runtimehelper

Helpers for Go’s runtime package.

Install

go get github.com/solsw/runtimehelper

import "github.com/solsw/runtimehelper"

Overview

The package provides two groups of helpers:

• Caller names — retrieve the name of a function somewhere up the call stack.
• Name trimming — reduce a full function name (as returned by runtime.Func.Name) to just the package-qualified name or the bare function name.

API

Caller names

NthCallerName(n int) string

Returns the name of the n-th caller function of NthCallerName. On any failure an empty string is returned. The meaning of n matches runtime.Caller: 0 identifies NthCallerName itself, 1 its caller, and so on.

func work() string {
	return runtimehelper.NthCallerName(1) // "...work" — work itself (the direct caller)
}

NthCallerName(2) from inside work would instead return the name of whoever called work.

CallerName() string

Returns the name of the function that called CallerName.

func work() {
	name := runtimehelper.CallerName() // name of work's caller
	_ = name
}

CallerCallerName() string

Returns the name of the function that called the function that called CallerCallerName (one frame further up than CallerName).

CallerName and CallerCallerName are marked //go:noinline so they always occupy their own stack frame, keeping the fixed skip count passed to NthCallerName correct.

Name trimming

These operate on the full function name string returned by runtime.Func.Name, e.g. "github.com/solsw/pkg.Foo".

JustPackageFunctionName(funcName string) string

Returns just the function name preceded by the package name. Generic type parameters (e.g. "[int]") are stripped.

Input	Output
github.com/solsw/pkg.Foo	pkg.Foo
github.com/solsw/pkg.Foo[int,string]	pkg.Foo
pkg.Foo	pkg.Foo
Foo	Foo
(empty) | (empty)

JustFunctionName(funcName string) string

Returns just the function name. If funcName contains no package separator, it is returned (with generic type parameters stripped) unchanged.

Input	Output
github.com/solsw/pkg.Foo	Foo
github.com/solsw/pkg.Foo[int,string]	Foo
Foo	Foo
Foo[int]	Foo
(empty) | (empty)

Example

package main

import (
	"fmt"

	"github.com/solsw/runtimehelper"
)

func main() {
	full := runtimehelper.NthCallerName(1) // "main.main"
	fmt.Println(runtimehelper.JustPackageFunctionName(full)) // "main.main"
	fmt.Println(runtimehelper.JustFunctionName(full))        // "main"
}

This site is open source. Improve this page.