[PATCH] Only set TREE_NO_WARNING after warning if warning returned true (PR tree-optimization/89550)

Richard Biener rguenther@suse.de
Fri Mar 8 10:07:00 GMT 2019


On Thu, 7 Mar 2019, Jakub Jelinek wrote:

> Hi!
> 
> While looking at why we didn't warn before Richi's commit, I've discovered
> is that the change is that in a different pass we used to call c_strlen too,
> but at that point with a location from system headers, so no warning has
> been printed, but TREE_NO_WARNING has been set anyway and later on when
> c_strlen was called again with a location not from system header, we
> wouldn't warn because TREE_NO_WARNING is set.
> 
> Apparently there are quite a few spots that have similar bug (and quite a
> few spots that do it right).
> 
> The following patch fixes what I found.  Bootstrapped/regtested on
> x86_64-linux and i686-linux, ok for trunk?

OK.

Thanks,
Richard.

> 2019-03-07  Jakub Jelinek  <jakub@redhat.com>
> 
> 	PR tree-optimization/89550
> 	* builtins.c (c_strlen): Only set TREE_NO_WARNING if warning_at
> 	returned true.  Formatting fixes.
> 	(expand_builtin_strnlen): Formatting fixes.
> 	* tree-vrp.c (vrp_prop::check_mem_ref): Only set TREE_NO_WARNING
> 	if warning_at returned true.
> 	* tree-cfg.c (pass_warn_function_return::execute): Likewise.
> c-family/
> 	* c-common.c (c_common_truthvalue_conversion): Only set
> 	TREE_NO_WARNING if warning_at returned true.
> 	* c-warn.c (overflow_warning, warn_logical_operator): Likewise.
> c/
> 	* c-decl.c (finish_function): Only set TREE_NO_WARNING if warning_at
> 	returned true.
> 	(c_write_global_declarations_1): Only set TREE_NO_WARNING if pedwarn
> 	or warning returned true.
> cp/
> 	* semantics.c (maybe_convert_cond): Only set TREE_NO_WARNING if
> 	warning_at returned true.
> 	* decl2.c (c_parse_final_cleanups): Likewise.
> 	* typeck.c (convert_for_assignment): Likewise.
> 	* decl.c (finish_function): Likewise.
> 
> --- gcc/builtins.c.jj	2019-03-05 17:21:42.536993265 +0100
> +++ gcc/builtins.c	2019-03-07 12:01:23.114479128 +0100
> @@ -760,15 +760,13 @@ c_strlen (tree src, int only_value, c_st
>       runtime.  */
>    if (eltoff < 0 || eltoff >= maxelts)
>      {
> -     /* Suppress multiple warnings for propagated constant strings.  */
> +      /* Suppress multiple warnings for propagated constant strings.  */
>        if (only_value != 2
> -	  && !TREE_NO_WARNING (src))
> -        {
> -	  warning_at (loc, OPT_Warray_bounds,
> -		      "offset %qwi outside bounds of constant string",
> -		      eltoff);
> -          TREE_NO_WARNING (src) = 1;
> -        }
> +	  && !TREE_NO_WARNING (src)
> +	  && warning_at (loc, OPT_Warray_bounds,
> +			 "offset %qwi outside bounds of constant string",
> +			 eltoff))
> +	TREE_NO_WARNING (src) = 1;
>        return NULL_TREE;
>      }
>  
> @@ -3099,7 +3097,7 @@ expand_builtin_strnlen (tree exp, rtx ta
>  			 "%K%qD specified bound %E "
>  			 "exceeds maximum object size %E",
>  			 exp, func, bound, maxobjsize))
> -	  TREE_NO_WARNING (exp) = true;
> +	TREE_NO_WARNING (exp) = true;
>  
>        bool exact = true;
>        if (!len || TREE_CODE (len) != INTEGER_CST)
> @@ -3158,7 +3156,7 @@ expand_builtin_strnlen (tree exp, rtx ta
>  		     "%K%qD specified bound [%wu, %wu] "
