Problem

The WT_RET_MSG_CHK macro introduced in WT-17565 (PR #13821) fails to compile when used in a function because it internally calls WT_RET_MSG, which declares its own int _ret = (v). This creates a nested declaration that shadows the outer _ret from WT_RET_MSG_CHK's own do { } while(0) block, triggering -Werror,-Wshadow and -Werror,-Wuninitialized:

error: declaration shadows a local variable [-Werror,-Wshadow]
error: variable '__ret' is uninitialized when used within its own initialization [-Werror,-Wuninitialized]

The self-initialization happens because when WT_RET_MSG(session, _ret, ...) is expanded, the inner int __ret = (ret) refers to itself rather than the outer _ret (which was shadowed at the point of declaration).

The analogous WT_ERR_MSG_CHK macro does not have this problem because WT_ERR_MSG does not declare a new __ret variable — it uses the existing ret in scope and jumps to err:.

Fix

Inline the body of WT_RET_MSG directly inside WT_RET_MSG_CHK instead of calling the macro, so there is only one __ret declaration:

#define WT_RET_MSG_CHK(session, v, ...)                                \
    do {                                                               \
        int __ret = (v);                                               \
        if (__ret != 0) {                                              \
            __wt_error_log_add_helper(#v, __ret, WT_NONE);            \
            __wt_err(session, __ret, __VA_ARGS__);                     \
            __wt_session_set_last_error(session, __ret, WT_NONE, __VA_ARGS__); \
            return (__ret);                                            \
        }                                                              \
    } while (0)

Discovery

Found while adding the first callsite of WT_RET_MSG_CHK in WT-17550.