[evolution] Clarify a configure.ac comment.

[Matthew Barnes <mbarnes src gnome org>]

commit 0727097ac13ad746184ba0580247bff70cefbb68
Author: Matthew Barnes <mbarnes redhat com>
Date:   Tue Feb 2 13:19:40 2010 -0500

    Clarify a configure.ac comment.

 configure.ac |   12 +++++++-----
 1 files changed, 7 insertions(+), 5 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index b034b76..643d691 100644
--- a/configure.ac
+++ b/configure.ac
@@ -84,17 +84,19 @@ AS_COMPILER_FLAGS(WARNING_FLAGS,
 AC_SUBST(WARNING_FLAGS)
 
 dnl Other useful compiler warnings for test builds only.
-dnl These may produce warnings we have no control over.
+dnl These may produce warnings we have no control over,
+dnl or false positives we don't always want to see.
+dnl
 dnl	-Wmissing-format-attribute
 dnl	-Wshadow
 dnl	-Wformat-nonliteral
+dnl	-Wstrict-aliasing=2
 
-dnl GCC 4.4 got more aggressive in it's aliasing optimizations, changing
+dnl GCC 4.4 got more aggressive in its aliasing optimizations, changing
 dnl behavior that -- according to the C99 standard -- is supposed to be
 dnl undefined.  We may still have aliasing abuses lying around that rely
-dnl on GCC's previous "undefined" behavior but are hidden by type casts,
-dnl so disable the strict-aliasing optimzation until GCC (or even LLVM)
-dnl learns how to detect them and warn us about it.
+dnl on GCC's previous "undefined" behavior, so disable strict-aliasing
+dnl optimzation until we can find and fix all the abuses.
 dnl XXX This really belongs in AM_CFLAGS.
 AM_CPPFLAGS="$WARNING_FLAGS -fno-strict-aliasing"
 AC_SUBST(AM_CPPFLAGS)