Re: new AC_ERLANG_SUBST_ERTS_VER macro

[Eric Blake]

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According to Romain Lenglet on 5/28/2009 5:14 AM:
> On Wednesday 27 May 2009 20:19:15 Eric Blake wrote:
>> OK, I think this patch is safe to apply from a copyright perspective.
>> However, before we do that, can you find an email address for Ruslan, or
>> at least a URL containing his suggestion, rather than just putting a ? in
>> the THANKS?
> 
> OK, here is an updated patch with Ruslan's email address.

Thanks for the updated patch.  After fixing your trailing whitespace, I
made some further minor tweaks, including a NEWS entry and corrected
texinfo markup.  Here's a trimmed version of what I'm pushing.  It would
be really nice if someone familiar with Erlang added an Erlang test to the
testsuite, so that we could exercise this macro; meanwhile, since I'm not
familiar with Erlang, I'm trusting your patch.

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
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>From 9e380c5ada53c8212506aabc8971caaf5eae6137 Mon Sep 17 00:00:00 2001
From: Romain Lenglet <address@hidden>
Date: Thu, 28 May 2009 20:14:07 +0900
Subject: [PATCH] New AC_ERLANG_SUBST_ERTS_VER macro.

* lib/autoconf/erlang.m4: Add macro AC_ERLANG_SUBST_ERTS_VER.
* doc/autoconf.texi (Erlang Libraries): Document
AC_ERLANG_SUBST_ERTS_VER.
* NEWS: Likewise.
* AUTHORS: Update Romain Lenglet's email address.
* THANKS: Update.
Suggested by Ruslan Babayev.

Signed-off-by: Eric Blake <address@hidden>
---
 AUTHORS                |    2 +-
 ChangeLog              |   11 +++++
 NEWS                   |    3 +
 THANKS                 |    3 +-
 doc/autoconf.texi      |   45 ++++++++++++++++++++-
 lib/autoconf/erlang.m4 |  102 ++++++++++++++++++++++++++++-------------------
 6 files changed, 120 insertions(+), 46 deletions(-)

diff --git a/AUTHORS b/AUTHORS
index 9c07a86..aac3f00 100644
--- a/AUTHORS
+++ b/AUTHORS
diff --git a/ChangeLog b/ChangeLog
index e07b300..a9f3ca8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2009-05-28  Romain Lenglet  <address@hidden>
+
+       New AC_ERLANG_SUBST_ERTS_VER macro.
+       * lib/autoconf/erlang.m4: Add macro AC_ERLANG_SUBST_ERTS_VER.
+       * doc/autoconf.texi (Erlang Libraries): Document
+       AC_ERLANG_SUBST_ERTS_VER.
+       * NEWS: Likewise.
+       * AUTHORS: Update Romain Lenglet's email address.
+       * THANKS: Update.
+       Suggested by Ruslan Babayev.
+
 2009-05-26  Eric Blake  <address@hidden>

        Sanitize more problematic environment variables.
diff --git a/NEWS b/NEWS
index 9626cac..82ba635 100644
--- a/NEWS
+++ b/NEWS
@@ -6,6 +6,9 @@ GNU Autoconf NEWS - User visible changes.
 ** AS_IF and AS_CASE have been taught to avoid syntax errors even when
    given arguments that expand to just whitespace.

+** The following documented autoconf macros are new:
+   AC_ERLANG_SUBST_ERTS_VER
+
 ** Ensure AT_CHECK can support commands that include a # given with
    proper m4 quoting.  For shell comments, this is a new feature; for
    non-shell comments, this fixes a regression introduced in 2.63b.
diff --git a/THANKS b/THANKS
index 3c2843b..eab63f2 100644
--- a/THANKS
+++ b/THANKS
diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index 3ddecdf..632058d 100644
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -7798,10 +7798,22 @@ Erlang Libraries
 configuration of an Erlang interpreter and an Erlang compiler
 (@pxref{Erlang Compiler and Interpreter}).

