view anagram/agcore/bpu.cpp @ 21:1c9dac05d040

Add lint-style FALLTHROUGH annotations to fallthrough cases. (in the parse engine and thus the output code) Document this, because the old output causes warnings with gcc10.
author David A. Holland
date Mon, 13 Jun 2022 00:04:38 -0400
parents 13d2b8934445
children
line wrap: on
line source

/*
 * AnaGram, A System for Syntax Directed Programming
 * Copyright 1993-1999 Parsifal Software. All Rights Reserved.
 * See the file COPYING for license and usage terms.
 *
 * bpu.cpp - Utility routines for bpe3
 */

#include <ctype.h>
#include <stdarg.h>
#include "port.h"

#include "arrays.h"
#include "bpe3.h"
#include "bpu.h"
#include "cd.h"
#include "data.h"
#include "dict.h"
#include "engdef.h"
#include "keyword.h"
#include "myalloc.h"
#include "q1glbl.h"
#include "rule.h"
#include "stacks.h"
#include "symbol.h"
#include "token.h"

//#define INCLUDE_LOGGING
#include "log.h"


void template_string(const char *name, const char *tp, const char tc) {
  ics();
  while (*tp) {
    char c = *tp++;
    if (c == tc) {
      ass(name);
      continue;
    }
    acs(c);
  }
  tss();
}

AgString subs_template(const char *name, const char *tp, const char tc) {
  template_string(name, tp, tc);
  return buildAgString();
}

unsigned find_token_number(const char *name) {
  return Symbol(name)->token_number;
  //return map_token_name[identify_string(name,tkn_dict)].token_number;
}

int find_completions(int s, const unsigned **q) {
  state_number_map *sp = &map_state_number[s];
  const unsigned *p = lstptr(*sp, chain_completions);
  int n = sp->n_chain_completions;
  if (n == 0 && sp->chain_gotos_index == 0) {
    p = lstptr(*sp, completions);
    n = sp->n_completions;
  }
  *q = p;
  return n;
}

void select_actions(int k) {
  int n = tis()/3;
  int *lb;

  list_space(n+1);
  lb = list_base;
  iws();
  while (n--) {
    aws(lb[k]);
    k += 3;
  }
}

void find_key_tokens(const int *pl, int n, int tw /*, int ct */) {
  LOGSECTION("find_key_tokens");
  LOGV(n);
  for (; n--; pl += tw) {
    //int tn = *pl;
    Token token = *pl;
    LOGV(token);
    //if (map_token_number[tn].key == 0) continue;
    //if (token->key == 0) continue;
    if (token->key.isNull()) {
      continue;
    }
    isws(token);
  }
}


/*
 * Note that the text of the defined format must not contain a newline.
 * Failure to abide by this rule will cause the line count to be
 * incorrect.
 */

void define_macro(const char *n, const char *fmt, ...) {
  va_list ap;
  fprintf(pe_file, "#define %s ", n);
  va_start(ap, fmt);
  vfprintf(pe_file, fmt, ap);
  va_end(ap);
  fputc('\n', pe_file);
  pe_line_count++;
}

void define_macro_default(const char *n, const char *fmt, ...) {
  va_list ap;
  char name_only[80];
  char *ptr;

  strcpy(name_only, n);
  ptr = strchr(name_only, '(');

  if (ptr != NULL) {
    *ptr = 0;
  }

  fprintf(pe_file, "#ifndef %s\n#define %s ", name_only, n);
  va_start(ap, fmt);
  vfprintf(pe_file, fmt, ap);
  va_end(ap);
  fprintf(pe_file, "\n#endif\n");
  pe_line_count += 3;
}

unsigned char *key_string(int tn) {
  LOGSECTION("key_string");
  Keyword key = map_token_number[tn].key;
  LOGV(tn) LCV(key) LCV(Keyword::count());

  if (key.isNull()) {
    return NULL;
  }
  LOGV(key->string);
  return (unsigned char *) key->string.pointer();
}

/*
 * Function:  reducing_token
 * Arguments:
 *   token number, tn
 *   state number, sn
 * Returns: 0 if tn is _not_ a reducing token in the given state
 * Otherwise, returns the number of the rule it reduces.
 */

#if 0 /* no longer used */
unsigned reducing_token(unsigned tn, unsigned sn) {
  state_number_map *sp = &map_state_number[sn];
  const unsigned *p;
  unsigned n = sp->n_reductions;     /* number of reductions in this state */

  if (n) {
    p = lstptr(*sp, reductions);
    while (n--) {
      if (*p++ == tn) {
        return *p;
      }
      p++;
    }
    return 0;
  }
  if (sp->n_completed_forms != 1) {
    return 0;
  }
  if (shift_token(tn, sn)) {
    return 0;
  }
  return *(lstptr(*sp,completed_forms));
}
#endif /* 0 - no longer used */

