Re: [PATCH 1/3] c-family: add name_hint/deferred_diagnostic
On 07/03/2017 11:32 AM, David Malcolm wrote:
> On Mon, 2017-07-03 at 10:25 -0600, Jeff Law wrote:
>> On 05/05/2017 11:51 AM, David Malcolm wrote:
>>> In various places we use lookup_name_fuzzy to provide a hint,
>>> and can report messages of the form:
>>> error: unknown foo named 'bar'
>>> or:
>>> error: unknown foo named 'bar'; did you mean 'SUGGESTION?
>>>
>>> This patch provides a way for lookup_name_fuzzy to provide
>>> both the suggestion above, and (optionally) additional hints
>>> that can be printed e.g.
>>>
>>> note: did you forget to include ?
>>>
>>> This patch provides the mechanism and ports existing users
>>> of lookup_name_fuzzy to the new return type.
>>> There are no uses of such hints in this patch, but followup
>>> patches provide various front-end specific uses of this.
>>>
>>> gcc/c-family/ChangeLog:
>>> * c-common.h (class deferred_diagnostic): New class.
>>> (class name_hint): New class.
>>> (lookup_name_fuzzy): Convert return type from const char *
>>> to name_hint. Add location_t param.
>>>
>>> gcc/c/ChangeLog:
>>> * c-decl.c (implicit_decl_warning): Convert "hint" from
>>> const char * to name_hint. Pass location to
>>> lookup_name_fuzzy. Suppress any deferred diagnostic if the
>>> warning was not printed.
>>> (undeclared_variable): Likewise for "guessed_id".
>>> (lookup_name_fuzzy): Convert return type from const char *
>>> to name_hint. Add location_t param.
>>> * c-parser.c (c_parser_declaration_or_fndef): Convert "hint"
>>> from
>>> const char * to name_hint. Pass location to lookup_name_fuzzy.
>>> (c_parser_parameter_declaration): Pass location to
>>> lookup_name_fuzzy.
>>>
>>> gcc/cp/ChangeLog:
>>> * name-lookup.c (suggest_alternatives_for): Convert
>>> "fuzzy_name" from
>>> const char * to name_hint, and rename to "hint". Pass location
>>> to
>>> lookup_name_fuzzy.
>>> (lookup_name_fuzzy): Convert return type from const char *
>>> to name_hint. Add location_t param.
>>> * parser.c (cp_parser_diagnose_invalid_type_name): Convert
>>> "suggestion" from const char * to name_hint, and rename to
>>> "hint".
>>> Pass location to lookup_name_fuzzy.
>>
>>> ---
>>> gcc/c-family/c-common.h | 121
>>> +++-
>>> gcc/c/c-decl.c | 35 +++---
>>> gcc/c/c-parser.c| 16 ---
>>> gcc/cp/name-lookup.c| 17 +++
>>> gcc/cp/parser.c | 12 ++---
>>> 5 files changed, 163 insertions(+), 38 deletions(-)
>>>
>>> diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
>>> index 138a0a6..83c1a68 100644
>>> --- a/gcc/c-family/c-common.h
>>> +++ b/gcc/c-family/c-common.h
>>> @@ -1009,7 +1009,126 @@ enum lookup_name_fuzzy_kind {
>>>/* Any name. */
>>>FUZZY_LOOKUP_NAME
>>> };
>>> -extern const char *lookup_name_fuzzy (tree, enum
>>> lookup_name_fuzzy_kind);
>>> +
>>> +/* A deferred_diagnostic is a wrapper around optional extra
>>> diagnostics
>>> + that we may want to bundle into a name_hint.
