I don't understand the code for following questions, I wonder if you can solve the following problem

3116 PM Tue Apr'ld 9'?32% 4 E studentcs.uwaterlooca CS 241 Winter 2020 Final Assessment Mgnments for 25 241 e Assignment 8 F inal Assessment Friday, March 27th, at 5:00 pm Monday, April 13th, at 5:00 pm P_1-m-m-m-m-m-ar-m-m-m-m-m-m-m In the Final Assessment you will complete the WLP4 compiler for which you wrote a scanner in Assignment 6, a parser in Assignment 7, and a context- sensitive analyzer in Assignment 8. For each problem, you will write a MIPS code generator for an increasingly larger subset of WLP4, culminating with a full WLP4-toMIPS compiler. Each code generator will be a Racket or C++ program that takes as input a .wlp4i le and, if it conforms to the context- sensitive syntax of WLP4, produces as output a MIPS .asm le that may be assembled with c5241 .binasm (or a new assembler called csZ41.linkasm for Problem 4 onwards) and then executed with mips.twoints or mips.array. For the Final Assessment, you should start with your context-sensitive analyzer from Assignment 8. However, all of the test inputs for the F inal Assessment will be valid WLP4 programs. Therefore, if you did not complete Assignment 8 to reject all invalid WLP4 programs, you can still use your partial solution as a starting point for the Final Assessment. In particular, if your program passes all non-blind tests for Assignment 8 Problems 1 to 5, you should have no issues doing the Final Assessment. Even if you do not pass all non-blind tests, you may still be ne provided the tests you fail only involve invalid programs. Additionally, for Problems 1 to 10, the only part of Assigrurient 8 you need is the symbol table. However, for Problem 11 and onwards you will need a working type checker. Grading Scheme The grading scheme for the assessment is divided into two portions: Marmoset tests and handmarking. The assessment itself is divided into four parts: Part 1: Returning values, arithmetic, and printing Part 2: Assignment statements and control structures Part 3: Pointers and memory allocation Part 4: Procedures Each part is worth 25% of the assessment grade. Since the assessment is worth 20% of your final grade, this means each part is worth 5% of your nal grade. Marmoset Tests The vast majority of your marks on this assessment will come from passing the tests on Mannoset. Abi g difference from the assignments is that this assessment has hidden tests which do not show up on Marmoset, but will still be worth marks! To make sure you pass these hidden tests, you should develop thorough test suites for each problem. Do not rely on Marmoset to do all your testing for you. 70% of the marks for Marmoset tests come from public and release tests, while the other 30% comes from hidden tests. We will not reveal the exact breakdown per problem. The mark values listed beside each problem {and shown on Marmoset) do not include hidden test marks, but they should give you an idea of the relative weight of the non-hidden tests for each problem. Handmarking There will be a small amount of marks based on the design and style of your code. We will not reveal exactly how much this factors into the assessment grade, but it will be a small portion. Our advice is to simply try your best to write good code and not worry about the exact percentage this will be worth. If your grade is low enough that you are concerned that handmarking will be the deciding factor in whether you pass the course, you should do the Bonus Essay (see below). Bonus Essay If you do not think you can pass the course based on the above grading scheme. or you are unsure whether you will pass (for example if passing depends on how many hidden test marks or handmarking marks you get) then you have the opportunity to increase your chances of passing by submitting an essay. This essay is not worth any marks (so students who are not close to failing should not submit one) but it will be used to determine whether borderline cases pass or fail the course. Submit by email directly to your instructor (Carmen or Mark) a 1000 word essay on how to write a compiler. We will not count words exactly but the essay should be no more than 2 pages, with 11 or 12 pt font and 0.75 inch margins all around. Again we must stress this is only for students who are failing or close to failing. This is a measure to give students who did poorly on the midterm a chance to pass. Do not submit an essay if you are doing well in the course as it will not affect your grade. Testing your Code Generator 3:17 PM Tue Apr 14 * 33% student.cs.uwaterloo.ca Testing your Code Generator You must test your code generator yourself in Linux. To test your code generator, you will need . wip4i files as generated by the parser specified in A7P5. In case you do not wish to use your own parser, you can use one that we have provided. Invoke it using the command wlp4parse. Starting from a . wip4 source file, the complete sequence of commands to generate MIPS machine language and run it is: wlp4scan foo . scanned wlp4parse foo. wlp4i racket wlp4gen.rkt