bpo-45020: Fix build out of source tree (GH-28410)

* Makefile.pre.in: Add $(srcdir) when needed, remove it when it was
  used by mistake.
* freeze_modules.py tool uses ./Programs/_freeze_module if the
  executable doesn't exist in the source tree.

Author: vstinner

Makefile.pre.in

@@ -728,7 +728,7 @@ regen-test-frozenmain: $(BUILDPYTHON)
 	# Regenerate Programs/test_frozenmain.h
 	# from Programs/test_frozenmain.py
 	# using Programs/freeze_test_frozenmain.py
-	$(RUNSHARED) ./$(BUILDPYTHON) Programs/freeze_test_frozenmain.py Programs/test_frozenmain.h
+	$(RUNSHARED) ./$(BUILDPYTHON) $(srcdir)/Programs/freeze_test_frozenmain.py Programs/test_frozenmain.h
 
 Programs/_testembed: Programs/_testembed.o $(LIBRARY_DEPS)
 	$(LINKCC) $(PY_CORE_LDFLAGS) $(LINKFORSHARED) -o $@ Programs/_testembed.o $(BLDLIBRARY) $(LIBS) $(MODLIBS) $(SYSLIBS)
@@ -751,40 +751,40 @@ regen-frozen: Tools/scripts/freeze_modules.py $(FROZEN_FILES)
 # BEGIN: freezing modules
 
 Python/frozen_modules/importlib__bootstrap.h: Programs/_freeze_module Lib/importlib/_bootstrap.py
-	$(srcdir)/Programs/_freeze_module importlib._bootstrap $(srcdir)/Lib/importlib/_bootstrap.py $(srcdir)/Python/frozen_modules/importlib__bootstrap.h
+	Programs/_freeze_module importlib._bootstrap $(srcdir)/Lib/importlib/_bootstrap.py $(srcdir)/Python/frozen_modules/importlib__bootstrap.h
 
 Python/frozen_modules/importlib__bootstrap_external.h: Programs/_freeze_module Lib/importlib/_bootstrap_external.py
-	$(srcdir)/Programs/_freeze_module importlib._bootstrap_external $(srcdir)/Lib/importlib/_bootstrap_external.py $(srcdir)/Python/frozen_modules/importlib__bootstrap_external.h
+	Programs/_freeze_module importlib._bootstrap_external $(srcdir)/Lib/importlib/_bootstrap_external.py $(srcdir)/Python/frozen_modules/importlib__bootstrap_external.h
 
 Python/frozen_modules/zipimport.h: Programs/_freeze_module Lib/zipimport.py
-	$(srcdir)/Programs/_freeze_module zipimport $(srcdir)/Lib/zipimport.py $(srcdir)/Python/frozen_modules/zipimport.h
+	Programs/_freeze_module zipimport $(srcdir)/Lib/zipimport.py $(srcdir)/Python/frozen_modules/zipimport.h
 
 Python/frozen_modules/abc.h: Programs/_freeze_module Lib/abc.py
-	$(srcdir)/Programs/_freeze_module abc $(srcdir)/Lib/abc.py $(srcdir)/Python/frozen_modules/abc.h
+	Programs/_freeze_module abc $(srcdir)/Lib/abc.py $(srcdir)/Python/frozen_modules/abc.h
 
 Python/frozen_modules/io.h: Programs/_freeze_module Lib/io.py
-	$(srcdir)/Programs/_freeze_module io $(srcdir)/Lib/io.py $(srcdir)/Python/frozen_modules/io.h
+	Programs/_freeze_module io $(srcdir)/Lib/io.py $(srcdir)/Python/frozen_modules/io.h
 
 Python/frozen_modules/_collections_abc.h: Programs/_freeze_module Lib/_collections_abc.py
-	$(srcdir)/Programs/_freeze_module _collections_abc $(srcdir)/Lib/_collections_abc.py $(srcdir)/Python/frozen_modules/_collections_abc.h
+	Programs/_freeze_module _collections_abc $(srcdir)/Lib/_collections_abc.py $(srcdir)/Python/frozen_modules/_collections_abc.h
 
