New fails_with infrastructure

 - Formulae can now declare failures on any compiler.
 - FailsWithLLVM and associated formula elements have been moved to
   compat.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

8 files changed, 370 insertions, 73 deletions

diff --git a/Library/Homebrew/build.rb b/Library/Homebrew/build.rb
index 8f1fe3924..319f58df9 100755
--- a/Library/Homebrew/build.rb
+++ b/Library/Homebrew/build.rb
@@ -58,6 +58,12 @@ def install f
     end
   end
 
+  if f.fails_with? ENV.compiler
+    cs = CompilerSelector.new f
+    cs.select_compiler
+    cs.advise
+  end
+
   f.brew do
     if ARGV.flag? '--interactive'
       ohai "Entering interactive mode"
diff --git a/Library/Homebrew/compat/compatibility.rb b/Library/Homebrew/compat/compatibility.rb
index 3d67de077..acb03a75f 100644
--- a/Library/Homebrew/compat/compatibility.rb
+++ b/Library/Homebrew/compat/compatibility.rb
@@ -76,6 +76,16 @@ class Formula
   def fails_with_llvm msg=nil, data=nil
     FailsWithLLVM.new(msg, data).handle_failure
   end
+
+  def fails_with_llvm?
+    fails_with? :llvm
+  end
+
+  def self.fails_with_llvm msg=nil, data=nil
+    fails_with_llvm_reason = FailsWithLLVM.new(msg, data)
+    @cc_failures ||= CompilerFailures.new
+    @cc_failures << fails_with_llvm_reason
+  end
 end
 