foo. asm cs241 . binasm foo.mips mips . twoints foo.mips OR mips . array foo. mips OR wlp4scan foo. scanned wip4parse foo.wlp4i . /wlp4gen foo. asm cs241. binasm foo.mips mips . twoints foo. mips OR mips . array foo . mips This can be abbreviated to cat foo. wlp4 | wlp4scan | wlp4parse | racket wlp4gen. rkt | cs241. binasm > foo.mips mips . twoints foo. mip OR cat foo. wlp4 | wlp4scan | wlp4parse | ./wlp4gen | cs241. binasm > foo.mips mips . twoints foo.mips The above can be made much easier to do with a shell script. Part 1: Returning values, arithmetic, and printing Problem 1 - 8 marks (filename: wlp4gen . rkt or wlp4gen. cc) Write a code generator for correct WLP4 programs that conform to the syntax rules: start - BOF procedures EOF procedures - main main - INT WAIN LPAREN del COMMA del RPAREN LBRACE dcls statements RETURN expr SEMI RBRACE type - INT dcls - dol - type ID statements - expr - term term - factor factor - II You may assume that the test input is a valid WLP4 program that satisfies the context-sensitive syntax of WLP4, and whose derivation contains only the above production rules. Note: All that a WLP4 program conforming to this syntax can do is return the value of one of its parameters. Your MIPS output should assume that the parameter values are in $1 and $2 respectively, and return the result in $3. Click here to go back to the top of the Final Assessment. Problem 2 - 4 marks (filename: wlp4gen . rkt or wlp4gen. cc) Extend your solution for Problem 1 to handle inputs whose context-free syntax conforms to the rules for Problem 1, and in addition: factor - LPAREN expr RPAREN Click here to go back to the top of the Final Assessment. Problem 3 - 16 marks (filename: wip4gen . rkt or wlp4gen. cc) Extend your WLP4 compiler to handle WLP4 programs whose syntax is described by the production rules for Problems 1 and 2, and in addition: expr - expr PLUS term3:17 PM Tue Apr 14 * 33% A student.cs.uwaterloo.ca Problem 3 - 16 marks (filename: wlp4gen . rkt or wlp4gen .cc) Extend your WLP4 compiler to handle WLP4 programs whose syntax is described by the production rules for Problems 1 and 2, and in addition: expr - expr PLUS term expr - expr MINUS term term - term STAR factor term - term SLASH factor term - term PCT factor factor - NUM That is, you are to implement expressions with integer constants and the operators {+, -, *, /, %} You do not need to worry about integer overflow for this problem. In particular, for multiplication, you should use mflo to get the result and ignore the value in the hi register. Click here to go back to the top of the Final Assessment. Problem 4- 12 marks (filename: wlp4gen . rkt or wlp4gen. cc) Extend your WLP4 compiler to handle WLP4 programs whose syntax is described by the production rules for Problems 1 to 3, and in addition: statements - statements statement statement - PRINTLN LPAREN expr RPAREN SEMI That is, you are to implement the printIn statement. You may use the provided print.merl module to implement the printin statement. You must download this file from the link in the previous sentence and transfer it to your Linux environment account - it is not accessed using source /u/cs241/setup. (If you are unable to access this file and you are enrolled in the course, contact the ISA at cs241@uwaterloo.ca.) The output from your compiler should now and henceforth be an assembly source file containing the line: . import print The . import directive lets you use a procedure from an external file via linking. You can assemble files containing . import directives by using cs241 . linkasm instead of cs241 . binasm. This assembler generates MERL files (MIPS assembly language programs with extra metadata to allow for relocation and linking). You should link this file with the library print.merl that we provide, using the command cs241. linker. This library contains a procedure labelled print, which outputs a decimal representation of the number passed to it in register $1. For example, you could assemble, link, and run the output of your code generator using the following commands: cs241 . linkasm output.merl cs241 . linker output . merl print . merl > final .mips mips . twoints final . mips Click here to go back to the top of the Final Assessment. Part 2: Assignment statements and control structures Problem 5- 6 marks (filename: wlp4gen . rkt or wlp4gen. cc) Extend your WLP4 compiler to handle variable declarations and assignment statements. Your solution should handle WLP4 programs whose syntax conforms to the rules given in Problems 1 to 4, and in addition: dels - dels del BECOMES NUM SEMI statement - Ivalue BECOMES expr SEMI 1value - ID 1value - LPAREN Ivalue RPAREN Click here to go back to the top of the Final Assessment. Problem 6 - 8 marks (filename: wlp4gen . rkt or wlp4gen . cc) Extend your WLP4 compiler to handle WLP4 programs whose syntax is described by the production rules in Problems 1 to 5 and in addition: test - expr LT expr statement - WHILE LPAREN test RPAREN LBRACE statements RBRACE That is, you are to implement while loops whose continuation condition is expressed with "