#Developing Quickstep with IDEs

##Who should read this document? Any developer who prefers to work with IDEs instead of a terminal and vi, emacs, or the like. In other words, this document aims to make it easier for developers of Quickstep to work with IDEs. Over time, there will be information about working with other IDEs, but to start out, here are instructions for working with XCode on OSX.

##Developing Quickstep with Xcode on OSX The instructions here were first written and verified on OSX El Capitan, v.10.11.2, using Xcode v.7.2.

###1: Install Xcode and command line tools First, you will need to download and install Xcode and the associated command line tools. There are multiple ways to do this, including going to https://developer.apple.com/xcode/ and downloading both Xcode and the command line tools from there. Another way that works well if you do not have Xcode already installed is to simply open up the Terminal app and enter:


This command should trigger a sequence of downloads to get you both Xcode and the assocaited command line tools.

###2: Install cmake Unfortunately, the command line tools do not package cmake, which is needed to build Quickstep. You can install cmake using brew as follows:

Visit http://brew.sh to determine the instructions to install brew. It will look something like:

ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

Once you have brew installed, simply use brew to install cmake from the Terminal app by typing:

brew install cmake

###3: Build Quicktep Checkout the Quickstep code from git, and also checkout the associated submodules. If you have not read it already, this would be good time to read the file BUILDING.md, but do not run the cmake command mentioned there. Instead, go into the build directory of the Quickstep code that you checked out (i.e. the directory quickstep/build) and run the following command in your Terminal app:

cmake -D CMAKE_BUILD_TYPE=Debug -D USE_LINENOISE=0 -G "Xcode" ..

This will take a minute but will build the Xcode project file. You can start Xcode by typing in:

open QUICKSTEP.xcodeproj

Xcode should start and the first thing you should see is a pop-up box that asks if you want to Manually Manage Schemes or Automatically Create Schemes. Pick the latter and let Xcode genreate the schemes, which will essentially generate a build target for each target in the cmake files. There are a lot of these, but that is ok -- you can pick just the target you want to build easily.

Xcode will take a while to index the files. When it is done, you should see at the top of your screen a button with the text: ALL_BUILD > My Mac

Click on that button, and a long list of targets will show up. Pick quickstep_cli_shell as the target -- this creates the main quickstep program. (Above, you can also pick other targets if you are working on a different more focused part of the code).

To build the source, select from the top menu bar Product -> Build or simply hit Command-B. Xcode should spin into action and build the sources. It will take a while, but the nice thing is that Xcode automatically will try to parallelize the build. So, you should be done with building in few minutes.

You should end up with a directory quickstep/build/Debug, where the binary is created. You will need to go into this directory and issue the command:

cp -R ../qsstor .

The above command ensures that you now have the appropriate directory structure and a starting catalog file to start Quickstep. The default database is called simply “default” and no relations in it upfront.

There are other ways of specifying where Quickstep stores the data and catalog. In particular there is a -storage_path option that could be an alternative way of specifying the storage path and avoiding the copy above. You can find these and other command line options by typing:

./quickstep_cli_shell -help

###4: Debug Quickstep Now you can debug as you would any normal process in Xcode. Note the linenoise option in the cmake command above is important if you are going to run quickstep from Xcode (by hitting the “play” button). If you are curious why we have that option, see https://github.com/antirez/linenoise/issues/85. Quickstep uses the linenoise package, and Xcode's embedded terminal has limited functionality. With the cmake option above, we turn off using linenoise.

Sometimes you may want to run quickstep from the command line and still debug with Xcode. For that scenario, you do the following: a) In Xcode, go to Debug -> Attach to Processs and type in quickstep_cli_shell. If you want to set a breakpoint, you can do that here. Open the file in which you want to insert a breakpoint, go to the line in the code where you want to set a breakpoint, and hit Debug -> Breakpoints -> Add Breakpoint at Current Line or simply press Command-\.

b) Then go to the Terminal app, and go to the Debug directory using:

cd quickstep/build/Debug

c) Start quickstep using something like ./quickstep_cli.shell or ./quickstep_cli_shell < query.sql where query.sql contains the SQL commands you want to run/debug. Xcode will automatically attach the quickstep process when it starts up. It you had set a breakpoint and the program executes that code, then Xcode (lldb) will stop at the breakpoint. Or, if there is a crash, you can examine the stack in Xcode.

###5: Unit Tests Individual unit tests show up as target schemas, so you can simply select them and run the unit test of interest.

Running all the unit tests is complicated, and simply picking the RUN_TESTS does not work. So, this is a known limitation at this point. You can, however, follow the instructions for a [BUILDING.md](command-line build) with cmake and then run ctest to run the full suite of unit tests.

###6: Other known issues

####Modifying CMake Files If you change any of the cmake files (such as any of the CMakeLists.txt files), then you will have to redo step 3 above to create a new Xcode project file.

####Running Python Validation Scripts Quickstep developers have a few python scripts that are used to mechanically check code. These scripts are written in Python 2 and are not compatible with Python 3, so they use python2 as the interpreter in their shebangs. While OSX does include some version of Python 2, it does not have a symlink for python2, so the scripts will fail to run out of the box. An easy fix is just to create a symlink yourself:

sudo ln -s /usr/bin/python2.7 /usr/local/bin/python2

(Note that if you have an older version of Mac OS X, you may need to replace python2.7 in the above command with python2.6, or whatever the most recent 2.X version is on your machine.)

After putting the symlink in place, you should be able to run ./third_party/cpplint/lint_everything.py (which applies a modified version of Google cpplint to all C++ sources) and ./validate_cmakelists.py (which checks that dependencies in CMakeLists.txt files exactly match included headers in C++ sources) from the root quickstep source directory to check your code. There is a third validation script ./cyclic_dependency.py that checks that there are no cyclic linking dependencies, but this script also requires that the python networkx package is installed ([https://networkx.github.io/documentation/latest/install.html](see instructions here)).