auto merge of #8329 : michaelwoerister/rust/lexical_scopes_alt, r=graydon

This pull request re-implements handling of visibility scopes and source code positions in debug info. It should now be very stable and properly handle

+ variable shadowing
+ expanded code (macros and the new for-loop de-sugaring, for example)
+ variables in the middle of nested scopes
+ bindings declared in the head of match statement arms. 

all of which did not work at all or did not work reliably before. Those interested in a more detailed description of the problems at hand, I kindly refer to http://michaelwoerister.github.io/2013/08/03/visibility-scopes.html

Why doesn't the `populate_scope_map()` function use `syntax::visit`?
Because it would not improve this particular AST walker (see: https://github.com/michaelwoerister/rust/commit/69dc7908490b8b492e9730cb1c34fa83c2ef30eb#commitcomment-3781426)

Cheers,
Michael

1 files changed, 58 insertions, 0 deletions

diff --git a/src/test/debug-info/shadowed-variable.rs b/src/test/debug-info/shadowed-variable.rs
new file mode 100644
index 00000000000..a532f7fbc2e
--- /dev/null
+++ b/src/test/debug-info/shadowed-variable.rs
@@ -0,0 +1,58 @@
+// Copyright 2013 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.
+
+// xfail-win32 Broken because of LLVM bug: http://llvm.org/bugs/show_bug.cgi?id=16249
+
+// compile-flags:-Z extra-debug-info
+// debugger:break zzz
+// debugger:run
+
+// debugger:finish
+// debugger:print x
+// check:$1 = false
+// debugger:print y
+// check:$2 = true
+// debugger:continue
+
+// debugger:finish
+// debugger:print x
+// check:$3 = 10
+// debugger:print y
+// check:$4 = true
+// debugger:continue
+
+// debugger:finish
+// debugger:print x
+// check:$5 = 10.5
+// debugger:print y
+// check:$6 = 20
+// debugger:continue
+
+fn main() {
+    let x = false;
+    let y = true;
+
+    zzz();
+    sentinel();
+
+    let x = 10;
+
+    zzz();
+    sentinel();
+
+    let x = 10.5;
+    let y = 20;
+
+    zzz();
+    sentinel();
+}
+
+fn zzz() {()}
+fn sentinel() {()}