github.com/llvm-mirror/llgo@v0.0.0-20190322182713-bf6f0a60fce1/third_party/gotools/go/ssa/stdlib_test.go (about)

     1  // Copyright 2013 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package ssa_test
     6  
     7  // This file runs the SSA builder in sanity-checking mode on all
     8  // packages beneath $GOROOT and prints some summary information.
     9  //
    10  // Run with "go test -cpu=8 to" set GOMAXPROCS.
    11  
    12  import (
    13  	"go/ast"
    14  	"go/build"
    15  	"go/token"
    16  	"runtime"
    17  	"testing"
    18  	"time"
    19  
    20  	"llvm.org/llgo/third_party/gotools/go/buildutil"
    21  	"llvm.org/llgo/third_party/gotools/go/loader"
    22  	"llvm.org/llgo/third_party/gotools/go/ssa"
    23  	"llvm.org/llgo/third_party/gotools/go/ssa/ssautil"
    24  )
    25  
    26  func bytesAllocated() uint64 {
    27  	runtime.GC()
    28  	var stats runtime.MemStats
    29  	runtime.ReadMemStats(&stats)
    30  	return stats.Alloc
    31  }
    32  
    33  func TestStdlib(t *testing.T) {
    34  	// Load, parse and type-check the program.
    35  	t0 := time.Now()
    36  	alloc0 := bytesAllocated()
    37  
    38  	// Load, parse and type-check the program.
    39  	ctxt := build.Default // copy
    40  	ctxt.GOPATH = ""      // disable GOPATH
    41  	conf := loader.Config{Build: &ctxt}
    42  	if _, err := conf.FromArgs(buildutil.AllPackages(conf.Build), true); err != nil {
    43  		t.Errorf("FromArgs failed: %v", err)
    44  		return
    45  	}
    46  
    47  	iprog, err := conf.Load()
    48  	if err != nil {
    49  		t.Fatalf("Load failed: %v", err)
    50  	}
    51  
    52  	t1 := time.Now()
    53  	alloc1 := bytesAllocated()
    54  
    55  	// Create SSA packages.
    56  	var mode ssa.BuilderMode
    57  	// Comment out these lines during benchmarking.  Approx SSA build costs are noted.
    58  	mode |= ssa.SanityCheckFunctions // + 2% space, + 4% time
    59  	mode |= ssa.GlobalDebug          // +30% space, +18% time
    60  	prog := ssa.Create(iprog, mode)
    61  
    62  	t2 := time.Now()
    63  
    64  	// Build SSA.
    65  	prog.BuildAll()
    66  
    67  	t3 := time.Now()
    68  	alloc3 := bytesAllocated()
    69  
    70  	numPkgs := len(prog.AllPackages())
    71  	if want := 140; numPkgs < want {
    72  		t.Errorf("Loaded only %d packages, want at least %d", numPkgs, want)
    73  	}
    74  
    75  	// Keep iprog reachable until after we've measured memory usage.
    76  	if len(iprog.AllPackages) == 0 {
    77  		print() // unreachable
    78  	}
    79  
    80  	allFuncs := ssautil.AllFunctions(prog)
    81  
    82  	// Check that all non-synthetic functions have distinct names.
    83  	// Synthetic wrappers for exported methods should be distinct too,
    84  	// except for unexported ones (explained at (*Function).RelString).
    85  	byName := make(map[string]*ssa.Function)
    86  	for fn := range allFuncs {
    87  		if fn.Synthetic == "" || ast.IsExported(fn.Name()) {
    88  			str := fn.String()
    89  			prev := byName[str]
    90  			byName[str] = fn
    91  			if prev != nil {
    92  				t.Errorf("%s: duplicate function named %s",
    93  					prog.Fset.Position(fn.Pos()), str)
    94  				t.Errorf("%s:   (previously defined here)",
    95  					prog.Fset.Position(prev.Pos()))
    96  			}
    97  		}
    98  	}
    99  
   100  	// Dump some statistics.
   101  	var numInstrs int
   102  	for fn := range allFuncs {
   103  		for _, b := range fn.Blocks {
   104  			numInstrs += len(b.Instrs)
   105  		}
   106  	}
   107  
   108  	// determine line count
   109  	var lineCount int
   110  	prog.Fset.Iterate(func(f *token.File) bool {
   111  		lineCount += f.LineCount()
   112  		return true
   113  	})
   114  
   115  	// NB: when benchmarking, don't forget to clear the debug +
   116  	// sanity builder flags for better performance.
   117  
   118  	t.Log("GOMAXPROCS:           ", runtime.GOMAXPROCS(0))
   119  	t.Log("#Source lines:        ", lineCount)
   120  	t.Log("Load/parse/typecheck: ", t1.Sub(t0))
   121  	t.Log("SSA create:           ", t2.Sub(t1))
   122  	t.Log("SSA build:            ", t3.Sub(t2))
   123  
   124  	// SSA stats:
   125  	t.Log("#Packages:            ", numPkgs)
   126  	t.Log("#Functions:           ", len(allFuncs))
   127  	t.Log("#Instructions:        ", numInstrs)
   128  	t.Log("#MB AST+types:        ", int64(alloc1-alloc0)/1e6)
   129  	t.Log("#MB SSA:              ", int64(alloc3-alloc1)/1e6)
   130  }