>  		     "exceeds maximum object size %E",
>  		     exp, func, min.to_uhwi (), max.to_uhwi (), maxobjsize))
> -      TREE_NO_WARNING (exp) = true;
> +    TREE_NO_WARNING (exp) = true;
>  
>    bool exact = true;
>    if (!len || TREE_CODE (len) != INTEGER_CST)
> --- gcc/tree-vrp.c.jj	2019-02-01 09:43:40.264757408 +0100
> +++ gcc/tree-vrp.c	2019-03-07 12:05:05.959845856 +0100
> @@ -4749,7 +4749,8 @@ vrp_prop::check_mem_ref (location_t loca
>        if (warned && DECL_P (arg))
>  	inform (DECL_SOURCE_LOCATION (arg), "while referencing %qD", arg);
>  
> -      TREE_NO_WARNING (ref) = 1;
> +      if (warned)
> +	TREE_NO_WARNING (ref) = 1;
>        return;
>      }
>  
> @@ -4762,11 +4763,10 @@ vrp_prop::check_mem_ref (location_t loca
>      {
>        HOST_WIDE_INT tmpidx = extrema[i].to_shwi () / eltsize.to_shwi ();
>  
> -      warning_at (location, OPT_Warray_bounds,
> -		  "intermediate array offset %wi is outside array bounds "
> -		  "of %qT",
> -		  tmpidx,  reftype);
> -      TREE_NO_WARNING (ref) = 1;
> +      if (warning_at (location, OPT_Warray_bounds,
> +		      "intermediate array offset %wi is outside array bounds "
> +		      "of %qT", tmpidx, reftype))
> +	TREE_NO_WARNING (ref) = 1;
>      }
>  }
>  
> --- gcc/tree-cfg.c.jj	2019-02-22 23:02:47.768118220 +0100
> +++ gcc/tree-cfg.c	2019-03-07 12:02:52.662019138 +0100
> @@ -9328,9 +9328,9 @@ pass_warn_function_return::execute (func
>  	      location = gimple_location (last);
>  	      if (LOCATION_LOCUS (location) == UNKNOWN_LOCATION)
>  		location = fun->function_end_locus;
> -	      warning_at (location, OPT_Wreturn_type,
> -			  "control reaches end of non-void function");
> -	      TREE_NO_WARNING (fun->decl) = 1;
> +	      if (warning_at (location, OPT_Wreturn_type,
> +			      "control reaches end of non-void function"))
> +		TREE_NO_WARNING (fun->decl) = 1;
>  	      break;
>  	    }
>  	}
> @@ -9360,9 +9360,9 @@ pass_warn_function_return::execute (func
>  		    location = gimple_location (prev);
>  		  if (LOCATION_LOCUS (location) == UNKNOWN_LOCATION)
>  		    location = fun->function_end_locus;
> -		  warning_at (location, OPT_Wreturn_type,
> -			      "control reaches end of non-void function");
> -		  TREE_NO_WARNING (fun->decl) = 1;
> +		  if (warning_at (location, OPT_Wreturn_type,
> +				  "control reaches end of non-void function"))
> +		    TREE_NO_WARNING (fun->decl) = 1;
>  		  break;
>  		}
>  	    }
> --- gcc/c-family/c-common.c.jj	2019-02-18 20:48:34.420703158 +0100
> +++ gcc/c-family/c-common.c	2019-03-07 12:09:45.187293329 +0100
> @@ -3546,13 +3546,11 @@ c_common_truthvalue_conversion (location
>  
>      case MODIFY_EXPR:
>        if (!TREE_NO_WARNING (expr)
> -	  && warn_parentheses)
> -	{
> -	  warning_at (location, OPT_Wparentheses,
> -		      "suggest parentheses around assignment used as "
> -		      "truth value");
> -	  TREE_NO_WARNING (expr) = 1;
> -	}
> +	  && warn_parentheses
> +	  && warning_at (location, OPT_Wparentheses,
> +			 "suggest parentheses around assignment used as "
> +			 "truth value"))
> +	TREE_NO_WARNING (expr) = 1;
>        break;
>  
>      case CONST_DECL:
> --- gcc/c-family/c-warn.c.jj	2019-02-11 18:04:18.143588036 +0100
> +++ gcc/c-family/c-warn.c	2019-03-07 12:11:44.097354618 +0100
