all remaining *.c *.h files from hp merge.

1 files changed, 324 insertions, 31 deletions

diff --git a/gdb/fork-child.c b/gdb/fork-child.c
index 243bed4..e262f89 100644
--- a/gdb/fork-child.c
+++ b/gdb/fork-child.c
@@ -33,12 +33,67 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
 #include <unistd.h>
 #endif
 
-extern char **environ;
+#define DEBUGGING 0
 
+/* This just gets used as a default if we can't find SHELL */
 #ifndef SHELL_FILE
 #define SHELL_FILE "/bin/sh"
 #endif
 
+extern char **environ;
+
+/* This function breaks up an argument string into an argument
+ * vector suitable for passing to execvp().
+ * E.g., on "run a b c d" this routine would get as input
+ * the string "a b c d", and as output it would fill in argv with
+ * the four arguments "a", "b", "c", "d".
+ */ 
+static void
+breakup_args (
+  scratch,
+  argv)
+char *scratch;
+char **argv;
+{
+    char *cp = scratch;
+
+#if DEBUGGING
+    printf("breakup_args: input = %s\n", scratch);
+#endif
+    for (;;) {
+
+        /* Scan past leading separators */
+        while (*cp == ' ' || *cp == '\t' || *cp == '\n') {
+          cp++;
+        }
+
+        /* Break if at end of string */
+        if (*cp == '\0') break;
+
+        /* Take an arg */
+        *argv++ = cp;
+
+        /* Scan for next arg separator */
+        cp = strchr (cp, ' ');
+        if (cp == NULL)
+          cp = strchr (cp, '\t');
+        if (cp == NULL)
+          cp = strchr (cp, '\n');
+
+        /* No separators => end of string => break */
+        if (cp == NULL)
+          break;
+
+        /* Replace the separator with a terminator */
+        *cp++ = '\0';
+    }
+
+    /* execv requires a null-terminated arg vector */
+    *argv = NULL;
+
+}
+
+
 /* Start an inferior Unix child process and sets inferior_pid to its pid.
    EXEC_FILE is the file to run.
    ALLARGS is a string containing the arguments to the program.
@@ -47,12 +102,13 @@ extern char **environ;
 
 void
 fork_inferior (exec_file, allargs, env, traceme_fun, init_trace_fun,
-	       shell_file)
+	       pre_trace_fun, shell_file)
      char *exec_file;
      char *allargs;
      char **env;
      void (*traceme_fun) PARAMS ((void));
-     int (*init_trace_fun) PARAMS ((int));
+     void (*init_trace_fun) PARAMS ((int));
+     void (*pre_trace_fun) PARAMS ((void));
      char *shell_file;
 {
   int pid;
@@ -65,22 +121,31 @@ fork_inferior (exec_file, allargs, env, traceme_fun, init_trace_fun,
      to you in the parent process.  It's only used by humans for debugging.  */
   static int debug_setpgrp = 657473;
   char **save_our_env;
+  int shell = 0;
+  char **argv;
+  char *tryname;
 
   /* If no exec file handed to us, get it from the exec-file command -- with
      a good, common error message if none is specified.  */
   if (exec_file == 0)
     exec_file = get_exec_file(1);
 
-  /* The user might want tilde-expansion, and in general probably wants
-     the program to behave the same way as if run from
-     his/her favorite shell.  So we let the shell run it for us.
-     FIXME-maybe, we might want a "set shell" command so the user can change
-     the shell from within GDB (if so, change callers which pass in a non-NULL
-     shell_file too).  */
-  if (shell_file == NULL)
-    shell_file = getenv ("SHELL");
-  if (shell_file == NULL)
-    shell_file = default_shell_file;
+  /* STARTUP_WITH_SHELL is defined in inferior.h.
+   * If 0, we'll just do a fork/exec, no shell, so don't
+   * bother figuring out what shell.
+   */
+  if (STARTUP_WITH_SHELL) {
+    /* Figure out what shell to start up the user program under. */
+    if (shell_file == NULL)
+      shell_file = getenv ("SHELL");
+    if (shell_file == NULL)
+      shell_file = default_shell_file;
+    shell = 1;
+  } 
+
+#if DEBUGGING
+  printf("shell is %s\n", shell_file);
+#endif
 
