Tab: track C++ stdlib in use

There are subtle incompatibilities between Apple's libstdc++ and the
libstdc++ used by the various GNU GCC formulae. In addition, we'll
likely also be supporting libc++ in the future, and that's also
incompatible with the other stdlibs.

Tracking it in the tab lets us make sure that dependencies are all
built against the same stdlib to avoid subtle breakage.

1 files changed, 18 insertions, 4 deletions

diff --git a/Library/Homebrew/tab.rb b/Library/Homebrew/tab.rb
index a55df156d..9b19e9510 100644
--- a/Library/Homebrew/tab.rb
+++ b/Library/Homebrew/tab.rb
@@ -1,3 +1,4 @@
+require 'cxxstdlib'
 require 'ostruct'
 require 'options'
 require 'utils/json'
@@ -9,7 +10,7 @@ require 'utils/json'
 class Tab < OpenStruct
   FILENAME = 'INSTALL_RECEIPT.json'
 
-  def self.create f, args
+  def self.create f, stdlib, compiler, args
     f.build.args = args
 
     sha = HOMEBREW_REPOSITORY.cd do
@@ -23,7 +24,9 @@ class Tab < OpenStruct
             :poured_from_bottle => false,
             :tapped_from => f.tap,
             :time => Time.now.to_i, # to_s would be better but Ruby has no from_s function :P
-            :HEAD => sha
+            :HEAD => sha,
+            :compiler => compiler,
+            :stdlib => stdlib
   end
 
   def self.from_file path
@@ -59,7 +62,9 @@ class Tab < OpenStruct
             :poured_from_bottle => false,
             :tapped_from => "",
             :time => nil,
-            :HEAD => nil
+            :HEAD => nil,
+            :stdlib => :libstdcxx,
+            :compiler => :clang
   end
 
   def with? name
@@ -92,6 +97,13 @@ class Tab < OpenStruct
     used_options + unused_options
   end
 
+  def cxxstdlib
+    # Older tabs won't have these values, so provide sensible defaults
+    lib = stdlib || :libstdcxx
+    cc = compiler || MacOS.default_compiler
+    CxxStdlib.new(lib.to_sym, cc.to_sym)
+  end
+
   def to_json
     Utils::JSON.dump({
       :used_options => used_options.map(&:to_s),
@@ -100,7 +112,9 @@ class Tab < OpenStruct
       :poured_from_bottle => poured_from_bottle,
       :tapped_from => tapped_from,
       :time => time,
-      :HEAD => send("HEAD")})
+      :HEAD => send("HEAD"),
+      :stdlib => (stdlib.to_s if stdlib),
+      :compiler => (compiler.to_s if compiler)})
   end
 
   def write