# This is a shell archive.  Save it in a file, remove anything before
# this line, and then unpack it by entering "sh file".  Note, it may
# create directories; files and directories will be owned by you and
# have default permissions.
#
# This archive contains:
#
#	Makefile
#	common
#	common/classes.cc
#	common/classes.h
#	lib
#	lib/Makefile
#	lib/downcast.cc
#	prog
#	prog/Makefile
#	prog/dynamic_cast.1
#	prog/dynamic_cast.cc
#
echo x - Makefile
sed 's/^X//' >Makefile << 'b67911656ef5d18c4ae36cb6741b7965'
XSUBDIR=lib prog
X
Xrun::
X	/usr/bin/env LD_LIBRARY_PATH=${.OBJDIR}/lib:${LD_LIBRARY_PATH} ${.OBJDIR}/prog/dynamic_cast
X
X.include <bsd.subdir.mk>
b67911656ef5d18c4ae36cb6741b7965
echo c - common
mkdir -p common > /dev/null 2>&1
echo x - common/classes.cc
sed 's/^X//' >common/classes.cc << 'a07ef8e0bbcd013b1ad299f7d8b2489a'
X#include "classes.h"
X
Xint Parent::something(void) { return 1; }
Xint Child::something(void) { return 2; }
a07ef8e0bbcd013b1ad299f7d8b2489a
echo x - common/classes.h
sed 's/^X//' >common/classes.h << '8bd6b113f0957a684f12533972e2849f'
Xclass Parent {
X  public:
X    virtual int something(void);
X};
Xclass Child : public Parent {
X  public:
X    virtual int something(void);
X};
8bd6b113f0957a684f12533972e2849f
echo c - lib
mkdir -p lib > /dev/null 2>&1
echo x - lib/Makefile
sed 's/^X//' >lib/Makefile << '94e18c7e8b5bab8a1215265cdb5ca1f4'
XSRCDIR=		${.CURDIR}/../common
X
XSHLIB_MAJOR=	1
X
X.PATH: ${SRCDIR}
X
XLIB=		dynamic_cast
X
XSRCS+=		\
X    classes.cc \
X    downcast.cc
X
XWARNS=		9
XCXXFLAGS+=	-I${SRCDIR}
X
X.include <bsd.lib.mk>
94e18c7e8b5bab8a1215265cdb5ca1f4
echo x - lib/downcast.cc
sed 's/^X//' >lib/downcast.cc << '83e7bd6954b57f3f10f791ff49167079'
X#include <classes.h>
X
X#if __cplusplus
Xextern "C" int runsomething(Parent *ptr);
Xextern "C" void *downcast(Parent *ptr);
X#endif
X
Xint
Xrunsomething(Parent *ptr)
X{
X  return ptr->something();
X}
X
Xvoid *
Xdowncast(Parent *ptr)
X{
X  Child *n = dynamic_cast<Child *>(ptr);
X  return n;
X}
83e7bd6954b57f3f10f791ff49167079
echo c - prog
mkdir -p prog > /dev/null 2>&1
echo x - prog/Makefile
sed 's/^X//' >prog/Makefile << '10dda222a2d60d4d7795f25f4761aac9'
XSRCDIR=   ${.CURDIR}/../common
X
X.PATH: ${SRCDIR}
X
XPROG= dynamic_cast
XPROG_CXX:= ${PROG}
X
XSRCS+= \
X	classes.cc \
X	dynamic_cast.cc 
X
X
XCFLAGS+= -I${SRCDIR}
XCXXFLAGS+=	-std=c++11
X
XWARNS= 9
X
X.include <bsd.prog.mk>
X
XTARGET_OSNAME ?= BSD
X.if ${TARGET_OSNAME} == "Linux"
X_CCLINK= ${CXX}
XLDADD += -ldl
X.endif
X
10dda222a2d60d4d7795f25f4761aac9
echo x - prog/dynamic_cast.1
sed 's/^X//' >prog/dynamic_cast.1 << '862ebc4528faab8809aa13cd743cdf1f'
X.Dd July 20, 2015
X.Dt dynamic_cast 1
X.Os
X.Sh NAME
X.Nm dynamic_cast
X.Nd Test C++ dynamic_cast feature of the runtime C++11 library
X.Sh SYNOPSIS
X.Nm
X.Sh DESCRIPTION
XThis utility tests how C++ 
X.Fn dynamic_cast<Child*>
Xcasting works across shared modules linked at run-time.
X.Pp
XDowncasting is an attempt to cast a pointer of the value of a base class
Xto the value of a derived class, provided the runtime type information
X(RTTI) is provided. The
X.Fn dynamic_cast
Xoperator fails if the object is not an intance of a derived class.
X.Pp
XIn this example downcasting is attempted in one module as well
Xas via the library provided at run-time.
X.Sh AUTHOR
XMarcin Cieslak <saper@saper.info>
862ebc4528faab8809aa13cd743cdf1f
echo x - prog/dynamic_cast.cc
sed 's/^X//' >prog/dynamic_cast.cc << 'fdbd0639903ecb20c6c82f358a55b0fc'
X#include <dlfcn.h>
X#include <stdio.h>
X#include <sysexits.h>
X
X#include "classes.h"
X
Xstatic const char *libpath = "libdynamic_cast.so";
Xint
Xmain()
X{
X  void *lib, *sym;
X  Parent obj1 = Parent();
X  Child  obj2 = Child();
X  Parent *objptr1 = &obj1;
X  Parent *objptr2 = &obj2;
X  if ((lib = dlopen(libpath, RTLD_LAZY))) {
X    if ((sym = dlsym(lib, "runsomething"))) {
X      printf("Parent::something() = %d\n", (*(int(*)(Parent *))sym)(objptr1));
X      printf("Child::something() = %d\n", (*(int(*)(Parent *))sym)(objptr2));
X    } else {
X      fprintf(stderr, "dlsym(\"runsomething\"): %s\n", dlerror());
X      return EX_SOFTWARE;
X    }
X    if ((sym = dlsym(lib, "downcast"))) {
X      printf("library dynamic_cast<Child *>(Parent *) = %p\n",
X            (*(void *(*)(Parent *))sym)(objptr1));
X      printf("library dynamic_cast<Child *>(Child *) = %p\n",
X            (*(void *(*)(Parent *))sym)(objptr2));
X      printf("local dynamic_cast<Child *>(Parent *) = %p\n",
X            dynamic_cast<Child *>(objptr1));
X      printf("local dynamic_cast<Child *>(Child *) = %p\n",
X            dynamic_cast<Child *>(objptr2));
X    } else {
X      fprintf(stderr, "dlsym(\"downcast\"): %s\n", dlerror());
X      return EX_SOFTWARE;
X    }
X    return 0;
X  } else {
X    fprintf(stderr, "dlopen: %s\n", dlerror());
X    return EX_SOFTWARE;
X  }
X}
fdbd0639903ecb20c6c82f358a55b0fc
exit