From 4d9d889dbfcccf324aba268eb6f8069514ed18e7 Mon Sep 17 00:00:00 2001
From: Brian Anderson <banderson@mozilla.com>
Date: Mon, 17 Oct 2011 15:41:38 -0700
Subject: [PATCH] Don't allow assignment to mutable-wha?

---
 src/comp/middle/mut.rs                         | 18 +++++++++---------
 .../compile-fail/mutable-huh-box-assign.rs     | 12 ++++++++++++
 .../compile-fail/mutable-huh-field-assign.rs   | 12 ++++++++++++
 .../compile-fail/mutable-huh-ptr-assign.rs     | 16 ++++++++++++++++
 .../compile-fail/mutable-huh-unique-assign.rs  | 12 ++++++++++++
 .../compile-fail/mutable-huh-vec-assign.rs     | 12 ++++++++++++
 6 files changed, 73 insertions(+), 9 deletions(-)
 create mode 100644 src/test/compile-fail/mutable-huh-box-assign.rs
 create mode 100644 src/test/compile-fail/mutable-huh-field-assign.rs
 create mode 100644 src/test/compile-fail/mutable-huh-ptr-assign.rs
 create mode 100644 src/test/compile-fail/mutable-huh-unique-assign.rs
 create mode 100644 src/test/compile-fail/mutable-huh-vec-assign.rs

diff --git a/src/comp/middle/mut.rs b/src/comp/middle/mut.rs
index 836f6de87e3..7ba13f3e7c2 100644
--- a/src/comp/middle/mut.rs
+++ b/src/comp/middle/mut.rs
@@ -49,19 +49,19 @@ fn expr_root(tcx: ty::ctxt, ex: @expr, autoderef: bool) ->
         alt copy ex.node {
           expr_field(base, ident) {
             let auto_unbox = maybe_auto_unbox(tcx, ty::expr_ty(tcx, base));
-            let mut = false;
+            let is_mut = false;
             alt ty::struct(tcx, auto_unbox.t) {
               ty::ty_rec(fields) {
                 for fld: ty::field in fields {
                     if str::eq(ident, fld.ident) {
-                        mut = fld.mt.mut != imm;
+                        is_mut = fld.mt.mut == mut;
                         break;
                     }
                 }
               }
               ty::ty_obj(_) { }
             }
-            ds += [@{mut: mut, kind: field, outer_t: auto_unbox.t}];
+            ds += [@{mut: is_mut, kind: field, outer_t: auto_unbox.t}];
             ds += auto_unbox.ds;
             ex = base;
           }
@@ -70,7 +70,7 @@ fn expr_root(tcx: ty::ctxt, ex: @expr, autoderef: bool) ->
             alt ty::struct(tcx, auto_unbox.t) {
               ty::ty_vec(mt) {
                 ds +=
-                    [@{mut: mt.mut != imm,
+                    [@{mut: mt.mut == mut,
                        kind: index,
                        outer_t: auto_unbox.t}];
               }
@@ -84,15 +84,15 @@ fn expr_root(tcx: ty::ctxt, ex: @expr, autoderef: bool) ->
           expr_unary(op, base) {
             if op == deref {
                 let base_t = ty::expr_ty(tcx, base);
-                let mut = false;
+                let is_mut = false;
                 alt ty::struct(tcx, base_t) {
-                  ty::ty_box(mt) { mut = mt.mut != imm; }
-                  ty::ty_uniq(mt) { mut = mt.mut != imm; }
+                  ty::ty_box(mt) { is_mut = mt.mut == mut; }
+                  ty::ty_uniq(mt) { is_mut = mt.mut == mut; }
                   ty::ty_res(_, _, _) { }
                   ty::ty_tag(_, _) { }
-                  ty::ty_ptr(mt) { mut = mt.mut != imm; }
+                  ty::ty_ptr(mt) { is_mut = mt.mut == mut; }
                 }
-                ds += [@{mut: mut, kind: unbox, outer_t: base_t}];
+                ds += [@{mut: is_mut, kind: unbox, outer_t: base_t}];
                 ex = base;
             } else { break; }
           }
diff --git a/src/test/compile-fail/mutable-huh-box-assign.rs b/src/test/compile-fail/mutable-huh-box-assign.rs
new file mode 100644
index 00000000000..9a3b35a47c6
--- /dev/null
+++ b/src/test/compile-fail/mutable-huh-box-assign.rs
@@ -0,0 +1,12 @@
+// error-pattern: assigning to immutable box
+
+fn main() {
+    fn f(&&v: @mutable? int) {
+        // This shouldn't be possible
+        *v = 1
+    }
+
+    let v = @0;
+
+    f(v);
+}
diff --git a/src/test/compile-fail/mutable-huh-field-assign.rs b/src/test/compile-fail/mutable-huh-field-assign.rs
new file mode 100644
index 00000000000..e6535c43f01
--- /dev/null
+++ b/src/test/compile-fail/mutable-huh-field-assign.rs
@@ -0,0 +1,12 @@
+// error-pattern: assigning to immutable field
+
+fn main() {
+    fn f(&&v: {mutable? field: int}) {
+        // This shouldn't be possible
+        v.field = 1
+    }
+
+    let v = {field: 0};
+
+    f(v);
+}
diff --git a/src/test/compile-fail/mutable-huh-ptr-assign.rs b/src/test/compile-fail/mutable-huh-ptr-assign.rs
new file mode 100644
index 00000000000..964a57a19db
--- /dev/null
+++ b/src/test/compile-fail/mutable-huh-ptr-assign.rs
@@ -0,0 +1,16 @@
+// error-pattern: assigning to immutable box
+
+use std;
+
+fn main() {
+    unsafe fn f(&&v: *mutable? int) {
+        // This shouldn't be possible
+        *v = 1
+    }
+
+    unsafe {
+        let a = 0;
+        let v = std::ptr::addr_of(a);
+        f(v);
+    }
+}
diff --git a/src/test/compile-fail/mutable-huh-unique-assign.rs b/src/test/compile-fail/mutable-huh-unique-assign.rs
new file mode 100644
index 00000000000..deb6adfb06c
--- /dev/null
+++ b/src/test/compile-fail/mutable-huh-unique-assign.rs
@@ -0,0 +1,12 @@
+// error-pattern: assigning to immutable box
+
+fn main() {
+    fn f(&&v: ~mutable? int) {
+        // This shouldn't be possible
+        *v = 1
+    }
+
+    let v = ~0;
+
+    f(v);
+}
diff --git a/src/test/compile-fail/mutable-huh-vec-assign.rs b/src/test/compile-fail/mutable-huh-vec-assign.rs
new file mode 100644
index 00000000000..1f273d376f1
--- /dev/null
+++ b/src/test/compile-fail/mutable-huh-vec-assign.rs
@@ -0,0 +1,12 @@
+// error-pattern: assigning to immutable vec content
+
+fn main() {
+    fn f(&&v: [mutable? int]) {
+        // This shouldn't be possible
+        v[0] = 1
+    }
+
+    let v = [0];
+
+    f(v);
+}