Adding C++ extractor + documentation

Author: dejo1307

ARCHITECTURE.md

@@ -111,7 +111,7 @@ File Walker ──▶ Extractors ──▶ Fact Store ──▶ Cross-Repo Linke
  (apply        (Go, Kotlin,    (indexed by     (only with 2+         (bidirectional)
   ignore        Python, TS,     kind / file /    repos loaded)             │
   globs)        Swift, Ruby,    name / repo)                               ▼
-                OpenAPI)                                              Explainers
+                C++, OpenAPI)                                         Explainers
                                                                   (cycles, layers,
                                                                      crossrepo)
                                                                           │
@@ -321,7 +321,7 @@ The bundled [`mcp-arch.yaml`](mcp-arch.yaml) ships a much fuller `ignore` list (
 |-------|-------------|---------|
 | `repo` | Repository root path | `"."` |
 | `ignore` | Glob patterns for files/dirs to skip | vendor, node_modules, .git, tests, build dirs, docs, config data, … |
-| `extractors` | Enabled extractors | `["go", "kotlin", "openapi", "python", "typescript", "swift", "ruby"]` |
+| `extractors` | Enabled extractors | `["cpp", "go", "kotlin", "openapi", "python", "typescript", "swift", "ruby"]` |
 | `explainers` | Enabled explainers | `["cycles", "layers", "crossrepo"]` |
 | `renderers` | Enabled renderers | `["llm_context"]` |
 | `output.dir` | Output directory for artifacts | `".enola"` |
@@ -341,6 +341,7 @@ Each extractor is detected by characteristic project files and then parses what
 | TypeScript | tree-sitter      | `tsconfig.json`, `tsconfig.base.json`, or `package.json` with TypeScript (root or one level deep) |
 | Swift      | tree-sitter      | `Package.swift`, `.xcodeproj`, or `.xcworkspace` present |
 | Ruby       | regex scanner    | `Gemfile` present |
+| C++        | tree-sitter      | a C++ source (`.cpp`/`.cc`/`.cxx`/`.hpp`/...) present, or a build file (`CMakeLists.txt`/`Makefile`/`meson.build`/`*.vcxproj`) plus any header |
 | OpenAPI    | YAML/JSON scanner| any file containing `openapi:` or `swagger:` |
 
 **Go** uses the standard-library parser directly, so symbols, methods, interfaces, imports, and call edges are exact.
@@ -357,6 +358,8 @@ Each extractor is detected by characteristic project files and then parses what
 
 **Ruby** is Rails-aware: ActiveRecord models (`has_many`, `belongs_to`, scopes, table inference), the route DSL in `config/routes.rb` (resources, namespaces, member/collection blocks), and Packwerk package boundaries (`package.yml` dependency enforcement). It also tracks modules, classes, methods with visibility, mixins (`include`/`extend`/`prepend`), `ActiveSupport::Concern`, constants, and attributes.
 
+**C++** is parsed with tree-sitter and handles the header/source split that defines the language. Classes, structs, unions, enums (incl. `enum class`), namespaces, free functions and methods, data members, and `typedef`/`using` aliases become symbol facts named `<dir>.<ns1::ns2::Class::member>` — enola's `<dir>.` module convention on the outside, native C++ `::` scope inside. Because an out-of-line definition `Class::method` (parsed from a `qualified_identifier`) yields the same canonical name as its in-class declaration, a dedup pass **merges a header's method prototype with its `.cpp` definition** into a single symbol (the definition wins for file/line and carries the call-graph edges). Base classes become `implements` edges; method bodies are walked for `calls`/`instantiates` edges; quoted `#include "x.h"` becomes a `dependency` resolved to the declaring module, while system `<...>` includes are skipped. Templates are unwrapped to their inner declaration and flagged `templated`, and the walker descends through `#if`/`#ifdef` preprocessor guards (so code wrapped in `#if defined(HAVE_*)` and headers behind include guards are still extracted). *Limitation:* header/source merging relies on the `.h` and `.cpp` living in the same directory (the common layout); split `include/` + `src/` trees are not merged.
+
 ---
 
 ## Output artifacts

README.md

@@ -101,13 +101,22 @@ Binaries are published for Linux, macOS (amd64/arm64), and Windows (amd64). You
 
