Add C++ golden file test suite

compiler/back_end/cpp/BUILD

@@ -16,8 +16,7 @@
 
 load("@rules_python//python:py_binary.bzl", "py_binary")
 load("@rules_python//python:py_library.bzl", "py_library")
-load("@rules_python//python:py_test.bzl", "py_test")
-load(":build_defs.bzl", "emboss_cc_test")
+load(":build_defs.bzl", "cpp_golden_test", "emboss_cc_test")
 
 package(
     default_visibility = [
@@ -388,3 +387,213 @@ emboss_cc_test(
         "@com_google_googletest//:gtest_main",
     ],
 )
+
+# New golden test infrastructure
+py_library(
+    name = "one_golden_test_lib",
+    srcs = ["one_golden_test.py"],
+)
+
+py_binary(
+    name = "run_one_golden_test",
+    srcs = ["run_one_golden_test.py"],
+    deps = [":one_golden_test_lib"],
+)
+
+cpp_golden_test(
+    name = "anonymous_bits_golden_test",
+    emb_file = "//testdata:anonymous_bits.emb",
+    golden_file = "//testdata/golden_cpp:anonymous_bits.emb.h",
+)
+
+cpp_golden_test(
+    name = "bits_golden_test",
+    emb_file = "//testdata:bits.emb",
+    golden_file = "//testdata/golden_cpp:bits.emb.h",
+)
+
+cpp_golden_test(
+    name = "absolute_cpp_namespace_golden_test",
+    emb_file = "//testdata:absolute_cpp_namespace.emb",
+    golden_file = "//testdata/golden_cpp:absolute_cpp_namespace.emb.h",
+)
+
+cpp_golden_test(
+    name = "alignments_golden_test",
+    emb_file = "//testdata:alignments.emb",
+    golden_file = "//testdata/golden_cpp:alignments.emb.h",
+)
+
+cpp_golden_test(
+    name = "auto_array_size_golden_test",
+    emb_file = "//testdata:auto_array_size.emb",
+    golden_file = "//testdata/golden_cpp:auto_array_size.emb.h",
+)
+
+cpp_golden_test(
+    name = "bcd_golden_test",
+    emb_file = "//testdata:bcd.emb",
+    golden_file = "//testdata/golden_cpp:bcd.emb.h",
+)
+
+cpp_golden_test(
+    name = "complex_offset_golden_test",
+    emb_file = "//testdata:complex_offset.emb",
+    golden_file = "//testdata/golden_cpp:complex_offset.emb.h",
+)
+
+cpp_golden_test(
+    name = "complex_structure_golden_test",
+    emb_file = "//testdata:complex_structure.emb",
+    golden_file = "//testdata/golden_cpp:complex_structure.emb.h",
+)
+
+cpp_golden_test(
+    name = "condition_golden_test",
+    emb_file = "//testdata:condition.emb",
+    golden_file = "//testdata/golden_cpp:condition.emb.h",
+)
+
+cpp_golden_test(
+    name = "cpp_namespace_golden_test",
+    emb_file = "//testdata:cpp_namespace.emb",
+    golden_file = "//testdata/golden_cpp:cpp_namespace.emb.h",
+)
+
+cpp_golden_test(
+    name = "dynamic_size_golden_test",
+    emb_file = "//testdata:dynamic_size.emb",
+    golden_file = "//testdata/golden_cpp:dynamic_size.emb.h",
+)
+
+cpp_golden_test(
+    name = "enum_case_golden_test",
+    emb_file = "//testdata:enum_case.emb",
+    golden_file = "//testdata/golden_cpp:enum_case.emb.h",
+)
+
+cpp_golden_test(
+    name = "enum_golden_test",
+    emb_file = "//testdata:enum.emb",
+    golden_file = "//testdata/golden_cpp:enum.emb.h",
+)
+
+cpp_golden_test(
+    name = "explicit_sizes_golden_test",
+    emb_file = "//testdata:explicit_sizes.emb",
+    golden_file = "//testdata/golden_cpp:explicit_sizes.emb.h",
+)
+
+cpp_golden_test(
+    name = "float_golden_test",
+    emb_file = "//testdata:float.emb",
+    golden_file = "//testdata/golden_cpp:float.emb.h",
