randlee · randlee · Jan 21, 2026 · Jan 20, 2026 · Jan 20, 2026 · Jan 20, 2026
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -13,6 +13,84 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Git integration (compare commits, branches)
 - F# support via FSharp.Compiler.Service
 
+## [0.8.0] - 2026-01-20
+
+### Added
+
+#### Impact Classification
+- **Automatic Impact Classification** - Every change is categorized by its potential impact on consumers
+  - Breaking Public API - Changes that break external consumers (method signature changes, removed public members)
+  - Breaking Internal API - Changes that break internal consumers (internal method renames, parameter changes)
+  - Non-Breaking - Safe changes with no execution impact (private field renames, code reordering)
+  - Formatting Only - Pure whitespace/comment changes
+- **Visibility Tracking** - Each change includes visibility information (public, internal, private, protected)
+- **Caveat Warnings** - Warnings for edge cases (e.g., "parameter rename may break named arguments")
+- **Impact Filtering** - Filter changes by impact level in JSON output
+
+#### Whitespace Intelligence
+- **4 Whitespace Modes** - Fine-grained whitespace handling
+  - Exact - Preserve all whitespace (default)
+  - IgnoreLeadingTrailing - Ignore leading/trailing whitespace
+  - IgnoreAll - Ignore all whitespace differences
+  - LanguageAware - Language-specific handling (exact for Python/YAML, normalized for C#/Java)
+- **Automatic Issue Detection** - Detects indentation changes, mixed tabs/spaces, trailing whitespace, line ending changes
+- **Whitespace Warnings** - Visual indicators in HTML output for whitespace issues
+- **CLI Options** - `--whitespace-mode` and `-w` shortcut for `--whitespace-mode ignore-all`
+
+#### Multi-Target Framework (Multi-TFM) Support
+- **Target Framework Analysis** - Analyze code differences across multiple .NET target frameworks simultaneously
+- **TFM-Specific Change Detection** - Identify which changes apply to specific target frameworks vs. all frameworks
+- **Conditional Compilation Awareness** - Properly handles `#if` directives and framework-specific code
+- **Per-TFM Semantic Analysis** - Runs full Roslyn analysis for each target framework with correct compilation symbols
+- **Parallel TFM Processing** - Optimized multi-TFM analysis with parallel processing
+
+#### CLI Enhancements
+- `--impact-level` - Filter by impact: `breaking-public`, `breaking-internal`, `non-breaking`, `all`
+- `--include-non-impactful` - Include non-breaking and formatting changes in JSON output
+- `--include-formatting` - Include formatting-only changes
+- `--whitespace-mode` - Whitespace handling mode
+- `--target-framework` / `-t` - Specify one or more target frameworks for analysis (can be repeated)
+- `-T` / `--target-frameworks` - Specify semicolon-separated list of target frameworks (e.g., "net8.0;net10.0")
+- TFM validation with helpful error messages for invalid framework identifiers
+- Support for common TFM formats: `net8.0`, `net10.0`, `netcoreapp3.1`, `netstandard2.0`, `net462`, etc.
+
+#### Output Format Enhancements
+- **Impact Indicators** - Color-coded impact badges in HTML, impact properties in JSON
+- **Whitespace Warnings** - Visual indicators for whitespace issues in HTML output
+- **TFM Annotations** - Target framework information in all output formats
+  - JSON: `targetFrameworks` array in metadata and `applicableToTfms` per change
+  - HTML: TFM badges and framework-specific indicators
+  - Text/Plain: TFM annotations like `[.NET 8.0]` for framework-specific changes
+
+#### Architecture Improvements
+- `ImpactClassifier` - Analyzes and classifies change impact
+- `WhitespaceAnalyzer` - Detects whitespace issues
+- `TfmSymbolResolver` - Maps TFMs to preprocessor symbols
+- `TfmParser` - Validates and parses TFM strings
+- `PreprocessorDirectiveDetector` - Pre-scan optimization for conditional compilation
+- `TfmResultMerger` - Intelligent merging of per-TFM analysis results
+- Enhanced `DiffResult` model with impact breakdown and TFM metadata
+- Enhanced `Change` model with `Impact`, `Visibility`, `Caveats`, and `ApplicableToTfms` properties
+
+#### Documentation
+- **Impact Classification Guide** (`docs/impact-classification.md`) - Complete guide to impact levels, filtering, and use cases
+- **Whitespace Handling Guide** (`docs/whitespace-handling.md`) - Whitespace modes and best practices
+- **Multi-TFM Support Guide** (`docs/tfm-support.md`) - Multi-target framework analysis and conditional compilation
+- Sample files demonstrating TFM scenarios and whitespace handling
+- Updated API documentation with programmatic examples
+
+### Changed
+- Enhanced `DiffOptions` with `ImpactLevel`, `IncludeNonImpactful`, `IncludeFormatting`, `WhitespaceMode`, and `TargetFrameworks` properties
+- Updated all output formatters to display impact, whitespace warnings, and TFM metadata
+- JSON output defaults to showing only breaking changes (`IncludeNonImpactful: false`)
+- HTML output defaults to showing all changes for review
+
+### Performance
+- Multi-TFM overhead is minimal (~2-2.5x for 3 frameworks vs. single framework)
+- Pre-scan optimization skips multi-TFM analysis when no `#if` directives exist
+- Parallel TFM processing where possible
+- Efficient change correlation algorithms
+
 ## [0.5.0] - 2026-01-15
 
 ### Added

diff --git a/README.md b/README.md
@@ -45,6 +45,19 @@ Fine-grained whitespace handling with language-aware detection:
 
 See [Whitespace Handling Guide](docs/whitespace-handling.md) for comprehensive details.
 
