SWFRecomp: Differences Between wasm-support and master Branches

Overview

The wasm-support branch contains significant enhancements to the SWFRecomp project, adding WebAssembly build support, improved documentation, better build automation, and enhanced ActionScript variable handling. This document comprehensively lists all differences between the two branches.

Note: This document was updated on 2025-11-02 to reflect the current state of the branches. The wasm-hello-world example files and docs/ directory (GitHub Pages) were moved to SWFRecompDocs and are no longer part of this diff.

Statistics:

24 files changed
1,848 insertions (+)
72 deletions (-)
18 commits ahead of master

Commit History

The wasm-support branch includes 18 commits beyond master:

7dc144c - cleanup documentation and build artifacts
9ba9419 - variable optimization
961031e - updated next steps doc
21ee82e - added two more docs
f624fb6 - Implement StringAdd variable storage with Copy-on-Store
00b9801 - added STRING_VARIABLE_STORAGE_PLAN.md
ecbce76 - corrected several details in the documents
e285712 - added 2 font planning docs
2ade8d6 - minor document updates
03905a5 - added AS3_TEST_SWF_GENERATION_GUIDE.md
15edc43 - added ABC_PARSER_RESEARCH.md and ABC_IMPLEMENTATION_INFO.md
bf32dfe - added ABC_PARSER_GUIDE.md
f51802a - added 2 more planning docs, deprecated most of the old docs
abaa0e5 - added 3 more planning docs
41e103f - added 5 more planning docs
cf3892a - added AS3_IMPLEMENTATION_PLAN.md
8fef768 - initial commit for this fork

Major Changes by Category

1. Documentation (README.md)

Complete rewrite of the main README - transformed from a casual/experimental tone to professional project documentation.

Key Changes:

Project Description: Changed from "This is a stupid idea" to a proper technical description explaining it's a static recompiler for Flash SWF files
Added Live Demo Link: https://swfrecomp.github.io/SWFRecompDocs/
Added Comprehensive Sections:
- What is This? (explains static recompilation concept)
- Documentation (links to all guides)
- Quick Start (prerequisites, build instructions, examples)
- Project Structure (directory layout)
- How It Works (detailed workflow diagram)
- Current Features (feature status table)
- Related Projects (links to SWFModernRuntime, N64Recomp)
- Legal Note (Adobe Open Screen Project info)

New Features Documented:

Improved build system with automated builds
Better project structure with clean separation
Enhanced documentation with complete guides
WebAssembly examples that run in browser

Documentation Improvements:

Added step-by-step build instructions for both native and WASM
Added complete example workflow (from SWF to WASM)
Added visual workflow diagram showing compilation pipeline
Added feature status table
Added links to related projects

Tone Change:

From: Casual, self-deprecating ("This is a stupid idea. Let's do it anyway")
To: Professional, technical, comprehensive project documentation

Size: README grew from ~100 lines to ~266 lines

Note: The README references live demos at https://swfrecomp.github.io/SWFRecompDocs/ - these demo files are hosted in the SWFRecompDocs repository, not in SWFRecomp.

2. Core ActionScript Implementation Changes (src/action/action.cpp)

Major Enhancements to Variable Handling:

2.1 String Deduplication System

Added:

std::map<std::string, size_t> string_to_id - Tracks declared strings to prevent duplicates
getStringId() method - Retrieves ID for previously declared strings

Deduplication logic in declareString():

auto it = string_to_id.find(str);
if (it != string_to_id.end()) {
    // String already exists - don't create duplicate
    return;
}

Benefits:

Eliminates duplicate string constants in generated C code
Reduces memory footprint
More efficient code generation

2.2 Simplified Variable Operations

Changed GetVariable implementation:

// OLD:
temp_val = getVariable((char*) STACK_TOP_VALUE, STACK_TOP_N);
POP();
PUSH_VAR(temp_val);

// NEW:
actionGetVariable(stack, sp);

Changed SetVariable implementation:

// OLD:
temp_val = getVariable((char*) STACK_SECOND_TOP_VALUE, STACK_SECOND_TOP_N);
SET_VAR(temp_val, STACK_TOP_TYPE, STACK_TOP_N, STACK_TOP_VALUE);
POP_2();

// NEW:
actionSetVariable(stack, sp);

Benefits:

Cleaner generated code
Better encapsulation of variable operations
Easier to maintain and extend

2.3 Enhanced String Push with ID Tracking

Changed:

// OLD:
PUSH_STR(str_X, length);

// NEW:
PUSH_STR_ID(str_X, length, string_id);

Benefits:

Runtime can track string IDs for variable storage
Enables more efficient string variable handling
Supports Copy-on-Store optimization

2.4 MAX_STRING_ID Constant Generation

Added:

// Generate MAX_STRING_ID constant for runtime initialization
context.out_script_defs << endl << endl
    << "// Maximum string ID for variable array allocation" << endl
    << "#define MAX_STRING_ID " << next_str_i << endl;
context.out_script_decls << endl
    << "#define MAX_STRING_ID " << next_str_i << endl;

Benefits:

Runtime knows how many string variables to allocate
Enables static array allocation instead of dynamic
Better performance and memory management

3. Header Changes (include/action/action.hpp)

Added:

#include <map>  // For string deduplication

// In SWFAction class:
std::map<std::string, size_t> string_to_id;  // Track declared strings
size_t getStringId(const char* str);         // Get ID for previously declared string

4. New Test Cases

4.1 trace_swf_4 Test (Complete WASM Example)

NEW: Complete working example with automated builds

Added files:

tests/trace_swf_4/config.toml (4 lines) - Recompiler configuration
tests/trace_swf_4/Makefile (62 lines) - Automated native build
tests/trace_swf_4/build_wasm.sh (71 lines) - Automated WASM build
tests/trace_swf_4/README.md (186 lines) - Complete documentation

Native Runtime:

tests/trace_swf_4/runtime/native/include/recomp.h (105 lines)
tests/trace_swf_4/runtime/native/include/stackvalue.h (4 lines)
tests/trace_swf_4/runtime/native/main.c (6 lines)
tests/trace_swf_4/runtime/native/runtime.c (305 lines)

WASM Runtime:

tests/trace_swf_4/runtime/wasm/main.c (27 lines)
tests/trace_swf_4/runtime/wasm/recomp.h (62 lines)
tests/trace_swf_4/runtime/wasm/runtime.c (76 lines)
tests/trace_swf_4/runtime/wasm/stackvalue.h (4 lines)
tests/trace_swf_4/runtime/wasm/index.html (199 lines)

Features:

Complete build automation (no manual file copying)
Separate native and WASM runtime implementations
Comprehensive documentation
Working live demo

4.2 dyna_string_vars_swf_4 Test (Variable Storage)

NEW: Test case for dynamic string variable storage

Added files:

tests/dyna_string_vars_swf_4/config.toml (4 lines)
tests/dyna_string_vars_swf_4/test_main.c (12 lines)
tests/dyna_string_vars_swf_4/runtime/native/include/recomp.h (105 lines)
tests/dyna_string_vars_swf_4/runtime/native/include/stackvalue.h (4 lines)
tests/dyna_string_vars_swf_4/runtime/native/main.c (6 lines)
tests/dyna_string_vars_swf_4/runtime/native/runtime.c (305 lines)

Purpose:

Tests dynamic string variable storage
Tests Copy-on-Store optimization
Validates variable handling improvements

4.3 string_add_to_var_test

NEW: Documentation for string concatenation tests

Added files:

tests/string_add_to_var_test/README.md (35 lines)

Purpose:

Documents string concatenation behavior
Explains variable storage patterns

5. Build System Improvements

5.1 .gitignore Enhancements

Added entries:

NewDocs/
docs/specs/

# Temporary files
COMMIT_MESSAGE.txt

# Test executables
test_vars

Purpose:

Ignore documentation drafts
Ignore downloaded specifications
Ignore build artifacts
Ignore temporary files

