Auto merge of #65227 - Centril:rollup-6qslas2, r=Centril

Rollup of 6 pull requests

Successful merges:

 - #64656 (Implement (HashMap) Entry::insert as per #60142)
 - #64986 (Function pointers as const generic arguments)
 - #65037 (`#[track_caller]` feature gate (RFC 2091 1/N))
 - #65166 (Suggest to add `move` keyword for generator capture)
 - #65175 (add more info in debug traces for gcu merging)
 - #65220 (Update LLVM for Emscripten exception handling support)

Failed merges:

r? @ghost

Cargo.lock

@@ -107,6 +107,12 @@ dependencies = [
  "winapi 0.3.6",
 ]
 
+[[package]]
+name = "autocfg"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b671c8fb71b457dd4ae18c4ba1e59aa81793daacc361d82fcd410cef0d491875"
+
 [[package]]
 name = "backtrace"
 version = "0.3.37"
@@ -1269,7 +1275,7 @@ version = "2.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "df044dd42cdb7e32f28557b661406fc0f2494be75199779998810dbc35030e0d"
 dependencies = [
- "hashbrown",
+ "hashbrown 0.5.0",
  "lazy_static 1.3.0",
  "log",
  "pest",
@@ -1286,10 +1292,19 @@ version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e1de41fb8dba9714efd92241565cdff73f78508c95697dd56787d3cba27e2353"
 dependencies = [
+ "serde",
+]
+
+[[package]]
+name = "hashbrown"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6587d09be37fb98a11cb08b9000a3f592451c1b1b613ca69d949160e313a430a"
+dependencies = [
+ "autocfg",
  "compiler_builtins",
  "rustc-std-workspace-alloc",
  "rustc-std-workspace-core",
- "serde",
 ]
 
 [[package]]
@@ -4109,7 +4124,7 @@ dependencies = [
  "core",
  "dlmalloc",
  "fortanix-sgx-abi",
- "hashbrown",
+ "hashbrown 0.6.1",
  "libc",
  "panic_abort",
  "panic_unwind",

src/doc/unstable-book/src/language-features/track-caller.md

@@ -0,0 +1,5 @@
+# `track_caller`
+
+The tracking issue for this feature is: [#47809](https://github.com/rust-lang/rust/issues/47809).
+
+------------------------

src/librustc/error_codes.rs

@@ -2120,6 +2120,25 @@ These attributes are meant to only be used by the standard library and are
 rejected in your own crates.
 "##,
 
+E0736: r##"
+#[track_caller] and #[naked] cannot be applied to the same function.
+
+Erroneous code example:
+
+```compile_fail,E0736
+#![feature(track_caller)]
+
+#[naked]
+#[track_caller]
+fn foo() {}
+```
+
+This is primarily due to ABI incompatibilities between the two attributes.
+See [RFC 2091] for details on this and other limitations.
+
+[RFC 2091]: https://github.com/rust-lang/rfcs/blob/master/text/2091-inline-semantic.md
+"##,
+
 ;
 //  E0006, // merged with E0005
 //  E0101, // replaced with E0282
@@ -2179,4 +2198,5 @@ rejected in your own crates.
     E0726, // non-explicit (not `'_`) elided lifetime in unsupported position
     E0727, // `async` generators are not yet supported
     E0728, // `await` must be in an `async` function or block
+    E0739, // invalid track_caller application/syntax
 }

src/librustc/hir/check_attr.rs

@@ -11,7 +11,7 @@ use crate::ty::TyCtxt;
 use crate::ty::query::Providers;
 
 use std::fmt::{self, Display};
-use syntax::symbol::sym;
+use syntax::{attr, symbol::sym};
 use syntax_pos::Span;
 
 #[derive(Copy, Clone, PartialEq)]
@@ -103,6 +103,8 @@ impl CheckAttrVisitor<'tcx> {
                 self.check_marker(attr, item, target)
             } else if attr.check_name(sym::target_feature) {
                 self.check_target_feature(attr, item, target)
+            } else if attr.check_name(sym::track_caller) {
+                self.check_track_caller(attr, &item, target)
             } else {
                 true
             };
@@ -135,6 +137,32 @@ impl CheckAttrVisitor<'tcx> {
         }
     }
 
