From 0ebd5a8de05823109263bef31b38be8c29d2cd54 Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Mon, 21 Jun 2021 14:48:54 -0700 Subject: [PATCH] cmd/go: update ToolTags based on GOARCH value The build.Context ToolTags value is set based on the set of enabled experiments, which in turn depends on GOARCH. Before this CL the set of experiments was being set based on GOARCH in the environment. That is normally fine, but fails with cmd/go when somebody has run "go env -w GOARCH=val"; in that case cmd/go changes its GOARCH value after initialization. The new GOARCH value was affect the set of enabled experiments, which can affect the ToolTags value. With this CL, we update ToolTags in cmd/go based on the GOARCH value it is using. This is a pretty ugly fix. We should do something cleaner for 1.18. Fixes #46815 Change-Id: Ie9416781a168248813c3da8afdc257acdd3fef7e Reviewed-on: https://go-review.googlesource.com/c/go/+/329930 Trust: Ian Lance Taylor Run-TryBot: Ian Lance Taylor TryBot-Result: Go Bot Reviewed-by: Matthew Dempsky --- src/cmd/go/internal/cfg/cfg.go | 8 +++++ .../go/testdata/script/env_cross_build.txt | 29 +++++++++++++++++++ src/internal/buildcfg/exp.go | 13 +++++++-- 3 files changed, 47 insertions(+), 3 deletions(-) create mode 100644 src/cmd/go/testdata/script/env_cross_build.txt diff --git a/src/cmd/go/internal/cfg/cfg.go b/src/cmd/go/internal/cfg/cfg.go index b47eb812b5..fc6989097e 100644 --- a/src/cmd/go/internal/cfg/cfg.go +++ b/src/cmd/go/internal/cfg/cfg.go @@ -77,6 +77,14 @@ func defaultContext() build.Context { ctxt.GOOS = envOr("GOOS", ctxt.GOOS) ctxt.GOARCH = envOr("GOARCH", ctxt.GOARCH) + // The experiments flags are based on GOARCH, so they may + // need to change. TODO: This should be cleaned up. + buildcfg.UpdateExperiments(ctxt.GOARCH) + ctxt.ToolTags = nil + for _, exp := range buildcfg.EnabledExperiments() { + ctxt.ToolTags = append(ctxt.ToolTags, "goexperiment."+exp) + } + // The go/build rule for whether cgo is enabled is: // 1. If $CGO_ENABLED is set, respect it. // 2. Otherwise, if this is a cross-compile, disable cgo. diff --git a/src/cmd/go/testdata/script/env_cross_build.txt b/src/cmd/go/testdata/script/env_cross_build.txt new file mode 100644 index 0000000000..3feeba6b14 --- /dev/null +++ b/src/cmd/go/testdata/script/env_cross_build.txt @@ -0,0 +1,29 @@ +# Test that the corect default GOEXPERIMENT is used when cross +# building with GOENV (#46815). + +# Unset variables set by the TestScript harness. Users typically won't +# explicitly configure these, and #46815 doesn't repro if they are. +env GOOS= +env GOARCH= +env GOEXPERIMENT= + +env GOENV=windows-amd64 +go build internal/abi + +env GOENV=ios-arm64 +go build internal/abi + +env GOENV=linux-mips +go build internal/abi + +-- windows-amd64 -- +GOOS=windows +GOARCH=amd64 + +-- ios-arm64 -- +GOOS=ios +GOARCH=arm64 + +-- linux-mips -- +GOOS=linux +GOARCH=mips diff --git a/src/internal/buildcfg/exp.go b/src/internal/buildcfg/exp.go index 2435a79dce..640aa1934d 100644 --- a/src/internal/buildcfg/exp.go +++ b/src/internal/buildcfg/exp.go @@ -18,7 +18,7 @@ import ( // // (This is not necessarily the set of experiments the compiler itself // was built with.) -var Experiment goexperiment.Flags = parseExperiments() +var Experiment goexperiment.Flags = parseExperiments(GOARCH) var regabiSupported = GOARCH == "amd64" && (GOOS == "android" || GOOS == "linux" || GOOS == "darwin" || GOOS == "windows") @@ -42,7 +42,7 @@ var experimentBaseline = goexperiment.Flags{ // Note: must agree with runtime.framepointer_enabled. var FramePointerEnabled = GOARCH == "amd64" || GOARCH == "arm64" -func parseExperiments() goexperiment.Flags { +func parseExperiments(goarch string) goexperiment.Flags { // Start with the statically enabled set of experiments. flags := experimentBaseline @@ -99,7 +99,7 @@ func parseExperiments() goexperiment.Flags { } // regabi is only supported on amd64. - if GOARCH != "amd64" { + if goarch != "amd64" { flags.RegabiWrappers = false flags.RegabiG = false flags.RegabiReflect = false @@ -165,3 +165,10 @@ func EnabledExperiments() []string { func AllExperiments() []string { return expList(&Experiment, nil, true) } + +// UpdateExperiments updates the Experiment global based on a new GOARCH value. +// This is only required for cmd/go, which can change GOARCH after +// program startup due to use of "go env -w". +func UpdateExperiments(goarch string) { + Experiment = parseExperiments(goarch) +} -- 2.50.0