test/codegen: document -all_codegen option in README
It is useful to know about the -all_codegen option for running
codegen tests for all platforms. I was puzzling that some codegen
test was not failing on my local machine or on trybot, until I
found this option.
Change-Id: I062cf4d73f6a6c9ebc2258195779d2dab21bc36d
Reviewed-on: https://go-review.googlesource.com/c/go/+/192101
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/test/codegen/README b/test/codegen/README
index f6877e7..1afefd9 100644
--- a/test/codegen/README
+++ b/test/codegen/README
@@ -30,6 +30,12 @@
toolchain from a released Go version (and verify that the new tests
fail), and then re-runnig the tests using the devel toolchain.
+By default, only checks that are relevant to the current GOOS/GOARCH
+are run. Checks for all platforms can be enabled by specifiying the
+-all_codegen option, as
+
+ $ ../bin/go run run.go -all_codegen codegen
+
- Regexps comments syntax
