CPL

Front-end for a made-up language as part of a compilers course.

Project Structure

• cpl.py - Driver program
• lexer.py - Reads the textual source-code and converts it into a stream of tokens described in tokens.py
• parser.py - Parses variable declarations and builds and AST out of the statements in the code. Also does semantic analysis.
• codegen.py - Divides the AST into basic-blocks, maps IR instructions into the back-end's instructions and finally flattens the instructions into a single sequence.
• quad.py - Contains conversions between IR instructions into Quad instructions.

Examples

CPL	Quad
/* Finding minimum between two numbers */ a, b: float; { input(a); input(b); if (a < b) output(a); else output(b); }	RINP a RINP b RLSS t1 a b JMPZ 7 t1 RPRT a JUMP 8 RPRT b HALT
/* Sum a variadic list of integers */ N, num, sum : int; { sum = 0; while (N > 0) { input(num); sum = sum + num; N = N - 1; } output(sum); }	IASN sum 0 IGRT t1 N 0 JMPZ 8 t1 IINP num IADD sum sum num ISUB N N 1 JUMP 2 IPRT sum HALT
/* Tell if an integer is prime */ N, p, limit, result : int; { result = 1; if (N < 2) result = 0; p = 2; limit = N / 2; while (p < limit) { if ((N / p) * p == N) { result = 0; break; } p = p + 1; } output(result); }	IASN result 1 ILSS t1 N 2 JMPZ 5 t1 IASN result 0 IASN p 2 IDIV limit N 2 ILSS t2 p limit JMPZ 17 t2 IDIV t3 N p IMLT t4 t3 p IEQL t5 t4 N JMPZ 15 t5 IASN result 0 JUMP 17 IADD p p 1 JUMP 7 IPRT result HALT
/* * Simple Calculator * Accepts two floats and outputs a float if successful. * On error, the output is an integer. Error values: * 1: Invalid operation * 2: Division by zero */ /* Input numbers */ A, B : float; /* * Desired operation: * - Addition=0 * - Subtraction=1 * - Multiplication=2 * - Divison=3 */ operation : int; { input(A); input(B); input(operation); switch (operation) { default: output(1); break; case 0: output(A + B); break; case 1: output(A - B); break; case 2: output(A * B); break; case 3: /* B is a float so the immediate 0 is * implicitly casted to a float */ if (B == 0) output(2); else output(A / B); break; } }	RINP A RINP B IINP operation INQL t1 operation 0 JMPZ 15 t1 INQL t2 operation 1 JMPZ 18 t2 INQL t3 operation 2 JMPZ 21 t3 INQL t4 operation 3 JMPZ 24 t4 JUMP 31 IPRT 1 JUMP 31 RADD t5 A B RPRT t5 JUMP 31 RSUB t6 A B RPRT t6 JUMP 31 RMLT t7 A B RPRT t7 JUMP 31 ITOR t8 0 REQL t9 B t8 JMPZ 29 t9 IPRT 2 JUMP 31 RDIV t10 A B RPRT t10 HALT