pyslang-verilog-context

pyslang-verilog-context

Use pyslang-mcp as read-only compiler-backed context for Verilog and SystemVerilog work. Keep normal file editing outside the MCP tools.

First Decision

Use pyslang-mcp when the answer depends on any of these:

• parse or semantic diagnostics
• filelist expansion, include dirs, or defines
• module, interface, or package inventory
• ports, declarations, child instances, or hierarchy
• declaration/reference lookup
• syntax-shape or preprocessing metadata
• RTL edits that should preserve an existing compile context

Use direct file reads and rg first for tiny lexical questions, comments, renames, or incomplete snippets where a compiler frontend cannot add much.

Workflow

1. Establish the HDL input boundary.

   • Prefer user-provided project_root, files, filelist, include dirs, defines, and top modules.
   • Otherwise infer the smallest conservative project root that contains the source set.
   • Keep all paths under project_root.

2. Load the project.

   • Use pyslang_parse_filelist for .f inputs.
   • Use pyslang_parse_files for explicit .sv, .svh, .v, or .vh inputs.
   • Pass known include_dirs, defines, and top_modules; do not invent them when the repo does not provide them.

3. Check diagnostics early.

   • Call pyslang_get_diagnostics before making structural claims.
   • Treat parse or semantic errors as primary evidence and explain how they limit downstream analysis.
   • Do not claim the RTL is functionally correct because diagnostics are clean.

4. Ask focused follow-up questions.

   • Use pyslang_list_design_units to discover modules, interfaces, and packages.
   • Use pyslang_describe_design_unit for ports, declarations, and child instances.
   • Use pyslang_get_hierarchy for instance tree questions.
   • Use pyslang_find_symbol for declarations and references.
   • Use pyslang_summarize_diagnostics_by_code before scanning long raw diagnostics in large RTL projects.
   • Use pyslang_find_member when the question is local to one design unit and pyslang_find_symbol is too broad.
   • Use pyslang_get_assignments for "what drives this signal" or "where is this signal used on the RHS" questions.
   • Use pyslang_get_instance_connections when one instance's port bindings are needed without a full hierarchy dump.
   • Use pyslang_trace_connectivity for bounded structural tracing through assignments and instance port bindings.
   • Use pyslang_preprocess_files for include/define questions.
   • Use pyslang_dump_syntax_tree_summary for syntax-shape questions.
   • Use pyslang_get_project_summary when a compact overview is enough.