Typestate 2

.gitignore

@@ -55,3 +55,5 @@ config.mk
 src/.DS_Store
 /stage0/
 /dl/
+/stage1/
+*.bz2

src/comp/driver/rustc.rs

@@ -9,7 +9,7 @@ import middle::trans;
 import middle::resolve;
 import middle::ty;
 import middle::typeck;
-import middle::typestate_check;
+import middle::tstate::ck;
 import back::link;
 import lib::llvm;
 import util::common;
@@ -105,7 +105,8 @@ fn compile_input(session::session sess,
 
     if (sess.get_opts().run_typestate) {
         crate = time(time_passes, "typestate checking",
-                     bind typestate_check::check_crate(crate, def_map));
+                     bind middle::tstate::ck::check_crate(node_type_table,
+                                                          ty_cx, crate));
     }
 
     auto llmod = time[llvm::ModuleRef](time_passes, "translation",
@@ -165,26 +166,31 @@ options:
 }
 
 fn get_os(str triple) -> session::os {
-    if (_str::find(triple, "win32") > 0 ||
-        _str::find(triple, "mingw32") > 0 ) {
+    if (_str::find(triple, "win32") >= 0 ||
+        _str::find(triple, "mingw32") >= 0 ) {
         ret session::os_win32;
-    } else if (_str::find(triple, "darwin") > 0) { ret session::os_macos; }
-    else if (_str::find(triple, "linux") > 0) { ret session::os_linux; }
+    } else if (_str::find(triple, "darwin") >= 0) { ret session::os_macos; }
+    else if (_str::find(triple, "linux") >= 0) { ret session::os_linux; }
+    else { log_err "Unknown operating system!"; fail; }
 }
 
 fn get_arch(str triple) -> session::arch {
-    if (_str::find(triple, "i386") > 0 ||
-        _str::find(triple, "i486") > 0 ||
-        _str::find(triple, "i586") > 0 ||
-        _str::find(triple, "i686") > 0 ||
-        _str::find(triple, "i786") > 0 ) {
+    if (_str::find(triple, "i386") >= 0 ||
+        _str::find(triple, "i486") >= 0 ||
+        _str::find(triple, "i586") >= 0 ||
+        _str::find(triple, "i686") >= 0 ||
+        _str::find(triple, "i786") >= 0 ) {
         ret session::arch_x86;
-    } else if (_str::find(triple, "x86_64") > 0) {
+    } else if (_str::find(triple, "x86_64") >= 0) {
         ret session::arch_x64;
-    } else if (_str::find(triple, "arm") > 0 ||
-        _str::find(triple, "xscale") > 0 ) {
+    } else if (_str::find(triple, "arm") >= 0 ||
+        _str::find(triple, "xscale") >= 0 ) {
         ret session::arch_arm;
     }
+    else {
+        log_err ("Unknown architecture! " + triple);
+        fail;
+    }
 }
 
 fn get_default_sysroot(str binary) -> str {

src/comp/front/ast.rs

@@ -1,4 +1,3 @@
-
 import std::map::hashmap;
 import std::option;
 import std::_str;
@@ -7,7 +6,7 @@ import util::common::span;
 import util::common::spanned;
 import util::common::ty_mach;
 import util::common::filename;
-import util::typestate_ann::ts_ann;
+import middle::tstate::ann::ts_ann;
 
 type ident = str;
 
@@ -323,6 +322,12 @@ type ty_method = rec(proto proto, ident ident,
 type ty = spanned[ty_];
 tag ty_ {
     ty_nil;
+    ty_bot; /* return type of ! functions and type of
+             ret/fail/break/cont. there is no syntax
+             for this type. */
+    /* bot represents the value of functions that don't return a value
+       locally to their context. in contrast, things like log that do
+       return, but don't return a meaningful value, have result type nil. */
     ty_bool;
     ty_int;
     ty_uint;
@@ -354,12 +359,19 @@ type constr = spanned[constr_];
 type arg = rec(mode mode, @ty ty, ident ident, def_id id);
 type fn_decl = rec(vec[arg] inputs,
                    @ty output,
-                   purity purity);
+                   purity purity,
+                   controlflow cf);
 tag purity {
     pure_fn;   // declared with "pred"
     impure_fn; // declared with "fn"
 }
 
