An opinionated interface for creating C- and Python-compatible shared libraries in Common Lisp with SBCL. Requires SBCL version >2.1.10.
You can build the example library using the Makefile in the examples/libcalc
directory, which produces a header file, a source file, and a core
file
You can compile the example like so with:
export SBCL_SRC=~/.roswell/src/sbcl-2.2.4
cd examples/libcalc
make
./example
which creates a shared library and executable using the functions
defined in the example system, assuming you have libsbcl.so
in a ${SBCL_SRC}/src/runtime/.
The file add-on.lisp in the example/libcalc directory shows how to add new
API symbols at link time - the final artifact should be relinked into
the final executable either by static or dynamic linkage - things work
better on Windows with static linkage. add-on.fasl should be loaded
explicitly via the C function lisp_load or the Lisp function
lisp-load at runtime.
If you don't have libsbcl.so, make will try to build it for you
by calling make-shared-library.sh at ${SBCL_SRC} directory.
On Intel macOS you MUST specify -pagezero_size 0x100000
when linking the final executable, otherwise SBCL will fail to mmap
its static space into the address 0x5000000. This is because Mac
decides to make page zero take up a whole 4GB (!), which prevents
access to the 32-bit address space. (Ostensibly to prevent null
pointer or other such bad (truncated?) pointer dereferences.)
The SBCL runtime includes a garbage collector and memory allocator.
Process resources SBCL uses:
- Signal handlers into the process for things like keyboard interrupts (can be turned off). On some platforms this may also entail a stop-the-world GC signal.
- File descriptors like standard input and output.
- A fixed address space somewhere in memory. On x86 (32-bit and 64-bit) this needs to be a fixed address space under 4 GB. This is so the compiler can generate manifest literal addresses in machine code on some platforms, as well as to compute stable hashes of certain constants like NIL.
