Stowage/go
2
0
Fork 0
mirror of https://github.com/golang/go.git synced 2025-12-08 06:10:04 +00:00
Code Issues Projects Releases Packages Wiki Activity

cmd/go, cmd/compile: always optimize when building runtime

Browse source 
When optimizations are disabled, the compiler
cannot eliminate enough write barriers to satisfy
the runtime's nowritebarrier and nowritebarrierrec
annotations.

Enforce that requirement, and for convenience,
have cmd/go elide -N when compiling the runtime.

This came up in practice for me when running
toolstash -cmp. When toolstash -cmp detected
mismatches, it recompiled with -N, which caused
runtime compilation failures.

Change-Id: Ifcdef22c725baf2c59a09470f00124361508a8f3
Reviewed-on: https://go-review.googlesource.com/38380
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This commit is contained in:
Josh Bleecher Snyder 2017-03-20 09:56:50 -07:00
parent a955ece6cd
commit f8b0231639
2 changed files with 21 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

3
src/cmd/compile/internal/gc/main.go
View file

@ -268,6 +268,9 @@ func Main(archInit func(*Arch)) {
} else if flag_race || flag_msan {
instrumenting = true
}
if compiling_runtime && Debug['N'] != 0 {
log.Fatal("cannot disable optimizations while compiling runtime")
}
// parse -d argument
if debugstr != "" {

20
src/cmd/go/internal/work/build.go
View file

@ -2176,7 +2176,8 @@ func (gcToolchain) gc(b *Builder, p *load.Package, archive, obj string, asmhdr b
if p.Name == "main" {
gcargs[1] = "main"
}
if p.Standard && (p.ImportPath == "runtime" || strings.HasPrefix(p.ImportPath, "runtime/internal")) {
compilingRuntime := p.Standard && (p.ImportPath == "runtime" || strings.HasPrefix(p.ImportPath, "runtime/internal"))
if compilingRuntime {
// runtime compiles with a special gc flag to emit
// additional reflect type data.
gcargs = append(gcargs, "-+")
@ -2211,7 +2212,22 @@ func (gcToolchain) gc(b *Builder, p *load.Package, archive, obj string, asmhdr b
}
}
args := []interface{}{cfg.BuildToolexec, base.Tool("compile"), "-o", ofile, "-trimpath", b.WorkDir, buildGcflags, gcargs, "-D", p.Internal.LocalPrefix, importArgs}
gcflags := buildGcflags
if compilingRuntime {
// Remove -N, if present.
// It is not possible to build the runtime with no optimizations,
// because the compiler cannot eliminate enough write barriers.
gcflags = make([]string, len(buildGcflags))
copy(gcflags, buildGcflags)
for i := 0; i < len(gcflags); i++ {
if gcflags[i] == "-N" {
copy(gcflags[i:], gcflags[i+1:])
gcflags = gcflags[:len(gcflags)-1]
i--
}
}
}
args := []interface{}{cfg.BuildToolexec, base.Tool("compile"), "-o", ofile, "-trimpath", b.WorkDir, gcflags, gcargs, "-D", p.Internal.LocalPrefix, importArgs}
if ofile == archive {
args = append(args, "-pack")
}