Auto merge of #70653 - Centril:rollup-vh5x5e5, r=Centril

Rollup of 6 pull requests

Successful merges:

 - #70511 (Add `-Z dump-mir-dataflow` flag for dumping dataflow results visualization)
 - #70522 (Improve error messages for raw strings (#60762))
 - #70547 (Add `can_unwind` field to `FnAbi`)
 - #70591 (Ensure LLVM is in the link path for "fulldeps" tests)
 - #70627 (Use place directly its copy)
 - #70652 (Add git repo address to unstable book)

Failed merges:

 - #70634 (Remove some reexports in `rustc_middle`)

r? @ghost

src/bootstrap/test.rs

@@ -21,7 +21,7 @@ use crate::flags::Subcommand;
 use crate::native;
 use crate::tool::{self, SourceType, Tool};
 use crate::toolstate::ToolState;
-use crate::util::{self, dylib_path, dylib_path_var};
+use crate::util::{self, add_link_lib_path, dylib_path, dylib_path_var};
 use crate::Crate as CargoCrate;
 use crate::{envify, DocTests, GitRepo, Mode};
 
@@ -1178,6 +1178,15 @@ impl Step for Compiletest {
                 cmd.arg("--system-llvm");
             }
 
+            // Tests that use compiler libraries may inherit the `-lLLVM` link
+            // requirement, but the `-L` library path is not propagated across
+            // separate compilations. We can add LLVM's library path to the
+            // platform-specific environment variable as a workaround.
+            if !builder.config.dry_run && suite.ends_with("fulldeps") {
+                let llvm_libdir = output(Command::new(&llvm_config).arg("--libdir"));
+                add_link_lib_path(vec![llvm_libdir.trim().into()], &mut cmd);
+            }
+
             // Only pass correct values for these flags for the `run-make` suite as it
             // requires that a C++ compiler was configured which isn't always the case.
             if !builder.config.dry_run && suite == "run-make-fulldeps" {

src/doc/unstable-book/book.toml

@@ -1,3 +1,6 @@
 [book]
 title = "The Rust Unstable Book"
 author = "The Rust Community"
+
+[output.html]
+git-repository-url = "https://github.com/rust-lang/rust/tree/master/src/doc/unstable-book"

src/librustc_codegen_llvm/abi.rs

@@ -396,6 +396,11 @@ impl<'tcx> FnAbiLlvmExt<'tcx> for FnAbi<'tcx, Ty<'tcx>> {
             llvm::Attribute::NoReturn.apply_llfn(llvm::AttributePlace::Function, llfn);
         }
 
+        // FIXME(eddyb, wesleywiser): apply this to callsites as well?
+        if !self.can_unwind {
+            llvm::Attribute::NoUnwind.apply_llfn(llvm::AttributePlace::Function, llfn);
+        }
+
         let mut i = 0;
         let mut apply = |attrs: &ArgAttributes, ty: Option<&Type>| {
             attrs.apply_llfn(llvm::AttributePlace::Argument(i), llfn, ty);
@@ -431,6 +436,8 @@ impl<'tcx> FnAbiLlvmExt<'tcx> for FnAbi<'tcx, Ty<'tcx>> {
     }
 
     fn apply_attrs_callsite(&self, bx: &mut Builder<'a, 'll, 'tcx>, callsite: &'ll Value) {
+        // FIXME(wesleywiser, eddyb): We should apply `nounwind` and `noreturn` as appropriate to this callsite.
+
         let mut i = 0;
         let mut apply = |attrs: &ArgAttributes, ty: Option<&Type>| {
             attrs.apply_callsite(llvm::AttributePlace::Argument(i), callsite, ty);

src/librustc_codegen_llvm/attributes.rs

@@ -10,13 +10,10 @@ use rustc_hir::def_id::{DefId, LOCAL_CRATE};
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
 use rustc_middle::ty::layout::HasTyCtxt;
 use rustc_middle::ty::query::Providers;
-use rustc_middle::ty::{self, Ty, TyCtxt};
+use rustc_middle::ty::{self, TyCtxt};
 use rustc_session::config::{OptLevel, Sanitizer};
 use rustc_session::Session;
-use rustc_target::abi::call::Conv;
-use rustc_target::spec::PanicStrategy;
 
-use crate::abi::FnAbi;
 use crate::attributes;
 use crate::llvm::AttributePlace::Function;
 use crate::llvm::{self, Attribute};
@@ -77,12 +74,6 @@ pub fn emit_uwtable(val: &'ll Value, emit: bool) {
     Attribute::UWTable.toggle_llfn(Function, val, emit);
 }
 