   /* Multiplying the length of exec_file by 4 is to account for the fact
      that it may expand when quoted; it is a worst-case number based on
@@ -95,20 +160,40 @@ fork_inferior (exec_file, allargs, env, traceme_fun, init_trace_fun,
   shell_command = (char *) alloca (len);
   shell_command[0] = '\0';
 #endif
-  strcat (shell_command, "exec ");
 
-  /* Now add exec_file, quoting as necessary.  */
-  {
+  if (!shell) {
+    /* We're going to call execvp. Create argv */
+    /* Largest case: every other character is a separate arg */
+#if DEBUGGING
+    printf("allocating argv, length = %d\n", 
+            (
+              (strlen (allargs) + 1) / (unsigned) 2  
+              + 2
+            ) * sizeof (*argv)
+          );
+#endif
+    argv = (char **) xmalloc(((strlen (allargs) + 1) / (unsigned) 2 + 2) * sizeof (*argv));
+    argv[0] = exec_file;
+    breakup_args(allargs, &argv[1]);
+
+  } else {
+
+    /* We're going to call a shell */
+
+    /* Now add exec_file, quoting as necessary.  */
+
     char *p;
     int need_to_quote;
 
+    strcat (shell_command, "exec ");
+
     /* Quoting in this style is said to work with all shells.  But csh
        on IRIX 4.0.1 can't deal with it.  So we only quote it if we need
        to.  */
     p = exec_file;
     while (1)
       {
-	switch (*p)
+        switch (*p)
 	  {
 	  case '\'':
 	  case '"':
@@ -137,8 +222,8 @@ fork_inferior (exec_file, allargs, env, traceme_fun, init_trace_fun,
   end_scan:
     if (need_to_quote)
       {
-	strcat (shell_command, "'");
-	for (p = exec_file; *p != '\0'; ++p)
+        strcat (shell_command, "'");
+        for (p = exec_file; *p != '\0'; ++p)
 	  {
 	    if (*p == '\'')
 	      strcat (shell_command, "'\\''");
@@ -149,10 +234,11 @@ fork_inferior (exec_file, allargs, env, traceme_fun, init_trace_fun,
       }
     else
       strcat (shell_command, exec_file);
-  }
+    
+    strcat (shell_command, " ");
+    strcat (shell_command, allargs);
 
-  strcat (shell_command, " ");
-  strcat (shell_command, allargs);
+  } 
 
   /* exec is said to fail if the executable is open.  */
   close_exec_file ();
@@ -174,6 +260,12 @@ fork_inferior (exec_file, allargs, env, traceme_fun, init_trace_fun,
   gdb_flush (gdb_stdout);
   gdb_flush (gdb_stderr);
 
+  /* If there's any initialization of the target layers that must happen
+   to prepare to handle the child we're about fork, do it now...
+   */
+  if (pre_trace_fun != NULL)
+    (*pre_trace_fun) ();
+
 #if defined(USG) && !defined(HAVE_VFORK)
   pid = fork ();
 #else
@@ -209,6 +301,14 @@ fork_inferior (exec_file, allargs, env, traceme_fun, init_trace_fun,
 
       /* "Trace me, Dr. Memory!" */
       (*traceme_fun) ();
+      /* The call above set this process (the "child") as debuggable
+       * by the original gdb process (the "parent").  Since processes
+       * (unlike people) can have only one parent, if you are
+       * debugging gdb itself (and your debugger is thus _already_ the
+       * controller/parent for this child),  code from here on out
+       * is undebuggable.  Indeed, you probably got an error message
+       * saying "not parent".  Sorry--you'll have to use print statements!
+       */
 
       /* There is no execlpe call, so we have to set the environment
 	 for our child in the global variable.  If we've vforked, this
@@ -216,12 +316,65 @@ fork_inferior (exec_file, allargs, env, traceme_fun, init_trace_fun,
 	 in the parent.  By the way, yes we do need to look down the
 	 path to find $SHELL.  Rich Pixley says so, and I agree.  */
       environ = env;
-      execlp (shell_file, shell_file, "-c", shell_command, (char *)0);
 
