OTP-8323 Cross compilation improvements and other build system

          improvements.

          Most notable:

          Lots of cross compilation improvements. The old cross compilation
          support was more or less non-existing as well as broken. Please,
          note that the cross compilation support should still be
          considered as experimental. Also note that old cross compilation
          configurations cannot be used without modifications. For more
          information on cross compiling Erlang/OTP see the
          $ERL_TOP/xcomp/README file.

          Support for staged install using <url
          href="http://www.gnu.org/prep/standards/html_node/DESTDIR.html">D
          ESTDIR</url>. The old broken INSTALL_PREFIX has also been fixed.
          For more information see the $ERL_TOP/README file.

          Documentation of the release target of the top Makefile. For more
          information see the $ERL_TOP/README file.

          make install now by default creates relative symbolic links
          instead of absolute ones. For more information see the
          $ERL_TOP/README file.

          $ERL_TOP/configure --help=recursive now works and prints help for
          all applications with configure scripts.

          Doing make install, or make release directly after make all no
          longer triggers miscellaneous rebuilds.

          Existing bootstrap system is now used when doing make install, or
          make release without a preceding make all.

          The crypto and ssl applications use the same runtime library path
          when dynamically linking against libssl.so and libcrypto.so. The
          runtime library search path has also been extended.

          The configure scripts of erl_interface and odbc now search for
          thread libraries and thread library quirks the same way as erts
          do.

          The configure script of the odbc application now also looks for
          odbc libraries in lib64 and lib/64 directories when building on a
          64-bit system.

          The config.h.in file in the erl_interface application is now
          automatically generated in instead of statically updated which
          reduces the risk of configure tests without any effect.

          (Thanks to Henrik Riomar and Winston Smith for testing)

1 files changed, 143 insertions, 144 deletions

diff --git a/xcomp/erl-xcomp.conf.template b/xcomp/erl-xcomp.conf.template
index afbef66af1..090f92c15f 100644
--- a/xcomp/erl-xcomp.conf.template
+++ b/xcomp/erl-xcomp.conf.template
@@ -21,239 +21,238 @@
 #### Author: Rickard Green
 ####
 #### --------------------------------------------------------------------------
-#### When cross compiling Erlang/OTP using `otp_build', copy this file and set
+#### When cross compiling Erlang/OTP using `otp_build`, copy this file and set
 #### the variables needed below. Then pass the path to the copy of this file as
-#### an argument to `otp_build' in the configure stage:
-####   `otp_build configure --xcomp-conf=<FILE>'
+#### an argument to `otp_build` in the configure stage:
+####   `otp_build configure --xcomp-conf=<FILE>`
 #### --------------------------------------------------------------------------
 
 ### Note that you cannot define arbitrary variables in a cross compilation
 ### configuration file. Only the ones listed below will be guaranteed to be
-### visible throughout the whole execution of all `configure' scripts. Other
-### variables needs to be defined as arguments to `configure' or exported in
+### visible throughout the whole execution of all `configure` scripts. Other
+### variables needs to be defined as arguments to `configure` or exported in
 ### the environment.
 
-### ---- `otp_build' only variables -------------------------------------------
+### ### Variables for `otp_build` Only ###
 
 ### Variables in this section are only used, when configuring Erlang/OTP for
-### cross compilation using `$ERL_TOP/otp_build configure'.
-
-### NOTE! These variables currently have *no* effect if you configure using the
-### `configure' script directly.
-
-## erl_xcomp_build - Build system.
-##    This value will be passed as `--build=$erl_xcomp_build' argument to the
-##    `configure' script. It does not have to be a full CPU-VENDOR-OS triplet,
-##    but can be. The full CPU-VENDOR-OS triplet will be created by:
-##      `$ERL_TOP/erts/autoconf/config.sub $erl_xcomp_build'
-##    If `erl_xcomp_build=guess', the build system will be guessed using:
-##      `$ERL_TOP/erts/autoconf/config.guess'. 
+### cross compilation using `$ERL_TOP/otp_build configure`.
+
+### *NOTE*! These variables currently have *no* effect if you configure using
+### the `configure` script directly.
+
+## `erl_xcomp_build` - The build system used. This value will be passed as
+##    `--build=$erl_xcomp_build` argument to the `configure` script. It does
+##    not have to be a full `CPU-VENDOR-OS` triplet, but can be. The full
+##    `CPU-VENDOR-OS` triplet will be created by
+##      `$ERL_TOP/erts/autoconf/config.sub $erl_xcomp_build`.
+##    If set to `guess`, the build system will be guessed using
+##      `$ERL_TOP/erts/autoconf/config.guess`.
 #erl_xcomp_build=
 
