MSVS: revise the vcxproj embedded python script contents

Changes:
* Revert setting SCONS_HOME in the testenv in runtest.py.
* Simplify the generated embedded python script.
* Simplified evaluation order:
  1. If scons_home is defined:
     * If SCons is not found using scons_home, display an error message and exit the embedded python script
  2. If scons_abspath is defined:
     * If SCons is not found using scons_abspath, display an error message and exit the embedded python script
  3. Evaluate local library locations plus the python system path:
     * If SCons is not found using the extended python system path, display an error message and exit the embedded python script
  4. Add the found SCons path to the front of the python system path
  5. Display the SCons path
  6. Import and run SCons/Tool/msvs.py

Author: jcbrill

SCons/Tool/msvs.py

@@ -177,9 +177,6 @@ def getExecScriptMain(env, xml=None):
     if not scons_home and 'SCONS_LIB_DIR' in os.environ:
         scons_home = os.environ['SCONS_LIB_DIR']
 
-    if scons_home is None:
-        scons_home = ''
-
     scons_abspath = os.path.abspath(os.path.dirname(os.path.dirname(SCons.__file__)))
 
     def _in_pytree(scons_abspath):
@@ -198,79 +195,29 @@ def _in_pytree(scons_abspath):
     in_pytree = _in_pytree(scons_abspath)
     # print(f"in_pytree={in_pytree}, scons_abspath=`{scons_abspath}', sys.prefix='{sys.prefix}', sys.exec_prefix='{sys.exec_prefix}'")
 
-    if in_pytree:
-        scons_abspath = ''
-
     if _exec_script_main_template is None:
-        _exec_script_main_template = "; ".join([line for block in [textwrap.dedent(s).splitlines() for s in [
-            # Import libraries and functions.
+        _exec_script_main_template = "; ".join(textwrap.dedent(
             """\
             import importlib.util
             import sys
-            from os.path import abspath, dirname, isdir, isfile, join, normcase, realpath
-            """,
-            # Initialize the generated paths:
-            # * convert scons_home to an absolute path,
-            # * clear scons_abspath when equal to the scons_home absolute path.
-            """\
-            usrinit = lambda p: abspath(p) if p else p
-            geninit = lambda p, u: '' if (p and u and normcase(p) == normcase(u)) else p
-            usr_path = usrinit(r'{scons_home}')
-            gen_path = geninit(r'{scons_abspath}', usr_path)
-            """,
-            # Evaluate candidate lists:
-            # 1. If scons_home is defined:
-            #    * Record scons_home as found iff the path contains SCons.
-            #    * Stop evaluating remaining alternatives.
-            # 2. If scons_abspath is defined:
-            #    * Record scons_abspath as found iff the path contains SCons.
-            #    * Stop evaluating remaining alternatives.
-            # 3. Evaluate known library locations:
-            #    * Record the first library path that contains SCons as found.
-            """\
-            state = {{}}
-            isvalid = lambda p: p and isdir(p) and isfile(join(p, 'SCons', '__init__.py'))
-            store = lambda k, l, s: {{k: l[0], 'Found': l[0], 'Stop': True}} if l else {{k: '', 'Stop': s}}
-            check = lambda k, l, s: state.update(store(k, [p for p in l if isvalid(p)], s)) if not state.get('Stop') else None
-            _ = [check(k, l, s) for k, l, s in [('usr', [usr_path], bool(usr_path)), ('gen', [gen_path], bool(gen_path)), ('lib', [join(sys.prefix, *t) for t in [('Lib', 'site-packages', 'scons-{scons_version}'), ('scons-{scons_version}',), ('Lib', 'site-packages', 'scons'), ('scons',), ('Lib', 'site-packages')]], False)]]
-            """,
-            # If an SCons module path was found, add the path to the front of
-            # the sys.path list.
-            """\
-            path = state.get('Found', '')
-            _  = sys.path.insert(0, path) if path else None
-            """,
-            # Use importlib to find the SCons module path prior to import.
-            # Add a valid module spec origin path to the front of the sys.path list if:
-            # * a module path was not found earlier, or
-            # * the module spec origin path is different than the module
-            #   path found earlier.
-            """\
+            from os.path import abspath, dirname, isdir, isfile, join, realpath
+            usr_path = r'{scons_home}'
+            gen_path = r'{scons_abspath}'
+            syspath = sys.path
+            search, path = ([usr_path], usr_path) if usr_path else ([gen_path], gen_path) if gen_path else ([join(sys.prefix, *t) for t in [('Lib', 'site-packages', 'scons-{scons_version}'), ('scons-{scons_version}',), ('Lib', 'site-packages', 'scons'), ('scons',), ('Lib', 'site-packages')]] + sys.path, None)
+            sys.path = search
             spec = importlib.util.find_spec('SCons')
             orig = dirname(dirname(abspath(spec.origin))) if (spec and spec.origin) else ''
-            syspath = orig and (not path or normcase(abspath(path)) != normcase(orig))
-            _ = sys.path.insert(0, orig) if syspath else None
-            """,
-            # Display diagnostic messages.
-            """\
-            _ = print(f'proj: *** SCons not found at user path \\\'{{usr_path}}\\\'. ***') if (usr_path and state.get('usr') == '') else None
-            _ = print(f'proj: *** SCons not found at generated path \\\'{{gen_path}}\\\' ***.') if (gen_path and state.get('gen') == '') else None
-            _ = print( 'proj: *** SCons not found. ***') if (not orig) else None
-            """,
-            # Display SCons module path (if found).
-            """\
-            _ = print(f'proj: Using SCons path \\\'{{orig}}\\\' (realpath=\\\'{{realpath(orig)}}\\\', syspath={{syspath}}).') if (orig) else None
-            """,
-            # Import SCons and run main script.
-            """\
+            sys.path = [orig] + syspath if orig else syspath
+            _ = print(f'proj: Using SCons path \\\'{{orig}}\\\' (realpath=\\\'{{realpath(orig)}}\\\').') if orig else (print(f'proj: Error: SCons not found (path=\\\'{{path if path else search}}\\\').'), sys.exit(1))
             import SCons.Script
             SCons.Script.main()
-            """,
-        ]] for line in block])
+            """
+        ).splitlines())
 
