GCC plugin speller.c

/******************************************************************************
 * speller.c 
 *
 * speller - GCC Spell Checking Plugin
 *
 * Copyright (C) 2011 Matt Davis (enferex) of 757Labs mattdavis9@gmail.com
 *
 * speller is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * speller is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with speller.  If not, see .
 *****************************************************************************/

#include <aspell.h>
#include <gcc-plugin.h>
#include <coretypes.h>
#include <diagnostic.h>
#include <gimple.h>
#include <tree.h>
#include <tree-flow.h>
#include <tree-pass.h>


#define is_alpha(c) (((c)>64 && (c)<91) || ((c)>96 && (c)<123))


int plugin_is_GPL_compatible = 1;
static AspellSpeller *speller_g;


/* Help info about the plugin if one were to use gcc's --version --help */
static struct plugin_info speller_info =
{
    .version = "42",
    .help = "Hahahaha yeaaaaa....",
};


static struct plugin_gcc_version speller_ver =
{
    .basever = "4.6",
};


/* We don't need to run any tests before we execute our plugin pass */
static bool speller_gate(void)
{
    return true;
}


static const_tree is_str_cst(const_tree node)
{
    const_tree str = node;

    /* Filter out types we are ignoring */
    if (TREE_CODE(str) == VAR_DECL)
    {
        if (!(str = DECL_INITIAL(node)))
          return NULL_TREE;
        else if (TREE_OPERAND_LENGTH(str))
          str = TREE_OPERAND(str, 0);
    }
    else if (TREE_CODE(str) == ADDR_EXPR &&
             TREE_OPERAND_LENGTH(str) > 0)
      str = TREE_OPERAND(str, 0);

    if (TREE_CODE(str) != STRING_CST &&
        TREE_OPERAND_LENGTH(str) > 0)
      str = TREE_OPERAND(str, 0);

    if (TREE_CODE(str) != STRING_CST)
      return NULL_TREE;
    else
      return str;
}


static AspellSpeller *init_spellchecker(void)
{
    AspellConfig *cfg;
    AspellCanHaveError *err;

    /* Configure and instantiate a spell checker */
    cfg = new_aspell_config();
    aspell_config_replace(cfg, "lang", "en_US");
    err = new_aspell_speller(cfg);
    if (aspell_error_number(err) != 0)
    {
        puts(aspell_error_message(err));
        return NULL;
    }

    return to_aspell_speller(err);
}


static void spell_check(const_gimple stmt, const_tree str)
{
    char buf[32] = {0};
    const char *data, *end;

    data = TREE_STRING_POINTER(str);
    printf("Spell checking string: \'%s\'\n", data);

    while (*data)
    {
        /* Skip non alphas including whitespace */
        while (!is_alpha(data[0]))
        {
            if (data[0] == '\0')
              return;
            ++data;
        }

        /* Find the end of the word */
        end = data;
        while (is_alpha(end[0]))
          ++end;

        if ((end - data) > sizeof(buf))
          return;
       
        memcpy(buf, data, end - data);
        buf[end-data] = '\0';
        if (!(aspell_speller_check(speller_g, buf, end - data)))
          warning_at(gimple_location(stmt), 0, "%s (bad spelling)", buf);
        data = end;
    }
}


static unsigned speller_exec(void)
{
    unsigned i;
    const_tree str, op;
    basic_block bb;
    gimple stmt;
    gimple_stmt_iterator gsi;

    FOR_EACH_BB(bb)
      for (gsi=gsi_start_bb(bb); !gsi_end_p(gsi); gsi_next(&gsi))
      {
          stmt = gsi_stmt(gsi);
          for (i=0; i<gimple_num_ops(stmt); ++i)
            if ((op = gimple_op(stmt, i)) && (str = is_str_cst(op)))
              spell_check(stmt, str);
      }

    return 0;
}


/* See tree-pass.h for a list and desctiptions for the fields of this struct */
static struct gimple_opt_pass speller_pass = 
{
    .pass.type = GIMPLE_PASS,
    .pass.name = "speller",       /* For use in the dump file */
    .pass.gate = speller_gate,
    .pass.execute = speller_exec, /* Pass handler/callback */
};


/* Return 0 on success or error code on failure */
int plugin_init(struct plugin_name_args   *info,  /* Argument infor */
                struct plugin_gcc_version *ver)   /* Version of GCC */
{
    struct register_pass_info pass;

     if (strncmp(ver->basever, speller_ver.basever, strlen("4.6")))
       return -1; /* Incorrect version of gcc */

    pass.pass = &speller_pass.pass;
    pass.reference_pass_name = "ssa";
    pass.ref_pass_instance_number = 1;
    pass.pos_op = PASS_POS_INSERT_AFTER;

    /* Tell gcc we want to be called after the first SSA pass */
    register_callback("speller", PLUGIN_PASS_MANAGER_SETUP, NULL, &pass);
    register_callback("speller", PLUGIN_INFO, NULL, &speller_info);

    /* Initilize our spell checker */
    if (!(speller_g = init_spellchecker()))
      return -1;

    return 0;
}