added 'making a C compiler' dir

2025/making_a_c_compiler/compiler_driver.py

@@ -0,0 +1,76 @@
+from pathlib import Path
+import subprocess
+import sys
+from typing import Sequence
+
+from lexer import Token, TokenWithValue, lex as _lex
+
+
+def preprocess(fn: str) -> str:
+    output_fn = fn + ".i"
+    subprocess.run(f"gcc -E -P {fn} -o {output_fn}", shell=True)
+    return output_fn
+
+
+def lex(fn) -> Sequence[Token | TokenWithValue]:
+    return _lex(Path(fn).read_text())
+
+
+def parse(tokens: list[Token | TokenWithValue]):
+    pass
+
+
+def generate_assembly():
+    pass
+
+
+def emit_code(fn):
+    subprocess.run(f"gcc {fn} -o {fn.split('.')[0]}")
+    Path(fn).unlink()
+
+
+FLAGS = "--lex, --parse, --codegen".split(", ")
+
+
+def main():
+    args = sys.argv
+    len_args = len(args)
+    skip_parse, skip_codegen, skip_emit = False, False, False
+    if len_args < 2:
+        print("please provide an input filename")
+        sys.exit(1)
+    elif len_args > 3:
+        print("provide one of --lex, --parse, --codegen, or no flags")
+        sys.exit(1)
+    elif len_args == 3:
+        flag = args[2].strip()
+        if flag not in FLAGS:
+            print("provide one of --lex, --parse, --codegen, or no flags")
+            sys.exit(1)
+        match flag:
+            case "--lex":
+                skip_parse = True
+                skip_codegen = True
+                skip_emit = True
+            case "--parse":
+                skip_codegen = True
+                skip_emit = True
+            case "--codegen":
+                skip_emit = True
+    fn = args[1]
+    print("preprocessing")
+    fni = preprocess(fn)
+    print("lexing")
+    tokens = lex(fni)
+    if not skip_parse:
+        print("parsing")
+        parse(tokens)
+    if not skip_codegen:
+        print("generating assembly (codegen)")
+        generate_assembly()
+    if not skip_emit:
+        emit_code()
+
+
+if __name__ == "__main__":
+    main()