mini_compiler

Mini Compiler - CS F363 (Python)

Compiler construction project for CS F363, designed as a step-by-step implementation of core compiler phases.

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Goal

The goal was to build the full pipeline step by step:

• Lexical analysis
• Syntax analysis
• Semantic analysis + symbol table
• Intermediate code (TAC)
• Basic optimisation + pseudo assembly

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Implementation Status

Phase	Status
Lexical Analysis	Implemented
Syntax Analysis (Recursive Descent + AST)	Implemented
LL(1) Parser Evaluation	Implemented
SLR(1) Parser Evaluation	Implemented
FIRST/FOLLOW + Parsing Tables	Implemented
Symbol Table with Nested Scopes	Implemented
Semantic Analysis	Implemented
TAC Generation	Implemented
Optimization	Implemented
Target/Pseudo Assembly Generation	Implemented

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Architecture Snapshot

Source Program
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   v
Lexer
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   v
Token Stream
   |
   v
Parser (AST)
   |
   v
Symbol Table (Scoped Bindings)
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   v
Semantic Analyzer

Supporting parser-evaluation path:

• LL(1) stack trace
• SLR shift/reduce trace
• FIRST/FOLLOW and table construction materials

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Project Structure

Root

• compiler.py - main entry point (menu-driven compiler runner)
• README.md - project overview and run/demo guide
• contribution.md - team contribution details

reports/

• lexical_specification.md - formal lexical specification artifact

docs/

• 00_overall_compiler.md
• 01_lexer.md
• 02_parser.md
• 03_grammar.md
• 04_symbol_table.md
• 05_compiler_driver.md
• 06_semantic_analysis.md

testPrograms/

• evaluation_program.txt - official evaluation program
• demo.txt - integrated demo program
• Q1_Lexical/ ... Q8_Optimization_TargetCode/ - question-wise categorized tests

modules/

• tokens.py - token enums + error/report dataclasses
• lexer.py - lexical analyzer (regex-based scanner)
• parser.py - recursive-descent parser + AST node model
• grammar_utils.py - CFG, FIRST/FOLLOW, LL(1)/SLR table generation
• ll1_parser.py - LL(1) parser with trace
• slr_parser.py - SLR parser with trace
• syntax_analyzer.py - CFG/derivation/parse-tree display utilities
• symbol_table.py - AST-driven scoped symbol table
• semantic_analyzer.py - semantic checks using AST + symbol table
• tac_generator.py - planned module (not implemented yet)
• optimizer.py - planned module (not implemented yet)
• target_codegen.py - planned module (not implemented yet)

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Quick Start

Run with default source:

python compiler.py

Run with explicit file:

python compiler.py testPrograms/evaluation_program.txt

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Demo Flow (Evaluator-Friendly)

Use this sequence during viva/demo:

1. Run testPrograms/evaluation_program.txt
2. Option 2 -> token stream
3. Option 3 -> AST
4. Option 1 -> lexical/syntax/semantic summary
5. Option 8 -> symbol table trace + scoped tables
6. Options 4, 5, 7 -> LL(1)/SLR traces + FIRST/FOLLOW/tables
7. Option 9 -> TAC
8. Option 10 -> optimize target code

Error-case demonstration:

• Syntax errors: testPrograms/Q3_SyntaxErrors/
• Semantic errors: testPrograms/Q6_Semantic/

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Contributors

• Shambhavi Jha [2023A7PS0009U]
• Venkata Shreya Vella [2023A7PS0096U]
• Yuvaraj Nayak [2023A7PS0006U]
• Krishna Nagpal [2023A7PS0321U]