Add tests for SConscript(must_warn) option

Testcases added to confirm the behavior of: first attempt
to call a non-existent script gives a deprecation warning,
additional ones give plain warning; True/False values for
must_warn behave as expected; if scons default is changed
to exception the call fails but if must_warn=False it
still works.

Tweaked the logic to actually get that last bit to work.
Also minor doc update.

Signed-off-by: Mats Wichmann <mats@linux.com>

2 files changed, 11 insertions, 9 deletions

diff --git a/src/engine/SCons/Script/SConscript.py b/src/engine/SCons/Script/SConscript.py
index 5968346..fb6ec0d 100644
--- a/src/engine/SCons/Script/SConscript.py
+++ b/src/engine/SCons/Script/SConscript.py
@@ -153,14 +153,14 @@ def Return(*vars, **kw):
 
 stack_bottom = '% Stack boTTom %' # hard to define a variable w/this name :)
 
-def handle_missing_SConscript(f, must_exist):
+def handle_missing_SConscript(f, must_exist=None):
     """Take appropriate action on missing file in SConscript() call.
 
     The action may be to raise an exception, or print a warning.
     On first warning, also print a deprecation warning.
     """
 
-    if SCons.Script._no_missing_sconscript or must_exist:
+    if must_exist or (SCons.Script._no_missing_sconscript and must_exist is not False):
         msg = "Fatal: missing SConscript '%s'" % f.get_internal_path()
         raise SCons.Errors.UserError(msg)
 
@@ -285,7 +285,7 @@ def _SConscript(fs, *files, **kw):
                         if old_file is not None:
                             call_stack[-1].globals.update({__file__:old_file})
                 else:
-                    handle_missing_SConscript(f, kw.get('must_exist', False))
+                    handle_missing_SConscript(f, kw.get('must_exist', None))
 
         finally:
             SCons.Script.sconscript_reading = SCons.Script.sconscript_reading - 1
@@ -568,6 +568,7 @@ class SConsEnvironment(SCons.Environment.Base):
 
         files, exports = self._get_SConscript_filenames(ls, subst_kw)
         subst_kw['exports'] = exports
+        
         return _SConscript(self.fs, *files, **subst_kw)
 
     def SConscriptChdir(self, flag):
diff --git a/src/engine/SCons/Script/SConscript.xml b/src/engine/SCons/Script/SConscript.xml
index 29a89c2..a6258c4 100644
--- a/src/engine/SCons/Script/SConscript.xml
+++ b/src/engine/SCons/Script/SConscript.xml
@@ -357,12 +357,12 @@ Return('val1 val2')
 
 <scons_function name="SConscript">
 <arguments>
-(scripts, [exports, variant_dir, duplicate, must_exist=flag])
-<!-- (scripts, [exports, variant_dir, src_dir, duplicate, must_exist=flag]) -->
+(scripts, [exports, variant_dir, duplicate, must_exist])
+<!-- (scripts, [exports, variant_dir, src_dir, duplicate, must_exist]) -->
 </arguments>
 <arguments>
-(dirs=subdirs, [name=script, exports, variant_dir, duplicate, must_exist=flag])
-<!-- (dirs=subdirs, [name=script, exports, variant_dir, src_dir, duplicate, must_exist=flag]) -->
+(dirs=subdirs, [name=script, exports, variant_dir, duplicate, must_exist])
+<!-- (dirs=subdirs, [name=script, exports, variant_dir, src_dir, duplicate, must_exist]) -->
 </arguments>
 <summary>
 <para>
@@ -562,12 +562,13 @@ and what about this alternative?
 TODO??? SConscript('build/SConscript', src_dir='src')
 -->
 </para>
+
 <para>
 The optional
 <varname>must_exist</varname>
 argument, if true, causes an exception to be raised if a requested
-&SConscript; file is not found. The default is false,
-which only prints a warning, but this behavior is deprecated.
+&SConscript; file is not found. The current default is false,
+causing only a warning to be omitted, but this behavior is deprecated.
 For scripts which truly intend to be optional, transition to
 explicty supplying
 <literal>must_exist=False</literal> to the call.