Bug#759407: gnat-4.9: gnat1 not found on kfreebsd-i386

[Nicolas Boulenguez <nicolas@debian.org>]

Package: src:gnat-4.9
Followup-For: Bug #759407

Svante's suggestion seems to work for the binutils package: it
installs /usr/lib/i486* symlinks to make the /usr/lib/i586* tools
visible to callers.

A bootstrap issue will remain: building a new gnat-4.9 package
installing these symlinks requires a working compiler.

In case this helps finding a better solution:

--  Where does gcc search for gnat1?

gcc-4.9-source/gcc_tarball/gcc/gcc.c searches gnat1 in
static const char *spec_machine = DEFAULT_TARGET_MACHINE;

gcc-4.9-source/gcc_tarball/gcc/Makefile.in sets DEFAULT_TARGET_MACHINE
from @target_noncanonical@.

gcc-4.9-source/gcc_tarball/gcc/configure.ac calls
ACX_NONCANONICAL_TARGET in config/acx.m4, which set
target_noncanonical from $target_alias or $host_noncanonical if blank.

gcc-4.9-source/gcc_tarball/debian/rules2 sets in CONFARGS
  --build=$(DEB_BUILD_GNU_TYPE)
  --host=$(DEB_HOST_GNU_TYPE)
  --target=$(TARGET_ALIAS)

--  Where is gnat1 actually installed?

gnat-4.9/debian/rules.d/binary-ada.mk installs gnat1 under
../$(gcc_lexec_dir)/...

gnat-4.9/debian/rules2 sets gcc_lexec_dir to ../$(TARGET_ALIAS)/..

-- Common part. The commented stanzas seem to show that a similar
   problem has been encountered in the past.

gnat-4.9/debian/rules.defs:
ifeq ($(DEB_CROSS),yes)
  DEB_TARGET_ALIAS ?= $(DEB_TARGET_GNU_TYPE)
  TARGET_ALIAS := $(DEB_TARGET_ALIAS)
else
  TARGET_ALIAS := $(DEB_TARGET_GNU_TYPE)
  ifeq ($(TARGET_ALIAS),i386-gnu)
    TARGET_ALIAS := i586-gnu
  endif

  #ifeq ($(TARGET_ALIAS),i486-linux-gnu)
  #  TARGET_ALIAS := i686-linux-gnu
  #endif

  TARGET_ALIAS := $(subst i386,i486,$(TARGET_ALIAS))

  # configure as linux-gnu, not linux
  #ifeq ($(findstring linux,$(TARGET_ALIAS))/$(findstring linux-gnu,$(TARGET_ALIAS)),linux/)
  #  TARGET_ALIAS := $(TARGET_ALIAS)-gnu
  #endif

  # configure as linux, not linux-gnu
  #TARGET_ALIAS := $(subst linux-gnu,linux,$(TARGET_ALIAS))