HDS COMPILER

The following repository holds the code for a compiler that compiles basic Python scripts, as a course project for CS335: Semester II (2024-25), under the guidance of Prof. Swarnendu Biswas. This compiler was made in a team of three which included me, along with Siddhant Jakhotiya and Danish Mehmood.

A near-to exhaustive list of the features supported by our compiler...

• Statically typed version of Python, supported. Basically C-like semantics in Python. View the examples in ./milestone3/tests/.
• Integer (int) and string (str) data types.
• 1-D lists of uniform data types.
• All basic arithmetic, relational logical, bitwise and augmented assigment operators supported. Note that ternary operations are not supported.
• Basic language features like the if-elif-else, while and for - loops supported. Note that the for loop supported is only of the type:

for i in range(a):
	# code

for i in range(a, b):
	# code

• Recursive methods supported.

• Support the library function print() for only printing the primitive Python types, one at a time.

• Support of classes and objects with a __init__ method, including multilevel inheritance and constructors, with their method calls supported and also access to members declared with a self directive.

• Static polymorphism via method overloading.

• The compiler requires the following block:

  if __name__ == "__main__":
  	# your function calls.
  

• Do note that format specifiers within print statements are not supported and neither are sequence of object receivers. import statements are not supported, no string operations except string comparison.

• Multiple function calls can be executed within a single line.

• Can return lists and class objects from functions and can also take them as arguments to function calls.

• Support for the len(array) within well-defined scopes.

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Requirements

Our compiler requires to have flex, bison installed along with the gcc compiler.

Working...

cd into the milestone3 directory and:

make

This generates our pycompiler.o

./pycompiler.o -i ../tests/test1.py -o graph.dot -a asm1.s -s sym_tab.csv -t tac.txt -v

is the complete set of flags, supported (optionally run ./pycompiler -h for more information). You can omit the -o, -t, -s, and -v flags. However, the -a flag is needed to generate the x86 code for the python script, which can be run using

./pyrun.sh asm1.s

You can optionally provide the .dot file (if generated using the -o from the pycompiler) to generate the AST (abstract symbol table) of the python script, in a .pdf file, much like:

./pyrun.sh asm1.s graph.dot 

The project is divided into 3 milestones, the first of which developed the frontend of the compiler, the lexer and the scanner. The second accomplished the making of the IR (intermediate representation) - 3AC code and the last milestone was based off around generating x86 code for the generated IR.

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~In small deeds do we live, in lesser we die...