Rollup of 7 pull requests

.gitignore

@@ -33,7 +33,6 @@ __pycache__/
 /mingw-build/
 # Created by default with `src/ci/docker/run.sh`:
 /obj/
-/rustllvm/
 /unicode-downloads
 /target
 # Generated by compiletest for incremental:

compiler/rustc_ast/src/tokenstream.rs

@@ -403,8 +403,8 @@ impl Cursor {
         self.index = index;
     }
 
-    pub fn look_ahead(&self, n: usize) -> Option<&TokenTree> {
-        self.stream.0[self.index..].get(n).map(|(tree, _)| tree)
+    pub fn look_ahead(&self, n: usize) -> Option<TokenTree> {
+        self.stream.0[self.index..].get(n).map(|(tree, _)| tree.clone())
     }
 }
 

compiler/rustc_codegen_llvm/Cargo.toml

@@ -25,7 +25,7 @@ rustc_fs_util = { path = "../rustc_fs_util" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_incremental = { path = "../rustc_incremental" }
 rustc_index = { path = "../rustc_index" }
-rustc_llvm = { path = "../../src/librustc_llvm" }
+rustc_llvm = { path = "../rustc_llvm" }
 rustc_session = { path = "../rustc_session" }
 rustc_serialize = { path = "../rustc_serialize" }
 rustc_target = { path = "../rustc_target" }

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -96,7 +96,7 @@ pub enum DLLStorageClass {
     DllExport = 2, // Function to be accessible from DLL.
 }
 
-/// Matches LLVMRustAttribute in rustllvm.h
+/// Matches LLVMRustAttribute in LLVMWrapper.h
 /// Semantically a subset of the C++ enum llvm::Attribute::AttrKind,
 /// though it is not ABI compatible (since it's a C++ enum)
 #[repr(C)]
@@ -1705,7 +1705,7 @@ extern "C" {
         PM: &PassManager<'_>,
     );
 
-    // Stuff that's in rustllvm/ because it's not upstream yet.
+    // Stuff that's in llvm-wrapper/ because it's not upstream yet.
 
     /// Opens an object file.
     pub fn LLVMCreateObjectFile(

compiler/rustc_expand/src/proc_macro_server.rs

@@ -47,26 +47,15 @@ impl ToInternal<token::DelimToken> for Delimiter {
     }
 }
 
-impl
-    FromInternal<(
-        TreeAndJoint,
-        Option<&'_ tokenstream::TokenTree>,
-        &'_ ParseSess,
-        &'_ mut Vec<Self>,
-    )> for TokenTree<Group, Punct, Ident, Literal>
+impl FromInternal<(TreeAndJoint, &'_ ParseSess, &'_ mut Vec<Self>)>
+    for TokenTree<Group, Punct, Ident, Literal>
 {
     fn from_internal(
-        ((tree, is_joint), look_ahead, sess, stack): (
-            TreeAndJoint,
-            Option<&tokenstream::TokenTree>,
-            &ParseSess,
-            &mut Vec<Self>,
-        ),
+        ((tree, is_joint), sess, stack): (TreeAndJoint, &ParseSess, &mut Vec<Self>),
     ) -> Self {
         use rustc_ast::token::*;
 
-        let joint = is_joint == Joint
-            && matches!(look_ahead, Some(tokenstream::TokenTree::Token(t)) if t.is_op());
+        let joint = is_joint == Joint;
         let Token { kind, span } = match tree {
             tokenstream::TokenTree::Delimited(span, delim, tts) => {
                 let delimiter = Delimiter::from_internal(delim);
@@ -456,8 +445,7 @@ impl server::TokenStreamIter for Rustc<'_> {
         loop {
             let tree = iter.stack.pop().or_else(|| {
                 let next = iter.cursor.next_with_joint()?;
-                let lookahead = iter.cursor.look_ahead(0);
-                Some(TokenTree::from_internal((next, lookahead, self.sess, &mut iter.stack)))
+                Some(TokenTree::from_internal((next, self.sess, &mut iter.stack)))
             })?;
             // A hack used to pass AST fragments to attribute and derive macros
             // as a single nonterminal token instead of a token stream.

