Encode produces copious warnings during build under gcc

[demerphq]

Module:
Encode aka cpan/Encode

Description
During build Encode in core produces copious warnings due to -Wc++-compat

byte_t.c:10394:24: warning: duplicate declaration of ‘utf8_viscii’ is invalid in C++ [-Wc++-compat]
10394 | static const encpage_t utf8_viscii[12] = {
      |                        ^~~~~~~~~~~
byte_t.c:322:24: note: previous declaration of ‘utf8_viscii’ was here
  322 | static const encpage_t utf8_viscii[];
      |                        ^~~~~~~~~~~

These warnings are bogus as the code generator produces code which is tailored for C++ or C, and the C code that is being warned about simply isn't used in a C++ build.

gcc --version
gcc (Ubuntu 9.4.0-1ubuntu1~20.04.1) 9.4.0
Copyright (C) 2019 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Note this is a placeholder issue to record this for Perl, an issues exists for the upstream repo for this module:
dankogai/p5-encode#144

Steps to Reproduce
make

Expected behavior
No warnings.

Perl configuration

 ./perl -Ilib -V
Summary of my perl5 (revision 5 version 35 subversion 11) configuration:
  Derived from: 8cdf7451cf04f2fe6ab382f1dad065efb19b53a1
  Ancestor: 2caf82775aff58fd4599ee9fb0841a887715c56b
  Platform:
    osname=linux
    osvers=5.14.0-1032-oem
    archname=x86_64-linux-thread-multi
    uname='linux oncidium 5.14.0-1032-oem #35-ubuntu smp thu mar 31 12:49:29 utc 2022 x86_64 x86_64 x86_64 gnulinux '
    config_args='-des -Dusethreads -Dusedevel -DDEBUGGING'
    hint=recommended
    useposix=true
    d_sigaction=define
    useithreads=define
    usemultiplicity=define
    use64bitint=define
    use64bitall=define
    uselongdouble=undef
    usemymalloc=n
    default_inc_excludes_dot=define
  Compiler:
    cc='cc'
    ccflags ='-D_REENTRANT -D_GNU_SOURCE -fwrapv -DDEBUGGING -fno-strict-aliasing -pipe -fstack-protector-strong -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64'
    optimize='-O2 -g'
    cppflags='-D_REENTRANT -D_GNU_SOURCE -fwrapv -DDEBUGGING -fno-strict-aliasing -pipe -fstack-protector-strong -I/usr/local/include'
    ccversion=''
    gccversion='9.4.0'
    gccosandvers=''
    intsize=4
    longsize=8
    ptrsize=8
    doublesize=8
    byteorder=12345678
    doublekind=3
    d_longlong=define
    longlongsize=8
    d_longdbl=define
    longdblsize=16
    longdblkind=3
    ivtype='long'
    ivsize=8
    nvtype='double'
    nvsize=8
    Off_t='off_t'
    lseeksize=8
    alignbytes=8
    prototype=define
  Linker and Libraries:
    ld='cc'
    ldflags =' -fstack-protector-strong -L/usr/local/lib'
    libpth=/usr/local/lib /usr/lib/x86_64-linux-gnu /usr/lib /usr/lib64
    libs=-lpthread -lnsl -ldl -lm -lcrypt -lutil -lc
    perllibs=-lpthread -lnsl -ldl -lm -lcrypt -lutil -lc
    libc=libc-2.31.so
    so=so
    useshrplib=false
    libperl=libperl.a
    gnulibc_version='2.31'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs
    dlext=so
    d_dlsymun=undef
    ccdlflags='-Wl,-E'
    cccdlflags='-fPIC'
    lddlflags='-shared -O2 -g -L/usr/local/lib -fstack-protector-strong'


Characteristics of this binary (from libperl): 
  Compile-time options:
    DEBUGGING
    HAS_TIMES
    MULTIPLICITY
    PERLIO_LAYERS
    PERL_COPY_ON_WRITE
    PERL_DONT_CREATE_GVSV
    PERL_MALLOC_WRAP
    PERL_OP_PARENT
    PERL_PRESERVE_IVUV
    PERL_TRACK_MEMPOOL
    PERL_USE_DEVEL
    USE_64_BIT_ALL
    USE_64_BIT_INT
    USE_ITHREADS
    USE_LARGE_FILES
    USE_LOCALE
    USE_LOCALE_COLLATE
    USE_LOCALE_CTYPE
    USE_LOCALE_NUMERIC
    USE_LOCALE_TIME
    USE_PERLIO
    USE_PERL_ATOF
    USE_REENTRANT_API
    USE_THREAD_SAFE_LOCALE
  Locally applied patches:
    uncommitted-changes
    8cdf7451cf04f2fe6ab382f1dad065efb19b53a1
  Built under linux
  Compiled at Apr  5 2022 18:20:19
  %ENV:
    PERLBREW_CONFIGURE_FLAGS="-de -Dcc=ccache\ gcc -Dld=gcc"
    PERLBREW_HOME="/home/yorton/.perlbrew"
    PERLBREW_MANPATH="/home/yorton/perl5/perlbrew/perls/perl-5.34.1/man"
    PERLBREW_PATH="/home/yorton/perl5/perlbrew/bin:/home/yorton/perl5/perlbrew/perls/perl-5.34.1/bin"
    PERLBREW_PERL="perl-5.34.1"
    PERLBREW_ROOT="/home/yorton/perl5/perlbrew"
    PERLBREW_SHELLRC_VERSION="0.88"
    PERLBREW_VERSION="0.88"
  @INC:
    lib
    /usr/local/lib/perl5/site_perl/5.35.11/x86_64-linux-thread-multi
    /usr/local/lib/perl5/site_perl/5.35.11
    /usr/local/lib/perl5/5.35.11/x86_64-linux-thread-multi
    /usr/local/lib/perl5/5.35.11

[demerphq]

The fix is not merged yet, reopening until it is.

[jkeenan]

Module: Encode aka cpan/Encode

Description During build Encode in core produces copious warnings due to -Wc++-compat

byte_t.c:10394:24: warning: duplicate declaration of ‘utf8_viscii’ is invalid in C++ [-Wc++-compat]
10394 | static const encpage_t utf8_viscii[12] = {
      |                        ^~~~~~~~~~~
byte_t.c:322:24: note: previous declaration of ‘utf8_viscii’ was here
  322 | static const encpage_t utf8_viscii[];
      |                        ^~~~~~~~~~~

Note that this was first reported in #17014 three years ago. I look forward to this correction.

[demerphq]

On Wed, 6 Apr 2022 at 13:51, James E Keenan ***@***.***> wrote: Module: Encode aka cpan/Encode *Description* During build Encode in core produces copious warnings due to -Wc++-compat byte_t.c:10394:24: warning: duplicate declaration of ‘utf8_viscii’ is invalid in C++ [-Wc++-compat] 10394 | static const encpage_t utf8_viscii[12] = { | ^~~~~~~~~~~ byte_t.c:322:24: note: previous declaration of ‘utf8_viscii’ was here 322 | static const encpage_t utf8_viscii[]; | ^~~~~~~~~~~ Note that this was first reported in #17014 <#17014> three years ago. I look forward to this correction.

Me too. And some. It's up to Dan Kogai now. :-) Yves -- perl -Mre=debug -e "/just|another|perl|hacker/"

[demerphq]

Fixed with the merge of Encode 3.17.