From 2d5e1e1d0dfa5cd0d40c1d87a5dd41abcdc907c8 Mon Sep 17 00:00:00 2001
From: Eric Cousineau <eric.cousineau@tri.global>
Date: Wed, 22 Jan 2020 11:50:15 -0500
Subject: [PATCH] Add `rcpputils` for `find_library` (#57)

* Add `rcpputils` for `find_library`

Signed-off-by: Eric Cousineau <eric.cousineau@tri.global>

* Address review

Signed-off-by: Eric Cousineau <eric.cousineau@tri.global>

* Fix dependency declarations

Signed-off-by: Eric Cousineau <eric.cousineau@tri.global>

* Fix errors

Signed-off-by: Eric Cousineau <eric.cousineau@tri.global>

* fix CMake ordering

Signed-off-by: Eric Cousineau <eric.cousineau@tri.global>

* functions: Revert back to custom get_env_var

Signed-off-by: Eric Cousineau <eric.cousineau@tri.global>

* use rcutils_get_env, remove added namespace

Signed-off-by: Dirk Thomas <dirk-thomas@users.noreply.github.com>

* export new dependencies when necessary

Signed-off-by: Dirk Thomas <dirk-thomas@users.noreply.github.com>

Co-authored-by: Dirk Thomas <dirk-thomas@users.noreply.github.com>
---
 rmw_implementation/CMakeLists.txt    |  7 ++-
 rmw_implementation/package.xml       |  3 +-
 rmw_implementation/src/functions.cpp | 92 ++++------------------------
 3 files changed, 18 insertions(+), 84 deletions(-)

diff --git a/rmw_implementation/CMakeLists.txt b/rmw_implementation/CMakeLists.txt
index 2a6d8d70..68a4d144 100644
--- a/rmw_implementation/CMakeLists.txt
+++ b/rmw_implementation/CMakeLists.txt
@@ -14,8 +14,6 @@ endif()
 find_package(ament_cmake REQUIRED)
 find_package(ament_cmake_python REQUIRED)
 
-find_package(rcutils REQUIRED)
-
 find_package(rmw_implementation_cmake REQUIRED)
 
 ament_python_install_package(${PROJECT_NAME})
@@ -55,18 +53,23 @@ else()
   # provides FindPoco.cmake and Poco on platforms without it
   find_package(poco_vendor REQUIRED)
   find_package(Poco REQUIRED COMPONENTS Foundation)
+  find_package(rcpputils REQUIRED)
+  find_package(rcutils REQUIRED)
   find_package(rmw REQUIRED)
 
   add_library(${PROJECT_NAME} SHARED
     src/functions.cpp)
   ament_target_dependencies(${PROJECT_NAME}
     "Poco"
+    "rcpputils"
+    "rcutils"
     "rmw")
   target_compile_definitions(${PROJECT_NAME}
     PUBLIC "DEFAULT_RMW_IMPLEMENTATION=${RMW_IMPLEMENTATION}")
   configure_rmw_library(${PROJECT_NAME})
 
   ament_export_libraries(${PROJECT_NAME})
+  ament_export_dependencies(rcpputils rcutils)
 
   install(
     TARGETS ${PROJECT_NAME}
diff --git a/rmw_implementation/package.xml b/rmw_implementation/package.xml
index 9ef196c1..e5165128 100644
--- a/rmw_implementation/package.xml
+++ b/rmw_implementation/package.xml
@@ -10,7 +10,8 @@
   <buildtool_depend>ament_cmake</buildtool_depend>
   <buildtool_depend>ament_cmake_python</buildtool_depend>
 
-  <build_depend>rcutils</build_depend>
+  <depend>rcpputils</depend>
+  <depend>rcutils</depend>
   <build_depend>rmw</build_depend>
   <!--
   Bloom does not support group_depend so entries below duplicate the group rmw_implementation_packages.
diff --git a/rmw_implementation/src/functions.cpp b/rmw_implementation/src/functions.cpp
index a3d7e841..229f46c1 100644
--- a/rmw_implementation/src/functions.cpp
+++ b/rmw_implementation/src/functions.cpp
@@ -13,21 +13,17 @@
 // limitations under the License.
 
