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

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