+    /// Checks if a `#[track_caller]` is applied to a non-naked function. Returns `true` if valid.
+    fn check_track_caller(&self, attr: &hir::Attribute, item: &hir::Item, target: Target) -> bool {
+        if target != Target::Fn {
+            struct_span_err!(
+                self.tcx.sess,
+                attr.span,
+                E0739,
+                "attribute should be applied to function"
+            )
+            .span_label(item.span, "not a function")
+            .emit();
+            false
+        } else if attr::contains_name(&item.attrs, sym::naked) {
+            struct_span_err!(
+                self.tcx.sess,
+                attr.span,
+                E0736,
+                "cannot use `#[track_caller]` with `#[naked]`",
+            )
+            .emit();
+            false
+        } else {
+            true
+        }
+    }
+
     /// Checks if the `#[non_exhaustive]` attribute on an `item` is valid. Returns `true` if valid.
     fn check_non_exhaustive(
         &self,

src/librustc/hir/mod.rs

@@ -2734,7 +2734,9 @@ bitflags! {
         const USED                      = 1 << 9;
         /// #[ffi_returns_twice], indicates that an extern function can return
         /// multiple times
-        const FFI_RETURNS_TWICE = 1 << 10;
+        const FFI_RETURNS_TWICE         = 1 << 10;
+        /// #[track_caller]: allow access to the caller location
+        const TRACK_CALLER              = 1 << 11;
     }
 }
 

src/librustc/mir/interpret/mod.rs

@@ -470,6 +470,14 @@ impl<'tcx> AllocMap<'tcx> {
         }
     }
 
+    /// Panics if the `AllocId` does not refer to a function
+    pub fn unwrap_fn(&self, id: AllocId) -> Instance<'tcx> {
+        match self.get(id) {
+            Some(GlobalAlloc::Function(instance)) => instance,
+            _ => bug!("expected allocation ID {} to point to a function", id),
+        }
+    }
+
     /// Freezes an `AllocId` created with `reserve` by pointing it at an `Allocation`. Trying to
     /// call this function twice, even with the same `Allocation` will ICE the compiler.
     pub fn set_alloc_id_memory(&mut self, id: AllocId, mem: &'tcx Allocation) {

