cmd/internal/objabi,cmd/compile: move NoInstrumentPkgs and NoRacePkgs to PkgSpecials

This consolidates the NoInstrumentPkgs and NoRacePkgs lists into the
objabi.LookupPkgSpecial mechanism.

Change-Id: I411654afdd690fb01c412e7e8b57ddfbe85415e3
Reviewed-on: https://go-review.googlesource.com/c/go/+/521702
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Austin Clements <austin@google.com>

src/cmd/compile/internal/base/base.go

@@ -219,44 +219,3 @@ func AdjustStartingHeap(requestedHeapGoal uint64) {
 
 	forEachGC(adjustFunc)
 }
-
-func Compiling(pkgs []string) bool {
-	if Ctxt.Pkgpath != "" {
-		for _, p := range pkgs {
-			if Ctxt.Pkgpath == p {
-				return true
-			}
-		}
-	}
-
-	return false
-}
-
-// Do not instrument the following packages at all,
-// at best instrumentation would cause infinite recursion.
-var NoInstrumentPkgs = []string{
-	"runtime/internal/atomic",
-	"runtime/internal/math",
-	"runtime/internal/sys",
-	"runtime/internal/syscall",
-	"runtime",
-	"runtime/race",
-	"runtime/msan",
-	"runtime/asan",
-	"internal/cpu",
-	"internal/abi",
-	// We omit bytealg even though it's imported by runtime because it also
-	// backs a lot of package bytes. Currently we don't have a way to omit race
-	// instrumentation when used from the runtime while keeping race
-	// instrumentation when used from user code. Somehow this doesn't seem to
-	// cause problems, though we may be skating on thin ice. See #61204.
-	//"internal/bytealg",
-	"internal/coverage/rtcov",
-	"internal/godebugs",
-	"internal/goexperiment",
-	"internal/goos",
-}
-
-// Don't insert racefuncenter/racefuncexit into the following packages.
-// Memory accesses in the packages are either uninteresting or will cause false positives.
-var NoRacePkgs = []string{"sync", "sync/atomic"}

src/cmd/compile/internal/gc/main.go

@@ -151,7 +151,7 @@ func Main(archInit func(*ssagen.ArchInfo)) {
 		symABIs.ReadSymABIs(base.Flag.SymABIs)
 	}
 
-	if base.Compiling(base.NoInstrumentPkgs) {
+	if objabi.LookupPkgSpecial(base.Ctxt.Pkgpath).NoInstrument {
 		base.Flag.Race = false
 		base.Flag.MSan = false
 		base.Flag.ASan = false

src/cmd/compile/internal/types/type.go

@@ -6,6 +6,7 @@ package types
 
 import (
 	"cmd/compile/internal/base"
+	"cmd/internal/objabi"
 	"cmd/internal/src"
 	"fmt"
 	"internal/types/errors"
@@ -1862,23 +1863,13 @@ func ReflectSymName(s *Sym) string {
 // IsNoInstrumentPkg reports whether p is a package that
 // should not be instrumented.
 func IsNoInstrumentPkg(p *Pkg) bool {
-	for _, np := range base.NoInstrumentPkgs {
-		if p.Path == np {
-			return true
-		}
-	}
-	return false
+	return objabi.LookupPkgSpecial(p.Path).NoInstrument
 }
 
 // IsNoRacePkg reports whether p is a package that
 // should not be race instrumented.
 func IsNoRacePkg(p *Pkg) bool {
-	for _, np := range base.NoRacePkgs {
-		if p.Path == np {
-			return true
-		}
-	}
-	return false
+	return objabi.LookupPkgSpecial(p.Path).NoRaceFunc
 }
 
 // ReceiverBaseType returns the underlying type, if any,

src/cmd/compile/internal/walk/race.go

@@ -8,6 +8,7 @@ import (
 	"cmd/compile/internal/base"
 	"cmd/compile/internal/ir"
 	"cmd/compile/internal/types"
+	"cmd/internal/objabi"
 	"cmd/internal/src"
 )
 
@@ -36,7 +37,7 @@ func instrument(fn *ir.Func) {
 		return
 	}
 
-	if !base.Flag.Race || !base.Compiling(base.NoRacePkgs) {
+	if !base.Flag.Race || !objabi.LookupPkgSpecial(base.Ctxt.Pkgpath).NoRaceFunc {
 		fn.SetInstrumentBody(true)
 	}
 

src/cmd/internal/objabi/pkgspecial.go

@@ -22,6 +22,17 @@ type PkgSpecial struct {
 	// set for additional packages.
 	Runtime bool
 
+	// NoInstrument indicates this package should not receive sanitizer
+	// instrumentation. In many of these, instrumentation could cause infinite
+	// recursion. This is all runtime packages, plus those that support the
+	// sanitizers.
+	NoInstrument bool
+
+	// NoRaceFunc indicates functions in this package should not get
+	// racefuncenter/racefuncexit instrumentation Memory accesses in these
+	// packages are either uninteresting or will cause false positives.
+	NoRaceFunc bool
+
 	// AllowAsmABI indicates that assembly in this package is allowed to use ABI
 	// selectors in symbol names. Generally this is needed for packages that
 	// interact closely with the runtime package or have performance-critical
@@ -47,6 +58,22 @@ var runtimePkgs = []string{
 	"internal/goos",
 }
 
+// extraNoInstrumentPkgs is the set of packages in addition to runtimePkgs that
+// should have NoInstrument set.
+var extraNoInstrumentPkgs = []string{
+	"runtime/race",
+	"runtime/msan",
+	"runtime/asan",
+	// We omit bytealg even though it's imported by runtime because it also
+	// backs a lot of package bytes. Currently we don't have a way to omit race
+	// instrumentation when used from the runtime while keeping race
+	// instrumentation when used from user code. Somehow this doesn't seem to
+	// cause problems, though we may be skating on thin ice. See #61204.
+	"-internal/bytealg",
+}
+
+var noRaceFuncPkgs = []string{"sync", "sync/atomic"}
+
 var allowAsmABIPkgs = []string{
 	"runtime",
 	"reflect",
@@ -74,7 +101,17 @@ func LookupPkgSpecial(pkgPath string) PkgSpecial {
 			pkgSpecials[elt] = s
 		}
 		for _, pkg := range runtimePkgs {
-			set(pkg, func(ps *PkgSpecial) { ps.Runtime = true })
+			set(pkg, func(ps *PkgSpecial) { ps.Runtime = true; ps.NoInstrument = true })
+		}
+		for _, pkg := range extraNoInstrumentPkgs {
+			if pkg[0] == '-' {
+				set(pkg[1:], func(ps *PkgSpecial) { ps.NoInstrument = false })
+			} else {
+				set(pkg, func(ps *PkgSpecial) { ps.NoInstrument = true })
+			}
+		}
+		for _, pkg := range noRaceFuncPkgs {
+			set(pkg, func(ps *PkgSpecial) { ps.NoRaceFunc = true })
 		}
 		for _, pkg := range allowAsmABIPkgs {
 			set(pkg, func(ps *PkgSpecial) { ps.AllowAsmABI = true })