Re: [patch] un-#ifdef GATHER_STATISTICS

[Markus Trippelsdorf <markus at trippelsdorf dot de>]

On 2012.07.23 at 19:01 +0200, Steven Bosscher wrote:
> Hello,
> 
> This large patch makes GATHER_STATISTICS always take a value, 0
> (disabled) or 1 (enabled), and turns all related #ifdef code into
> conditional branches.
> 
> This slightly increases the data section of cc1, but only marginally.
> There is no impact on compile time, because all tests are simply
> optimized away if GATHER_STATISTICS is 0.
> 
> The benefit is that this improves the coverage of this code, and less
> #ifdef'ed code (which is IMHO a Good Thing).
>
>...
>
> Index: alloc-pool.c
> ===================================================================
> --- alloc-pool.c	(revision 189784)
> +++ alloc-pool.c	(working copy)
> @@ -62,8 +62,6 @@ typedef struct allocation_object_def
>  static ALLOC_POOL_ID_TYPE last_id;
>  #endif
>  
> -#ifdef GATHER_STATISTICS
> -
>  /* Store information about each particular alloc_pool.  Note that this
>     will underestimate the amount the amount of storage used by a small amount:
>     1) The overhead in a pool is not accounted for.
> @@ -123,7 +121,6 @@ alloc_pool_descriptor (const char *name)
>    (*slot)->name = name;
>    return *slot;
>  }
> -#endif
>  
>  /* Create a pool of things of size SIZE, with NUM in each block we
>     allocate.  */
> @@ -133,9 +130,6 @@ create_alloc_pool (const char *name, siz
>  {
>    alloc_pool pool;
>    size_t header_size;
> -#ifdef GATHER_STATISTICS
> -  struct alloc_pool_descriptor *desc;
> -#endif
>  
>    gcc_checking_assert (name);
>  
> @@ -146,10 +140,11 @@ create_alloc_pool (const char *name, siz
>    /* Now align the size to a multiple of 4.  */
>    size = align_eight (size);
>  
> -#ifdef ENABLE_CHECKING
> -  /* Add the aligned size of ID.  */
> -  size += offsetof (allocation_object, u.data);
> -#endif
> +  if (ENABLE_CHECKING)
> +    {
> +      /* Add the aligned size of ID.  */
> +      size += offsetof (allocation_object, u.data);
> +    }

The change above causes a build failure with --enable-checking=release:

x86_64-pc-linux-gnu-gcc -c   -g -O2 -DIN_GCC   -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wstrict-prototypes -Wmissing-prototypes -Wmissing-format-attribute -pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -Wold-style-definition -Wc++-compat   -DHAVE_CONFIG_H -I. -I. -I../../gcc/gcc -I../../gcc/gcc/. -I../../gcc/gcc/../include -I../../gcc/gcc/../libcpp/include  -I../../gcc/gcc/../libdecnumber -I../../gcc/gcc/../libdecnumber/bid -I../libdecnumber    ../../gcc/gcc/alloc-pool.c -o alloc-pool.o
../../gcc/gcc/alloc-pool.c: In function â??create_alloc_poolâ??:
../../gcc/gcc/alloc-pool.c:143:7: error: â??ENABLE_CHECKINGâ?? undeclared (first use in this function)
   if (ENABLE_CHECKING)
       ^
../../gcc/gcc/alloc-pool.c:143:7: note: each undeclared identifier is reported only once for each function it appears in


-- 
Markus