From a2a2ef62ecb8a349eae0cd90df75c44f5e7e83a5 Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Thu, 26 Jan 2017 13:13:18 -0800 Subject: [PATCH 1/2] Add castNode(type, ptr) for safe casting between NodeTag based types. Author: Peter Eisentraut and Andres Freund Discussion: https://postgr.es/m/c5d387d9-3440-f5e0-f9d4-71d53b9fbe52@2ndquadrant.com --- src/include/nodes/nodes.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h index fa4932a902..b462a5ffde 100644 --- a/src/include/nodes/nodes.h +++ b/src/include/nodes/nodes.h @@ -558,6 +558,26 @@ extern PGDLLIMPORT Node *newNodeMacroHolder; #define IsA(nodeptr,_type_) (nodeTag(nodeptr) == T_##_type_) +/* + * castNode(type, ptr) casts ptr to type and, if cassert is enabled, verifies + * that the the c actually has the appropriate type (using it's nodeTag()). + * + * Use an inline function when assertions are enabled, to avoid multiple + * evaluations of the ptr argument (which could e.g. be a function call). + */ +#ifdef USE_ASSERT_CHECKING +static inline Node* +castNodeImpl(enum NodeTag type, void *ptr) +{ + Assert(ptr == NULL || nodeTag(ptr) == type); + return ptr; +} +#define castNode(_type_, nodeptr) ((_type_ *) castNodeImpl(T_##_type_, nodeptr)) +#else +#define castNode(_type_,nodeptr) ((_type_ *)(nodeptr)) +#endif + + /* ---------------------------------------------------------------- * extern declarations follow * ---------------------------------------------------------------- -- 2.11.0.22.g8d7a455.dirty