Rule ruleReducedBy(Token token, unsigned sn) {
  state_number_map *sp = &map_state_number[sn];
  const unsigned *p;
  unsigned n = sp->n_reductions;     /* number of reductions in this state */

  if (n) {
    p = lstptr(*sp, reductions);
    while (n--) {
      if (*p++ == (unsigned) token) {
        return *p;
      }
      p++;
    }
    return 0;
  }
  if (sp->n_completed_forms != 1) {
    // Exit if more than one completed rule
    return 0;
  }
  if (shift_token(token, sn)) {
    // Exit if there's a shift
    return 0;
  }
  // Default reduction, return rule #
  return *(lstptr(*sp, completed_forms));
}

void select_write_fragment(const char *name, const char *modes,
			   const char *suffix) {
  char fragment[80];

  strcpy(fragment, name);
  strcat(fragment, modes);
  strcat(fragment, suffix);
  write_code_segment(fragment);
}

int shift_token(unsigned tn, unsigned sn) {
  const unsigned *p;
  unsigned n;

  n = find_gotos(sn, &p);
  while (n--) {
    if (*p == tn) {
      return 1; 
    }
    else {
      p += 2;
    }
  }

  n = find_completions(sn, &p);
  while (n--) {
    if (*p == tn) {
      return 1;
    }
    else {
      p += 2;
    }
  }

  return 0;
}

void count_pe_line(const char *s, int k) {
  LOGSECTION("count_pe_line");

  while (k--) {
    if (s[k] == '\n') {
      pe_line_count++;
    }
  }
  LOGV(pe_line_count);
}

int wps(const char *s) {
  LOGSECTION("wps");
  int k = strlen(s);

  fputs(s, pe_file);
  count_pe_line(s, k);
  return k;
}

int wss(void) {
  count_pe_line(string_base, tis());
  fputs(string_base, pe_file);
  return rcs();
}

int wpe(const char *fs, ...) {
  LOGSECTION("wpe");
  va_list ap;
  char buf[2000];

  va_start(ap, fs);
  vsprintf(buf, fs, ap);
  va_end(ap);
  return wps(buf);
}

void write_code_segment(const char *name) {
  LOGSECTION("write_code_segment");
  LOGV(name);
  if (name == NULL) {
    return;
  }
  AgString text = code_segment(name);
  if (!text.exists()) {
    return;
  }
  char *buf = text.pointer();
  wps(buf);
  wps("\n\n");
}

static AgString expand_my_macros(const char *s) {
  LOGSECTION("expand_my_macros");
  char *p;
  int col_no = 0, lb = 0, k;

  LOGV(s);
  if (my_macros == NULL) {
    return AgString(s);
  }
  ics();
  while (*s) {
    char *word;
    int index;

    while (*s && !isalpha(*s) && *s != '_') {
      if (*s == '\n') {
        acs(*s++);
        col_no = 0;
        while (*s && *s == ' ') {
	  col_no++, s++;
	}
        lb = col_no;
        continue;
      }
      if (lb == col_no) {
	for (k = lb; k--; ) {
	  acs(' ');
	}
      }
      col_no++;
      acs(*s++);
    }
    if (*s == 0) {
      break;
    }
    ics();
    while (*s && (isalpha(*s) || *s == '_')) {
      acs(*s++);
    }
    word = build_string();
    index = identify_string(word, my_macros);
    if (index == 0) {
      if (lb == col_no) {
	for (k = lb; k--; ) {
	  acs(' ');
	}
      }
      col_no += strlen(word);
      ass(word);
      DEALLOCATE(word);
      continue;
    }
    DEALLOCATE(word);
    p = my_macros_subs[index];
    if (*p == 0 && lb == col_no && (*s == '\n' || strncmp(s,"\\\n",2) == 0)) {
      if (*s == '\\') {
	s++;
      }
      s++;
      col_no = 0;
      while (*s && *s == ' ') {
	col_no++;
	s++;
      }
      lb = col_no;
      continue;
    }
    if (lb == col_no) for (k = lb; k--;) acs(' ');
    for (; *p; p++ ) {
      acs(*p);
      col_no++;
      if (*p == '\n') {
        for (k = lb; k--; ) {
	  acs(' ');
	}
        col_no = lb;
        continue;
      }
    }
    if (*s == '#') {
      s++;
    }
  }
  LOGV(string_base);
  return buildAgString();
}


AgString code_segment(const char *name) {
  LOGSECTION("code_segment");

  const char *rawtext = engdef_get(name);
  LOGV(rawtext);

  AgString mx = expand_my_macros(rawtext);
  LOGV(mx);

  return mx;
}