compile.c

C++的一个好库。。。现在很流行

            ++python_instance_number;
            
            m = bindmodule(instance_name);

            /* This is expected to get bound method. */
            method = PyObject_GetAttr(py_result, method_name);
            
            r = bindrule( imported_method_name, root_module() );

            r->python_function = method;

            result = list_new(0, newstr(instance_name));    

            Py_DECREF(method_name);
        }
        else if (py_result == Py_None)
        {
            result = L0;
        }
        else
        {
            fprintf(stderr, "Non-list object returned by Python call\n");
        }

        Py_DECREF(py_result);
    }
    else {
        PyErr_Print();
        fprintf(stderr,"Call failed\n");
    }
    
    return result;
}
#endif

/*
 * evaluate_rule() - execute a rule invocation
 */

LIST *
evaluate_rule(
    char    *rulename,
    FRAME *frame )
{
    LIST      *result = L0;
    RULE          *rule;
    profile_frame prof[1];
    module_t    *prev_module = frame->module;
    
    LIST      *l;
    {
        LOL arg_context_, *arg_context = &arg_context_;
        if ( !frame->prev )
            lol_init(arg_context);
        else
            arg_context = frame->prev->args;
        
        l = var_expand( L0, rulename, rulename+strlen(rulename), arg_context, 0 );
    }

    if ( !l )
    {
        backtrace_line( frame->prev );
        printf( "warning: rulename %s expands to empty string\n", rulename );
        backtrace( frame->prev );
        return result;
    }

    rulename = l->string;
    rule = bindrule( l->string, frame->module );

#ifdef HAVE_PYTHON
    if (rule->python_function)
    {
        return call_python_function(rule, frame);
    }
#endif

    /* drop the rule name */
    l = list_pop_front( l );

    /* tack the rest of the expansion onto the front of the first argument */
    frame->args->list[0] = list_append( l, lol_get( frame->args, 0 ) );

    if ( DEBUG_COMPILE )
    {
        /* Try hard to indicate in which module the rule is going to execute */
        if ( rule->module != frame->module
             && rule->procedure != 0 && strcmp(rulename, rule->procedure->rulename) )
        {
            char buf[256] = "";
            strncat( buf, rule->module->name, sizeof(buf) - 1 );
            strncat( buf, rule->name, sizeof(buf) - 1 );
            debug_compile( 1, buf, frame);
        }
        else
        {
            debug_compile( 1, rulename, frame);
        }

        lol_print( frame->args );
        printf( "\n" );
    }
    
    if ( rule->procedure && rule->module != prev_module )
    {
        /* propagate current module to nested rule invocations */
        frame->module = rule->module;
        
        /* swap variables */
        exit_module( prev_module );
        enter_module( rule->module );
    }
        
    /* record current rule name in frame */
    if ( rule->procedure )
    {
        frame->rulename = rulename;
        /* and enter record profile info */
        if ( DEBUG_PROFILE )
            profile_enter( rule->procedure->rulename, prof );
    }

    /* Check traditional targets $(<) and sources $(>) */

    if( !rule->actions && !rule->procedure )
    {
        backtrace_line( frame->prev );
        printf( "rule %s unknown in module %s\n", rule->name, frame->module->name );
        backtrace( frame->prev );
        exit(1);
    }

    /* If this rule will be executed for updating the targets */
    /* then construct the action for make(). */

    if( rule->actions )
    {
        TARGETS *t;
        ACTION  *action;

        /* The action is associated with this instance of this rule */

        action = (ACTION *)malloc( sizeof( ACTION ) );
        memset( (char *)action, '\0', sizeof( *action ) );

        action->rule = rule;
        action->targets = targetlist( (TARGETS *)0, lol_get( frame->args, 0 ) );
        action->sources = targetlist( (TARGETS *)0, lol_get( frame->args, 1 ) );

        /* Append this action to the actions of each target */

        for( t = action->targets; t; t = t->next )
            t->target->actions = actionlist( t->target->actions, action );
    }

