Add a sig module to save-analysis

Generates signatures for use in Rustdoc and similar tools.

src/librustc_save_analysis/lib.rs

@@ -44,6 +44,7 @@
 pub mod external_data;
 #[macro_use]
 pub mod span_utils;
+mod sig;
 
 use rustc::hir;
 use rustc::hir::def::Def;

src/librustc_save_analysis/sig.rs

+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// FIXME? None of these include visibility info.
+// Large outstanding things - where clauses, defs/refs for generics
+// paresable - each sig ends with `;` of ` {}`
+
+use SaveContext;
+
+use rls_data::{Signature, SigElement, Id};
+
+use rustc::hir::def::Def;
+use rustc::hir::def_id::DefId;
+use syntax::ast::{self, NodeId};
+use syntax::print::pprust;
+
+
+// TODO dup from json_dumper
+fn id_from_def_id(id: DefId) -> Id {
+    Id {
+        krate: id.krate.as_u32(),
+        index: id.index.as_u32(),
+    }
+}
+
+fn id_from_node_id(id: NodeId, scx: &SaveContext) -> Id {
+    let def_id = scx.tcx.hir.local_def_id(id);
+    id_from_def_id(def_id)
+}
+
+type Result = ::std::result::Result<Signature, &'static str>;
+
+trait Sig {
+    fn make(&self, offset: usize, id: Option<NodeId>, scx: &SaveContext) -> Result;
+}
+
+fn extend_sig(mut sig: Signature,
+              text: String,
+              defs: Vec<SigElement>,
+              refs: Vec<SigElement>)
+              -> Signature {
+    sig.text = text;
+    sig.defs.extend(defs.into_iter());
+    sig.refs.extend(refs.into_iter());
+    sig
+}
+
+fn replace_text(mut sig: Signature, text: String) -> Signature {
+    sig.text = text;
+    sig
+}
+
+fn merge_sigs(text: String, sigs: Vec<Signature>) -> Signature {
+    let mut result = Signature {
+        text,
+        defs: vec![],
+        refs: vec![],
+    };
+
+    let (defs, refs): (Vec<_>, Vec<_>) = sigs.into_iter().map(|s| (s.defs, s.refs)).unzip();
+
+    result.defs.extend(defs.into_iter().flat_map(|ds| ds.into_iter()));
+    result.refs.extend(refs.into_iter().flat_map(|rs| rs.into_iter()));
+
+    result
+}
+
+fn text_sig(text: String) -> Signature {
+    Signature {
+        text: text,
+        defs: vec![],
+        refs: vec![],
+    }
+}
+
+impl Sig for ast::Ty {
+    fn make(&self, offset: usize, _parent_id: Option<NodeId>, scx: &SaveContext) -> Result {
+        let id = Some(self.id);
+        match self.node {
+            ast::TyKind::Slice(ref ty) => {
+                let nested = ty.make(offset + 1, id, scx)?;
+                let text = format!("[{}]", nested.text);
+                Ok(replace_text(nested, text))
+            }
+            ast::TyKind::Ptr(ref mt) => {
+                let prefix = match mt.mutbl {
+                    ast::Mutability::Mutable => "*mut ",
+                    ast::Mutability::Immutable => "*const ",
+                };
+                let nested = mt.ty.make(offset + prefix.len(), id, scx)?;
+                let text = format!("{}{}", prefix, nested.text);
+                Ok(replace_text(nested, text))
+            }
+            ast::TyKind::Rptr(ref lifetime, ref mt) => {
+                let mut prefix = "&".to_owned();
+                if let &Some(ref l) = lifetime {
+                    prefix.push_str(&l.ident.to_string());
+                    prefix.push(' ');
+                }
+                if let ast::Mutability::Mutable = mt.mutbl {
+                    prefix.push_str("mut ");
+                };
+
+                let nested = mt.ty.make(offset + prefix.len(), id, scx)?;
+                let text = format!("{}{}", prefix, nested.text);
+                Ok(replace_text(nested, text))
+            }
+            ast::TyKind::Never => {
+                Ok(text_sig("!".to_owned()))
+            },
+            ast::TyKind::Tup(ref ts) => {
+                let mut text = "(".to_owned();
+                let mut defs = vec![];
+                let mut refs = vec![];
+                for t in ts {
+                    let nested = t.make(offset + text.len(), id, scx)?;
+                    text.push_str(&nested.text);
+                    text.push(',');
+                    defs.extend(nested.defs.into_iter());
+                    refs.extend(nested.refs.into_iter());
+                }
+                text.push(')');
+                Ok(Signature { text, defs, refs })
+            }
+            ast::TyKind::Paren(ref ty) => {
+                let nested = ty.make(offset + 1, id, scx)?;
+                let text = format!("({})", nested.text);
+                Ok(replace_text(nested, text))
+            }
+            ast::TyKind::BareFn(ref f) => {
+                let mut text = String::new();
+                if !f.lifetimes.is_empty() {
+                    // FIXME defs, bounds on lifetimes
+                    text.push_str("for<");
+                    text.push_str(&f.lifetimes.iter().map(|l|
+                        l.lifetime.ident.to_string()).collect::<Vec<_>>().join(", "));
+                    text.push('>');
+                }
+
+                if f.unsafety == ast::Unsafety::Unsafe {
+                    text.push_str("unsafe ");
+                }
+                if f.abi != ::syntax::abi::Abi::Rust {
+                    text.push_str("extern");
+                    text.push_str(&f.abi.to_string());
+                    text.push(' ');
+                }
+                text.push_str("fn(");
+
+                let mut defs = vec![];
+                let mut refs = vec![];
+                for i in &f.decl.inputs {
