document a problem with AIX native compiler and Apache 2+,

and describe how to avoid it

PR:   30487

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/APACHE_2_0_BRANCH@105039 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/README.platforms b/README.platforms
index 3b5cc358d5797ba8992f02154dcebb037942e750..3c8e61802581b55e66b2dc2e0b15e84411df1387 100644 (file)
--- a/README.platforms
+++ b/README.platforms
@@ -77,4 +77,16 @@
        - OR -
      gcc -c -fPIC cpprt0_stub.s
 
+================
+  AIX, using the vendor C compiler with optimization:
+    There is an issue with compiling server/core.c with optimization enabled
+    which has been seen with C for AIX 5.0.2.3 and above.  (5.0.2.0, 5.0.2.1,
+    and 5.0.2.2 have an additional problem with Apache 2.0.x, so either upgrade 
+    the compiler or don't use optimization in order to avoid it.)
+
+    cc_r works fine with -O2 but xlc_r does not.  In order to use xlc_r with
+    -O2, apply the patch at 
+
+    http://www.apache.org/dist/httpd/patches/apply_to_2.0.49/aix_xlc_optimization.patch
 
+    (That patch works with many recent levels of Apache 2+.)