support/support.h

   1 /* Common extra functions.
   2    Copyright (C) 2016-2021 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 <stdbool.h>
  27 #include <stddef.h>
  28 #include <sys/cdefs.h>
  29 /* For mode_t.  */
  30 #include <sys/stat.h>
  31 /* For ssize_t and off64_t.  */
  32 #include <sys/types.h>
  33 /* For locale_t.  */
  34 #include <locale.h>
  35
  36 __BEGIN_DECLS
  37
  38 /* Write a message to standard output.  Can be used in signal
  39    handlers.  */
  40 void write_message (const char *message) __attribute__ ((nonnull (1)));
  41
  42 /* Avoid all the buffer overflow messages on stderr.  */
  43 void ignore_stderr (void);
  44
  45 /* Set fortification error handler.  Used when tests want to verify that bad
  46    code is caught by the library.  */
  47 void set_fortify_handler (void (*handler) (int sig));
  48
  49 /* Report an out-of-memory error for the allocation of SIZE bytes in
  50    FUNCTION, terminating the process.  */
  51 void oom_error (const char *function, size_t size)
  52   __attribute__ ((nonnull (1)));
  53
  54 /* Return a pointer to a memory region of SIZE bytes.  The memory is
  55    initialized to zero and will be shared with subprocesses (across
  56    fork).  The returned pointer must be freed using
  57    support_shared_free; it is not compatible with the malloc
  58    functions.  */
  59 void *support_shared_allocate (size_t size);
  60
  61 /* Deallocate a pointer returned by support_shared_allocate.  */
  62 void support_shared_free (void *);
  63
  64 /* Write CONTENTS to the file PATH.  Create or truncate the file as
  65    needed.  The file mode is 0666 masked by the umask.  Terminate the
  66    process on error.  */
  67 void support_write_file_string (const char *path, const char *contents);
  68
  69 /* Quote the contents of the byte array starting at BLOB, of LENGTH
  70    bytes, in such a way that the result string can be included in a C
  71    literal (in single/double quotes, without putting the quotes into
  72    the result).  */
  73 char *support_quote_blob (const void *blob, size_t length);
  74
  75 /* Quote the contents of the string, in such a way that the result
  76    string can be included in a C literal (in single/double quotes,
  77    without putting the quotes into the result).  */
  78 char *support_quote_string (const char *);
  79
  80 /* Returns non-zero if the file descriptor is a regular file on a file
  81    system which supports holes (that is, seeking and writing does not
  82    allocate storage for the range of zeros).  FD must refer to a
  83    regular file open for writing, and initially empty.  */
  84 int support_descriptor_supports_holes (int fd);
  85
  86 /* Error-checking wrapper functions which terminate the process on
  87    error.  */
  88
  89 void *xmalloc (size_t) __attribute__ ((malloc));
  90 void *xcalloc (size_t n, size_t s) __attribute__ ((malloc));
  91 void *xrealloc (void *p, size_t n);
  92 void *xposix_memalign (size_t alignment, size_t n);
  93 char *xasprintf (const char *format, ...)
  94   __attribute__ ((format (printf, 1, 2), malloc));
  95 char *xstrdup (const char *);
  96 char *xstrndup (const char *, size_t);
  97 char *xsetlocale (int category, const char *locale);
  98 locale_t xnewlocale (int category_mask, const char *locale, locale_t base);
  99 char *xuselocale (locale_t newloc);
 100
 101 /* These point to the TOP of the source/build tree, not your (or
 102    support's) subdirectory.  */
 103 extern const char support_srcdir_root[];
 104 extern const char support_objdir_root[];
 105
 106 /* Corresponds to the path to the runtime linker used by the testsuite,
 107    e.g. OBJDIR_PATH/elf/ld-linux-x86-64.so.2  */
 108 extern const char support_objdir_elf_ldso[];
 109
 110 /* Corresponds to the --prefix= passed to configure.  */
 111 extern const char support_install_prefix[];
 112 /* Corresponds to the install's lib/ or lib64/ directory.  */
 113 extern const char support_libdir_prefix[];
 114 /* Corresponds to the install's bin/ directory.  */
 115 extern const char support_bindir_prefix[];
 116 /* Corresponds to the install's sbin/ directory.  */
 117 extern const char support_sbindir_prefix[];
 118 /* Corresponds to the install's system /lib or /lib64 directory.  */
 119 extern const char support_slibdir_prefix[];
 120 /* Corresponds to the install's sbin/ directory (without prefix).  */
 121 extern const char support_install_rootsbindir[];
 122 /* Corresponds to the install's compiled locale directory.  */
 123 extern const char support_complocaledir_prefix[];
 124
 125 /* Copies the file at the path FROM to TO.  If TO does not exist, it
 126    is created.  If TO is a regular file, it is truncated before
 127    copying.  The file mode is copied, but the permissions are not.  */
 128 extern void support_copy_file (const char *from, const char *to);
 129
 130 extern ssize_t support_copy_file_range (int, off64_t *, int, off64_t *,
 131                                         size_t, unsigned int);
 132
 133 /* Return true is PATH supports 64-bit time_t interfaces for file
 134    operations (such as fstatat or utimensat).  */
 135 extern bool support_path_support_time64 (const char *path);
 136
 137 /* Return true if stat supports nanoseconds resolution.  */
 138 extern bool support_stat_nanoseconds (void);
 139
 140 __END_DECLS
 141
 142 #endif /* SUPPORT_H */