llvm-project/llvm/utils/Burg/fe.c

char rcsid_fe[] = "$Id$";

#include <stdio.h>
#include <string.h>
#include "b.h"
#include "fe.h"

int grammarflag;

static int arity;

List  ruleASTs;
List  grammarNts;

static void doBinding ARGS((Binding));
static void doDecl ARGS((Arity));
static NonTerminal lookup ARGS((Pattern));
static NonTerminal normalize ARGS((PatternAST, NonTerminal, Pattern *));
static void doEnterNonTerm ARGS((RuleAST));
static void doRule ARGS((RuleAST));
static void doTable ARGS((Operator));

static void
doBinding(b) Binding b;
{
  int new;
  Symbol s;

  s = enter(b->name, &new);
  if (!new) {
    fprintf(stderr, "Non-unique name: %s\n", b->name);
    exit(1);
  }
  s->tag = OPERATOR;
  s->u.op = newOperator(b->name, b->opnum, arity);
  if (arity == 0) {
    leaves = newList(s->u.op, leaves);
  }
}

static void
doDecl(a) Arity a;
{
  if (!a) {
    return;
  }
  arity = a->arity;
  foreachList((ListFn) doBinding, a->bindings);
}


static List xpatterns;
static int tcount;

static NonTerminal
lookup(p) Pattern p;
{
  char buf[10];
  char *s;
  List l;
  NonTerminal n;
  DeltaCost dummy;

  for (l = xpatterns; l; l = l->next) {
    Pattern x = (Pattern) l->x;
    if (x->op == p->op
        && x->children[0] == p->children[0]
        && x->children[1] == p->children[1]) {
      return x->normalizer;
    }
  }
  sprintf(buf, "n%%%d", tcount++);
  s = (char *) zalloc(strlen(buf)+1);
  strcpy(s, buf);
  n = newNonTerminal(s);
  p->normalizer = n;
  xpatterns = newList(p, xpatterns);
  ZEROCOST(dummy);
  (void) newRule(dummy, 0, n, p);
  return n;
}

static NonTerminal
normalize(ast, nt, patt) PatternAST ast; NonTerminal nt; Pattern *patt;
{
  Symbol s;
  int new;
  Pattern dummy;

  s = enter(ast->op, &new);
  ast->sym = s;
  if (new) {
    fprintf(stderr, "Illegal use of %s --- undefined symbol\n", s->name);
    exit(1);
    return 0; /* shut up compilers */
  } else if (s->tag == NONTERMINAL) {
    if (ast->children) {
      fprintf(stderr, "Illegal use of %s, a non-terminal, as a terminal\n", s->name);
      exit(1);
    }
    *patt = newPattern(0);
    (*patt)->children[0] = s->u.nt;
    return s->u.nt;
  } else {
    s->u.op->ref = 1;
    *patt = newPattern(s->u.op);
    if (s->u.op->arity == -1) {
      if (!ast->children) {
        s->u.op->arity = 0;
        leaves = newList(s->u.op, leaves);
      } else if (!ast->children->next) {
        s->u.op->arity = 1;
      } else if (!ast->children->next->next) {
        s->u.op->arity = 2;
      } else {
        fprintf(stderr, "ERROR: Too many children (max = 2) for \"%s\"\n", s->name);
        exit(1);
      }
      if (s->u.op->arity > max_arity) {
        max_arity = s->u.op->arity;
      }
    }
    switch (s->u.op->arity) {
    default:
      assert(0);
      break;
    case 0:
      if (ast->children) {
        fprintf(stderr, "ERROR: Incorrect number of children for leaf operator, \"%s\"\n", s->name);
        exit(1);
      }
      break;
    case 1:
      if (!ast->children || ast->children->next) {
        fprintf(stderr, "ERROR: Incorrect number of children for unary operator, \"%s\"\n", s->name);
        exit(1);
      }
      (*patt)->children[0] = normalize((PatternAST) ast->children->x, 0, &dummy);
      break;
    case 2:
      if (!ast->children || !ast->children->next) {
        fprintf(stderr, "ERROR: Incorrect number of children for binary operator, \"%s\"\n", s->name);
        exit(1);
      }
      (*patt)->children[0] = normalize((PatternAST) ast->children->x, 0, &dummy);
      (*patt)->children[1] = normalize((PatternAST) ast->children->next->x, 0, &dummy);
      break;
    }
    if (nt) {
      (*patt)->normalizer = nt;
      return nt;
    } else {
      return lookup(*patt);
    }
  }
}

static void
doEnterNonTerm(ast) RuleAST ast;
{
  int new;
  Symbol s;
  DeltaCost delta;
  int i;
  IntList p;


  s = enter(ast->lhs, &new);
  if (new) {
    s->u.nt = newNonTerminal(s->name);
    s->tag = NONTERMINAL;
  } else {
    if (s->tag != NONTERMINAL) {
      fprintf(stderr, "Illegal use of %s as a non-terminal\n", s->name);
      exit(1);
    }
  }
  ZEROCOST(delta);
  for (p = ast->cost, i = 0; p; p = p->next, i++) {
    int x = p->x;
#ifndef NOLEX
    if (lexical) {
      if (i < DELTAWIDTH) {
        delta[i] = x;
      }
    } else
#endif /* NOLEX */
    {
      if (i == principleCost) {
        PRINCIPLECOST(delta) = x;
      }
    }
  }
  ast->rule = newRule(delta, ast->erulenum, s->u.nt, 0);
}

static void
doRule(ast) RuleAST ast;
{
  Pattern pat;

