<html>
    <head>
      <base href="http://llvm.org/bugs/" />
    </head>
    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW --- - clang crashes on valid code at -O1 and above on x86_64-linux-gnu"
   href="http://llvm.org/bugs/show_bug.cgi?id=21445">21445</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>clang crashes on valid code at -O1 and above on x86_64-linux-gnu
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>clang
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>trunk
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>PC
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>All
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>NEW
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>normal
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>P
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>-New Bugs
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>unassignedclangbugs@nondot.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>su@cs.ucdavis.edu
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvmbugs@cs.uiuc.edu
          </td>
        </tr>

        <tr>
          <th>Classification</th>
          <td>Unclassified
          </td>
        </tr></table>
      <p>
        <div>
        <pre>The current clang trunk and 3.5.0 crash when compiling the following test case
at -O1 and above in both 32-bit and 64-bit modes on x86_64-linux-gnu. 

This is a regression from clang 3.4.x. 

$ clang-trunk -v
clang version 3.6.0 (trunk 220897)
Target: x86_64-unknown-linux-gnu
Thread model: posix
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6.4
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.7.3
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8.1
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64

$ clang-trunk -O0 -c small.c
$ clang-3.4.2 -O1 -c small.c

$ clang-trunk -O1 -c small.c
clang: /tmp/llvm/include/llvm/Support/Casting.h:237: typename cast_retty<X, Y
*>::ret_type llvm::cast(Y *) [X = llvm::Instruction, Y = llvm::Value]:
Assertion `isa<X>(Val) && "cast<Ty>() argument of incompatible type!"' failed.
#0 0x28de3fa llvm::sys::PrintStackTrace(_IO_FILE*)
(/usr/local/clang-trunk/bin/clang+0x28de3fa)
#1 0x28dfabb (/usr/local/clang-trunk/bin/clang+0x28dfabb)
#2 0x7f9caa08acb0 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0xfcb0)
#3 0x7f9ca93c30d5 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x360d5)
#4 0x7f9ca93c683b abort (/lib/x86_64-linux-gnu/libc.so.6+0x3983b)
#5 0x7f9ca93bbd9e (/lib/x86_64-linux-gnu/libc.so.6+0x2ed9e)
#6 0x7f9ca93bbe42 (/lib/x86_64-linux-gnu/libc.so.6+0x2ee42)
#7 0x24c3949 (/usr/local/clang-trunk/bin/clang+0x24c3949)
#8 0x24c0c54 (/usr/local/clang-trunk/bin/clang+0x24c0c54)
#9 0x247dcfb (/usr/local/clang-trunk/bin/clang+0x247dcfb)
#10 0x247ea30 (/usr/local/clang-trunk/bin/clang+0x247ea30)
#11 0x286d513 llvm::FPPassManager::runOnFunction(llvm::Function&)
(/usr/local/clang-trunk/bin/clang+0x286d513)
#12 0x286d78b llvm::FPPassManager::runOnModule(llvm::Module&)
(/usr/local/clang-trunk/bin/clang+0x286d78b)
#13 0x286dce7 llvm::legacy::PassManagerImpl::run(llvm::Module&)
(/usr/local/clang-trunk/bin/clang+0x286dce7)
#14 0x8f5d33 clang::EmitBackendOutput(clang::DiagnosticsEngine&,
clang::CodeGenOptions const&, clang::TargetOptions const&, clang::LangOptions
const&, llvm::StringRef, llvm::Module*, clang::BackendAction,
llvm::raw_ostream*) (/usr/local/clang-trunk/bin/clang+0x8f5d33)
#15 0x8eaa05 (/usr/local/clang-trunk/bin/clang+0x8eaa05)
#16 0xaed043 clang::ParseAST(clang::Sema&, bool, bool)
(/usr/local/clang-trunk/bin/clang+0xaed043)
#17 0x6fc02e clang::FrontendAction::Execute()
(/usr/local/clang-trunk/bin/clang+0x6fc02e)
#18 0x6cf3cc clang::CompilerInstance::ExecuteAction(clang::FrontendAction&)
(/usr/local/clang-trunk/bin/clang+0x6cf3cc)
#19 0x6b1622 clang::ExecuteCompilerInvocation(clang::CompilerInstance*)
(/usr/local/clang-trunk/bin/clang+0x6b1622)
#20 0x6a7d77 cc1_main(llvm::ArrayRef<char const*>, char const*, void*)
(/usr/local/clang-trunk/bin/clang+0x6a7d77)
#21 0x6afccb main (/usr/local/clang-trunk/bin/clang+0x6afccb)
#22 0x7f9ca93ae76d __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2176d)
#23 0x6a79e9 _start (/usr/local/clang-trunk/bin/clang+0x6a79e9)
Stack dump:
0.    Program arguments: /usr/local/clang-trunk/bin/clang -cc1 -triple
x86_64-unknown-linux-gnu -emit-obj -disable-free -main-file-name small.c
-mrelocation-model static -mthread-model posix -fmath-errno -masm-verbose
-mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64
-target-linker-version 2.22 -momit-leaf-frame-pointer -dwarf-column-info
-coverage-file /home/su/small.c -resource-dir
/usr/local/clang-trunk/bin/../lib/clang/3.6.0 -internal-isystem
/usr/local/include -internal-isystem
/usr/local/clang-trunk/bin/../lib/clang/3.6.0/include -internal-externc-isystem
/usr/include/x86_64-linux-gnu -internal-externc-isystem /include
-internal-externc-isystem /usr/include -O1 -fdebug-compilation-dir /home/su
-ferror-limit 19 -fmessage-length 113 -mstackrealign -fobjc-runtime=gcc
-fdiagnostics-show-option -fcolor-diagnostics -o small.o -x c small.c 
1.    <eof> parser at end of file
2.    Per-module optimization passes
3.    Running pass 'Function Pass Manager' on module 'small.c'.
4.    Running pass 'Combine redundant instructions' on function '@fn1'
clang: error: unable to execute command: Aborted (core dumped)
clang: error: clang frontend command failed due to signal (use -v to see
invocation)
clang version 3.6.0 (trunk 220897)
Target: x86_64-unknown-linux-gnu
Thread model: posix
clang: note: diagnostic msg: PLEASE submit a bug report to
<a href="http://llvm.org/bugs/">http://llvm.org/bugs/</a> and include the crash backtrace, preprocessed source, and
associated run script.
clang: note: diagnostic msg: 
********************

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang: note: diagnostic msg: /tmp/small-de8c1c.c
clang: note: diagnostic msg: /tmp/small-de8c1c.sh
clang: note: diagnostic msg: 

********************



----------------------------


int b[2], d;
static int *c = &b[1];
unsigned char e, g;

void
fn1 ()
{
  int *h = &d;
  g = (c != h) - 1;
  if (e * g)
    while (1)
      ;
}</pre>
        </div>
      </p>
      <hr>
      <span>You are receiving this mail because:</span>
      
      <ul>
          <li>You are on the CC list for the bug.</li>
      </ul>
    </body>
</html>