From f993771c70f5b0f63562259f7353d675275e8774 Mon Sep 17 00:00:00 2001 From: Roberto Ierusalimschy Date: Wed, 14 Nov 2012 15:21:34 -0200 Subject: [PATCH] avoids warning with 'clang' + comment explaining macro --- lmem.h | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/lmem.h b/lmem.h index 90dabd66..0eba1518 100644 --- a/lmem.h +++ b/lmem.h @@ -1,5 +1,5 @@ /* -** $Id: lmem.h,v 1.37 2011/11/30 12:42:49 roberto Exp roberto $ +** $Id: lmem.h,v 1.38 2011/12/02 13:26:54 roberto Exp $ ** Interface to Memory Manager ** See Copyright Notice in lua.h */ @@ -14,10 +14,17 @@ #include "lua.h" +/* +** This macro avoids the runtime division MAX_SIZET/(e), as 'e' is +** always constant. +** The macro is somewhat complex to avoid warnings: +** +1 avoids warnings of "comparsion has constant result"; +** cast to 'void' avoids warnings of "value unused". +*/ #define luaM_reallocv(L,b,on,n,e) \ - ((cast(size_t, (n)+1) > MAX_SIZET/(e)) ? /* +1 to avoid warnings */ \ - (luaM_toobig(L), (void *)0) : \ - luaM_realloc_(L, (b), (on)*(e), (n)*(e))) + (cast(void, \ + (cast(size_t, (n)+1) > MAX_SIZET/(e)) ? (luaM_toobig(L), 0) : 0), \ + luaM_realloc_(L, (b), (on)*(e), (n)*(e))) #define luaM_freemem(L, b, s) luaM_realloc_(L, (b), (s), 0) #define luaM_free(L, b) luaM_realloc_(L, (b), sizeof(*(b)), 0)