[dev.link] all: merge branch 'master' into dev.link

The only conflict is in cmd/internal/obj/link.go and the
resolution is trivial.

Change-Id: Ic79b760865a972a0ab68291d06386531d012de86

1 files changed, 22 insertions, 1 deletions

diff --git a/src/cmd/go/internal/work/build.go b/src/cmd/go/internal/work/build.go
index 6264593c34..45dd165ce0 100644
--- a/src/cmd/go/internal/work/build.go
+++ b/src/cmd/go/internal/work/build.go
@@ -102,6 +102,16 @@ and test commands:
 	-mod mode
 		module download mode to use: readonly or vendor.
 		See 'go help modules' for more.
+	-modcacherw
+		leave newly-created directories in the module cache read-write
+		instead of making them read-only.
+	-modfile file
+		in module aware mode, read (and possibly write) an alternate go.mod
+		file instead of the one in the module root directory. A file named
+		"go.mod" must still be present in order to determine the module root
+		directory, but it is not accessed. When -modfile is specified, an
+		alternate go.sum file is also used: its path is derived from the
+		-modfile flag by trimming the ".mod" extension and appending ".sum".
 	-pkgdir dir
 		install and load all packages from dir instead of the usual locations.
 		For example, when building with a non-standard configuration,
@@ -221,9 +231,10 @@ type BuildFlagMask int
 const (
 	DefaultBuildFlags BuildFlagMask = 0
 	OmitModFlag       BuildFlagMask = 1 << iota
+	OmitModCommonFlags
 )
 
-// addBuildFlags adds the flags common to the build, clean, get,
+// AddBuildFlags adds the flags common to the build, clean, get,
 // install, list, run, and test commands.
 func AddBuildFlags(cmd *base.Command, mask BuildFlagMask) {
 	cmd.Flag.BoolVar(&cfg.BuildA, "a", false, "")
@@ -240,6 +251,9 @@ func AddBuildFlags(cmd *base.Command, mask BuildFlagMask) {
 	if mask&OmitModFlag == 0 {
 		cmd.Flag.StringVar(&cfg.BuildMod, "mod", "", "")
 	}
+	if mask&OmitModCommonFlags == 0 {
+		AddModCommonFlags(cmd)
+	}
 	cmd.Flag.StringVar(&cfg.BuildContext.InstallSuffix, "installsuffix", "", "")
 	cmd.Flag.Var(&load.BuildLdflags, "ldflags", "")
 	cmd.Flag.BoolVar(&cfg.BuildLinkshared, "linkshared", false, "")
@@ -255,6 +269,13 @@ func AddBuildFlags(cmd *base.Command, mask BuildFlagMask) {
 	cmd.Flag.StringVar(&cfg.DebugActiongraph, "debug-actiongraph", "", "")
 }
 
+// AddModCommonFlags adds the module-related flags common to build commands
+// and 'go mod' subcommands.
+func AddModCommonFlags(cmd *base.Command) {
+	cmd.Flag.BoolVar(&cfg.ModCacheRW, "modcacherw", false, "")
+	cmd.Flag.StringVar(&cfg.ModFile, "modfile", "", "")
+}
+
 // tagsFlag is the implementation of the -tags flag.
 type tagsFlag []string