On Mon, 2018-08-27 at 09:14 +0200, Jakub Jelinek wrote:
> Hi!
>
> This patch improves location of the cxx_readonly_error diagnostics by
> letting caller's pass the preferred location for it rather than
> always using
> input_location.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Looks good to me (with my "diagnostic messages" hat on)
Dave
> 2018-08-27 Jakub Jelinek <ja...@redhat.com>
>
> PR c++/86993
> * cp-tree.h (cxx_readonly_error): Add location_t argument.
> * typeck2.c (cxx_readonly_error): Add LOC argument, pass it to
> ERROR_FOR_ASSIGNMENT macro and readonly_error. Add LOC
> argument
> to ERROR_FOR_ASSIGNMENT macro, use error_at instead of error
> and
> pass LOC to it. Formatting fixes.
> * typeck.c (cp_build_unary_op): Pass location to
> cxx_readonly_error.
> (cp_build_modify_expr): Pass loc to cxx_readonly_error.
> * semantics.c (finish_asm_stmt): Pass input_location to
> cxx_readonly_error.
>
> * g++.dg/diagnostic/pr86993.C: New test.
>
> --- gcc/cp/cp-tree.h.jj 2018-08-24 08:55:23.000000000 +0200
> +++ gcc/cp/cp-tree.h 2018-08-24 09:10:42.400933523 +0200
> @@ -7388,7 +7388,8 @@ cxx_incomplete_type_error (const_tree va
> extern void cxx_incomplete_type_inform (const_tree);
> extern tree error_not_base_type (tree, tree);
> extern tree binfo_or_else (tree, tree);
> -extern void cxx_readonly_error (tree, enum
> lvalue_use);
> +extern void cxx_readonly_error (location_t,
> tree,
> + enum lvalue_use);
> extern void complete_type_check_abstract (tree);
> extern int abstract_virtuals_error (tree, tree);
> extern int abstract_virtuals_error (abstract_class_us
> e, tree);
> --- gcc/cp/typeck2.c.jj 2018-08-24 08:55:23.000000000 +0200
> +++ gcc/cp/typeck2.c 2018-08-24 09:17:11.495798270 +0200
> @@ -67,28 +67,28 @@ binfo_or_else (tree base, tree type)
> value may not be changed thereafter. */
>
> void
> -cxx_readonly_error (tree arg, enum lvalue_use errstring)
> +cxx_readonly_error (location_t loc, tree arg, enum lvalue_use
> errstring)
> {
>
> /* This macro is used to emit diagnostics to ensure that all format
> strings are complete sentences, visible to gettext and checked at
> compile time. */
>
> -#define ERROR_FOR_ASSIGNMENT(AS, ASM, IN, DE,
> ARG) \
> +#define ERROR_FOR_ASSIGNMENT(LOC, AS, ASM, IN, DE, ARG)
> \
> do
> { \
> switch
> (errstring) \
> {
> \
> case lv_assign:
> \
> - error(AS,
> ARG); \
> + error_at (LOC, AS, ARG);
> \
> break;
> \
> case lv_asm:
> \
> - error(ASM,
> ARG); \
> + error_at (LOC, ASM, ARG);
> \
> break;
> \
> case lv_increment:
> \
> - error (IN,
> ARG); \
> + error_at (LOC, IN, ARG);
> \
> break;
> \
> - case
> lv_decrement: \
> - error (DE,
> ARG); \
> + case
> lv_decrement: \
> + error_at (LOC, DE, ARG);
> \
> break;
> \
> default:
> \
> gcc_unreachable
> (); \
> @@ -101,32 +101,25 @@ cxx_readonly_error (tree arg, enum lvalu
> && DECL_LANG_SPECIFIC (arg)
> && DECL_IN_AGGR_P (arg)
> && !TREE_STATIC (arg))
> - ERROR_FOR_ASSIGNMENT (G_("assignment of "
> - "constant field %qD"),
> - G_("constant field %qD "
> - "used as %<asm%> output"),
> - G_("increment of "
> - "constant field %qD"),
