This is the mail archive of the gdb@sources.redhat.com mailing list for the GDB project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: suggested compile warnings


Hi,

I've always been configuring gdb with --enable-gdb-build-warnings=-Werror
and thought that there where a bunch of gcc compile warnings issued.
Looking more closely at my builds, that doesn't seem to be true.

For my own apps, I like to use '-Wall -Werror' as it lets the compiler
catch a lot of my stupid mistakes. I tried '-Wall -Werror' for gdb,
but that seems to be too restrictive for gdb source.

Does anyone else compile gdb with any of the -W<foo> gcc options?
Is there a recommended list of these which should be used?

For example, adding -Wunused (without -Werror), turns up 149 wanrings.
Most are unused variables, some are static decl's for functions that
aren't defined. Most if not all of these should be trivial to fix.

See: 13.4.3 Compiler Warnings http://sources.redhat.com/gdb/current/onlinedocs/gdbint_13.html#SEC118

Instead of -Wunused, look at the individual -Wunused-function, -Wunused-variable, ...

Off hand, other intersting ones are:

-Wwrite-strings
It's just hard and really messy. People occasionally chip away at the edges. Last time I tried, I came across what appeared to be an effective xfree("string"), outch!


-W
More for the sign VS unsigned checks it throws up, but it throws up some non problems :-(


-Wswitch-default
-Wswitch-enum
-Wswitch-fallthrough (doesn't actually exist)
But that could be religious :-)

-Wstrict-prototypes
-Wmissing-prototypes
-Wmissing-declarations
But tread carefully, it tends to run a foul of head files.

The trick is to first identify warnings that add real value (-Wformat for instance is good++) and then ensure that the fix is not worse than the problem being identified (using a cast to hide a problem, for instance, isn't a good idea vis: xffree ((char *) "a string")).

I've appended an old list of the error counts for various flags that was generated by compiling all the cross targets on a Red Hat GNU/Linux 7.2 system and then deleting duplicates (which GCC? I don't remember).

Have fun.
Andrew

    590 W
    217 Waggregate-return
    335 Wall
      8 Wbad-function-cast
      4 Wcast-align
    106 Wcast-qual
      4 Wchar-subscripts
      4 Wcomment
   2913 Wconversion
      4 Wdeprecated-declarations
      4 Werror
     11 Wfloat-equal
      4 Wformat-extra-args
      4 Wformat-nonliteral
      4 Wformat-security
      4 Wformat-y2k
      4 Wformat
    109 Wformat=2
      7 Wimplicit-function-declaration
      4 Wimplicit-int
      7 Wimplicit
      4 Wimport
      4 Winline
      4 Wlong-long
      6 Wmain
     20 Wmissing-braces
    314 Wmissing-declarations
     57 Wmissing-noreturn
    341 Wmissing-prototypes
      4 Wmultichar
     51 Wnested-externs
      5 Wpacked
    101 Wpadded
      4 Wparentheses
      4 Wpointer-arith
    356 Wredundant-decls
      4 Wreturn-type
    840 Wshadow
    340 Wsign-compare
     74 Wstrict-prototypes
     44 Wswitch
    488 Wtraditional
      4 Wtrigraphs
     26 Wundef
      4 Wuninitialized
      4 Wunknown-pragmas
    213 Wunreachable-code
     66 Wunused-function
      8 Wunused-label
   1420 Wunused-parameter
     12 Wunused-value
    200 Wunused-variable
    274 Wunused
   4421 Wwrite-strings



Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]