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<base href="http://llvm.org/bugs/" />
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - FileCheck mishandles buffering on Windows when Cygwin is on PATH?"
href="http://llvm.org/bugs/show_bug.cgi?id=19744">19744</a>
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<th>Summary</th>
<td>FileCheck mishandles buffering on Windows when Cygwin is on PATH?
</td>
</tr>
<tr>
<th>Product</th>
<td>Test Suite
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
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<th>OS</th>
<td>Windows NT
</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>
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<th>Component</th>
<td>lit
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>timurrrr@google.com
</td>
</tr>
<tr>
<th>CC</th>
<td>daniel@zuster.org, llvmbugs@cs.uiuc.edu
</td>
</tr>
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<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>Steps to repro as of r208805:
1) Have LLVM+Clang+compiler-rt checkout on a Windows machine
2) Do a cmake/ninja build
4) Put cygwin at the end of your PATH like so:
$ set PATH=%PATH%;C:\cygwin\bin
3) Run
$ python bin\llvm-lit.py -v
projects\compiler-rt\test\asan\32bitConfig\TestCases --filter=thread_stack
and make sure it passes
4) Apply the following simple patch to compiler-rt:
diff --git lib/sanitizer_common/sanitizer_win.cc
lib/sanitizer_common/sanitizer_win.cc
index ec6ce99..f82f78e 100644
--- lib/sanitizer_common/sanitizer_win.cc
+++ lib/sanitizer_common/sanitizer_win.cc
@@ -304,6 +304,7 @@ uptr internal_write(fd_t fd, const void *buf, uptr count) {
}
DWORD ret;
+ Sleep(100); // Make the failure stable rather than flaky.
if (WriteFile(output_stream, buf, count, &ret, 0))
return ret;
diff --git test/asan/TestCases/Windows/thread_stack_array_left_oob.cc
test/asan/TestCases/Windows/thread_stack_array_left_oob.cc
index 31a58bb..e6db163 100644
--- test/asan/TestCases/Windows/thread_stack_array_left_oob.cc
+++ test/asan/TestCases/Windows/thread_stack_array_left_oob.cc
@@ -1,7 +1,7 @@
// RUN: %clangxx_asan -O0 %s -Fe%t 2>&1
// 'cat' is used below to work around FileCheck buffering bug which makes this
// test flaky. FIXME: file an issue.
-// RUN: not %run %t 2>&1 | cat | FileCheck %s
+// RUN: not %run %t 2>&1 | FileCheck %s
#include <windows.h>
5) Run the same test again.
I observe a failure like this:
Command Output (stderr):
--
projects/compiler-rt/test/asan/TestCases/Windows/thread_stack_array_left_oob.cc:12:11:
error: expected string not found in input
// CHECK: AddressSanitizer: stack-buffer-overflow on address
[[ADDR:0x[0-9a-f]+]]
^
<stdin>:1:1: note: scanning from here
=================================================================
^
--
********************
Testing Time: 5.02s
********************
Failing Tests (1):
AddressSanitizer32 :: TestCases/Windows/thread_stack_array_left_oob.cc
It looks like the pipe between the binary and FileCheck gets interrupted
without waiting for the writer process to finish/close it.</pre>
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