Enhance the output sync mode.

Create a new file, output.c, and collect functions that generate output there.
We introduce a new global context specifying where output should go (to stdout
or to a sync file), and the lowest level output generator chooses where to
write output based on that context.

This allows us to set the context globally, and all operations that write
output (including functions like $(info ...) etc.) will use it.

Removed the "--trace=dir" capability.  It was too confusing.  If you have
directory tracking enabled then output sync will print the enter/leave message
for each synchronized block.  If you don't want that, disable directory
tracking.

1 files changed, 601 insertions, 0 deletions

diff --git a/output.c b/output.c
new file mode 100644
index 0000000..6d621c2
--- /dev/null
+++ b/output.c
@@ -0,0 +1,601 @@
+/* Output to stdout / stderr for GNU make
+Copyright (C) 2013 Free Software Foundation, Inc.
+This file is part of GNU Make.
+
+GNU Make is free software; you can redistribute it and/or modify it under the
+terms of the GNU General Public License as published by the Free Software
+Foundation; either version 3 of the License, or (at your option) any later
+version.
+
+GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "makeint.h"
+#include "job.h"
+
+/* GNU make no longer supports pre-ANSI89 environments.  */
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <unistd.h>
+
+#ifdef HAVE_FCNTL_H
+# include <fcntl.h>
+#else
+# include <sys/file.h>
+#endif
+
+struct output *output_context = NULL;
+static unsigned int stdio_traced = 0;
+
+#define OUTPUT_NONE (-1)
+
+#define OUTPUT_ISSET(_out) ((_out)->out >= 0 || (_out)->err >= 0)
+
+/* I really want to move to gnulib.  However, this is a big undertaking
+   especially for non-UNIX platforms: how to get bootstrapping to work, etc.
+   I don't want to take the time to do it right now.  Use a hack to get a
+   useful version of vsnprintf() for Windows.  */
+#ifdef _MSC_VER
+#define va_copy(_d, _s) ((_d) = (_s))
+#define snprintf msc_vsnprintf
+static int
+msc_vsnprintf(char *str, size_t size, const char *format, va_list ap)
+{
+  int len = -1;
+
+  if (size > 0)
+    len = _vsnprintf_s (str, size, _TRUNCATE, format, ap);
+  if (len == -1)
+    len = _vscprintf (format, ap);
+
+  return len;
+}
+#endif
+
+/* Write a string to the current STDOUT or STDERR.  */
+static void
+_outputs (int is_err, const char *msg)
+{
+  if (! output_context || ! output_context->syncout)
+    {
+      FILE *f = is_err ? stderr : stdout;
+      fputs (msg, f);
+      fflush (f);
+    }
+  else
+    {
+      int fd = is_err ? output_context->err : output_context->out;
+      int len = strlen (msg);
+      int r;
+
+      EINTRLOOP (r, lseek (fd, 0, SEEK_END));
+      while (1)
+        {
+          EINTRLOOP (r, write (fd, msg, len));
+          if (r == len)
+            break;
+          if (r <= 0)
+            return;
+          len -= r;
+          msg += r;
+        }
+    }
+}
+
+/* Write a message indicating that we've just entered or
+   left (according to ENTERING) the current directory.  */
+
+static int
+log_working_directory (int entering)
+{
+  static char *buf = NULL;
+  static unsigned int len = 0;
+  unsigned int need;
+  const char *fmt;
+  char *p;
+
+  /* Only print if directory logging is enabled.  */
+  if (entering && ! print_directory_flag)
+    return 0;
+
+  /* Get enough space for the longest possible output.  */
+  need = strlen (program) + INTEGER_LENGTH + 2 + 1;
+  if (starting_directory)
+    need += strlen (starting_directory);
+
+  /* Use entire sentences to give the translators a fighting chance.  */
+  if (makelevel == 0)
+    if (starting_directory == 0)
+      if (entering)
+        fmt = _("%s: Entering an unknown directory\n");
+      else
+        fmt = _("%s: Leaving an unknown directory\n");
+    else
+      if (entering)
+        fmt = _("%s: Entering directory '%s'\n");
+      else
+        fmt = _("%s: Leaving directory '%s'\n");
+  else
+    if (starting_directory == 0)
