[Tarantool-patches] [PATCH] test: fix warning for old gcc at testgetmetrics.c

[Sergey Kaplun <skaplun@tarantool.org>]

This patch fixes the regression introduced in scope of
5a61e1ab54b5c66bfebd836db1ac47996611e065 ('misc: add C and Lua
API for platform metrics').

Old gcc compiler (gcc-4.8.5-39) throws warnings like:
"error: comparison is always true due to limited range of data type
[-Werror=type-limits]", when you cast syze_t value to ssyze_t type and
compare its to >= 0. This leads to failing compilation with -Werror
flag.

Taking into account that this base test check only API format, not
values by themself, it will be enough to use (void) construction here.

Follows up tarantool/tarantool#5187
---
Bug was reported by Sasha Tikhonov. He faced it up when test his own
branch (avtikhon/gh-4941-gcc-old) with enabled default gcc at Centos 7.
There was failure like [1]:
===================================================================
/build/usr/src/debug/tarantool-2.6.0.208/third_party/luajit/test/misclib-getmetrics-capi/testgetmetrics.c:41:9: error: comparison is always true due to limited range of data type [-Werror=type-limits]
  assert((ssize_t)metrics.jit_trace_num >= 0);
         ^
===================================================================

Branch: https://github.com/tarantool/luajit/tree/skaplun/gh-5187-old-gcc-warning

Branch for test CI was rebased on top of avtikhon/gh-4941-gcc-old which
enables CI-checks with default gcc on CentOS 7

CI is still red but now there are tons of warnings like [2]:
===================================================================
/usr/include/features.h:330:4: error: #warning _FORTIFY_SOURCE requires compiling with optimization (-O) [-Werror=cpp]
 #  warning _FORTIFY_SOURCE requires compiling with optimization (-O)
===================================================================
or replication|txn_manager (see also [3]) tests failures not related to
LuaJIT.

Side note: This is old pipeline, but I changed only comment format
before repushed branch.

CI: https://gitlab.com/tarantool/tarantool/-/pipelines/203899226

[1]: https://gitlab.com/tarantool/tarantool/-/jobs/795394423#L1999
[2]: https://gitlab.com/tarantool/tarantool/-/jobs/796433283#L1637
[3]: https://github.com/tarantool/tarantool/issues/5423

 test/misclib-getmetrics-capi/testgetmetrics.c | 51 +++++++++----------
 1 file changed, 24 insertions(+), 27 deletions(-)

diff --git a/test/misclib-getmetrics-capi/testgetmetrics.c b/test/misclib-getmetrics-capi/testgetmetrics.c
index 3b6f599..fc19680 100644
--- a/test/misclib-getmetrics-capi/testgetmetrics.c
+++ b/test/misclib-getmetrics-capi/testgetmetrics.c
@@ -12,33 +12,30 @@ static int base(lua_State *L)
 	struct luam_Metrics metrics;
 	luaM_metrics(L, &metrics);
 
-	/*
-	 * Just check API.
-	 * (ssize_t) cast need for not always-true unsigned >= 0 check.
-	 */
-	assert((ssize_t)metrics.strhash_hit >= 0);
-	assert((ssize_t)metrics.strhash_miss >= 0);
-
-	assert((ssize_t)metrics.gc_strnum >= 0);
-	assert((ssize_t)metrics.gc_tabnum >= 0);
-	assert((ssize_t)metrics.gc_udatanum >= 0);
-	assert((ssize_t)metrics.gc_cdatanum >= 0);
-
-	assert((ssize_t)metrics.gc_total >= 0);
-	assert((ssize_t)metrics.gc_freed >= 0);
-	assert((ssize_t)metrics.gc_allocated >= 0);
-
-	assert((ssize_t)metrics.gc_steps_pause >= 0);
-	assert((ssize_t)metrics.gc_steps_propagate >= 0);
-	assert((ssize_t)metrics.gc_steps_atomic >= 0);
-	assert((ssize_t)metrics.gc_steps_sweepstring >= 0);
-	assert((ssize_t)metrics.gc_steps_sweep >= 0);
-	assert((ssize_t)metrics.gc_steps_finalize >= 0);
-
-	assert((ssize_t)metrics.jit_snap_restore >= 0);
-	assert((ssize_t)metrics.jit_trace_abort >= 0);
-	assert((ssize_t)metrics.jit_mcode_size >= 0);
-	assert((ssize_t)metrics.jit_trace_num >= 0);
+	/* Just check API, not values by itself. */
+	(void)metrics.strhash_hit;
+	(void)metrics.strhash_miss;
+
+	(void)metrics.gc_strnum;
+	(void)metrics.gc_tabnum;
+	(void)metrics.gc_udatanum;
+	(void)metrics.gc_cdatanum;
+
+	(void)metrics.gc_total;
+	(void)metrics.gc_freed;
+	(void)metrics.gc_allocated;
+
+	(void)metrics.gc_steps_pause;
+	(void)metrics.gc_steps_propagate;
+	(void)metrics.gc_steps_atomic;
+	(void)metrics.gc_steps_sweepstring;
+	(void)metrics.gc_steps_sweep;
+	(void)metrics.gc_steps_finalize;
+
+	(void)metrics.jit_snap_restore;
+	(void)metrics.jit_trace_abort;
+	(void)metrics.jit_mcode_size;
+	(void)metrics.jit_trace_num;
 
 	lua_pushboolean(L, 1);
 	return 1;
-- 
2.28.0