From 3a89cbb0ff0352fc6ab4bf329124f961fddb1e2a Mon Sep 17 00:00:00 2001
From: Josh Stone <jistone@redhat.com>
Date: Mon, 18 Aug 2025 17:11:07 -0700
Subject: [PATCH 1/2] bootstrap: allow disabling target self-contained

---
 bootstrap.example.toml                        | 5 +++++
 src/bootstrap/src/core/build_steps/compile.rs | 4 ++++
 src/bootstrap/src/core/config/config.rs       | 3 +++
 src/bootstrap/src/core/config/toml/target.rs  | 5 +++++
 src/bootstrap/src/lib.rs                      | 5 +++++
 5 files changed, 22 insertions(+)

diff --git a/bootstrap.example.toml b/bootstrap.example.toml
index eac939577979..db72e0fd29c5 100644
--- a/bootstrap.example.toml
+++ b/bootstrap.example.toml
@@ -1060,3 +1060,8 @@
 # Link the compiler and LLVM against `jemalloc` instead of the default libc allocator.
 # This overrides the global `rust.jemalloc` option. See that option for more info.
 #jemalloc = rust.jemalloc (bool)
+
+# Copy libc and CRT objects into the target lib/self-contained/ directory.
+# Enabled by default on `musl`, `wasi`, and `windows-gnu` targets. Other
+# targets may ignore this setting if they have nothing to be contained.
+#self-contained = <platform-specific> (bool)
diff --git a/src/bootstrap/src/core/build_steps/compile.rs b/src/bootstrap/src/core/build_steps/compile.rs
index 1458b0beefa8..08757f3283cf 100644
--- a/src/bootstrap/src/core/build_steps/compile.rs
+++ b/src/bootstrap/src/core/build_steps/compile.rs
@@ -370,6 +370,10 @@ fn copy_self_contained_objects(
     compiler: &Compiler,
     target: TargetSelection,
 ) -> Vec<(PathBuf, DependencyType)> {
+    if builder.self_contained(target) != Some(true) {
+        return vec![];
+    }
+
     let libdir_self_contained =
         builder.sysroot_target_libdir(*compiler, target).join("self-contained");
     t!(fs::create_dir_all(&libdir_self_contained));
diff --git a/src/bootstrap/src/core/config/config.rs b/src/bootstrap/src/core/config/config.rs
index 678a9b639522..9e45efc72d1a 100644
--- a/src/bootstrap/src/core/config/config.rs
+++ b/src/bootstrap/src/core/config/config.rs
@@ -819,6 +819,9 @@ pub(crate) fn parse_inner(
                 if let Some(s) = cfg.no_std {
                     target.no_std = s;
                 }
+                if let Some(s) = cfg.self_contained {
+                    target.self_contained = s;
+                }
                 target.cc = cfg.cc.map(PathBuf::from);
                 target.cxx = cfg.cxx.map(PathBuf::from);
                 target.ar = cfg.ar.map(PathBuf::from);
diff --git a/src/bootstrap/src/core/config/toml/target.rs b/src/bootstrap/src/core/config/toml/target.rs
index 020602e6a199..a944e1d194dd 100644
--- a/src/bootstrap/src/core/config/toml/target.rs
+++ b/src/bootstrap/src/core/config/toml/target.rs
@@ -43,6 +43,7 @@ struct TomlTarget {
         runner: Option<String> = "runner",
         optimized_compiler_builtins: Option<CompilerBuiltins> = "optimized-compiler-builtins",
         jemalloc: Option<bool> = "jemalloc",
+        self_contained: Option<bool> = "self-contained",
     }
 }
 
@@ -75,6 +76,7 @@ pub struct Target {
     pub codegen_backends: Option<Vec<CodegenBackendKind>>,
     pub optimized_compiler_builtins: Option<CompilerBuiltins>,
     pub jemalloc: Option<bool>,
+    pub self_contained: bool,
 }
 
 impl Target {
@@ -86,6 +88,9 @@ pub fn from_triple(triple: &str) -> Self {
         if triple.contains("emscripten") {
             target.runner = Some("node".into());
         }
+        if triple.contains("-musl") || triple.contains("-wasi") || triple.contains("-windows-gnu") {
+            target.self_contained = true;
+        }
         target
     }
 }
diff --git a/src/bootstrap/src/lib.rs b/src/bootstrap/src/lib.rs
index a2aeed20948e..e530e1ceb99e 100644
--- a/src/bootstrap/src/lib.rs
+++ b/src/bootstrap/src/lib.rs
@@ -1453,6 +1453,11 @@ fn no_std(&self, target: TargetSelection) -> Option<bool> {
         self.config.target_config.get(&target).map(|t| t.no_std)
     }
 
+    /// Returns `true` if this is a self-contained `target`, if defined
+    fn self_contained(&self, target: TargetSelection) -> Option<bool> {
+        self.config.target_config.get(&target).map(|t| t.self_contained)
+    }
+
     /// Returns `true` if the target will be tested using the `remote-test-client`
     /// and `remote-test-server` binaries.
     fn remote_tested(&self, target: TargetSelection) -> bool {
-- 
2.51.0