time usage for subprocesses

[Zack Weinberg <zack at rabi dot columbia dot edu>]

This is an interesting little hack which makes the gcc driver report user
and system time consumed by the compilation subprocesses.  It prints out
decimal seconds like this:

# cpp 1.21 0.04
# cc1 3.60 0.10
# as 0.12 0.02

-first user, then system.  The format is intended to be readily crunched by
a script.  You can get statistics like these:

# libc compile, -O2
cpp   	  851.09   178.59	  14:11.09    2:58.59
cc1   	 2400.45   123.45	  40:00.44    2:03.45
as    	  266.54    49.52	   4:26.54      49.52
total  	 3518.08   351.56	  58:38.08    5:51.56

# same with -O2 -pipe
cpp   	  854.05   171.45	  14:14.05    2:51.45
cc1   	 2405.74   104.15	  40:05.73    1:44.15
as    	  273.37    42.62	   4:33.37      42.62
total  	 3533.16   318.22	  58:53.16    5:18.22


The changes to gcc itself are not that exciting, but I had to modify
libiberty; I'm not sure about the portability issues there.  The feature
only works on Unix systems, and I assume wait4 is available if getrusage is,
which may not be safe.

zw

Index: libiberty/pexecute.c
===================================================================
RCS file: /cvs/egcs/egcs/libiberty/pexecute.c,v
retrieving revision 1.13
diff -u -r1.13 pexecute.c
--- pexecute.c	1999/04/11 22:21:27	1.13
+++ pexecute.c	1999/06/15 00:33:22
@@ -228,6 +228,17 @@
   return last_pid;
 }
 
+/* MSDOS does not support retrieving resource usage.  */
+int
+pwaitr (pid, status, flags, rusage)
+     int pid;
+     int *status;
+     int flags;
+     void *rusage;
+{
+  return pwait (pid, status, flags);
+}
+
 #endif /* MSDOS */
 
 #if defined (_WIN32) && ! defined (_UWIN)
@@ -419,6 +430,18 @@
 #endif /* __CYGWIN__ */
 }
 
+/* Win32 probably supports retrieving resource usage, but I don't
+   know how to do it.  FIXME */
+int
+pwaitr (pid, status, flags, rusage)
+     int pid;
+     int *status;
+     int flags;
+     void *rusage;
+{
+  return pwait (pid, status, flags);
+}
+
 #endif /* _WIN32 && ! _UWIN */
 
 #ifdef OS2
@@ -463,6 +486,18 @@
   return pid;
 }
 
+/* OS/2 probably supports retrieving resource usage, but I don't
+   know how to do it.  FIXME */
+int
+pwaitr (pid, status, flags, rusage)
+     int pid;
+     int *status;
+     int flags;
+     void *rusage;
+{
+  return pwait (pid, status, flags);
+}
+
 #endif /* OS2 */
 
 #ifdef MPW
@@ -589,6 +624,17 @@
   return 0;
 }
 
+/* MPW does not support retrieving resource usage.  */
+int
+pwaitr (pid, status, flags, rusage)
+     int pid;
+     int *status;
+     int flags;
+     void *rusage;
+{
+  return pwait (pid, status, flags);
+}
+
 /* Write out commands that will exit with the correct error code
    if something in the script failed.  */
 
@@ -730,5 +776,21 @@
 #endif
   return pid;
 }
+
+/* XXX Assumes wait4 exists if HAVE_GETRUSAGE - probably wrong */
+int
+pwaitr (pid, status, flags, rusage)
+     int pid;
+     int *status;
+     int flags;
+     void *rusage;
+{
+#ifdef HAVE_GETRUSAGE
+  return wait4 (-1, status, 0, rusage);
+#else
+  return pwait (pid, status, flags);
+#endif
+}
+
 
 #endif /* ! __MSDOS__ && ! OS2 && ! MPW && ! (_WIN32 && ! _UWIN) */
Index: gcc/gcc.c
===================================================================
RCS file: /cvs/egcs/egcs/gcc/gcc.c,v
retrieving revision 1.102
diff -u -r1.102 gcc.c
--- gcc.c	1999/05/17 23:37:17	1.102
+++ gcc.c	1999/06/15 00:33:38
@@ -43,6 +43,10 @@
 #define exit __posix_exit
 #endif
 
+#ifdef HAVE_SYS_RESOURCE_H
+#include <sys/resource.h>
+#endif
+
 /* By default there is no special suffix for executables.  */
 #ifdef EXECUTABLE_SUFFIX
 #define HAVE_EXECUTABLE_SUFFIX
@@ -125,6 +129,11 @@
 
 static int verbose_flag;
 
+/* Flag indicating whether we should report subprocess execution times
+   (if this is supported by the system - see pexecute.c).  */
+
+static int report_times;
+
 /* Nonzero means write "temp" files in source directory
    and use the source file's name in them, and don't delete them.  */
 
@@ -874,6 +883,7 @@
    {"--std", "-std=", "aj"},
    {"--symbolic", "-symbolic", 0},
    {"--target", "-b", "a"},
+   {"--time", "-time", 0},
    {"--trace-includes", "-H", 0},
    {"--traditional", "-traditional", 0},
    {"--traditional-cpp", "-traditional-cpp", 0},
@@ -2209,6 +2219,9 @@
     };
 
   struct command *commands;	/* each command buffer with above info.  */
+#ifdef HAVE_SYS_RESOURCE_H
+  struct rusage rus;
+#endif
 
   /* Count # of piped commands.  */
   for (n_commands = 1, i = 0; i < argbuf_index; i++)
@@ -2322,6 +2335,14 @@
 	int status;
 	int pid;
 
+#ifdef HAVE_SYS_RESOURCE_H
+	if (report_times)
+	  {
+	    bzero (&rus, sizeof (struct rusage));
+	    pid = pwaitr (commands[i].pid, &status, 0, &rus);
+	  }
+	else
+#endif		   
 	pid = pwait (commands[i].pid, &status, 0);
 	if (pid < 0)
 	  abort ();
@@ -2343,6 +2364,16 @@
 			   && WEXITSTATUS (status) >= MIN_FATAL_STATUS)
 		    ret_code = -1;
 		}
+#ifdef HAVE_SYS_RESOURCE_H
+	      if (report_times
+		  && rus.ru_utime.tv_sec + rus.ru_utime.tv_usec != 0)
+		notice ("# %s %.2f %.2f\n",
+			commands[j].prog,
+			(double)rus.ru_utime.tv_sec +
+			(double)rus.ru_utime.tv_usec / 1.0e6,
+			(double)rus.ru_stime.tv_sec +
+			(double)rus.ru_stime.tv_usec / 1.0e6);
+#endif
 	      break;
 	    }
       }
@@ -2867,6 +2898,8 @@
 	    user_specs_head = user;
 	  user_specs_tail = user;
 	}
+      else if (strcmp (argv[i], "-time") == 0)
+	report_times = 1;
       else if (argv[i][0] == '-' && argv[i][1] != 0)
 	{
 	  register char *p = &argv[i][1];
@@ -3206,6 +3239,8 @@
       else if (strcmp (argv[i], "-specs") == 0)
 	i++;
       else if (strncmp (argv[i], "-specs=", 7) == 0)
+	;
+      else if (strcmp (argv[i], "-time") == 0)
 	;
       /* -save-temps overrides -pipe, so that temp files are produced */
       else if (save_temps_flag && strcmp (argv[i], "-pipe") == 0)