compiler/rustc_graphviz/src/lib.rs

@@ -599,6 +599,7 @@ pub enum RenderOption {
     NoNodeStyles,
 
     Monospace,
+    DarkTheme,
 }
 
 /// Returns vec holding all the default render options.
@@ -630,10 +631,23 @@ where
     writeln!(w, "digraph {} {{", g.graph_id().as_slice())?;
 
     // Global graph properties
+    let mut graph_attrs = Vec::new();
+    let mut content_attrs = Vec::new();
     if options.contains(&RenderOption::Monospace) {
-        writeln!(w, r#"    graph[fontname="monospace"];"#)?;
-        writeln!(w, r#"    node[fontname="monospace"];"#)?;
-        writeln!(w, r#"    edge[fontname="monospace"];"#)?;
+        let font = r#"fontname="Courier, monospace""#;
+        graph_attrs.push(font);
+        content_attrs.push(font);
+    };
+    if options.contains(&RenderOption::DarkTheme) {
+        graph_attrs.push(r#"bgcolor="black""#);
+        content_attrs.push(r#"color="white""#);
+        content_attrs.push(r#"fontcolor="white""#);
+    }
+    if !(graph_attrs.is_empty() && content_attrs.is_empty()) {
+        writeln!(w, r#"    graph[{}];"#, graph_attrs.join(" "))?;
+        let content_attrs_str = content_attrs.join(" ");
+        writeln!(w, r#"    node[{}];"#, content_attrs_str)?;
+        writeln!(w, r#"    edge[{}];"#, content_attrs_str)?;
     }
 
     for n in g.nodes().iter() {

src/librustc_llvm/Cargo.toml → compiler/rustc_llvm/Cargo.toml

@@ -4,9 +4,6 @@ name = "rustc_llvm"
 version = "0.0.0"
 edition = "2018"
 
-[lib]
-path = "lib.rs"
-
 [features]
 static-libstdcpp = []
 emscripten = []
@@ -15,5 +12,5 @@ emscripten = []
 libc = "0.2.73"
 
 [build-dependencies]
-build_helper = { path = "../build_helper" }
+build_helper = { path = "../../src/build_helper" }
 cc = "1.0.58"

src/librustc_llvm/build.rs → compiler/rustc_llvm/build.rs

@@ -175,15 +175,15 @@ fn main() {
         cfg.debug(false);
     }
 
-    build_helper::rerun_if_changed_anything_in_dir(Path::new("../rustllvm"));
-    cfg.file("../rustllvm/PassWrapper.cpp")
-        .file("../rustllvm/RustWrapper.cpp")
-        .file("../rustllvm/ArchiveWrapper.cpp")
-        .file("../rustllvm/CoverageMappingWrapper.cpp")
-        .file("../rustllvm/Linker.cpp")
+    build_helper::rerun_if_changed_anything_in_dir(Path::new("llvm-wrapper"));
+    cfg.file("llvm-wrapper/PassWrapper.cpp")
+        .file("llvm-wrapper/RustWrapper.cpp")
+        .file("llvm-wrapper/ArchiveWrapper.cpp")
+        .file("llvm-wrapper/CoverageMappingWrapper.cpp")
+        .file("llvm-wrapper/Linker.cpp")
         .cpp(true)
         .cpp_link_stdlib(None) // we handle this below
-        .compile("rustllvm");
+        .compile("llvm-wrapper");
 
     let (llvm_kind, llvm_link_arg) = detect_llvm_link();
 
@@ -259,7 +259,7 @@ fn main() {
     }
 
     // Some LLVM linker flags (-L and -l) may be needed even when linking
-    // librustc_llvm, for example when using static libc++, we may need to
+    // rustc_llvm, for example when using static libc++, we may need to
     // manually specify the library search path and -ldl -lpthread as link
     // dependencies.
     let llvm_linker_flags = tracked_env_var_os("LLVM_LINKER_FLAGS");

src/rustllvm/ArchiveWrapper.cpp → compiler/rustc_llvm/llvm-wrapper/ArchiveWrapper.cpp

@@ -1,4 +1,4 @@
-#include "rustllvm.h"
+#include "LLVMWrapper.h"
 
 #include "llvm/Object/Archive.h"
 #include "llvm/Object/ArchiveWriter.h"

src/rustllvm/CoverageMappingWrapper.cpp → compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp

@@ -1,4 +1,4 @@
-#include "rustllvm.h"
+#include "LLVMWrapper.h"
 #include "llvm/ProfileData/Coverage/CoverageMapping.h"
 #include "llvm/ProfileData/Coverage/CoverageMappingWriter.h"
 #include "llvm/ProfileData/InstrProf.h"

src/rustllvm/Linker.cpp → compiler/rustc_llvm/llvm-wrapper/Linker.cpp

@@ -1,6 +1,6 @@
 #include "llvm/Linker/Linker.h"
 
-#include "rustllvm.h"
+#include "LLVMWrapper.h"
 
 using namespace llvm;
 

src/rustllvm/PassWrapper.cpp → compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp

@@ -3,7 +3,7 @@
 #include <vector>
 #include <set>
 
-#include "rustllvm.h"
+#include "LLVMWrapper.h"
 
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/Analysis/TargetTransformInfo.h"

src/rustllvm/RustWrapper.cpp → compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -1,4 +1,4 @@
-#include "rustllvm.h"
+#include "LLVMWrapper.h"
 #include "llvm/IR/DebugInfoMetadata.h"
 #include "llvm/IR/DiagnosticInfo.h"
 #include "llvm/IR/DiagnosticPrinter.h"

compiler/rustc_mir/src/dataflow/framework/engine.rs

@@ -306,7 +306,11 @@ where
     let mut buf = Vec::new();
 
     let graphviz = graphviz::Formatter::new(body, def_id, results, style);
-    dot::render_opts(&graphviz, &mut buf, &[dot::RenderOption::Monospace])?;
+    let mut render_opts = vec![dot::RenderOption::Monospace];
+    if tcx.sess.opts.debugging_opts.graphviz_dark_mode {
+        render_opts.push(dot::RenderOption::DarkTheme);
+    }
+    dot::render_opts(&graphviz, &mut buf, &render_opts)?;
 
     if let Some(parent) = path.parent() {
         fs::create_dir_all(parent)?;

compiler/rustc_mir/src/util/graphviz.rs

@@ -55,16 +55,28 @@ where
     writeln!(w, "{} {}Mir_{} {{", kind, cluster, def_name)?;
 
     // Global graph properties
-    writeln!(w, r#"    graph [fontname="monospace"];"#)?;
-    writeln!(w, r#"    node [fontname="monospace"];"#)?;
-    writeln!(w, r#"    edge [fontname="monospace"];"#)?;
+    let font = r#"fontname="Courier, monospace""#;
+    let mut graph_attrs = vec![font];
+    let mut content_attrs = vec![font];
+
+    let dark_mode = tcx.sess.opts.debugging_opts.graphviz_dark_mode;
+    if dark_mode {
+        graph_attrs.push(r#"bgcolor="black""#);
+        content_attrs.push(r#"color="white""#);
+        content_attrs.push(r#"fontcolor="white""#);
+    }
+
+    writeln!(w, r#"    graph [{}];"#, graph_attrs.join(" "))?;
+    let content_attrs_str = content_attrs.join(" ");
+    writeln!(w, r#"    node [{}];"#, content_attrs_str)?;
+    writeln!(w, r#"    edge [{}];"#, content_attrs_str)?;
 
     // Graph label
     write_graph_label(tcx, def_id, body, w)?;
 
     // Nodes
     for (block, _) in body.basic_blocks().iter_enumerated() {
-        write_node(def_id, block, body, w)?;
+        write_node(def_id, block, body, dark_mode, w)?;
     }
 
     // Edges
@@ -84,6 +96,7 @@ where
 pub fn write_node_label<W: Write, INIT, FINI>(
     block: BasicBlock,
     body: &Body<'_>,
+    dark_mode: bool,
     w: &mut W,
     num_cols: u32,
     init: INIT,
@@ -100,8 +113,9 @@ where
     // Basic block number at the top.
     write!(
         w,
-        r#"<tr><td {attrs} colspan="{colspan}">{blk}</td></tr>"#,
-        attrs = r#"bgcolor="gray" align="center""#,
+        r#"<tr><td bgcolor="{bgcolor}" {attrs} colspan="{colspan}">{blk}</td></tr>"#,
+        bgcolor = if dark_mode { "dimgray" } else { "gray" },
+        attrs = r#"align="center""#,
         colspan = num_cols,
         blk = block.index()
     )?;
@@ -134,11 +148,12 @@ fn write_node<W: Write>(
     def_id: DefId,
     block: BasicBlock,
     body: &Body<'_>,
+    dark_mode: bool,
     w: &mut W,
 ) -> io::Result<()> {
     // Start a new node with the label to follow, in one of DOT's pseudo-HTML tables.
     write!(w, r#"    {} [shape="none", label=<"#, node(def_id, block))?;
-    write_node_label(block, body, w, 1, |_| Ok(()), |_| Ok(()))?;
+    write_node_label(block, body, dark_mode, w, 1, |_| Ok(()), |_| Ok(()))?;
     // Close the node label and the node itself.
     writeln!(w, ">];")
 }

compiler/rustc_parse/src/lexer/tokentrees.rs

@@ -262,7 +262,10 @@ impl<'a> TokenTreesReader<'a> {
             }
             _ => {
                 let tt = TokenTree::Token(self.token.take());
-                let is_joint = self.bump();
+                let mut is_joint = self.bump();
+                if !self.token.is_op() {
+                    is_joint = NonJoint;
+                }
                 Ok((tt, is_joint))
             }
         }

compiler/rustc_parse/src/parser/mod.rs

@@ -822,15 +822,15 @@ impl<'a> Parser<'a> {
         }
 
         let frame = &self.token_cursor.frame;
-        match frame.tree_cursor.look_ahead(dist - 1) {
+        looker(&match frame.tree_cursor.look_ahead(dist - 1) {
             Some(tree) => match tree {
-                TokenTree::Token(token) => looker(token),
+                TokenTree::Token(token) => token,
                 TokenTree::Delimited(dspan, delim, _) => {
-                    looker(&Token::new(token::OpenDelim(delim.clone()), dspan.open))
+                    Token::new(token::OpenDelim(delim), dspan.open)
                 }
             },
-            None => looker(&Token::new(token::CloseDelim(frame.delim), frame.span.close)),
-        }
+            None => Token::new(token::CloseDelim(frame.delim), frame.span.close),
+        })
     }
 
     /// Returns whether any of the given keywords are `dist` tokens ahead of the current one.

compiler/rustc_session/src/options.rs

@@ -909,6 +909,8 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
         "force all crates to be `rustc_private` unstable (default: no)"),
     fuel: Option<(String, u64)> = (None, parse_optimization_fuel, [TRACKED],
         "set the optimization fuel quota for a crate"),
+    graphviz_dark_mode: bool = (false, parse_bool, [UNTRACKED],
+        "use dark-themed colors in graphviz output (default: no)"),
     hir_stats: bool = (false, parse_bool, [UNTRACKED],
         "print some statistics about AST and HIR (default: no)"),
     human_readable_cgu_names: bool = (false, parse_bool, [TRACKED],

config.toml.example

@@ -45,7 +45,7 @@
 # this flag will indicate that this version check should not be done.
 #version-check = true
 
-# Link libstdc++ statically into the librustc_llvm instead of relying on a
+# Link libstdc++ statically into the rustc_llvm instead of relying on a
 # dynamic version to be available.
 #static-libstdcpp = false
 

library/alloc/src/collections/btree/mod.rs

@@ -13,6 +13,9 @@ trait Recover<Q: ?Sized> {
     fn replace(&mut self, key: Self::Key) -> Option<Self::Key>;
 }
 
+/// Same purpose as `Option::unwrap` but doesn't always guarantee a panic
+/// if the option contains no value.
+/// SAFETY: the caller must ensure that the option contains a value.
 #[inline(always)]
 pub unsafe fn unwrap_unchecked<T>(val: Option<T>) -> T {
     val.unwrap_or_else(|| {