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-rw-r--r--compiler/rustc_llvm/build.rs368
1 files changed, 368 insertions, 0 deletions
diff --git a/compiler/rustc_llvm/build.rs b/compiler/rustc_llvm/build.rs
new file mode 100644
index 000000000..62ef5804d
--- /dev/null
+++ b/compiler/rustc_llvm/build.rs
@@ -0,0 +1,368 @@
+use std::env;
+use std::ffi::{OsStr, OsString};
+use std::fmt::Display;
+use std::path::{Path, PathBuf};
+use std::process::{Command, Stdio};
+
+const OPTIONAL_COMPONENTS: &[&str] = &[
+ "x86",
+ "arm",
+ "aarch64",
+ "amdgpu",
+ "avr",
+ "m68k",
+ "mips",
+ "powerpc",
+ "systemz",
+ "jsbackend",
+ "webassembly",
+ "msp430",
+ "sparc",
+ "nvptx",
+ "hexagon",
+ "riscv",
+ "bpf",
+];
+
+const REQUIRED_COMPONENTS: &[&str] =
+ &["ipo", "bitreader", "bitwriter", "linker", "asmparser", "lto", "coverage", "instrumentation"];
+
+fn detect_llvm_link() -> (&'static str, &'static str) {
+ // Force the link mode we want, preferring static by default, but
+ // possibly overridden by `configure --enable-llvm-link-shared`.
+ if tracked_env_var_os("LLVM_LINK_SHARED").is_some() {
+ ("dylib", "--link-shared")
+ } else {
+ ("static", "--link-static")
+ }
+}
+
+// Because Cargo adds the compiler's dylib path to our library search path, llvm-config may
+// break: the dylib path for the compiler, as of this writing, contains a copy of the LLVM
+// shared library, which means that when our freshly built llvm-config goes to load it's
+// associated LLVM, it actually loads the compiler's LLVM. In particular when building the first
+// compiler (i.e., in stage 0) that's a problem, as the compiler's LLVM is likely different from
+// the one we want to use. As such, we restore the environment to what bootstrap saw. This isn't
+// perfect -- we might actually want to see something from Cargo's added library paths -- but
+// for now it works.
+fn restore_library_path() {
+ let key = tracked_env_var_os("REAL_LIBRARY_PATH_VAR").expect("REAL_LIBRARY_PATH_VAR");
+ if let Some(env) = tracked_env_var_os("REAL_LIBRARY_PATH") {
+ env::set_var(&key, &env);
+ } else {
+ env::remove_var(&key);
+ }
+}
+
+/// Reads an environment variable and adds it to dependencies.
+/// Supposed to be used for all variables except those set for build scripts by cargo
+/// <https://doc.rust-lang.org/cargo/reference/environment-variables.html#environment-variables-cargo-sets-for-build-scripts>
+fn tracked_env_var_os<K: AsRef<OsStr> + Display>(key: K) -> Option<OsString> {
+ println!("cargo:rerun-if-env-changed={}", key);
+ env::var_os(key)
+}
+
+fn rerun_if_changed_anything_in_dir(dir: &Path) {
+ let mut stack = dir
+ .read_dir()
+ .unwrap()
+ .map(|e| e.unwrap())
+ .filter(|e| &*e.file_name() != ".git")
+ .collect::<Vec<_>>();
+ while let Some(entry) = stack.pop() {
+ let path = entry.path();
+ if entry.file_type().unwrap().is_dir() {
+ stack.extend(path.read_dir().unwrap().map(|e| e.unwrap()));
+ } else {
+ println!("cargo:rerun-if-changed={}", path.display());
+ }
+ }
+}
+
+#[track_caller]
+fn output(cmd: &mut Command) -> String {
+ let output = match cmd.stderr(Stdio::inherit()).output() {
+ Ok(status) => status,
+ Err(e) => {
+ println!("\n\nfailed to execute command: {:?}\nerror: {}\n\n", cmd, e);
+ std::process::exit(1);
+ }
+ };
+ if !output.status.success() {
+ panic!(
+ "command did not execute successfully: {:?}\n\
+ expected success, got: {}",
+ cmd, output.status
+ );
+ }
+ String::from_utf8(output.stdout).unwrap()
+}
+
+fn main() {
+ for component in REQUIRED_COMPONENTS.iter().chain(OPTIONAL_COMPONENTS.iter()) {
+ println!("cargo:rustc-check-cfg=values(llvm_component,\"{}\")", component);
+ }
+
+ if tracked_env_var_os("RUST_CHECK").is_some() {
+ // If we're just running `check`, there's no need for LLVM to be built.
