这是一篇来自美国的关于运用GitHub存储库进行相关任务的编程代写，具体要求是开发一个更好地理解语义分析作为一个前端编译阶段。练习使用访问者模式来遍历AST和编码。实践编写单元测试，并开发一套整套解析器回归测试

Goals:

• Develop a better understanding of semantic analysis as a front-end compilation stage.
• Practice working with the visitor pattern for traversing and coding against the AST.
• Practice writing unit tests and develop a full suite of parser regression tests.

You are free to use whatever IDE and machine you prefer for this class. However, to complete the assignment, you will need git, g++ (version 11 or higher), cmake, make, the google test framework, and valgrind installed. It can also be useful to have a debugger such as gdb installed as well. Each of these are already installed on the remote development server (ada.gonzaga.edu) provided by the CS Department.

However, you may also install these programs on your own machine, via a virtual machine, running WSL2,or on your own remote server. Note that you will also need a GitHub account for obtaining starter code and for submitting your assignment.

Instructions:

1. Use the GitHub Classroom link (posted in Piazza) to copy the starter code into your own repository.

Clone the repository in the directory where you will be working on the assignment (e.g., onto ada or your own machine).

2. Copy your various implementation files to date into the HW5 src directory. Your lexer, simple parser, ast parser, and HW4 mypl file is is required for this assignment.

3. Modify your mypl.cpp program from HW-4 (see below).
4. Complete the SemanticChecker.
5. Ensure your code passes the unit tests provided in semantic_checer_tests.cpp within the tests subdirectory.

6. Ensure your parser correctly handles the example files provided within the examples subdirectory.

Note that correct handling here means running ./mypl –check over each file does not throw any errors and does not print anything.

7. Create ten additional unit tests for your SemanticChecker. Include a description of the tests you created in your homework writeup.

8. Create a short write up as a pdf file named hw5-writeup.pdf. For this assignment, your write up should provide a short description of any challenges and/or issues you faced in finishing the assignment and how you addressed them along with a description of each of the unit tests you created. Be sure your hw5-writeup.pdf file is in the main directory of your assignment (and not within the src directory or any other subdirectory).

9. Submit your program. Be sure to add, commit, and push all assignment files to your GitHub repo.

You can verify that your work has been submitted via the GitHub page for your repo.

Additional Requirements: Note that the majority of information related to this assignment will be provided in class, in lecture notes, and in the discussion section.

• Modify your mypl.cpp file from HW-4 so that the –check flag calls your semantic checker visitor.

Your code within mypl.cpp should look something like the following. Note that the snippet below assumes that the lexer has already been created.

try {

ASTParser parser(lexer);

Program p = parser.parse();

SemanticChecker v;

p.accept(v);

} catch (MyPLException& ex) {

cerr << ex.what() << endl;

}

• Be sure to look through the typing rules provided as part of the lectures. While not comprehensive in terms of all checks that must be performed by your SemanticChecker (e.g., see the unit tests), many of the details are captured in the typing rules.

• You must develop interesting and non-trivial unit tests for this assignment. There are a number of cases that are not covered in the unit tests. In addition, you might also try writing some MyPL programs to get a better sense of what could go wrong in terms of types, etc. Your write up should state why you thought each test would be interesting.

• While you have a good amount of time to finish the assignment, you will need to spread out your work and get started early. This is likely the most difficult assignment of the MyPL implementation steps.

Homework Submission and Grading. Your homework will be graded using the files you have pushed to your GitHub repository. Thus, you must ensure that all of the files needed to compile and run your code have been successfully pushed to your GitHub repo for the assignment. Note that this also includes your homework writeup. This homework assignment is worth a total of 30 points. The points will be allocated according to the following.

1. Correct and Complete (24 points). Your homework will be evaluated using a variety of different tests (for most assignments, via unit tests as well as test runs using specific files). Each failed test will result in a loss of 2 points. If 10 or more tests fail, but some tests pass, 4 points (out of the 24) will be awarded as partial credit. Note that all 24 points may be deducted if your code does not compile, large portions of work are missing or incomplete (e.g., stubbed out), and/or the specified techniques, design, or instructions were not followed.

2. Evidence and Quality of Testing (2 points). For each assignment, you must provide additional tests that you used to ensure your program works correctly. Note that for most assignments, a specific set of tests will be requested. A score of 0 is given if no additional tests are provided, 1 if the tests are only partially completed (e.g., missing tests) or the tests provided are of low quality,and 2 if the minimum number of tests are provided and are of sufficient quality.

3. Clean Code (2 points). In this class, “clean code” refers to consistent and proper code formatting (indentation, white space, new lines), use of appropriate comments throughout the code (including file headers), no debugging output, no commented out code, meaningful variable names and helper functions (if allowed), and overall well-organized, efficient, and straightforward code that uses standard coding techniques. In addition, when compiled, your code should not have any warnings. A score of 0 is given if there are major issues, 1 if there are minor issues, and 2 if the “cleanliness” of the code submitted is satisfactory for the assignment.

4. Writeup (2 points). Each assignment will require you to provide a small writeup addressing challenges you faced and how you addressed them as well as an explanation of the tests you developed.

Homework writeups do not need to be long, and instead, should be clear and concise. A score of 0 is given if no writeup is provided, 1 if parts are missing, and 2 if the writeup is satisfactory.