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Re: [PATCH] v2: Show pertinent parameter (PR c++/85110)
- From: Jason Merrill <jason at redhat dot com>
- To: David Malcolm <dmalcolm at redhat dot com>
- Cc: gcc-patches List <gcc-patches at gcc dot gnu dot org>
- Date: Mon, 9 Apr 2018 15:04:38 -0400
- Subject: Re: [PATCH] v2: Show pertinent parameter (PR c++/85110)
- References: <CADzB+2=NSU=A4Dv_xRWOZyg6=i_eEcbChUP279QXwW6XpcPePw@mail.gmail.com> <1523044468-55815-1-git-send-email-dmalcolm@redhat.com>
OK.
On Fri, Apr 6, 2018 at 3:54 PM, David Malcolm <dmalcolm@redhat.com> wrote:
> On Thu, 2018-03-29 at 09:20 -0400, Jason Merrill wrote:
>> On Wed, Mar 28, 2018 at 4:44 PM, David Malcolm <dmalcolm@redhat.com>
>> wrote:
>> > This followup patch updates the specific error-handling path
>> > to add a note showing the pertinent parameter decl, taking
>> > the output from:
>> >
>> > test.cc: In function 'void caller(const char*)':
>> > test.cc:6:14: error: cannot convert 'const char*' to 'const char**'
>> > for argument '2' to 'void callee(int, const char**, int)'
>> > callee (1, fmt, 3);
>> > ^~~
>> >
>> > to:
>> >
>> > test.cc: In function 'void caller(const char*)':
>> > test.cc:6:14: error: cannot convert 'const char*' to 'const char**'
>> > for argument '2' to 'void callee(int, const char**, int)'
>> > callee (1, fmt, 3);
>> > ^~~
>> > test.cc:1:36: note: initializing argument 2 of 'void callee(int,
>> > const char**, int)'
>> > void callee (int one, const char **two, int three);
>> > ~~~~~~~~~~~~~^~~
>> >
>> > Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu; adds
>> > a further 18 PASS results to g++.sum.
>> >
>> > Again, not a regression as such, but I've been calling out the
>> > underlined
>> > arguments as a feature of gcc 8, so would be good to fix.
>> >
>> > OK for trunk?
>> >
>> > gcc/cp/ChangeLog:
>> > PR c++/85110
>> > * call.c (get_fndecl_argument_location): Make non-static.
>> > * cp-tree.h (get_fndecl_argument_location): New decl.
>> > * typeck.c (convert_for_assignment): When complaining due
>> > to
>> > conversions for an argument, show the location of the
>> > parameter
>> > within the decl.
>> >
>> > gcc/testsuite/ChangeLog:
>> > PR c++/85110
>> > * g++.dg/diagnostic/param-type-mismatch-2.C: Update for the
>> > cases
>> > where we now show the pertinent parameter.
>> > ---
>> > gcc/cp/call.c | 2 +-
>> > gcc/cp/cp-tree.h | 2 ++
>> > gcc/cp/typeck.c | 10 +++++++
>> > ---
>> > .../g++.dg/diagnostic/param-type-mismatch-2.C | 21
>> > ++++++++++++++++++---
>> > 4 files changed, 28 insertions(+), 7 deletions(-)
>> >
>> > diff --git a/gcc/cp/call.c b/gcc/cp/call.c
>> > index 1a87f99..e1a0639 100644
>> > --- a/gcc/cp/call.c
>> > +++ b/gcc/cp/call.c
>> > @@ -6598,7 +6598,7 @@ maybe_print_user_conv_context (conversion
>> > *convs)
>> > ARGNUM is zero based, -1 indicates the `this' argument of a
>> > method.
>> > Return the location of the FNDECL itself if there are
>> > problems. */
>> >
>> > -static location_t
>> > +location_t
>> > get_fndecl_argument_location (tree fndecl, int argnum)
>> > {
>> > int i;
>> > diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
>> > index d5382c2..b45880d 100644
>> > --- a/gcc/cp/cp-tree.h
>> > +++ b/gcc/cp/cp-tree.h
>> > @@ -5965,6 +5965,8 @@ extern bool
>> > can_convert_arg (tree, tree, tree, int,
>> > tsubst_flags_t);
>> > extern bool can_convert_arg_bad (tree,
>> > tree, tree, int,
>> > tsubst_flags_t);
>> > +extern location_t get_fndecl_argument_location (tree, int);
>> > +
>> >
>> > /* A class for recording information about access failures (e.g.