+                    let nested = i.ty.make(offset + text.len(), Some(i.id), scx)?;
+                    text.push_str(&nested.text);
+                    text.push(',');
+                    defs.extend(nested.defs.into_iter());
+                    refs.extend(nested.refs.into_iter());
+                }
+                text.push(')');
+                if let ast::FunctionRetTy::Ty(ref t) = f.decl.output {
+                    text.push_str(" -> ");
+                    let nested = t.make(offset + text.len(), None, scx)?;
+                    text.push_str(&nested.text);
+                    text.push(',');
+                    defs.extend(nested.defs.into_iter());
+                    refs.extend(nested.refs.into_iter());
+                }
+
+                Ok(Signature { text, defs, refs })
+            }
+            ast::TyKind::Path(None, ref path) => {
+                path.make(offset, id, scx)
+            }
+            ast::TyKind::Path(Some(ref qself), ref path) => {
+                let nested_ty = qself.ty.make(offset + 1, id, scx)?;
+                let prefix = if qself.position == 0 {
+                    format!("<{}>::", nested_ty.text)
+                } else if qself.position == 1 {
+                    let first = pprust::path_segment_to_string(&path.segments[0]);
+                    format!("<{} as {}>::", nested_ty.text, first)
+                } else {
+                    // FIXME handle path instead of elipses.
+                    format!("<{} as ...>::", nested_ty.text)                    
+                };
+
+                let name = pprust::path_segment_to_string(path.segments.last().ok_or("Bad path")?);
+                let def = scx.get_path_def(id.ok_or("Missing id for Path")?);
+                let id = id_from_def_id(def.def_id());
+                if path.segments.len() - qself.position == 1 {
+                    let start = offset + prefix.len();
+                    let end = start + name.len();
+
+                    Ok(Signature {
+                        text: prefix + &name,
+                        defs: vec![],
+                        refs: vec![SigElement { id, start, end }],
+                    })
+                } else {
+                    let start = offset + prefix.len() + 5;
+                    let end = start + name.len();
+                    // FIXME should put the proper path in there, not elipses.
+                    Ok(Signature {
+                        text: prefix + "...::" + &name,
+                        defs: vec![],
+                        refs: vec![SigElement { id, start, end }],
+                    })
+                }
+            }
+            ast::TyKind::TraitObject(ref bounds) => {
+                // FIXME recurse into bounds
+                let nested = pprust::bounds_to_string(bounds);
+                Ok(text_sig(nested))
+            }
+            ast::TyKind::ImplTrait(ref bounds) => {
+                // FIXME recurse into bounds
+                let nested = pprust::bounds_to_string(bounds);
+                Ok(text_sig(format!("impl {}", nested)))
+            }
+            ast::TyKind::Array(ref ty, ref v) => {
+                let nested_ty = ty.make(offset + 1, id, scx)?;
+                let expr = pprust::expr_to_string(v).replace('\n', " ");
+                let text = format!("[{}; {}]", nested_ty.text, expr);
+                Ok(replace_text(nested_ty, text))
+            }
+            ast::TyKind::Typeof(_) |
+            ast::TyKind::Infer |
+            ast::TyKind::Err |
+            ast::TyKind::ImplicitSelf |
+            ast::TyKind::Mac(_) => Err("Ty"),
+        }
+    }    
+}
+
+impl Sig for ast::Item {
+    fn make(&self, offset: usize, _parent_id: Option<NodeId>, scx: &SaveContext) -> Result {
+        let id = Some(self.id);
+
+        let name_and_generics = |mut text: String, generics: &ast::Generics| -> Result {
+            let name = self.ident.to_string();
+            let def = SigElement {
+                id: id_from_node_id(self.id, scx),
+                start: offset + 5,
+                end: offset + 5 + name.len(),
+            };
+            text.push_str(&name);
+            let generics: Signature = generics.make(offset + text.len(), id, scx)?;
+            // FIXME where clause
+            let text = format!("{}{}", text, generics.text);
+            Ok(extend_sig(generics, text, vec![def], vec![]))
+        };
+
+        match self.node {
+            ast::ItemKind::Static(ref ty, m, ref expr) => {
+                let mut text = "static ".to_owned();
+                if m == ast::Mutability::Mutable {
+                    text.push_str("mut ");
+                }
+                let name = self.ident.to_string();
+                let defs = vec![SigElement {
+                    id: id_from_node_id(self.id, scx),
+                    start: offset + text.len(),
+                    end: offset + text.len() + name.len(),
+                }];
+                text.push_str(&name);
+                text.push_str(": ");
+
+                let ty = ty.make(offset + text.len(), id, scx)?;
+                text.push_str(&ty.text);
+                text.push_str(" = ");
+
+                let expr = pprust::expr_to_string(expr).replace('\n', " ");
+                text.push_str(&expr);
+                text.push(';');
+
+                Ok(extend_sig(ty, text, defs, vec![]))
+            }
+            ast::ItemKind::Const(ref ty, ref expr) => {
+                let mut text = "const ".to_owned();
