Object files (or object code) are machine code files generated by a compiler from source code. The difference with an executable is that the object file isn’t linked, so references to functions, symbols, etc aren’t defined yet (their memory addresses is basically left blank). When you compile a C file with GCC: gcc -Wall -o … Read more
You do something along these lines if( CMAKE_SIZEOF_VOID_P EQUAL 8 ) set( BOOST_LIBRARY “/boost/win64/lib” ) else( CMAKE_SIZEOF_VOID_P EQUAL 8 ) set( BOOST_LIBRARY “/boost/win32/lib” ) endif( CMAKE_SIZEOF_VOID_P EQUAL 8 ) set( CMAKE_EXE_LINKER_FLAGS ${BOOST_LIBRARY} )
load-time linking is when symbols in the library, referenced by the executable (or another library) are handled when the executable/library is loaded into memory, by the operating system. Run-time linking is when you use an API provided by the OS or through a library to load a DLL or DSO when you need it, and … Read more
The problem is coming from the linker, ld, rather than gcc (hence the exit status message). In general ld requires objects and libraries to be specified in the order user supplier, where user is an object that uses a library function and supplier is the object which provides it. When your test.c is compiled to … Read more
C++ requires that an inline function definition be present in a translation unit that references the function. Template member functions are implicitly inline, but also by default are instantiated with external linkage. Hence the duplication of definitions that will be visible to the linker when the same template is instantiated with the same template arguments … Read more
Answering my own question because I just earned a Tumbleweed badge for it… and I found out subsequently But I was wondering whether there is perhaps a finer-grained control over this, like overwriting -Bsymbolic for individual function definitions of a library. Yes, there is the option –dynamic-list which does exactly that Should I be aware … Read more
According to the docs: This instructs the linker to add all symbols, not only used ones, to the dynamic symbol table. Those are not debug symbols, they are dynamic linker symbols. Those are not removed by strip since it would (in most cases) break the executable – they are used by the runtime linker to … Read more
extern means that the entity has external linkage, i.e. is visible outside its translation unit (C or CPP file). The implication of this is that a corresponding symbol will be placed in the object file, and it will hence also be visible if this object file is made part of a static library. However, extern … Read more
A .LIB file is a collection of .OBJ files concatenated together with an index. There should be no difference in how the linker treats either.