OK.
On Thu, Aug 23, 2018 at 11:01 AM, David Malcolm <dmalc...@redhat.com> wrote:
> Consider this bogus code (from g++.dg/diagnostic/param-type-mismatch-2.C):
>
> struct s4 { static int member_1 (int one, const char **two, float three); };
>
> int test_4 (int first, const char *second, float third)
> {
> return s4::member_1 (first, second, third);
> }
>
> Before this patch, g++ emits:
>
> demo.cc: In function 'int test_4(int, const char*, float)':
> demo.cc:5:44: error: no matching function for call to 's4::member_1(int&,
> const char*&, float&)'
> 5 | return s4::member_1 (first, second, third);
> | ^
> demo.cc:1:24: note: candidate: 'static int s4::member_1(int, const char**,
> float)'
> 1 | struct s4 { static int member_1 (int one, const char **two, float three);
> };
> | ^~~~~~~~
> demo.cc:1:24: note: no known conversion for argument 2 from 'const char*'
> to 'const char**'
>
> With this patch, it highlights the pertinent parameter in the
> "no known conversion" note:
>
> demo.cc: In function 'int test_4(int, const char*, float)':
> demo.cc:5:44: error: no matching function for call to 's4::member_1(int&,
> const char*&, float&)'
> 5 | return s4::member_1 (first, second, third);
> | ^
> demo.cc:1:24: note: candidate: 'static int s4::member_1(int, const char**,
> float)'
> 1 | struct s4 { static int member_1 (int one, const char **two, float three);
> };
> | ^~~~~~~~
> demo.cc:1:56: note: no known conversion for argument 2 from 'const char*'
> to 'const char**'
> 1 | struct s4 { static int member_1 (int one, const char **two, float three);
> };
> | ~~~~~~~~~~~~~^~~
>
> Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu; adds
> 15 PASS results to g++.sum.
>
> OK for trunk?
>
> I'm working on a followup to highlight the pertinent argument
> in the initial error diagnostic.
>
> gcc/cp/ChangeLog:
> PR c++/85110
> * call.c (print_conversion_rejection): Add "fn" param and use it
> for "no known conversion" messages to underline the pertinent
> param.
> (print_z_candidate): Supply "fn" to the new param above.
>
> gcc/testsuite/ChangeLog:
> PR c++/85110
> * g++.dg/diagnostic/param-type-mismatch-2.C: Update expected
> output to reflect underlining of pertinent parameter in decl
> for "no known conversion" messages.
> ---
> gcc/cp/call.c | 17 +++++++++------
> .../g++.dg/diagnostic/param-type-mismatch-2.C | 25
> +++++++++++++++++-----
> 2 files changed, 31 insertions(+), 11 deletions(-)
>
> diff --git a/gcc/cp/call.c b/gcc/cp/call.c
> index 626830c..ef445e0 100644
> --- a/gcc/cp/call.c
> +++ b/gcc/cp/call.c
> @@ -3432,10 +3432,11 @@ equal_functions (tree fn1, tree fn2)
> return fn1 == fn2;
> }
>
> -/* Print information about a candidate being rejected due to INFO. */
> +/* Print information about a candidate FN being rejected due to INFO. */
>
> static void
> -print_conversion_rejection (location_t loc, struct conversion_info *info)
> +print_conversion_rejection (location_t loc, struct conversion_info *info,
> + tree fn)
> {
> tree from = info->from;
> if (!TYPE_P (from))
> @@ -3466,8 +3467,12 @@ print_conversion_rejection (location_t loc, struct
> conversion_info *info)
> inform (loc, " no known conversion from %qH to %qI",
> from, info->to_type);
> else
> - inform (loc, " no known conversion for argument %d from %qH to %qI",
> - info->n_arg + 1, from, info->to_type);
> + {
> + if (TREE_CODE (fn) == FUNCTION_DECL)
> + loc = get_fndecl_argument_location (fn, info->n_arg);
> + inform (loc, " no known conversion for argument %d from %qH to %qI",
