Issue 2231: Add a --warn=future-deprecated option, along with

FutureDeprecatedWarning and MandatoryDeprecatedWarning subclasses.
Use these to future-deprecate the Taskmaster.Task class, which we intend
to turn into an abstract base class by requiring subclasses to implement
the .needs_execute() method.

3 files changed, 29 insertions, 3 deletions

diff --git a/src/engine/SCons/Taskmaster.py b/src/engine/SCons/Taskmaster.py
index f360402..934e28b 100644
--- a/src/engine/SCons/Taskmaster.py
+++ b/src/engine/SCons/Taskmaster.py
@@ -58,6 +58,7 @@ import traceback
 
 import SCons.Errors
 import SCons.Node
+import SCons.Warnings
 
 StateString = SCons.Node.StateString
 NODE_NO_STATE = SCons.Node.no_state
@@ -202,6 +203,9 @@ class Task:
         # Deprecation Cycle) so the desired behavior is explicitly
         # determined by which concrete subclass is used.
         #raise NotImplementedError
+        msg = ('Direct use of the Taskmaster.Task class will be deprecated\n'
+               + '\tin a future release.')
+        SCons.Warnings.warn(SCons.Warnings.TaskmasterNeedsExecuteWarning, msg)
         return True
 
     def execute(self):
diff --git a/src/engine/SCons/Warnings.py b/src/engine/SCons/Warnings.py
index 03ab9ae..83e3ccb 100644
--- a/src/engine/SCons/Warnings.py
+++ b/src/engine/SCons/Warnings.py
@@ -37,6 +37,21 @@ import SCons.Errors
 class Warning(SCons.Errors.UserError):
     pass
 
+class MandatoryWarning(Warning):
+    pass
+
+
+
+class FutureDeprecatedWarning(Warning):
+    pass
+
+class DeprecatedWarning(Warning):
+    pass
+
+class MandatoryDeprecatedWarning(MandatoryWarning):
+    pass
+
+
 
 # NOTE:  If you add a new warning class, add it to the man page, too!
 
@@ -49,9 +64,6 @@ class CorruptSConsignWarning(Warning):
 class DependencyWarning(Warning):
     pass
 
-class DeprecatedWarning(Warning):
-    pass
-
 class DeprecatedCopyWarning(DeprecatedWarning):
     pass
 
@@ -97,6 +109,9 @@ class ReservedVariableWarning(Warning):
 class StackSizeWarning(Warning):
     pass
 
+class TaskmasterNeedsExecuteWarning(FutureDeprecatedWarning):
+    pass
+
 class FortranCxxMixWarning(LinkWarning):
     pass
 
@@ -186,5 +201,8 @@ def process_warn_strings(arguments):
         else:
             if enable:
                 enableWarningClass(clazz)
+            elif issubclass(clazz, MandatoryDeprecatedWarning):
+                fmt = "Can not disable mandataory warning: '%s'\n"
+                sys.stderr.write(fmt % arg)
             else:
                 suppressWarningClass(clazz)
diff --git a/src/engine/SCons/WarningsTests.py b/src/engine/SCons/WarningsTests.py
index 0964699..228c82c 100644
--- a/src/engine/SCons/WarningsTests.py
+++ b/src/engine/SCons/WarningsTests.py
@@ -94,6 +94,10 @@ class WarningsTestCase(unittest.TestCase):
                             "Foo")
         assert to.out is None, to.out
 
+        SCons.Warnings.warn(SCons.Warnings.MandatoryWarning,
+                            "Foo")
+        assert to.out is None, to.out
+
         SCons.Warnings.enableWarningClass(SCons.Warnings.Warning)
         SCons.Warnings.warn(SCons.Warnings.DeprecatedWarning,
                             "Foo")