+      if (entering)
+        fmt = _("%s[%u]: Entering an unknown directory\n");
+      else
+        fmt = _("%s[%u]: Leaving an unknown directory\n");
+    else
+      if (entering)
+        fmt = _("%s[%u]: Entering directory '%s'\n");
+      else
+        fmt = _("%s[%u]: Leaving directory '%s'\n");
+
+  need += strlen (fmt);
+
+  if (need > len)
+    {
+      buf = xrealloc (buf, need);
+      len = need;
+    }
+
+  p = buf;
+  if (print_data_base_flag)
+    {
+      *(p++) = '#';
+      *(p++) = ' ';
+    }
+
+  if (makelevel == 0)
+    if (starting_directory == 0)
+      sprintf (p, fmt , program);
+    else
+      sprintf (p, fmt, program, starting_directory);
+  else if (starting_directory == 0)
+    sprintf (p, fmt, program, makelevel);
+  else
+    sprintf (p, fmt, program, makelevel, starting_directory);
+
+  _outputs (0, buf);
+
+  return 1;
+}
+
+
+#ifdef OUTPUT_SYNC
+
+/* Semaphore for use in -j mode with output_sync. */
+static sync_handle_t sync_handle = -1;
+
+#define STREAM_OK(_s)       ((fcntl (fileno (_s), F_GETFD) != -1) || (errno != EBADF))
+
+#define FD_NOT_EMPTY(_f)    ((_f) != OUTPUT_NONE && lseek ((_f), 0, SEEK_END) > 0)
+
+/* Set up the sync handle.  Disables output_sync on error.  */
+static int
+sync_init ()
+{
+  int combined_output;
+
+#ifdef WINDOWS32
+  if ((!STREAM_OK (stdout) && !STREAM_OK (stderr))
+      || (sync_handle = create_mutex ()) == -1)
+    {
+      perror_with_name ("output-sync suppressed: ", "stderr");
+      output_sync = 0;
+    }
+  else
+    {
+      combined_output = same_stream (stdout, stderr);
+      prepare_mutex_handle_string (sync_handle);
+    }
+
+#else
+  if (STREAM_OK (stdout))
+    {
+      struct stat stbuf_o, stbuf_e;
+
+      sync_handle = fileno (stdout);
+      combined_output = (fstat (fileno (stdout), &stbuf_o) == 0
+                         && fstat (fileno (stderr), &stbuf_e) == 0
+                         && stbuf_o.st_dev == stbuf_e.st_dev
+                         && stbuf_o.st_ino == stbuf_e.st_ino);
+    }
+  else if (STREAM_OK (stderr))
+    sync_handle = fileno (stderr);
+  else
+    {
+      perror_with_name ("output-sync suppressed: ", "stderr");
+      output_sync = 0;
+    }
+#endif
+
+  return combined_output;
+}
+
+/* Support routine for output_sync() */
+static void
+pump_from_tmp (int from, FILE *to)
+{
+  static char buffer[8192];
+
+#ifdef WINDOWS32
+  int prev_mode;
+
+  /* "from" is opened by open_tmpfd, which does it in binary mode, so
+     we need the mode of "to" to match that.  */
+  prev_mode = _setmode (fileno (to), _O_BINARY);
+#endif
+
+  if (lseek (from, 0, SEEK_SET) == -1)
+    perror ("lseek()");
+
+  while (1)
+    {
+      int len;
+      EINTRLOOP (len, read (from, buffer, sizeof (buffer)));
+      if (len < 0)
+        perror ("read()");
+      if (len <= 0)
+        break;
+      if (fwrite (buffer, len, 1, to) < 1)
+        perror ("fwrite()");
+    }
+
+#ifdef WINDOWS32
+  /* Switch "to" back to its original mode, so that log messages by
+     Make have the same EOL format as without --output-sync.  */
+  _setmode (fileno (to), prev_mode);
+#endif
+}
+
+/* Obtain the lock for writing output.  */
+static void *
+acquire_semaphore (void)
+{
+  static struct flock fl;
+
+  fl.l_type = F_WRLCK;
+  fl.l_whence = SEEK_SET;
+  fl.l_start = 0;
+  fl.l_len = 1;
+  if (fcntl (sync_handle, F_SETLKW, &fl) != -1)
+    return &fl;
+  perror ("fcntl()");
+  return NULL;
+}
+
+/* Release the lock for writing output.  */
+static void
+release_semaphore (void *sem)
+{
+  struct flock *flp = (struct flock *)sem;
+  flp->l_type = F_UNLCK;
+  if (fcntl (sync_handle, F_SETLKW, flp) == -1)
+    perror ("fcntl()");
+}
+
+/* Synchronize the output of jobs in -j mode to keep the results of
+   each job together. This is done by holding the results in temp files,
+   one for stdout and potentially another for stderr, and only releasing
+   them to "real" stdout/stderr when a semaphore can be obtained. */
+
+void
+output_dump (struct output *out)
+{
