Provision of prebuilt LLVM 10 for VS2022 (#4987)

CMakeLists.txt

@@ -2,7 +2,7 @@
 # The Taichi Programming Language
 #*********************************************************************
 
-cmake_minimum_required(VERSION 3.13)
+cmake_minimum_required(VERSION 3.15)
 
 project(taichi)
 
@@ -70,6 +70,19 @@ if (USE_MOLD)
     set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -fuse-ld=mold")
 endif()
 
+if (WIN32)
+  # For `Debug` configs MSVC links to a debuggable runtime by default which has
+  # symbol conflicts with the prebuilt LLVM in `Release`. We shoule be providing
+  # prebuilt LLVMs for both `Debug` and `Release` but LLVM 10 cannot be built by
+  # MSVC in `Debug` config because MSVC would try to fill uninitialize memory
+  # with `0xCC` but it too breaks `LLVMTableGen` which is depended on by almost
+  # every component in LLVM.
+  #
+  # FIXME: (penguinliong) This is fixed in later releases of LLVM so maybe
+  # someday we can distribute `Debug` libraries, if it's ever needed.
+  SET(CMAKE_MSVC_RUNTIME_LIBRARY MultiThreadedDLL)
+endif()
+
 # No support of Python for Android build
 if (NOT ANDROID)
     include(cmake/PythonNumpyPybind11.cmake)

build.ps1

@@ -3,6 +3,7 @@ param(
     [string] $BuildType = "Release",
     [string] $LlvmDir = "",
     [string] $ClangDir = "",
+    [string] $VisualStudioVersion = "",
     # Install python package in user-space.
     [switch] $UserSpace = $false,
     # Clean up compilation intermediates instead of building Taichi. Note that
@@ -45,12 +46,53 @@ function DownloadArchiveAndExpand($Uri, $ArchiveName) {
 
 
 
+# Identify Visual Studio version.
+if (-not $VisualStudioVersion) {
+    $VisualStudioVersion = (Get-CimInstance MSFT_VSInstance).Version.Split('.')[0]
+    Write-Host "Identified Visual Studio version from installation."
+}
+switch ($VisualStudioVersion) {
+    "2019" { $VisualStudioVersion = "16" }
+    "2022" { $VisualStudioVersion = "17" }
+}
+switch ($VisualStudioVersion) {
+    "16" {
+        Write-Host "Using MSVC from Visual Studio 2019."
+        $PrebuiltLlvmUri = "https://github.com/taichi-dev/taichi_assets/releases/download/llvm10/taichi-llvm-10.0.0-msvc2019.zip"
+        $LlvmArchiveName = "taichi-llvm-10.0.0-msvc2019"
+    }
+    "17" {
+        Write-Host "Using MSVC from Visual Studio 2022."
+        $PrebuiltLlvmUri = "https://github.com/taichi-dev/taichi_assets/releases/download/llvm10_msvc2022/taichi-llvm-10.0.0-msvc2022.zip"
+        $LlvmArchiveName = "taichi-llvm-10.0.0-msvc2022"
+    }
+    default {
+        Write-Error "Unsupported Visual Studio Version"
+    }
+}
+
 # Select build type, by default it's `Release`.
 switch ($BuildType) {
-    "Debug" { $env:DEBUG = 1; }
-    "Release" {}
-    "RelWithDebInfo" { $env:RELWITHDEBINFO = 1; }
-    "MinSizeRel" { $env:MINSIZEREL = 1; }
+    "Debug" {
+        $env:DEBUG = 1;
+        $env:RELWITHDEBINFO = 0;
+        $env:MINSIZEREL = 0;
+    }
+    "Release" {
+        $env:DEBUG = 0;
+        $env:RELWITHDEBINFO = 0;
+        $env:MINSIZEREL = 0;
+    }
+    "RelWithDebInfo" {
+        $env:DEBUG = 0;
+        $env:RELWITHDEBINFO = 1;
+        $env:MINSIZEREL = 0;
+    }
+    "MinSizeRel" {
+        $env:DEBUG = 0;
+        $env:RELWITHDEBINFO = 0;
+        $env:MINSIZEREL = 1;
+    }
     Default {
         Write-Error "Unknown build type '$BuildType'"
     }
@@ -63,8 +105,8 @@ if ($env:LLVM_DIR) {
     $LlvmDir = $env:LLVM_DIR;
 }
 if (-not $LlvmDir) {
-    DownloadArchiveAndExpand -Uri "https://github.com/taichi-dev/taichi_assets/releases/download/llvm10/taichi-llvm-10.0.0-msvc2019.zip" -ArchiveName "taichi-llvm"
-    $LlvmDir = "$TempDir/taichi-llvm"
+    DownloadArchiveAndExpand -Uri $PrebuiltLlvmUri -ArchiveName $LlvmArchiveName
+    $LlvmDir = "$TempDir/$LlvmArchiveName"
 }
 if (-not $LlvmDir -or -not (Test-Path $LlvmDir)) {
     throw "LLVM cannot be found in local environment and the script failed to download a prebuilt archive. " +

