Improve dependencies superbuild for Windows

mrexodia · mrexodia · commit 87de6179f9b1 · 2025-12-01T18:52:00.000+01:00
Closes lifting-bits#735
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
@@ -58,7 +58,7 @@ jobs:
 
         - name: Build dependencies
           run: |
-            cmake -G Ninja -S dependencies -B dependencies/build -DUSE_EXTERNAL_LLVM=ON "-DCMAKE_PREFIX_PATH=$LLVM_PREFIX"
+            cmake -G Ninja -S dependencies -B dependencies/build -DUSE_EXTERNAL_LLVM=ON "-DCMAKE_PREFIX_PATH:PATH=$LLVM_PREFIX"
             cmake --build dependencies/build
 
         - name: Python venv for tests
@@ -69,7 +69,7 @@ jobs:
         - name: Build remill
           run: |
             . .venv/bin/activate
-            cmake -G Ninja -B build "-DCMAKE_PREFIX_PATH=$LLVM_PREFIX;$PWD/dependencies/install" "-DCMAKE_INSTALL_PREFIX=$PWD/install"
+            cmake -G Ninja -B build "-DCMAKE_PREFIX_PATH:PATH=$PWD/dependencies/install" "-DCMAKE_INSTALL_PREFIX=$PWD/install"
             cmake --build build
 
         - name: Install remill
@@ -116,7 +116,7 @@ jobs:
 
         - name: Build dependencies
           run: |
-            cmake -G Ninja -S dependencies -B dependencies/build -DUSE_EXTERNAL_LLVM=ON "-DCMAKE_PREFIX_PATH=$LLVM_PREFIX"
+            cmake -G Ninja -S dependencies -B dependencies/build -DUSE_EXTERNAL_LLVM=ON "-DCMAKE_PREFIX_PATH:PATH=$LLVM_PREFIX"
             cmake --build dependencies/build
 
         - name: Python venv for tests
@@ -127,7 +127,7 @@ jobs:
         - name: Build remill
           run: |
             . .venv/bin/activate
-            cmake -G Ninja -B build "-DCMAKE_PREFIX_PATH=$LLVM_PREFIX;$PWD/dependencies/install" "-DCMAKE_INSTALL_PREFIX=$PWD/install"
+            cmake -G Ninja -B build "-DCMAKE_PREFIX_PATH:PATH=$PWD/dependencies/install" "-DCMAKE_INSTALL_PREFIX=$PWD/install"
             cmake --build build
 
         - name: Install remill
diff --git a/README.md b/README.md
@@ -68,21 +68,21 @@ cmake -G Ninja -S dependencies -B dependencies/build
 cmake --build dependencies/build
 
 # Step 2: Build remill
-cmake -G Ninja -B build -DCMAKE_PREFIX_PATH=$(pwd)/dependencies/install -DCMAKE_BUILD_TYPE=Release
+cmake -G Ninja -B build -DCMAKE_PREFIX_PATH:PATH=$(pwd)/dependencies/install -DCMAKE_BUILD_TYPE=Release
 cmake --build build
 ```
 
-### Windows (requires clang or clang-cl)
+### Windows (requires clang-cl)
 
 **Note**: This requires running from a Visual Studio developer prompt.
 
 ```bash
 # Step 1: Build dependencies
-cmake -G Ninja -S dependencies -B dependencies/build -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++
+cmake -G Ninja -S dependencies -B dependencies/build -DCMAKE_C_COMPILER=clang-cl -DCMAKE_CXX_COMPILER=clang-cl
 cmake --build dependencies/build
 
