It depends a bit on what you want: A) If you want to specify which libraries to link to, you can use find_library to find libs and then use link_directories and target_link_libraries to. Of course, it is often worth the effort to write a good find_package script, which nicely adds “imported” libraries with add_library( YourLib … Read more
File type breakdown .so files are dynamic libraries. The suffix stands for “shared object”, because all the applications that are linked with the library use the same file, rather than making a copy in the resulting executable. .a files are static libraries. The suffix stands for “archive”, because they’re actually just an archive (made with … Read more
Concepts Minimum concept of what such a shared library maybe about. same code different data There are variations on this. Do you support linking between libraries. Are the references a DAG structure or fully cyclic? Do you want to put the code in ROM, or support code updates? Do you wish to load libraries after … Read more
You could try using objcopy to convert it to a normal object you can link in, and then reference its symbols in the linker script like you would do to a normal object. From the objcopy manual page: -B bfdarch –binary-architecture=bfdarch Useful when transforming a raw binary input file into an object file. In this … Read more
I am puzzled by the answer given by max.haredoom (and that it was accepted). The answer deals with shared libraries and dynamic linking, whereas the question was clearly about the behavior of static linking using static libraries. I believe this is misleading. When linking static libraries, ld does not care about weak/strong symbols by default: … Read more
You should avoid setting LD_LIBRARY_PATH in your .bashrc. See “Why LD_LIBRARY_PATH is bad” for more information. Use the linker option -rpath while linking so that the dynamic linker knows where to find libsync.so during runtime. gcc … -Wl,-rpath /path/to/library -L/path/to/library -lsync -o sync_test EDIT: Another way would be to use a wrapper like this #!/bin/bash … Read more
The start address is usually set by a linker script. For example, on GNU/Linux, looking at /usr/lib/ldscripts/elf_x86_64.x we see: … PROVIDE (__executable_start = SEGMENT_START(“text-segment”, 0x400000)); \ . = SEGMENT_START(“text-segment”, 0x400000) + SIZEOF_HEADERS; The value 0x400000 is the default value for the SEGMENT_START() function on this platform. You can find out more about linker scripts by … Read more
I found the following working solution. First create file memcpy.c: #include <string.h> /* some systems do not have newest memcpy@@GLIBC_2.14 – stay with old good one */ asm (“.symver memcpy, memcpy@GLIBC_2.2.5”); void *__wrap_memcpy(void *dest, const void *src, size_t n) { return memcpy(dest, src, n); } No additional CFLAGS needed to compile this file. Then link … Read more
I needed a solution to this because I have a scriptable system that has no filesystem (using blobs from a database) and needs to load binary plugins to support some scripts. This is the solution I came up with which works on FreeBSD but may not be portable. void *dlblob(const void *blob, size_t len) { … Read more
This won’t work. From the man page for gcc: This option will not work on Mac OS X unless all libraries (including libgcc.a) have also been compiled with -static. Since neither a static version of libSystem.dylib nor crt0.o are provided, this option is not useful to most people.