mingw-w64-cross-clang: add idea for discussion

this is basically a prototype

mingw-w64-cross-clang/PKGBUILD

@@ -0,0 +1,89 @@
+declare -g -A _cross_arches=(
+  ["/clang64"]="x86_64-w64-mingw32"
+  ["/clang32"]="i686-w64-mingw32"
+  ["/clangarm64"]="aarch64-w64-mingw32"
+)
+pkgbase=mingw-w64-cross-clang
+pkgname=($(for _pfx in "${!_cross_arches[@]}"; do
+             if [[ "${_cross_arches[$_pfx]%%-*}" != "${CARCH}" ]]; then
+               echo "${MINGW_PACKAGE_PREFIX}-cross-clang-${_cross_arches[$_pfx]%%-*}"
+             fi
+           done))
+pkgver=13.0.0
+pkgrel=1
+arch=('any')
+mingw_arch=('mingw32' 'mingw64' 'ucrt64' 'clang64' 'clang32' 'clangarm64')
+license=('ISC')
+makedepends=("${MINGW_PACKAGE_PREFIX}-gcc")
+# this is unused but necessary to make CI happy
+depends=("${MINGW_PACKAGE_PREFIX}-clang=${pkgver}"
+         "${MINGW_PACKAGE_PREFIX}-cross-compiler-rt=${pkgver}")
+source=("native-wrapper.h"
+        "llvm-wrapper.c"
+        "clang-target-wrapper.c"
+        "dlltool-wrapper.c"
+        "windres-wrapper.c")
+sha256sums=('c9758342cb926605cd1b30ccb92e6b47f5cc930a15904462e0445959f9be49c1'
+            'd6bafc72309860e7a45a91047b5e4c4519b52d6d685069f77094ef6cc09385e5'
+            '10587323d163abe0ca1f094cba1c991ef8bbed71cde7a9b94ddbe36ae3e2868f'
+            '2adee7d81d71a167d28fc508e8b3427f63e7c064f08ca63fe330476e8ae4a2c8'
+            'b121e52bc752396f887e8e6a97138117fc9c2ee4f7efbe9f5ca2be4f451b6f45')
+build() {
+  CC=${CC:-cc}
+  cd "${srcdir}"
+
+  [[ -d "build-${MSYSTEM}" ]] && rm -rf "build-${MSYSTEM}"
+  mkdir "build-${MSYSTEM}" && cd "build-${MSYSTEM}"
+
+  for _pfx in "${!_cross_arches[@]}"; do
+    if [[ "${_cross_arches[$_pfx]%%-*}" != "${CARCH}" ]]; then
+      MSYS2_ARG_CONV_EXCL="-DSYSROOT=" \
+      $CC $CPPFLAGS $CFLAGS $LDFLAGS -municode -DDEFAULT_TARGET="\"${_cross_arches[$_pfx]}\"" -DSYSROOT="\"${_pfx}\"" ../llvm-wrapper.c -o ${_cross_arches[$_pfx]}-llvm-wrapper.exe
+      MSYS2_ARG_CONV_EXCL="-DSYSROOT=" \
+      $CC $CPPFLAGS $CFLAGS $LDFLAGS -municode -DDEFAULT_TARGET="\"${_cross_arches[$_pfx]}\"" -DSYSROOT="\"${_pfx}\"" ../clang-target-wrapper.c -o ${_cross_arches[$_pfx]}-clang.exe
+      MSYS2_ARG_CONV_EXCL="-DSYSROOT=" \
+      $CC $CPPFLAGS $CFLAGS $LDFLAGS -municode -DDEFAULT_TARGET="\"${_cross_arches[$_pfx]}\"" -DSYSROOT="\"${_pfx}\"" ../dlltool-wrapper.c -o ${_cross_arches[$_pfx]}-dlltool.exe
+      MSYS2_ARG_CONV_EXCL="-DSYSROOT=" \
+      $CC $CPPFLAGS $CFLAGS $LDFLAGS -municode -DDEFAULT_TARGET="\"${_cross_arches[$_pfx]}\"" -DSYSROOT="\"${_pfx}\"" ../windres-wrapper.c -o ${_cross_arches[$_pfx]}-windres.exe
+    fi
+  done
+}
+_real_package() {
+  local _pfx="@@@PREFIX@@@"
+  depends=("${MINGW_PACKAGE_PREFIX}-clang=${pkgver}"
+           "${MINGW_PACKAGE_PREFIX}-cross-compiler-rt=${pkgver}"
+           "${MINGW_PACKAGE_PREFIX}-llvm=${pkgver}"
+           "${MINGW_PACKAGE_PREFIX}-lld=${pkgver}"
+           "mingw-w64-clang-${_cross_arches[@@@PREFIX@@@]%%-*}-crt"
+           "mingw-w64-clang-${_cross_arches[@@@PREFIX@@@]%%-*}-headers"
+           "mingw-w64-clang-${_cross_arches[@@@PREFIX@@@]%%-*}-libc++=${pkgver}"
+           "mingw-w64-clang-${_cross_arches[@@@PREFIX@@@]%%-*}-libunwind=${pkgver}")
+
+  cd "${srcdir}/build-${MSYSTEM}"
+
+  mkdir -p "${pkgdir}${MINGW_PREFIX}/bin"
+  local _tool
+  # c11 c99 ?
+  for _tool in as c++ cc clang clang++ g++ gcc; do
+    cp -f ${_cross_arches[$_pfx]}-clang.exe "${pkgdir}${MINGW_PREFIX}/bin/${_cross_arches[$_pfx]}-${_tool}.exe"
+  done
+  for _tool in addr2line ar ranlib nm objcopy readelf strings strip; do
+    cp -f ${_cross_arches[$_pfx]}-llvm-wrapper.exe "${pkgdir}${MINGW_PREFIX}/bin/${_cross_arches[$_pfx]}-${_tool}.exe"
+  done
+  # windres and dlltool can't use llvm-wrapper, as that loses the original
+  # target arch prefix
+  for _tool in dlltool windres; do
+    cp -f ${_cross_arches[$_pfx]}-${_tool}.exe "${pkgdir}${MINGW_PREFIX}/bin/${_cross_arches[$_pfx]}-${_tool}.exe"
+  done
+
+  mkdir -p "${pkgdir}${MINGW_PREFIX}/share/licenses/${_cross_arches[${_pfx}]}-cross-clang"
+  sed -ne '1,/^ \*\//p' "${srcdir}/native-wrapper.h" > "${pkgdir}${MINGW_PREFIX}/share/licenses/${_cross_arches[${_pfx}]}-cross-clang/LICENSE"
+}
+
+_func="$(declare -f "_real_package")"
+for _pfx in "${!_cross_arches[@]}"; do
+  if [[ "${_pfx}" != "${MINGW_PREFIX}" ]]; then
+    _func2="${_func//@@@PREFIX@@@/${_pfx}}"
+    eval "${_func2/#_real_package/package_${MINGW_PACKAGE_PREFIX}-cross-clang-${_cross_arches[$_pfx]%%-*}}"
+  fi
+done