-## erl_xcomp_host - Cross host system.
-##    This value will be passed as `--host=$erl_xcomp_host' argument to the
-##    `configure' script. It does not have to be a full CPU-VENDOR-OS triplet,
-##    but can be. The full CPU-VENDOR-OS triplet will be created by:
-##      `$ERL_TOP/erts/autoconf/config.sub $erl_xcomp_host'
+## `erl_xcomp_host` - Cross host/target system to build for. This value will
+##    be passed as `--host=$erl_xcomp_host` argument to the `configure` script.
+##    It does not have to be a full `CPU-VENDOR-OS` triplet, but can be. The
+##    full `CPU-VENDOR-OS` triplet will be created by:
+##      `$ERL_TOP/erts/autoconf/config.sub $erl_xcomp_host`
 #erl_xcomp_host=
 
-## erl_xcomp_configure_flags - Extra configure flags.
-##    Extra flags to pass to the `configure' script.
+## `erl_xcomp_configure_flags` - Extra configure flags to pass to the
+##    `configure` script.
 #erl_xcomp_configure_flags=
 
-### ---- Cross compiler and other tools to use --------------------------------
+### ### Cross Compiler and Other Tools ###
 
-### If the cross compilation tools are prefixed by `<HOST>-' you probably do
-### not need to set these variables (where `<HOST>' is what has been passed as
-### `--host=<HOST>' argument to `configure').
+### If the cross compilation tools are prefixed by `<HOST>-` you probably do
+### not need to set these variables (where `<HOST>` is what has been passed as
+### `--host=<HOST>` argument to `configure`).
 
-## CC - C compiler.
+### All variables in this section can also be used when native compiling.
+
+## `CC` - C compiler.
 #CC=
 
-## CFLAGS - C compiler flags.
+## `CFLAGS` - C compiler flags.
 #CFLAGS=
 
-## STATIC_CFLAGS - Static C compiler flags.
+## `STATIC_CFLAGS` - Static C compiler flags.
 #STATIC_CFLAGS=
 
-## CFLAG_RUNTIME_LIBRARY_PATH - C compiler runtime library path flag.
-##    This flag should set a specific runtime library path for the shared
-##    library at link time. Note that this is actually a linker flag, but it
-##    needs to be passed via the compiler.
+## `CFLAG_RUNTIME_LIBRARY_PATH` - This flag should set runtime library
+##    search path for the shared libraries. Note that this actually is a
+##    linker flag, but it needs to be passed via the compiler.
 #CFLAG_RUNTIME_LIBRARY_PATH=
 
-## CPP - C pre-processor.
+## `CPP` - C pre-processor.
 #CPP=
 
-## CPPFLAGS - C pre-processor flags.
+## `CPPFLAGS` - C pre-processor flags.
 #CPPFLAGS=
 
-## CXX - C++ compiler.
+## `CXX` - C++ compiler.
 #CXX=
 
-## CXXFLAGS - C++ compiler flags.
+## `CXXFLAGS` - C++ compiler flags.
 #CXXFLAGS=
 
-## LD - Linker.
+## `LD` - Linker.
 #LD=
 
-## LDFLAGS - Linker flags.
+## `LDFLAGS` - Linker flags.
 #LDFLAGS=
 
-## LIBS - Libraries.
+## `LIBS` - Libraries.
 #LIBS=
 
-### -- Dynamic Erlang Driver linker flags --
+### #### *D*ynamic *E*rlang *D*river Linking ####
 
-### NOTE! Either set all or non of the DED_LD* variables.
+### *NOTE*! Either set all or none of the `DED_LD*` variables.
 
-## DED_LD - Linker.
+## `DED_LD` - Linker for Dynamically loaded Erlang Drivers.
 #DED_LD=
 
-## DED_LDFLAGS - Linker flags.
+## `DED_LDFLAGS` - Linker flags to use with `DED_LD`.
 #DED_LDFLAGS=
 
-## DED_LD_FLAG_RUNTIME_LIBRARY_PATH - Linker runtime library path flag.
-##    This flag should set a specific runtime library path for the shared
-##    library at link time.
+## `DED_LD_FLAG_RUNTIME_LIBRARY_PATH` - This flag should set runtime library
+##    search path for shared libraries when linking with `DED_LD`.
 #DED_LD_FLAG_RUNTIME_LIBRARY_PATH=
 
-### -- Large file support --
+### #### Large File Support ####
 
-### NOTE! Either set all or non of the LFS_* variables.
+### *NOTE*! Either set all or none of the `LFS_*` variables.
 
