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-rw-r--r--bitbake/doc/manual/usermanual.xml8
-rw-r--r--bitbake/lib/bb/parse/ast.py11
-rw-r--r--bitbake/lib/bb/parse/parse_py/ConfHandler.py2
3 files changed, 19 insertions, 2 deletions
diff --git a/bitbake/doc/manual/usermanual.xml b/bitbake/doc/manual/usermanual.xml
index c3403449f..450ac77d7 100644
--- a/bitbake/doc/manual/usermanual.xml
+++ b/bitbake/doc/manual/usermanual.xml
@@ -91,7 +91,13 @@ share common metadata between many packages.</para></listitem>
<section>
<title>Setting a default value (?=)</title>
<para><screen><varname>A</varname> ?= "aval"</screen></para>
- <para>If <varname>A</varname> is set before the above is called, it will retain it's previous value. If <varname>A</varname> is unset prior to the above call, <varname>A</varname> will be set to <literal>aval</literal>.</para>
+ <para>If <varname>A</varname> is set before the above is called, it will retain it's previous value. If <varname>A</varname> is unset prior to the above call, <varname>A</varname> will be set to <literal>aval</literal>. Note that this assignment is immediate, so if there are multiple ?= assignments to a single variable, the first of those will be used.</para>
+ </section>
+ <section>
+ <title>Setting a default value (??=)</title>
+ <para><screen><varname>A</varname> ??= "somevalue"</screen></para>
+ <para><screen><varname>A</varname> ??= "someothervalue"</screen></para>
+ <para>If <varname>A</varname> is set before the above, it will retain that value. If <varname>A</varname> is unset prior to the above, <varname>A</varname> will be set to <literal>someothervalue</literal>. This is a lazy version of ??=, in that the assignment does not occur until the end of the parsing process, so that the last, rather than the first, ??= assignment to a given variable will be used.</para>
</section>
<section>
<title>Immediate variable expansion (:=)</title>
diff --git a/bitbake/lib/bb/parse/ast.py b/bitbake/lib/bb/parse/ast.py
index e0b795fa6..70a69b8d1 100644
--- a/bitbake/lib/bb/parse/ast.py
+++ b/bitbake/lib/bb/parse/ast.py
@@ -99,9 +99,15 @@ class DataNode(AstNode):
val = "%s%s" % (groupd["value"], (self.getFunc(key, data) or ""))
else:
val = groupd["value"]
+
if 'flag' in groupd and groupd['flag'] != None:
bb.msg.debug(3, bb.msg.domain.Parsing, "setVarFlag(%s, %s, %s, data)" % (key, groupd['flag'], val))
bb.data.setVarFlag(key, groupd['flag'], val, data)
+ elif groupd["lazyques"]:
+ assigned = bb.data.getVar("__lazy_assigned", data) or []
+ assigned.append(key)
+ bb.data.setVar("__lazy_assigned", assigned, data)
+ bb.data.setVarFlag(key, "defaultval", val, data)
else:
bb.data.setVar(key, val, data)
@@ -286,6 +292,11 @@ def handleInherit(statements, m):
statements.append(InheritNode(m.group(1)))
def finalise(fn, d):
+ for lazykey in bb.data.getVar("__lazy_assigned", d) or ():
+ if bb.data.getVar(lazykey, d) is None:
+ val = bb.data.getVarFlag(lazykey, "defaultval", d)
+ bb.data.setVar(lazykey, val, d)
+
bb.data.expandKeys(d)
bb.data.update_data(d)
anonqueue = bb.data.getVar("__anonqueue", d, 1) or []
diff --git a/bitbake/lib/bb/parse/parse_py/ConfHandler.py b/bitbake/lib/bb/parse/parse_py/ConfHandler.py
index a1eaf317a..f4f85de24 100644
--- a/bitbake/lib/bb/parse/parse_py/ConfHandler.py
+++ b/bitbake/lib/bb/parse/parse_py/ConfHandler.py
@@ -28,7 +28,7 @@ import re, bb.data, os, sys
from bb.parse import ParseError, resolve_file, ast
#__config_regexp__ = re.compile( r"(?P<exp>export\s*)?(?P<var>[a-zA-Z0-9\-_+.${}]+)\s*(?P<colon>:)?(?P<ques>\?)?=\s*(?P<apo>['\"]?)(?P<value>.*)(?P=apo)$")
-__config_regexp__ = re.compile( r"(?P<exp>export\s*)?(?P<var>[a-zA-Z0-9\-_+.${}/]+)(\[(?P<flag>[a-zA-Z0-9\-_+.]+)\])?\s*((?P<colon>:=)|(?P<ques>\?=)|(?P<append>\+=)|(?P<prepend>=\+)|(?P<predot>=\.)|(?P<postdot>\.=)|=)\s*(?P<apo>['\"]?)(?P<value>.*)(?P=apo)$")
+__config_regexp__ = re.compile( r"(?P<exp>export\s*)?(?P<var>[a-zA-Z0-9\-_+.${}/]+)(\[(?P<flag>[a-zA-Z0-9\-_+.]+)\])?\s*((?P<colon>:=)|(?P<lazyques>\?\?=)|(?P<ques>\?=)|(?P<append>\+=)|(?P<prepend>=\+)|(?P<predot>=\.)|(?P<postdot>\.=)|=)\s*(?P<apo>['\"]?)(?P<value>.*)(?P=apo)$")
__include_regexp__ = re.compile( r"include\s+(.+)" )
__require_regexp__ = re.compile( r"require\s+(.+)" )
__export_regexp__ = re.compile( r"export\s+(.+)" )