pyo3/build.rs

546 lines
19 KiB
Rust

extern crate regex;
extern crate version_check;
use regex::Regex;
use std::collections::HashMap;
use std::env;
use std::fmt;
use std::process::Command;
use std::process::Stdio;
use version_check::{is_min_date, is_min_version, supports_features};
// Specifies the minimum nightly version needed to compile pyo3.
// This requirement is due to https://github.com/rust-lang/rust/issues/55380
const MIN_DATE: &'static str = "2018-11-02";
const MIN_VERSION: &'static str = "1.32.0-nightly";
#[derive(Debug)]
struct PythonVersion {
major: u8,
// minor == None means any minor version will do
minor: Option<u8>,
}
impl PartialEq for PythonVersion {
fn eq(&self, o: &PythonVersion) -> bool {
self.major == o.major && (self.minor.is_none() || self.minor == o.minor)
}
}
impl fmt::Display for PythonVersion {
fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
self.major.fmt(f)?;
f.write_str(".")?;
match self.minor {
Some(minor) => minor.fmt(f)?,
None => f.write_str("*")?,
};
Ok(())
}
}
const PY3_MIN_MINOR: u8 = 5;
const CFG_KEY: &'static str = "py_sys_config";
/// A list of python interpreter compile-time preprocessor defines that
/// we will pick up and pass to rustc via --cfg=py_sys_config={varname};
/// this allows using them conditional cfg attributes in the .rs files, so
///
/// #[cfg(py_sys_config="{varname}"]
///
/// is the equivalent of #ifdef {varname} name in C.
///
/// see Misc/SpecialBuilds.txt in the python source for what these mean.
///
/// (hrm, this is sort of re-implementing what distutils does, except
/// by passing command line args instead of referring to a python.h)
#[cfg(not(target_os = "windows"))]
static SYSCONFIG_FLAGS: [&'static str; 7] = [
"Py_USING_UNICODE",
"Py_UNICODE_WIDE",
"WITH_THREAD",
"Py_DEBUG",
"Py_REF_DEBUG",
"Py_TRACE_REFS",
"COUNT_ALLOCS",
];
static SYSCONFIG_VALUES: [&'static str; 1] = [
// cfg doesn't support flags with values, just bools - so flags
// below are translated into bools as {varname}_{val}
//
// for example, Py_UNICODE_SIZE_2 or Py_UNICODE_SIZE_4
"Py_UNICODE_SIZE", // note - not present on python 3.3+, which is always wide
];
/// Examine python's compile flags to pass to cfg by launching
/// the interpreter and printing variables of interest from
/// sysconfig.get_config_vars.
#[cfg(not(target_os = "windows"))]
fn get_config_vars(python_path: &String) -> Result<HashMap<String, String>, String> {
// FIXME: We can do much better here using serde:
// import json, sysconfig; print(json.dumps({k:str(v) for k, v in sysconfig.get_config_vars().items()}))
let mut script = "import sysconfig; \
config = sysconfig.get_config_vars();"
.to_owned();
for k in SYSCONFIG_FLAGS.iter().chain(SYSCONFIG_VALUES.iter()) {
script.push_str(&format!(
"print(config.get('{}', {}));",
k,
if is_value(k) { "None" } else { "0" }
));
}
let stdout = run_python_script(python_path, &script)?;
let split_stdout: Vec<&str> = stdout.trim_right().lines().collect();
if split_stdout.len() != SYSCONFIG_VALUES.len() + SYSCONFIG_FLAGS.len() {
return Err(format!(
"python stdout len didn't return expected number of lines: {}",
split_stdout.len()
));
}
let all_vars = SYSCONFIG_FLAGS.iter().chain(SYSCONFIG_VALUES.iter());
let mut all_vars = all_vars.zip(split_stdout.iter()).fold(
HashMap::new(),
|mut memo: HashMap<String, String>, (&k, &v)| {
if !(v.to_owned() == "None" && is_value(k)) {
memo.insert(k.to_owned(), v.to_owned());
}
memo
},
);
let debug = Some(&"1".to_string()) == all_vars.get("Py_DEBUG");
if debug {
all_vars.insert("Py_REF_DEBUG".to_owned(), "1".to_owned());
all_vars.insert("Py_TRACE_REFS".to_owned(), "1".to_owned());
all_vars.insert("COUNT_ALLOCS".to_owned(), "1".to_owned());
}
Ok(all_vars)
}
#[cfg(target_os = "windows")]
fn get_config_vars(_: &String) -> Result<HashMap<String, String>, String> {
// sysconfig is missing all the flags on windows, so we can't actually
// query the interpreter directly for its build flags.
