[PATCH PR/42686] Align the help text output

[Shujing Zhao]

On 03/11/2010 01:05 AM, Joseph S. Myers wrote:
> On Wed, 10 Mar 2010, Shujing Zhao wrote:
> 
>> +/* Expand the ROOM when the number of bytes of MSGSTR is larger than
>> +   the width in columns. */
>> +
>> +unsigned int
>> +get_col_width (const char *msgstr, unsigned int room)
> 
> The comment on this function makes no sense to me at all.  What does 
> "Expand the ROOM" mean?  It sounds as if ROOM is a parameter passed by 
> reference that might be changed by the function - but that clearly isn't 
> the case for a parameter of type unsigned int.  What are the semantics of 
> the operand ROOM?  What are the semantics of the return value?  (But see 
> below on how "the number of bytes of MSGSTR is larger than the width in 
> columns" is itself not a sensible concept for the code to be considering 
> in the first place.)
> 
>> +      if (screen_cols != nbytes)
> 
> This comparison is conceptually confused.  In logical terms, "columns" and 
> "bytes" are different data types that it does not make sense to compare.  
> It so happens that in the present C code they have the same static type so 
> the host compiler doesn't give an error for this comparison - but it is 
> still confused, and you need to arrange the code so it doesn't try to mix 
> different types like this.  This means having a very clear notion of 
> whether a particular variable counts columns, bytes or characters, and of 
> how you do explicit computations of the number of each kind of object in a 
> particular part of a string, and no comparisons between counts of 
> different things.

Thanks.
For the number of bytes of a wide character is different with the display column 
width, I have always tried to find the relationship between the display column 
width with justification width that printf counted by bytes.

This new patch fixed the function get_col_width totally. It is to return the 
really field width when left-justify print the wide character strings. The 
design splits the width to two parts. One is to print the strings, and the other 
is to print the spaces when the wide character display width less than 
LEFT_COLUMN. Composed the two parts would get the really width counted by bytes 
that can be used by printf.

The print of help strings looks very fine. Is it ok?

Thanks
Pearly
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 42686.patch
Type: text/x-patch
Size: 6137 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/gcc-patches/attachments/20100312/657ac1dd/attachment.bin>