diff --git a/src/backends/lalr.c b/src/backends/lalr.c
index 9c9b864e6fd2a976cdf9508ee2f12d33c3498b8c..e3a866bc741ebb01e4c826027646d92d822f72ea 100644
--- a/src/backends/lalr.c
+++ b/src/backends/lalr.c
@@ -56,6 +56,7 @@ typedef struct HLREnhGrammar_ {
HCFGrammar *grammar; // enhanced grammar
HHashTable *tmap; // maps transitions to enhanced-grammar symbols
HHashTable *smap; // maps enhanced-grammar symbols to transitions
+ HHashTable *corr; // maps symbols to sets of corresponding e. symbols
HArena *arena;
} HLREnhGrammar;
@@ -441,6 +442,7 @@ HLRTable *h_lr0_table(HCFGrammar *g, const HLRDFA *dfa)
// find reducible items in state
H_FOREACH_KEY(dfa->states[i], HLRItem *item)
if(item->mark == item->len) { // mark at the end
+ // check for conflicts
// XXX store more informative stuff in the inadeq records?
if(table->forall[i]) {
// reduce/reduce conflict with a previous item
@@ -448,10 +450,10 @@ HLRTable *h_lr0_table(HCFGrammar *g, const HLRDFA *dfa)
} else if(!h_hashtable_empty(table->rows[i])) {
// shift/reduce conflict with one of the row's entries
h_slist_push(table->inadeq, (void *)(uintptr_t)i);
- } else {
- // set reduce action for the entire row
- table->forall[i] = reduce_action(arena, item);
}
+
+ // set reduce action for the entire row
+ table->forall[i] = reduce_action(arena, item);
}
H_END_FOREACH
}
@@ -478,12 +480,24 @@ static size_t follow_transition(const HLRTable *table, size_t x, HCFChoice *A)
return action->nextstate;
}
-static HCFChoice *transform_symbol(const HLRTable *table, HLREnhGrammar *eg,
- size_t x, HCFChoice *B, size_t z);
+static inline HLRTransition *transition(HArena *arena,
+ size_t x, const HCFChoice *A, size_t y)
+{
+ HLRTransition *t = h_arena_malloc(arena, sizeof(HLRTransition));
+ t->from = x;
+ t->symbol = A;
+ t->to = y;
+ return t;
+}
-static HCFChoice *transform_productions(const HLRTable *table, HLREnhGrammar *eg,
- size_t x, HCFChoice *xAy)
+// no-op on terminal symbols
+static void transform_productions(const HLRTable *table, HLREnhGrammar *eg,
+ size_t x, HCFChoice *xAy)
{
+ if(xAy->type != HCF_CHOICE)
+ return;
+ // XXX CHARSET?
+
HArena *arena = eg->arena;
HCFSequence **seq = h_arena_malloc(arena, seqsize(xAy->seq)
@@ -491,81 +505,86 @@ static HCFChoice *transform_productions(const HLRTable *table, HLREnhGrammar *eg
HCFSequence **p, **q;
for(p=xAy->seq, q=seq; *p; p++, q++) {
// trace rhs starting in state x and following the transitions
- // xAy -> xBz ...
+ // xAy -> ... iBj ...
