Bug 996714

Summary: Invalid -Wno-xxxx flags are only reported in code generating other unrelated warnings
Product: [Fedora] Fedora Reporter: Christophe Fergeau <cfergeau>
Component: gccAssignee: Jakub Jelinek <jakub>
Status: CLOSED NOTABUG QA Contact: Fedora Extras Quality Assurance <extras-qa>
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Version: 19CC: jakub, law
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Last Closed: 2013-08-13 19:05:45 UTC Type: Bug
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Description Christophe Fergeau 2013-08-13 19:01:34 UTC 
Using gcc-4.8.1-1.fc19.x86_64 (but I've seen it with rhel6 gcc as well):

$ touch foo.c (works with a regular C program as well such as an hello world)
$ gcc -Wbadflag -c ./foo.c
gcc: error: unrecognized command line option '-Wbadflag'
$ gcc -Wno-badflag -c ./foo.c
$

$ echo '#warning foo' >>foo.c
$ gcc -Wno-badflag -c ./foo.c
./foo.c:1:2: warning: #warning foo [-Wcpp]
 #warning foo
  ^
cc1: warning: unrecognized command line option "-Wno-badflag" [enabled by default]

Expected result: -Wno-badflag and -Wbadflag gives the same result when they are used on a C file not producing any warnings (in this case, an empty foo.c).
Comment 1 Jakub Jelinek 2013-08-13 19:05:45 UTC 
That is intentional, design decision, even documented in gcc documentation.