feat: migrate over to meson

1 files changed, 128 insertions, 0 deletions

diff --git a/tools/fetch_llvm.py b/tools/fetch_llvm.py
new file mode 100644
index 0000000..8a596a8
--- /dev/null
+++ b/tools/fetch_llvm.py
@@ -0,0 +1,128 @@
+#!/usr/bin/env python3
+# Download the pinned LLVM release and unpack it into ext/llvm, mirroring the old
+# premake5.lua `fetch-llvm` action. Run this once before `meson setup` on a
+# machine without a suitable LLVM install:
+#
+#   python3 tools/fetch_llvm.py
+#
+# It is a no-op when ext/llvm already carries the LLDB headers.
+
+import os
+import platform
+import shutil
+import sys
+import tarfile
+import urllib.request
+
+LLVM_VERSION = "22.1.0"
+
+REPO_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+EXT = os.path.join(REPO_ROOT, "ext")
+VENDORED = os.path.join(EXT, "llvm")
+STAGING = os.path.join(EXT, "llvm-staging")
+
+
+def is_arm():
+    machine = platform.machine().lower()
+    return machine in ("arm64", "aarch64")
+
+
+def release_asset():
+    host = platform.system()
+
+    if host == "Darwin":
+        # LLVM only publishes an Apple-silicon macOS binary
+        return f"LLVM-{LLVM_VERSION}-macOS-ARM64.tar.xz" if is_arm() else None
+
+    if host == "Linux":
+        arch = "ARM64" if is_arm() else "X64"
+        return f"LLVM-{LLVM_VERSION}-Linux-{arch}.tar.xz"
+
+    if host == "Windows":
+        arch = "aarch64" if is_arm() else "x86_64"
+        return f"clang+llvm-{LLVM_VERSION}-{arch}-pc-windows-msvc.tar.xz"
+
+    return None
+
+
+def download(url, dest):
+    print("downloading " + url)
+    reported = [0]
+
+    def hook(block, block_size, total):
+        current = block * block_size
+        if total > 0 and current - reported[0] >= total / 20:
+            reported[0] = current
+            pct = min(100, int(current / total * 100))
+            print(f"  {pct}% ({current / 1048576:.0f} mb)")
+
+    tmp = dest + ".part"
+    try:
+        urllib.request.urlretrieve(url, tmp, hook)
+    except OSError as error:
+        if os.path.isfile(tmp):
+            os.remove(tmp)
+        raise SystemExit(f"download failed: {error}")
+    os.replace(tmp, dest)
+
+
+def extract(archive, dest):
+    print("extracting " + os.path.basename(archive))
+    try:
+        with tarfile.open(archive, "r:xz") as tar:
+            tar.extractall(dest)
+        return
+    except (tarfile.TarError, OSError, EOFError) as error:
+        # some stripped-down Pythons lack the lzma module; fall back to system tar
+        print(f"  python extraction failed ({error}), trying system tar")
+
+    if os.system(f'tar -xf "{archive}" -C "{dest}"') != 0:
+        raise SystemExit(
+            f"could not extract {archive}; unpack it into {VENDORED} by hand"
+        )
+
+
+def main():
+    if os.path.isdir(os.path.join(VENDORED, "include", "lldb")):
+        print(f"{VENDORED} already has an llvm with lldb headers")
+        return 0
+
+    asset = release_asset()
+    if asset is None:
+        raise SystemExit(
+            f"no pinned llvm release for {platform.system()} "
+            f"{platform.machine()}; install llvm yourself and set LLVM_PREFIX"
+        )
+
+    archive = os.path.join(EXT, asset)
+    if not os.path.isfile(archive):
+        url = (
+            "https://github.com/llvm/llvm-project/releases/download/"
+            f"llvmorg-{LLVM_VERSION}/{asset}"
+        )
+        download(url, archive)
+
+    shutil.rmtree(STAGING, ignore_errors=True)
+    os.makedirs(STAGING)
+    extract(archive, STAGING)
+
+    unpacked = [
+        os.path.join(STAGING, name)
+        for name in os.listdir(STAGING)
+        if os.path.isdir(os.path.join(STAGING, name))
+    ]
+    if not unpacked:
+        raise SystemExit(f"{archive} did not contain an llvm directory")
+
+    shutil.rmtree(VENDORED, ignore_errors=True)
+    os.rename(unpacked[0], VENDORED)
+
+    shutil.rmtree(STAGING, ignore_errors=True)
+    os.remove(archive)
+
+    print(f"llvm {LLVM_VERSION} is ready in {VENDORED}")
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())