2 files changed, 28 insertions, 7 deletions
diff --git a/library/unwind/build.rs b/library/unwind/build.rs
index f88e6a924..31af39025 100644
--- a/library/unwind/build.rs
+++ b/library/unwind/build.rs
@@ -2,8 +2,14 @@ use std::env;
 
 fn main() {
     println!("cargo:rerun-if-changed=build.rs");
-    let target = env::var("TARGET").expect("TARGET was not set");
+    println!("cargo:rerun-if-env-changed=CARGO_CFG_MIRI");
+
+    if env::var_os("CARGO_CFG_MIRI").is_some() {
+        // Miri doesn't need the linker flags or a libunwind build.
+        return;
+    }
 
+    let target = env::var("TARGET").expect("TARGET was not set");
     if target.contains("android") {
         let build = cc::Build::new();
 
@@ -13,13 +19,8 @@ fn main() {
         let has_unwind = build.is_flag_supported("-lunwind").expect("Unable to invoke compiler");
 
         if has_unwind {
-            println!("cargo:rustc-link-lib=unwind");
-        } else {
-            println!("cargo:rustc-link-lib=gcc");
+            println!("cargo:rustc-cfg=feature=\"system-llvm-libunwind\"");
         }
-
-        // Android's unwinding library depends on dl_iterate_phdr in `libdl`.
-        println!("cargo:rustc-link-lib=dl");
     } else if target.contains("freebsd") {
         println!("cargo:rustc-link-lib=gcc_s");
     } else if target.contains("netbsd") {
diff --git a/library/unwind/src/lib.rs b/library/unwind/src/lib.rs
index 4a6ba6e10..46fe50cb9 100644
--- a/library/unwind/src/lib.rs
+++ b/library/unwind/src/lib.rs
@@ -55,6 +55,26 @@ cfg_if::cfg_if! {
     }
 }
 
+#[cfg(target_os = "android")]
+cfg_if::cfg_if! {
+    if #[cfg(feature = "llvm-libunwind")] {
+        compile_error!("`llvm-libunwind` is not supported for Android targets");
+    } else if #[cfg(feature = "system-llvm-libunwind")] {
+        #[link(name = "unwind", kind = "static", modifiers = "-bundle", cfg(target_feature = "crt-static"))]
+        #[link(name = "unwind", cfg(not(target_feature = "crt-static")))]
+        extern "C" {}
+    } else {
+        #[link(name = "gcc", kind = "static", modifiers = "-bundle", cfg(target_feature = "crt-static"))]
+        #[link(name = "gcc", cfg(not(target_feature = "crt-static")))]
+        extern "C" {}
+    }
+}
+// Android's unwinding library depends on dl_iterate_phdr in `libdl`.
+#[cfg(target_os = "android")]
+#[link(name = "dl", kind = "static", modifiers = "-bundle", cfg(target_feature = "crt-static"))]
+#[link(name = "dl", cfg(not(target_feature = "crt-static")))]
+extern "C" {}
+
 // When building with crt-static, we get `gcc_eh` from the `libc` crate, since
 // glibc needs it, and needs it listed later on the linker command line. We
 // don't want to duplicate it here.