pyo3-build-config: fix cross compilation

This commit is contained in:
David Hewitt 2021-06-01 18:31:34 +01:00
parent e16bc16568
commit 8fb4ce6fbc
9 changed files with 191 additions and 94 deletions

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@ -185,11 +185,16 @@ fn emit_cargo_configuration(interpreter_config: &InterpreterConfig) -> Result<()
Ok(())
}
/// Generates the interpreter config suitable for the host / target / cross-compilation at hand.
///
/// The result is written to pyo3_build_config::PATH, which downstream scripts can read from
/// (including `pyo3-macros-backend` during macro expansion).
fn configure_pyo3() -> Result<()> {
let interpreter_config = pyo3_build_config::get();
let interpreter_config = pyo3_build_config::make_interpreter_config()?;
ensure_python_version(&interpreter_config)?;
ensure_target_architecture(&interpreter_config)?;
emit_cargo_configuration(&interpreter_config)?;
interpreter_config.to_writer(&mut std::fs::File::create(pyo3_build_config::PATH)?)?;
interpreter_config.emit_pyo3_cfgs();
// Enable use of const generics on Rust 1.51 and greater

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@ -11,6 +11,7 @@ license = "Apache-2.0"
edition = "2018"
[dependencies]
once_cell = "1"
[features]
default = []

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@ -1,11 +1,3 @@
#[allow(dead_code)]
#[path = "src/impl_.rs"]
mod impl_;
fn main() {
// Print out error messages using display, to get nicer formatting.
if let Err(e) = impl_::configure() {
eprintln!("error: {}", e);
std::process::exit(1)
}
// Empty build script to force cargo to produce the "OUT_DIR" environment variable.
}