> - G_("decrement of "
> - "constant field %qD"),
> + ERROR_FOR_ASSIGNMENT (loc,
> + G_("assignment of constant field %qD"),
> + G_("constant field %qD used as %<asm%>
> output"),
> + G_("increment of constant field %qD"),
> + G_("decrement of constant field %qD"),
> arg);
> else if (INDIRECT_REF_P (arg)
> && TYPE_REF_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
> && (VAR_P (TREE_OPERAND (arg, 0))
> || TREE_CODE (TREE_OPERAND (arg, 0)) == PARM_DECL))
> - ERROR_FOR_ASSIGNMENT (G_("assignment of "
> - "read-only reference %qD"),
> - G_("read-only reference %qD "
> - "used as %<asm%> output"),
> - G_("increment of "
> - "read-only reference %qD"),
> - G_("decrement of "
> - "read-only reference %qD"),
> - TREE_OPERAND (arg, 0));
> + ERROR_FOR_ASSIGNMENT (loc,
> + G_("assignment of read-only reference
> %qD"),
> + G_("read-only reference %qD used as
> %<asm%> output"),
> + G_("increment of read-only reference
> %qD"),
> + G_("decrement of read-only reference
> %qD"),
> + TREE_OPERAND (arg, 0));
> else
> - readonly_error (input_location, arg, errstring);
> + readonly_error (loc, arg, errstring);
> }
> -
>
> /* Structure that holds information about declarations whose type
> was
> incomplete and we could not check whether it was abstract or
> not. */
> --- gcc/cp/typeck.c.jj 2018-08-24 08:55:23.000000000 +0200
> +++ gcc/cp/typeck.c 2018-08-24 09:22:47.579231878 +0200
> @@ -6228,9 +6228,10 @@ cp_build_unary_op (enum tree_code code,
> || TREE_READONLY (arg))
> {
> if (complain & tf_error)
> - cxx_readonly_error (arg, ((code == PREINCREMENT_EXPR
> - || code == POSTINCREMENT_EXPR)
> - ? lv_increment :
> lv_decrement));
> + cxx_readonly_error (location, arg,
> + ((code == PREINCREMENT_EXPR
> + || code == POSTINCREMENT_EXPR)
> + ? lv_increment : lv_decrement));
> else
> return error_mark_node;
> }
> @@ -8159,7 +8160,7 @@ cp_build_modify_expr (location_t loc, tr
> && C_TYPE_FIELDS_READONLY (lhstype))))
> {
> if (complain & tf_error)
> - cxx_readonly_error (lhs, lv_assign);
> + cxx_readonly_error (loc, lhs, lv_assign);
> return error_mark_node;
> }
>
> --- gcc/cp/semantics.c.jj 2018-08-08 10:27:23.000000000 +0200
> +++ gcc/cp/semantics.c 2018-08-24 09:23:56.122504523 +0200
> @@ -1532,7 +1532,7 @@ finish_asm_stmt (int volatile_p, tree st
> effectively const. */
> || (CLASS_TYPE_P (TREE_TYPE (operand))
> && C_TYPE_FIELDS_READONLY (TREE_TYPE
> (operand)))))
> - cxx_readonly_error (operand, lv_asm);
> + cxx_readonly_error (input_location, operand, lv_asm);
>
> tree *op = &operand;
> while (TREE_CODE (*op) == COMPOUND_EXPR)
> --- gcc/testsuite/g++.dg/diagnostic/pr86993.C.jj 2018-08-24
> 09:34:35.065756093 +0200
> +++ gcc/testsuite/g++.dg/diagnostic/pr86993.C 2018-08-24
> 09:35:22.489262138 +0200
> @@ -0,0 +1,13 @@
> +// PR c++/86993
> +// { dg-options "-fdiagnostics-show-caret" }
> +
> +int
> +main ()
> +{
> + const int i = 5; // { dg-error "assignment of read-only
> variable 'i'" "" { target *-*-* } .+1 }
> + i = 5 + 6;
> +/* { dg-begin-multiline-output "" }
> + i = 5 + 6;
> + ~~^~~~~~~
> + { dg-end-multiline-output "" } */
> +}
>
> Jakub
