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(major: u32, minor: u32, llvm_config: &Path)
21 -> (&'static str, Option<&'static str>) {
22 if major > 3 || (major == 3 && minor >= 9) {
23 // Force the link mode we want, preferring static by default, but
24 // possibly overridden by `configure --enable-llvm-link-shared`.
25 if env::var_os("LLVM_LINK_SHARED").is_some() {
26 return ("dylib", Some("--link-shared"));
28 return ("static", Some("--link-static"));
30 } else if major == 3 && minor == 8 {
31 // Find out LLVM's default linking mode.
32 let mut mode_cmd = Command::new(llvm_config);
33 mode_cmd.arg("--shared-mode");
34 if output(&mut mode_cmd).trim() == "shared" {
35 return ("dylib", None);
37 return ("static", None);
44 let target = env::var("TARGET").expect("TARGET was not set");
45 let llvm_config = env::var_os("LLVM_CONFIG")
48 if let Some(dir) = env::var_os("CARGO_TARGET_DIR").map(PathBuf::from) {
49 let to_test = dir.parent()
54 .join("llvm/bin/llvm-config");
55 if Command::new(&to_test).output().is_ok() {
59 PathBuf::from("llvm-config")
62 println!("cargo:rerun-if-changed={}", llvm_config.display());
63 println!("cargo:rerun-if-env-changed=LLVM_CONFIG");
65 // Test whether we're cross-compiling LLVM. This is a pretty rare case
66 // currently where we're producing an LLVM for a different platform than
67 // what this build script is currently running on.
69 // In that case, there's no guarantee that we can actually run the target,
70 // so the build system works around this by giving us the LLVM_CONFIG for
71 // the host platform. This only really works if the host LLVM and target
72 // LLVM are compiled the same way, but for us that's typically the case.
74 // We *want* detect this cross compiling situation by asking llvm-config
75 // what it's host-target is. If that's not the TARGET, then we're cross
76 // compiling. Unfortunately `llvm-config` seems either be buggy, or we're
77 // misconfiguring it, because the `i686-pc-windows-gnu` build of LLVM will
78 // report itself with a `--host-target` of `x86_64-pc-windows-gnu`. This
79 // tricks us into thinking we're doing a cross build when we aren't, so
82 // In any case, if we're cross compiling, this generally just means that we
83 // can't trust all the output of llvm-config becaues it might be targeted
84 // for the host rather than the target. As a result a bunch of blocks below
85 // are gated on `if !is_crossed`
86 let target = env::var("TARGET").expect("TARGET was not set");
87 let host = env::var("HOST").expect("HOST was not set");
88 let is_crossed = target != host;
90 let mut optional_components =
91 vec!["x86", "arm", "aarch64", "mips", "powerpc", "pnacl",
92 "systemz", "jsbackend", "webassembly", "msp430", "sparc", "nvptx"];
94 let mut version_cmd = Command::new(&llvm_config);
95 version_cmd.arg("--version");
96 let version_output = output(&mut version_cmd);
97 let mut parts = version_output.split('.').take(2)
98 .filter_map(|s| s.parse::<u32>().ok());
100 if let (Some(major), Some(minor)) = (parts.next(), parts.next()) {
107 optional_components.push("hexagon");
110 // FIXME: surely we don't need all these components, right? Stuff like mcjit
111 // or interpreter the compiler itself never uses.
