extract-instructions-from-subsection

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Extract RISC-V instruction names from a named subsection of an AsciiDoc file and write them to /tmp/<subsection-title>.yaml.

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Extract all RISC-V instruction names mentioned in the specified subsection of the given AsciiDoc file, then write them to /tmp/<subsection-title>.yaml, where <subsection-title> is argument 1 lowercased with spaces replaced by hyphens (e.g., "Multiplication Operations" → /tmp/multiplication-operations.yaml).

Arguments

$ARGUMENTS

Argument 1: The subsection title to search for (e.g., "Multiplication Operations" or "Integer Register-Immediate Instructions").
Argument 2: Path to the AsciiDoc file (e.g., ext/riscv-isa-manual/src/m-st-ext.adoc).

If either argument is missing, ask the user to provide it.

Steps

1. Read the AsciiDoc file

Read the full content of the AsciiDoc file given as argument 2.

2. Locate the subsection

Find the subsection whose title matches argument 1. AsciiDoc section headings use = prefixes:

== Title — level 1 (chapter)
=== Title — level 2
==== Title — level 3
===== Title — level 4

Match the subsection title case-insensitively. The subsection's content starts on the line after the heading and ends just before the next heading of equal or higher level (i.e., same or fewer = characters).

3. Identify NOTE blocks to skip

Before scanning for instructions, mark all NOTE blocks in the subsection so they can be excluded. AsciiDoc NOTE blocks appear in two forms:

Delimited block: starts with [NOTE] followed by ==== on the next line, and ends at the closing ====.
Inline note: a single line starting with NOTE: (no delimiter).

Any instruction name that appears only inside NOTE blocks — and nowhere else in the subsection — must be excluded from the output. If an instruction appears both inside and outside a NOTE block, include it.

4. Extract instruction names

Scan the non-NOTE text of the subsection for RISC-V instruction names. Instruction names appear as uppercase tokens in the prose. Use the following rules to identify them:

Patterns that indicate an instruction name:

All-uppercase tokens of at least 2 characters that consist only of letters, and optionally digits or dots (e.g., ADD, ADDI, MULHSU, FENCE.TSO, LR.W, SC.D, C.ADD, C.ADDI16SP)
Uppercase tokens inside backticks: `ADD`, `JALR`
Uppercase tokens in AsciiDoc index entries: (((MUL, MULH))) — extract each comma-separated token
Uppercase tokens in AsciiDoc comment lines like //.Integer register-register — skip these (they are labels, not instructions)

Exclude pseudoinstructions: The prose explicitly signals pseudoinstructions with the phrase "assembler pseudoinstruction" or "pseudoinstruction" adjacent to the name, e.g.:

assembler pseudoinstruction SNEZ _rd, rs_
assembler pseudoinstruction MV _rd, rs1_
assembler pseudoinstruction SEQZ _rd, rs_
assembler pseudoinstruction NOT _rd, rs_
assembler pseudoinstruction J
assembler pseudoinstruction RET
assembler pseudoinstruction JR

Any token introduced by "pseudoinstruction" (with or without "assembler") must be excluded, even if it appears elsewhere in the subsection outside a pseudoinstruction context. Collect all pseudoinstruction names first, then exclude them from the final list.

Definitive exclusion list — never treat these as instructions: XLEN, RV32, RV64, RV32I, RV64I, RV128I, ISA, ABI, PC, CSR, IALIGN, BTB, RAS, FPGA, MIPS, RISC, RISCV, RISC-V

Tokens that are register names (x0–x31, rd, rs1, rs2) — exclude them.

5. Deduplicate and normalize

Convert all extracted names to lowercase (matching the RISC-V Unified Database YAML file naming convention, e.g., ADD → add, MULHSU → mulhsu, FENCE.TSO → fence.tso, LR.W → lr.w)
Remove duplicates
Sort alphabetically

6. Write the output

Derive the output filename from argument 1: lowercase it and replace spaces with hyphens (e.g., "Multiplication Operations" → multiplication-operations). Write /tmp/<derived-name>.yaml with the following format:

instructions:
  - add
  - addi
  - mul
  - mulh

Use the Write tool to create the file.

7. Report

Print a summary:

The subsection title found
The number of instructions extracted
The path written (e.g., /tmp/multiplication-operations.yaml)
The list of instructions

Example

For subsection "Multiplication Operations" in ext/riscv-isa-manual/src/m-st-ext.adoc, the output file is /tmp/multiplication-operations.yaml:

instructions:
  - mul
  - mulh
  - mulhsu
  - mulhu
  - mulw