Remove absl dependency

.gitmodules

@@ -10,7 +10,3 @@
 	path = third_party/protobuf
 	url = https://github.com/protocolbuffers/protobuf
 	branch = master
-[submodule "third_party/absl"]
-	path = third_party/absl
-	url = https://github.com/abseil/abseil-cpp
-	branch = master

CMakeLists.txt

@@ -12,19 +12,18 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-cmake_minimum_required(VERSION 3.0.2)
+cmake_minimum_required(VERSION 3.1)
 
 # Do not install gtest since we are embedding googletest.
 option(INSTALL_GTEST "Do not install gtest since we are embedding googletest" OFF)
 
 project(ukey2)
 
+set(CMAKE_CXX_STANDARD 11)
+
 option(ukey2_USE_LOCAL_PROTOBUF
        "Use local copy of protobuf library and compiler" OFF)
 
-option(ukey2_USE_LOCAL_ABSL
-       "Use local copy of abseil-cpp library" OFF)
-
 option(BYPASS_TESTING
        "Do not build or run tests" OFF)
 
@@ -35,14 +34,6 @@ if (ukey2_USE_LOCAL_PROTOBUF)
   include(cmake/local_build_protobuf.cmake)
 endif()
 
-if (ukey2_USE_LOCAL_ABSL)
-  if (NOT TARGET absl::base)
-    add_subdirectory(third_party/absl)
-  endif()
-else()
-  find_package(absl REQUIRED)
-endif()
-
 find_package(Protobuf REQUIRED)
 
 enable_testing()

README.md

@@ -343,7 +343,7 @@ git submodule update --init --recursive
 ```
 cd <source root>
 mkdir build; cd build
-cmake -Dukey2_USE_LOCAL_PROTOBUF=ON -Dukey2_USE_LOCAL_ABSL=ON -DCMAKE_INSTALL_PREFIX=/tmp/ukey2_install ..
+cmake -Dukey2_USE_LOCAL_PROTOBUF=ON -DCMAKE_INSTALL_PREFIX=/tmp/ukey2_install ..
 make
 make install
 ```

src/main/cpp/src/securegcm/CMakeLists.txt

@@ -40,8 +40,4 @@ target_link_libraries(ukey2_shell
   PUBLIC
     securemessage
     ukey2
-    absl::base
-    absl::fixed_array
-    absl::flags
-    absl::flags_parse
 )

src/main/cpp/src/securegcm/ukey2_shell.cc

@@ -39,21 +39,13 @@
 #include <iostream>
 #include <memory>
 
+#include <getopt.h>
+
 #include "securegcm/ukey2_handshake.h"
-#include "absl/container/fixed_array.h"
-#include "absl/flags/flag.h"
-#include "absl/flags/parse.h"
 
 #define LOG(ERROR) std::cerr
 #define CHECK_EQ(a, b) do { if ((a) != (b)) abort(); } while(0)
 
-ABSL_FLAG(
-    int, verification_string_length, 32,
-    "The length in bytes of the verification string. Must be a value between 1"
-    "and 32.");
-ABSL_FLAG(string, mode, "initiator",
-          "The mode to run as: one of [initiator, responder]");
-
 namespace securegcm {
 
 namespace {
@@ -86,10 +78,10 @@ string ReadFrame() {
   length |= static_cast<uint32_t>(length_data[3]) << (0 * 8);
 
   // Read |length| bytes from the stream.
-  absl::FixedArray<char> buffer(length);
-  CHECK_EQ(length, fread(buffer.data(), 1, length, stdin));
+  std::unique_ptr<char[]> buffer(new char[length]);
+  CHECK_EQ(length, fread(buffer.get(), 1, length, stdin));
 
-  return string(buffer.data(), length);
+  return string(buffer.get(), length);
 }
 
 }  // namespace
@@ -271,11 +263,54 @@ bool UKey2Shell::RunAsResponder() {
 
 }  // namespace securegcm
 
+static void printUsage(char* name) {
+  std::string exec_name(name);
+  std::string usage(
+
+      "ICACHE is a command-line based wrapper, exercising the\n"
+      "UKey2Handshake class. Its main use is to be run in a Java test, testing the\n"
+      "compatibility of the Java and C++ implementations.\n"
+      "\n"
+      "This program can be run in two modes, initiator or responder (default is\n"
+      "initiator):\n"
+      "  ukey2_shell --mode=initiator --verification_string_length=32\n"
+      "  ukey2_shell --mode=responder --verification_string_length=32\n"
+      );
+  const std::string from("ICACHE");
+  for (size_t pos = usage.find(from); pos != std::string::npos; pos = usage.find(from, pos)) {
+    usage.replace(pos, from.length(), exec_name);
+  }
+  printf("%s", usage.c_str());
+}
+
 int main(int argc, char** argv) {
-  absl::ParseCommandLine(argc, argv);
+  static constexpr const char* OPTSTR = "ha:";
+  static const struct option OPTIONS[] = {
+      { "help",                       no_argument, 0, 'h' },
+      { "mode",                       required_argument, 0, 'm' },
+      { "verification_string_length", required_argument, 0, 'l' },
+      { 0, 0, 0, 0 }  // termination of the option list
+  };
+  int opt;
+  int option_index = 0;
+  int verification_string_length = 32;
+  string mode = "initiator";
+
+  while ((opt = getopt_long(argc, argv, OPTSTR, OPTIONS, &option_index)) >= 0) {
+    switch (opt) {
+      default:
+      case 'h':
+        printUsage(argv[0]);
+        return 0;
+      case 'l':
+        verification_string_length = atoi(optarg);
+        break;
+      case 'm':
+        mode = optarg;
+        break;
+    }
+  }
 
-  const int verification_string_length =
-      absl::GetFlag(FLAGS_verification_string_length);
   if (verification_string_length < 1 || verification_string_length > 32) {
     LOG(ERROR) << "Invalid flag value, verification_string_length: "
                << verification_string_length;
@@ -284,7 +319,6 @@ int main(int argc, char** argv) {
 
   securegcm::UKey2Shell shell(verification_string_length);
   int exit_code = 0;
-  const string mode = absl::GetFlag(FLAGS_mode);
   if (mode == "initiator") {
     exit_code = !shell.RunAsInitiator();
   } else if (mode == "responder") {