Improve Bazel presubmit formatting

tools/bazel_build.py

@@ -15,6 +15,7 @@
     override_picotool_arg,
     parse_common_args,
     print_framed_string,
+    print_to_stderr,
     run_bazel,
     setup_logging,
 )
@@ -196,12 +197,12 @@ def build_all_configurations(picotool_dir):
         )
         if result.returncode != 0:
             failed_builds.append(config["name"])
-        print()
+        print_to_stderr()
 
     if failed_builds:
         print_framed_string("ERROR: One or more builds failed.")
         for build in failed_builds:
-            print(f"  * FAILED: {build} build")
+            print_to_stderr(f"  * FAILED: {build} build")
         return 1
 
     print_framed_string("All builds successfully passed!")

tools/bazel_common.py

@@ -13,6 +13,7 @@
 import shlex
 import shutil
 import subprocess
+import sys
 
 
 _LOG = logging.getLogger(__file__)
@@ -93,12 +94,16 @@ def run_bazel(args, check=False, **kwargs):
     return proc
 
 
+def print_to_stderr(*args, **kwargs):
+    print(*args, file=sys.stderr, **kwargs)
+
+
 def print_framed_string(s):
     """Frames a string of text and prints it to highlight script steps."""
     header_spacer = "#" * (len(s) + 12)
-    print(header_spacer)
-    print("###   " + s + "   ###")
-    print(header_spacer)
+    print_to_stderr(header_spacer)
+    print_to_stderr("###   " + s + "   ###")
+    print_to_stderr(header_spacer)
 
 
 def setup_logging():

tools/compare_build_systems.py

@@ -14,13 +14,16 @@
 
 from dataclasses import dataclass
 import glob
+import logging
 import os
 import re
 import sys
 from typing import Dict
 
 from bazel_common import SDK_ROOT
 
+_LOG = logging.getLogger(__file__)
+
 CMAKE_FILE_TYPES = (
     "**/CMakeLists.txt",
     "**/*.cmake",
@@ -182,17 +185,17 @@ def OptionsAreEqual(bazel_option, cmake_option):
     if bazel_option is None:
         if cmake_option.name in CMAKE_ONLY_ALLOWLIST:
             return True
-        print(f"    {cmake_option.name} does not exist in Bazel")
+        _LOG.warning(f"    {cmake_option.name} does not exist in Bazel")
         return False
     elif cmake_option is None:
         if bazel_option.name in BAZEL_ONLY_ALLOWLIST:
             return True
-        print(f"    {bazel_option.name} does not exist in CMake")
+        _LOG.warning(f"    {bazel_option.name} does not exist in CMake")
         return False
     elif not bazel_option.matches(cmake_option):
-        print("    Bazel and CMAKE definitions do not match:")
-        print(f"    [CMAKE]    {bazel_option}")
-        print(f"    [BAZEL]    {cmake_option}")
+        _LOG.error("    Bazel and CMAKE definitions do not match:")
+        _LOG.error(f"    [CMAKE]    {bazel_option}")
+        _LOG.error(f"    [BAZEL]    {cmake_option}")
         return False
 
     return True
@@ -224,22 +227,23 @@ def compare_build_systems():
         for f in glob.glob(os.path.join(SDK_ROOT, p), recursive=True)
     ]
 
-    print("[1/2] Checking build system configuration flags...")
+    _LOG.info("[1/2] Checking build system configuration flags...")
     build_options_ok = CompareOptions(
         "PICO_BAZEL_CONFIG", bazel_files, "PICO_CMAKE_CONFIG", cmake_files
     )
 
-    print("[2/2] Checking build system defines...")
+    _LOG.info("[2/2] Checking build system defines...")
     build_defines_ok = CompareOptions(
         "PICO_BUILD_DEFINE", bazel_files, "PICO_BUILD_DEFINE", cmake_files
     )
 
     if build_options_ok and build_defines_ok:
-        print("OK")
+        _LOG.info("OK")
         return 0
 
     return 1
 
 
 if __name__ == "__main__":
+    setup_logging()
     sys.exit(compare_build_systems())