<div dir="ltr">Hm, GCC never tries to import RTTI, so maybe it makes sense that we never export it. Anyway, there's a bug here. Maybe David knows what's up.</div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Aug 6, 2015 at 9:36 AM, Reid Kleckner <span dir="ltr"><<a href="mailto:rnk@google.com" target="_blank">rnk@google.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">I reproduced your example, and it looks like we are forgetting to export RTTI with dllexport in Itanium. We only export the vtable. This is what each compiler exports for ex_xml_exception.obj:<div><br></div><div><div>$ dumpbin -directives ex_xml_exception.clang.obj | grep -export:_ZT | c++filt --no-strip-underscore</div><div> -export:virtual thunk to ex_xml_exception::~ex_xml_exception()</div><div> -export:virtual thunk to ex_xml_exception::~ex_xml_exception()</div><div> -export:vtable for ex_xml_exception,data</div><div><br></div><div>$ dumpbin -directives ex_xml_exception.gcc.obj | grep -export:_ZT | c++filt --no-strip-underscore<br></div><div> -export:typeinfo for ex_exception,data</div><div> -export:typeinfo for ex_xml_exception,data</div><div> -export:construction vtable for ex_exception-in-ex_xml_exception,data</div><div> -export:VTT for ex_xml_exception,data</div><div> -export:vtable for ex_xml_exception,data</div><div> -export:virtual thunk to ex_xml_exception::~ex_xml_exception()</div><div> -export:virtual thunk to ex_xml_exception::~ex_xml_exception()</div></div><div><br></div><div>In your previous example where the whole class wasn't exported, I think we might be doing the wrong thing when the key function is dllimport / dllexport. We think that it will provide exported symbols for vtables and RTTI but it doesn't. This is something we didn't run into because the MSVC ABI doesn't have key functions.</div></div><div class="gmail_extra"><br><div class="gmail_quote"><div><div class="h5">On Thu, Aug 6, 2015 at 6:16 AM, Edward Diener <span dir="ltr"><<a href="mailto:eldlistmailingz@tropicsoft.com" target="_blank">eldlistmailingz@tropicsoft.com</a>></span> wrote:<br></div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div class="h5">
<div bgcolor="#FFFFFF" text="#000000">
<div style="font-family:-moz-fixed;font-size:14px" lang="x-unicode">Using clang on Windows
targeting mingw(-64)/gcc since it does not appear possible to
export individual member functions of a class, as well as export
the RTTI of the class, without exporting the entire class, I have
changed my example in my post "Linker error and obfuscated name"
to export the entire class itself. But I am still seeing a linker
error, Here is the changed code and command lines:
<br>
<br>
// ex_decl.hpp
<br>
<br>
#ifndef EX_DECL_HPP
<br>
#define EX_DECL_HPP
<br>
#if defined(BLD_EX_EXAMPLE)
<br>
#define EX_DECL __attribute__((__dllexport__))
<br>
#else
<br>
#define EX_DECL __attribute__((__dllimport__))
<br>
#endif
<br>
#endif // EX_DECL_HPP
<br>
<br>
// ex_exception.hpp
<br>
<br>
#ifndef EX_EXCEPTION_HPP
<br>
#define EX_EXCEPTION_HPP
<br>
#include <exception>
<br>
#include "ex_decl.hpp"
<br>
class EX_DECL ex_exception :
<br>
public virtual std::exception
<br>
{
<br>
private:
<br>
char m_buffer[128];
<br>
protected:
<br>
unsigned int append(unsigned int l, const char * a);
<br>
ex_exception() ;
<br>
public:
<br>
typedef enum {
<br>
no_exception,
<br>
other_exception
<br>
} ex_exception_code;
<br>
ex_exception_code code;
<br>
ex_exception(ex_exception_code c,const char * e1 = 0,const
char * e2 = 0) ;
<br>
ex_exception(ex_exception const &) ;
<br>
virtual ~ex_exception() throw() ;
<br>
virtual const char * what() const throw() ;
<br>
};
<br>
#endif // EX_EXCEPTION_HPP
<br>
<br>
// ex_exception.cpp
<br>
<br>
#include <exception>
<br>
#include <cstring>
<br>
#define BLD_EX_EXAMPLE
<br>
#include "ex_exception.hpp"
<br>
unsigned int ex_exception::append(unsigned int l, const char * a){
<br>
while(l < (sizeof(m_buffer) - 1)){
<br>
char c = *a++;
<br>
if('\0' == c)
<br>
break;
<br>
m_buffer[l++] = c;
<br>
}
<br>
m_buffer[l] = '\0';
<br>
return l;
<br>
}
<br>
ex_exception::ex_exception(ex_exception_code c,const char *
e1,const char * e2) : code(c)
<br>
{
<br>
unsigned int length = 0;
<br>
switch(code){
<br>
case no_exception:
<br>
length = append(length, "uninitialized exception");
<br>
break;
<br>
case other_exception:
<br>
length = append(length, "unknown derived exception");
<br>
break;
<br>