+tag controlflow {
+    noreturn; // functions with return type _|_ that always
+              // raise an error or exit (i.e. never return to the caller)
+    return;  // everything else
+}
+
 type _fn = rec(fn_decl decl,
                proto proto,
                block body);

src/comp/front/parser.rs

@@ -23,6 +23,11 @@ tag file_type {
     SOURCE_FILE;
 }
 
+tag ty_or_bang {
+    a_ty(@ast::ty);
+    a_bang;
+}
+
 state type parser =
     state obj {
           fn peek() -> token::token;
@@ -448,6 +453,13 @@ fn parse_ty_constrs(@ast::ty t, parser p) -> @ast::ty {
    ret t;
 }
 
+fn parse_ty_or_bang(parser p) -> ty_or_bang {
+    alt (p.peek()) {
+        case (token::NOT) { p.bump(); ret a_bang; }
+        case (_)         { ret a_ty(parse_ty(p)); }
+    }
+}
+
 fn parse_ty(parser p) -> @ast::ty {
     auto lo = p.get_lo_pos();
     auto hi = lo;
@@ -1713,20 +1725,31 @@ fn parse_fn_decl(parser p, ast::purity purity) -> ast::fn_decl {
          some(token::COMMA),
          pf, p);
 
-    let @ast::ty output;
+    let ty_or_bang res;
 
     // FIXME: dropping constrs on the floor at the moment.
     // pick them up when they're used by typestate pass.
     parse_constrs(p);
 
     if (p.peek() == token::RARROW) {
         p.bump();
-        output = parse_ty(p);
+        res = parse_ty_or_bang(p);
     } else {
-        output = @spanned(inputs.span.lo, inputs.span.hi, ast::ty_nil);
+        res = a_ty(@spanned(inputs.span.lo, inputs.span.hi, ast::ty_nil));
+    }
+
+    alt (res) {
+        case (a_ty(?t)) {
+            ret rec(inputs=inputs.node, output=t,
+              purity=purity, cf=ast::return);
+        }
+        case (a_bang) {
+            ret rec(inputs=inputs.node,
+                    output=@spanned(p.get_lo_pos(),
+                                    p.get_hi_pos(), ast::ty_bot),
+                    purity=purity, cf=ast::noreturn);
+        }
     }
-    // FIXME
-    ret rec(inputs=inputs.node, output=output, purity=purity);
 }
 
 fn parse_fn(parser p, ast::proto proto, ast::purity purity) -> ast::_fn {
@@ -1778,11 +1801,12 @@ fn parse_dtor(parser p) -> @ast::method {
     let vec[ast::arg] inputs = vec();
     let @ast::ty output = @spanned(lo, lo, ast::ty_nil);
     let ast::fn_decl d = rec(inputs=inputs,
-                            output=output,
-                            purity=ast::impure_fn);
+                             output=output,
+                             purity=ast::impure_fn,
+                             cf=ast::return); 
     let ast::_fn f = rec(decl = d,
-                        proto = ast::proto_fn,
-                        body = b);
+                         proto = ast::proto_fn,
+                         body = b);
     let ast::method_ m = rec(ident="drop",
                             meth=f,
                             id=p.next_def_id(),

src/comp/middle/fold.rs

@@ -7,13 +7,14 @@ import util::common::new_str_hash;
 import util::common::spanned;
 import util::common::span;
 import util::common::ty_mach;
-import util::typestate_ann::ts_ann;
+import middle::tstate::ann::ts_ann;
 
 import front::ast;
 import front::ast::fn_decl;
 import front::ast::ident;
 import front::ast::path;
 import front::ast::mutability;
+import front::ast::controlflow;
 import front::ast::ty;
 import front::ast::expr;
 import front::ast::stmt;
@@ -44,6 +45,7 @@ type ast_fold[ENV] =
 
      // Type folds.
      (fn(&ENV e, &span sp) -> @ty)                fold_ty_nil,
+     (fn(&ENV e, &span sp) -> @ty)                fold_ty_bot,
      (fn(&ENV e, &span sp) -> @ty)                fold_ty_bool,
      (fn(&ENV e, &span sp) -> @ty)                fold_ty_int,
      (fn(&ENV e, &span sp) -> @ty)                fold_ty_uint,
@@ -314,7 +316,7 @@ type ast_fold[ENV] =
      (fn(&ENV e,
          &vec[arg] inputs,
          &@ty output,
-         &purity p) -> ast::fn_decl)              fold_fn_decl,
+         &purity p, &controlflow c) -> ast::fn_decl) fold_fn_decl,
 
      (fn(&ENV e, &ast::_mod m) -> ast::_mod)      fold_mod,
 
@@ -375,6 +377,7 @@ fn fold_ty[ENV](&ENV env, &ast_fold[ENV] fld, &@ty t) -> @ty {
 
     alt (t.node) {
         case (ast::ty_nil) { ret fld.fold_ty_nil(env_, t.span); }
+        case (ast::ty_bot) { ret fld.fold_ty_bot(env_, t.span); }
         case (ast::ty_bool) { ret fld.fold_ty_bool(env_, t.span); }
         case (ast::ty_int) { ret fld.fold_ty_int(env_, t.span); }
         case (ast::ty_uint) { ret fld.fold_ty_uint(env_, t.span); }
@@ -926,7 +929,7 @@ fn fold_fn_decl[ENV](&ENV env, &ast_fold[ENV] fld,
         inputs += vec(fold_arg(env, fld, a));
     }
     auto output = fold_ty[ENV](env, fld, decl.output);
-    ret fld.fold_fn_decl(env, inputs, output, decl.purity);
+    ret fld.fold_fn_decl(env, inputs, output, decl.purity, decl.cf);
 }
 
 fn fold_fn[ENV](&ENV env, &ast_fold[ENV] fld, &ast::_fn f) -> ast::_fn {
@@ -1202,6 +1205,10 @@ fn identity_fold_ty_nil[ENV](&ENV env, &span sp) -> @ty {
     ret @respan(sp, ast::ty_nil);
 }
 
+fn identity_fold_ty_bot[ENV](&ENV env, &span sp) -> @ty {
+    ret @respan(sp, ast::ty_bot);
+}
+
 fn identity_fold_ty_bool[ENV](&ENV env, &span sp) -> @ty {
     ret @respan(sp, ast::ty_bool);
 }
@@ -1622,8 +1629,8 @@ fn identity_fold_block[ENV](&ENV e, &span sp, &ast::block_ blk) -> block {
 fn identity_fold_fn_decl[ENV](&ENV e,
                               &vec[arg] inputs,
                               &@ty output,
-                              &purity p) -> ast::fn_decl {
-    ret rec(inputs=inputs, output=output, purity=p);
+                              &purity p, &controlflow c) -> ast::fn_decl {
+    ret rec(inputs=inputs, output=output, purity=p, cf=c);
 }
 
 fn identity_fold_fn[ENV](&ENV e,
@@ -1722,6 +1729,7 @@ fn new_identity_fold[ENV]() -> ast_fold[ENV] {
          fold_path       = bind identity_fold_path[ENV](_,_,_),
 
          fold_ty_nil     = bind identity_fold_ty_nil[ENV](_,_),
+         fold_ty_bot     = bind identity_fold_ty_bot[ENV](_,_),
          fold_ty_bool    = bind identity_fold_ty_bool[ENV](_,_),
          fold_ty_int     = bind identity_fold_ty_int[ENV](_,_),
          fold_ty_uint    = bind identity_fold_ty_uint[ENV](_,_),
@@ -1821,7 +1829,7 @@ fn new_identity_fold[ENV]() -> ast_fold[ENV] {
          fold_ann = bind identity_fold_ann[ENV](_,_),
 
          fold_fn = bind identity_fold_fn[ENV](_,_,_,_),
-         fold_fn_decl = bind identity_fold_fn_decl[ENV](_,_,_,_),
+         fold_fn_decl = bind identity_fold_fn_decl[ENV](_,_,_,_,_),
          fold_mod = bind identity_fold_mod[ENV](_,_),
          fold_native_mod = bind identity_fold_native_mod[ENV](_,_),
          fold_crate = bind identity_fold_crate[ENV](_,_,_,_),

src/comp/middle/metadata.rs

@@ -228,6 +228,7 @@ mod Encode {
                 w.write_str(common::uistr(id));
             }
             case (ty::ty_type) {w.write_char('Y');}
+            case (ty::ty_task) {w.write_char('a');}
 
             // These two don't appear in crate metadata, but are here because
             // `hash_ty()` uses this function.

