Add rule for extracting C and C++ predefs

1 files changed, 7 insertions, 5 deletions

diff --git a/libbuild2/cxx/init.hxx b/libbuild2/cxx/init.hxx
index 0e42cbe..5b80fdc 100644
--- a/libbuild2/cxx/init.hxx
+++ b/libbuild2/cxx/init.hxx
@@ -19,11 +19,13 @@ namespace build2
     //
     // Submodules:
     //
-    // `cxx.guess`  -- registers and sets some variables.
-    // `cxx.config` -- loads cxx.guess and sets more variables.
-    // `cxx`        -- loads cxx.config and registers target types and rules.
-    // `cxx.objcxx` -- registers mm{} target type and enables Objective-C++
-    //                 compilation.
+    // `cxx.guess`   -- registers and sets some variables.
+    // `cxx.config`  -- loads cxx.guess and sets more variables.
+    // `cxx`         -- loads cxx.config and registers target types and rules.
+    // `cxx.objcxx`  -- registers mm{} target type and enables Objective-C++
+    //                  compilation.
+    // `cxx.predefs` -- registers rule for generating a C++ header with
+    //                  predefined compiler macros. Must be loaded after cxx.
     //
     extern "C" LIBBUILD2_CXX_SYMEXPORT const module_functions*
     build2_cxx_load ();