From 618617da7354befd8d6930bd7c2cda9a47988d76 Mon Sep 17 00:00:00 2001
From: Stephen Allred <stephenallred@stevesmiscellany.com>
Date: Fri, 1 Oct 2010 20:56:55 +0100
Subject: [PATCH] Added --use-gcc flag.

This allows you to use llvm as your default compiler and keep the cc symlink
pointed at llvm, while allowing you to build forumla that requires the gcc.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
---
 Library/Contributions/manpages/brew.1.md | 4 ++++
 Library/Homebrew/cmd/--env.rb            | 3 ++-
 Library/Homebrew/cmd/doctor.rb           | 3 +++
 Library/Homebrew/extend/ENV.rb           | 4 ++++
 share/man/man1/brew.1                    | 4 ++++
 5 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/Library/Contributions/manpages/brew.1.md b/Library/Contributions/manpages/brew.1.md
index 9281f68e6c..d5440189ff 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 07623171dc..2f6e421a0b 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 7ea616d763..9cbc9b8324 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 bb2bbd5442..fc4dc96aef 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'
diff --git a/share/man/man1/brew.1 b/share/man/man1/brew.1
index 5e40702fc9..f5979e5936 100644
--- a/share/man/man1/brew.1
+++ b/share/man/man1/brew.1
@@ -298,6 +298,10 @@ If set, instructs Homebrew to use \fBHOMEBREW_TEMP\fR as the temporary folder fo
 This issue typically occurs when using FileVault or custom SSD configurations\.
 .
 .TP
+HOMEBREW_USE_GCC
+If set, instructs Homebrew to use gcc, even if the system default is currently set to LLVM\.
+.
+.TP
 HOMEBREW_USE_LLVM
 If set, instructs Homebrew to use the LLVM front\-ends to the GCC compilers\.
 .