cmd/cgo: build failed when any code have CFLAGS: -Werror=unused-vairable · golang/go#8420

2014-07-24T09:45:13.000Z

by **Snyh1010**: 1. What is a short input program that triggers the error? package main //#cgo CFLAGS: -Werror=unused-variable //void test(){} import "C" func main() { C.test() } 2. What is the full compiler output? snyh:shm$go build # _/run/shm ./a.go: In function ‘_cgo_043ca501ac1f_Cfunc_test’: ./a.go:32:49: error: unused variable ‘a’ [-Werror=unused-variable] cc1: some warnings being treated as errors ------------------------------------------ I have fixed this by a CL https://golang.org/cl/118890044/ The CL( https://golang.org/cl/109640045) had fix this problem under gcc. The first time I hasn't notice clang, so when the CL has been submitted, it broken freebsd because clang. And the CL has been undo. The broken problem is not caused by my code, it's appeared upon the submission because the CL contains the test code let the problem appeared. I have fixed the problem both clang and gcc. But it seems no one have confidence to submit it this time, I have send the CL request. Anyway I want the problem be fixed, with or without my CL.

(6 comments) (0 reactions) (0 assignees)Go (19,008 forks)batch import

NeedsInvestigationhelp wanted

Repository metrics

Stars: (133,883 stars)
PR merge metrics: (No merged PRs in 30d)

Description

by Snyh1010:

Contributor guide

Research direction: Examine the cgo code generation to identify where an unused variable is introduced when compiling with Werror=unused variable. Look at the generated C code around the cgo ... functions and ensure the variable is either used or the flag is handled correctly.
Tech stack: goc
Domain: compilersbackend
Issue type: Bug
Difficulty: 3
Estimated time: 1-3 hours
Activity status: Active
Clarity: Clear
Prerequisites: GoC compiler
Newbie friendliness: 65

Repository metrics

Description

Contributor guide

Get fresh easy issues in your inbox.