From 35668d5b9f05b11697719792642da5c99c0314ac Mon Sep 17 00:00:00 2001
From: Teon Banek <theongugl@gmail.com>
Date: Fri, 24 Mar 2017 09:50:52 +0100
Subject: [PATCH] Make GNU Readline dependency optional

Reviewers: florijan, buda

Reviewed By: buda

Subscribers: pullbot

Differential Revision: https://phabricator.memgraph.io/D171
---
 CMakeLists.txt              | 12 ++++++++++--
 cmake/FindReadline.cmake    | 27 +++++++++++++++++++++++++++
 src/query/console.cpp       | 13 +++++++++++++
 tests/manual/CMakeLists.txt | 14 +++++++++++---
 4 files changed, 61 insertions(+), 5 deletions(-)
 create mode 100644 cmake/FindReadline.cmake

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c88bae3a8..a95637a6d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -57,7 +57,13 @@ add_custom_target(clean_all
 
 # threading
 find_package(Threads REQUIRED)
-# find_package(readline REQUIRED)
+# optional readline
+find_package(Readline REQUIRED)
+if (READLINE_FOUND)
+  include_directories(SYSTEM ${READLINE_INCLUDE_DIR})
+  add_definitions(-DHAS_READLINE)
+endif()
+
 # -----------------------------------------------------------------------------
 
 # c++14
@@ -424,7 +430,9 @@ if (MEMGRAPH)
     target_link_libraries(${MEMGRAPH_BUILD_NAME} yaml-cpp)
     target_link_libraries(${MEMGRAPH_BUILD_NAME} antlr_opencypher_parser_lib)
     target_link_libraries(${MEMGRAPH_BUILD_NAME} dl)
-    target_link_libraries(${MEMGRAPH_BUILD_NAME} readline)
+    if (READLINE_FOUND)
+      target_link_libraries(${MEMGRAPH_BUILD_NAME} ${READLINE_LIBRARY})
+    endif()
 endif()
 
 # utility target to copy hardcoded queries
diff --git a/cmake/FindReadline.cmake b/cmake/FindReadline.cmake
new file mode 100644
index 000000000..a2c93348f
--- /dev/null
+++ b/cmake/FindReadline.cmake
@@ -0,0 +1,27 @@
+# Find the GNU Readline library.
+# This module plugs into CMake's `find_package` so the example usage is:
+# `find_package(Readline REQUIRED)`
+# Options to `find_package` are as documented in CMake documentation.
+# READLINE_LIBRARY will be a path to the library.
+# READLINE_INCLUDE_DIR will be a path to the include directory.
+# READLINE_FOUND will be TRUE if the library is found.
+if (READLINE_LIBRARY AND READLINE_INCLUDE_DIR)
+  set(READLINE_FOUND TRUE)
+else()
+  find_library(READLINE_LIBRARY readline)
+  find_path(READLINE_INCLUDE_DIR readline/readline.h)
+  if (READLINE_LIBRARY AND READLINE_INCLUDE_DIR)
+    set(READLINE_FOUND TRUE)
+    if (NOT READLINE_FIND_QUIETLY)
+      message(STATUS "Found Readline: ${READLINE_LIBRARY} ${READLINE_INCLUDE_DIR}")
+    endif()
+  else()
+    set(READLINE_FOUND FALSE)
+    if (READLINE_FIND_REQUIRED)
+      message(FATAL_ERROR "Could not find Readline")
+    elseif (NOT READLINE_FIND_QUIETLY)
+      message(STATUS "Could not find Readline")
+    endif()
+  endif()
+  mark_as_advanced(READLINE_LIBRARY READLINE_INCLUDE_DIR)
+endif()
diff --git a/src/query/console.cpp b/src/query/console.cpp
index 92838a52d..198d35129 100644
--- a/src/query/console.cpp
+++ b/src/query/console.cpp
@@ -12,6 +12,8 @@
 #include "query/exceptions.hpp"
 #include "query/interpreter.hpp"
 
+#ifdef HAS_READLINE
+
 #include "readline/history.h"
 #include "readline/readline.h"
 
@@ -34,6 +36,17 @@ std::string ReadLine(const char *prompt) {
   return r_val;
 }
 
+#else
+
+std::string ReadLine(const char *prompt) {
+  std::cout << prompt;
+  std::string line;
+  std::getline(std::cin, line);
+  return line;
+}
+
+#endif  // HAS_READLINE
+
 /**
  * Helper function that outputs a collection of items to
  * the given stream, separating them with the given delimiter.
diff --git a/tests/manual/CMakeLists.txt b/tests/manual/CMakeLists.txt
index d07669988..b1417422f 100644
--- a/tests/manual/CMakeLists.txt
+++ b/tests/manual/CMakeLists.txt
@@ -1,5 +1,11 @@
 find_package(Threads REQUIRED)
-# find_package(readline REQUIRED)
+
+# optional readline
+find_package(Readline)
+if (READLINE_FOUND)
+  include_directories(SYSTEM ${READLINE_INCLUDE_DIR})
+  add_definitions(-DHAS_READLINE)
+endif()
 
 # set current directory name as a test type
 get_filename_component(test_type ${CMAKE_CURRENT_SOURCE_DIR} NAME)
@@ -38,10 +44,12 @@ foreach(test_cpp ${test_type_cpps})
     # yaml parser lib
     target_link_libraries(${target_name} yaml-cpp)
     # antlr
-	target_link_libraries(${target_name} antlr_opencypher_parser_lib)
+    target_link_libraries(${target_name} antlr_opencypher_parser_lib)
     # dynamic lib
     target_link_libraries(${target_name} dl)
     # readline lib
-    target_link_libraries(${target_name} readline)
+    if (READLINE_FOUND)
+      target_link_libraries(${target_name} ${READLINE_LIBRARY})
+    endif()
 
 endforeach()