Golang x/tools/cmd/gorename: takes 20s+ for a package that imports cgo package

gorename is not usable for the program pasted below. That program imports a package that is build in cgo mode. The reason for this is the way gorename deals with cgo file. It processes them with the co preprocessor. The example below leads to this command being run (that takes 24 seconds): go tool cgo -objdir /var/folders/km/50gy6_q557v6_7vxbf9b29v00000gn/T/github.com_veandco_go-sdl2_sdl_C598351148 -- -D_THREAD_SAFE -I/opt/local/include/SDL2 -I /var/folders/km/50gy6_q557v6_7vxbf9b29v00000gn/T/github.com_veandco_go-sdl2_sdl_C598351148 audio.go blendmode.go clipboard.go cpuinfo.go endian.go error.go events.go filesystem.go gamecontroller.go gesture.go haptic.go hints.go joystick.go keyboard.go keycode.go loadso.go log.go mouse.go mutex.go pixels.go power.go rect.go render.go rwops.go scancode.go sdl.go sdl_cgo.go surface.go sysrender.go syswm.go timer.go touch.go version.go video.go

It's been called from parsePackageFiles of x/tools/go/loader/loader.go

I think it's a problem of go/loader.

@alandonovan, is there a way to fix this? I would be glad to tackle it.

% cat main.go
package main

import (
    "github.com/veandco/go-sdl2/sdl"
)

const w = 800
const h = 600

func main() {
    println(sdl.INIT_VIDEO)
}

% gtime gorename -v -offset=main.go:#66 -to A
gorename: Loading package: gorenameclib
gorename: Updating package gorenameclib

24.36user 4.18system 0:25.95elapsed 110%CPU (0avgtext+0avgdata 310689792maxresident)k
0inputs+55outputs (1major+1165748minor)pagefaults 0swaps

% go env
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/thorn/Library/Caches/go-build"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/thorn/go"
GOPROXY=""
GORACE=""
GOROOT="/Users/thorn/golang"
GOTMPDIR=""
GOTOOLDIR="/Users/thorn/golang/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/km/50gy6_q557v6_7vxbf9b29v00000gn/T/go-build052892133=/tmp/go-build -gno-record-gcc-switches -fno-common"

Comment From: ysmolski

Interesting, that it happened on that particular packaged mentioned above. I worked with other CGO packages and it was blazing fast.

Comment From: seankhliao

closing as obsoleted by #69360