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;
20 fn detect_llvm_link() -> (&'static str, &'static str) {
21 // Force the link mode we want, preferring static by default, but
22 // possibly overridden by `configure --enable-llvm-link-shared`.
23 if env::var_os("LLVM_LINK_SHARED").is_some() {
24 ("dylib", "--link-shared")
26 ("static", "--link-static")
31 if env::var_os("RUST_CHECK").is_some() {
32 // If we're just running `check`, there's no need for LLVM to be built.
33 println!("cargo:rerun-if-env-changed=RUST_CHECK");
37 let target = env::var("TARGET").expect("TARGET was not set");
38 let llvm_config = env::var_os("LLVM_CONFIG")
41 if let Some(dir) = env::var_os("CARGO_TARGET_DIR").map(PathBuf::from) {
42 let to_test = dir.parent()
47 .join("llvm/bin/llvm-config");
48 if Command::new(&to_test).output().is_ok() {
52 PathBuf::from("llvm-config")
55 println!("cargo:rerun-if-changed={}", llvm_config.display());
56 println!("cargo:rerun-if-env-changed=LLVM_CONFIG");
58 // Test whether we're cross-compiling LLVM. This is a pretty rare case
59 // currently where we're producing an LLVM for a different platform than
60 // what this build script is currently running on.
62 // In that case, there's no guarantee that we can actually run the target,
63 // so the build system works around this by giving us the LLVM_CONFIG for
64 // the host platform. This only really works if the host LLVM and target
65 // LLVM are compiled the same way, but for us that's typically the case.
67 // We *want* detect this cross compiling situation by asking llvm-config
68 // what it's host-target is. If that's not the TARGET, then we're cross
69 // compiling. Unfortunately `llvm-config` seems either be buggy, or we're
70 // misconfiguring it, because the `i686-pc-windows-gnu` build of LLVM will
71 // report itself with a `--host-target` of `x86_64-pc-windows-gnu`. This
72 // tricks us into thinking we're doing a cross build when we aren't, so
75 // In any case, if we're cross compiling, this generally just means that we
76 // can't trust all the output of llvm-config becaues it might be targeted
77 // for the host rather than the target. As a result a bunch of blocks below
78 // are gated on `if !is_crossed`
79 let target = env::var("TARGET").expect("TARGET was not set");
80 let host = env::var("HOST").expect("HOST was not set");
81 let is_crossed = target != host;
83 let mut optional_components =
84 vec!["x86", "arm", "aarch64", "amdgpu", "mips", "powerpc",
85 "systemz", "jsbackend", "webassembly", "msp430", "sparc", "nvptx"];
87 let mut version_cmd = Command::new(&llvm_config);
88 version_cmd.arg("--version");
89 let version_output = output(&mut version_cmd);
90 let mut parts = version_output.split('.').take(2)
91 .filter_map(|s| s.parse::<u32>().ok());
93 if let (Some(major), Some(minor)) = (parts.next(), parts.next()) {
100 optional_components.push("hexagon");
104 optional_components.push("riscv");
107 // FIXME: surely we don't need all these components, right? Stuff like mcjit
108 // or interpreter the compiler itself never uses.
109 let required_components = &["ipo",
119 let components = output(Command::new(&llvm_config).arg("--components"));
120 let mut components = components.split_whitespace().collect::<Vec<_>>();
121 components.retain(|c| optional_components.contains(c) || required_components.contains(c));
123 for component in required_components {
124 if !components.contains(component) {
125 panic!("require llvm component {} but wasn't found", component);
129 for component in components.iter() {
130 println!("cargo:rustc-cfg=llvm_component=\"{}\"", component);
133 // Link in our own LLVM shims, compiled with the same flags as LLVM
134 let mut cmd = Command::new(&llvm_config);
135 cmd.arg("--cxxflags");
136 let cxxflags = output(&mut cmd);
137 let mut cfg = cc::Build::new();
139 for flag in cxxflags.split_whitespace() {
140 // Ignore flags like `-m64` when we're doing a cross build
141 if is_crossed && flag.starts_with("-m") {
145 // -Wdate-time is not supported by the netbsd cross compiler
146 if is_crossed && target.contains("netbsd") && flag.contains("date-time") {
153 for component in &components {
154 let mut flag = String::from("LLVM_COMPONENT_");
155 flag.push_str(&component.to_uppercase());
156 cfg.define(&flag, None);
159 println!("cargo:rerun-if-changed-env=LLVM_RUSTLLVM");
160 if env::var_os("LLVM_RUSTLLVM").is_some() {
161 cfg.define("LLVM_RUSTLLVM", None);
164 build_helper::rerun_if_changed_anything_in_dir(Path::new("../rustllvm"));
165 cfg.file("../rustllvm/PassWrapper.cpp")
166 .file("../rustllvm/RustWrapper.cpp")
167 .file("../rustllvm/ArchiveWrapper.cpp")
168 .file("../rustllvm/Linker.cpp")
170 .cpp_link_stdlib(None) // we handle this below
171 .compile("rustllvm");
173 let (llvm_kind, llvm_link_arg) = detect_llvm_link();
175 // Link in all LLVM libraries, if we're uwring the "wrong" llvm-config then
176 // we don't pick up system libs because unfortunately they're for the host
177 // of llvm-config, not the target that we're attempting to link.
178 let mut cmd = Command::new(&llvm_config);
179 cmd.arg(llvm_link_arg).arg("--libs");
182 cmd.arg("--system-libs");
184 cmd.args(&components);
186 for lib in output(&mut cmd).split_whitespace() {
187 let name = if lib.starts_with("-l") {
189 } else if lib.starts_with("-") {
191 } else if Path::new(lib).exists() {
192 // On MSVC llvm-config will print the full name to libraries, but
193 // we're only interested in the name part
194 let name = Path::new(lib).file_name().unwrap().to_str().unwrap();
195 name.trim_right_matches(".lib")
196 } else if lib.ends_with(".lib") {
197 // Some MSVC libraries just come up with `.lib` tacked on, so chop
199 lib.trim_right_matches(".lib")
204 // Don't need or want this library, but LLVM's CMake build system
205 // doesn't provide a way to disable it, so filter it here even though we
206 // may or may not have built it. We don't reference anything from this
207 // library and it otherwise may just pull in extra dependencies on
208 // libedit which we don't want
209 if name == "LLVMLineEditor" {
213 let kind = if name.starts_with("LLVM") {
218 println!("cargo:rustc-link-lib={}={}", kind, name);
223 // If we're a cross-compile of LLVM then unfortunately we can't trust these
224 // ldflags (largely where all the LLVM libs are located). Currently just
225 // hack around this by replacing the host triple with the target and pray
226 // that those -L directories are the same!
227 let mut cmd = Command::new(&llvm_config);
228 cmd.arg(llvm_link_arg).arg("--ldflags");
229 for lib in output(&mut cmd).split_whitespace() {
230 if lib.starts_with("-LIBPATH:") {
231 println!("cargo:rustc-link-search=native={}", &lib[9..]);
232 } else if is_crossed {
233 if lib.starts_with("-L") {
234 println!("cargo:rustc-link-search=native={}",
235 lib[2..].replace(&host, &target));
237 } else if lib.starts_with("-l") {
238 println!("cargo:rustc-link-lib={}", &lib[2..]);
239 } else if lib.starts_with("-L") {
240 println!("cargo:rustc-link-search=native={}", &lib[2..]);
244 let llvm_static_stdcpp = env::var_os("LLVM_STATIC_STDCPP");
246 let stdcppname = if target.contains("openbsd") {
247 // llvm-config on OpenBSD doesn't mention stdlib=libc++
249 } else if target.contains("freebsd") {
251 } else if target.contains("netbsd") && llvm_static_stdcpp.is_some() {
252 // NetBSD uses a separate library when relocation is required
258 // C++ runtime library
259 if !target.contains("msvc") {
260 if let Some(s) = llvm_static_stdcpp {
261 assert!(!cxxflags.contains("stdlib=libc++"));
262 let path = PathBuf::from(s);
263 println!("cargo:rustc-link-search=native={}",
264 path.parent().unwrap().display());
265 println!("cargo:rustc-link-lib=static={}", stdcppname);
266 } else if cxxflags.contains("stdlib=libc++") {
267 println!("cargo:rustc-link-lib=c++");
269 println!("cargo:rustc-link-lib={}", stdcppname);
273 // LLVM requires symbols from this library, but apparently they're not printed
274 // during llvm-config?
275 if target.contains("windows-gnu") {
276 println!("cargo:rustc-link-lib=static-nobundle=gcc_s");
277 println!("cargo:rustc-link-lib=static-nobundle=pthread");
278 println!("cargo:rustc-link-lib=dylib=uuid");