skip the linkage of libstdc++ in rustc_llvm

Since we already statically link to libLLVM.so (which includes libstdc++),
we shouldn't need to link libstdc++ again for rustc_llvm.

Signed-off-by: onur-ozkan <[email protected]>

Author: onur-ozkan

compiler/rustc_llvm/build.rs

@@ -327,26 +327,8 @@ fn main() {
         }
     }
 
-    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")
-        || target.contains("aix")
-    {
-        "c++"
-    } else if target.contains("netbsd") && llvm_static_stdcpp.is_some() {
-        // NetBSD uses a separate library when relocation is required
-        "stdc++_p"
-    } else if llvm_use_libcxx.is_some() {
-        "c++"
-    } else {
-        "stdc++"
-    };
-
     // RISC-V GCC erroneously requires libatomic for sub-word
     // atomic operations. Some BSD uses Clang as its system
     // compiler and provides no libatomic in its base system so
@@ -355,24 +337,6 @@ fn main() {
         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}");
-        }
-    }
-
     // libc++abi and libunwind have to be specified explicitly on AIX.
     if target.contains("aix") {
         println!("cargo:rustc-link-lib=c++abi");

src/bootstrap/src/core/build_steps/compile.rs

@@ -1201,23 +1201,6 @@ fn rustc_llvm_env(builder: &Builder<'_>, cargo: &mut Cargo, target: TargetSelect
         cargo.env("LLVM_LINKER_FLAGS", llvm_linker_flags);
     }
 
-    // Building with a static libstdc++ is only supported on linux right now,
-    // not for MSVC or macOS
-    if builder.config.llvm_static_stdcpp
-        && !target.contains("freebsd")
-        && !target.is_msvc()
-        && !target.contains("apple")
-        && !target.contains("solaris")
-    {
-        let file = compiler_file(
-            builder,
-            &builder.cxx(target).unwrap(),
-            target,
-            CLang::Cxx,
-            "libstdc++.a",
-        );
-        cargo.env("LLVM_STATIC_STDCPP", file);
-    }
     if builder.llvm_link_shared() {
         cargo.env("LLVM_LINK_SHARED", "1");
     }