cmd/compile: escape package path for PGO symbol matching

Symbol names in the final executable apply escaping to the final
component of a package path (main in example.com becomes
example%2ecom.main).

ir.PkgFuncName does not perform this escaping, meaning we'd fail to
match functions that are escaped in the profile.

Add ir.LinkFuncName which does perform escaping and use it for PGO.

Fixes #59887.

Change-Id: I10634d63d99d0a6fd2f72b929ab35ea227e1336f
Reviewed-on: https://go-review.googlesource.com/c/go/+/490555
Reviewed-by: Cherry Mui <cherryyz@google.com>
Auto-Submit: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

diff --git a/src/cmd/compile/internal/inline/inl.go b/src/cmd/compile/internal/inline/inl.go
index 1a65e16f5199f6a139db27470d1c3bde12907c11..df12f9a625caab2f8479ee59ade20a20ca96fbcb 100644 (file)
--- a/src/cmd/compile/internal/inline/inl.go
+++ b/src/cmd/compile/internal/inline/inl.go
@@ -163,7 +163,7 @@ func pgoInlineEpilogue(p *pgo.Profile, decls []ir.Node) {
        if base.Debug.PGOInline >= 2 {
                ir.VisitFuncsBottomUp(decls, func(list []*ir.Func, recursive bool) {
                        for _, f := range list {
-                               name := ir.PkgFuncName(f)
+                               name := ir.LinkFuncName(f)
                                if n, ok := p.WeightedCG.IRNodes[name]; ok {
                                        p.RedirectEdges(n, inlinedCallSites)
                                }
@@ -352,7 +352,7 @@ func CanInline(fn *ir.Func, profile *pgo.Profile) {
        // Update the budget for profile-guided inlining.
        budget := int32(inlineMaxBudget)
        if profile != nil {
-               if n, ok := profile.WeightedCG.IRNodes[ir.PkgFuncName(fn)]; ok {
+               if n, ok := profile.WeightedCG.IRNodes[ir.LinkFuncName(fn)]; ok {
                        if _, ok := candHotCalleeMap[n]; ok {
                                budget = int32(inlineHotMaxBudget)
                                if base.Debug.PGOInline > 0 {

diff --git a/src/cmd/compile/internal/ir/func.go b/src/cmd/compile/internal/ir/func.go
index 2886185f0ab9afc4890800a92b5185cda10c2539..b36b1fa49475afbb8847cfc509356d37f100de98 100644 (file)
--- a/src/cmd/compile/internal/ir/func.go
+++ b/src/cmd/compile/internal/ir/func.go
@@ -8,6 +8,7 @@ import (
        "cmd/compile/internal/base"
        "cmd/compile/internal/types"
        "cmd/internal/obj"
+       "cmd/internal/objabi"
        "cmd/internal/src"
        "fmt"
 )
@@ -263,7 +264,7 @@ func (f *Func) SetWBPos(pos src.XPos) {
        }
 }
 
-// FuncName returns the name (without the package) of the function n.
+// FuncName returns the name (without the package) of the function f.
 func FuncName(f *Func) string {
        if f == nil || f.Nname == nil {
                return "<nil>"
@@ -271,10 +272,12 @@ func FuncName(f *Func) string {
        return f.Sym().Name
 }
 
-// PkgFuncName returns the name of the function referenced by n, with package prepended.
-// This differs from the compiler's internal convention where local functions lack a package
-// because the ultimate consumer of this is a human looking at an IDE; package is only empty
-// if the compilation package is actually the empty string.
+// PkgFuncName returns the name of the function referenced by f, with package
+// prepended.
+//
+// This differs from the compiler's internal convention where local functions
+// lack a package. This is primarily useful when the ultimate consumer of this
+// is a human looking at message.
 func PkgFuncName(f *Func) string {
        if f == nil || f.Nname == nil {
                return "<nil>"
@@ -285,6 +288,18 @@ func PkgFuncName(f *Func) string {
        return pkg.Path + "." + s.Name
 }
 
+// LinkFuncName returns the name of the function f, as it will appear in the
+// symbol table of the final linked binary.
+func LinkFuncName(f *Func) string {
+       if f == nil || f.Nname == nil {
+               return "<nil>"
+       }
+       s := f.Sym()
+       pkg := s.Pkg
+
+       return objabi.PathToPrefix(pkg.Path) + "." + s.Name
+}
+
 // IsEqOrHashFunc reports whether f is type eq/hash function.
 func IsEqOrHashFunc(f *Func) bool {
        if f == nil || f.Nname == nil {

diff --git a/src/cmd/compile/internal/pgo/irgraph.go b/src/cmd/compile/internal/pgo/irgraph.go
index ff0995eaeafa7f621e063600b85a08097924f102..72ffc8ce78abdf69ad120e9b22bcb07885da3a62 100644 (file)
--- a/src/cmd/compile/internal/pgo/irgraph.go
+++ b/src/cmd/compile/internal/pgo/irgraph.go
@@ -270,7 +270,7 @@ func (p *Profile) VisitIR(fn *ir.Func) {
        if g.InEdges == nil {
                g.InEdges = make(map[*IRNode][]*IREdge)
        }
-       name := ir.PkgFuncName(fn)
+       name := ir.LinkFuncName(fn)
        node := new(IRNode)
        node.AST = fn
        if g.IRNodes[name] == nil {
@@ -308,7 +308,7 @@ func (p *Profile) addIREdge(caller *IRNode, callername string, call ir.Node, cal
        // Create an IRNode for the callee.
        calleenode := new(IRNode)
        calleenode.AST = callee
-       calleename := ir.PkgFuncName(callee)
+       calleename := ir.LinkFuncName(callee)
 
