Description
Write a complete module used to maintain the symbol table for the SIC/XE assembler:
• use a binary search tree implementation to store each symbol along with its associated attributes
o exportable binary search tree operations: insert, search, view (non-class based: create, destroy)
Write a complete main/driver program that uses the symbol table module to process two text files:
• symtable.dat is used to populate the symbol table.
o file format (each line): SYMBOL RFLAG VALUE
▪ zero or more leading spaces in front of the SYMBOL attribute.
▪ one or more leading spaces in front of the RFLAG and VALUE attributes.
• search file used to search for symbols stored in the symbol table.
o search file name obtained from the command line.
o file format (each line): SYMBOL
▪ zero or more leading spaces in front of the SYMBOL attribute.
Basic Algorithm
1. read symbols and their attributes one line at a time from the file named symtable.dat.
o invalid symbols and/or invalid symbol attributes are not inserted into the symbol table.
▪ display the symbol/attribute along with a detailed error message.
o valid symbols with valid attributes are inserted into the symbol table.
2. read symbols one at a time from the search file.
o if no file name was specified on the command line then prompt the user for the file name.
o invalid symbol: display the symbol along with a detailed error message.
o valid symbol: search for the symbol in the symbol table (significant portion only).
▪ found: display the symbol and its associated attributes.
▪ not found: display the symbol along with a detailed error message.
3. perform an inorder traversal of the symbol table.
o display all symbols and associated attributes in a tabular format using output formatting techniques.
SYMBOL (also referred to as a label in assembly language programing)
• starts with a letter (A..Z, a..z).
• followed by letters (A..Z, a..z) and digits (0..9).
• maximum of 16 characters in length in the source program
o only the first 6 characters are significant.
o only the first 6 characters are stored in the symbol table.
• case sensitive (CSc354, CSc354S1 – same symbol – stored as CSc354).
• case sensitive (CSc354, CSC354 – not same symbol – stored as CSc354 & CSC354 respectively).
RFLAG (Boolean) // not case sensitive
• 0, false
• 1, true
VALUE
• signed integer value (–, 0..9).
IFLAG (Boolean)
• indicates whether or not a symbol has been defined within the current control section (true for now).
MFLAG (Boolean)
• indicates whether or not a symbol has been defined more than one time in the same control section.
• each valid symbol is inserted into the symbol table exactly one time (invalid symbols are never inserted).
Sample Program Run
Step #1 – symtable.dat // File names are case sensitive in Linux as well as some languages
ABCDEF True 50 // Valid – insert ABCDEF and all attributes into symbol table (*)
b123456 false -3 // Valid – insert b12345 and all attributes into symbol table (*)
a1B2c3D4e5F6g7H8 1 -45 // Valid – insert a1B2c3 and all attributes into symbol table (*)
abcdef 0 83 // Valid – insert abcdef and all attributes into symbol table (*)
1234567890 0 0 // ERROR – symbol must start with a letter: 1234567890
ABCDEFgh tRuE 100 // ERROR – symbol previously defined: ABCDEF (+)
a1B2c3D4e5F6g7H8i TRUE 0 // ERROR – symbol maximum length 16: a1B2c3D4e5F6g7H8i
a1234 FALSE 3.5 // ERROR – symbol a1234 invalid value: 3.5
XYZ F 100 // ERROR – symbol XYZ invalid rflag: F
(*) no message displayed for valid symbols with valid attributes – set IFLAG to true – set MFLAG to false
(+) set MFLAG attribute to true for symbol ABCDEF
Step #2 – search file
ABCDEF // Found – display symbol ABCDEF and all attributes
b12345XYZ // Found – display symbol b12345 and all attributes
CDEF // ERROR – CDEF not found in symbol table
abc_def // ERROR – symbols contain only letters and digits: abc_def
Step #3 – view the symbol table (required output order and format)
Symbol Value RFlag IFlag MFlag // Do not allow the data to scroll off screen
// Hold the output every 20 lines – Tera Term screen size
ABCDEF 50 1 1 1 // Continue when user indicates to do so
a1B2c3 -45 1 1 0
abcdef 83 0 1 0
b12345 -3 0 1 0 // Perform an inorder traversal of symbol table
Notes and Suggestions
• Do NOT stop on error!!! Process all data in both files completely!!! Display detailed error messages!!!
• Check for errors in all symbols and all symbol attributes read from both files
o Step #1 SYMBOL RFLAG VALUE
o Step #2 SYMBOL
o Only access the symbol table after verifying that the current symbol and all attributes are valid.
• All flag values were converted to 0 or 1 for ease of processing in the examples above.
Other Requirements
• The module/program must use proper data abstraction techniques.
o See the Assignment Requirements document on the course web site.
• All module/program files must be fully documented.
o See the Documentation Requirements document on the course web site.
• All C/C++ programs must compile and run using the Computer Science Linux server: cscssh.sdstate.edu
• All C# programs must compile and run as a Visual Studio Community 2017 Edition solution/project.
• All Java programs must compile and run as a NetBeans 8.2 project: Java SE 8 Update 144
• Zip all files together and send them to the account listed on the course syllabus before class on the due date.
o Visual Studio zip entire solution folder or project folder (if no solution folder was created).
o NetBeans zip entire project folder.
• All duplicate or near duplicate assignments will earn a grade of 0.