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@ -4,8 +4,8 @@ use std::{
env,
ffi::OsString,
fmt::Display,
fs::{self, DirEntry, File},
io::Write,
fs::{self, DirEntry},
io::{BufRead, BufReader, Read, Write},
path::{Path, PathBuf},
process::{Command, Stdio},
str::FromStr,
@ -55,7 +55,7 @@ fn env_var(var: &str) -> Option<OsString> {
/// Usually this is queried directly from the Python interpreter. When the `PYO3_NO_PYTHON` variable
/// is set, or during cross compile situations, then alternative strategies are used to populate
/// this type.
#[derive(Debug)]
#[cfg_attr(test, derive(Debug, PartialEq))]
pub struct InterpreterConfig {
pub version: PythonVersion,
pub libdir: Option<String>,
@ -99,6 +99,70 @@ impl InterpreterConfig {
pub fn is_pypy(&self) -> bool {
self.implementation == PythonImplementation::PyPy
}
#[doc(hidden)]
pub fn from_reader(reader: impl Read) -> Result<Self> {
let reader = BufReader::new(reader);
let mut lines = reader.lines();
let major = lines.next().ok_or("expected major version")??.parse()?;
let minor = lines.next().ok_or("expected minor version")??.parse()?;
let libdir = parse_option_string(lines.next().ok_or("expected libdir")??)?;
let shared = lines.next().ok_or("expected shared")??.parse()?;
let abi3 = lines.next().ok_or("expected abi3")??.parse()?;
let ld_version = parse_option_string(lines.next().ok_or("expected ld_version")??)?;
let base_prefix = parse_option_string(lines.next().ok_or("expected base_prefix")??)?;
let executable = parse_option_string(lines.next().ok_or("expected executable")??)?;
let calcsize_pointer =
parse_option_string(lines.next().ok_or("expected calcsize_pointer")??)?;
let implementation = lines.next().ok_or("expected implementation")??.parse()?;
let mut build_flags = BuildFlags(HashSet::new());
for line in lines {
build_flags.0.insert(line?.parse()?);
}
Ok(InterpreterConfig {
version: PythonVersion { major, minor },
libdir,
shared,
abi3,
ld_version,
base_prefix,
executable,
calcsize_pointer,
implementation,
build_flags,
})
}
#[doc(hidden)]
pub fn to_writer(&self, mut writer: impl Write) -> Result<()> {
writeln!(writer, "{}", self.version.major)?;
writeln!(writer, "{}", self.version.minor)?;
writeln!(writer, "{:?}", self.libdir)?;
writeln!(writer, "{}", self.shared)?;
writeln!(writer, "{}", self.abi3)?;
writeln!(writer, "{:?}", self.ld_version)?;
writeln!(writer, "{:?}", self.base_prefix)?;
writeln!(writer, "{:?}", self.executable)?;
writeln!(writer, "{:?}", self.calcsize_pointer)?;
writeln!(writer, "{:?}", self.implementation)?;
for flag in &self.build_flags.0 {
writeln!(writer, "{}", flag)?;
}
Ok(())
}
}
fn parse_option_string<T: FromStr>(string: String) -> Result<Option<T>>
where
<T as FromStr>::Err: std::error::Error + 'static,
{
if string == "None" {
Ok(None)
} else if string.starts_with("Some(") && string.ends_with(')') {
Ok(string[5..(string.len() - 1)].parse().map(Some)?)
} else {
Err("expected None or Some(value)".into())
}
}
#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
@ -234,6 +298,37 @@ fn cross_compiling() -> Result<Option<CrossCompileConfig>> {
}))
}
#[allow(non_camel_case_types)]
#[derive(Debug, Clone, Hash, PartialEq, Eq)]
pub enum BuildFlag {
WITH_THREAD,
Py_DEBUG,
Py_REF_DEBUG,
Py_TRACE_REFS,
COUNT_ALLOCS,
Other(String),
}
impl Display for BuildFlag {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "{:?}", self)
}
}
impl FromStr for BuildFlag {
type Err = Box<dyn std::error::Error>;
fn from_str(s: &str) -> Result<Self> {
match s {
"WITH_THREAD" => Ok(BuildFlag::WITH_THREAD),
"Py_DEBUG" => Ok(BuildFlag::Py_DEBUG),
"Py_REF_DEBUG" => Ok(BuildFlag::Py_REF_DEBUG),
"Py_TRACE_REFS" => Ok(BuildFlag::Py_TRACE_REFS),
"COUNT_ALLOCS" => Ok(BuildFlag::COUNT_ALLOCS),
other => Ok(BuildFlag::Other(other.to_owned())),
}
}
}
/// 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
@ -243,25 +338,29 @@ fn cross_compiling() -> Result<Option<CrossCompileConfig>> {
/// is the equivalent of `#ifdef {varname}` in C.
///
/// see Misc/SpecialBuilds.txt in the python source for what these mean.
#[derive(Debug)]
pub struct BuildFlags(pub HashSet<&'static str>);
#[cfg_attr(test, derive(Debug, PartialEq))]
pub struct BuildFlags(pub HashSet<BuildFlag>);
impl BuildFlags {
const ALL: [&'static str; 5] = [
const ALL: [BuildFlag; 5] = [
// TODO: Remove WITH_THREAD once Python 3.6 support dropped (as it's always on).
"WITH_THREAD",
"Py_DEBUG",
"Py_REF_DEBUG",
"Py_TRACE_REFS",
"COUNT_ALLOCS",
BuildFlag::WITH_THREAD,
BuildFlag::Py_DEBUG,
BuildFlag::Py_REF_DEBUG,
BuildFlag::Py_TRACE_REFS,
BuildFlag::COUNT_ALLOCS,
];
fn from_config_map(config_map: &HashMap<String, String>) -> Self {
Self(
BuildFlags::ALL
.iter()
.copied()
.filter(|flag| config_map.get(*flag).map_or(false, |value| value == "1"))
.cloned()
.filter(|flag| {
config_map
.get(&flag.to_string())
.map_or(false, |value| value == "1")
})
.collect(),
)
}
@ -292,7 +391,7 @@ impl BuildFlags {
.iter()
.zip(split_stdout)
.filter(|(_, flag_value)| *flag_value == "1")
.map(|(&flag, _)| flag)
.map(|(flag, _)| flag.clone())
.collect();
Ok(Self(flags))
@ -302,36 +401,36 @@ impl BuildFlags {
// sysconfig is missing all the flags on windows, so we can't actually
// query the interpreter directly for its build flags.
let mut flags = HashSet::new();
flags.insert("WITH_THREAD");
flags.insert(BuildFlag::WITH_THREAD);
// Uncomment these manually if your python was built with these and you want
// the cfg flags to be set in rust.
//
// map.insert("Py_DEBUG", "1");
// map.insert("Py_REF_DEBUG", "1");
// map.insert("Py_TRACE_REFS", "1");
// map.insert("COUNT_ALLOCS", 1");
// flags.insert(BuildFlag::Py_DEBUG);
// flags.insert(BuildFlag::Py_REF_DEBUG);
// flags.insert(BuildFlag::Py_TRACE_REFS);
// flags.insert(BuildFlag::COUNT_ALLOCS;
Self(flags)
}
fn abi3() -> Self {
let mut flags = HashSet::new();
flags.insert("WITH_THREAD");
flags.insert(BuildFlag::WITH_THREAD);
Self(flags)
}
fn fixup(mut self, version: PythonVersion, implementation: PythonImplementation) -> Self {
if self.0.contains("Py_DEBUG") {
self.0.insert("Py_REF_DEBUG");
if self.0.contains(&BuildFlag::Py_DEBUG) {
self.0.insert(BuildFlag::Py_REF_DEBUG);
if version <= PythonVersion::PY37 {
// Py_DEBUG only implies Py_TRACE_REFS until Python 3.7
self.0.insert("Py_TRACE_REFS");
self.0.insert(BuildFlag::Py_TRACE_REFS);
}
}
// WITH_THREAD is always on for Python 3.7, and for PyPy.
if implementation == PythonImplementation::PyPy || version >= PythonVersion::PY37 {
self.0.insert("WITH_THREAD");
self.0.insert(BuildFlag::WITH_THREAD);
}
self
@ -764,7 +863,7 @@ fn get_abi3_minor_version() -> Option<u8> {
.find(|i| cargo_env_var(&format!("CARGO_FEATURE_ABI3_PY3{}", i)).is_some())
}
fn get_interpreter_config() -> Result<InterpreterConfig> {
pub fn make_interpreter_config() -> Result<InterpreterConfig> {
let abi3_version = get_abi3_minor_version();
// If PYO3_NO_PYTHON is set with abi3, we can build PyO3 without calling Python.
@ -809,53 +908,32 @@ fn get_interpreter_config() -> Result<InterpreterConfig> {
Ok(interpreter_config)
}
pub fn configure() -> Result<()> {
let interpreter_config = get_interpreter_config()?;
write_interpreter_config(&interpreter_config)
}
#[cfg(test)]
mod tests {
use std::io::Cursor;
fn write_interpreter_config(interpreter_config: &InterpreterConfig) -> Result<()> {
let out_dir = env::var_os("OUT_DIR").unwrap();
let mut out = File::create(Path::new(&out_dir).join("pyo3-build-config.rs"))?;
use super::*;
writeln!(out, "{{")?;
writeln!(
out,
"let mut build_flags = std::collections::HashSet::new();"
)?;
for flag in &interpreter_config.build_flags.0 {
writeln!(out, "build_flags.insert({:?});", flag)?;
#[test]
pub fn test_read_write_roundtrip() {
let config = InterpreterConfig {
abi3: true,
base_prefix: Some("base_prefix".into()),
build_flags: BuildFlags::abi3(),
calcsize_pointer: Some(32),
executable: Some("executable".into()),
implementation: PythonImplementation::CPython,
ld_version: Some("ld_version".into()),
libdir: Some("libdir".into()),
shared: true,
version: MINIMUM_SUPPORTED_VERSION,
};
let mut buf: Vec<u8> = Vec::new();
config.to_writer(&mut buf).unwrap();
assert_eq!(
config,
InterpreterConfig::from_reader(Cursor::new(buf)).unwrap()
);
}
writeln!(
out,
r#"crate::impl_::InterpreterConfig {{
version: crate::impl_::PythonVersion {{
major: {major},
minor: {minor},
}},
implementation: crate::impl_::PythonImplementation::{implementation:?},
libdir: {libdir:?}.map(|str: &str| str.to_string()),
abi3: {abi3},
build_flags: crate::impl_::BuildFlags(build_flags),
base_prefix: {base_prefix:?}.map(|str: &str| str.to_string()),
calcsize_pointer: {calcsize_pointer:?},
executable: {executable:?}.map(|str: &str| str.to_string()),
ld_version: {ld_version:?}.map(|str: &str| str.to_string()),
shared: {shared:?}
}}"#,
major = interpreter_config.version.major,
minor = interpreter_config.version.minor,
implementation = interpreter_config.implementation,
base_prefix = interpreter_config.base_prefix,
calcsize_pointer = interpreter_config.calcsize_pointer,
executable = interpreter_config.executable,
ld_version = interpreter_config.ld_version,
libdir = interpreter_config.libdir,
shared = interpreter_config.shared,
abi3 = interpreter_config.abi3,
)?;
writeln!(out, "}}")?;
Ok(())
}

