Initial commit of an platform-indepdendent implementation for the
"Program" operating system concept (find and execute programs).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16084 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/System/Unix/Program.cpp b/lib/System/Unix/Program.cpp
new file mode 100644
index 0000000..6943d52
--- /dev/null
+++ b/lib/System/Unix/Program.cpp
@@ -0,0 +1,133 @@
+//===- llvm/System/Unix/Program.cpp -----------------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by Reid Spencer and is distributed under the
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the Unix specific portion of the Program class.
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only generic UNIX code that
+//=== is guaranteed to work on *all* UNIX variants.
+//===----------------------------------------------------------------------===//
+
+#include "Unix.h"
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <Config/config.h>
+#ifdef HAVE_SYS_WAIT_H
+#include <sys/wait.h>
+#endif
+
+namespace llvm {
+using namespace sys;
+
+// This function just uses the PATH environment variable to find the program.
+Program
+Program::FindProgramByName(const std::string& progName) {
+
+ // Check some degenerate cases
+ if (progName.length() == 0) // no program
+ return Program();
+ Program temp;
+ if (!temp.set_file(progName)) // invalid name
+ return Program();
+ if (temp.executable()) // already executable as is
+ return temp;
+
+ // At this point, the file name is valid and its not executable
+
+ // Get the path. If its empty, we can't do anything to find it.
+ const char *PathStr = getenv("PATH");
+ if (PathStr == 0)
+ return Program();
+
+ // Now we have a colon separated list of directories to search; try them.
+ unsigned PathLen = strlen(PathStr);
+ while (PathLen) {
+ // Find the first colon...
+ const char *Colon = std::find(PathStr, PathStr+PathLen, ':');
+
+ // Check to see if this first directory contains the executable...
+ Program FilePath;
+ if (FilePath.set_directory(std::string(PathStr,Colon))) {
+ FilePath.append_file(progName);
+ if (FilePath.executable())
+ return FilePath; // Found the executable!
+ }
+
+ // Nope it wasn't in this directory, check the next path in the list!
+ PathLen -= Colon-PathStr;
+ PathStr = Colon;
+
+ // Advance past duplicate colons
+ while (*PathStr == ':') {
+ PathStr++;
+ PathLen--;
+ }
+ }
+ return Program();
+}
+
+//
+int
+Program::ExecuteAndWait(const std::vector<std::string>& args) const {
+ if (!executable())
+ throw get() + " is not executable";
+
+#ifdef HAVE_SYS_WAIT_H
+ // Create local versions of the parameters that can be passed into execve()
+ // without creating const problems.
+ const char* argv[ args.size() + 2 ];
+ unsigned index = 0;
+ std::string progname(this->getLast());
+ argv[index++] = progname.c_str();
+ for (unsigned i = 0; i < args.size(); i++)
+ argv[index++] = args[i].c_str();
+ argv[index] = 0;
+
+ // Create a child process.
+ switch (fork()) {
+ // An error occured: Return to the caller.
+ case -1:
+ ThrowErrno(std::string("Couldn't execute program '") + get() + "'");
+ break;
+
+ // Child process: Execute the program.
+ case 0:
+ execve (get().c_str(), (char** const)argv, environ);
+ // If the execve() failed, we should exit and let the parent pick up
+ // our non-zero exit status.
+ exit (errno);
+
+ // Parent process: Break out of the switch to do our processing.
+ default:
+ break;
+ }
+
+ // Parent process: Wait for the child process to terminate.
+ int status;
+ if ((::wait (&status)) == -1)
+ ThrowErrno(std::string("Failed waiting for program '") + get() + "'");
+
+ // If the program exited normally with a zero exit status, return success!
+ if (WIFEXITED (status))
+ return WEXITSTATUS(status);
+ else if (WIFSIGNALED(status))
+ throw std::string("Program '") + get() + "' received terminating signal.";
+ else
+ return 0;
+
+#else
+ throw std::string("Program::ExecuteAndWait not implemented on this platform!\n");
+#endif
+
+}
+
+}
+// vim: sw=2 smartindent smarttab tw=80 autoindent expandtab