 class UnidentifiedFormula < Formula
@@ -94,3 +104,52 @@ module HomebrewEnvExtension extend self
     compiler == :llvm
   end
 end
+
+class FailsWithLLVM
+  attr_reader :compiler, :build, :cause
+
+  def initialize msg=nil, data=nil
+    if msg.nil? or msg.kind_of? Hash
+      @cause = "(No specific reason was given)"
+      data = msg
+    else
+      @cause = msg
+    end
+    @build = (data.delete :build rescue nil).to_i
+    @compiler = :llvm
+  end
+
+  def handle_failure
+    return unless ENV.compiler == :llvm
+
+    # version 2336 is the latest version as of Xcode 4.2, so it is the
+    # latest version we have tested against so we will switch to GCC and
+    # bump this integer when Xcode 4.3 is released. TODO do that!
+    if build.to_i >= 2336
+      if MacOS.xcode_version < "4.2"
+        opoo "Formula will not build with LLVM, using GCC"
+        ENV.gcc
+      else
+        opoo "Formula will not build with LLVM, trying Clang"
+        ENV.clang
+      end
+      return
+    end
+    opoo "Building with LLVM, but this formula is reported to not work with LLVM:"
+    puts
+    puts cause
+    puts
+    puts <<-EOS.undent
+      We are continuing anyway so if the build succeeds, please open a ticket with
+      the following information: #{MacOS.llvm_build_version}-#{MACOS_VERSION}. So
+      that we can update the formula accordingly. Thanks!
+      EOS
+    puts
+    if MacOS.xcode_version < "4.2"
+      puts "If it doesn't work you can: brew install --use-gcc"
+    else
+      puts "If it doesn't work you can try: brew install --use-clang"
+    end
+    puts
+  end
+end
diff --git a/Library/Homebrew/compilers.rb b/Library/Homebrew/compilers.rb
new file mode 100644
index 000000000..ff56d34a0
--- /dev/null
+++ b/Library/Homebrew/compilers.rb
@@ -0,0 +1,138 @@
+class Compilers < Array
+  def include? cc
+    cc = cc.name if cc.is_a? Compiler
+    self.any? { |c| c.name == cc }
+  end
+end
+
+
+class CompilerFailures < Array
+  def include? cc
+    cc = Compiler.new(cc) unless cc.is_a? Compiler
+    self.any? { |failure| failure.compiler == cc.name }
+  end
+
+  def <<(failure)
+    super(failure) unless self.include? failure.compiler
+  end
+end
+
+
+class Compiler
+  attr_reader :name, :build
+
+  def initialize name
+    @name = name
+    @build = case name
+    when :clang then MacOS.clang_build_version.to_i
+    when :llvm then MacOS.llvm_build_version.to_i
+    when :gcc then MacOS.gcc_42_build_version.to_i
+    end
+  end
+
+  def ==(other)
+    @name.to_sym == other.to_sym
+  end
+end
+
+
+class CompilerFailure
+  attr_reader :compiler
+
+  def initialize compiler, &block
+    @compiler = compiler
+    instance_eval(&block) if block_given?
+  end
+
+  def build val=nil
+    val.nil? ? @build.to_i : @build = val.to_i
+  end
+
+  def cause val=nil
+    val.nil? ? @cause : @cause = val
+  end
+end
+
+
+# CompilerSelector is used to process a formula's CompilerFailures.
+# If no viable compilers are available, ENV.compiler is left as-is.
+class CompilerSelector
+  NAMES = { :clang => "Clang", :gcc => "GCC", :llvm => "LLVM" }
+
+  def initialize f
+    @f = f
+    @old_compiler = ENV.compiler
+    @compilers = Compilers.new
+    @compilers << Compiler.new(:clang) if MacOS.clang_build_version
+    @compilers << Compiler.new(:llvm) if MacOS.llvm_build_version
+    @compilers << Compiler.new(:gcc) if MacOS.gcc_42_build_version
+  end
+
+  def select_compiler
+    # @compilers is our list of available compilers. If @f declares a
+    # failure with compiler foo, then we remove foo from the list if
+    # the failing build is >= the currently installed version of foo.
+    @compilers.reject! do |cc|
+      failure = @f.fails_with? cc
+      next unless failure
+      failure.build >= cc.build
+    end
+
+    return if @compilers.empty? or @compilers.include? ENV.compiler
+
+    ENV.send case ENV.compiler
+    when :clang
+      if @compilers.include? :llvm then :llvm
+      elsif @compilers.include? :gcc then :gcc
+      else ENV.compiler
+      end
+    when :llvm
+      if @compilers.include? :clang and MacOS.clang_build_version >= 211 then :clang
+      elsif @compilers.include? :gcc then :gcc
+      elsif @compilers.include? :clang then :clang
+      else ENV.compiler
+      end
+    when :gcc
+      if @compilers.include? :clang and MacOS.clang_build_version >= 211 then :clang
+      elsif @compilers.include? :llvm then :llvm
+      elsif @compilers.include? :clang then :clang
+      else ENV.compiler
+      end
+    end
+  end
+
+  def advise
+    failure = @f.fails_with? @old_compiler
+    return unless failure
+
+    # If we're still using the original ENV.compiler, then the formula did not
+    # declare a specific failing build, so we continue and print some advice.
+    # Otherwise, tell the user that we're switching compilers.
+    if @old_compiler == ENV.compiler
+      cc = Compiler.new(ENV.compiler)
+      subject = "#{@f.name}-#{@f.version}: builds with #{NAMES[cc.name]}-#{cc.build}-#{MACOS_VERSION}"
+      warning = "Using #{NAMES[cc.name]}, but this formula is reported to fail with #{NAMES[cc.name]}."
+      warning += "\n\n#{failure.cause.strip}\n" unless failure.cause.nil?
+      warning += <<-EOS.undent
+
+        We are continuing anyway so if the build succeeds, please open a ticket with
+        the subject
+
+          #{subject}
+
+        so that we can update the formula accordingly. Thanks!
+        EOS
+
+      viable = @compilers.reject { |cc| @f.fails_with? cc }
+      unless viable.empty?
+        warning += "\nIf it fails you can use "
+        options = viable.map { |cc| "--use-#{cc.name}" }
+        warning += "#{options*' or '} to try a different compiler."
+      end
+
+      opoo warning
+    else
+      opoo "Formula will not build with #{NAMES[@old_compiler]}, trying #{NAMES[ENV.compiler]}"
+    end
+  end
+end
diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index c8ef58e50..eb1d7dcbe 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -5,6 +5,7 @@ require 'hardware'
 require 'bottles'
 require 'extend/fileutils'
 require 'patches'
+require 'compilers'
 
 # Derive and define at least @url, see Library/Formula for examples
 class Formula
@@ -156,14 +157,12 @@ class Formula
     self.class.keg_only_reason || false
   end
 
-  def fails_with_llvm?
-    llvm = self.class.fails_with_llvm_reason
-    if llvm
-      if llvm.build and MacOS.llvm_build_version.to_i > llvm.build.to_i
-        false
-      else
-        llvm
-      end
+  def fails_with? cc
+    return false if self.class.cc_failures.nil?
+    cc = Compiler.new(cc) unless cc.is_a? Compiler
+    return self.class.cc_failures.find do |failure|
+      next unless failure.compiler == cc.name
+      failure.build.zero? or failure.build >= cc.build
     end
   end
 
@@ -182,8 +181,6 @@ class Formula
     validate_variable :name
     validate_variable :version
 
