various improvements to ioctl tests

Author: cowtoolz

libc/test/src/sys/ioctl/linux/ioctl_test.cpp

@@ -5,30 +5,77 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
-
 #include "src/errno/libc_errno.h"
+#include "src/fcntl/open.h"
 #include "src/sys/ioctl/ioctl.h"
+#include "src/unistd/close.h"
+#include "src/unistd/read.h"
 #include "test/UnitTest/ErrnoSetterMatcher.h"
-#include <sys/ioctl.h>
 
 using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Fails;
 using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
 
-TEST(LlvmLibcSysIoctlTest, StdinFIONREAD) {
+TEST(LlvmLibcSysIoctlTest, NullAndTestFileFIONREAD) {
   LIBC_NAMESPACE::libc_errno = 0;
 
-  // FIONREAD reports the number of readable bytes for fd
-  int bytes;
-  int ret = LIBC_NAMESPACE::ioctl(0, FIONREAD, &bytes);
+  // FIONREAD reports the number of available bytes to read for the passed fd
+  int dev_zero_fd = LIBC_NAMESPACE::open("/dev/zero", O_RDONLY);
+  ASSERT_GT(dev_zero_fd, 0);
+  ASSERT_ERRNO_SUCCESS();
+
+  // For /dev/zero, this is always 0
+  int dev_zero_n = -1;
+  int ret = LIBC_NAMESPACE::ioctl(dev_zero_fd, FIONREAD, &dev_zero_n);
+  ASSERT_GT(ret, -1);
+  ASSERT_ERRNO_SUCCESS();
+  ASSERT_EQ(dev_zero_n, 0);
+
+  ASSERT_THAT(LIBC_NAMESPACE::close(dev_zero_fd), Succeeds(0));
+
+  // Now, with a file known to have a non-zero size
+  constexpr const char TEST_MSG[] = "ioctl test";
+  constexpr ssize_t TEST_MSG_SIZE = sizeof(TEST_MSG) - 1;
+  constexpr const char *TEST_FILE = "testdata/ioctl.test";
+  int test_file_fd = LIBC_NAMESPACE::open(TEST_FILE, O_RDONLY);
+  ASSERT_GT(test_file_fd, 0);
+  ASSERT_ERRNO_SUCCESS();
+
+  // This reports the full size of the file, as we haven't read anything yet
+  int test_file_n = -1;
+  ret = LIBC_NAMESPACE::ioctl(test_file_fd, FIONREAD, &test_file_n);
+  ASSERT_GT(ret, -1);
   ASSERT_ERRNO_SUCCESS();
+  ASSERT_EQ(test_file_n, TEST_MSG_SIZE);
+
+  // But if we read some bytes...
+  constexpr int READ_COUNT = 5;
+  char buffer[READ_COUNT];
+  ASSERT_THAT(LIBC_NAMESPACE::read(test_file_fd, buffer, READ_COUNT),
+              Succeeds(READ_COUNT));
+
+  // ... n should have decreased by the number of bytes we've read
+  int test_file_n_after_reading = -1;
+  ret =
+      LIBC_NAMESPACE::ioctl(test_file_fd, FIONREAD, &test_file_n_after_reading);
+  ASSERT_GT(ret, -1);
+  ASSERT_ERRNO_SUCCESS();
+  ASSERT_EQ(test_file_n - READ_COUNT, test_file_n_after_reading);
+
+  ASSERT_THAT(LIBC_NAMESPACE::close(test_file_fd), Succeeds(0));
 }
 
-TEST(LlvmLibcSysIoctlTest, InvalidCommandENOTTY) {
+TEST(LlvmLibcSysIoctlTest, InvalidIoctlCommand) {
   LIBC_NAMESPACE::libc_errno = 0;
 
+  int fd = LIBC_NAMESPACE::open("/dev/zero", O_RDONLY);
+  ASSERT_GT(fd, 0);
+  ASSERT_ERRNO_SUCCESS();
+
   // 0xDEADBEEF is just a random nonexistent command;
   // calling this should always fail with ENOTTY
-  int ret = LIBC_NAMESPACE::ioctl(3, 0xDEADBEEF, NULL);
+  int ret = LIBC_NAMESPACE::ioctl(fd, 0xDEADBEEF, NULL);
   ASSERT_EQ(ret, -1);
   ASSERT_ERRNO_EQ(ENOTTY);
+
+  ASSERT_THAT(LIBC_NAMESPACE::close(fd), Succeeds(0));
 }

libc/test/src/sys/ioctl/linux/testdata/CMakeLists.txt

@@ -0,0 +1 @@
+file(GENERATE OUTPUT ioctl.test CONTENT "ioctl test")