Merge pull request #9012 from dlqs/lua-poly

Refactor decoder for Lua hook system

doc/developer/scripting.rst

@@ -488,12 +488,6 @@ match *exactly*.
 In the above example, we defined encoders/decoders for a value of
 ``struct prefix *``, but not ``struct prefix`` or ``const struct prefix *``.
 
-``const`` values are a special case. We want to use them in our Lua scripts
-but not modify them, so creating a decoder for them would be meaningless.
-But we still need a decoder for the type of value so that the compiler will be
-satisfied.
-For that, use ``lua_decode_noop``:
-
 .. code-block:: diff
 
      #define DECODE_ARGS_WITH_STATE(L, value) \

lib/frrlua.c

@@ -259,12 +259,12 @@ void *lua_tosockunion(lua_State *L, int idx)
 	return su;
 }
 
-void lua_pushintegerp(lua_State *L, const long long *num)
+void lua_pushintegerp(lua_State *L, const int *num)
 {
 	lua_pushinteger(L, *num);
 }
 
-void lua_decode_integerp(lua_State *L, int idx, long long *num)
+void lua_decode_integerp(lua_State *L, int idx, int *num)
 {
 	int isnum;
 	*num = lua_tonumberx(L, idx, &isnum);
@@ -274,7 +274,7 @@ void lua_decode_integerp(lua_State *L, int idx, long long *num)
 
 void *lua_tointegerp(lua_State *L, int idx)
 {
-	long long *num = XCALLOC(MTYPE_SCRIPT_RES, sizeof(long long));
+	int *num = XCALLOC(MTYPE_SCRIPT_RES, sizeof(int));
 
 	lua_decode_integerp(L, idx, num);
 	return num;
@@ -332,6 +332,28 @@ void lua_pushnexthop_group(lua_State *L, const struct nexthop_group *ng)
 	}
 }
 
+void lua_pushlonglongp(lua_State *L, const long long *num)
+{
+	/* lua library function; this can take a long long */
+	lua_pushinteger(L, *num);
+}
+
+void lua_decode_longlongp(lua_State *L, int idx, long long *num)
+{
+	int isnum;
+	*num = lua_tonumberx(L, idx, &isnum);
+	lua_pop(L, 1);
+	assert(isnum);
+}
+
+void *lua_tolonglongp(lua_State *L, int idx)
+{
+	long long *num = XCALLOC(MTYPE_SCRIPT_RES, sizeof(long long));
+
+	lua_decode_longlongp(L, idx, num);
+	return num;
+}
+
 void lua_decode_stringp(lua_State *L, int idx, char *str)
 {
 	strlcpy(str, lua_tostring(L, idx), strlen(str) + 1);
@@ -345,21 +367,6 @@ void *lua_tostringp(lua_State *L, int idx)
 	return string;
 }
 
-/*
- * Decoder for const values, since we cannot modify them.
- */
-void lua_decode_noop(lua_State *L, int idx, const void *ptr)
-{
-}
-
-
-/*
- * Noop decoder for int.
- */
-void lua_decode_integer_noop(lua_State *L, int idx, int i)
-{
-}
-
 /*
  * Logging.
  *

lib/frrlua.h

@@ -121,9 +121,9 @@ void lua_pushnexthop(lua_State *L, const struct nexthop *nexthop);
 /*
  * Converts an int to a Lua value and pushes it on the stack.
  */
-void lua_pushintegerp(lua_State *L, const long long *num);
+void lua_pushintegerp(lua_State *L, const int *num);
 
-void lua_decode_integerp(lua_State *L, int idx, long long *num);
+void lua_decode_integerp(lua_State *L, int idx, int *num);
 
 /*
  * Converts the Lua value at idx to an int.
@@ -133,6 +133,21 @@ void lua_decode_integerp(lua_State *L, int idx, long long *num);
  */
 void *lua_tointegerp(lua_State *L, int idx);
 
+/*
+ * Converts a long long to a Lua value and pushes it on the stack.
+ */
+void lua_pushlonglongp(lua_State *L, const long long *num);
+
+void lua_decode_longlongp(lua_State *L, int idx, long long *num);
+
+/*
+ * Converts the Lua value at idx to a long long.
+ *
+ * Returns:
+ *    long long allocated with MTYPE_TMP.
+ */
+void *lua_tolonglongp(lua_State *L, int idx);
+
 void lua_decode_stringp(lua_State *L, int idx, char *str);
 
 /*
@@ -143,13 +158,6 @@ void lua_decode_stringp(lua_State *L, int idx, char *str);
  */
 void *lua_tostringp(lua_State *L, int idx);
 