112 let required_components = &["ipo",
121 let components = output(Command::new(&llvm_config).arg("--components"));
122 let mut components = components.split_whitespace().collect::<Vec<_>>();
123 components.retain(|c| optional_components.contains(c) || required_components.contains(c));
125 for component in required_components {
126 if !components.contains(component) {
127 panic!("require llvm component {} but wasn't found", component);
131 for component in components.iter() {
132 println!("cargo:rustc-cfg=llvm_component=\"{}\"", component);
135 // Link in our own LLVM shims, compiled with the same flags as LLVM
136 let mut cmd = Command::new(&llvm_config);
137 cmd.arg("--cxxflags");
138 let cxxflags = output(&mut cmd);
139 let mut cfg = cc::Build::new();
141 for flag in cxxflags.split_whitespace() {
142 // Ignore flags like `-m64` when we're doing a cross build
143 if is_crossed && flag.starts_with("-m") {
147 // -Wdate-time is not supported by the netbsd cross compiler
148 if is_crossed && target.contains("netbsd") && flag.contains("date-time") {
155 for component in &components {
156 let mut flag = String::from("-DLLVM_COMPONENT_");
157 flag.push_str(&component.to_uppercase());
161 if env::var_os("LLVM_RUSTLLVM").is_some() {
162 cfg.flag("-DLLVM_RUSTLLVM");
165 build_helper::rerun_if_changed_anything_in_dir(Path::new("../rustllvm"));
166 cfg.file("../rustllvm/PassWrapper.cpp")
167 .file("../rustllvm/RustWrapper.cpp")
168 .file("../rustllvm/ArchiveWrapper.cpp")
170 .cpp_link_stdlib(None) // we handle this below
171 .compile("librustllvm.a");
173 let (llvm_kind, llvm_link_arg) = detect_llvm_link(major, minor, &llvm_config);
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);
181 if let Some(link_arg) = llvm_link_arg {
186 cmd.arg("--system-libs");
188 cmd.args(&components);
190 for lib in output(&mut cmd).split_whitespace() {
191 let name = if lib.starts_with("-l") {
193 } else if lib.starts_with("-") {
195 } else if Path::new(lib).exists() {
196 // On MSVC llvm-config will print the full name to libraries, but
197 // we're only interested in the name part
198 let name = Path::new(lib).file_name().unwrap().to_str().unwrap();
199 name.trim_right_matches(".lib")
200 } else if lib.ends_with(".lib") {
201 // Some MSVC libraries just come up with `.lib` tacked on, so chop
203 lib.trim_right_matches(".lib")
208 // Don't need or want this library, but LLVM's CMake build system
209 // doesn't provide a way to disable it, so filter it here even though we
210 // may or may not have built it. We don't reference anything from this
211 // library and it otherwise may just pull in extra dependencies on
212 // libedit which we don't want
213 if name == "LLVMLineEditor" {
217 let kind = if name.starts_with("LLVM") {
222 println!("cargo:rustc-link-lib={}={}", kind, name);
227 // If we're a cross-compile of LLVM then unfortunately we can't trust these
228 // ldflags (largely where all the LLVM libs are located). Currently just
229 // hack around this by replacing the host triple with the target and pray
230 // that those -L directories are the same!
231 let mut cmd = Command::new(&llvm_config);
232 if let Some(link_arg) = llvm_link_arg {
235 cmd.arg("--ldflags");
236 for lib in output(&mut cmd).split_whitespace() {
237 if lib.starts_with("-LIBPATH:") {
238 println!("cargo:rustc-link-search=native={}", &lib[9..]);
239 } else if is_crossed {
240 if lib.starts_with("-L") {
241 println!("cargo:rustc-link-search=native={}",
242 lib[2..].replace(&host, &target));
244 } else if lib.starts_with("-l") {
245 println!("cargo:rustc-link-lib={}", &lib[2..]);
246 } else if lib.starts_with("-L") {
247 println!("cargo:rustc-link-search=native={}", &lib[2..]);
251 let llvm_static_stdcpp = env::var_os("LLVM_STATIC_STDCPP");
253 let stdcppname = if target.contains("openbsd") {
254 // OpenBSD has a particular C++ runtime library name
256 } else if target.contains("netbsd") && llvm_static_stdcpp.is_some() {
257 // NetBSD uses a separate library when relocation is required
263 // C++ runtime library
264 if !target.contains("msvc") {
265 if let Some(s) = llvm_static_stdcpp {
266 assert!(!cxxflags.contains("stdlib=libc++"));
267 let path = PathBuf::from(s);
268 println!("cargo:rustc-link-search=native={}",
269 path.parent().unwrap().display());
270 println!("cargo:rustc-link-lib=static={}", stdcppname);
271 } else if cxxflags.contains("stdlib=libc++") {
272 println!("cargo:rustc-link-lib=c++");
274 println!("cargo:rustc-link-lib={}", stdcppname);
278 // LLVM requires symbols from this library, but apparently they're not printed
279 // during llvm-config?
280 if target.contains("windows-gnu") {
281 println!("cargo:rustc-link-lib=static-nobundle=gcc_s");
282 println!("cargo:rustc-link-lib=static-nobundle=pthread");