On Mon, Jan 16, 2023 at 11:29 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
Xing Guo <higuoxing@gmail.com> writes: > Are there any unsafe codes in pltcl.c? The return statement is in the > PG_CATCH() block, I think the exception stack has been recovered in > PG_CATCH block so the return statement in PG_CATCH block should be ok?
Yes, the stack has already been unwound at the start of a PG_CATCH (or PG_FINALLY) block, so there is no reason to avoid returning out of those.
In principle you could also mess things up with a "continue", "break", or "goto" leading out of PG_TRY. That's probably far less likely than "return", but I wonder whether Andres' compiler hack will catch that.
regards, tom lane
Thank you Tom,
Based on your comments, I've refactored my clang checker[1], now it can warn about the following patterns:
1. return statement in PG_TRY(). We've catched all of them in this thread.
2. continue statement in PG_TRY() *unless* it's in for/while/do-while statements.
3. break statement in PG_TRY() *unless* it's in for/while/do-while/switch statements.
4. goto statement in PG_TRY() *unless* the label it points to is in the same PG_TRY block.
Good news is that, there's no patterns (2, 3, 4) in Postgres source tree and we've catched all of the return statements in the PG_TRY block in this thread.
