/**
* mds — A micro-display server
* Copyright © 2014 Mattias Andrée (maandree@member.fsf.org)
*
* This program 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.
*
* This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "simplify-tree.h"
#include <stdlib.h>
#include <string.h>
/**
* Add an error the to error list
*
* @param NODE:const mds_kbdc_tree_t* The node the triggered the error
* @param SEVERITY:identifier * in `MDS_KBDC_PARSE_ERROR_*` to indicate severity
* @param ...:const char*, ... Error description format string and arguments
* @scope error:mds_kbdc_parse_error_t* Variable where the new error will be stored
*/
#define NEW_ERROR(NODE, SEVERITY, ...) \
NEW_ERROR_(result, SEVERITY, 1, (NODE)->loc_line, \
(NODE)->loc_start, (NODE)->loc_end, 1, __VA_ARGS__)
/**
* Variable whether the latest created error is stored
*/
static mds_kbdc_parse_error_t* error;
/**
* The parameter of `simplify_tree`
*/
static mds_kbdc_parsed_t* restrict result;
/**
* Simplify a subtree
*
* @param tree The tree
* @return Zero on success, -1 on error
*/
static int simplify(mds_kbdc_tree_t* restrict tree);
/**
* Simplify a macro call-subtree
*
* @param tree The macro call-subtree
* @return Zero on success, -1 on error
*/
static int simplify_macro_call(mds_kbdc_tree_macro_call_t* restrict tree)
{
mds_kbdc_tree_t* argument = tree->arguments;
mds_kbdc_tree_t** here;
/* Simplify arguments. */
for (argument = tree->arguments; argument; argument = argument->next)
simplify(argument);
/* Remove ‘.’:s. */
for (here = &(tree->arguments); *here; here = &((*here)->next))
while (*here && (*here)->type == MDS_KBDC_TREE_TYPE_NOTHING)
{
mds_kbdc_tree_t* temp = (*here)->next;
(*here)->next = NULL;
NEW_ERROR(*here, WARNING, "‘.’ outside alternation has no effect");
mds_kbdc_tree_free(*here);
*here = temp;
}
return 0;
pfail:
return -1;
}
/**
* Simplify a subtree
*
* @param tree The tree
* @return Zero on success, -1 on error
*/
static int simplify(mds_kbdc_tree_t* restrict tree)
{
#define s(expr) if ((r = simplify(tree->expr))) return r;
int r;
again:
if (tree == NULL)
return 0;
switch (tree->type)
{
case MDS_KBDC_TREE_TYPE_INFORMATION: s (information.inner); break;
case MDS_KBDC_TREE_TYPE_FUNCTION: s (function.inner); break;
case MDS_KBDC_TREE_TYPE_MACRO: s (macro.inner); break;
case MDS_KBDC_TREE_TYPE_ASSUMPTION: s (assumption.inner); break;
case MDS_KBDC_TREE_TYPE_FOR: s (for_.inner); break;
case MDS_KBDC_TREE_TYPE_IF:
s (if_.inner);
s (if_.otherwise);
break;
case MDS_KBDC_TREE_TYPE_MAP:
/* TODO */
break;
case MDS_KBDC_TREE_TYPE_ALTERNATION:
/* TODO find alternations inside alternations */
break;
case MDS_KBDC_TREE_TYPE_UNORDERED:
/* TODO find unordered and nothing inside unordered */
break;
case MDS_KBDC_TREE_TYPE_MACRO_CALL:
if ((r = simplify_macro_call(&(tree->macro_call))))
return r;
break;
default:
break;
}
tree = tree->next;
goto again;
#undef s
}
/**
* Simplify a tree and generate related warnings in the process
*
* @param result_ `result` from `parse_to_tree`, same sematics, will be updated
* @return -1 if an error occursed that cannot be stored in `result`, zero otherwise
*/
int simplify_tree(mds_kbdc_parsed_t* restrict result_)
{
result = result_;
return simplify(result_->tree);
}
#undef NEW_ERROR
