rust/src/librustc_llvm/build.rs
Jorge Aparicio f5a05adb25 enable the MSP430 LLVM backend
to let people experiment with this target out of tree.

The MSP430 architecture is used in 16-bit microcontrollers commonly used
in Digital Signal Processing applications.
2016-11-12 17:33:35 -05:00

222 lines
8.6 KiB
Rust

// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
extern crate gcc;
extern crate build_helper;
use std::process::Command;
use std::env;
use std::path::{PathBuf, Path};
use build_helper::output;
fn main() {
println!("cargo:rustc-cfg=cargobuild");
let target = env::var("TARGET").expect("TARGET was not set");
let llvm_config = env::var_os("LLVM_CONFIG")
.map(PathBuf::from)
.unwrap_or_else(|| {
if let Some(dir) = env::var_os("CARGO_TARGET_DIR").map(PathBuf::from) {
let to_test = dir.parent()
.unwrap()
.parent()
.unwrap()
.join(&target)
.join("llvm/bin/llvm-config");
if Command::new(&to_test).output().is_ok() {
return to_test;
}
}
PathBuf::from("llvm-config")
});
println!("cargo:rerun-if-changed={}", llvm_config.display());
// Test whether we're cross-compiling LLVM. This is a pretty rare case
// currently where we're producing an LLVM for a different platform than
// what this build script is currently running on.
//
// In that case, there's no guarantee that we can actually run the target,
// so the build system works around this by giving us the LLVM_CONFIG for
// the host platform. This only really works if the host LLVM and target
// LLVM are compiled the same way, but for us that's typically the case.
//
// We *want* detect this cross compiling situation by asking llvm-config
// what it's host-target is. If that's not the TARGET, then we're cross
// compiling. Unfortunately `llvm-config` seems either be buggy, or we're
// misconfiguring it, because the `i686-pc-windows-gnu` build of LLVM will
// report itself with a `--host-target` of `x86_64-pc-windows-gnu`. This
// tricks us into thinking we're doing a cross build when we aren't, so
// havoc ensues.
//
// In any case, if we're cross compiling, this generally just means that we
// can't trust all the output of llvm-config becaues it might be targeted
// for the host rather than the target. As a result a bunch of blocks below
// are gated on `if !is_crossed`
let target = env::var("TARGET").expect("TARGET was not set");
let host = env::var("HOST").expect("HOST was not set");
let is_crossed = target != host;
let optional_components =
["x86", "arm", "aarch64", "mips", "powerpc", "pnacl", "systemz", "jsbackend", "msp430"];
// FIXME: surely we don't need all these components, right? Stuff like mcjit
// or interpreter the compiler itself never uses.
let required_components = &["ipo",
"bitreader",
"bitwriter",
"linker",
"asmparser",
"mcjit",
"interpreter",
"instrumentation"];
let components = output(Command::new(&llvm_config).arg("--components"));
let mut components = components.split_whitespace().collect::<Vec<_>>();
components.retain(|c| optional_components.contains(c) || required_components.contains(c));
for component in required_components {
if !components.contains(component) {
panic!("require llvm component {} but wasn't found", component);
}
}
for component in components.iter() {
println!("cargo:rustc-cfg=llvm_component=\"{}\"", component);
}
// Link in our own LLVM shims, compiled with the same flags as LLVM
let mut cmd = Command::new(&llvm_config);
cmd.arg("--cxxflags");
let cxxflags = output(&mut cmd);
let mut cfg = gcc::Config::new();
for flag in cxxflags.split_whitespace() {
// Ignore flags like `-m64` when we're doing a cross build
if is_crossed && flag.starts_with("-m") {
continue;
}
cfg.flag(flag);
}
for component in &components[..] {
let mut flag = String::from("-DLLVM_COMPONENT_");
flag.push_str(&component.to_uppercase());
cfg.flag(&flag);
}
if env::var_os("LLVM_RUSTLLVM").is_some() {
cfg.flag("-DLLVM_RUSTLLVM");
}
cfg.file("../rustllvm/PassWrapper.cpp")
.file("../rustllvm/RustWrapper.cpp")
.file("../rustllvm/ArchiveWrapper.cpp")
.cpp(true)
.cpp_link_stdlib(None) // we handle this below
.compile("librustllvm.a");
// Link in all LLVM libraries, if we're uwring the "wrong" llvm-config then
// we don't pick up system libs because unfortunately they're for the host
// of llvm-config, not the target that we're attempting to link.
let mut cmd = Command::new(&llvm_config);
cmd.arg("--libs");
// Force static linking with "--link-static" if available.
let mut version_cmd = Command::new(&llvm_config);
version_cmd.arg("--version");
let version_output = output(&mut version_cmd);
let mut parts = version_output.split('.');
if let (Some(major), Some(minor)) = (parts.next().and_then(|s| s.parse::<u32>().ok()),
parts.next().and_then(|s| s.parse::<u32>().ok())) {
if major > 3 || (major == 3 && minor >= 9) {
cmd.arg("--link-static");
}
}
if !is_crossed {
cmd.arg("--system-libs");
}
cmd.args(&components[..]);
for lib in output(&mut cmd).split_whitespace() {
let name = if lib.starts_with("-l") {
&lib[2..]
} else if lib.starts_with("-") {
&lib[1..]
} else if Path::new(lib).exists() {
// On MSVC llvm-config will print the full name to libraries, but
// we're only interested in the name part
let name = Path::new(lib).file_name().unwrap().to_str().unwrap();
name.trim_right_matches(".lib")
} else if lib.ends_with(".lib") {
// Some MSVC libraries just come up with `.lib` tacked on, so chop
// that off
lib.trim_right_matches(".lib")
} else {
continue;
};
// Don't need or want this library, but LLVM's CMake build system
// doesn't provide a way to disable it, so filter it here even though we
// may or may not have built it. We don't reference anything from this
// library and it otherwise may just pull in extra dependencies on
// libedit which we don't want
if name == "LLVMLineEditor" {
continue;
}
let kind = if name.starts_with("LLVM") {
"static"
} else {
"dylib"
};
println!("cargo:rustc-link-lib={}={}", kind, name);
}
// LLVM ldflags
//
// If we're a cross-compile of LLVM then unfortunately we can't trust these
// ldflags (largely where all the LLVM libs are located). Currently just
// hack around this by replacing the host triple with the target and pray
// that those -L directories are the same!
let mut cmd = Command::new(&llvm_config);
cmd.arg("--ldflags");
for lib in output(&mut cmd).split_whitespace() {
if lib.starts_with("-LIBPATH:") {
println!("cargo:rustc-link-search=native={}", &lib[9..]);
} else if is_crossed {
if lib.starts_with("-L") {
println!("cargo:rustc-link-search=native={}",
lib[2..].replace(&host, &target));
}
} else if lib.starts_with("-l") {
println!("cargo:rustc-link-lib={}", &lib[2..]);
} else if lib.starts_with("-L") {
println!("cargo:rustc-link-search=native={}", &lib[2..]);
}
}
// C++ runtime library
if !target.contains("msvc") {
if let Some(s) = env::var_os("LLVM_STATIC_STDCPP") {
assert!(!cxxflags.contains("stdlib=libc++"));
let path = PathBuf::from(s);
println!("cargo:rustc-link-search=native={}",
path.parent().unwrap().display());
println!("cargo:rustc-link-lib=static=stdc++");
} else if cxxflags.contains("stdlib=libc++") {
println!("cargo:rustc-link-lib=c++");
} else {
println!("cargo:rustc-link-lib=stdc++");
}
}
}