'struct agent_expr *' -> unique_ptr<agent_expr>

This patch makes the gen_* functions return a unique_ptr instead of
raw pointer:

  typedef gdb::unique_ptr<agent_expr> agent_expr_up;

and then adjusts the codebase throughout to stop using
make_cleanup_free_agent_expr.

The cond_bytecode and cmd_bytecode fields of struct bp_location are
owning pointers, so they're changed to be unique_ptr's instead of raw
pointers.

gdb/ChangeLog:
2016-11-08  Pedro Alves  <palves@redhat.com>

	* ax-gdb.c (is_nontrivial_conversion): Use agent_expr_up.
	(gen_trace_for_var, gen_trace_for_expr, gen_eval_for_expr)
	(gen_trace_for_return_address, gen_printf): Use and return an
	agent_expr_up.  Don't use make_cleanup_free_agent_expr.
	(agent_eval_command_one, maint_agent_printf_command): Use
	agent_expr_up.  Don't use make_cleanup_free_agent_expr.
	* ax-gdb.h (gen_trace_for_expr, gen_trace_for_var)
	(gen_trace_for_return_address, gen_eval_for_expr, gen_printf): Use
	agent_expr_up.
	* ax-general.c (new_agent_expr): Rename to ...
	(agent_expr::agent_expr): ... this, and now a constructor.
	(free_agent_expr): Rename to ...
	(agent_expr::~agent_exp): ... this, and now a destructor.
	(do_free_agent_expr_cleanup, make_cleanup_free_agent_expr):
	Delete.
	* ax.h (struct agent_expr): Add ctor/dtor.
	(agent_expr_up): New typedef.
	(new_agent_expr, free_agent_expr, make_cleanup_free_agent_expr):
	Delete declarations.
	* breakpoint.c (parse_cond_to_aexpr): Use and return an
	agent_expr_up.  Don't use make_cleanup_free_agent_expr.
	(build_target_condition_list): Adjust to use agent_expr_up.
	(parse_cmd_to_aexpr): Use and return an agent_expr_up.  Don't use
	make_cleanup_free_agent_expr.
	(build_target_command_list): Adjust to use agent_expr_up.
	(force_breakpoint_reinsertion): Adjust to use agent_expr_up.
	(bp_location_dtor): Remove unnecessary free_agent_expr and xfree
	calls.
	* breakpoint.h (struct bp_target_info) <cond_bytecode,
	cmd_bytecode>: Now agent_expr_up's.
	* remote.c (remote_download_tracepoint): Adjust to use
	agent_expr_up and remove use of make_cleanup_free_agent_expr.
	* tracepoint.c (validate_actionline, collect_symbol): Adjust to
	use agent_expr_up and remove uses of make_cleanup_free_agent_expr.
	(collection_list::~collection_list): Call delete instead of
	free_agent_expr.
	(encode_actions_1): Adjust to use agent_expr_up and remove uses of
	make_cleanup_free_agent_expr.
	(add_aexpr): Change parameter type to agent_expr_up; Return a raw
	agent_expr pointer.

1 files changed, 49 insertions, 91 deletions

diff --git a/gdb/ax-gdb.c b/gdb/ax-gdb.c
index ccd16f2..1816ba6 100644
--- a/gdb/ax-gdb.c
+++ b/gdb/ax-gdb.c
@@ -910,7 +910,7 @@ gen_conversion (struct agent_expr *ax, struct type *from, struct type *to)
 static int
 is_nontrivial_conversion (struct type *from, struct type *to)
 {
-  struct agent_expr *ax = new_agent_expr (NULL, 0);
+  agent_expr_up ax (new agent_expr (NULL, 0));
   int nontrivial;
 
   /* Actually generate the code, and see if anything came out.  At the
@@ -919,9 +919,8 @@ is_nontrivial_conversion (struct type *from, struct type *to)
      floating point and the like, it may not be.  Doing things this
      way allows this function to be independent of the logic in
      gen_conversion.  */
-  gen_conversion (ax, from, to);
+  gen_conversion (ax.get (), from, to);
   nontrivial = ax->len > 0;
-  free_agent_expr (ax);
   return nontrivial;
 }
 
@@ -2391,38 +2390,28 @@ gen_expr_binop_rest (struct expression *exp,
    variable's name, and no parsed expression; for instance, when the
    name comes from a list of local variables of a function.  */
 
-struct agent_expr *
+agent_expr_up
 gen_trace_for_var (CORE_ADDR scope, struct gdbarch *gdbarch,
 		   struct symbol *var, int trace_string)
 {
-  struct cleanup *old_chain = 0;
-  struct agent_expr *ax = new_agent_expr (gdbarch, scope);
+  agent_expr_up ax (new agent_expr (gdbarch, scope));
   struct axs_value value;
 
-  old_chain = make_cleanup_free_agent_expr (ax);
-
   ax->tracing = 1;
   ax->trace_string = trace_string;
-  gen_var_ref (gdbarch, ax, &value, var);
+  gen_var_ref (gdbarch, ax.get (), &value, var);
 
   /* If there is no actual variable to trace, flag it by returning
      an empty agent expression.  */
   if (value.optimized_out)
-    {
-      do_cleanups (old_chain);
-      return NULL;
-    }
+    return agent_expr_up ();
 
   /* Make sure we record the final object, and get rid of it.  */
-  gen_traced_pop (gdbarch, ax, &value);
+  gen_traced_pop (gdbarch, ax.get (), &value);
 
   /* Oh, and terminate.  */
-  ax_simple (ax, aop_end);
+  ax_simple (ax.get (), aop_end);
 
-  /* We have successfully built the agent expr, so cancel the cleanup
-     request.  If we add more cleanups that we always want done, this
-     will have to get more complicated.  */
-  discard_cleanups (old_chain);
   return ax;
 }
 
@@ -2433,33 +2422,27 @@ gen_trace_for_var (CORE_ADDR scope, struct gdbarch *gdbarch,
    record the value of all memory touched by the expression.  The
    caller can then use the ax_reqs function to discover which
    registers it relies upon.  */
-struct agent_expr *
+
+agent_expr_up
 gen_trace_for_expr (CORE_ADDR scope, struct expression *expr,
 		    int trace_string)
 {
-  struct cleanup *old_chain = 0;
-  struct agent_expr *ax = new_agent_expr (expr->gdbarch, scope);
+  agent_expr_up ax (new agent_expr (expr->gdbarch, scope));
   union exp_element *pc;
   struct axs_value value;
 
-  old_chain = make_cleanup_free_agent_expr (ax);
-
   pc = expr->elts;
   ax->tracing = 1;
   ax->trace_string = trace_string;
   value.optimized_out = 0;
-  gen_expr (expr, &pc, ax, &value);
+  gen_expr (expr, &pc, ax.get (), &value);
 
   /* Make sure we record the final object, and get rid of it.  */
-  gen_traced_pop (expr->gdbarch, ax, &value);
+  gen_traced_pop (expr->gdbarch, ax.get (), &value);
 
   /* Oh, and terminate.  */
-  ax_simple (ax, aop_end);
+  ax_simple (ax.get (), aop_end);
 
-  /* We have successfully built the agent expr, so cancel the cleanup
-     request.  If we add more cleanups that we always want done, this
-     will have to get more complicated.  */
-  discard_cleanups (old_chain);
   return ax;
 }
 
@@ -2470,58 +2453,44 @@ gen_trace_for_expr (CORE_ADDR scope, struct expression *expr,
    gen_trace_for_expr does.  The generated bytecode sequence leaves
    the result of expression evaluation on the top of the stack.  */
 