 # Step 2: Build remill
-cmake -G Ninja -B build -DCMAKE_PREFIX_PATH=%CD%/dependencies/install -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_BUILD_TYPE=Release
+cmake -G Ninja -B build -DCMAKE_PREFIX_PATH:PATH=%CD%/dependencies/install -DCMAKE_C_COMPILER=clang-cl -DCMAKE_CXX_COMPILER=clang-cl -DCMAKE_BUILD_TYPE=Release
 cmake --build build
 ```
 
@@ -94,11 +94,11 @@ brew install llvm@17
 LLVM_PREFIX=$(brew --prefix llvm@17)
 
 # Build dependencies with external LLVM
-cmake -G Ninja -S dependencies -B dependencies/build -DUSE_EXTERNAL_LLVM=ON "-DCMAKE_PREFIX_PATH=$LLVM_PREFIX"
+cmake -G Ninja -S dependencies -B dependencies/build -DUSE_EXTERNAL_LLVM=ON "-DCMAKE_PREFIX_PATH:PATH=$LLVM_PREFIX"
 cmake --build dependencies/build
 
 # Build remill
-cmake -G Ninja -B build "-DCMAKE_PREFIX_PATH=$LLVM_PREFIX;$(pwd)/dependencies/install" -DCMAKE_BUILD_TYPE=Release
+cmake -G Ninja -B build "-DCMAKE_PREFIX_PATH:PATH=$(pwd)/dependencies/install" -DCMAKE_BUILD_TYPE=Release
 cmake --build build
 ```
 
@@ -110,6 +110,6 @@ cmake -G Ninja -S dependencies -B dependencies/build -DUSE_EXTERNAL_LLVM=ON
 cmake --build dependencies/build
 
 # Build remill
-cmake -G Ninja -B build "-DCMAKE_PREFIX_PATH=$LLVM_PREFIX;$(pwd)/dependencies/install" -DCMAKE_BUILD_TYPE=Release
+cmake -G Ninja -B build "-DCMAKE_PREFIX_PATH:PATH=$(pwd)/dependencies/install" -DCMAKE_BUILD_TYPE=Release
 cmake --build build
 ```
diff --git a/dependencies/CMakeLists.txt b/dependencies/CMakeLists.txt
@@ -51,6 +51,22 @@ simple_git(https://github.com/google/googletest v1.17.0
 
 include(xed.cmake)
 
-if(NOT USE_EXTERNAL_LLVM)
+set(LLVM_CONFIG "${CMAKE_INSTALL_PREFIX}/lib/cmake/llvm/LLVMConfig.cmake")
+if(USE_EXTERNAL_LLVM)
+    # Create a forwarding LLVMConfig.cmake file that adds the external LLVM to CMAKE_PREFIX_PATH
+    # and then includes the external LLVMConfig.cmake
+    if(NOT EXISTS "${LLVM_DIR}/LLVMConfig.cmake")
+        message(FATAL_ERROR "LLVMConfig.cmake not found in LLVM_DIR (${LLVM_DIR})")
+    endif()
+    file(WRITE "${CMAKE_INSTALL_PREFIX}/lib/cmake/llvm/LLVMConfig.cmake"
+        "if(NOT \"${LLVM_INSTALL_PREFIX}\" IN_LIST CMAKE_PREFIX_PATH)\n"
+        "  list(PREPEND CMAKE_PREFIX_PATH \"${LLVM_INSTALL_PREFIX}\")\n"
+        "  set(CMAKE_PREFIX_PATH \"\${CMAKE_PREFIX_PATH}\" CACHE PATH \"\" FORCE)\n"
+        "  message(STATUS \"Updating CMAKE_PREFIX_PATH: \${CMAKE_PREFIX_PATH}\")\n"
+        "endif()\n"
+        "include(\"${LLVM_DIR}/LLVMConfig.cmake\")\n"
+    )
+else()
+    file(REMOVE "${LLVM_CONFIG}")
     include(llvm.cmake)
 endif()
diff --git a/dependencies/README.md b/dependencies/README.md
@@ -9,4 +9,4 @@ cmake -B build -DCMAKE_BUILD_TYPE=Release
 cmake --build build
 ```
 
