add stuff

configure.py

@@ -0,0 +1,132 @@
+#!/usr/bin/env python3
+"""generates a Ninja build file
+
+usage:
+    python3 configure.py
+    python3 configure.py --asan      # enable address/undefined sanitizers
+    python3 configure.py --debug     # -O0 instead of -O2
+"""
+import argparse
+import os
+import shutil
+import sys
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parent
+SRC = ROOT / "src"
+BUILD = ROOT / "build"
+
+CXX = os.environ.get("CXX", "g++")
+CXXFLAGS = ["-std=c++20", "-O2", "-g"]
+WARNINGS = ["-Wall", "-Wextra", "-Wpedantic", "-Wshadow", "-Wconversion", "-Wnull-dereference"]
+linkflags = []
+
+def discover_sources():
+    return sorted(
+        p.name for p in SRC.glob("*.cpp")
+        if not p.name.endswith("_main.cpp") and not p.name.startswith(".")
+    )
+
+def write_makefile_convenience():
+    make = ROOT / "Makefile"
+    make.write_text(
+        """# convenience wrapper around configure.py + ninja.
+#
+#   make            -> configure + build
+#   make configure  -> regenerate build.ninja
+#   make clean      -> remove build dir
+#   make format     -> clang-format all sources (if available)
+#
+.PHONY: all configure clean format
+all: configure
+\t@ninja -C build
+
+configure:
+\t@python3 configure.py
+
+clean:
+\t@rm -rf build
+
+format:
+\t@command -v clang-format >/dev/null && clang-format -i src/*.cpp src/*.hpp || true
+""",
+        encoding="utf-8",
+    )
+
+
+def emit_ninja(cxx, cxxflags, dst):
+    sources = discover_sources()
+    objs = ["obj/" + Path(s).stem + ".o" for s in sources]
+    target = "bajia"
+
+    rule_cxx = (
+        "rule cxx\n"
+        "  command = {cxx} {cxxflags} -MMD -MF $out.d -c $in -o $out\n"
+        "  depfile = $out.d\n"
+        "  deps = gcc\n"
+        "  description = CXX $out\n"
+    ).format(cxx=cxx, cxxflags=" ".join(cxxflags))
+
+    rule_link = (
+        "rule link\n"
+        "  command = {cxx} {ldflags} $in -o $out -lpthread\n"
+        "  description = LINK $out\n"
+    ).format(cxx=cxx, ldflags=" ".join(linkflags))
+
+    lines = ["# generated by configure.py -- do not edit", "ninja_required_version = 1.8", ""]
+    lines.append(rule_cxx)
+    lines.append(rule_link)
+    lines.append('build {target}: link {objs}'.format(target=target, objs=" ".join(objs)))
+    lines.append("")
+    for o, s in zip(objs, sources):
+        lines.append('build {o}: cxx {src}/{s}'.format(o=o, src=SRC, s=s))
+    lines.append("")
+    lines.append('build all: phony {target}'.format(target=target))
+    lines.append("default all")
+    lines.append("")
+
+    (BUILD / "obj").mkdir(exist_ok=True)
+    dst.write_text("\n".join(lines) + "\n", encoding="utf-8")
+
+def parse_args():
+    p = argparse.ArgumentParser(description="Configure bajia build (generates build.ninja)")
+    p.add_argument("--asan", action="store_true", help="enable address + UB sanitizers")
+    p.add_argument("--debug", action="store_true", help="disable -O2, enable -O0")
+    p.add_argument("--clean", action="store_true", help="remove build dir")
+    return p.parse_args()
+
+def main():
+    args = parse_args()
+    if args.clean:
+        shutil.rmtree(BUILD, ignore_errors=True)
+        print("removed build/")
+        return 0
+
+    if not shutil.which("ninja"):
+        print("error: ninja not found in PATH", file=sys.stderr)
+        return 1
+
+    BUILD.mkdir(exist_ok=True)
+
+    cxxflags = list(CXXFLAGS)
+    global linkflags
+    linkflags = []
+    if args.debug:
+        cxxflags = [f for f in cxxflags if f != "-O2"]
+        cxxflags += ["-O0"]
+    if args.asan:
+        cxxflags += ["-fsanitize=address,undefined", "-fno-omit-frame-pointer"]
+        linkflags += ["-fsanitize=address,undefined"]
+
+    cxxflags = [f for f in cxxflags if f not in WARNINGS]
+    cxxflags = WARNINGS + cxxflags
+
+    emit_ninja(CXX, cxxflags, BUILD / "build.ninja")
+    write_makefile_convenience()
+
+    print(f"configured {len(discover_sources())} sources -> build/build.ninja")
+    print("run: ninja -C build")
+    return 0
+
+if __name__ == "__main__":
+    sys.exit(main())