Fix pretty-printer test failure by carrying the bound lifetime names through

the types.  Initially I thought it would be necessary to thread this data
through not only the AST but the types themselves, but then I remembered that
the pretty printer only cares about the AST.  Regardless, I have elected to
leave the changes to the types intact since they will eventually be needed.  I
left a few FIXMEs where it didn't seem worth finishing up since the code wasn't
crucial yet.

Author: nikomatsakis

src/librustc/metadata/tydecode.rs

@@ -24,6 +24,7 @@ use core::vec;
 use syntax::ast;
 use syntax::ast::*;
 use syntax::codemap::{respan, dummy_sp};
+use syntax::opt_vec;
 
 // Compact string representation for ty::t values. API ty_str &
 // parse_from_str. Extra parameters are for converting to/from def_ids in the
@@ -479,7 +480,9 @@ fn parse_sig(st: @mut PState, conv: conv_did) -> ty::FnSig {
     }
     st.pos += 1u; // eat the ']'
     let ret_ty = parse_ty(st, conv);
-    ty::FnSig {inputs: inputs, output: ret_ty}
+    ty::FnSig {bound_lifetime_names: opt_vec::Empty, // FIXME(#4846)
+               inputs: inputs,
+               output: ret_ty}
 }
 
 // Rust metadata parsing

src/librustc/middle/trans/foreign.rs

@@ -40,6 +40,7 @@ use util::ppaux::ty_to_str;
 use syntax::codemap::span;
 use syntax::{ast, ast_util};
 use syntax::{attr, ast_map};
+use syntax::opt_vec;
 use syntax::parse::token::special_idents;
 
 fn abi_info(arch: session::arch) -> @cabi::ABIInfo {
@@ -615,7 +616,8 @@ pub fn trans_intrinsic(ccx: @CrateContext,
                 sigil: ast::BorrowedSigil,
                 onceness: ast::Many,
                 region: ty::re_bound(ty::br_anon(0)),
-                sig: FnSig {inputs: ~[arg {mode: ast::expl(ast::by_copy),
+                sig: FnSig {bound_lifetime_names: opt_vec::Empty,
+                            inputs: ~[arg {mode: ast::expl(ast::by_copy),
                                            ty: star_u8}],
                             output: ty::mk_nil(bcx.tcx())}
             });

src/librustc/middle/trans/monomorphize.rs

@@ -37,6 +37,7 @@ use syntax::ast;
 use syntax::ast_map;
 use syntax::ast_map::{path, path_mod, path_name};
 use syntax::ast_util::local_def;
+use syntax::opt_vec;
 use syntax::parse::token::special_idents;
 
 pub fn monomorphic_fn(ccx: @CrateContext,
@@ -282,7 +283,8 @@ pub fn normalize_for_monomorphization(tcx: ty::ctxt,
                 ty::BareFnTy {
                     purity: ast::impure_fn,
                     abi: ast::RustAbi,
-                    sig: FnSig {inputs: ~[],
+                    sig: FnSig {bound_lifetime_names: opt_vec::Empty,
+                                inputs: ~[],
                                 output: ty::mk_nil(tcx)}}))
         }
         ty::ty_closure(ref fty) => {
@@ -316,7 +318,8 @@ pub fn normalize_for_monomorphization(tcx: ty::ctxt,
                 sigil: sigil,
                 onceness: ast::Many,
                 region: ty::re_static,
-                sig: ty::FnSig {inputs: ~[],
+                sig: ty::FnSig {bound_lifetime_names: opt_vec::Empty,
+                                inputs: ~[],
                                 output: ty::mk_nil(tcx)}})
     }
 }

src/librustc/middle/ty.rs

@@ -45,6 +45,8 @@ use syntax::codemap::span;
 use syntax::codemap;
 use syntax::print::pprust;
 use syntax::{ast, ast_map};
+use syntax::opt_vec::OptVec;
+use syntax::opt_vec;
 use syntax;
 
 // Data types
@@ -376,10 +378,12 @@ pub struct ClosureTy {
  * Signature of a function type, which I have arbitrarily
  * decided to use to refer to the input/output types.
  *
+ * - `lifetimes` is the list of region names bound in this fn.
  * - `inputs` is the list of arguments and their modes.
  * - `output` is the return type. */
 #[deriving(Eq)]
 pub struct FnSig {
+    bound_lifetime_names: OptVec<ast::ident>,
     inputs: ~[arg],
     output: t
 }
@@ -1062,7 +1066,8 @@ pub fn mk_ctor_fn(cx: ctxt, input_tys: &[ty::t], output: ty::t) -> t {
                BareFnTy {
                    purity: ast::pure_fn,
                    abi: ast::RustAbi,
-                   sig: FnSig {inputs: input_args,
+                   sig: FnSig {bound_lifetime_names: opt_vec::Empty,
+                               inputs: input_args,
                                output: output}})
 }
 
@@ -1203,6 +1208,7 @@ pub fn fold_sig(sig: &FnSig, fldop: &fn(t) -> t) -> FnSig {
     };
 
