4 files changed, 13 insertions, 1 deletions
diff --git a/Library/Contributions/manpages/brew.1.md b/Library/Contributions/manpages/brew.1.md
index 9281f68e6..d5440189f 100644
--- a/Library/Contributions/manpages/brew.1.md
+++ b/Library/Contributions/manpages/brew.1.md
@@ -275,6 +275,10 @@ Some sample commands ship with Homebrew and are enabled by default.
     This issue typically occurs when using FileVault or custom SSD
     configurations.
 
+  * HOMEBREW\_USE\_GCC:
+    If set, instructs Homebrew to use gcc, even if the system default
+    is currently set to LLVM.
+
   * HOMEBREW\_USE\_LLVM:
     If set, instructs Homebrew to use the LLVM front-ends to the GCC
     compilers.
diff --git a/Library/Homebrew/cmd/--env.rb b/Library/Homebrew/cmd/--env.rb
index 07623171d..2f6e421a0 100644
--- a/Library/Homebrew/cmd/--env.rb
+++ b/Library/Homebrew/cmd/--env.rb
@@ -10,6 +10,7 @@ module Homebrew extend self
 
   def dump_build_env env
     puts %["--use-llvm" was specified] if ARGV.include? '--use-llvm'
+    puts "\"--use-gcc\" was specified" if ARGV.include? '--use-gcc'
 
     %w[ CC CXX LD ].each do |k|
       value = env[k]
@@ -24,7 +25,7 @@ module Homebrew extend self
     end
 
     %w[ CFLAGS CXXFLAGS CPPFLAGS LDFLAGS MACOSX_DEPLOYMENT_TARGET MAKEFLAGS PKG_CONFIG_PATH
-        HOMEBREW_DEBUG HOMEBREW_VERBOSE HOMEBREW_USE_LLVM HOMEBREW_SVN ].each do |k|
+        HOMEBREW_DEBUG HOMEBREW_VERBOSE HOMEBREW_USE_GCC HOMEBREW_USE_LLVM HOMEBREW_SVN ].each do |k|
       value = env[k]
       puts "#{k}: #{value}" if value
     end
diff --git a/Library/Homebrew/cmd/doctor.rb b/Library/Homebrew/cmd/doctor.rb
index 7ea616d76..9cbc9b832 100644
--- a/Library/Homebrew/cmd/doctor.rb
+++ b/Library/Homebrew/cmd/doctor.rb
@@ -147,6 +147,9 @@ def check_cc_symlink
         To force Homebrew to use LLVM, you can set the "HOMEBREW_LLVM" environmental
         variable, or pass "--use-llvm" to "brew install".
 
+        To force Homebrew to use gcc, you can set the "HOMEBREW_GCC" environmental
+        variable, or pass "--use-gcc" to "brew install".
+
       EOS
     end
 end
diff --git a/Library/Homebrew/extend/ENV.rb b/Library/Homebrew/extend/ENV.rb
index bb2bbd544..fc4dc96ae 100644
--- a/Library/Homebrew/extend/ENV.rb
+++ b/Library/Homebrew/extend/ENV.rb
@@ -24,6 +24,10 @@ module HomebrewEnvExtension
       self['CC'] = "#{xcode_path}/usr/bin/llvm-gcc"
       self['CXX'] = "#{xcode_path}/usr/bin/llvm-g++"
       cflags = ['-O4'] # link time optimisation baby!
+    elsif MACOS_VERSION >= 10.6 and (self['HOMEBREW_USE_GCC'] or ARGV.include? '--use-gcc')
+      self['CC'] = '/usr/bin/gcc'
+      self['CXX'] = '/usr/bin/g++'
+      cflags = ['-O3']
     else
       # If these aren't set, many formulae fail to build
       self['CC'] = '/usr/bin/cc'