src/comp/middle/resolve.rs

@@ -10,7 +10,7 @@ import util::common::new_int_hash;
 import util::common::new_uint_hash;
 import util::common::new_str_hash;
 import util::common::span;
-import util::typestate_ann::ts_ann;
+import middle::tstate::ann::ts_ann;
 import std::map::hashmap;
 import std::list::list;
 import std::list::nil;

src/comp/middle/trans.rs

@@ -757,6 +757,7 @@ fn type_of_inner(&@crate_ctxt cx, &ty::t t) -> TypeRef {
     alt (ty::struct(cx.tcx, t)) {
         case (ty::ty_native) { llty = T_ptr(T_i8()); }
         case (ty::ty_nil) { llty = T_nil(); }
+        case (ty::ty_bot) { llty = T_nil(); } /* ...I guess? */
         case (ty::ty_bool) { llty = T_bool(); }
         case (ty::ty_int) { llty = T_int(); }
         case (ty::ty_float) { llty = T_float(); }
@@ -3186,8 +3187,8 @@ fn copy_ty(&@block_ctxt cx,
     if (ty::type_is_scalar(cx.fcx.lcx.ccx.tcx, t) ||
             ty::type_is_native(cx.fcx.lcx.ccx.tcx, t)) {
         ret res(cx, cx.build.Store(src, dst));
-
-    } else if (ty::type_is_nil(cx.fcx.lcx.ccx.tcx, t)) {
+    } else if (ty::type_is_nil(cx.fcx.lcx.ccx.tcx, t) ||
+               ty::type_is_bot(cx.fcx.lcx.ccx.tcx, t)) {
         ret res(cx, C_nil());
 
     } else if (ty::type_is_boxed(cx.fcx.lcx.ccx.tcx, t)) {
@@ -3552,6 +3553,8 @@ fn autoderef(&@block_ctxt cx, ValueRef v, &ty::t t) -> result {
             }
         }
     }
+
+    fail; // fools the return-checker
 }
 
 fn autoderefed_ty(&@crate_ctxt ccx, &ty::t t) -> ty::t {
@@ -3567,6 +3570,8 @@ fn autoderefed_ty(&@crate_ctxt ccx, &ty::t t) -> ty::t {
             }
         }
     }
+
+    fail; // fools the return-checker
 }
 
 fn trans_binary(&@block_ctxt cx, ast::binop op,
@@ -3591,12 +3596,17 @@ fn trans_binary(&@block_ctxt cx, ast::binop op,
             auto lhs_false_cx = new_scope_block_ctxt(cx, "lhs false");
             auto lhs_false_res = res(lhs_false_cx, C_bool(false));
 
+            // The following line ensures that any cleanups for rhs
+            // are done within the block for rhs. This is necessary 
+            // because and/or are lazy. So the rhs may never execute,
+            // and the cleanups can't be pushed into later code.
+            auto rhs_bcx = trans_block_cleanups(rhs_res.bcx, rhs_cx);
+
             lhs_res.bcx.build.CondBr(lhs_res.val,
                                      rhs_cx.llbb,
                                      lhs_false_cx.llbb);
-
             ret join_results(cx, T_bool(),
-                             vec(lhs_false_res, rhs_res));
+                  vec(lhs_false_res, rec(bcx=rhs_bcx with rhs_res)));
         }
 
         case (ast::or) {
@@ -3615,12 +3625,15 @@ fn trans_binary(&@block_ctxt cx, ast::binop op,
             auto lhs_true_cx = new_scope_block_ctxt(cx, "lhs true");
             auto lhs_true_res = res(lhs_true_cx, C_bool(true));
 
+            // see the and case for an explanation
+            auto rhs_bcx = trans_block_cleanups(rhs_res.bcx, rhs_cx);
+
             lhs_res.bcx.build.CondBr(lhs_res.val,
                                      lhs_true_cx.llbb,
                                      rhs_cx.llbb);
 
             ret join_results(cx, T_bool(),
-                             vec(lhs_true_res, rhs_res));
+                  vec(lhs_true_res, rec(bcx=rhs_bcx with rhs_res)));
         }
 
         case (_) {
@@ -4984,6 +4997,8 @@ fn trans_bind(&@block_ctxt cx, &@ast::expr f,
             ret res(bcx, pair_v);
         }
     }
+
+    fail; // sadly needed b/c the compiler doesn't know yet that unimpl fails
 }
 
 fn trans_arg_expr(&@block_ctxt cx,