5.2 Automated Build Scripts

trace_swf_4/Makefile Features:

Clean separation of source and build directories
Automatic directory creation
Native compilation with gcc
Proper dependency tracking
Clean target for rebuild

trace_swf_4/build_wasm.sh Features:

Emscripten environment setup
WASM compilation with emcc
Automatic file organization
HTML/JS generation
Output bundling for deployment

Benefits:

No manual file copying required
Reproducible builds
Clear build process
Easy deployment to GitHub Pages

File-by-File Summary

Modified Files (4 files)

README.md
- Complete rewrite: casual � professional
- Added: Quick start, documentation, examples, diagrams
- Size: ~100 lines � 266 lines
- +204 lines, -20 lines
.gitignore
- Added: NewDocs/, docs/specs/, COMMIT_MESSAGE.txt, test_vars
- +8 lines
include/action/action.hpp
- Added: std::map for string deduplication
- Added: getStringId() method
- +7 lines, -1 line
src/action/action.cpp
- Added: String deduplication system
- Changed: GetVariable/SetVariable to use action functions
- Changed: PUSH_STR � PUSH_STR_ID with ID tracking
- Added: MAX_STRING_ID constant generation
- +62 lines, -38 lines

New Files (20 files)

trace_swf_4 Test (13 files):

tests/trace_swf_4/config.toml (4 lines)
tests/trace_swf_4/Makefile (62 lines)
tests/trace_swf_4/build_wasm.sh (71 lines)
tests/trace_swf_4/README.md (186 lines)
tests/trace_swf_4/runtime/native/include/recomp.h (105 lines)
tests/trace_swf_4/runtime/native/include/stackvalue.h (4 lines)
tests/trace_swf_4/runtime/native/main.c (6 lines)
tests/trace_swf_4/runtime/native/runtime.c (305 lines)
tests/trace_swf_4/runtime/wasm/main.c (27 lines)
tests/trace_swf_4/runtime/wasm/recomp.h (62 lines)
tests/trace_swf_4/runtime/wasm/runtime.c (76 lines)
tests/trace_swf_4/runtime/wasm/stackvalue.h (4 lines)
tests/trace_swf_4/runtime/wasm/index.html (199 lines)

dyna_string_vars_swf_4 Test (6 files):

tests/dyna_string_vars_swf_4/config.toml (4 lines)
tests/dyna_string_vars_swf_4/test_main.c (12 lines)
tests/dyna_string_vars_swf_4/runtime/native/include/recomp.h (105 lines)
tests/dyna_string_vars_swf_4/runtime/native/include/stackvalue.h (4 lines)
tests/dyna_string_vars_swf_4/runtime/native/main.c (6 lines)
tests/dyna_string_vars_swf_4/runtime/native/runtime.c (305 lines)

string_add_to_var_test (1 file):

tests/string_add_to_var_test/README.md (35 lines)

Technical Improvements Summary

1. Code Quality

String Deduplication: Eliminates duplicate string constants
Cleaner Generated Code: Simplified variable operations
Better Encapsulation: Action functions instead of inline operations

2. Build System

Automated Builds: Makefile + build scripts
No Manual Steps: All file copying automated
Reproducible: Same results every time
Multi-Target: Native + WASM from same source

3. Documentation

Professional README: Complete project overview
Live Demos: Working examples in browser
Comprehensive Guides: Step-by-step instructions
Better Structure: Clear organization

4. WASM Support

Complete Pipeline: SWF � C � WASM
Working Examples: trace_swf_4 demo
Browser Integration: HTML + JavaScript interface
Deployment Ready: GitHub Pages compatible

5. Testing Infrastructure

Multiple Test Cases: trace_swf_4, dyna_string_vars_swf_4, string_add_to_var_test
Dual Runtimes: Native and WASM variants
Comprehensive Tests: Console output, variable storage, string operations

