Turn BuildStatus into an interface

Make BuildStatus an abstract interface, and move the current
implementation to StatusPrinter, to make way for a serialized
Status output.

7 files changed, 426 insertions, 327 deletions

diff --git a/src/build.cc b/src/build.cc
index 3b1a3f4..3d1e76b 100644
--- a/src/build.cc
+++ b/src/build.cc
@@ -20,11 +20,6 @@
 #include <stdlib.h>
 #include <functional>
 
-#ifdef _WIN32
-#include <fcntl.h>
-#include <io.h>
-#endif
-
 #if defined(__SVR4) && defined(__sun)
 #include <sys/termios.h>
 #endif
@@ -38,6 +33,7 @@
 #include "graph.h"
 #include "metrics.h"
 #include "state.h"
+#include "status.h"
 #include "subprocess.h"
 #include "util.h"
 
@@ -79,225 +75,6 @@ bool DryRunCommandRunner::WaitForCommand(Result* result) {
 
 }  // namespace
 
-BuildStatus::BuildStatus(const BuildConfig& config)
-    : config_(config),
-      started_edges_(0), finished_edges_(0), total_edges_(0), running_edges_(0),
-      time_millis_(0), progress_status_format_(NULL),
-      current_rate_(config.parallelism) {
-  // Don't do anything fancy in verbose mode.
-  if (config_.verbosity != BuildConfig::NORMAL)
-    printer_.set_smart_terminal(false);
-
-  progress_status_format_ = getenv("NINJA_STATUS");
-  if (!progress_status_format_)
-    progress_status_format_ = "[%f/%t] ";
-}
-
-void BuildStatus::PlanHasTotalEdges(int total) {
-  total_edges_ = total;
-}
-
-void BuildStatus::BuildEdgeStarted(const Edge* edge,
-                                   int64_t start_time_millis) {
-  ++started_edges_;
-  time_millis_ = start_time_millis;
-
-  if (edge->use_console() || printer_.is_smart_terminal())
-    PrintStatus(edge, start_time_millis);
-
-  if (edge->use_console())
-    printer_.SetConsoleLocked(true);
-}
-
-void BuildStatus::BuildEdgeFinished(Edge* edge, int64_t end_time_millis,
-                                    bool success,
-                                    const string& output) {
-  time_millis_ = end_time_millis;
-  ++finished_edges_;
-
-  if (edge->use_console())
-    printer_.SetConsoleLocked(false);
-
-  if (config_.verbosity == BuildConfig::QUIET)
-    return;
-
-  if (!edge->use_console())
-    PrintStatus(edge, end_time_millis);
-
-  // Update running_edges_ after PrintStatus so that the number of running
-  // edges doesn't oscillate between config.parallelism_ and
-  // config.parallelism_ - 1.
-  --running_edges_;
-
-  // Print the command that is spewing before printing its output.
-  if (!success) {
-    string outputs;
-    for (vector<Node*>::const_iterator o = edge->outputs_.begin();
-         o != edge->outputs_.end(); ++o)
-      outputs += (*o)->path() + " ";
-
-    if (printer_.supports_color()) {
-        printer_.PrintOnNewLine("\x1B[31m" "FAILED: " "\x1B[0m" + outputs + "\n");
-    } else {
-        printer_.PrintOnNewLine("FAILED: " + outputs + "\n");
-    }
-    printer_.PrintOnNewLine(edge->EvaluateCommand() + "\n");
-  }
-
-  if (!output.empty()) {
-    // ninja sets stdout and stderr of subprocesses to a pipe, to be able to
-    // check if the output is empty. Some compilers, e.g. clang, check
-    // isatty(stderr) to decide if they should print colored output.
-    // To make it possible to use colored output with ninja, subprocesses should
-    // be run with a flag that forces them to always print color escape codes.
-    // To make sure these escape codes don't show up in a file if ninja's output
-    // is piped to a file, ninja strips ansi escape codes again if it's not
-    // writing to a |smart_terminal_|.
-    // (Launching subprocesses in pseudo ttys doesn't work because there are
-    // only a few hundred available on some systems, and ninja can launch
-    // thousands of parallel compile commands.)
-    string final_output;
-    if (!printer_.supports_color())
-      final_output = StripAnsiEscapeCodes(output);
-    else
-      final_output = output;
-
-#ifdef _WIN32
-    // Fix extra CR being added on Windows, writing out CR CR LF (#773)
-    _setmode(_fileno(stdout), _O_BINARY);  // Begin Windows extra CR fix
-#endif
-
-    printer_.PrintOnNewLine(final_output);
-
-#ifdef _WIN32
-    _setmode(_fileno(stdout), _O_TEXT);  // End Windows extra CR fix
-#endif
-  }
-}
-
-void BuildStatus::BuildLoadDyndeps() {
-  // The DependencyScan calls EXPLAIN() to print lines explaining why
-  // it considers a portion of the graph to be out of date.  Normally
-  // this is done before the build starts, but our caller is about to
