Initial Commit

scripts/build_test.py

@@ -0,0 +1,105 @@
+#!/usr/bin/env python3
+"""Assemble one tests/<name>/program.asm and generate its golden (Expected outputs)."""
+
+from __future__ import annotations
+
+import argparse
+import os
+from pathlib import Path
+import shutil
+import struct
+import subprocess
+
+from rv32_model import RV32Model, read_words, write_words
+
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+
+
+def find_assembler(explicit: str | None) -> str:
+    candidates = [
+        explicit,
+        os.environ.get("RISCV_AS"),
+        REPO_ROOT / "scripts" / "riscv-none-elf-as",
+        "riscv-none-elf-as",
+        "riscv32-unknown-elf-as",
+        "riscv64-unknown-elf-as",
+    ]
+    for candidate in candidates:
+        if not candidate:
+            continue
+        candidate = str(candidate)
+        resolved = shutil.which(candidate)
+        if resolved:
+            return resolved
+        path = Path(candidate)
+        try:
+            if path.is_file() and os.access(path, os.X_OK):
+                return str(path)
+        except OSError:
+            continue
+    raise RuntimeError(
+        "RISC-V GNU assembler not found; "
+        "or set RISCV_AS=/path/to/riscv-*-as"
+    )
+
+
+def elf_text(path: Path) -> bytes:
+    image = path.read_bytes()
+    if image[:4] != b"\x7fELF" or image[4] != 1 or image[5] != 1:
+        raise RuntimeError(f"{path} is not a little-endian ELF32 object")
+    section_offset = struct.unpack_from("<I", image, 32)[0]
+    section_size = struct.unpack_from("<H", image, 46)[0]
+    section_count = struct.unpack_from("<H", image, 48)[0]
+    names_index = struct.unpack_from("<H", image, 50)[0]
+    names_header = section_offset + names_index * section_size
+    names_offset, names_size = struct.unpack_from("<II", image, names_header + 16)
+    names = image[names_offset:names_offset + names_size]
+
+    for index in range(section_count):
+        header = section_offset + index * section_size
+        name_index = struct.unpack_from("<I", image, header)[0]
+        end = names.find(b"\0", name_index)
+        name = names[name_index:end].decode()
+        if name == ".text":
+            offset, size = struct.unpack_from("<II", image, header + 16)
+            return image[offset:offset + size]
+    raise RuntimeError(f"{path} has no .text section")
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser()
+    parser.add_argument("test_dir", type=Path)
+    parser.add_argument("--assembler")
+    parser.add_argument("--max-instructions", type=int, default=10000)
+    args = parser.parse_args()
+
+    test_dir = args.test_dir.resolve()
+    source = test_dir / "program.asm"
+    if not source.is_file():
+        raise RuntimeError(f"missing required {source}")
+
+    assembler = find_assembler(args.assembler)
+    obj = test_dir / "program.o"
+    subprocess.run(
+        [assembler, "-march=rv32i", "-mabi=ilp32", "-mno-relax", str(source), "-o", str(obj)],
+        check=True,
+    )
+    text = elf_text(obj)
+    if len(text) % 4:
+        raise RuntimeError(".text size is not a multiple of four bytes")
+    program = [int.from_bytes(text[i:i + 4], "little") for i in range(0, len(text), 4)]
+    program_path = test_dir / "program.hex"
+    write_words(program_path, program)
+
+    data_path = test_dir / "data.hex"
+    initial_data = read_words(data_path if data_path.exists() else None)
+    model = RV32Model(program, initial_data)
+    count = model.run(args.max_instructions)
+    write_words(test_dir / "expected_regs.hex", model.regs)
+    write_words(test_dir / "expected_data.hex", model.data_words())
+    print(f"Built {test_dir.name}: {len(program)} words, halted after {count} instructions")
+
+
+if __name__ == "__main__":
+    main()