Warn only for source-like suffix drops, batch ar argv, name non-iterable dependencies

The unmapped-suffix warning fired for every header-only library (the
default +<*> filter matches headers), so ArduinoJson would have warned
on every ESP8266 build. It now names exactly the source-like files
(.CPP, .ino and case-variants of the map) the case-sensitive suffix map
rejects, partial drops included, and stays quiet for headers and
metadata.

The ar shim batches the expanded object list by argv length (rc then q
appends), keeping the command line under the Windows 32767-char limit
the rspfile existed to avoid. A non-iterable dependencies value in a
manifest now warns by library name instead of raising a bare
TypeError.

esphome/arduino/library.py

@@ -180,25 +180,30 @@ def _library_info(name: str, read_path: Path, data: dict) -> ArduinoLibrary:
         for f in matched
         if (path := Path(f)).suffix in SRC_FILE_EXTENSIONS
     )
-    if skipped := [f for f in matched if Path(f).suffix not in SRC_FILE_EXTENSIONS]:
-        _LOGGER.debug(
-            "Library %s: %d matched files are not sources", name, len(skipped)
+    # A source-like suffix the case-sensitive map rejects (.CPP, .ino) is a
+    # dropped compilation unit that surfaces as undefined symbols at link;
+    # headers and metadata files fall through silently (header-only
+    # libraries are routine)
+    source_like = {s.lower() for s in SRC_FILE_EXTENSIONS} | {".ino"}
+    if dropped := [
+        Path(f).name
+        for f in matched
+        if Path(f).suffix not in SRC_FILE_EXTENSIONS
+        and Path(f).suffix.lower() in source_like
+    ]:
+        _LOGGER.warning(
+            "Library %s: %d file(s) with unmapped source suffixes are not compiled: %s",
+            name,
+            len(dropped),
+            ", ".join(sorted(dropped)),
+        )
+    if not lib.sources and not matched and ("srcFilter" in build or "srcDir" in build):
+        # A default probe finding nothing is a header-only library; a
+        # declared filter matching nothing is a manifest/tree problem.
+        _LOGGER.warning(
+            "Library %s declares srcFilter/srcDir but no source files matched",
+            name,
         )
-    if not lib.sources:
-        if matched:
-            # Every matched file fell through the suffix map: an empty
-            # archive would fail far away at link
-            _LOGGER.warning(
-                "Library %s: no matched file has a recognized source suffix",
-                name,
-            )
-        elif "srcFilter" in build or "srcDir" in build:
-            # A default probe finding nothing is a header-only library; a
-            # declared filter matching nothing is a manifest/tree problem.
-            _LOGGER.warning(
-                "Library %s declares srcFilter/srcDir but no source files matched",
-                name,
-            )
     return lib
 
 

esphome/build_gen/build_tool.py

@@ -40,9 +40,23 @@ def main() -> int:
             # An empty archive would "succeed" here and fail far away at link
             print(f"ar: no objects listed in {rspfile} for {archive}", file=sys.stderr)
             return 1
-        return subprocess.run(
-            [ar, "rc", archive, *objects], check=False, close_fds=False
-        ).returncode
+        # Batch by argv length: expanding the rspfile gives back the Windows
+        # 32767-char command-line limit it existed to avoid. "rc" creates,
+        # "q" appends the remainder.
+        op = "rc"
+        while objects:
+            batch = [objects.pop(0)]
+            batch_len = len(batch[0])
+            while objects and batch_len + len(objects[0]) < 25000:
+                batch_len += len(objects[0]) + 1
+                batch.append(objects.pop(0))
+            rc = subprocess.run(
+                [ar, op, archive, *batch], check=False, close_fds=False
+            ).returncode
+            if rc != 0:
+                return rc
+            op = "q"
+        return 0
     if mode == "copy":
         src, dst = sys.argv[2:4]
         shutil.copyfile(src, dst)

esphome/platformio/library.py

@@ -699,6 +699,13 @@ def normalize_dependencies(
                 continue
             normalized.append(entry)
         return normalized
+    if not isinstance(dependencies, (list, tuple)):
+        _LOGGER.warning(
+            "Ignoring unrecognized dependencies %r of %s",
+            dependencies,
+            manifest_name,
+        )
+        return []
     normalized = []
     for entry in dependencies:
         if isinstance(entry, dict):