address@hidden AC_ERLANG_SUBST_ERTS_VER
address@hidden
address@hidden ERLANG_ERTS_VER
+Set the output variable @code{ERLANG_ERTS_VER} to the version of the
+Erlang runtime system (as returned by Erlang's
address@hidden:system_info(version)} function).  The result of this test
+is cached if caching is enabled when running @command{configure}.  The
address@hidden variable is not intended to be used for testing
+for features of specific ERTS versions, but to be used for substituting
+the ERTS version in Erlang/OTP release resource files (@code{.rel}
+files), as shown below.
address@hidden defmac
+
 @defmac AC_ERLANG_SUBST_ROOT_DIR
 @acindex{ERLANG_SUBST_ROOT_DIR}
 @ovindex ERLANG_ROOT_DIR
-
 Set the output variable @code{ERLANG_ROOT_DIR} to the path to the base
 directory in which Erlang/OTP is installed (as returned by Erlang's
 @code{code:root_dir/0} function).  The result of this test is cached if
@@ -7811,7 +7823,6 @@ Erlang Libraries
 @defmac AC_ERLANG_SUBST_LIB_DIR
 @acindex{ERLANG_SUBST_LIB_DIR}
 @ovindex ERLANG_LIB_DIR
-
 Set the output variable @code{ERLANG_LIB_DIR} to the path of the library
 directory of Erlang/OTP (as returned by Erlang's
 @code{code:lib_dir/0} function), which subdirectories each contain an installed
@@ -7824,7 +7835,6 @@ Erlang Libraries
 @acindex{ERLANG_CHECK_LIB}
 @ovindex address@hidden
 @ovindex address@hidden
-
 Test whether the Erlang/OTP library @var{library} is installed by
 calling Erlang's @code{code:lib_dir/1} function.  The result of this
 test is cached if caching is enabled when running @command{configure}.
@@ -7848,6 +7858,35 @@ Erlang Libraries
    echo "is installed in \"$ERLANG_LIB_DIR_stdlib\""],
   [AC_MSG_ERROR([stdlib was not found!])])
 @end example
+
+The @address@hidden variables (set by
address@hidden) and the @code{ERLANG_ERTS_VER} variable (set
+by @code{AC_ERLANG_SUBST_ERTS_VER}) are not intended to be used for
+testing for features of specific versions of libraries or of the Erlang
+runtime system.  Those variables are intended to be substituted in
+Erlang release resource files (@code{.rel} files).  For instance, to
+generate a @file{example.rel} file for an application depending on the
address@hidden library, @file{configure.ac} could contain:
+
address@hidden
+AC_ERLANG_SUBST_ERTS_VER
+AC_ERLANG_CHECK_LIB([stdlib],
+  [],
+  [AC_MSG_ERROR([stdlib was not found!])])
+AC_CONFIG_FILES([example.rel])
address@hidden example
+
address@hidden
+The @file{example.rel.in} file used to generate @file{example.rel}
+should contain:
+
address@hidden
+{release,
+    {"@@PACKAGE@@", "@@VERSION@@"},
+    {erts, "@@ERLANG_ERTS_VER@@"},
+    [{stdlib, "@@ERLANG_LIB_VER_stdlib@@"},
+     {@@PACKAGE@@, "@@VERSION@@"}]}.
address@hidden example
 @end defmac

 In addition to the above macros, which test installed Erlang libraries, the
diff --git a/lib/autoconf/erlang.m4 b/lib/autoconf/erlang.m4
index 7f6d92d..1e4418b 100644
--- a/lib/autoconf/erlang.m4
+++ b/lib/autoconf/erlang.m4
@@ -1,6 +1,6 @@
 # This file is part of Autoconf.                       -*- Autoconf -*-
 # Erlang/OTP language support.
-# Copyright (C) 2006, 2008 Free Software Foundation, Inc.
+# Copyright (C) 2006, 2008, 2009 Free Software Foundation, Inc.
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -175,8 +175,7 @@ AC_DEFUN([AC_LANG_COMPILER(Erlang)],
 # AC_ERLANG_CHECK_LIB(LIBRARY, [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
 # ----------------------------------------------------------------------
 # Macro for checking if an Erlang library is installed, and to
-# determine its version
-#
+# determine its version.
 AC_DEFUN([AC_ERLANG_CHECK_LIB],
 [AC_REQUIRE([AC_ERLANG_PATH_ERLC])[]dnl
 AC_REQUIRE([AC_ERLANG_PATH_ERL])[]dnl
@@ -216,8 +215,7 @@ AS_IF([test "$erlang_cv_lib_dir_$1" = "not found"], [$3], 
[$2])

