Add basic support for Python functions.

It unexpectedly made me fix unmarshalling of code, which made me merge the two unmarshalling passes.

Author: progval

Cargo.toml

@@ -2,6 +2,7 @@
 name = "pythonvm"
 version = "0.1.0"
 authors = ["Valentin Lorentz <progval+git@progval.net>"]
+build = "build.rs"
 
 [lib]
 name = "pythonvm"

README.md

@@ -12,7 +12,7 @@ A Python virtual machine, written in Rust.
 
 ## Try it
 
-1. Install git, [Rust](https://www.rust-lang.org/downloads.html) and [Cargo](https://crates.io/install)
+1. Install Python 3.4 (used as a parser and bytecode compiler), git, [Rust](https://www.rust-lang.org/downloads.html) and [Cargo](https://crates.io/install)
 2. `git clone https://github.com/ProgVal/pythonvm-rust.git`
 3. `cd pythonvm-rust`
-4. `cargo run examples/helloworld.pyc`
+4. `cargo run pythonlib/ examples/helloworld.pyc`

build.rs

@@ -0,0 +1,15 @@
+use std::process::Command;
+
+fn main() {
+    Command::new("/usr/bin/env")
+            .arg("python3")
+            .arg("-m")
+            .arg("compileall")
+            .arg("-b") // old-style bytecode layout
+            .arg("pythonlib/")
+            .arg("examples/")
+            .spawn()
+            .unwrap()
+            .wait()
+            .unwrap();
+}

examples/helloworld.py

@@ -0,0 +1 @@
+print('hello world')

examples/helloworld.pyc

@@ -0,0 +1,3 @@
+def print(value):
+    __primitives__.write_stdout(value)
+    __primitives__.write_stdout("\n")

pythonlib/builtins.py

@@ -2,28 +2,32 @@ extern crate pythonvm;
 
 use std::env::args;
 use std::fs::File;
+use std::path::PathBuf;
 
-fn parse_args() -> (String, Option<String>) {
+fn parse_args() -> (String, Option<(String, String)>) {
     let mut args = args();
     let executable = args.next().unwrap();
+    let libdir = args.next();
     let filename = args.next();
     let extra = args.next();
-    match (filename, extra) {
-        (Some(filename), None) => (executable, Some(filename)),
+    match (libdir, filename, extra) {
+        (Some(libdir), Some(filename), None) => (executable, Some((libdir, filename))),
         _ => (executable, None),
     }
 }
 
 
 pub fn main() {
-    let filename = match parse_args() {
-        (_, Some(filename)) => filename,
+    let (libdir, filename) = match parse_args() {
+        (_, Some((libdir, filename))) => (libdir, filename),
         (executable, None) => {
-            println!("Syntax: {} filename.pyc", executable);
+            println!("Syntax: {} pythonlib/ filename.pyc", executable);
             return
         }
     };
     let mut file = File::open(filename).unwrap();
-    let env_proxy = pythonvm::RealEnvProxy::new();
+    let mut path = PathBuf::new();
+    path.push(&libdir);
+    let env_proxy = pythonvm::RealEnvProxy::new(path);
     let (_processor, _result) = pythonvm::run_module(&mut file, env_proxy).unwrap();
 }

pythonlib/builtins.pyc

@@ -3,10 +3,13 @@ mod objects;
 mod processor;
 mod sandbox;
 mod stack;
+mod primitives;
 
 use std::fmt;
 use std::io;
 use processor::Processor;
+use std::path::PathBuf;
+use std::env;
 
 pub use sandbox::{RealEnvProxy, MockEnvProxy};
 
@@ -33,15 +36,18 @@ pub fn run_module<R: io::Read, EP: sandbox::EnvProxy>(reader: &mut R, envproxy:
     // TODO: do something with the content of the buffer
     let mut store = objects::ObjectStore::new();
     let module = try!(marshal::read_object(reader, &mut store).map_err(InterpreterError::Unmarshal));
-    let mut processor = Processor { envproxy: envproxy, store: store, builtin_functions: Processor::get_default_builtins() };
+    let mut processor = Processor { envproxy: envproxy, store: store, primitives: primitives::get_default_primitives() };
     let result = try!(processor.run_code_object(module).map_err(InterpreterError::Processor));
     Ok((processor, result))
 }
 
 #[test]
-fn test_hello_world() {
-    let mut reader: &[u8] = b"\xee\x0c\r\n\x15j\nW\x15\x00\x00\x00\xe3\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00@\x00\x00\x00s\x0e\x00\x00\x00e\x00\x00d\x00\x00\x83\x01\x00\x01d\x01\x00S)\x02z\x0bHello worldN)\x01\xda\x05print\xa9\x00r\x02\x00\x00\x00r\x02\x00\x00\x00\xfa\x0b/tmp/foo.py\xda\x08<module>\x01\x00\x00\x00s\x00\x00\x00\x00";
-    let envproxy = sandbox::MockEnvProxy::new();
+fn test_primitive_hello_world() {
+    let mut reader: &[u8] = b"\xee\x0c\r\n\xb0\x92\x0fW\x15\x00\x00\x00\xe3\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00@\x00\x00\x00s\x0e\x00\x00\x00e\x00\x00d\x00\x00\x83\x01\x00\x01d\x01\x00S)\x02z\x0bHello worldN)\x01\xda\x05print\xa9\x00r\x02\x00\x00\x00r\x02\x00\x00\x00\xfa\x16examples/helloworld.py\xda\x08<module>\x01\x00\x00\x00s\x00\x00\x00\x00";
+    let mut path = PathBuf::new();
+    path.push(env::current_dir().unwrap());
+    path.push("pythonlib/");
+    let envproxy = sandbox::MockEnvProxy::new(path);
     let (processor, result) = run_module(&mut reader, envproxy).unwrap();
     println!("{:?}", result);
     assert_eq!(*processor.envproxy.stdout_content.lock().unwrap(), b"Hello world\n");