| //===-- Unittests for ungetc ----------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "src/stdio/fclose.h" |
| #include "src/stdio/fopen.h" |
| #include "src/stdio/fread.h" |
| #include "src/stdio/fseek.h" |
| #include "src/stdio/fwrite.h" |
| #include "src/stdio/ungetc.h" |
| #include "test/UnitTest/Test.h" |
| |
| #include <stdio.h> |
| |
| TEST(LlvmLibcUngetcTest, UngetAndReadBack) { |
| constexpr char FILENAME[] = "testdata/ungetc_test.test"; |
| ::FILE *file = LIBC_NAMESPACE::fopen(FILENAME, "w"); |
| ASSERT_FALSE(file == nullptr); |
| constexpr char CONTENT[] = "abcdef"; |
| constexpr size_t CONTENT_SIZE = sizeof(CONTENT); |
| ASSERT_EQ(CONTENT_SIZE, |
| LIBC_NAMESPACE::fwrite(CONTENT, 1, CONTENT_SIZE, file)); |
| #ifndef LIBC_TARGET_ARCH_IS_GPU // Behavior varies between libc implementations. |
| // Cannot unget to an un-readable file. |
| ASSERT_EQ(EOF, LIBC_NAMESPACE::ungetc('1', file)); |
| #endif |
| ASSERT_EQ(0, LIBC_NAMESPACE::fclose(file)); |
| |
| file = LIBC_NAMESPACE::fopen(FILENAME, "r+"); |
| ASSERT_FALSE(file == nullptr); |
| // Calling with an EOF should always return EOF without doing anything. |
| ASSERT_EQ(EOF, LIBC_NAMESPACE::ungetc(EOF, file)); |
| char c; |
| ASSERT_EQ(LIBC_NAMESPACE::fread(&c, 1, 1, file), size_t(1)); |
| ASSERT_EQ(c, CONTENT[0]); |
| ASSERT_EQ(LIBC_NAMESPACE::ungetc(int(c), file), int(c)); |
| |
| char data[CONTENT_SIZE]; |
| ASSERT_EQ(CONTENT_SIZE, LIBC_NAMESPACE::fread(data, 1, CONTENT_SIZE, file)); |
| ASSERT_STREQ(CONTENT, data); |
| |
| ASSERT_EQ(0, LIBC_NAMESPACE::fseek(file, 0, SEEK_SET)); |
| // ungetc should not fail after a seek operation. |
| int unget_char = 'z'; |
| ASSERT_EQ(unget_char, LIBC_NAMESPACE::ungetc(unget_char, file)); |
| #ifndef LIBC_TARGET_ARCH_IS_GPU // Behavior varies between libc implementations. |
| // Another unget should fail. |
| ASSERT_EQ(EOF, LIBC_NAMESPACE::ungetc(unget_char, file)); |
| #endif |
| // ungetting a char at the beginning of the file will allow us to fetch |
| // one additional character. |
| char new_data[CONTENT_SIZE + 1]; |
| ASSERT_EQ(CONTENT_SIZE + 1, |
| LIBC_NAMESPACE::fread(new_data, 1, CONTENT_SIZE + 1, file)); |
| ASSERT_STREQ("zabcdef", new_data); |
| |
| ASSERT_EQ(size_t(1), LIBC_NAMESPACE::fwrite("x", 1, 1, file)); |
| #ifndef LIBC_TARGET_ARCH_IS_GPU // Behavior varies between libc implementations. |
| // unget should fail after a write operation. |
| ASSERT_EQ(EOF, LIBC_NAMESPACE::ungetc('1', file)); |
| #endif |
| |
| ASSERT_EQ(0, LIBC_NAMESPACE::fclose(file)); |
| } |