5/llvm: Add LLVM as a package for RTEMS.

- Add '%source download <source>' to only download the source
  and do not unpack and prep. This can used when a package
  internally needs another source package.

- Install the staging root only if it is present. A package
  may internally build another package that is not staged as it
  is not suitable for installing.

Updates #3250
Updatew #3797

9 files changed, 363 insertions, 73 deletions

diff --git a/source-builder/config/llvm-common-1.cfg b/source-builder/config/llvm-common-1.cfg
new file mode 100644
index 0000000..c75769f
--- /dev/null
+++ b/source-builder/config/llvm-common-1.cfg
@@ -0,0 +1,152 @@
+#
+# LLVM Common Support.
+#
+# This configuration file configure's, make's and install's LLVM and some of
+# it projects.
+#
+
+%include %{_configdir}/checks.cfg
+
+#
+# The package description.
+#
+Name:      rtems-llvm-%{llvm_version}-%{_host}-%{release}
+Summary:   LLVM v%{llvm_version} on host %{_host}
+Version:   %{llvm_version}
+Release:   %{release}
+URL: 	   http://llvm.org/
+
+#
+# The LLVM version depends on the type of build we are doing.
+#
+%if %{rsb_released}
+ %define rtems_llvm_version %{rsb_version}
+%else
+ %define rtems_llvm_version %{rtems_version}
+%endif
+
+#
+# LLVM Download URL.
+#
+%define llvm_url https://github.com/llvm/llvm-project/releases/download/llvmorg-%{llvm_version}
+
+#
+# Packages
+#
+%source set cfe                %{llvm_url}/cfe-%{llvm_version}.src.tar.xz
+%source set clang-tools-extra  %{llvm_url}/clang-tools-extra-%{llvm_version}.src.tar.xz
+%source set compiler-rt        %{llvm_url}/compiler-rt-%{llvm_version}.src.tar.xz
+%source set libcxx             %{llvm_url}/libcxx-%{llvm_version}.src.tar.xz
+%source set libcxxabi          %{llvm_url}/libcxxabi-%{llvm_version}.src.tar.xz
+%source set libunwind          %{llvm_url}/libunwind-%{llvm_version}.src.tar.xz
+%source set lld                %{llvm_url}/lld-%{llvm_version}.src.tar.xz
+%source set lldb               %{llvm_url}/lldb-%{llvm_version}.src.tar.xz
+%source set llvm               %{llvm_url}/llvm-%{llvm_version}.src.tar.xz
+%source set openmp             %{llvm_url}/openmp-%{llvm_version}.src.tar.xz
+
+#
+# Build LLDB on all hosts except MacOS as it reqires a codesign login key of
+# name 'llvm'.
+#
+%if %{_build_os} != darwin
+ %define with_llvm_lldb 1
+%endif
+
+%if %{defined with_llvm_lldb}
+ %define lldb_codesign_identity -DLLDB_CODESIGN_IDENTITY=llvm
+%else
+ %define lldb_codesign_identity %{nil}
+%endif
+
+#
+# Prepare the source code.
+#
+%prep
+  # save the build top directory and cd back to it rather than
+  # using 'cd ..' because some shells change $PWD to a symlink's
+  # target location and 'cd ..' fails.
+  build_top=$(pwd)
+
+  llvm_source=%{?llvm_external:%{llvm_expand_name}}%{!?llvm_external:"llvm-%{llvm_version}"}
+
+  # llvm is a collection of separate packages, download them and then create
+  # the source tree.
