Add option to specify the path of the stats file

Summary: Fix a FILE* leak along the way.

Reviewed By: @jdelong

Differential Revision: D2194625

hphp/hhbbc/hhbbc.h

@@ -256,12 +256,18 @@ struct Options {
    */
   bool HardPrivatePropInference = true;
 
-  /**
+  /*
    * If true, we'll assume that dynamic function calls (like '$f()') do not
    * have effects on unknown locals (i.e. are not extract / compact /...).
    * See, e.g. __SystemLib\\extract vs extract.
    */
   bool DisallowDynamicVarEnvFuncs = true;
+
+  /*
+   * The filepath where to save the stats file.  If the path is empty, then we
+   * save the stats file to a temporary file.
+   */
+  std::string stats_file;
 };
 extern Options options;
 

hphp/hhbbc/main.cpp

@@ -39,6 +39,7 @@
 #include "hphp/runtime/vm/repo-global-data.h"
 
 #include "hphp/hhbbc/misc.h"
+#include "hphp/hhbbc/stats.h"
 #include "hphp/hhbbc/parallel.h"
 
 namespace HPHP { namespace HHBBC {
@@ -75,6 +76,9 @@ void parse_options(int argc, char** argv) {
     ("input",
       po::value(&input_repo)->default_value("hhvm.hhbc"),
       "input hhbc repo path")
+    ("stats-file",
+      po::value(&options.stats_file)->default_value(""),
+      "stats file path")
     ("no-optimizations",
       po::bool_switch(&options.NoOptimizations),
       "turn off all optimizations")

hphp/hhbbc/stats.cpp

@@ -520,17 +520,32 @@ void print_stats(const Index& index, const php::Program& program) {
     std::cout << str;
   }
 
-  char fileBuf[] = "/tmp/hhbbcXXXXXX";
-  int fd = mkstemp(fileBuf);
-  if (fd == -1) {
-    std::cerr << "couldn't open temporary file for stats: "
+  auto stats_file = options.stats_file;
+
+  auto const file = [&] () -> std::FILE* {
+    if (!stats_file.empty()) {
+      return fopen(stats_file.c_str(), "w");
+    }
+
+    char fileBuf[] = "/tmp/hhbbcXXXXXX";
+    auto const fd = mkstemp(fileBuf);
+    stats_file = fileBuf;
+    if (fd == -1) return nullptr;
+
+    if (auto const fp = fdopen(fd, "w")) return fp;
+    close(fd);
+    return nullptr;
+  }();
+
+  if (file == nullptr) {
+    std::cerr << "couldn't open file for stats: "
               << folly::errnoStr(errno) << '\n';
     return;
   }
-  SCOPE_EXIT { close(fd); };
-  auto file = fdopen(fd, "w");
-  std::cout << "stats saved to " << fileBuf << '\n';
-  std::fprintf(file, "%s", str.c_str());
+
+  SCOPE_EXIT { fclose(file); };
+  std::cout << "stats saved to " << stats_file << '\n';
+  std::fwrite(str.c_str(), sizeof(char), str.size(), file);
   std::fflush(file);
 }