pyo3/build.rs

656 lines
22 KiB
Rust

use regex::Regex;
use serde::Deserialize;
use std::collections::HashMap;
use std::convert::AsRef;
use std::env;
use std::fmt;
use std::fs::File;
use std::io;
use std::io::{BufRead, BufReader};
use std::path::Path;
use std::process::exit;
use std::process::Command;
use std::process::Stdio;
use version_check::{Channel, Date, Version};
/// Specifies the minimum nightly version needed to compile pyo3.
/// Keep this synced up with the travis ci config,
/// But note that this is the rustc version which can be lower than the nightly version
const MIN_DATE: &'static str = "2019-07-18";
const MIN_VERSION: &'static str = "1.37.0-nightly";
/// Information returned from python interpreter
#[derive(Deserialize, Debug)]
struct InterpreterConfig {
version: PythonVersion,
libdir: Option<String>,
shared: bool,
ld_version: String,
/// Prefix used for determining the directory of libpython
base_prefix: String,
}
#[derive(Deserialize, Debug, Clone, PartialEq)]
pub enum PythonInterpreterKind {
CPython,
PyPy,
}
#[derive(Deserialize, Debug, Clone)]
struct PythonVersion {
major: u8,
// minor == None means any minor version will do
minor: Option<u8>,
implementation: PythonInterpreterKind,
}
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
];
/// Attempts to parse the header at the given path, returning a map of definitions to their values.
/// Each entry in the map directly corresponds to a `#define` in the given header.
fn parse_header_defines<P: AsRef<Path>>(header_path: P) -> Result<HashMap<String, String>, String> {
// This regex picks apart a C style, single line `#define` statement into an identifier and a
// value. e.g. for the line `#define Py_DEBUG 1`, this regex will capture `Py_DEBUG` into
// `ident` and `1` into `value`.
let define_regex =
Regex::new(r"^\s*#define\s+(?P<ident>[a-zA-Z0-9_]+)\s+(?P<value>.+)\s*$").unwrap();
let header_file = File::open(header_path.as_ref()).map_err(|e| e.to_string())?;
let header_reader = BufReader::new(&header_file);
let definitions = header_reader
.lines()
.filter_map(|maybe_line| {
let line = maybe_line.unwrap_or_else(|err| {
panic!("failed to read {}: {}", header_path.as_ref().display(), err);
});
let captures = define_regex.captures(&line)?;
if captures.name("ident").is_some() && captures.name("value").is_some() {
Some((
captures.name("ident").unwrap().as_str().to_owned(),
captures.name("value").unwrap().as_str().to_owned(),
))
} else {
None
}
})
.collect();
Ok(definitions)
}
fn fix_config_map(mut config_map: HashMap<String, String>) -> HashMap<String, String> {
if let Some("1") = config_map.get("Py_DEBUG").as_ref().map(|s| s.as_str()) {
config_map.insert("Py_REF_DEBUG".to_owned(), "1".to_owned());
config_map.insert("Py_TRACE_REFS".to_owned(), "1".to_owned());
config_map.insert("COUNT_ALLOCS".to_owned(), "1".to_owned());
}
config_map
}
fn load_cross_compile_info() -> Result<(InterpreterConfig, HashMap<String, String>), String> {
let python_include_dir = env::var("PYO3_CROSS_INCLUDE_DIR").unwrap();
let python_include_dir = Path::new(&python_include_dir);
let patchlevel_defines = parse_header_defines(python_include_dir.join("patchlevel.h"))?;
let major = patchlevel_defines
.get("PY_MAJOR_VERSION")
.and_then(|major| major.parse::<u8>().ok())
.expect("PY_MAJOR_VERSION undefined");
let minor = patchlevel_defines
.get("PY_MINOR_VERSION")
.and_then(|minor| minor.parse::<u8>().ok())
.expect("PY_MINOR_VERSION undefined");
let python_version = PythonVersion {
major,
minor: Some(minor),
implementation: PythonInterpreterKind::CPython,
};
let config_map = parse_header_defines(python_include_dir.join("pyconfig.h"))?;
let shared = match config_map
.get("Py_ENABLE_SHARED")
.map(|x| x.as_str())
.ok_or("Py_ENABLE_SHARED is not defined".to_string())?