-    fails_with_llvm?.handle_failure if fails_with_llvm?
-
     stage do
       begin
         patch
@@ -571,8 +568,8 @@ private
     end
 
     attr_rw :version, :homepage, :mirrors, :specs
-    attr_rw :keg_only_reason, :fails_with_llvm_reason, :skip_clean_all
-    attr_rw :bottle_url, :bottle_sha1
+    attr_rw :keg_only_reason, :skip_clean_all, :bottle_url, :bottle_sha1
+    attr_rw :cc_failures
     attr_rw(*CHECKSUM_TYPES)
 
     def head val=nil, specs=nil
@@ -675,8 +672,13 @@ private
       @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)
+    def fails_with compiler, &block
+      @cc_failures ||= CompilerFailures.new
+      @cc_failures << if block_given?
+        CompilerFailure.new(compiler, &block)
+      else
+        CompilerFailure.new(compiler)
+      end
     end
   end
 end
diff --git a/Library/Homebrew/formula_support.rb b/Library/Homebrew/formula_support.rb
index df98f3cb4..3bda65dcd 100644
--- a/Library/Homebrew/formula_support.rb
+++ b/Library/Homebrew/formula_support.rb
@@ -69,61 +69,3 @@ EOS
     end
   end
 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
-    if msg.nil? or msg.kind_of? Hash
-      @msg = "(No specific reason was given)"
-      data = msg
-    else
-      @msg = msg
-    end
-    @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
-
-  def handle_failure
-    return unless ENV.compiler == :llvm
-
-    # version 2336 is the latest version as of Xcode 4.2, so it is the
-    # latest version we have tested against so we will switch to GCC and
-    # bump this integer when Xcode 4.3 is released. TODO do that!
-    if build.to_i >= 2336
-      if MacOS.xcode_version < "4.2"
-        opoo "Formula will not build with LLVM, using GCC"
-        ENV.gcc
-      else
-        opoo "Formula will not build with LLVM, trying Clang"
-        ENV.clang
-      end
-      return
-    end
-    opoo "Building with LLVM, but this formula is reported to not work with LLVM:"
-    puts
-    puts reason
-    puts
-    puts <<-EOS.undent
-      We are continuing anyway so if the build succeeds, please open a ticket with
-      the following information: #{MacOS.llvm_build_version}-#{MACOS_VERSION}. So
-      that we can update the formula accordingly. Thanks!
-      EOS
-    puts
-    if MacOS.xcode_version < "4.2"
-      puts "If it doesn't work you can: brew install --use-gcc"
-    else
-      puts "If it doesn't work you can try: brew install --use-clang"
-    end
-    puts
-  end
-end
diff --git a/Library/Homebrew/test/test_formula.rb b/Library/Homebrew/test/test_formula.rb
index a819e5751..0735d55d6 100644
--- a/Library/Homebrew/test/test_formula.rb
+++ b/Library/Homebrew/test/test_formula.rb
@@ -3,8 +3,12 @@ require 'testing_env'
 require 'extend/ARGV' # needs to be after test/unit to avoid conflict with OptionsParser
 ARGV.extend(HomebrewArgvExtension)
 
+require 'extend/ENV'
+ENV.extend(HomebrewEnvExtension)
+
 require 'test/testball'
-require 'utils'
+
+require 'hardware'
 