-struct agent_expr *
+agent_expr_up
 gen_eval_for_expr (CORE_ADDR scope, struct expression *expr)
 {
-  struct cleanup *old_chain = 0;
-  struct agent_expr *ax = new_agent_expr (expr->gdbarch, scope);
+  agent_expr_up ax (new agent_expr (expr->gdbarch, scope));
   union exp_element *pc;
   struct axs_value value;
 
-  old_chain = make_cleanup_free_agent_expr (ax);
-
   pc = expr->elts;
   ax->tracing = 0;
   value.optimized_out = 0;
-  gen_expr (expr, &pc, ax, &value);
+  gen_expr (expr, &pc, ax.get (), &value);
 
-  require_rvalue (ax, &value);
+  require_rvalue (ax.get (), &value);
 
   /* Oh, and terminate.  */
-  ax_simple (ax, aop_end);
+  ax_simple (ax.get (), aop_end);
 
-  /* We have successfully built the agent expr, so cancel the cleanup
-     request.  If we add more cleanups that we always want done, this
-     will have to get more complicated.  */
-  discard_cleanups (old_chain);
   return ax;
 }
 
-struct agent_expr *
+agent_expr_up
 gen_trace_for_return_address (CORE_ADDR scope, struct gdbarch *gdbarch,
 			      int trace_string)
 {
-  struct cleanup *old_chain = 0;
-  struct agent_expr *ax = new_agent_expr (gdbarch, scope);
+  agent_expr_up ax (new agent_expr (gdbarch, scope));
   struct axs_value value;
 
-  old_chain = make_cleanup_free_agent_expr (ax);
-
   ax->tracing = 1;
   ax->trace_string = trace_string;
 
-  gdbarch_gen_return_address (gdbarch, ax, &value, scope);
+  gdbarch_gen_return_address (gdbarch, ax.get (), &value, scope);
 
   /* Make sure we record the final object, and get rid of it.  */
-  gen_traced_pop (gdbarch, ax, &value);
+  gen_traced_pop (gdbarch, ax.get (), &value);
 
   /* Oh, and terminate.  */
-  ax_simple (ax, aop_end);
+  ax_simple (ax.get (), aop_end);
 
-  /* We have successfully built the agent expr, so cancel the cleanup
-     request.  If we add more cleanups that we always want done, this
-     will have to get more complicated.  */
-  discard_cleanups (old_chain);
   return ax;
 }
 
@@ -2529,21 +2498,18 @@ gen_trace_for_return_address (CORE_ADDR scope, struct gdbarch *gdbarch,
    evaluate the arguments and pass everything to a special
    bytecode.  */
 
-struct agent_expr *
+agent_expr_up
 gen_printf (CORE_ADDR scope, struct gdbarch *gdbarch,
 	    CORE_ADDR function, LONGEST channel,
 	    const char *format, int fmtlen,
 	    struct format_piece *frags,
 	    int nargs, struct expression **exprs)
 {
-  struct cleanup *old_chain = 0;
-  struct agent_expr *ax = new_agent_expr (gdbarch, scope);
+  agent_expr_up ax (new agent_expr (gdbarch, scope));
   union exp_element *pc;
   struct axs_value value;
   int tem;
 
-  old_chain = make_cleanup_free_agent_expr (ax);
-
   /* We're computing values, not doing side effects.  */
   ax->tracing = 0;
 
@@ -2553,26 +2519,21 @@ gen_printf (CORE_ADDR scope, struct gdbarch *gdbarch,
     {
       pc = exprs[tem]->elts;
       value.optimized_out = 0;
-      gen_expr (exprs[tem], &pc, ax, &value);
-      require_rvalue (ax, &value);
+      gen_expr (exprs[tem], &pc, ax.get (), &value);
+      require_rvalue (ax.get (), &value);
     }
 
   /* Push function and channel.  */
-  ax_const_l (ax, channel);
-  ax_const_l (ax, function);
+  ax_const_l (ax.get (), channel);
+  ax_const_l (ax.get (), function);
 
