contrib/tre/lib/tre-stack.h

   1 /*
   2   tre-stack.h: Stack definitions
   3
   4   This software is released under a BSD-style license.
   5   See the file LICENSE for details and copyright.
   6
   7 */
   8
   9
  10 #ifndef TRE_STACK_H
  11 #define TRE_STACK_H 1
  12
  13 #include "tre.h"
  14
  15 typedef struct tre_stack_rec tre_stack_t;
  16
  17 /* Creates a new stack object.  `size' is initial size in bytes, `max_size'
  18    is maximum size, and `increment' specifies how much more space will be
  19    allocated with realloc() if all space gets used up.  Returns the stack
  20    object or NULL if out of memory. */
  21 tre_stack_t *
  22 tre_stack_new(int size, int max_size, int increment);
  23
  24 /* Frees the stack object. */
  25 void
  26 tre_stack_destroy(tre_stack_t *s);
  27
  28 /* Returns the current number of objects in the stack. */
  29 int
  30 tre_stack_num_objects(tre_stack_t *s);
  31
  32 /* Each tre_stack_push_*(tre_stack_t *s, <type> value) function pushes
  33    `value' on top of stack `s'.  Returns REG_ESPACE if out of memory.
  34    This tries to realloc() more space before failing if maximum size
  35    has not yet been reached.  Returns REG_OK if successful. */
  36 #define declare_pushf(typetag, type)                                          \
  37   reg_errcode_t tre_stack_push_ ## typetag(tre_stack_t *s, type value)
  38
  39 declare_pushf(voidptr, void *);
  40 declare_pushf(int, int);
  41
  42 /* Each tre_stack_pop_*(tre_stack_t *s) function pops the topmost
  43    element off of stack `s' and returns it.  The stack must not be
  44    empty. */
  45 #define declare_popf(typetag, type)               \
  46   type tre_stack_pop_ ## typetag(tre_stack_t *s)
  47
  48 declare_popf(voidptr, void *);
  49 declare_popf(int, int);
  50
  51 /* Just to save some typing. */
  52 #define STACK_PUSH(s, typetag, value)                                         \
  53   do                                                                          \
  54     {                                                                         \
  55       status = tre_stack_push_ ## typetag(s, value);                          \
  56     }                                                                         \
  57   while (/*CONSTCOND*/0)
  58
  59 #define STACK_PUSHX(s, typetag, value)                                        \
  60   {                                                                           \
  61     status = tre_stack_push_ ## typetag(s, value);                            \
  62     if (status != REG_OK)                                                     \
  63       break;                                                                  \
  64   }
  65
  66 #define STACK_PUSHR(s, typetag, value)                                        \
  67   {                                                                           \
  68     reg_errcode_t _status;                                                    \
  69     _status = tre_stack_push_ ## typetag(s, value);                           \
  70     if (_status != REG_OK)                                                    \
  71       return _status;                                                         \
  72   }
  73
  74 #endif /* TRE_STACK_H */
  75
  76 /* EOF */