Decouple from OSX, Xcode, Brew

This patch decouples the build from OSX, Xcode, and Brew.

This represents the theoretical state of dependencies: there's no
dependency on OSX, Xcode or Brew!

These build parameters are expressed as fallback values: they are only
used if the user has not provided their own parameters.

Refactor CMakeLists in a way that is more configurable
- allow the user to provide a boost installation
- allow the user to provide a sourcekit installation

Now, all source code related operations of the build system are governed
by CMake: bootstrapping just calls configure and build.

The fact that it defaults to homebrew for boost isn't really a
requirement, but it is what it uses for now. This is a marginal default
and I added a FIXME, to improve it in the future.

Note: As of writing, my development environments meet these requirements
and it seems like sensible default for many potential users. As much as
I don't enjoy Xcode, this is pragmatic for reasons described in the
README, and CMakeLists, and Swift YCMD RFC.

CMakeLists.txt

@@ -1,20 +1,36 @@
-message("__SSVI CMAKE START")
+message("SSVIM CMAKE START")
 
 cmake_minimum_required(VERSION 2.8)
 
 # Boost
-#
 
-SET(CMAKE_INCLUDE_PATH ${CMAKE_INCLUDE_PATH} /usr/local/include/boost)
-SET(CMAKE_INCLUDE_PATH ${CMAKE_INCLUDE_PATH} /usr/local/lib)
+# Optionally the user may provide a custom boost.
+# For now, we default to homebrew provided boosts.
+# FIXME: This isn't really an ideal default, but it is
+# what it has.
+if(NOT DEFINED ENV{OVERRIDE_BOOST})
+    message("Attempting to use brew boost")
+    # if this command fails, the build will explode in a future step
+    execute_process (
+        COMMAND bash -c "${CMAKE_CURRENT_SOURCE_DIR}/install_brew_boost_if_needed.sh"
+        OUTPUT_VARIABLE XCODE_PATH
+    )
+    set(BOOST_INCLUDEDIR /usr/local/include/boost)
+    set(BOOST_ROOT /usr/local/lib)
+endif()
+
+## Boost includes
 
-option (Boost_USE_STATIC_LIBS "Use static libraries for boost" ON)
+set(CMAKE_INCLUDE_PATH ${CMAKE_INCLUDE_PATH} ${BOOST_INCLUDEDIR})
+set(CMAKE_INCLUDE_PATH ${CMAKE_INCLUDE_PATH} ${BOOST_ROOT})
 
-set (BOOST_INCLUDEDIR /usr/local/Cellar/boost/1.64.0_1)
-set (BOOST_ROOT /usr/local/lib)
-set (BOOST_USE_MULTITHREADED ON)
+include_directories(SYSTEM ${Boost_INCLUDE_DIRS})
+include_directories(${BOOST_INCLUDEDIR})
 
-find_package (Boost REQUIRED COMPONENTS
+option(Boost_USE_STATIC_LIBS "Use static libraries for boost" ON)
+set(BOOST_USE_MULTITHREADED ON)
+
+find_package(Boost REQUIRED COMPONENTS
     coroutine
     context
     filesystem
@@ -23,16 +39,15 @@ find_package (Boost REQUIRED COMPONENTS
     thread
     )
 
-include_directories (SYSTEM ${Boost_INCLUDE_DIRS})
-include_directories(/usr/local/include/boost)
-link_libraries (${Boost_LIBRARIES})
-add_definitions (-DBOOST_COROUTINES_NO_DEPRECATION_WARNING=1) # for asio
+link_libraries(${Boost_LIBRARIES})
+add_definitions(-DBOOST_COROUTINES_NO_DEPRECATION_WARNING=1) # for asio
 
 ## Beast HTTP
 
 include_directories(vendor/Beast/include/)
 
 set(THREADS_PREFER_PTHREAD_FLAG ON)
+
 find_package(Threads)
 