-  // load a dyndep file during the build.  Doing so may generate more
-  // explanation lines (via fprintf directly to stderr), but in an
-  // interactive console the cursor is currently at the end of a status
-  // line.  Start a new line so that the first explanation does not
-  // append to the status line.  After the explanations are done a
-  // new build status line will appear.
-  if (g_explaining)
-    printer_.PrintOnNewLine("");
-}
-
-void BuildStatus::BuildStarted() {
-  started_edges_ = 0;
-  finished_edges_ = 0;
-  running_edges_ = 0;
-}
-
-void BuildStatus::BuildFinished() {
-  printer_.SetConsoleLocked(false);
-  printer_.PrintOnNewLine("");
-}
-
-string BuildStatus::FormatProgressStatus(
-    const char* progress_status_format, int64_t time) const {
-  string out;
-  char buf[32];
-  for (const char* s = progress_status_format; *s != '\0'; ++s) {
-    if (*s == '%') {
-      ++s;
-      switch (*s) {
-      case '%':
-        out.push_back('%');
-        break;
-
-        // Started edges.
-      case 's':
-        snprintf(buf, sizeof(buf), "%d", started_edges_);
-        out += buf;
-        break;
-
-        // Total edges.
-      case 't':
-        snprintf(buf, sizeof(buf), "%d", total_edges_);
-        out += buf;
-        break;
-
-        // Running edges.
-      case 'r': {
-        snprintf(buf, sizeof(buf), "%d", running_edges_);
-        out += buf;
-        break;
-      }
-
-        // Unstarted edges.
-      case 'u':
-        snprintf(buf, sizeof(buf), "%d", total_edges_ - started_edges_);
-        out += buf;
-        break;
-
-        // Finished edges.
-      case 'f':
-        snprintf(buf, sizeof(buf), "%d", finished_edges_);
-        out += buf;
-        break;
-
-        // Overall finished edges per second.
-      case 'o':
-        SnprintfRate(finished_edges_ / (time_millis_ / 1e3), buf, "%.1f");
-        out += buf;
-        break;
-
-        // Current rate, average over the last '-j' jobs.
-      case 'c':
-        current_rate_.UpdateRate(finished_edges_, time_millis_);
-        SnprintfRate(current_rate_.rate(), buf, "%.1f");
-        out += buf;
-        break;
-
-        // Percentage
-      case 'p': {
-        int percent = (100 * finished_edges_) / total_edges_;
-        snprintf(buf, sizeof(buf), "%3i%%", percent);
-        out += buf;
-        break;
-      }
-
-      case 'e': {
-        snprintf(buf, sizeof(buf), "%.3f", time_millis_ / 1e3);
-        out += buf;
-        break;
-      }
-
-      default:
-        Fatal("unknown placeholder '%%%c' in $NINJA_STATUS", *s);
-        return "";
-      }
-    } else {
-      out.push_back(*s);
-    }
-  }
-
-  return out;
-}
-
-void BuildStatus::PrintStatus(const Edge* edge, int64_t time) {
-  if (config_.verbosity == BuildConfig::QUIET)
-    return;
-
-  bool force_full_command = config_.verbosity == BuildConfig::VERBOSE;
-
-  string to_print = edge->GetBinding("description");
-  if (to_print.empty() || force_full_command)
-    to_print = edge->GetBinding("command");
-
-  to_print = FormatProgressStatus(progress_status_format_, time) + to_print;
-
-  printer_.Print(to_print,
-                 force_full_command ? LinePrinter::FULL : LinePrinter::ELIDE);
-}
-
 Plan::Plan(Builder* builder)
   : builder_(builder)
   , command_edges_(0)
@@ -722,12 +499,12 @@ bool RealCommandRunner::WaitForCommand(Result* result) {
 
 Builder::Builder(State* state, const BuildConfig& config,
                  BuildLog* build_log, DepsLog* deps_log,
-                 DiskInterface* disk_interface, int64_t start_time_millis)
-    : state_(state), config_(config), plan_(this),
+                 DiskInterface* disk_interface, Status *status,
+                 int64_t start_time_millis)
+    : state_(state), config_(config), plan_(this), status_(status),
       start_time_millis_(start_time_millis), disk_interface_(disk_interface),
       scan_(state, build_log, deps_log, disk_interface,
             &config_.depfile_parser_options) {
-  status_ = new BuildStatus(config);
 }
 
 Builder::~Builder() {
diff --git a/src/build.h b/src/build.h
index 265723a..06823c2 100644
--- a/src/build.h
+++ b/src/build.h
@@ -25,16 +25,15 @@
 #include "depfile_parser.h"
 #include "graph.h"  // XXX needed for DependencyScan; should rearrange.
 #include "exit_status.h"
-#include "line_printer.h"
 #include "util.h"  // int64_t
 
 struct BuildLog;
-struct BuildStatus;
 struct Builder;
 struct DiskInterface;
 struct Edge;
 struct Node;
 struct State;
+struct Status;
 
