libutil: remove runProgram2 stdin functionality

this was only used in one place, and that place has been rewritten to
use a temporary file instead. keeping this around is not very helpful
at this time, and in any case we'd be better off rewriting subprocess
handling in rust where we not only have a much safer library for such
things but also async frameworks necessary for this easily available.

Change-Id: I6f8641b756857c84ae2602cdf41f74ee7a1fda02

5 files changed, 10 insertions, 65 deletions

diff --git a/src/libcmd/repl.cc b/src/libcmd/repl.cc
index 99abbe44b..32cbf8e33 100644
--- a/src/libcmd/repl.cc
+++ b/src/libcmd/repl.cc
@@ -242,8 +242,7 @@ NixRepl::NixRepl(const SearchPath & searchPath, nix::ref<Store> store, ref<EvalS
 {
 }
 
-void runNix(Path program, const Strings & args,
-    const std::optional<std::string> & input = {})
+void runNix(Path program, const Strings & args)
 {
     auto subprocessEnv = getEnv();
     subprocessEnv["NIX_CONFIG"] = globalConfig.toKeyValue();
@@ -252,7 +251,6 @@ void runNix(Path program, const Strings & args,
         .program = settings.nixBinDir+ "/" + program,
         .args = args,
         .environment = subprocessEnv,
-        .input = input,
     });
 
     return;
diff --git a/src/libfetchers/git.cc b/src/libfetchers/git.cc
index f2d577914..a06bc86b2 100644
--- a/src/libfetchers/git.cc
+++ b/src/libfetchers/git.cc
@@ -358,7 +358,7 @@ struct GitInputScheme : InputScheme
 
         args.push_back(destDir);
 
-        runProgram("git", true, args, {}, true);
+        runProgram("git", true, args, true);
     }
 
     std::optional<Path> getSourcePath(const Input & input) const override
@@ -589,7 +589,7 @@ struct GitInputScheme : InputScheme
                             : ref == "HEAD"
                                 ? *ref
                                 : "refs/heads/" + *ref;
-                    runProgram("git", true, { "-C", repoDir, "--git-dir", gitDir, "fetch", "--quiet", "--force", "--", actualUrl, fmt("%s:%s", fetchRef, fetchRef) }, {}, true);
+                    runProgram("git", true, { "-C", repoDir, "--git-dir", gitDir, "fetch", "--quiet", "--force", "--", actualUrl, fmt("%s:%s", fetchRef, fetchRef) }, true);
                 } catch (Error & e) {
                     if (!pathExists(localRefFile)) throw;
                     warn("could not update local clone of Git repository '%s'; continuing with the most recent version", actualUrl);
@@ -656,7 +656,7 @@ struct GitInputScheme : InputScheme
                 // everything to ensure we get the rev.
                 Activity act(*logger, lvlTalkative, actUnknown, fmt("making temporary clone of '%s'", repoDir));
                 runProgram("git", true, { "-C", tmpDir, "fetch", "--quiet", "--force",
-                        "--update-head-ok", "--", repoDir, "refs/*:refs/*" }, {}, true);
+                        "--update-head-ok", "--", repoDir, "refs/*:refs/*" }, true);
             }
 
             runProgram("git", true, { "-C", tmpDir, "checkout", "--quiet", input.getRev()->gitRev() });
@@ -683,7 +683,7 @@ struct GitInputScheme : InputScheme
 
             {
                 Activity act(*logger, lvlTalkative, actUnknown, fmt("fetching submodules of '%s'", actualUrl));
-                runProgram("git", true, { "-C", tmpDir, "submodule", "--quiet", "update", "--init", "--recursive" }, {}, true);
+                runProgram("git", true, { "-C", tmpDir, "submodule", "--quiet", "update", "--init", "--recursive" }, true);
             }
 
             filter = isNotDotGitDirectory;
diff --git a/src/libfetchers/mercurial.cc b/src/libfetchers/mercurial.cc
index 6015f8ec7..b4150e9df 100644
--- a/src/libfetchers/mercurial.cc
+++ b/src/libfetchers/mercurial.cc
@@ -28,10 +28,9 @@ static RunOptions hgOptions(const Strings & args)
 }
 