     FnSig {
+        bound_lifetime_names: copy sig.bound_lifetime_names,
         inputs: args,
         output: fldop(sig.output)
     }

src/librustc/middle/typeck/astconv.rs

@@ -58,7 +58,7 @@ use middle::const_eval;
 use middle::ty::{arg, field, substs};
 use middle::ty::{ty_param_substs_and_ty};
 use middle::ty;
-use middle::typeck::rscope::{in_binding_rscope, in_binding_rscope_ext};
+use middle::typeck::rscope::{in_binding_rscope};
 use middle::typeck::rscope::{region_scope, type_rscope, RegionError};
 use middle::typeck::rscope::{RegionParamNames};
 
@@ -67,6 +67,7 @@ use core::vec;
 use syntax::{ast, ast_util};
 use syntax::codemap::span;
 use syntax::opt_vec::OptVec;
+use syntax::opt_vec;
 use syntax::print::pprust::{lifetime_to_str, path_to_str};
 use syntax::parse::token::special_idents;
 use util::common::indenter;
@@ -347,7 +348,7 @@ pub fn ast_ty_to_ty<AC:AstConv, RS:region_scope + Copy + Durable>(
       }
       ast::ty_bare_fn(ref bf) => {
           ty::mk_bare_fn(tcx, ty_of_bare_fn(self, rscope, bf.purity,
-                                            bf.abi, &bf.decl))
+                                            bf.abi, &bf.lifetimes, &bf.decl))
       }
       ast::ty_closure(ref f) => {
           let fn_decl = ty_of_closure(self,
@@ -508,45 +509,50 @@ pub fn ty_of_arg<AC:AstConv,RS:region_scope + Copy + Durable>(
     arg {mode: mode, ty: ty}
 }
 
-pub fn ty_of_bare_fn<AC:AstConv,RS:region_scope + Copy + Durable>(
-        self: &AC,
-        rscope: &RS,
-        purity: ast::purity,
-        abi: ast::Abi,
-        decl: &ast::fn_decl)
-     -> ty::BareFnTy {
-    debug!("ty_of_bare_fn");
-
-    // new region names that appear inside of the fn decl are bound to
-    // that function type
-    let rb = in_binding_rscope(rscope);
-
-    let input_tys = decl.inputs.map(|a| ty_of_arg(self, &rb, *a, None));
-    let output_ty = match decl.output.node {
-        ast::ty_infer => self.ty_infer(decl.output.span),
-        _ => ast_ty_to_ty(self, &rb, decl.output)
-    };
-
-    ty::BareFnTy {
-        purity: purity,
-        abi: abi,
-        sig: ty::FnSig {inputs: input_tys, output: output_ty}
-    }
+pub fn bound_lifetimes<AC:AstConv>(
+    self: &AC,
+    ast_lifetimes: &OptVec<ast::Lifetime>) -> OptVec<ast::ident>
+{
+    /*!
+     *
+     * Converts a list of lifetimes into a list of bound identifier
+     * names.  Does not permit special names like 'static or 'self to
+     * be bound.  Note that this function is for use in closures,
+     * methods, and fn definitions.  It is legal to bind 'self in a
+     * type.  Eventually this distinction should go away and the same
+     * rules should apply everywhere ('self would not be a special name
+     * at that point).
+     */
+
+    let special_idents = [special_idents::static, special_idents::self_];
+    let mut bound_lifetime_names = opt_vec::Empty;
+    ast_lifetimes.map_to_vec(|ast_lifetime| {
+        if special_idents.any(|&i| i == ast_lifetime.ident) {
+            self.tcx().sess.span_err(
+                ast_lifetime.span,
+                fmt!("illegal lifetime parameter name: `%s`",
+                     lifetime_to_str(ast_lifetime, self.tcx().sess.intr())));
+        } else {
+            bound_lifetime_names.push(ast_lifetime.ident);
+        }
+    });
+    bound_lifetime_names
 }
 
-pub fn ty_of_bare_fn_ext<AC:AstConv,RS:region_scope + Copy + Durable>(
-        self: &AC,
-        rscope: &RS,
-        purity: ast::purity,
-        abi: ast::Abi,
-        decl: &ast::fn_decl,
-        +region_param_names: RegionParamNames)
-     -> ty::BareFnTy {
-    debug!("ty_of_bare_fn_ext");
+pub fn ty_of_bare_fn<AC:AstConv,RS:region_scope + Copy + Durable>(
+    self: &AC,
+    rscope: &RS,
+    purity: ast::purity,
+    abi: ast::Abi,
+    lifetimes: &OptVec<ast::Lifetime>,
+    decl: &ast::fn_decl) -> ty::BareFnTy
+{
+    debug!("ty_of_bare_fn");
 
     // new region names that appear inside of the fn decl are bound to
     // that function type
-    let rb = in_binding_rscope_ext(rscope, region_param_names);
+    let bound_lifetime_names = bound_lifetimes(self, lifetimes);
+    let rb = in_binding_rscope(rscope, RegionParamNames(copy bound_lifetime_names));
 
     let input_tys = decl.inputs.map(|a| ty_of_arg(self, &rb, *a, None));
     let output_ty = match decl.output.node {
@@ -557,7 +563,9 @@ pub fn ty_of_bare_fn_ext<AC:AstConv,RS:region_scope + Copy + Durable>(
     ty::BareFnTy {
         purity: purity,
         abi: abi,
-        sig: ty::FnSig {inputs: input_tys, output: output_ty}
+        sig: ty::FnSig {bound_lifetime_names: bound_lifetime_names,
+                        inputs: input_tys,
+                        output: output_ty}
     }
 }
 
@@ -569,10 +577,16 @@ pub fn ty_of_closure<AC:AstConv,RS:region_scope + Copy + Durable>(
         onceness: ast::Onceness,
         opt_lifetime: Option<@ast::Lifetime>,
         decl: &ast::fn_decl,
-        expected_tys: Option<ty::FnSig>,
+        expected_sig: Option<ty::FnSig>,
         lifetimes: &OptVec<ast::Lifetime>,
         span: span)
-     -> ty::ClosureTy {
+     -> ty::ClosureTy
+{
+    // The caller should not both provide explicit bound lifetime
+    // names and expected types.  Either we infer the bound lifetime
+    // names or they are provided, but not both.
+    fail_unless!(lifetimes.is_empty() || expected_sig.is_none());
+
     debug!("ty_of_fn_decl");
     let _i = indenter();
 
@@ -599,19 +613,19 @@ pub fn ty_of_closure<AC:AstConv,RS:region_scope + Copy + Durable>(
 
     // new region names that appear inside of the fn decl are bound to
     // that function type
-    let region_param_names = RegionParamNames::from_lifetimes(lifetimes);
-    let rb = in_binding_rscope_ext(rscope, region_param_names);
+    let bound_lifetime_names = bound_lifetimes(self, lifetimes);
+    let rb = in_binding_rscope(rscope, RegionParamNames(copy bound_lifetime_names));
 
     let input_tys = do decl.inputs.mapi |i, a| {
-        let expected_arg_ty = do expected_tys.chain_ref |e| {
+        let expected_arg_ty = do expected_sig.chain_ref |e| {
             // no guarantee that the correct number of expected args
             // were supplied
             if i < e.inputs.len() {Some(e.inputs[i])} else {None}
         };
         ty_of_arg(self, &rb, *a, expected_arg_ty)
     };
 
-    let expected_ret_ty = expected_tys.map(|e| e.output);
+    let expected_ret_ty = expected_sig.map(|e| e.output);
     let output_ty = match decl.output.node {
         ast::ty_infer if expected_ret_ty.is_some() => expected_ret_ty.get(),
         ast::ty_infer => self.ty_infer(decl.output.span),
@@ -623,7 +637,8 @@ pub fn ty_of_closure<AC:AstConv,RS:region_scope + Copy + Durable>(
         sigil: sigil,
         onceness: onceness,
         region: bound_region,
-        sig: ty::FnSig {inputs: input_tys,
+        sig: ty::FnSig {bound_lifetime_names: bound_lifetime_names,
+                        inputs: input_tys,
                         output: output_ty}
     }
 }

src/librustc/middle/typeck/check/mod.rs

@@ -1633,7 +1633,7 @@ pub fn check_expr_with_unifier(fcx: @mut FnCtxt,
         // sigils.
         let expected_sty = unpack_expected(fcx, expected, |x| Some(copy *x));
         let mut error_happened = false;
-        let (expected_tys,
+        let (expected_sig,
              expected_purity,
              expected_sigil,
              expected_onceness) = {
@@ -1668,13 +1668,14 @@ pub fn check_expr_with_unifier(fcx: @mut FnCtxt,
                                                expected_onceness,
                                                None,
                                                decl,
-                                               expected_tys,
+                                               expected_sig,
                                                &opt_vec::Empty,
                                                expr.span);
 
         let mut fty_sig;
         let fty = if error_happened {
             fty_sig = FnSig {
+                bound_lifetime_names: opt_vec::Empty,
                 inputs: fn_ty.sig.inputs.map(|an_arg| {
                     arg { mode: an_arg.mode,
                          ty: ty::mk_err(tcx)
@@ -3492,6 +3493,7 @@ pub fn check_intrinsic_type(ccx: @mut CrateCtxt, it: @ast::foreign_item) {
             onceness: ast::Once,
             region: ty::re_bound(ty::br_anon(0)),
             sig: ty::FnSig {
+                bound_lifetime_names: opt_vec::Empty,
                 inputs: ~[arg {mode: ast::expl(ast::by_copy),
                                ty: ty::mk_imm_ptr(
                                    ccx.tcx,
@@ -3723,7 +3725,8 @@ pub fn check_intrinsic_type(ccx: @mut CrateCtxt, it: @ast::foreign_item) {
     let fty = ty::mk_bare_fn(tcx, ty::BareFnTy {
         purity: ast::unsafe_fn,
         abi: ast::RustAbi,
-        sig: FnSig {inputs: inputs,
+        sig: FnSig {bound_lifetime_names: opt_vec::Empty,
+                    inputs: inputs,
                     output: output}
     });
     let i_ty = ty::lookup_item_type(ccx.tcx, local_def(it.id));