Ping:
https://gcc.gnu.org/ml/gcc-patches/2016-04/msg01834.html
On Thu, 2016-04-28 at 10:28 -0400, David Malcolm wrote:
> Similar to the C++ case, but more involved as the location of the
> pertinent token isn't readily available. The patch adds it as a
> param
> to build_component_ref. All callers are updated to provide the info,
> apart from objc_build_component_ref; fixing the latter would lead to
> a cascade of other changes, so it's simplest to provide
> UNKNOWN_LOCATION
> there and have build_component_ref fall back gracefully for this case
> to the old behavior of showing a hint in the message, without a fixit
> replacement in the source view.
>
> This does slightly change the location of the error; before we had:
>
> test.c:11:13: error: 'union u' has no member named 'colour'; did you
> mean 'color'?
> return ptr->colour;
> ^~
>
> with the patch we have:
>
> test.c:11:15: error: 'union u' has no member named 'colour'; did you
> mean 'color'?
> return ptr->colour;
> ^~~~~~
> color
>
> I think the location change is an improvement.
>
> Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu.
>
> OK for trunk?
>
> gcc/c/ChangeLog:
> * c-parser.c (c_parser_postfix_expression): In
> __builtin_offsetof
> and structure element reference, capture the location of the
> element name token and pass it to build_component_ref.
> (c_parser_postfix_expression_after_primary): Likewise for
> structure element dereference.
> (c_parser_omp_variable_list): Likewise for
> OMP_CLAUSE_{_CACHE, MAP, FROM, TO},
> * c-tree.h (build_component_ref): Add location_t param.
> * c-typeck.c (build_component_ref): Add location_t param
> COMPONENT_LOC. Use it, if available, when issuing hints about
> mispelled member names to provide a fixit replacement hint.
>
> gcc/objc/ChangeLog:
> * objc-act.c (objc_build_component_ref): Update call
> to build_component_ref for added param, passing
> UNKNOWN_LOCATION.
>
> gcc/testsuite/ChangeLog:
> * gcc.dg/spellcheck-fields-2.c: New test case.
> ---
> gcc/c/c-parser.c | 34
> +++++++++++++++++++++---------
> gcc/c/c-tree.h | 2 +-
> gcc/c/c-typeck.c | 26 +++++++++++++++++++-
> ---
> gcc/objc/objc-act.c | 3 ++-
> gcc/testsuite/gcc.dg/spellcheck-fields-2.c | 19 +++++++++++++++++
> 5 files changed, 68 insertions(+), 16 deletions(-)
> create mode 100644 gcc/testsuite/gcc.dg/spellcheck-fields-2.c
>
> diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
> index 36c44ab..19e6772 100644
> --- a/gcc/c/c-parser.c
> +++ b/gcc/c/c-parser.c
> @@ -7707,8 +7707,9 @@ c_parser_postfix_expression (c_parser *parser)
> accept sub structure and sub array references. */
> if (c_parser_next_token_is (parser, CPP_NAME))
> {
> + c_token *comp_tok = c_parser_peek_token (parser);
> offsetof_ref = build_component_ref
> - (loc, offsetof_ref, c_parser_peek_token (parser)
> ->value);
> + (loc, offsetof_ref, comp_tok->value, comp_tok
> ->location);
> c_parser_consume_token (parser);
> while (c_parser_next_token_is (parser, CPP_DOT)
> || c_parser_next_token_is (parser,
> @@ -7734,9 +7735,10 @@ c_parser_postfix_expression (c_parser *parser)
> c_parser_error (parser, "expected
> identifier");
> break;
> }
> + c_token *comp_tok = c_parser_peek_token
> (parser);
> offsetof_ref = build_component_ref
> - (loc, offsetof_ref,
> - c_parser_peek_token (parser)->value);
> + (loc, offsetof_ref, comp_tok->value,
> + comp_tok->location);
> c_parser_consume_token (parser);
> }
> else
> @@ -8213,7 +8215,7 @@ c_parser_postfix_expression_after_primary
> (c_parser *parser,
> {
> struct c_expr orig_expr;
> tree ident, idx;
> - location_t sizeof_arg_loc[3];
> + location_t sizeof_arg_loc[3], comp_loc;
> tree sizeof_arg[3];
> unsigned int literal_zero_mask;
> unsigned int i;
> @@ -8327,7 +8329,11 @@ c_parser_postfix_expression_after_primary
> (c_parser *parser,
> c_parser_consume_token (parser);
> expr = default_function_array_conversion (expr_loc, expr);
> if (c_parser_next_token_is (parser, CPP_NAME))
> - ident = c_parser_peek_token (parser)->value;
> + {
> + c_token *comp_tok = c_parser_peek_token (parser);
> + ident = comp_tok->value;
> + comp_loc = comp_tok->location;
> + }
> else
> {
> c_parser_error (parser, "expected identifier");
> @@ -8339,7 +8345,8 @@ c_parser_postfix_expression_after_primary
> (c_parser *parser,
> start = expr.get_start ();
> finish = c_parser_peek_token (parser)->get_finish ();
> c_parser_consume_token (parser);
> - expr.value = build_component_ref (op_loc, expr.value,
> ident);
> + expr.value = build_component_ref (op_loc, expr.value,
> ident,
> + comp_loc);
> set_c_expr_source_range (&expr, start, finish);
> expr.original_code = ERROR_MARK;
> if (TREE_CODE (expr.value) != COMPONENT_REF)
> @@ -8359,7 +8366,11 @@ c_parser_postfix_expression_after_primary
