Building all plats takes a while, so make the user select which plats to build.

Author: davidgiven

Makefile

@@ -7,6 +7,13 @@
 
 DEFAULT_PLATFORM ?= pc86
 
+# Which architectures should get built?
+
+PLATS = 
+# PLATS = all
+# PLATS = linux386 linuxppc linuxmips
+$(if $(PLATS),, $(error Supply PLATS='something' to specify which architectures to build for. (Use 'all' for all of them.) (Edit the Makefile to set the default.))
+
 # Where should the ACK put its temporary files?
 
 ifeq ($(TMPDIR),)
@@ -60,6 +67,7 @@ ack-setup.exe: etc/windows-installer.nsi all
 
 PLATIND = $(INSDIR)/share/ack
 PLATDEP = $(INSDIR)/lib/ack
+export PLATS
 
 AB_ENABLE_PROGRESS_INFO = false
 include build/ab.mk

build.py

@@ -1,28 +1,19 @@
 from build.ab import export
 from build.config import IS_WINDOWS
+import os
+from os.path import *
+from glob import glob
 
-# This is the list of which plats to build.
-PLATS = (
-    [
-        "linux386",
-        "linux68k",
-        "linuxmips",
-        "linuxppc",
-        "minix68k",
-        "msdos386",
-        "msdos86",
-        "osx386",
-        "osxppc",
-        "pc86",
-        "rpi",
-        "pdpv7",
-        "em22",
-    ]
-    +
-    # The i80 mach doesn't build on Windows because the ludicrous number of
-    # object files blows the Windows command line limit.
-    (["cpm"] if not IS_WINDOWS else [])
-)
+_plats = os.getenv("PLATS")
+if _plats == "all":
+    PLATS = {dirname(p) for p in glob("*/build.py", root_dir="plat")}
+else:
+    PLATS = _plats.split(" ")
+    
+if IS_WINDOWS and ("cpm" in PLATS):
+    print("Warning: the cpm plat can't be built on Windows because of reasons; skipping.")
+    PLATS.discard("cpm")
+print("Building plats: " + (" ".join(PLATS)))
 
 # This is the list of which plats to test.
 TEST_PLATS = [