newlib/libc/stdlib/assert.c

   1 /*
   2 FUNCTION
   3 <<assert>>---macro for debugging diagnostics
   4
   5 INDEX
   6         assert
   7
   8 SYNOPSIS
   9         #include <assert.h>
  10         void assert(int <[expression]>);
  11
  12 DESCRIPTION
  13         Use this macro to embed debuggging diagnostic statements in
  14         your programs.  The argument <[expression]> should be an
  15         expression which evaluates to true (nonzero) when your program
  16         is working as you intended.
  17
  18         When <[expression]> evaluates to false (zero), <<assert>>
  19         calls <<abort>>, after first printing a message showing what
  20         failed and where:
  21
  22 . Assertion failed: <[expression]>, file <[filename]>, line <[lineno]>, function: <[func]>
  23
  24         If the name of the current function is not known (for example,
  25         when using a C89 compiler that does not understand __func__),
  26         the function location is omitted.
  27
  28         The macro is defined to permit you to turn off all uses of
  29         <<assert>> at compile time by defining <<NDEBUG>> as a
  30         preprocessor variable.   If you do this, the <<assert>> macro
  31         expands to
  32
  33 . (void(0))
  34
  35 RETURNS
  36         <<assert>> does not return a value.
  37
  38 PORTABILITY
  39         The <<assert>> macro is required by ANSI, as is the behavior
  40         when <<NDEBUG>> is defined.
  41
  42 Supporting OS subroutines required (only if enabled): <<close>>, <<fstat>>,
  43 <<getpid>>, <<isatty>>, <<kill>>, <<lseek>>, <<read>>, <<sbrk>>, <<write>>.
  44 */
  45
  46 #include <assert.h>
  47 #include <stdlib.h>
  48 #include <stdio.h>
  49
  50 #ifndef HAVE_ASSERT_FUNC
  51 /* func can be NULL, in which case no function information is given.  */
  52 void
  53 __assert_func (const char *file,
  54         int line,
  55         const char *func,
  56         const char *failedexpr)
  57 {
  58   fiprintf(stderr,
  59            "assertion \"%s\" failed: file \"%s\", line %d%s%s\n",
  60            failedexpr, file, line,
  61            func ? ", function: " : "", func ? func : "");
  62   abort();
  63   /* NOTREACHED */
  64 }
  65 #endif /* HAVE_ASSERT_FUNC */
  66
  67 void
  68 __assert (const char *file,
  69         int line,
  70         const char *failedexpr)
  71 {
  72    __assert_func (file, line, NULL, failedexpr);
  73   /* NOTREACHED */
  74 }