// test just strchr()

//----------------------------------------------------------------------
// glibc-2.36/string/tester.c original from http://ftp.gnu.org/gnu/glibc/glibc-2.36.tar.xz
// added extra DEBUG printing and removed libc-diag.h dependency and all tests except:
//  strspn, strcspn, strcat, strcpy, strncpy, strchr, strrchr, strstr, memcpy, memset,
//  which are renamed to my_str... and my_mem... via rename.h
//
// generate tester.o using -w to disable warnings: gcc -c -w tester.c
// to get continuous messages as tests are passed: gcc -c -w tester.c -DDEBUG 
//
// link with your code: gcc -std=c11 -pedantic -Wall p1.c tester.o
//----------------------------------------------------------------------

/* Tester for string functions.
   Copyright (C) 1995-2022 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif

/* Make sure we don't test the optimized inline functions if we want to
   test the real implementation.  */
#if !defined DO_STRING_INLINES
#undef __USE_STRING_INLINES
#endif

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

#include "rename.h"

/* This file tests a range of corner cases of string functions,
   including cases where truncation occurs or where sizes specified
   are larger than the actual buffers, which result in various
   warnings.  */

#define	STREQ(a, b)	(strcmp((a), (b)) == 0)

const char *it = "<UNSET>";	/* Routine name for message routines. */
size_t errors = 0;

/* Complain if condition is not true.  */
static void
check (int thing, int number)
{
  if (!thing)
    {
      printf ("%s flunked test %d\n", it, number);
      ++errors;
    }
#ifdef DEBUG
  else
      printf("%s passed test %d\n", it, number);
#endif
}

/* Complain if first two args don't strcmp as equal.  */
static void
equal (const char *a, const char *b, int number)
{
  check (a != NULL && b != NULL && STREQ (a, b), number);
}

char one[50];
char two[50];
char *cp;

#define SIMPLE_COPY(fn, n, str, ntest) \
  do {									      \
    int __n;								      \
    char *cp;								      \
    for (__n = 0; __n < (int) sizeof (one); ++__n)			      \
      one[__n] = 'Z';							      \
    fn (one, str);							      \
    for (cp = one, __n = 0; __n < n; ++__n, ++cp)			      \
      check (*cp == '0' + (n % 10), ntest);				      \
    check (*cp == '\0', ntest);						      \
  } while (0)

static void
test_strcpy (void)
{
  int i;
  it = "strcpy";
  check (strcpy (one, "abcd") == one, 1); /* Returned value. */
  equal (one, "abcd", 2);		/* Basic test. */

  (void) strcpy (one, "x");
  equal (one, "x", 3);			/* Writeover. */
  equal (one+2, "cd", 4);		/* Wrote too much? */

  (void) strcpy (two, "hi there");
  (void) strcpy (one, two);
  equal (one, "hi there", 5);		/* Basic test encore. */
  equal (two, "hi there", 6);		/* Stomped on source? */

  (void) strcpy (one, "");
  equal (one, "", 7);			/* Boundary condition. */

  for (i = 0; i < 16; i++)
    {
      (void) strcpy (one + i, "hi there");	/* Unaligned destination. */
      equal (one + i, "hi there", 8 + (i * 2));
      (void) strcpy (two, one + i);		/* Unaligned source. */
      equal (two, "hi there", 9 + (i * 2));
    }

  SIMPLE_COPY(strcpy, 0, "", 41);
  SIMPLE_COPY(strcpy, 1, "1", 42);
  SIMPLE_COPY(strcpy, 2, "22", 43);
  SIMPLE_COPY(strcpy, 3, "333", 44);
  SIMPLE_COPY(strcpy, 4, "4444", 45);
  SIMPLE_COPY(strcpy, 5, "55555", 46);
  SIMPLE_COPY(strcpy, 6, "666666", 47);
  SIMPLE_COPY(strcpy, 7, "7777777", 48);
  SIMPLE_COPY(strcpy, 8, "88888888", 49);
  SIMPLE_COPY(strcpy, 9, "999999999", 50);
  SIMPLE_COPY(strcpy, 10, "0000000000", 51);
  SIMPLE_COPY(strcpy, 11, "11111111111", 52);
  SIMPLE_COPY(strcpy, 12, "222222222222", 53);
  SIMPLE_COPY(strcpy, 13, "3333333333333", 54);
  SIMPLE_COPY(strcpy, 14, "44444444444444", 55);
  SIMPLE_COPY(strcpy, 15, "555555555555555", 56);
  SIMPLE_COPY(strcpy, 16, "6666666666666666", 57);

