Re: Define _STRING_ARCH_unaligned unconditionally

[Adhemerval Zanella <azanella at linux dot vnet dot ibm dot com>]

Ping.

On 27-03-2014 11:27, Adhemerval Zanella wrote:
> On 26-03-2014 14:42, Joseph S. Myers wrote:
>> On Wed, 26 Mar 2014, Adhemerval Zanella wrote:
>>
>>> This is a respin on my initial try to remove the undefined _STRING_ARCH_unaligned
>>> from PPC64 builds, but now extended to all arch that do not define it.  This patch
>>> defines _STRING_ARCH_unaligned to 0, mimicking old undefined behavior.
>>>
>>> --
>>>
>>> 	* bits/string.h (_STRING_ARCH_unaligned): Define it to 0.
>> I see various files in the source tree with #ifdef / #ifndef / "defined" 
>> conditionals on _STRING_ARCH_unaligned.  I don't think those are correct 
>> with it defined to 0, so I think you need to change all of those are part 
>> of the patch introducing the possibility that it might be defined to 0.
>>
>> crypt/sha256.c
>> iconv/gconv_simple.c
>> iconv/loop.c
>> iconv/skeleton.c
>> nscd/nscd_gethst_r.c
>> nscd/nscd_getserv_r.c
>> nscd/nscd_helper.c
>> resolv/res_send.c
>>
> Indeed and fixed:
>
> --
>
> 	* bits/string.h (_STRING_ARCH_unaligned): Define it to 0.
> 	* crypt/sha256.c (_STRING_ARCH_unaligned): Check its value instead of its
> 	definition.
> 	* iconv/gconv_simple.c (_STRING_ARCH_unaligned): Likewise.
> 	* iconv/loop.c (_STRING_ARCH_unaligned): Likewise.
> 	* iconv/skeleton.c (_STRING_ARCH_unaligned): Likewise.
> 	* nscd/nscd_gethst_r.c (_STRING_ARCH_unaligned): Likewise.
> 	* nscd/nscd_getserv_r.c (_STRING_ARCH_unaligned): Likewise.
> 	* nscd/nscd_helper.c (_STRING_ARCH_unaligned): Likewise.
> 	* resolv/res_send.c (_STRING_ARCH_unaligned): Likewise.
>
> ---
>
> diff --git a/bits/string.h b/bits/string.h
> index f8630d2..b88a6bc 100644
> --- a/bits/string.h
> +++ b/bits/string.h
> @@ -8,5 +8,7 @@
>  #ifndef _BITS_STRING_H
>  #define _BITS_STRING_H	1
>
> +/* Define if architecture can access unaligned multi-byte variables.  */
> +#define _STRING_ARCH_unaligned   0
>
>  #endif /* bits/string.h */
> diff --git a/crypt/sha256.c b/crypt/sha256.c
> index a5df83e..4e1b504 100644
> --- a/crypt/sha256.c
> +++ b/crypt/sha256.c
> @@ -125,7 +125,7 @@ __sha256_finish_ctx (ctx, resbuf)
>    memcpy (&ctx->buffer[bytes], fillbuf, pad);
>
>    /* Put the 64-bit file length in *bits* at the end of the buffer.  */
> -#ifdef _STRING_ARCH_unaligned
> +#if _STRING_ARCH_unaligned
>    ctx->buffer64[(bytes + pad) / 8] = SWAP64 (ctx->total64 << 3);
>  #else
>    ctx->buffer32[(bytes + pad + 4) / 4] = SWAP (ctx->total[TOTAL64_low] << 3);
> diff --git a/iconv/gconv_simple.c b/iconv/gconv_simple.c
> index e11e2ee..f357713 100644
> --- a/iconv/gconv_simple.c
> +++ b/iconv/gconv_simple.c
> @@ -112,7 +112,7 @@ internal_ucs4_loop (struct __gconv_step *step,
>    return result;
>  }
>
> -#ifndef _STRING_ARCH_unaligned
> +#if !_STRING_ARCH_unaligned
>  static inline int
>  __attribute ((always_inline))
>  internal_ucs4_loop_unaligned (struct __gconv_step *step,
> @@ -289,7 +289,7 @@ ucs4_internal_loop (struct __gconv_step *step,
>    return result;
>  }