>> > private
>> > fields), so that we can potentially supply a fix-it hint about
>> > diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
>> > index e733c79..742b2e9 100644
>> > --- a/gcc/cp/typeck.c
>> > +++ b/gcc/cp/typeck.c
>> > @@ -8781,9 +8781,13 @@ convert_for_assignment (tree type, tree rhs,
>> > parmnum,
>> > complain, flags);
>> > }
>> > else if (fndecl)
>> > - error_at (EXPR_LOC_OR_LOC (rhs, input_location),
>> > - "cannot convert %qH to %qI for argument
>> > %qP to %qD",
>> > - rhstype, type, parmnum, fndecl);
>> > + {
>> > + error_at (EXPR_LOC_OR_LOC (rhs, input_location),
>> > + "cannot convert %qH to %qI for argument
>> > %qP to %qD",
>> > + rhstype, type, parmnum, fndecl);
>> > + inform (get_fndecl_argument_location (fndecl,
>> > parmnum),
>> > + " initializing argument %P of %qD",
>> > parmnum, fndecl);
>>
>> If you're adding the inform, you don't need the %P of %D in the
>> initial error.
>>
>> Jason
>
> Thanks. Here's an updated version of the patch which removes them.
>
> Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu; adds
> 18 PASS results to g++.sum.
>
> OK for trunk?
>
> gcc/cp/ChangeLog:
> PR c++/85110
> * call.c (get_fndecl_argument_location): Make non-static.
> * cp-tree.h (get_fndecl_argument_location): New decl.
> * typeck.c (convert_for_assignment): When complaining due to
> conversions for an argument, show the location of the parameter
> within the decl.
>
> gcc/testsuite/ChangeLog:
> PR c++/85110
> * g++.dg/cpp1z/direct-enum-init1.C: Update for the cases
> where we now show the pertinent parameter.
> * g++.dg/diagnostic/aka2.C: Likewise.
> * g++.dg/diagnostic/param-type-mismatch-2.C: Likewise.
> ---
> gcc/cp/call.c | 2 +-
> gcc/cp/cp-tree.h | 2 ++
> gcc/cp/typeck.c | 10 +++++---
> gcc/testsuite/g++.dg/cpp1z/direct-enum-init1.C | 6 ++---
> gcc/testsuite/g++.dg/diagnostic/aka2.C | 2 +-
> .../g++.dg/diagnostic/param-type-mismatch-2.C | 27 +++++++++++++++++-----
> 6 files changed, 35 insertions(+), 14 deletions(-)
>
> diff --git a/gcc/cp/call.c b/gcc/cp/call.c
> index f2ada27..53850c1 100644
> --- a/gcc/cp/call.c
> +++ b/gcc/cp/call.c
> @@ -6595,7 +6595,7 @@ maybe_print_user_conv_context (conversion *convs)
> ARGNUM is zero based, -1 indicates the `this' argument of a method.
