From dccc9a5161264d2f98411c24ae22495ca3a09b60 Mon Sep 17 00:00:00 2001 From: Tulio Magno Quites Machado Filho Date: Thu, 29 Aug 2024 14:12:41 -0300 Subject: [PATCH] Add a new fwrite test for memory streams Ensure that fwrite() behaves correctly when using memory streams. Reviewed-by: Carlos O'Donell --- stdio-common/Makefile | 1 + stdio-common/tst-fwrite-memstrm.c | 177 ++++++++++++++++++++++++++++++ 2 files changed, 178 insertions(+) create mode 100644 stdio-common/tst-fwrite-memstrm.c diff --git a/stdio-common/Makefile b/stdio-common/Makefile index 0e18045038..ce7f7cdd3b 100644 --- a/stdio-common/Makefile +++ b/stdio-common/Makefile @@ -223,6 +223,7 @@ tests := \ tst-freopen64-3 \ tst-fseek \ tst-fwrite \ + tst-fwrite-memstrm \ tst-fwrite-ro \ tst-getline \ tst-getline-enomem \ diff --git a/stdio-common/tst-fwrite-memstrm.c b/stdio-common/tst-fwrite-memstrm.c new file mode 100644 index 0000000000..7ee3831430 --- /dev/null +++ b/stdio-common/tst-fwrite-memstrm.c @@ -0,0 +1,177 @@ +/* Test fwrite on a memory stream. + Copyright (C) 2024 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include +#include +#include +#include +#include +#include + +void +test_ro (void) +{ + FILE *f; + char *out; + + /* Try to allocate a small buffer for this test. */ + out = malloc (2); + TEST_VERIFY_EXIT (out != NULL); + + /* Try to open the allocated buffer as a read-only stream. */ + f = fmemopen (out, 2, "r"); + TEST_VERIFY_EXIT (f != NULL); + + /* Try to write to the temporary file with nmemb = 0, then check that + fwrite returns 0. No errors are expected from this. */ + TEST_COMPARE (fwrite ("a", 1, 0, f), 0); + TEST_COMPARE (ferror (f), 0); + + /* Try to write to the temporary file with size = 0, then check that + fwrite returns 0. No errors are expected from this. */ + TEST_COMPARE (fwrite ("a", 0, 1, f), 0); + TEST_COMPARE (ferror (f), 0); + + /* Try to write a single byte to the temporary file, then check that + fwrite returns 0. Check if an error was reported. */ + TEST_COMPARE (fwrite ("a", 1, 1, f), 0); + TEST_COMPARE (ferror (f), 1); + + clearerr (f); + xfclose (f); + free (out); +} + +/* Length of the output buffer in bytes. */ +#define RWBUF_SIZE 16 * 1024 +/* Maximum number of bytes to be written in output buffer. The rest will be + used to check against overflow. */ +#define RWBUF_SIZE_WRITABLE RWBUF_SIZE-2048 + +/* Use the following byte to identify areas that should have not been + modified. */ +#define KNOWN_BYTE 0xaa + +void +test_one_rw (const char *in, size_t size, size_t nmemb, + size_t expected_ret) +{ + FILE *f; + char *out, *expected_out; + /* Total number of bytes expected to be written. */ + size_t expected_bytes = size * nmemb; + + printf ("Testing with size = %zd, nmemb = %zd\n", size, nmemb); + + TEST_VERIFY_EXIT (expected_ret <= RWBUF_SIZE_WRITABLE); + TEST_VERIFY_EXIT (expected_bytes <= RWBUF_SIZE_WRITABLE); + + /* Try to allocate a buffer for this test and initialize it with + known contents. */ + out = malloc (RWBUF_SIZE); + TEST_VERIFY_EXIT (out != NULL); + memset (out, KNOWN_BYTE, RWBUF_SIZE); + + /* Try to allocate a buffer and fill it with the contents that are expected + to be in memory after flushing/closing the memory stream. */ + expected_out = malloc (RWBUF_SIZE); + TEST_VERIFY_EXIT (expected_out != NULL); + if (expected_bytes > 0) + { + memcpy (expected_out, in, expected_bytes); + expected_out[expected_bytes] = 0; + memset (expected_out + expected_bytes + 1, KNOWN_BYTE, + RWBUF_SIZE - expected_bytes - 1); + } + else + { + /* No changes to the output are expected. */ + memset (expected_out, KNOWN_BYTE, RWBUF_SIZE); + } + + /* Try to open the allocated buffer as a read-write stream. */ + f = fmemopen (out, RWBUF_SIZE, "w"); + TEST_VERIFY_EXIT (f != NULL); + + /* Try to write to the memory stream. Check if fwrite() returns the + expected value. No errors are expected. */ + TEST_COMPARE (fwrite (in, size, nmemb, f), expected_ret); + TEST_COMPARE (ferror (f), 0); + + xfclose (f); + + /* Ensure the output has the expected contents. */ + TEST_COMPARE (memcmp (out, expected_out, expected_bytes), 0); + + free (expected_out); + free (out); +} + +void +test_rw (void) +{ + char * in; + int i, j; + size_t size[] = {1, 8, 11, 16, 17, 0}; + size_t nmemb[] = {32, 83, 278, 709, 4097, RWBUF_SIZE / 2, + RWBUF_SIZE_WRITABLE, 0}; + size_t n; + + /* Try to write to the temporary file with nmemb = 0, then check that + fwrite returns 0; */ + test_one_rw ("a", 1, 0, 0); + + /* Try to write to the temporary file with size = 0, then check that + fwrite returns 0; */ + test_one_rw ("a", 0, 1, 0); + + /* Try to write a single byte to the temporary file, then check that + fwrite returns 1; */ + test_one_rw ("a", 1, 2, 2); + + in = malloc (RWBUF_SIZE); + TEST_VERIFY_EXIT (in != NULL); + for (i = 0; i < RWBUF_SIZE / 2; i++) + in[i] = i % 0xff; + + /* Test with all posibilities of size[] x nmemb[]. */ + for (i = 0; nmemb[i] != 0; i++) + { + for (j = 0; size[j] != 0; j++) + { + n = nmemb[i] / size[j]; + test_one_rw (in, size[j], n, n); + } + /* Run the test with a single item of maximum size. */ + test_one_rw (in, nmemb[i], 1, 1); + } + + free (in); +} + +static int +do_test (void) +{ + test_ro (); + test_rw (); + + return 0; +} + +#include