 # Include vendored deps
@@ -41,27 +56,45 @@ include_directories(vendor)
 
 # Sourcekit
 
-# OSX First
-# Use Xcode'd sourcekitd build.
-execute_process (
-    COMMAND bash -c "xcode-select --print-path | tr -d '\n'"
-    OUTPUT_VARIABLE XCODE_PATH
-)
-
-message(${XCODE_PATH})
-
-set(SKT_FLAGS "-framework sourcekitd")
-set(SKT_FLAGS " ${SKT_FLAGS} -F ${XCODE_PATH}/Toolchains/XcodeDefault.xctoolchain/usr/lib")
-set(SKT_FLAGS " ${SKT_FLAGS} -rpath ${XCODE_PATH}/Toolchains/XcodeDefault.xctoolchain/usr/lib")
-
-set(GLOBAL_CXX_FLAGS "-std=c++1y -stdlib=libc++")
+# Try using Xcode's sourcekitd build.
+# We provide this as a fallback ( and sensible default ) so that the user
+# doesn't have to build SourceKit from source.
+macro(TryXcodeSourceKit)
+    message("Attempting to find system SourceKit")
+    if (NOT ${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
+        message (FATAL_ERROR "SourceKit default option requires OSX.")
+    endif()
+    execute_process(
+        COMMAND bash -c "xcode-select --print-path | tr -d '\n'"
+        OUTPUT_VARIABLE XCODE_PATH
+    )
+    if("${XCODE_PATH}" STREQUAL "")
+        message(FATAL_ERROR "Cannot find Xcode install.")
+    endif()
+
+    message("Using Sourcekit from Xcode install at: ${XCODE_PATH}.")
+
+    set(SKT_FLAGS "-framework sourcekitd")
+    set(SKT_FLAGS " ${SKT_FLAGS} -F ${XCODE_PATH}/Toolchains/XcodeDefault.xctoolchain/usr/lib")
+    set(SKT_FLAGS " ${SKT_FLAGS} -rpath ${XCODE_PATH}/Toolchains/XcodeDefault.xctoolchain/usr/lib")
+endmacro()
+
+# The user can provide a SourceKit via SOURCEKIT_FLAGS
+if(DEFINED ENV{SOURCEKIT_FLAGS})
+    message("Using user provided SourceKit")
+    set(SKT_FLAGS ENV{SOURCEKIT_FLAGS})
+else()
+    TryXcodeSourceKit()
+endif()
+
+set(GLOBAL_CXX_FLAGS "-std=c++1z -stdlib=libc++")
 set(GLOBAL_CXX_FLAGS "${GLOBAL_CXX_FLAGS} -Wall -Wextra -Wpedantic  -Wno-unused-parameter")
 set(GLOBAL_CXX_FLAGS "${GLOBAL_CXX_FLAGS} -Wno-import-preprocessor-directive-pedantic -Wno-unused-command-line-argument")
 
 add_definitions(${GLOBAL_CXX_FLAGS})
 set(CMAKE_CXX_FLAGS ${SKT_FLAGS})
 
-add_executable (http_server
+add_executable(http_server
     file_body.hpp
     Logging.hpp
     SemanticHTTPServer.hpp
@@ -71,7 +104,7 @@ add_executable (http_server
     HTTPServerMain.cpp
 )
 
-add_executable (test_driver
+add_executable(test_driver
     Logging.hpp
     SwiftCompleter.hpp
     SwiftCompleter.cpp
@@ -85,4 +118,4 @@ INSTALL( TARGETS http_server
 INSTALL( FILES scripts/activate
     DESTINATION . )
 
-message("__SSVI CMAKE FINISH")
+message("SSVIM CMAKE FINISH")

bootstrap

@@ -2,22 +2,6 @@
 set -e
 cd `dirname $0`
 
-# System Dependencies
-if [[ ! -d /Applications/Xcode.app/ ]]; then
-    >&2 echo "Needs OSX and Xcode for SourceKitD"
-    exit 1
-fi
-
-# Use boost is installed via brew for now
-EXPECTED_BOOST=/usr/local/Cellar/boost/1.64.0_1 
-if [[ ! -d $EXPECTED_BOOST ]]; then
-    echo "Missing Boost $EXPECTED_BOOST. \
-        trying $ brew install boost 1.64"
-    brew install [email protected]
-fi
-
-echo "Deps satisfied.."
-
 echo "Configure.."
 ./configure
 

install_brew_boost_if_needed.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+set -e
+
+EXPECTED_BOOST=/usr/local/include/boost/
+if [[ ! -d $EXPECTED_BOOST ]]; then
+    echo "Missing Boost $EXPECTED_BOOST. \
+        trying $ brew install boost 1.64"
+    brew install [email protected]
+fi
+