Further zOS updates: Wrap C compiler.

1 files changed, 71 insertions, 30 deletions

diff --git a/m4/arch.m4 b/m4/arch.m4
index ec1e9ed9..fc25d8e9 100644
--- a/m4/arch.m4
+++ b/m4/arch.m4
@@ -72,32 +72,34 @@ fi
 AC_MSG_RESULT([${ac_cv_zos_uss}])
 if test "x$ac_cv_zos_uss" = "xyes"
 then
+  dnl Identify the compiler.
+  ac_zos_uss_cc_id=unknown
+  echo " $CC " | $EGREP ' (/bin/)?c89[ |_]' >/dev/null && ac_zos_uss_cc_id=c89
+  echo " $CC " | $EGREP ' (/bin/)?c99[ |_]' >/dev/null && ac_zos_uss_cc_id=xlc
+  echo " $CC " | $EGREP ' (/bin/)?cc[ |_]'  >/dev/null && ac_zos_uss_cc_id=cc
+  echo " $CC " | $EGREP ' (/bin/)?xlc[ |_]' >/dev/null && ac_zos_uss_cc_id=xlc
+  echo " $CC " | $EGREP ' (/bin/)?xlC[ |_]' >/dev/null && ac_zos_uss_cc_id=xlc++
+  echo " $CC " | $EGREP ' (/bin/)?xlc\+\+[ |_]' >/dev/null && ac_zos_uss_cc_id=xlc++
+  test "x$GCC" = "xyes" && ac_zos_uss_cc_id=gcc
   dnl These feature test macros are needed on z/OS.
-  CPPFLAGS="$CPPFLAGS -D_ALL_SOURCE -D_XOPEN_SOURCE=600"
-  dnl If _C89_OPTIONS is set, then assume the user is building with the c89
-  dnl compiler frontend, and knows what they are doing. c89 (as well as cc)
-  dnl pre-dates xlc, and accepts an option syntax that involves parentheses
-  dnl and cannot be handled in the usual way in C(PP)FLAGS. However, c89
-  dnl will also accept options via the aforementioned environment variable,
-  dnl which gives the user one way around the problem. (If you're wondering
-  dnl about cc, it is meant for programs written in "Common Usage C"
-  dnl [a.k.a. K&R C] as opposed to "Standard C" [a.k.a. ANSI], and does not
-  dnl build gawk correctly.)
-  if test -n "$_C89_OPTIONS"
-  then
-    AC_MSG_NOTICE([_C89_OPTIONS = $_C89_OPTIONS])
-  elif test "x$GCC" != "xyes"
-  then
-    if echo " $CC " | $EGREP ' (/bin/)?cc ' >/dev/null
-    then
-      AC_MSG_ERROR([cc-invalid
-The z/OS "cc" compiler does not build GNU Awk correctly.
-
-If the "xlc" or "c89" compiler is available, please set CC accordingly
-and reconfigure. ("xlc" is the recommended compiler on z/OS.)])
-    fi
-    if echo " $CC " | $EGREP ' (/bin/)?c89 ' >/dev/null
+  CPPFLAGS="$CPPFLAGS -D_ALL_SOURCE"
+  test "$ac_zos_uss_cc_id" != xlc++ && CPPFLAGS="$CPPFLAGS -D_XOPEN_SOURCE=600"
+  case "$ac_zos_uss_cc_id" in
+  c89)
+    dnl If the user has set CC=c89 and _C89_OPTIONS, then don't get in
+    dnl their way.  c89 (as well as cc) pre-dates xlc, and accepts an
+    dnl option syntax that involves parentheses and cannot be handled
+    dnl in the usual way in C(PP)FLAGS.  However, c89 will also accept
+    dnl options via the aforementioned environment variable, which
+    dnl gives the user one way around the problem.  (If you're
+    dnl wondering about cc, it is meant for programs written in
+    dnl "Common Usage C" [a.k.a. K&R C] as opposed to "Standard C"
+    dnl [a.k.a. ANSI], and does not build gawk correctly.)
+    if test -n "$_C89_OPTIONS"
     then
+      AC_MSG_NOTICE([CC = $CC])
+      AC_MSG_NOTICE([_C89_OPTIONS = $_C89_OPTIONS])
+    else
       AC_MSG_ERROR([c89-setup-required
 To build GNU Awk using "c89", please set
 
@@ -106,12 +108,51 @@ To build GNU Awk using "c89", please set
 in your environment, and reconfigure. (The above flags cannot be specified
 in CFLAGS/CPPFLAGS, due to the parentheses.)])
     fi
+    ;;
+  gcc)
+    dnl GCC has not yet been ported to z/OS as of this writing
+    ;;
+  cc)
+    AC_MSG_ERROR([cc-invalid
+The z/OS "cc" compiler does not build GNU Awk correctly.
+
+If the "xlc" or "c89" compiler is available, please set CC accordingly
+and reconfigure. ("xlc" is the recommended compiler on z/OS.)])
+    ;;
+  xlc*)
     dnl This enables C99, and on z/OS 1.11, the setenv() prototype.
     CFLAGS="$CFLAGS -qlanglvl=stdc99:libext"
-    dnl This is needed so that xlc considers a missing header file to be an
-    dnl error and not a warning. (Yes, the latter is in fact the default
-    dnl behavior on z/OS.)
-    CPPFLAGS="$CPPFLAGS -qhaltonmsg=CCN3296"
-  fi
-fi
+    dnl Use a compiler wrapper script to address some annoyances.
+    cat >zos-cc <<EOF
+#!/bin/sh
+#
+# This wrapper script addresses two annoying peculiarities of the IBM
+# xlc/c99 compiler on z/OS:
+#
+# 1. Missing header files are considered warnings by default rather
+#    than fatal errors;
+#
+# 2. Include directories specified with -I are searched _after_ the
+#    system include directories (for #include<> directives) rather
+#    than before.
+#
+# This script allows the code and the build system to assume standard
+# compiler behavior.
+#
+
+PS4='zos-cc: '
+REAL_CC="$CC"
+
+set -x
+\$REAL_CC -qhaltonmsg=CCN3296 -qnosearch "\$[]@" -qsearch=/usr/include
+EOF
+    chmod +x zos-cc
+    AC_MSG_NOTICE([wrapping $CC with zos-cc to obtain standard behavior])
+    CC="`pwd`/zos-cc"
+    ;;
+  *)
+    AC_MSG_WARN([unrecognized compiler environment])
+    ;;
+  esac
+fi # ac_cv_zos_uss = yes
 ])dnl