixes fdo#36594 Syntax error in SQL on "--" comment (and "//" and "/**/")

The SQL parser implementation does not handle comments.
Temporarily remove "-- ..." and "// ..." end-of-line comments and "/* ... */"
inline comments of a query and append comments after recomposition of the
query.

NOTE: The original comment positions are not preserved, all comments are
      appended to the query!

Based on the original patch further development was done for inline comments
and preserving comments' line order.

1 files changed, 65 insertions, 1 deletions

diff --git a/connectivity/source/parse/sqlbison.y b/connectivity/source/parse/sqlbison.y
index d7e7c678a890..d559c292df63 100755
--- a/connectivity/source/parse/sqlbison.y
+++ b/connectivity/source/parse/sqlbison.y
@@ -4570,6 +4570,67 @@ void OSQLParser::setParseTree(OSQLParseNode * pNewParseTree)
 	m_pParseTree = pNewParseTree;
 }
 //-----------------------------------------------------------------------------
+
+/** Delete all comments in a query.
+
+    See also getComment()/concatComment() implementation for
+    OQueryController::translateStatement().
+ */
+static ::rtl::OUString delComment( const ::rtl::OUString& rQuery )
+{
+    // First a quick search if there is any "--" or "//" or "/*", if not then the whole 
+    // copying loop is pointless.
+    if (rQuery.indexOfAsciiL( "--", 2, 0) < 0 && rQuery.indexOfAsciiL( "//", 2, 0) < 0 &&
+            rQuery.indexOfAsciiL( "/*", 2, 0) < 0)
+        return rQuery;
+
+    const sal_Unicode* pCopy = rQuery.getStr();
+    sal_Int32 nQueryLen = rQuery.getLength();
+    bool bIsText1  = false;     // "text"
+    bool bIsText2  = false;     // 'text'
+    bool bComment2 = false;     // /* comment */
+    bool bComment  = false;     // -- or // comment
+    ::rtl::OUStringBuffer aBuf(nQueryLen);
+    for (size_t i=0; i < nQueryLen; ++i)
+    {
+        if (bComment2)
+        {
+            if ((i+1) < nQueryLen)
+            {
+                if (pCopy[i]=='*' && pCopy[i+1]=='/')
+                {
+                    bComment2 = false;
+                    ++i;
+                }
+            }
+            else
+            {
+                // comment can't close anymore, actually an error, but..
+            }
+            continue;
+        }
+        if (pCopy[i] == '\n')
+            bComment = false;
+        else if (!bComment)
+        {
+            if (pCopy[i] == '\"' && !bIsText2)
+                bIsText1 = !bIsText1;
+            else if (pCopy[i] == '\'' && !bIsText1)
+                bIsText2 = !bIsText2;
+            if (!bIsText1 && !bIsText2 && (i+1) < nQueryLen)
+            {
+                if ((pCopy[i]=='-' && pCopy[i+1]=='-') || (pCopy[i]=='/' && pCopy[i+1]=='/'))
+                    bComment = true;
+                else if ((pCopy[i]=='/' && pCopy[i+1]=='*'))
+                    bComment2 = true;
+            }
+        }
+        if (!bComment && !bComment2)
+            aBuf.append( &pCopy[i], 1);
+    }
+    return aBuf.makeStringAndClear();
+}
+//-----------------------------------------------------------------------------
 OSQLParseNode* OSQLParser::parseTree(::rtl::OUString& rErrorMessage,
 									 const ::rtl::OUString& rStatement,
 								     sal_Bool bInternational)
@@ -4581,9 +4642,12 @@ OSQLParseNode* OSQLParser::parseTree(::rtl::OUString& rErrorMessage,
 	// must be reset
 	setParser(this);
 
+	// delete comments before parsing
+	::rtl::OUString sTemp = delComment(rStatement);
+
 	// defines how to scan
 	s_pScanner->SetRule(s_pScanner->GetSQLRule()); // initial
-	s_pScanner->prepareScan(rStatement, m_pContext, bInternational);
+	s_pScanner->prepareScan(sTemp, m_pContext, bInternational);
 
 	SQLyylval.pParseNode = NULL;
 	//	SQLyypvt = NULL;