[sanitizers] extracted process management functions

Differential Revision: http://reviews.llvm.org/D16542

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@258710 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 68 insertions, 0 deletions

diff --git a/lib/sanitizer_common/sanitizer_linux_libcdep.cc b/lib/sanitizer_common/sanitizer_linux_libcdep.cc
index 8cf2c73b1..7a4592e6b 100644
--- a/lib/sanitizer_common/sanitizer_linux_libcdep.cc
+++ b/lib/sanitizer_common/sanitizer_linux_libcdep.cc
@@ -34,6 +34,7 @@
 #include <pthread.h>
 #include <signal.h>
 #include <sys/resource.h>
+#include <sys/wait.h>
 
 #if SANITIZER_FREEBSD
 #include <pthread_np.h>
@@ -546,6 +547,73 @@ void LogMessageOnPrintf(const char *str) {
     WriteToSyslog(str);
 }
 
+int StartSubprocess(const char *program, char *const argv[], fd_t std_in_fd,
+                    fd_t std_out_fd, fd_t std_err_fd) {
+  auto file_closer = at_scope_exit([&] {
+    if (std_in_fd >= 0) {
+      internal_close(std_in_fd);
+    }
+    if (std_out_fd >= 0) {
+      internal_close(std_out_fd);
+    }
+    if (std_err_fd >= 0) {
+      internal_close(std_err_fd);
+    }
+  });
+
+  if (!FileExists(program)) {
+    Report("WARNING: Program %s not found!\n", program);
+    return -1;
+  }
+
+  int pid = internal_fork();
+
+  if (pid < 0) {
+    int rverrno;
+    if (internal_iserror(pid, &rverrno)) {
+      Report("WARNING: failed to fork (errno %d)\n", rverrno);
+    }
+    return pid;
+  }
+
+  if (pid == 0) {
+    // Child subprocess
+    if (std_in_fd >= 0) {
+      internal_close(STDIN_FILENO);
+      internal_dup2(std_in_fd, STDIN_FILENO);
+      internal_close(std_in_fd);
+    }
+    if (std_out_fd >= 0) {
+      internal_close(STDOUT_FILENO);
+      internal_dup2(std_out_fd, STDOUT_FILENO);
+      internal_close(std_out_fd);
+    }
+    if (std_err_fd >= 0) {
+      internal_close(STDERR_FILENO);
+      internal_dup2(std_err_fd, STDERR_FILENO);
+      internal_close(std_err_fd);
+    }
+
+    for (int fd = sysconf(_SC_OPEN_MAX); fd > 2; fd--) internal_close(fd);
+
+    internal_execve(program, argv, nullptr);
+    internal__exit(1);
+  }
+
+  return pid;
+}
+
+bool IsProcessRunning(int pid) {
+  int process_status;
+  uptr waitpid_status = internal_waitpid(pid, &process_status, WNOHANG);
+  int local_errno;
+  if (internal_iserror(waitpid_status, &local_errno)) {
+    VReport(1, "Waiting on the process failed (errno %d).\n", local_errno);
+    return false;
+  }
+  return waitpid_status == 0;
+}
+
 #endif // SANITIZER_LINUX
 
 } // namespace __sanitizer