Automtically build the Autotools to bootstrap RTEMS.

This changes adds support to build the autotools if the host installed
version is not a suitable version. Autoconf and automake have hard coded
references to the install prefix and host tools and this makes it impossible
to relocate, that is use in any path other than the install prefix. To
bootstrap automake you need to first build a suitable autoconf and with that
you can built automake for the install prefix. The other complication is
not referencing the install prefix in the path when building in the RSB.
Having the install prefix in the path can result in strange issues appearing
such as gcc using a new assembler feature not present in an older assember
installed under the install prefix.

The process is to build the autotools using an install prefix to an
internal path inside the RSB temporary path and to use that autoconf
to build the version for the install prefix. The internal install
prefix version is also used to bootstrap RTEMS.

source-builder/sb/build.py

@@ -273,14 +273,15 @@ class build:
     def prep(self, package):
         self.script.append('echo "==> %prep:"')
         _prep = package.prep()
-        for l in _prep:
-            args = l.split()
-            if args[0] == '%setup':
-                self.setup(package, args)
-            elif args[0].startswith('%patch'):
-                self.patch(package, args)
-            else:
-                self.script.append(' '.join(args))
+        if _prep:
+            for l in _prep:
+                args = l.split()
+                if args[0] == '%setup':
+                    self.setup(package, args)
+                elif args[0].startswith('%patch'):
+                    self.patch(package, args)
+                else:
+                    self.script.append(' '.join(args))
 
     def build(self, package):
         self.script.append('echo "==> clean %{buildroot}: ${SB_BUILD_ROOT}"')
@@ -290,18 +291,21 @@ class build:
                            (self.config.expand('%{__mkdir_p}')))
         self.script.append('echo "==> %build:"')
         _build = package.build()
-        for l in _build:
-            self.script.append(l)
+        if _build:
+            for l in _build:
+                self.script.append(l)
 
     def install(self, package):
         self.script.append('echo "==> %install:"')
         _install = package.install()
-        for l in _install:
-            args = l.split()
-            self.script.append(' '.join(args))
+        if _install:
+            for l in _install:
+                args = l.split()
+                self.script.append(' '.join(args))
 
     def files(self, package):
-        if self.create_tar_files:
+        if self.create_tar_files \
+           and not self.macros.get('%{_disable_packaging'):
             self.script.append('echo "==> %files:"')
             inpath = path.abspath(self.config.expand('%{buildroot}'))
             tardir = path.abspath(self.config.expand('%{_tardir}'))
@@ -335,7 +339,8 @@ class build:
             self.clean(package)
 
     def cleanup(self):
-        if not self.opts.no_clean():
+        package = self.main_package()
+        if not package.disabled() and not self.opts.no_clean():
             buildroot = self.config.abspath('buildroot')
             builddir = self.config.abspath('_builddir')
             buildcxcdir = self.config.abspath('_buildcxcdir')
@@ -356,35 +361,43 @@ class build:
 
     def make(self):
         package = self.main_package()
-        name = package.name()
-        if self.canadian_cross():
-            log.notice('package: (Cxc) %s' % (name))
+        if package.disabled():
+            log.notice('package: nothing to build')
         else:
-            log.notice('package: %s' % (name))
-        log.trace('---- macro maps %s' % ('-' * 55))
-        log.trace('%s' % (str(self.config.macros)))
-        log.trace('-' * 70)
-        self.script.reset()
-        self.script.append(self.config.expand('%{___build_template}'))
-        self.script.append('echo "=> ' + name + ':"')
-        self.prep(package)
-        self.build_package(package)
-        if not self.opts.dry_run():
-            self.builddir()
-            sn = path.join(self.config.expand('%{_builddir}'), 'doit')
-            log.output('write script: ' + sn)
-            self.script.write(sn)
+            name = package.name()
             if self.canadian_cross():
-                log.notice('building: (Cxc) %s' % (name))
+                log.notice('package: (Cxc) %s' % (name))
             else:
-                log.notice('building: %s' % (name))
-            self.run(sn)
+                log.notice('package: %s' % (name))
+                log.trace('---- macro maps %s' % ('-' * 55))
+                log.trace('%s' % (str(self.config.macros)))
+                log.trace('-' * 70)
+            self.script.reset()
+            self.script.append(self.config.expand('%{___build_template}'))
+            self.script.append('echo "=> ' + name + ':"')
+            self.prep(package)
+            self.build_package(package)
+            if not self.opts.dry_run():
+                self.builddir()
+                sn = path.join(self.config.expand('%{_builddir}'), 'doit')
+                log.output('write script: ' + sn)
+                self.script.write(sn)
+                if self.canadian_cross():
+                    log.notice('building: (Cxc) %s' % (name))
+                else:
+                    log.notice('building: %s' % (name))
+                self.run(sn)
 
     def name(self):
         packages = self.config.packages()
         package = packages['main']
         return package.name()
 
+    def disabled(self):
+        packages = self.config.packages()
+        package = packages['main']
+        return package.disabled()
+
 def get_configs(opts):
 
     def _scan(_path, ext):