Mark some coverage-related bindings as safe

Author: Zalathar

compiler/rustc_codegen_llvm/src/coverageinfo/llvm_cov.rs

@@ -6,21 +6,21 @@ use crate::coverageinfo::ffi;
 use crate::llvm;
 
 pub(crate) fn covmap_var_name() -> CString {
-    CString::new(llvm::build_byte_buffer(|s| unsafe {
+    CString::new(llvm::build_byte_buffer(|s| {
         llvm::LLVMRustCoverageWriteCovmapVarNameToString(s);
     }))
     .expect("covmap variable name should not contain NUL")
 }
 
 pub(crate) fn covmap_section_name(llmod: &llvm::Module) -> CString {
-    CString::new(llvm::build_byte_buffer(|s| unsafe {
+    CString::new(llvm::build_byte_buffer(|s| {
         llvm::LLVMRustCoverageWriteCovmapSectionNameToString(llmod, s);
     }))
     .expect("covmap section name should not contain NUL")
 }
 
 pub(crate) fn covfun_section_name(llmod: &llvm::Module) -> CString {
-    CString::new(llvm::build_byte_buffer(|s| unsafe {
+    CString::new(llvm::build_byte_buffer(|s| {
         llvm::LLVMRustCoverageWriteCovfunSectionNameToString(llmod, s);
     }))
     .expect("covfun section name should not contain NUL")
@@ -95,5 +95,5 @@ pub(crate) fn hash_bytes(bytes: &[u8]) -> u64 {
 /// as a raw numeric value. For historical reasons, the numeric value is 1 less
 /// than the number in the version's name, so `Version7` is actually `6u32`.
 pub(crate) fn mapping_version() -> u32 {
-    unsafe { llvm::LLVMRustCoverageMappingVersion() }
+    llvm::LLVMRustCoverageMappingVersion()
 }

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -2115,13 +2115,17 @@ unsafe extern "C" {
         NumBytes: size_t,
     ) -> u64;
 
-    pub(crate) fn LLVMRustCoverageWriteCovmapSectionNameToString(M: &Module, OutStr: &RustString);
-
-    pub(crate) fn LLVMRustCoverageWriteCovfunSectionNameToString(M: &Module, OutStr: &RustString);
-
-    pub(crate) fn LLVMRustCoverageWriteCovmapVarNameToString(OutStr: &RustString);
+    pub(crate) safe fn LLVMRustCoverageWriteCovmapSectionNameToString(
+        M: &Module,
+        OutStr: &RustString,
+    );
+    pub(crate) safe fn LLVMRustCoverageWriteCovfunSectionNameToString(
+        M: &Module,
+        OutStr: &RustString,
+    );
+    pub(crate) safe fn LLVMRustCoverageWriteCovmapVarNameToString(OutStr: &RustString);
 
-    pub(crate) fn LLVMRustCoverageMappingVersion() -> u32;
+    pub(crate) safe fn LLVMRustCoverageMappingVersion() -> u32;
     pub(crate) fn LLVMRustDebugMetadataVersion() -> u32;
     pub(crate) fn LLVMRustVersionMajor() -> u32;
     pub(crate) fn LLVMRustVersionMinor() -> u32;