Modify tensorflow command line flag parsing:

- Allow help text to be specified for each flag
- Add a flag "--help" to print the help text
- Rename ParseFlags to Flags::Parse(); new routine Flags::Usage() returns a
  usage message.
- Change uses to new format
  In some cases reorder with InitMain(), which should be called after flag parsing.
Change: 136212902

1 files changed, 59 insertions, 11 deletions

diff --git a/tensorflow/core/util/command_line_flags.cc b/tensorflow/core/util/command_line_flags.cc
index 2048126338..03eb076f30 100644
--- a/tensorflow/core/util/command_line_flags.cc
+++ b/tensorflow/core/util/command_line_flags.cc
@@ -13,9 +13,13 @@ See the License for the specific language governing permissions and
 limitations under the License.
 ==============================================================================*/
 
-#include "tensorflow/core/util/command_line_flags.h"
+#include <string>
+#include <vector>
+
 #include "tensorflow/core/lib/core/stringpiece.h"
+#include "tensorflow/core/lib/strings/stringprintf.h"
 #include "tensorflow/core/platform/logging.h"
+#include "tensorflow/core/util/command_line_flags.h"
 
 namespace tensorflow {
 namespace {
@@ -91,17 +95,26 @@ bool ParseBoolFlag(tensorflow::StringPiece arg, tensorflow::StringPiece flag,
 
 }  // namespace
 
-Flag::Flag(const char* name, tensorflow::int32* dst)
-    : name_(name), type_(TYPE_INT), int_value_(dst) {}
+Flag::Flag(const char* name, tensorflow::int32* dst, const string& usage_text)
+    : name_(name), type_(TYPE_INT), int_value_(dst), usage_text_(usage_text) {}
 
-Flag::Flag(const char* name, tensorflow::int64* dst)
-    : name_(name), type_(TYPE_INT64), int64_value_(dst) {}
+Flag::Flag(const char* name, tensorflow::int64* dst, const string& usage_text)
+    : name_(name),
+      type_(TYPE_INT64),
+      int64_value_(dst),
+      usage_text_(usage_text) {}
 
-Flag::Flag(const char* name, bool* dst)
-    : name_(name), type_(TYPE_BOOL), bool_value_(dst) {}
+Flag::Flag(const char* name, bool* dst, const string& usage_text)
+    : name_(name),
+      type_(TYPE_BOOL),
+      bool_value_(dst),
+      usage_text_(usage_text) {}
 
-Flag::Flag(const char* name, string* dst)
-    : name_(name), type_(TYPE_STRING), string_value_(dst) {}
+Flag::Flag(const char* name, string* dst, const string& usage_text)
+    : name_(name),
+      type_(TYPE_STRING),
+      string_value_(dst),
+      usage_text_(usage_text) {}
 
 bool Flag::Parse(string arg, bool* value_parsing_ok) const {
   bool result = false;
@@ -117,7 +130,8 @@ bool Flag::Parse(string arg, bool* value_parsing_ok) const {
   return result;
 }
 
-bool ParseFlags(int* argc, char** argv, const std::vector<Flag>& flag_list) {
+/*static*/ bool Flags::Parse(int* argc, char** argv,
+                             const std::vector<Flag>& flag_list) {
   bool result = true;
   std::vector<char*> unknown_flags;
   for (int i = 1; i < *argc; ++i) {
@@ -151,7 +165,41 @@ bool ParseFlags(int* argc, char** argv, const std::vector<Flag>& flag_list) {
   }
   argv[dst++] = nullptr;
   *argc = unknown_flags.size() + 1;
-  return result;
+  return result && (*argc < 2 || strcmp(argv[1], "--help") != 0);
+}
+
+/*static*/ string Flags::Usage(const string& cmdline,
+                               const std::vector<Flag>& flag_list) {
+  string usage_text;
+  if (!flag_list.empty()) {
+    strings::Appendf(&usage_text, "usage: %s\nFlags:\n", cmdline.c_str());
+  } else {
+    strings::Appendf(&usage_text, "usage: %s\n", cmdline.c_str());
+  }
+  for (const Flag& flag : flag_list) {
+    const char* type_name = "";
+    string flag_string;
+    if (flag.type_ == Flag::TYPE_INT) {
+      type_name = "int32";
+      flag_string =
+          strings::Printf("--%s=%d", flag.name_.c_str(), *flag.int_value_);
+    } else if (flag.type_ == Flag::TYPE_INT64) {
+      type_name = "int64";
+      flag_string = strings::Printf("--%s=%lld", flag.name_.c_str(),
+                                    static_cast<long long>(*flag.int64_value_));
+    } else if (flag.type_ == Flag::TYPE_BOOL) {
+      type_name = "bool";
+      flag_string = strings::Printf("--%s=%s", flag.name_.c_str(),
+                                    *flag.bool_value_ ? "true" : "false");
+    } else if (flag.type_ == Flag::TYPE_STRING) {
+      type_name = "string";
+      flag_string = strings::Printf("--%s=\"%s\"", flag.name_.c_str(),
+                                    flag.string_value_->c_str());
+    }
+    strings::Appendf(&usage_text, "\t%-33s\t%s\t%s\n", flag_string.c_str(),
+                     type_name, flag.usage_text_.c_str());
+  }
+  return usage_text;
 }
 
 }  // namespace tensorflow