+
+  source_dir_llvm=${llvm_source}
+
+  %source setup llvm -q
+  %{__mv} llvm-%{llvm_version}.src ${source_dir_llvm}
+
+  %source setup cfe -q
+  %{__mv} cfe-%{llvm_version}.src ${source_dir_llvm}/tools/clang
+
+  %source setup clang-tools-extra -q
+  %{__mv} clang-tools-extra-%{llvm_version}.src ${source_dir_llvm}/tools/clang/extra
+
+  %source setup compiler-rt -q
+  %{__mv} compiler-rt-%{llvm_version}.src ${source_dir_llvm}/projects/compiler-rt
+
+  %source setup libcxx -q
+  %{__mv} libcxx-%{llvm_version}.src ${source_dir_llvm}/projects/libcxx
+
+  %source setup libcxxabi -q
+  %{__mv} libcxxabi-%{llvm_version}.src ${source_dir_llvm}/projects/libcxxabi
+
+  %source setup libunwind -q
+  %{__mv} libunwind-%{llvm_version}.src ${source_dir_llvm}/projects/libunwind
+
+  %source setup lld -q
+  %{__mv} lld-%{llvm_version}.src ${source_dir_llvm}/tools/lld
+
+  %if %{defined with_llvm_lldb}
+   %source setup lldb -q
+   %{__mv} lldb-%{llvm_version}.src ${source_dir_llvm}/tools/lldb
+  %endif
+
+  %source setup openmp -q
+  %{__mv} openmp-%{llvm_version}.src ${source_dir_llvm}/tools/openmp
+
+  %patch setup llvm -p1
+
+  cd ${build_top}
+
+%build
+  build_top=$(pwd)
+
+  # SWIG will be built and installed into %{swig_prefix} if defined
+  # so add it as a path.
+  %if %{defined swig_prefix}
+    export PATH=%{swig_prefix}/bin:$PATH
+  %endif
+
+  %{build_directory}
+
+  mkdir -p ${build_dir}
+  cd ${build_dir}
+
+  %{__cmake} -Wno-dev \
+    -G "Unix Makefiles" \
+    -DCMAKE_BUILD_TYPE=Release \
+    -DCMAKE_INSTALL_PREFIX=%{_prefix} \
+    -DPACKAGE_VERSION="%{llvm_version} (%{llvm_version_message})" \
+    %{lldb_codesign_identity} \
+    ../${source_dir_llvm}
+
+  version_inc="tools/clang/include/clang/Basic/Version.inc"
+  %{__cat} ${version_inc} | \
+    sed -e 's/CLANG_VERSION_STRING "[0-9]*\.[0-9]*\.[0-9]*/& \(%{llvm_version_message}\)/g' \
+      > ${version_inc}.tmp
+  %{__mv} ${version_inc}.tmp ${version_inc}
+
+  %{__make} %{?_smp_mflags}
+
+  cd ${build_top}
+
+%install
+  build_top=$(pwd)
+
+  %{__rmdir} $SB_BUILD_ROOT
+
+  cd ${build_dir}
+  %{__make} DESTDIR=$SB_BUILD_ROOT install
+  cd ${build_top}
diff --git a/source-builder/config/swig-4-1.cfg b/source-builder/config/swig-4-1.cfg
new file mode 100644
index 0000000..6c10114
--- /dev/null
+++ b/source-builder/config/swig-4-1.cfg
@@ -0,0 +1,97 @@
+#
+# SWIG 4.xx Version 1.
+#
+# This configuration file configure's, make's and install's m4
+#
+# Warning: this package is only for bootstrapping within a build.
+#
+
+
+Name:      swig-%{swig_version}-%{_host}-%{release}
+Summary:   SWIG v%{swig_version} for host %{_host}
+Version:   %{swig_version}
+Release:   %{release}
+URL: 	   http://www.swig.org/
+
+#
+# Source
+#
+%source set swig --rsb-file=swig-rel-%{swig_version}.tar.gz https://github.com/swig/swig/archive/rel-%{swig_version}.tar.gz
+%source set pcre https://ftp.pcre.org/pub/pcre/pcre-%{pcre_version}.tar.bz2
+
+#
+# See if a special swig prefix is provided
+#
+%if %{defined swig_prefix}
+  %define _disable_collecting yes
+  %define _disable_packaging  yes
+  %define _disable_reporting  yes
+  %define _disable_installing yes
+%endif
+
+#
+# Prepare the source code.