> @@ -143,12 +143,16 @@ overflow_warning (location_t loc, tree v
>        return;
>      }
>  
> +  bool warned;
>    if (expr)
> -    warning_at (loc, OPT_Woverflow, warnfmt, expr, TREE_TYPE (expr), value);
> +    warned = warning_at (loc, OPT_Woverflow, warnfmt, expr, TREE_TYPE (expr),
> +			 value);
>    else
> -    warning_at (loc, OPT_Woverflow, warnfmt, TREE_TYPE (value), value);
> +    warned = warning_at (loc, OPT_Woverflow, warnfmt, TREE_TYPE (value),
> +			 value);
>  
> -  TREE_NO_WARNING (value) = 1;
> +  if (warned)
> +    TREE_NO_WARNING (value) = 1;
>  }
>  
>  /* Helper function for walk_tree.  Unwrap C_MAYBE_CONST_EXPRs in an expression
> @@ -216,13 +220,17 @@ warn_logical_operator (location_t locati
>  	  && !integer_zerop (folded_op_right)
>  	  && !integer_onep (folded_op_right))
>  	{
> +	  bool warned;
>  	  if (or_op)
> -	    warning_at (location, OPT_Wlogical_op, "logical %<or%>"
> -			" applied to non-boolean constant");
> +	    warned
> +	      = warning_at (location, OPT_Wlogical_op,
> +			    "logical %<or%> applied to non-boolean constant");
>  	  else
> -	    warning_at (location, OPT_Wlogical_op, "logical %<and%>"
> -			" applied to non-boolean constant");
> -	  TREE_NO_WARNING (op_left) = true;
> +	    warned
> +	      = warning_at (location, OPT_Wlogical_op,
> +			    "logical %<and%> applied to non-boolean constant");
> +	  if (warned)
> +	    TREE_NO_WARNING (op_left) = true;
>  	  return;
>  	}
>      }
> --- gcc/c/c-decl.c.jj	2019-02-15 08:37:06.893222441 +0100
> +++ gcc/c/c-decl.c	2019-03-07 12:08:41.932324639 +0100
> @@ -9664,12 +9664,10 @@ finish_function (void)
>        && !C_FUNCTION_IMPLICIT_INT (fndecl)
>        /* Normally, with -Wreturn-type, flow will complain, but we might
>           optimize out static functions.  */
> -      && !TREE_PUBLIC (fndecl))
> -    {
> -      warning (OPT_Wreturn_type,
> -	       "no return statement in function returning non-void");
> -      TREE_NO_WARNING (fndecl) = 1;
> -    }
> +      && !TREE_PUBLIC (fndecl)
> +      && warning (OPT_Wreturn_type,
> +		  "no return statement in function returning non-void"))
> +    TREE_NO_WARNING (fndecl) = 1;
>  
>    /* Complain about parameters that are only set, but never otherwise used.  */
>    if (warn_unused_but_set_parameter)
> @@ -11486,17 +11484,19 @@ c_write_global_declarations_1 (tree glob
>  	{
>  	  if (C_DECL_USED (decl))
>  	    {
> -	      pedwarn (input_location, 0, "%q+F used but never defined", decl);
> -	      TREE_NO_WARNING (decl) = 1;
> +	      if (pedwarn (input_location, 0, "%q+F used but never defined",
> +			   decl))
> +		TREE_NO_WARNING (decl) = 1;
>  	    }
>  	  /* For -Wunused-function warn about unused static prototypes.  */
>  	  else if (warn_unused_function
>  		   && ! DECL_ARTIFICIAL (decl)
>  		   && ! TREE_NO_WARNING (decl))
>  	    {
> -	      warning (OPT_Wunused_function,
> -		       "%q+F declared %<static%> but never defined", decl);
> -	      TREE_NO_WARNING (decl) = 1;
> +	      if (warning (OPT_Wunused_function,
> +			   "%q+F declared %<static%> but never defined",
> +			   decl))
> +		TREE_NO_WARNING (decl) = 1;
>  	    }
>  	}
>  
> --- gcc/cp/semantics.c.jj	2019-03-06 19:45:40.367751642 +0100