+)
+
+cpp_golden_test(
+    name = "imported_golden_test",
+    emb_file = "//testdata:imported.emb",
+    golden_file = "//testdata/golden_cpp:imported.emb.h",
+)
+
+cpp_golden_test(
+    name = "inline_type_golden_test",
+    emb_file = "//testdata:inline_type.emb",
+    golden_file = "//testdata/golden_cpp:inline_type.emb.h",
+)
+
+cpp_golden_test(
+    name = "int_sizes_golden_test",
+    emb_file = "//testdata:int_sizes.emb",
+    golden_file = "//testdata/golden_cpp:int_sizes.emb.h",
+)
+
+cpp_golden_test(
+    name = "large_array_golden_test",
+    emb_file = "//testdata:large_array.emb",
+    golden_file = "//testdata/golden_cpp:large_array.emb.h",
+)
+
+cpp_golden_test(
+    name = "nested_structure_golden_test",
+    emb_file = "//testdata:nested_structure.emb",
+    golden_file = "//testdata/golden_cpp:nested_structure.emb.h",
+)
+
+cpp_golden_test(
+    name = "next_keyword_golden_test",
+    emb_file = "//testdata:next_keyword.emb",
+    golden_file = "//testdata/golden_cpp:next_keyword.emb.h",
+)
+
+cpp_golden_test(
+    name = "no_cpp_namespace_golden_test",
+    emb_file = "//testdata:no_cpp_namespace.emb",
+    golden_file = "//testdata/golden_cpp:no_cpp_namespace.emb.h",
+)
+
+cpp_golden_test(
+    name = "no_enum_traits_golden_test",
+    emb_file = "//testdata:no_enum_traits.emb",
+    golden_file = "//testdata/golden_cpp:no_enum_traits.emb.h",
+)
+
+cpp_golden_test(
+    name = "parameters_golden_test",
+    emb_file = "//testdata:parameters.emb",
+    golden_file = "//testdata/golden_cpp:parameters.emb.h",
+)
+
+cpp_golden_test(
+    name = "requires_golden_test",
+    emb_file = "//testdata:requires.emb",
+    golden_file = "//testdata/golden_cpp:requires.emb.h",
+)
+
+cpp_golden_test(
+    name = "start_size_range_golden_test",
+    emb_file = "//testdata:start_size_range.emb",
+    golden_file = "//testdata/golden_cpp:start_size_range.emb.h",
+)
+
+cpp_golden_test(
+    name = "subtypes_golden_test",
+    emb_file = "//testdata:subtypes.emb",
+    golden_file = "//testdata/golden_cpp:subtypes.emb.h",
+)
+
+cpp_golden_test(
+    name = "text_format_golden_test",
+    emb_file = "//testdata:text_format.emb",
+    golden_file = "//testdata/golden_cpp:text_format.emb.h",
+)
+
+cpp_golden_test(
+    name = "uint_sizes_golden_test",
+    emb_file = "//testdata:uint_sizes.emb",
+    golden_file = "//testdata/golden_cpp:uint_sizes.emb.h",
+)
+
+cpp_golden_test(
+    name = "virtual_field_golden_test",
+    emb_file = "//testdata:virtual_field.emb",
+    golden_file = "//testdata/golden_cpp:virtual_field.emb.h",
+)
+
+cpp_golden_test(
+    name = "importer_golden_test",
+    emb_file = "//testdata:importer.emb",
+    golden_file = "//testdata/golden_cpp:importer.emb.h",
+)
+
+cpp_golden_test(
+    name = "importer2_golden_test",
+    emb_file = "//testdata:importer2.emb",
+    golden_file = "//testdata/golden_cpp:importer2.emb.h",
+)
+
+cpp_golden_test(
+    name = "imported_genfiles_golden_test",
+    emb_file = "//testdata:imported_genfiles.emb",
+    golden_file = "//testdata/golden_cpp:imported_genfiles.emb.h",
+)

compiler/back_end/cpp/build_defs.bzl

@@ -16,6 +16,8 @@
 # vim:set ft=blazebuild:
 """Rule to generate cc_tests with and without system-specific optimizations."""
 
