diff options
| -rw-r--r-- | src/mds-kbdc/simplify-tree.c | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/src/mds-kbdc/simplify-tree.c b/src/mds-kbdc/simplify-tree.c index 608485d..f032dd6 100644 --- a/src/mds-kbdc/simplify-tree.c +++ b/src/mds-kbdc/simplify-tree.c @@ -115,8 +115,12 @@ static int simplify_macro_call(mds_kbdc_tree_macro_call_t* restrict tree) if (argument->type != MDS_KBDC_TREE_TYPE_ALTERNATION) continue; + /* Detach next statement, we do not want to duplicate all following statements. */ next_statement = tree->next, tree->next = NULL; + /* Detach alternation, we replace it in all duplcates, + no need to duplicate all alternatives. */ alternative = argument->alternation.inner, argument->alternation.inner = NULL; + /* Eliminate. */ for (first = last = NULL; alternative; alternative = next_alternative) { /* Duplicate statement. */ @@ -145,10 +149,13 @@ static int simplify_macro_call(mds_kbdc_tree_macro_call_t* restrict tree) /* Left-join alternative. */ *here = alternative; } + /* Replace the statement with the first generated statement without the alternation. */ mds_kbdc_tree_destroy((mds_kbdc_tree_t*)tree); memcpy(tree, first, sizeof(mds_kbdc_tree_t)); - last->next = next_statement; + if (first == last) last = (mds_kbdc_tree_t*)tree; free(first); + /* Reattach the statement that followed to the last generated statement. */ + last->next = next_statement; } mds_kbdc_tree_free(dup_argument); @@ -279,24 +286,28 @@ static int simplify_alternation(mds_kbdc_tree_alternation_t* restrict tree) else if (argument->type == MDS_KBDC_TREE_TYPE_ALTERNATION) { /* Alternation nesting. */ - temp = argument->next; NEW_ERROR(argument, WARNING, "alternation inside alternation is unnecessary"); if (simplify_alternation(&(argument->alternation))) return -1; - *here = argument, redo = 1; - if (argument->type != MDS_KBDC_TREE_TYPE_ALTERNATION) - argument->next = temp; - else + if (argument->type == MDS_KBDC_TREE_TYPE_ALTERNATION) { + /* Remember the alternation and the argument that follows it. */ eliminated_argument = argument; + temp = argument->next; + /* Find the last alternative. */ for (argument->next = argument->alternation.inner; argument->next;) argument = argument->next; + /* Attach the argument that was after the alternation to the end of the alternation, + that is, flatten the right side. */ argument->next = temp; - eliminated_argument->alternation.inner = NULL; + /* Flatten the left side. */ *here = eliminated_argument->next; + /* Free the memory of the alternation. */ + eliminated_argument->alternation.inner = NULL; eliminated_argument->next = NULL; mds_kbdc_tree_free(eliminated_argument); } + redo = 1; } /* TODO unordered */ |