Make *_config_checks_*.h automatically generated files

For the time being, only do this if the generation script
`scripts/generate_config_checks.py` exists in the consuming repository. This
way we can use this framework revision before the scripts are added to the
consuming repositories.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>

Author: gilles-peskine-arm

scripts/make_generated_files.py

@@ -10,6 +10,7 @@
 """
 import argparse
 import filecmp
+import os
 import shutil
 import subprocess
 import sys
@@ -66,6 +67,18 @@ def get_generation_script_files(generation_script: str):
 
     return files
 
+COMMON_GENERATION_SCRIPTS = [
+]
+
+# Once the script has been added to both Mbed TLS and TF-PSA-Crypto,
+# we can include this unconditionally.
+# https://github.com/Mbed-TLS/mbedtls/issues/10305
+if os.path.exists("scripts/generate_config_checks.py"):
+    COMMON_GENERATION_SCRIPTS.append(GenerationScript(
+        Path("scripts/generate_config_checks.py"),
+        get_generation_script_files("scripts/generate_config_checks.py"),
+        "", None))
+
 if build_tree.looks_like_tf_psa_crypto_root("."):
     TF_PSA_CRYPTO_GENERATION_SCRIPTS = [
         GenerationScript(
@@ -244,6 +257,7 @@ def main():
         generation_scripts = MBEDTLS_GENERATION_SCRIPTS
     else:
         raise Exception("No support for Mbed TLS 3.6")
+    generation_scripts += COMMON_GENERATION_SCRIPTS
 
     if args.list:
         files = get_generated_files(generation_scripts)

scripts/mbedtls_framework/config_checks_generator.py

@@ -189,6 +189,16 @@ def __init__(self, branch_data: BranchData, position: Position) -> None:
         self.prefix = branch_data.project_cpp_prefix + '_CONFIG_CHECK'
         self.bypass_checks = self.prefix + '_BYPASS'
 
+    @staticmethod
+    def filename(root: str,
+                 branch_data: BranchData,
+                 position: Position) -> str:
+        """The file name for this header, under the given root."""
+        suffix = f'config_check_{position.name.lower()}.h'
+        return os.path.join(root,
+                            branch_data.header_directory,
+                            branch_data.header_prefix + suffix)
+
     def write_stanza(self, out: typing_util.Writable, checker: Checker) -> None:
         """Write the part of the output corresponding to one config option."""
         code = checker.code(self.position, self.prefix)
@@ -199,8 +209,9 @@ def write_content(self, out: typing_util.Writable) -> None:
         for checker in self.branch_data.checkers:
             self.write_stanza(out, checker)
 
-    def write(self, filename: str) -> None:
+    def write(self, root: str) -> None:
         """Write the whole output file."""
+        filename = self.filename(root, self.branch_data, self.position)
         with open(filename, 'w') as out:
             out.write(f"""\
 /* {os.path.basename(filename)}: checks before including the user configuration file. */
@@ -223,19 +234,19 @@ def write(self, filename: str) -> None:
 def generate_header_files(root: str, branch_data: BranchData) -> None:
     """Generate the header files to include before and after *config.h."""
     before_generator = HeaderGenerator(branch_data, Position.BEFORE)
-    before_generator.write(os.path.join(root,
-                                        branch_data.header_directory,
-                                        branch_data.header_prefix +
-                                        'config_check_before.h'))
+    before_generator.write(root)
     after_generator = HeaderGenerator(branch_data, Position.AFTER)
-    after_generator.write(os.path.join(root,
-                                       branch_data.header_directory,
-                                       branch_data.header_prefix +
-                                       'config_check_after.h'))
+    after_generator.write(root)
 
 
 def main(branch_data: BranchData) -> None:
     parser = argparse.ArgumentParser(description=__doc__)
-    _options = parser.parse_args()
+    parser.add_argument('--list', action='store_true',
+                        help='List generated files and exit')
+    options = parser.parse_args()
     root = build_tree.guess_project_root()
+    if options.list:
+        for position in [Position.BEFORE, Position.AFTER]:
+            print(HeaderGenerator.filename(root, branch_data, position))
+        return
     generate_header_files(root, branch_data)