CMSC 430 Project 1

CMSC 430 Project 1
The first project involves modifying the attached lexical analyzer and the compilation listing
generator code. You need to make the following modifications to the lexical analyzer,
scanner.l:
1. A second type of comment should be added that begins with // and ends with the end of
line. As with the existing comment, no token should be returned.
2. The definition for the identifiers should be modified so that underscores can be included,
however, consecutive underscores, leading and trailing underscores should not be
permitted.
3. A real literal token should be added. It should begin with a sequence of one or more
digits following by a decimal point followed by zero or more additional digits. It may
optionally end with an exponent. If present, the exponent should begin with an e or E,
followed by an optional plus or minus sign followed by one or more digits. The token
should be named REAL_LITERAL.
4. A Boolean literal token should be added. It should have two lexemes, which are true and
false. The token should be named BOOL_LITERAL.
5. Two additional logical operators should be added. The lexeme for the first should be or
and its token should be OROP. The second logical operator added should be not and its
token should be NOTOP.
6. Five relational operators should be added. They are =, /=, >, >= and <=. All of the
lexemes should be represented by the single token RELOP.
7. One additional lexeme should be added for the ADDOP token. It is binary -.
8. One additional lexeme should be added for the MULOP token. It is/.
9. A new token REMOP should be added for the remainder operator. Its lexeme should be
rem.
10. A new token EXPOP should be added for the exponentiation operator. Its lexeme should
be **.
11. A new token ARROW should be added for the two character punctuation symbol =>.
12. The following reserved words should be added:
case, else, endcase, endif, if, others, real, then, when
Each reserved words should be a separate token. The token name should be the same as
the lexeme, but in all upper case.
You must also modify the header file tokens.h to include each the new tokens mentioned
above.
The compilation listing generator code should be modified as follows:
1. The lastLine function should be modified to compute the total number of errors. If any
errors occurred the number of lexical, syntactic and semantic errors should be displayed.
If no errors occurred, it should display Compiled Successfully. It should return the
total number of errors.
2. The appendError function should be modified to count the number of lexical, syntactic
and semantic errors. The error message passed to it should be added to a queue of
messages that occurred on that line.
3. The displayErrors function should be modified to display all the error messages that
have occurred on the previous line and then clear the queue of messages.
An example of the output of a program with no lexical errors is shown below:
1 (* Program with no errors *)
2
3 function test1 returns boolean;
4 begin
5 7 + 2 > 6 and 8 = 5 * (7 – 4);
6 end;
Compiled Successfully
Here is the required output for a program that contains more than one lexical error on the same
line:

1 — Function with two lexical errors
2

3 function test2 returns integer;
4 begin
5 7 $ 2 ^ (2 + 4);
Lexical Error, Invalid Character $
Lexical Error, Invalid Character ^
6 end;
Lexical Errors 2
Syntax Errors 0
Semantic Errors 0
You are to submit two files.
1. The first is a .zip file that contains all the source code for the project. The .zip file
should contain the flex input file, which should be a .l file, all .cc and .h files and a
makefile that builds the project.
2. The second is a Word document (PDF or RTF is also acceptable) that contains the
documentation for the project, which should include the following:
a. A discussion of how you approached the project
b. A test plan that includes test cases that you have created indicating what aspects
of the program each one is testing and a screen shot of your compiler run on that
test case
c. A discussion of lessons learned from the project and any improvements that could
be made
Grading Rubric

Criteria Meets Does Not Meet
Functionality70 points 0 points
Defines new comment lexeme (5) Does not define new comment lexeme
(0)
Correctly modifies identifier definition
to include underscores (5)
Does not correctly modify identifier
definition to include underscores (0)
Modifies integer literal token and adds
real and Boolean tokens (5)
Does not modify integer literal token
and add real and Boolean tokens (0)
Defines additional logical operators (5) Does not define additional logical
operators (0)
Defines additional relational operators
(5)
Does not define additional relational
operators (0)
Defines additional arithmetic operators
(5)
Does not define additional arithmetic
operators (0)
Defines additional reserved words and
arrow symbol(5)
Does not define additional reserved
words and arrow symbol (0)
Adds new tokens to the token header
file (5)
Does not add new tokens to the token
header file (0)
Implements modifications to display
multiple errors on the same line (15)
Does not implement modifications to
display multiple errors on the same line
(0)
Implements modifications to count and
display each type of compilation error
(15)
Does not Implement modifications to
count and display each type of
compilation error (0)
Test Cases15 points 0 points
Includes test case containing all
lexemes (5)
Does not include test case containing
all lexemes (0)
Includes test case with multiple errors
on one line (5)
Does not include test case with
multiple errors on one line (0)
Includes test case with no errors (5) Does not include test case with no
errors (0)
Documentation15 points 0 points
Discussion of approach included (5) Discussion of approach not included (0)
Lessons learned included (5) Lessons learned not included (0)
Comment blocks with student name,
project, date and code description
included in each file (5)
Comment blocks with student name,
project, date and code description not
included in each file (0)

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