feat: bundle LLVM on Windows

.github/workflows/ci.yml

@@ -28,6 +28,7 @@ jobs:
             release: true
             shell: nix-shell --arg pkgs "import (fetchTarball \"channel:nixos-19.03\") {{}}" --argstr llvmPackages latest --run "bash -euxo pipefail {0}"
             llvm-url: https://github.com/llvm/llvm-project/releases/download/llvmorg-13.0.0/clang+llvm-13.0.0-x86_64-linux-gnu-ubuntu-16.04.tar.xz
+            prepare-llvm: script/prepare-llvm-linux.sh clang*.tar.*
           - name: Linux
             os: ubuntu-latest
             check-stage3: true
@@ -52,6 +53,7 @@ jobs:
             CMAKE_OPTIONS: -G "Unix Makefiles" -DAUTO_THREAD_FINALIZATION=OFF
             # for reasons unknown, interactivetests are flaky on Windows
             CTEST_OPTIONS: --repeat until-pass:2
+            prepare-llvm: script/prepare-llvm-mingw.sh
       # complete all jobs
       fail-fast: false
     name: ${{ matrix.name }}
@@ -103,10 +105,8 @@ jobs:
           mkdir build
           cd build
           OPTIONS=()
-          if [[ '${{ matrix.llvm-url }}' && "${{ matrix.name }}" == "Linux release" ]]; then
-            wget -q ${{ matrix.llvm-url }}
-            eval "OPTIONS+=($(../script/prepare-llvm-linux.sh clang*.tar.*))"
-          fi
+          [[ -z '${{ matrix.llvm-url }}' ]] || wget -q ${{ matrix.llvm-url }}
+          [[ -z '${{ matrix.prepare-llvm }}' ]] || eval "OPTIONS+=($(../${{ matrix.prepare-llvm }}))"
           if [[ $GITHUB_EVENT_NAME == 'schedule' && -n '${{ matrix.release }}' && -n '${{ secrets.PUSH_NIGHTLY_TOKEN }}' ]]; then
             git remote add nightly https://foo:'${{ secrets.PUSH_NIGHTLY_TOKEN }}'@github.com/${{ github.repository_owner }}/lean4-nightly.git
             git fetch nightly --tags
@@ -120,11 +120,10 @@ jobs:
           # contortion to support empty OPTIONS with old macOS bash
           cmake .. ${{ matrix.CMAKE_OPTIONS }} ${OPTIONS[@]+"${OPTIONS[@]}"}
           make -j4
-      - name: Check binaries
-        if: matrix.name == 'Linux release'
+      - name: Check Binaries
+        if: matrix.os != 'macos-latest'
         run: |
           ldd -v build/stage1/bin/* || true
-          ls -l build/stage1/lib/
       - name: Patch
         if: matrix.name == 'macOS'
         run: |
@@ -136,18 +135,6 @@ jobs:
             otool -L $f
           done
           ls -l lib/
-      - name: Patch
-        if: matrix.name == 'Windows'
-        run: |
-          cd build/stage1
-          cp $(ldd bin/lean.exe | cut -f3 -d' ' | grep mingw) bin/
-          ldd bin/lean.exe
-          ls -l bin/
-      - name: Test Binary without Nix Shell
-        if: matrix.name != 'Windows'
-        shell: bash {0}
-        run: |
-          build/stage1/bin/lean -h
       - name: Pack
         run: |
           cd build/stage1

script/prepare-llvm-mingw.sh

@@ -0,0 +1,37 @@
+#!/usr/bin/env bash
+set -uo pipefail
+
+# use with clang64 MinGW shell!
+# run from root build directory (from inside nix-shell or otherwise defining GLIBC/GCC_DEV/GCC_LIBS/GMP) as in
+# ```
+# eval cmake ../.. $(../../script/prepare-llvm-mingw.sh)
+# ```
+
+# use full mingw clang for compiling C++ code, but subset for compiling C code and distribution
+
+root="$(realpath .)/stage1"
+mkdir -p stage1/{bin,lib,lib/windows,include/clang}
+# a C compiler!
+cp $(which clang) stage1/bin/
+# a linker!
+cp $(which ld.lld) stage1/bin/
+# many dependencies!
+cp $(ldd stage1/bin/* | cut -f3 -d' ' | grep clang64) stage1/bin
+# lean.h dependencies
+cp /clang64/lib/clang/*/include/{std*,__std*,limits}.h stage1/include/clang
+# single Windows dependency
+echo '
+// https://docs.microsoft.com/en-us/windows/win32/api/errhandlingapi/nf-errhandlingapi-seterrormode
+#define SEM_FAILCRITICALERRORS 0x0001
+__declspec(dllimport) __stdcall unsigned int SetErrorMode(unsigned int uMode);' > stage1/include/clang/windows.h
+# COFF dependencies
+cp /clang64/x86_64-w64-mingw32/lib/{crtbegin,crtend,crt2,dllcrt2}.o stage1/lib/
+# further dependencies
+cp /clang64/x86_64-w64-mingw32/lib/lib{m,bcrypt,mingw32,moldname,mingwex,msvcrt,pthread,advapi32,shell32,user32,kernel32}.* /clang64/lib/lib{c++,gmp,unwind}.* stage1/lib/
+(cd /clang64; cp --parents lib/clang/*/lib/windows/libclang_rt.builtins-x86_64.a "$root")
+cp /clang64/bin/libgmp-* stage1/bin/
+echo -n " -DLEAN_USE_LIBCXX=ON"
+echo -n " -DLEANC_INTERNAL_FLAGS='--sysroot ROOT -I ROOT/include/clang' -DLEANC_CC=ROOT/bin/clang.exe -DCMAKE_C_COMPILER=$PWD/stage1/bin/clang.exe"
+echo -n " -DLEANC_INTERNAL_LINKER_FLAGS='-L ROOT/lib -fuse-ld=ROOT/bin/ld.lld.exe'"
+echo -n " -DAUTO_THREAD_FINALIZATION=OFF -DSTAGE0_AUTO_THREAD_FINALIZATION=OFF"
+#echo -n " -DLEAN_TEST_VARS='LD_LIBRARY_PATH=$PWD/stage1/lib:\${LD_LIBRARY_PATH:-}'"