cmd/go: fix build config before creating actions for 'go list -cover'

When -covermode is set to atomic, instrumented packages need to import sync/atomic. If this is not already imported by a package being instrumented, the build needs to ensure that sync/atomic is compiled whenever 'go list' is run in a way that triggers package builds. The build config was already being made to ensure the import, but only after the action graph had been created, so there was no guarantee that sync/atomic would be built when needed. Fixes #65264. Change-Id: Ib3f1e102ce2ef554ea08330d9db69a8c98790ac5 Reviewed-on: https://go-review.googlesource.com/c/go/+/560236 Run-TryBot: Bryan Mills <bcmills@google.com> Auto-Submit: Bryan Mills <bcmills@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Bryan Mills <bcmills@google.com> Reviewed-by: Michael Matloob <matloob@golang.org>

Author: cixel

src/cmd/go/internal/list/list.go

@@ -725,16 +725,16 @@ func runList(ctx context.Context, cmd *base.Command, args []string) {
 b.IsCmdList = true
 b.NeedExport = *listExport
 b.NeedCompiledGoFiles = *listCompiled
+if cfg.Experiment.CoverageRedesign && cfg.BuildCover {
+load.PrepareForCoverageBuild(pkgs)
+}
 a := &work.Action{}
 // TODO: Use pkgsFilter?
 for _, p := range pkgs {
 if len(p.GoFiles)+len(p.CgoFiles) > 0 {
 a.Deps = append(a.Deps, b.AutoAction(work.ModeInstall, work.ModeInstall, p))
 }
 }
-if cfg.Experiment.CoverageRedesign && cfg.BuildCover {
-load.PrepareForCoverageBuild(pkgs)
-}
 b.Do(ctx, a)
 }
 

src/cmd/go/testdata/script/cover_list.txt

@@ -38,6 +38,10 @@ cp stdout $WORK/toolbuildid.txt
 # Build IDs should match here.
 cmp $WORK/toolbuildid.txt $WORK/listbuildid.txt
 
+# Make sure that the build succeeds regardless of covermode.
+go list -export -covermode=atomic m/example
+go list -export -covermode=count m/example
+
 -- go.mod --
 module m