We had better memorialize what the actual requirements are for this.
* not without taking thought for what will happen during ereport(FATAL).
* The PG_ENSURE_ERROR_CLEANUP macros provided by storage/ipc.h may be
* helpful in such cases.
+ *
+ * Note: if a local variable of the function containing PG_TRY is modified
+ * in the PG_TRY section and used in the PG_CATCH section, that variable
+ * must be declared "volatile" for POSIX compliance. This is not mere
+ * pedantry; we have seen bugs from compilers improperly optimizing code
+ * away when such a variable was not marked. Beware that gcc's -Wclobbered
+ * warnings are just about entirely useless for catching such oversights.
*----------
*/
#define PG_TRY() \