 class AbstractDownloadStrategy
   attr_reader :url
@@ -62,4 +66,67 @@ class FormulaTests < Test::Unit::TestCase
     assert_equal f.url, "file:///#{TEST_FOLDER}/bad_url/testball-0.1.tbz"
     assert_equal downloader.url, "file:///#{TEST_FOLDER}/tarballs/testball-0.1.tbz"
   end
+
+  def test_compiler_selection
+    %W{HOMEBREW_USE_CLANG HOMEBEW_USE_LLVM HOMEBREW_USE_GCC}.each { |e| ENV.delete(e) }
+
+    f = TestAllCompilerFailures.new
+    assert f.fails_with? :clang
+    assert f.fails_with? :llvm
+    assert f.fails_with? :gcc
+    cs = CompilerSelector.new(f)
+    cs.select_compiler
+    assert_equal MacOS.default_compiler, ENV.compiler
+
+    f = TestNoCompilerFailures.new
+    assert !(f.fails_with? :clang)
+    assert !(f.fails_with? :llvm)
+    assert !(f.fails_with? :gcc)
+    cs = CompilerSelector.new(f)
+    cs.select_compiler
+    assert_equal MacOS.default_compiler, ENV.compiler
+
+    f = TestLLVMFailure.new
+    assert !(f.fails_with? :clang)
+    assert f.fails_with? :llvm
+    assert !(f.fails_with? :gcc)
+    cs = CompilerSelector.new(f)
+    cs.select_compiler
+    assert ENV.compiler, case MacOS.clang_build_version
+    when 0..210 then :gcc
+    else :clang
+    end
+
+    f = TestMixedCompilerFailures.new
+    assert f.fails_with? :clang
+    assert !(f.fails_with? :llvm)
+    assert f.fails_with? :gcc
+    cs = CompilerSelector.new(f)
+    cs.select_compiler
+    assert_equal :llvm, ENV.compiler
+
+    f = TestMoreMixedCompilerFailures.new
+    assert !(f.fails_with? :clang)
+    assert f.fails_with? :llvm
+    assert f.fails_with? :gcc
+    cs = CompilerSelector.new(f)
+    cs.select_compiler
+    assert_equal :clang, ENV.compiler
+
+    f = TestEvenMoreMixedCompilerFailures.new
+    assert f.fails_with? :clang
+    assert f.fails_with? :llvm
+    assert !(f.fails_with? :gcc)
+    cs = CompilerSelector.new(f)
+    cs.select_compiler
+    assert_equal :clang, ENV.compiler
+
+    f = TestBlockWithoutBuildCompilerFailure.new
+    assert f.fails_with? :clang
+    assert !(f.fails_with? :llvm)
+    assert !(f.fails_with? :gcc)
+    cs = CompilerSelector.new(f)
+    cs.select_compiler
+    assert_equal MacOS.default_compiler, ENV.compiler
+  end
 end
diff --git a/Library/Homebrew/test/testball.rb b/Library/Homebrew/test/testball.rb
index aae18115c..a77d7709c 100644
--- a/Library/Homebrew/test/testball.rb
+++ b/Library/Homebrew/test/testball.rb
@@ -39,3 +39,85 @@ class ConfigureFails <Formula
     system "./configure"
   end
 end
+
+class TestAllCompilerFailures < Formula
+  def initialize name=nil
+    @url="file:///#{TEST_FOLDER}/tarballs/testball-0.1.tbz"
+    @homepage = 'http://example.com/'
+    super "compilerfailures"
+  end
+
+  fails_with :clang
+  fails_with :llvm
+  fails_with :gcc
+end
+
+class TestNoCompilerFailures < Formula
+  def initialize name=nil
+    @url="file:///#{TEST_FOLDER}/tarballs/testball-0.1.tbz"
+    @homepage = 'http://example.com/'
+    super "nocompilerfailures"
+  end
+
+  fails_with(:clang) { build 42 }
+  fails_with(:llvm) { build 42 }
+  fails_with(:gcc) { build 42 }
+end
+
+class TestLLVMFailure < Formula
+  def initialize name=nil
+    @url="file:///#{TEST_FOLDER}/tarballs/testball-0.1.tbz"
+    @homepage = 'http://example.com/'
+    super "llvmfailure"
+  end
+
+  fails_with :llvm
+end
+
+class TestMixedCompilerFailures < Formula
+  def initialize name=nil
+    @url="file:///#{TEST_FOLDER}/tarballs/testball-0.1.tbz"
+    @homepage = 'http://example.com/'
+    super "mixedcompilerfailures"
+  end
+
+  fails_with(:clang) { build MacOS.clang_build_version }
+  fails_with(:llvm) { build 42 }
+  fails_with(:gcc) { build 5666 }
+end
+
+class TestMoreMixedCompilerFailures < Formula
+  def initialize name=nil
+    @url="file:///#{TEST_FOLDER}/tarballs/testball-0.1.tbz"
+    @homepage = 'http://example.com/'
+    super "moremixedcompilerfailures"
+  end
+
+  fails_with(:clang) { build 42 }
+  fails_with(:llvm) { build 2336 }
+  fails_with(:gcc) { build 5666 }
+end
+
+class TestEvenMoreMixedCompilerFailures < Formula
+  def initialize name=nil
+    @url="file:///#{TEST_FOLDER}/tarballs/testball-0.1.tbz"
+    @homepage = 'http://example.com/'
+    super "evenmoremixedcompilerfailures"
+  end
+
+  fails_with :clang
+  fails_with(:llvm) { build 2336 }
+  fails_with(:gcc) { build 5648 }
+end
+
+class TestBlockWithoutBuildCompilerFailure < Formula
+  def initialize name=nil
+    @url="file:///#{TEST_FOLDER}/tarballs/testball-0.1.tbz"
+    @homepage = 'http://example.com/'
+    super "blockwithoutbuildcompilerfailure"
+  end
+
+  fails_with :clang do
+    cause "failure"
+  end
+end
diff --git a/Library/Homebrew/test/testing_env.rb b/Library/Homebrew/test/testing_env.rb
index c0556651c..1e183287a 100644
--- a/Library/Homebrew/test/testing_env.rb
+++ b/Library/Homebrew/test/testing_env.rb
@@ -9,6 +9,7 @@ ABS__FILE__=File.expand_path(__FILE__)
 $:.push(File.expand_path(__FILE__+'/../..'))
 require 'extend/pathname'
 require 'exceptions'
+require 'utils'
 
 # these are defined in global.rb, but we don't want to break our actual
 # homebrew tree, and we do want to test everything :)