> Return the location of the FNDECL itself if there are problems. */
>
> -static location_t
> +location_t
> get_fndecl_argument_location (tree fndecl, int argnum)
> {
> int i;
> diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
> index dbe34c0..0538351 100644
> --- a/gcc/cp/cp-tree.h
> +++ b/gcc/cp/cp-tree.h
> @@ -5994,6 +5994,8 @@ extern bool can_convert_arg (tree, tree, tree, int,
> tsubst_flags_t);
> extern bool can_convert_arg_bad (tree, tree, tree, int,
> tsubst_flags_t);
> +extern location_t get_fndecl_argument_location (tree, int);
> +
>
> /* A class for recording information about access failures (e.g. private
> fields), so that we can potentially supply a fix-it hint about
> diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
> index e5ad54d..b449b1f 100644
> --- a/gcc/cp/typeck.c
> +++ b/gcc/cp/typeck.c
> @@ -8785,9 +8785,13 @@ convert_for_assignment (tree type, tree rhs,
> parmnum, complain, flags);
> }
> else if (fndecl)
> - error_at (EXPR_LOC_OR_LOC (rhs, input_location),
> - "cannot convert %qH to %qI for argument %qP to %qD",
> - rhstype, type, parmnum, fndecl);
> + {
> + error_at (EXPR_LOC_OR_LOC (rhs, input_location),
> + "cannot convert %qH to %qI",
> + rhstype, type);
> + inform (get_fndecl_argument_location (fndecl, parmnum),
> + " initializing argument %P of %qD", parmnum, fndecl);
> + }
> else
> switch (errtype)
> {
> diff --git a/gcc/testsuite/g++.dg/cpp1z/direct-enum-init1.C b/gcc/testsuite/g++.dg/cpp1z/direct-enum-init1.C
> index d8cffb4..fa2934e 100644
> --- a/gcc/testsuite/g++.dg/cpp1z/direct-enum-init1.C
> +++ b/gcc/testsuite/g++.dg/cpp1z/direct-enum-init1.C
> @@ -40,7 +40,7 @@ foo ()
> D *d7 = new D { 9 }; // { dg-error "cannot convert \[^\n\r]* to 'D' in initialization" "" { target c++14_down } }
> E *e5 = new E { -4 }; // { dg-error "cannot convert \[^\n\r]* to 'E' in initialization" "" { target c++14_down } }
> // { dg-error "narrowing conversion of '-4' from 'int' to 'unsigned char' inside" "" { target c++17 } .-1 }
> - bar ({ 10 }); // { dg-error "cannot convert \[^\n\r]* to 'E' for argument" }
> + bar ({ 10 }); // { dg-error "cannot convert \[^\n\r]* to 'E'" }
> bar (E { 9 }); // { dg-error "cannot convert 'int' to 'E' in initialization" "" { target c++14_down } }
> V v1 = { { 11 } }; // { dg-error "braces around scalar initializer for type 'E'" }
> V v2 = { E { 12 } }; // { dg-error "cannot convert 'int' to 'E' in initialization" "" { target c++14_down } }
> @@ -106,7 +106,7 @@ foo2 ()
> D *d7 = new D { 9 }; // { dg-error "cannot convert \[^\n\r]* to 'D' in initialization" "" { target c++14_down } }
> E *e5 = new E { -4 }; // { dg-error "cannot convert \[^\n\r]* to 'E' in initialization" "" { target c++14_down } }
> // { dg-error "narrowing conversion of '-4' from 'int' to 'unsigned char' inside" "" { target c++17 } .-1 }
> - bar ({ 10 }); // { dg-error "cannot convert \[^\n\r]* to 'E' for argument" }
> + bar ({ 10 }); // { dg-error "cannot convert \[^\n\r]* to 'E'" }
> bar (E { 9 }); // { dg-error "cannot convert 'int' to 'E' in initialization" "" { target c++14_down } }
> V v1 = { { 11 } }; // { dg-error "braces around scalar initializer for type 'E'" }
> V v2 = { E { 12 } }; // { dg-error "cannot convert 'int' to 'E' in initialization" "" { target c++14_down } }
> @@ -174,7 +174,7 @@ foo3 ()
> K *d7 = new K { 9 }; // { dg-error "cannot convert \[^\n\r]* to 'D' in initialization" "" { target c++14_down } }
> L *e5 = new L { -4 }; // { dg-error "cannot convert \[^\n\r]* to 'E' in initialization" "" { target c++14_down } }
> // { dg-error "narrowing conversion of '-4' from 'int' to 'unsigned char' inside" "" { target c++17 } .-1 }
> - bar3 ({ 10 }); // { dg-error "cannot convert \[^\n\r]* to 'E' for argument" }
> + bar3 ({ 10 }); // { dg-error "cannot convert \[^\n\r]* to 'E'" }
> bar3 (E { 9 }); // { dg-error "cannot convert 'int' to 'E' in initialization" "" { target c++14_down } }
