updated README and included Homebrew build script with patch

README

@@ -1,3 +1,13 @@
 Ceres Solver - A non-linear least squares minimizer
 ==================================================
 Please see docs/html/index.html for a tutorial and reference.
+
+
+Note: This fork is no longer supported. llvm clang now supports OpenMP natively.
+However, since Xcode's clang does not support OpenMP yet, I have included a homebrew
+build script, including patch, to enable ceres to use homebrew's llvm.
+
+To install Ceres with OpenMP on OSX (as of 7 Aug 2016):
+1. Download this repository's ceres-solver.rb
+2. brew install llvm
+3. brew install ceres-solver.rb

ceres-solver.rb

@@ -0,0 +1,86 @@
+class CeresSolver < Formula
+  desc "C++ library for large-scale optimization"
+  homepage "http://ceres-solver.org/"
+  url "http://ceres-solver.org/ceres-solver-1.11.0.tar.gz"
+  sha256 "4d666cc33296b4c5cd77bad18ffc487b3223d4bbb7d1dfb342ed9a87dc9af844"
+  revision 2
+  head "https://ceres-solver.googlesource.com/ceres-solver.git"
+
+  # bottle do
+  #   sha256 "f11c49891b9e084fc4d82aac72c85c04595435502e7f92014c3b5910e56211cd" => :el_capitan
+  #   sha256 "6ceffb043d52314e66ec22ba947af3944b30c86c41b06ea4db17e640066723ab" => :yosemite
+  #   sha256 "f0ff74807c03feabd7430ad886af57a1c8e1beb0d8f8e731adb442570d046a50" => :mavericks
+  # end
+
+  option "without-test", "Do not build and run the tests (not recommended)."
+  deprecated_option "without-tests" => "without-test"
+
+  depends_on "cmake" => :run
+  depends_on "glog"
+  depends_on "gflags"
+  depends_on "eigen"
+  depends_on "suite-sparse" => :recommended
+
+  def suite_sparse_options
+    Tab.for_formula(Formula["suite-sparse"])
+  end
+
+  patch :DATA
+
+  def install
+    ENV['CC'] = '/usr/local/opt/llvm/bin/clang'
+    ENV['CXX'] = '/usr/local/opt/llvm/bin/clang++ -stdlib=libc++'
+    ENV['CXXFLAGS'] = '-nostdinc++ -I/usr/local/opt/llvm/include/c++/v1'
+    ENV['LDFLAGS'] = '-L/usr/local/opt/llvm/lib'
+    cmake_args = std_cmake_args + ["-DBUILD_SHARED_LIBS=ON"]
+    cmake_args << "-DMETIS_LIBRARY=#{Formula["metis4"].opt_lib}/libmetis.dylib" if suite_sparse_options.with? "metis4"
+    cmake_args << "-DEIGEN_INCLUDE_DIR=#{Formula["eigen"].opt_include}/eigen3"
+    system "cmake", ".", *cmake_args
+    system "make"
+    system "make", "test" if build.with? "test"
+    system "make", "install"
+    pkgshare.install "examples"
+    pkgshare.install "data"
+    doc.install "docs/html"
+  end
+end
+
+__END__
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 25c8ae2..07e39d3 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -400,12 +400,6 @@ if (NOT CUSTOM_BLAS)
+ endif (NOT CUSTOM_BLAS)
+
+ if (OPENMP)
+-  # Clang does not (yet) support OpenMP.
+-  if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+-    update_cache_variable(OPENMP OFF)
+-    message("-- Compiler is Clang, disabling OpenMP.")
+-    list(APPEND CERES_COMPILE_OPTIONS CERES_NO_THREADS)
+-  else (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+     # Find quietly s/t as we can continue without OpenMP if it is not found.
+     find_package(OpenMP QUIET)
+     if (OPENMP_FOUND)
+@@ -424,7 +418,6 @@ if (OPENMP)
+       update_cache_variable(OPENMP OFF)
+       list(APPEND CERES_COMPILE_OPTIONS CERES_NO_THREADS)
+     endif (OPENMP_FOUND)
+-  endif (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+ else (OPENMP)
+   message("-- Building without OpenMP (disabling multithreading).")
+   list(APPEND CERES_COMPILE_OPTIONS CERES_NO_THREADS)
+diff --git a/internal/ceres/CMakeLists.txt b/internal/ceres/CMakeLists.txt
+index 5d24a8a..c65609e 100644
+--- a/internal/ceres/CMakeLists.txt
++++ b/internal/ceres/CMakeLists.txt
+@@ -151,7 +151,7 @@ endif (BLAS_FOUND AND LAPACK_FOUND)
+
+ if (OPENMP_FOUND)
+   if (NOT MSVC)
+-    list(APPEND CERES_LIBRARY_PRIVATE_DEPENDENCIES gomp)
++    list(APPEND CERES_LIBRARY_PRIVATE_DEPENDENCIES /usr/local/opt/llvm/lib/libomp.dylib)
+     list(APPEND CERES_LIBRARY_PRIVATE_DEPENDENCIES ${CMAKE_THREAD_LIBS_INIT})
+   endif (NOT MSVC)
+ endif (OPENMP_FOUND)