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| -rw-r--r-- | README.org | 39 |
1 files changed, 31 insertions, 8 deletions
@@ -8,9 +8,9 @@ assertions about typing and is very simple to target. * How to build Requires =GNU make= and a compliant C11 compiler. Code base has been tested against =gcc= and =clang=, but given how the project has been -written without use of GNU'isms it shouldn't be an issue to compile -using something like =tcc= or another compiler (look at -[[file:Makefile::CC=gcc][here]] to change the compiler). +written without use of GNU'isms (that I'm aware of) it shouldn't be an +issue to compile using something like =tcc= or another compiler (look +at [[file:Makefile::CC=gcc][here]] to change the compiler). To build everything simply run ~make~. This will build: + [[file:lib/inst.c][instruction bytecode system]] which provides @@ -23,7 +23,7 @@ To build everything simply run ~make~. This will build: how to write compliant assembly. Also a good test of both the VM and assembler. -One may also build each component individually through the +You may also build each component individually through the corresponding recipe: + ~make lib~ + ~make vm~ @@ -33,14 +33,37 @@ corresponding recipe: You need to link with the object files for [[file:lib/base.c][base.c]], [[file:lib/darr.c][darr.c]] and [[file:lib/inst.c][inst.c]] to be able to properly target the OVM. -The basic idea is to create instructions via ~inst_t~ then using the -~inst(s)_write_*~ API to generate bytecode (and write to a file). +The basic idea is to create some instructions via ~inst_t~, +instantiating a ~prog_t~ structure which wraps those instructions +(includes a header and other useful things for the runtime), then +using ~prog_write_file~ to serialise and write bytecode to a file +pointer. -Then to execute the program, the virtual machine interpreter ~ovm.out~ -is used. +To execute directly compiled bytecode use the ~ovm.out~ executable on +the bytecode file. For clarity, one may build ~lib~ (~make lib~) then use the resulting object files to link and create bytecode for the virtual machine. +** In memory virtual machine +Instead of serialising and writing bytecode to a file, one may instead +serialise bytecode in memory using ~prog_write_bytecode~ which writes +bytecode to a dynamic byte buffer, so called *in memory compilation*. +To execute this bytecode, deserialise the bytecode into a program then +load it into a complete ~vm_t~ structure (linking with +[[file:vm/runtime.c][runtime.c]]). + +In fact, you may skip the process of serialising entirely. You can +emit a ~prog_t~ structure corresponding to source code, load it +directly into the ~vm_t~ structure, then execute. To do so is a bit +involved, so I recommend looking at [[file:vm/main.c]]. In rough +steps: ++ Create a virtual machine "from scratch" (load the necessary + components (the stack, heap and call stack) by hand) ++ Load program into VM (~vm_load_program~) ++ Run ~vm_execute_all~ + +This is recommended if writing an interpreted language such as a Lisp, +where on demand execution of code is more suitable. * Lines of code #+begin_src sh :results table :exports results find -name '*.[ch]' -exec wc -l '{}' ';' |