  /* Simple test using implicitly coerced `void *' arguments.  */
  const void *src = "frobozz";
  void *dst = one;
  check (strcpy (dst, src) == dst, 1);
  equal (dst, "frobozz", 2);
}

static void
test_strcat (void)
{
  it = "strcat";
  (void) strcpy (one, "ijk");
  check (strcat (one, "lmn") == one, 1); /* Returned value. */
  equal (one, "ijklmn", 2);		/* Basic test. */

  (void) strcpy (one, "x");
  (void) strcat (one, "yz");
  equal (one, "xyz", 3);			/* Writeover. */
  equal (one+4, "mn", 4);			/* Wrote too much? */

  (void) strcpy (one, "gh");
  (void) strcpy (two, "ef");
  (void) strcat (one, two);
  equal (one, "ghef", 5);			/* Basic test encore. */
  equal (two, "ef", 6);			/* Stomped on source? */

  (void) strcpy (one, "");
  (void) strcat (one, "");
  equal (one, "", 7);			/* Boundary conditions. */
  (void) strcpy (one, "ab");
  (void) strcat (one, "");
  equal (one, "ab", 8);
  (void) strcpy (one, "");
  (void) strcat (one, "cd");
  equal (one, "cd", 9);

  int ntest = 10;
  char buf1[80] __attribute__ ((aligned (16)));
  char buf2[32] __attribute__ ((aligned (16)));
  for (size_t n1 = 0; n1 < 16; ++n1)
    for (size_t n2 = 0; n2 < 16; ++n2)
      for (size_t n3 = 0; n3 < 32; ++n3)
	{
	  size_t olderrors = errors;

	  memset (buf1, 'b', sizeof (buf1));

	  memset (buf1 + n2, 'a', n3);
	  buf1[n2 + n3] = '\0';
	  strcpy (buf2 + n1, "123");

	  check (strcat (buf1 + n2, buf2 + n1) == buf1 + n2, ntest);
	  if (errors == olderrors)
	    for (size_t i = 0; i < sizeof (buf1); ++i)
	      {
		if (i < n2)
		  check (buf1[i] == 'b', ntest);
		else if (i < n2 + n3)
		  check (buf1[i] == 'a', ntest);
		else if (i < n2 + n3 + 3)
		  check (buf1[i] == "123"[i - (n2 + n3)], ntest);
		else if (i == n2 + n3 + 3)
		  check (buf1[i] == '\0', ntest);
		else
		  check (buf1[i] == 'b', ntest);

		if (errors != olderrors)
		  {
		    printf ("n1=%zu, n2=%zu, n3=%zu, buf1=%02hhx",
			    n1, n2, n3, buf1[0]);
		    for (size_t j = 1; j < sizeof (buf1); ++j)
		      printf (",%02hhx", buf1[j]);
		    putchar_unlocked ('\n');
		    break;
		  }
	      }
	}
}

static void
test_strncpy (void)
{
  /* Testing is a bit different because of odd semantics.  */
  it = "strncpy";
  check (strncpy (one, "abc", 4) == one, 1);	/* Returned value. */
  equal (one, "abc", 2);			/* Did the copy go right? */

  (void) strcpy (one, "abcdefgh");
  (void) strncpy (one, "xyz", 2);
  equal (one, "xycdefgh", 3);			/* Copy cut by count. */

  (void) strcpy (one, "abcdefgh");
  (void) strncpy (one, "xyz", 3);		/* Copy cut just before NUL. */
  equal (one, "xyzdefgh", 4);

  (void) strcpy (one, "abcdefgh");
  (void) strncpy (one, "xyz", 4);		/* Copy just includes NUL. */
  equal (one, "xyz", 5);
  equal (one+4, "efgh", 6);			/* Wrote too much? */

  (void) strcpy (one, "abcdefgh");
  (void) strncpy (one, "xyz", 5);		/* Copy includes padding. */
  equal (one, "xyz", 7);
  equal (one+4, "", 8);
  equal (one+5, "fgh", 9);

  (void) strcpy (one, "abc");
  (void) strncpy (one, "xyz", 0);		/* Zero-length copy. */
  equal (one, "abc", 10);

  (void) strncpy (one, "", 2);		/* Zero-length source. */
  equal (one, "", 11);
  equal (one+1, "", 12);
  equal (one+2, "c", 13);

