Compilador Portugol para Python

You are an expert in the Portugol-to-Python educational compiler architecture. This compiler implements a classic 6-phase pipeline for translating Portugol (Portuguese-based pseudocode) into executable Python.

Architecture Overview

The compiler follows a unidirectional pipeline where each phase consumes the output of the previous phase without modifying earlier stages:

```

Source (.por) → Lexer (RE/DFA) → Parser → Semantic Analyzer → Intermediate Code (3-address) → Optimizer → Python Code Generator

```

Module Responsibilities

1. `lexer.py` - Lexical Analysis

2. `automaton.py` - Deterministic Finite Automata

3. `parser.py` - Syntax Analysis

4. `semantic.py` - Semantic Analysis

5. `intermediate.py` - Intermediate Code Generation

6. `optimizer.py` - Classic Optimizations

Implements:

7. `codegen.py` - Python Code Generation

8. `main.py` - Pipeline Orchestration

9. `compilar.py` - CLI Entry Point

Workflow Commands

```bash

Compile and execute

python compilar.py programa.por

Debug mode (shows all phases)

python compilar.py programa.por --debug

Generate intermediate code

python compilar.py programa.por --intermediate

Optimize intermediate code

python compilar.py programa.por --optimize

Save generated Python (don't execute)

python compilar.py programa.por --save

```

Adding New Language Features

Follow this exact sequence:

1. **Add token** to `ast_nodes.py` (`TipoToken` enum)

2. **Update keywords** in `lexer.py` (`palavras_chave` dict) if reserved word

3. **Create AST class** in `ast_nodes.py`

4. **Implement parsing** in `parser.py`

5. **Add semantic validation** in `semantic.py`

6. **Implement intermediate code generation** in `intermediate.py`

7. **Add optimization** in `optimizer.py` (if applicable)

8. **Implement Python generation** in `codegen.py`

Error Handling

Use custom exceptions from `exceptions.py`:

All exceptions include line/column for precise error location.

Portugol Language Patterns

Type System

Weak typing: semantic validation only, no runtime type checking.

Test Files

Common Pitfalls

1. **Lookahead:** Always use `self.token_atual` and `_avancar()` in parser

2. **Indentation:** Always use `_adicionar_linha()` in codegen

3. **Scope:** Only global scope is supported

4. **Comments:** Can appear anywhere; lexer must consume before tokenizing

5. **EOF:** Lexer must explicitly emit `TipoToken.EOF`

Environment Requirements

When Working on This Codebase

1. **Never modify earlier pipeline stages** when adding features to later stages

2. **Always test with `exemplos/demo_completa.por`** after any change

3. **Follow the 8-step process** for adding language features

4. **Maintain explicit DFA documentation** in `automaton.py` for any new tokens

5. **Use custom exceptions** with line/column information for all errors

6. **Respect the unidirectional pipeline** - data flows forward only