17.28 Parameters for Precompiled Header Validity Checking
This hook returns the data needed by
TARGET_PCH_VALID_Pand sets *sz to the size of the data in bytes.
This hook checks whether the options used to create a PCH file are compatible with the current settings. It returns
NULLif so and a suitable error message if not. Error messages will be presented to the user and must be localized using _(msg).
data is the data that was returned by
TARGET_GET_PCH_VALIDITYwhen the PCH file was created and sz is the size of that data in bytes. It's safe to assume that the data was created by the same version of the compiler, so no format checking is needed.
The default definition of
default_pch_valid_pshould be suitable for most targets.
If this hook is nonnull, the default implementation of
TARGET_PCH_VALID_Pwill use it to check for compatible values of
target_flags. pch_flags specifies the value that
target_flagshad when the PCH file was created. The return value is the same as for