Assembly toolchains: In which way(s) can a macro processor for an assembly language be implemented within a toolchain or assembler workflow?

Introduction / Context:
Macro processors expand parameterized templates into concrete assembly code, improving readability and reuse. Toolchain designers choose different integration points for macro expansion depending on performance and complexity requirements.

Given Data / Assumptions:

• We are considering macro expansion relative to an assembler’s passes.
• Possible approaches include separate preprocessors or integration into an assembler pass.
• All listed approaches are technically feasible.

Concept / Approach:

A macro system need only ensure that by the time symbol resolution and code generation occur, macros have been expanded. This can be done in a distinct one-pass or two-pass macro stage, or embedded in the first pass of a traditional two-pass assembler so that symbols introduced by expansions are properly recorded.

Step-by-Step Solution:

Verification / Alternative check:

Historical assemblers and modern toolchains document each approach (e.g., separate macro preprocessors versus integrated macro facilities in MASM/NASM/AS).

Why Other Options Are Wrong:

• Each single option alone is incomplete; multiple designs exist and are common.
• None of the above is incorrect because these are well-established methods.

Common Pitfalls:

Assuming macro expansion must be a separate preprocessor; overlooking symbol scope and forward reference handling which motivates integration with pass 1.

Final Answer:

all of the above