1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
12 extern crate build_helper;
14 use std::process::Command;
16 use std::path::{PathBuf, Path};
18 use build_helper::output;
21 println!("cargo:rustc-cfg=cargobuild");
23 let target = env::var("TARGET").unwrap();
24 let llvm_config = env::var_os("LLVM_CONFIG")
27 if let Some(dir) = env::var_os("CARGO_TARGET_DIR")
29 let to_test = dir.parent()
34 .join("llvm/bin/llvm-config");
35 if Command::new(&to_test).output().is_ok() {
39 PathBuf::from("llvm-config")
42 println!("cargo:rerun-if-changed={}", llvm_config.display());
44 // Test whether we're cross-compiling LLVM. This is a pretty rare case
45 // currently where we're producing an LLVM for a different platform than
46 // what this build script is currently running on.
48 // In that case, there's no guarantee that we can actually run the target,
49 // so the build system works around this by giving us the LLVM_CONFIG for
50 // the host platform. This only really works if the host LLVM and target
51 // LLVM are compiled the same way, but for us that's typically the case.
53 // We *want* detect this cross compiling situation by asking llvm-config
54 // what it's host-target is. If that's not the TARGET, then we're cross
55 // compiling. Unfortunately `llvm-config` seems either be buggy, or we're
56 // misconfiguring it, because the `i686-pc-windows-gnu` build of LLVM will
57 // report itself with a `--host-target` of `x86_64-pc-windows-gnu`. This
58 // tricks us into thinking we're doing a cross build when we aren't, so
61 // In any case, if we're cross compiling, this generally just means that we
62 // can't trust all the output of llvm-config becaues it might be targeted
63 // for the host rather than the target. As a result a bunch of blocks below
64 // are gated on `if !is_crossed`
65 let target = env::var("TARGET").unwrap();
66 let host = env::var("HOST").unwrap();
67 let is_crossed = target != host;
69 let optional_components = ["x86", "arm", "aarch64", "mips", "powerpc", "pnacl", "systemz"];
71 // FIXME: surely we don't need all these components, right? Stuff like mcjit
72 // or interpreter the compiler itself never uses.
73 let required_components = &["ipo",
82 let components = output(Command::new(&llvm_config).arg("--components"));
83 let mut components = components.split_whitespace().collect::<Vec<_>>();
84 components.retain(|c| optional_components.contains(c) || required_components.contains(c));
86 for component in required_components {
87 if !components.contains(component) {
88 panic!("require llvm component {} but wasn't found", component);
92 for component in components.iter() {
93 println!("cargo:rustc-cfg=llvm_component=\"{}\"", component);
96 // Link in our own LLVM shims, compiled with the same flags as LLVM
97 let mut cmd = Command::new(&llvm_config);
98 cmd.arg("--cxxflags");
99 let cxxflags = output(&mut cmd);
100 let mut cfg = gcc::Config::new();
101 for flag in cxxflags.split_whitespace() {
102 // Ignore flags like `-m64` when we're doing a cross build
103 if is_crossed && flag.starts_with("-m") {
109 for component in &components[..] {
110 let mut flag = String::from("-DLLVM_COMPONENT_");
111 flag.push_str(&component.to_uppercase());
115 if env::var_os("LLVM_RUSTLLVM").is_some() {
116 cfg.flag("-DLLVM_RUSTLLVM");
119 cfg.file("../rustllvm/PassWrapper.cpp")
120 .file("../rustllvm/RustWrapper.cpp")
121 .file("../rustllvm/ArchiveWrapper.cpp")
123 .cpp_link_stdlib(None) // we handle this below
124 .compile("librustllvm.a");
126 // Link in all LLVM libraries, if we're uwring the "wrong" llvm-config then
127 // we don't pick up system libs because unfortunately they're for the host
128 // of llvm-config, not the target that we're attempting to link.
129 let mut cmd = Command::new(&llvm_config);
132 cmd.arg("--system-libs");
134 cmd.args(&components[..]);
136 for lib in output(&mut cmd).split_whitespace() {
137 let name = if lib.starts_with("-l") {
139 } else if lib.starts_with("-") {
141 } else if Path::new(lib).exists() {
142 // On MSVC llvm-config will print the full name to libraries, but
143 // we're only interested in the name part
144 let name = Path::new(lib).file_name().unwrap().to_str().unwrap();
145 name.trim_right_matches(".lib")
146 } else if lib.ends_with(".lib") {
147 // Some MSVC libraries just come up with `.lib` tacked on, so chop
149 lib.trim_right_matches(".lib")
154 // Don't need or want this library, but LLVM's CMake build system
155 // doesn't provide a way to disable it, so filter it here even though we
156 // may or may not have built it. We don't reference anything from this
157 // library and it otherwise may just pull in extra dependencies on
158 // libedit which we don't want
159 if name == "LLVMLineEditor" {
163 let kind = if name.starts_with("LLVM") {
168 println!("cargo:rustc-link-lib={}={}", kind, name);
173 // If we're a cross-compile of LLVM then unfortunately we can't trust these
174 // ldflags (largely where all the LLVM libs are located). Currently just
175 // hack around this by replacing the host triple with the target and pray
176 // that those -L directories are the same!
177 let mut cmd = Command::new(&llvm_config);
178 cmd.arg("--ldflags");
179 for lib in output(&mut cmd).split_whitespace() {
180 if lib.starts_with("-LIBPATH:") {
181 println!("cargo:rustc-link-search=native={}", &lib[9..]);
182 } else if is_crossed {
183 if lib.starts_with("-L") {
184 println!("cargo:rustc-link-search=native={}",
185 lib[2..].replace(&host, &target));
187 } else if lib.starts_with("-l") {
188 println!("cargo:rustc-link-lib={}", &lib[2..]);
189 } else if lib.starts_with("-L") {
190 println!("cargo:rustc-link-search=native={}", &lib[2..]);
194 // C++ runtime library
195 if !target.contains("msvc") {
196 if let Some(s) = env::var_os("LLVM_STATIC_STDCPP") {
197 assert!(!cxxflags.contains("stdlib=libc++"));
198 let path = PathBuf::from(s);
199 println!("cargo:rustc-link-search=native={}",
200 path.parent().unwrap().display());
201 println!("cargo:rustc-link-lib=static=stdc++");
202 } else if cxxflags.contains("stdlib=libc++") {
203 println!("cargo:rustc-link-lib=c++");
205 println!("cargo:rustc-link-lib=stdc++");