Shell: Switch to using Core::EventLoop

This commit refactors Shell to a Core::Object and switches its looping
to Core::EventLoop.

Shell/CMakeLists.txt

@@ -1,6 +1,7 @@
 set(SOURCES
     main.cpp
     Parser.cpp
+    Shell.cpp
 )
 
 serenity_bin(Shell)

Shell/Execution.h

@@ -26,28 +26,19 @@
 
 #pragma once
 
-#include "Job.h"
-#include <AK/CircularQueue.h>
-#include <AK/HashMap.h>
+#include <AK/Forward.h>
 #include <AK/String.h>
 #include <AK/Vector.h>
-#include <termios.h>
+#include <LibCore/ElapsedTimer.h>
 
-struct GlobalState {
-    String cwd;
-    String username;
-    String home;
-    char ttyname[32];
-    char hostname[64];
-    uid_t uid;
-    struct termios termios;
-    struct termios default_termios;
-    bool was_interrupted { false };
-    bool was_resized { false };
-    int last_return_code { 0 };
-    Vector<String> directory_stack;
-    CircularQueue<String, 8> cd_history; // FIXME: have a configurable cd history length
-    HashMap<u64, Job> jobs;
+class FileDescriptionCollector {
+public:
+    FileDescriptionCollector() { }
+    ~FileDescriptionCollector();
+
+    void collect();
+    void add(int fd);
+
+private:
+    Vector<int, 32> m_fds;
 };
-
-extern GlobalState g;

Shell/Job.h

@@ -26,7 +26,13 @@
 
 #pragma once
 
+#include "Execution.h"
+#include <AK/JsonObject.h>
+#include <AK/JsonValue.h>
+#include <AK/OwnPtr.h>
 #include <AK/String.h>
+#include <LibCore/ElapsedTimer.h>
+#include <LibCore/Object.h>
 
 class Job {
 public:
@@ -34,22 +40,52 @@ public:
     {
     }
 
+    ~Job()
+    {
+        auto elapsed = m_command_timer.elapsed();
+        dbg() << "Command \"" << m_cmd << "\" finished in " << elapsed << " ms";
+    }
+
     Job(pid_t pid, unsigned pgid, String cmd, u64 job_id)
         : m_pgid(pgid)
         , m_pid(pid)
         , m_job_id(job_id)
         , m_cmd(move(cmd))
     {
+        set_running_in_background(false);
+        m_command_timer.start();
     }
 
     unsigned pgid() const { return m_pgid; }
     pid_t pid() const { return m_pid; }
     const String& cmd() const { return m_cmd; }
     u64 job_id() const { return m_job_id; }
+    bool exited() const { return m_exited; }
+    int exit_code() const { return m_exit_code; }
+    bool is_running_in_background() const { return m_running_in_background; }
+
+    Core::ElapsedTimer& timer() { return m_command_timer; }
+
+    void set_has_exit(int exit_code)
+    {
+        if (m_exited)
+            return;
+        m_exit_code = exit_code;
+        m_exited = true;
+    }
+
+    void set_running_in_background(bool running_in_background)
+    {
+        m_running_in_background = running_in_background;
+    }
 
 private:
     unsigned m_pgid { 0 };
     pid_t m_pid { 0 };
     u64 m_job_id { 0 };
     String m_cmd;
+    bool m_exited { false };
+    bool m_running_in_background { false };
+    int m_exit_code { -1 };
+    Core::ElapsedTimer m_command_timer;
 };

