diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/nimbase.h | 65 |
1 files changed, 42 insertions, 23 deletions
diff --git a/lib/nimbase.h b/lib/nimbase.h index 5b0dcc2c8..597a5317f 100644 --- a/lib/nimbase.h +++ b/lib/nimbase.h @@ -262,6 +262,21 @@ __AVR__ #include <limits.h> #include <stddef.h> +// define NIM_STATIC_ASSERT +// example use case: CT sizeof for importc types verification +// where we have {.completeStruct.} (or lack of {.incompleteStruct.}) +#if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L) +#define NIM_STATIC_ASSERT(x, msg) _Static_assert((x), msg) +#elif defined(__cplusplus) +#define NIM_STATIC_ASSERT(x, msg) static_assert((x), msg) +#else +#define NIM_STATIC_ASSERT(x, msg) typedef int NIM_STATIC_ASSERT_AUX[(x) ? 1 : -1]; +// On failure, your C compiler will say something like: +// "error: 'NIM_STATIC_ASSERT_AUX' declared as an array with a negative size" +// we could use a better fallback to also show line number, using: +// http://www.pixelbeat.org/programming/gcc/static_assert.html +#endif + /* C99 compiler? */ #if (defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901)) # define HAVE_STDINT_H @@ -288,34 +303,40 @@ __AVR__ namespace USE_NIM_NAMESPACE { #endif +// preexisting check, seems paranoid, maybe remove +#if defined(NIM_TRUE) || defined(NIM_FALSE) || defined(NIM_BOOL) +#error "nim reserved preprocessor macros clash" +#endif + /* bool types (C++ has it): */ #ifdef __cplusplus -# ifndef NIM_TRUE -# define NIM_TRUE true -# endif -# ifndef NIM_FALSE -# define NIM_FALSE false -# endif -# define NIM_BOOL bool +#define NIM_BOOL bool +#elif (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901) +// see #13798: to avoid conflicts for code emitting `#include <stdbool.h>` +#define NIM_BOOL _Bool +#else +typedef unsigned char NIM_BOOL; // best effort +#endif + +NIM_STATIC_ASSERT(sizeof(NIM_BOOL) == 1, ""); // check whether really needed + +#define NIM_TRUE true +#define NIM_FALSE false + +#ifdef __cplusplus # if __cplusplus >= 201103L # /* nullptr is more type safe (less implicit conversions than 0) */ # define NIM_NIL nullptr # else -# /* consider using NULL if comment below for NIM_NIL doesn't apply to C++ */ +# // both `((void*)0)` and `NULL` would cause codegen to emit +# // error: assigning to 'Foo *' from incompatible type 'void *' +# // but codegen could be fixed if need. See also potential caveat regarding +# // NULL. +# // However, `0` causes other issues, see #13798 # define NIM_NIL 0 # endif #else -# ifdef bool -# define NIM_BOOL bool -# else - typedef unsigned char NIM_BOOL; -# endif -# ifndef NIM_TRUE -# define NIM_TRUE ((NIM_BOOL) 1) -# endif -# ifndef NIM_FALSE -# define NIM_FALSE ((NIM_BOOL) 0) -# endif +# include <stdbool.h> # define NIM_NIL ((void*)0) /* C's NULL is fucked up in some C compilers, so the generated code does not rely on it anymore */ #endif @@ -516,10 +537,8 @@ static inline void GCGuard (void *ptr) { asm volatile ("" :: "X" (ptr)); } # define GC_GUARD #endif -/* Test to see if Nim and the C compiler agree on the size of a pointer. - On disagreement, your C compiler will say something like: - "error: 'Nim_and_C_compiler_disagree_on_target_architecture' declared as an array with a negative size" */ -typedef int Nim_and_C_compiler_disagree_on_target_architecture[sizeof(NI) == sizeof(void*) && NIM_INTBITS == sizeof(NI)*8 ? 1 : -1]; +// Test to see if Nim and the C compiler agree on the size of a pointer. +NIM_STATIC_ASSERT(sizeof(NI) == sizeof(void*) && NIM_INTBITS == sizeof(NI)*8, ""); #ifdef USE_NIM_NAMESPACE } |