LLVM 20 bump

.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
 
@@ -138,7 +138,7 @@ jobs:
       fail-fast: false
       matrix:
         llvm:
-          - 19
+          - 20
     steps:
       - uses: actions/checkout@v4
         with:
@@ -166,7 +166,7 @@ jobs:
       fail-fast: false
       matrix:
         llvm:
-          - 19
+          - 20
     steps:
       - uses: actions/checkout@v4
         with:

PCbuild/get_externals.bat

@@ -82,7 +82,7 @@ if NOT "%IncludeLibffi%"=="false"  set binaries=%binaries% libffi-3.4.4
 if NOT "%IncludeSSL%"=="false"     set binaries=%binaries% openssl-bin-3.0.18
 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
+if NOT "%IncludeLLVM%"=="false"    set binaries=%binaries% llvm-20.1.8.0
 
 for %%b in (%binaries%) do (
     if exist "%EXTERNALS_DIR%\%%b" (
@@ -117,4 +117,4 @@ echo.anything new.
 echo.
 exit /b -1
 
-:end
+:end

PCbuild/regen.targets

@@ -187,4 +187,4 @@
   </Target>
 
   <Target Name="PostBuildRegen" DependsOnTargets="_RegenTestFrozenmain;_RegenLicense" />
-</Project>
+</Project>

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
 ```
 
 ### Dev Containers

Tools/jit/_llvm.py

@@ -10,9 +10,9 @@
 
 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"
+_EXTERNALS_LLVM_TAG = "llvm-20.1.8.0"
 
 _P = typing.ParamSpec("_P")
 _R = typing.TypeVar("_R")

Tools/jit/_targets.py

@@ -161,10 +161,6 @@ 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",
@@ -565,31 +561,32 @@ def get_target(host: str) -> _COFF32 | _COFF64 | _ELF | _MachO:
         host = "aarch64-unknown-linux-gnu"
         condition = "defined(__aarch64__) && defined(__linux__)"
         # -mno-outline-atomics: Keep intrinsics from being emitted.
-        args = ["-fpic", "-mno-outline-atomics"]
+        args = ["-fpic", "-mno-outline-atomics", "-fno-plt"]
         optimizer = _optimizers.OptimizerAArch64
         target = _ELF(host, condition, args=args, optimizer=optimizer)
     elif re.fullmatch(r"i686-pc-windows-msvc", host):
         host = "i686-pc-windows-msvc"
         condition = "defined(_M_IX86)"
         # -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
         target = _COFF32(host, condition, args=args, optimizer=optimizer)
     elif re.fullmatch(r"x86_64-apple-darwin.*", host):
         host = "x86_64-apple-darwin"
         condition = "defined(__x86_64__) && defined(__APPLE__)"
+        args = ["-fno-pic", "-mcmodel=medium", "-mlarge-data-threshold=0", "-fno-plt"]
         optimizer = _optimizers.OptimizerX86
         target = _MachO(host, condition, optimizer=optimizer)
     elif re.fullmatch(r"x86_64-pc-windows-msvc", host):
         host = "x86_64-pc-windows-msvc"
         condition = "defined(_M_X64)"
-        args = ["-fms-runtime-lib=dll"]
+        args = ["-fms-runtime-lib=dll", "-fno-plt"]
         optimizer = _optimizers.OptimizerX86
         target = _COFF64(host, condition, args=args, optimizer=optimizer)
     elif re.fullmatch(r"x86_64-.*-linux-gnu", host):
         host = "x86_64-unknown-linux-gnu"
         condition = "defined(__x86_64__) && defined(__linux__)"
-        args = ["-fno-pic", "-mcmodel=medium", "-mlarge-data-threshold=0"]
+        args = ["-fno-pic", "-mcmodel=medium", "-mlarge-data-threshold=0", "-fno-plt"]
         optimizer = _optimizers.OptimizerX86
         target = _ELF(host, condition, args=args, optimizer=optimizer)
     else: