Build fix with MinGW GCC 9.2.0 (#12084)

* Build fix with MinGW GCC 9.2.0

* Fix MinGW tripplets

Fixes #12065

* clang-format

* Fix unused read_symlink_implementation warning marked as error

read_symlink_implementation was used only in copy_symlink_implementation
when #if defined(_WIN32) && !VCPKG_USE_STD_FILESYSTEM  was true.

Removed the warning otherwise.

Co-authored-by: JackBoosY <yuzaiyang@beyondsoft.com>

scripts/ports.cmake

@@ -17,6 +17,9 @@ if((NOT DEFINED VCPKG_ROOT_DIR)
     ]])
 endif()
 
+file(TO_CMAKE_PATH ${BUILDTREES_DIR} BUILDTREES_DIR)
+file(TO_CMAKE_PATH ${PACKAGES_DIR} PACKAGES_DIR)
+
 list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_LIST_DIR}/cmake)
 set(CURRENT_INSTALLED_DIR ${_VCPKG_INSTALLED_DIR}/${TARGET_TRIPLET} CACHE PATH "Location to install final packages")
 set(SCRIPTS ${CMAKE_CURRENT_LIST_DIR} CACHE PATH "Location to stored scripts")

toolsrc/include/vcpkg/base/system_headers.h

@@ -2,8 +2,13 @@
 
 #if defined(_WIN32)
 
+#ifndef NOMINMAX
 #define NOMINMAX
+#endif
+
+#ifndef WIN32_LEAN_AND_MEAN
 #define WIN32_LEAN_AND_MEAN
+#endif
 
 #pragma warning(suppress : 4768)
 #include <windows.h>

toolsrc/src/vcpkg/base/files.cpp

@@ -102,9 +102,9 @@ namespace vcpkg::Files
             return status_implementation(false, p, ec);
         }
 
+#if defined(_WIN32) && !VCPKG_USE_STD_FILESYSTEM
         fs::path read_symlink_implementation(const fs::path& oldpath, std::error_code& ec)
         {
-#if defined(_WIN32) && !VCPKG_USE_STD_FILESYSTEM
             ec.clear();
             auto handle = CreateFileW(oldpath.c_str(),
                                       0, // open just the metadata
@@ -132,10 +132,8 @@ namespace vcpkg::Files
             }
             CloseHandle(handle);
             return target;
-#else  // ^^^ defined(_WIN32) && !VCPKG_USE_STD_FILESYSTEM // !defined(_WIN32) || VCPKG_USE_STD_FILESYSTEM vvv
-            return fs::stdfs::read_symlink(oldpath, ec);
-#endif // ^^^ !defined(_WIN32) || VCPKG_USE_STD_FILESYSTEM
         }
+#endif // ^^^ !defined(_WIN32) || VCPKG_USE_STD_FILESYSTEM
 
         void copy_symlink_implementation(const fs::path& oldpath, const fs::path& newpath, std::error_code& ec)
         {

toolsrc/src/vcpkg/base/system.process.cpp

@@ -598,7 +598,7 @@ namespace vcpkg
 #if defined(_WIN32)
         using vcpkg::g_ctrl_c_state;
         g_ctrl_c_state.transition_to_spawn_process();
-        auto proc_info = windows_create_process(cmd_line, env, NULL);
+        auto proc_info = windows_create_process(cmd_line, env, 0);
         auto long_exit_code = [&]() -> unsigned long {
             if (auto p = proc_info.get())
                 return p->wait();
@@ -660,7 +660,7 @@ namespace vcpkg
         using vcpkg::g_ctrl_c_state;
 
         g_ctrl_c_state.transition_to_spawn_process();
-        auto maybe_proc_info = windows_create_process_redirect(cmd_line, env, NULL);
+        auto maybe_proc_info = windows_create_process_redirect(cmd_line, env, 0);
         auto exit_code = [&]() -> unsigned long {
             if (auto p = maybe_proc_info.get())
                 return p->wait_and_stream_output(data_cb);

toolsrc/src/vcpkg/build.cpp

@@ -490,7 +490,7 @@ namespace vcpkg::Build
         std::ofstream out_file(stdoutlog.native().c_str(), std::ios::out | std::ios::binary | std::ios::trunc);
         Checks::check_exit(VCPKG_LINE_INFO, out_file, "Failed to open '%s' for writing", stdoutlog.u8string());
         std::string compiler_hash;
-        const int return_code = System::cmd_execute_and_stream_lines(
+        System::cmd_execute_and_stream_lines(
             command,
             [&](const std::string& s) {
                 static const StringLiteral s_marker = "#COMPILER_HASH#";
@@ -616,6 +616,10 @@ namespace vcpkg::Build
         {
             return m_paths.scripts / fs::u8path("toolchains/ios.cmake");
         }
+        else if (cmake_system_name == "MinGW")
+        {
+            return m_paths.scripts / fs::u8path("toolchains/mingw.cmake");
+        }
         else if (cmake_system_name.empty() || cmake_system_name == "Windows" || cmake_system_name == "WindowsStore")
         {
             return m_paths.scripts / fs::u8path("toolchains/windows.cmake");
@@ -1148,7 +1152,7 @@ namespace vcpkg::Build
     PreBuildInfo::PreBuildInfo(const VcpkgPaths& paths,
                                Triplet triplet,
                                const std::unordered_map<std::string, std::string>& cmakevars)
-        : m_paths(paths), triplet(triplet)
+        : triplet(triplet), m_paths(paths)
     {
         enum class VcpkgTripletVar
         {