Add readline support to cli

This PR adds readline support to the daemon and monero-wallet-cli. Only
GNU readline is supported (e.g. not libedit) and there are cmake checks
to ensure this.

There is a cmake variable, Readline_ROOT_DIR that can specify a
directory to find readline, otherwise some default paths are searched.

There is also a cmake option, USE_READLINE, that defaults to ON. If set
to ON, if readline is not found, the build continues but without
readline support.

One negative side effect of using readline is that the color prompt in
the wallet-cli now has no color and just uses terminal default. I know
how to fix this but it's quite a big change so will tackle another time.

1 files changed, 66 insertions, 0 deletions

diff --git a/cmake/FindReadline.cmake b/cmake/FindReadline.cmake
new file mode 100644
index 000000000..9ccef7ad8
--- /dev/null
+++ b/cmake/FindReadline.cmake
@@ -0,0 +1,66 @@
+# - Try to find readline include dirs and libraries 
+#
+# Usage of this module as follows:
+#
+#     find_package(Readline)
+#
+# Variables used by this module, they can change the default behaviour and need
+# to be set before calling find_package:
+#
+#  Readline_ROOT_DIR         Set this variable to the root installation of
+#                            readline if the module has problems finding the
+#                            proper installation path.
+#
+# Variables defined by this module:
+#
+#  READLINE_FOUND            System has readline, include and lib dirs found
+#  GNU_READLINE_FOUND        Version of readline found is GNU readline, not libedit!
+#  Readline_INCLUDE_DIR      The readline include directories. 
+#  Readline_LIBRARY          The readline library.
+
+find_path(Readline_ROOT_DIR
+    NAMES include/readline/readline.h
+    PATHS /opt/local/ /usr/local/ /usr/
+    NO_DEFAULT_PATH
+)
+
+find_path(Readline_INCLUDE_DIR
+    NAMES readline/readline.h
+    PATHS ${Readline_ROOT_DIR}/include
+    NO_DEFAULT_PATH
+)
+
+find_library(Readline_LIBRARY
+    NAMES readline
+    PATHS ${Readline_ROOT_DIR}/lib
+    NO_DEFAULT_PATH
+)
+
+if(Readline_INCLUDE_DIR AND Readline_LIBRARY AND Ncurses_LIBRARY)
+  set(READLINE_FOUND TRUE)
+else(Readline_INCLUDE_DIR AND Readline_LIBRARY AND Ncurses_LIBRARY)
+  FIND_LIBRARY(Readline_LIBRARY NAMES readline PATHS Readline_ROOT_DIR)
+  include(FindPackageHandleStandardArgs)
+  FIND_PACKAGE_HANDLE_STANDARD_ARGS(Readline DEFAULT_MSG Readline_INCLUDE_DIR Readline_LIBRARY )
+  MARK_AS_ADVANCED(Readline_INCLUDE_DIR Readline_LIBRARY)
+endif(Readline_INCLUDE_DIR AND Readline_LIBRARY AND Ncurses_LIBRARY)
+
+mark_as_advanced(
+    Readline_ROOT_DIR
+    Readline_INCLUDE_DIR
+    Readline_LIBRARY
+)
+
+set(CMAKE_REQUIRED_INCLUDES ${Readline_INCLUDE_DIR})
+set(CMAKE_REQUIRED_LIBRARIES ${Readline_LIBRARY})
+INCLUDE(CheckCXXSourceCompiles) 
+CHECK_CXX_SOURCE_COMPILES(
+"
+#include <stdio.h>
+#include <readline/readline.h>
+int
+main()
+{
+  char * s  = rl_copy_text(0, 0);
+}
+" GNU_READLINE_FOUND)