-This will create a [CMake prefix](https://cmake.org/cmake/help/latest/command/find_package.html#search-procedure), which you pass to your project with `-DCMAKE_PREFIX_PATH=/path/to/dependencies/install`. See [presentation.md](https://github.com/LLVMParty/packages/blob/main/presentation.md) and [dependencies.md](https://github.com/LLVMParty/packages/blob/main/dependencies.md) for more information.
+This will create a [CMake prefix](https://cmake.org/cmake/help/latest/command/find_package.html#search-procedure), which you pass to your project with `-DCMAKE_PREFIX_PATH:FILEPATH=/path/to/dependencies/install`. See [presentation.md](https://github.com/LLVMParty/packages/blob/main/presentation.md) and [dependencies.md](https://github.com/LLVMParty/packages/blob/main/dependencies.md) for more information.
diff --git a/dependencies/llvm.cmake b/dependencies/llvm.cmake
@@ -21,6 +21,29 @@ set(LLVM_ARGS
     "-DLLVM_LINK_LLVM_DYLIB:STRING=${BUILD_SHARED_LIBS}"
 )
 
+# LLVM has a bug on Windows where using clang.exe as the compiler fails to detect
+# the host target triple, so we have to specify it manually.
+# Reference: https://github.com/lifting-bits/remill/issues/735#issuecomment-3590986077
+if(WIN32)
+    if(CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND NOT CMAKE_CXX_COMPILER_FRONTEND_VARIANT MATCHES "^MSVC$")
+        message(WARNING
+            "Using clang.exe as the compiler on Windows is not well supported.\n"
+            "If you run into issues, use clang-cl instead:\n"
+            "  cmake -DCMAKE_C_COMPILER=clang-cl -DCMAKE_CXX_COMPILER=clang-cl ...\n"
+        )
+        if(CMAKE_SIZEOF_VOID_P EQUAL 8)
+            if(CMAKE_SYSTEM_PROCESSOR MATCHES "^(ARM64|arm64|aarch64)$")
+                set(LLVM_ARCH "aarch64")
+            else()
+                set(LLVM_ARCH "x86_64")
+            endif()
+        else()
+            set(LLVM_ARCH "i686")
+        endif()
+        list(APPEND LLVM_ARGS "-DLLVM_HOST_TRIPLE:STRING=${LLVM_ARCH}-pc-windows-msvc")
+    endif()
+endif()
+
 if(USE_SANITIZERS)
     list(APPEND LLVM_ARGS "-DLLVM_USE_SANITIZER:STRING=Address;Undefined")
 endif()
diff --git a/dependencies/superbuild.cmake b/dependencies/superbuild.cmake
@@ -20,11 +20,37 @@ message(STATUS "Configuration: ${CMAKE_BUILD_TYPE}")
 if(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
     set(CMAKE_INSTALL_PREFIX "${CMAKE_CURRENT_BINARY_DIR}/../install" CACHE PATH "Install prefix" FORCE)
 endif()
+cmake_path(ABSOLUTE_PATH CMAKE_INSTALL_PREFIX NORMALIZE)
+set(CMAKE_INSTALL_PREFIX "${CMAKE_INSTALL_PREFIX}" CACHE PATH "Install prefix" FORCE)
 message(STATUS "Install prefix: ${CMAKE_INSTALL_PREFIX}")
 
-# Save the host platform in the install prefix
-make_directory(${CMAKE_INSTALL_PREFIX})
-file(TOUCH ${CMAKE_INSTALL_PREFIX}/${CMAKE_SYSTEM}.build)
+# Verify build configuration hasn't changed
+set(BUILD_CONFIG_FILE "${CMAKE_INSTALL_PREFIX}/.build_config")
+string(JOIN "\n" CURRENT_BUILD_CONFIG
+    "CMAKE_SYSTEM=${CMAKE_SYSTEM}"
+    "CMAKE_SYSTEM_PROCESSOR=${CMAKE_SYSTEM_PROCESSOR}"
+    "CMAKE_CXX_COMPILER_ID=${CMAKE_CXX_COMPILER_ID}"
+    "CMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}"
+    "CMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}"
+)
+
+if(EXISTS "${BUILD_CONFIG_FILE}")
+    file(READ "${BUILD_CONFIG_FILE}" PREVIOUS_BUILD_CONFIG)
+    if(NOT PREVIOUS_BUILD_CONFIG STREQUAL CURRENT_BUILD_CONFIG)
+        message(FATAL_ERROR
+            "Build configuration changed!\n"
+            "[previous]\n${PREVIOUS_BUILD_CONFIG}\n"
+            "[current]\n${CURRENT_BUILD_CONFIG}\n"
+            "\n"
+            "Please delete the build and install directories, then reconfigure:\n"
+            "  cmake -E rm -rf \"${CMAKE_BINARY_DIR}\"\n"
+            "  cmake -E rm -rf \"${CMAKE_INSTALL_PREFIX}\"\n"
+        )
+    endif()
+else()
+    file(MAKE_DIRECTORY "${CMAKE_INSTALL_PREFIX}")
+    file(WRITE "${BUILD_CONFIG_FILE}" "${CURRENT_BUILD_CONFIG}")
+endif()
 