+ return;
+ }
+
+ restore_library_path();
+
+ let target = env::var("TARGET").expect("TARGET was not set");
+ let llvm_config =
+ tracked_env_var_os("LLVM_CONFIG").map(|x| Some(PathBuf::from(x))).unwrap_or_else(|| {
+ if let Some(dir) = tracked_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 Some(to_test);
+ }
+ }
+ None
+ });
+
+ if let Some(llvm_config) = &llvm_config {
+ println!("cargo:rerun-if-changed={}", llvm_config.display());
+ }
+ let llvm_config = llvm_config.unwrap_or_else(|| PathBuf::from("llvm-config"));
+
+ // 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 its 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 because 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 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 = cc::Build::new();
+ cfg.warnings(false);
+ 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;
+ }
+
+ if flag.starts_with("-flto") {
+ continue;
+ }
+
+ // -Wdate-time is not supported by the netbsd cross compiler
+ if is_crossed && target.contains("netbsd") && flag.contains("date-time") {
+ continue;
+ }
+
+ // Include path contains host directory, replace it with target
+ if is_crossed && flag.starts_with("-I") {
+ cfg.flag(&flag.replace(&host, &target));
+ continue;
+ }
+
+ cfg.flag(flag);
+ }
+
+ for component in &components {
+ let mut flag = String::from("LLVM_COMPONENT_");
+ flag.push_str(&component.to_uppercase());
+ cfg.define(&flag, None);
+ }
+
+ if tracked_env_var_os("LLVM_RUSTLLVM").is_some() {
+ cfg.define("LLVM_RUSTLLVM", None);
+ }
+
+ if tracked_env_var_os("LLVM_NDEBUG").is_some() {
+ cfg.define("NDEBUG", None);
+ cfg.debug(false);
+ }
+
+ rerun_if_changed_anything_in_dir(Path::new("llvm-wrapper"));
+ cfg.file("llvm-wrapper/PassWrapper.cpp")
+ .file("llvm-wrapper/RustWrapper.cpp")
+ .file("llvm-wrapper/ArchiveWrapper.cpp")
+ .file("llvm-wrapper/CoverageMappingWrapper.cpp")
+ .file("llvm-wrapper/Linker.cpp")
+ .cpp(true)
+ .cpp_link_stdlib(None) // we handle this below
+ .compile("llvm-wrapper");
+
+ let (llvm_kind, llvm_link_arg) = detect_llvm_link();
+
+ // Link in all LLVM libraries, if we're using 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(llvm_link_arg).arg("--libs");
+
+ if !is_crossed {
+ cmd.arg("--system-libs");
+ } else if target.contains("windows-gnu") {
+ println!("cargo:rustc-link-lib=shell32");
+ println!("cargo:rustc-link-lib=uuid");
+ } else if target.contains("netbsd") || target.contains("haiku") || target.contains("darwin") {
+ println!("cargo:rustc-link-lib=z");
+ }
+ cmd.args(&components);
+
+ for lib in output(&mut cmd).split_whitespace() {
+ let name = if let Some(stripped) = lib.strip_prefix("-l") {
+ stripped
+ } else if let Some(stripped) = lib.strip_prefix('-') {
+ stripped
+ } 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_end_matches(".lib")
+ } else if lib.ends_with(".lib") {
+ // Some MSVC libraries just come up with `.lib` tacked on, so chop
+ // that off
+ lib.trim_end_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") { llvm_kind } 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(llvm_link_arg).arg("--ldflags");