> M v1 = { { 11 } }; // { dg-error "braces around scalar initializer for type 'E'" }
> M v2 = { L { 12 } }; // { dg-error "cannot convert 'int' to 'E' in initialization" "" { target c++14_down } }
> diff --git a/gcc/testsuite/g++.dg/diagnostic/aka2.C b/gcc/testsuite/g++.dg/diagnostic/aka2.C
> index a43f9e3..d7a3b35 100644
> --- a/gcc/testsuite/g++.dg/diagnostic/aka2.C
> +++ b/gcc/testsuite/g++.dg/diagnostic/aka2.C
> @@ -11,7 +11,7 @@ int foo(t1 *);
> void test_1 () {
> t2 pos;
>
> - foo (&pos); // { dg-error "cannot convert 't2\\*' {aka 's2\\*'} to 't1\\*' {aka 's1\\*'} for argument '1' to 'int foo\\(t1\\*\\)'" }
> + foo (&pos); // { dg-error "cannot convert 't2\\*' {aka 's2\\*'} to 't1\\*' {aka 's1\\*'}" }
> }
>
> /* Exercise %T. */
> 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 ae84248..c3b6f00 100644
> --- a/gcc/testsuite/g++.dg/diagnostic/param-type-mismatch-2.C
> +++ b/gcc/testsuite/g++.dg/diagnostic/param-type-mismatch-2.C
> @@ -4,44 +4,59 @@
>
> /* decl, with argname. */
>
> -extern int callee_1 (int one, const char **two, float three);
> +extern int callee_1 (int one, const char **two, float three); // { dg-line callee_1 }
>
> int test_1 (int first, const char *second, float third)
> {
> - return callee_1 (first, second, third); // { dg-error "27: cannot convert 'const char\\*' to 'const char\\*\\*' for argument '2' to 'int callee_1\\(int, const char\\*\\*, float\\)'" }
> + return callee_1 (first, second, third); // { dg-error "27: cannot convert 'const char\\*' to 'const char\\*\\*'" }
> /* { dg-begin-multiline-output "" }
> return callee_1 (first, second, third);
> ^~~~~~
> { dg-end-multiline-output "" } */
> + // { dg-message "initializing argument 2 of 'int callee_1\\(int, const char\\*\\*, float\\)'" "" { target *-*-* } callee_1 }
> + /* { dg-begin-multiline-output "" }
> + extern int callee_1 (int one, const char **two, float three);
> + ~~~~~~~~~~~~~^~~
> + { dg-end-multiline-output "" } */
> }
>
> /* decl, without argname. */
>
> -extern int callee_2 (int, const char **, float);
> +extern int callee_2 (int, const char **, float); // { dg-line callee_2 }
>
> int test_2 (int first, const char *second, float third)
> {
> - return callee_2 (first, second, third); // { dg-error "27: cannot convert 'const char\\*' to 'const char\\*\\*' for argument '2' to 'int callee_2\\(int, const char\\*\\*, float\\)'" }
> + return callee_2 (first, second, third); // { dg-error "27: cannot convert 'const char\\*' to 'const char\\*\\*'" }
> /* { dg-begin-multiline-output "" }
> return callee_2 (first, second, third);
> ^~~~~~
> { dg-end-multiline-output "" } */
> + // { dg-message "initializing argument 2 of 'int callee_2\\(int, const char\\*\\*, float\\)'" "" { target *-*-* } callee_2 }
> + /* { dg-begin-multiline-output "" }
> + extern int callee_2 (int, const char **, float);
> + ^~~~~~~~~~~~~
> + { dg-end-multiline-output "" } */
> }
>
> /* defn, with argname. */
>
> -static int callee_3 (int one, const char **two, float three)
> +static int callee_3 (int one, const char **two, float three) // { dg-line callee_3 }
> {
> return callee_2 (one, two, three);
> }
>
> int test_3 (int first, const char *second, float third)
> {
> - return callee_3 (first, second, third); // { dg-error "27: cannot convert 'const char\\*' to 'const char\\*\\*' for argument '2' to 'int callee_3\\(int, const char\\*\\*, float\\)'" }
> + return callee_3 (first, second, third); // { dg-error "27: cannot convert 'const char\\*' to 'const char\\*\\*'" }
> /* { dg-begin-multiline-output "" }
> return callee_3 (first, second, third);
> ^~~~~~
> { dg-end-multiline-output "" } */
> + // { dg-message "initializing argument 2 of 'int callee_3\\(int, const char\\*\\*, float\\)'" "" { target *-*-* } callee_3 }
> + /* { dg-begin-multiline-output "" }
> + static int callee_3 (int one, const char **two, float three)
> + ~~~~~~~~~~~~~^~~
> + { dg-end-multiline-output "" } */
> }
>
> /* static member, with argname. */
> --
> 1.8.5.3
>