as: As Sections
4.3 Assembler Internal Sections
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These sections are meant only for the internal use of 'as'. They have
no meaning at run-time. You do not really need to know about these
sections for most purposes; but they can be mentioned in 'as' warning
messages, so it might be helpful to have an idea of their meanings to
'as'. These sections are used to permit the value of every expression
in your assembly language program to be a section-relative address.
ASSEMBLER-INTERNAL-LOGIC-ERROR!
An internal assembler logic error has been found. This means there
is a bug in the assembler.
expr section
The assembler stores complex expression internally as combinations
of symbols. When it needs to represent an expression as a symbol,
it puts it in the expr section.