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 21 class LlvmLibcFTellTest : public LIBC_NAMESPACE::testing::Test { 22 protected: 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 66 TEST_F(LlvmLibcFTellTest, TellWithFBF) { test_with_bufmode(_IOFBF); } 67 68 TEST_F(LlvmLibcFTellTest, TellWithNBF) { test_with_bufmode(_IONBF); } 69 70 TEST_F(LlvmLibcFTellTest, TellWithLBF) { test_with_bufmode(_IOLBF); } 71