To adopt PR avrdudes#1264 approach of using Readline replacement for MinGW build

Author: mcuee

CMakeLists.txt

@@ -225,6 +225,8 @@ if(HAVE_LIBREADLINE)
     find_library(LIB_NCURSES NAMES ncurses)
 elseif(MSVC)
     set(HAVE_LIBREADLINE 1)
+elseif(MINGW)
+    set(HAVE_LIBREADLINE 1)
 endif()
 
 #-------------------------------------

src/CMakeLists.txt

@@ -75,6 +75,15 @@ if(MSVC)
     set(EXTRA_WINDOWS_INCLUDES ${EXTRA_WINDOWS_INCLUDES}
         "msvc"
         )
+elseif(MINGW)
+    set(LIB_MATH m)
+    add_compile_options(-Wall -Wextra -Wno-unused-parameter)
+    set(EXTRA_WINDOWS_SOURCES ${EXTRA_WINDOWS_SOURCES}
+        "mingw/readline.cpp"
+        )
+    set(EXTRA_WINDOWS_INCLUDES ${EXTRA_WINDOWS_INCLUDES}
+        "mingw"
+        )
 else()
     set(LIB_MATH m)
     add_compile_options(-Wall -Wextra -Wno-unused-parameter)

src/mingw/readline.cpp

@@ -0,0 +1,95 @@
+//
+// readline.cpp
+// Copyright (C) 2022 Marius Greuel
+// SPDX-License-Identifier: GPL-2.0-or-later
+//
+
+#include <string.h>
+#include <iostream>
+#include <memory>
+#include <mutex>
+#include <string>
+#include <thread>
+#include "readline/readline.h"
+#include "readline/history.h"
+
+int rl_readline_version = 0x0502;
+
+static rl_vcpfunc_t* rl_handler;
+static std::unique_ptr<std::thread> rl_thread;
+static std::mutex rl_mutex;
+static std::string rl_line;
+static bool rl_has_line = false;
+
+static void get_line_thread()
+{
+    std::string line;
+    std::getline(std::cin, line);
+
+    const std::lock_guard<std::mutex> lock(rl_mutex);
+    rl_line = line;
+    rl_has_line = true;
+}
+
+static void call_handler(const char* string)
+{
+    if (rl_thread)
+    {
+        rl_thread->join();
+        rl_thread = nullptr;
+    }
+
+    if (rl_handler != nullptr)
+    {
+        if (string == nullptr)
+        {
+            rl_handler(nullptr);
+        }
+        else
+        {
+            rl_handler(_strdup(string));
+        }
+    }
+}
+
+int rl_input_available(void)
+{
+    return 1;
+}
+
+void rl_callback_read_char(void)
+{
+    if (std::cin.eof())
+    {
+        call_handler(nullptr);
+    }
+    else if (!rl_thread)
+    {
+        rl_thread = std::make_unique<std::thread>(get_line_thread);
+    }
+    else
+    {
+        const std::lock_guard<std::mutex> lock(rl_mutex);
+        if (rl_has_line)
+        {
+            rl_has_line = false;
+            call_handler(rl_line.c_str());
+        }
+    }
+}
+
+void rl_callback_handler_install(char* prompt, rl_vcpfunc_t* handler)
+{
+    rl_handler = handler;
+
+    std::cout << prompt;
+}
+
+void rl_callback_handler_remove(void)
+{
+    rl_handler = nullptr;
+}
+
+void add_history(const char*)
+{
+}

src/mingw/readline/history.h

@@ -0,0 +1,17 @@
+//
+// history.h
+// Copyright (C) 2022 Marius Greuel
+// SPDX-License-Identifier: GPL-2.0-or-later
+//
+
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+    
+void add_history(const char* string);
+
+#ifdef __cplusplus
+}
+#endif

src/mingw/readline/readline.h

@@ -0,0 +1,24 @@
+//
+// readline.h
+// Copyright (C) 2022 Marius Greuel
+// SPDX-License-Identifier: GPL-2.0-or-later
+//
+
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef void (rl_vcpfunc_t)(char* line);
+
+extern int rl_readline_version;
+
+int rl_input_available(void);
+void rl_callback_read_char(void);
+void rl_callback_handler_install(char* prompt, rl_vcpfunc_t* handler);
+void rl_callback_handler_remove(void);
+
+#ifdef __cplusplus
+}
+#endif

src/term.c

@@ -2089,7 +2089,7 @@ static int term_running;
 
 // Any character in standard input available (without sleeping)?
 static int readytoread() {
-#ifdef _MSC_VER
+#ifdef _MSC_VER || MINGW
     return rl_input_available();
 #elif defined(WIN32)
   HANDLE hStdin = GetStdHandle(STD_INPUT_HANDLE);