Move 'fails_with_llvm' into formula DSL.

Existing method moved to compatibility layer.

Library/Homebrew/compatibility.rb

@@ -70,4 +70,11 @@ class Formula
       name
     end
   end
+
+  # This used to be called in "def install", but should now be used
+  # up in the DSL section.
+  def fails_with_llvm msg=nil, data=nil
+    handle_llvm_failure FailsWithLLVM.new(msg, data)
+  end
+
 end

Library/Homebrew/formula.rb

@@ -47,7 +47,7 @@ end
 
 
 # Used to annotate formulae that duplicate OS X provided software
-# :provided_by_osx
+# or cause conflicts when linked in.
 class KegOnlyReason
   attr_reader :reason, :explanation
 
@@ -71,6 +71,25 @@ EOS
 end
 
 
+# Used to annotate formulae that won't build correctly with LLVM.
+class FailsWithLLVM
+  attr_reader :msg, :data, :build
+
+  def initialize msg=nil, data=nil
+    @msg = msg || "(No specific reason was given)"
+    @data = data
+    @build = data.delete :build rescue nil
+  end
+
+  def reason
+    s = @msg
+    s += "Tested with LLVM build #{@build}" unless @build == nil
+    s += "\n"
+    return s
+  end
+end
+
+
 # Derive and define at least @url, see Library/Formula for examples
 class Formula
   include FileUtils
@@ -198,6 +217,10 @@ class Formula
     self.class.keg_only_reason || false
   end
 
+  def fails_with_llvm?
+    self.class.fails_with_llvm_reason || false
+  end
+
   # sometimes the clean process breaks things
   # skip cleaning paths in a formula with a class method like this:
   #   skip_clean [bin+"foo", lib+"bar"]
@@ -213,6 +236,8 @@ class Formula
     validate_variable :name
     validate_variable :version
 
+    handle_llvm_failure(fails_with_llvm?) if fails_with_llvm?
+
     stage do
       begin
         patch
@@ -264,28 +289,24 @@ class Formula
     "-DCMAKE_INSTALL_PREFIX='#{prefix}' -DCMAKE_BUILD_TYPE=None -Wno-dev"
   end
 
-  def fails_with_llvm msg="", data=nil
+  def handle_llvm_failure llvm
     unless (ENV['HOMEBREW_USE_LLVM'] or ARGV.include? '--use-llvm')
       ENV.gcc_4_2 if default_cc =~ /llvm/
       return
     end
 
-    build = data.delete :build rescue nil
-    msg = "(No specific reason was given)" if msg.empty?
-
     opoo "LLVM was requested, but this formula is reported as not working with LLVM:"
-    puts msg
-    puts "Tested with LLVM build #{build}" unless build == nil
-    puts
+    puts llvm.reason
 
     if ARGV.force?
-      puts "Continuing anyway. If this works, let us know so we can update the\n"+
-           "formula to remove the warning."
+      puts "Continuing anyway.\n" +
+           "If this works, let us know so we can update the formula to remove the warning."
     else
       puts "Continuing with GCC 4.2 instead.\n"+
            "(Use `brew install --force #{name}` to force use of LLVM.)"
       ENV.gcc_4_2
     end
+    puts
   end
 
   def self.class_s name
@@ -604,7 +625,7 @@ EOF
     end
 
     attr_rw :version, :homepage, :specs, :deps, :external_deps
-    attr_rw :keg_only_reason, :skip_clean_all
+    attr_rw :keg_only_reason, :fails_with_llvm_reason, :skip_clean_all
     attr_rw(*CHECKSUM_TYPES)
 
     def head val=nil, specs=nil
@@ -679,6 +700,10 @@ EOF
     def keg_only reason, explanation=nil
       @keg_only_reason = KegOnlyReason.new(reason, explanation.to_s.chomp)
     end
+
+    def fails_with_llvm msg=nil, data=nil
+      @fails_with_llvm_reason = FailsWithLLVM.new(msg, data)
+    end
   end
 end