> +++ gcc/cp/semantics.c	2019-03-07 12:14:50.144321301 +0100
> @@ -657,12 +657,11 @@ maybe_convert_cond (tree cond)
>  
>    if (TREE_CODE (cond) == MODIFY_EXPR
>        && !TREE_NO_WARNING (cond)
> -      && warn_parentheses)
> -    {
> -      warning_at (cp_expr_loc_or_loc (cond, input_location), OPT_Wparentheses,
> -		  "suggest parentheses around assignment used as truth value");
> -      TREE_NO_WARNING (cond) = 1;
> -    }
> +      && warn_parentheses
> +      && warning_at (cp_expr_loc_or_loc (cond, input_location),
> +		     OPT_Wparentheses, "suggest parentheses around "
> +				       "assignment used as truth value"))
> +    TREE_NO_WARNING (cond) = 1;
>  
>    return condition_conversion (cond);
>  }
> --- gcc/cp/decl2.c.jj	2019-02-21 13:04:01.833547350 +0100
> +++ gcc/cp/decl2.c	2019-03-07 12:12:41.467419247 +0100
> @@ -5022,13 +5022,11 @@ c_parse_final_cleanups (void)
>  	  /* Don't complain if the template was defined.  */
>  	  && !(DECL_TEMPLATE_INSTANTIATION (decl)
>  	       && DECL_INITIAL (DECL_TEMPLATE_RESULT
> -				(template_for_substitution (decl)))))
> -	{
> -	  warning_at (DECL_SOURCE_LOCATION (decl), 0,
> -		      "inline function %qD used but never defined", decl);
> -	  /* Avoid a duplicate warning from check_global_declaration.  */
> -	  TREE_NO_WARNING (decl) = 1;
> -	}
> +				(template_for_substitution (decl))))
> +	  && warning_at (DECL_SOURCE_LOCATION (decl), 0,
> +			 "inline function %qD used but never defined", decl))
> +	/* Avoid a duplicate warning from check_global_declaration.  */
> +	TREE_NO_WARNING (decl) = 1;
>      }
>  
>    /* So must decls that use a type with no linkage.  */
> --- gcc/cp/typeck.c.jj	2019-03-06 19:45:40.330752248 +0100
> +++ gcc/cp/typeck.c	2019-03-07 12:16:02.319144554 +0100
> @@ -9063,12 +9063,11 @@ convert_for_assignment (tree type, tree
>        && TREE_CODE (rhs) == MODIFY_EXPR
>        && !TREE_NO_WARNING (rhs)
>        && TREE_CODE (TREE_TYPE (rhs)) != BOOLEAN_TYPE
> -      && (complain & tf_warning))
> -    {
> -      warning_at (rhs_loc, OPT_Wparentheses,
> -		  "suggest parentheses around assignment used as truth value");
> -      TREE_NO_WARNING (rhs) = 1;
> -    }
> +      && (complain & tf_warning)
> +      && warning_at (rhs_loc, OPT_Wparentheses,
> +		     "suggest parentheses around assignment used as "
> +		     "truth value"))
> +    TREE_NO_WARNING (rhs) = 1;
>  
>    if (complain & tf_warning)
>      warn_for_address_or_pointer_of_packed_member (type, rhs);
> --- gcc/cp/decl.c.jj	2019-03-02 09:05:44.412524821 +0100
> +++ gcc/cp/decl.c	2019-03-07 12:13:36.500521990 +0100
> @@ -16169,9 +16169,9 @@ finish_function (bool inline_p)
>  					    global_dc->option_state))
>  	    add_return_star_this_fixit (&richloc, fndecl);
>  	}
> -      warning_at (&richloc, OPT_Wreturn_type,
> -		  "no return statement in function returning non-void");
> -      TREE_NO_WARNING (fndecl) = 1;
> +      if (warning_at (&richloc, OPT_Wreturn_type,
> +	  "no return statement in function returning non-void"))
> +	TREE_NO_WARNING (fndecl) = 1;
>      }
>  
>    /* Store the end of the function, so that we get good line number
> 
> 	Jakub
> 
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nuernberg)



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