-## LFS_CFLAGS - Large file support C compiler flags.
+## `LFS_CFLAGS` - Large file support C compiler flags.
 #LFS_CFLAGS=
 
-## LFS_LDFLAGS - Large file support linker flags.
+## `LFS_LDFLAGS` - Large file support linker flags.
 #LFS_LDFLAGS=
 
-## LFS_LIBS - Large file support libraries.
+## `LFS_LIBS` - Large file support libraries.
 #LFS_LIBS=
 
-### -- Other tools --
+### #### Other Tools ####
 
-## RANLIB - `ranlib' archive index tool.
+## `RANLIB` - `ranlib` archive index tool.
 #RANLIB=
 
-## AR - `ar' archiving tool.
+## `AR` - `ar` archiving tool.
 #AR=
 
-## GETCONF - `getconf' system configuration inspection tool.
+## `GETCONF` - `getconf` system configuration inspection tool. `getconf` is
+##    currently used for finding out large file support flags to use, and
+##    on Linux systems for finding out if we have an NPTL thread library or
+##    not.
 #GETCONF=
 
-### ---- Cross System Root Locations ------------------------------------------
+### ### Cross System Root Locations ###
 
-## erl_xcomp_sysroot - Absolute cross system root path.
-##    The absolute path to the system root of the cross compilation
-##    environment. Currently, the `crypto', `odbc', `ssh' and `ssl'
-##    applications need the system root. These applications will be skipped
-##    if the system root has not been set. The system root might be needed
-##    for other things too. If this is the case and the system root has not
-##    been set, `configure' will fail and request you to set it.
+## `erl_xcomp_sysroot` - The absolute path to the system root of the cross
+##    compilation environment. Currently, the `crypto`, `odbc`, `ssh` and
+##    `ssl` applications need the system root. These applications will be
+##    skipped if the system root has not been set. The system root might be
+##    needed for other things too. If this is the case and the system root
+##    has not been set, `configure` will fail and request you to set it.
 #erl_xcomp_sysroot=
 
-## erl_xcomp_isysroot - Absolute cross include system root path.
-##    The absolute path to the system root for includes of the cross
-##    compilation environment. If not set, this value defaults to
-##    `$erl_xcomp_sysroot', i.e., only set this value if the include system
+## `erl_xcomp_isysroot` - The absolute path to the system root for includes
+##    of the cross compilation environment. If not set, this value defaults
+##    to `$erl_xcomp_sysroot`, i.e., only set this value if the include system
 ##    root path is not the same as the system root path.
 #erl_xcomp_isysroot=
 
-### ---- Optional feature, or bug tests ---------------------------------------
+### ### Optional Feature, and 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
+### usually do not need to set these variables. Only set these if you really
 ### know what you are doing.
 
 ### Note that some of these values will override results of tests performed
-### by `configure', and some will not be used until `configure' is sure that
+### by `configure`, and some will not be used until `configure` is sure that
 ### it cannot figure the result out.
 
-### The `configure' script will issue a warning when a default value is used.
+### The `configure` script will issue a warning when a default value is used.
 ### When a variable has been set, no warning will be issued.
 
-## 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=
+## `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.
+##    This is currently only used by unsupported features.
+#erl_xcomp_after_morecore_hook=
 
-## erl_xcomp_linux_clock_gettime_correction - yes|no (defaults to `yes' on
-##                                                    Linux; otherwise, `no')
-##    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_bigendian` - `yes|no`. No default. 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. Since no default
+##    value is used, `configure` will try to figure this out automatically.
+#erl_xcomp_bigendian=
 
-## 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_clock_gettime_cpu_time` - `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_cpu_time=
 
-## erl_xcomp_linux_usable_sigusrx - yes|no (defaults to `yes')
-##    If `yes', the `SIGUSR1' and `SIGUSR2' signals 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_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=
 
-## erl_xcomp_linux_usable_sigaltstack - yes|no (defaults to `yes' on Linux;
-##                                              otherwise, `no')
-##    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_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=
 
-## 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=
+## `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. This is currently only used by unsupported features.
+#erl_xcomp_dlsym_brk_wrappers=
 
-## 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` - `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=
 
-## 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=
+## `erl_xcomp_linux_clock_gettime_correction` - `yes|no`. Defaults to `yes` on
+##    Linux; otherwise, `no`. 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_reliable_fpe - yes|no (defaults to `no')
-##    If `yes', the target system must have reliable floating point exceptions.
-#erl_xcomp_reliable_fpe=
+## `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_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=
+## `erl_xcomp_linux_usable_sigaltstack` - `yes|no`. Defaults to `yes` on Linux;
+##    otherwise, `no`. 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_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=
+## `erl_xcomp_linux_usable_sigusrx` - `yes|no`. Defaults to `yes`. If `yes`,
+##    the `SIGUSR1` and `SIGUSR2` signals must be usable by the ERTS. Old
+##    LinuxThreads thread libraries (Linux kernel versions typically less than
+##    2.2) used these signals and made them unusable by the ERTS.
+#erl_xcomp_linux_usable_sigusrx=
 
-## erl_xcomp_clock_gettime_cpu_time - 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_cpu_time=
+## `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=
 
-## 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=
+## `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=
 
-## 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_dlsym_brk_wrappers=
+## `erl_xcomp_reliable_fpe` - `yes|no`. Defaults to `no`. If `yes`, the target
+##    system must have reliable floating point exceptions.
+#erl_xcomp_reliable_fpe=
 
-#### --------------------------------------------------------------------------
+####