//
// For the time being, this is the flags as defined in the python source's
// PC\pyconfig.h. This won't work correctly if someone has built their
// python with a modified pyconfig.h - sorry if that is you, you will have
// to comment/uncomment the lines below.
let mut map: HashMap<String, String> = HashMap::new();
map.insert("Py_USING_UNICODE".to_owned(), "1".to_owned());
map.insert("Py_UNICODE_WIDE".to_owned(), "0".to_owned());
map.insert("WITH_THREAD".to_owned(), "1".to_owned());
map.insert("Py_UNICODE_SIZE".to_owned(), "2".to_owned());
// This is defined #ifdef _DEBUG. The visual studio build seems to produce
// a specially named pythonXX_d.exe and pythonXX_d.dll when you build the
// Debug configuration, which this script doesn't currently support anyway.
// map.insert("Py_DEBUG", "1");
// Uncomment these manually if your python was built with these and you want
// the cfg flags to be set in rust.
//
// map.insert("Py_REF_DEBUG", "1");
// map.insert("Py_TRACE_REFS", "1");
// map.insert("COUNT_ALLOCS", 1");
Ok(map)
}
fn is_value(key: &str) -> bool {
SYSCONFIG_VALUES.iter().find(|x| **x == key).is_some()
}
fn cfg_line_for_var(key: &str, val: &str) -> Option<String> {
if is_value(key) {
// is a value; suffix the key name with the value
Some(format!("cargo:rustc-cfg={}=\"{}_{}\"\n", CFG_KEY, key, val))
} else if val != "0" {
// is a flag that isn't zero
Some(format!("cargo:rustc-cfg={}=\"{}\"", CFG_KEY, key))
} else {
// is a flag that is zero
None
}
}
/// Run a python script using the specified interpreter binary.
fn run_python_script(interpreter: &str, script: &str) -> Result<String, String> {
let out = Command::new(interpreter)
.args(&["-c", script])
.stderr(Stdio::inherit())
.output()
.map_err(|e| {
format!(
"Failed to run the python interpreter at {}: {}",
interpreter, e
)
})?;
if !out.status.success() {
return Err(format!("python script failed"));
}
Ok(String::from_utf8(out.stdout).unwrap())
}
#[cfg(not(target_os = "macos"))]
#[cfg(not(target_os = "windows"))]
fn get_rustc_link_lib(
_: &PythonVersion,
ld_version: &str,
enable_shared: bool,
) -> Result<String, String> {
if enable_shared {
Ok(format!("cargo:rustc-link-lib=python{}", ld_version))
} else {
Ok(format!("cargo:rustc-link-lib=static=python{}", ld_version))
}
}
#[cfg(target_os = "macos")]
fn get_macos_linkmodel() -> Result<String, String> {
let script = r#"
import sysconfig
if sysconfig.get_config_var("PYTHONFRAMEWORK"):
print("framework")
elif sysconfig.get_config_var("Py_ENABLE_SHARED"):
print("shared")
else:
print("static")
"#;
let out = run_python_script("python", script).unwrap();
Ok(out.trim_right().to_owned())
}
#[cfg(target_os = "macos")]
fn get_rustc_link_lib(_: &PythonVersion, ld_version: &str, _: bool) -> Result<String, String> {
// os x can be linked to a framework or static or dynamic, and
// Py_ENABLE_SHARED is wrong; framework means shared library
match get_macos_linkmodel().unwrap().as_ref() {
"static" => Ok(format!("cargo:rustc-link-lib=static=python{}", ld_version)),
"shared" => Ok(format!("cargo:rustc-link-lib=python{}", ld_version)),
"framework" => Ok(format!("cargo:rustc-link-lib=python{}", ld_version)),
other => Err(format!("unknown linkmodel {}", other)),
}
}
/// Parse string as interpreter version.
fn get_interpreter_version(line: &str) -> Result<PythonVersion, String> {
let version_re = Regex::new(r"\((\d+), (\d+)\)").unwrap();
match version_re.captures(&line) {
Some(cap) => Ok(PythonVersion {
major: cap.get(1).unwrap().as_str().parse().unwrap(),
minor: Some(cap.get(2).unwrap().as_str().parse().unwrap()),
}),
None => Err(format!("Unexpected response to version query {}", line)),
}
}
#[cfg(target_os = "windows")]
fn get_rustc_link_lib(version: &PythonVersion, _: &str, _: bool) -> Result<String, String> {
// Py_ENABLE_SHARED doesn't seem to be present on windows.
Ok(format!(
"cargo:rustc-link-lib=pythonXY:python{}{}",
version.major,
match version.minor {
Some(minor) => minor.to_string(),
None => "".to_owned(),
}
))
}
/// Locate a suitable python interpreter and extract config from it.
///
/// The following locations are checked in the order listed:
///
/// 1. If `PYTHON_SYS_EXECUTABLE` is set, this intepreter is used and an error is raised if the
/// version doesn't match.