{
"1" | "true" | "True" => true,
"0" | "false" | "False" => false,
_ => panic!("Py_ENABLE_SHARED must be a bool (1/true/True or 0/false/False"),
};
let intepreter_config = InterpreterConfig {
version: python_version,
libdir: Some(env::var("PYO3_CROSS_LIB_DIR").expect("PYO3_CROSS_LIB_DIR is not set")),
shared,
ld_version: "".to_string(),
base_prefix: "".to_string(),
};
Ok((intepreter_config, fix_config_map(config_map)))
}
/// 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: &str) -> 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_end().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 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
},
);
Ok(fix_config_map(all_vars))
}
#[cfg(target_os = "windows")]
fn get_config_vars(_: &str) -> 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();
let out = match out {
Err(err) => {
if err.kind() == io::ErrorKind::NotFound {
return Err(format!(
"Could not find any interpreter at {}, \
are you sure you have python installed on your PATH?",
interpreter
));
} else {
return Err(format!(
"Failed to run the python interpreter at {}: {}",
interpreter, err
));
}
}
Ok(ok) => ok,
};
if !out.status.success() {
return Err(format!("python script failed"));
}
Ok(String::from_utf8(out.stdout).unwrap())
}
fn get_library_link_name(version: &PythonVersion, ld_version: &str) -> String {
if cfg!(target_os = "windows") {
let minor_or_empty_string = match version.minor {
Some(minor) => format!("{}", minor),
None => String::new(),
};
match version.implementation {
PythonInterpreterKind::CPython => {
format!("python{}{}", version.major, minor_or_empty_string)
}
PythonInterpreterKind::PyPy => format!("pypy{}-c", version.major),
}
} else {
match version.implementation {
PythonInterpreterKind::CPython => format!("python{}", ld_version),
PythonInterpreterKind::PyPy => format!("pypy{}-c", version.major),
}
}
}
#[cfg(not(target_os = "macos"))]
#[cfg(not(target_os = "windows"))]
fn get_rustc_link_lib(
version: &PythonVersion,
ld_version: &str,
enable_shared: bool,
) -> Result<String, String> {
if enable_shared {
Ok(format!(
"cargo:rustc-link-lib={}",
get_library_link_name(&version, ld_version)
))
} else {
Ok(format!(
"cargo:rustc-link-lib=static={}",
get_library_link_name(&version, 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_end().to_owned())
}
#[cfg(target_os = "macos")]
fn get_rustc_link_lib(
version: &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={}",
get_library_link_name(&version, ld_version)
)),
"shared" => Ok(format!(
"cargo:rustc-link-lib={}",
get_library_link_name(&version, ld_version)
)),
"framework" => Ok(format!(
"cargo:rustc-link-lib={}",
get_library_link_name(&version, ld_version)
)),
other => Err(format!("unknown linkmodel {}", other)),
}
}
#[cfg(target_os = "windows")]
fn get_rustc_link_lib(
version: &PythonVersion,
ld_version: &str,
_: bool,
) -> Result<String, String> {
// Py_ENABLE_SHARED doesn't seem to be present on windows.
Ok(format!(
"cargo:rustc-link-lib=pythonXY:{}",
get_library_link_name(&version, ld_version)
))
}
/// 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() -> Result<(InterpreterConfig, HashMap<String, 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_config = get_config_from_interpreter(interpreter_path)?;
return Ok((
interpreter_config,
fix_config_map(get_config_vars(interpreter_path)?),
));
};
// check default python
let interpreter_path = "python";
let interpreter_config = get_config_from_interpreter(interpreter_path)?;
if interpreter_config.version.major == 3 {
return Ok((
interpreter_config,
fix_config_map(get_config_vars(interpreter_path)?),
));
}
let major_interpreter_path = "python3";
let interpreter_config = get_config_from_interpreter(major_interpreter_path)?;
if interpreter_config.version.major == 3 {
return Ok((
interpreter_config,
fix_config_map(get_config_vars(major_interpreter_path)?),
));
}
Err(format!("No python interpreter found"))
}
/// Extract compilation vars from the specified interpreter.
