[matter] add --pretend flag, makes possible to run matter in pretend mode directly

matter/matter/builder.py

@@ -70,7 +70,7 @@ class PackageBuilder(object):
     PORTAGE_BUILTIN_ARGS = ["--accept-properties=-interactive"]
 
     def __init__(self, emerge_config, packages, params,
-        spec_number, tot_spec, pkg_number, tot_pkgs):
+        spec_number, tot_spec, pkg_number, tot_pkgs, pretend):
         self._emerge_config = emerge_config
         self._packages = packages
         self._params = params
@@ -78,6 +78,7 @@ class PackageBuilder(object):
         self._tot_spec = tot_spec
         self._pkg_number = pkg_number
         self._tot_pkgs = tot_pkgs
+        self._pretend = pretend
         self._built_packages = []
         self._uninstalled_packages = []
         self._not_found_packages = []
@@ -611,12 +612,11 @@ class PackageBuilder(object):
         build_args = []
         build_args += PackageBuilder.PORTAGE_BUILD_ARGS
         build_args += PackageBuilder.PORTAGE_BUILTIN_ARGS
+        if self._pretend and "--pretend" not in myopts:
+            build_args.append("--pretend")
         build_args += ["=" + best_v for _x, best_v in packages]
         myaction, myopts, myfiles = parse_opts(build_args)
 
-        if "--pretend" in myopts:
-            print_warning("cannot use --pretend emerge argument, you idiot")
-            del myopts["--pretend"]
         if "--ask" in myopts:
             print_warning("cannot use --ask emerge argument, you idiot")
             del myopts["--ask"]

matter/matter/main.py

@@ -101,7 +101,8 @@ def matter_main(binary_pms, nsargs, cwd, specs):
 
             builder = PackageBuilder(
                 emerge_config, packages,
-                spec, spec_count, tot_spec, pkg_count, tot_pkgs)
+                spec, spec_count, tot_spec, pkg_count, tot_pkgs,
+                nsargs.pretend)
             _rc = builder.run()
 
             not_found.extend(builder.get_not_found_packages())
@@ -336,6 +337,12 @@ Available Binary PMSs:
         help="disable prerserved libraries check.",
         action="store_true")
 
+    parser.add_argument(
+        "--pretend",
+        dest="pretend", default=False,
+        help="show what would be done without alterint the current system.",
+        action="store_true")
+
     # extend parser arguments
     for k in avail_binpms:
         k.extend_parser(parser)