Auto merge of #26351 - eddyb:tls-tcx, r=nikomatsakis

Pre-requisite for splitting the type context into global and local parts.
The `Repr` and `UserString` traits were also replaced by `Debug` and `Display`.

2 files changed, 83 insertions, 11 deletions

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 5b03b3bf038..e844b206cc0 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -63,8 +63,10 @@ use owned_slice::OwnedSlice;
 use parse::token::{InternedString, str_to_ident};
 use parse::token;
 use parse::lexer;
+use print::pprust;
 use ptr::P;
 
+use std::cell::Cell;
 use std::fmt;
 use std::rc::Rc;
 use serialize::{Encodable, Decodable, Encoder, Decoder};
@@ -200,14 +202,19 @@ impl Decodable for Ident {
 /// Function name (not all functions have names)
 pub type FnIdent = Option<Ident>;
 
-#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash,
-           Debug, Copy)]
+#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Copy)]
 pub struct Lifetime {
     pub id: NodeId,
     pub span: Span,
     pub name: Name
 }
 
+impl fmt::Debug for Lifetime {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "lifetime({}: {})", self.id, pprust::lifetime_to_string(self))
+    }
+}
+
 /// A lifetime definition, eg `'a: 'b+'c+'d`
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub struct LifetimeDef {
@@ -218,7 +225,7 @@ pub struct LifetimeDef {
 /// A "Path" is essentially Rust's notion of a name; for instance:
 /// std::cmp::PartialEq  .  It's represented as a sequence of identifiers,
 /// along with a bunch of supporting information.
-#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
+#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash)]
 pub struct Path {
     pub span: Span,
     /// A `::foo` path, is relative to the crate root rather than current
@@ -228,6 +235,18 @@ pub struct Path {
     pub segments: Vec<PathSegment>,
 }
 
+impl fmt::Debug for Path {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "path({})", pprust::path_to_string(self))
+    }
+}
+
+impl fmt::Display for Path {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", pprust::path_to_string(self))
+    }
+}
+
 /// A segment of a path: an identifier, an optional lifetime, and a set of
 /// types.
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
@@ -358,12 +377,25 @@ pub type CrateNum = u32;
 pub type NodeId = u32;
 
 #[derive(Clone, Eq, Ord, PartialOrd, PartialEq, RustcEncodable,
-           RustcDecodable, Hash, Debug, Copy)]
+           RustcDecodable, Hash, Copy)]
 pub struct DefId {
     pub krate: CrateNum,
     pub node: NodeId,
 }
 
+fn default_def_id_debug(_: DefId, _: &mut fmt::Formatter) -> fmt::Result { Ok(()) }
+
+thread_local!(pub static DEF_ID_DEBUG: Cell<fn(DefId, &mut fmt::Formatter) -> fmt::Result> =
+                Cell::new(default_def_id_debug));
+
+impl fmt::Debug for DefId {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        try!(write!(f, "DefId {{ krate: {}, node: {} }}",
+                    self.krate, self.node));
+        DEF_ID_DEBUG.with(|def_id_debug| def_id_debug.get()(*self, f))
+    }
+}
+
 impl DefId {
     /// Read the node id, asserting that this def-id is krate-local.
     pub fn local_id(&self) -> NodeId {
@@ -539,13 +571,19 @@ pub struct Block {
     pub span: Span,
 }
 
-#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
+#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash)]
 pub struct Pat {
     pub id: NodeId,
     pub node: Pat_,
     pub span: Span,
 }
 
+impl fmt::Debug for Pat {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "pat({}: {})", self.id, pprust::pat_to_string(self))
+    }
+}
+
 /// A single field in a struct pattern
 ///
 /// Patterns like the fields of Foo `{ x, ref y, ref mut z }`
@@ -682,7 +720,16 @@ pub enum UnOp {
 /// A statement
 pub type Stmt = Spanned<Stmt_>;
 
-#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
+impl fmt::Debug for Stmt {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "stmt({}: {})",
+               ast_util::stmt_id(self),
+               pprust::stmt_to_string(self))
+    }
+}
+
+
+#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash)]
 pub enum Stmt_ {
     /// Could be an item or a local (let) binding:
     StmtDecl(P<Decl>, NodeId),
@@ -695,7 +742,6 @@ pub enum Stmt_ {
 
     StmtMac(P<Mac>, MacStmtStyle),
 }
-
 #[derive(Clone, Copy, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub enum MacStmtStyle {
     /// The macro statement had a trailing semicolon, e.g. `foo! { ... };`
@@ -772,13 +818,19 @@ pub enum UnsafeSource {
 }
 
 /// An expression
-#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
+#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash,)]
 pub struct Expr {
     pub id: NodeId,
     pub node: Expr_,
     pub span: Span,
 }
 
+impl fmt::Debug for Expr {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "expr({}: {})", self.id, pprust::expr_to_string(self))
+    }
+}
+
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub enum Expr_ {
     /// First expr is the place; second expr is the value.
@@ -1357,13 +1409,19 @@ pub struct TypeBinding {
 
 
 // NB PartialEq method appears below.
-#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
+#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash)]
 pub struct Ty {
     pub id: NodeId,
     pub node: Ty_,
     pub span: Span,
 }
 
+impl fmt::Debug for Ty {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "type({})", pprust::ty_to_string(self))
+    }
+}
+
 /// Not represented directly in the AST, referred to by name through a ty_path.
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
 pub enum PrimTy {
diff --git a/src/libsyntax/codemap.rs b/src/libsyntax/codemap.rs
index ea27ed6b360..5ddcfaef9ea 100644
--- a/src/libsyntax/codemap.rs
+++ b/src/libsyntax/codemap.rs
@@ -19,7 +19,7 @@
 
 pub use self::ExpnFormat::*;
 
-use std::cell::RefCell;
+use std::cell::{Cell, RefCell};
 use std::ops::{Add, Sub};
 use std::path::Path;
 use std::rc::Rc;
@@ -115,7 +115,7 @@ impl Sub for CharPos {
 /// are *absolute* positions from the beginning of the codemap, not positions
 /// relative to FileMaps. Methods on the CodeMap can be used to relate spans back
 /// to the original source.
-#[derive(Clone, Copy, Debug, Hash)]
+#[derive(Clone, Copy, Hash)]
 pub struct Span {
     pub lo: BytePos,
     pub hi: BytePos,
@@ -164,6 +164,20 @@ impl Decodable for Span {
     }
 }
 
+fn default_span_debug(span: Span, f: &mut fmt::Formatter) -> fmt::Result {
+    write!(f, "Span {{ lo: {:?}, hi: {:?}, expn_id: {:?} }}",
+           span.lo, span.hi, span.expn_id)
+}
+
+thread_local!(pub static SPAN_DEBUG: Cell<fn(Span, &mut fmt::Formatter) -> fmt::Result> =
+                Cell::new(default_span_debug));
+
+impl fmt::Debug for Span {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        SPAN_DEBUG.with(|span_debug| span_debug.get()(*self, f))
+    }
+}
+
 pub fn spanned<T>(lo: BytePos, hi: BytePos, t: T) -> Spanned<T> {
     respan(mk_sp(lo, hi), t)
 }