Fix build and tests with --disable-tunables

  Remove unused code and declare __libc_mallopt when !IS_IN (libc) to
allow the debug hook to build with --disable-tunables.

Also, run tst-ifunc-isa-2* tests only when tunables are enabled since
the result depends on it.

Tested on x86_64.

Reported-by: Matheus Castanho <msc@linux.ibm.com>
---

It's a trivial non-ABI change that is needed to get --disable-tunables
working correctly, so I'll push this if there are no objections.

 malloc/arena.c        |  5 -----
 malloc/malloc-check.c |  2 ++
 malloc/malloc.c       | 51 ++++++++++++++++++++++---------------------
 sysdeps/x86/Makefile  |  8 +++++--
 4 files changed, 34 insertions(+), 32 deletions(-)
  

On 7/22/21 10:25 PM, Siddhesh Poyarekar wrote:
> Remove unused code and declare __libc_mallopt when !IS_IN (libc) to
> allow the debug hook to build with --disable-tunables.
> 
> Also, run tst-ifunc-isa-2* tests only when tunables are enabled since
> the result depends on it.
> 
> Tested on x86_64.

LGTM.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
 
> Reported-by: Matheus Castanho <msc@linux.ibm.com>
> ---
> 
> It's a trivial non-ABI change that is needed to get --disable-tunables
> working correctly, so I'll push this if there are no objections.
> 
>  malloc/arena.c        |  5 -----
>  malloc/malloc-check.c |  2 ++
>  malloc/malloc.c       | 51 ++++++++++++++++++++++---------------------
>  sysdeps/x86/Makefile  |  8 +++++--
>  4 files changed, 34 insertions(+), 32 deletions(-)
> 
> diff --git a/malloc/arena.c b/malloc/arena.c
> index edcaa8816d..667484630e 100644
> --- a/malloc/arena.c
> +++ b/malloc/arena.c
> @@ -332,7 +332,6 @@ ptmalloc_init (void)
>  # endif
>    TUNABLE_GET (mxfast, size_t, TUNABLE_CALLBACK (set_mxfast));
>  #else
> -  const char *s = NULL;

OK.

>    if (__glibc_likely (_environ != NULL))
>      {
>        char **runp = _environ;
> @@ -351,10 +350,6 @@ ptmalloc_init (void)
>  
>            switch (len)
>              {
> -            case 6:
> -              if (memcmp (envline, "CHECK_", 6) == 0)
> -                s = &envline[7];
> -              break;

OK.

>              case 8:
>                if (!__builtin_expect (__libc_enable_secure, 0))
>                  {
> diff --git a/malloc/malloc-check.c b/malloc/malloc-check.c
> index a444c7478e..8ed67de3ff 100644
> --- a/malloc/malloc-check.c
> +++ b/malloc/malloc-check.c
> @@ -376,6 +376,7 @@ memalign_check (size_t alignment, size_t bytes)
>    return mem2mem_check (tag_new_usable (mem), bytes);
>  }
>  
> +#if HAVE_TUNABLES
>  static void
>  TUNABLE_CALLBACK (set_mallopt_check) (tunable_val_t *valp)
>  {
> @@ -383,6 +384,7 @@ TUNABLE_CALLBACK (set_mallopt_check) (tunable_val_t *valp)
>    if (value != 0)
>      __malloc_debug_enable (MALLOC_CHECK_HOOK);
>  }
> +#endif

OK.

