Auto merge of #125463 - GuillaumeGomez:rollup-287wx4y, r=GuillaumeGomez

Rollup of 6 pull requests

Successful merges:

 - #125263 (rust-lld: fallback to rustc's sysroot if there's no path to the linker in the target sysroot)
 - #125345 (rustc_codegen_llvm: add support for writing summary bitcode)
 - #125362 (Actually use TAIT instead of emulating it)
 - #125412 (Don't suggest adding the unexpected cfgs to the build-script it-self)
 - #125445 (Migrate `run-make/rustdoc-with-short-out-dir-option` to `rmake.rs`)
 - #125452 (Cleanup check-cfg handling in core and std)

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 22 insertions, 1 deletions

diff --git a/compiler/rustc_codegen_llvm/src/back/write.rs b/compiler/rustc_codegen_llvm/src/back/write.rs
index 97d2e1670e5..02e3bb06dda 100644
--- a/compiler/rustc_codegen_llvm/src/back/write.rs
+++ b/compiler/rustc_codegen_llvm/src/back/write.rs
@@ -709,13 +709,15 @@ pub(crate) unsafe fn codegen(
         //   asm from LLVM and use `gcc` to create the object file.
 
         let bc_out = cgcx.output_filenames.temp_path(OutputType::Bitcode, module_name);
+        let bc_summary_out =
+            cgcx.output_filenames.temp_path(OutputType::ThinLinkBitcode, module_name);
         let obj_out = cgcx.output_filenames.temp_path(OutputType::Object, module_name);
 
         if config.bitcode_needed() {
             let _timer = cgcx
                 .prof
                 .generic_activity_with_arg("LLVM_module_codegen_make_bitcode", &*module.name);
-            let thin = ThinBuffer::new(llmod, config.emit_thin_lto);
+            let thin = ThinBuffer::new(llmod, config.emit_thin_lto, config.emit_thin_lto_summary);
             let data = thin.data();
 
             if let Some(bitcode_filename) = bc_out.file_name() {
@@ -726,6 +728,25 @@ pub(crate) unsafe fn codegen(
                 );
             }
 
+            if config.emit_thin_lto_summary
+                && let Some(thin_link_bitcode_filename) = bc_summary_out.file_name()
+            {
+                let summary_data = thin.thin_link_data();
+                cgcx.prof.artifact_size(
+                    "llvm_bitcode_summary",
+                    thin_link_bitcode_filename.to_string_lossy(),
+                    summary_data.len() as u64,
+                );
+
+                let _timer = cgcx.prof.generic_activity_with_arg(
+                    "LLVM_module_codegen_emit_bitcode_summary",
+                    &*module.name,
+                );
+                if let Err(err) = fs::write(&bc_summary_out, summary_data) {
+                    dcx.emit_err(WriteBytecode { path: &bc_summary_out, err });
+                }
+            }
+
             if config.emit_bc || config.emit_obj == EmitObj::Bitcode {
                 let _timer = cgcx
                     .prof