  (void) normalize(ast->pat, ast->rule->lhs, &pat);
  ast->rule->pat = pat;
}

static void
doTable(op) Operator op;
{
  op->table = newTable(op);
}

void
doSpec(decls, rules) List decls; List rules;
{
  foreachList((ListFn) doDecl, decls);
  debug(debugTables, foreachList((ListFn) dumpOperator_l, operators));

  ruleASTs = rules;
  reveachList((ListFn) doEnterNonTerm, rules);

  last_user_nonterminal = max_nonterminal;

  reveachList((ListFn) doRule, rules);
  debug(debugTables, foreachList((ListFn) dumpRule, rules));

  foreachList((ListFn) doTable, operators);
}

void
doStart(name) char *name;
{
  Symbol s;
  int new;

  if (start) {
    yyerror1("Redeclaration of start symbol to be ");
    fprintf(stderr, "\"%s\"\n", name);
    exit(1);
  }
  s = enter(name, &new);
  if (new) {
    s->u.nt = newNonTerminal(s->name);
    s->tag = NONTERMINAL;
  } else {
    if (s->tag != NONTERMINAL) {
      fprintf(stderr, "Illegal use of %s as a non-terminal\n", s->name);
      exit(1);
    }
  }
}

void
doGrammarNts()
{
  List l;
  int new;

  for (l = grammarNts; l; l = l->next) {
    char *n = (char*) l->x;
    Symbol s;

    s = enter(n, &new);
    if (new) {
      fprintf(stderr, "ERROR: %%gram, unused non-terminal: \"%s\"\n", n);
      exit(1);
    }
    if (s->tag != NONTERMINAL) {
      fprintf(stderr, "ERROR: %%gram, Not a non-terminal: \"%s\"\n", n);
      exit(1);
    }
    l->x = s;
  }
}

void
doGram(nts) List nts;
{
  if (grammarNts) {
    yyerror1("Redeclaration of %%gram\n");
    exit(1);
  }
  grammarNts = nts;
}

Arity
newArity(ar, b) int ar; List b;
{
  Arity a = (Arity) zalloc(sizeof(struct arity));
  a->arity = ar;
  a->bindings = b;
  return a;
}

Binding
newBinding(name, opnum) char *name; int opnum;
{
  Binding b = (Binding) zalloc(sizeof(struct binding));
  if (opnum == 0) {
    yyerror1("ERROR: Non-positive external symbol number, ");
    fprintf(stderr, "%d", opnum);
    exit(1);
  }
  b->name = name;
  b->opnum = opnum;
  return b;
}

PatternAST
newPatternAST(op, children) char *op; List children;
{
  PatternAST p = (PatternAST) zalloc(sizeof(struct patternAST));
  p->op = op;
  p->children = children;
  return p;
}

int max_ruleAST;

RuleAST
newRuleAST(lhs, pat, erulenum, cost) char *lhs; PatternAST pat; int erulenum; IntList cost;
{
  RuleAST p = (RuleAST) zalloc(sizeof(struct ruleAST));
  p->lhs = lhs;
  p->pat = pat;
  if (erulenum <= 0) {
    yyerror1("External Rulenumber ");
    fprintf(stderr, "(%d) <= 0\n", erulenum);
    exit(1);
  }
  p->erulenum = erulenum;
  p->cost = cost;
  max_ruleAST++;
  return p;
}

void
dumpBinding(b) Binding b;
{
  printf("%s=%d ", b->name, b->opnum);
}

void
dumpArity(a) Arity a;
{
  List l;

  printf("Arity(%d) ", a->arity);
  for (l = a->bindings; l; l = l->next) {
    Binding b = (Binding) l->x;
    dumpBinding(b);
  }
  printf("\n");
}

void
dumpPatternAST(p) PatternAST p;
{
  List l;

  printf("%s", p->op);
  if (p->children) {
    printf("(");
    for (l = p->children; l; l = l->next) {
      PatternAST past = (PatternAST) l->x;
      dumpPatternAST(past);
      if (l->next) {
        printf(", ");
      }
    }
    printf(")");
  }
}

void
dumpRuleAST(p) RuleAST p;
{
  printf("%s : ", p->lhs);
  dumpPatternAST(p->pat);
  printf(" = %d (%ld)\n", p->erulenum, (long) p->cost);
}

void
dumpDecls(decls) List decls;
{
  List l;

  for (l = decls; l; l = l->next) {
    Arity a = (Arity) l->x;
    dumpArity(a);
  }
}

void
dumpRules(rules) List rules;
{
  List l;

  for (l = rules; l; l = l->next) {
    RuleAST p = (RuleAST) l->x;
    dumpRuleAST(p);
  }
}