lib/c-stack.h

   1 /* Stack overflow handling.
   2
   3    Copyright (C) 2002, 2004, 2008-2024 Free Software Foundation, Inc.
   4
   5    This program is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation, either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program 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
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 /* This file uses _GL_ASYNC_SAFE.  */
  19 #if !_GL_CONFIG_H_INCLUDED
  20  #error "Please include config.h first."
  21 #endif
  22
  23 #ifdef __cplusplus
  24 extern "C"
  25 {
  26 #endif
  27
  28 /* Set up ACTION so that it is invoked on C stack overflow and on other,
  29    stack-unrelated, segmentation violation.
  30    Return -1 (setting errno) if this cannot be done.
  31
  32    When a stack overflow or segmentation violation occurs:
  33    1) ACTION is called.  It is passed an argument equal to
  34         - 0, for a stack overflow,
  35         - SIGSEGV, for a segmentation violation that does not appear related
  36           to stack overflow.
  37       On many platforms the two cases are hard to distinguish; when in doubt,
  38       zero is passed.
  39    2) If ACTION returns, a message is written to standard error, and the
  40       program is terminated: in the case of stack overflow, with exit code
  41       exit_failure (see "exitfail.h"), otherwise through a signal SIGSEGV.
  42
  43    A null ACTION acts like an action that does nothing.
  44
  45    Restrictions:
  46    - ACTION must be async-signal-safe.
  47    - ACTION together with its callees must not require more than 64 KiB of
  48      stack space.
  49    - ACTION must not create and then invoke nested functions
  50      <https://gcc.gnu.org/onlinedocs/gcc/Nested-Functions.html>, because
  51      this implementation does not guarantee an executable stack.
  52    - ACTION should not call longjmp, because this implementation does not
  53      guarantee that it is safe to return to the original stack.
  54
  55    This function may install a handler for the SIGSEGV signal or for the SIGBUS
  56    signal or exercise other system dependent exception handling APIs.  */
  57
  58 extern int c_stack_action (_GL_ASYNC_SAFE void (* /*action*/) (int));
  59
  60 #ifdef __cplusplus
  61 }
  62 #endif