<p dir="auto"><code class="notranslate">rustc 1.0.0-dev (00b112c45 2015-01-08 18:40:04 +0000)</code></p>
<div class="highlight highlight-source-rust notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="struct JSVal(u8);

fn main() {
    let mut jsval = JSVal(0);
    let p: *mut JSVal = &amp;mut jsval;
    unsafe {
        let _v = *p;
    }
}"><pre class="notranslate"><span class="pl-k">struct</span> <span class="pl-smi">JSVal</span><span class="pl-kos">(</span><span class="pl-smi">u8</span><span class="pl-kos">)</span><span class="pl-kos">;</span>

<span class="pl-k">fn</span> <span class="pl-en">main</span><span class="pl-kos">(</span><span class="pl-kos">)</span> <span class="pl-kos">{</span>
    <span class="pl-k">let</span> <span class="pl-k">mut</span> jsval = <span class="pl-v">JSVal</span><span class="pl-kos">(</span><span class="pl-c1">0</span><span class="pl-kos">)</span><span class="pl-kos">;</span>
    <span class="pl-k">let</span> p<span class="pl-kos">:</span> <span class="pl-c1">*</span><span class="pl-k">mut</span> <span class="pl-smi">JSVal</span> = <span class="pl-c1">&amp;</span><span class="pl-k">mut</span> jsval<span class="pl-kos">;</span>
    <span class="pl-k">unsafe</span> <span class="pl-kos">{</span>
        <span class="pl-k">let</span> _v = <span class="pl-c1">*</span>p<span class="pl-kos">;</span>
    <span class="pl-kos">}</span>
<span class="pl-kos">}</span></pre></div>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="godot2:servo jdm$ ./mach rustc /tmp/badmove.rs
/tmp/badmove.rs:7:18: 7:20 error: internal compiler error: this path should not cause illegal move
/tmp/badmove.rs:7         let _v = *p;
                                   ^~
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: http://doc.rust-lang.org/complement-bugreport.html
note: run with `RUST_BACKTRACE=1` for a backtrace
thread 'rustc' panicked at 'Box&lt;Any&gt;', /Users/larsberg/rust/src/libsyntax/diagnostic.rs:123"><pre class="notranslate"><code class="notranslate">godot2:servo jdm$ ./mach rustc /tmp/badmove.rs
/tmp/badmove.rs:7:18: 7:20 error: internal compiler error: this path should not cause illegal move
/tmp/badmove.rs:7         let _v = *p;
                                   ^~
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: http://doc.rust-lang.org/complement-bugreport.html
note: run with `RUST_BACKTRACE=1` for a backtrace
thread 'rustc' panicked at 'Box&lt;Any&gt;', /Users/larsberg/rust/src/libsyntax/diagnostic.rs:123
</code></pre></div>
<p dir="auto">Input:</p>
<div class="highlight highlight-source-rust notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="struct T(u8);

fn t() -&gt; *mut T {
    unsafe { 0u8 as *mut T }
}

fn main() {
    let a = unsafe { *t() };
}"><pre class="notranslate"><span class="pl-k">struct</span> <span class="pl-smi">T</span><span class="pl-kos">(</span><span class="pl-smi">u8</span><span class="pl-kos">)</span><span class="pl-kos">;</span>

<span class="pl-k">fn</span> <span class="pl-en">t</span><span class="pl-kos">(</span><span class="pl-kos">)</span> -&gt; <span class="pl-c1">*</span><span class="pl-k">mut</span> <span class="pl-smi">T</span> <span class="pl-kos">{</span>
    <span class="pl-k">unsafe</span> <span class="pl-kos">{</span> <span class="pl-c1">0u8</span> <span class="pl-k">as</span> <span class="pl-c1">*</span><span class="pl-k">mut</span> <span class="pl-smi">T</span> <span class="pl-kos">}</span>
<span class="pl-kos">}</span>

<span class="pl-k">fn</span> <span class="pl-en">main</span><span class="pl-kos">(</span><span class="pl-kos">)</span> <span class="pl-kos">{</span>
    <span class="pl-k">let</span> a = <span class="pl-k">unsafe</span> <span class="pl-kos">{</span> <span class="pl-c1">*</span><span class="pl-en">t</span><span class="pl-kos">(</span><span class="pl-kos">)</span> <span class="pl-kos">}</span><span class="pl-kos">;</span>
<span class="pl-kos">}</span></pre></div>
<p dir="auto">Output:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="$ rustc ../test.rs 
../test.rs:9:19: 9:23 error: internal compiler error: this path should not cause illegal move
../test.rs:9    let a = unsafe { *t() };
                                 ^~~~
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: http://doc.rust-lang.org/complement-bugreport.html
note: run with `RUST_BACKTRACE=1` for a backtrace
thread 'rustc' panicked at 'Box&lt;Any&gt;', /Users/John/Documents/dev/rust/src/libsyntax/diagnostic.rs:123

