main.c

#include "defs.h"
#define extern_
#include "data.h"
#undef extern_
#include "decl.h"
#include <errno.h>

// Compiler setup and top-level execution
// Copyright (c) 2019 Warren Toomey, GPL3

// Initialise global variables
static void init() {
  Line = 1;
  Putback = '\n';
  Globs = 0;
  Locls = NSYMBOLS - 1;
  O_dumpAST = 0;
}

// Print out a usage if started incorrectly
static void usage(char *prog) {
  fprintf(stderr, "Usage: %s [-T] infile\n", prog);
  exit(1);
}

// Main program: check arguments and print a usage
// if we don't have an argument. Open up the input
// file and call scanfile() to scan the tokens in it.
int main(int argc, char *argv[]) {
  int i;

  // Initialise the globals
  init();

  // Scan for command-line options
  for (i = 1; i < argc; i++) {
    if (*argv[i] != '-')
      break;
    for (int j = 1; argv[i][j]; j++) {
      switch (argv[i][j]) {
	case 'T':
	  O_dumpAST = 1;
	  break;
	default:
	  usage(argv[0]);
      }
    }
  }

  // Ensure we have an input file argument
  if (i >= argc)
    usage(argv[0]);

  // Open up the input file
  if ((Infile = fopen(argv[i], "r")) == NULL) {
    fprintf(stderr, "Unable to open %s: %s\n", argv[i], strerror(errno));
    exit(1);
  }
  // Create the output file
  if ((Outfile = fopen("out.s", "w")) == NULL) {
    fprintf(stderr, "Unable to create out.s: %s\n", strerror(errno));
    exit(1);
  }
  // For now, ensure that printint() and printchar() are defined
  addglob("printint", P_INT, S_FUNCTION, 0, 0);
  addglob("printchar", P_VOID, S_FUNCTION, 0, 0);

  scan(&Token);			// Get the first token from the input
  genpreamble();		// Output the preamble
  global_declarations();	// Parse the global declarations
  genpostamble();		// Output the postamble
  fclose(Outfile);		// Close the output file and exit
  return (0);
}