+#
+%prep
+  build_top=$(pwd)
+
+  source_dir_swig="swig-rel-%{swig_version}"
+
+  %source setup swig -q -n swig-rel-%{swig_version}
+  %source download pcre
+
+  %patch setup swig -p1
+
+  # SWIG does not ship from github with it's generated files. We
+  # need to generate them.
+  # Add the path to the internal autoconf tools
+  SWIG_XPATH=$PATH
+  %if %{defined _internal_autotools_path}
+    export PATH=%{_internal_autotools_path}/bin:$PATH
+  %endif
+  ./autogen.sh
+  export PATH=$SWIG_XPATH
+
+  cd ${build_top}
+
+%build
+  build_top=$(pwd)
+
+  %{build_directory}
+
+  mkdir -p ${build_dir}
+  cd ${build_dir}
+
+  %{host_build_flags}
+
+  # build PCRE using the SWIG script as it is a static link
+  %{__cp} %{_sourcedir}/pcre-%{pcre_version}.tar.bz2 pcre-%{pcre_version}.tar.bz2
+  ../${source_dir_swig}/Tools/pcre-build.sh
+
+  %if %{defined swig_prefix}
+   prefix=%{swig_prefix}
+  %else
+   prefix=%{_prefix}
+  %endif
+
+  ../${source_dir_swig}/configure \
+    --host=%{_host} \
+    --prefix=${prefix}
+
+  %{__make} %{?_smp_mflags}
+
+  cd ${build_top}
+
+%install
+  build_top=$(pwd)
+
+  %{__rmdir} ${SB_BUILD_ROOT}
+
+  cd ${build_dir}
+  %if %{!defined swig_prefix}
+   %define destdir DESTDIR=${SB_BUILD_ROOT}
+  %else
+   %define destdir %{nil}
+  %endif
+  %{__make} %{destdir} install
+  cd ${build_top}
diff --git a/source-builder/defaults.mc b/source-builder/defaults.mc
index 9d5dd44..273bd31 100644
--- a/source-builder/defaults.mc
+++ b/source-builder/defaults.mc
@@ -157,6 +157,7 @@ __cc:                exe,     required, 'gcc'
 __chgrp:             exe,     required, '/usr/bin/chgrp'
 __chmod:             exe,     required, '/bin/chmod'
 __chown:             exe,     required, '/usr/sbin/chown'
+__cmake:             exe,     optional, '/usr/bin/cmake'
 __cp:                exe,     required, '/bin/cp'
 __cpp:               exe,     none,     '%{__cc} -E'
 __cvs:               exe,     optional, '/usr/bin/cvs'
@@ -205,7 +206,7 @@ ___build_cmd:        none,    none,     '%{?_sudo:%{_sudo} }%{?_remsh:%{_remsh}
 ___build_post:       none,    none,     'exit 0'
 
 # Prebuild set up script.
-___build_pre:        none,    none,     '''# ___build_pre in as set up in defaults.py
+___build_pre:        none,    none,     '''# ___build_pre as set up in defaults.py
 # Save the original path away.
 export SB_ORIG_PATH=${PATH}
 # Directories
diff --git a/source-builder/sb/build.py b/source-builder/sb/build.py
index abc50c0..69f95cf 100644
--- a/source-builder/sb/build.py
+++ b/source-builder/sb/build.py
@@ -203,7 +203,7 @@ class build:
             not _disable_installing and \
             not _canadian_cross
 
-    def source(self, name, strip_components):
+    def source(self, name, strip_components, download_only):
