assert macro expand as expression #138
Description
In cosmopolitan.h, assert is defined as a macro using __ASSERT_FAIL:
#define assert(EXPR) \
do { \
if (!(EXPR)) { \
__ASSERT_FAIL(#EXPR, __FILE__, __LINE__); \
unreachable; \
} \
} while (0)This works fine when calling assert individually, but triggers an error when assert is part of another macro.
Example compiler output when enabling C API tests in Lua source:
././libcosmo/cosmopolitan.h:3371:3: error: expected expression before ‘do’
do { \
^~
llimits.h:93:33: note: in expansion of macro ‘assert’
#define lua_assert(c) assert(c)
^~~~~~
llimits.h:110:38: note: in expansion of macro ‘lua_assert’
#define luai_apicheck(l,e) ((void)l, lua_assert(e))
^~~~~~~~~~
llimits.h:113:28: note: in expansion of macro ‘luai_apicheck’
#define api_check(l,e,msg) luai_apicheck(l,(e) && msg)
^~~~~~~~~~~~~
lapi.c:87:5: note: in expansion of macro ‘api_check’
api_check(L, o < L->top, "unacceptable index");
Changing the assert macro to the below expression (Reference: assert in musl) prevents the error:
#ifdef NDEBUG
#define assert(EXPR) ((void) 0)
#else
#define assert(EXPR) ((void)((EXPR) || (__assert_fail(#EXPR, __FILE__, __LINE__),0)))
#endif