+  int outfd_not_empty = FD_NOT_EMPTY (out->out);
+  int errfd_not_empty = FD_NOT_EMPTY (out->err);
+
+  if (outfd_not_empty || errfd_not_empty)
+    {
+      int logged = 0;
+
+      /* Try to acquire the semaphore.  If it fails, dump the output
+         unsynchronized; still better than silently discarding it.  */
+      void *sem = acquire_semaphore ();
+
+      /* Log the working directory, if we need to.  */
+      if (out->syncout)
+        logged = log_working_directory (1);
+
+      /* We've entered the "critical section" during which a lock is held.  We
+         want to keep it as short as possible.  */
+      if (outfd_not_empty)
+        pump_from_tmp (out->out, stdout);
+      if (errfd_not_empty && out->err != out->out)
+        pump_from_tmp (out->err, stderr);
+
+      if (logged)
+        log_working_directory (0);
+
+      /* Exit the critical section.  */
+      if (sem)
+        release_semaphore (sem);
+
+      /* Truncate and reset the output, in case we use it again.  */
+      if (out->out != OUTPUT_NONE)
+        {
+          int e;
+          lseek (out->out, 0, SEEK_SET);
+          EINTRLOOP (e, ftruncate (out->out, 0));
+        }
+      if (out->err != OUTPUT_NONE && out->err != out->out)
+        {
+          int e;
+          lseek (out->err, 0, SEEK_SET);
+          EINTRLOOP (e, ftruncate (out->err, 0));
+        }
+    }
+}
+
+/* Adds file descriptors to the child structure to support output_sync; one
+   for stdout and one for stderr as long as they are open.  If stdout and
+   stderr share a device they can share a temp file too.
+   Will reset output_sync on error.  */
+static void
+setup_tmpfile (struct output *out)
+{
+  /* Is make's stdout going to the same place as stderr?  */
+  static int combined_output = -1;
+
+  if (combined_output < 0)
+    combined_output = sync_init ();
+
+  if (STREAM_OK (stdout))
+    {
+      int fd = open_tmpfd ();
+      if (fd < 0)
+        goto error;
+      CLOSE_ON_EXEC (fd);
+      out->out = fd;
+    }
+
+  if (STREAM_OK (stderr))
+    {
+      if (out->out != OUTPUT_NONE && combined_output)
+        out->err = out->out;
+      else
+        {
+          int fd = open_tmpfd ();
+          if (fd < 0)
+            goto error;
+          CLOSE_ON_EXEC (fd);
+          out->err = fd;
+        }
+    }
+
+  return;
+
+  /* If we failed to create a temp file, disable output sync going forward.  */
+ error:
+  output_close (out);
+  output_sync = 0;
+}
+#endif /* OUTPUT_SYNC */
+
+
+void
+output_init (struct output *out, unsigned int syncout)
+{
+  out->out = out->err = OUTPUT_NONE;
+  out->syncout = !!syncout;
+}
+
+void
+output_close (struct output *out)
+{
+  if (! out)
+    {
+      if (stdio_traced)
+        log_working_directory (0);
+      return;
+    }
+
+#ifdef OUTPUT_SYNC
+  output_dump (out);
+#endif
+
+  if (out->out >= 0)
+    close (out->out);
+  if (out->err >= 0 && out->err != out->out)
+    close (out->err);
+
+  output_init (out, 0);
+}
+
+/* We're about to run a sub-process so ensure we've got our output set up.  */
+void
+output_start ()
+{
+  if (! output_context)
+    {
+      if (! stdio_traced)
+        stdio_traced = log_working_directory (1);
+    }
+#ifdef OUTPUT_SYNC
+  else if (output_context->syncout && ! OUTPUT_ISSET(output_context))
+    setup_tmpfile (output_context);
+#endif
+}
+
+void
+outputs (int is_err, const char *msg)
+{
+  /* For stdio, an empty msg means we're about to invoke a shell command,
+     which may or may not generate output, so log the directory.  */
+  if (! output_context && ! stdio_traced)
+    stdio_traced = log_working_directory (1);
+
+  /* Don't bother to do anything with empty strings.  */
+  if (! msg || *msg == '\0')
+    return;
+
+#ifdef OUTPUT_SYNC
+  if (output_context)
+    {
+      /* Create a temporary file to write to, if necessary.  */
+      if (output_context->syncout && ! OUTPUT_ISSET(output_context))
+        setup_tmpfile (output_context);
+    }
+#endif
+
+  _outputs (is_err, msg);
+}
+
+
+/* Return formatted string buffers.
