diff --git a/configure b/configure index 566d665b9cc78..133af075795c6 100755 --- a/configure +++ b/configure @@ -624,6 +624,7 @@ opt ccache 0 "invoke gcc/clang via ccache to reuse object files between builds" opt local-rust 0 "use an installed rustc rather than downloading a snapshot" opt local-rebuild 0 "assume local-rust matches the current version, for rebuilds; implies local-rust, and is implied if local-rust already matches the current version" opt llvm-static-stdcpp 0 "statically link to libstdc++ for LLVM" +opt llvm-link-shared 0 "prefer shared linking to LLVM (llvm-config --link-shared)" opt rpath 1 "build rpaths into rustc itself" opt stage0-landing-pads 1 "enable landing pads during bootstrap with stage0" # This is used by the automation to produce single-target nightlies diff --git a/src/bootstrap/compile.rs b/src/bootstrap/compile.rs index 5fc4f006729d3..236989dbcfeb5 100644 --- a/src/bootstrap/compile.rs +++ b/src/bootstrap/compile.rs @@ -212,6 +212,9 @@ pub fn rustc<'a>(build: &'a Build, target: &str, compiler: &Compiler<'a>) { cargo.env("LLVM_STATIC_STDCPP", compiler_file(build.cxx(target), "libstdc++.a")); } + if build.config.llvm_link_shared { + cargo.env("LLVM_LINK_SHARED", "1"); + } if let Some(ref s) = build.config.rustc_default_linker { cargo.env("CFG_DEFAULT_LINKER", s); } diff --git a/src/bootstrap/config.rs b/src/bootstrap/config.rs index 996544a25996f..60f65f623006c 100644 --- a/src/bootstrap/config.rs +++ b/src/bootstrap/config.rs @@ -53,6 +53,7 @@ pub struct Config { pub llvm_release_debuginfo: bool, pub llvm_version_check: bool, pub llvm_static_stdcpp: bool, + pub llvm_link_shared: bool, // rust codegen options pub rust_optimize: bool, @@ -346,6 +347,7 @@ impl Config { ("OPTIMIZE_LLVM", self.llvm_optimize), ("LLVM_VERSION_CHECK", self.llvm_version_check), ("LLVM_STATIC_STDCPP", self.llvm_static_stdcpp), + ("LLVM_LINK_SHARED", self.llvm_link_shared), ("OPTIMIZE", self.rust_optimize), ("DEBUG_ASSERTIONS", self.rust_debug_assertions), ("DEBUGINFO", self.rust_debuginfo), diff --git a/src/librustc_llvm/build.rs b/src/librustc_llvm/build.rs index ca80a5269c95a..6be3d1172dc23 100644 --- a/src/librustc_llvm/build.rs +++ b/src/librustc_llvm/build.rs @@ -17,6 +17,35 @@ use std::path::{PathBuf, Path}; use build_helper::output; +fn detect_llvm_link(llvm_config: &Path) -> (&'static str, Option<&'static str>) { + 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('.').take(2) + .filter_map(|s| s.parse::().ok()); + if let (Some(major), Some(minor)) = (parts.next(), parts.next()) { + if major > 3 || (major == 3 && minor >= 9) { + // Force the link mode we want, preferring static by default, but + // possibly overridden by `configure --enable-llvm-link-shared`. + if env::var_os("LLVM_LINK_SHARED").is_some() { + return ("dylib", Some("--link-shared")); + } else { + return ("static", Some("--link-static")); + } + } else if major == 3 && minor == 8 { + // Find out LLVM's default linking mode. + let mut mode_cmd = Command::new(llvm_config); + mode_cmd.arg("--shared-mode"); + if output(&mut mode_cmd).trim() == "shared" { + return ("dylib", None); + } else { + return ("static", None); + } + } + } + ("static", None) +} + fn main() { println!("cargo:rustc-cfg=cargobuild"); @@ -123,22 +152,16 @@ fn main() { .cpp_link_stdlib(None) // we handle this below .compile("librustllvm.a"); + let (llvm_kind, llvm_link_arg) = detect_llvm_link(&llvm_config); + // 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::().ok()), - parts.next().and_then(|s| s.parse::().ok())) { - if major > 3 || (major == 3 && minor >= 9) { - cmd.arg("--link-static"); - } + if let Some(link_arg) = llvm_link_arg { + cmd.arg(link_arg); } if !is_crossed { @@ -174,7 +197,7 @@ fn main() { } let kind = if name.starts_with("LLVM") { - "static" + llvm_kind } else { "dylib" };