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Re: [patch] Fix gdb.cp/gdb2495.exp regression with gcc-4.7


On 12/22/2011 08:20 PM, Jan Kratochvil wrote:
@@ -634,9 +635,32 @@ call_function_by_hand (struct value *function, int nargs, struct value **args)
      case AT_ENTRY_POINT:
        {
  	CORE_ADDR dummy_addr;
+	gdb_byte *insn;
+	CORE_ADDR insn_len;

  	real_pc = funaddr;
  	dummy_addr = entry_point_address ();
+
+	/* If the inferior call throws an uncaught C++ exception the inferior
+	   unwinder will try to unwind all the frames incl. the dummy frame.
+	   Using the entry_point_address directly will try to find FDE at the
+	   function right before the entry_point_address address as the
+	   unwinder subtracts 1 to get at the call instruction.  FDE of the
+	   preceding function, if found, would be invalid for the dummy frame
+	   and it would crash the inferior's unwinder.  Therefore attempt to
+	   skip the very first instruction of entry_point_address.  */
+

I'm confused. Shouldn't this instead be handled in the unwind machinery? Is this subtraction you refer to the get_frame_address_in_block one? That already has special
handling for something like this. Why doesn't it work?



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