 /// Plan stores the state of a build plan: what we intend to build,
 /// which steps we're ready to execute.
@@ -178,7 +177,8 @@ struct BuildConfig {
 struct Builder {
   Builder(State* state, const BuildConfig& config,
           BuildLog* build_log, DepsLog* deps_log,
-          DiskInterface* disk_interface, int64_t start_time_millis);
+          DiskInterface* disk_interface, Status* status,
+          int64_t start_time_millis);
   ~Builder();
 
   /// Clean up after interrupted commands by deleting output files.
@@ -219,7 +219,7 @@ struct Builder {
 #else
   std::unique_ptr<CommandRunner> command_runner_;  // auto_ptr was removed in C++17.
 #endif
-  BuildStatus* status_;
+  Status* status_;
 
  private:
   bool ExtractDeps(CommandRunner::Result* result, const std::string& deps_type,
@@ -241,72 +241,4 @@ struct Builder {
   void operator=(const Builder &other); // DO NOT IMPLEMENT
 };
 
-/// Tracks the status of a build: completion fraction, printing updates.
-struct BuildStatus {
-  explicit BuildStatus(const BuildConfig& config);
-  void PlanHasTotalEdges(int total);
-  void BuildEdgeStarted(const Edge* edge, int64_t start_time_millis);
-  void BuildEdgeFinished(Edge* edge, int64_t end_time_millis, bool success,
-                         const std::string& output);
-  void BuildLoadDyndeps();
-  void BuildStarted();
-  void BuildFinished();
-
-  /// Format the progress status string by replacing the placeholders.
-  /// See the user manual for more information about the available
-  /// placeholders.
-  /// @param progress_status_format The format of the progress status.
-  /// @param status The status of the edge.
-  std::string FormatProgressStatus(const char* progress_status_format,
-                                   int64_t time) const;
-
- private:
-  void PrintStatus(const Edge* edge, int64_t time);
-
-  const BuildConfig& config_;
-
-  int started_edges_, finished_edges_, total_edges_, running_edges_;
-  int64_t time_millis_;
-
-  /// Prints progress output.
-  LinePrinter printer_;
-
-  /// The custom progress status format to use.
-  const char* progress_status_format_;
-
-  template<size_t S>
-  void SnprintfRate(double rate, char(&buf)[S], const char* format) const {
-    if (rate == -1)
-      snprintf(buf, S, "?");
-    else
-      snprintf(buf, S, format, rate);
-  }
-
-  struct SlidingRateInfo {
-    SlidingRateInfo(int n) : rate_(-1), N(n), last_update_(-1) {}
-
-    double rate() { return rate_; }
-
-    void UpdateRate(int update_hint, int64_t time_millis_) {
-      if (update_hint == last_update_)
-        return;
-      last_update_ = update_hint;
-
-      if (times_.size() == N)
-        times_.pop();
-      times_.push(time_millis_);
-      if (times_.back() != times_.front())
-        rate_ = times_.size() / ((times_.back() - times_.front()) / 1e3);
-    }
-
-  private:
-    double rate_;
-    const size_t N;
-    std::queue<double> times_;
-    int last_update_;
-  };
-
-  mutable SlidingRateInfo current_rate_;
-};
-
 #endif  // NINJA_BUILD_H_
diff --git a/src/build_test.cc b/src/build_test.cc
index 1baec65..f58a7de 100644
--- a/src/build_test.cc
+++ b/src/build_test.cc
@@ -19,6 +19,7 @@
 #include "build_log.h"
 #include "deps_log.h"
 #include "graph.h"
+#include "status.h"
 #include "test.h"
 
 using namespace std;
@@ -485,14 +486,13 @@ struct FakeCommandRunner : public CommandRunner {
 };
 
 struct BuildTest : public StateTestWithBuiltinRules, public BuildLogUser {
-  BuildTest() : config_(MakeConfig()), command_runner_(&fs_),
-                builder_(&state_, config_, NULL, NULL, &fs_, 0),
-                status_(config_) {
+  BuildTest() : config_(MakeConfig()), command_runner_(&fs_), status_(config_),
+                builder_(&state_, config_, NULL, NULL, &fs_, &status_, 0) {
   }
 
   explicit BuildTest(DepsLog* log)
-      : config_(MakeConfig()), command_runner_(&fs_),
-        builder_(&state_, config_, NULL, log, &fs_, 0), status_(config_) {}
+      : config_(MakeConfig()), command_runner_(&fs_), status_(config_),
+        builder_(&state_, config_, NULL, log, &fs_, &status_, 0) {}
 
   virtual void SetUp() {
     StateTestWithBuiltinRules::SetUp();
@@ -532,9 +532,8 @@ struct BuildTest : public StateTestWithBuiltinRules, public BuildLogUser {
   BuildConfig config_;
   FakeCommandRunner command_runner_;
   VirtualFileSystem fs_;
+  StatusPrinter status_;
   Builder builder_;
-
-  BuildStatus status_;
 };
 
 void BuildTest::RebuildTarget(const string& target, const char* manifest,
@@ -563,7 +562,7 @@ void BuildTest::RebuildTarget(const string& target, const char* manifest,
     pdeps_log = &deps_log;
   }
 