6. Variable Storage Optimization

Copy-on-Store: Efficient string variable handling
ID Tracking: Runtime can identify string literals
Static Allocation: MAX_STRING_ID enables fixed-size arrays
Memory Efficiency: Reduced allocations and copying

Impact Assessment

Compatibility

Backward Compatible: No breaking changes to master functionality
Additive Only: All changes are additions or improvements
Optional WASM: Native builds still work exactly as before

Performance

String Deduplication: Reduces code size and memory usage
Optimized Variables: Copy-on-Store reduces string copying
Static Allocation: MAX_STRING_ID enables compile-time sizing

Maintainability

Better Organization: Clear project structure
Comprehensive Docs: Easy for new contributors
Automated Testing: Build scripts make testing easier
Cleaner Code: Better encapsulation and separation

Usability

GitHub Pages: Live demos attract users
Quick Start: Easy to try out the project
Examples: Multiple working examples to learn from
Documentation: Complete guides for all workflows

Summary

The wasm-support branch represents a significant maturation of the SWFRecomp project:

Professional Documentation: Transformed from experimental project to production-ready
WebAssembly Support: Complete pipeline from SWF to browser-runnable WASM
Build Automation: No manual steps, reproducible builds
Code Quality: String deduplication, cleaner variable handling, better encapsulation
Live Demos: Working examples accessible via GitHub Pages
Testing Infrastructure: Multiple test cases with dual runtime support
Developer Experience: Comprehensive guides, clear structure, easy to contribute

Total Changes:

24 files changed (4 modified, 20 added)
1,848 additions
72 deletions
18 commits

Key Achievement: Successfully demonstrates SWF → C → WASM pipeline with live demo at https://swfrecomp.github.io/SWFRecompDocs/ (demos hosted in SWFRecompDocs repository)

This branch is ready for merging into master and represents the project's evolution from proof-of-concept to a viable tool for Flash preservation through static recompilation.

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SWFRecomp: Differences Between wasm-support and master Branches

Overview

Commit History

Major Changes by Category

1. Documentation (README.md)

2. Core ActionScript Implementation Changes (src/action/action.cpp)

2.1 String Deduplication System

2.2 Simplified Variable Operations

2.3 Enhanced String Push with ID Tracking

2.4 MAX_STRING_ID Constant Generation

3. Header Changes (include/action/action.hpp)

4. New Test Cases

4.1 trace_swf_4 Test (Complete WASM Example)

4.2 dyna_string_vars_swf_4 Test (Variable Storage)

4.3 string_add_to_var_test

5. Build System Improvements

5.1 .gitignore Enhancements

5.2 Automated Build Scripts

File-by-File Summary

Modified Files (4 files)

New Files (20 files)

Technical Improvements Summary

1. Code Quality

2. Build System

3. Documentation

4. WASM Support

5. Testing Infrastructure

6. Variable Storage Optimization

Impact Assessment

Compatibility

Performance

Maintainability

Usability

Summary

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swfrecomp-branch-differences.md

Latest commit

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swfrecomp-branch-differences.md

File metadata and controls

SWFRecomp: Differences Between wasm-support and master Branches

Overview

Commit History

Major Changes by Category

1. Documentation (README.md)

2. Core ActionScript Implementation Changes (src/action/action.cpp)

2.1 String Deduplication System

2.2 Simplified Variable Operations

2.3 Enhanced String Push with ID Tracking

2.4 MAX_STRING_ID Constant Generation

3. Header Changes (include/action/action.hpp)

4. New Test Cases

4.1 trace_swf_4 Test (Complete WASM Example)

4.2 dyna_string_vars_swf_4 Test (Variable Storage)

4.3 string_add_to_var_test

5. Build System Improvements

5.1 .gitignore Enhancements

5.2 Automated Build Scripts

File-by-File Summary

Modified Files (4 files)

New Files (20 files)

Technical Improvements Summary

1. Code Quality

2. Build System

3. Documentation

4. WASM Support

5. Testing Infrastructure

6. Variable Storage Optimization

Impact Assessment

Compatibility

Performance

Maintainability

Usability

Summary