`run_process_utility_hook` is tangled everywhere, making logic hard to follow and properly review PRs

[steve-chavez]

Problem

Right now the different modules logic are tangled per statement and the standard hook (run_process_utility_hook) is scattered everywhere. This makes it hard to:

• maintain the code and to disable modules according to the pg version (pg 16: granting BYPASSRLS doesn't require SUPERUSER anymore #78, PostgreSQL 16 fixes the CREATEROLE problem #50 (comment)).

• properly review PRs, and we already had a consequence on fix: not allowing to alter schema on non-extension #100

  • essentially, we have many case statements that have a return instead of a break. It's easy to do a return in some cases and miss hitting the run_process_utility_hook.

Solution

Refactor the codebase so each module has a single entrypoint and the standard hook is always invoked in one single place. Basically:

static void
supautils_hook(PROCESS_UTILITY_PARAMS)
{
  Node   *utility_stmt = pstmt->utilityStmt;
  ret1 = privileged_role_setup(utility_stmt)
  ret2 = reserved_roles_setup(utility_stmt)
  ret3 = privileged_extensions_setup(utility_stmt)
  ret4 = constrained_extensions_setup(utility_stmt)
  
  run_process_utility_hook(prev_hook);

  cleanup(ret1, ret2, ret3, ret4); // or have multiple cleanups depending on the module