WIP: Massive refactoring of trans

Fixes rust-lang#3387

Author: nikomatsakis

Makefile.in

@@ -100,6 +100,9 @@ endif
 ifdef TIME_LLVM_PASSES
   CFG_RUSTC_FLAGS += -Z time-llvm-passes
 endif
+ifdef TRACE
+  CFG_RUSTC_FLAGS += -Z trace
+endif
 
 # platform-specific auto-configuration
 include $(CFG_SRC_DIR)mk/platform.mk

src/libstd/getopts.rs

@@ -767,10 +767,11 @@ mod tests {
         let rs = getopts(args, opts);
         match rs {
           Ok(m) => {
-            assert (opt_present(m, ~"test"));
-            assert (opt_str(m, ~"test") == ~"20");
-            assert (opt_strs(m, ~"test")[0] == ~"20");
-            assert (opt_strs(m, ~"test")[1] == ~"30");
+              assert (opt_present(m, ~"test"));
+              assert (opt_str(m, ~"test") == ~"20");
+              let pair = opt_strs(m, ~"test");
+              assert (pair[0] == ~"20");
+              assert (pair[1] == ~"30");
           }
           _ => fail
         }
@@ -821,8 +822,9 @@ mod tests {
           Ok(m) => {
             assert (opt_present(m, ~"t"));
             assert (opt_str(m, ~"t") == ~"20");
-            assert (opt_strs(m, ~"t")[0] == ~"20");
-            assert (opt_strs(m, ~"t")[1] == ~"30");
+            let pair = opt_strs(m, ~"t");
+            assert (pair[0] == ~"20");
+            assert (pair[1] == ~"30");
           }
           _ => fail
         }
@@ -870,10 +872,12 @@ mod tests {
             assert (opt_present(m, ~"flag"));
             assert (opt_str(m, ~"long") == ~"30");
             assert (opt_present(m, ~"f"));
-            assert (opt_strs(m, ~"m")[0] == ~"40");
-            assert (opt_strs(m, ~"m")[1] == ~"50");
-            assert (opt_strs(m, ~"n")[0] == ~"-A B");
-            assert (opt_strs(m, ~"n")[1] == ~"-60 70");
+            let pair = opt_strs(m, ~"m");
+            assert (pair[0] == ~"40");
+            assert (pair[1] == ~"50");
+            let pair = opt_strs(m, ~"n");
+            assert (pair[0] == ~"-A B");
+            assert (pair[1] == ~"-60 70");
             assert (!opt_present(m, ~"notpresent"));
           }
           _ => fail

src/libstd/test.rs

@@ -12,6 +12,7 @@ import libc::size_t;
 import task::TaskBuilder;
 import comm = core::comm;
 
+/*
 export test_name;
 export test_fn;
 export test_desc;
@@ -22,6 +23,7 @@ export tr_ok;
 export tr_failed;
 export tr_ignored;
 export run_tests_console;
+*/
 
 #[abi = "cdecl"]
 extern mod rustrt {

src/libsyntax/print/pprust.rs

@@ -1165,29 +1165,38 @@ fn print_expr(s: ps, &&expr: @ast::expr) {
               None => ()
             }
             word_space(s, ~"=>");
+
             // Extract the expression from the extra block the parser adds
-            assert arm.body.node.view_items.is_empty();
-            assert arm.body.node.stmts.is_empty();
-            assert arm.body.node.rules == ast::default_blk;
-            match arm.body.node.expr {
-              Some(expr) => {
-                match expr.node {
-                  ast::expr_block(blk) => {
-                    // the block will close the pattern's ibox
-                    print_block_unclosed_indent(s, blk, alt_indent_unit);
-                  }
-                  _ => {
-                    end(s); // close the ibox for the pattern
-                    print_expr(s, expr);
-                  }
-                }
-                if !expr_is_simple_block(expr)
-                    && i < len - 1 {
-                    word(s.s, ~",");
+            // in the case of foo => expr
+            if arm.body.node.view_items.is_empty() &&
+                arm.body.node.stmts.is_empty() &&
+                arm.body.node.rules == ast::default_blk &&
+                arm.body.node.expr.is_some()
+            {
+                match arm.body.node.expr {
+                    Some(expr) => {
+                        match expr.node {
+                            ast::expr_block(blk) => {
+                                // the block will close the pattern's ibox
+                                print_block_unclosed_indent(
+                                    s, blk, alt_indent_unit);
+                            }
+                            _ => {
+                                end(s); // close the ibox for the pattern
+                                print_expr(s, expr);
+                            }
+                        }
+                        if !expr_is_simple_block(expr)
+                            && i < len - 1 {
+                            word(s.s, ~",");
+                        }
+                        end(s); // close enclosing cbox
+                    }
+                    None => fail
                 }
-                end(s); // close enclosing cbox
-              }
-              None => fail
+            } else {
+                // the block will close the pattern's ibox
+                print_block_unclosed_indent(s, arm.body, alt_indent_unit);
             }
         }
         bclose_(s, expr.span, alt_indent_unit);

src/rt/memory_region.h

@@ -22,7 +22,7 @@
 //
 // NB: please do not commit code with level 2. It's
 // hugely expensive and should only be used as a last resort.
-#define RUSTRT_TRACK_ALLOCATIONS 0
+#define RUSTRT_TRACK_ALLOCATIONS 2
 
 struct rust_env;
 

src/rt/rust_upcall.cpp

@@ -147,7 +147,6 @@ extern "C" CDECL void
 upcall_s_exchange_malloc(s_exchange_malloc_args *args) {
     rust_task *task = args->task;
     LOG_UPCALL_ENTRY(task);
-    LOG(task, mem, "upcall exchange malloc(0x%" PRIxPTR ")", args->td);
 
     size_t total_size = get_box_size(args->size, args->td->align);
     // FIXME--does this have to be calloc? (Issue #2682)
@@ -159,6 +158,9 @@ upcall_s_exchange_malloc(s_exchange_malloc_args *args) {
     header->prev = 0;
     header->next = 0;
 
+    LOG(task, mem, "exchange malloced %p of size %" PRIuPTR,
+        header, args->size);
+
     args->retval = (uintptr_t)header;
 }
 
@@ -187,6 +189,7 @@ extern "C" CDECL void
 upcall_s_exchange_free(s_exchange_free_args *args) {
     rust_task *task = args->task;
     LOG_UPCALL_ENTRY(task);
+    LOG(task, mem, "exchange freed %p", args->ptr);
     task->kernel->free(args->ptr);
 }
 

src/rustc/middle/borrowck.rs

@@ -220,7 +220,8 @@ import syntax::visit;
 import syntax::ast_util;
 import syntax::ast_map;
 import syntax::codemap::span;
-import util::ppaux::{ty_to_str, region_to_str, explain_region};
+import util::ppaux::{ty_to_str, region_to_str, explain_region,
+                     note_and_explain_region};
 import std::map::{int_hash, hashmap, set};
 import std::list;
 import std::list::{list, cons, nil};
@@ -414,6 +415,7 @@ impl borrowck_ctxt {
             err.cmt.span,
             fmt!("illegal borrow: %s",
                  self.bckerr_code_to_str(err.code)));
+        self.note_and_explain_bckerr(err.code);
     }
 
     fn span_err(s: span, m: ~str) {
@@ -438,37 +440,65 @@ impl borrowck_ctxt {
 
     fn bckerr_code_to_str(code: bckerr_code) -> ~str {
         match code {
-          err_mutbl(req, act) => {
-            fmt!("creating %s alias to aliasable, %s memory",
-                 self.mut_to_str(req), self.mut_to_str(act))
-          }
-          err_mut_uniq => {
-            ~"unique value in aliasable, mutable location"
-          }
-          err_mut_variant => {
-            ~"enum variant in aliasable, mutable location"
-          }
-          err_root_not_permitted => {
-            // note: I don't expect users to ever see this error
-            // message, reasons are discussed in attempt_root() in
-            // preserve.rs.
-            ~"rooting is not permitted"
-          }
-          err_out_of_root_scope(super_scope, sub_scope) => {
-            fmt!("managed value would have to be rooted for %s, \
-                  but can only be rooted for %s",
-                  explain_region(self.tcx, sub_scope),
-                  explain_region(self.tcx, super_scope))
-          }
-          err_out_of_scope(super_scope, sub_scope) => {
-            fmt!("borrowed pointer must be valid for %s, \
-                  but the borrowed value is only valid for %s",
-                  explain_region(self.tcx, sub_scope),
-                  explain_region(self.tcx, super_scope))
+            err_mutbl(req, act) => {
+                fmt!("creating %s alias to aliasable, %s memory",
+                     self.mut_to_str(req), self.mut_to_str(act))
+            }
+            err_mut_uniq => {
+                ~"unique value in aliasable, mutable location"
+            }
+            err_mut_variant => {
+                ~"enum variant in aliasable, mutable location"
+            }
+            err_root_not_permitted => {
+                // note: I don't expect users to ever see this error
+                // message, reasons are discussed in attempt_root() in
+                // preserve.rs.
+                ~"rooting is not permitted"
+            }
+            err_out_of_root_scope(*) => {
+                ~"cannot root managed value long enough"
+            }
+            err_out_of_scope(*) => {
+                ~"borrowed value does not live long enough"
+            }
+        }
+    }
+
+    fn note_and_explain_bckerr(code: bckerr_code) {
+        match code {
+            err_mutbl(*) | err_mut_uniq | err_mut_variant |
+            err_root_not_permitted => {}
+
+            err_out_of_root_scope(super_scope, sub_scope) => {
+                note_and_explain_region(
+                    self.tcx,
+                    ~"managed value would have to be rooted for ",
+                    sub_scope,
+                    ~"...");
+                note_and_explain_region(
+                    self.tcx,
+                    ~"...but can only be rooted for ",
+                    super_scope,
+                    ~"");
+            }
+
+            err_out_of_scope(super_scope, sub_scope) => {
+                note_and_explain_region(
+                    self.tcx,
+                    ~"borrowed pointer must be valid for ",
+                    sub_scope,
+                    ~"...");
+                note_and_explain_region(
+                    self.tcx,
+                    ~"...but borrowed value is only valid for ",
+                    super_scope,
+                    ~"");
           }
         }
     }
 
