BUILD: lua: silence some compiler warnings about potential null derefs
These ones are on error paths that are properly handled by luaL_error()
which does a longjmp() but the compiler cannot know it. By adding an
__unreachable() statement in WILL_LJMP(), there is no ambiguity anymore.
This may be backported to 1.8 but the previous patch (BUILD: compiler:
add a new statement "__unreachable()") is needed for this.
diff --git a/src/hlua.c b/src/hlua.c
index aaa8840..fe7c909 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -25,6 +25,7 @@
#include <ebpttree.h>
#include <common/cfgparse.h>
+#include <common/compiler.h>
#include <common/xref.h>
#include <common/hathreads.h>
@@ -67,7 +68,7 @@
* MAY_LJMP() marks an lua function that may use longjmp.
*/
#define __LJMP
-#define WILL_LJMP(func) func
+#define WILL_LJMP(func) do { func; __unreachable(); } while (0)
#define MAY_LJMP(func) func
/* This couple of function executes securely some Lua calls outside of
@@ -2361,7 +2362,7 @@
return 2;
}
- appctx = objt_appctx(s->si[0].end);
+ appctx = __objt_appctx(s->si[0].end);
/* Check for connection established. */
if (appctx->ctx.hlua_cosocket.connected) {
@@ -2473,7 +2474,7 @@
}
hlua = hlua_gethlua(L);
- appctx = objt_appctx(s->si[0].end);
+ appctx = __objt_appctx(s->si[0].end);
/* inform the stream that we want to be notified whenever the
* connection completes.
@@ -5723,6 +5724,9 @@
WILL_LJMP(luaL_error(L, "Lua out of memory error."));
task = task_new(MAX_THREADS_MASK);
+ if (!task)
+ WILL_LJMP(luaL_error(L, "Lua out of memory error."));
+
task->context = hlua;
task->process = hlua_process_task;