 ### Connect it to your agent
 
-Add enola to your MCP client configuration. For example, in Cursor's `mcp.json`:
+**Claude Code** — register enola as an MCP server with one command. This assumes the `enola` binary is on your `PATH` (the install script above puts it in `~/.local/bin`):
+
+```bash
+claude mcp add enola enola /path/to/enola/mcp-arch.yaml
+```
+
+The shape is `claude mcp add <name> <command> [args…]`: the first `enola` names the server, the second is the binary, and the trailing path is the config it reads. That config's `repo:` is only the *default* repository — you can still snapshot any repo by passing `repo_path` to `generate_snapshot`. Verify it registered with `claude mcp list`, then start Claude Code and ask it to generate a snapshot.
+
+**Cursor / other MCP clients** — add enola to your client's MCP configuration. For example, in Cursor's `mcp.json`:
 
 ```json
 {
   "mcpServers": {
     "enola": {
-      "command": "enola"
+      "command": "enola",
+      "args": ["/path/to/enola/mcp-arch.yaml"]
     }
   }
 }
@@ -149,6 +158,7 @@ Working across several repos? Generate the first, then add the rest with append
 | Kotlin     | `build.gradle(.kts)` with Kotlin/Android (Compose / Hilt / Room aware) |
 | Swift      | `Package.swift`, `.xcodeproj`, `.xcworkspace` (SwiftUI / UIKit aware) |
 | Ruby       | `Gemfile` (Rails / ActiveRecord / Packwerk aware) |
+| C++        | `.cpp`/`.hpp`/… source or `CMakeLists.txt`/`Makefile` + header (header/source method merging, namespaces, templates) |
 | OpenAPI    | any spec with an `openapi:` / `swagger:` key |
 
 Framework- and platform-specific detection for each language is described in **[ARCHITECTURE.md → Supported languages](ARCHITECTURE.md#supported-languages)**.

examples/cpp.yaml

@@ -0,0 +1,51 @@
+# enola configuration for a C++ project.
+#
+# Detection: The C++ extractor activates when an unambiguous C++ source
+#            (.cpp/.cc/.cxx/.hpp/...) is present, or a build file
+#            (CMakeLists.txt/Makefile/meson.build/*.vcxproj) plus any header.
+# Features:  Classes, structs, unions, enums (incl. enum class), free functions
+#            and methods (inline AND out-of-line "Class::method" definitions,
+#            merged into one symbol), namespaces (qualified "<dir>.ns::Class::member"
+#            naming), inheritance edges (base classes), a call graph
+#            (calls / instantiations), and #include dependency edges. Templates are
+#            unwrapped and flagged; system <...> includes are skipped.
+
+repo: "."
+ignore:
+  # VCS and tooling
+  - ".git/**"
+  - ".enola/**"
+  # CMake / build output (at any depth)
+  - "build/**"
+  - "**/build/**"
+  - "cmake-build-*/**"
+  - "**/cmake-build-*/**"
+  - "CMakeFiles/**"
+  - "**/CMakeFiles/**"
+  - "**/*.o"
+  - "**/*.obj"
+  - "**/*.a"
+  - "**/*.so"
+  - "**/*.dylib"
+  # Vendored third-party code
+  - "contrib/**"
+  - "third_party/**"
+  - "extern/**"
+  # Pure C sources (handled by a future C extractor, not this one)
+  - "**/*.c"
+  # Documentation / config / data
+  - "**/*.md"
+  - "**/*.yml"
+  - "**/*.yaml"
+  - "**/*.json"
+extractors:
+  - cpp
+explainers:
+  - cycles
+  - layers
+  - crossrepo
+renderers:
+  - llm_context
+output:
+  dir: ".enola"
+  max_context_tokens: 16000

examples/full.yaml

@@ -10,6 +10,7 @@
 #   - typescript (detection: tsconfig.json or package.json with TypeScript)
 #   - swift      (detection: Package.swift, .xcodeproj, or .xcworkspace)
 #   - ruby       (detection: Gemfile)
+#   - cpp        (detection: .cpp/.hpp/... or CMakeLists.txt/Makefile + header)
 
 repo: "."
 ignore:
@@ -83,6 +84,7 @@ ignore:
   - "**/.env*"
 
 extractors:
+  - cpp
   - go
   - kotlin
   - typescript

go.mod

@@ -6,6 +6,7 @@ require (
 	github.com/modelcontextprotocol/go-sdk v1.3.0
 	github.com/tree-sitter-grammars/tree-sitter-kotlin v1.1.0
 	github.com/tree-sitter/go-tree-sitter v0.24.0
+	github.com/tree-sitter/tree-sitter-cpp v0.22.4-0.20240818224355-b1a4e2b25148
 	github.com/tree-sitter/tree-sitter-python v0.23.6
 	github.com/tree-sitter/tree-sitter-typescript v0.23.2
 	gopkg.in/yaml.v3 v3.0.1

go.sum

@@ -12,6 +12,8 @@ github.com/modelcontextprotocol/go-sdk v1.3.0 h1:gMfZkv3DzQF5q/DcQePo5rahEY+sguy
 github.com/modelcontextprotocol/go-sdk v1.3.0/go.mod h1:AnQ//Qc6+4nIyyrB4cxBU7UW9VibK4iOZBeyP/rF1IE=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/smacker/go-tree-sitter v0.0.0-20230720070738-0d0a9f78d8f8 h1:DxgjlvWYsb80WEN2Zv3WqJFAg2DKjUQJO6URGdf1x6Y=
+github.com/smacker/go-tree-sitter v0.0.0-20230720070738-0d0a9f78d8f8/go.mod h1:q99oHDsbP0xRwmn7Vmob8gbSMNyvJ83OauXPSuHQuKE=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 github.com/tree-sitter-grammars/tree-sitter-kotlin v1.1.0 h1:SWIUDASa+WPhDDem1U5IJpYwQEezkqXrUI61OcnORzM=

internal/config/config.go

@@ -57,7 +57,7 @@ func Default() *Config {
 			"**/Pods/**",
 			"**/.gradle/**",
 		},
-		Extractors: []string{"go", "kotlin", "openapi", "python", "typescript", "swift", "ruby"},
+		Extractors: []string{"cpp", "go", "kotlin", "openapi", "python", "typescript", "swift", "ruby"},
 		Explainers: []string{"cycles", "layers", "crossrepo"},
 		Renderers:  []string{"llm_context"},
 		Output: OutputConfig{