Fix problem handling EXTENDED_ARGs from SF bug # 1333982

diff --git a/Python/compile.c b/Python/compile.c
index 604c8a1676aec45f44c660602e64aae1576e0a7b..8426038221b05d89addefec4c23ebe822cde8e87 100644 (file)
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -3886,17 +3886,20 @@ static void
 assemble_jump_offsets(struct assembler *a, struct compiler *c)
 {
        basicblock *b;
-       int bsize, totsize = 0;
+       int bsize, totsize, extended_arg_count, last_extended_arg_count = 0;
        int i;
 
        /* Compute the size of each block and fixup jump args.
           Replace block pointer with position in bytecode. */
+start:
+       totsize = 0;
        for (i = a->a_nblocks - 1; i >= 0; i--) {
                b = a->a_postorder[i];
                bsize = blocksize(b);
                b->b_offset = totsize;
                totsize += bsize;
        }
+       extended_arg_count = 0;
        for (b = c->u->u_blocks; b != NULL; b = b->b_list) {
                bsize = b->b_offset;
                for (i = 0; i < b->b_iused; i++) {
@@ -3912,8 +3915,34 @@ assemble_jump_offsets(struct assembler *a, struct compiler *c)
                                int delta = instr->i_target->b_offset - bsize;
                                instr->i_oparg = delta;
                        }
+                       else
+                               continue;
+                       if (instr->i_oparg > 0xffff)
+                               extended_arg_count++;
                }
        }
+
+       /* XXX: This is an awful hack that could hurt performance, but
+               on the bright side it should work until we come up
+               with a better solution.
+
+               In the meantime, should the goto be dropped in favor
+               of a loop?
+
+               The issue is that in the first loop blocksize() is called
+               which calls instrsize() which requires i_oparg be set
+               appropriately.  There is a bootstrap problem because
+               i_oparg is calculated in the second loop above.
+
+               So we loop until we stop seeing new EXTENDED_ARGs.
+               The only EXTENDED_ARGs that could be popping up are
+               ones in jump instructions.  So this should converge
+               fairly quickly.
+       */
+       if (last_extended_arg_count != extended_arg_count) {
+               last_extended_arg_count = extended_arg_count;
+               goto start;
+       }
 }
 
 static PyObject *