Drop the app archive from ldgen_libraries too and add a fragment check

tests/unit_tests/test_espidf_framework.py

@@ -876,6 +876,9 @@ _LDGEN_CMAKE_STOCK = """\
 function(__ldgen_create_target exe_target)
     idf_build_get_property(python PYTHON)
 
+    list(JOIN ldgen_libraries_expr "\\n" ldgen_libraries_str)
+    file(WRITE ${build_dir}/ldgen_libraries.in "${ldgen_libraries_str}")
+
     add_custom_command(
         OUTPUT ${output}
         COMMAND ${python} "${idf_path}/tools/ldgen/ldgen.py"
@@ -899,6 +902,10 @@ def test_patch_ldgen_cmake_inserts_guarded_filter(tmp_path: Path) -> None:
     _patch_ldgen_cmake(tmp_path)
     content = ldgen_cmake.read_text(encoding="utf-8")
     assert _LDGEN_DEP_FILTER in content
+    # The libraries list must be filtered before it is serialized to disk
+    assert content.index("REMOVE_ITEM ldgen_libraries_expr") < content.index(
+        "list(JOIN ldgen_libraries_expr"
+    )
     assert "DEPENDS     ${template}" in content
 
 
@@ -931,8 +938,9 @@ def test_patch_ldgen_cmake_unreadable_file_warns_and_skips(
             id="no_ldgen_deps",
         ),
         pytest.param(
-            _LDGEN_CMAKE_STOCK + "\n    add_custom_command(\n        OUTPUT x)\n",
-            id="duplicate_command",
+            _LDGEN_CMAKE_STOCK
+            + '\n    list(JOIN ldgen_libraries_expr "\\n" ldgen_libraries_str)\n',
+            id="duplicate_join",
         ),
     ],
 )

tests/unit_tests/test_espidf_toolchain.py

@@ -623,6 +623,45 @@ def test_component_cache_ignores_corrupt_file(setup_core: Path, tmp_path: Path)
         assert toolchain.load_cached_builtin_components() is None
 
 
+def _write_fragments_build_ninja(tmp_path: Path, fragments: list[Path]) -> None:
+    build_dir = CORE.relative_build_path("build")
+    build_dir.mkdir(parents=True, exist_ok=True)
+    frag_list = ";".join(str(f) for f in fragments)
+    (build_dir / "build.ninja").write_text(
+        f'  COMMAND = python ldgen.py --fragments-list "{frag_list}" --input x\n'
+    )
+
+
+def test_warn_if_app_archive_mapped_warns(
+    setup_core: Path, tmp_path: Path, caplog: pytest.LogCaptureFixture
+) -> None:
+    """A fragment naming the app archive triggers the loud warning."""
+    _setup_build(setup_core)
+    frag = tmp_path / "linker.lf"
+    frag.write_text("[mapping:evil]\narchive: libsrc.a\nentries:\n    * (noflash)\n")
+    _write_fragments_build_ninja(tmp_path, [frag])
+    toolchain._warn_if_app_archive_mapped()
+    assert "maps the app archive" in caplog.text
+
+
+def test_warn_if_app_archive_mapped_clean(
+    setup_core: Path, tmp_path: Path, caplog: pytest.LogCaptureFixture
+) -> None:
+    """Normal fragments produce no warning; missing files are non-fatal."""
+    _setup_build(setup_core)
+    frag = tmp_path / "linker.lf"
+    frag.write_text("[mapping:freertos]\narchive: libfreertos.a\n")
+    _write_fragments_build_ninja(tmp_path, [frag, tmp_path / "missing.lf"])
+    toolchain._warn_if_app_archive_mapped()
+    assert "maps the app archive" not in caplog.text
+
+
+def test_warn_if_app_archive_mapped_no_build_ninja(setup_core: Path) -> None:
+    """No build.ninja yet is a quiet no-op."""
+    _setup_build(setup_core)
+    toolchain._warn_if_app_archive_mapped()
+
+
 def test_run_compile_passes_compile_process_limit(setup_core: Path) -> None:
     """compile_process_limit is forwarded to run_idf_py as the job limit."""
     _setup_build(setup_core)