Shell/Shell.h

@@ -0,0 +1,185 @@
+/*
+ * Copyright (c) 2020, The SerenityOS developers.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include "Job.h"
+#include "Parser.h"
+#include <AK/CircularQueue.h>
+#include <AK/HashMap.h>
+#include <AK/String.h>
+#include <AK/StringBuilder.h>
+#include <AK/Types.h>
+#include <AK/Vector.h>
+#include <LibCore/Notifier.h>
+#include <LibCore/Object.h>
+#include <LibLine/Editor.h>
+#include <termios.h>
+
+struct ExitCodeOrContinuationRequest {
+    enum ContinuationRequest {
+        Nothing,
+        Pipe,
+        DoubleQuotedString,
+        SingleQuotedString,
+    };
+
+    ExitCodeOrContinuationRequest(ContinuationRequest continuation)
+        : continuation(continuation)
+    {
+    }
+
+    ExitCodeOrContinuationRequest(int exit)
+        : exit_code(exit)
+    {
+    }
+
+    bool has_value() const { return exit_code.has_value(); }
+    int value() const
+    {
+        ASSERT(has_value());
+        return exit_code.value();
+    }
+
+    Optional<int> exit_code;
+    ContinuationRequest continuation { Nothing };
+};
+
+using ContinuationRequest = ExitCodeOrContinuationRequest::ContinuationRequest;
+
+#define ENUMERATE_SHELL_BUILTINS()     \
+    __ENUMERATE_SHELL_BUILTIN(cd)      \
+    __ENUMERATE_SHELL_BUILTIN(cdh)     \
+    __ENUMERATE_SHELL_BUILTIN(pwd)     \
+    __ENUMERATE_SHELL_BUILTIN(exit)    \
+    __ENUMERATE_SHELL_BUILTIN(export)  \
+    __ENUMERATE_SHELL_BUILTIN(unset)   \
+    __ENUMERATE_SHELL_BUILTIN(history) \
+    __ENUMERATE_SHELL_BUILTIN(umask)   \
+    __ENUMERATE_SHELL_BUILTIN(dirs)    \
+    __ENUMERATE_SHELL_BUILTIN(pushd)   \
+    __ENUMERATE_SHELL_BUILTIN(popd)    \
+    __ENUMERATE_SHELL_BUILTIN(time)    \
+    __ENUMERATE_SHELL_BUILTIN(jobs)    \
+    __ENUMERATE_SHELL_BUILTIN(fg)      \
+    __ENUMERATE_SHELL_BUILTIN(bg)
+
+class Shell;
+
+class Shell : public Core::Object {
+    C_OBJECT(Shell);
+
+public:
+    ExitCodeOrContinuationRequest run_command(const StringView&);
+    bool run_builtin(int argc, const char** argv, int& retval);
+    String prompt() const;
+
+    static String expand_tilde(const String&);
+    static Vector<String> expand_globs(const StringView& path, const StringView& base);
+    Vector<String> expand_parameters(const StringView&) const;
+
+    static String escape_token(const String& token);
+    static String unescape_token(const String& token);
+
+    static bool is_glob(const StringView&);
+    static Vector<StringView> split_path(const StringView&);
+
+    Vector<String> process_arguments(const Vector<Token>&);
+
+    static ContinuationRequest is_complete(const Vector<Command>&);
+
+    void highlight(Line::Editor&) const;
+    Vector<Line::CompletionSuggestion> complete_first(const String&);
+    Vector<Line::CompletionSuggestion> complete_other(const String&);
+
+    String get_history_path();
+    void load_history();
+    void save_history();
+    void print_path(const String& path);
+
+    bool should_read_more() const { return m_should_continue != ContinuationRequest::Nothing; }
+    void finish_command() { m_should_break_current_command = true; }
+
+    void read_single_line();
+
+    struct termios termios;
+    struct termios default_termios;
+    bool was_interrupted { false };
+    bool was_resized { false };
+
+    String cwd;
+    String username;
+    String home;
+
+    constexpr static auto TTYNameSize = 32;
+    constexpr static auto HostNameSize = 64;
+
+    char ttyname[TTYNameSize];
+    char hostname[HostNameSize];
+
+    uid_t uid;
+    int last_return_code { 0 };
+    Vector<String> directory_stack;
+    CircularQueue<String, 8> cd_history; // FIXME: have a configurable cd history length
+    HashMap<u64, OwnPtr<Job>> jobs;
+    Vector<String, 256> cached_path;
+
+    enum ShellEventType {
+        ReadLine,
+        ChildExited,
+    };
+
+private:
+    Shell();
+    virtual ~Shell() override;
+
+    struct SpawnedProcess {
+        String name;
+        pid_t pid;
+    };
+
+    void cache_path();
+
+    IterationDecision wait_for_pid(const SpawnedProcess&, bool is_first_command_in_chain, int& return_value);
+
+    virtual void custom_event(Core::CustomEvent&) override;
+
+#define __ENUMERATE_SHELL_BUILTIN(builtin) \
+    int builtin_##builtin(int argc, const char** argv);
+
+    ENUMERATE_SHELL_BUILTINS();
+
+#undef __ENUMERATE_SHELL_BUILTIN
+
+    ExitCodeOrContinuationRequest::ContinuationRequest m_should_continue { ExitCodeOrContinuationRequest::Nothing };
+    StringBuilder m_complete_line_builder;
+    bool m_should_break_current_command { false };
+};
+
+static constexpr bool is_word_character(char c)
+{
+    return c == '_' || (c <= 'Z' && c >= 'A') || (c <= 'z' && c >= 'a');
+}