From b15e7ba470d09e521963257b9cc173f65096d8b5 Mon Sep 17 00:00:00 2001 From: Jehan Date: Sun, 15 Mar 2020 23:29:37 +0100 Subject: Fixes various Wreturn-type and Wimplicit-fallthrough errors on Mingw-w64 This is a recent regression since commit 6359b798479d379a3202e02c6a938d9b40c0d856 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. --- json_util.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'json_util.c') diff --git a/json_util.c b/json_util.c index 1c1fa46..b7c25af 100644 --- a/json_util.c +++ b/json_util.c @@ -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(); +} + -- cgit v1.2.1