Anonymous avatar Anonymous committed 6a87401

Remove dependence on Aegis symlinks by adding a bootstrap.py script (suggested by Anthony Roach) to collect the current SCons into a bootstrap/ subdirectory for execution.

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         there's a copy of the script we use to translate an Aegis change
         into a CVS checkin.
 
+bootstrap.py
+        A build script for use with Aegis.  This collects a current copy
+        of SCons from the Aegis baseline directories in a bootstrap/
+        subdirectory, and then executes SCons with the supplied
+        command-line arguments.
+
 build/
         This doesn't exist yet if you're looking at a vanilla source
         tree.  This is generated as part of our build process, and it's
+"""bootstrap.py
+
+This is an Aegis-to-SCons build script that collects a copy of the
+current SCons into a bootstrap/ subdirectory and then executes it with
+the supplied command-line options.
+
+Right now, it only understands the SCons -Y option, which is the only
+one currently used.  It collects the repositories specified by -Y and
+searches them, in order, for the pieces of SCons to copy into the local
+bootstrap/ subdirectory.
+
+This is essentially a minimal build of SCons to bootstrap ourselves into
+executing it for the full build of all the packages, as specified in our
+local SConstruct file.
+
+"""
+
+#
+# Copyright (c) 2001, 2002 Steven Knight
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+#
+
+import os
+import os.path
+import getopt
+import string
+import sys
+
+search = ['.']
+
+opts, args = getopt.getopt(sys.argv[1:], "Y:", [])
+
+for o, a in opts:
+    if o == '-Y':
+        search.append(a)
+
+def find(file, search=search):
+    for dir in search:
+        f = os.path.join(dir, file)
+	if os.path.exists(f):
+	    return os.path.normpath(f)
+    sys.stderr.write("could not find `%s' in search path:\n" % file)
+    sys.stderr.write("\t" + string.join(search, "\n\t") + "\n")
+    sys.exit(2)
+
+scons_py = os.path.join('src', 'script', 'scons.py')
+src_engine = os.path.join('src', 'engine')
+MANIFEST_in = find(os.path.join(src_engine, 'MANIFEST.in'))
+
+files = [ scons_py ] + map(lambda x: os.path.join(src_engine, x[:-1]),
+                           open(MANIFEST_in).readlines())
+
+subdir = 'bootstrap'
+
+for file in files:
+    src = find(file)
+    dst = os.path.join(subdir, file)
+    dir, _ = os.path.split(dst)
+    if not os.path.isdir(dir):
+        os.makedirs(dir)
+    contents = open(src, 'rb').read()
+    try: os.unlink(dst)
+    except: pass
+    open(dst, 'wb').write(contents)
+
+args = [ sys.executable, os.path.join(subdir, scons_py) ] + sys.argv[1:]
+
+sys.stdout.write(string.join(args, " ") + '\n')
+sys.stdout.flush()
+
+os.environ['SCONS_LIB_DIR'] = os.path.join(subdir, src_engine)
+
+os.execve(sys.executable, args, os.environ)
  * the relevant build command.  This command tells SCons where to find
  * the rules.
  *
- * The ${bl}/build/scons-src/src/engine points $SCONS_LIB_DIR points
- * SCons at the last-built scons-src package, which should have
- * everything.  This means that, under Aegis, we're really using the
- * currently-checked-in baseline to build the current version.  This
- * implies that using a new feature in our own SConscripts is a
- * two-stage process: check in the underlying feature, then check in a
- * change to use it in our SConscripts.
+ * Our chicken-and-egg dilemma is this: we want to use the version of
+ * SCons under development in an Aegis change to build itself.  But the
+ * pieces of SCons are likely only partly in this change, and partly in
+ * baselines.
  *
- * The ${s src/script/scons.py} expands to a path into the baseline
- * during development if the script file is not in the change.
+ * Python only imports things on a module-by-module basis--which is to
+ * say, once it finds __init__.py in a given directory, it assumes that
+ * all other files in that module are in the same directory.  But that's
+ * not the way Aegis works, because if a file hasn't changed on the
+ * branch, it will only be in its parent's baseline directory.
+ *
+ * Aegis' mechanism for working around this sort of problem is to make
+ * symlinks to the proper baseline versions of each file, which makes
+ * it look like everything is in the local tree.  That's unattractive,
+ * though, because we really want to eat our own dog food and use the
+ * SCons -Y options to pull things from the baseline repositories.
+ *
+ * So our solution (suggested by Anthony Roach) is a bootstrap.py script
+ * that does some Aegis-like searching through the baseline directories
+ * and makes a bootstrap copy of the version of SCons under development
+ * that we can use for building.  After it makes this copy of SCons, it
+ * executes it with the same command-line arguments we supplied (and
+ * setting $SCONS_LIB_DIR to the right directory) so we can use it
+ * here with command-line options as if it were SCons itself.  (Note,
+ * however, that bootstrap.py only understands the specific command-line
+ * options already in use here, so if you change the call below to add
+ * some other SCons options, you may have to modify bootstrap.py to
+ * recognize them.
+ *
+ * The ${Source bootstrap.py} substitution finds bootstrap.py wherever
+ * it may be in the Aegis baselines.
+ *
+ * The long -Y${SUBSTitute...} substitution takes the Aegis baseline
+ * search path and turns it into the right -Y command-line options for
+ * SCons.
+ *
+ * The rest of the substitutions (${DEVeloper}, etc.) should be obvious.
  *
  * Look in aesub(5) for more information about command substitutions.
  */
-build_command = "SCONS_LIB_DIR=src/engine python ${Source src/script/scons.py} -Y${SUBSTitute : \\ -Y $Search_Path} date='${DAte %Y/%m/%d %H:%M:%S}' developer=${DEVeloper} version=${VERsion} change=${Change}";
+build_command = "python ${Source bootstrap.py} -Y${SUBSTitute : \\ -Y $Search_Path} date='${DAte %Y/%m/%d %H:%M:%S}' developer=${DEVeloper} version=${VERsion} change=${Change}";
 
 /*
  * SCons removes its targets before constructing them, which qualifies it
  * for the following entry in the config file.  The files must be removed
  * first, otherwise the baseline would cease to be self-consistent.
+link_integration_directory = true;
  */
-link_integration_directory = true;
 
 /*
  * This is set temporarily to allow us to build using the SCons
  * currently checked in to the src directory.
+create_symlinks_before_build = true;
  */
-create_symlinks_before_build = true;
 
 /*
  *	aegis - project change supervisor
Tip: Filter by directory path e.g. /media app.js to search for public/media/app.js.
Tip: Use camelCasing e.g. ProjME to search for ProjectModifiedEvent.java.
Tip: Filter by extension type e.g. /repo .js to search for all .js files in the /repo directory.
Tip: Separate your search with spaces e.g. /ssh pom.xml to search for src/ssh/pom.xml.
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