Allow to change also order of description in NINJA_STATUS

This commit adds new format string %d for printing description. When %d is
not specified in NINJA_STATUS, then description is automatically printed at
the end of line.

This allows to add additional strings after description, for example
changing colors on ANSI terminals via NINJA_STATUS variable.

src/build.cc

@@ -156,10 +156,12 @@ void BuildStatus::BuildFinished() {
 }
 
 string BuildStatus::FormatProgressStatus(
-    const char* progress_status_format) const {
+    const char* progress_status_format,
+    const string to_print) const {
   string out;
   char buf[32];
   int percent;
+  bool has_desc = false;
   char total_edges_str[32];
   snprintf(total_edges_str, sizeof(total_edges_str), "%d", total_edges_);
   int total_edges_len = strlen(total_edges_str);
@@ -228,6 +230,12 @@ string BuildStatus::FormatProgressStatus(
         break;
       }
 
+        // Description (to_print)
+      case 'd':
+        out += to_print;
+        has_desc = true;
+        break;
+
       default:
         Fatal("unknown placeholder '%%%c' in $NINJA_STATUS", *s);
         return "";
@@ -237,6 +245,9 @@ string BuildStatus::FormatProgressStatus(
     }
   }
 
+  if (!has_desc)
+    out += to_print;
+
   return out;
 }
 
@@ -254,7 +265,7 @@ void BuildStatus::PrintStatus(Edge* edge) {
     overall_rate_.Restart();
     current_rate_.Restart();
   }
-  to_print = FormatProgressStatus(progress_status_format_) + to_print;
+  to_print = FormatProgressStatus(progress_status_format_, to_print);
 
   printer_.Print(to_print,
                  force_full_command ? LinePrinter::FULL : LinePrinter::ELIDE);

src/build.h

@@ -202,7 +202,7 @@ struct BuildStatus {
   /// See the user manual for more information about the available
   /// placeholders.
   /// @param progress_status_format The format of the progress status.
-  string FormatProgressStatus(const char* progress_status_format) const;
+  string FormatProgressStatus(const char* progress_status_format, const string to_print) const;
 
  private:
   void PrintStatus(Edge* edge);

src/build_test.cc

@@ -1181,7 +1181,7 @@ TEST_F(BuildWithLogTest, RestatTest) {
   ASSERT_EQ("", err);
   EXPECT_TRUE(builder_.Build(&err));
   ASSERT_EQ("", err);
-  EXPECT_EQ("[3/3]", builder_.status_->FormatProgressStatus("[%s/%t]"));
+  EXPECT_EQ("[3/3]", builder_.status_->FormatProgressStatus("[%s/%t]", ""));
   command_runner_.commands_ran_.clear();
   state_.Reset();
 
@@ -1621,7 +1621,7 @@ TEST_F(BuildTest, DepsGccWithEmptyDepfileErrorsOut) {
 
 TEST_F(BuildTest, StatusFormatReplacePlaceholder) {
   EXPECT_EQ("[%/s0/t0/r0/u0/f0]",
-            status_.FormatProgressStatus("[%%/s%s/t%t/r%r/u%u/f%f]"));
+            status_.FormatProgressStatus("[%%/s%s/t%t/r%r/u%u/f%f]", ""));
 }
 
 TEST_F(BuildTest, FailedDepsParse) {