>  
>  static bool
>  initialize_malloc_check (void)
> diff --git a/malloc/malloc.c b/malloc/malloc.c
> index 38b649fcba..e065785af7 100644
> --- a/malloc/malloc.c
> +++ b/malloc/malloc.c
> @@ -687,31 +687,6 @@ void*  __libc_valloc(size_t);
>  
>  
>  
> -/*
> -  mallopt(int parameter_number, int parameter_value)
> -  Sets tunable parameters The format is to provide a
> -  (parameter-number, parameter-value) pair.  mallopt then sets the
> -  corresponding parameter to the argument value if it can (i.e., so
> -  long as the value is meaningful), and returns 1 if successful else
> -  0.  SVID/XPG/ANSI defines four standard param numbers for mallopt,
> -  normally defined in malloc.h.  Only one of these (M_MXFAST) is used
> -  in this malloc. The others (M_NLBLKS, M_GRAIN, M_KEEP) don't apply,
> -  so setting them has no effect. But this malloc also supports four
> -  other options in mallopt. See below for details.  Briefly, supported
> -  parameters are as follows (listed defaults are for "typical"
> -  configurations).
> -
> -  Symbol            param #   default    allowed param values
> -  M_MXFAST          1         64         0-80  (0 disables fastbins)
> -  M_TRIM_THRESHOLD -1         128*1024   any   (-1U disables trimming)
> -  M_TOP_PAD        -2         0          any
> -  M_MMAP_THRESHOLD -3         128*1024   any   (or 0 if no MMAP support)
> -  M_MMAP_MAX       -4         65536      any   (0 disables use of mmap)
> -*/
> -int      __libc_mallopt(int, int);
> -libc_hidden_proto (__libc_mallopt)
> -
> -
>  /*
>    mallinfo()
>    Returns (by copy) a struct containing various summary statistics:
> @@ -820,6 +795,32 @@ void     __malloc_stats(void);
>  int      __posix_memalign(void **, size_t, size_t);
>  #endif /* IS_IN (libc) */
>  
> +/*
> +  mallopt(int parameter_number, int parameter_value)
> +  Sets tunable parameters The format is to provide a
> +  (parameter-number, parameter-value) pair.  mallopt then sets the
> +  corresponding parameter to the argument value if it can (i.e., so
> +  long as the value is meaningful), and returns 1 if successful else
> +  0.  SVID/XPG/ANSI defines four standard param numbers for mallopt,
> +  normally defined in malloc.h.  Only one of these (M_MXFAST) is used
> +  in this malloc. The others (M_NLBLKS, M_GRAIN, M_KEEP) don't apply,
> +  so setting them has no effect. But this malloc also supports four
> +  other options in mallopt. See below for details.  Briefly, supported
> +  parameters are as follows (listed defaults are for "typical"
> +  configurations).
> +
> +  Symbol            param #   default    allowed param values
> +  M_MXFAST          1         64         0-80  (0 disables fastbins)
> +  M_TRIM_THRESHOLD -1         128*1024   any   (-1U disables trimming)
> +  M_TOP_PAD        -2         0          any
> +  M_MMAP_THRESHOLD -3         128*1024   any   (or 0 if no MMAP support)
> +  M_MMAP_MAX       -4         65536      any   (0 disables use of mmap)
> +*/
> +int      __libc_mallopt(int, int);
> +#if IS_IN (libc)
> +libc_hidden_proto (__libc_mallopt)
> +#endif
> +
>  /* mallopt tuning options */
>  
>  /*
> diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile
> index 346ec491b3..bd4f6a13b9 100644
> --- a/sysdeps/x86/Makefile
> +++ b/sysdeps/x86/Makefile
> @@ -19,14 +19,18 @@ ifeq (yes,$(have-ifunc))
>  ifeq (yes,$(have-gcc-ifunc))
>  tests += \
>    tst-ifunc-isa-1 \
> -  tst-ifunc-isa-1-static \
> +  tst-ifunc-isa-1-static
> +tests-static += \
> +  tst-ifunc-isa-1-static
> +ifneq ($(have-tunables),no)
> +tests += \
>    tst-ifunc-isa-2 \
>    tst-ifunc-isa-2-static
>  tests-static += \
> -  tst-ifunc-isa-1-static \
>    tst-ifunc-isa-2-static
>  endif
>  endif
> +endif

OK.

>  ifeq (yes,$(enable-x86-isa-level))
>  tests += tst-isa-level-1
>  modules-names += tst-isa-level-mod-1-baseline \
>