>>> +
>>> + The emit method is called when no name_hint instances reference
>>> + the deferred_diagnostic. In the simple case this is when the
>>> name_hint
>>> + goes out of scope, but a reference-counting scheme is used to
>>> allow
>>> + name_hint instances to be copied. */
>>> +
>>> +class deferred_diagnostic
>>> +{
>>> + public:
>>> + virtual ~deferred_diagnostic () {}
>>> + virtual void emit () = 0;
>>> +
>>> + void incref () { m_refcnt++; }
>>> + void decref ()
>>> + {
>>> +if (--m_refcnt == 0)
>>> + {
>>> + if (!m_suppress)
>>> + emit ();
>>> + delete this;
>>> + }
>>> + }
>>> +
>>> + location_t get_location () const { return m_loc; }
>>> +
>>> + /* Call this if the corresponding warning was not emitted,
>>> + in which case we should also not emit the
>>> deferred_diagnostic. */
>>> + void suppress ()
>>> + {
>>> +m_suppress = true;
>>> + }
>>> +
>>> + protected:
>>> + deferred_diagnostic (location_t loc)
>>> + : m_refcnt (0), m_loc (loc), m_suppress (false) {}
>>> +
>>> + private:
>>> + int m_refcnt;
>>> + location_t m_loc;
>>> + bool m_suppress;
>>> +};
>> So what stands out here is "delete this" and the need for explicit
>> reference counting. Also doesn't that imply that deferred_diagnostic
>> objects must be allocated on the heap? Is there another way to get
>> the
>> behavior you want without resorting to something like this?
>>
>
> Thanks for looking at this.
>
> Yes: deferred_diagnostic instances are heap-allocated. This is because
> it's an abstract base class; each concrete subclass is an
> implementation detail within the frontends, for isolating the special
> -case logic for each different kind of hint, and thus these concrete
> subclasses are hidden within the FE code.
>
> My initial implementation of the above had the name_hint class directly
> "own" the deferred_diagnostic ptr, with a:
> delete m_deferred;
> within
Re: [PATCH 1/3] c-family: add name_hint/deferred_diagnostic
On Mon, Jul 03, 2017 at 01:32:46PM -0400, David Malcolm wrote:
> On Mon, 2017-07-03 at 10:25 -0600, Jeff Law wrote:
> > On 05/05/2017 11:51 AM, David Malcolm wrote:
> > > In various places we use lookup_name_fuzzy to provide a hint,
> > > and can report messages of the form:
> > > error: unknown foo named 'bar'
> > > or:
> > > error: unknown foo named 'bar'; did you mean 'SUGGESTION?
> > >
> > > This patch provides a way for lookup_name_fuzzy to provide
> > > both the suggestion above, and (optionally) additional hints
> > > that can be printed e.g.
> > >
> > > note: did you forget to include ?
> > >
> > > This patch provides the mechanism and ports existing users
> > > of lookup_name_fuzzy to the new return type.
> > > There are no uses of such hints in this patch, but followup
> > > patches provide various front-end specific uses of this.
> > >
> > > gcc/c-family/ChangeLog:
> > > * c-common.h (class deferred_diagnostic): New class.
> > > (class name_hint): New class.
> > > (lookup_name_fuzzy): Convert return type from const char *
> > > to name_hint. Add location_t param.
> > >
> > > gcc/c/ChangeLog:
> > > * c-decl.c (implicit_decl_warning): Convert "hint" from
> > > const char * to name_hint. Pass location to
> > > lookup_name_fuzzy. Suppress any deferred diagnostic if the
> > > warning was not printed.
> > > (undeclared_variable): Likewise for "guessed_id".
> > > (lookup_name_fuzzy): Convert return type from const char *
> > > to name_hint. Add location_t param.
> > > * c-parser.c (c_parser_declaration_or_fndef): Convert "hint"
> > > from
> > > const char * to name_hint. Pass location to lookup_name_fuzzy.
> > > (c_parser_parameter_declaration): Pass location to
> > > lookup_name_fuzzy.
> > >
> > > gcc/cp/ChangeLog:
> > > * name-lookup.c (suggest_alternatives_for): Convert
> > > "fuzzy_name" from
> > > const char * to name_hint, and rename to "hint". Pass location
> > > to
> > > lookup_name_fuzzy.
> > > (lookup_name_fuzzy): Convert return type from const char *
> > > to name_hint. Add location_t param.
> > > * parser.c (cp_parser_diagnose_invalid_type_name): Convert
> > > "suggestion" from const char * to name_hint, and rename to
> > > "hint".
> > > Pass location to lookup_name_fuzzy.
