port class 'process' to Windows

src/process.cpp

@@ -26,13 +26,23 @@
 #include <migraphx/env.hpp>
 #include <functional>
 #include <iostream>
+#include <optional>
+
+#ifdef _WIN32
+// cppcheck-suppress definePrefix
+#define WIN32_LEAN_AND_MEAN
+#include <Windows.h>
+#else
 #include <unistd.h>
+#endif
 
 namespace migraphx {
 inline namespace MIGRAPHX_INLINE_NS {
 
 MIGRAPHX_DECLARE_ENV_VAR(MIGRAPHX_TRACE_CMD_EXECUTE)
 
+#ifndef _WIN32
+
 std::function<void(const char*)> redirect_to(std::ostream& os)
 {
     return [&](const char* x) { os << x; };
@@ -74,6 +84,155 @@
     });
 }
 
+#else
+
+constexpr std::size_t MIGRAPHX_PROCESS_BUFSIZE = 4096;
+
+class pipe
+{
+    public:
+    explicit pipe(bool inherit_handle = true)
+    {
+        SECURITY_ATTRIBUTES attrs;
+        attrs.nLength              = sizeof(SECURITY_ATTRIBUTES);
+        attrs.bInheritHandle       = inherit_handle ? TRUE : FALSE;
+        attrs.lpSecurityDescriptor = nullptr;
+
+        if(CreatePipe(&m_read, &m_write, &attrs, 0) == FALSE)
+            throw GetLastError();
+
+        if(SetHandleInformation(&m_read, HANDLE_FLAG_INHERIT, 0) == FALSE)
+            throw GetLastError();
+    }
+
+    pipe(const pipe&) = delete;
+    pipe& operator=(const pipe&) = delete;
+
+    pipe(pipe&&) = default;
+
+    ~pipe()
+    {
+        CloseHandle(m_read);
+        m_read = nullptr;
+        CloseHandle(m_write);
+        m_write = nullptr;
+    }
+
+    std::optional<std::pair<bool, DWORD>> read(LPVOID buffer, DWORD length) const
+    {
+        DWORD bytes_read;
+        if(ReadFile(m_read, buffer, length, &bytes_read, nullptr) == FALSE)
+        {
+            DWORD error{GetLastError()};
+            if(error != ERROR_MORE_DATA)
+            {
+                return std::nullopt;
+            }
+            return {{true, bytes_read}};
+        }
+        return {{false, bytes_read}};
+    }
+
+    HANDLE get_read_handle() const { return m_read; }
+
+    bool write(LPCVOID buffer, DWORD length) const
+    {
+        DWORD bytes_written;
+        return WriteFile(m_write, buffer, length, &bytes_written, nullptr) == TRUE;
+    }
+
+    HANDLE get_write_handle() const { return m_write; }
+
+    private:
+    HANDLE m_write = nullptr, m_read = nullptr;
+};
+
+template <typename F>
+int exec(const std::string& cmd, F f)
+{
+    try
+    {
+        if(enabled(MIGRAPHX_TRACE_CMD_EXECUTE{}))
+            std::cout << cmd << std::endl;
+
+        STARTUPINFO info;
+        PROCESS_INFORMATION process_info;
+
+        pipe in{}, out{};
+
+        ZeroMemory(&info, sizeof(STARTUPINFO));
+        info.cb         = sizeof(STARTUPINFO);
+        info.hStdError  = out.get_write_handle();
+        info.hStdOutput = out.get_write_handle();
+        info.hStdInput  = in.get_read_handle();
+        info.dwFlags |= STARTF_USESTDHANDLES;
+
+        ZeroMemory(&process_info, sizeof(process_info));
+
+        if(CreateProcess(nullptr,
+                         const_cast<LPSTR>(cmd.c_str()),
+                         nullptr,
+                         nullptr,
+                         TRUE,
+                         0,
+                         nullptr,
+                         nullptr,
+                         &info,
+                         &process_info) == FALSE)
+        {
+            return GetLastError();
+        }
+
+        f(in, out);
+
+        WaitForSingleObject(process_info.hProcess, INFINITE);
+
+        DWORD status{};
+        GetExitCodeProcess(process_info.hProcess, &status);
+
+        CloseHandle(process_info.hProcess);
+        CloseHandle(process_info.hThread);
+
+        return static_cast<int>(status);
+    }
+    // cppcheck-suppress catchExceptionByValue
+    catch(DWORD last_error)
+    {
+        return last_error;
+    }
+}
+
+int exec(const std::string& cmd)
+{
+    TCHAR buffer[MIGRAPHX_PROCESS_BUFSIZE];
+    HANDLE std_out{GetStdHandle(STD_OUTPUT_HANDLE)};
+    return (std_out == nullptr || std_out == INVALID_HANDLE_VALUE)
+               ? GetLastError()
+               : exec(cmd, [&](const pipe&, const pipe& out) {
+                     for(;;)
+                     {
+                         if(auto result = out.read(buffer, MIGRAPHX_PROCESS_BUFSIZE))
+                         {
+                             auto [more_data, bytes_read] = *result;
+                             if(!more_data || bytes_read == 0)
+                                 break;
+                             DWORD written;
+                             if(WriteFile(std_out, buffer, bytes_read, &written, nullptr) == FALSE)
+                                 break;
+                         }
+                     }
+                 });
+}
+
+int exec(const std::string& cmd, std::function<void(process::writer)> std_in)
+{
+    return exec(cmd, [&](const pipe& in, const pipe&) {
+        std_in([&](const char* buffer, std::size_t n) { in.write(buffer, n); });
+    });
+}
+
+#endif
+
 struct process_impl
 {
     std::string command{};
@@ -119,7 +278,14 @@
     return *this;
 }
 
-void process::exec() { impl->check_exec(impl->get_command(), redirect_to(std::cout)); }
+void process::exec()
+{
+#ifndef _WIN32
+    impl->check_exec(impl->get_command(), redirect_to(std::cout));
+#else
+    impl->check_exec(impl->get_command());
+#endif
+}
 
 void process::write(std::function<void(process::writer)> pipe_in)
 {