LLVM 20 bump

Author: savannahostrowski

.github/workflows/jit.yml

@@ -68,7 +68,7 @@ jobs:
           - true
           - false
         llvm:
-          - 19
+          - 20
         include:
           - target: i686-pc-windows-msvc/msvc
             architecture: Win32
@@ -99,10 +99,10 @@ jobs:
         with:
           python-version: '3.11'
 
-      # PCbuild downloads LLVM automatically:
       - name: Windows
         if: runner.os == 'Windows'
         run: |
+          choco install llvm --allow-downgrade --no-progress --version ${{ matrix.llvm }}.1.8
           ./PCbuild/build.bat --experimental-jit ${{ matrix.debug && '-d' || '' }} -p ${{ matrix.architecture }}
           ./PCbuild/rt.bat ${{ matrix.debug && '-d' || '' }} -p ${{ matrix.architecture }} -q --multiprocess 0 --timeout 4500 --verbose2 --verbose3
 
@@ -143,7 +143,7 @@ jobs:
       fail-fast: false
       matrix:
         llvm:
-          - 19
+          - 20
     steps:
       - uses: actions/checkout@v4
         with:
@@ -171,7 +171,7 @@ jobs:
   #     fail-fast: false
   #     matrix:
   #       llvm:
-  #         - 19
+  #         - 20
   #   steps:
   #     - uses: actions/checkout@v4
   #       with:

PCbuild/build.bat

@@ -111,7 +111,6 @@ if "%IncludeExternals%"=="" set IncludeExternals=true
 if "%IncludeCTypes%"=="" set IncludeCTypes=true
 if "%IncludeSSL%"=="" set IncludeSSL=true
 if "%IncludeTkinter%"=="" set IncludeTkinter=true
-if "%UseJIT%" NEQ "true" set IncludeLLVM=false
 
 if "%IncludeExternals%"=="true" call "%dir%get_externals.bat"
 

PCbuild/get_externals.bat

@@ -15,7 +15,6 @@ set IncludeSSLSrc=false
 if "%~1"=="--no-tkinter" (set IncludeTkinter=false) & shift & goto CheckOpts
 if "%~1"=="--no-openssl" (set IncludeSSL=false) & shift & goto CheckOpts
 if "%~1"=="--no-libffi" (set IncludeLibffi=false) & shift & goto CheckOpts
-if "%~1"=="--no-llvm" (set IncludeLLVM=false) & shift & goto CheckOpts
 if "%~1"=="--tkinter-src" (set IncludeTkinterSrc=true) & shift & goto CheckOpts
 if "%~1"=="--openssl-src" (set IncludeSSLSrc=true) & shift & goto CheckOpts
 if "%~1"=="--libffi-src" (set IncludeLibffiSrc=true) & shift & goto CheckOpts
@@ -82,7 +81,6 @@ if NOT "%IncludeLibffi%"=="false"  set binaries=%binaries% libffi-3.4.4
 if NOT "%IncludeSSL%"=="false"     set binaries=%binaries% openssl-bin-3.0.16.2
 if NOT "%IncludeTkinter%"=="false" set binaries=%binaries% tcltk-8.6.15.0
 if NOT "%IncludeSSLSrc%"=="false"  set binaries=%binaries% nasm-2.11.06
-if NOT "%IncludeLLVM%"=="false"    set binaries=%binaries% llvm-19.1.7.0
 
 for %%b in (%binaries%) do (
     if exist "%EXTERNALS_DIR%\%%b" (
@@ -101,7 +99,7 @@ goto end
 
 :usage
 echo.Valid options: -c, --clean, --clean-only, --organization, --python,
-echo.--no-tkinter, --no-openssl, --no-llvm
+echo.--no-tkinter, --no-openssl
 echo.
 echo.Pull all sources and binaries necessary for compiling optional extension
 echo.modules that rely on external libraries.

Tools/jit/README.md

@@ -9,32 +9,32 @@ Python 3.11 or newer is required to build the JIT.
 
 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 20 is required. Both `clang` and `llvm-readobj` need to be installed and discoverable (version suffixes, like `clang-20`, 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:
 
 ### Linux
 
-Install LLVM 19 on Ubuntu/Debian:
+Install LLVM 20 on Ubuntu/Debian:
 
 ```sh
 wget https://apt.llvm.org/llvm.sh
 chmod +x llvm.sh
-sudo ./llvm.sh 19
+sudo ./llvm.sh 20
 ```
 
-Install LLVM 19 on Fedora Linux 40 or newer:
+Install LLVM 20 on Fedora Linux 40 or newer:
 
 ```sh
-sudo dnf install 'clang(major) = 19' 'llvm(major) = 19'
+sudo dnf install 'clang(major) = 20' 'llvm(major) = 20'
 ```
 
 ### macOS
 
-Install LLVM 19 with [Homebrew](https://brew.sh):
+Install LLVM 20 with [Homebrew](https://brew.sh):
 
 ```sh
-brew install llvm@19
+brew install llvm@20
 ```
 
 Homebrew won't add any of the tools to your `$PATH`. That's okay; the build script knows how to find them.
@@ -43,12 +43,12 @@ Homebrew won't add any of the tools to your `$PATH`. That's okay; the build scri
 
 LLVM is downloaded automatically (along with other external binary dependencies) by `PCbuild\build.bat`.
 