+                let name = self.ident.to_string();
+                let defs = vec![SigElement {
+                    id: id_from_node_id(self.id, scx),
+                    start: offset + text.len(),
+                    end: offset + text.len() + name.len(),
+                }];
+                text.push_str(&name);
+                text.push_str(": ");
+
+                let ty = ty.make(offset + text.len(), id, scx)?;
+                text.push_str(&ty.text);
+                text.push_str(" = ");
+
+                let expr = pprust::expr_to_string(expr).replace('\n', " ");
+                text.push_str(&expr);
+                text.push(';');
+
+                Ok(extend_sig(ty, text, defs, vec![]))
+            }
+            ast::ItemKind::Fn(ref decl, unsafety, constness, abi, ref generics, _) => {
+                let mut text = String::new();
+                if constness.node == ast::Constness::Const {
+                    text.push_str("const ");
+                }
+                if unsafety == ast::Unsafety::Unsafe {
+                    text.push_str("unsafe ");
+                }
+                if abi != ::syntax::abi::Abi::Rust {
+                    text.push_str("extern");
+                    text.push_str(&abi.to_string());
+                    text.push(' ');
+                }
+                text.push_str("fn ");
+
+                let mut sig = name_and_generics(text, generics)?;
+
+                sig.text.push('(');
+                for i in &decl.inputs {
+                    // FIXME shoudl descend into patterns to add defs.
+                    sig.text.push_str(&pprust::pat_to_string(&i.pat));
+                    sig.text.push_str(": ");
+                    let nested = i.ty.make(offset + sig.text.len(), Some(i.id), scx)?;
+                    sig.text.push_str(&nested.text);
+                    sig.text.push(',');
+                    sig.defs.extend(nested.defs.into_iter());
+                    sig.refs.extend(nested.refs.into_iter());
+                }
+                sig.text.push(')');
+
+                if let ast::FunctionRetTy::Ty(ref t) = decl.output {
+                    sig.text.push_str(" -> ");
+                    let nested = t.make(offset + sig.text.len(), None, scx)?;
+                    sig.text.push_str(&nested.text);
+                    sig.text.push(',');
+                    sig.defs.extend(nested.defs.into_iter());
+                    sig.refs.extend(nested.refs.into_iter());
+                }
+
+                Ok(sig)
+            }
+            ast::ItemKind::Mod(ref _mod) => {
+                let mut text = "mod ".to_owned();
+                let name = self.ident.to_string();
+                let defs = vec![SigElement {
+                    id: id_from_node_id(self.id, scx),
+                    start: offset + text.len(),
+                    end: offset + text.len() + name.len(),
+                }];
+                text.push_str(&name);
+                // Could be either `mod foo;` or `mod foo { ... }`, but we'll just puck one.
+                text.push(';');
+
+                Ok(Signature {
+                    text,
+                    defs,
+                    refs: vec![],
+                })
+            }
+            ast::ItemKind::Ty(ref ty, ref generics) => {
+                let text = "type ".to_owned();
+                let mut sig = name_and_generics(text, generics)?;
+
+                sig.text.push_str(" = ");
+                let ty = ty.make(offset + sig.text.len(), id, scx)?;
+                sig.text.push_str(&ty.text);
+                sig.text.push(';');
+
+                Ok(merge_sigs(sig.text.clone(), vec![sig, ty]))
+            }
+            ast::ItemKind::Enum(_, ref generics) => {
+                let text = "enum ".to_owned();
+                let mut sig = name_and_generics(text, generics)?;
+                sig.text.push_str(" {}");
+                Ok(sig)
+            }
+            ast::ItemKind::Struct(_, ref generics) => {
+                let text = "struct ".to_owned();
+                let mut sig = name_and_generics(text, generics)?;
+                sig.text.push_str(" {}");
+                Ok(sig)
+            }
+            ast::ItemKind::Union(_, ref generics) => {
+                let text = "union ".to_owned();
+                let mut sig = name_and_generics(text, generics)?;
+                sig.text.push_str(" {}");
+                Ok(sig)
+            }
+            ast::ItemKind::Trait(unsafety, ref generics, ref bounds, _) => {
+                let mut text = String::new();
+                if unsafety == ast::Unsafety::Unsafe {
+                    text.push_str("unsafe ");
+                }
+                text.push_str("trait ");
+                let mut sig = name_and_generics(text, generics)?;
+
+                if !bounds.is_empty() {
+                    sig.text.push_str(": ");
+                    sig.text.push_str(&pprust::bounds_to_string(bounds));
+                }
+                // FIXME where clause
+                sig.text.push_str(" {}");
+
+                Ok(sig)
+            }
+            ast::ItemKind::DefaultImpl(unsafety, ref trait_ref) => {
+                let mut text = String::new();
+                if unsafety == ast::Unsafety::Unsafe {
+                    text.push_str("unsafe ");
+                }
+                text.push_str("impl ");
+                let trait_sig = trait_ref.path.make(offset + text.len(), id, scx)?;
+                text.push_str(&trait_sig.text);
+                text.push_str(" for .. {}");
+                Ok(replace_text(trait_sig, text))
+            }
+            ast::ItemKind::Impl(unsafety,
+                                polarity,
+                                defaultness,
+                                ref generics,
+                                ref opt_trait,
+                                ref ty,
+                                _) => {
+                let mut text = String::new();
+                if let ast::Defaultness::Default = defaultness {
+                    text.push_str("default ");
+                }
+                if unsafety == ast::Unsafety::Unsafe {
+                    text.push_str("unsafe ");
+                }
+                text.push_str("impl");
+
+                let generics_sig = generics.make(offset + text.len(), id, scx)?;
+                text.push_str(&generics_sig.text);
+
+                text.push(' ');
+
+                let trait_sig = if let Some(ref t) = *opt_trait {
+                    if polarity == ast::ImplPolarity::Negative {
+                        text.push('!');
+                    }
+                    let trait_sig = t.path.make(offset + text.len(), id, scx)?;
+                    text.push_str(&trait_sig.text);
+                    text.push_str(" for ");
+                    trait_sig
+                } else {
+                    text_sig(String::new())
+                };
+
+                let ty_sig = ty.make(offset + text.len(), id, scx)?;
+                text.push_str(&ty_sig.text);
+                
+                text.push_str(" {}");
+
+                Ok(merge_sigs(text, vec![generics_sig, trait_sig, ty_sig]))
+
+                // FIXME where clause
+            }
+            ast::ItemKind::ForeignMod(_) => Err("extern mod"),
+            ast::ItemKind::GlobalAsm(_) => Err("glboal asm"),
+            ast::ItemKind::ExternCrate(_) => Err("extern crate"),
+            // FIXME should implement this (e.g., pub use).
+            ast::ItemKind::Use(_) => Err("import"),
+            ast::ItemKind::Mac(..) |
+            ast::ItemKind::MacroDef(_) => Err("Macro"),
+        }
+    }
+}
+
+impl Sig for ast::Path {
+    fn make(&self, offset: usize, id: Option<NodeId>, scx: &SaveContext) -> Result {
+        let def = scx.get_path_def(id.ok_or("Missing id for Path")?);
+        let id = id_from_def_id(def.def_id());
+
+        let (name, start, end) = match def {
+            Def::AssociatedConst(..) |
+            Def::Variant(..) |
+            Def::VariantCtor(..) => {
+                let len = self.segments.len();
+                if len < 2 {
+                    return Err("Bad path");
+                }
+                // FIXME: really we should descend into the generics here and add SigElements for
+                // them.
+                // FIXME: would be nice to have a def for the first path segment.
+                let seg1 = pprust::path_segment_to_string(&self.segments[len - 2]);
+                let seg2 = pprust::path_segment_to_string(&self.segments[len - 1]);
+                let start = offset + seg1.len() + 2;
+                (format!("{}::{}", seg1, seg2), start, start + seg2.len())
+            }
+            _ => {
+                let name = pprust::path_segment_to_string(self.segments.last().ok_or("Bad path")?);
+                let end = offset + name.len();
+                (name, offset, end)
+            }
+        };
+
+        Ok(Signature {
+            text: name,
+            defs: vec![],
+            refs: vec![SigElement { id, start, end }],
+        })
+    }
+}
+
+// This does not cover the where clause, which must be processed separately.
+impl Sig for ast::Generics {
+    fn make(&self, offset: usize, _parent_id: Option<NodeId>, scx: &SaveContext) -> Result {
+        let total = self.lifetimes.len() + self.ty_params.len();
+        if total == 0 {
+            return Ok(text_sig(String::new()));
+        }
+
+        let mut text = "<".to_owned();
+
+        let mut defs = vec![];
+        for l in &self.lifetimes {
+            let mut l_text = l.lifetime.ident.to_string();
+            defs.push(SigElement {
+                id: id_from_node_id(l.lifetime.id, scx),
+                start: offset + text.len(),
+                end: offset + text.len() + l_text.len(),
+            });
+
+            if !l.bounds.is_empty() {
+                l_text.push_str(": ");
+                let bounds = l.bounds.iter().map(|l| l.ident.to_string()).collect::<Vec<_>>().join(" + ");
+                l_text.push_str(&bounds);
+                // FIXME add lifetime bounds refs.
+            }
+            text.push_str(&l_text);
+            text.push(',');
+        }
+        for t in &self.ty_params {
+            let mut t_text = t.ident.to_string();
+            defs.push(SigElement {
+                id: id_from_node_id(t.id, scx),
+                start: offset + text.len(),
+                end: offset + text.len() + t_text.len(),
+            });
+
+            if !t.bounds.is_empty() {
+                t_text.push_str(": ");
+                t_text.push_str(&pprust::bounds_to_string(&t.bounds));
+                // FIXME descend properly into bounds.
+            }
+            text.push_str(&t_text);
+            text.push(',');
+        }
+
+        text.push('>');
+        Ok(Signature {text, defs, refs: vec![] })
+    }
+}
+
+// TODO impl items, trait items

src/libsyntax/print/pprust.rs

@@ -370,6 +370,10 @@ pub fn path_to_string(p: &ast::Path) -> String {
     to_string(|s| s.print_path(p, false, 0, false))
 }
 
+pub fn path_segment_to_string(p: &ast::PathSegment) -> String {
+    to_string(|s| s.print_path_segment(p, false))
+}
+
 pub fn ident_to_string(id: ast::Ident) -> String {
     to_string(|s| s.print_ident(id))
 }
@@ -2359,18 +2363,27 @@ fn print_path(&mut self,
             if i > 0 {
                 word(&mut self.s, "::")?
             }
-            if segment.identifier.name != keywords::CrateRoot.name() &&
-               segment.identifier.name != "$crate" {
-                self.print_ident(segment.identifier)?;
-                if let Some(ref parameters) = segment.parameters {
-                    self.print_path_parameters(parameters, colons_before_params)?;
-                }
-            }
+            self.print_path_segment(segment, colons_before_params)?;
         }
 
         Ok(())
     }
 
+    fn print_path_segment(&mut self,
+                          segment: &ast::PathSegment,
+                          colons_before_params: bool)
+                          -> io::Result<()>
+    {
+        if segment.identifier.name != keywords::CrateRoot.name() &&
+           segment.identifier.name != "$crate" {
+            self.print_ident(segment.identifier)?;
+            if let Some(ref parameters) = segment.parameters {
+                self.print_path_parameters(parameters, colons_before_params)?;
+            }
+        }
+        Ok(())
+    }
+
     fn print_qpath(&mut self,
                    path: &ast::Path,
                    qself: &ast::QSelf,