+
     fn cmt_to_str(cmt: cmt) -> ~str {
         let mc = &mem_categorization_ctxt {tcx: self.tcx,
                                            method_map: self.method_map};

src/rustc/middle/borrowck/check_loans.rs

@@ -404,6 +404,7 @@ impl check_loan_ctxt {
                     e.cmt.span,
                     fmt!("illegal borrow unless pure: %s",
                          self.bccx.bckerr_code_to_str(e.code)));
+                self.bccx.note_and_explain_bckerr(e.code);
                 self.tcx().sess.span_note(
                     sp,
                     fmt!("impure due to %s", msg));
@@ -465,10 +466,14 @@ impl check_loan_ctxt {
     // when there is an outstanding loan.  In that case, it is not
     // safe to consider the use a last_use.
     fn check_last_use(expr: @ast::expr) {
+        debug!("Checking last use of expr %?", expr.id);
         let cmt = self.bccx.cat_expr(expr);
         let lp = match cmt.lp {
-          None => return,
-          Some(lp) => lp
+            None => {
+                debug!("Not a loanable expression");
+                return;
+            }
+            Some(lp) => lp
         };
         for self.walk_loans_of(cmt.id, lp) |_loan| {
             debug!("Removing last use entry %? due to outstanding loan",
@@ -573,6 +578,9 @@ fn check_loans_in_local(local: @ast::local,
 fn check_loans_in_expr(expr: @ast::expr,
                        &&self: check_loan_ctxt,
                        vt: visit::vt<check_loan_ctxt>) {
+    debug!("check_loans_in_expr(expr=%?/%s)",
+           expr.id, pprust::expr_to_str(expr, self.tcx().sess.intr()));
+
     self.check_for_conflicting_loans(expr.id);
 
     match expr.node {

src/rustc/middle/borrowck/gather_loans.rs

@@ -90,8 +90,8 @@ fn req_loans_in_expr(ex: @ast::expr,
     let tcx = bccx.tcx;
     let old_root_ub = self.root_ub;
 
-    debug!("req_loans_in_expr(ex=%s)",
-           pprust::expr_to_str(ex, tcx.sess.intr()));
+    debug!("req_loans_in_expr(expr=%?/%s)",
+           ex.id, pprust::expr_to_str(ex, tcx.sess.intr()));
 
     // If this expression is borrowed, have to ensure it remains valid:
     for tcx.borrowings.find(ex.id).each |borrow| {
@@ -200,6 +200,20 @@ fn req_loans_in_expr(ex: @ast::expr,
         visit::visit_expr(ex, self, vt);
       }
 
+      ast::expr_binary(_, lhs, rhs) => {
+          // Universal comparison operators like ==, >=, etc
+          // take their arguments by reference.
+          let lhs_ty = ty::expr_ty(self.tcx(), lhs);
+          if !ty::type_is_scalar(lhs_ty) {
+              let scope_r = ty::re_scope(ex.id);
+              let lhs_cmt = self.bccx.cat_expr(lhs);
+              self.guarantee_valid(lhs_cmt, m_imm, scope_r);
+              let rhs_cmt = self.bccx.cat_expr(rhs);
+              self.guarantee_valid(rhs_cmt, m_imm, scope_r);
+          }
+          visit::visit_expr(ex, self, vt);
+      }
+
       ast::expr_field(rcvr, _, _)
       if self.bccx.method_map.contains_key(ex.id) => {
         // Receivers in method calls are always passed by ref.
@@ -395,14 +409,15 @@ impl gather_loan_ctxt {
     }
 
     fn add_loans(scope_id: ast::node_id, loans: @DVec<loan>) {
+        debug!("adding %u loans to scope_id %?", loans.len(), scope_id);
         match self.req_maps.req_loan_map.find(scope_id) {
-          Some(l) => {
-            (*l).push(loans);
-          }
-          None => {
-            self.req_maps.req_loan_map.insert(
-                scope_id, @dvec::from_vec(~[mut loans]));
-          }
+            Some(l) => {
+                l.push(loans);
+            }
+            None => {
+                self.req_maps.req_loan_map.insert(
+                    scope_id, @dvec::from_vec(~[mut loans]));
+            }
         }
     }
 

src/rustc/middle/kind.rs

@@ -419,7 +419,7 @@ fn is_nullary_variant(cx: ctx, ex: @expr) -> bool {
 
 fn check_copy_ex(cx: ctx, ex: @expr, implicit_copy: bool,
                  why: Option<(&str,&str)>) {
-    if ty::expr_is_lval(cx.method_map, ex) &&
+    if ty::expr_is_lval(cx.tcx, cx.method_map, ex) &&
 
         // this is a move
         !cx.last_use_map.contains_key(ex.id) &&