utils.h: Some utility functions and macros

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
This commit is contained in:
Yuxuan Shui 2018-09-29 23:37:15 +01:00
parent ab12467c3f
commit 3f4c05720d
1 changed files with 80 additions and 0 deletions

80
src/utils.h Normal file
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#pragma once
#include <ctype.h>
#include <stddef.h>
#include <stdlib.h>
static inline const char *
skip_space_const(const char *src) {
if (!src)
return NULL;
while (*src && isspace(*src))
src++;
return src;
}
static inline char *
skip_space_mut(char *src) {
if (!src)
return NULL;
while (*src && isspace(*src))
src++;
return src;
}
#define skip_space(x) _Generic((x), \
char *: skip_space_mut, \
const char *: skip_space_const \
)(x)
/// RC_TYPE generates a reference counted type from `type`
///
/// parameters:
/// name = the generated type will be called `name`_t.
/// ctor = the constructor of `type`, will be called when
/// a value of `type` is created. should take one
/// argument of `type *`.
/// dtor = the destructor. will be called when all reference
/// is gone. has same signature as ctor
/// Q = function qualifier. this is the qualifier that
/// will be put before generated functions
//
/// functions generated:
/// `name`_new: create a new reference counted object of `type`
/// `name`_ref: increment the reference counter, return a
/// reference to the object
/// `name`_unref: decrement the reference counter. take a `type **`
/// because it needs to nullify the reference.
#define RC_TYPE(type, name, ctor, dtor, Q) \
typedef struct { \
type inner; \
int ref_count; \
} name##_internal_t; \
typedef type name##_t; \
Q type *name##_new(void) { \
name##_internal_t *ret = malloc(sizeof(name##_internal_t)); \
ctor((type *)ret); \
ret->ref_count = 1; \
return (type *)ret; \
} \
Q type *name##_ref(type *a) { \
__auto_type b = (name##_internal_t *)a; \
b->ref_count++; \
return a; \
} \
Q void name##_unref(type **a) { \
__auto_type b = (name##_internal_t *)*a; \
if (!b) \
return; \
b->ref_count--; \
if (!b->ref_count) {\
dtor((type *)b); \
free(b); \
} \
*a = NULL; \
}
/// Generate prototypes for functions generated by RC_TYPE
#define RC_TYPE_PROTO(type, name) \
typedef type name##_t; \
type *name##_new(void); \
void name##_ref(type *a); \
void name##_unref(type **a);