+ size_t i = x;
HCFChoice **B = (*p)->items;
- HCFChoice **xBz = h_arena_malloc(arena, seqsize(B) * sizeof(HCFChoice *));
- for(; *B; B++, xBz++) {
- size_t z = follow_transition(table, x, *B);
- *xBz = transform_symbol(table, eg, x, *B, z);
- x=z;
+ HCFChoice **items = h_arena_malloc(arena, seqsize(B) * sizeof(HCFChoice *));
+ HCFChoice **iBj = items;
+ for(; *B; B++, iBj++) {
+ size_t j = follow_transition(table, i, *B);
+ HLRTransition *i_B_j = transition(arena, i, *B, j);
+ *iBj = h_hashtable_get(eg->tmap, i_B_j);
+ assert(*iBj != NULL);
+ i = j;
}
- *xBz = NULL;
+ *iBj = NULL;
*q = h_arena_malloc(arena, sizeof(HCFSequence));
- (*q)->items = xBz;
+ (*q)->items = items;
}
*q = NULL;
xAy->seq = seq;
-
- return xAy; // pass-through
-}
-
-static inline HLRTransition *transition(HArena *arena,
- size_t x, const HCFChoice *A, size_t y)
-{
- HLRTransition *t = h_arena_malloc(arena, sizeof(HLRTransition));
- t->from = x;
- t->symbol = A;
- t->to = y;
- return t;
-}
-
-static HCFChoice *transform_symbol(const HLRTable *table, HLREnhGrammar *eg,
- size_t x, HCFChoice *B, size_t z)
-{
- HArena *arena = eg->arena;
-
- // look up the transition in map, create symbol if not found
- HLRTransition *x_B_z = transition(arena, x, B, z);
- HCFChoice *xBz = h_hashtable_get(eg->tmap, x_B_z);
- if(!xBz) {
- HCFChoice *xBz = h_arena_malloc(arena, sizeof(HCFChoice));
- *xBz = *B;
- h_hashtable_put(eg->tmap, x_B_z, xBz);
- h_hashtable_put(eg->smap, xBz, x_B_z);
- }
-
- return transform_productions(table, eg, x, xBz);
}
static bool eq_transition(const void *p, const void *q)
{
const HLRTransition *a=p, *b=q;
- return (a->from == b->from && a->to == b->to && a->symbol == b->symbol);
+ return (a->from == b->from && a->to == b->to && eq_symbol(a->symbol, b->symbol));
}
static HHashValue hash_transition(const void *p)
{
const HLRTransition *t = p;
- return (h_hash_ptr(t->symbol) + t->from + t->to); // XXX ?
+ return (hash_symbol(t->symbol) + t->from + t->to); // XXX ?
}
-static HLREnhGrammar *enhance_grammar(const HCFGrammar *g, const HLRTable *tbl)
+HCFChoice *new_enhanced_symbol(HLREnhGrammar *eg, const HCFChoice *sym)
+{
+ HArena *arena = eg->arena;
+ HCFChoice *esym = h_arena_malloc(arena, sizeof(HCFChoice));
+ *esym = *sym;
+
+ HHashSet *cs = h_hashtable_get(eg->corr, sym);
+ if(!cs) {
+ cs = h_hashset_new(arena, eq_symbol, hash_symbol);
+ h_hashtable_put(eg->corr, sym, cs);
+ }
+ h_hashset_put(cs, esym);
+
+ return esym;
+}
+static HLREnhGrammar *enhance_grammar(const HCFGrammar *g, const HLRDFA *dfa,
+ const HLRTable *table)
{
HAllocator *mm__ = g->mm__;
HArena *arena = g->arena; // XXX ?
HLREnhGrammar *eg = h_arena_malloc(arena, sizeof(HLREnhGrammar));
eg->tmap = h_hashtable_new(arena, eq_transition, hash_transition);
- eg->smap = h_hashtable_new(arena, eq_transition, hash_transition);
+ eg->smap = h_hashtable_new(arena, eq_symbol, hash_symbol);
+ eg->corr = h_hashtable_new(arena, eq_symbol, hash_symbol);
eg->arena = arena;
- // copy the start symbol over
- HCFChoice *start = h_arena_malloc(arena, sizeof(HCFChoice));
- *start = *(g->start);
+ // establish mapping between transitions and symbols
+ for(HSlistNode *x=dfa->transitions->head; x; x=x->next) {
+ HLRTransition *t = x->elem;
+
+ assert(!h_hashtable_present(eg->tmap, t));
- transform_productions(tbl, eg, 0, start);
+ HCFChoice *sym = new_enhanced_symbol(eg, t->symbol);
+ h_hashtable_put(eg->tmap, t, sym);
+ h_hashtable_put(eg->smap, sym, t);
+ }
+
+ // transform the productions
+ H_FOREACH(eg->tmap, HLRTransition *t, HCFChoice *sym)
+ transform_productions(table, eg, t->from, sym);
+ H_END_FOREACH
+
+ // add the start symbol
+ HCFChoice *start = new_enhanced_symbol(eg, g->start);
+ transform_productions(table, eg, 0, start);
eg->grammar = h_cfgrammar_(mm__, start);
return eg;
@@ -638,7 +657,7 @@ int h_lalr_compile(HAllocator* mm__, HParser* parser, const void* params)
if(has_conflicts(table)) {
HArena *arena = table->arena;
- HLREnhGrammar *eg = enhance_grammar(g, table);
+ HLREnhGrammar *eg = enhance_grammar(g, dfa, table);
if(eg == NULL) { // this should normally not happen
h_cfgrammar_free(g);
h_lrtable_free(table);
@@ -664,10 +683,10 @@ int h_lalr_compile(HAllocator* mm__, HParser* parser, const void* params)
HLRAction *action = reduce_action(arena, item);
// find all LR(0)-enhanced productions matching item
- H_FOREACH(eg->smap, HCFChoice *lhs, HLRTransition *t)
- if(t->symbol != item->lhs)
- continue;
- assert(lhs->type == HCF_CHOICE); // XXX could be CHARSET
+ HHashSet *lhss = h_hashtable_get(eg->corr, item->lhs);
+ assert(lhss != NULL);
+ H_FOREACH_KEY(lhss, HCFChoice *lhs)
+ assert(lhs->type == HCF_CHOICE); // XXX could be CHARSET?
