[lmi] 'Wconversion' warnings with xmlwrapp and x86_64 gcc-8.3

[Greg Chicares]

I don't know why I didn't notice this before. It occurs only with
x86_64 (not production), not with i686 (production). Probably I
should just suppress the warning for this library.

x86_64-w64-mingw32-g++ -MMD -MP -MT xml_xslt_wrapp.o -MF xml_xslt_wrapp.d  -c 
-I /opt/lmi/src/lmi -I /opt/lmi/src/lmi/tools/pete-2.1.1 -I 
/opt/lmi/third_party/src -isystem 
/opt/lmi/local/gcc_x86_64-w64-mingw32/lib/wx/include/x86_64-w64-mingw32-msw-unicode-3.1
 -isystem /opt/lmi/local/include/wx-3.1 -isystem /opt/lmi/third_party/include 
-isystem /opt/lmi/local/include -isystem /opt/lmi/local/include/libxml2 
-DLMI_WX_NEW_USE_SO  -DLIBXML_USE_DLL -DSTRICT    -D_FILE_OFFSET_BITS=64 
-DWXUSINGDLL -D__WXMSW__ -D_FILE_OFFSET_BITS=64 -DBOOST_NO_AUTO_PTR 
-DBOOST_NO_STD_ALLOCATOR -DBOOST_STRICT_CONFIG -DBOOST_STATIC_ASSERT_HPP   
-fno-ms-extensions -frounding-math -std=c++17 -pedantic-errors -Werror -Wall 
-Walloc-zero -Walloca -Wcast-align -Wcast-function-type -Wconversion 
-Wdangling-else -Wdeprecated-declarations -Wdisabled-optimization 
-Wdouble-promotion -Wduplicated-branches -Wduplicated-cond -Wextra 
-Wformat-nonliteral -Wformat-security -Wformat-signedness -Wformat-y2k -Wimport 
-Winit-self -Winvalid-pch -Wlogical-op -Wmissing-include-dirs -Wmultichar 
-Wnull-dereference -Wpacked -Wpointer-arith -Wredundant-decls -Wrestrict 
-Wshadow -Wsign-compare -Wstack-protector -Wswitch-enum -Wtrampolines -Wundef 
-Wunreachable-code -Wunused-macros -Wvector-operation-performance 
-Wwrite-strings -Wno-parentheses  -Wc++11-compat -Wc++14-compat -Wc++1z-compat 
-Wcatch-value=3 -Wconditionally-supported -Wctor-dtor-privacy 
-Wdelete-non-virtual-dtor -Wdeprecated -Wextra-semi -Wnoexcept -Wnoexcept-type 
-Wnon-template-friend -Wnon-virtual-dtor -Wold-style-cast -Woverloaded-virtual 
-Wplacement-new=2 -Wpmf-conversions -Wregister -Wreorder -Wstrict-null-sentinel 
-Wsuggest-override -Wsynth -Wuseless-cast -Wzero-as-null-pointer-constant  
-Wcast-qual    -D'BOOST_STATIC_ASSERT(A)=static_assert((A))'   -ggdb -O2 
-fno-omit-frame-pointer   -fomit-frame-pointer 
/opt/lmi/src/lmi/xml_xslt_wrapp.cpp -oxml_xslt_wrapp.o
In file included from /opt/lmi/third_party/src/libxml/ait_impl.h:39,
                 from /opt/lmi/third_party/src/libxml/ait_impl.cxx:34,
                 from /opt/lmi/src/lmi/xml_xslt_wrapp.cpp:34:
/opt/lmi/third_party/src/libxml/pimpl_base.h: In static member function ‘static 
void* xml::impl::pi
mpl_base<T>::operator new(size_t)’:
/opt/lmi/third_party/src/libxml/pimpl_base.h:61:50: error: conversion from 
‘long long unsigned int’ to ‘unsigned int’ may change value [-Werror=conversion]
         boost::singleton_pool<xmlwrapp_pool_tag, sizeof(T)>
                                                  ^~~~~~~~~
/opt/lmi/third_party/src/libxml/pimpl_base.h:66:16: note: in expansion of macro 
‘XMLWRAPP_PIMPL_ALLOCATOR_TYPE’
         return XMLWRAPP_PIMPL_ALLOCATOR_TYPE(T)::malloc();
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/opt/lmi/third_party/src/libxml/pimpl_base.h: In static member function ‘static 
void xml::impl::pimpl_base<T>::operator delete(void*, size_t)’:
/opt/lmi/third_party/src/libxml/pimpl_base.h:61:50: error: conversion from 
‘long long unsigned int’ to ‘unsigned int’ may change value [-Werror=conversion]
         boost::singleton_pool<xmlwrapp_pool_tag, sizeof(T)>
                                                  ^~~~~~~~~
/opt/lmi/third_party/src/libxml/pimpl_base.h:73:13: note: in expansion of macro 
‘XMLWRAPP_PIMPL_ALLOCATOR_TYPE’
             XMLWRAPP_PIMPL_ALLOCATOR_TYPE(T)::free(ptr);
             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /opt/lmi/src/lmi/xml_xslt_wrapp.cpp:39:
/opt/lmi/third_party/src/libxml/event_parser.cxx: In member function ‘bool 
xml::event_parser::parse_chunk(const char*, xml::event_parser::size_type)’:
/opt/lmi/third_party/src/libxml/event_parser.cxx:403:51: error: conversion from 
‘xml::event_parser::size_type’ {aka ‘long long unsigned int’} to ‘int’ may 
change value [-Werror=conversion]
     xmlParseChunk(pimpl_->parser_context_, chunk, length, 0);
                                                   ^~~~~~
In file included from /opt/lmi/src/lmi/xml_xslt_wrapp.cpp:41:
/opt/lmi/third_party/src/libxml/node.cxx: In constructor 
‘xml::node::node(xml::node::cdata)’:
/opt/lmi/third_party/src/libxml/node.cxx:324:109: error: conversion from 
‘size_t’ {aka ‘long long unsigned int’} to ‘int’ may change value 
[-Werror=conversion]
     if ( (pimpl_->xmlnode_ = xmlNewCDataBlock(0, reinterpret_cast<const 
xmlChar*>(cdata_info.t), std::strlen(cdata_info.t))) == 0)
                                                                                
                  ~~~~~~~~~~~^~~~~~~~~~~~~~
In file included from /opt/lmi/src/lmi/xml_xslt_wrapp.cpp:47:
/opt/lmi/third_party/src/libxml/tree_parser.cxx: In member function ‘void 
xml::tree_parser::init(const char*, xml::tree_parser::size_type, 
xml::error_handler*)’:
/opt/lmi/third_party/src/libxml/tree_parser.cxx:202:50: error: conversion from 
‘xml::tree_parser::size_type’ {aka ‘long long unsigned int’} to ‘int’ may 
change value [-Werror=conversion]
     if ( (ctxt = xmlCreateMemoryParserCtxt(data, size)) == 0)
                                                  ^~~~
cc1plus: all warnings being treated as errors
make[1]: *** [/opt/lmi/src/lmi/workhorse.make:918: xml_xslt_wrapp.o] Error 1