>
> -#ifndef _STRING_ARCH_unaligned
> +#if !_STRING_ARCH_unaligned
>  static inline int
>  __attribute ((always_inline))
>  ucs4_internal_loop_unaligned (struct __gconv_step *step,
> @@ -478,7 +478,7 @@ internal_ucs4le_loop (struct __gconv_step *step,
>    return result;
>  }
>
> -#ifndef _STRING_ARCH_unaligned
> +#if !_STRING_ARCH_unaligned
>  static inline int
>  __attribute ((always_inline))
>  internal_ucs4le_loop_unaligned (struct __gconv_step *step,
> @@ -658,7 +658,7 @@ ucs4le_internal_loop (struct __gconv_step *step,
>    return result;
>  }
>
> -#ifndef _STRING_ARCH_unaligned
> +#if !_STRING_ARCH_unaligned
>  static inline int
>  __attribute ((always_inline))
>  ucs4le_internal_loop_unaligned (struct __gconv_step *step,
> diff --git a/iconv/loop.c b/iconv/loop.c
> index f836d08..f86f627 100644
> --- a/iconv/loop.c
> +++ b/iconv/loop.c
> @@ -63,7 +63,7 @@
>     representations with a fixed width of 2 or 4 bytes.  But if we cannot
>     access unaligned memory we still have to read byte-wise.  */
>  #undef FCTNAME2
> -#if defined _STRING_ARCH_unaligned || !defined DEFINE_UNALIGNED
> +#if _STRING_ARCH_unaligned || !defined DEFINE_UNALIGNED
>  /* We can handle unaligned memory access.  */
>  # define get16(addr) *((const uint16_t *) (addr))
>  # define get32(addr) *((const uint32_t *) (addr))
> @@ -342,7 +342,7 @@ FCTNAME (LOOPFCT) (struct __gconv_step *step,
>
>  /* Include the file a second time to define the function to handle
>     unaligned access.  */
> -#if !defined DEFINE_UNALIGNED && !defined _STRING_ARCH_unaligned \
> +#if !defined DEFINE_UNALIGNED && !_STRING_ARCH_unaligned \
>      && MIN_NEEDED_INPUT != 1 && MAX_NEEDED_INPUT % MIN_NEEDED_INPUT == 0 \
>      && MIN_NEEDED_OUTPUT != 1 && MAX_NEEDED_OUTPUT % MIN_NEEDED_OUTPUT == 0
>  # undef get16
> diff --git a/iconv/skeleton.c b/iconv/skeleton.c
> index 14318a6..c3f161a 100644
> --- a/iconv/skeleton.c
> +++ b/iconv/skeleton.c
> @@ -204,7 +204,7 @@
>  /* Define macros which can access unaligned buffers.  These macros are
>     supposed to be used only in code outside the inner loops.  For the inner
>     loops we have other definitions which allow optimized access.  */
> -#ifdef _STRING_ARCH_unaligned
> +#if _STRING_ARCH_unaligned
>  /* We can handle unaligned memory access.  */
>  # define get16u(addr) *((const uint16_t *) (addr))
>  # define get32u(addr) *((const uint32_t *) (addr))
> @@ -523,7 +523,7 @@ FUNCTION_NAME (struct __gconv_step *step, struct __gconv_step_data *data,
>  	 INTERNAL, for which the subexpression evaluates to 1, but INTERNAL
>  	 buffers are always aligned correctly.  */
>  #define POSSIBLY_UNALIGNED \
> -  (!defined _STRING_ARCH_unaligned					      \
> +  (!_STRING_ARCH_unaligned					              \
>     && (((FROM_LOOP_MIN_NEEDED_FROM != 1					      \
>  	 && FROM_LOOP_MAX_NEEDED_FROM % FROM_LOOP_MIN_NEEDED_FROM == 0)	      \
>  	&& (FROM_LOOP_MIN_NEEDED_TO != 1				      \
> diff --git a/nscd/nscd_gethst_r.c b/nscd/nscd_gethst_r.c
> index fe885ee..265f4d0 100644
> --- a/nscd/nscd_gethst_r.c
> +++ b/nscd/nscd_gethst_r.c