> >
> > > ---
> > > gcc/c-family/c-common.h | 121
> > > +++-
> > > gcc/c/c-decl.c | 35 +++---
> > > gcc/c/c-parser.c| 16 ---
> > > gcc/cp/name-lookup.c| 17 +++
> > > gcc/cp/parser.c | 12 ++---
> > > 5 files changed, 163 insertions(+), 38 deletions(-)
> > >
> > > diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
> > > index 138a0a6..83c1a68 100644
> > > --- a/gcc/c-family/c-common.h
> > > +++ b/gcc/c-family/c-common.h
> > > @@ -1009,7 +1009,126 @@ enum lookup_name_fuzzy_kind {
> > >/* Any name. */
> > >FUZZY_LOOKUP_NAME
> > > };
> > > -extern const char *lookup_name_fuzzy (tree, enum
> > > lookup_name_fuzzy_kind);
> > > +
> > > +/* A deferred_diagnostic is a wrapper around optional extra
> > > diagnostics
> > > + that we may want to bundle into a name_hint.
> > > +
> > > + The emit method is called when no name_hint instances reference
> > > + the deferred_diagnostic. In the simple case this is when the
> > > name_hint
> > > + goes out of scope, but a reference-counting scheme is used to
> > > allow
> > > + name_hint instances to be copied. */
> > > +
> > > +class deferred_diagnostic
> > > +{
> > > + public:
> > > + virtual ~deferred_diagnostic () {}
> > > + virtual void emit () = 0;
> > > +
> > > + void incref () { m_refcnt++; }
> > > + void decref ()
> > > + {
> > > +if (--m_refcnt == 0)
> > > + {
> > > + if (!m_suppress)
> > > + emit ();
> > > + delete this;
> > > + }
> > > + }
> > > +
> > > + location_t get_location () const { return m_loc; }
> > > +
> > > + /* Call this if the corresponding warning was not emitted,
> > > + in which case we should also not emit the
> > > deferred_diagnostic. */
> > > + void suppress ()
> > > + {
> > > +m_suppress = true;
> > > + }
> > > +
> > > + protected:
> > > + deferred_diagnostic (location_t loc)
> > > + : m_refcnt (0), m_loc (loc), m_suppress (false) {}
> > > +
> > > + private:
> > > + int m_refcnt;
> > > + location_t m_loc;
> > > + bool m_suppress;
> > > +};
> > So what stands out here is "delete this" and the need for explicit
> > reference counting. Also doesn't that imply that deferred_diagnostic
> > objects must be allocated on the heap? Is there another way to get
> > the
> > behavior you want without resorting to something like this?
> >
>
> Thanks for looking at this.
>
> Yes: deferred_diagnostic instances are heap-allocated. This is because
> it's an abstract base class; each concrete subclass is an
> implementation detail within the frontends, for isolating the special
> -case logic for each different kind of hint, and thus
Re: [PATCH 1/3] c-family: add name_hint/deferred_diagnostic
On Mon, 2017-07-03 at 10:25 -0600, Jeff Law wrote:
> On 05/05/2017 11:51 AM, David Malcolm wrote:
> > In various places we use lookup_name_fuzzy to provide a hint,
> > and can report messages of the form:
> > error: unknown foo named 'bar'
> > or:
> > error: unknown foo named 'bar'; did you mean 'SUGGESTION?
> >
> > This patch provides a way for lookup_name_fuzzy to provide
> > both the suggestion above, and (optionally) additional hints
> > that can be printed e.g.
> >
> > note: did you forget to include ?
> >
> > This patch provides the mechanism and ports existing users
> > of lookup_name_fuzzy to the new return type.
> > There are no uses of such hints in this patch, but followup
> > patches provide various front-end specific uses of this.
> >
> > gcc/c-family/ChangeLog:
> > * c-common.h (class deferred_diagnostic): New class.
> > (class name_hint): New class.
> > (lookup_name_fuzzy): Convert return type from const char *
> > to name_hint. Add location_t param.
> >
> > gcc/c/ChangeLog:
> > * c-decl.c (implicit_decl_warning): Convert "hint" from
> > const char * to name_hint. Pass location to
> > lookup_name_fuzzy. Suppress any deferred diagnostic if the
> > warning was not printed.
> > (undeclared_variable): Likewise for "guessed_id".
> > (lookup_name_fuzzy): Convert return type from const char *
> > to name_hint. Add location_t param.
> > * c-parser.c (c_parser_declaration_or_fndef): Convert "hint"
> > from
> > const char * to name_hint. Pass location to lookup_name_fuzzy.