-      fprintf_unfiltered (gdb_stderr, "Cannot exec %s: %s.\n", shell_file,
-	       safe_strerror (errno));
-      gdb_flush (gdb_stderr);
-      _exit (0177);
+      /* If we decided above to start up with a shell,
+       * we exec the shell, 
+       * "-c" says to interpret the next arg as a shell command
+       * to execute, and this command is "exec <target-program> <args>".
+       * "-f" means "fast startup" to the c-shell, which means
+       * don't do .cshrc file. Doing .cshrc may cause fork/exec
+       * events which will confuse debugger start-up code.
+       */
+      if (shell) {
+#if 0
+
+	/* HP change is problematic. The -f option has different meanings
+	   for different shells. It is particularly inappropriate for 
+	   bourne shells. */
+        execlp (shell_file, shell_file, "-f", "-c", shell_command, (char *)0);
+#else
+        execlp (shell_file, shell_file, "-c", shell_command, (char *)0);
+#endif
+   
+
+        /* If we get here, it's an error */
+        fprintf_unfiltered (gdb_stderr, "Cannot exec %s: %s.\n", shell_file,
+	         safe_strerror (errno));
+        gdb_flush (gdb_stderr);
+        _exit (0177);
+      } else {
+        /* Otherwise, we directly exec the target program with execvp. */
+        int i;
+        char * errstring;
+#if DEBUGGING
+        printf("about to exec target, exec_file = %s\n", exec_file);
+        i = 0;
+        while (argv[i] != NULL) {
+          printf("strlen(argv[%d]) is %d\n", i, strlen(argv[i]));
+          printf("argv[%d] is %s\n", i, argv[i]);
+          i++;
+        }
+#endif
+        execvp (exec_file, argv);
+
+        /* If we get here, it's an error */
+        errstring = safe_strerror (errno);
+        fprintf_unfiltered (gdb_stderr, "Cannot exec %s ", exec_file);
+        
+        i = 1;
+        while (argv[i] != NULL) {
+          if (i != 1)
+            fprintf_unfiltered (gdb_stderr, " ");
+          fprintf_unfiltered (gdb_stderr, "%s", argv[i]);
+          i++;
+        }
+        fprintf_unfiltered (gdb_stderr, ".\n");
+        /* This extra info seems to be useless
+        fprintf_unfiltered (gdb_stderr, "Got error %s.\n", errstring);
+         */
+        gdb_flush (gdb_stderr);
+        _exit (0177);
+      }
     }
 
   /* Restore our environment in case a vforked child clob'd it.  */
@@ -234,8 +387,7 @@ fork_inferior (exec_file, allargs, env, traceme_fun, init_trace_fun,
   /* Now that we have a child process, make it our target, and
      initialize anything target-vector-specific that needs initializing.  */
 
-  /* Note that pid may be modified by this function.  */
-  inferior_pid = pid = (*init_trace_fun)(pid);
+ (*init_trace_fun)(pid);
 
   /* We are now in the child process of interest, having exec'd the
      correct program, and are poised at the first instruction of the
@@ -251,6 +403,137 @@ fork_inferior (exec_file, allargs, env, traceme_fun, init_trace_fun,
 #endif
 }
 
