“gobuild”后没有二进制符号
我正在关注这篇文章以了解 eBPF 跟踪的工作原理，第一步是识别函数的符号，示例代码取自此处：https : //github.com/pixie-labs/pixie-demos /blob/main/simple-gotracing/app/app.go
但是，在进行构建后，我无法找到该符号。为什么会这样？
$ ls
go.mod main.go
$ grep func main.go
func computeE(iterations int64) float64 {
func main() {
http.HandleFunc("/e", func(w http.ResponseWriter, r *http.Request) {
$ go build
$ objdump --syms ./demowebservice | grep compute
0000000000840a40 g O .bss 0000000000000008 crypto/elliptic.p256Precomputed
00000000008704c0 g O .noptrbss 000000000000000c crypto/elliptic.precomputeOnce
$
转到版本：-
$ go version
go version go1.16.5 linux/amd64
回答
您的computeE()函数将被内联，因此函数名称将不会在可执行二进制文件中留下“标记”。您可以使用go build -gcflags=-m查看inlined构建过程中正在使用哪些函数。
$ go build -gcflags=-m |& grep inlining
./main.go:24:17: inlining call to http.HandleFunc
./main.go:24:17: inlining call to http.(*ServeMux).HandleFunc
./main.go:43:12: inlining call to fmt.Printf
./main.go:44:28: inlining call to http.ListenAndServe
./main.go:46:13: inlining call to fmt.Printf
./main.go:40:53: inlining call to computeE <-- NOTE THIS
如果禁用内联：
//go:noinline
func computeE(iterations int64) float64 {
// ...
}
然后构建并再次检查：
$ go build -gcflags=-m |& grep inlining
./main.go:24:17: inlining call to http.HandleFunc
./main.go:24:17: inlining call to http.(*ServeMux).HandleFunc
./main.go:43:12: inlining call to fmt.Printf
./main.go:44:28: inlining call to http.ListenAndServe
./main.go:46:13: inlining call to fmt.Printf
$ objdump --syms ./demowebservice | grep compute
然后输出将是这样的：
000000000062a940 g F .text 000000000000004c main.computeE
0000000000840a40 g O .bss 0000000000000008 crypto/elliptic.p256Precomputed
00000000008704c0 g O .noptrbss 000000000000000c crypto/elliptic.precomputeOnce
参见相关：禁止在 golang 内联