[Xen-devel] [PATCH 5/7] Mute some compiler warnings

[Andrew Cooper]

On 12/07/13 14:48, Daniel Kiper wrote:
> This patch mutes follwing compiler warnings:
>   - warning: assignment discards ‘const’ qualifier from
>     pointer target type [enabled by default],
>   - warning: variable ‘page_offset’ set but not used
>     [-Wunused-but-set-variable].
>
> Signed-off-by: Daniel Kiper <daniel.kiper at oracle.com>
> ---
>  dwarf_info.c  |    4 ++--
>  sadump_info.c |    2 --
>  2 files changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/dwarf_info.c b/dwarf_info.c
> index 6e21b8a..86cae69 100644
> --- a/dwarf_info.c
> +++ b/dwarf_info.c
> @@ -1427,7 +1427,7 @@ get_die_member(unsigned long long die_off, int index, long *offset,
>  	if (!get_data_member_location(die, offset))
>  		*offset = 0;
>  
> -	*name = dwarf_diename(die);
> +	*name = (char *)dwarf_diename(die);

Discarding a const qualifier like this is usually a good sign that you
are misusing name in the first place.

Indeed, name is merely non-const to strdup() and reuse the same variable.

This would be more clearly done using

const char * diename = dwarf_diename(&result) ;

and

name = strdup(diename);

~Andrew

>  	/*
>  	 * Duplicate the string before we pass it to eppic layer. The
>  	 * original string returned by dwarf layer will become invalid
> @@ -1513,7 +1513,7 @@ get_die_name(unsigned long long die_off)
>  		return NULL;
>  	}
>  
> -	name = dwarf_diename(&result);
> +	name = (char *)dwarf_diename(&result);
>  	if (name)
>  		name = strdup(name);
>  	clean_dwfl_info();
> diff --git a/sadump_info.c b/sadump_info.c
> index be6cf55..01cf5eb 100644
> --- a/sadump_info.c
> +++ b/sadump_info.c
> @@ -948,7 +948,6 @@ int
>  readpage_sadump(unsigned long long paddr, void *bufptr)
>  {
>  	unsigned long long pfn, block, whole_offset, perdisk_offset;
> -	ulong page_offset;
>  	int fd_memory;
>  
>  	if (si->kdump_backed_up &&
> @@ -957,7 +956,6 @@ readpage_sadump(unsigned long long paddr, void *bufptr)
>  		paddr += si->backup_offset - si->backup_src_start;
>  
>  	pfn = paddr_to_pfn(paddr);
> -	page_offset = paddr % info->page_size;
>  
>  	if (pfn >= si->sh_memory->max_mapnr)
>  		return FALSE;