> @@ -191,7 +191,7 @@ nscd_gethst_r (const char *key, size_t keylen, request_type type,
>  	      goto out;
>  	    }
>
> -#ifndef _STRING_ARCH_unaligned
> +#if !_STRING_ARCH_unaligned
>  	  /* The aliases_len array in the mapped database might very
>  	     well be unaligned.  We will access it word-wise so on
>  	     platforms which do not tolerate unaligned accesses we
> diff --git a/nscd/nscd_getserv_r.c b/nscd/nscd_getserv_r.c
> index 4e3f702..f079a77 100644
> --- a/nscd/nscd_getserv_r.c
> +++ b/nscd/nscd_getserv_r.c
> @@ -141,7 +141,7 @@ nscd_getserv_r (const char *crit, size_t critlen, const char *proto,
>  				> recend, 0))
>  	    goto out;
>
> -#ifndef _STRING_ARCH_unaligned
> +#if !_STRING_ARCH_unaligned
>  	  /* The aliases_len array in the mapped database might very
>  	     well be unaligned.  We will access it word-wise so on
>  	     platforms which do not tolerate unaligned accesses we
> diff --git a/nscd/nscd_helper.c b/nscd/nscd_helper.c
> index 0d61643..9fe1f46 100644
> --- a/nscd/nscd_helper.c
> +++ b/nscd/nscd_helper.c
> @@ -490,7 +490,7 @@ __nscd_cache_search (request_type type, const char *key, size_t keylen,
>        struct hashentry *here = (struct hashentry *) (mapped->data + work);
>        ref_t here_key, here_packet;
>
> -#ifndef _STRING_ARCH_unaligned
> +#if !_STRING_ARCH_unaligned
>        /* Although during garbage collection when moving struct hashentry
>  	 records around we first copy from old to new location and then
>  	 adjust pointer from previous hashentry to it, there is no barrier
> @@ -512,7 +512,7 @@ __nscd_cache_search (request_type type, const char *key, size_t keylen,
>  	  struct datahead *dh
>  	    = (struct datahead *) (mapped->data + here_packet);
>
> -#ifndef _STRING_ARCH_unaligned
> +#if !_STRING_ARCH_unaligned
>  	  if ((uintptr_t) dh & (__alignof__ (*dh) - 1))
>  	    return NULL;
>  #endif
> @@ -536,7 +536,7 @@ __nscd_cache_search (request_type type, const char *key, size_t keylen,
>  	  struct hashentry *trailelem;
>  	  trailelem = (struct hashentry *) (mapped->data + trail);
>
> -#ifndef _STRING_ARCH_unaligned
> +#if !_STRING_ARCH_unaligned
>  	  /* We have to redo the checks.  Maybe the data changed.  */
>  	  if ((uintptr_t) trailelem & (__alignof__ (*trailelem) - 1))
>  	    return NULL;
> diff --git a/resolv/res_send.c b/resolv/res_send.c
> index ce7127e..60743df 100644
> --- a/resolv/res_send.c
> +++ b/resolv/res_send.c
> @@ -787,7 +787,7 @@ send_vc(res_state statp,
>  			/* No buffer allocated for the first
>  			   reply.  We can try to use the rest
>  			   of the user-provided buffer.  */
> -#ifdef _STRING_ARCH_unaligned
> +#if _STRING_ARCH_unaligned
>  			*anssizp2 = orig_anssizp - resplen;
>  			*ansp2 = *ansp + resplen;
>  #else
> @@ -1205,7 +1205,7 @@ send_dg(res_state statp,
>  				/* No buffer allocated for the first
>  				   reply.  We can try to use the rest
>  				   of the user-provided buffer.  */
> -#ifdef _STRING_ARCH_unaligned
> +#if _STRING_ARCH_unaligned
>  				*anssizp2 = orig_anssizp - resplen;
>  				*ansp2 = *ansp + resplen;
>  #else
>