Auto merge of rust-lang#69919 - Centril:rollup-fxo33zs, r=Centril

Rollup of 8 pull requests

Successful merges:

 - rust-lang#66472 (--show-coverage json)
 - rust-lang#69603 (tidy: replace `make check` with `./x.py test` in documentation)
 - rust-lang#69760 (Improve expression & attribute parsing)
 - rust-lang#69828 (fix memory leak when vec::IntoIter panics during drop)
 - rust-lang#69850 (panic_bounds_check: use caller_location, like PanicFnLangItem)
 - rust-lang#69876 (Add long error explanation for E0739)
 - rust-lang#69888 ([Miri] Use a session variable instead of checking for an env var always)
 - rust-lang#69893 (librustc_codegen_llvm: Use slices instead of 0-terminated strings)

Failed merges:

r? @ghost

Author: bors

CONTRIBUTING.md

@@ -142,7 +142,7 @@ the issue in question.
 Please make sure your pull request is in compliance with Rust's style
 guidelines by running
 
-    $ python x.py test src/tools/tidy
+    $ python x.py test tidy
 
 Make this check before every pull request (and every new commit in a pull
 request); you can add [git hooks](https://git-scm.com/book/en/v2/Customizing-Git-Git-Hooks)

src/bootstrap/README.md

@@ -55,6 +55,9 @@ The script accepts commands, flags, and arguments to determine what to do:
   # run all unit tests
   ./x.py test
 
+  # execute tool tests
+  ./x.py test tidy
+
   # execute the UI test suite
   ./x.py test src/test/ui
 

src/bootstrap/flags.rs

@@ -359,7 +359,7 @@ Arguments:
                 subcommand_help.push_str(
                     "\n
 Arguments:
-    This subcommand accepts a number of paths to directories to tests that
+    This subcommand accepts a number of paths to test directories that
     should be compiled and run. For example:
 
         ./x.py test src/test/ui
@@ -372,6 +372,10 @@ Arguments:
     just like `build src/libstd --stage N` it tests the compiler produced by the previous
     stage.
 
+    Execute tool tests with a tool name argument:
+
+        ./x.py test tidy
+
     If no arguments are passed then the complete artifacts for that stage are
     compiled and tested.
 

src/liballoc/vec.rs

@@ -2626,13 +2626,21 @@ impl<T: Clone> Clone for IntoIter<T> {
 #[stable(feature = "rust1", since = "1.0.0")]
 unsafe impl<#[may_dangle] T> Drop for IntoIter<T> {
     fn drop(&mut self) {
+        struct DropGuard<'a, T>(&'a mut IntoIter<T>);
+
+        impl<T> Drop for DropGuard<'_, T> {
+            fn drop(&mut self) {
+                // RawVec handles deallocation
+                let _ = unsafe { RawVec::from_raw_parts(self.0.buf.as_ptr(), self.0.cap) };
+            }
+        }
+
+        let guard = DropGuard(self);
         // destroy the remaining elements
         unsafe {
-            ptr::drop_in_place(self.as_mut_slice());
+            ptr::drop_in_place(guard.0.as_mut_slice());
         }
-
-        // RawVec handles deallocation
-        let _ = unsafe { RawVec::from_raw_parts(self.buf.as_ptr(), self.cap) };
+        // now `guard` will be dropped and do the rest
     }
 }
 

src/libcore/macros/mod.rs

@@ -1,3 +1,4 @@
+#[cfg(bootstrap)]
 #[doc(include = "panic.md")]
 #[macro_export]
 #[allow_internal_unstable(core_panic, track_caller)]
@@ -20,6 +21,26 @@ macro_rules! panic {
     );
 }
 