-Otherwise, you can install LLVM 19 [by searching for it on LLVM's GitHub releases page](https://github.com/llvm/llvm-project/releases?q=19), clicking on "Assets", downloading the appropriate Windows installer for your platform (likely the file ending with `-win64.exe`), and running it. **When installing, be sure to select the option labeled "Add LLVM to the system PATH".**
+Otherwise, you can install LLVM 20 [by searching for it on LLVM's GitHub releases page](https://github.com/llvm/llvm-project/releases?q=20), clicking on "Assets", downloading the appropriate Windows installer for your platform (likely the file ending with `-win64.exe`), and running it. **When installing, be sure to select the option labeled "Add LLVM to the system PATH".**
 
 Alternatively, you can use [chocolatey](https://chocolatey.org):
 
 ```sh
-choco install llvm --version=19.1.0
+choco install llvm --version=20.1.8
 ```
 
 

Tools/jit/_llvm.py

@@ -8,11 +8,8 @@
 import subprocess
 import typing
 
-import _targets
-
-_LLVM_VERSION = 19
+_LLVM_VERSION = 20
 _LLVM_VERSION_PATTERN = re.compile(rf"version\s+{_LLVM_VERSION}\.\d+\.\d+\S*\s+")
-_EXTERNALS_LLVM_TAG = "llvm-19.1.7.0"
 
 _P = typing.ParamSpec("_P")
 _R = typing.TypeVar("_R")
@@ -75,11 +72,6 @@ async def _find_tool(tool: str, *, echo: bool = False) -> str | None:
         return path
     # Versioned executables:
     path = f"{tool}-{_LLVM_VERSION}"
-    if await _check_tool_version(path, 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):
         return path
     # Homebrew-installed executables:

Tools/jit/_targets.py

@@ -25,7 +25,6 @@
 TOOLS_JIT = TOOLS_JIT_BUILD.parent
 TOOLS = TOOLS_JIT.parent
 CPYTHON = TOOLS.parent
-EXTERNALS = CPYTHON / "externals"
 PYTHON_EXECUTOR_CASES_C_H = CPYTHON / "Python" / "executor_cases.c.h"
 TOOLS_JIT_TEMPLATE_C = TOOLS_JIT / "template.c"
 
@@ -161,10 +160,6 @@ async def _compile(
             "-fno-asynchronous-unwind-tables",
             # Don't call built-in functions that we can't find or patch:
             "-fno-builtin",
-            # Emit relaxable 64-bit calls/jumps, so we don't have to worry about
-            # about emitting in-range trampolines for out-of-range targets.
-            # We can probably remove this and emit trampolines in the future:
-            "-fno-plt",
             # Don't call stack-smashing canaries that we can't find or patch:
             "-fno-stack-protector",
             "-std=c11",
@@ -561,13 +556,13 @@ def get_target(host: str) -> _COFF32 | _COFF64 | _ELF | _MachO:
         target = _COFF64(host, condition, args=args, optimizer=optimizer)
     elif re.fullmatch(r"aarch64-.*-linux-gnu", host):
         # -mno-outline-atomics: Keep intrinsics from being emitted.
-        args = ["-fpic", "-mno-outline-atomics"]
+        args = ["-fpic", "-mno-outline-atomics", "-fno-plt"]
         condition = "defined(__aarch64__) && defined(__linux__)"
         optimizer = _optimizers.OptimizerAArch64
         target = _ELF(host, condition, args=args, optimizer=optimizer)
     elif re.fullmatch(r"i686-pc-windows-msvc", host):
         # -Wno-ignored-attributes: __attribute__((preserve_none)) is not supported here.
-        args = ["-DPy_NO_ENABLE_SHARED", "-Wno-ignored-attributes"]
+        args = ["-DPy_NO_ENABLE_SHARED", "-Wno-ignored-attributes", "-fno-plt"]
         optimizer = _optimizers.OptimizerX86
         condition = "defined(_M_IX86)"
         target = _COFF32(host, condition, args=args, optimizer=optimizer)
@@ -576,12 +571,12 @@ def get_target(host: str) -> _COFF32 | _COFF64 | _ELF | _MachO:
         optimizer = _optimizers.OptimizerX86
         target = _MachO(host, condition, optimizer=optimizer)
     elif re.fullmatch(r"x86_64-pc-windows-msvc", host):
-        args = ["-fms-runtime-lib=dll"]
+        args = ["-fms-runtime-lib=dll", "-fno-plt"]
         condition = "defined(_M_X64)"
         optimizer = _optimizers.OptimizerX86
         target = _COFF64(host, condition, args=args, optimizer=optimizer)
     elif re.fullmatch(r"x86_64-.*-linux-gnu", host):
-        args = ["-fno-pic", "-mcmodel=medium", "-mlarge-data-threshold=0"]
+        args = ["-fno-pic", "-mcmodel=medium", "-mlarge-data-threshold=0", "-fno-plt"]
         condition = "defined(__x86_64__) && defined(__linux__)"
         optimizer = _optimizers.OptimizerX86
         target = _ELF(host, condition, args=args, optimizer=optimizer)