Add host-triplet aliasing feature to mkheader.

* src/Makefile.am (lock_obj_pub): Rename i586-pc-linux-gnu to
i686-pc-linux-gnu.  Remove i486-pc-linux-gnu.
* src/mkheader.c (canon_host_triplet): New.
(main): Use it.
--

config.sub does not map i{4,5,6}86-pc-linux-gnu to one common triplet.
However, they all use the same ABI and thus we do not need several
versions of the syscfg files.

Signed-off-by: Werner Koch <wk@gnupg.org>

4 files changed, 51 insertions, 8 deletions

diff --git a/README b/README
index d0a1d47..be7b7dc 100644
--- a/README
+++ b/README
@@ -116,7 +116,9 @@ need to figure out these values.  You may use these commands:
 If you are using a VPATH build adjust accordingly.  If this all works
 for you (make sure to run the test programs on the target platform),
 please send the generated file to the gnupg-devel mailing list so that
-we can include it in the next release.
+we can include it in the next release.  Note that in addition to the
+aliasing done by config.sub the src/mkheader build tool does some
+extra aliasing to avoid having too much identical syscfg files.
 
 
 
diff --git a/src/Makefile.am b/src/Makefile.am
index 18a4cb7..99c2c53 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -51,8 +51,7 @@ lock_obj_pub = \
         syscfg/lock-obj-pub.hppa-unknown-linux-gnu.h        \
         syscfg/lock-obj-pub.i486-pc-gnu.h                   \
         syscfg/lock-obj-pub.i486-pc-kfreebsd-gnu.h          \
-        syscfg/lock-obj-pub.i486-pc-linux-gnu.h             \
-        syscfg/lock-obj-pub.i586-pc-linux-gnu.h             \
+        syscfg/lock-obj-pub.i686-pc-linux-gnu.h             \
         syscfg/lock-obj-pub.m68k-unknown-linux-gnu.h        \
         syscfg/lock-obj-pub.mips-unknown-linux-gnu.h        \
         syscfg/lock-obj-pub.mips64el-unknown-linux-gnuabi64.h \
diff --git a/src/mkheader.c b/src/mkheader.c
index 9fe0695..3481771 100644
--- a/src/mkheader.c
+++ b/src/mkheader.c
@@ -23,7 +23,7 @@
 #define LINESIZE 1024
 
 static const char *host_os;
-static const char *host_triplet;
+static char *host_triplet;
 static char *srcdir;
 static const char *hdr_version;
 static const char *hdr_version_number;
@@ -63,6 +63,40 @@ xstrdup (const char *string)
 }
 
 
+/* Return a malloced string with TRIPLET.  If TRIPLET has an alias
+   return that instead.  In general build-aux/config.sub should do the
+   aliasing but some returned triplets are anyway identical and thus we
+   use this function to map it to the canonical form.  */
+static char *
+canon_host_triplet (const char *triplet)
+{
+  struct {
+    const char *name;
+    const char *alias;
+  } tbl[] = {
+    {"i486-pc-linux-gnu", "i686-pc-linux-gnu" },
+    {"i586-pc-linux-gnu" },
+
+    { NULL }
+  };
+  int i;
+  const char *lastalias = NULL;
+
+  for (i=0; tbl[i].name; i++)
+    {
+      if (tbl[i].alias)
+        lastalias = tbl[i].alias;
+      if (!strcmp (tbl[i].name, triplet))
+        {
+          if (!lastalias)
+            break; /* Ooops: first entry has no alias.  */
+          return xstrdup (lastalias);
+        }
+    }
+  return xstrdup (triplet);
+}
+
+
 /* Parse the supplied config.h file and extract required info.
    Returns 0 on success.  */
 static int
@@ -481,6 +515,7 @@ main (int argc, char **argv)
   const char *fname, *s;
   char *p1, *p2;
   const char *config_h;
+  const char *host_triplet_raw;
 
   if (argc)
     {
@@ -496,12 +531,14 @@ main (int argc, char **argv)
       return 1;
     }
   host_os = argv[0];
-  host_triplet = argv[1];
+  host_triplet_raw = argv[1];
   fname = argv[2];
   config_h = argv[3];
   hdr_version = argv[4];
   hdr_version_number = argv[5];
 
+  host_triplet = canon_host_triplet (host_triplet_raw);
+
   srcdir = malloc (strlen (fname) + 2 + 1);
   if (!srcdir)
     {
@@ -554,8 +591,12 @@ main (int argc, char **argv)
       if (!strcmp (p1, "configure_input"))
         {
           s = strrchr (fname, '/');
-          printf ("Do not edit.  Generated from %s for %s.",
-                  s? s+1 : fname, host_triplet);
+          printf ("Do not edit.  Generated from %s for:\n%*s",
+                  s? s+1 : fname, (int)(p1 - line) + 13, "");
+          if (!strcmp (host_triplet, host_triplet_raw))
+            printf ("%s", host_triplet);
+          else
+            printf ("%s (%s)", host_triplet, host_triplet_raw);
           fputs (p2, stdout);
         }
       else if (!write_special (fname, lnr, p1))
@@ -593,5 +634,6 @@ main (int argc, char **argv)
 
   fclose (fp);
 
+  xfree (host_triplet);
   return 0;
 }
diff --git a/src/syscfg/lock-obj-pub.i586-pc-linux-gnu.h b/src/syscfg/lock-obj-pub.i686-pc-linux-gnu.h
index fc2d132..b97273b 100644
--- a/src/syscfg/lock-obj-pub.i586-pc-linux-gnu.h
+++ b/src/syscfg/lock-obj-pub.i686-pc-linux-gnu.h
@@ -1,4 +1,4 @@
-## lock-obj-pub.i586-pc-linux-gnu.h
+## lock-obj-pub.i686-pc-linux-gnu.h
 ## File created by gen-posix-lock-obj - DO NOT EDIT
 ## To be included by mkheader into gpg-error.h