buildman: make board selector argument a regex

A common use-case is to build all boards for a particular SoC. This can
be achieved by:

./tools/buildman/buildman -b mainline_dev tegra20

However, when the SoC is a member of a family of SoCs, and each SoC has
a different name, it would be even more useful to build all boards for
every SoC in that family. This currently isn't possible since buildman's
board selection command-line arguments are compared to board definitions
using pure string equality.

To enable this, compare using a regex match instead. This matches
MAKEALL's handling of command-line arguments. This enables:

(all Tegra)
./tools/buildman/buildman -b mainline_dev tegra

(all Tegra)
./tools/buildman/buildman -b mainline_dev '^tegra.*$'

(all Tegra20, Tegra30 boards, but not Tegra114)
./tools/buildman/buildman -b mainline_dev 'tegra[23]'

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>

tools/buildman/README

@@ -89,10 +89,16 @@ a few commits or boards, it will be pretty slow. As a tip, if you don't
 plan to use your machine for anything else, you can use -T to increase the
 number of threads beyond the default.
 
-Buildman lets you build all boards, or a subset. Specify the subset using
-the board name, architecture name, SOC name, or anything else in the
-boards.cfg file. So 'at91' will build all AT91 boards (arm), powerpc will
-build all PowerPC boards.
+Buildman lets you build all boards, or a subset. Specify the subset by passing
+command-line arguments that list the desired board name, architecture name,
+SOC name, or anything else in the boards.cfg file. Multiple arguments are
+allowed. Each argument will be interpreted as a regular expression, so
+behaviour is a superset of exact or substring matching. Examples are:
+
+* 'tegra20'      All boards with a Tegra20 SoC
+* 'tegra'        All boards with any Tegra Soc (Tegra20, Tegra30, Tegra114...)
+* '^tegra[23]0$' All boards with either Tegra20 or Tegra30 SoC
+* 'powerpc'      All PowerPC boards
 
 Buildman does not store intermediate object files. It optionally copies
 the binary output into a directory when a build is successful. Size

tools/buildman/board.py

@@ -3,6 +3,8 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
+import re
+
 class Board:
     """A particular board that we can build"""
     def __init__(self, status, arch, cpu, soc, vendor, board_name, target, options):
@@ -135,14 +137,22 @@ class Boards:
             due to each argument, arranged by argument.
         """
         result = {}
+        argres = {}
         for arg in args:
             result[arg] = 0
+            argres[arg] = re.compile(arg)
         result['all'] = 0
 
         for board in self._boards:
             if args:
                 for arg in args:
-                    if arg in board.props:
+                    argre = argres[arg]
+                    match = False
+                    for prop in board.props:
+                        match = argre.match(prop)
+                        if match:
+                            break
+                    if match:
                         if not board.build_it:
                             board.build_it = True
                             result[arg] += 1