[llvm-commits] CVS: llvm/lib/Support/SystemUtils.cpp

[John Criswell]

Changes in directory llvm/lib/Support:

SystemUtils.cpp updated: 1.13 -> 1.14

---
Log message:

Added the ExecWait() function.  It executes a program with the specified
arguments and environment.
Perhaps it should be merged with the RunProgramWithTimeout function, but I'd
want to allow it to inherit the parent process's stdin and stdout.
I'll save that for a rainy day...



---
Diffs of the changes:

Index: llvm/lib/Support/SystemUtils.cpp
diff -u llvm/lib/Support/SystemUtils.cpp:1.13 llvm/lib/Support/SystemUtils.cpp:1.14
--- llvm/lib/Support/SystemUtils.cpp:1.13	Tue Sep 16 10:31:46 2003
+++ llvm/lib/Support/SystemUtils.cpp	Wed Sep 17 10:13:59 2003
@@ -156,3 +156,101 @@
   }
   return Status;
 }
+
+
+//
+// Function: ExecWait ()
+//
+// Description:
+//  This function executes a program with the specified arguments and
+//  environment.  It then waits for the progarm to termiante and then returns
+//  to the caller.
+//
+// Inputs:
+//  argv - The arguments to the program as an array of C strings.  The first
+//         argument should be the name of the program to execute, and the
+//         last argument should be a pointer to NULL.
+//
+//  envp - The environment passes to the program as an array of C strings in
+//         the form of "name=value" pairs.  The last element should be a
+//         pointer to NULL.
+//
+// Outputs:
+//  None.
+//
+// Return value:
+//  0 - No errors.
+//  1 - The program could not be executed.
+//  1 - The program returned a non-zero exit status.
+//  1 - The program terminated abnormally.
+//
+// Notes:
+//  The program will inherit the stdin, stdout, and stderr file descriptors
+//  as well as other various configuration settings (umask).
+//
+//  This function should not print anything to stdout/stderr on its own.  It is
+//  a generic library function.  The caller or executed program should report
+//  errors in the way it sees fit.
+//
+int
+ExecWait (char ** argv, char **envp)
+{
+  // Child process ID
+  register int child;
+
+  // Status from child process when it exits
+  int status;
+ 
+  //
+  // Because UNIX is sometimes less than convenient, we need to use
+  // FindExecutable() to find the full pathname to the file to execute.
+  //
+  // This is becausse execvp() doesn't use PATH, and we want to look for
+  // programs in the LLVM binary directory first anyway.
+  //
+  std::string Program = FindExecutable (argv[0], "");
+  if (Program.empty())
+  {
+    return 1;
+  }
+
+  //
+  // Create a child process.
+  //
+  switch (child=fork())
+  {
+    case -1:
+      return 1;
+      break;
+
+    case 0:
+      execve (Program.c_str(), argv, envp);
+      return 1;
+      break;
+
+    default:
+      break;
+  }
+
+  //
+  // Parent process: Wait for the child process to termiante.
+  //
+  if ((wait (&status)) == -1)
+  {
+    return 1;
+  }
+
+  //
+  // If the program exited normally with a zero exit status, return success!
+  //
+  if (WIFEXITED (status) && (WEXITSTATUS(status) == 0))
+  {
+    return 0;
+  }
+
+  //
+  // Otherwise, return failure.
+  //
+  return 1;
+}
+