cmd/go: refactor -mod flag parsing

Keep track of whether the -mod flag was set explicitly. When
-mod=readonly is the default, we'll want to adjust our error messages
if it's set explicitly.

Also, register the -mod, -modcacherw, and -modfile flags in functions
in internal/base instead of internal/work. 'go mod' commands that
don't load packages shouldn't depend on internal/work.

For #40728

Change-Id: I272aea9e19908ba37e151baac4ea8630e90f241f
Run-TryBot: Jay Conrod <>
TryBot-Result: Gobot Gobot <>
Reviewed-by: Michael Matloob <>
Reviewed-by: Bryan C. Mills <>
14 files changed
tree: 100ee42a33775207098a2e8e70f12cd1bc976bed
  1. .gitattributes
  2. .github/
  3. .gitignore
  11. api/
  12. doc/
  13. favicon.ico
  14. lib/
  15. misc/
  16. robots.txt
  17. src/
  18. test/

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