+### Multi-Target Framework Analysis (v0.8.0) 🎯
+
+Analyze code changes across multiple .NET target frameworks simultaneously:
+
+- **Multi-TFM diff support**: Compare code compiled for different target frameworks (net8.0, net10.0, etc.)
+- **Conditional compilation detection**: Identifies changes within `#if`, `#elif`, preprocessor blocks
+- **Symbol resolution**: Automatically resolves TFM-specific symbols (NET8_0, NET10_0_OR_GREATER, etc.)
+- **TFM-specific change tracking**: Each change indicates which frameworks it applies to
+- **Performance optimized**: Pre-scan detects preprocessor directives, skips multi-TFM analysis when not needed
+- **Parallel processing**: Analyzes multiple TFMs concurrently for faster results
+
+See [Multi-TFM Support Guide](docs/tfm-support.md) for comprehensive details.
+
 ### Core Features
 
 - **Semantic Diff** - Understands code structure, not just text changes
@@ -115,6 +128,25 @@ roslyn-diff diff old.cs new.cs --html report.html --open
 roslyn-diff diff old.cs new.cs --git
 ```
 
+### Multi-Target Framework Analysis
+
+```bash
+# Analyze for a single target framework
+roslyn-diff diff old.cs new.cs -t net8.0
+
+# Analyze multiple target frameworks (repeatable flag)
+roslyn-diff diff old.cs new.cs -t net8.0 -t net10.0
+
+# Analyze multiple TFMs (semicolon-separated)
+roslyn-diff diff old.cs new.cs -T "net8.0;net10.0"
+
+# Multi-TFM with JSON output
+roslyn-diff diff old.cs new.cs -t net8.0 -t net10.0 --json
+
+# Multi-TFM with HTML report
+roslyn-diff diff old.cs new.cs -T "net8.0;net9.0;net10.0" --html report.html --open
+```
+
 ### Compare Specific Classes
 
 ```bash
@@ -175,6 +207,12 @@ roslyn-diff diff <old-file> <new-file> [options]
 | `--whitespace-mode <mode>` | | Whitespace handling: `exact`, `ignore-leading-trailing`, `ignore-all`, `language-aware` | `exact` |
 | `--ignore-whitespace` | `-w` | Shortcut for `--whitespace-mode ignore-all` | `false` |
 
+**Multi-TFM Options (v0.8.0):**
+| Option | Short | Description | Default |
+|--------|-------|-------------|---------|
+| `--target-framework <tfm>` | `-t` | Target framework moniker (repeatable: `-t net8.0 -t net10.0`) | `null` (NET10_0 assumed) |
+| `--target-frameworks <tfms>` | `-T` | Semicolon-separated TFMs (e.g., `"net8.0;net10.0"`) | `null` |
+
 **Diff Mode Options:**
 | Option | Short | Description | Default |
 |--------|-------|-------------|---------|
@@ -249,8 +287,10 @@ roslyn-diff diff old.cs new.cs --json analysis.json
     "version": "0.8.0",
     "timestamp": "2026-01-19T22:45:12Z",
     "mode": "roslyn",
+    "analyzedTfms": ["net8.0", "net10.0"],
     "options": {
-      "includeNonImpactful": false
+      "includeNonImpactful": false,
+      "targetFrameworks": ["net8.0", "net10.0"]
     }
   },
   "summary": {
@@ -272,6 +312,7 @@ roslyn-diff diff old.cs new.cs --json analysis.json
       "name": "Process",
       "impact": "breakingPublicApi",
       "visibility": "public",
+      "applicableToTfms": ["net8.0", "net10.0"],
       "caveats": ["Parameter rename may break callers using named arguments"]
     }]
   }]
@@ -284,6 +325,7 @@ See [Output Formats Guide](docs/output-formats.md) for complete schema documenta
 
 Interactive HTML report with:
 - **Impact classification badges** - Color-coded indicators (Breaking Public API, Breaking Internal API, Non-Breaking, Formatting Only)
+- **TFM badges** - Framework-specific indicators (net8.0, net10.0) showing which TFMs each change applies to
 - **Caveat warnings** - Yellow warning boxes for edge cases (e.g., "Parameter rename may break named arguments")
 - **Whitespace issue indicators** - Warnings for indentation changes, mixed tabs/spaces, etc.
 - Side-by-side diff view with syntax highlighting
@@ -313,13 +355,14 @@ roslyn-diff diff old.cs new.cs --text
 ```
 Diff: old.cs -> new.cs
 Mode: Roslyn (semantic)
+Target Frameworks: net8.0, net10.0
 
 Summary: +2 (2 total changes)
 
 Changes:
   File: new.cs
-    [+] Method: Multiply (line 5-8)
-    [+] Method: Divide (line 10-13)
+    [+] Method: Multiply (line 5-8) [net8.0, net10.0]
+    [+] Method: Divide (line 10-13) [net8.0, net10.0]
 ```
 
 ### Git Unified Diff (`--git`)
@@ -525,6 +568,7 @@ See the [Synaptic Canvas documentation](https://github.com/randlee/synaptic-canv
 
 - **[Impact Classification Guide](docs/impact-classification.md)** - Complete guide to impact levels, filtering, caveats, and use cases (v0.7.0)
 - **[Whitespace Handling Guide](docs/whitespace-handling.md)** - Whitespace modes, language-aware detection, and best practices (v0.8.0)
+- **[Multi-TFM Support Guide](docs/tfm-support.md)** - Multi-target framework analysis, conditional compilation detection, and advanced scenarios (v0.8.0)
 - [Output Formats](docs/output-formats.md) - Format specifications, JSON Schema v2, and feature comparison
 - [Sample Outputs](samples/README.md) - Example diffs with impact classification