preprocessor: handling the '\' in preprocessor code

preprocessor.cpp

@@ -152,6 +152,17 @@ void preprocess(std::istream &istr, std::map<std::string, std::string> &result,
     while ( codestr.find(" \n") != std::string::npos )
         codestr.erase( codestr.find(" \n"), 1 );
 
+    // Using the backslash at the end of a line..
+    while ( codestr.find("\\\n") != std::string::npos )
+    {
+        std::string::size_type pos = codestr.rfind("\\\n");
+        codestr.erase(pos,2);
+        if (pos > 0 && codestr[pos-1] != ' ')
+            codestr.insert(pos, " ");
+        if ( codestr.find("\n", pos) != std::string::npos)
+            codestr.insert( codestr.find("\n", pos), "\n" );
+    }
+
     // Get all possible configurations..
     std::list<std::string> cfgs = getcfgs( codestr );
 

testpreprocessor.cpp

@@ -57,6 +57,8 @@ private:
         TEST_CASE( include1 );
 
         TEST_CASE( if_cond1 );
+
+        TEST_CASE( multiline );
     }
 
     bool cmpmaps(const std::map<std::string, std::string> &m1, const std::map<std::string, std::string> &m2)
@@ -393,6 +395,24 @@ private:
         ASSERT_EQUALS( true, cmpmaps(actual, expected));
     }
 
+
+    void multiline()
+    {
+        const char filedata[] = "#define str \"abc\" \\\n"
+                                "            \"def\"\n";
+
+        std::map<std::string, std::string> expected;
+        expected[""] = "#define str \"abc\" \"def\"\n\n";
+
+        // Preprocess => actual result..
+        std::istringstream istr(filedata);
+        std::map<std::string, std::string> actual;
+        preprocess( istr, actual, "" );
+
+        // Compare results..
+        ASSERT_EQUALS( true, cmpmaps(actual, expected));
+    }
+
 };
 
 REGISTER_TEST( TestPreprocessor )