fn get_config_from_interpreter(interpreter: &str) -> Result<InterpreterConfig, String> {
let script = r#"
import sys
import sysconfig
import platform
import json
PYPY = platform.python_implementation() == "PyPy"
try:
base_prefix = sys.base_prefix
except AttributeError:
base_prefix = sys.exec_prefix
print(json.dumps({
"version": {
"major": sys.version_info[0],
"minor": sys.version_info[1],
"implementation": platform.python_implementation()
},
"libdir": sysconfig.get_config_var('LIBDIR'),
"ld_version": sysconfig.get_config_var('LDVERSION') or sysconfig.get_config_var('py_version_short'),
"base_prefix": base_prefix,
"shared": PYPY or bool(sysconfig.get_config_var('Py_ENABLE_SHARED'))
}))
"#;
let json = run_python_script(interpreter, script)?;
serde_json::from_str(&json).map_err(|e| format!("Deserializing failed: {}", e))
}
fn configure(interpreter_config: &InterpreterConfig) -> Result<(String), String> {
if let Some(minor) = interpreter_config.version.minor {
if minor < PY3_MIN_MINOR {
return Err(format!(
"Python 3 required version is 3.{}, current version is 3.{}",
PY3_MIN_MINOR, minor
));
}
}
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_config.version,
&interpreter_config.ld_version,
interpreter_config.shared
)
.unwrap()
);
if let Some(libdir) = &interpreter_config.libdir {
println!("cargo:rustc-link-search=native={}", libdir);
} else if cfg!(target_os = "windows") {
println!(
"cargo:rustc-link-search=native={}\\libs",
interpreter_config.base_prefix
);
}
}
let mut flags = String::new();
if interpreter_config.version.implementation == PythonInterpreterKind::PyPy {
println!("cargo:rustc-cfg=PyPy");
flags += format!("CFG_PyPy").as_ref();
};
if interpreter_config.version.major == 2 {
// fail PYTHON_SYS_EXECUTABLE=python2 cargo ...
return Err("Python 2 is not supported".to_string());
}
if env::var_os("CARGO_FEATURE_ABI3").is_some() {
println!("cargo:rustc-cfg=Py_LIMITED_API");
}
if let Some(minor) = interpreter_config.version.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");
return Ok(flags);
}
fn check_rustc_version() {
let channel = Channel::read().expect("Failed to determine rustc channel");
if !channel.supports_features() {
panic!("Error: pyo3 requires a nightly or dev version of Rust.");
}
let actual_version = Version::read().expect("Failed to determine the rustc version");
if !actual_version.at_least(MIN_VERSION) {
panic!(
"pyo3 requires at least rustc {}, while the current version is {}",
MIN_VERSION, actual_version
)
}
let actual_date = Date::read().expect("Failed to determine the rustc date");
if !actual_date.at_least(MIN_DATE) {
panic!(
"pyo3 requires at least rustc {}, while the current rustc date is {}",
MIN_DATE, actual_date
)
}
}
fn main() -> Result<(), String> {
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. First check if we're cross compiling, if so, we cannot run the
// target Python interpreter and have to parse pyconfig.h instead. If we're not cross
// compiling, locate the python interpreter based on the PATH, which should work smoothly with
// an activated virtualenv, and load from there.
//
// 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 cross_compiling =
env::var("PYO3_CROSS_INCLUDE_DIR").is_ok() && env::var("PYO3_CROSS_LIB_DIR").is_ok();
let (interpreter_config, mut config_map) = if cross_compiling {
load_cross_compile_info()?
} else {
find_interpreter_and_get_config()?
};
let flags;
match configure(&interpreter_config) {
Ok(val) => flags = val,
Err(err) => {
eprintln!("{}", err);
exit(1);
}
}
// These flags need to be enabled manually for PyPy, because it does not expose
// them in `sysconfig.get_config_vars()`
if interpreter_config.version.implementation == PythonInterpreterKind::PyPy {
config_map.insert("WITH_THREAD".to_owned(), "1".to_owned());
config_map.insert("Py_USING_UNICODE".to_owned(), "1".to_owned());
config_map.insert("Py_UNICODE_SIZE".to_owned(), "4".to_owned());
config_map.insert("Py_UNICODE_WIDE".to_owned(), "1".to_owned());
}
// WITH_THREAD is always on for 3.7
if interpreter_config.version.major == 3 && interpreter_config.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);
}
Ok(())
}