[v10,2/6] elf: Add tests for the dl hash funcs (_dl_new_hash and _dl_elf_hash)

  If we want to further optimize the functions tests are needed.
---
 elf/Makefile         |   1 +
 elf/simple-dl-hash.h |  42 ++++++++++++++++
 elf/tst-dl-hash.c    | 115 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 158 insertions(+)
 create mode 100644 elf/simple-dl-hash.h
 create mode 100644 elf/tst-dl-hash.c
  

On 18/05/2022 22:56, Noah Goldstein via Libc-alpha wrote:
> If we want to further optimize the functions tests are needed.
> ---
>   elf/Makefile         |   1 +
>   elf/simple-dl-hash.h |  42 ++++++++++++++++
>   elf/tst-dl-hash.c    | 115 +++++++++++++++++++++++++++++++++++++++++++
>   3 files changed, 158 insertions(+)
>   create mode 100644 elf/simple-dl-hash.h
>   create mode 100644 elf/tst-dl-hash.c

LGTM.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

> 
> diff --git a/elf/Makefile b/elf/Makefile
> index ce3345ed92..adf1bcf6ce 100644
> --- a/elf/Makefile
> +++ b/elf/Makefile
> @@ -312,6 +312,7 @@ tests := \
>     tst-array4 \
>     tst-array5 \
>     tst-auxv \
> +  tst-dl-hash \
>     tst-leaks1 \
>     tst-stringtable \
>     tst-tls9 \
> diff --git a/elf/simple-dl-hash.h b/elf/simple-dl-hash.h
> new file mode 100644
> index 0000000000..53702b3c55
> --- /dev/null
> +++ b/elf/simple-dl-hash.h
> @@ -0,0 +1,42 @@
> +/* __simple_dl_elf_hash for testing true elf symbol lookup.
> +   Copyright (C) 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 _SIMPLE_DL_ELF_HASH_H
> +#define _SIMPLE_DL_ELF_HASH_H 1
> +
> +#include <stdint.h>
> +
> +/* For testing/benchmarking purposes.  Real implementation in
> +   sysdeps/generic/dl-hash.h.  */
> +static uint32_t
> +__attribute__ ((unused))
> +__simple_dl_elf_hash (const char *name_arg)
> +{
> +  unsigned long int hash = 0;
> +  for (unsigned char c = *name_arg; c != '\0'; c = *(++name_arg))
> +    {
> +      unsigned long int hi;
> +      hash = (hash << 4) + c;
> +      hi = hash & 0xf0000000;
> +      hash ^= hi >> 24;
> +      hash &= 0x0fffffff;
> +    }
> +  return hash;
> +}
> +
> +#endif /* simple-dl-hash.h */
> diff --git a/elf/tst-dl-hash.c b/elf/tst-dl-hash.c
> new file mode 100644
> index 0000000000..8697eb73a0
> --- /dev/null
> +++ b/elf/tst-dl-hash.c
> @@ -0,0 +1,115 @@
> +/* Test dl-hash functions.
> +   Copyright (C) 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/>.  */
> +
> +
> +#include <simple-dl-hash.h>
> +#include <dl-hash.h>
> +#include <dl-new-hash.h>
> +#include <support/support.h>
> +#include <support/check.h>
> +#include <stdio.h>
> +#include <string.h>
> +#include <stdlib.h>
> +
> +typedef unsigned int (*hash_f) (const char *);
> +
> +
> +
> +static int
> +do_fill_test (size_t len, int fill, const char *name, hash_f testf,
> +	      hash_f expecf)
> +{
> +  uint32_t expec, res;
> +  char buf[len + 1];
> +  memset (buf, fill, len);
> +  buf[len] = '\0';
> +
> +  expec = expecf (buf);
> +  res = testf (buf);
> +  if (expec != res)
> +    FAIL_EXIT1 ("FAIL: fill(%d) %s(%zu), %x != %x\n", fill, name, len, expec,
> +		res);
> +
> +  return 0;
> +}
> +
> +static int
> +do_fill_tests (size_t len, int fill)
> +{
> +  if (do_fill_test (len, fill, "dl_new_hash", &_dl_new_hash,
> +		    &__simple_dl_new_hash))
> +    return 1;
> +
> +  return do_fill_test (len, fill, "dl_elf_hash", &_dl_elf_hash,
> +		       &__simple_dl_elf_hash);
> +}
> +
> +static int
> +do_rand_test (size_t len, const char *name, hash_f testf, hash_f expecf)
> +{
> +  uint32_t expec, res;
> +  size_t i;
> +  char buf[len + 1];
> +  char v;
> +  for (i = 0; i < len; ++i)
> +    {
> +      v = random ();
> +      if (v == 0)
> +	v = 1;
> +
> +      buf[i] = v;
> +    }
> +  buf[len] = '\0';
> +
> +  expec = expecf (buf);
> +  res = testf (buf);
> +  if (expec != res)
> +    FAIL_EXIT1 ("FAIL: random %s(%zu), %x != %x\n", name, len, expec, res);
> +
> +  return 0;
> +}
> +
> +static int
> +do_rand_tests (size_t len)
> +{
> +  if (do_rand_test (len, "dl_new_hash", &_dl_new_hash, &__simple_dl_new_hash))
> +    return 1;
> +
> +  return do_rand_test (len, "dl_elf_hash", &_dl_elf_hash, &__simple_dl_elf_hash);
> +}
> +
> +static int
> +do_test (void)
> +{
> +  size_t i, j;
> +  for (i = 0; i < 100; ++i)
> +    {
> +      for (j = 0; j < 8192; ++j)
> +	{
> +	  if (do_rand_tests (i))
> +	    return 1;
> +
> +	  if (do_fill_tests (i, -1) || do_fill_tests (i, 1)
> +	      || do_fill_tests (i, 0x80) || do_fill_tests (i, 0x88))
> +	    return 1;
> +	}
> +    }
> +  return 0;
> +}
> +
> +#include <support/test-driver.c>