Re: [Qemu-devel] [PATCH v3 3/3] util/uri.c: add brackets to `if` statements

[苏航]

Thanks for your reply. ^_^
I will apply all your suggestion in my next patch.

> -----Original Messages-----
> From: "Thomas Huth" <address@hidden>
> Sent Time: 2018-02-23 17:34:12 (Friday)
> To: "Su Hang" <address@hidden>, address@hidden
> Cc: address@hidden
> Subject: Re: [Qemu-devel] [PATCH v3 3/3] util/uri.c: add brackets to `if` 
> statements
> 
> On 23.02.2018 08:51, Su Hang wrote:
> > Add brackets that wrap `if`, `else`, `while` that hold single
> > statements.
> > 
> > In order to do this, I write a simple python regex script.
> > 
> > Since then, all complaints rised by checkpatch.pl has been suppressed.
> > 
> > Signed-off-by: Su Hang <address@hidden>
> > ---
> >  util/uri.c | 462 
> > ++++++++++++++++++++++++++++++++++++++-----------------------
> >  1 file changed, 291 insertions(+), 171 deletions(-)
> > 
> > diff --git a/util/uri.c b/util/uri.c
> > index 278e876ab8b1..48f7298787b1 100644
> > --- a/util/uri.c
> > +++ b/util/uri.c
> > @@ -105,18 +105,18 @@ static void uri_clean(URI *uri);
> >   */
> >  
> >  #define IS_UNWISE(p)                                                       
> >     \
> > -      (((*(p) == '{')) || ((*(p) == '}')) || ((*(p) == '|')) ||            
> >     \
> > -       ((*(p) == '\\')) || ((*(p) == '^')) || ((*(p) == '[')) ||           
> >     \
> > -       ((*(p) == ']')) || ((*(p) == '`')))
> > +    (((*(p) == '{')) || ((*(p) == '}')) || ((*(p) == '|')) ||              
> >     \
> > +     ((*(p) == '\\')) || ((*(p) == '^')) || ((*(p) == '[')) ||             
> >     \
> > +     ((*(p) == ']')) || ((*(p) == '`')))
> >  /*
> >   * reserved = ";" | "/" | "?" | ":" | "@" | "&" | "=" | "+" | "$" | "," |
> >   *            "[" | "]"
> >   */
> >  
> >  #define IS_RESERVED(x) (((x) == ';') || ((x) == '/') || ((x) == '?') ||    
> >     \
> > -        ((x) == ':') || ((x) == '@') || ((x) == '&') || ((x) == '=') ||    
> >     \
> > -        ((x) == '+') || ((x) == '$') || ((x) == ',') || ((x) == '[') ||    
> >     \
> > -        ((x) == ']'))
> > +      ((x) == ':') || ((x) == '@') || ((x) == '&') || ((x) == '=') ||      
> >     \
> > +      ((x) == '+') || ((x) == '$') || ((x) == ',') || ((x) == '[') ||      
> >     \
> > +      ((x) == ']'))
> 
> The above whitespace changes should ideally be done in the first patch 
> instead.
> 
> >  /*
> >   * unreserved = alphanum | mark
> > @@ -211,15 +211,17 @@ static int rfc3986_parse_scheme(URI *uri, const char 
> > **str)
> >  {
> >      const char *cur;
> >  
> > -    if (str == NULL)
> > +    if (str == NULL) {
> >          return -1;
> > +    }
> >  
> >      cur = *str;
> > -    if (!ISA_ALPHA(cur))
> > +    if (!ISA_ALPHA(cur)) {
> >          return 2;
> > +    }
> >      cur++;
> > -    while (ISA_ALPHA(cur) || ISA_DIGIT(cur) ||
> > -           (*cur == '+') || (*cur == '-') || (*cur == '.'))
> > +    while (ISA_ALPHA(cur) || ISA_DIGIT(cur) || (*cur == '+') || (*cur == 
> > '-') ||
> > +           (*cur == '.'))
> >          cur++;
> 
> You've changed the while statement, but checkpatch.pl apparently does not
> complain about missing curly braces here ... that's strange, I thought we'd
> also wanted to enforce curly braces for while loops. Anyway, could you please
> add curly braces around the "*cur++;" here, too?
> 
> > @@ -1437,15 +1503,18 @@ done_cd:
> >          /* string will overlap, do not use strcpy */
> >          tmp = cur;
> >          segp += 3;
> > -        while ((*tmp++ = *segp++) != 0)
> > +        while ((*tmp++ = *segp++) != 0) {
> >              ;
> > +        }
> 
> A bikeshed-painting-friday question for everybody on qemu-devel:
> Should there be a single semicolon inside curly braces in this case, or not?
> 
> >          /* If there are no previous segments, then keep going from here.  
> > */
> >          segp = cur;
> > -        while ((segp > path) && ((--segp)[0] == '/'))
> > +        while ((segp > path) && ((--segp)[0] == '/')) {
> >              ;
> 
> (dito)
> 
> > -        if (segp == path)
> > +        }
> > +        if (segp == path) {
> >              continue;
> > +        }
> >  
> >          /* "segp" is pointing to the end of a previous segment; find it's
> >           * start.  We need to back up to the previous segment and start
> [...]
> > @@ -1491,8 +1562,9 @@ done_cd:
> >  static int is_hex(char c)
> >  {
> >      if (((c >= '0') && (c <= '9')) || ((c >= 'a') && (c <= 'f')) ||
> > -        ((c >= 'A') && (c <= 'F')))
> > +        ((c >= 'A') && (c <= 'F'))) {
> >          return 1;
> > +    }
> >      return 0;
> >  }
> 
> Not related to your patch, but an idea for a future clean-up patch:
> We've already got qemu_isxdigit(), so there is no real need for this
> separate is_hex() function.
> 
> [...]
> > @@ -2020,17 +2127,19 @@ char *uri_resolve_relative(const char *uri, const 
> > char *base)
> >           */
> >          if (bptr[pos] != ref->path[pos]) { /* check for trivial URI == 
> > base */
> >              for (; bptr[ix] != 0; ix++) {
> > -                if (bptr[ix] == '/')
> > +                if (bptr[ix] == '/') {
> >                      nbslash++;
> > +                }
> >              }
> >          }
> >          len = strlen(uptr) + 1;
> >      }
> >  
> >      if (nbslash == 0) {
> > -        if (uptr != NULL)
> > +        if (uptr != NULL) {
> >              /* exception characters from uri_to_string */
> > -            val = uri_string_escape(uptr, "/;&=+$,");
> > +        }
> > +        val = uri_string_escape(uptr, "/;&=+$,");
> 
> That's a bug: uri_string_escape() should be within the curly braces instead.
> 
> By the way, found that one with the following trick: Compare the disassemblies
> before and after you're changes:
> 
>  git checkout master
>  make util/uri.o
>  strip util/uri.o
>  objdump -Drx util/uri.o > /tmp/uri-master.txt
>  git checkout cleanupbranch
>  make util/uri.o
>  strip util/uri.o
>  objdump -Drx util/uri.o > /tmp/uri-cleanup.txt
>  diff -u /tmp/uri-*.txt
> 
> Since you're only doing coding style clean-up, there should not be
> any diff in the resulting assembler code.
> 
>  Cheers,
>   Thomas