> > (c_parser_parameter_declaration): Pass location to
> > lookup_name_fuzzy.
> >
> > gcc/cp/ChangeLog:
> > * name-lookup.c (suggest_alternatives_for): Convert
> > "fuzzy_name" from
> > const char * to name_hint, and rename to "hint". Pass location
> > to
> > lookup_name_fuzzy.
> > (lookup_name_fuzzy): Convert return type from const char *
> > to name_hint. Add location_t param.
> > * parser.c (cp_parser_diagnose_invalid_type_name): Convert
> > "suggestion" from const char * to name_hint, and rename to
> > "hint".
> > Pass location to lookup_name_fuzzy.
>
> > ---
> > gcc/c-family/c-common.h | 121
> > +++-
> > gcc/c/c-decl.c | 35 +++---
> > gcc/c/c-parser.c| 16 ---
> > gcc/cp/name-lookup.c| 17 +++
> > gcc/cp/parser.c | 12 ++---
> > 5 files changed, 163 insertions(+), 38 deletions(-)
> >
> > diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
> > index 138a0a6..83c1a68 100644
> > --- a/gcc/c-family/c-common.h
> > +++ b/gcc/c-family/c-common.h
> > @@ -1009,7 +1009,126 @@ enum lookup_name_fuzzy_kind {
> >/* Any name. */
> >FUZZY_LOOKUP_NAME
> > };
> > -extern const char *lookup_name_fuzzy (tree, enum
> > lookup_name_fuzzy_kind);
> > +
> > +/* A deferred_diagnostic is a wrapper around optional extra
> > diagnostics
> > + that we may want to bundle into a name_hint.
> > +
> > + The emit method is called when no name_hint instances reference
> > + the deferred_diagnostic. In the simple case this is when the
> > name_hint
> > + goes out of scope, but a reference-counting scheme is used to
> > allow
> > + name_hint instances to be copied. */
> > +
> > +class deferred_diagnostic
> > +{
> > + public:
> > + virtual ~deferred_diagnostic () {}
> > + virtual void emit () = 0;
> > +
> > + void incref () { m_refcnt++; }
> > + void decref ()
> > + {
> > +if (--m_refcnt == 0)
> > + {
> > + if (!m_suppress)
> > + emit ();
> > + delete this;
> > + }
> > + }
> > +
> > + location_t get_location () const { return m_loc; }
> > +
> > + /* Call this if the corresponding warning was not emitted,
> > + in which case we should also not emit the
> > deferred_diagnostic. */
> > + void suppress ()
> > + {
> > +m_suppress = true;
> > + }
> > +
> > + protected:
> > + deferred_diagnostic (location_t loc)
> > + : m_refcnt (0), m_loc (loc), m_suppress (false) {}
> > +
> > + private:
> > + int m_refcnt;
> > + location_t m_loc;
> > + bool m_suppress;
> > +};
> So what stands out here is "delete this" and the need for explicit
> reference counting. Also doesn't that imply that deferred_diagnostic
> objects must be allocated on the heap? Is there another way to get
> the
> behavior you want without resorting to something like this?
>
Thanks for looking at this.
Yes: deferred_diagnostic instances are heap-allocated. This is because
it's an abstract base class; each concrete subclass is an
implementation detail within the frontends, for isolating the special
-case logic for each different kind of hint, and thus these concrete
subclasses are hidden within the FE code.
My initial implementation of the above had the name_hint class directly
"own" the deferred_diagnostic ptr, with a:
delete m_deferred;
within name_hint's dtor.
This worked OK, until I encountered places in the C and
Re: [PATCH 1/3] c-family: add name_hint/deferred_diagnostic
On 05/05/2017 11:51 AM, David Malcolm wrote:
> In various places we use lookup_name_fuzzy to provide a hint,
> and can report messages of the form:
> error: unknown foo named 'bar'
> or:
> error: unknown foo named 'bar'; did you mean 'SUGGESTION?
>
> This patch provides a way for lookup_name_fuzzy to provide
> both the suggestion above, and (optionally) additional hints
> that can be printed e.g.
>
> note: did you forget to include ?
>
> This patch provides the mechanism and ports existing users
> of lookup_name_fuzzy to the new return type.
> There are no uses of such hints in this patch, but followup
> patches provide various front-end specific uses of this.
