From 4c0b6a6add0c361c962b0b8f96b29e1b5d7a107c Mon Sep 17 00:00:00 2001
From: ridiculousfish <corydoras@ridiculousfish.com>
Date: Tue, 29 Jan 2019 00:34:38 -0800
Subject: [PATCH] Use dup2_list_t in posix_spawn

This simplifies the posix_spawn path and unifies it with the fork execution
path.
---
 src/exec.cpp     |  3 +--
 src/postfork.cpp | 58 ++++++++----------------------------------------
 src/postfork.h   |  5 ++---
 3 files changed, 12 insertions(+), 54 deletions(-)

diff --git a/src/exec.cpp b/src/exec.cpp
index 3d51914b2..bf978345f 100644
--- a/src/exec.cpp
+++ b/src/exec.cpp
@@ -691,8 +691,7 @@ static bool exec_external_command(env_stack_t &vars, const std::shared_ptr<job_t
         pid_t pid = 0;
         posix_spawnattr_t attr = posix_spawnattr_t();
         posix_spawn_file_actions_t actions = posix_spawn_file_actions_t();
-        bool made_it =
-            fork_actions_make_spawn_properties(&attr, &actions, j.get(), p, proc_io_chain);
+        bool made_it = fork_actions_make_spawn_properties(&attr, &actions, j.get(), *dup2s);
         if (made_it) {
             // We successfully made the attributes and actions; actually call
             // posix_spawn.
diff --git a/src/postfork.cpp b/src/postfork.cpp
index 4326d077a..d8ce8272e 100644
--- a/src/postfork.cpp
+++ b/src/postfork.cpp
@@ -223,9 +223,8 @@ pid_t execute_fork(bool wait_for_threads_to_die) {
 
 #if FISH_USE_POSIX_SPAWN
 bool fork_actions_make_spawn_properties(posix_spawnattr_t *attr,
-                                        posix_spawn_file_actions_t *actions, job_t *j, process_t *p,
-                                        const io_chain_t &io_chain) {
-    UNUSED(p);
+                                        posix_spawn_file_actions_t *actions, const job_t *j,
+                                        const dup2_list_t &dup2s) {
     // Initialize the output.
     if (posix_spawnattr_init(attr) != 0) {
         return false;
@@ -279,52 +278,13 @@ bool fork_actions_make_spawn_properties(posix_spawnattr_t *attr,
     sigemptyset(&sigmask);
     if (!err && reset_sigmask) err = posix_spawnattr_setsigmask(attr, &sigmask);
 
-    for (size_t idx = 0; idx < io_chain.size(); idx++) {
-        const shared_ptr<const io_data_t> io = io_chain.at(idx);
-
-        if (io->io_mode == io_mode_t::fd) {
-            const io_fd_t *io_fd = static_cast<const io_fd_t *>(io.get());
-            if (io->fd == io_fd->old_fd) continue;
-        }
-
-        switch (io->io_mode) {
-            case io_mode_t::close: {
-                if (!err) err = posix_spawn_file_actions_addclose(actions, io->fd);
-                break;
-            }
-
-            case io_mode_t::file: {
-                const io_file_t *io_file = static_cast<const io_file_t *>(io.get());
-                if (!err)
-                    err = posix_spawn_file_actions_addopen(actions, io->fd, io_file->filename_cstr,
-                                                           io_file->flags /* mode */, OPEN_MASK);
-                break;
-            }
-
-            case io_mode_t::fd: {
-                const io_fd_t *io_fd = static_cast<const io_fd_t *>(io.get());
-                if (!err)
-                    err = posix_spawn_file_actions_adddup2(actions, io_fd->old_fd /* from */,
-                                                           io->fd /* to */);
-                break;
-            }
-
-            case io_mode_t::buffer:
-            case io_mode_t::pipe: {
-                const io_pipe_t *io_pipe = static_cast<const io_pipe_t *>(io.get());
-                unsigned int write_pipe_idx = (io_pipe->is_input ? 0 : 1);
-                int from_fd = io_pipe->pipe_fd[write_pipe_idx];
-                int to_fd = io->fd;
-                if (!err) err = posix_spawn_file_actions_adddup2(actions, from_fd, to_fd);
-
-                if (write_pipe_idx > 0) {
-                    if (!err) err = posix_spawn_file_actions_addclose(actions, io_pipe->pipe_fd[0]);
-                    if (!err) err = posix_spawn_file_actions_addclose(actions, io_pipe->pipe_fd[1]);
-                } else {
-                    if (!err) err = posix_spawn_file_actions_addclose(actions, io_pipe->pipe_fd[0]);
-                }
-                break;
-            }
+    // Apply our dup2s.
+    for (const auto &act : dup2s.get_actions()) {
+        if (err) break;
+        if (act.target < 0) {
+            err = posix_spawn_file_actions_addclose(actions, act.src);
+        } else {
+            err = posix_spawn_file_actions_adddup2(actions, act.src, act.target);
         }
     }
 
diff --git a/src/postfork.h b/src/postfork.h
index 8ac8e82a3..d91d335cf 100644
--- a/src/postfork.h
+++ b/src/postfork.h
@@ -15,7 +15,6 @@
 #endif
 
 class dup2_list_t;
-class io_chain_t;
 class job_t;
 class process_t;
 
@@ -56,8 +55,8 @@ void run_as_keepalive(pid_t parent_pid);
 /// Initializes and fills in a posix_spawnattr_t; on success, the caller should destroy it via
 /// posix_spawnattr_destroy.
 bool fork_actions_make_spawn_properties(posix_spawnattr_t *attr,
-                                        posix_spawn_file_actions_t *actions, job_t *j, process_t *p,
-                                        const io_chain_t &io_chain);
+                                        posix_spawn_file_actions_t *actions, const job_t *j,
+                                        const dup2_list_t &dup2s);
 #endif
 
 #endif