HALF WORK: refactor something and implement part of subprocess.

1 files changed, 87 insertions, 1 deletions

diff --git a/src/common/platform/unix/PosixSpawnSubProcess.cpp b/src/common/platform/unix/PosixSpawnSubProcess.cpp
index 0eb5615d..8b9a9a47 100644
--- a/src/common/platform/unix/PosixSpawnSubProcess.cpp
+++ b/src/common/platform/unix/PosixSpawnSubProcess.cpp
@@ -1,8 +1,14 @@
 #include "cru/common/platform/unix/PosixSpawnSubProcess.h"
+#include "cru/common/Exception.h"
+#include "cru/common/Format.h"
+#include "cru/common/Guard.h"
+#include "cru/common/String.h"
 #include "cru/common/SubProcess.h"
 
 #include <spawn.h>
+#include <unistd.h>
 #include <memory>
+#include <unordered_map>
 
 namespace cru::platform::unix {
 PosixSpawnSubProcess::PosixSpawnSubProcess(
@@ -40,7 +46,87 @@ io::Stream* PosixSpawnSubProcess::GetStderrStream() {
   return stderr_buffer_stream_.get();
 }
 
-void PosixSpawnSubProcess::PlatformCreateProcess() {}
+namespace {
+char** CreateCstrArray(const std::vector<String>& argv) {
+  std::vector<Buffer> utf8_argv;
+  for (const auto& arg : argv) {
+    utf8_argv.push_back(arg.ToUtf8Buffer());
+  }
+  char** result = new char*[utf8_argv.size() + 1];
+  for (int i = 0; i < utf8_argv.size(); i++) {
+    result[i] = reinterpret_cast<char*>(utf8_argv[i].Detach());
+  }
+  result[utf8_argv.size()] = nullptr;
+  return result;
+}
+
+char** CreateCstrArray(const std::unordered_map<String, String>& envp) {
+  std::vector<String> str_array;
+  for (auto& [key, value] : envp) {
+    str_array.push_back(cru::Format(u"{}={}", key, value));
+  }
+  return CreateCstrArray(str_array);
+}
+
+void DestroyCstrArray(char** argv) {
+  int index = 0;
+  char* arg = argv[index];
+  while (arg) {
+    delete[] arg;
+    index++;
+    arg = argv[index];
+  }
+  delete[] argv;
+}
+}  // namespace
+
+void PosixSpawnSubProcess::PlatformCreateProcess() {
+  int error;
+  auto check_error = [&error](String message) {
+    if (error == 0) return;
+    std::unique_ptr<ErrnoException> inner(new ErrnoException({}, error));
+    throw SubProcessFailedToStartException(std::move(message),
+                                           std::move(inner));
+  };
+
+  posix_spawn_file_actions_t file_actions;
+  error = posix_spawn_file_actions_init(&file_actions);
+  check_error(u"Failed to call posix_spawn_file_actions_init.");
+  Guard file_actions_guard(
+      [&file_actions] { posix_spawn_file_actions_destroy(&file_actions); });
+
+  // dup2 stdin/stdout/stderr
+  error = posix_spawn_file_actions_adddup2(
+      &file_actions, stdin_pipe_.GetOtherFileDescriptor(), STDIN_FILENO);
+  check_error(u"Failed to call posix_spawn_file_actions_adddup2 on stdin.");
+  error = posix_spawn_file_actions_adddup2(
+      &file_actions, stdout_pipe_.GetOtherFileDescriptor(), STDOUT_FILENO);
+  check_error(u"Failed to call posix_spawn_file_actions_adddup2 on stdout.");
+  error = posix_spawn_file_actions_adddup2(
+      &file_actions, stderr_pipe_.GetOtherFileDescriptor(), STDERR_FILENO);
+  check_error(u"Failed to call posix_spawn_file_actions_adddup2 on stderr.");
+
+  posix_spawnattr_t attr;
+  error = posix_spawnattr_init(&attr);
+  check_error(u"Failed to call posix_spawnattr_init.");
+  Guard attr_guard([&attr] { posix_spawnattr_destroy(&attr); });
+
+#ifdef CRU_PLATFORM_OSX
+  error = posix_spawnattr_setflags(&attr, POSIX_SPAWN_CLOEXEC_DEFAULT);
+  check_error(u"Failed to set flag POSIX_SPAWN_CLOEXEC_DEFAULT (osx).");
+#endif
+
+  auto exe = start_info_.program.ToUtf8();
+
+  auto argv = CreateCstrArray(start_info_.arguments);
+  Guard argv_guard([argv] { DestroyCstrArray(argv); });
+
+  auto envp = CreateCstrArray(start_info_.environments);
+  Guard envp_guard([envp] { DestroyCstrArray(envp); });
+
+  error = posix_spawnp(&pid_, exe.c_str(), &file_actions, &attr, argv, envp);
+  check_error(u"Failed to call posix_spawnp.");
+}
 
 PlatformSubProcessExitResult PosixSpawnSubProcess::PlatformWaitForProcess() {}