tests/unit_tests/build_gen/test_build_tool.py

@@ -124,3 +124,48 @@ def test_ar_empty_object_list_fails(
         rc = build_tool.main()
     assert rc == 1
     assert "no objects listed" in capsys.readouterr().err
+
+
+def test_ar_batches_long_object_lists(tmp_path: Path) -> None:
+    """The expanded argv must stay under the Windows 32767-char limit: a
+    long object list creates with rc, then appends with q."""
+    archive = tmp_path / "lib.a"
+    rsp = tmp_path / "lib.a.rsp"
+    objects = [f"dir/{'x' * 120}_{i}.o" for i in range(400)]
+    rsp.write_text("\n".join(objects) + "\n")
+    with (
+        patch.object(
+            build_tool.sys,
+            "argv",
+            ["build_tool", "ar", "ar-bin", str(archive), str(rsp)],
+        ),
+        patch.object(
+            build_tool.subprocess, "run", return_value=MagicMock(returncode=0)
+        ) as mock_run,
+    ):
+        assert build_tool.main() == 0
+    calls = [c[0][0] for c in mock_run.call_args_list]
+    assert len(calls) > 1
+    assert calls[0][1] == "rc"
+    assert all(c[1] == "q" for c in calls[1:])
+    assert [o for c in calls for o in c[3:]] == objects
+    assert all(sum(len(a) + 1 for a in c) < 32000 for c in calls)
+
+
+def test_ar_batch_failure_stops(tmp_path: Path) -> None:
+    """A failing batch propagates its exit code without running the rest."""
+    archive = tmp_path / "lib.a"
+    rsp = tmp_path / "lib.a.rsp"
+    rsp.write_text("\n".join(f"{'y' * 200}_{i}.o" for i in range(300)) + "\n")
+    with (
+        patch.object(
+            build_tool.sys,
+            "argv",
+            ["build_tool", "ar", "ar-bin", str(archive), str(rsp)],
+        ),
+        patch.object(
+            build_tool.subprocess, "run", return_value=MagicMock(returncode=3)
+        ) as mock_run,
+    ):
+        assert build_tool.main() == 3
+    assert mock_run.call_count == 1

tests/unit_tests/test_arduino_library.py

@@ -477,13 +477,32 @@ def test_library_info_dropped_link_fields_warn(
 def test_library_info_unmapped_sources_warn(
     tmp_path: Path, caplog: pytest.LogCaptureFixture
 ) -> None:
-    """Matched files that all fall through the suffix map are visible; an
-    empty archive would fail far away at link."""
+    """Source-like files the case-sensitive suffix map rejects are named,
+    even when other sources compiled (a partial drop links with undefined
+    symbols far from the cause)."""
     read_path = tmp_path / "lib"
     (read_path / "src").mkdir(parents=True)
     (read_path / "src" / "impl.CPP").write_text("")
-    component._library_info("x", read_path, {"build": {}})
-    assert "no matched file has a recognized source suffix" in caplog.text
+    (read_path / "src" / "sketch.ino").write_text("")
+    (read_path / "src" / "ok.cpp").write_text("")
+    lib = component._library_info("x", read_path, {"build": {}})
+    assert [s.name for s in lib.sources] == ["ok.cpp"]
+    assert "not compiled: impl.CPP, sketch.ino" in caplog.text
+
+
+def test_library_info_header_only_src_stays_quiet(
+    tmp_path: Path, caplog: pytest.LogCaptureFixture
+) -> None:
+    """A header-only library (real headers in src/) is routine, not a
+    warning (the default +<*> filter matches the headers too)."""
+    read_path = tmp_path / "lib"
+    (read_path / "src").mkdir(parents=True)
+    (read_path / "src" / "ArduinoJson.h").write_text("")
+    (read_path / "keywords.txt").write_text("")
+    lib = component._library_info("x", read_path, {"build": {}})
+    assert lib.sources == []
+    assert "not compiled" not in caplog.text
+    assert "srcFilter" not in caplog.text
 
 
 def test_library_info_lib_archive_malformed_raises(tmp_path: Path) -> None:

tests/unit_tests/test_platformio_library.py

@@ -645,6 +645,9 @@ def test_normalize_dependencies_forms(caplog) -> None:
         {"name": "SPI"},
     ]
     assert normalize_dependencies("Wire") == [{"name": "Wire"}]
+    # A non-iterable value fails by manifest name, never a bare TypeError
+    assert normalize_dependencies(5, "libx") == []
+    assert "Ignoring unrecognized dependencies 5 of libx" in caplog.text
     # The dict-shorthand form validates names like the list form: an empty
     # key and a spec overriding name with a non-string both warn and drop
     assert normalize_dependencies(