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Fix ScriptHook_t initialization order #320

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Fix ScriptHook_t initialization order #320

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Commits on Sep 5, 2024

  1. Fix ScriptHook_t initialization order 

    When a ScriptClassDesc_t for is initialized (SCRIPTDESC), it recursively
invokes its parents initializers in order to obtain their pHelper
member.
Initialization is only done once, so repeated initialization is skipped.
Initialization includes assignment of a vector of ScriptHook_t's
(DEFINE_SCRIPTFUNC/BEGIN_SCRIPTHOOK), which must be initialized
beforehand.
Both of these use (static) globals; Within a translation unit,
initialization order is defined to be the same as the order of
declaration. So within a translation unit we must define all
ScriptHook_t's before the ScriptClassDesc_t using them.
A problem occurs with the parent initialization though, since there is
no defined order between translation units, meaning initialization of a
ScriptClassDesc_t can happen before its ScriptHook_t's, despite being
the correct order within its translation unit.

On MSVC it seems this issue is benign. On GCC/Linux however the
initialization of a ScriptHook_t essentially cleared whatever happened
during the initialization of the ScriptClassDesc_t, meaning many hooks
simply didn't work.

This situation is remedied by delaying the initialization of the
ScriptClassDesc_t's ScriptHook_t vector to only when the constructor of
it is invoked from its translation unit. This is accomplished simply by
adding a boolean parameter to the function (GetScriptDesc()) that is
true in the global constructor invocation, and false by default
(including when doing parent ScriptClassDesc_t initialization).
When false, a valid ScriptClassDesc_t pointer is still returned, with
the proper value for pHelper, which is all that is needed for the
initialization of the child ScriptClassDesc_t. The value of the returned
pointer is a fixed memory location, and does not change due to the
delayed initialization.

Fixes entropy-zero#244.
    @z33ky
    z33ky committed Sep 5, 2024
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