Simple Go Compiler

Directory Structure

• The grammar file for the Go (subset) language is located in the grammar directory.
• The necessary runtime library for ANTLR4 is in the lib directory
• All the source files are contained in src
  • ast: AST visitor & AST printer
  • commandlineparser: Simple command line parser
  • common: Cross-package classes
  • errorlisteners: Custom ANTLR error listeners to generate nicer error messages
  • functionresolver: First tree walk pass to collect function information
  • generated: Contains generated ANTLR classes
  • scopes: Environment class to facilitate scope-based symbol lookup
  • typechecking: Typechecking visitor
• Some example test cases for the compiler are in tests
  • All test cases can be run using the run_tests.py script
• The build.py script can be used to build the project
• The cleanup.py script is used to delete all .class files generated after compilation using javac

Dependencies

This project is built and executed using OpenJDK 16.0.2

λ java -version
openjdk version "16.0.2" 2021-07-20
OpenJDK Runtime Environment Temurin-16.0.2+7 (build 16.0.2+7)
OpenJDK 64-Bit Server VM Temurin-16.0.2+7 (build 16.0.2+7, mixed mode, sharing)

λ javac -version
javac 16.0.2

Also, ANTLR version 4.11.1 was used.

Building and running

NOTE: If you do not want to execute all these steps, there is a simple build.py script that automates everything.

1. It is first needed to generate the ANTLR base classes from the grammar file SimpleGo.g4

   SimpleGoCompiler being the current working directory, execute the following command:

   antlr4 -o src/generated -no-listener -visitor -package generated -Xexact-output-dir grammar/SimpleGo.g4

   As a result, a generated directory should be created inside of the src directory, containing all required ANTLR API base classes.

   NOTE: In case this command yields an error, make sure you have the ANTLR toolchain installed:

   pip install antlr4-tools

2. To build the actual project, execute the following commands:

   # Windows
   cd src
   javac -cp .;../lib/antlr-4.11.1-complete.jar SimpleGoCompiler.java -d ../build
   
   # Alternatively
   cd src
   set classpath=.;../lib/antlr-4.11.1-complete.jar
   javac SimpleGoCompiler.java -d ../build

   This will place all class files into the build directory.

3. Running the program is then simply done using:

   cd ../build
   java -cp .;../lib/antlr-4.11.1-complete.jar SimpleGoCompiler -compile <Test.go>

   Or if the classpath has been set temporarily using set:

   cd ../build
   java SimpleGoCompiler -compile <Test.go>

   Example:

   java SimpleGoCompiler -compile ../tests/test_fibonacci.go

Command line options

java SimpleGoCompiler [-compile | -liveness | -printast <true | false>] <Filename.go>

Options:
  -compile: Typechecks and compiles an input .go file into Jasmin bytecode.
  -liveness: Prints out the required number of registers to run program.
  -printast: Prints the AST. When given 'true', all node attributes are also printed.

Cleanup

The included cleanup.py script can be used to quickly get rid of .class files and the generated ANTLR files:

python cleanup.py [--clean-generated]