Add YAML definition for code-related semantic attributes. (#1229)

* Introduce code-related semantic attributes.

* Generate table for `code` semantic attributes from the yaml spec.

* Update semantic_conventions/trace/general.yaml

Co-authored-by: Christian Neumüller <christian+github@neumueller.me>

* Update semantic_conventions/trace/general.yaml

Co-authored-by: Christian Neumüller <christian+github@neumueller.me>

* Generate table for `code` semantic attributes from the yaml spec.

* Revert line-endings-only change

* Better function name for code.function example.

Co-authored-by: Armin Ruech <armin.ruech@dynatrace.com>

Co-authored-by: Christian Neumüller <christian+github@neumueller.me>
Co-authored-by: Armin Ruech <armin.ruech@dynatrace.com>

semantic_conventions/trace/general.yaml

@@ -95,3 +95,29 @@ groups:
           with an [OAuth 2.0 Access Token](https://tools.ietf.org/html/rfc6749#section-3.3)
           or an attribute value in a [SAML 2.0 Assertion](http://docs.oasis-open.org/security/saml/Post2.0/sstc-saml-tech-overview-2.0.html).
         examples: 'read:message, write:files'
+  - id: code
+    prefix: code
+    brief: >
+      These attributes allow to report this unit of code and therefore to provide more context about the span.
+    attributes:
+      - id: function
+        type: string
+        brief: >
+          The method or function name, or equivalent (usually rightmost part of the code unit's name).
+        examples: serveRequest
+      - id: namespace
+        type: string
+        brief: >
+          The "namespace" within which `code.function` is defined. Usually the qualified class or module name,
+          such that `code.namespace` + some separator + `code.function` form a unique identifier for the code unit.
+        examples: com.example.MyHttpService
+      - id: filepath
+        type: string
+        brief: >
+          The source code file name that identifies the code unit as uniquely as possible (preferably an absolute file path).
+        examples: /usr/local/MyApplication/content_root/app/index.php
+      - id: lineno
+        type: number
+        brief: >
+          The line number in `code.filepath` best representing the operation. It SHOULD point within the code unit named in `code.function`.
+        examples: 42

specification/trace/semantic_conventions/span-general.md

@@ -168,9 +168,11 @@ For an HTTP server span, this would be the function that handles the incoming re
 The attributes listed below allow to report this unit of code and therefore to provide more context
 about the span.
 
+<!-- semconv code -->
 | Attribute  | Type | Description  | Example  | Required |
 |---|---|---|---|---|
 | `code.function` | string | The method or function name, or equivalent (usually rightmost part of the code unit's name). | `serveRequest` | No |
 | `code.namespace` | string | The "namespace" within which `code.function` is defined. Usually the qualified class or module name, such that `code.namespace` + some separator + `code.function` form a unique identifier for the code unit. | `com.example.MyHttpService` | No |
-| `code.filepath` | string | The source code file name that identifies the code unit as uniquely as possible (preferably an absolute file path). | `/usr/local/MyApplication/src/main/java/com/example/MyHttpService.java` | No |
+| `code.filepath` | string | The source code file name that identifies the code unit as uniquely as possible (preferably an absolute file path). | `/usr/local/MyApplication/content_root/app/index.php` | No |
 | `code.lineno` | number | The line number in `code.filepath` best representing the operation. It SHOULD point within the code unit named in `code.function`. | `42` | No |
+<!-- endsemconv -->