modules.c

C++的一个好库。。。现在很流行

/*
 *  Copyright 2001-2004 David Abrahams.
 *  Distributed under the Boost Software License, Version 1.0.
 *  (See accompanying file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
 */
#include "modules.h"
#include "jam.h"
#include "string.h"
#include "hash.h"
#include "newstr.h"
#include "lists.h"
#include "parse.h"
#include "rules.h"
#include "variable.h"
#include "strings.h"
#include <assert.h>

static struct hash* module_hash = 0;

static char* new_module_str( module_t* m, char* suffix )
{
    char* result;
    string s;
    string_copy( &s, m->name );
    string_append( &s, suffix );
    result = newstr( s.value );
    string_free( &s );
    return result;
}

module_t* bindmodule( char* name )
{
    string s;
    module_t m_, *m = &m_;

    if( !module_hash )
        module_hash = hashinit( sizeof( module_t ), "modules" );

    string_new( &s );
    if (name)
    {
        string_append( &s, name );
        string_push_back( &s, '.' );
    }
        
    m->name = s.value;
    
    if ( hashenter( module_hash, (HASHDATA **)&m ) )
    {
        m->name = newstr( m->name );
        m->variables = 0;
        m->rules = 0;
        m->imported_modules = 0;
        m->class_module = 0;
        m->native_rules = 0;
        m->user_module = 0;
    }
    string_free( &s );
    return m;
}

/*
 * demand_rules() - Get the module's "rules" hash on demand
 */
struct hash* demand_rules( module_t* m )
{
    if ( !m->rules )
        m->rules = hashinit( sizeof( RULE ), new_module_str( m, "rules" ) );
    return m->rules;
}

/*
 * delete_module() - wipe out the module's rules and variables
 */
static void delete_rule_( void* xrule, void* data )
{
    rule_free( (RULE*)xrule );
}

void delete_module( module_t* m )
{
    /* clear out all the rules */
    if ( m->rules )
    {
        hashenumerate( m->rules, delete_rule_, (void*)0 );
        hashdone( m->rules );
        m->rules = 0;
    }

    if ( m->variables )
    {
        var_hash_swap( &m->variables );
        var_done();
        var_hash_swap( &m->variables );
        m->variables = 0;
    }
}

module_t* root_module()
{
    static module_t* root = 0;
    if ( !root )
        root = bindmodule(0);
    return root;
}

void enter_module( module_t* m )
{
    var_hash_swap( &m->variables );
}

void exit_module( module_t* m )
{
    var_hash_swap( &m->variables );
}

void import_module(LIST* module_names, module_t* target_module)
{ 
    struct hash* h;

    if (!target_module->imported_modules)
        target_module->imported_modules = hashinit( sizeof(char*), "imported");
    h = target_module->imported_modules;

    for(;module_names; module_names = module_names->next) {
        
        char* s = module_names->string;
        char** ss = &s;
        
        hashenter(h, (HASHDATA**)&ss);
    }
}

static void add_module_name( void* r_, void* result_ )
{
    char** r = (char**)r_;
    LIST** result = (LIST**)result_;

    *result = list_new( *result, copystr( *r ) );
}

LIST* imported_modules(module_t* module)
{
    LIST *result = L0;

    if ( module->imported_modules )
        hashenumerate( module->imported_modules, add_module_name, &result );

    return result;
}