 Python/frozen_modules/_sitebuiltins.h: Programs/_freeze_module Lib/_sitebuiltins.py
-	$(srcdir)/Programs/_freeze_module _sitebuiltins $(srcdir)/Lib/_sitebuiltins.py $(srcdir)/Python/frozen_modules/_sitebuiltins.h
+	Programs/_freeze_module _sitebuiltins $(srcdir)/Lib/_sitebuiltins.py $(srcdir)/Python/frozen_modules/_sitebuiltins.h
 
 Python/frozen_modules/genericpath.h: Programs/_freeze_module Lib/genericpath.py
-	$(srcdir)/Programs/_freeze_module genericpath $(srcdir)/Lib/genericpath.py $(srcdir)/Python/frozen_modules/genericpath.h
+	Programs/_freeze_module genericpath $(srcdir)/Lib/genericpath.py $(srcdir)/Python/frozen_modules/genericpath.h
 
 Python/frozen_modules/ntpath.h: Programs/_freeze_module Lib/ntpath.py
-	$(srcdir)/Programs/_freeze_module ntpath $(srcdir)/Lib/ntpath.py $(srcdir)/Python/frozen_modules/ntpath.h
+	Programs/_freeze_module ntpath $(srcdir)/Lib/ntpath.py $(srcdir)/Python/frozen_modules/ntpath.h
 
 Python/frozen_modules/posixpath.h: Programs/_freeze_module Lib/posixpath.py
-	$(srcdir)/Programs/_freeze_module posixpath $(srcdir)/Lib/posixpath.py $(srcdir)/Python/frozen_modules/posixpath.h
+	Programs/_freeze_module posixpath $(srcdir)/Lib/posixpath.py $(srcdir)/Python/frozen_modules/posixpath.h
 
 Python/frozen_modules/stat.h: Programs/_freeze_module Lib/stat.py
-	$(srcdir)/Programs/_freeze_module stat $(srcdir)/Lib/stat.py $(srcdir)/Python/frozen_modules/stat.h
+	Programs/_freeze_module stat $(srcdir)/Lib/stat.py $(srcdir)/Python/frozen_modules/stat.h
 
 Python/frozen_modules/__hello__.h: Programs/_freeze_module Lib/__hello__.py
-	$(srcdir)/Programs/_freeze_module __hello__ $(srcdir)/Lib/__hello__.py $(srcdir)/Python/frozen_modules/__hello__.h
+	Programs/_freeze_module __hello__ $(srcdir)/Lib/__hello__.py $(srcdir)/Python/frozen_modules/__hello__.h
 
 # END: freezing modules
 

Tools/scripts/freeze_modules.py

@@ -15,9 +15,8 @@
 from update_file import updating_file_with_tmpfile
 
 
-SCRIPTS_DIR = os.path.abspath(os.path.dirname(__file__))
-TOOLS_DIR = os.path.dirname(SCRIPTS_DIR)
-ROOT_DIR = os.path.dirname(TOOLS_DIR)
+ROOT_DIR = os.path.dirname(os.path.dirname(os.path.dirname(__file__)))
+ROOT_DIR = os.path.abspath(ROOT_DIR)
 
 STDLIB_DIR = os.path.join(ROOT_DIR, 'Lib')
 # If MODULES_DIR is changed then the .gitattributes and .gitignore files
@@ -26,6 +25,13 @@
 
 if sys.platform != "win32":
     TOOL = os.path.join(ROOT_DIR, 'Programs', '_freeze_module')
+    if not os.path.isfile(TOOL):
+        # When building out of the source tree, get the tool from the current
+        # directory
+        TOOL = os.path.join('Programs', '_freeze_module')
+        TOOL = os.path.abspath(TOOL)
+        if not os.path.isfile(TOOL):
+            sys.exit("ERROR: missing _freeze_module")
 else:
     def find_tool():
         for arch in ['amd64', 'win32']:
@@ -547,7 +553,7 @@ def regen_makefile(modules):
         # instead of going through an intermediate file like we used to.
         rules.append(f'{header}: Programs/_freeze_module {pyfile}')
         rules.append(
-            (f'\t$(srcdir)/Programs/_freeze_module {src.frozenid} '
+            (f'\tPrograms/_freeze_module {src.frozenid} '
              f'$(srcdir)/{pyfile} $(srcdir)/{header}'))
         rules.append('')