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Re: Implement -Wimplicit-fallthrough (version 9)
On Tue, Sep 27, 2016 at 10:13 AM, Jakub Jelinek <jakub@redhat.com> wrote:
> On Tue, Sep 27, 2016 at 10:03:10AM +0200, Andreas Schwab wrote:
>> This breaks building with gcc-4.3.
>>
>> g++ -std=gnu++98 -fno-PIE -c -DUSE_LIBUNWIND_EXCEPTIONS -g -DIN_GCC -fno-exceptions -fno-rtti -fasynchronous-unwind-tables -W -Wall -Wwrite-strings -Wcast-qual -Wno-format -Wmissing-format-attribute -Woverloaded-virtual -pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -Wno-implicit-fallthrough -DHAVE_CONFIG_H -I. -I. -I../../gcc -I../../gcc/. -I../../gcc/../include -I../../gcc/../libcpp/include -I../../gcc/../libdecnumber -I../../gcc/../libdecnumber/dpd -I../libdecnumber -I../../gcc/../libbacktrace -o insn-emit.o -MT insn-emit.o -MMD -MP -MF ./.deps/insn-emit.TPo insn-emit.c
>> cc1plus: error: unrecognized command line option "-Wno-implicit-fallthrough"
>> make[3]: *** [insn-emit.o] Error 1
>
> Guess it must have been some mistake against the policy that unknown -Wno-*
> options aren't complained about, unless something else is diagnosed.
>
> Anyway, Marek, can you add configure check for that?
Existing practice is to instead use -Wno-error rather than warning
flags that were not present in those early GCC versions.
Richard.
> Jakub