        // Create key for NodeMapKey.
        nodeinfo := NodeMapKey{
@@ -395,7 +395,7 @@ func (p *Profile) PrintWeightedCallGraphDOT(edgeThreshold float64) {
        funcs := make(map[string]struct{})
        ir.VisitFuncsBottomUp(typecheck.Target.Decls, func(list []*ir.Func, recursive bool) {
                for _, f := range list {
-                       name := ir.PkgFuncName(f)
+                       name := ir.LinkFuncName(f)
                        funcs[name] = struct{}{}
                }
        })
@@ -405,15 +405,15 @@ func (p *Profile) PrintWeightedCallGraphDOT(edgeThreshold float64) {
        for name := range funcs {
                if n, ok := p.WeightedCG.IRNodes[name]; ok {
                        for _, e := range p.WeightedCG.OutEdges[n] {
-                               if _, ok := nodes[ir.PkgFuncName(e.Src.AST)]; !ok {
-                                       nodes[ir.PkgFuncName(e.Src.AST)] = e.Src.AST
+                               if _, ok := nodes[ir.LinkFuncName(e.Src.AST)]; !ok {
+                                       nodes[ir.LinkFuncName(e.Src.AST)] = e.Src.AST
                                }
-                               if _, ok := nodes[ir.PkgFuncName(e.Dst.AST)]; !ok {
-                                       nodes[ir.PkgFuncName(e.Dst.AST)] = e.Dst.AST
+                               if _, ok := nodes[ir.LinkFuncName(e.Dst.AST)]; !ok {
+                                       nodes[ir.LinkFuncName(e.Dst.AST)] = e.Dst.AST
                                }
                        }
-                       if _, ok := nodes[ir.PkgFuncName(n.AST)]; !ok {
-                               nodes[ir.PkgFuncName(n.AST)] = n.AST
+                       if _, ok := nodes[ir.LinkFuncName(n.AST)]; !ok {
+                               nodes[ir.LinkFuncName(n.AST)] = n.AST
                        }
                }
        }
@@ -424,16 +424,16 @@ func (p *Profile) PrintWeightedCallGraphDOT(edgeThreshold float64) {
                        nodeweight := WeightInPercentage(n.Flat, p.TotalNodeWeight)
                        color := "black"
                        if ast.Inl != nil {
-                               fmt.Printf("\"%v\" [color=%v,label=\"%v,freq=%.2f,inl_cost=%d\"];\n", ir.PkgFuncName(ast), color, ir.PkgFuncName(ast), nodeweight, ast.Inl.Cost)
+                               fmt.Printf("\"%v\" [color=%v,label=\"%v,freq=%.2f,inl_cost=%d\"];\n", ir.LinkFuncName(ast), color, ir.LinkFuncName(ast), nodeweight, ast.Inl.Cost)
                        } else {
-                               fmt.Printf("\"%v\" [color=%v, label=\"%v,freq=%.2f\"];\n", ir.PkgFuncName(ast), color, ir.PkgFuncName(ast), nodeweight)
+                               fmt.Printf("\"%v\" [color=%v, label=\"%v,freq=%.2f\"];\n", ir.LinkFuncName(ast), color, ir.LinkFuncName(ast), nodeweight)
                        }
                }
        }
        // Print edges.
        ir.VisitFuncsBottomUp(typecheck.Target.Decls, func(list []*ir.Func, recursive bool) {
                for _, f := range list {
-                       name := ir.PkgFuncName(f)
+                       name := ir.LinkFuncName(f)
                        if n, ok := p.WeightedCG.IRNodes[name]; ok {
                                for _, e := range p.WeightedCG.OutEdges[n] {
                                        edgepercent := WeightInPercentage(e.Weight, p.TotalEdgeWeight)
@@ -443,7 +443,7 @@ func (p *Profile) PrintWeightedCallGraphDOT(edgeThreshold float64) {
                                                fmt.Printf("edge [color=black, style=solid];\n")
                                        }
 
-                                       fmt.Printf("\"%v\" -> \"%v\" [label=\"%.2f\"];\n", ir.PkgFuncName(n.AST), ir.PkgFuncName(e.Dst.AST), edgepercent)
+                                       fmt.Printf("\"%v\" -> \"%v\" [label=\"%.2f\"];\n", ir.LinkFuncName(n.AST), ir.LinkFuncName(e.Dst.AST), edgepercent)
                                }
                        }
                }