In cflags.SH trim the case statement of file basenames.

Add examples showing how to use cflags.SH to tweak the compiler flags used
for individual object files.

Previously cflags.SH contained a somewhat stale pre-canned list of file
basenames including removed files such as usersub (deleted before 5.000
shipped), and a partial list of 5.000 XS extensions. Whilst it's possible
to generate the correct list in cflags by parsing MANIFEST (and adding a few
fixups), it's still not actually *useful*, as cflags gets overwritten as
soon as config.sh changes. Hence the most end-user useful solution with
minimal maintenance is to eliminate the list entirely, and document how the
user should add to it as necessary.

1 files changed, 14 insertions, 47 deletions

diff --git a/cflags.SH b/cflags.SH
index ac03b85f1f..6420bf3916 100755
--- a/cflags.SH
+++ b/cflags.SH
@@ -273,56 +273,23 @@ for file do
     : or customize here
 
     case "$file" in
-    DB_File) ;;
-    GDBM_File) ;;
-    NDBM_File) ;;
-    ODBM_File) ;;
-    POSIX) ;;
-    SDBM_File) ;;
-    av) ;;
-    byterun) ;;
-    deb) ;;
-    dl) ;;
-    doio) ;;
-    doop) ;;
-    dump) ;;
-    globals) ;;
-    gv) ;;
-    hv) ;;
-    locale) ;;
-    madly) ;;
-    main) ;;
-    malloc) ;;
-    mg) ;;
-    miniperlmain) ;;
-    numeric) ;;
-    op) ;;
-    opmini) ;;
-    pad) ;;
-    perl) ;;
-    perlapi) ;;
-    perlmain) ;;
-    perly) ;;
-    pp) ;;
-    pp_ctl) ;;
-    pp_hot) ;;
-    pp_pack) ;;
-    pp_sort) ;;
-    pp_sys) ;;
-    regcomp) ;;
-    regexec) ;;
-    run) ;;
-    scope) ;;
-    sv) ;;
-    taint) ;;
-    toke) ;;
-    universal) ;;
-    usersub) ;;
-    utf8) ;;
-    util) ;;
     *) ;;
+
+    *) : Customization examples follow: ;;
+    av) ccflags=`echo $ccflags | sed -e s/-pipe//` ;;
+    deb) ccflags="$ccflags -fno-jump-tables" ;;
+    hv) warn=`echo $warn | sed -e s/-Wextra//` ;;
+    toke) optimize=-O0 ;;
     esac
 
+    : The examples are intentionally unreachable as the '*)' case always
+    : matches. To use them, move before the '*)' and edit as appropriate.
+    : It is not a good idea to set ccflags to an absolute value here, as it
+    : often contains general -D defines which are needed for correct
+    : compilation. It is better to edit ccflags as shown, using interpolation
+    : to add flags, or sed to remove flags.
+
+
     case "$cc" in
     *g++*)
       # Extra paranoia in case people have bad canned ccflags: