Auto merge of #78162 - GuillaumeGomez:rollup-6a4qiqu, r=GuillaumeGomez

Rollup of 9 pull requests

Successful merges:

 - #78046 (Add codegen test for issue #73827)
 - #78061 (Optimize const value interning for ZST types)
 - #78070 (we can test std and core panic macros together)
 - #78076 (Move orphan module-name/mod.rs files into module-name.rs files)
 - #78129 (Wrapping intrinsics doc links update.)
 - #78133 (Add some MIR-related regression tests)
 - #78144 (Don't update `entries` in `TypedArena` if T does not need drop)
 - #78145 (Drop unneeded `mut`)
 - #78157 (Remove unused type from librustdoc)

Failed merges:

r? `@ghost`

Author: bors

compiler/rustc_arena/src/lib.rs

@@ -217,8 +217,12 @@ impl<T> TypedArena<T> {
             let mut chunks = self.chunks.borrow_mut();
             let mut new_cap;
             if let Some(last_chunk) = chunks.last_mut() {
-                let used_bytes = self.ptr.get() as usize - last_chunk.start() as usize;
-                last_chunk.entries = used_bytes / mem::size_of::<T>();
+                // If a type is `!needs_drop`, we don't need to keep track of how many elements
+                // the chunk stores - the field will be ignored anyway.
+                if mem::needs_drop::<T>() {
+                    let used_bytes = self.ptr.get() as usize - last_chunk.start() as usize;
+                    last_chunk.entries = used_bytes / mem::size_of::<T>();
+                }
 
                 // If the previous chunk's len is less than HUGE_PAGE
                 // bytes, then this chunk will be least double the previous

compiler/rustc_ast_pretty/src/pp.rs

@@ -390,7 +390,7 @@ impl Printer {
         self.scan_stack.pop_front().unwrap()
     }
 
-    fn scan_top(&mut self) -> usize {
+    fn scan_top(&self) -> usize {
         *self.scan_stack.front().unwrap()
     }
 
@@ -484,7 +484,7 @@ impl Printer {
         self.pending_indentation += amount;
     }
 
-    fn get_top(&mut self) -> PrintStackElem {
+    fn get_top(&self) -> PrintStackElem {
         *self.print_stack.last().unwrap_or({
             &PrintStackElem { offset: 0, pbreak: PrintStackBreak::Broken(Breaks::Inconsistent) }
         })

compiler/rustc_ast_pretty/src/pprust/state.rs

@@ -63,7 +63,7 @@ impl<'a> Comments<'a> {
     }
 
     pub fn trailing_comment(
-        &mut self,
+        &self,
         span: rustc_span::Span,
         next_pos: Option<BytePos>,
     ) -> Option<Comment> {

compiler/rustc_middle/src/mir/coverage/mod.rs renamed to compiler/rustc_middle/src/mir/coverage.rs

@@ -187,6 +187,12 @@ impl<'rt, 'mir, 'tcx: 'mir, M: CompileTimeMachine<'mir, 'tcx>> ValueVisitor<'mir
                 return walked;
             }
         }
+
+        // ZSTs do not need validation unless they're uninhabited
+        if mplace.layout.is_zst() && !mplace.layout.abi.is_uninhabited() {
+            return Ok(());
+        }
+
         self.walk_aggregate(mplace, fields)
     }
 

compiler/rustc_middle/src/mir/terminator/mod.rs renamed to compiler/rustc_middle/src/mir/terminator.rs

@@ -1660,22 +1660,22 @@ extern "rust-intrinsic" {
     /// Returns (a + b) mod 2<sup>N</sup>, where N is the width of T in bits.
     ///
     /// The stabilized versions of this intrinsic are available on the integer
-    /// primitives via the `checked_add` method. For example,
-    /// [`u32::checked_add`]
+    /// primitives via the `wrapping_add` method. For example,
+    /// [`u32::wrapping_add`]
     #[rustc_const_stable(feature = "const_int_wrapping", since = "1.40.0")]
     pub fn wrapping_add<T: Copy>(a: T, b: T) -> T;
     /// Returns (a - b) mod 2<sup>N</sup>, where N is the width of T in bits.
     ///
     /// The stabilized versions of this intrinsic are available on the integer
-    /// primitives via the `checked_sub` method. For example,
-    /// [`u32::checked_sub`]
+    /// primitives via the `wrapping_sub` method. For example,
+    /// [`u32::wrapping_sub`]
     #[rustc_const_stable(feature = "const_int_wrapping", since = "1.40.0")]
     pub fn wrapping_sub<T: Copy>(a: T, b: T) -> T;
     /// Returns (a * b) mod 2<sup>N</sup>, where N is the width of T in bits.
     ///
     /// The stabilized versions of this intrinsic are available on the integer
-    /// primitives via the `checked_mul` method. For example,
-    /// [`u32::checked_mul`]
+    /// primitives via the `wrapping_mul` method. For example,
+    /// [`u32::wrapping_mul`]
     #[rustc_const_stable(feature = "const_int_wrapping", since = "1.40.0")]
     pub fn wrapping_mul<T: Copy>(a: T, b: T) -> T;
 

compiler/rustc_mir/src/interpret/intern.rs

@@ -85,12 +85,6 @@ mod theme;
 mod visit_ast;
 mod visit_lib;
 
-struct Output {
-    krate: clean::Crate,
-    renderinfo: config::RenderInfo,
-    renderopts: config::RenderOptions,
-}
-
 pub fn main() {
     rustc_driver::set_sigpipe_handler();
     rustc_driver::install_ice_hook();
@@ -521,15 +515,12 @@ fn main_options(options: config::Options) -> MainResult {
 
     krate.version = crate_version;
 
-    let out = Output { krate, renderinfo, renderopts };
-
     if show_coverage {
         // if we ran coverage, bail early, we don't need to also generate docs at this point
         // (also we didn't load in any of the useful passes)
         return Ok(());
     }
 
-    let Output { krate, renderinfo, renderopts } = out;
     info!("going to format");
     let (error_format, edition, debugging_options) = diag_opts;
     let diag = core::new_handler(error_format, None, &debugging_options);

compiler/rustc_trait_selection/src/traits/codegen/mod.rs renamed to compiler/rustc_trait_selection/src/traits/codegen.rs

@@ -0,0 +1,18 @@
+// This test checks that bounds checks are elided when
+// index is part of a (x | y) < C style condition
+
+// min-llvm-version: 11.0.0
+// compile-flags: -O
+
+#![crate_type = "lib"]
+
+// CHECK-LABEL: @get
+#[no_mangle]
+pub fn get(array: &[u8; 8], x: usize, y: usize) -> u8 {
+    if x > 7 || y > 7 {
+        0
+    } else {
+        // CHECK-NOT: panic_bounds_check
+        array[y]
+    }
+}