mirror/json-c
1
0
Fork 0
mirror of https://github.com/json-c/json-c.git synced 2026-03-24 07:29:07 +08:00
Code Issues Packages Projects Releases Wiki Activity

Fixes various Wreturn-type and Wimplicit-fallthrough errors on Mingw-w64

Browse Source 
This is a recent regression since commit
6359b79847 which added various assert(0)
calls (often replacing return-s).
With Ming-W64 compiler, json-c build was failing with various errors of
the sort:

> /home/jehan/dev/src/json-c/json_object.c: In function 'json_object_int_inc':
> /home/jehan/dev/src/json-c/json_object.c:841:1: error: control reaches end of non-void function [-Werror=return-type]
>   841 | }
>       | ^
> In file included from /home/jehan/dev/src/json-c/json_object.c:17:
> /home/jehan/dev/src/json-c/json_object.c: In function 'json_object_get_double':
> /home/jehan/.local/share/crossroad/roads/w64/json-c/include/assert.h:76:4: error: this statement may fall through [-Werror=implicit-fallthrough=]
>    76 |   (_assert(#_Expression,__FILE__,__LINE__),0))
>       |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> /home/jehan/dev/src/json-c/json_object.c:1070:7: note: in expansion of macro 'assert'
>  1070 |       assert(0);
>       |       ^~~~~~
> /home/jehan/dev/src/json-c/json_object.c:1072:3: note: here
>  1072 |   case json_type_boolean:
>       |   ^~~~

The problem is that Mingw-w64 does not consider assert() as a noreturn
(even assert(0)), because it has to be compatible by Microsoft
libraries. See the discussion here:
https://sourceforge.net/p/mingw-w64/bugs/306/

Instead let's create a new json_abort() function which is basically just
an abort() function with an optional message, for such cases where
abortion was non-conditional (using assert() and using the assertion
condition as a message here was clearly a misuse of the function). And
mark json_abort() as 'noreturn', as well as 'cold' for optimization
purpose (this is code we expect to never run, unless there is a bug,
that is).

Finally let's use this json_abort() instead of previous misused assert()
calls.
This commit is contained in:
Jehan
2020-03-15 23:29:37 +01:00
parent e94eb90f9f
commit b15e7ba470
3 changed files with 29 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
json_object.c
View File

@@ -597,7 +597,7 @@ json_bool json_object_get_boolean(const struct json_object *jso)
case json_object_int_type_uint64:
return (jso->o.c_int.cint.c_uint64 != 0);
default:
assert(!"invalid cint_type");
json_abort("invalid cint_type");
}
case json_type_double:
return (jso->o.c_double != 0);
@@ -734,7 +734,7 @@ int64_t json_object_get_int64(const struct json_object *jso)
return INT64_MAX;
return (int64_t)jso->o.c_int.cint.c_uint64;
default:
assert(!"invalid cint_type");
json_abort("invalid cint_type");
}
case json_type_double:
// INT64_MAX can't be exactly represented as a double
@@ -772,7 +772,7 @@ uint64_t json_object_get_uint64(const struct json_object *jso)
case json_object_int_type_uint64:
return jso->o.c_int.cint.c_uint64;
default:
assert(!"invalid cint_type");
json_abort("invalid cint_type");
}
case json_type_double:
// UINT64_MAX can't be exactly represented as a double
@@ -836,7 +836,7 @@ int json_object_int_inc(struct json_object *jso, int64_t val) {
}
return 1;
default:
assert(!"invalid cint_type");
json_abort("invalid cint_type");
}
}
@@ -1067,7 +1067,7 @@ double json_object_get_double(const struct json_object *jso)
case json_object_int_type_uint64:
return jso->o.c_int.cint.c_uint64;
default:
assert(!"invalid cint_type");
json_abort("invalid cint_type");
}
case json_type_boolean:
return jso->o.c_boolean;

7
json_util.c
View File

@@ -282,3 +282,10 @@ const char *json_type_to_name(enum json_type o_type)
return json_type_name[o_type];
}
void json_abort(const char *message)
{
if (message != NULL)
fprintf (stderr, "json-c aborts with error: %s\n", message);
abort();
}

17
json_util.h
View File

@@ -112,6 +112,23 @@ JSON_EXPORT int json_parse_double(const char *buf, double *retval);
*/
JSON_EXPORT const char *json_type_to_name(enum json_type o_type);
#ifndef JSON_NORETURN
#if defined(_MSC_VER)
#define JSON_NORETURN __declspec(noreturn)
#else
/* 'cold' attribute is for optimization, telling the computer this code
* path is unlikely.
*/
#define JSON_NORETURN __attribute__ ((noreturn, cold))
#endif
#endif
/**
* Abort and optionally print a message on standard error.
* This should be used rather than assert() for unconditional abortion
* (in particular for code paths which are never supposed to be run).
* */
JSON_NORETURN JSON_EXPORT void json_abort(const char *message);
#ifdef __cplusplus
}
#endif