docs/lang/articles/contribution/dev_install.md

@@ -168,7 +168,7 @@ We provide pre-built, customized LLVM binaries. For now, Taichi supports LLVM 10
     {label: 'LLVM 10.0.0 for Linux', value: 'llvm_linux'},
     {label: 'LLVM 10.0.0 for macOS (without M1 chip)', value: 'llvm_macos_sans_m1'},
     {label: 'LLVM 10.0.0 for macOS (with M1 chip)', value: 'llvm_macos_m1'},
-    {label: 'LLVM 10.0.0 for Windows MSVC 2019', value: 'llvm_windows'},
+    {label: 'LLVM 10.0.0 for Windows', value: 'llvm_windows'},
   ]}>
 
 <TabItem value="llvm_linux">
@@ -182,6 +182,7 @@ We provide pre-built, customized LLVM binaries. For now, Taichi supports LLVM 10
 </TabItem>
 <TabItem value="llvm_windows">
     <a href="https://github.com/taichi-dev/taichi_assets/releases/download/llvm10/taichi-llvm-10.0.0-msvc2019.zip">LLVM 10.0.0 for Windows MSVC 2019</a>
+    <a href="https://github.com/taichi-dev/taichi_assets/releases/download/llvm10_msvc2022/taichi-llvm-10.0.0-msvc2022.zip">LLVM 10.0.0 for Windows MSVC 2022</a>
 </TabItem>
 </Tabs>
 
@@ -269,12 +270,13 @@ llvm-config --version  # You should get 10.0.0
 
 # LLVM 10.0.0 + MSVC 2019
 
-cmake .. -G "Visual Studio 16 2019" -A x64 -DLLVM_ENABLE_RTTI:BOOL=ON -DBUILD_SHARED_LIBS:BOOL=OFF   -DCMAKE_BUILD_TYPE=Release -DLLVM_TARGETS_TO_BUILD="X86;NVPTX" -DLLVM_ENABLE_ASSERTIONS=ON -Thost=x64   -DLLVM_BUILD_TESTS:BOOL=OFF -DCMAKE_INSTALL_PREFIX=installed
+cmake .. -G "Visual Studio 16 2019" -A x64 -DLLVM_ENABLE_RTTI:BOOL=ON -DBUILD_SHARED_LIBS:BOOL=OFF -DCMAKE_BUILD_TYPE=Release -DLLVM_TARGETS_TO_BUILD="X86;NVPTX" -DLLVM_ENABLE_ASSERTIONS=ON -Thost=x64 -DLLVM_BUILD_TESTS:BOOL=OFF -DCMAKE_INSTALL_PREFIX=installed -DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreadedDLL -DCMAKE_CXX_STANDARD=17
+cmake --build . --target=INSTALL --config=Release
 ```
 
 1. Use Visual Studio 2017+ to build **LLVM.sln**.
 2. Ensure that you use the **Release** configuration. After building the `INSTALL` project (under folde **CMakePredefinedTargets** in the Solution Explorer window).
-3. If you use MSVC 2019, ensure that you use **C++17** for the `INSTALL` project.
+3. If you use MSVC 2019+, ensure that you use **C++17** for the `INSTALL` project.
 4. When the build completes, add an environment variable `LLVM_DIR` with value `<PATH_TO_BUILD>/build/installed/lib/cmake/llvm`.
 
 </TabItem>