Implement source debugging for interpreter and AOT (#769)

Implement source debugging feature for classic interpreter and AOT:
- use `cmake -DWAMR_BUILD_DEBUG_INTERP=1` to enable interpreter debugging
- use `cmake -DWAMR_BUILD_DEBUG_AOT=1` to enable AOT debugging

See doc/source_debugging.md for more details.

core/iwasm/libraries/debug-engine/gdbserver.c

@@ -0,0 +1,177 @@
+/*
+ * Copyright (C) 2021 Ant Group.  All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+ */
+
+#include "gdbserver.h"
+
+#include <arpa/inet.h>
+#include <fcntl.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/poll.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+#include "bh_log.h"
+#include "handler.h"
+#include "packets.h"
+#include "utils.h"
+
+typedef void (*PacketHandler)(WASMGDBServer *server, char *payload);
+
+struct packet_handler_elem {
+    char request;
+    PacketHandler handler;
+};
+
+#define DEL_HANDLER(r, h) [r] = { .request = r, .handler = h }
+
+static struct packet_handler_elem packet_handler_table[255] = {
+    DEL_HANDLER('Q', handle_generay_set),
+    DEL_HANDLER('q', handle_generay_query),
+    DEL_HANDLER('v', handle_v_packet),
+    DEL_HANDLER('?', handle_threadstop_request),
+    DEL_HANDLER('H', handle_set_current_thread),
+    DEL_HANDLER('p', handle_get_register),
+    DEL_HANDLER('j', handle_get_json_request),
+    DEL_HANDLER('m', handle_get_read_memory),
+    DEL_HANDLER('M', handle_get_write_memory),
+    DEL_HANDLER('x', handle_get_read_binary_memory),
+    DEL_HANDLER('Z', handle_add_break),
+    DEL_HANDLER('z', handle_remove_break),
+    DEL_HANDLER('c', handle_continue_request),
+    DEL_HANDLER('k', handle_kill_request),
+    DEL_HANDLER('_', handle____request),
+};
+
+WASMGDBServer *
+wasm_launch_gdbserver(char *host, int port)
+{
+    int listen_fd = -1;
+    const int one = 1;
+    struct sockaddr_in addr;
+    int ret;
+    int sockt_fd = 0;
+
+    WASMGDBServer *server;
+
+    if (!(server = wasm_runtime_malloc(sizeof(WASMGDBServer)))) {
+        LOG_ERROR("wasm gdb server error: failed to allocate memory");
+        return NULL;
+    }
+
+    listen_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+    if (listen_fd < 0) {
+        LOG_ERROR("wasm gdb server error: socket() failed");
+        goto fail;
+    }
+
+    ret = fcntl(listen_fd, F_SETFD, FD_CLOEXEC);
+    if(ret < 0) {
+        LOG_ERROR("wasm gdb server error: fcntl() failed on setting FD_CLOEXEC");
+        goto fail;
+    }
+
+    ret = setsockopt(listen_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
+    if (ret < 0) {
+        LOG_ERROR("wasm gdb server error: setsockopt() failed");
+        goto fail;
+    }
+
+    LOG_VERBOSE("Listening on %s:%d\n", host, port);
+    addr.sin_family = AF_INET;
+    addr.sin_addr.s_addr = inet_addr(host);
+    addr.sin_port = htons(port);
+
+    ret = bind(listen_fd, (struct sockaddr *)&addr, sizeof(addr));
+    if (ret < 0) {
+        LOG_ERROR("wasm gdb server error: bind() failed");
+        goto fail;
+    }
+
+    ret = listen(listen_fd, 1);
+    if (ret < 0) {
+        LOG_ERROR("wasm gdb server error: listen() failed");
+        goto fail;
+    }
+
+    server->listen_fd = listen_fd;
+
+    sockt_fd = accept(listen_fd, NULL, NULL);
+    if (sockt_fd < 0) {
+        LOG_ERROR("wasm gdb server error: accept() failed");
+        goto fail;
+    }
+    LOG_VERBOSE("accept gdb client");
+    server->socket_fd = sockt_fd;
+    server->noack = false;
+    return server;
+
+fail:
+    if (listen_fd > 0) {
+        shutdown(listen_fd, SHUT_RDWR);
+        close(listen_fd);
+    }
+    if (server)
+        wasm_runtime_free(server);
+    return NULL;
+}
+
+void
+wasm_close_gdbserver(WASMGDBServer *server)
+{
+    if (server->socket_fd > 0) {
+        shutdown(server->socket_fd, SHUT_RDWR);
+        close(server->socket_fd);
+    }
+    if (server->listen_fd > 0) {
+        shutdown(server->listen_fd, SHUT_RDWR);
+        close(server->listen_fd);
+    }
+}
+
+static inline void
+handler_packet(WASMGDBServer *server, char request, char *payload)
+{
+    if (packet_handler_table[(int)request].handler != NULL)
+        packet_handler_table[(int)request].handler(server, payload);
+}
+
+static void
+process_packet(WASMGDBServer *server)
+{
+    uint8_t *inbuf = server->pkt.buf;
+    int inbuf_size = server->pkt.end;
+    uint8_t *packetend_ptr = (uint8_t *)memchr(inbuf, '#', inbuf_size);
+    int packetend = packetend_ptr - inbuf;
+    bh_assert('$' == inbuf[0]);
+    char request = inbuf[1];
+    char *payload = (char *)&inbuf[2];
+    inbuf[packetend] = '\0';
+
+    uint8_t checksum = 0;
+    for (int i = 1; i < packetend; i++)
+        checksum += inbuf[i];
+    bh_assert(checksum
+              == (hex(inbuf[packetend + 1]) << 4 | hex(inbuf[packetend + 2])));
+
+    LOG_VERBOSE("receive request:%c %s\n", request, payload);
+    handler_packet(server, request, payload);
+    inbuf_erase_head(server, packetend + 3);
+}
+
+bool
+wasm_gdbserver_handle_packet(WASMGDBServer *server)
+{
+    bool ret;
+    ret = read_packet(server);
+    if (ret)
+        process_packet(server);
+    return ret;
+}