-/// Tell LLVM whether the function can or cannot unwind.
-#[inline]
-fn unwind(val: &'ll Value, can_unwind: bool) {
-    Attribute::NoUnwind.toggle_llfn(Function, val, !can_unwind);
-}
-
 /// Tell LLVM if this function should be 'naked', i.e., skip the epilogue and prologue.
 #[inline]
 fn naked(val: &'ll Value, is_naked: bool) {
@@ -246,12 +237,7 @@ pub(crate) fn default_optimisation_attrs(sess: &Session, llfn: &'ll Value) {
 
 /// Composite function which sets LLVM attributes for function depending on its AST (`#[attribute]`)
 /// attributes.
-pub fn from_fn_attrs(
-    cx: &CodegenCx<'ll, 'tcx>,
-    llfn: &'ll Value,
-    instance: ty::Instance<'tcx>,
-    fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
-) {
+pub fn from_fn_attrs(cx: &CodegenCx<'ll, 'tcx>, llfn: &'ll Value, instance: ty::Instance<'tcx>) {
     let codegen_fn_attrs = cx.tcx.codegen_fn_attrs(instance.def_id());
 
     match codegen_fn_attrs.optimize {
@@ -315,46 +301,6 @@ pub fn from_fn_attrs(
     }
     sanitize(cx, codegen_fn_attrs.flags, llfn);
 
-    unwind(
-        llfn,
-        if cx.tcx.sess.panic_strategy() != PanicStrategy::Unwind {
-            // In panic=abort mode we assume nothing can unwind anywhere, so
-            // optimize based on this!
-            false
-        } else if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::UNWIND) {
-            // If a specific #[unwind] attribute is present, use that.
-            true
-        } else if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::RUSTC_ALLOCATOR_NOUNWIND) {
-            // Special attribute for allocator functions, which can't unwind.
-            false
-        } else {
-            if fn_abi.conv == Conv::Rust {
-                // Any Rust method (or `extern "Rust" fn` or `extern
-                // "rust-call" fn`) is explicitly allowed to unwind
-                // (unless it has no-unwind attribute, handled above).
-                true
-            } else {
-                // Anything else is either:
-                //
-                //  1. A foreign item using a non-Rust ABI (like `extern "C" { fn foo(); }`), or
-                //
-                //  2. A Rust item using a non-Rust ABI (like `extern "C" fn foo() { ... }`).
-                //
-                // Foreign items (case 1) are assumed to not unwind; it is
-                // UB otherwise. (At least for now; see also
-                // rust-lang/rust#63909 and Rust RFC 2753.)
-                //
-                // Items defined in Rust with non-Rust ABIs (case 2) are also
-                // not supposed to unwind. Whether this should be enforced
-                // (versus stating it is UB) and *how* it would be enforced
-                // is currently under discussion; see rust-lang/rust#58794.
-                //
-                // In either case, we mark item as explicitly nounwind.
-                false
-            }
-        },
-    );
-
     // Always annotate functions with the target-cpu they are compiled for.
     // Without this, ThinLTO won't inline Rust functions into Clang generated
     // functions (because Clang annotates functions this way too).

src/librustc_codegen_llvm/callee.rs

@@ -78,7 +78,7 @@ pub fn get_fn(cx: &CodegenCx<'ll, 'tcx>, instance: Instance<'tcx>) -> &'ll Value
         let llfn = cx.declare_fn(&sym, &fn_abi);
         debug!("get_fn: not casting pointer!");
 
-        attributes::from_fn_attrs(cx, llfn, instance, &fn_abi);
+        attributes::from_fn_attrs(cx, llfn, instance);
 
         let instance_def_id = instance.def_id();
 

src/librustc_codegen_llvm/mono_item.rs

@@ -77,7 +77,7 @@ impl PreDefineMethods<'tcx> for CodegenCx<'ll, 'tcx> {
 
         debug!("predefine_fn: instance = {:?}", instance);
 
-        attributes::from_fn_attrs(self, lldecl, instance, &fn_abi);
+        attributes::from_fn_attrs(self, lldecl, instance);
 
         self.instances.borrow_mut().insert(instance, lldecl);
     }

src/librustc_codegen_ssa/mir/block.rs

@@ -299,7 +299,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         &mut self,
         helper: TerminatorCodegenHelper<'tcx>,
         mut bx: Bx,
-        location: &mir::Place<'tcx>,
+        location: mir::Place<'tcx>,
         target: mir::BasicBlock,
         unwind: Option<mir::BasicBlock>,
     ) {
@@ -580,7 +580,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
 
         if intrinsic == Some("transmute") {
             if let Some(destination_ref) = destination.as_ref() {
-                let &(ref dest, target) = destination_ref;
+                let &(dest, target) = destination_ref;
                 self.codegen_transmute(&mut bx, &args[0], dest);
                 helper.maybe_sideeffect(self.mir, &mut bx, &[target]);
                 helper.funclet_br(self, &mut bx, target);
@@ -619,7 +619,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         let mut llargs = Vec::with_capacity(arg_count);
 