> + info->n_arg + 1, from, info->to_type);
> + }
> }
>
> /* Print information about a candidate with WANT parameters and we found
> @@ -3542,10 +3547,10 @@ print_z_candidate (location_t loc, const char *msgstr,
> r->u.arity.expected);
> break;
> case rr_arg_conversion:
> - print_conversion_rejection (cloc, &r->u.conversion);
> + print_conversion_rejection (cloc, &r->u.conversion, fn);
> break;
> case rr_bad_arg_conversion:
> - print_conversion_rejection (cloc, &r->u.bad_conversion);
> + print_conversion_rejection (cloc, &r->u.bad_conversion, fn);
> break;
> case rr_explicit_conversion:
> inform (cloc, " return type %qT of explicit conversion function "
> diff --git a/gcc/testsuite/g++.dg/diagnostic/param-type-mismatch-2.C
> b/gcc/testsuite/g++.dg/diagnostic/param-type-mismatch-2.C
> index 8cf2dab..4957f61 100644
> --- a/gcc/testsuite/g++.dg/diagnostic/param-type-mismatch-2.C
> +++ b/gcc/testsuite/g++.dg/diagnostic/param-type-mismatch-2.C
> @@ -82,7 +82,10 @@ int test_4 (int first, const char *second, float third)
> ^~~~~~~~
> { dg-end-multiline-output "" } */
> // { dg-message "no known conversion for argument 2 from 'const char\\*'
> to 'const char\\*\\*'" "" { target *-*-* } s4_member_1 }
> - // TODO: underline the pertinent param
> + /* { dg-begin-multiline-output "" }
> + struct s4 { static int member_1 (int one, const char **two, float three); };
> + ~~~~~~~~~~~~~^~~
> + { dg-end-multiline-output "" } */
> }
>
> /* non-static member, with argname. */
> @@ -103,7 +106,10 @@ int test_5 (int first, const char *second, float third)
> ^~~~~~~~
> { dg-end-multiline-output "" } */
> // { dg-message "no known conversion for argument 2 from 'const char\\*'
> to 'const char\\*\\*'" "" { target *-*-* } s5_member_1 }
> - // TODO: underline the pertinent param
> + /* { dg-begin-multiline-output "" }
> + struct s5 { int member_1 (int one, const char **two, float three); };
> + ~~~~~~~~~~~~~^~~
> + { dg-end-multiline-output "" } */
> }
>
> /* non-static member, with argname, via a ptr. */
> @@ -123,7 +129,10 @@ int test_6 (int first, const char *second, float third,
> s6 *ptr)
> ^~~~~~~~
> { dg-end-multiline-output "" } */
> // { dg-message "no known conversion for argument 2 from 'const char\\*'
> to 'const char\\*\\*'" "" { target *-*-* } s6_member_1 }
> - // TODO: underline the pertinent param
> + /* { dg-begin-multiline-output "" }
> + struct s6 { int member_1 (int one, const char **two, float three); };
> + ~~~~~~~~~~~~~^~~
> + { dg-end-multiline-output "" } */
> }
>
> /* Template function. */
> @@ -170,7 +179,10 @@ int test_8 (int first, const char *second, float third)
> ^~~~~~~~
> { dg-end-multiline-output "" } */
> // { dg-message "no known conversion for argument 2 from 'const char\\*'
> to 'const char\\*\\*'" "" { target *-*-* } s8_member_1 }
> - // TODO: underline the pertinent param
> + /* { dg-begin-multiline-output "" }
> + struct s8 { static int member_1 (int one, T two, float three); };
> + ~~^~~
> + { dg-end-multiline-output "" } */
> }
>
> /* Template class, non-static function. */
> @@ -192,5 +204,8 @@ int test_9 (int first, const char *second, float third)
> ^~~~~~~~
> { dg-end-multiline-output "" } */
> // { dg-message "no known conversion for argument 2 from 'const char\\*'
> to 'const char\\*\\*'" "" { target *-*-* } s9_member_1 }
> - // TODO: underline the pertinent param
> + /* { dg-begin-multiline-output "" }
> + struct s9 { int member_1 (int one, T two, float three); };
> + ~~^~~
> + { dg-end-multiline-output "" } */
> }
> --
> 1.8.5.3
>
