fix strict-aliasing warnings in ngx_http_lua_clfactory_bytecode_prepare

Author: jinglong

src/ngx_http_lua_clfactory.c

@@ -283,8 +283,9 @@ ngx_http_lua_clfactory_bytecode_prepare(lua_State *L, clfactory_file_ctx_t *lf,
 {
     int                 x = 1, size_of_int, size_of_size_t, little_endian,
                         size_of_inst, version, stripped;
-    size_t              size, bytecode_len;
+    static int          num_of_inst = 3, num_of_inter_func = 1;
     const char         *filename, *emsg, *serr, *bytecode;
+    size_t              size, bytecode_len;
     ngx_file_info_t     fi;
 
     serr = NULL;
@@ -404,12 +405,13 @@ ngx_http_lua_clfactory_bytecode_prepare(lua_State *L, clfactory_file_ctx_t *lf,
             goto error;
         }
 
-        /* source string length */
-        *(size_t *) (lf->begin_code.str + POS_SOURCE_STR_LEN) = 0;
-        /* start line */
-        *(int *) (lf->begin_code.str + POS_START_LINE) = 0;
-        /* last line */
-        *(int *) (lf->begin_code.str + POS_LAST_LINE) = 0;
+        /* clear the following fields to zero:
+         * - source string length
+         * - start line
+         * - last line
+         */
+        ngx_memzero(lf->begin_code.str + POS_SOURCE_STR_LEN,
+                    sizeof(size_t) + sizeof(int) * 2);
         /* number of upvalues */
         *(lf->begin_code.str + POS_NUM_OF_UPVS) = 0;
         /* number of paramters */
@@ -419,7 +421,8 @@ ngx_http_lua_clfactory_bytecode_prepare(lua_State *L, clfactory_file_ctx_t *lf,
         /* max stack size */
         *(lf->begin_code.str + POS_MAX_STACK_SIZE) = 2;
         /* number of bytecode instructions */
-        *(int *) (lf->begin_code.str + POS_NUM_OF_INST) = 3;
+        ngx_memcpy(lf->begin_code.str + POS_NUM_OF_INST, &num_of_inst,
+                   sizeof(int));
 
         lf->begin_code_len = POS_BYTECODE;
 
@@ -448,10 +451,11 @@ ngx_http_lua_clfactory_bytecode_prepare(lua_State *L, clfactory_file_ctx_t *lf,
         ngx_memcpy(lf->begin_code.str + POS_BYTECODE, bytecode, bytecode_len);
 
         /* number of consts */
-        *(int *) (lf->begin_code.str + POS_BYTECODE + bytecode_len) = 0;
+        ngx_memzero(lf->begin_code.str + POS_BYTECODE + bytecode_len,
+                    sizeof(int));
         /* number of internal functions */
-        *(int *) (lf->begin_code.str + POS_BYTECODE + bytecode_len
-                  + sizeof(int)) = 1;
+        ngx_memcpy(lf->begin_code.str + POS_BYTECODE + bytecode_len
+                   + sizeof(int), &num_of_inter_func, sizeof(int));
 
         lf->begin_code_len += bytecode_len + sizeof(int) + sizeof(int);