race build does not respect race build tag

[dvyukov]

I am trying to build gvisor in race more:

git clone https://gvisor.googlesource.com/gvisor
cd gvisor
bazel build --features=race runsc

This will also require disabling pure mode for the binary, as it silently disables race more:

diff --git a/runsc/BUILD b/runsc/BUILD
index 2f0bbaf..c2e7510 100644
--- a/runsc/BUILD
+++ b/runsc/BUILD
@@ -7,7 +7,7 @@ go_binary(
     srcs = [
         "main.go",
     ],
-    pure = "on",
+    #pure = "on",
     visibility = [
         "//runsc:__subpackages__",
     ],

runsc/boot/filter/extra_filters_race.go file contains race build tag // +build race, but if I do:

diff --git a/runsc/boot/filter/extra_filters_race.go b/runsc/boot/filter/extra_filters_race.go
index c810773..b2599f1 100644
--- a/runsc/boot/filter/extra_filters_race.go
+++ b/runsc/boot/filter/extra_filters_race.go
@@ -22,6 +22,8 @@ import (
        "gvisor.googlesource.com/gvisor/pkg/seccomp"
 )
 
+this won't compile
+
 // instrumentationFilters returns additional filters for syscalls used by TSAN.
 func instrumentationFilters() seccomp.SyscallRules {
        Report("TSAN is enabled: syscall filters less restrictive!")

The build still passes. Which suggests that --features=race does not respect race tag.

Both --features=race and race = "on" binary attribute need to respect race build tag.

While we are here, it can make sense to do the same for msan and --features=msan, there is a similar file runsc/boot/filter/extra_filters_msan.go.

[dvyukov]

@amscanne @prattmic

[jayconrod]

Thanks for reporting. This was overlooked functionality. #1562 will enable race and msan tags in those modes.

[dvyukov]

After pulling this change into gvisor I am getting:

$ bazel build //runsc:runsc-race
INFO: Analysed target //runsc:runsc-race (0 packages loaded).
INFO: Found 1 target...
ERROR: /usr/local/google/home/dvyukov/.cache/bazel/_bazel_dvyukov/42571c499bb753a6e5c4fdf61e6007b2/external/org_golang_x_sys/unix/BUILD.bazel:3:1: GoCompile external/org_golang_x_sys/unix/linux_amd64_static_race_stripped/go_default_library~/golang.org/x/sys/unix.a~partial.a failed (Exit 1)
/usr/local/google/home/dvyukov/.cache/bazel/_bazel_dvyukov/42571c499bb753a6e5c4fdf61e6007b2/sandbox/linux-sandbox/4/execroot/__main__/bazel-out/k8-fastbuild/bin/external/org_golang_x_sys/unix/linux_amd64_stripped/go_default_library.cgo_codegen~/syscall_unix.cgo1.go:115:5: undefined: raceenabled

golang.org/x/sys has 2 files which define raceenabled :

$ head -n 10 /gopath/src/golang.org/x/sys/unix/race0.go 
// +build darwin,!race linux,!race freebsd,!race netbsd openbsd solaris dragonfly

$ head -n 10 /gopath/src/golang.org/x/sys/unix/race.go 
// +build darwin,race linux,race freebsd,race

Is it that bazel is somehow confused by these complex expressions in build tags?

[jayconrod]

Bazel is doing the right thing. The problem is that Gazelle is not including race.go in the srcs attribute for that rule because it doesn't recognize the race tag. I've filed bazel-contrib/bazel-gazelle#233 to track this.