svparse

README

svparse

An error-tolerant SystemVerilog/Verilog parser library for Go, built for language-server-style tooling: it never panics or stops on malformed or mid-edit source.

Capabilities

svparse is declaration-grade, not a full expression/statement parser:

• Parsed for real: ports, nets/variables, parameters, typedef/struct/enum, function/task signatures, class members, package imports, containers (module/interface/program), and instantiations.
• Intentionally not parsed: expression and statement grammar, and procedural block bodies (always, function/task bodies, constraint blocks). These are recognized and skipped via balanced-token matching, and kept as raw token spans on the AST rather than an expression tree.

The pipeline is layered across four packages:

Package	Role
token	Token vocabulary (Token{Kind, Text, Line, Character})
lexer	Scans source into a token stream
preprocessor	Macro expansion, conditional compilation, `include resolution, with source maps back to real positions
parser	Builds the ast.File declaration tree

Install

go get github.com/jfetkotto/svparse

Usage

import (
    "github.com/jfetkotto/svparse/parser"
    "github.com/jfetkotto/svparse/preprocessor"
)

toks, ppErrs := preprocessor.Preprocess(path, text, resolver)
file, parseErrs := parser.Parse(path, toks)

• lexer.Lex(src string) ([]token.Token, []Error): tokenize only.
• preprocessor.Preprocess(path, text string, resolver IncludeResolver) ([]Token, []Error): tokenize, expand macros, and resolve `includes. PreprocessWithOptions takes an Options struct for finer control.
• parser.Parse(path string, toks []preprocessor.Token) (*ast.File, []Error): parse preprocessed tokens into an ast.File.
• parser.ParseTokens(path string, toks []token.Token) (*ast.File, []Error): parse raw lexer tokens directly, skipping preprocessing.

None of these functions ever panic; malformed input is recorded in the returned []Error and parsing/lexing continues.

Testing

go test ./...

This runs unit and integration tests for every package, fuzz tests asserting the lexer/preprocessor/parser never panic on arbitrary input, and a corpus test (parser/corpus_test.go) that runs the parser over a vendored real-world SystemVerilog corpus under testdata/sv-tests/ against a checked-in baseline.

License

BSD 3-Clause. See LICENSE.