         #
         # Return the list of sources. Merge in any macro defined sources as
         # these may be overridden by user loaded macros.
@@ -238,31 +238,37 @@ class build:
                     if o.startswith('--rsb-file'):
                        os_ = o.split('=')
                        if len(os_) != 2:
-                           raise error.general('invalid --rsb-file option: %s' % (' '.join(args)))
+                           raise error.general('invalid --rsb-file option: %s' % \
+                                               (' '.join(args)))
                        if os_[0] != '--rsb-file':
-                           raise error.general('invalid --rsb-file option: %s' % (' '.join(args)))
+                           raise error.general('invalid --rsb-file option: %s' % \
+                                               (' '.join(args)))
                        file_override = os_[1]
                 opts = [o for o in opts if not o.startswith('--rsb-')]
             url = self.config.expand(' '.join(url))
-            src = download.parse_url(url, '_sourcedir', self.config, self.opts, file_override)
+            src = download.parse_url(url, '_sourcedir',
+                                     self.config, self.opts, file_override)
             download.get_file(src['url'], src['local'], self.opts, self.config)
-            if strip_components > 0:
-                tar_extract = '%%{__tar_extract} --strip-components %d' % (strip_components)
-            else:
-                tar_extract = '%{__tar_extract}'
-            if 'symlink' in src:
-                sname = name.replace('-', '_')
-                src['script'] = '%%{__ln_s} %s ${source_dir_%s}' % (src['symlink'], sname)
-            elif 'compressed' in src:
-                #
-                # Zip files unpack as well so do not use tar.
-                #
-                src['script'] = '%s %s' % (src['compressed'], src['local'])
-                if src['compressed-type'] != 'zip':
-                    src['script'] += ' | %s -f -' % (tar_extract)
-            else:
-                src['script'] = '%s -f %s' % (tar_extract, src['local'])
-            srcs += [src]
+            if not download_only:
+                if strip_components > 0:
+                    tar_extract = '%%{__tar_extract} --strip-components %d' % \
+                        (strip_components)
+                else:
+                    tar_extract = '%{__tar_extract}'
+                if 'symlink' in src:
+                    sname = name.replace('-', '_')
+                    src['script'] = '%%{__ln_s} %s ${source_dir_%s}' % \
+                        (src['symlink'], sname)
+                elif 'compressed' in src:
+                    #
+                    # Zip files unpack as well so do not use tar.
+                    #
+                    src['script'] = '%s %s' % (src['compressed'], src['local'])
+                    if src['compressed-type'] != 'zip':
+                        src['script'] += ' | %s -f -' % (tar_extract)
+                else:
+                    src['script'] = '%s -f %s' % (tar_extract, src['local'])
+                srcs += [src]
         return srcs
 
     def source_setup(self, package, args):
@@ -270,7 +276,7 @@ class build:
         setup_name = args[1]
         args = args[1:]
         try:
-            opts, args = getopt.getopt(args[1:], 'qDcn:bas:')
+            opts, args = getopt.getopt(args[1:], 'qDcn:bas:g')
         except getopt.GetoptError as ge:
             raise error.general('source setup error: %s' % str(ge))
         quiet = False
@@ -282,6 +288,7 @@ class build:
         changed_dir = False
         strip_components = 0
         opt_name = None
+        download_only = False
         for o in opts:
             if o[0] == '-q':
                 quiet = True
@@ -297,30 +304,37 @@ class build:
                 unpack_before_chdir = False
             elif o[0] == '-s':
                 if not o[1].isdigit():
-                    raise error.general('source setup error: invalid strip count: %s' % (o[1]))
+                    raise error.general('source setup error: invalid strip count: %s' % \
+                                        (o[1]))
                 strip_components = int(o[1])
+            elif o[0] == '-g':
+                download_only = True
         name = None
