llvm: fix python binding

This commit fixes three things:
* Python 2.7 is required, so using brew python for old Mac OS X.
* Install python bindings no matter which python we build aginst
  system or brew
* Clarify `with-python` option

Closes #36229.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

1 files changed, 8 insertions, 9 deletions

diff --git a/Library/Formula/llvm.rb b/Library/Formula/llvm.rb
index 1872a2fd2..5f5802450 100644
--- a/Library/Formula/llvm.rb
+++ b/Library/Formula/llvm.rb
@@ -70,6 +70,7 @@ class Llvm < Formula
   option "with-lldb", "Build LLDB debugger"
   option "with-rtti", "Build with C++ RTTI"
   option "with-all-targets", "Build all target backends"
+  option "with-python", "Build Python bindings against Homebrew Python"
   option "without-shared", "Don't build LLVM as a shared library"
   option "without-assertions", "Speeds up LLVM, but provides less debug information"
 
@@ -78,7 +79,11 @@ class Llvm < Formula
   deprecated_option "disable-shared" => "without-shared"
   deprecated_option "disable-assertions" => "without-assertions"
 
-  depends_on :python => :optional
+  if MacOS.version <= :snow_leopard
+    depends_on :python
+  else
+    depends_on :python => :optional
+  end
   depends_on "swig" if build.with? "lldb"
 
   keg_only :provided_by_osx
@@ -91,10 +96,6 @@ class Llvm < Formula
     # Apple's libstdc++ is too old to build LLVM
     ENV.libcxx if ENV.compiler == :clang
 
-    if build.with?("python") && build.without?("shared")
-      fail "The Python bindings need the shared library."
-    end
-
     if build.with?("lldb") && build.without?("clang")
       fail "Building LLDB needs Clang support library."
     end
@@ -148,10 +149,8 @@ class Llvm < Formula
     end
 
     # install llvm python bindings
-    if build.with? "python"
-      (lib+"python2.7/site-packages").install buildpath/"bindings/python/llvm"
-      (lib+"python2.7/site-packages").install buildpath/"tools/clang/bindings/python/clang" if build.with? "clang"
-    end
+    (lib+"python2.7/site-packages").install buildpath/"bindings/python/llvm"
+    (lib+"python2.7/site-packages").install buildpath/"tools/clang/bindings/python/clang" if build.with? "clang"
   end
 
   test do