Auto merge of #113430 - Zalathar:hash, r=b-naber

Remove `LLVMRustCoverageHashCString`

Coverage has two FFI functions for computing the hash of a byte string. One takes a ptr/len pair (`LLVMRustCoverageHashByteArray`), and the other takes a NUL-terminated C string (`LLVMRustCoverageHashCString`).

But on closer inspection, the C string version is unnecessary. The calling-side code converts a Rust `&str` into a `CString`, and the C++ code then immediately turns it back into a ptr/len string before actually hashing it. So we can just call the ptr/len version directly instead.

---

This PR also fixes a bug in the C++ declaration of `LLVMRustCoverageHashByteArray`. It should be `size_t`, since that's what is declared and passed on the Rust side, and it's what `StrRef`'s constructor expects to receive on the callee side.

1 files changed, 1 insertions, 6 deletions

diff --git a/compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp
index 87906dee4d3..80b6c0fb439 100644
--- a/compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp
@@ -158,14 +158,9 @@ extern "C" LLVMValueRef LLVMRustCoverageCreatePGOFuncNameVar(LLVMValueRef F, con
   return wrap(createPGOFuncNameVar(*cast<Function>(unwrap(F)), FuncNameRef));
 }
 
-extern "C" uint64_t LLVMRustCoverageHashCString(const char *StrVal) {
-  StringRef StrRef(StrVal);
-  return IndexedInstrProf::ComputeHash(StrRef);
-}
-
 extern "C" uint64_t LLVMRustCoverageHashByteArray(
     const char *Bytes,
-    unsigned NumBytes) {
+    size_t NumBytes) {
   StringRef StrRef(Bytes, NumBytes);
   return IndexedInstrProf::ComputeHash(StrRef);
 }