Merge maint into master

* upstream/maint:
  fix generated comments
  traces: provide a means to get short m4 traces
  traces: show the full m4 invocation

src/getargs.c

@@ -257,7 +257,8 @@ static const argmatch_trace_doc argmatch_trace_docs[] =
   { "sets",       "grammar sets: firsts, nullable etc." },
   { "muscles",    "m4 definitions passed to the skeleton" },
   { "tools",      "m4 invocation" },
-  { "m4",         "m4 traces" },
+  { "m4-early",   "m4 traces starting from the start" },
+  { "m4",         "m4 traces starting from the skeleton evaluation" },
   { "skeleton",   "skeleton postprocessing" },
   { "time",       "time consumption" },
   { "ielr",       "IELR conversion" },
@@ -280,6 +281,7 @@ static const argmatch_trace_arg argmatch_trace_args[] =
   { "sets",      trace_sets },
   { "muscles",   trace_muscles },
   { "tools",     trace_tools },
+  { "m4-early",  trace_m4_early },
   { "m4",        trace_m4 },
   { "skeleton",  trace_skeleton },
   { "time",      trace_time },

src/getargs.h

@@ -100,12 +100,13 @@ enum trace
     trace_grammar   = 1 << 7,  /**< Reading, reducing the grammar. */
     trace_time      = 1 << 8,  /**< Time consumption. */
     trace_skeleton  = 1 << 9,  /**< Skeleton postprocessing. */
-    trace_m4        = 1 << 10, /**< M4 traces. */
-    trace_muscles   = 1 << 11, /**< M4 definitions of the muscles. */
-    trace_ielr      = 1 << 12, /**< IELR conversion. */
-    trace_closure   = 1 << 13, /**< Input/output of closure(). */
-    trace_locations = 1 << 14, /**< Full display of locations. */
-    trace_cex       = 1 << 15, /**< Counterexample generation */
+    trace_m4_early  = 1 << 10, /**< M4 early traces. */
+    trace_m4        = 1 << 11, /**< M4 traces. */
+    trace_muscles   = 1 << 12, /**< M4 definitions of the muscles. */
+    trace_ielr      = 1 << 13, /**< IELR conversion. */
+    trace_closure   = 1 << 14, /**< Input/output of closure(). */
+    trace_locations = 1 << 15, /**< Full display of locations. */
+    trace_cex       = 1 << 16, /**< Counterexample generation */
     trace_all       = ~0       /**< All of the above.  */
   };
 /** What debug items bison displays during its run.  */

src/output.c

@@ -687,6 +687,7 @@ output_skeleton (void)
   char *skeldir = xpath_join (datadir, "skeletons");
   char *m4sugar = xpath_join (datadir, "m4sugar/m4sugar.m4");
   char *m4bison = xpath_join (skeldir, "bison.m4");
+  char *traceon = xpath_join (skeldir, "traceon.m4");
   char *skel = (IS_PATH_WITH_DIR (skeleton)
                 ? xstrdup (skeleton)
                 : xpath_join (skeldir, skeleton));
@@ -698,21 +699,10 @@ output_skeleton (void)
 
   /* Create an m4 subprocess connected to us via two pipes.  */
 
-  if (trace_flag & trace_tools)
-    fprintf (stderr, "running: %s %s - %s %s\n",
-             m4, m4sugar, m4bison, skel);
-
-  /* Some future version of GNU M4 (most likely 1.6) may treat the -dV in a
-     position-dependent manner.  Keep it as the first argument so that all
-     files are traced.
-
-     See the thread starting at
-     <http://lists.gnu.org/archive/html/bug-bison/2008-07/msg00000.html>
-     for details.  */
   int filter_fd[2];
   pid_t pid;
   {
-    char const *argv[10];
+    char const *argv[11];
     int i = 0;
     argv[i++] = m4;
 
@@ -730,15 +720,29 @@ output_skeleton (void)
 
     argv[i++] = "-I";
     argv[i++] = datadir;
-    if (trace_flag & trace_m4)
+    /* Some future version of GNU M4 (most likely 1.6) may treat the
+       -dV in a position-dependent manner.  See the thread starting at
+       <http://lists.gnu.org/archive/html/bug-bison/2008-07/msg00000.html>
+       for details.  */
+    if (trace_flag & trace_m4_early)
       argv[i++] = "-dV";
     argv[i++] = m4sugar;
     argv[i++] = "-";
     argv[i++] = m4bison;
+    if (trace_flag & trace_m4)
+      argv[i++] = traceon;
     argv[i++] = skel;
     argv[i++] = NULL;
     aver (i <= ARRAY_CARDINALITY (argv));
 
+    if (trace_flag & trace_tools)
+      {
+        fputs ("running:", stderr);
+        for (int j = 0; argv[j]; ++j)
+          fprintf (stderr, " %s", argv[j]);
+        fputc ('\n', stderr);
+      }
+
     /* The ugly cast is because gnulib gets the const-ness wrong.  */
     pid = create_pipe_bidi ("m4", m4, (char **)(void*)argv, false, true,
                             true, filter_fd);
@@ -747,6 +751,7 @@ output_skeleton (void)
   free (skeldir);
   free (m4sugar);
   free (m4bison);
+  free (traceon);
   free (skel);
 
   if (trace_flag & trace_muscles)