Auto merge of #111248 - Dylan-DPC:rollup-lbp0ui3, r=Dylan-DPC

Rollup of 6 pull requests

Successful merges:

 - #103056 (Fix `checked_{add,sub}_duration` incorrectly returning `None` when `other` has more than `i64::MAX` seconds)
 - #108801 (Implement RFC 3348, `c"foo"` literals)
 - #110773 (Reduce MIR dump file count for MIR-opt tests)
 - #110876 (Added default target cpu to `--print target-cpus` output and updated docs)
 - #111068 (Improve check-cfg implementation)
 - #111238 (btree_map: `Cursor{,Mut}::peek_prev` must agree)

Failed merges:

 - #110694 (Implement builtin # syntax and use it for offset_of!(...))

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

2 files changed, 9 insertions, 2 deletions

diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
index c95148013eb..53d97f35201 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
@@ -2249,7 +2249,7 @@ extern "C" {
 
     pub fn LLVMRustHasFeature(T: &TargetMachine, s: *const c_char) -> bool;
 
-    pub fn LLVMRustPrintTargetCPUs(T: &TargetMachine);
+    pub fn LLVMRustPrintTargetCPUs(T: &TargetMachine, cpu: *const c_char);
     pub fn LLVMRustGetTargetFeaturesCount(T: &TargetMachine) -> size_t;
     pub fn LLVMRustGetTargetFeature(
         T: &TargetMachine,
diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs
index 46692fd5e8b..2fbdab9f8ce 100644
--- a/compiler/rustc_codegen_llvm/src/llvm_util.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs
@@ -329,7 +329,14 @@ pub(crate) fn print(req: PrintRequest, sess: &Session) {
     require_inited();
     let tm = create_informational_target_machine(sess);
     match req {
-        PrintRequest::TargetCPUs => unsafe { llvm::LLVMRustPrintTargetCPUs(tm) },
+        PrintRequest::TargetCPUs => {
+            // SAFETY generate a C compatible string from a byte slice to pass
+            // the target CPU name into LLVM, the lifetime of the reference is
+            // at least as long as the C function
+            let cpu_cstring = CString::new(handle_native(sess.target.cpu.as_ref()))
+                .unwrap_or_else(|e| bug!("failed to convert to cstring: {}", e));
+            unsafe { llvm::LLVMRustPrintTargetCPUs(tm, cpu_cstring.as_ptr()) };
+        }
         PrintRequest::TargetFeatures => print_target_features(sess, tm),
         _ => bug!("rustc_codegen_llvm can't handle print request: {:?}", req),
     }