-        for source in self.source(setup_name, strip_components):
+        for source in self.source(setup_name, strip_components, download_only):
             if name is None:
                 if opt_name is None:
                     if source:
                         opt_name = source['name']
                     else:
-                        raise error.general('setup source tag not found: %d' % (source_tag))
+                        raise error.general('setup source tag not found: %d' % \
+                                            (source_tag))
                 else:
                     name = opt_name
-            self.script_build.append(self.config.expand('cd %{_builddir}'))
-            if not deleted_dir and delete_before_unpack:
-                self.script_build.append(self.config.expand('%{__rm} -rf ' + name))
-                deleted_dir = True
-            if not created_dir and create_dir:
-                self.script_build.append(self.config.expand('%{__mkdir_p} ' + name))
-                created_dir = True
-            if not changed_dir and (not unpack_before_chdir or create_dir):
-                self.script_build.append(self.config.expand('cd ' + name))
-                changed_dir = True
-            self.script_build.append(self.config.expand(source['script']))
-        if not changed_dir and (unpack_before_chdir and not create_dir):
+            if not download_only:
+                self.script_build.append(self.config.expand('cd %{_builddir}'))
+                if not deleted_dir and delete_before_unpack and name is not None:
+                    self.script_build.append(self.config.expand('%{__rm} -rf ' + name))
+                    deleted_dir = True
+                if not created_dir and create_dir and name is not None:
+                    self.script_build.append(self.config.expand('%{__mkdir_p} ' + name))
+                    created_dir = True
+                if not changed_dir and (not unpack_before_chdir or create_dir) and \
+                   name is not None:
+                    self.script_build.append(self.config.expand('cd ' + name))
+                    changed_dir = True
+                self.script_build.append(self.config.expand(source['script']))
+        if not changed_dir and (unpack_before_chdir and not create_dir) and \
+           name is not None and not download_only:
             self.script_build.append(self.config.expand('cd ' + name))
             changed_dir = True
         self.script_build.append(self.config.expand('%{__setup_post}'))
@@ -345,7 +359,7 @@ class build:
                 else:
                     url += [pp]
             if len(url) == 0:
-                raise error.general('patch URL not found: %s' % (' '.join(args)))
+                raise error.general('patch URL not found: %s' % (' '.join(opts)))
             #
             # Look for --rsb-file as an option we use as a local file name.
             # This can be used if a URL has no reasonable file name the
@@ -357,9 +371,11 @@ class build:
                     if o.startswith('--rsb-file'):
                        os_ = o.split('=')
                        if len(os_) != 2:
-                           raise error.general('invalid --rsb-file option: %s' % (' '.join(args)))
+                           raise error.general('invalid --rsb-file option: %s' % \
+                                               (' '.join(opts)))
                        if os_[0] != '--rsb-file':
-                           raise error.general('invalid --rsb-file option: %s' % (' '.join(args)))
+                           raise error.general('invalid --rsb-file option: %s' % \
+                                               (' '.join(opts)))
                        file_override = os_[1]
                 opts = [o for o in opts if not o.startswith('--rsb-')]
             if len(opts) == 0:
@@ -371,7 +387,8 @@ class build:
             #
             # Parse the URL first in the source builder's patch directory.
             #
-            patch = download.parse_url(url, '_patchdir', self.config, self.opts, file_override)
+            patch = download.parse_url(url, '_patchdir', self.config,
+                                       self.opts, file_override)
             #
             # Download the patch
             #
diff --git a/source-builder/sb/darwin.py b/source-builder/sb/darwin.py
index d79cf47..a21a6bc 100644
