OTP-8323 Miscellaneous cross compilation improvements. For example, one

          new mandatory configuration variable that replaces all other
          previously mandatory configuration variables, and better
          documentation. Note that old cross compilation configurations
          cannot be used without modifications.

          For more information see the $ERL_TOP/xcomp/README file.

1 files changed, 84 insertions, 90 deletions

diff --git a/xcomp/erl-xcomp.conf.template b/xcomp/erl-xcomp.conf.template
index cc604a80e5..bed365e754 100644
--- a/xcomp/erl-xcomp.conf.template
+++ b/xcomp/erl-xcomp.conf.template
@@ -31,66 +31,26 @@
 ###
 
 ##
-## Operating system and hardware architecture.
-##
-# Operating system: linux|solaris<ver>|darwin|freebsd|win32|<...>
-erl_xcomp_os=
-# Hardware architecture: x86|x86_64|ultrasparc|sparc64|ppc|arm|tile|<...>
-# Note that this will be the host parameter to configure, so it
-# should be both recognizable by config.sub and a valid prefix for
-# i.e. gcc etc if compiler is not specified further down. 
-erl_xcomp_hw=
-# Manufacturer: (unknown is ok)
-erl_xcomp_man=
-# Extra target info (unknown is ok)
-erl_xcomp_target_xtra=
-
-# Target (change if default isn't satisfactory)
-# Note that this has to correspond to what config.sub thinks the machine is.
-# Edit config.sub if not satisfactory, or set this explicitly 
-# to what output you will get from running 
-# $ERL_TOP/erts/autoconf/config.sub $erl_xcomp_hw
-
-erl_xcomp_target=${erl_xcomp_hw}-${erl_xcomp_man}-${erl_xcomp_os}-${erl_xcomp_target_xtra}
-
-##
-## Sizes (in bytes) of some important types.
-##
-# void *
-erl_xcomp_void_p=
-# short
-erl_xcomp_short=
-# int
-erl_xcomp_int=
-# long
-erl_xcomp_long=
-# long long (use 0 if no 'long long' type exist)
-erl_xcomp_long_long=
-# size_t
-erl_xcomp_sizeof_size_t=
-# off_t
-erl_xcomp_sizeof_off_t=
-
-### ----------------------------------------------------------------------------
-### The variables in the following section have to be set for linux systems
-###
-# linux kernel version (as reported by "uname -r")
-erl_xcomp_linux_kernel=
+## Target system. The value will be passed as '--host' argument to the configure
+## script. It does not have to be a full CPU-VENDOR-OS tripplet, but can be. The
+## full CPU-VENDOR-OS tripplet will be created by:
+##  $ERL_TOP/erts/autoconf/config.sub $erl_xcomp_host
+##
+erl_xcomp_host=
 
 ### ----------------------------------------------------------------------------
-### ---------------------------------------------------------------------------
 ### To override the configure flags for a special target system, You
 ### can set this variable which overrides configure parameters on the 
 ### command line and instead uses the specified options. The variable
 ### leaves the build-host system untouched.
-### ---------------------------------------------------------------------------
+### ----------------------------------------------------------------------------
 erl_xcomp_configure_flags=
 
-###----------------------------------------------------------------------------
+###-----------------------------------------------------------------------------
 ### You can specify a specific CC or LD for the build target (the cross 
 ### compiler) here along with magic CFLAGS and/or LDFLAGS if needed
 ### ar and ranlib might also be specified if needed.
-###----------------------------------------------------------------------------
+###-----------------------------------------------------------------------------
 
 erl_xcomp_cc=
 
@@ -106,7 +66,7 @@ erl_xcomp_ranlib=
 
 erl_xcomp_ar=
 
-###----------------------------------------------------------------------------
+###-----------------------------------------------------------------------------
 ### The ded_ls and ded_ldflags variables control linking of dynamically loaded
 ### erlang drivers. On i.e. Linux these are set to
 ### $(CC) and "-shared" respectively, but other OS'es might need other
@@ -114,7 +74,7 @@ erl_xcomp_ar=
 ### erl_xcomp_ded_ld_runtime_library_path is the flag to set a
 ### specific runtime library path for the shared library at link time, 
 ### usually this should be left empty.
-###----------------------------------------------------------------------------
+###-----------------------------------------------------------------------------
 
 erl_xcomp_ded_ld=
 
@@ -122,83 +82,117 @@ erl_xcomp_ded_ldflags=
 
 erl_xcomp_ded_ld_runtime_library_path=
 
-### The variables in the following section does not need to be set. Only
-### set these if you really know what you are doing.
+###
+### Optional feature, or bug tests
+###
+### These tests cannot (always) be done automatically when cross compiling.
+### You usually does not need to set these variables. Only set these if you
+### really know what you are doing.
 ###
 
 ##
-## Big endian/little endian can usually be determined by configure correctly, 
-## but if not, set this variable
-##
+## erl_xcomp_bigendian - yes|no
+##  If yes, the target system must be big endian. If no, little endian. This
+##  can often be automatically detected, but not always. If not automatically
+##  detected, configure will fail unless this variable is set. No default value
+##  is used, i.e., configure will try to figure this out automatically.
 erl_xcomp_bigendian=
 