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@ -14,17 +14,32 @@
//!
//! For examples of how to use these attributes, [see PyO3's guide](https://pyo3.rs/main/building_and_distribution/multiple_python_versions.html).
#[allow(dead_code)] // TODO cover this using tests
mod impl_;
#[doc(hidden)]
pub use crate::impl_::{InterpreterConfig, PythonImplementation, PythonVersion};
use once_cell::sync::OnceCell;
#[doc(hidden)]
pub fn get() -> InterpreterConfig {
include!(concat!(env!("OUT_DIR"), "/pyo3-build-config.rs"))
pub use crate::impl_::{
make_interpreter_config, InterpreterConfig, PythonImplementation, PythonVersion,
};
/// Reads the configuration written by PyO3's build.rs
///
/// Because this will never change in a given compilation run, this is cached in a `once_cell`.
#[doc(hidden)]
pub fn get() -> &'static InterpreterConfig {
static CONFIG: OnceCell<InterpreterConfig> = OnceCell::new();
CONFIG.get_or_init(|| {
let config_file = std::fs::File::open(PATH).expect("config file missing");
let reader = std::io::BufReader::new(config_file);
InterpreterConfig::from_reader(reader).expect("failed to parse config file")
})
}
/// Path where PyO3's build.rs will write configuration.
#[doc(hidden)]
pub const PATH: &str = concat!(env!("OUT_DIR"), "/pyo3-build-config.txt");
pub fn use_pyo3_cfgs() {
get().emit_pyo3_cfgs();
}

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@ -16,11 +16,9 @@ edition = "2018"
[dependencies]
quote = { version = "1", default-features = false }
proc-macro2 = { version = "1", default-features = false }
pyo3-build-config = { path = "../pyo3-build-config", version = "=0.14.0-alpha.0" }
[dependencies.syn]
version = "1"
default-features = false
features = ["derive", "parsing", "printing", "clone-impls", "full", "extra-traits"]
[build-dependencies]
pyo3-build-config = { path = "../pyo3-build-config", version = "=0.14.0-alpha.0" }

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@ -1,3 +0,0 @@
fn main() {
pyo3_build_config::use_pyo3_cfgs();
}

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@ -177,7 +177,7 @@ impl CallingConvention {
} else if accept_kwargs {
// for functions that accept **kwargs, always prefer varargs
Self::Varargs
} else if cfg!(all(Py_3_7, not(Py_LIMITED_API))) {
} else if can_use_fastcall() {
Self::Fastcall
} else {
Self::Varargs
@ -185,6 +185,13 @@ impl CallingConvention {
}
}
fn can_use_fastcall() -> bool {
const PY37: pyo3_build_config::PythonVersion =
pyo3_build_config::PythonVersion { major: 3, minor: 7 };
let config = pyo3_build_config::get();
config.version >= PY37 && !config.abi3
}
pub struct FnSpec<'a> {
pub tp: FnType,
// Rust function name

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@ -133,7 +133,11 @@ fn impl_proto_methods(
let mut maybe_buffer_methods = None;
if cfg!(not(Py_3_9)) && proto.name == "Buffer" {
let build_config = pyo3_build_config::get();
const PY39: pyo3_build_config::PythonVersion =
pyo3_build_config::PythonVersion { major: 3, minor: 9 };
if build_config.version <= PY39 && proto.name == "Buffer" {
maybe_buffer_methods = Some(quote! {
impl pyo3::class::impl_::PyBufferProtocolProcs<#ty>
for pyo3::class::impl_::PyClassImplCollector<#ty>