Merge pull request #2 from wamckee/patch-2

Minor bug fix interpreting parse() return value

Author: jonathan-beard

mc_driver.cpp

@@ -4,26 +4,40 @@
 
 #include "mc_driver.hpp"
 
-#ifndef FAIL
-#define FAIL -1
+// wamckee 2013 APR 2 - Instead of testing for == FAIL below,
+// we test for != ACCEPT (in which ACCEPT has a value of zero).
+// When compiling on a MSVC 2010 platform using cygwin's Flex and Bison,
+// we note that the return value from parse() is not -1 but rather +1.
+// It is more likely that on different platforms the return value of zero
+// will be used consistantly to indicate an accept state. Whereas, the
+// value of the abort or fail state will be more likely not to be a specific
+// value but rather a value that is not equal to zero.
+
+#ifndef ACCEPT
+#define ACCEPT 0
 #endif
 
 MC::MC_Driver::~MC_Driver(){ 
-   if( scanner != nullptr ) delete(scanner); 
-   if( parser  != nullptr ) delete(parser);
+   delete(scanner);  // wamckee 2013 APR 2
+   delete(parser);   // wamckee 2013 APR 2
 }
 
 void MC::MC_Driver::parse( const char *filename ){
    assert( filename != nullptr );
    std::ifstream in_file( filename );
    if( ! in_file.good() ) exit( EXIT_FAILURE );
+   
+   delete(scanner); // wamckee 2013 APR 2
    scanner = new MC::MC_Scanner( &in_file );
    /* check to see if its initialized */
    assert( scanner != nullptr );
+   
+   delete(parser); // wamckee 2013 APR 2
    parser = new MC::MC_Parser( (*scanner) /* scanner */, 
                                (*this) /* driver */ );
    assert( parser != nullptr );
-   if(parser->parse() == FAIL)
+   
+   if(parser->parse() != ACCEPT) // wamckee 2013 APR 2
    {
       std::cerr << "Parse failed!!\n";
    }