From 96c59a6e427fab32d0bca89b77febca8cba8aada Mon Sep 17 00:00:00 2001 From: danigm Date: Tue, 7 Oct 2025 16:54:31 +0200 Subject: [PATCH] gh-138497: Support LLVM_VERSION configuration via env (#138498) Co-authored-by: Savannah Ostrowski --- ...-09-04-12-16-31.gh-issue-138497.Y_5YXh.rst | 4 ++ Tools/jit/README.md | 2 +- Tools/jit/_llvm.py | 49 ++++++++++++------- Tools/jit/_targets.py | 19 +++++-- Tools/jit/build.py | 3 ++ configure | 2 +- configure.ac | 2 +- 7 files changed, 56 insertions(+), 25 deletions(-) create mode 100644 Misc/NEWS.d/next/Build/2025-09-04-12-16-31.gh-issue-138497.Y_5YXh.rst --- /dev/null +++ b/Misc/NEWS.d/next/Build/2025-09-04-12-16-31.gh-issue-138497.Y_5YXh.rst @@ -0,0 +1,4 @@ +The LLVM version used by the JIT at build time can now be modified using +the ``LLVM_VERSION`` environment variable. Use this at your own risk, as +there is only one officially supported LLVM version. For more information, +please check ``Tools/jit/README.md``. --- a/Tools/jit/README.md +++ b/Tools/jit/README.md @@ -9,7 +9,7 @@ The JIT compiler does not require end users to install any third-party dependencies, but part of it must be *built* using LLVM[^why-llvm]. You are *not* required to build the rest of CPython using LLVM, or even the same version of LLVM (in fact, this is uncommon). -LLVM version 19 is required. Both `clang` and `llvm-readobj` need to be installed and discoverable (version suffixes, like `clang-19`, are okay). It's highly recommended that you also have `llvm-objdump` available, since this allows the build script to dump human-readable assembly for the generated code. +LLVM version 19 is the officially supported version. You can modify if needed using the `LLVM_VERSION` env var during configure. Both `clang` and `llvm-readobj` need to be installed and discoverable (version suffixes, like `clang-19`, are okay). It's highly recommended that you also have `llvm-objdump` available, since this allows the build script to dump human-readable assembly for the generated code. It's easy to install all of the required tools: --- a/Tools/jit/_llvm.py +++ b/Tools/jit/_llvm.py @@ -10,8 +10,8 @@ import _targets -_LLVM_VERSION = 19 -_LLVM_VERSION_PATTERN = re.compile(rf"version\s+{_LLVM_VERSION}\.\d+\.\d+\S*\s+") + +_LLVM_VERSION = "21" _EXTERNALS_LLVM_TAG = "llvm-19.1.7.0" _P = typing.ParamSpec("_P") @@ -56,53 +56,66 @@ @_async_cache -async def _check_tool_version(name: str, *, echo: bool = False) -> bool: +async def _check_tool_version( + name: str, llvm_version: str, *, echo: bool = False +) -> bool: output = await _run(name, ["--version"], echo=echo) - return bool(output and _LLVM_VERSION_PATTERN.search(output)) + _llvm_version_pattern = re.compile(rf"version\s+{llvm_version}\.\d+\.\d+\S*\s+") + return bool(output and _llvm_version_pattern.search(output)) @_async_cache -async def _get_brew_llvm_prefix(*, echo: bool = False) -> str | None: - output = await _run("brew", ["--prefix", f"llvm@{_LLVM_VERSION}"], echo=echo) +async def _get_brew_llvm_prefix(llvm_version: str, *, echo: bool = False) -> str | None: + output = await _run("brew", ["--prefix", f"llvm@{llvm_version}"], echo=echo) return output and output.removesuffix("\n") @_async_cache -async def _find_tool(tool: str, *, echo: bool = False) -> str | None: +async def _find_tool(tool: str, llvm_version: str, *, echo: bool = False) -> str | None: # Unversioned executables: path = tool - if await _check_tool_version(path, echo=echo): + if await _check_tool_version(path, llvm_version, echo=echo): return path # Versioned executables: - path = f"{tool}-{_LLVM_VERSION}" - if await _check_tool_version(path, echo=echo): + path = f"{tool}-{llvm_version}" + if await _check_tool_version(path, llvm_version, echo=echo): return path # PCbuild externals: externals = os.environ.get("EXTERNALS_DIR", _targets.EXTERNALS) path = os.path.join(externals, _EXTERNALS_LLVM_TAG, "bin", tool) - if await _check_tool_version(path, echo=echo): + if await _check_tool_version(path, llvm_version, echo=echo): return path # Homebrew-installed executables: - prefix = await _get_brew_llvm_prefix(echo=echo) + prefix = await _get_brew_llvm_prefix(llvm_version, echo=echo) if prefix is not None: path = os.path.join(prefix, "bin", tool) - if await _check_tool_version(path, echo=echo): + if await _check_tool_version(path, llvm_version, echo=echo): return path # Nothing found: return None async def maybe_run( - tool: str, args: typing.Iterable[str], echo: bool = False + tool: str, + args: typing.Iterable[str], + echo: bool = False, + llvm_version: str = _LLVM_VERSION, ) -> str | None: """Run an LLVM tool if it can be found. Otherwise, return None.""" - path = await _find_tool(tool, echo=echo) + + path = await _find_tool(tool, llvm_version, echo=echo) return path and await _run(path, args, echo=echo) -async def run(tool: str, args: typing.Iterable[str], echo: bool = False) -> str: +async def run( + tool: str, + args: typing.Iterable[str], + echo: bool = False, + llvm_version: str = _LLVM_VERSION, +) -> str: """Run an LLVM tool if it can be found. Otherwise, raise RuntimeError.""" - output = await maybe_run(tool, args, echo=echo) + + output = await maybe_run(tool, args, echo=echo, llvm_version=llvm_version) if output is None: - raise RuntimeError(f"Can't find {tool}-{_LLVM_VERSION}!") + raise RuntimeError(f"Can't find {tool}-{llvm_version}!") return output --- a/Tools/jit/_targets.py +++ b/Tools/jit/_targets.py @@ -48,6 +48,7 @@ debug: bool = False verbose: bool = False cflags: str = "" + llvm_version: str = _llvm._LLVM_VERSION known_symbols: dict[str, int] = dataclasses.field(default_factory=dict) pyconfig_dir: pathlib.Path = pathlib.Path.cwd().resolve() @@ -79,7 +80,9 @@ async def _parse(self, path: pathlib.Path) -> _stencils.StencilGroup: group = _stencils.StencilGroup() args = ["--disassemble", "--reloc", f"{path}"] - output = await _llvm.maybe_run("llvm-objdump", args, echo=self.verbose) + output = await _llvm.maybe_run( + "llvm-objdump", args, echo=self.verbose, llvm_version=self.llvm_version + ) if output is not None: # Make sure that full paths don't leak out (for reproducibility): long, short = str(path), str(path.name) @@ -97,7 +100,9 @@ "--sections", f"{path}", ] - output = await _llvm.run("llvm-readobj", args, echo=self.verbose) + output = await _llvm.run( + "llvm-readobj", args, echo=self.verbose, llvm_version=self.llvm_version + ) # --elf-output-style=JSON is only *slightly* broken on Mach-O... output = output.replace("PrivateExtern\n", "\n") output = output.replace("Extern\n", "\n") @@ -164,7 +169,7 @@ # Allow user-provided CFLAGS to override any defaults *shlex.split(self.cflags), ] - await _llvm.run("clang", args, echo=self.verbose) + await _llvm.run("clang", args, echo=self.verbose, llvm_version=self.llvm_version) return await self._parse(o) async def _build_stencils(self) -> dict[str, _stencils.StencilGroup]: @@ -212,6 +217,8 @@ if not self.stable: warning = f"JIT support for {self.triple} is still experimental!" request = "Please report any issues you encounter.".center(len(warning)) + if self.llvm_version != _llvm._LLVM_VERSION: + request = f"Warning! Building with an LLVM version other than {_llvm._LLVM_VERSION} is not supported." outline = "=" * len(warning) print("\n".join(["", outline, warning, request, outline, ""])) digest = f"// {self._compute_digest()}\n" --- a/Tools/jit/build.py +++ b/Tools/jit/build.py @@ -42,6 +42,7 @@ parser.add_argument( "--cflags", help="additional flags to pass to the compiler", default="" ) + parser.add_argument("--llvm-version", help="LLVM version to use") args = parser.parse_args() for target in args.target: target.debug = args.debug @@ -49,6 +50,8 @@ target.verbose = args.verbose target.cflags = args.cflags target.pyconfig_dir = args.pyconfig_dir + if args.llvm_version: + target.llvm_version = args.llvm_version target.build( comment=comment, force=args.force, --- a/configure.ac +++ b/configure.ac @@ -2787,7 +2787,7 @@ [], [AS_VAR_APPEND([CFLAGS_NODIST], [" $jit_flags"]) AS_VAR_SET([REGEN_JIT_COMMAND], - ["\$(PYTHON_FOR_REGEN) \$(srcdir)/Tools/jit/build.py ${ARCH_TRIPLES:-$host} --output-dir . --pyconfig-dir . --cflags=\"$CFLAGS_JIT\""]) + ["\$(PYTHON_FOR_REGEN) \$(srcdir)/Tools/jit/build.py ${ARCH_TRIPLES:-$host} --output-dir . --pyconfig-dir . --cflags=\"$CFLAGS_JIT\" --llvm-version=\"$LLVM_VERSION\""]) AS_VAR_SET([JIT_STENCILS_H], ["jit_stencils.h"]) AS_VAR_IF([Py_DEBUG], [true],