llvm-6502/unittests/Support/raw_pwrite_stream_test.cpp
Rafael Espindola f30ac8f5ec Don't allow pwrite to resize a stream.
The current implementations could exhibit some behavior differences:

raw_fd_ostream: Whatever the underlying fd does with seek+write. In a normal
file, the write position would be back to the old offset.

raw_svector_ostream: The write position is always the end of the stream, so
after pwrite the write position would be the new end. This matches what OS_X
(all BSD?) do with a pwrite in a O_APPEND fd.

Given that we don't need that feature and don't use O_APPEND a lot in LLVM,
just disallow it.

I am open to suggestions on renaming pwrite to something else, but this fixes
the issue for now.

Thanks to Yaron Keren for reporting it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235303 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-20 13:04:30 +00:00

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//===- raw_pwrite_stream_test.cpp - raw_pwrite_stream tests ---------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "gtest/gtest.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
namespace {
TEST(raw_pwrite_ostreamTest, TestSVector) {
SmallVector<char, 0> Buffer;
raw_svector_ostream OS(Buffer);
OS << "abcd";
StringRef Test = "test";
OS.pwrite(Test.data(), Test.size(), 0);
EXPECT_EQ(Test, OS.str());
#ifdef GTEST_HAS_DEATH_TEST
#ifndef NDEBUG
EXPECT_DEATH(OS.pwrite("12345", 5, 0),
"We don't support extending the stream");
#endif
#endif
}
}