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CF backends weren't checking whether a grammar is CF; they are now. Also, brace-fixing.

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This commit is contained in:
Meredith L. Patterson 2014-04-20 16:57:01 +02:00
parent d947c6aede
commit c9419f4c34
5 changed files with 204 additions and 125 deletions
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58
src/backends/lalr.c
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@ -49,8 +49,9 @@ static inline HLRTransition *transition(HArena *arena,
static void transform_productions(const HLRTable *table, HLREnhGrammar *eg,
size_t x, HCFChoice *xAy)
{
if(xAy->type != HCF_CHOICE)
if (xAy->type != HCF_CHOICE) {
return;
}
// XXX CHARSET?
HArena *arena = eg->arena;
@ -89,7 +90,7 @@ static HCFChoice *new_enhanced_symbol(HLREnhGrammar *eg, const HCFChoice *sym)
*esym = *sym;
HHashSet *cs = h_hashtable_get(eg->corr, sym);
if(!cs) {
if (!cs) {
cs = h_hashset_new(arena, h_eq_symbol, h_hash_symbol);
h_hashtable_put(eg->corr, sym, cs);
}
@ -151,9 +152,9 @@ static int terminals_put(HStringMap *tmap, const HStringMap *fs, HLRAction *acti
{
int ret = 0;
if(fs->epsilon_branch) {
if (fs->epsilon_branch) {
HLRAction *prev = tmap->epsilon_branch;
if(prev && prev != action) {
if (prev && prev != action) {
// conflict
tmap->epsilon_branch = h_lr_conflict(tmap->arena, prev, action);
ret = -1;
@ -162,9 +163,9 @@ static int terminals_put(HStringMap *tmap, const HStringMap *fs, HLRAction *acti
}
}
if(fs->end_branch) {
if (fs->end_branch) {
HLRAction *prev = tmap->end_branch;
if(prev && prev != action) {
if (prev && prev != action) {
// conflict
tmap->end_branch = h_lr_conflict(tmap->arena, prev, action);
ret = -1;
@ -176,13 +177,14 @@ static int terminals_put(HStringMap *tmap, const HStringMap *fs, HLRAction *acti
H_FOREACH(fs->char_branches, void *key, HStringMap *fs_)
HStringMap *tmap_ = h_hashtable_get(tmap->char_branches, key);
if(!tmap_) {
if (!tmap_) {
tmap_ = h_stringmap_new(tmap->arena);
h_hashtable_put(tmap->char_branches, key, tmap_);
}
if(terminals_put(tmap_, fs_, action) < 0)
if (terminals_put(tmap_, fs_, action) < 0) {
ret = -1;
}
H_END_FOREACH
return ret;
@ -197,8 +199,9 @@ static bool match_production(HLREnhGrammar *eg, HCFChoice **p,
for(; *p && *rhs; p++, rhs++) {
HLRTransition *t = h_hashtable_get(eg->smap, *p);
assert(t != NULL);
if(!h_eq_symbol(t->symbol, *rhs))
if (!h_eq_symbol(t->symbol, *rhs)) {
return false;
}
state = t->to;
}
return (*p == *rhs // both NULL
@ -231,18 +234,21 @@ int h_lalr_compile(HAllocator* mm__, HParser* parser, const void* params)
// build LR(0) table
// if necessary, resolve conflicts "by conversion to SLR"
if (!parser->vtable->isValidCF(parser->env)) {
return -1;
}
HCFGrammar *g = h_cfgrammar_(mm__, h_desugar_augmented(mm__, parser));
if(g == NULL) // backend not suitable (language not context-free)
return -1;
HLRDFA *dfa = h_lr0_dfa(g);
if(dfa == NULL) { // this should normally not happen
if (dfa == NULL) { // this should normally not happen
h_cfgrammar_free(g);
return -1;
}
HLRTable *table = h_lr0_table(g, dfa);
if(table == NULL) { // this should normally not happen
if (table == NULL) { // this should normally not happen
h_cfgrammar_free(g);
return -1;
}
@ -282,10 +288,11 @@ int h_lalr_compile(HAllocator* mm__, HParser* parser, const void* params)
H_FOREACH_KEY(lhss, HCFChoice *lhs)
assert(lhs->type == HCF_CHOICE); // XXX could be CHARSET?
for(HCFSequence **p=lhs->seq; *p; p++) {
for(HCFSequence **p=lhs->seq; *p; p++) {
HCFChoice **rhs = (*p)->items;
if(!match_production(eg, rhs, item->rhs, state))
if(!match_production(eg, rhs, item->rhs, state)) {
continue;
}
// the left-hand symbol's follow set is this production's
// contribution to the lookahead
@ -297,11 +304,12 @@ int h_lalr_compile(HAllocator* mm__, HParser* parser, const void* params)
// for each lookahead symbol, put action into table cell
if(terminals_put(table->tmap[state], fs, action) < 0)
inadeq = true;
} H_END_FOREACH // enhanced production
} H_END_FOREACH // enhanced production
H_END_FOREACH // reducible item
if(inadeq)
if(inadeq) {
h_slist_push(table->inadeq, (void *)(uintptr_t)state);
}
}
}
@ -350,7 +358,7 @@ int test_lalr(void)
printf("\n==== G R A M M A R ====\n");
HCFGrammar *g = h_cfgrammar_(mm__, h_desugar_augmented(mm__, p));
if(g == NULL) {
if (g == NULL) {
fprintf(stderr, "h_cfgrammar failed\n");
return 1;
}
@ -358,21 +366,23 @@ int test_lalr(void)
printf("\n==== D F A ====\n");
HLRDFA *dfa = h_lr0_dfa(g);
if(dfa)
if (dfa) {
h_pprint_lrdfa(stdout, g, dfa, 0);
else
} else {
fprintf(stderr, "h_lalr_dfa failed\n");
}
printf("\n==== L R ( 0 ) T A B L E ====\n");
HLRTable *table0 = h_lr0_table(g, dfa);
if(table0)
if (table0) {
h_pprint_lrtable(stdout, g, table0, 0);
else
} else {
fprintf(stderr, "h_lr0_table failed\n");
}
h_lrtable_free(table0);
printf("\n==== L A L R T A B L E ====\n");
if(h_compile(p, PB_LALR, NULL)) {
if (h_compile(p, PB_LALR, NULL)) {
fprintf(stderr, "does not compile\n");
return 2;
}
@ -380,10 +390,10 @@ int test_lalr(void)
printf("\n==== P A R S E R E S U L T ====\n");
HParseResult *res = h_parse(p, (uint8_t *)"n-(n-((n)))-n", 13);
if(res)
if (res) {
h_pprint(stdout, res->ast, 0, 2);
else
} else {
printf("no parse\n");
}
return 0;
}