The current AutoGen.c creates a function ProcessLibraryConstructorList() which
is called from the standard entry point for UEFI Shell applications. We
recently ran into a case where shell applications fail because of the lack of
error handling in this function. Currently, this function calls all of the
functions declared with CONSTRUCTOR in their INF. For example:
Status = __wchar_construct (ImageHandle, SystemTable);
ASSERT_EFI_ERROR (Status);
Status = UefiBootServicesTableLibConstructor (ImageHandle, SystemTable);
ASSERT_EFI_ERROR (Status);
Status = __Cons_construct (ImageHandle, SystemTable);
ASSERT_EFI_ERROR (Status);
Status = UefiRuntimeServicesTableLibConstructor (ImageHandle, SystemTable);
ASSERT_EFI_ERROR (Status);
The problem is that this function is a VOID. So, even if these constructors
fail, there is no way to terminate the application.
We found this issue where a CONSTRUCTOR function looked for a protocol and
returned an error if it failed. We always use the release version. It fails in
mysterious ways because the constructor function succeeds and then launched the
declared entry point, which tries to use a library function that uses the
protocol, which is some garbage value and goes off in the weeds.
Instead, this function should return a status code and _ModuleEntryPoint (from
UefiApplicationEntryPoint, etc.) should return EFI_LOAD_ERROR so that the
application will fail.
This would prevent undefined behavior when the protocol does not exist on a
platform. Otherwise the application (or the library) must still check for the
protocol pointer validity, which defeats the purpose of using a CONSTRUCTOR.
Tim
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