-  Builder builder(pstate, config_, pbuild_log, pdeps_log, &fs_, 0);
+  Builder builder(pstate, config_, pbuild_log, pdeps_log, &fs_, &status_, 0);
   EXPECT_TRUE(builder.AddTarget(target, &err));
 
   command_runner_.commands_ran_.clear();
@@ -1400,7 +1399,8 @@ TEST_F(BuildWithLogTest, RestatTest) {
   ASSERT_EQ("", err);
   EXPECT_TRUE(builder_.Build(&err));
   ASSERT_EQ("", err);
-  EXPECT_EQ("[3/3]", builder_.status_->FormatProgressStatus("[%s/%t]", 0));
+  EXPECT_EQ(3u, command_runner_.commands_ran_.size());
+  EXPECT_EQ(3u, builder_.plan_.command_edge_count());
   command_runner_.commands_ran_.clear();
   state_.Reset();
 
@@ -2117,7 +2117,7 @@ TEST_F(BuildWithDepsLogTest, Straightforward) {
     ASSERT_TRUE(deps_log.OpenForWrite("ninja_deps", &err));
     ASSERT_EQ("", err);
 
-    Builder builder(&state, config_, NULL, &deps_log, &fs_, 0);
+    Builder builder(&state, config_, NULL, &deps_log, &fs_, &status_, 0);
     builder.command_runner_.reset(&command_runner_);
     EXPECT_TRUE(builder.AddTarget("out", &err));
     ASSERT_EQ("", err);
@@ -2147,7 +2147,7 @@ TEST_F(BuildWithDepsLogTest, Straightforward) {
     ASSERT_TRUE(deps_log.Load("ninja_deps", &state, &err));
     ASSERT_TRUE(deps_log.OpenForWrite("ninja_deps", &err));
 
-    Builder builder(&state, config_, NULL, &deps_log, &fs_, 0);
+    Builder builder(&state, config_, NULL, &deps_log, &fs_, &status_, 0);
     builder.command_runner_.reset(&command_runner_);
     command_runner_.commands_ran_.clear();
     EXPECT_TRUE(builder.AddTarget("out", &err));
@@ -2188,7 +2188,7 @@ TEST_F(BuildWithDepsLogTest, ObsoleteDeps) {
     ASSERT_TRUE(deps_log.OpenForWrite("ninja_deps", &err));
     ASSERT_EQ("", err);
 
-    Builder builder(&state, config_, NULL, &deps_log, &fs_, 0);
+    Builder builder(&state, config_, NULL, &deps_log, &fs_, &status_, 0);
     builder.command_runner_.reset(&command_runner_);
     EXPECT_TRUE(builder.AddTarget("out", &err));
     ASSERT_EQ("", err);
@@ -2217,7 +2217,7 @@ TEST_F(BuildWithDepsLogTest, ObsoleteDeps) {
     ASSERT_TRUE(deps_log.Load("ninja_deps", &state, &err));
     ASSERT_TRUE(deps_log.OpenForWrite("ninja_deps", &err));
 
-    Builder builder(&state, config_, NULL, &deps_log, &fs_, 0);
+    Builder builder(&state, config_, NULL, &deps_log, &fs_, &status_, 0);
     builder.command_runner_.reset(&command_runner_);
     command_runner_.commands_ran_.clear();
     EXPECT_TRUE(builder.AddTarget("out", &err));
@@ -2253,7 +2253,7 @@ TEST_F(BuildWithDepsLogTest, DepsIgnoredInDryRun) {
 
   // The deps log is NULL in dry runs.
   config_.dry_run = true;
-  Builder builder(&state, config_, NULL, NULL, &fs_, 0);
+  Builder builder(&state, config_, NULL, NULL, &fs_, &status_, 0);
   builder.command_runner_.reset(&command_runner_);
   command_runner_.commands_ran_.clear();
 
@@ -2311,7 +2311,7 @@ TEST_F(BuildWithDepsLogTest, RestatDepfileDependencyDepsLog) {
     ASSERT_TRUE(deps_log.OpenForWrite("ninja_deps", &err));
     ASSERT_EQ("", err);
 
