build: Use enabled by for defaults

Merge the "default" and "default-by-variant" attributes.  Use an
"enabled-by" expression to select the default value based on the enabled
set.  This makes it possible to select default values depending on other
options.  For example you could choose memory settings based on whether
RTEMS_SMP is enabled or disabled.

The change was tested by comparing the output of

  ./waf bspdefaults

before and after the change.

1 files changed, 18 insertions, 30 deletions

diff --git a/wscript b/wscript
index a622ed3941..a34cac51e2 100755
--- a/wscript
+++ b/wscript
@@ -203,11 +203,11 @@ class Item(object):
     def get_enabled_by(self):
         return self.data["enabled-by"]
 
-    def defaults(self, enable, variant, family):
-        if _is_enabled(enable, self.get_enabled_by()):
+    def defaults(self, enabled):
+        if _is_enabled(enabled, self.get_enabled_by()):
             for p in self.links():
-                p.defaults(enable, variant, family)
-            self.do_defaults(variant, family)
+                p.defaults(enabled)
+            self.do_defaults(enabled)
 
     def configure(self, conf, cic):
         if _is_enabled(conf.env.ENABLE, self.get_enabled_by()):
@@ -223,7 +223,7 @@ class Item(object):
                 p.build(bld, bic)
             self.do_build(bld, bic)
 
-    def do_defaults(self, variant, family):
+    def do_defaults(self, enabled):
         return
 
     def prepare_configure(self, conf, cic):
@@ -750,25 +750,12 @@ class OptionItem(Item):
     def __init__(self, uid, data):
         super(OptionItem, self).__init__(uid, data)
 
-    @staticmethod
-    def _is_variant(variants, variant):
-        for pattern in variants:
-            if re.match(pattern + "$", variant):
-                return True
-        return False
-
-    def default_value(self, variant, family):
-        value = self.data["default"]
-        for default in self.data["default-by-variant"]:
-            if OptionItem._is_variant(default["variants"], variant):
+    def default_value(self, enabled):
+        value = None
+        for default in self.data["default"]:
+            if _is_enabled(enabled, default["enabled-by"]):
                 value = default["value"]
                 break
-        else:
-            family = "bsps/" + family
-            for default in self.data["default-by-variant"]:
-                if OptionItem._is_variant(default["variants"], family):
-                    value = default["value"]
-                    break
         if value is None:
             return value
         if isinstance(value, list):
@@ -777,8 +764,8 @@ class OptionItem(Item):
             return value
         return self.data["format"].format(value)
 
-    def do_defaults(self, variant, family):
-        value = self.default_value(variant, family)
+    def do_defaults(self, enabled):
+        value = self.default_value(enabled)
         if value is None:
             return
         description = self.data["description"]
@@ -961,7 +948,7 @@ class OptionItem(Item):
             value = cic.cp.getboolean(conf.variant, name)
             cic.add_option(name)
         except configparser.NoOptionError:
-            value = self.default_value(conf.env.ARCH_BSP, conf.env.ARCH_FAMILY)
+            value = self.default_value(conf.env.ENABLE)
         except ValueError as ve:
             conf.fatal("Invalid value for configuration option {}: {}".format(
                 name, ve))
@@ -976,7 +963,7 @@ class OptionItem(Item):
             value = cic.cp.get(conf.variant, name)
             cic.add_option(name)
         except configparser.NoOptionError:
-            value = self.default_value(conf.env.ARCH_BSP, conf.env.ARCH_FAMILY)
+            value = self.default_value(conf.env.ENABLE)
             if value is None:
                 return value
         try:
@@ -993,7 +980,7 @@ class OptionItem(Item):
             cic.add_option(name)
             value = no_unicode(value)
         except configparser.NoOptionError:
-            value = self.default_value(conf.env.ARCH_BSP, conf.env.ARCH_FAMILY)
+            value = self.default_value(conf.env.ENABLE)
         return value
 
     def _get_string_command_line(self, conf, cic, value, arg):
@@ -1661,9 +1648,10 @@ def bspdefaults(ctx):
 COMPILER = {}""".format(variant, compiler))
                 enable = [compiler, arch, variant]
                 bsp_item = bsps[arch][bsp]
-                family = arch + "/" + bsp_item.data["family"]
-                items[top_group].defaults(enable, variant, family)
-                bsp_item.defaults(enable, variant, family)
+                family = "bsps/" + arch + "/" + bsp_item.data["family"]
+                enabled = [compiler, arch, family, variant]
+                items[top_group].defaults(enabled)
+                bsp_item.defaults(enabled)
     if first:
         no_matches_error(ctx, white_list)