* bytecode.c (exec_byte_code): Use some more volatile variables

to work around local variables getting clobbered by longjmp.
Port to pre-C99, which doesn't allow decls after stmts.

diff --git a/src/ChangeLog b/src/ChangeLog
index 85411622ba156ec0049a13f9bc35c7b23f6d4daf..4fae03d69656edcaf41c6e7c6875834525f3f431 100644 (file)
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,9 @@
+2013-10-04  Paul Eggert  <eggert@cs.ucla.edu>
+
+       * bytecode.c (exec_byte_code): Use some more volatile variables
+       to work around local variables getting clobbered by longjmp.
+       Port to pre-C99, which doesn't allow decls after stmts.
+
 2013-10-03  Paul Eggert  <eggert@cs.ucla.edu>
 
        * lisp.h (eassert): Assume that COND is true when optimizing.

diff --git a/src/bytecode.c b/src/bytecode.c
index f7ccd35cbba9b2cb38a6989d69b57cfed1a4d994..b9cb36c871f9a1fe8e63444ab894cb3320d640b0 100644 (file)
--- a/src/bytecode.c
+++ b/src/bytecode.c
@@ -332,7 +332,7 @@ struct byte_stack
 
 /* A list of currently active byte-code execution value stacks.
    Fbyte_code adds an entry to the head of this list before it starts
-   processing byte-code, and it removed the entry again when it is
+   processing byte-code, and it removes the entry again when it is
    done.  Signaling an error truncates the list analogous to
    gcprolist.  */
 
@@ -501,19 +501,22 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
                Lisp_Object args_template, ptrdiff_t nargs, Lisp_Object *args)
 {
   ptrdiff_t count = SPECPDL_INDEX ();
+  ptrdiff_t volatile count_volatile;
 #ifdef BYTE_CODE_METER
-  int this_op = 0;
+  int volatile this_op = 0;
   int prev_op;
 #endif
   int op;
   /* Lisp_Object v1, v2; */
   Lisp_Object *vectorp;
+  Lisp_Object *volatile vectorp_volatile;
 #ifdef BYTE_CODE_SAFE
-  ptrdiff_t const_length;
-  Lisp_Object *stacke;
-  ptrdiff_t bytestr_length;
+  ptrdiff_t volatile const_length;
+  Lisp_Object *volatile stacke;
+  ptrdiff_t volatile bytestr_length;
 #endif
   struct byte_stack stack;
+  struct byte_stack volatile stack_volatile;
   Lisp_Object *top;
   Lisp_Object result;
   enum handlertype type;
@@ -1119,16 +1122,25 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
            PUSH_HANDLER (c, tag, type);
            c->bytecode_dest = dest;
            c->bytecode_top = top;
+           count_volatile = count;
+           stack_volatile = stack;
+           vectorp_volatile = vectorp;
+
            if (sys_setjmp (c->jmp))
              {
                struct handler *c = handlerlist;
+               int dest;
                top = c->bytecode_top;
-               int dest = c->bytecode_dest;
+               dest = c->bytecode_dest;
                handlerlist = c->next;
                PUSH (c->val);
                CHECK_RANGE (dest);
+               stack = stack_volatile;
                stack.pc = stack.byte_string_start + dest;
              }
+
+           count = count_volatile;
+           vectorp = vectorp_volatile;
            NEXT;
          }