for(HCFSequence **p=lhs->seq; *p; p++) {
HCFChoice **rhs = (*p)->items;
@@ -952,26 +971,35 @@ void h_pprint_lrtable(FILE *f, const HCFGrammar *g, const HLRTable *table,
for(size_t i=0; i<table->nrows; i++) {
for(unsigned int j=0; j<indent; j++) fputc(' ', f);
fprintf(f, "%4lu:", i);
- if(table->forall[i] && h_hashtable_empty(table->rows[i])) {
+ if(table->forall[i]) {
fputs(" - ", f);
pprint_lraction(f, g, table->forall[i]);
fputs(" -", f);
- } else {
- H_FOREACH(table->rows[i], HCFChoice *symbol, HLRAction *action)
- fputc(' ', f); // separator
- h_pprint_symbol(f, g, symbol);
- fputc(':', f);
- if(table->forall[i]) {
- fputc(action->type == HLR_SHIFT? 's' : 'r', f);
- fputc('/', f);
- fputc(table->forall[i]->type == HLR_SHIFT? 's' : 'r', f);
- } else {
- pprint_lraction(f, g, action);
- }
- H_END_FOREACH
+ if(!h_hashtable_empty(table->rows[i]))
+ fputs(" !!", f);
}
+ H_FOREACH(table->rows[i], HCFChoice *symbol, HLRAction *action)
+ fputc(' ', f); // separator
+ h_pprint_symbol(f, g, symbol);
+ fputc(':', f);
+ if(table->forall[i]) {
+ fputc(action->type == HLR_SHIFT? 's' : 'r', f);
+ fputc('/', f);
+ fputc(table->forall[i]->type == HLR_SHIFT? 's' : 'r', f);
+ } else {
+ pprint_lraction(f, g, action);
+ }
+ H_END_FOREACH
fputc('\n', f);
}
+
+#if 0
+ fputs("inadeq=", f);
+ for(HSlistNode *x=table->inadeq->head; x; x=x->next) {
+ fprintf(f, "%lu ", (uintptr_t)x->elem);
+ }
+ fputc('\n', f);
+#endif
}
@@ -993,13 +1021,12 @@ int test_lalr(void)
E -> E '-' T
| T
T -> '(' E ')'
- | N
- N -> '0' -- also try [0-9] for the charset paths
+ | 'n' -- also try [0-9] for the charset paths
*/
- HParser *N = h_sequence(h_ch('n'), NULL);
+ HParser *n = h_ch('n');
HParser *E = h_indirect();
- HParser *T = h_choice(h_sequence(h_ch('('), E, h_ch(')'), NULL), N, NULL);
+ HParser *T = h_choice(h_sequence(h_ch('('), E, h_ch(')'), NULL), n, NULL);
HParser *E_ = h_choice(h_sequence(E, h_ch('-'), T, NULL), T, NULL);
h_bind_indirect(E, E_);
HParser *p = h_sequence(E, NULL);
@@ -1035,7 +1062,7 @@ int test_lalr(void)
h_pprint_lrtable(stdout, g, (HLRTable *)p->backend_data, 0);
printf("\n==== P A R S E R E S U L T ====\n");
- HParseResult *res = h_parse(p, (uint8_t *)"syya", 4);
+ HParseResult *res = h_parse(p, (uint8_t *)"n-(n-((n)))-n", 11);
if(res)
h_pprint(stdout, res->ast, 0, 2);
else