> (c_parser *parser,
> c_parser_consume_token (parser);
> expr = convert_lvalue_to_rvalue (expr_loc, expr, true,
> false);
> if (c_parser_next_token_is (parser, CPP_NAME))
> - ident = c_parser_peek_token (parser)->value;
> + {
> + c_token *comp_tok = c_parser_peek_token (parser);
> + ident = comp_tok->value;
> + comp_loc = comp_tok->location;
> + }
> else
> {
> c_parser_error (parser, "expected identifier");
> @@ -8375,7 +8386,7 @@ c_parser_postfix_expression_after_primary
> (c_parser *parser,
> build_indirect_ref
> (op_loc,
> expr
> .value,
> RO_A
> RROW),
> - ident);
> + ident, comp_loc);
> set_c_expr_source_range (&expr, start, finish);
> expr.original_code = ERROR_MARK;
> if (TREE_CODE (expr.value) != COMPONENT_REF)
> @@ -10621,9 +10632,12 @@ c_parser_omp_variable_list (c_parser
> *parser,
> t = error_mark_node;
> break;
> }
> - tree ident = c_parser_peek_token (parser)->value;
> +
> + c_token *comp_tok = c_parser_peek_token (parser);
> + tree ident = comp_tok->value;
> + location_t comp_loc = comp_tok->location;
> c_parser_consume_token (parser);
> - t = build_component_ref (op_loc, t, ident);
> + t = build_component_ref (op_loc, t, ident,
> comp_loc);
> }
> /* FALLTHROUGH */
> case OMP_CLAUSE_DEPEND:
> diff --git a/gcc/c/c-tree.h b/gcc/c/c-tree.h
> index 4633182..3201a71 100644
> --- a/gcc/c/c-tree.h
> +++ b/gcc/c/c-tree.h
> @@ -604,7 +604,7 @@ extern struct c_expr convert_lvalue_to_rvalue
> (location_t, struct c_expr,
> bool, bool);
> extern void mark_exp_read (tree);
> extern tree composite_type (tree, tree);
> -extern tree build_component_ref (location_t, tree, tree);
> +extern tree build_component_ref (location_t, tree, tree,
> location_t);
> extern tree build_array_ref (location_t, tree, tree);
> extern tree build_external_ref (location_t, tree, int, tree *);
> extern void pop_maybe_used (bool);
> diff --git a/gcc/c/c-typeck.c b/gcc/c/c-typeck.c
> index 58c2139..8aece1a 100644
> --- a/gcc/c/c-typeck.c
> +++ b/gcc/c/c-typeck.c
> @@ -2309,10 +2309,12 @@ should_suggest_deref_p (tree datum_type)
>
> /* Make an expression to refer to the COMPONENT field of structure
> or
> union value DATUM. COMPONENT is an IDENTIFIER_NODE. LOC is the
> - location of the COMPONENT_REF. */
> + location of the COMPONENT_REF. COMPONENT_LOC is the location
> + of COMPONENT. */
>
> tree
> -build_component_ref (location_t loc, tree datum, tree component)
> +build_component_ref (location_t loc, tree datum, tree component,
> + location_t component_loc)
> {
> tree type = TREE_TYPE (datum);
> enum tree_code code = TREE_CODE (type);
> @@ -2344,8 +2346,24 @@ build_component_ref (location_t loc, tree
> datum, tree component)
> {
> tree guessed_id = lookup_field_fuzzy (type, component);
> if (guessed_id)
> - error_at (loc, "%qT has no member named %qE; did you
> mean %qE?",
> - type, component, guessed_id);
> + {
> + /* Attempt to provide a fixit replacement hint, if
> + we have a valid range for the component. */
> + location_t reported_loc
> + = (component_loc != UNKNOWN_LOCATION) ?
> component_loc : loc;
> + rich_location rich_loc (line_table, reported_loc);
> + if (component_loc != UNKNOWN_LOCATION)
> + {
> + source_range component_range =
> + get_range_from_loc (line_table, component_loc);
> + rich_loc.add_fixit_replace (component_range,
> + IDENTIFIER_POINTER
> (guessed_id));
> + }
> + error_at_rich_loc
> + (&rich_loc,
> + "%qT has no member named %qE; did you mean %qE?",
> + type, component, guessed_id);
> + }
> else
> error_at (loc, "%qT has no member named %qE", type,
> component);
> return error_mark_node;
> diff --git a/gcc/objc/objc-act.c b/gcc/objc/objc-act.c
> index 4856457..44f01d2 100644
> --- a/gcc/objc/objc-act.c
> +++ b/gcc/objc/objc-act.c
> @@ -2654,7 +2654,8 @@ objc_build_component_ref (tree datum, tree
> component)
> return finish_class_member_access_expr (datum, component, false,
> tf_warning_or_error);
> #else
> - return build_component_ref (input_location, datum, component);
> + return build_component_ref (input_location, datum, component,
> + UNKNOWN_LOCATION);
> #endif
> }
>
> diff --git a/gcc/testsuite/gcc.dg/spellcheck-fields-2.c
> b/gcc/testsuite/gcc.dg/spellcheck-fields-2.c
> new file mode 100644
> index 0000000..d6ebff1
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/spellcheck-fields-2.c
> @@ -0,0 +1,19 @@
> +/* { dg-options "-fdiagnostics-show-caret" } */
> +
> +union u
> +{
> + int color;
> + int shape;
> +};
> +
> +int test (union u *ptr)
> +{
> + return ptr->colour; /* { dg-error "did you mean .color.?" } */
> +}
> +
> +/* Verify that we get an underline and a fixit hint. */
> +/* { dg-begin-multiline-output "" }
> + return ptr->colour;
> + ^~~~~~
> + color
> + { dg-end-multiline-output "" } */