-    Builder builder(&state, config_, NULL, &deps_log, &fs_, 0);
+    Builder builder(&state, config_, NULL, &deps_log, &fs_, &status_, 0);
     builder.command_runner_.reset(&command_runner_);
     EXPECT_TRUE(builder.AddTarget("out", &err));
     ASSERT_EQ("", err);
@@ -2337,7 +2337,7 @@ TEST_F(BuildWithDepsLogTest, RestatDepfileDependencyDepsLog) {
     ASSERT_TRUE(deps_log.Load("ninja_deps", &state, &err));
     ASSERT_TRUE(deps_log.OpenForWrite("ninja_deps", &err));
 
-    Builder builder(&state, config_, NULL, &deps_log, &fs_, 0);
+    Builder builder(&state, config_, NULL, &deps_log, &fs_, &status_, 0);
     builder.command_runner_.reset(&command_runner_);
     command_runner_.commands_ran_.clear();
     EXPECT_TRUE(builder.AddTarget("out", &err));
@@ -2370,7 +2370,7 @@ TEST_F(BuildWithDepsLogTest, DepFileOKDepsLog) {
     ASSERT_TRUE(deps_log.OpenForWrite("ninja_deps", &err));
     ASSERT_EQ("", err);
 
-    Builder builder(&state, config_, NULL, &deps_log, &fs_, 0);
+    Builder builder(&state, config_, NULL, &deps_log, &fs_, &status_, 0);
     builder.command_runner_.reset(&command_runner_);
     EXPECT_TRUE(builder.AddTarget("fo o.o", &err));
     ASSERT_EQ("", err);
@@ -2391,7 +2391,7 @@ TEST_F(BuildWithDepsLogTest, DepFileOKDepsLog) {
     ASSERT_TRUE(deps_log.OpenForWrite("ninja_deps", &err));
     ASSERT_EQ("", err);
 
-    Builder builder(&state, config_, NULL, &deps_log, &fs_, 0);
+    Builder builder(&state, config_, NULL, &deps_log, &fs_, &status_, 0);
     builder.command_runner_.reset(&command_runner_);
 
     Edge* edge = state.edges_.back();
@@ -2432,7 +2432,7 @@ TEST_F(BuildWithDepsLogTest, DepFileDepsLogCanonicalize) {
     ASSERT_TRUE(deps_log.OpenForWrite("ninja_deps", &err));
     ASSERT_EQ("", err);
 
-    Builder builder(&state, config_, NULL, &deps_log, &fs_, 0);
+    Builder builder(&state, config_, NULL, &deps_log, &fs_, &status_, 0);
     builder.command_runner_.reset(&command_runner_);
     EXPECT_TRUE(builder.AddTarget("a/b/c/d/e/fo o.o", &err));
     ASSERT_EQ("", err);
@@ -2455,7 +2455,7 @@ TEST_F(BuildWithDepsLogTest, DepFileDepsLogCanonicalize) {
     ASSERT_TRUE(deps_log.OpenForWrite("ninja_deps", &err));
     ASSERT_EQ("", err);
 
-    Builder builder(&state, config_, NULL, &deps_log, &fs_, 0);
+    Builder builder(&state, config_, NULL, &deps_log, &fs_, &status_, 0);
     builder.command_runner_.reset(&command_runner_);
 
     Edge* edge = state.edges_.back();
diff --git a/src/ninja.cc b/src/ninja.cc
index 57690be..d92e95b 100644
--- a/src/ninja.cc
+++ b/src/ninja.cc
@@ -43,6 +43,7 @@
 #include "manifest_parser.h"
 #include "metrics.h"
 #include "state.h"
+#include "status.h"
 #include "util.h"
 #include "version.h"
 
@@ -145,11 +146,11 @@ struct NinjaMain : public BuildLogUser {
   /// Rebuild the manifest, if necessary.
   /// Fills in \a err on error.
   /// @return true if the manifest was rebuilt.
-  bool RebuildManifest(const char* input_file, string* err);
+  bool RebuildManifest(const char* input_file, string* err, Status* status);
 
   /// Build the targets listed on the command line.
   /// @return an exit code.
-  int RunBuild(int argc, char** argv);
+  int RunBuild(int argc, char** argv, Status* status);
 
   /// Dump the output requested by '-d stats'.
   void DumpMetrics();
@@ -243,7 +244,8 @@ int GuessParallelism() {
 
 /// Rebuild the build manifest, if necessary.
 /// Returns true if the manifest was rebuilt.
-bool NinjaMain::RebuildManifest(const char* input_file, string* err) {
+bool NinjaMain::RebuildManifest(const char* input_file, string* err,
+                                Status *status) {
   string path = input_file;
   uint64_t slash_bits;  // Unused because this path is only used for lookup.
   if (!CanonicalizePath(&path, &slash_bits, err))
@@ -253,7 +255,7 @@ bool NinjaMain::RebuildManifest(const char* input_file, string* err) {
     return false;
 
