[PATCH] Fix invalid asm goto error recovery (PR middle-end/52650)

[Jakub Jelinek]

Hi!

delete_insn_and_edges doesn't DTRT here, there is __builtin_unreachable
after the invalid inline asm goto.  Rather than changing the CFG and trying
to figure out what to do to remove the bogus asm goto successfully, it seems
much easier to just turn it into asm goto ("" : : : clobbers... : lab1...);
i.e. clear template and inputs.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2012-11-27  Jakub Jelinek  <jakub@redhat.com>

	PR middle-end/52650
	* function.c (instantiate_virtual_regs_in_insn): Don't delete invalid
	asm gotos, instead just clear their template and inputs.

--- gcc/function.c.jj	2012-11-21 16:00:12.000000000 +0100
+++ gcc/function.c	2012-11-26 16:47:24.907472155 +0100
@@ -1738,7 +1738,18 @@ instantiate_virtual_regs_in_insn (rtx in
       if (!check_asm_operands (PATTERN (insn)))
 	{
 	  error_for_asm (insn, "impossible constraint in %<asm%>");
-	  delete_insn_and_edges (insn);
+	  /* For asm goto, instead of fixing up all the edges
+	     just clear the template and clear input operands
+	     (asm goto doesn't have any output operands).  */
+	  if (JUMP_P (insn))
+	    {
+	      rtx asm_op = extract_asm_operands (PATTERN (insn));
+	      ASM_OPERANDS_TEMPLATE (asm_op) = ggc_strdup ("");
+	      ASM_OPERANDS_INPUT_VEC (asm_op) = rtvec_alloc (0);
+	      ASM_OPERANDS_INPUT_CONSTRAINT_VEC (asm_op) = rtvec_alloc (0);
+	    }
+	  else
+	    delete_insn (insn);
 	}
     }
   else

	Jakub