/// 2. `python`
/// 3. `python{major version}`
/// 4. `python{major version}.{minor version}`
///
/// If none of the above works, an error is returned
fn find_interpreter_and_get_config(
expected_version: &PythonVersion,
) -> Result<(PythonVersion, String, Vec<String>), String> {
if let Some(sys_executable) = env::var_os("PYTHON_SYS_EXECUTABLE") {
let interpreter_path = sys_executable
.to_str()
.expect("Unable to get PYTHON_SYS_EXECUTABLE value");
let (interpreter_version, lines) = get_config_from_interpreter(interpreter_path)?;
if expected_version == &interpreter_version {
return Ok((interpreter_version, interpreter_path.to_owned(), lines));
} else {
return Err(format!(
"Unsupported python version in PYTHON_SYS_EXECUTABLE={}\n\
\tmin version {} != found {}",
interpreter_path, expected_version, interpreter_version
));
}
}
// check default python
let interpreter_path = "python";
let (interpreter_version, lines) = get_config_from_interpreter(interpreter_path)?;
if expected_version == &interpreter_version {
return Ok((interpreter_version, interpreter_path.to_owned(), lines));
}
let major_interpreter_path = &format!("python{}", expected_version.major);
let (interpreter_version, lines) = get_config_from_interpreter(major_interpreter_path)?;
if expected_version == &interpreter_version {
return Ok((
interpreter_version,
major_interpreter_path.to_owned(),
lines,
));
}
if let Some(minor) = expected_version.minor {
let minor_interpreter_path = &format!("python{}.{}", expected_version.major, minor);
let (interpreter_version, lines) = get_config_from_interpreter(minor_interpreter_path)?;
if expected_version == &interpreter_version {
return Ok((
interpreter_version,
minor_interpreter_path.to_owned(),
lines,
));
}
}
Err(format!("No python interpreter found"))
}
/// Extract compilation vars from the specified interpreter.
fn get_config_from_interpreter(interpreter: &str) -> Result<(PythonVersion, Vec<String>), String> {
let script = r#"
import sys
import sysconfig
print(sys.version_info[0:2])
print(sysconfig.get_config_var('LIBDIR'))
print(sysconfig.get_config_var('Py_ENABLE_SHARED'))
print(sysconfig.get_config_var('LDVERSION') or sysconfig.get_config_var('py_version_short'))
print(sys.exec_prefix)
"#;
let out = run_python_script(interpreter, script)?;
let lines: Vec<String> = out.lines().map(|line| line.to_owned()).collect();
let interpreter_version = get_interpreter_version(&lines[0])?;
Ok((interpreter_version, lines))
}
/// Deduce configuration from the 'python' in the current PATH and print
/// cargo vars to stdout.
///
/// Note that if the python doesn't satisfy expected_version, this will error.
fn configure_from_path(expected_version: &PythonVersion) -> Result<(String, String), String> {
let (interpreter_version, interpreter_path, lines) =
find_interpreter_and_get_config(expected_version)?;
let libpath: &str = &lines[1];
let enable_shared: &str = &lines[2];
let ld_version: &str = &lines[3];
let exec_prefix: &str = &lines[4];
let is_extension_module = env::var_os("CARGO_FEATURE_EXTENSION_MODULE").is_some();
if !is_extension_module || cfg!(target_os = "windows") {
println!(
"{}",
get_rustc_link_lib(&interpreter_version, ld_version, enable_shared == "1").unwrap()
);
if libpath != "None" {
println!("cargo:rustc-link-search=native={}", libpath);
} else if cfg!(target_os = "windows") {
println!("cargo:rustc-link-search=native={}\\libs", exec_prefix);
}
}
let mut flags = String::new();
if let PythonVersion {
major: 3,
minor: some_minor,
} = interpreter_version
{
if env::var_os("CARGO_FEATURE_ABI3").is_some() {
println!("cargo:rustc-cfg=Py_LIMITED_API");
}
if let Some(minor) = some_minor {
if minor < PY3_MIN_MINOR {
return Err(format!(
"Python 3 required version is 3.{}, current version is 3.{}",
PY3_MIN_MINOR, minor
));
}
for i in 5..(minor + 1) {
println!("cargo:rustc-cfg=Py_3_{}", i);
flags += format!("CFG_Py_3_{},", i).as_ref();
}
println!("cargo:rustc-cfg=Py_3");
}
} else {
println!("cargo:rustc-cfg=Py_2");
flags += format!("CFG_Py_2,").as_ref();
}
return Ok((interpreter_path, flags));
}
/// Determine the python version we're supposed to be building
/// from the features passed via the environment.