mingw-w64-cross-clang/clang-target-wrapper.c

@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 2018 Martin Storsjo
+ *
+ * This file is part of llvm-mingw.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "native-wrapper.h"
+
+#ifndef CLANG
+#define CLANG "clang"
+#endif
+#ifndef DEFAULT_TARGET
+#define DEFAULT_TARGET "x86_64-w64-mingw32"
+#endif
+#ifndef SYSROOT
+#define SYSROOT "/clang64"
+#endif
+
+int _tmain(int argc, TCHAR* argv[]) {
+    const TCHAR *dir;
+    const TCHAR *target;
+    const TCHAR *exe;
+    split_argv(argv[0], &dir, NULL, &target, &exe);
+    if (!target)
+        target = _T(DEFAULT_TARGET);
+    TCHAR *arch = _tcsdup(target);
+    TCHAR *dash = _tcschr(arch, '-');
+    if (dash)
+        *dash = '\0';
+    TCHAR *target_os = _tcsrchr(target, '-');
+    if (target_os)
+        target_os++;
+
+    // Check if trying to compile Ada; if we try to do this, invoking clang
+    // would end up invoking <triplet>-gcc with the same arguments, which ends
+    // up in an infinite recursion.
+    for (int i = 1; i < argc - 1; i++) {
+        if (!_tcscmp(argv[i], _T("-x")) && !_tcscmp(argv[i + 1], _T("ada"))) {
+            fprintf(stderr, "Ada is not supported\n");
+            return 1;
+        }
+    }
+
+    int max_arg = argc + 20;
+    const TCHAR **exec_argv = malloc((max_arg + 1) * sizeof(*exec_argv));
+    int arg = 0;
+    if (getenv("CCACHE"))
+        exec_argv[arg++] = _T("ccache");
+    exec_argv[arg++] = concat(dir, _T(CLANG));
+
+    // If changing this wrapper, change clang-target-wrapper.sh accordingly.
+    if (!_tcscmp(exe, _T("clang++")) || !_tcscmp(exe, _T("g++")) || !_tcscmp(exe, _T("c++")))
+        exec_argv[arg++] = _T("--driver-mode=g++");
+
+    if (target_os && !_tcscmp(target_os, _T("mingw32uwp"))) {
+        // the UWP target is for Windows 10
+        exec_argv[arg++] = _T("-D_WIN32_WINNT=0x0A00");
+        exec_argv[arg++] = _T("-DWINVER=0x0A00");
+        // the UWP target can only use Windows Store APIs
+        exec_argv[arg++] = _T("-DWINAPI_FAMILY=WINAPI_FAMILY_APP");
+        // the Windows Store API only supports Windows Unicode (some rare ANSI ones are available)
+        exec_argv[arg++] = _T("-DUNICODE");
+        // add the minimum runtime to use for UWP targets
+        exec_argv[arg++] = _T("-Wl,-lwindowsapp");
+        // This still requires that the toolchain (in particular, libc++.a) has
+        // been built targeting UCRT originally.
+        exec_argv[arg++] = _T("-Wl,-lucrtapp");
+        // force the user of Universal C Runtime
+        exec_argv[arg++] = _T("-D_UCRT");
+    }
+
+    exec_argv[arg++] = _T("-target");
+    exec_argv[arg++] = target;
+    exec_argv[arg++] = _T("--sysroot");
+    exec_argv[arg++] = concat(dir, _T("../..") _T(SYSROOT));
+    exec_argv[arg++] = _T("-rtlib=compiler-rt");
+    exec_argv[arg++] = _T("-unwindlib=libunwind");
+    exec_argv[arg++] = _T("-stdlib=libc++");
+    exec_argv[arg++] = _T("-fuse-ld=lld");
+    exec_argv[arg++] = _T("-Qunused-arguments");
+
+    for (int i = 1; i < argc; i++)
+        exec_argv[arg++] = argv[i];
+
+    exec_argv[arg] = NULL;
+    if (arg > max_arg) {
+        fprintf(stderr, "Too many options added\n");
+        abort();
+    }
+
+    return run_final(exec_argv[0], exec_argv);
+}

