| /* IELR's inadequacy annotation list. |
| |
| Copyright (C) 2009-2012 Free Software Foundation, Inc. |
| |
| This file is part of Bison, the GNU Compiler Compiler. |
| |
| 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/>. */ |
| |
| #ifndef ANNOTATION_LIST_H_ |
| # define ANNOTATION_LIST_H_ |
| |
| #include <bitsetv.h> |
| #include "Sbitset.h" |
| #include "InadequacyList.h" |
| #include "state.h" |
| |
| typedef unsigned int AnnotationIndex; |
| |
| /** |
| * A node in a list of annotations on a particular LR(0) state. Each |
| * annotation records how isocores of that LR(0) state might contribute to an |
| * individual inadequacy, which might manifest in a different state. Don't |
| * break encapsulation by modifying the fields directly. Use the provided |
| * interface functions. |
| */ |
| typedef struct AnnotationList |
| { |
| /** The next node in the list or \c NULL if none. */ |
| struct AnnotationList *next; |
| /** The \c InadequacyList node describing how this inadequacy manifests. */ |
| InadequacyList *inadequacyNode; |
| /** |
| * List of how the "always", "never", and potential contributions of the |
| * inadequacy might be made by isocores of the annotated LR(0) state: |
| * - The number of rows is the number of contributions. That is, |
| * <tt>AnnotationList::inadequacyNode->contributionCount</tt>. |
| * - The token associated with contribution \c i is |
| * <tt>InadequacyList__getContributionToken (AnnotationList::inadequacyNode, i)</tt>. |
| * - Iff <tt>AnnotationList::contributions[i] = NULL</tt>, contribution |
| * \c i is an "always" contribution. That is, for every isocore of the |
| * annotated LR(0) state, its core or the core of one its eventual |
| * successors will definitely make this contribution to the inadequacy. |
| * It may contribute by either: |
| * - Creating a shift of contribution <tt>i</tt>'s token in the state |
| * that can manifest the inadequacy. |
| * - Propagating that token to the lookahead set of contribution |
| * <tt>i</tt>'s reduction in the state that can manifest the |
| * inadequacy. |
| * - Otherwise: |
| * - The number of columns in <tt>AnnotationList::contributions[i]</tt> |
| * is the number of kernel items in any isocore of the annotated LR(0) |
| * state. |
| * - Iff <tt>AnnotationList::contributions[i]</tt> is empty, contribution |
| * \c i is a "never" contribution. That is, no isocore of the |
| * annotated LR(0) state can make this contribution to the inadequacy. |
| * - Otherwise, for each bit \c j that is set in |
| * <tt>AnnotationList::contributions[i]</tt>, if the token associated |
| * with contribution \c i is present in the lookahead set of kernel |
| * item \c j of an isocore of the annotated LR(0) state, that isocore |
| * will make contribution \c i to the inadequacy by propagating the |
| * contribution's token to the lookahead set of the contribution's |
| * reduction in the state that can manifest the inadequacy. |
| */ |
| Sbitset contributions[1]; |
| } AnnotationList; |
| |
| /** |
| * \pre |
| * - <tt>s != NULL</tt>. |
| * - \c follow_kernel_items, \c always_follows, and \c predecessors were |
| * computed by \c ielr_compute_auxiliary_tables. |
| * - The size of each of \c annotation_lists and \c annotation_counts is |
| * \c ::nstates. |
| * - If no \c InadequacyList nodes are currently allocated for the |
| * parser tables to which \c s belongs, then it is best if |
| * <tt>*inadequacy_list_node_count</tt> is zero to avoid overflow. |
| * Otherwise, <tt>*inadequacy_list_node_count</tt> has not been |
| * modified by any function except |
| * \c AnnotationList__compute_from_inadequacies since the invocation |
| * of \c AnnotationList__compute_from_inadequacies that constructed |
| * the first of the \c InadequacyList nodes currently allocated for |
| * those parser tables. |
| * \post |
| * - <tt>inadequacy_lists[s->number]</tt> now describes all inadequacies that |
| * manifest in \c s. |
| * - For every state <tt>states[i]</tt>, <tt>annotation_lists[i]</tt> now |
| * contains all annotations associated with all inadequacies that manifest |
| * in \c s. |
| * - <tt>annotation_counts[i]</tt> was incremented by the number of new |
| * annotations added to <tt>states[i]</tt>. |
| * - <tt>*max_contributionsp</tt> is the higher of: |
| * - The maximum number of contributions computed per annotation. |
| * - <tt>*max_contributionsp \@pre</tt>. |
| * - All memory for all new annotations was allocated on |
| * \c annotations_obstackp. |
| */ |
| void |
| AnnotationList__compute_from_inadequacies ( |
| state *s, bitsetv follow_kernel_items, bitsetv always_follows, |
| state ***predecessors, bitset **item_lookahead_sets, |
| InadequacyList **inadequacy_lists, AnnotationList **annotation_lists, |
| AnnotationIndex *annotation_counts, |
| ContributionIndex *max_contributionsp, |
| struct obstack *annotations_obstackp, |
| InadequacyListNodeCount *inadequacy_list_node_count); |
| |
| /** |
| * \pre |
| * - <tt>self != NULL</tt>. |
| * - \c nitems is the number of kernel items in the LR(0) state that every |
| * node in the list \c self annotates. |
| * \post |
| * - A textual representation of all nodes in the list \c self was printed to |
| * stderr. \c spaces spaces were printed before each line of the text. |
| */ |
| void AnnotationList__debug (AnnotationList const *self, size_t nitems, |
| int spaces); |
| |
| /** |
| * \pre |
| * - <tt>self != NULL</tt>. |
| * - \c nitems is the number of kernel items in the LR(0) state that \c self |
| * annotates. |
| * - The number of rows in \c lookahead_filter is at least \c nitems, and the |
| * number of columns is \c ::ntokens. |
| * \post |
| * - <tt>lookahead_filter[i][j]</tt> is set iff some annotation in the list |
| * \c self lists token \c j in kernel item \c i as a contributor. |
| */ |
| void AnnotationList__computeLookaheadFilter (AnnotationList const *self, |
| size_t nitems, |
| bitsetv lookahead_filter); |
| |
| /** |
| * \pre |
| * - <tt>self != NULL</tt>. |
| * - \c nitems is the number of kernel items in the LR(0) state that \c self |
| * annotates. |
| * - \c lookaheads describes the lookahead sets on the kernel items of some |
| * isocore of the LR(0) state that \c self annotates. Either: |
| * - <tt>lookaheads = NULL</tt> only if the lookahead set on every kernel |
| * item is empty. |
| * - For any <tt>0 <= i < nitems</tt>, <tt>lookaheads[i]</tt> is either: |
| * - \c NULL only if the lookahead set on kernel item \c i is empty. |
| * - The (possibly empty) lookahead set on kernel item \c i. |
| * \post |
| * - If <tt>require_split_stable = false</tt>, \c result = either: |
| * - \c ContributionIndex__none iff the state described by \c lookaheads |
| * makes none of the contributions in \c self. |
| * - The index of the dominating contribution in \c self that is made by |
| * that state. |
| * - \c ContributionIndex__error_action to indicate that the inadequacy |
| * manifests as a conflict and that a syntax error action (because of a |
| * %nonassoc) dominates instead. |
| * - Otherwise, \c result is the same as if <tt>require_split_stable = |
| * false</tt> except that it is also \c ContributionIndex__none if there |
| * are contributions made by the state but the dominating contribution is |
| * not split-stable. By split-stable, we mean that the dominating |
| * contribution cannot change due to loss of one or more potential |
| * contributions due to loss of lookaheads due to splitting of the state. |
| * - After determining which contributions are actually made by the state, |
| * the algorithm for determining which contribution dominates in the |
| * conflict is intended to choose exactly the same action as conflicts.c |
| * would choose... no matter how crazy conflicts.c's choice is. |
| */ |
| ContributionIndex |
| AnnotationList__computeDominantContribution (AnnotationList const *self, |
| size_t nitems, bitset *lookaheads, |
| bool require_split_stable); |
| |
| #endif /* !ANNOTATION_LIST_H_ */ |