+/* An inferior Unix process CHILD_PID has been created by a call to
+   fork() (or variants like vfork).  It is presently stopped, and waiting
+   to be resumed.  clone_and_follow_inferior will fork the debugger,
+   and that clone will "follow" (attach to) CHILD_PID.  The original copy
+   of the debugger will not touch CHILD_PID again.
+
+   Also, the original debugger will set FOLLOWED_CHILD FALSE, while the
+   clone will set it TRUE.
+   */
+void
+clone_and_follow_inferior (child_pid, followed_child)
+  int  child_pid;
+  int  *followed_child;
+{
+  extern int auto_solib_add;
+
+  int  debugger_pid;
+  int  status;
+  char  pid_spelling [100];  /* Arbitrary but sufficient length. */
+
+  /* This semaphore is used to coordinate the two debuggers' handoff
+     of CHILD_PID.  The original debugger will detach from CHILD_PID,
+     and then the clone debugger will attach to it.  (It must be done
+     this way because on some targets, only one process at a time can
+     trace another.  Thus, the original debugger must relinquish its
+     tracing rights before the clone can pick them up.)
+     */
+#define SEM_TALK (1)
+#define SEM_LISTEN (0)
+  int  handoff_semaphore[2];   /* Original "talks" to [1], clone "listens" to [0] */
+  int  talk_value = 99;
+  int  listen_value;
+
+  /* Set debug_fork then attach to the child while it sleeps, to debug. */
+  static int debug_fork = 0;
+
+  /* It is generally good practice to flush any possible pending stdio
+     output prior to doing a fork, to avoid the possibility of both the
+     parent and child flushing the same data after the fork. */
+
+  gdb_flush (gdb_stdout);
+  gdb_flush (gdb_stderr);
+
+  /* Open the semaphore pipes.
+     */
+  status = pipe (handoff_semaphore);
+  if (status < 0)
+    error ("error getting pipe for handoff semaphore");
+
+  /* Clone the debugger. */
+#if defined(USG) && !defined(HAVE_VFORK)
+  debugger_pid = fork ();
+#else
+  if (debug_fork)
+    debugger_pid = fork ();
+  else
+    debugger_pid = vfork ();
+#endif
+
+  if (debugger_pid < 0)
+    perror_with_name ("fork");
+
+  /* Are we the original debugger?  If so, we must relinquish all claims
+   to CHILD_PID. */
+  if (debugger_pid != 0)
+    {
+      char  signal_spelling[100];  /* Arbitrary but sufficient length */
+
+      /* Detach from CHILD_PID.  Deliver a "stop" signal when we do, though,
+       so that it remains stopped until the clone debugger can attach
+       to it.
+       */
+      detach_breakpoints (child_pid);
+
+      sprintf (signal_spelling, "%d", target_signal_to_host (TARGET_SIGNAL_STOP));
+      target_require_detach (child_pid, signal_spelling, 1);
+
+      /* Notify the clone debugger that it should attach to CHILD_PID. */
+      write (handoff_semaphore[SEM_TALK], &talk_value, sizeof (talk_value));
+
+      *followed_child = 0;
+    }
+
+  /* We're the child. */
+  else
+    {
+      if (debug_fork) 
+        sleep (debug_fork);
+
+      /* The child (i.e., the cloned debugger) must now attach to
+         CHILD_PID.  inferior_pid is presently set to the parent process
+         of the fork, while CHILD_PID should be the child process of the
+         fork.
+
+         Wait until the original debugger relinquishes control of CHILD_PID,
+         though.
+         */
+      read (handoff_semaphore[SEM_LISTEN], &listen_value, sizeof (listen_value));
+
+      /* Note that we DON'T want to actually detach from inferior_pid,
+         because that would allow it to run free.  The original
+         debugger wants to retain control of the process.  So, we
+         just reset inferior_pid to CHILD_PID, and then ensure that all
+         breakpoints are really set in CHILD_PID.
+         */
+      target_mourn_inferior ();
+
+      /* Ask the tty subsystem to switch to the one we specified earlier
+         (or to share the current terminal, if none was specified).  */
+
+      new_tty ();
+
+      dont_repeat ();
+      sprintf(pid_spelling, "%d", child_pid);
+      target_require_attach (pid_spelling, 1);
+
+      /* Perform any necessary cleanup, after attachment.  (This form
+         of attaching can behave differently on some targets than the
+         standard method, where a process formerly not under debugger
+         control was suddenly attached to..)
+         */
+      target_post_follow_inferior_by_clone ();
+
+      *followed_child = 1;
+    }
+
+  /* Discard the handoff sempahore. */
+  (void) close (handoff_semaphore[SEM_LISTEN]);
+  (void) close (handoff_semaphore[SEM_TALK]);
+}
+
 /* Accept NTRAPS traps from the inferior.  */
 
 void
@@ -270,6 +553,13 @@ startup_inferior (ntraps)
 
   terminal_initted = 0;
 
+  if (STARTUP_WITH_SHELL)
+    inferior_ignoring_startup_exec_events = ntraps;
+  else
+    inferior_ignoring_startup_exec_events = 0;
+  inferior_ignoring_leading_exec_events =
+    target_reported_exec_events_per_exec_call () - 1;
+
 #ifdef STARTUP_INFERIOR
   STARTUP_INFERIOR (pending_execs);
 #else
@@ -301,9 +591,12 @@ startup_inferior (ntraps)
 
 	      terminal_initted = 1;
 	    }
-	  if (0 == --pending_execs)
+
+          pending_execs = pending_execs - 1;
+	  if (0 == pending_execs)
 	    break;
-	  resume (0, TARGET_SIGNAL_0);		/* Just make it go on */
+
+          resume (0, TARGET_SIGNAL_0);		/* Just make it go on */
 	}
     }
 #endif /* STARTUP_INFERIOR */