    /* Now recursively compile any parse tree associated with this rule */
    /* refer/free to ensure rule not freed during use */

    if( rule->procedure )
    {
        SETTINGS *local_args = collect_arguments( rule, frame );
        PARSE *parse = rule->procedure;
        parse_refer( parse );
        
        pushsettings( local_args );
        result = parse_evaluate( parse, frame );
        popsettings( local_args );
        freesettings( local_args );
        
        parse_free( parse );
    }

    if ( frame->module != prev_module )
    {
        exit_module( frame->module );
        enter_module( prev_module );
    }

    if ( DEBUG_PROFILE && rule->procedure )
        profile_exit( prof );

    if( DEBUG_COMPILE )
        debug_compile( -1, 0, frame);

    return result;
}

/*
 * Call the given rule with the specified parameters.
 * The parameters should be of LIST* and end with NULL pointer.
 * This differs from the 'evaluate_rule' in that frame
 * for called rule is prepared in 'call_rule'.
 *
 * This function is usefull when builtin rule (in C) wants to
 * call another rule, which might be implemented in Jam.
 */
LIST *call_rule( char *rulename, FRAME* caller_frame, ...)
{
    va_list va;
    LIST *result;

    FRAME       inner[1];
    frame_init( inner );
    inner->prev = caller_frame;
    inner->prev_user = caller_frame->module->user_module ? 
        caller_frame : caller_frame->prev_user;
    inner->module = caller_frame->module;    
    inner->procedure = 0;

    va_start(va, caller_frame);    
    for(;;)
    {
        LIST* l = va_arg(va, LIST*);
        if (!l)
            break;
        lol_add(inner->args, l);
    }
    va_end(va);
                
    result = evaluate_rule(rulename, inner);    

    frame_free(inner);

    return result;
}

/*
 * compile_rules() - compile a chain of rules
 *
 *	parse->left	single rule
 *	parse->right	more compile_rules() by right-recursion
 */

LIST *
compile_rules(
    PARSE   *parse,
    FRAME *frame )
{
    /* Ignore result from first statement; return the 2nd. */
	/* Optimize recursion on the right by looping. */

    do list_free( parse_evaluate( parse->left, frame ) );
    while( (parse = parse->right)->func == compile_rules );

    return parse_evaluate( parse, frame );
}

/*
 * compile_set() - compile the "set variable" statement
 *
 *  parse->left variable names
 *  parse->right    variable values 
 *  parse->num  ASSIGN_SET/APPEND/DEFAULT
 */

LIST *
compile_set(
    PARSE   *parse,
    FRAME *frame )
{
    LIST    *nt = parse_evaluate( parse->left, frame );
    LIST    *ns = parse_evaluate( parse->right, frame );
    LIST    *l;
    int     setflag;
    char    *trace;

    switch( parse->num )
    {
    case ASSIGN_SET:    setflag = VAR_SET; trace = "="; break;
    case ASSIGN_APPEND: setflag = VAR_APPEND; trace = "+="; break;
    case ASSIGN_DEFAULT:    setflag = VAR_DEFAULT; trace = "?="; break;
    default:        setflag = VAR_SET; trace = ""; break;
    }

    if( DEBUG_COMPILE )
    {
        debug_compile( 0, "set", frame);
        list_print( nt );
        printf( " %s ", trace );
        list_print( ns );
        printf( "\n" );
    }

    /* Call var_set to set variable */
    /* var_set keeps ns, so need to copy it */

    for( l = nt; l; l = list_next( l ) )
        var_set( l->string, list_copy( L0, ns ), setflag );

    list_free( nt );

    return ns;
}

/*
 * compile_setcomp() - support for `rule` - save parse tree 
 *
 *  parse->string   rule name
 *  parse->left rules for rule
 *  parse->right optional list-of-lists describing arguments
 */

LIST *
compile_setcomp(
    PARSE   *parse,
    FRAME *frame)
{
    argument_list* arg_list = 0;
    
