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