///
/// The environment variable can choose to omit a minor
/// version if the user doesn't care.
fn version_from_env() -> Result<PythonVersion, String> {
let re = Regex::new(r"CARGO_FEATURE_PYTHON(\d+)(_(\d+))?").unwrap();
// sort env::vars so we get more explicit version specifiers first
// so if the user passes e.g. the python-3 feature and the python-3-5
// feature, python-3-5 takes priority.
let mut vars = env::vars().collect::<Vec<_>>();
vars.sort_by(|a, b| b.cmp(a));
for (key, _) in vars {
match re.captures(&key) {
Some(cap) => {
return Ok(PythonVersion {
major: cap.get(1).unwrap().as_str().parse().unwrap(),
minor: match cap.get(3) {
Some(s) => Some(s.as_str().parse().unwrap()),
None => None,
},
});
}
None => (),
}
}
Err(
"Python version feature was not found. At least one python version \
feature must be enabled."
.to_owned(),
)
}
fn check_rustc_version() {
let ok_channel = supports_features();
let ok_version = is_min_version(MIN_VERSION);
let ok_date = is_min_date(MIN_DATE);
let print_version_err = |version: &str, date: &str| {
eprintln!(
"Installed version is: {} ({}). Minimum required: {} ({}).",
version, date, MIN_VERSION, MIN_DATE
);
};
match (ok_channel, ok_version, ok_date) {
(Some(ok_channel), Some((ok_version, version)), Some((ok_date, date))) => {
if !ok_channel {
eprintln!("Error: pyo3 requires a nightly or dev version of Rust.");
print_version_err(&*version, &*date);
panic!("Aborting compilation due to incompatible compiler.")
}
if !ok_version || !ok_date {
eprintln!("Error: pyo3 requires a more recent version of rustc.");
eprintln!("Use `rustup update` or your preferred method to update Rust");
print_version_err(&*version, &*date);
panic!("Aborting compilation due to incompatible compiler.")
}
}
_ => {
println!(
"cargo:warning={}",
"pyo3 was unable to check rustc compatibility."
);
println!(
"cargo:warning={}",
"Build may fail due to incompatible rustc version."
);
}
}
}
fn main() {
check_rustc_version();
// 1. Setup cfg variables so we can do conditional compilation in this
// library based on the python interpeter's compilation flags. This is
// necessary for e.g. matching the right unicode and threading interfaces.
//
// This locates the python interpreter based on the PATH, which should
// work smoothly with an activated virtualenv.
//
// If you have troubles with your shell accepting '.' in a var name,
// try using 'env' (sorry but this isn't our fault - it just has to
// match the pkg-config package name, which is going to have a . in it).
let version = match version_from_env() {
Ok(v) => v,
Err(_) => PythonVersion {
major: 3,
minor: None,
},
};
let (python_interpreter_path, flags) = configure_from_path(&version).unwrap();
let mut config_map = get_config_vars(&python_interpreter_path).unwrap();
// WITH_THREAD is always on for 3.7
let (interpreter_version, _, _) = find_interpreter_and_get_config(&version).unwrap();
if interpreter_version.major == 3 && interpreter_version.minor.unwrap_or(0) >= 7 {
config_map.insert("WITH_THREAD".to_owned(), "1".to_owned());
}
for (key, val) in &config_map {
match cfg_line_for_var(key, val) {
Some(line) => println!("{}", line),
None => (),
}
}
// 2. Export python interpreter compilation flags as cargo variables that
// will be visible to dependents. All flags will be available to dependent
// build scripts in the environment variable DEP_PYTHON27_PYTHON_FLAGS as
// comma separated list; each item in the list looks like
//
// {VAL,FLAG}_{flag_name}=val;
//
// FLAG indicates the variable is always 0 or 1
// VAL indicates it can take on any value
//
// rust-cypthon/build.rs contains an example of how to unpack this data
// into cfg flags that replicate the ones present in this library, so
// you can use the same cfg syntax.
let flags: String = config_map.iter().fold("".to_owned(), |memo, (key, val)| {
if is_value(key) {
memo + format!("VAL_{}={},", key, val).as_ref()
} else if val != "0" {
memo + format!("FLAG_{}={},", key, val).as_ref()
} else {
memo
}
}) + flags.as_str();
println!(
"cargo:python_flags={}",
if flags.len() > 0 {
&flags[..flags.len() - 1]
} else {
""
}
);
if env::var_os("TARGET") == Some("x86_64-apple-darwin".into()) {
// TODO: Find out how we can set -undefined dynamic_lookup here (if this is possible)
}
let env_vars = ["LD_LIBRARY_PATH", "PATH", "PYTHON_SYS_EXECUTABLE", "LIB"];
for var in env_vars.iter() {
println!("cargo:rerun-if-env-changed={}", var);
}
}