New test and fixes for AlwaysBuild when using ninja execution engine.

CHANGES.txt

@@ -14,7 +14,7 @@ RELEASE  VERSION/DATE TO BE FILLED IN LATER
 
   From John Doe:
     - Whatever John Doe did.
-
+  
   From Joseph Brill:
     - Add possible build failure when targeting 32-bit arm using
       Visual Studio 2022 with Windows SDK version 10.0.26100.0 or later
@@ -78,6 +78,8 @@ RELEASE  VERSION/DATE TO BE FILLED IN LATER
     - Fix typos in preface, Chapter 6, Chapter 9 and Chapter 10 of User Guide
     - Fix broken links in Chapter 1 of User Guide
 
+  From Paul Movall:
+    - Fix a problem where AlwaysBuild is now honored by ninja
 
   From Mats Wichmann:
     - Introduce some unit tests for the file locking utility routines

RELEASE.txt

@@ -51,6 +51,8 @@ FIXES
   directory for each writer before doing the move, instead of depending
   on a one-time uuid to make a path to the file.
 
+- Fix ninja to honor AlwaysBuild on a target
+
 IMPROVEMENTS
 ------------
 

SCons/Tool/ninja_tool/NinjaState.py

@@ -407,6 +407,11 @@ def generate(self):
 
         ninja.variable("builddir", get_path(self.env.Dir(self.env['NINJA_DIR']).path))
 
+        ninja.build(
+            "SconsAlwaysBuildPhony",
+            rule="phony",
+        )
+
         for pool_name, size in sorted(self.pools.items()):
             ninja.pool(pool_name, min(self.env.get('NINJA_MAX_JOBS', size), size))
 
@@ -783,6 +788,9 @@ def action_to_ninja_build(self, node, action=None):
             if callable(node_callback):
                 node_callback(env, node, build)
 
+        if node.always_build:
+            build["implicit"] = build.get("implicit", []) + ["SconsAlwaysBuildPhony"]
+
         return build
 
     def handle_func_action(self, node, action):

test/ninja/always_build.py

@@ -0,0 +1,85 @@
+#!/usr/bin/env python
+#
+# Copyright The SCons Foundation
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+#
+
+import os
+
+import TestSCons
+from TestCmd import IS_WINDOWS
+
+test = TestSCons.TestSCons()
+
+try:
+    import ninja
+except ImportError:
+    test.skip_test("Could not find module in python")
+
+_python_ = TestSCons._python_
+_exe = TestSCons._exe
+
+ninja_bin = TestSCons.NINJA_BINARY
+
+test.dir_fixture('ninja-fixture')
+
+test.file_fixture('ninja_test_sconscripts/sconstruct_always_build',
+                  'SConstruct')
+
+# generate simple build
+test.run()
+test.must_contain_all_lines(test.stdout(), ['Generating: build.ninja'])
+test.must_contain_all(test.stdout(), 'Executing:')
+test.must_contain_all(test.stdout(), 'ninja%(_exe)s -f' % locals())
+test.run(program=test.workpath('always_build' + _exe), stdout="print_function")
+
+# Rerun the build to ensure that the AlwaysBuild target is rebuilt
+test.run()
+test.must_contain_all_lines(test.stdout(), ['Generating: build.ninja'])
+test.must_contain_all(test.stdout(), 'Executing:')
+test.must_contain_all(test.stdout(), 'ninja%(_exe)s -f' % locals())
+test.must_not_contain_any_line(test.stdout(), ['ninja: no work to do.'])
+test.run(program=test.workpath('always_build' + _exe), stdout="print_function")
+
+# clean build and ninja files
+test.run(arguments='-c', stdout=None)
+test.must_contain_all_lines(test.stdout(), [
+    'Removed test2.o',
+    'Removed always_build',
+    'Removed build.ninja'])
+
+# only generate the ninja file
+test.run(arguments='--disable-execute-ninja', stdout=None)
+test.must_contain_all_lines(test.stdout(), ['Generating: build.ninja'])
+test.must_not_exist(test.workpath('always_build' + _exe))
+
+# run ninja independently
+program = test.workpath('run_ninja_env.bat') if IS_WINDOWS else ninja_bin
+test.run(program=program)
+test.must_not_contain_any_line(test.stdout(), ['ninja: no work to do.'])
+test.run(program=test.workpath('always_build' + _exe), stdout="print_function")
+
+# Rerun the build to ensure that the AlwaysBuild target is rebuilt
+test.run(program=program)
+test.must_not_contain_any_line(test.stdout(), ['ninja: no work to do.'])
+test.run(program=test.workpath('always_build' + _exe), stdout="print_function")
+
+test.pass_test()

test/ninja/ninja_test_sconscripts/sconstruct_always_build

@@ -0,0 +1,16 @@
+# SPDX-License-Identifier: MIT
+#
+# Copyright The SCons Foundation
+
+SetOption('experimental','ninja')
+DefaultEnvironment(tools=[])
+env = Environment()
+env.Tool('ninja')
+
+# Compile source to object
+obj = env.Object('test2.cpp')
+# Force rebuild of object file every time
+env.AlwaysBuild(obj)
+
+# Link object to executable
+env.Program(target='always_build', source=obj)