process: separate stderr from stdout

- Add the option of redirecting stderr to a file. With the old
behaviour, stderr would follow stdout if stdout was to a file, but
stderr went to the host stderr if stdout went to the host stdout.  The
new default maintains stdout and stderr going to the host.  Now the
two can specify different files, but they will share a file descriptor
if the name of the files is the same.
- Add --output and --errout options to se.py to go with --input.

2 files changed, 31 insertions, 7 deletions

diff --git a/src/sim/Process.py b/src/sim/Process.py
index 37a27bf3b..81108dd70 100644
--- a/src/sim/Process.py
+++ b/src/sim/Process.py
@@ -34,7 +34,8 @@ class Process(SimObject):
     type = 'Process'
     abstract = True
     input = Param.String('cin', "filename for stdin")
-    output = Param.String('cout', 'filename for stdout/stderr')
+    output = Param.String('cout', 'filename for stdout')
+    errout = Param.String('cerr', 'filename for stderr')
     system = Param.System(Parent.any, "system process will run on")
     max_stack_size = Param.MemorySize('64MB', 'maximum size of the stack')
 
diff --git a/src/sim/process.cc b/src/sim/process.cc
index 046a6bf9b..23e890b06 100644
--- a/src/sim/process.cc
+++ b/src/sim/process.cc
@@ -92,6 +92,7 @@ Process::Process(ProcessParams * params)
 {
     string in = params->input;
     string out = params->output;
+    string err = params->errout;
 
     // initialize file descriptors to default: same as simulator
     int stdin_fd, stdout_fd, stderr_fd;
@@ -112,7 +113,16 @@ Process::Process(ProcessParams * params)
     else
         stdout_fd = Process::openOutputFile(out);
 
-    stderr_fd = (stdout_fd != STDOUT_FILENO) ? stdout_fd : STDERR_FILENO;
+    if (err == "stdout" || err == "cout")
+        stderr_fd = STDOUT_FILENO;
+    else if (err == "stderr" || err == "cerr")
+        stderr_fd = STDERR_FILENO;
+    else if (err == "None")
+        stderr_fd = -1;
+    else if (err == out)
+        stderr_fd = stdout_fd;
+    else
+        stderr_fd = Process::openOutputFile(err);
 
     M5_pid = system->allocatePID();
     // initialize first 3 fds (stdin, stdout, stderr)
@@ -132,7 +142,7 @@ Process::Process(ProcessParams * params)
 
     fdo = &fd_map[STDERR_FILENO];
     fdo->fd = stderr_fd;
-    fdo->filename = "STDERR";
+    fdo->filename = err;
     fdo->flags = O_WRONLY;
     fdo->mode = -1;
     fdo->fileOffset = 0;
@@ -183,7 +193,7 @@ Process::openInputFile(const string &filename)
 int
 Process::openOutputFile(const string &filename)
 {
-    int fd = open(filename.c_str(), O_WRONLY | O_CREAT | O_TRUNC, 0774);
+    int fd = open(filename.c_str(), O_WRONLY | O_CREAT | O_TRUNC, 0664);
 
     if (fd == -1) {
         perror(NULL);
@@ -355,6 +365,7 @@ Process::fix_file_offsets() {
     Process::FdMap *fdo_stderr = &fd_map[STDERR_FILENO];
     string in = fdo_stdin->filename;
     string out = fdo_stdout->filename;
+    string err = fdo_stderr->filename;
 
     // initialize file descriptors to default: same as simulator
     int stdin_fd, stdout_fd, stderr_fd;
@@ -378,11 +389,23 @@ Process::fix_file_offsets() {
         stdout_fd = -1;
     else{
         stdout_fd = Process::openOutputFile(out);
-        if (lseek(stdin_fd, fdo_stdout->fileOffset, SEEK_SET) < 0)
-            panic("Unable to seek to correct in file: %s", out);
+        if (lseek(stdout_fd, fdo_stdout->fileOffset, SEEK_SET) < 0)
+            panic("Unable to seek to correct location in file: %s", out);
     }
 
-    stderr_fd = (stdout_fd != STDOUT_FILENO) ? stdout_fd : STDERR_FILENO;
+    if (err == "stdout" || err == "cout")
+        stderr_fd = STDOUT_FILENO;
+    else if (err == "stderr" || err == "cerr")
+        stderr_fd = STDERR_FILENO;
+    else if (err == "None")
+        stderr_fd = -1;
+    else if (err == out)
+        stderr_fd = stdout_fd;
+    else {
+        stderr_fd = Process::openOutputFile(err);
+        if (lseek(stderr_fd, fdo_stderr->fileOffset, SEEK_SET) < 0)
+            panic("Unable to seek to correct location in file: %s", err);
+    }
 
     fdo_stdin->fd = stdin_fd;
     fdo_stdout->fd = stdout_fd;