+#[cfg(not(bootstrap))]
+#[doc(include = "panic.md")]
+#[macro_export]
+#[allow_internal_unstable(core_panic, track_caller)]
+#[stable(feature = "core", since = "1.6.0")]
+macro_rules! panic {
+    () => (
+        $crate::panic!("explicit panic")
+    );
+    ($msg:expr) => (
+        $crate::panicking::panic($msg)
+    );
+    ($msg:expr,) => (
+        $crate::panic!($msg)
+    );
+    ($fmt:expr, $($arg:tt)+) => (
+        $crate::panicking::panic_fmt($crate::format_args!($fmt, $($arg)+))
+    );
+}
+
 /// Asserts that two expressions are equal to each other (using [`PartialEq`]).
 ///
 /// On panic, this macro will print the values of the expressions with their

src/libcore/panicking.rs

@@ -32,6 +32,7 @@
 use crate::fmt;
 use crate::panic::{Location, PanicInfo};
 
+/// The underlying implementation of libcore's `panic!` macro when no formatting is used.
 #[cold]
 // never inline unless panic_immediate_abort to avoid code
 // bloat at the call sites as much as possible
@@ -49,9 +50,28 @@ pub fn panic(expr: &str) -> ! {
     // truncation and padding (even though none is used here). Using
     // Arguments::new_v1 may allow the compiler to omit Formatter::pad from the
     // output binary, saving up to a few kilobytes.
-    panic_fmt(fmt::Arguments::new_v1(&[expr], &[]), Location::caller())
+    #[cfg(not(bootstrap))]
+    panic_fmt(fmt::Arguments::new_v1(&[expr], &[]));
+    #[cfg(bootstrap)]
+    panic_fmt(fmt::Arguments::new_v1(&[expr], &[]), Location::caller());
 }
 
+#[cfg(not(bootstrap))]
+#[cold]
+#[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))]
+#[track_caller]
+#[lang = "panic_bounds_check"] // needed by codegen for panic on OOB array/slice access
+fn panic_bounds_check(index: usize, len: usize) -> ! {
+    if cfg!(feature = "panic_immediate_abort") {
+        unsafe { super::intrinsics::abort() }
+    }
+
+    panic!("index out of bounds: the len is {} but the index is {}", len, index)
+}
+
+// For bootstrap, we need a variant with the old argument order, and a corresponding
+// `panic_fmt`.
+#[cfg(bootstrap)]
 #[cold]
 #[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))]
 #[lang = "panic_bounds_check"] // needed by codegen for panic on OOB array/slice access
@@ -66,10 +86,12 @@ fn panic_bounds_check(location: &Location<'_>, index: usize, len: usize) -> ! {
     )
 }
 
+/// The underlying implementation of libcore's `panic!` macro when formatting is used.
 #[cold]
 #[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))]
 #[cfg_attr(feature = "panic_immediate_abort", inline)]
-pub fn panic_fmt(fmt: fmt::Arguments<'_>, location: &Location<'_>) -> ! {
+#[cfg_attr(not(bootstrap), track_caller)]
+pub fn panic_fmt(fmt: fmt::Arguments<'_>, #[cfg(bootstrap)] location: &Location<'_>) -> ! {
     if cfg!(feature = "panic_immediate_abort") {
         unsafe { super::intrinsics::abort() }
     }
@@ -81,6 +103,10 @@ pub fn panic_fmt(fmt: fmt::Arguments<'_>, location: &Location<'_>) -> ! {
         fn panic_impl(pi: &PanicInfo<'_>) -> !;
     }
 
+    #[cfg(bootstrap)]
     let pi = PanicInfo::internal_constructor(Some(&fmt), location);
+    #[cfg(not(bootstrap))]
+    let pi = PanicInfo::internal_constructor(Some(&fmt), Location::caller());
+
     unsafe { panic_impl(&pi) }
 }

src/librustc/mir/interpret/error.rs

@@ -5,15 +5,18 @@ use crate::mir;
 use crate::mir::interpret::ConstValue;
 use crate::ty::layout::{Align, LayoutError, Size};
 use crate::ty::query::TyCtxtAt;
+use crate::ty::tls;
 use crate::ty::{self, layout, Ty};
 