 ##
-## If you have a working poll that can be used: yes|no
+## erl_xcomp_linux_clock_gettime_correction - yes|no (defaults to yes)
+##  If yes, clock_gettime(CLOCK_MONOTONIC, _) on the target system must work.
+##  This variable is recommended to be set to no on Linux systems with kernel
+##  versions less than 2.6.
+##
+erl_xcomp_linux_clock_gettime_correction=
+
+##
+## erl_xcomp_linux_nptl - yes|no (defaults to yes on Linux; otherwise, no)
+##  If yes, the target system must have NPTL (Native POSIX Thread Library).
+##  Older Linux systems have LinuxThreads instead of NPTL (Linux kernel
+##  versions typically less than 2.6).
+##
+erl_xcomp_linux_nptl=
+
+##
+## erl_xcomp_linux_usable_sigusrx - yes|no (defaults to yes)
+##  If yes, the SIGUSR1 and SIGUSR2 must be usable by the ERTS. Old
+##  LinuxThreads thread libraries (Linux kernel versions less than 2.2) used
+##  these signals and made them unusable by the ERTS.
+##
+erl_xcomp_linux_usable_sigusrx=
+
+##
+## erl_xcomp_linux_usable_sigaltstack - yes|no (defaults to yes)
+##  If yes, sigaltstack() must be usable on the target system. sigaltstack()
+##  on Linux kernel versions less than 2.4 are broken.
+##
+erl_xcomp_linux_usable_sigaltstack=
+
+##
+## erl_xcomp_poll - yes|no (defaults to no on Darwin/MacOSX; otherwise, yes)
+##  If yes, the target system must have a working poll() implementation that
+##  also can handle devices. If no, select() will be used instead of poll().
 ##
 erl_xcomp_poll=
 
 ##
-## If you have a working kqueue() that can be used: yes|no
+## erl_xcomp_kqueue - yes|no (defaults to no)
+##  If yes, the target system must have a working kqueue() implementation that
+##  returns a file descriptor which can be used by poll() and/or select().
+##  If no and the target system has not got epoll() or /dev/poll, the
+##  kernel-poll feature will be disabled.
 ##
 erl_xcomp_kqueue=
 
 ##
-## If you have a putenv() that stores a copy of the key-value pair: yes|no
+## erl_xcomp_putenv_copy - yes|no (defaults to no)
+##  If yes, the target system must have a putenv() implementation that stores a
+##  copy of the key/value pair.
 ##
 erl_xcomp_putenv_copy=
 
 ##
-## If you have reliable floating point exeptions that can be
-## used: yes|no
+## erl_xcomp_reliable_fpe - yes|no (defaults to no)
+##  If yes, the target system must have reliable floating point exceptions.
 ##
 erl_xcomp_reliable_fpe=
 
 ##
-## If you have getaddrinfo() usable for ipv6: yes|no
+## erl_xcomp_getaddrinfo - yes|no (defaults to no)
+##  If yes, the target system must have a working getaddrinfo() implementation
+##  that can handle both IPv4 and IPv6.
 ##
 erl_xcomp_getaddrinfo=
 
 ##
-## If you have a gethrvtime() that works and uses ioctl()
-## to /proc/self: yes|no
+## erl_xcomp_gethrvtime_procfs_ioctl - yes|no (defaults to no)
+##  If yes, the target system must have a working gethrvtime() implementation
+##  and is used with procfs ioctl().
 ##
 erl_xcomp_gethrvtime_procfs_ioctl=
 
 ##
-## If you have a working clock_gettime(): yes|no
+## erl_xcomp_clock_gettime - yes|no (defaults to no)
+##  If yes, the target system must have a working clock_gettime()
+##  implementation that can be used for retrieving process CPU time.
 ##
 erl_xcomp_clock_gettime=
 
 ##
-## If you have a __after_morecore_hook that can track malloc()s
-## core memory use: yes|no
+## erl_xcomp_after_morecore_hook - yes|no (defaults to no)
+##  If yes, the target system must have a working __after_morecore_hook that
+##  can be used for tracking used malloc() implementations core memory usage.
 ##
 erl_xcomp_after_morecore_hook=
 
 ##
-## If you have brk, sbrk and end symbols: yes|no
-##
-# brk
-erl_xcomp_have_brk=
-# _brk
-erl_xcomp_have__brk=
-# __brk
-erl_xcomp_have___brk=
-# sbrk
-erl_xcomp_have_sbrk=
-# _sbrk
-erl_xcomp_have__sbrk=
-# __sbrk
-erl_xcomp_have___sbrk=
-# end
-erl_xcomp_end=
-# _end
-erl_xcomp__end=
-
-##
-## If sbrk/brk wrappers using dlsym(RTLD_NEXT, _) can track malloc()s
-## core memory use: yes|no
+## erl_xcomp_dlsym_brk_wrappers - yes|no (defaults to no)
+##  If yes, the target system must have a working dlsym(RTLD_NEXT, <S>)
+##  implementation that can be used on 'brk' and 'sbrk' symbols used by the
+##  malloc() implementation in use, and by this track the malloc()
+##  implementations core memory usage.
 ##
-erl_xcomp_brk_wrappers=
+erl_xcomp_dlsym_brk_wrappers=
 
 ### ----------------------------------------------------------------------------