   Builder builder(&state_, config_, &build_log_, &deps_log_, &disk_interface_,
-                  start_time_millis_);
+                  status, start_time_millis_);
   if (!builder.AddTarget(node, err))
     return false;
 
@@ -1193,7 +1195,7 @@ bool NinjaMain::EnsureBuildDirExists() {
   return true;
 }
 
-int NinjaMain::RunBuild(int argc, char** argv) {
+int NinjaMain::RunBuild(int argc, char** argv, Status* status) {
   string err;
   vector<Node*> targets;
   if (!CollectTargetsFromArgs(argc, argv, &targets, &err)) {
@@ -1204,7 +1206,7 @@ int NinjaMain::RunBuild(int argc, char** argv) {
   disk_interface_.AllowStatCache(g_experimental_statcache);
 
   Builder builder(&state_, config_, &build_log_, &deps_log_, &disk_interface_,
-                  start_time_millis_);
+                  status, start_time_millis_);
   for (size_t i = 0; i < targets.size(); ++i) {
     if (!builder.AddTarget(targets[i], &err)) {
       if (!err.empty()) {
@@ -1364,6 +1366,8 @@ NORETURN void real_main(int argc, char** argv) {
   if (exit_code >= 0)
     exit(exit_code);
 
+  Status* status = new StatusPrinter(config);
+
   if (options.working_dir) {
     // The formatting of this string, complete with funny quotes, is
     // so Emacs can properly identify that the cwd has changed for
@@ -1416,7 +1420,7 @@ NORETURN void real_main(int argc, char** argv) {
       exit((ninja.*options.tool->func)(&options, argc, argv));
 
     // Attempt to rebuild the manifest before building anything else
-    if (ninja.RebuildManifest(options.input_file, &err)) {
+    if (ninja.RebuildManifest(options.input_file, &err, status)) {
       // In dry_run mode the regeneration will succeed without changing the
       // manifest forever. Better to return immediately.
       if (config.dry_run)
@@ -1428,7 +1432,7 @@ NORETURN void real_main(int argc, char** argv) {
       exit(1);
     }
 
