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,
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
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
10. A new token EXPOP should be added for the exponentiation operator. Its lexeme should
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
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 *)
3 function test1 returns boolean;
5 7 + 2 > 6 and 8 = 5 * (7 – 4);
Here is the required output for a program that contains more than one lexical error on the same
|1||— Function with two lexical errors|
3 function test2 returns integer;
5 7 $ 2 ^ (2 + 4);
Lexical Error, Invalid Character $
Lexical Error, Invalid Character ^
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
c. A discussion of lessons learned from the project and any improvements that could
|Criteria||Meets||Does Not Meet|
|Functionality||70 points||0 points|
|Defines new comment lexeme (5)||Does not define new comment lexeme|
|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|
|Defines additional relational operators|
|Does not define additional relational|
|Defines additional arithmetic operators|
|Does not define additional arithmetic|
|Defines additional reserved words and|
|Does not define additional reserved|
words and arrow symbol (0)
|Adds new tokens to the token header|
|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
|Implements modifications to count and|
display each type of compilation error
|Does not Implement modifications to|
count and display each type of
compilation error (0)
|Test Cases||15 points||0 points|
|Includes test case containing all|
|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|
|Documentation||15 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)