stack backtrace:
   1:        0x10f825b75 - sys::backtrace::write::h757d4037fec4513elCt
   2:        0x10f84800f - failure::on_fail::he99e1d2cd81a67a80Hz
   3:        0x10f7b3c8a - rt::unwind::begin_unwind_inner::hede15ebc165353e0Qpz
   4:        0x10d508707 - rt::unwind::begin_unwind::h5150449308391082809
   5:        0x10d50869c - diagnostic::SpanHandler::span_bug::h1cc7aa850b4525b9nQF
   6:        0x10c93bc1d - session::Session::span_bug::h9dff6f0c981e0b95mRq
   7:        0x10c547999 - borrowck::build_borrowck_dataflow_data::hbfab9f3785e58ec8QRe
   8:        0x10c5432fb - borrowck::borrowck_fn::h9d4d5a57ec1e26a2cPe
   9:        0x10c5440f2 - borrowck::borrowck_item::hd3de64f0b51b624a9Ne
  10:        0x10c54461f - borrowck::check_crate::hab49ad1d67fb67e9ZIe
  11:        0x10c09e8aa - driver::phase_3_run_analysis_passes::h3bf5eb3f470c8788gwa
  12:        0x10c082d90 - driver::compile_input::h63293298907e332cxba
  13:        0x10c14e7ba - monitor::unboxed_closure.22558
  14:        0x10c14cf15 - thunk::F.Invoke&lt;A, R&gt;::invoke::h15985566512806182469
  15:        0x10c14bcf0 - rt::unwind::try::try_fn::h5957420952141477940
  16:        0x10f8b1189 - rust_try_inner
  17:        0x10f8b1176 - rust_try
  18:        0x10c14c3ec - thunk::F.Invoke&lt;A, R&gt;::invoke::h12578415658120090831
  19:        0x10f835814 - sys::thread::thread_start::he6c5dcba45c95bf2drw
  20:     0x7fff933e22fc - _pthread_body
  21:     0x7fff933e2279 - _pthread_body"><pre class="notranslate"><code class="notranslate">$ rustc ../test.rs 
../test.rs:9:19: 9:23 error: internal compiler error: this path should not cause illegal move
../test.rs:9    let a = unsafe { *t() };
                                 ^~~~
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: http://doc.rust-lang.org/complement-bugreport.html
note: run with `RUST_BACKTRACE=1` for a backtrace
thread 'rustc' panicked at 'Box&lt;Any&gt;', /Users/John/Documents/dev/rust/src/libsyntax/diagnostic.rs:123

stack backtrace:
   1:        0x10f825b75 - sys::backtrace::write::h757d4037fec4513elCt
   2:        0x10f84800f - failure::on_fail::he99e1d2cd81a67a80Hz
   3:        0x10f7b3c8a - rt::unwind::begin_unwind_inner::hede15ebc165353e0Qpz
   4:        0x10d508707 - rt::unwind::begin_unwind::h5150449308391082809
   5:        0x10d50869c - diagnostic::SpanHandler::span_bug::h1cc7aa850b4525b9nQF
   6:        0x10c93bc1d - session::Session::span_bug::h9dff6f0c981e0b95mRq
   7:        0x10c547999 - borrowck::build_borrowck_dataflow_data::hbfab9f3785e58ec8QRe
   8:        0x10c5432fb - borrowck::borrowck_fn::h9d4d5a57ec1e26a2cPe
   9:        0x10c5440f2 - borrowck::borrowck_item::hd3de64f0b51b624a9Ne
  10:        0x10c54461f - borrowck::check_crate::hab49ad1d67fb67e9ZIe
  11:        0x10c09e8aa - driver::phase_3_run_analysis_passes::h3bf5eb3f470c8788gwa
  12:        0x10c082d90 - driver::compile_input::h63293298907e332cxba
  13:        0x10c14e7ba - monitor::unboxed_closure.22558
  14:        0x10c14cf15 - thunk::F.Invoke&lt;A, R&gt;::invoke::h15985566512806182469
  15:        0x10c14bcf0 - rt::unwind::try::try_fn::h5957420952141477940
  16:        0x10f8b1189 - rust_try_inner
  17:        0x10f8b1176 - rust_try
  18:        0x10c14c3ec - thunk::F.Invoke&lt;A, R&gt;::invoke::h12578415658120090831
  19:        0x10f835814 - sys::thread::thread_start::he6c5dcba45c95bf2drw
  20:     0x7fff933e22fc - _pthread_body
  21:     0x7fff933e2279 - _pthread_body
</code></pre></div>