 # Git is necessary for submodules
 find_package(Git REQUIRED)
@@ -87,21 +113,30 @@ list(JOIN ADDITIONAL_FLAGS " " ADDITIONAL_FLAGS)
 
 # Default cache variables for all projects
 list(APPEND CMAKE_ARGS
-    "-DCMAKE_PREFIX_PATH:FILEPATH=${CMAKE_INSTALL_PREFIX};${CMAKE_PREFIX_PATH}"
-    "-DCMAKE_INSTALL_PREFIX:FILEPATH=${CMAKE_INSTALL_PREFIX}"
+    "-DCMAKE_PREFIX_PATH:PATH=${CMAKE_INSTALL_PREFIX};${CMAKE_PREFIX_PATH}"
+    "-DCMAKE_INSTALL_PREFIX:PATH=${CMAKE_INSTALL_PREFIX}"
     "-DCMAKE_BUILD_TYPE:STRING=${CMAKE_BUILD_TYPE}"
     "-DBUILD_SHARED_LIBS:STRING=${BUILD_SHARED_LIBS}"
     "-DCMAKE_C_COMPILER:FILEPATH=${CMAKE_C_COMPILER}"
     "-DCMAKE_CXX_COMPILER:FILEPATH=${CMAKE_CXX_COMPILER}"
     "-DCMAKE_C_FLAGS:STRING=${CMAKE_C_FLAGS} ${ADDITIONAL_FLAGS}"
     "-DCMAKE_CXX_FLAGS:STRING=${CMAKE_CXX_FLAGS} ${ADDITIONAL_FLAGS}"
+    "-DCMAKE_POSITION_INDEPENDENT_CODE:STRING=ON"
+    "-DCMAKE_ERROR_DEPRECATED:STRING=OFF"
+    "-DCMAKE_ERROR_DEVELOPER_WARNINGS:STRING=OFF"
 )
 
+if(CMAKE_VERSION VERSION_GREATER_EQUAL "4.0")
+    list(APPEND CMAKE_ARGS
+        "-DCMAKE_POLICY_VERSION_MINIMUM:STRING=${CMAKE_MINIMUM_REQUIRED_VERSION}"
+    )
+endif()
+
 if(CMAKE_C_COMPILER_LAUNCHER)
-    list(APPEND CMAKE_ARGS "-DCMAKE_C_COMPILER_LAUNCHER:STRING=${CMAKE_C_COMPILER_LAUNCHER}")
+    list(APPEND CMAKE_ARGS "-DCMAKE_C_COMPILER_LAUNCHER:FILEPATH=${CMAKE_C_COMPILER_LAUNCHER}")
 endif()
 if(CMAKE_CXX_COMPILER_LAUNCHER)
-    list(APPEND CMAKE_ARGS "-DCMAKE_CXX_COMPILER_LAUNCHER:STRING=${CMAKE_CXX_COMPILER_LAUNCHER}")
+    list(APPEND CMAKE_ARGS "-DCMAKE_CXX_COMPILER_LAUNCHER:FILEPATH=${CMAKE_CXX_COMPILER_LAUNCHER}")
 endif()
 
 message(STATUS "Compiling all dependencies with the following CMake arguments:")
