1 files changed, 9 insertions, 3 deletions
diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
index 0679f55ab7f..52c24169f89 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
@@ -2080,8 +2080,11 @@ unsafe extern "C" {
         ConstraintsLen: size_t,
     ) -> bool;
 
+    /// A list of pointer-length strings is passed as two pointer-length slices,
+    /// one slice containing pointers and one slice containing their corresponding
+    /// lengths. The implementation will check that both slices have the same length.
     pub(crate) fn LLVMRustCoverageWriteFilenamesToBuffer(
-        Filenames: *const *const c_char,
+        Filenames: *const *const c_uchar, // See "PTR_LEN_STR".
         FilenamesLen: size_t,
         Lengths: *const size_t,
         LengthsLen: size_t,
@@ -2104,10 +2107,13 @@ unsafe extern "C" {
 
     pub(crate) fn LLVMRustCoverageCreatePGOFuncNameVar(
         F: &Value,
-        FuncName: *const c_char,
+        FuncName: *const c_uchar, // See "PTR_LEN_STR".
         FuncNameLen: size_t,
     ) -> &Value;
-    pub(crate) fn LLVMRustCoverageHashBytes(Bytes: *const c_char, NumBytes: size_t) -> u64;
+    pub(crate) fn LLVMRustCoverageHashBytes(
+        Bytes: *const c_uchar, // See "PTR_LEN_STR".
+        NumBytes: size_t,
+    ) -> u64;
 
     pub(crate) fn LLVMRustCoverageWriteCovmapSectionNameToString(M: &Module, OutStr: &RustString);