Re: warning options

[Bruno Haible]

I wrote:
> Thanks. I've updated my build script to include these for glibc/x86 builds
> (except -Werror, which causes a configuration error already in
> "checking whether the compiler works...").

But now I see the warnings coming out.

I won't use -Wold-style-definition and -Wstrict-prototypes because it leads
to pointless warnings in lib/:

glob.c:258:1: warning: old-style function definition [-Wold-style-definition]
glob.c:1096:1: warning: old-style function definition [-Wold-style-definition]
glob.c:1193:1: warning: old-style function definition [-Wold-style-definition]
glob.c:1232:1: warning: old-style function definition [-Wold-style-definition]
fatal-signal.c:135:1: warning: function declaration isn’t a prototype 
[-Wstrict-prototypes]
fatal-signal.c:135:1: warning: old-style function definition 
[-Wold-style-definition]
fatal-signal.c:180:1: warning: function declaration isn’t a prototype 
[-Wstrict-prototypes]
fatal-signal.c:180:1: warning: old-style function definition 
[-Wold-style-definition]
fatal-signal.c:254:1: warning: function declaration isn’t a prototype 
[-Wstrict-prototypes]
fatal-signal.c:254:1: warning: old-style function definition 
[-Wold-style-definition]
fatal-signal.c:274:1: warning: old-style function definition 
[-Wold-style-definition]
fatal-signal.c:282:1: warning: old-style function definition 
[-Wold-style-definition]

and hundreds of warnings in tests/. Most of them pointless, because an empty
function argument list (in a function definition!) is equivalent to (void).
Nothing to warn about.

I also won't use -Wunused-macros since it produces warnings that are pointless
to fix:

printf-frexp.c:63:0: warning: macro "L_" is not used
tempname.c:70:0: warning: macro "__open64" is not used
tempname.c:72:0: warning: macro "__xstat64" is not used
fnmatch.c:171:0: warning: macro "STRCOLL" is not used
fnmatch.c:199:0: warning: macro "STRCOLL" is not used
fnmatch.c:91:0: warning: macro "STREQ" is not used
getcwd.c:86:0: warning: macro "__opendir" is not used
glob.c:148:0: warning: macro "__stat" is not used
glob.c:151:0: warning: macro "__readdir64" is not used
glob.c:73:0: warning: macro "DIRENT_MUST_BE" is not used
strerror_r.c:23:0: warning: macro "_NETBSD_SOURCE" is not used
vasnprintf.c:145:0: warning: macro "DCHAR_SET" is not used
vasnprintf.c:210:0: warning: macro "remainder" is not used
vasnprintf.c:208:0: warning: macro "exp" is not used
vasnprintf.c:273:0: warning: macro "decimal_point_char_defined" is not used

-Wstrict-overflow give spurious warnings with gcc 4.5:

utimecmp.c:279:14: warning: assuming signed overflow does not occur when 
simplifying conditional to constant [-Wstrict-overflow]

Even -Wshadow fires back unreasonably:

fma.c:393:26: warning: declaration of ‘yn’ shadows a global declaration 
[-Wshadow]

And -Wtype-limits warnings in dead code are not useful either:

fma.c:172:7: warning: comparison of unsigned expression < 0 is always false 
[-Wtype-limits]
fma.c:210:7: warning: comparison of unsigned expression < 0 is always false 
[-Wtype-limits]
fma.c:248:7: warning: comparison of unsigned expression < 0 is always false 
[-Wtype-limits]


The fallout is small:


2011-11-20  Bruno Haible  <address@hidden>

        fma: Remove unused code.
        * lib/fma.c (DECL_ROUNDING, BEGIN_ROUNDING, END_ROUNDING): Remove
        unused macros.

--- lib/fma.c.orig      Sun Nov 20 15:51:09 2011
+++ lib/fma.c   Sun Nov 20 15:44:00 2011
@@ -41,9 +41,6 @@
 # define LDEXP ldexpl
 # define MIN_EXP LDBL_MIN_EXP
 # define MANT_BIT LDBL_MANT_BIT
-# define DECL_ROUNDING DECL_LONG_DOUBLE_ROUNDING
-# define BEGIN_ROUNDING() BEGIN_LONG_DOUBLE_ROUNDING ()
-# define END_ROUNDING() END_LONG_DOUBLE_ROUNDING ()
 # define L_(literal) literal##L
 #elif ! defined USE_FLOAT
 # define FUNC fma
@@ -52,9 +49,6 @@
 # define LDEXP ldexp
 # define MIN_EXP DBL_MIN_EXP
 # define MANT_BIT DBL_MANT_BIT
-# define DECL_ROUNDING
-# define BEGIN_ROUNDING()
-# define END_ROUNDING()
 # define L_(literal) literal
 #else /* defined USE_FLOAT */
 # define FUNC fmaf
@@ -63,9 +57,6 @@
 # define LDEXP ldexpf
 # define MIN_EXP FLT_MIN_EXP
 # define MANT_BIT FLT_MANT_BIT
-# define DECL_ROUNDING
-# define BEGIN_ROUNDING()
-# define END_ROUNDING()
 # define L_(literal) literal##f
 #endif
 

-- 
In memoriam Kerem Yılmazer <http://en.wikipedia.org/wiki/Kerem_Yılmazer>