     exec_script_main = _exec_script_main_template.format(
-        scons_home=scons_home,
-        scons_abspath=scons_abspath,
+        scons_home=scons_home if scons_home else '',
+        scons_abspath=scons_abspath if not in_pytree else '',
         scons_version=SCons.__version__,
     )
     # print("exec_script_main:\n", ' ' + '\n  '.join(exec_script_main.split("; ")))

runtest.py

@@ -540,7 +540,6 @@ def footer(self, f):
     # Because SCons is really aggressive about finding its modules,
     # it sometimes finds SCons modules elsewhere on the system.
     # This forces SCons to use the modules that are being tested.
-    testenv['SCONS_HOME'] = scons_lib_dir
     testenv['SCONS_LIB_DIR'] = scons_lib_dir
 
 if args.scons_exec:

testing/framework/TestSConsMSVS.py

@@ -842,14 +842,15 @@ def get_exec_script_main(scons_home=None):
     global _exec_script_main_template
 
     scons_home = scons_home
-    if not scons_home and 'SCONS_HOME' in os.environ:
-        scons_home = os.environ['SCONS_HOME']
+    # Some tests may fail if SCONS_HOME is defined in the os environment when
+    # the tests are run.  The SCons location set in the user's os environment
+    # may point to a different SCons than the SCons currently being tested.
+    # This behavior is consistent with the main branch code at the time.
+    # if not scons_home and 'SCONS_HOME' in os.environ:
+    #     scons_home = os.environ['SCONS_HOME']
     if not scons_home and 'SCONS_LIB_DIR' in os.environ:
         scons_home = os.environ['SCONS_LIB_DIR']
 
