diff --git a/config.toml.example b/config.toml.example index f5a34859369..c68d358b6a6 100644 --- a/config.toml.example +++ b/config.toml.example @@ -90,6 +90,12 @@ # with clang-cl, so this is special in that it only compiles LLVM with clang-cl #clang-cl = '/path/to/clang-cl.exe' +# Use libc++ when building LLVM instead of libstdc++. This is the default on +# platforms already use libc++ as the default C++ library, but this option +# allows you to use libc++ even on platforms when it's not. You need to ensure +# that your host compiler ships with libc++. +#use-libcxx = true + # ============================================================================= # General build configuration options # ============================================================================= diff --git a/src/bootstrap/compile.rs b/src/bootstrap/compile.rs index 0d2546a0e9c..8bc7c5838ed 100644 --- a/src/bootstrap/compile.rs +++ b/src/bootstrap/compile.rs @@ -723,6 +723,9 @@ pub fn build_codegen_backend(builder: &Builder, { cargo.env("LLVM_LINK_SHARED", "1"); } + if builder.config.llvm_use_libcxx { + cargo.env("LLVM_USE_LIBCXX", "1"); + } } _ => panic!("unknown backend: {}", backend), } diff --git a/src/bootstrap/config.rs b/src/bootstrap/config.rs index 8655cf0eb30..9421817ae6d 100644 --- a/src/bootstrap/config.rs +++ b/src/bootstrap/config.rs @@ -82,6 +82,8 @@ pub struct Config { pub lldb_enabled: bool, pub llvm_tools_enabled: bool, + pub llvm_use_libcxx: bool, + // rust codegen options pub rust_optimize: bool, pub rust_codegen_units: Option, @@ -252,6 +254,7 @@ struct Llvm { link_shared: Option, version_suffix: Option, clang_cl: Option, + use_libcxx: Option, } #[derive(Deserialize, Default, Clone)] @@ -513,6 +516,7 @@ impl Config { config.llvm_link_jobs = llvm.link_jobs; config.llvm_version_suffix = llvm.version_suffix.clone(); config.llvm_clang_cl = llvm.clang_cl.clone(); + set(&mut config.llvm_use_libcxx, llvm.use_libcxx); } if let Some(ref rust) = toml.rust { diff --git a/src/bootstrap/configure.py b/src/bootstrap/configure.py index d13a3dc7834..b0c3c970249 100755 --- a/src/bootstrap/configure.py +++ b/src/bootstrap/configure.py @@ -62,6 +62,7 @@ o("full-tools", None, "enable all tools") o("lld", "rust.lld", "build lld") o("lldb", "rust.lldb", "build lldb") o("missing-tools", "dist.missing-tools", "allow failures when building tools") +o("use-libcxx", "llvm.use_libcxx", "build LLVM with libc++") # Optimization and debugging options. These may be overridden by the release # channel, etc. diff --git a/src/librustc_llvm/build.rs b/src/librustc_llvm/build.rs index 98cf20a7ba7..d4a3ae273fc 100644 --- a/src/librustc_llvm/build.rs +++ b/src/librustc_llvm/build.rs @@ -236,6 +236,7 @@ fn main() { } let llvm_static_stdcpp = env::var_os("LLVM_STATIC_STDCPP"); + let llvm_use_libcxx = env::var_os("LLVM_USE_LIBCXX"); let stdcppname = if target.contains("openbsd") { // llvm-config on OpenBSD doesn't mention stdlib=libc++ @@ -245,6 +246,8 @@ fn main() { } 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++" };