-/*
- * No-op decoders
- */
-void lua_decode_noop(lua_State *L, int idx, const void *ptr);
-
-void lua_decode_integer_noop(lua_State *L, int idx, int i);
-
 /*
  * Retrieve an integer from table on the top of the stack.
  *

lib/frrscript.c

@@ -25,6 +25,8 @@ DEFINE_MTYPE_STATIC(LIB, SCRIPT, "Scripting");
 
 struct frrscript_names_head frrscript_names_hash;
 
+void _lua_decode_noop(lua_State *L, ...) {}
+
 /*
  * Wrapper for frrscript_names_add
  * Use this to register hook calls when a daemon starts up

lib/frrscript.h

@@ -180,6 +180,11 @@ void frrscript_fini(void);
 		assert(lua_gettop(lfs->L) == 1);                               \
 	} while (0)
 
+/*
+ * Noop function. Used below where we need a noop decoder for any type.
+ */
+void _lua_decode_noop(lua_State *, ...);
+
 /*
  * Maps the type of value to its encoder/decoder.
  * Add new mappings here.
@@ -192,7 +197,9 @@ void frrscript_fini(void);
 #define ENCODE_ARGS_WITH_STATE(L, value)                                       \
 	_Generic((value), \
 int : lua_pushinteger,                                          \
-long long * : lua_pushintegerp,                                 \
+int * : lua_pushintegerp,                                       \
+long long : lua_pushinteger,                                    \
+long long * : lua_pushlonglongp,                                \
 struct prefix * : lua_pushprefix,                               \
 struct interface * : lua_pushinterface,                         \
 struct in_addr * : lua_pushinaddr,                              \
@@ -211,8 +218,8 @@ struct zebra_dplane_ctx * : lua_pushzebra_dplane_ctx            \
 
 #define DECODE_ARGS_WITH_STATE(L, value)                                       \
 	_Generic((value), \
-int : lua_decode_integer_noop,                                  \
-long long * : lua_decode_integerp,                              \
+int * : lua_decode_integerp,                                    \
+long long * : lua_decode_longlongp,                             \
 struct prefix * : lua_decode_prefix,                            \
 struct interface * : lua_decode_interface,                      \
 struct in_addr * : lua_decode_inaddr,                           \
@@ -220,13 +227,7 @@ struct in6_addr * : lua_decode_in6addr,                         \
 union sockunion * : lua_decode_sockunion,                       \
 char * : lua_decode_stringp,                                    \
 struct attr * : lua_decode_attr,                                \
-struct peer * : lua_decode_noop,                                \
-const struct prefix * : lua_decode_noop,                        \
-const struct ipaddr * : lua_decode_noop,                        \
-const struct ethaddr * : lua_decode_noop,                       \
-const struct nexthop_group * : lua_decode_noop,                 \
-const struct nexthop * : lua_decode_noop,                       \
-struct zebra_dplane_ctx * : lua_decode_noop                     \
+default : _lua_decode_noop                                      \
 )((L), -1, (value))
 
 /*

tests/lib/test_frrlua.c

@@ -13,14 +13,22 @@ static void test_encode_decode(void)
 {
 	lua_State *L = luaL_newstate();
 
-	long long a = 123;
-	long long b = a;
+	int a = 123;
+	int b = a;
 
 	lua_pushintegerp(L, &a);
 	lua_decode_integerp(L, -1, &a);
 	assert(a == b);
 	assert(lua_gettop(L) == 0);
 
+	long long ll_a = 123L;
+	long long ll_b = a;
+
+	lua_pushlonglongp(L, &ll_a);
+	lua_decode_longlongp(L, -1, &ll_a);
+	assert(ll_a == ll_b);
+	assert(lua_gettop(L) == 0);
+
 	time_t time_a = 100;
 	time_t time_b;
 

tests/lib/test_frrscript.c

@@ -32,7 +32,7 @@ int main(int argc, char **argv)
 	assert(result == 0);
 	result = frrscript_call(fs, "bar", ("a", &a), ("b", &b));
 	assert(result == 0);
-	long long *cptr = frrscript_get_result(fs, "bar", "c", lua_tointegerp);
+	long long *cptr = frrscript_get_result(fs, "bar", "c", lua_tolonglongp);
 
 	/* a should not occur in the returned table in script */
 	assert(a == 100);
@@ -47,7 +47,7 @@ int main(int argc, char **argv)
 	result = frrscript_call(fs, "fact", ("n", &n));
 	assert(result == 0);
 	long long *ansptr =
-		frrscript_get_result(fs, "fact", "ans", lua_tointegerp);
+		frrscript_get_result(fs, "fact", "ans", lua_tolonglongp);
 	assert(*ansptr == 120);
 
 	/* check consecutive call + get_result without re-loading */