+ for lib in output(&mut cmd).split_whitespace() {
+ if is_crossed {
+ if let Some(stripped) = lib.strip_prefix("-LIBPATH:") {
+ println!("cargo:rustc-link-search=native={}", stripped.replace(&host, &target));
+ } else if let Some(stripped) = lib.strip_prefix("-L") {
+ println!("cargo:rustc-link-search=native={}", stripped.replace(&host, &target));
+ }
+ } else if let Some(stripped) = lib.strip_prefix("-LIBPATH:") {
+ println!("cargo:rustc-link-search=native={}", stripped);
+ } else if let Some(stripped) = lib.strip_prefix("-l") {
+ println!("cargo:rustc-link-lib={}", stripped);
+ } else if let Some(stripped) = lib.strip_prefix("-L") {
+ println!("cargo:rustc-link-search=native={}", stripped);
+ }
+ }
+
+ // Some LLVM linker flags (-L and -l) may be needed even when linking
+ // rustc_llvm, for example when using static libc++, we may need to
+ // manually specify the library search path and -ldl -lpthread as link
+ // dependencies.
+ let llvm_linker_flags = tracked_env_var_os("LLVM_LINKER_FLAGS");
+ if let Some(s) = llvm_linker_flags {
+ for lib in s.into_string().unwrap().split_whitespace() {
+ if let Some(stripped) = lib.strip_prefix("-l") {
+ println!("cargo:rustc-link-lib={}", stripped);
+ } else if let Some(stripped) = lib.strip_prefix("-L") {
+ println!("cargo:rustc-link-search=native={}", stripped);
+ }
+ }
+ }
+
+ let llvm_static_stdcpp = tracked_env_var_os("LLVM_STATIC_STDCPP");
+ let llvm_use_libcxx = tracked_env_var_os("LLVM_USE_LIBCXX");
+
+ let stdcppname = if target.contains("openbsd") {
+ if target.contains("sparc64") { "estdc++" } else { "c++" }
+ } else if target.contains("darwin")
+ || target.contains("freebsd")
+ || target.contains("windows-gnullvm")
+ {
+ "c++"
+ } else if target.contains("netbsd") && llvm_static_stdcpp.is_some() {
+ // NetBSD uses a separate library when relocation is required
+ "stdc++_pic"
+ } else if llvm_use_libcxx.is_some() {
+ "c++"
+ } else {
+ "stdc++"
+ };
+
+ // RISC-V GCC erroneously requires libatomic for sub-word
+ // atomic operations. FreeBSD uses Clang as its system
+ // compiler and provides no libatomic in its base system so
+ // does not want this.
+ if !target.contains("freebsd") && target.starts_with("riscv") {
+ println!("cargo:rustc-link-lib=atomic");
+ }
+
+ // C++ runtime library
+ if !target.contains("msvc") {
+ if let Some(s) = llvm_static_stdcpp {
+ assert!(!cxxflags.contains("stdlib=libc++"));
+ let path = PathBuf::from(s);
+ println!("cargo:rustc-link-search=native={}", path.parent().unwrap().display());
+ if target.contains("windows") {
+ println!("cargo:rustc-link-lib=static:-bundle={}", stdcppname);
+ } else {
+ println!("cargo:rustc-link-lib=static={}", stdcppname);
+ }
+ } else if cxxflags.contains("stdlib=libc++") {
+ println!("cargo:rustc-link-lib=c++");
+ } else {
+ println!("cargo:rustc-link-lib={}", stdcppname);
+ }
+ }
+
+ // Libstdc++ depends on pthread which Rust doesn't link on MinGW
+ // since nothing else requires it.
+ if target.ends_with("windows-gnu") {
+ println!("cargo:rustc-link-lib=static:-bundle=pthread");
+ }
+}
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