--- a/source-builder/sb/darwin.py
+++ b/source-builder/sb/darwin.py
@@ -52,6 +52,7 @@ def load():
         '_var':             ('dir',     'optional', '/usr/local/var'),
         '_prefix':          ('dir',     'optional', '%{_usr}'),
         '__ldconfig':       ('exe',     'none',     ''),
+        '__cmake':          ('exe',     'optional', 'cmake'),
         '__cvs':            ('exe',     'optional', 'cvs'),
         '__xz':             ('exe',     'required', 'xz'),
         'with_zlib':        ('none',    'none',     '--with-zlib=no'),
diff --git a/source-builder/sb/freebsd.py b/source-builder/sb/freebsd.py
index decd1c9..8fc7db1 100644
--- a/source-builder/sb/freebsd.py
+++ b/source-builder/sb/freebsd.py
@@ -63,6 +63,7 @@ def load():
         '_var':             ('dir',     'optional', '/usr/local/var'),
         '__bash':           ('exe',     'optional', '/usr/local/bin/bash'),
         '__bison':          ('exe',     'required', '/usr/local/bin/bison'),
+        '__cmake':          ('exe',     'optional', '/usr/local/bin/cmake'),
         '__git':            ('exe',     'required', '/usr/local/bin/git'),
         '__svn':            ('exe',     'optional', '/usr/local/bin/svn'),
         '__unzip':          ('exe',     'optional', '/usr/local/bin/unzip'),
diff --git a/source-builder/sb/options.py b/source-builder/sb/options.py
index 9fe0269..8063734 100644
--- a/source-builder/sb/options.py
+++ b/source-builder/sb/options.py
@@ -293,6 +293,8 @@ class command_line:
                               '--without-log',
                               '--without-error-report',
                               '--without-release-url']
+            if a == '--dry-run':
+                self.args += ['--without-error-report']
             arg += 1
 
     def post_process(self, logfile = True):
diff --git a/source-builder/sb/setbuilder.py b/source-builder/sb/setbuilder.py
index 380fa00..3d10d58 100644
--- a/source-builder/sb/setbuilder.py
+++ b/source-builder/sb/setbuilder.py
@@ -405,18 +405,6 @@ class buildset:
         if nesting_count != 1:
             if self.installing():
                 self.macros['install_mode'] = 'staging'
-                #
-                # Prepend staging areas, bin directory tothe
-                # path. Lets the later package depend on the eailier
-                # ones.
-                #
-                pathprepend = ['%{stagingroot}/bin'] + \
-                    macro_expand(self.macros, '%{_pathprepend}').split(':')
-                pathprepend = [pp for pp in pathprepend if len(pp)]
-                if len(pathprepend) == 1:
-                    self.macros['_pathprepend'] = pathprepend[0]
-                else:
-                    self.macros['_pathprepend'] = ':'.join(pathprepend)
 
         #
         # Only the outter build set can have staging to install. Get the staging
@@ -430,6 +418,20 @@ class buildset:
             log.trace('_bset: %2d: %s: configs: %s'  % (nesting_count,
                                                         self.bset, ', '.join(configs)))
 
+            if nesting_count == 1 and len(configs) > 1:
+                #
+                # Prepend staging areas, bin directory to the
+                # path. Lets the later package depend on the earlier
+                # ones.
+                #
+                pathprepend = ['%{stagingroot}/bin'] + \
+                    macro_expand(self.macros, '%{_pathprepend}').split(':')
+                pathprepend = [pp for pp in pathprepend if len(pp)]
+                if len(pathprepend) == 1:
+                    self.macros['_pathprepend'] = pathprepend[0]
+                else:
+                    self.macros['_pathprepend'] = ':'.join(pathprepend)
+
             sizes_valid = False
             builds = []
             for s in range(0, len(configs)):
@@ -519,7 +521,7 @@ class buildset:
             log.trace('_bset: %2d: %s: builds: %s' % \
                       (nesting_count, self.install_mode(),
                        ', '.join([b.name() for b in builds])))
-            if deps is None and not have_errors:
+            if deps is None and not self.opts.no_install() and not have_errors:
                 for b in builds:
                     log.trace('_bset:   : %s: %r' % (self.install_mode(),
                                                      b.installable()))
@@ -586,18 +588,22 @@ class buildset:
             # If builds have been staged install into the finaly prefix.
             #
             if have_staging and not self.opts.no_install() and not have_errors:
-                log.trace('_bset: %2d: install staging' % (nesting_count))
                 stagingroot = macro_expand(self.macros, '%{stagingroot}')
-                prefix = macro_expand(self.macros, '%{_prefix}')
-                self.install(self.install_mode(), self.bset, stagingroot, prefix)
-                staging_size = path.get_size(stagingroot)
-                if not self.opts.no_clean() or self.opts.always_clean():
-                    log.notice('clean staging: %s' % (self.bset))
-                    log.trace('removing: %s' % (stagingroot))
-                    if not self.opts.dry_run():
-                        if path.exists(stagingroot):
-                            path.removeall(stagingroot)
-                log.notice('Staging Size: %s' % (build.humanize_number(staging_size, 'B')))
+                have_stagingroot = path.exists(stagingroot)
+                log.trace('_bset: %2d: install staging, present: %s' % \
+                          (nesting_count, have_stagingroot))
+                if have_stagingroot:
+                    prefix = macro_expand(self.macros, '%{_prefix}')
+                    self.install(self.install_mode(), self.bset, stagingroot, prefix)
+                    staging_size = path.get_size(stagingroot)
+                    if not self.opts.no_clean() or self.opts.always_clean():
+                        log.notice('clean staging: %s' % (self.bset))
+                        log.trace('removing: %s' % (stagingroot))
+                        if not self.opts.dry_run():
+                            if path.exists(stagingroot):
+                                path.removeall(stagingroot)
+                    log.notice('Staging Size: %s' % \
+                               (build.humanize_number(staging_size, 'B')))
         except error.general as gerr:
             if not build_error:
                 log.stderr(str(gerr))
diff --git a/source-builder/sb/sources.py b/source-builder/sb/sources.py
index 967becc..c5f0037 100644
--- a/source-builder/sb/sources.py
+++ b/source-builder/sb/sources.py
@@ -49,8 +49,8 @@ def add(label, args, macros, error):
 def set(label, args, macros, error):
     args = _args(args)
     if len(args) < 2:
-        error('%%%s requires at least 2 arguments' % (label))
-        return
+        error('%%%s set requires at least 2 arguments' % (label))
+        return []
     _map = '%s-%s' % (label, args[0])
     macros.create_map(_map)
     key = _make_key(label, 0)
@@ -63,12 +63,26 @@ def set(label, args, macros, error):
 def setup(label, args, macros, error):
     args = _args(args)
     if len(args) < 2:
-        error('%%%s requires at least 2 arguments: %s' % (label, ' '.join(args)))
+        error('%%%s setup requires at least 2 arguments: %s' % (label, ' '.join(args)))
     ss = '%%setup %s %s' % (label, ' '.join(args))
     _map = '%s-%s' % (label, args[0])
     if 'setup' in macros.map_keys(_map):
         error('%%%s already setup source: %s' % (label, ' '.join(args)))
-        return
+        return []
+    macros.set_write_map(_map)
+    macros.define('setup', ss)
+    macros.unset_write_map()
+    return [ss]
+
+def download(label, args, macros, error):
+    args = _args(args)
+    if len(args) != 1:
+        error('%%%s download requires 1 argument: %s' % (label, ' '.join(args)))
+    ss = '%%setup %s %s -g' % (label, ' '.join(args))
+    _map = '%s-%s' % (label, args[0])
+    if 'setup' in macros.map_keys(_map):
+        error('%%%s already setup source: %s' % (label, ' '.join(args)))
+        return []
     macros.set_write_map(_map)
     macros.define('setup', ss)
     macros.unset_write_map()
@@ -79,15 +93,14 @@ def process(label, args, macros, error):
         error('invalid source type: %s' % (label))
     args = _args(args)
     log.trace('sources: %s' % (' '.join(args)))
-    if len(args) < 3:
-        error('%%%s requires at least 3 arguments: %s' % (label, ' '.join(args)))
-        return
     if args[0] == 'set':
         return set(label, args[1:], macros, error)
     elif args[0] == 'add':
         return add(label, args[1:], macros, error)
     elif args[0] == 'setup':
         return setup(label, args[1:], macros, error)
+    elif args[0] == 'download':
+        return download(label, args[1:], macros, error)
     error('invalid %%%s command: %s' % (label, args[0]))
 
 def hash(args, macros, error):