fix bugs

Author: saidctb

tests/parser/test_cli.py

@@ -285,8 +285,9 @@ def test_cli_formats_parse_errors_without_traceback(tmp_path: Path):
     assert res.returncode == 1
     assert res.stdout == ""
     assert "Traceback" not in res.stderr
-    assert f"{f90}:2:1: error[PARSE_UNSUPPORTED_DECLARATION]:" in res.stderr
-    assert "2 |   weirdtype :: x" in res.stderr
+    assert f"{f90}:" in res.stderr
+    assert "error[PARSE_UNSUPPORTED_DECLARATION]:" in res.stderr
+    assert "|   weirdtype :: x" in res.stderr
 
 
 def test_cli_debug_flag_reraises_parse_errors(tmp_path: Path):
@@ -369,7 +370,8 @@ def test_cli_no_color_env_disables_default_ansi(tmp_path: Path):
 
     assert res.returncode == 1
     assert "\033[" not in res.stderr
-    assert f"{f90}:2:1: error[PARSE_UNSUPPORTED_DECLARATION]:" in res.stderr
+    assert f"{f90}:" in res.stderr
+    assert "error[PARSE_UNSUPPORTED_DECLARATION]:" in res.stderr
 
 
 def test_cli_semantics_out_writes_json_without_stdout(tmp_path: Path):

tests/parser/test_preprocessing_cli.py

@@ -143,6 +143,22 @@ def test_direct_fortran_preprocess_invocation_uses_exact_compiler_and_cpp(tmp_pa
     )
 
 
+def test_direct_fortran_preprocess_invocation_hints_unknown_suffix_language(tmp_path: Path):
+    source = tmp_path / "solver.source"
+    config = PreprocessingConfig(mode="compiler", compiler="/usr/bin/gfortran-12")
+
+    invocation = build_direct_preprocess_invocation(source, language="fortran", config=config)
+
+    assert invocation.argv == [
+        "/usr/bin/gfortran-12",
+        "-E",
+        "-cpp",
+        "-x",
+        "f95-cpp-input",
+        str(source),
+    ]
+
+
 def test_preprocessing_config_internal_macros_recipe_and_validation(tmp_path: Path):
     source = tmp_path / "source.F90"
     plain = PreprocessingConfig()

x2py/preprocessing.py

@@ -376,6 +376,12 @@ def _preprocessor_options(config: PreprocessingConfig, *, language: str, include
     return args
 
 
+def _fortran_source_language_hint(source: Path) -> list[str]:
+    if source.suffix.lower() in _FORTRAN_SOURCE_SUFFIXES:
+        return []
+    return ["-x", "f95-cpp-input"]
+
+
 class GCCCompatibleCAdapter:
     name = "gcc-compatible-c"
     capabilities: ClassVar[dict[str, bool]] = {"dependency_output": True, "macro_dump": True, "linemarkers": True}
@@ -431,6 +437,7 @@ def build_direct_preprocess_invocation(
     argv = [
         compiler,
         *_preprocessor_options(config, language=language, include_language_flag=language == "c"),
+        *(_fortran_source_language_hint(source) if language == "fortran" else []),
         str(source),
     ]
     adapter = "gnu-fortran" if language == "fortran" else "gcc-compatible-c"