 use backtrace::Backtrace;
+use rustc_data_structures::sync::Lock;
 use rustc_errors::{struct_span_err, DiagnosticBuilder};
 use rustc_hir as hir;
 use rustc_macros::HashStable;
+use rustc_session::CtfeBacktrace;
 use rustc_span::{Pos, Span};
 use rustc_target::spec::abi::Abi;
-use std::{any::Any, env, fmt};
+use std::{any::Any, fmt};
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq, HashStable, RustcEncodable, RustcDecodable)]
 pub enum ErrorHandled {
@@ -257,21 +260,25 @@ impl From<ErrorHandled> for InterpErrorInfo<'_> {
 
 impl<'tcx> From<InterpError<'tcx>> for InterpErrorInfo<'tcx> {
     fn from(kind: InterpError<'tcx>) -> Self {
-        let backtrace = match env::var("RUSTC_CTFE_BACKTRACE") {
-            // Matching `RUST_BACKTRACE` -- we treat "0" the same as "not present".
-            Ok(ref val) if val != "0" => {
-                let mut backtrace = Backtrace::new_unresolved();
+        let capture_backtrace = tls::with_context_opt(|ctxt| {
+            if let Some(ctxt) = ctxt {
+                *Lock::borrow(&ctxt.tcx.sess.ctfe_backtrace)
+            } else {
+                CtfeBacktrace::Disabled
+            }
+        });
 
-                if val == "immediate" {
-                    // Print it now.
-                    print_backtrace(&mut backtrace);
-                    None
-                } else {
-                    Some(Box::new(backtrace))
-                }
+        let backtrace = match capture_backtrace {
+            CtfeBacktrace::Disabled => None,
+            CtfeBacktrace::Capture => Some(Box::new(Backtrace::new_unresolved())),
+            CtfeBacktrace::Immediate => {
+                // Print it now.
+                let mut backtrace = Backtrace::new_unresolved();
+                print_backtrace(&mut backtrace);
+                None
             }
-            _ => None,
         };
+
         InterpErrorInfo { kind, backtrace }
     }
 }

src/librustc_ast/token.rs

@@ -535,6 +535,16 @@ impl Token {
         false
     }
 
+    // Is the token an interpolated block (`$b:block`)?
+    pub fn is_whole_block(&self) -> bool {
+        if let Interpolated(ref nt) = self.kind {
+            if let NtBlock(..) = **nt {
+                return true;
+            }
+        }
+        false
+    }
+
     /// Returns `true` if the token is either the `mut` or `const` keyword.
     pub fn is_mutability(&self) -> bool {
         self.is_keyword(kw::Mut) || self.is_keyword(kw::Const)

src/librustc_codegen_llvm/allocator.rs

@@ -1,5 +1,3 @@
-use std::ffi::CString;
-
 use crate::attributes;
 use libc::c_uint;
 use rustc::bug;
@@ -50,8 +48,8 @@ pub(crate) unsafe fn codegen(tcx: TyCtxt<'_>, mods: &mut ModuleLlvm, kind: Alloc
             args.len() as c_uint,
             False,
         );
-        let name = CString::new(format!("__rust_{}", method.name)).unwrap();
-        let llfn = llvm::LLVMRustGetOrInsertFunction(llmod, name.as_ptr(), ty);
+        let name = format!("__rust_{}", method.name);
+        let llfn = llvm::LLVMRustGetOrInsertFunction(llmod, name.as_ptr().cast(), name.len(), ty);
 
         if tcx.sess.target.target.options.default_hidden_visibility {
             llvm::LLVMRustSetVisibility(llfn, llvm::Visibility::Hidden);
@@ -60,8 +58,9 @@ pub(crate) unsafe fn codegen(tcx: TyCtxt<'_>, mods: &mut ModuleLlvm, kind: Alloc
             attributes::emit_uwtable(llfn, true);
         }
 