default:
<br>
length = append(length, "programming error");
<br>
break;
<br>
}
<br>
}
<br>
ex_exception::ex_exception(ex_exception const & oth) :
std::exception(oth),code(oth.code)
<br>
{
<br>
std::memcpy(m_buffer,oth.m_buffer,sizeof m_buffer);
<br>
}
<br>
ex_exception::~ex_exception() throw() {}
<br>
const char * ex_exception::what() const throw() { return m_buffer;
}
<br>
ex_exception::ex_exception() : code(no_exception) {}
<br>
<br>
// Compile ex_exception.cpp
<br>
<br>
clang++.exe -c -x c++ -D__MINGW_FORCE_SYS_INTRINS
-Wno-unused-local-typedef -Wno-dll-attribute-on-redeclaration -O0
-g -fno-inline -Wall -g -march=i686 -m32 -o "ex_exception.obj"
"ex_exception.cpp"
<br>
<br>
// ex_xml_exception.hpp
<br>
<br>
#ifndef EX_XML_EXCEPTION_HPP
<br>
#define EX_XML_EXCEPTION_HPP
<br>
#include <exception>
<br>
#include "ex_decl.hpp"
<br>
#include "ex_exception.hpp"
<br>
class EX_DECL ex_xml_exception :
<br>
public virtual ex_exception
<br>
{
<br>
public:
<br>
typedef enum {
<br>
xml_archive_parsing_error,
<br>
xml_archive_tag_mismatch,
<br>
xml_archive_tag_name_error
<br>
} ex_exception_code;
<br>
ex_xml_exception(ex_exception_code c,const char * e1 = 0,const
char * e2 = 0);
<br>
ex_xml_exception(ex_xml_exception const &) ;
<br>
virtual ~ex_xml_exception() throw() ;
<br>
};
<br>
#endif // EX_XML_EXCEPTION_HPP
<br>
<br>
// ex_xml_exception.cpp
<br>
<br>
#include <exception>
<br>
#define BLD_EX_EXAMPLE
<br>
#include "ex_xml_exception.hpp"
<br>
ex_xml_exception::ex_xml_exception(ex_exception_code c,const char
* e1,const char * e2) :
<br>
ex_exception(other_exception, e1, e2)
<br>
{
<br>
switch(c){
<br>
case xml_archive_parsing_error:
<br>
ex_exception::append(0, "unrecognized XML syntax");
<br>
break;
<br>
case xml_archive_tag_mismatch:
<br>
ex_exception::append(0, "XML start/end tag mismatch");
<br>
if(0 != e1){
<br>
ex_exception::append(0, " - ");
<br>
ex_exception::append(0, e1);
<br>
}
<br>
break;
<br>
case xml_archive_tag_name_error:
<br>
ex_exception::append(0, "Invalid XML tag name");
<br>
break;
<br>
default:
<br>
ex_exception::append(0, "programming error");
<br>
break;
<br>
}
<br>
}
<br>
ex_xml_exception::ex_xml_exception(ex_xml_exception const &
oth) : std::exception(oth),ex_exception(oth){}
<br>
ex_xml_exception::~ex_xml_exception() throw() {}
<br>
<br>
// Compile ex_xml_exception.cpp
<br>
<br>
clang++.exe -c -x c++ -D__MINGW_FORCE_SYS_INTRINS
-Wno-unused-local-typedef -Wno-dll-attribute-on-redeclaration -O0
-g -fno-inline -Wall -g -march=i686 -m32 -o "ex_xml_exception.obj"
"ex_xml_exception.cpp"
<br>
<br>
// Link exmp-clang37-d-1_59.dll
<br>
<br>
clang++.exe -o "exmp-clang37-d-1_59.dll" -Wl,-soname
-Wl,exmp-clang37-d-1_59.dll -shared -Wl,--start-group
"ex_exception.obj" "ex_xml_exception.obj" -Wl,-Bstatic
-Wl,-Bdynamic -Wl,--end-group -g -march=i686 -m32
<br>
<br>
// throw_exception_ex.cpp
<br>
<br>
#include "ex_xml_exception.hpp"
<br>
template<class E> void throw_exception(E const & e) {
throw e; }
<br>
int main(int argc,char * argv[])
<br>
{
<br>
if (argc > 1)
<br>
{
<br>
<br>
throw_exception(ex_xml_exception(ex_xml_exception::xml_archive_parsing_error));
<br>
}
<br>
return 0;
<br>
}
<br>
<br>
// Compile throw_exception_ex.cpp
<br>
<br>
clang++.exe -c -x c++ -D__MINGW_FORCE_SYS_INTRINS
-Wno-unused-local-typedef -Wno-dll-attribute-on-redeclaration -O0
-g -fno-inline -Wall -g -march=i686 -m32 -o
"throw_exception_ex.obj" "throw_exception_ex.cpp"
<br>
<br>
// Link thr_exmp.exe
<br>
<br>
clang++.exe -Wl,-R -Wl,"." -Wl,-rpath-link -Wl,"." -o
"thr_exmp.exe" -Wl,--start-group "throw_exception_ex.obj"
"exmp-clang37-d-1_59.dll" -Wl,-Bstatic -Wl,-Bdynamic
-Wl,--end-group -g -march=i686 -m32
<br>
<br>
// Error message from this link
<br>
<br>
throw_exception_ex.obj: In function
`Z15throw_exceptionI16ex_xml_exceptionEvRKT_':
<br>
throw_exception_ex.cpp:2: undefined reference to
`_imp___ZTI16ex_xml_exception'
<br>
clang++.exe: error: linker command failed with exit code 1 (use -v
to see invocation)
<br>
<br>
So even when I export/import the entire class rather than
individual member functions, I can not link my final module
successfully as it is still looking for something in the shared
library that it says is not there.
<br>
<br>
This same code succeeds without problem with mingw(-64)/gcc on
Windows.
<br>
</div>
</div>
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<br></blockquote></div><br></div>
</blockquote></div><br></div>