 # AC_ERLANG_SUBST_ROOT_DIR
 # ------------------------
-# Determines the Erlang/OTP root directory
-#
+# Determines the Erlang/OTP root directory.
 AC_DEFUN([AC_ERLANG_SUBST_ROOT_DIR],
 [AC_REQUIRE([AC_ERLANG_NEED_ERLC])[]dnl
 AC_REQUIRE([AC_ERLANG_NEED_ERL])[]dnl
@@ -262,11 +260,9 @@ AC_SUBST([ERLANG_LIB_DIR], [$erlang_cv_lib_dir])

 # AC_ERLANG_SUBST_INSTALL_LIB_DIR
 # -------------------------------
-#
 # Directories for installing Erlang/OTP packages are separated from the
 # directories determined by running the Erlang/OTP installation that is used
 # for building.
-#
 AC_DEFUN([AC_ERLANG_SUBST_INSTALL_LIB_DIR],
 [AC_MSG_CHECKING([for Erlang/OTP library installation base directory])
 AC_ARG_VAR([ERLANG_INSTALL_LIB_DIR],
@@ -286,7 +282,8 @@ AC_DEFUN([AC_ERLANG_SUBST_INSTALL_LIB_SUBDIR],
 [AC_REQUIRE([AC_ERLANG_SUBST_INSTALL_LIB_DIR])[]dnl
 AC_MSG_CHECKING([for Erlang/OTP '$1' library installation subdirectory])
 AC_ARG_VAR([ERLANG_INSTALL_LIB_DIR_$1],
-    [Erlang/OTP '$1' library installation subdirectory 
[ERLANG_INSTALL_LIB_DIR/$1-$2]])
+    [Erlang/OTP '$1' library installation subdirectory
+       [ERLANG_INSTALL_LIB_DIR/$1-$2]])
 if test -n "$ERLANG_INSTALL_LIB_DIR_$1"; then
     AC_MSG_RESULT([$ERLANG_INSTALL_LIB_DIR_$1])
 else
@@ -294,3 +291,26 @@ else
     AC_MSG_RESULT([$ERLANG_INSTALL_LIB_DIR/$1-$2])
 fi
 ])# AC_ERLANG_SUBST_INSTALL_LIB_SUBDIR
+
+
+# AC_ERLANG_SUBST_ERTS_VER
+# ------------------------
+# Determines the Erlang runtime system version.
+AC_DEFUN([AC_ERLANG_SUBST_ERTS_VER],
+[AC_REQUIRE([AC_ERLANG_NEED_ERLC])[]dnl
+AC_REQUIRE([AC_ERLANG_NEED_ERL])[]dnl
+AC_CACHE_CHECK([for Erlang/OTP ERTS version],
+    [erlang_cv_erts_ver],
+    [AC_LANG_PUSH([Erlang])[]dnl
+     AC_RUN_IFELSE(
+       [AC_LANG_PROGRAM([], [dnl
+           Version = erlang:system_info(version),
+           file:write_file("conftest.out", Version),
+           ReturnValue = 0,
+           halt(ReturnValue)])],
+       [erlang_cv_erts_ver=`cat conftest.out`],
+       [AC_MSG_FAILURE([test Erlang program execution failed])])
+     AC_LANG_POP([Erlang])[]dnl
+    ])
+AC_SUBST([ERLANG_ERTS_VER], [$erlang_cv_erts_ver])
+])# AC_ERLANG_SUBST_ERTS_VER
-- 
1.6.3.rc3.2.g4b51