Auto merge of #121569 - matthiaskrgr:rollup-awglrax, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #121343 (Add examples for some methods on slices)
 - #121374 (match lowering: Split off `test_candidates` into several functions and improve comments)
 - #121474 (Ignore compiletest test directive migration commits)
 - #121515 (promotion: don't promote int::MIN / -1)
 - #121530 (Fix incorrect doc of ScopedJoinHandle::is_finished)
 - #121551 (Forbid use of `extern "C-unwind"` inside standard library)
 - #121556 (Use `addr_of!`)

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

Author: bors

.git-blame-ignore-revs

@@ -20,3 +20,6 @@ f97fddab91fbf290ea5b691fe355d6f915220b6e
 cc907f80b95c6ec530c5ee1b05b044a468f07eca
 # format let-chains
 b2d2184edea578109a48ec3d8decbee5948e8f35
+# test directives migration
+6e48b96692d63a79a14563f27fe5185f122434f8
+ec2cc761bc7067712ecc7734502f703fe3b024c8

compiler/rustc_codegen_llvm/src/back/archive.rs

@@ -313,7 +313,7 @@ fn get_llvm_object_symbols(
             llvm::LLVMRustGetSymbols(
                 buf.as_ptr(),
                 buf.len(),
-                &mut *state as *mut &mut _ as *mut c_void,
+                std::ptr::addr_of_mut!(*state) as *mut c_void,
                 callback,
                 error_callback,
             )

compiler/rustc_codegen_llvm/src/lib.rs

@@ -169,7 +169,7 @@ impl WriteBackendMethods for LlvmCodegenBackend {
     fn print_pass_timings(&self) {
         unsafe {
             let mut size = 0;
-            let cstr = llvm::LLVMRustPrintPassTimings(&mut size as *mut usize);
+            let cstr = llvm::LLVMRustPrintPassTimings(std::ptr::addr_of_mut!(size));
             if cstr.is_null() {
                 println!("failed to get pass timings");
             } else {
@@ -182,7 +182,7 @@ impl WriteBackendMethods for LlvmCodegenBackend {
     fn print_statistics(&self) {
         unsafe {
             let mut size = 0;
-            let cstr = llvm::LLVMRustPrintStatistics(&mut size as *mut usize);
+            let cstr = llvm::LLVMRustPrintStatistics(std::ptr::addr_of_mut!(size));
             if cstr.is_null() {
                 println!("failed to get pass stats");
             } else {

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -435,7 +435,7 @@ pub(crate) fn print(req: &PrintRequest, mut out: &mut dyn PrintBackendInfo, sess
                     &tm,
                     cpu_cstring.as_ptr(),
                     callback,
-                    &mut out as *mut &mut dyn PrintBackendInfo as *mut c_void,
+                    std::ptr::addr_of_mut!(out) as *mut c_void,
                 );
             }
         }

compiler/rustc_data_structures/src/sync.rs

@@ -429,7 +429,7 @@ impl<T> RwLock<T> {
     #[inline(always)]
     pub fn leak(&self) -> &T {
         let guard = self.read();
-        let ret = unsafe { &*(&*guard as *const T) };
+        let ret = unsafe { &*std::ptr::addr_of!(*guard) };
         std::mem::forget(guard);
         ret
     }

compiler/rustc_middle/src/query/on_disk_cache.rs

@@ -233,7 +233,7 @@ impl<'sess> OnDiskCache<'sess> {
 
                 for (index, file) in files.iter().enumerate() {
                     let index = SourceFileIndex(index as u32);
-                    let file_ptr: *const SourceFile = &**file as *const _;
+                    let file_ptr: *const SourceFile = std::ptr::addr_of!(**file);
                     file_to_file_index.insert(file_ptr, index);
                     let source_file_id = EncodedSourceFileId::new(tcx, file);
                     file_index_to_stable_id.insert(index, source_file_id);
@@ -835,7 +835,7 @@ pub struct CacheEncoder<'a, 'tcx> {
 impl<'a, 'tcx> CacheEncoder<'a, 'tcx> {
     #[inline]
     fn source_file_index(&mut self, source_file: Lrc<SourceFile>) -> SourceFileIndex {
-        self.file_to_file_index[&(&*source_file as *const SourceFile)]
+        self.file_to_file_index[&std::ptr::addr_of!(*source_file)]
     }
 
     /// Encode something with additional information that allows to do some

compiler/rustc_middle/src/ty/list.rs

@@ -61,7 +61,7 @@ impl<T> List<T> {
         // length) that is 64-byte aligned, thus featuring the necessary
         // trailing padding for elements with up to 64-byte alignment.
         static EMPTY_SLICE: InOrder<usize, MaxAlign> = InOrder(0, MaxAlign);
-        unsafe { &*(&EMPTY_SLICE as *const _ as *const List<T>) }
+        unsafe { &*(std::ptr::addr_of!(EMPTY_SLICE) as *const List<T>) }
     }
 
     pub fn len(&self) -> usize {