Consider superenv “servile” during configure

superenv defaults to servile mode. In servile mode:

* If 'gcc' is called, then 'gcc' is run (we ignore HOMEBREW_CC)
* CFLAGS (optimizations) are not applied
* ARGV is not mangled (TODO though we should apply fixes)
* -I and -L environment is still forcibly inserted.

This fixes, eg. jack which was still broken with stdenv. Jack was broken because we set CC in stdenv, and Jack has a stupid build-system. Unsetting CC allowed Jack to find and use the gcc tool it so demanded, but (previously) we would then substitute clang under its nose. The configure still failed. In servile mode (llvm-)gcc is used and Jack compiles.

In normal circumstances clang would then be inserted again during the make phase. But Jack uses the niche-wag build tool that we don't support for setting the O HOMEBREW_CCCFG flag that disables servile mode.

Library/ENV/4.3/bsdmake

@@ -0,0 +1 @@
+make

Library/ENV/4.3/cc

@@ -15,6 +15,13 @@ require 'set'
 def cccfg? flags
   flags.split('').all?{|c| ENV['HOMEBREW_CCCFG'].include? c } if ENV['HOMEBREW_CCCFG']
 end
+def servile?
+  # we are servile when we are called from configure etc.
+  # * we give the callee the tools it asks for
+  # * we leave ARGV alone
+  # when callee is make we optimize and force HOMEBREW_CC
+  not cccfg? 'O'
+end
 def nclt?
   $sdkroot != nil
 end
@@ -29,12 +36,12 @@ end
 
 class Cmd
   def initialize path, args
-    @cmd = path.basename.freeze
+    @arg0 = path.basename.freeze
     @args = args.freeze
   end
   def mode
-    if @cmd == 'cpp' or @cmd == 'ld'
+    if @arg0 == 'cpp' or @arg0 == 'ld'
-      @cmd.to_sym
+      @arg0.to_sym
     elsif @args.include? '-c'
       :cc
     elsif @args.include? '-E'
@@ -44,25 +51,25 @@ class Cmd
     end
   end
   def tool
-    @tool ||= if @cmd.include? '++'
+    @tool ||= if servile? or @arg0 == 'ld'
+      @arg0
+    elsif @arg0.include? '++'
       if ENV['HOMEBREW_CC'].chuzzle =~ /gcc/
         'g++'
       else
         'clang++'
       end
-    elsif @cmd == 'ld'
-      'ld'
     else
       ENV['HOMEBREW_CC'].chuzzle or 'clang'
     end
   end
   def args
-    args = if cccfg? 'O' and tool != 'ld'
+    args = if servile? or tool == 'ld'
-      refurbished_args
-    else
       @args.dup
+    else
+      refurbished_args
     end
-    if @cmd != 'ld'
+    if tool != 'ld'
       args.unshift("--sysroot=#$sdkroot")
     else
       args.unshift($sdkroot).unshift("-syslibroot")
@@ -152,7 +159,7 @@ class Cmd
 end
 
 ####################################################################### sanity
-abort "The build-tool has reset ENV. --lame-env required." unless ENV['HOMEBREW_BREW_FILE']
+abort "The build-tool has reset ENV. --env=std required." unless ENV['HOMEBREW_BREW_FILE']
 
 ######################################################################### main
 cmd = Cmd.new($0, ARGV)