support/support.h

   1 /* Common extra functions.
   2    Copyright (C) 2016-2020 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 /* This header file should only contain definitions compatible with
  20    C90.  (Using __attribute__ is fine because <features.h> provides a
  21    fallback.)  */
  22
  23 #ifndef SUPPORT_H
  24 #define SUPPORT_H
  25
  26 #include <stddef.h>
  27 #include <sys/cdefs.h>
  28 /* For mode_t.  */
  29 #include <sys/stat.h>
  30 /* For ssize_t and off64_t.  */
  31 #include <sys/types.h>
  32
  33 __BEGIN_DECLS
  34
  35 /* Write a message to standard output.  Can be used in signal
  36    handlers.  */
  37 void write_message (const char *message) __attribute__ ((nonnull (1)));
  38
  39 /* Avoid all the buffer overflow messages on stderr.  */
  40 void ignore_stderr (void);
  41
  42 /* Set fortification error handler.  Used when tests want to verify that bad
  43    code is caught by the library.  */
  44 void set_fortify_handler (void (*handler) (int sig));
  45
  46 /* Report an out-of-memory error for the allocation of SIZE bytes in
  47    FUNCTION, terminating the process.  */
  48 void oom_error (const char *function, size_t size)
  49   __attribute__ ((nonnull (1)));
  50
  51 /* Return a pointer to a memory region of SIZE bytes.  The memory is
  52    initialized to zero and will be shared with subprocesses (across
  53    fork).  The returned pointer must be freed using
  54    support_shared_free; it is not compatible with the malloc
  55    functions.  */
  56 void *support_shared_allocate (size_t size);
  57
  58 /* Deallocate a pointer returned by support_shared_allocate.  */
  59 void support_shared_free (void *);
  60
  61 /* Write CONTENTS to the file PATH.  Create or truncate the file as
  62    needed.  The file mode is 0666 masked by the umask.  Terminate the
  63    process on error.  */
  64 void support_write_file_string (const char *path, const char *contents);
  65
  66 /* Quote the contents of the byte array starting at BLOB, of LENGTH
  67    bytes, in such a way that the result string can be included in a C
  68    literal (in single/double quotes, without putting the quotes into
  69    the result).  */
  70 char *support_quote_blob (const void *blob, size_t length);
  71
  72 /* Quote the contents of the string, in such a way that the result
  73    string can be included in a C literal (in single/double quotes,
  74    without putting the quotes into the result).  */
  75 char *support_quote_string (const char *);
  76
  77 /* Returns non-zero if the file descriptor is a regular file on a file
  78    system which supports holes (that is, seeking and writing does not
  79    allocate storage for the range of zeros).  FD must refer to a
  80    regular file open for writing, and initially empty.  */
  81 int support_descriptor_supports_holes (int fd);
  82
  83 /* Error-checking wrapper functions which terminate the process on
  84    error.  */
  85
  86 void *xmalloc (size_t) __attribute__ ((malloc));
  87 void *xcalloc (size_t n, size_t s) __attribute__ ((malloc));
  88 void *xrealloc (void *p, size_t n);
  89 void *xposix_memalign (size_t alignment, size_t n);
  90 char *xasprintf (const char *format, ...)
  91   __attribute__ ((format (printf, 1, 2), malloc));
  92 char *xstrdup (const char *);
  93 char *xstrndup (const char *, size_t);
  94 char *xsetlocale (int category, const char *locale);
  95
  96 /* These point to the TOP of the source/build tree, not your (or
  97    support's) subdirectory.  */
  98 extern const char support_srcdir_root[];
  99 extern const char support_objdir_root[];
 100
 101 /* Corresponds to the path to the runtime linker used by the testsuite,
 102    e.g. OBJDIR_PATH/elf/ld-linux-x86-64.so.2  */
 103 extern const char support_objdir_elf_ldso[];
 104
 105 /* Corresponds to the --prefix= passed to configure.  */
 106 extern const char support_install_prefix[];
 107 /* Corresponds to the install's lib/ or lib64/ directory.  */
 108 extern const char support_libdir_prefix[];
 109 /* Corresponds to the install's bin/ directory.  */
 110 extern const char support_bindir_prefix[];
 111 /* Corresponds to the install's sbin/ directory.  */
 112 extern const char support_sbindir_prefix[];
 113 /* Corresponds to the install's sbin/ directory (without prefix).  */
 114 extern const char support_install_rootsbindir[];
 115
 116 extern ssize_t support_copy_file_range (int, off64_t *, int, off64_t *,
 117                                         size_t, unsigned int);
 118
 119 __END_DECLS
 120
 121 #endif /* SUPPORT_H */