  (void) strcpy (one, "hi there");
  (void) strncpy (two, one, 9);
  equal (two, "hi there", 14);		/* Just paranoia. */
  equal (one, "hi there", 15);		/* Stomped on source? */
}

static void
test_strchr (void)
{
  it = "strchr";
  check (strchr ("abcd", 'z') == NULL, 1);	/* Not found. */
  (void) strcpy (one, "abcd");
  check (strchr (one, 'c') == one+2, 2);	/* Basic test. */
  check (strchr (one, 'd') == one+3, 3);	/* End of string. */
  check (strchr (one, 'a') == one, 4);		/* Beginning. */
  check (strchr (one, '\0') == one+4, 5);	/* Finding NUL. */
  (void) strcpy (one, "ababa");
  check (strchr (one, 'b') == one+1, 6);	/* Finding first. */
  (void) strcpy (one, "");
  check (strchr (one, 'b') == NULL, 7);		/* Empty string. */
  check (strchr (one, '\0') == one, 8);		/* NUL in empty string. */
  {
    char buf[4096];
    int i;
    char *p;
    for (i=0; i < 0x100; i++)
      {
	p = (char *) ((unsigned long int) (buf + 0xff) & ~0xff) + i;
	strcpy (p, "OK");
	strcpy (p+3, "BAD/WRONG");
	check (strchr (p, '/') == NULL, 9+i);
      }
   }
}

static void
test_strrchr (void)
{
  it = "strrchr";
  check (strrchr ("abcd", 'z') == NULL, 1);	/* Not found. */
  (void) strcpy (one, "abcd");
  check (strrchr (one, 'c') == one+2, 2);	/* Basic test. */
  check (strrchr (one, 'd') == one+3, 3);	/* End of string. */
  check (strrchr (one, 'a') == one, 4);		/* Beginning. */
  check (strrchr (one, '\0') == one+4, 5);	/* Finding NUL. */
  (void) strcpy (one, "ababa");
  check (strrchr (one, 'b') == one+3, 6);	/* Finding last. */
  (void) strcpy (one, "");
  check (strrchr (one, 'b') == NULL, 7);	/* Empty string. */
  check (strrchr (one, '\0') == one, 8);	/* NUL in empty string. */
  {
    char buf[4096];
    int i;
    char *p;
    for (i=0; i < 0x100; i++)
      {
	p = (char *) ((unsigned long int) (buf + 0xff) & ~0xff) + i;
	strcpy (p, "OK");
	strcpy (p+3, "BAD/WRONG");
	check (strrchr (p, '/') == NULL, 9+i);
      }
   }
}

static void
test_strstr (void)
{
  it = "strstr";
  check(strstr("abcd", "z") == NULL, 1);	/* Not found. */
  check(strstr("abcd", "abx") == NULL, 2);	/* Dead end. */
  (void) strcpy(one, "abcd");
  check(strstr(one, "c") == one+2, 3);	/* Basic test. */
  check(strstr(one, "bc") == one+1, 4);	/* Multichar. */
  check(strstr(one, "d") == one+3, 5);	/* End of string. */
  check(strstr(one, "cd") == one+2, 6);	/* Tail of string. */
  check(strstr(one, "abc") == one, 7);	/* Beginning. */
  check(strstr(one, "abcd") == one, 8);	/* Exact match. */
  check(strstr(one, "abcde") == NULL, 9);	/* Too long. */
  check(strstr(one, "de") == NULL, 10);	/* Past end. */
  check(strstr(one, "") == one, 11);	/* Finding empty. */
  (void) strcpy(one, "ababa");
  check(strstr(one, "ba") == one+1, 12);	/* Finding first. */
  (void) strcpy(one, "");
  check(strstr(one, "b") == NULL, 13);	/* Empty string. */
  check(strstr(one, "") == one, 14);	/* Empty in empty string. */
  (void) strcpy(one, "bcbca");
  check(strstr(one, "bca") == one+2, 15);	/* False start. */
  (void) strcpy(one, "bbbcabbca");
  check(strstr(one, "bbca") == one+1, 16);	/* With overlap. */
}

static void
test_strspn (void)
{
  it = "strspn";
  check(strspn("abcba", "abc") == 5, 1);	/* Whole string. */
  check(strspn("abcba", "ab") == 2, 2);	/* Partial. */
  check(strspn("abc", "qx") == 0, 3);	/* None. */
  check(strspn("", "ab") == 0, 4);	/* Null string. */
  check(strspn("abc", "") == 0, 5);	/* Null search list. */
}

static void
test_strcspn (void)
{
  it = "strcspn";
  check(strcspn("abcba", "qx") == 5, 1);	/* Whole string. */
  check(strcspn("abcba", "cx") == 2, 2);	/* Partial. */
  check(strcspn("abc", "abc") == 0, 3);	/* None. */
  check(strcspn("", "ab") == 0, 4);	/* Null string. */
  check(strcspn("abc", "") == 3, 5);	/* Null search list. */
}

static void
test_memcpy (void)
{
  int i;
  it = "memcpy";
  check(memcpy(one, "abc", 4) == one, 1);	/* Returned value. */
  equal(one, "abc", 2);			/* Did the copy go right? */