 #include <cstddef>
-#include <cstdio>
-#include <cstring>
 
-#include <list>
 #include <string>
 
-#include <fstream>
-#include <sstream>
-
 #include "rcutils/allocator.h"
 #include "rcutils/format_string.h"
+#include "rcutils/get_env.h"
 #include "rcutils/types/string_array.h"
 
 #include "Poco/SharedLibrary.h"
 
+#include "rcpputils/find_library.hpp"
 #include "rmw/error_handling.h"
 #include "rmw/event.h"
 #include "rmw/names_and_types.h"
@@ -37,85 +33,19 @@
 #include "rmw/get_topic_names_and_types.h"
 #include "rmw/rmw.h"
 
-std::string get_env_var(const char * env_var)
-{
-  char * value = nullptr;
-#ifndef _WIN32
-  value = getenv(env_var);
-#else
-  size_t value_size;
-  _dupenv_s(&value, &value_size, env_var);
-#endif
-  std::string value_str = "";
-  if (value) {
-    value_str = value;
-#ifdef _WIN32
-    free(value);
-#endif
-  }
-  // printf("get_env_var(%s) = %s\n", env_var, value_str.c_str());
-  return value_str;
-}
-
-std::list<std::string> split(const std::string & value, const char delimiter)
-{
-  std::list<std::string> list;
-  std::istringstream ss(value);
-  std::string s;
-  while (std::getline(ss, s, delimiter)) {
-    list.push_back(s);
-  }
-  // printf("split(%s) = %zu\n", value.c_str(), list.size());
-  return list;
-}
-
-bool is_file_exist(const char * filename)
-{
-  std::ifstream h(filename);
-  // printf("is_file_exist(%s) = %s\n", filename, h.good() ? "true" : "false");
-  return h.good();
-}
+#define STRINGIFY_(s) #s
+#define STRINGIFY(s) STRINGIFY_(s)
 
-std::string find_library_path(const std::string & library_name)
+std::string get_env_var(const char * env_var)
 {
-  const char * env_var;
-  char separator;
-  const char * filename_prefix;
-  const char * filename_extension;
-#ifdef _WIN32
-  env_var = "PATH";
-  separator = ';';
-  filename_prefix = "";
-  filename_extension = ".dll";
-#elif __APPLE__
-  env_var = "DYLD_LIBRARY_PATH";
-  separator = ':';
-  filename_prefix = "lib";
-  filename_extension = ".dylib";
-#else
-  env_var = "LD_LIBRARY_PATH";
-  separator = ':';
-  filename_prefix = "lib";
-  filename_extension = ".so";
-#endif
-  std::string search_path = get_env_var(env_var);
-  std::list<std::string> search_paths = split(search_path, separator);
-
-  std::string filename = filename_prefix;
-  filename += library_name + filename_extension;
-
-  for (auto it : search_paths) {
-    std::string path = it + "/" + filename;
-    if (is_file_exist(path.c_str())) {
-      return path;
-    }
+  const char * value{};
+  const char * err = rcutils_get_env(env_var, &value);
+  if (err) {
+    throw std::runtime_error(err);
   }
-  return "";
+  return value ? value : "";
 }
 
-#define STRINGIFY_(s) #s
-#define STRINGIFY(s) STRINGIFY_(s)
-
 Poco::SharedLibrary *
 get_library()
 {
@@ -125,7 +55,7 @@ get_library()
     if (env_var.empty()) {
       env_var = STRINGIFY(DEFAULT_RMW_IMPLEMENTATION);
     }
-    std::string library_path = find_library_path(env_var);
+    std::string library_path = rcpputils::find_library_path(env_var);
     if (library_path.empty()) {
       RMW_SET_ERROR_MSG(
         ("failed to find shared library of rmw implementation. Searched " + env_var).c_str());