src/librustc/ty/print/pretty.rs

@@ -863,125 +863,120 @@ pub trait PrettyPrinter<'tcx>:
         }
 
         let u8 = self.tcx().types.u8;
-        if let ty::FnDef(did, substs) = ct.ty.kind {
-            p!(print_value_path(did, substs));
-            return Ok(self);
-        }
-        if let ConstValue::Unevaluated(did, substs) = ct.val {
-            match self.tcx().def_kind(did) {
-                | Some(DefKind::Static)
-                | Some(DefKind::Const)
-                | Some(DefKind::AssocConst) => p!(print_value_path(did, substs)),
-                _ => if did.is_local() {
-                    let span = self.tcx().def_span(did);
-                    if let Ok(snip) = self.tcx().sess.source_map().span_to_snippet(span) {
-                        p!(write("{}", snip))
+
+        match (ct.val, &ct.ty.kind) {
+            (_,  ty::FnDef(did, substs)) => p!(print_value_path(*did, substs)),
+            (ConstValue::Unevaluated(did, substs), _) => {
+                match self.tcx().def_kind(did) {
+                    | Some(DefKind::Static)
+                    | Some(DefKind::Const)
+                    | Some(DefKind::AssocConst) => p!(print_value_path(did, substs)),
+                    _ => if did.is_local() {
+                        let span = self.tcx().def_span(did);
+                        if let Ok(snip) = self.tcx().sess.source_map().span_to_snippet(span) {
+                            p!(write("{}", snip))
+                        } else {
+                            p!(write("_: "), print(ct.ty))
+                        }
                     } else {
                         p!(write("_: "), print(ct.ty))
-                    }
+                    },
+                }
+            },
+            (ConstValue::Infer(..), _) =>  p!(write("_: "), print(ct.ty)),
+            (ConstValue::Param(ParamConst { name, .. }), _) => p!(write("{}", name)),
+            (ConstValue::Scalar(Scalar::Raw { data, .. }), ty::Bool) =>
+                p!(write("{}", if data == 0 { "false" } else { "true" })),
+            (ConstValue::Scalar(Scalar::Raw { data, .. }), ty::Float(ast::FloatTy::F32)) =>
+                p!(write("{}f32", Single::from_bits(data))),
+            (ConstValue::Scalar(Scalar::Raw { data, .. }), ty::Float(ast::FloatTy::F64)) =>
+                p!(write("{}f64", Double::from_bits(data))),
+            (ConstValue::Scalar(Scalar::Raw { data, .. }), ty::Uint(ui)) => {
+                let bit_size = Integer::from_attr(&self.tcx(), UnsignedInt(*ui)).size();
+                let max = truncate(u128::max_value(), bit_size);
+
+                if data == max {
+                    p!(write("std::{}::MAX", ui))
                 } else {
-                    p!(write("_: "), print(ct.ty))
-                },
-            }
-            return Ok(self);
-        }
-        if let ConstValue::Infer(..) = ct.val {
-            p!(write("_: "), print(ct.ty));
-            return Ok(self);
-        }
-        if let ConstValue::Param(ParamConst { name, .. }) = ct.val {
-            p!(write("{}", name));
-            return Ok(self);
-        }
-        if let ConstValue::Scalar(Scalar::Raw { data, .. }) = ct.val {
-            match ct.ty.kind {
-                ty::Bool => {
-                    p!(write("{}", if data == 0 { "false" } else { "true" }));
-                    return Ok(self);
-                },
-                ty::Float(ast::FloatTy::F32) => {
-                    p!(write("{}f32", Single::from_bits(data)));
-                    return Ok(self);
-                },
-                ty::Float(ast::FloatTy::F64) => {
-                    p!(write("{}f64", Double::from_bits(data)));
-                    return Ok(self);
-                },
-                ty::Uint(ui) => {
-                    let bit_size = Integer::from_attr(&self.tcx(), UnsignedInt(ui)).size();
-                    let max = truncate(u128::max_value(), bit_size);
+                    p!(write("{}{}", data, ui))
+                };
+            },
+            (ConstValue::Scalar(Scalar::Raw { data, .. }), ty::Int(i)) => {
+                let bit_size = Integer::from_attr(&self.tcx(), SignedInt(*i))
+                    .size().bits() as u128;
+                let min = 1u128 << (bit_size - 1);
+                let max = min - 1;
+
+                let ty = self.tcx().lift(&ct.ty).unwrap();
+                let size = self.tcx().layout_of(ty::ParamEnv::empty().and(ty))
+                    .unwrap()
+                    .size;
+                match data {
+                    d if d == min => p!(write("std::{}::MIN", i)),
+                    d if d == max => p!(write("std::{}::MAX", i)),
+                    _ => p!(write("{}{}", sign_extend(data, size) as i128, i))
+                }
+            },
+            (ConstValue::Scalar(Scalar::Raw { data, .. }), ty::Char) =>
+                p!(write("{:?}", ::std::char::from_u32(data as u32).unwrap())),
+            (ConstValue::Scalar(Scalar::Ptr(ptr)), ty::FnPtr(_)) => {
+                let instance = {
+                    let alloc_map = self.tcx().alloc_map.lock();
+                    alloc_map.unwrap_fn(ptr.alloc_id)
+                };
+                p!(print_value_path(instance.def_id(), instance.substs));
+            },
+            _ => {
+                let printed = if let ty::Ref(_, ref_ty, _) = ct.ty.kind {
+                    let byte_str = match (ct.val, &ref_ty.kind) {
+                        (ConstValue::Scalar(Scalar::Ptr(ptr)), ty::Array(t, n)) if *t == u8 => {
+                            let n = n.eval_usize(self.tcx(), ty::ParamEnv::empty());
+                            Some(self.tcx()
+                                .alloc_map.lock()
+                                .unwrap_memory(ptr.alloc_id)
+                                .get_bytes(&self.tcx(), ptr, Size::from_bytes(n)).unwrap())
+                        },
+                        (ConstValue::Slice { data, start, end }, ty::Slice(t)) if *t == u8 => {
+                            // The `inspect` here is okay since we checked the bounds, and there are
+                            // no relocations (we have an active slice reference here). We don't use
+                            // this result to affect interpreter execution.
+                            Some(data.inspect_with_undef_and_ptr_outside_interpreter(start..end))
+                        },
+                        _ => None,
+                    };
 
