Remove/make private the default ***Holder constructor to allow compile time detection...

[folly.git] / folly / Subprocess.h

diff --git a/folly/Subprocess.h b/folly/Subprocess.h
index e922ee0d261a8cfdeb348b95cbafb2d215eb1484..44e3fad6b08cbfd8e85ff7a21e010600d06e17df 100644 (file)
--- a/folly/Subprocess.h
+++ b/folly/Subprocess.h
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 Facebook, Inc.
+ * Copyright 2017 Facebook, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -34,12 +34,12 @@
  *
  * A thread-safe [1] version of popen() (type="r", to read from the child):
  *    Subprocess proc(cmd, Subprocess::pipeStdout());
- *    // read from proc.stdout()
+ *    // read from proc.stdoutFd()
  *    proc.wait();
  *
  * A thread-safe [1] version of popen() (type="w", to write to the child):
  *    Subprocess proc(cmd, Subprocess::pipeStdin());
- *    // write to proc.stdin()
+ *    // write to proc.stdinFd()
  *    proc.wait();
  *
  * If you want to redirect both stdin and stdout to pipes, you can, but note
@@ -298,19 +298,19 @@ class Subprocess {
     /**
      * Shortcut to change the action for standard input.
      */
-    Options& stdin(int action) { return fd(STDIN_FILENO, action); }
+    Options& stdinFd(int action) { return fd(STDIN_FILENO, action); }
 
     /**
      * Shortcut to change the action for standard output.
      */
-    Options& stdout(int action) { return fd(STDOUT_FILENO, action); }
+    Options& stdoutFd(int action) { return fd(STDOUT_FILENO, action); }
 
     /**
      * Shortcut to change the action for standard error.
      * Note that stderr(1) will redirect the standard error to the same
      * file descriptor as standard output; the equivalent of bash's "2>&1"
      */
-    Options& stderr(int action) { return fd(STDERR_FILENO, action); }
+    Options& stderrFd(int action) { return fd(STDERR_FILENO, action); }
 
     Options& pipeStdin() { return fd(STDIN_FILENO, PIPE_IN); }
     Options& pipeStdout() { return fd(STDOUT_FILENO, PIPE_OUT); }
@@ -416,9 +416,9 @@ class Subprocess {
       dangerousPostForkPreExecCallback_{nullptr};
   };
 
-  static Options pipeStdin() { return Options().stdin(PIPE); }
-  static Options pipeStdout() { return Options().stdout(PIPE); }
-  static Options pipeStderr() { return Options().stderr(PIPE); }
+  static Options pipeStdin() { return Options().stdinFd(PIPE); }
+  static Options pipeStdout() { return Options().stdoutFd(PIPE); }
+  static Options pipeStderr() { return Options().stderrFd(PIPE); }
 
   // Non-copiable, but movable
   Subprocess(const Subprocess&) = delete;
@@ -426,6 +426,14 @@ class Subprocess {
   Subprocess(Subprocess&&) = default;
   Subprocess& operator=(Subprocess&&) = default;
 
+  /**
+   * Create an uninitialized subprocess.
+   *
+   * In this state it can only be destroyed, or assigned to using the move
+   * assignment operator.
+   */
+  Subprocess();
+
   /**
    * Create a subprocess from the given arguments.  argv[0] must be listed.
    * If not-null, executable must be the actual executable
@@ -448,6 +456,7 @@ class Subprocess {
    * The shell to use is taken from the environment variable $SHELL,
    * or /bin/sh if $SHELL is unset.
    */
+  FOLLY_DEPRECATED("Prefer not running in a shell or use `shellify`.")
   explicit Subprocess(
       const std::string& cmd,
       const Options& options = Options(),
@@ -662,7 +671,7 @@ class Subprocess {
       uint64_t maxLineLength = 0,  // No line length limit by default
       char delimiter = '\n',
       uint64_t bufSize = 1024
-    ) : fdLineCb_(std::move(fdLineCb)),
+    ) : fdLineCb_(std::forward<Callback>(fdLineCb)),
         maxLineLength_(maxLineLength),
         delimiter_(delimiter),
         bufSize_(bufSize) {}
@@ -759,9 +768,9 @@ class Subprocess {
   int parentFd(int childFd) const {
     return pipes_[findByChildFd(childFd)].pipe.fd();
   }
-  int stdin() const { return parentFd(0); }
-  int stdout() const { return parentFd(1); }
-  int stderr() const { return parentFd(2); }
+  int stdinFd() const { return parentFd(0); }
+  int stdoutFd() const { return parentFd(1); }
+  int stderrFd() const { return parentFd(2); }
 
   /**
    * The child's pipes are logically separate from the process metadata
@@ -821,9 +830,8 @@ class Subprocess {
   // Returns an index into pipes_. Throws std::invalid_argument if not found.
   size_t findByChildFd(const int childFd) const;
 
-
-  pid_t pid_;
-  ProcessReturnCode returnCode_;
+  pid_t pid_{-1};
+  ProcessReturnCode returnCode_{RV_NOT_STARTED};
 
   /**
    * Represents a pipe between this process, and the child process (or its