    /* Create new LOL describing argument requirements if supplied */
    if ( parse->right )
    {
        PARSE *p;
        arg_list = args_new();
        for( p = parse->right; p; p = p->left )
            lol_add( arg_list->data, parse_evaluate( p->right, frame ) );
    }
    
    new_rule_body( frame->module, parse->string, arg_list, parse->left, !parse->num );
    return L0;
}

/*
 * compile_setexec() - support for `actions` - save execution string 
 *
 *  parse->string   rule name
 *  parse->string1  OS command string
 *  parse->num  flags
 *  parse->left `bind` variables
 *
 * Note that the parse flags (as defined in compile.h) are transfered
 * directly to the rule flags (as defined in rules.h).
 */

LIST *
compile_setexec(
    PARSE   *parse,
    FRAME *frame )
{
    LIST* bindlist = parse_evaluate( parse->left, frame );

    new_rule_actions( frame->module, parse->string, parse->string1, bindlist, parse->num );

    return L0;
}

/*
 * compile_settings() - compile the "on =" (set variable on exec) statement
 *
 *  parse->left variable names
 *  parse->right    target name 
 *  parse->third    variable value 
 *  parse->num  ASSIGN_SET/APPEND   
 */

LIST *
compile_settings(
    PARSE   *parse,
    FRAME *frame )
{
    LIST    *nt = parse_evaluate( parse->left, frame );
    LIST    *ns = parse_evaluate( parse->third, frame );
    LIST    *targets = parse_evaluate( parse->right, frame );
    LIST    *ts;
    int append = parse->num == ASSIGN_APPEND;

    if( DEBUG_COMPILE )
    {
        debug_compile( 0, "set", frame);
        list_print( nt );
        printf( " on " );
        list_print( targets );
        printf( " %s ", append ? "+=" : "=" );
        list_print( ns );
        printf( "\n" );
    }

    /* Call addsettings to save variable setting */
    /* addsettings keeps ns, so need to copy it */
    /* Pass append flag to addsettings() */

    for( ts = targets; ts; ts = list_next( ts ) )
    {
        TARGET  *t = bindtarget( ts->string );
        LIST    *l;

        for( l = nt; l; l = list_next( l ) )
        t->settings = addsettings( t->settings, append, 
                l->string, list_copy( (LIST*)0, ns ) );
    }

    list_free( nt );
    list_free( targets );

    return ns;
}

/*
 * compile_switch() - compile 'switch' rule
 *
 *  parse->left switch value (only 1st used)
 *  parse->right    cases
 *
 *  cases->left 1st case
 *  cases->right    next cases
 *
 *  case->string    argument to match
 *  case->left  parse tree to execute
 */

LIST *
compile_switch(
    PARSE   *parse,
    FRAME *frame )
{
    LIST    *nt = parse_evaluate( parse->left, frame );
    LIST    *result = 0;

    if( DEBUG_COMPILE )
    {
        debug_compile( 0, "switch", frame);
        list_print( nt );
        printf( "\n" );
    }

    /* Step through cases */

    for( parse = parse->right; parse; parse = parse->right )
    {
        if( !glob( parse->left->string, nt ? nt->string : "" ) )
        {
        /* Get & exec parse tree for this case */
        parse = parse->left->left;
        result = parse_evaluate( parse, frame );
        break;
        }
    }

    list_free( nt );

    return result;
}

/*
 * debug_compile() - printf with indent to show rule expansion.
 */

static void
debug_compile( int which, char *s, FRAME* frame )
{
    static int level = 0;
    static char indent[36] = ">>>>|>>>>|>>>>|>>>>|>>>>|>>>>|>>>>|";

    if ( which >= 0 )
    {
      int i;
      
      print_source_line( frame->procedure );
      
      i = (level+1)*2;
      while ( i > 35 )
      {
        printf( indent );
        i -= 35;
      }

      printf( "%*.*s ", i, i, indent );
    }

    if( s )
        printf( "%s ", s );

    level += which;
}