[Emacs-diffs] /srv/bzr/emacs/trunk r104830: * eval.c (struct backtrace): Simplify and port the data structure.

[Paul Eggert]

------------------------------------------------------------
revno: 104830
committer: Paul Eggert <address@hidden>
branch nick: trunk
timestamp: Thu 2011-06-30 22:12:00 -0700
message:
  * eval.c (struct backtrace): Simplify and port the data structure.
  
  Do not assume that "int nargs : BITS_PER_INT - 2;" produces a
  signed bit field, as this assumption is not portable and it makes
  Emacs crash when compiled with Sun C 5.8 on sparc.  Do not use
  "char debug_on_exit : 1" as this is not portable either; instead,
  use the portable "unsigned int debug_on_exit : 1".  Remove unused
  member evalargs.  Remove obsolete comments about cc bombing out.
modified:
  src/ChangeLog
  src/eval.c

=== modified file 'src/ChangeLog'
--- a/src/ChangeLog     2011-06-30 15:07:40 +0000
+++ b/src/ChangeLog     2011-07-01 05:12:00 +0000
@@ -1,3 +1,13 @@
+2011-07-01  Paul Eggert  <address@hidden>
+
+       * eval.c (struct backtrace): Simplify and port the data structure.
+       Do not assume that "int nargs : BITS_PER_INT - 2;" produces a
+       signed bit field, as this assumption is not portable and it makes
+       Emacs crash when compiled with Sun C 5.8 on sparc.  Do not use
+       "char debug_on_exit : 1" as this is not portable either; instead,
+       use the portable "unsigned int debug_on_exit : 1".  Remove unused
+       member evalargs.  Remove obsolete comments about cc bombing out.
+
 2011-06-30  Jan Djärv  <address@hidden>
 
        * xsettings.c: Include glib-object.h, gio/gio.h if HAVE_GSETTINGS.

=== modified file 'src/eval.c'
--- a/src/eval.c        2011-06-24 21:25:22 +0000
+++ b/src/eval.c        2011-07-01 05:12:00 +0000
@@ -32,25 +32,14 @@
 #include "xterm.h"
 #endif
 
-/* This definition is duplicated in alloc.c and keyboard.c.  */
-/* Putting it in lisp.h makes cc bomb out!  */
-
 struct backtrace
 {
   struct backtrace *next;
   Lisp_Object *function;
   Lisp_Object *args;   /* Points to vector of args.  */
-#define NARGS_BITS (BITS_PER_INT - 2)
-  /* Let's not use size_t because we want to allow negative values (for
-     UNEVALLED).  Also let's steal 2 bits so we save a word (or more for
-     alignment).  In any case I doubt Emacs would survive a function call with
-     more than 500M arguments.  */
-  int nargs : NARGS_BITS; /* Length of vector.
-                            If nargs is UNEVALLED, args points
-                            to slot holding list of unevalled args.  */
-  char evalargs : 1;
+  ptrdiff_t nargs;     /* Length of vector.  */
   /* Nonzero means call value of debugger when done with this operation.  */
-  char debug_on_exit : 1;
+  unsigned int debug_on_exit : 1;
 };
 
 static struct backtrace *backtrace_list;
@@ -2291,7 +2280,6 @@
   backtrace.function = &original_fun; /* This also protects them from gc.  */
   backtrace.args = &original_args;
   backtrace.nargs = UNEVALLED;
-  backtrace.evalargs = 1;
   backtrace.debug_on_exit = 0;
 
   if (debug_on_next_call)
@@ -2325,10 +2313,7 @@
        xsignal2 (Qwrong_number_of_arguments, original_fun, numargs);
 
       else if (XSUBR (fun)->max_args == UNEVALLED)
-       {
-         backtrace.evalargs = 0;
-         val = (XSUBR (fun)->function.aUNEVALLED) (args_left);
-       }
+       val = (XSUBR (fun)->function.aUNEVALLED) (args_left);
       else if (XSUBR (fun)->max_args == MANY)
        {
          /* Pass a vector of evaluated arguments.  */
@@ -2984,7 +2969,6 @@
   backtrace.function = &args[0];
   backtrace.args = &args[1];
   backtrace.nargs = nargs - 1;
-  backtrace.evalargs = 0;
   backtrace.debug_on_exit = 0;
 
   if (debug_on_next_call)
@@ -3141,7 +3125,6 @@
 
   backtrace_list->args = arg_vector;
   backtrace_list->nargs = i;
-  backtrace_list->evalargs = 0;
   tem = funcall_lambda (fun, numargs, arg_vector);
 
   /* Do the debug-on-exit now, while arg_vector still exists.  */