-    int result = ninja.RunBuild(argc, argv);
+    int result = ninja.RunBuild(argc, argv, status);
     if (g_metrics)
       ninja.DumpMetrics();
     exit(result);
diff --git a/src/status.cc b/src/status.cc
new file mode 100644
index 0000000..a308f62
--- /dev/null
+++ b/src/status.cc
@@ -0,0 +1,244 @@
+// Copyright 2016 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "status.h"
+
+#include <stdlib.h>
+
+#ifdef _WIN32
+#include <fcntl.h>
+#include <io.h>
+#endif
+
+#include "debug_flags.h"
+
+using namespace std;
+
+StatusPrinter::StatusPrinter(const BuildConfig& config)
+    : config_(config),
+      started_edges_(0), finished_edges_(0), total_edges_(0), running_edges_(0),
+      time_millis_(0), progress_status_format_(NULL),
+      current_rate_(config.parallelism) {
+
+  // Don't do anything fancy in verbose mode.
+  if (config_.verbosity != BuildConfig::NORMAL)
+    printer_.set_smart_terminal(false);
+
+  progress_status_format_ = getenv("NINJA_STATUS");
+  if (!progress_status_format_)
+    progress_status_format_ = "[%f/%t] ";
+}
+
+void StatusPrinter::PlanHasTotalEdges(int total) {
+  total_edges_ = total;
+}
+
+void StatusPrinter::BuildEdgeStarted(const Edge* edge,
+                                     int64_t start_time_millis) {
+  ++started_edges_;
+  ++running_edges_;
+  time_millis_ = start_time_millis;
+
+  if (edge->use_console() || printer_.is_smart_terminal())
+    PrintStatus(edge, start_time_millis);
+
+  if (edge->use_console())
+    printer_.SetConsoleLocked(true);
+}
+
+void StatusPrinter::BuildEdgeFinished(Edge* edge, int64_t end_time_millis,
+                                      bool success, const string& output) {
+  time_millis_ = end_time_millis;
+  ++finished_edges_;
+
+  if (edge->use_console())
+    printer_.SetConsoleLocked(false);
+
+  if (config_.verbosity == BuildConfig::QUIET)
+    return;
+
+  if (!edge->use_console())
+    PrintStatus(edge, end_time_millis);
+
+  --running_edges_;
+
+  // Print the command that is spewing before printing its output.
+  if (!success) {
+    string outputs;
+    for (vector<Node*>::const_iterator o = edge->outputs_.begin();
+         o != edge->outputs_.end(); ++o)
+      outputs += (*o)->path() + " ";
+
+    if (printer_.supports_color()) {
+        printer_.PrintOnNewLine("\x1B[31m" "FAILED: " "\x1B[0m" + outputs + "\n");
+    } else {
+        printer_.PrintOnNewLine("FAILED: " + outputs + "\n");
+    }
+    printer_.PrintOnNewLine(edge->EvaluateCommand() + "\n");
+  }
+
+  if (!output.empty()) {
+    // ninja sets stdout and stderr of subprocesses to a pipe, to be able to
+    // check if the output is empty. Some compilers, e.g. clang, check
+    // isatty(stderr) to decide if they should print colored output.
+    // To make it possible to use colored output with ninja, subprocesses should
+    // be run with a flag that forces them to always print color escape codes.
+    // To make sure these escape codes don't show up in a file if ninja's output
+    // is piped to a file, ninja strips ansi escape codes again if it's not
+    // writing to a |smart_terminal_|.
+    // (Launching subprocesses in pseudo ttys doesn't work because there are
+    // only a few hundred available on some systems, and ninja can launch
+    // thousands of parallel compile commands.)
+    string final_output;
+    if (!printer_.supports_color())
+      final_output = StripAnsiEscapeCodes(output);
+    else
+      final_output = output;
+
+#ifdef _WIN32
+    // Fix extra CR being added on Windows, writing out CR CR LF (#773)
+    _setmode(_fileno(stdout), _O_BINARY);  // Begin Windows extra CR fix
+#endif
+
+    printer_.PrintOnNewLine(final_output);
+
+#ifdef _WIN32
+    _setmode(_fileno(stdout), _O_TEXT);  // End Windows extra CR fix
+#endif
+  }
+}
+
+void StatusPrinter::BuildLoadDyndeps() {
+  // The DependencyScan calls EXPLAIN() to print lines explaining why
+  // it considers a portion of the graph to be out of date.  Normally
+  // this is done before the build starts, but our caller is about to
+  // load a dyndep file during the build.  Doing so may generate more
+  // explanation lines (via fprintf directly to stderr), but in an
+  // interactive console the cursor is currently at the end of a status
+  // line.  Start a new line so that the first explanation does not
+  // append to the status line.  After the explanations are done a
+  // new build status line will appear.
+  if (g_explaining)
+    printer_.PrintOnNewLine("");
+}
+
+void StatusPrinter::BuildStarted() {
+  started_edges_ = 0;
+  finished_edges_ = 0;
+  running_edges_ = 0;
+}
+
+void StatusPrinter::BuildFinished() {
+  printer_.SetConsoleLocked(false);
+  printer_.PrintOnNewLine("");
+}
+
+string StatusPrinter::FormatProgressStatus(const char* progress_status_format,
+                                           int64_t time_millis) const {
+  string out;
+  char buf[32];
+  for (const char* s = progress_status_format; *s != '\0'; ++s) {
+    if (*s == '%') {
+      ++s;
+      switch (*s) {
+      case '%':
+        out.push_back('%');
+        break;
+
+        // Started edges.
+      case 's':
+        snprintf(buf, sizeof(buf), "%d", started_edges_);
+        out += buf;
+        break;
+
+        // Total edges.
+      case 't':
+        snprintf(buf, sizeof(buf), "%d", total_edges_);
+        out += buf;
+        break;
+
+        // Running edges.
+      case 'r': {
+        snprintf(buf, sizeof(buf), "%d", running_edges_);
+        out += buf;
+        break;
+      }
+
+        // Unstarted edges.
+      case 'u':
+        snprintf(buf, sizeof(buf), "%d", total_edges_ - started_edges_);
