libc/test/src/unistd/dup2_test.cpp

   1 //===-- Unittests for dup -------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "src/fcntl/open.h"
  10 #include "src/unistd/close.h"
  11 #include "src/unistd/dup2.h"
  12 #include "src/unistd/read.h"
  13 #include "src/unistd/unlink.h"
  14 #include "src/unistd/write.h"
  15 #include "test/ErrnoSetterMatcher.h"
  16 #include "test/UnitTest/Test.h"
  17 #include "utils/testutils/FDReader.h"
  18
  19 #include <errno.h>
  20
  21 TEST(LlvmLibcdupTest, ReadAndWriteViaDup) {
  22   constexpr int DUPFD = 0xD0;
  23   errno = 0;
  24   using __llvm_libc::testing::ErrnoSetterMatcher::Succeeds;
  25   constexpr const char *TEST_FILE = "testdata/dup2.test";
  26   int fd = __llvm_libc::open(TEST_FILE, O_WRONLY | O_CREAT, S_IRWXU);
  27   ASSERT_EQ(errno, 0);
  28   ASSERT_GT(fd, 0);
  29   int dupfd = __llvm_libc::dup2(fd, DUPFD);
  30   ASSERT_EQ(errno, 0);
  31   ASSERT_EQ(dupfd, DUPFD);
  32
  33   // Write something via the dup
  34   constexpr char WRITE_DATA[] = "Hello, dup!";
  35   constexpr size_t WRITE_SIZE = sizeof(WRITE_DATA);
  36   ASSERT_EQ(ssize_t(WRITE_SIZE),
  37             __llvm_libc::write(dupfd, WRITE_DATA, WRITE_SIZE));
  38   ASSERT_THAT(__llvm_libc::close(dupfd), Succeeds(0));
  39
  40   // Reopen the file for reading and create a dup.
  41   fd = __llvm_libc::open(TEST_FILE, O_RDONLY);
  42   ASSERT_EQ(errno, 0);
  43   ASSERT_GT(fd, 0);
  44   dupfd = __llvm_libc::dup2(fd, DUPFD);
  45   ASSERT_EQ(errno, 0);
  46   ASSERT_EQ(dupfd, DUPFD);
  47
  48   // Read the file content via the dup.
  49   char buf[WRITE_SIZE];
  50   ASSERT_THAT(__llvm_libc::read(dupfd, buf, WRITE_SIZE), Succeeds(WRITE_SIZE));
  51   ASSERT_STREQ(buf, WRITE_DATA);
  52
  53   // Verify that duping to the same fd value succeeds.
  54   ASSERT_THAT(__llvm_libc::dup2(dupfd, dupfd), Succeeds(dupfd));
  55
  56   ASSERT_THAT(__llvm_libc::close(dupfd), Succeeds(0));
  57   ASSERT_THAT(__llvm_libc::unlink(TEST_FILE), Succeeds(0));
  58 }
  59
  60 TEST(LlvmLibcdupTest, DupBadFD) {
  61   using __llvm_libc::testing::ErrnoSetterMatcher::Fails;
  62   ASSERT_THAT(__llvm_libc::dup2(-1, 123), Fails(EBADF));
  63 }