-                    if data == max {
-                        p!(write("std::{}::MAX", ui))
+                    if let Some(byte_str) = byte_str {
+                        p!(write("b\""));
+                        for &c in byte_str {
+                            for e in std::ascii::escape_default(c) {
+                                self.write_char(e as char)?;
+                            }
+                        }
+                        p!(write("\""));
+                        true
+                    } else if let (ConstValue::Slice { data, start, end }, ty::Str) =
+                        (ct.val, &ref_ty.kind)
+                    {
+                        // The `inspect` here is okay since we checked the bounds, and there are no
+                        // relocations (we have an active `str` reference here). We don't use this
+                        // result to affect interpreter execution.
+                        let slice = data.inspect_with_undef_and_ptr_outside_interpreter(start..end);
+                        let s = ::std::str::from_utf8(slice)
+                            .expect("non utf8 str from miri");
+                        p!(write("{:?}", s));
+                        true
                     } else {
-                        p!(write("{}{}", data, ui))
-                    };
-                    return Ok(self);
-                },
-                ty::Int(i) =>{
-                    let bit_size = Integer::from_attr(&self.tcx(), SignedInt(i))
-                        .size().bits() as u128;
-                    let min = 1u128 << (bit_size - 1);
-                    let max = min - 1;
-
-                    let ty = self.tcx().lift(&ct.ty).unwrap();
-                    let size = self.tcx().layout_of(ty::ParamEnv::empty().and(ty))
-                        .unwrap()
-                        .size;
-                    match data {
-                        d if d == min => p!(write("std::{}::MIN", i)),
-                        d if d == max => p!(write("std::{}::MAX", i)),
-                        _ => p!(write("{}{}", sign_extend(data, size) as i128, i))
-                    }
-                    return Ok(self);
-                },
-                ty::Char => {
-                    p!(write("{:?}", ::std::char::from_u32(data as u32).unwrap()));
-                    return Ok(self);
-                }
-                _ => {},
-            }
-        }
-        if let ty::Ref(_, ref_ty, _) = ct.ty.kind {
-            let byte_str = match (ct.val, &ref_ty.kind) {
-                (ConstValue::Scalar(Scalar::Ptr(ptr)), ty::Array(t, n)) if *t == u8 => {
-                    let n = n.eval_usize(self.tcx(), ty::ParamEnv::empty());
-                    Some(self.tcx()
-                        .alloc_map.lock()
-                        .unwrap_memory(ptr.alloc_id)
-                        .get_bytes(&self.tcx(), ptr, Size::from_bytes(n)).unwrap())
-                },
-                (ConstValue::Slice { data, start, end }, ty::Slice(t)) if *t == u8 => {
-                    // The `inspect` here is okay since we checked the bounds, and there are no
-                    // relocations (we have an active slice reference here). We don't use this
-                    // result to affect interpreter execution.
-                    Some(data.inspect_with_undef_and_ptr_outside_interpreter(start..end))
-                },
-                (ConstValue::Slice { data, start, end }, ty::Str) => {
-                    // The `inspect` here is okay since we checked the bounds, and there are no
-                    // relocations (we have an active `str` reference here). We don't use this
-                    // result to affect interpreter execution.
-                    let slice = data.inspect_with_undef_and_ptr_outside_interpreter(start..end);
-                    let s = ::std::str::from_utf8(slice)
-                        .expect("non utf8 str from miri");
-                    p!(write("{:?}", s));
-                    return Ok(self);
-                },
-                _ => None,
-            };
-            if let Some(byte_str) = byte_str {
-                p!(write("b\""));
-                for &c in byte_str {
-                    for e in std::ascii::escape_default(c) {
-                        self.write_char(e as char)?;
+                        false
                     }
+                } else {
+                    false
+                };
+                if !printed {
+                    // fallback
+                    p!(write("{:?} : ", ct.val), print(ct.ty))
                 }
-                p!(write("\""));
-                return Ok(self);
             }
-        }
-        p!(write("{:?} : ", ct.val), print(ct.ty));
-
+        };
         Ok(self)
     }
 }