diff options
Diffstat (limited to 'shared/nm-utils/nm-macros-internal.h')
| -rw-r--r-- | shared/nm-utils/nm-macros-internal.h | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/shared/nm-utils/nm-macros-internal.h b/shared/nm-utils/nm-macros-internal.h index 2e3940fd76..63d0128739 100644 --- a/shared/nm-utils/nm-macros-internal.h +++ b/shared/nm-utils/nm-macros-internal.h @@ -441,6 +441,41 @@ NM_G_ERROR_MSG (GError *error) #endif #if _NM_CC_SUPPORT_GENERIC +/* these macros cast (value) to + * - "const char **" (for "MC", mutable-const) + * - "const char *const*" (for "CC", const-const) + * The point is to do this cast, but only accepting pointers + * that are compatible already. + * + * The problem is, if you add a function like g_strdupv(), the input + * argument is not modified (CC), but you want to make it work also + * for "char **". C doesn't allow this form of casting (for good reasons), + * so the function makes a choice like g_strdupv(char**). That means, + * every time you want to call ith with a const argument, you need to + * explicitly cast it. + * + * These macros do the cast, but they only accept a compatible input + * type, otherwise they will fail compilation. + */ +#define NM_CAST_STRV_MC(value) \ + (_Generic ((value), \ + const char * *: (const char * *) (value), \ + char * *: (const char * *) (value), \ + void *: (const char * *) (value))) +#define NM_CAST_STRV_CC(value) \ + (_Generic ((value), \ + const char *const*: (const char *const*) (value), \ + const char * *: (const char *const*) (value), \ + char *const*: (const char *const*) (value), \ + char * *: (const char *const*) (value), \ + const void *: (const char *const*) (value), \ + void *: (const char *const*) (value))) +#else +#define NM_CAST_STRV_MC(value) ((const char * *) (value)) +#define NM_CAST_STRV_CC(value) ((const char *const*) (value)) +#endif + +#if _NM_CC_SUPPORT_GENERIC #define NM_PROPAGATE_CONST(test_expr, ptr) \ (_Generic ((test_expr), \ const typeof (*(test_expr)) *: ((const typeof (*(ptr)) *) (ptr)), \ |