docs: update README.md (#18)

README.md

@@ -64,4 +64,5 @@ Also there are several documents that you may find useful:
 
 - [How it works](./docs/how-it-works.md)
 - [How to add a new rule](./docs/how-to-add-a-new-rule.md)
-- [Discussion on this topic at OpenTelemetry community](https://github.com/open-telemetry/community/issues/1961)
+- [Discussion on this topic at OpenTelemetry community](https://github.com/open-telemetry/community/issues/1961)
+- [面向OpenTelemetry的Golang应用无侵入插桩技术](https://mp.weixin.qq.com/s/FKCwzRB5Ujhe1stOH2ibXg)

tool/instrument/trampoline.go

@@ -375,6 +375,17 @@ func (rp *RuleProcessor) replenishCallContext(onEnter bool) bool {
 	return false
 }
 
+// -----------------------------------------------------------------------------
+// Dynamic CallContext API Generation
+//
+// This is somewhat challenging, as we need to generate type-aware CallContext
+// APIs, which means we need to generate a bunch of switch statements to handle
+// different types of parameters. Different RawFuncs in the same package may have
+// different types of parameters, all of them should have their own CallContext
+// implementation, thus we need to generate a bunch of CallContextImpl{suffix}
+// types and methods to handle them. The suffix is generated based on the rule
+// suffix, so that we can distinguish them from each other.
+
 // implementCallContext effectively "implements" the CallContext interface by
 // renaming occurrences of CallContextImpl to CallContextImpl{suffix} in the
 // trampoline template