Shell: Move out run_commands and expand_aliases to be Shell member fns

This makes running commands from outside the AST chain easier.

4 files changed, 99 insertions, 87 deletions

diff --git a/Shell/AST.cpp b/Shell/AST.cpp
index 4bbf3777ba..1e2261ba2e 100644
--- a/Shell/AST.cpp
+++ b/Shell/AST.cpp
@@ -742,79 +742,7 @@ RefPtr<Value> Execute::run(RefPtr<Shell> shell)
     if (m_command->would_execute())
         return m_command->run(shell);
 
-    auto initial_commands = m_command->run(shell)->resolve_as_commands(shell);
-    decltype(initial_commands) commands;
-
-    Function<void(Command&)> resolve_aliases_and_append = [&](auto& command) {
-        if (!command.argv.is_empty()) {
-            auto alias = shell->resolve_alias(command.argv[0]);
-            if (!alias.is_null()) {
-                auto argv0 = command.argv.take_first();
-                auto subcommand_ast = Parser { alias }.parse();
-                if (subcommand_ast) {
-                    while (subcommand_ast->is_execute()) {
-                        auto* ast = static_cast<Execute*>(subcommand_ast.ptr());
-                        subcommand_ast = ast->command();
-                    }
-                    RefPtr<Node> substitute = create<Join>(position(), move(subcommand_ast), create<CommandLiteral>(position(), command));
-                    for (auto& subst_command : substitute->run(shell)->resolve_as_commands(shell)) {
-                        if (!subst_command.argv.is_empty() && subst_command.argv.first() == argv0) // Disallow an alias resolving to itself.
-                            commands.append(subst_command);
-                        else
-                            resolve_aliases_and_append(subst_command);
-                    }
-                } else {
-                    commands.append(command);
-                }
-            } else {
-                commands.append(command);
-            }
-        } else {
-            commands.append(command);
-        }
-    };
-
-    for (auto& command : initial_commands)
-        resolve_aliases_and_append(command);
-
-    Vector<RefPtr<Job>> jobs_to_wait_for;
-
-    auto run_commands = [&](auto& commands) {
-        for (auto& command : commands) {
-#ifdef EXECUTE_DEBUG
-            dbg() << "Command";
-            for (auto& arg : command.argv)
-                dbg() << "argv: " << arg;
-            for (auto& redir : command.redirections) {
-                if (redir->is_path_redirection()) {
-                    auto path_redir = (const PathRedirection*)redir.ptr();
-                    dbg() << "redir path " << (int)path_redir->direction << " " << path_redir->path << " <-> " << path_redir->fd;
-                } else if (redir->is_fd_redirection()) {
-                    auto fd_redir = (const FdRedirection*)redir.ptr();
-                    dbg() << "redir fd " << fd_redir->source_fd << " -> " << fd_redir->dest_fd;
-                } else if (redir->is_close_redirection()) {
-                    auto close_redir = (const CloseRedirection*)redir.ptr();
-                    dbg() << "close fd " << close_redir->fd;
-                } else {
-                    ASSERT_NOT_REACHED();
-                }
-            }
-#endif
-            job = shell->run_command(command);
-
-            if (command.should_wait) {
-                shell->block_on_job(job);
-            } else {
-                if (command.is_pipe_source) {
-                    jobs_to_wait_for.append(job);
-                } else if (command.should_notify_if_in_background) {
-                    if (job)
-                        job->set_running_in_background(true);
-                    shell->restore_stdin();
-                }
-            }
-        }
-    };
+    auto commands = shell->expand_aliases(m_command->run(shell)->resolve_as_commands(shell));
 
     if (m_capture_stdout) {
         int pipefd[2];
@@ -860,9 +788,7 @@ RefPtr<Value> Execute::run(RefPtr<Shell> shell)
             try_read();
         };
 
-        run_commands(commands);
-
-        for (auto job : jobs_to_wait_for) {
+        for (auto job : shell->run_commands(commands)) {
             shell->block_on_job(job);
         }
 
@@ -877,12 +803,14 @@ RefPtr<Value> Execute::run(RefPtr<Shell> shell)
         return create<StringValue>(builder.build(), shell->local_variable_or("IFS", "\n"), shell->options.inline_exec_keep_empty_segments);
     }
 
-    run_commands(commands);
-    for (auto job : jobs_to_wait_for) {
+    RefPtr<Job> last_job;
+
+    for (auto& job : shell->run_commands(commands)) {
         shell->block_on_job(job);
+        last_job = move(job);
     }
 
-    return create<JobValue>(move(job));
+    return create<JobValue>(move(last_job));
 }
 
 void Execute::highlight_in_editor(Line::Editor& editor, Shell& shell, HighlightMetadata metadata)
@@ -1969,7 +1897,7 @@ Vector<String> TildeValue::resolve_as_list(RefPtr<Shell> shell)
     return { shell->expand_tilde(builder.to_string()) };
 }
 
-Result<RefPtr<Rewiring>, String> CloseRedirection::apply()
+Result<RefPtr<Rewiring>, String> CloseRedirection::apply() const
 {
     return static_cast<RefPtr<Rewiring>>((adopt(*new Rewiring(fd, fd, Rewiring::Close::ImmediatelyCloseDestination))));
 }
@@ -1978,7 +1906,7 @@ CloseRedirection::~CloseRedirection()
 {
 }
 
-Result<RefPtr<Rewiring>, String> PathRedirection::apply()
+Result<RefPtr<Rewiring>, String> PathRedirection::apply() const
 {
     auto check_fd_and_return = [my_fd = this->fd](int fd, const String& path) -> Result<RefPtr<Rewiring>, String> {
         if (fd < 0) {
diff --git a/Shell/AST.h b/Shell/AST.h
index 4c30150a84..2e9c74ea5c 100644
--- a/Shell/AST.h
+++ b/Shell/AST.h
@@ -77,7 +77,7 @@ struct Rewiring : public RefCounted<Rewiring> {
 };
 
 struct Redirection : public RefCounted<Redirection> {
-    virtual Result<RefPtr<Rewiring>, String> apply() = 0;
+    virtual Result<RefPtr<Rewiring>, String> apply() const = 0;
     virtual ~Redirection();
     virtual bool is_path_redirection() const { return false; }
     virtual bool is_fd_redirection() const { return false; }
@@ -87,7 +87,7 @@ struct Redirection : public RefCounted<Redirection> {
 struct CloseRedirection : public Redirection {
     int fd { -1 };
 
-    virtual Result<RefPtr<Rewiring>, String> apply() override;
+    virtual Result<RefPtr<Rewiring>, String> apply() const override;
     virtual ~CloseRedirection();
     CloseRedirection(int fd)
         : fd(fd)
@@ -108,7 +108,7 @@ struct PathRedirection : public Redirection {
         ReadWrite,
     } direction { Read };
 
-    virtual Result<RefPtr<Rewiring>, String> apply() override;
+    virtual Result<RefPtr<Rewiring>, String> apply() const override;
     virtual ~PathRedirection();
     PathRedirection(String path, int fd, decltype(direction) direction)
         : path(move(path))
@@ -124,7 +124,7 @@ private:
 struct FdRedirection : public Redirection
     , public Rewiring {
 
-    virtual Result<RefPtr<Rewiring>, String> apply() override { return static_cast<RefPtr<Rewiring>>(this); }
+    virtual Result<RefPtr<Rewiring>, String> apply() const override { return static_cast<RefPtr<Rewiring>>(this); }
     virtual ~FdRedirection();
     FdRedirection(int source, int dest, Rewiring::Close close)
         : Rewiring(source, dest, close)
diff --git a/Shell/Shell.cpp b/Shell/Shell.cpp
index 09faef91bb..2ee2e9f949 100644
--- a/Shell/Shell.cpp
+++ b/Shell/Shell.cpp
@@ -271,6 +271,45 @@ Vector<String> Shell::expand_globs(Vector<StringView> path_segments, const Strin
     }
 }
 
+Vector<AST::Command> Shell::expand_aliases(Vector<AST::Command> initial_commands)
+{
+    Vector<AST::Command> commands;
+
+    Function<void(AST::Command&)> resolve_aliases_and_append = [&](auto& command) {
+        if (!command.argv.is_empty()) {
+            auto alias = resolve_alias(command.argv[0]);
+            if (!alias.is_null()) {
+                auto argv0 = command.argv.take_first();
+                auto subcommand_ast = Parser { alias }.parse();
+                if (subcommand_ast) {
+                    while (subcommand_ast->is_execute()) {
+                        auto* ast = static_cast<AST::Execute*>(subcommand_ast.ptr());
+                        subcommand_ast = ast->command();
+                    }
+                    AST::Node& substitute = *new AST::Join(subcommand_ast->position(), subcommand_ast, *new AST::CommandLiteral(subcommand_ast->position(), command));
+                    for (auto& subst_command : substitute.run(*this)->resolve_as_commands(*this)) {
+                        if (!subst_command.argv.is_empty() && subst_command.argv.first() == argv0) // Disallow an alias resolving to itself.
+                            commands.append(subst_command);
+                        else
+                            resolve_aliases_and_append(subst_command);
+                    }
+                } else {
+                    commands.append(command);
+                }
+            } else {
+                commands.append(command);
+            }
+        } else {
+            commands.append(command);
+        }
+    };
+
+    for (auto& command : initial_commands)
+        resolve_aliases_and_append(command);
+
+    return commands;
+}
+
 String Shell::resolve_path(String path) const
 {
     if (!path.starts_with('/'))
@@ -349,7 +388,7 @@ int Shell::run_command(const StringView& cmd)
     return last_return_code;
 }
 
-RefPtr<Job> Shell::run_command(AST::Command& command)
+RefPtr<Job> Shell::run_command(const AST::Command& command)
 {
     FileDescriptionCollector fds;
 
@@ -494,6 +533,49 @@ RefPtr<Job> Shell::run_command(AST::Command& command)
     return *job;
 }
 
+Vector<RefPtr<Job>> Shell::run_commands(Vector<AST::Command>& commands)
+{
+    Vector<RefPtr<Job>> jobs_to_wait_for;
+
+    for (auto& command : commands) {
+#ifdef SH_DEBUG
+        dbg() << "Command";
+        for (auto& arg : command.argv)
+            dbg() << "argv: " << arg;
+        for (auto& redir : command.redirections) {
+            if (redir->is_path_redirection()) {
+                auto path_redir = (const AST::PathRedirection*)redir.ptr();
+                dbg() << "redir path " << (int)path_redir->direction << " " << path_redir->path << " <-> " << path_redir->fd;
+            } else if (redir->is_fd_redirection()) {
+                auto fd_redir = (const AST::FdRedirection*)redir.ptr();
+                dbg() << "redir fd " << fd_redir->source_fd << " -> " << fd_redir->dest_fd;
+            } else if (redir->is_close_redirection()) {
+                auto close_redir = (const AST::CloseRedirection*)redir.ptr();
+                dbg() << "close fd " << close_redir->fd;
+            } else {
+                ASSERT_NOT_REACHED();
+            }
+        }
+#endif
+        auto job = run_command(command);
+
+        if (command.should_wait) {
+            block_on_job(job);
+            jobs_to_wait_for.append(job);
+        } else {
+            if (command.is_pipe_source) {
+                jobs_to_wait_for.append(job);
+            } else if (command.should_notify_if_in_background) {
+                if (job)
+                    job->set_running_in_background(true);
+                restore_stdin();
+            }
+        }
+    }
+
+    return jobs_to_wait_for;
+}
+
 bool Shell::run_file(const String& filename, bool explicitly_invoked)
 {
     auto file_result = Core::File::open(filename, Core::File::ReadOnly);
diff --git a/Shell/Shell.h b/Shell/Shell.h
index b122e38b5e..72b500ab40 100644
--- a/Shell/Shell.h
+++ b/Shell/Shell.h
@@ -73,7 +73,8 @@ public:
     constexpr static auto global_init_file_path = "/etc/shellrc";
 
     int run_command(const StringView&);
-    RefPtr<Job> run_command(AST::Command&);
+    RefPtr<Job> run_command(const AST::Command&);
+    Vector<RefPtr<Job>> run_commands(Vector<AST::Command>&);
     bool run_file(const String&, bool explicitly_invoked = true);
     bool run_builtin(int argc, const char** argv, int& retval);
     bool has_builtin(const StringView&) const;
@@ -83,6 +84,7 @@ public:
     static String expand_tilde(const String&);
     static Vector<String> expand_globs(const StringView& path, StringView base);
     static Vector<String> expand_globs(Vector<StringView> path_segments, const StringView& base);
+    Vector<AST::Command> expand_aliases(Vector<AST::Command>);
     String resolve_path(String) const;
     String resolve_alias(const String&) const;