   /* Issue the printf bytecode proper.  */
-  ax_simple (ax, aop_printf);
-  ax_raw_byte (ax, nargs);
-  ax_string (ax, format, fmtlen);
+  ax_simple (ax.get (), aop_printf);
+  ax_raw_byte (ax.get (), nargs);
+  ax_string (ax.get (), format, fmtlen);
 
   /* And terminate.  */
-  ax_simple (ax, aop_end);
-
-  /* We have successfully built the agent expr, so cancel the cleanup
-     request.  If we add more cleanups that we always want done, this
-     will have to get more complicated.  */
-  discard_cleanups (old_chain);
+  ax_simple (ax.get (), aop_end);
 
   return ax;
 }
@@ -2580,8 +2541,6 @@ gen_printf (CORE_ADDR scope, struct gdbarch *gdbarch,
 static void
 agent_eval_command_one (const char *exp, int eval, CORE_ADDR pc)
 {
-  struct cleanup *old_chain = 0;
-  struct agent_expr *agent;
   const char *arg;
   int trace_string = 0;
 
@@ -2591,33 +2550,33 @@ agent_eval_command_one (const char *exp, int eval, CORE_ADDR pc)
         exp = decode_agent_options (exp, &trace_string);
     }
 
+  agent_expr_up agent;
+
   arg = exp;
   if (!eval && strcmp (arg, "$_ret") == 0)
     {
-      agent = gen_trace_for_return_address (pc, get_current_arch (),
-					    trace_string);
-      old_chain = make_cleanup_free_agent_expr (agent);
+      agent = gdb::move (gen_trace_for_return_address (pc, get_current_arch (),
+						       trace_string));
     }
   else
     {
       expression_up expr = parse_exp_1 (&arg, pc, block_for_pc (pc), 0);
+
       if (eval)
 	{
 	  gdb_assert (trace_string == 0);
-	  agent = gen_eval_for_expr (pc, expr.get ());
+	  agent = gdb::move (gen_eval_for_expr (pc, expr.get ()));
 	}
       else
-	agent = gen_trace_for_expr (pc, expr.get (), trace_string);
-      old_chain = make_cleanup_free_agent_expr (agent);
+	agent = gdb::move (gen_trace_for_expr (pc, expr.get (), trace_string));
     }
 
-  ax_reqs (agent);
-  ax_print (gdb_stdout, agent);
+  ax_reqs (agent.get ());
+  ax_print (gdb_stdout, agent.get ());
 
   /* It would be nice to call ax_reqs here to gather some general info
      about the expression, and then print out the result.  */
 
-  do_cleanups (old_chain);
   dont_repeat ();
 }
 
@@ -2695,7 +2654,6 @@ maint_agent_printf_command (char *exp, int from_tty)
 {
   struct cleanup *old_chain = 0;
   struct expression *argvec[100];
-  struct agent_expr *agent;
   struct frame_info *fi = get_current_frame ();	/* need current scope */
   const char *cmdrest;
   const char *format_start, *format_end;
@@ -2755,12 +2713,12 @@ maint_agent_printf_command (char *exp, int from_tty)
     }
 
 
-  agent = gen_printf (get_frame_pc (fi), get_current_arch (), 0, 0,
-		      format_start, format_end - format_start,
-		      fpieces, nargs, argvec);
-  make_cleanup_free_agent_expr (agent);
-  ax_reqs (agent);
-  ax_print (gdb_stdout, agent);
+  agent_expr_up agent = gen_printf (get_frame_pc (fi), get_current_arch (),
+				    0, 0,
+				    format_start, format_end - format_start,
+				    fpieces, nargs, argvec);
+  ax_reqs (agent.get ());
+  ax_print (gdb_stdout, agent.get ());
 
   /* It would be nice to call ax_reqs here to gather some general info
      about the expression, and then print out the result.  */