From 8364de4cb8edab85efcb895824ce06f4a95bd26f Mon Sep 17 00:00:00 2001
From: Josh Stone <jistone@redhat.com>
Date: Mon, 18 Aug 2025 17:11:07 -0700
Subject: [PATCH] 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       | 4 ++++
 src/bootstrap/src/core/config/toml/target.rs  | 5 +++++
 src/bootstrap/src/lib.rs                      | 5 +++++
 5 files changed, 23 insertions(+)

diff --git a/bootstrap.example.toml b/bootstrap.example.toml
index 6f37e51a47d..ee21bc06bea 100644
--- a/bootstrap.example.toml
+++ b/bootstrap.example.toml
@@ -1077,3 +1077,8 @@
 # pass `off`:
 # - x86_64-unknown-linux-gnu
 #default-linker-linux-override = "off" (for most targets)
+
+# 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 6857a40ada8..9a98323a704 100644
--- a/src/bootstrap/src/core/build_steps/compile.rs
+++ b/src/bootstrap/src/core/build_steps/compile.rs
@@ -368,6 +368,10 @@ 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 4b7ae6df360..6bab269a33c 100644
--- a/src/bootstrap/src/core/config/config.rs
+++ b/src/bootstrap/src/core/config/config.rs
@@ -864,6 +864,7 @@ pub(crate) fn parse_inner(
                     runner: target_runner,
                     optimized_compiler_builtins: target_optimized_compiler_builtins,
                     jemalloc: target_jemalloc,
+                    self_contained: target_self_contained
                 } = cfg;
 
                 let mut target = Target::from_triple(&triple);
@@ -921,6 +922,9 @@ pub(crate) fn parse_inner(
                 if let Some(s) = target_no_std {
                     target.no_std = s;
                 }
+                if let Some(s) = target_self_contained {
+                    target.self_contained = s;
+                }
                 target.cc = target_cc.map(PathBuf::from);
                 target.cxx = target_cxx.map(PathBuf::from);
                 target.ar = target_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 4c7afa50b96..83b8a1b50ca 100644
--- a/src/bootstrap/src/core/config/toml/target.rs
+++ b/src/bootstrap/src/core/config/toml/target.rs
@@ -47,6 +47,7 @@ struct TomlTarget {
         runner: Option<String> = "runner",
         optimized_compiler_builtins: Option<CompilerBuiltins> = "optimized-compiler-builtins",
         jemalloc: Option<bool> = "jemalloc",
+        self_contained: Option<bool> = "self-contained",
     }
 }
 
@@ -80,6 +81,7 @@ 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 {
@@ -91,6 +93,9 @@ 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 dd30f05b728..cc89a84071e 100644
--- a/src/bootstrap/src/lib.rs
+++ b/src/bootstrap/src/lib.rs
@@ -1441,6 +1441,11 @@ 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