-        let callee = CString::new(kind.fn_name(method.name)).unwrap();
-        let callee = llvm::LLVMRustGetOrInsertFunction(llmod, callee.as_ptr(), ty);
+        let callee = kind.fn_name(method.name);
+        let callee =
+            llvm::LLVMRustGetOrInsertFunction(llmod, callee.as_ptr().cast(), callee.len(), ty);
         llvm::LLVMRustSetVisibility(callee, llvm::Visibility::Hidden);
 
         let llbb = llvm::LLVMAppendBasicBlockInContext(llcx, llfn, "entry\0".as_ptr().cast());
@@ -73,14 +72,8 @@ pub(crate) unsafe fn codegen(tcx: TyCtxt<'_>, mods: &mut ModuleLlvm, kind: Alloc
             .enumerate()
             .map(|(i, _)| llvm::LLVMGetParam(llfn, i as c_uint))
             .collect::<Vec<_>>();
-        let ret = llvm::LLVMRustBuildCall(
-            llbuilder,
-            callee,
-            args.as_ptr(),
-            args.len() as c_uint,
-            None,
-            "\0".as_ptr().cast(),
-        );
+        let ret =
+            llvm::LLVMRustBuildCall(llbuilder, callee, args.as_ptr(), args.len() as c_uint, None);
         llvm::LLVMSetTailCall(ret, True);
         if output.is_some() {
             llvm::LLVMBuildRet(llbuilder, ret);

src/librustc_codegen_llvm/asm.rs

@@ -12,7 +12,6 @@ use rustc_span::Span;
 
 use libc::{c_char, c_uint};
 use log::debug;
-use std::ffi::{CStr, CString};
 
 impl AsmBuilderMethods<'tcx> for Builder<'a, 'll, 'tcx> {
     fn codegen_inline_asm(
@@ -80,12 +79,11 @@ impl AsmBuilderMethods<'tcx> for Builder<'a, 'll, 'tcx> {
             _ => self.type_struct(&output_types, false),
         };
 
-        let asm = CString::new(ia.asm.as_str().as_bytes()).unwrap();
-        let constraint_cstr = CString::new(all_constraints).unwrap();
+        let asm = ia.asm.as_str();
         let r = inline_asm_call(
             self,
             &asm,
-            &constraint_cstr,
+            &all_constraints,
             &inputs,
             output_type,
             ia.volatile,
@@ -125,17 +123,17 @@ impl AsmBuilderMethods<'tcx> for Builder<'a, 'll, 'tcx> {
 
 impl AsmMethods for CodegenCx<'ll, 'tcx> {
     fn codegen_global_asm(&self, ga: &hir::GlobalAsm) {
-        let asm = CString::new(ga.asm.as_str().as_bytes()).unwrap();
+        let asm = ga.asm.as_str();
         unsafe {
-            llvm::LLVMRustAppendModuleInlineAsm(self.llmod, asm.as_ptr());
+            llvm::LLVMRustAppendModuleInlineAsm(self.llmod, asm.as_ptr().cast(), asm.len());
         }
     }
 }
 
 fn inline_asm_call(
     bx: &mut Builder<'a, 'll, 'tcx>,
-    asm: &CStr,
-    cons: &CStr,
+    asm: &str,
+    cons: &str,
     inputs: &[&'ll Value],
     output: &'ll llvm::Type,
     volatile: bool,
@@ -157,13 +155,15 @@ fn inline_asm_call(
     let fty = bx.cx.type_func(&argtys[..], output);
     unsafe {
         // Ask LLVM to verify that the constraints are well-formed.
-        let constraints_ok = llvm::LLVMRustInlineAsmVerify(fty, cons.as_ptr());
+        let constraints_ok = llvm::LLVMRustInlineAsmVerify(fty, cons.as_ptr().cast(), cons.len());
         debug!("constraint verification result: {:?}", constraints_ok);
         if constraints_ok {
             let v = llvm::LLVMRustInlineAsm(
                 fty,
-                asm.as_ptr(),
-                cons.as_ptr(),
+                asm.as_ptr().cast(),
+                asm.len(),
+                cons.as_ptr().cast(),
+                cons.len(),
                 volatile,
                 alignstack,
                 llvm::AsmDialect::from_generic(dia),