1//===-- Unittests for ftell -----------------------------------------------===//
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/stdio/fclose.h"
10#include "src/stdio/fopen.h"
11#include "src/stdio/fread.h"
12#include "src/stdio/fseek.h"
13#include "src/stdio/fseeko.h"
14#include "src/stdio/ftell.h"
15#include "src/stdio/ftello.h"
16#include "src/stdio/fwrite.h"
17#include "src/stdio/setvbuf.h"
18#include "test/UnitTest/Test.h"
19
20#include <stdio.h>
21
22class LlvmLibcFTellTest : public LIBC_NAMESPACE::testing::Test {
23protected:
24 void test_with_bufmode(int bufmode) {
25 constexpr char FILENAME[] = "testdata/ftell.test";
26 // We will set a special buffer to the file so that we guarantee buffering.
27 constexpr size_t BUFFER_SIZE = 1024;
28 char buffer[BUFFER_SIZE];
29 ::FILE *file = LIBC_NAMESPACE::fopen(name: FILENAME, mode: "w+");
30 ASSERT_FALSE(file == nullptr);
31 ASSERT_EQ(LIBC_NAMESPACE::setvbuf(file, buffer, bufmode, BUFFER_SIZE), 0);
32
33 // Include few '\n' chars to test when |bufmode| is _IOLBF.
34 constexpr char CONTENT[] = "12\n345\n6789";
35 constexpr size_t WRITE_SIZE = sizeof(CONTENT) - 1;
36 ASSERT_EQ(WRITE_SIZE, LIBC_NAMESPACE::fwrite(CONTENT, 1, WRITE_SIZE, file));
37 // The above write should have buffered the written data and not have
38 // trasferred it to the underlying stream. But, ftell operation should
39 // still return the correct effective offset.
40 ASSERT_EQ(size_t(LIBC_NAMESPACE::ftell(file)), WRITE_SIZE);
41
42 off_t offseto = 5;
43 ASSERT_EQ(0, LIBC_NAMESPACE::fseeko(file, offseto, SEEK_SET));
44 ASSERT_EQ(LIBC_NAMESPACE::ftello(file), offseto);
45 ASSERT_EQ(0, LIBC_NAMESPACE::fseeko(file, -offseto, SEEK_END));
46 ASSERT_EQ(size_t(LIBC_NAMESPACE::ftello(file)),
47 size_t(WRITE_SIZE - offseto));
48
49 long offset = 5;
50 ASSERT_EQ(0, LIBC_NAMESPACE::fseek(file, offset, SEEK_SET));
51 ASSERT_EQ(LIBC_NAMESPACE::ftell(file), offset);
52 ASSERT_EQ(0, LIBC_NAMESPACE::fseek(file, -offset, SEEK_END));
53 ASSERT_EQ(size_t(LIBC_NAMESPACE::ftell(file)), size_t(WRITE_SIZE - offset));
54
55 ASSERT_EQ(0, LIBC_NAMESPACE::fseek(file, 0, SEEK_SET));
56 constexpr size_t READ_SIZE = WRITE_SIZE / 2;
57 char data[READ_SIZE];
58 // Reading a small amount will actually read out much more data and
59 // buffer it. But, ftell should return the correct effective offset.
60 ASSERT_EQ(READ_SIZE, LIBC_NAMESPACE::fread(data, 1, READ_SIZE, file));
61 ASSERT_EQ(size_t(LIBC_NAMESPACE::ftell(file)), READ_SIZE);
62
63 ASSERT_EQ(0, LIBC_NAMESPACE::fclose(file));
64 }
65};
66
67TEST_F(LlvmLibcFTellTest, TellWithFBF) { test_with_bufmode(_IOFBF); }
68
69TEST_F(LlvmLibcFTellTest, TellWithNBF) { test_with_bufmode(_IONBF); }
70
71TEST_F(LlvmLibcFTellTest, TellWithLBF) { test_with_bufmode(_IOLBF); }
72

source code of libc/test/src/stdio/ftell_test.cpp