+load("@rules_python//python:py_test.bzl", "py_test")
+
 def emboss_cc_test(name, copts = None, no_w_sign_compare = False, **kwargs):
     """Generates cc_test rules with and without -DEMBOSS_NO_OPTIMIZATIONS."""
     native.cc_test(
@@ -43,3 +45,33 @@ def emboss_cc_test(name, copts = None, no_w_sign_compare = False, **kwargs):
         ] + ([] if no_w_sign_compare else ["-Wsign-compare"]) + (copts or []),
         **kwargs
     )
+
+def cpp_golden_test(name, emb_file, golden_file, import_dirs = []):
+    """Defines a C++ golden file test.
+
+    Args:
+        name: The name of the test.
+        emb_file: The .emb file to test.
+        golden_file: The golden .h file.
+        import_dirs: A list of import directories.
+    """
+    py_test(
+        name = name,
+        main = ":run_one_golden_test.py",
+        srcs = [":run_one_golden_test.py", ":one_golden_test.py"],
+        tags = ["golden"],
+        args = [
+            "$(location //compiler/front_end:emboss_front_end)",
+            "$(location :emboss_codegen_cpp)",
+            "$(location %s)" % emb_file,
+            "$(location %s)" % golden_file,
+        ] + ["--import-dir=" + d for d in import_dirs],
+        data = [
+            "//compiler/front_end:emboss_front_end",
+            ":emboss_codegen_cpp",
+            emb_file,
+            golden_file,
+            "//testdata:test_embs",
+        ] + import_dirs,
+        deps = [":one_golden_test_lib"],
+    )

compiler/back_end/cpp/one_golden_test.py

@@ -0,0 +1,95 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import difflib
+import os
+import subprocess
+import sys
+import unittest
+
+
+class OneGoldenTest(unittest.TestCase):
+    def __init__(
+        self,
+        emboss_front_end,
+        emboss_compiler,
+        emb_file,
+        golden_file,
+        include_dirs=None,
+    ):
+        super(OneGoldenTest, self).__init__("test_golden_file")
+        self.emboss_front_end = emboss_front_end
+        self.emboss_compiler = emboss_compiler
+        self.emb_file = emb_file
+        self.golden_file = golden_file
+        self.include_dirs = include_dirs if include_dirs is not None else []
+
+    def test_golden_file(self):
+        temp_dir = os.environ.get("TEST_TMPDIR", "")
+        ir_path = os.path.join(temp_dir, "ir.json")
+        output_path = os.path.join(temp_dir, os.path.basename(self.golden_file))
+
+        front_end_args = [
+            self.emboss_front_end,
+            self.emb_file,
+            "--output-file",
+            ir_path,
+        ]
+        for include_dir in self.include_dirs:
+            front_end_args.extend(["--import-dir", include_dir])
+
+        process = subprocess.run(front_end_args, capture_output=True, text=True)
+        self.assertEqual(
+            process.returncode, 0, f"Front end failed with error:\n{process.stderr}"
+        )
+
+        compiler_args = [
+            self.emboss_compiler,
+            "--input-file",
+            ir_path,
+            "--output-file",
+            output_path,
+        ]
+
+        process = subprocess.run(compiler_args, capture_output=True, text=True)
+
+        self.assertEqual(
+            process.returncode, 0, f"Compiler failed with error:\n{process.stderr}"
+        )
+
+        with open(output_path, "r") as f:
+            generated_contents = f.read()
+
+        with open(self.golden_file, "r") as f:
+            golden_contents = f.read()
+
+        self.assertMultiLineEqual(
+            golden_contents,
+            generated_contents,
+            msg="Generated file does not match golden file. Diff:\n"
+            + "".join(
+                difflib.unified_diff(
+                    golden_contents.splitlines(keepends=True),
+                    generated_contents.splitlines(keepends=True),
+                    fromfile=self.golden_file,
+                    tofile="Generated C++ Header",
+                )
+            ),
+        )
+
+
+if __name__ == "__main__":
+    # This script is not intended to be run directly.
+    # It should be invoked by a test runner.
+    pass