-    if scons_home is None:
-        scons_home = ''
-
     scons_abspath = os.path.abspath(os.path.dirname(os.path.dirname(SCons.__file__)))
 
     def _in_pytree(scons_abspath):
@@ -868,42 +869,29 @@ def _in_pytree(scons_abspath):
     in_pytree = _in_pytree(scons_abspath)
     # print(f"in_pytree={in_pytree}, scons_abspath=`{scons_abspath}', sys.prefix='{sys.prefix}', sys.exec_prefix='{sys.exec_prefix}'")
 
-    if in_pytree:
-        scons_abspath = ''
-
     if _exec_script_main_template is None:
         _exec_script_main_template = "; ".join(textwrap.dedent(
             """\
             import importlib.util
             import sys
-            from os.path import abspath, dirname, isdir, isfile, join, normcase, realpath
-            usrinit = lambda p: abspath(p) if p else p
-            geninit = lambda p, u: '' if (p and u and normcase(p) == normcase(u)) else p
-            usr_path = usrinit(r'{scons_home}')
-            gen_path = geninit(r'{scons_abspath}', usr_path)
-            state = {{}}
-            isvalid = lambda p: p and isdir(p) and isfile(join(p, 'SCons', '__init__.py'))
-            store = lambda k, l, s: {{k: l[0], 'Found': l[0], 'Stop': True}} if l else {{k: '', 'Stop': s}}
-            check = lambda k, l, s: state.update(store(k, [p for p in l if isvalid(p)], s)) if not state.get('Stop') else None
-            _ = [check(k, l, s) for k, l, s in [('usr', [usr_path], bool(usr_path)), ('gen', [gen_path], bool(gen_path)), ('lib', [join(sys.prefix, *t) for t in [('Lib', 'site-packages', 'scons-{scons_version}'), ('scons-{scons_version}',), ('Lib', 'site-packages', 'scons'), ('scons',), ('Lib', 'site-packages')]], False)]]
-            path = state.get('Found', '')
-            _  = sys.path.insert(0, path) if path else None
+            from os.path import abspath, dirname, isdir, isfile, join, realpath
+            usr_path = r'{scons_home}'
+            gen_path = r'{scons_abspath}'
+            syspath = sys.path
+            search, path = ([usr_path], usr_path) if usr_path else ([gen_path], gen_path) if gen_path else ([join(sys.prefix, *t) for t in [('Lib', 'site-packages', 'scons-{scons_version}'), ('scons-{scons_version}',), ('Lib', 'site-packages', 'scons'), ('scons',), ('Lib', 'site-packages')]] + sys.path, None)
+            sys.path = search
             spec = importlib.util.find_spec('SCons')
             orig = dirname(dirname(abspath(spec.origin))) if (spec and spec.origin) else ''
-            syspath = orig and (not path or normcase(abspath(path)) != normcase(orig))
-            _ = sys.path.insert(0, orig) if syspath else None
-            _ = print(f'proj: *** SCons not found at user path \\\'{{usr_path}}\\\'. ***') if (usr_path and state.get('usr') == '') else None
-            _ = print(f'proj: *** SCons not found at generated path \\\'{{gen_path}}\\\' ***.') if (gen_path and state.get('gen') == '') else None
-            _ = print( 'proj: *** SCons not found. ***') if (not orig) else None
-            _ = print(f'proj: Using SCons path \\\'{{orig}}\\\' (realpath=\\\'{{realpath(orig)}}\\\', syspath={{syspath}}).') if (orig) else None
+            sys.path = [orig] + syspath if orig else syspath
+            _ = print(f'proj: Using SCons path \\\'{{orig}}\\\' (realpath=\\\'{{realpath(orig)}}\\\').') if orig else (print(f'proj: Error: SCons not found (path=\\\'{{path if path else search}}\\\').'), sys.exit(1))
             import SCons.Script
             SCons.Script.main()
-            """,
+            """
         ).splitlines())
 
     exec_script_main = _exec_script_main_template.format(
-        scons_home=scons_home,
-        scons_abspath=scons_abspath,
+        scons_home=scons_home if scons_home else '',
+        scons_abspath=scons_abspath if not in_pytree else '',
         scons_version=SCons.__version__,
     )
     # print("exec_script_main:\n", ' ' + '\n  '.join(exec_script_main.split("; ")))