/*

  Source Code:  argcheck.c

  Date:         August of 2000

  Programmer:   Scott Wenger, Box 802, Stevens Point, WI 54481 USA
                panther@wctc.net

  Purpose:      To perform argument checking in C source code.
                This program detects and reports mismatches  
                between the number of conversion specifiers
                and the number of arguments in the following
                functions:  printf,  sprintf, and fprintf
                Double percent sign for percent symbol (%)
                is distinguished from conversion specifiers.

                This program is useful when using compilers
                and/or preprocessors that ignore argument
                checking.  Enhancements and modifications 
                of this program are left to the individual.
                                     
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <conio.h>

#define BUFF_SIZE 1000

int open_file();
int study(char funcname[], char lbuffer[]);

FILE *fp;
char filename[75];
int ln = 1;                        // line number
int total_errors = 0;              // total number of errors

main()
{
  char lbuffer[BUFF_SIZE];         // line buffer
  
  open_file();
  while (fgets(lbuffer, 1000, fp) != NULL)  {
    printf("%3d: %s", ln, lbuffer);
    if (strstr(lbuffer, "sprintf") != NULL) study("sprintf", lbuffer);
    else if (strstr(lbuffer, "fprintf") != NULL) study("fprintf", lbuffer);
    else if (strstr(lbuffer, "printf") != NULL) study("printf", lbuffer);
    ln++;   // increment line counter
  }
  fclose(fp);
   
  if (total_errors > 0)
    fprintf(stderr, "\n\nThere were a total of %d mismatches in this code.",
                     total_errors);
  else
    fprintf(stderr, "\n\nCompleted argument check and no errors were found.");                     
                   
  fprintf(stderr, "\nPress [Enter] to return to your operating system...");
  fflush(stdout);
  getch();
  exit(0);
}

/*-----------------------------------------------------------------------*/

int study(char funcname[], char lbuffer[])
{
  // this function looks for a match betwen 
  // conversion specifiers and args (in number only)
  // 0 is returned if there is a mismatch
  // 1 is returned if there is match

  
  int match = 1;
  int i = 0;
  int cs = 0;           // number of converion specifiers
  int ar = 0;           // number of arguments
  char *ch, *start;
  char possible[20];
  int pair = 0;         // a flag for two %% in a row
  

  ch = strchr(lbuffer, funcname[0]);  // start of possible function 
  start = ch;

  for (i = 0; i < strlen(funcname); i++) {
    possible[i] = *ch;
    ch++;  
  }
  possible[i] = '\0';
  
  ch = start;
  while (*ch && *ch != '"') ch++;  
  if (*ch) ch++;                // skip opening quote  
  while (*ch && *ch != '"') {   // scan format string
    if (pair == 1) pair = 0;
    if (*ch == '%')  {
      ch++;
      if (*ch && *ch == '%') pair = 1;
      else cs++; // count conversion specifiers
    }
    if (*ch) ch++;
  }	  
  if (*ch) ch++;                // skip closing quote
  while (*ch && *ch != ')') {
    if (*ch == ',') ar++;     // count arguments
    ch++;
  }	    

  if (cs != ar) {
    match = 0;	  
    total_errors++;           // total number of mismatches	  
    printf("\nError in line %d: mismatch in %s", ln, funcname);
    printf("\nFound %d conversion specifier(s) and %d argument(s)", cs, ar);
    printf("\nPress [Enter] to continue checking...\n\n");
    fflush(stdout);
    getch();
  }  	  
  return(match);
}

/*-----------------------------------------------------------------------*/

int open_file()
{
  printf("\nC source file to check: ");
  scanf("%s", filename);

  if ( (fp = fopen(filename, "r")) == NULL) {
    printf("\nInput file could not be opened.\n");
    printf("\nPress [Enter] to return to your operating system.");
    fflush(stdout);
    fclose(fp);
    getch();
    exit(1);
  }      
  return(1);
}

/*------------------------------- END -----------------------------------*/