  (void) strcpy(one, "abcdefgh");
  (void) memcpy(one+1, "xyz", 2);
  equal(one, "axydefgh", 3);		/* Basic test. */

  (void) strcpy(one, "abc");
  (void) memcpy(one, "xyz", 0);
  equal(one, "abc", 4);			/* Zero-length copy. */

  (void) strcpy(one, "hi there");
  (void) strcpy(two, "foo");
  (void) memcpy(two, one, 9);
  equal(two, "hi there", 5);		/* Just paranoia. */
  equal(one, "hi there", 6);		/* Stomped on source? */

  for (i = 0; i < 16; i++)
    {
      const char *x = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
      strcpy (one, x);
      check (memcpy (one + i, "hi there", 9) == one + i,
	     7 + (i * 6));		/* Unaligned destination. */
      check (memcmp (one, x, i) == 0, 8 + (i * 6));  /* Wrote under? */
      equal (one + i, "hi there", 9 + (i * 6));
      check (one[i + 9] == 'x', 10 + (i * 6));       /* Wrote over? */
      check (memcpy (two, one + i, 9) == two,
	     11 + (i * 6));		/* Unaligned source. */
      equal (two, "hi there", 12 + (i * 6));
    }
}

static void
test_memset (void)
{
  int i;

  it = "memset";
  (void) strcpy(one, "abcdefgh");
  check(memset(one+1, 'x', 3) == one+1, 1);	/* Return value. */
  equal(one, "axxxefgh", 2);		/* Basic test. */

  (void) memset(one+2, 'y', 0);
  equal(one, "axxxefgh", 3);		/* Zero-length set. */

  (void) memset(one+5, 0, 1);
  equal(one, "axxxe", 4);			/* Zero fill. */
  equal(one+6, "gh", 5);			/* And the leftover. */

  (void) memset(one+2, 010045, 1);
  equal(one, "ax\045xe", 6);		/* Unsigned char convert. */

  /* Non-8bit fill character.  */
  memset (one, 0x101, sizeof (one));
  for (i = 0; i < (int) sizeof (one); ++i)
    check (one[i] == '\01', 7);

  /* Test for more complex versions of memset, for all alignments and
     lengths up to 256. This test takes a little while, perhaps it should
     be made weaker?  */
  {
    char data[512];
    int j;
    int k;
    int c;

    for (i = 0; i < 512; i++)
      data[i] = 'x';
    for (c = 0; c <= 'y'; c += 'y')  /* check for memset(,0,) and
					memset(,'y',) */
      for (j = 0; j < 256; j++)
	for (i = 0; i < 256; i++)
	  {
	    memset (data + i, c, j);
	    for (k = 0; k < i; k++)
	      if (data[k] != 'x')
		goto fail;
	    for (k = i; k < i+j; k++)
	      {
		if (data[k] != c)
		  goto fail;
		data[k] = 'x';
	      }
	    for (k = i+j; k < 512; k++)
	      if (data[k] != 'x')
		goto fail;
	    continue;

	  fail:
	    check (0, 8 + i + j * 256 + (c != 0) * 256 * 256);
	  }
  }
}

int
main (void)
{
  int status;

#if 0
  /* Test strcpy next because we need it to set up other tests.  */
  test_strcpy ();

  /* strcat.  */
  test_strcat ();

  /* strncpy.  */
  test_strncpy ();

  /* strchr.  */
  test_strchr ();

  /* strrchr.  */
  test_strrchr ();

  /* strstr - somewhat like strchr.  */
  test_strstr ();

  /* strspn.  */
  test_strspn ();

  /* strcspn.  */
  test_strcspn ();

  /* memcpy - need not work for overlap.  */
  test_memcpy ();

  /* memset.  */
  test_memset ();
#endif

  // test_strchr ();

// is char signed or unsigned?
// signed char: -128 ... 127
// unsigned char: 0 ... 255

  char buf[] = { 'a'+128, 0 };

  check (strchr (buf, 'a'+128) == buf, 999);

  if (errors == 0)
    {
      status = EXIT_SUCCESS;
      puts("No errors.");
    }
  else
    {
      status = EXIT_FAILURE;
      printf("%Zd errors.\n", errors);
    }

  return status;
}

/* sample run:

$ make
gcc -c -w tester.c # -DDEBUG
gcc -std=c11 -pedantic -Wall -o p1 p1.c tester.o
$ ./p1
c = 225
c = -31
No errors.
$

*/