add -d keeprsp to preserve @rsp files on success on windows

configure.py

@@ -263,12 +263,12 @@ n.comment('Core source files all build into ninja library.')
 for name in ['build',
              'build_log',
              'clean',
+             'debug_flags',
              'depfile_parser',
              'deps_log',
              'disk_interface',
              'edit_distance',
              'eval_env',
-             'explain',
              'graph',
              'graphviz',
              'lexer',

src/build.cc

@@ -25,6 +25,7 @@
 #endif
 
 #include "build_log.h"
+#include "debug_flags.h"
 #include "depfile_parser.h"
 #include "deps_log.h"
 #include "disk_interface.h"
@@ -776,7 +777,7 @@ bool Builder::FinishCommand(CommandRunner::Result* result, string* err) {
 
   // Delete any left over response file.
   string rspfile = edge->GetBinding("rspfile");
-  if (!rspfile.empty())
+  if (!rspfile.empty() && !g_keep_rsp)
     disk_interface_->RemoveFile(rspfile);
 
   if (scan_.build_log()) {

src/debug_flags.cc

@@ -13,3 +13,5 @@
 // limitations under the License.
 
 bool g_explaining = false;
+
+bool g_keep_rsp = false;

src/debug_flags.h

@@ -24,4 +24,6 @@
 
 extern bool g_explaining;
 
+extern bool g_keep_rsp;
+
 #endif // NINJA_EXPLAIN_H_

src/graph.cc

@@ -18,10 +18,10 @@
 #include <stdio.h>
 
 #include "build_log.h"
+#include "debug_flags.h"
 #include "depfile_parser.h"
 #include "deps_log.h"
 #include "disk_interface.h"
-#include "explain.h"
 #include "manifest_parser.h"
 #include "metrics.h"
 #include "state.h"

src/ninja.cc

@@ -32,8 +32,8 @@
 #include "build_log.h"
 #include "deps_log.h"
 #include "clean.h"
+#include "debug_flags.h"
 #include "disk_interface.h"
-#include "explain.h"
 #include "graph.h"
 #include "graphviz.h"
 #include "manifest_parser.h"
@@ -747,6 +747,7 @@ bool DebugEnable(const string& name) {
     printf("debugging modes:\n"
 "  stats    print operation counts/timing info\n"
 "  explain  explain what caused a command to execute\n"
+"  keeprsp  don't delete @response files on success\n"
 "multiple modes can be enabled via -d FOO -d BAR\n");
     return false;
   } else if (name == "stats") {
@@ -755,6 +756,9 @@ bool DebugEnable(const string& name) {
   } else if (name == "explain") {
     g_explaining = true;
     return true;
+  } else if (name == "keeprsp") {
+    g_keep_rsp = true;
+    return true;
   } else {
     const char* suggestion =
         SpellcheckString(name.c_str(), "stats", "explain", NULL);