 // runProgram wrapper that uses hgOptions instead of stock RunOptions.
-static std::string runHg(const Strings & args, const std::optional<std::string> & input = {})
+static std::string runHg(const Strings & args)
 {
     RunOptions opts = hgOptions(args);
-    opts.input = input;
 
     auto res = runProgram(std::move(opts));
 
diff --git a/src/libutil/processes.cc b/src/libutil/processes.cc
index e8af12fbd..250092393 100644
--- a/src/libutil/processes.cc
+++ b/src/libutil/processes.cc
@@ -230,10 +230,9 @@ Pid startProcess(std::function<void()> fun, const ProcessOptions & options)
     return Pid{pid};
 }
 
-std::string runProgram(Path program, bool searchPath, const Strings & args,
-    const std::optional<std::string> & input, bool isInteractive)
+std::string runProgram(Path program, bool searchPath, const Strings & args, bool isInteractive)
 {
-    auto res = runProgram(RunOptions {.program = program, .searchPath = searchPath, .args = args, .input = input, .isInteractive = isInteractive});
+    auto res = runProgram(RunOptions {.program = program, .searchPath = searchPath, .args = args, .isInteractive = isInteractive});
 
     if (!statusOk(res.first))
         throw ExecError(res.first, "program '%1%' %2%", program, statusToString(res.first));
@@ -262,20 +261,9 @@ void runProgram2(const RunOptions & options)
 {
     checkInterrupt();
 
-    assert(!(options.standardIn && options.input));
-
-    std::unique_ptr<Source> source_;
-    Source * source = options.standardIn;
-
-    if (options.input) {
-        source_ = std::make_unique<StringSource>(*options.input);
-        source = source_.get();
-    }
-
     /* Create a pipe. */
-    Pipe out, in;
+    Pipe out;
     if (options.standardOut) out.create();
-    if (source) in.create();
 
     ProcessOptions processOptions;
 
@@ -298,8 +286,6 @@ void runProgram2(const RunOptions & options)
         if (options.mergeStderrToStdout)
             if (dup2(STDOUT_FILENO, STDERR_FILENO) == -1)
                 throw SysError("cannot dup stdout into stderr");
-        if (source && dup2(in.readSide.get(), STDIN_FILENO) == -1)
-            throw SysError("dupping stdin");
 
         if (options.chdir && chdir((*options.chdir).c_str()) == -1)
             throw SysError("chdir failed");
@@ -328,47 +314,12 @@ void runProgram2(const RunOptions & options)
 
     out.writeSide.close();
 
-    std::thread writerThread;
-
-    std::promise<void> promise;
-
-    Finally doJoin([&]() {
-        if (writerThread.joinable())
-            writerThread.join();
-    });
-
-
-    if (source) {
-        in.readSide.close();
-        writerThread = std::thread([&]() {
-            try {
-                std::vector<char> buf(8 * 1024);
-                while (true) {
-                    size_t n;
-                    try {
-                        n = source->read(buf.data(), buf.size());
-                    } catch (EndOfFile &) {
-                        break;
-                    }
-                    writeFull(in.writeSide.get(), {buf.data(), n});
-                }
-                promise.set_value();
-            } catch (...) {
-                promise.set_exception(std::current_exception());
-            }
-            in.writeSide.close();
-        });
-    }
-
     if (options.standardOut)
         drainFD(out.readSide.get(), *options.standardOut);
 
     /* Wait for the child to finish. */
     int status = pid.wait();
 
-    /* Wait for the writer thread to finish. */
-    if (source) promise.get_future().get();
-
     if (status)
         throw ExecError(status, "program '%1%' %2%", options.program, statusToString(status));
 }
diff --git a/src/libutil/processes.hh b/src/libutil/processes.hh
index 001e1fa12..48a195481 100644
--- a/src/libutil/processes.hh
+++ b/src/libutil/processes.hh
@@ -71,8 +71,7 @@ Pid startProcess(std::function<void()> fun, const ProcessOptions & options = Pro
  * shell backtick operator).
  */
 std::string runProgram(Path program, bool searchPath = false,
-    const Strings & args = Strings(),
-    const std::optional<std::string> & input = {}, bool isInteractive = false);
+    const Strings & args = Strings(), bool isInteractive = false);
 
 struct RunOptions
 {
@@ -83,8 +82,6 @@ struct RunOptions
     std::optional<uid_t> gid;
     std::optional<Path> chdir;
     std::optional<std::map<std::string, std::string>> environment;
-    std::optional<std::string> input;
-    Source * standardIn = nullptr;
     Sink * standardOut = nullptr;
     bool mergeStderrToStdout = false;
     bool isInteractive = false;