+        out += buf;
+        break;
+
+        // Finished edges.
+      case 'f':
+        snprintf(buf, sizeof(buf), "%d", finished_edges_);
+        out += buf;
+        break;
+
+        // Overall finished edges per second.
+      case 'o':
+        SnprintfRate(finished_edges_ / (time_millis_ / 1e3), buf, "%.1f");
+        out += buf;
+        break;
+
+        // Current rate, average over the last '-j' jobs.
+      case 'c':
+        current_rate_.UpdateRate(finished_edges_, time_millis_);
+        SnprintfRate(current_rate_.rate(), buf, "%.1f");
+        out += buf;
+        break;
+
+        // Percentage
+      case 'p': {
+        int percent = (100 * finished_edges_) / total_edges_;
+        snprintf(buf, sizeof(buf), "%3i%%", percent);
+        out += buf;
+        break;
+      }
+
+      case 'e': {
+        snprintf(buf, sizeof(buf), "%.3f", time_millis_ / 1e3);
+        out += buf;
+        break;
+      }
+
+      default:
+        Fatal("unknown placeholder '%%%c' in $NINJA_STATUS", *s);
+        return "";
+      }
+    } else {
+      out.push_back(*s);
+    }
+  }
+
+  return out;
+}
+
+void StatusPrinter::PrintStatus(const Edge* edge, int64_t time_millis) {
+  if (config_.verbosity == BuildConfig::QUIET)
+    return;
+
+  bool force_full_command = config_.verbosity == BuildConfig::VERBOSE;
+
+  string to_print = edge->GetBinding("description");
+  if (to_print.empty() || force_full_command)
+    to_print = edge->GetBinding("command");
+
+  to_print = FormatProgressStatus(progress_status_format_, time_millis)
+      + to_print;
+
+  printer_.Print(to_print,
+                 force_full_command ? LinePrinter::FULL : LinePrinter::ELIDE);
+}
diff --git a/src/status.h b/src/status.h
new file mode 100644
index 0000000..8344b8e
--- /dev/null
+++ b/src/status.h
@@ -0,0 +1,107 @@
+// Copyright 2016 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef NINJA_STATUS_H_
+#define NINJA_STATUS_H_
+
+#include <map>
+#include <string>
+
+#include "build.h"
+#include "line_printer.h"
+
+/// Abstract interface to object that tracks the status of a build:
+/// completion fraction, printing updates.
+struct Status {
+  virtual void PlanHasTotalEdges(int total) = 0;
+  virtual void BuildEdgeStarted(const Edge* edge, int64_t start_time_millis) = 0;
+  virtual void BuildEdgeFinished(Edge* edge, int64_t end_time_millis,
+                                 bool success, const std::string& output) = 0;
+  virtual void BuildLoadDyndeps() = 0;
+  virtual void BuildStarted() = 0;
+  virtual void BuildFinished() = 0;
+  virtual ~Status() { }
+};
+
+/// Implementation of the BuildStatus interface that prints the status as
+/// human-readable strings to stdout
+struct StatusPrinter : Status {
+  explicit StatusPrinter(const BuildConfig& config);
+  virtual void PlanHasTotalEdges(int total);
+  virtual void BuildEdgeStarted(const Edge* edge, int64_t start_time_millis);
+  virtual void BuildEdgeFinished(Edge* edge, int64_t end_time_millis,
+                                 bool success, const std::string& output);
+  virtual void BuildLoadDyndeps();
+  virtual void BuildStarted();
+  virtual void BuildFinished();
+  virtual ~StatusPrinter() { }
+
+  /// Format the progress status string by replacing the placeholders.
+  /// See the user manual for more information about the available
+  /// placeholders.
+  /// @param progress_status_format The format of the progress status.
+  /// @param status The status of the edge.
+  std::string FormatProgressStatus(const char* progress_status_format,
+                                   int64_t time_millis) const;
+
+ private:
+  void PrintStatus(const Edge* edge, int64_t time_millis);
+
+  const BuildConfig& config_;
+
+  int started_edges_, finished_edges_, total_edges_, running_edges_;
+  int64_t time_millis_;
+
+  /// Prints progress output.
+  LinePrinter printer_;
+
+  /// The custom progress status format to use.
+  const char* progress_status_format_;
+
+  template<size_t S>
+  void SnprintfRate(double rate, char(&buf)[S], const char* format) const {
+    if (rate == -1)
+      snprintf(buf, S, "?");
+    else
+      snprintf(buf, S, format, rate);
+  }
+
+  struct SlidingRateInfo {
+    SlidingRateInfo(int n) : rate_(-1), N(n), last_update_(-1) {}
+
+    double rate() { return rate_; }
+
+    void UpdateRate(int update_hint, int64_t time_millis_) {
+      if (update_hint == last_update_)
+        return;
+      last_update_ = update_hint;
+
+      if (times_.size() == N)
+        times_.pop();
+      times_.push(time_millis_);
+      if (times_.back() != times_.front())
+        rate_ = times_.size() / ((times_.back() - times_.front()) / 1e3);
+    }
+
+  private:
+    double rate_;
+    const size_t N;
+    std::queue<double> times_;
+    int last_update_;
+  };
+
+  mutable SlidingRateInfo current_rate_;
+};
+
+#endif // NINJA_STATUS_H_
diff --git a/src/status_test.cc b/src/status_test.cc
new file mode 100644
index 0000000..6e42490
--- /dev/null
+++ b/src/status_test.cc
@@ -0,0 +1,35 @@
+// Copyright 2011 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "status.h"
+
+#include "test.h"
+
+TEST(StatusTest, StatusFormatElapsed) {
+  BuildConfig config;
+  StatusPrinter status(config);
+
+  status.BuildStarted();
+  // Before any task is done, the elapsed time must be zero.
+  EXPECT_EQ("[%/e0.000]",
+            status.FormatProgressStatus("[%%/e%e]", 0));
+}
+
+TEST(StatusTest, StatusFormatReplacePlaceholder) {
+  BuildConfig config;
+  StatusPrinter status(config);
+
+  EXPECT_EQ("[%/s0/t0/r0/u0/f0]",
+            status.FormatProgressStatus("[%%/s%s/t%t/r%r/u%u/f%f]", 0));
+}