         // Prepare the return value destination
-        let ret_dest = if let Some((ref dest, _)) = *destination {
+        let ret_dest = if let Some((dest, _)) = *destination {
             let is_intrinsic = intrinsic.is_some();
             self.make_return_dest(&mut bx, dest, &fn_abi.ret, &mut llargs, is_intrinsic)
         } else {
@@ -873,7 +873,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 bx.unreachable();
             }
 
-            mir::TerminatorKind::Drop { ref location, target, unwind } => {
+            mir::TerminatorKind::Drop { location, target, unwind } => {
                 self.codegen_drop_terminator(helper, bx, location, target, unwind);
             }
 
@@ -1123,7 +1123,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
     fn make_return_dest(
         &mut self,
         bx: &mut Bx,
-        dest: &mir::Place<'tcx>,
+        dest: mir::Place<'tcx>,
         fn_ret: &ArgAbi<'tcx, Ty<'tcx>>,
         llargs: &mut Vec<Bx::Value>,
         is_intrinsic: bool,
@@ -1184,7 +1184,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         }
     }
 
-    fn codegen_transmute(&mut self, bx: &mut Bx, src: &mir::Operand<'tcx>, dst: &mir::Place<'tcx>) {
+    fn codegen_transmute(&mut self, bx: &mut Bx, src: &mir::Operand<'tcx>, dst: mir::Place<'tcx>) {
         if let Some(index) = dst.as_local() {
             match self.locals[index] {
                 LocalRef::Place(place) => self.codegen_transmute_into(bx, src, place),

src/librustc_codegen_ssa/mir/rvalue.rs

@@ -383,7 +383,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 (bx, OperandRef { val, layout: cast })
             }
 
-            mir::Rvalue::Ref(_, bk, ref place) => {
+            mir::Rvalue::Ref(_, bk, place) => {
                 let mk_ref = move |tcx: TyCtxt<'tcx>, ty: Ty<'tcx>| {
                     tcx.mk_ref(
                         tcx.lifetimes.re_erased,
@@ -393,14 +393,14 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 self.codegen_place_to_pointer(bx, place, mk_ref)
             }
 
-            mir::Rvalue::AddressOf(mutability, ref place) => {
+            mir::Rvalue::AddressOf(mutability, place) => {
                 let mk_ptr = move |tcx: TyCtxt<'tcx>, ty: Ty<'tcx>| {
                     tcx.mk_ptr(ty::TypeAndMut { ty, mutbl: mutability })
                 };
                 self.codegen_place_to_pointer(bx, place, mk_ptr)
             }
 
-            mir::Rvalue::Len(ref place) => {
+            mir::Rvalue::Len(place) => {
                 let size = self.evaluate_array_len(&mut bx, place);
                 let operand = OperandRef {
                     val: OperandValue::Immediate(size),
@@ -537,7 +537,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         }
     }
 
-    fn evaluate_array_len(&mut self, bx: &mut Bx, place: &mir::Place<'tcx>) -> Bx::Value {
+    fn evaluate_array_len(&mut self, bx: &mut Bx, place: mir::Place<'tcx>) -> Bx::Value {
         // ZST are passed as operands and require special handling
         // because codegen_place() panics if Local is operand.
         if let Some(index) = place.as_local() {
@@ -557,7 +557,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
     fn codegen_place_to_pointer(
         &mut self,
         mut bx: Bx,
-        place: &mir::Place<'tcx>,
+        place: mir::Place<'tcx>,
         mk_ptr_ty: impl FnOnce(TyCtxt<'tcx>, Ty<'tcx>) -> Ty<'tcx>,
     ) -> (Bx, OperandRef<'tcx, Bx::Value>) {
         let cg_place = self.codegen_place(&mut bx, place.as_ref());

src/librustc_interface/tests.rs

@@ -562,6 +562,8 @@ fn test_debugging_options_tracking_hash() {
     assert_eq!(reference.dep_tracking_hash(), opts.dep_tracking_hash());
     opts.debugging_opts.dump_mir_graphviz = true;
     assert_eq!(reference.dep_tracking_hash(), opts.dep_tracking_hash());
+    opts.debugging_opts.dump_mir_dataflow = true;
+    assert_eq!(reference.dep_tracking_hash(), opts.dep_tracking_hash());
 
     // Make sure changing a [TRACKED] option changes the hash
     opts = reference.clone();