Re: C++ cleanup : get rid of some compilation warnings (issue 353880043 by address@hidden)

[David Kastrup]

John Mandereau <address@hidden> writes:

> address@hidden wrote:
>
>> page-turn-page-breaking.cc: In instantiation of 'bool is_break(T*)
>> [with
>> T = Grob]':
>> page-turn-page-breaking.cc:50:54:   required from here
>> page-turn-page-breaking.cc:38:3: warning: operation on '*0' may be
>> undefined [-Wsequence-point]
>>     if (turnable
>>     ^~
>> page-turn-page-breaking.cc: In instantiation of 'bool is_break(T*)
>> [with
>> T = Prob]':
>> page-turn-page-breaking.cc:50:54:   required from here
>> page-turn-page-breaking.cc:38:3: warning: operation on '*0' may be
>> undefined [-Wsequence-point]
>
>
> FWIW I get this warning as well (building on Fedora 29 with GCC 8.2.1).

touch lily/page-turn-page-breaking.cc
CPU_COUNT=9 make -j9
[...]
make[1]: Leaving directory '/usr/local/tmp/lilypond/flower'
make[1]: Entering directory '/usr/local/tmp/lilypond/lily'
rm -f ./out/page-turn-page-breaking.dep; 
DEPENDENCIES_OUTPUT="./out/page-turn-page-breaking.dep 
./out/page-turn-page-breaking.o" g++ -c -Woverloaded-virtual  
-I/usr/include/python2.7 -I/usr/include/x86_64-linux-gnu/python2.7  
-fno-strict-aliasing -g 
-fdebug-prefix-map=/build/python2.7-YmcQQ3/python2.7-2.7.15=. 
-fstack-protector-strong  -g -fwrapv  -DHAVE_CONFIG_H  -DDEBUG -I./include 
-I./out -I../flower/include -I../flower/./out -I../flower/include  -O2 
-finline-functions -g -pipe -Wno-cast-function-type 
-I/usr/local/tmp/guile-1.8/include  -pthread -I/usr/include/freetype2 
-I/usr/include/libpng16 -I/usr/include/pango-1.0 -I/usr/include/harfbuzz 
-I/usr/include/pango-1.0 -I/usr/include/fribidi -I/usr/include/glib-2.0 
-I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/uuid 
-I/usr/include/freetype2 -I/usr/include/libpng16  -W -Wall -Wconversion -o 
out/page-turn-page-breaking.o page-turn-page-breaking.cc
make -C ../flower &&  true
make[2]: Entering directory '/usr/local/tmp/lilypond/flower'
true
make[2]: Leaving directory '/usr/local/tmp/lilypond/flower'
[...]
g++ --version
g++ (Ubuntu 8.2.0-21ubuntu1) 8.2.0

head config.log
This file contains any messages produced by compilers while
running configure, to aid debugging if configure makes a mistake.

It was created by configure, which was
generated by GNU Autoconf 2.69.  Invocation command line was

  $ ./configure GUILE_CONFIG=/usr/local/tmp/guile-1.8/bin/guile-config 
--enable-checking --no-create --no-recursion

## --------- ##
## Platform. ##


Huh.  Maybe the Ubuntu compilation of gcc/g++ disabled some warnings?

g++ --verbose
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/8/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 8.2.0-21ubuntu1' 
--with-bugurl=file:///usr/share/doc/gcc-8/README.Bugs 
--enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++ --prefix=/usr 
--with-gcc-major-version-only --program-suffix=-8 
--program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id 
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix 
--libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu 
--enable-libstdcxx-debug --enable-libstdcxx-time=yes 
--with-default-libstdcxx-abi=new --enable-gnu-unique-object 
--disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie 
--with-system-zlib --with-target-system-zlib --enable-objc-gc=auto 
--enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 
--with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic 
--enable-offload-targets=nvptx-none --without-cuda-driver 
--enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu 
--target=x86_64-linux-gnu
Thread model: posix
gcc version 8.2.0 (Ubuntu 8.2.0-21ubuntu1) 

Huh.  No idea.

-- 
David Kastrup