mingw-w64-cross-clang/dlltool-wrapper.c

@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2018 Martin Storsjo
+ *
+ * This file is part of llvm-mingw.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "native-wrapper.h"
+
+#ifndef DEFAULT_TARGET
+#define DEFAULT_TARGET "x86_64-w64-mingw32"
+#endif
+
+int _tmain(int argc, TCHAR* argv[]) {
+    const TCHAR *dir;
+    const TCHAR *target;
+    split_argv(argv[0], &dir, NULL, &target, NULL);
+    if (!target)
+        target = _tcsdup(_T(DEFAULT_TARGET));
+    TCHAR *dash = _tcschr(target, '-');
+    if (dash)
+        *dash = '\0';
+
+    int max_arg = argc + 2;
+    const TCHAR **exec_argv = malloc((max_arg + 1) * sizeof(*exec_argv));
+    int arg = 0;
+    exec_argv[arg++] = concat(dir, _T("llvm-dlltool"));
+
+    if (!_tcscmp(target, _T("i686"))) {
+        exec_argv[arg++] = _T("-m");
+        exec_argv[arg++] = _T("i386");
+    } else if (!_tcscmp(target, _T("x86_64"))) {
+        exec_argv[arg++] = _T("-m");
+        exec_argv[arg++] = _T("i386:x86-64");
+    } else if (!_tcscmp(target, _T("armv7"))) {
+        exec_argv[arg++] = _T("-m");
+        exec_argv[arg++] = _T("arm");
+    } else if (!_tcscmp(target, _T("aarch64"))) {
+        exec_argv[arg++] = _T("-m");
+        exec_argv[arg++] = _T("arm64");
+    } else {
+        _ftprintf(stderr, _T("Arch "TS" unsupported\n"), target);
+        return 1;
+    }
+
+    for (int i = 1; i < argc; i++)
+        exec_argv[arg++] = argv[i];
+
+    exec_argv[arg] = NULL;
+    if (arg > max_arg) {
+        fprintf(stderr, "Too many options added\n");
+        abort();
+    }
+
+    return run_final(exec_argv[0], exec_argv);
+}

mingw-w64-cross-clang/llvm-wrapper.c

@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2018 Martin Storsjo
+ *
+ * This file is part of llvm-mingw.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "native-wrapper.h"
+
+int _tmain(int argc, TCHAR* argv[]) {
+    const TCHAR *dir;
+    const TCHAR *exe;
+    split_argv(argv[0], &dir, NULL, NULL, &exe);
+    TCHAR *exe_path = concat(dir, concat(_T("llvm-"), exe));
+
+    return run_final(exe_path, (const TCHAR *const *) argv);
+}