+   If we move to gnulib we can use vasnprintf() etc. to make this simpler.
+   Note these functions use a static buffer, so each call overwrites the
+   results of the previous call.  */
+
+static struct fmtstring
+  {
+    char *buffer;
+    unsigned int size;
+    unsigned int len;
+  } fmtbuf = { NULL, 0, 0 };
+
+/* Concatenate a formatted string onto the format buffer.  */
+static const char *
+vfmtconcat (const char *fmt, va_list args)
+{
+  va_list vcopy;
+  int tot;
+  int unused = fmtbuf.size - fmtbuf.len;
+
+  va_copy(vcopy, args);
+
+  tot = vsnprintf (&fmtbuf.buffer[fmtbuf.len], unused, fmt, args);
+  assert (tot >= 0);
+
+  if (tot >= unused)
+    {
+      fmtbuf.size += tot * 2;
+      fmtbuf.buffer = xrealloc (fmtbuf.buffer, fmtbuf.size);
+
+      unused = fmtbuf.size - fmtbuf.len;
+      tot = vsnprintf (&fmtbuf.buffer[fmtbuf.len], unused, fmt, vcopy);
+    }
+
+  va_end(vcopy);
+
+  fmtbuf.len += tot;
+
+  return fmtbuf.buffer;
+}
+
+static const char *
+fmtconcat (const char *fmt, ...)
+{
+  const char *p;
+  va_list args;
+
+  va_start (args, fmt);
+  p = vfmtconcat (fmt, args);
+  va_end (args);
+
+  return p;
+}
+
+/* Print a message on stdout.  */
+
+void
+message (int prefix, const char *fmt, ...)
+{
+  va_list args;
+
+  assert (fmt != NULL);
+
+  fmtbuf.len = 0;
+
+  if (prefix)
+    {
+      if (makelevel == 0)
+        fmtconcat ("%s: ", program);
+      else
+        fmtconcat ("%s[%u]: ", program, makelevel);
+    }
+
+  va_start (args, fmt);
+  vfmtconcat (fmt, args);
+  va_end (args);
+
+  fmtconcat ("\n");
+
+  outputs (0, fmtbuf.buffer);
+}
+
+/* Print an error message.  */
+
+void
+error (const gmk_floc *flocp, const char *fmt, ...)
+{
+  va_list args;
+
+  assert (fmt != NULL);
+
+  fmtbuf.len = 0;
+
+  if (flocp && flocp->filenm)
+    fmtconcat ("%s:%lu: ", flocp->filenm, flocp->lineno);
+  else if (makelevel == 0)
+    fmtconcat ("%s: ", program);
+  else
+    fmtconcat ("%s[%u]: ", program, makelevel);
+
+  va_start (args, fmt);
+  vfmtconcat (fmt, args);
+  va_end (args);
+
+  fmtconcat ("\n");
+
+  outputs (1, fmtbuf.buffer);
+}
+
+/* Print an error message and exit.  */
+
+void
+fatal (const gmk_floc *flocp, const char *fmt, ...)
+{
+  va_list args;
+
+  assert (fmt != NULL);
+
+  fmtbuf.len = 0;
+
+  if (flocp && flocp->filenm)
+    fmtconcat ("%s:%lu: *** ", flocp->filenm, flocp->lineno);
+  else if (makelevel == 0)
+    fmtconcat ("%s: *** ", program);
+  else
+    fmtconcat ("%s[%u]: *** ", program, makelevel);
+
+  va_start (args, fmt);
+  vfmtconcat (fmt, args);
+  va_end (args);
+
+  fmtconcat (_(".  Stop.\n"));
+  outputs (1, fmtbuf.buffer);
+
+  die (2);
+}
+
+/* Print an error message from errno.  */
+
+void
+perror_with_name (const char *str, const char *name)
+{
+  error (NILF, _("%s%s: %s"), str, name, strerror (errno));
+}
+
+/* Print an error message from errno and exit.  */
+
+void
+pfatal_with_name (const char *name)
+{
+  fatal (NILF, _("%s: %s"), name, strerror (errno));
+
+  /* NOTREACHED */
+}