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go/ssa/stdlib_test.go
Alan Donovan c28bf6e069 go.tools/ssa: extend debug information to arbitrary ast.Exprs.
CanonicalPos was inadequate since many pairs of instruction share the same pos (e.g. Allocs and Phis).  Instead, we generalize the DebugRef instruction to associate not just Idents but Exprs with ssa.Values.

We no longer store any DebugRefs for constant expressions, to save space.  (The type and value of such expressions can be obtained by other means, at a cost in complexity.)

Function.ValueForExpr queries the DebugRef info to return the ssa.Value of a given Expr.

Added tests.

Also:
- the DebugInfo flag is now per package, not global.
   It must be set between Create and Build phases if desired.
- {Value,Instruction}.Pos() documentation updated: we still maintain
  this information in the instruction stream even in non-debug mode,
  but we make fewer claims about its invariants.
- Go and Defer instructions can now use their respective go/defer
   token positions (not the call's lparen), so they do.
- SelectState:
     Posn token.Pos indicates the <- position
     DebugNode ast.Expr is the send stmt or receive expr.
- In building SelectStmt, we introduce extra temporaries in debug
   mode to hold the result of the receive in 'case <-ch' even though
   this value isn't ordinarily needed.
- Use *SelectState (indirectly) since the struct is getting bigger.
- Document some missing instructions in doc.go.

R=gri
CC=golang-dev
https://golang.org/cl/12147043
2013-07-31 13:13:05 -04:00

121 lines
2.8 KiB
Go

package ssa_test
// This file runs the SSA builder in sanity-checking mode on all
// packages beneath $GOROOT and prints some summary information.
//
// Run test with GOMAXPROCS=8 and CGO_ENABLED=0. The latter cannot be
// set from the test because it's too late to stop go/build.init()
// from picking up the value from the parent's environment.
import (
"go/build"
"os"
"path/filepath"
"runtime"
"strings"
"testing"
"time"
"code.google.com/p/go.tools/importer"
"code.google.com/p/go.tools/ssa"
)
const debugMode = false
func allPackages() []string {
var pkgs []string
root := filepath.Join(runtime.GOROOT(), "src/pkg") + "/"
filepath.Walk(root, func(path string, info os.FileInfo, err error) error {
// Prune the search if we encounter any of these names:
switch filepath.Base(path) {
case "testdata", ".hg":
return filepath.SkipDir
}
if info.IsDir() {
pkg := strings.TrimPrefix(path, root)
switch pkg {
case "builtin", "pkg", "code.google.com":
return filepath.SkipDir // skip these subtrees
case "":
return nil // ignore root of tree
}
pkgs = append(pkgs, pkg)
}
return nil
})
return pkgs
}
func TestStdlib(t *testing.T) {
ctxt := build.Default
ctxt.CgoEnabled = false
impctx := importer.Config{Loader: importer.MakeGoBuildLoader(&ctxt)}
// Load, parse and type-check the program.
t0 := time.Now()
var hasErrors bool
imp := importer.New(&impctx)
for _, importPath := range allPackages() {
if _, err := imp.LoadPackage(importPath); err != nil {
t.Errorf("LoadPackage(%s): %s", importPath, err)
hasErrors = true
}
}
t1 := time.Now()
runtime.GC()
var memstats runtime.MemStats
runtime.ReadMemStats(&memstats)
alloc := memstats.Alloc
// Create SSA packages.
prog := ssa.NewProgram(imp.Fset, ssa.SanityCheckFunctions)
for _, info := range imp.Packages {
if info.Err == nil {
prog.CreatePackage(info).SetDebugMode(debugMode)
}
}
t2 := time.Now()
// Build SSA IR... if it's safe.
if !hasErrors {
prog.BuildAll()
}
t3 := time.Now()
runtime.GC()
runtime.ReadMemStats(&memstats)
numPkgs := len(prog.PackagesByPath)
if want := 140; numPkgs < want {
t.Errorf("Loaded only %d packages, want at least %d", numPkgs, want)
}
// Dump some statistics.
allFuncs := ssa.AllFunctions(prog)
var numInstrs int
for fn := range allFuncs {
for _, b := range fn.Blocks {
numInstrs += len(b.Instrs)
}
}
t.Log("GOMAXPROCS: ", runtime.GOMAXPROCS(0))
t.Log("Load/parse/typecheck: ", t1.Sub(t0))
t.Log("SSA create: ", t2.Sub(t1))
if !hasErrors {
t.Log("SSA build: ", t3.Sub(t2))
}
// SSA stats:
t.Log("#Packages: ", numPkgs)
t.Log("#Functions: ", len(allFuncs))
t.Log("#Instructions: ", numInstrs)
t.Log("#MB: ", (memstats.Alloc-alloc)/1000000)
}