>
> gcc/c-family/ChangeLog:
> * c-common.h (class deferred_diagnostic): New class.
> (class name_hint): New class.
> (lookup_name_fuzzy): Convert return type from const char *
> to name_hint. Add location_t param.
>
> gcc/c/ChangeLog:
> * c-decl.c (implicit_decl_warning): Convert "hint" from
> const char * to name_hint. Pass location to
> lookup_name_fuzzy. Suppress any deferred diagnostic if the
> warning was not printed.
> (undeclared_variable): Likewise for "guessed_id".
> (lookup_name_fuzzy): Convert return type from const char *
> to name_hint. Add location_t param.
> * c-parser.c (c_parser_declaration_or_fndef): Convert "hint" from
> const char * to name_hint. Pass location to lookup_name_fuzzy.
> (c_parser_parameter_declaration): Pass location to
> lookup_name_fuzzy.
>
> gcc/cp/ChangeLog:
> * name-lookup.c (suggest_alternatives_for): Convert "fuzzy_name" from
> const char * to name_hint, and rename to "hint". Pass location to
> lookup_name_fuzzy.
> (lookup_name_fuzzy): Convert return type from const char *
> to name_hint. Add location_t param.
> * parser.c (cp_parser_diagnose_invalid_type_name): Convert
> "suggestion" from const char * to name_hint, and rename to "hint".
> Pass location to lookup_name_fuzzy.
> ---
> gcc/c-family/c-common.h | 121
> +++-
> gcc/c/c-decl.c | 35 +++---
> gcc/c/c-parser.c| 16 ---
> gcc/cp/name-lookup.c| 17 +++
> gcc/cp/parser.c | 12 ++---
> 5 files changed, 163 insertions(+), 38 deletions(-)
>
> diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
> index 138a0a6..83c1a68 100644
> --- a/gcc/c-family/c-common.h
> +++ b/gcc/c-family/c-common.h
> @@ -1009,7 +1009,126 @@ enum lookup_name_fuzzy_kind {
>/* Any name. */
>FUZZY_LOOKUP_NAME
> };
> -extern const char *lookup_name_fuzzy (tree, enum lookup_name_fuzzy_kind);
> +
> +/* A deferred_diagnostic is a wrapper around optional extra diagnostics
> + that we may want to bundle into a name_hint.
> +
> + The emit method is called when no name_hint instances reference
> + the deferred_diagnostic. In the simple case this is when the name_hint
> + goes out of scope, but a reference-counting scheme is used to allow
> + name_hint instances to be copied. */
> +
> +class deferred_diagnostic
> +{
> + public:
> + virtual ~deferred_diagnostic () {}
> + virtual void emit () = 0;
> +
> + void incref () { m_refcnt++; }
> + void decref ()
> + {
> +if (--m_refcnt == 0)
> + {
> + if (!m_suppress)
> + emit ();
> + delete this;
> + }
> + }
> +
> + location_t get_location () const { return m_loc; }
> +
> + /* Call this if the corresponding warning was not emitted,
> + in which case we should also not emit the deferred_diagnostic. */
> + void suppress ()
> + {
> +m_suppress = true;
> + }
> +
> + protected:
> + deferred_diagnostic (location_t loc)
> + : m_refcnt (0), m_loc (loc), m_suppress (false) {}
> +
> + private:
> + int m_refcnt;
> + location_t m_loc;
> + bool m_suppress;
> +};
So what stands out here is "delete this" and the need for explicit
reference counting. Also doesn't that imply that deferred_diagnostic
objects must be allocated on the heap? Is there another way to get the
behavior you want without resorting to something like this?
Or is your argument that deferred_diagnostic is only used from within
class name_hint and thus the concerns around heap vs stack, explicit
counting, etc are all buried inside the name_hint class? If so, is
there any reasonable way to restrict the use of deferred_disagnostic to
within the name_hint class?
The rest of the changes seem non-controversial, so I think if we can
sort out the issues with those classes then this will be fine to move
forward.
jeff
[PING] Re: [PATCH 1/3] c-family: add name_hint/deferred_diagnostic
I'd like to ping the following patches:
[PATCH 1/3] c-family: add name_hint/deferred_diagnostic
https://gcc.gnu.org/ml/gcc-patches/2017-05/msg00439.html
[PATCH 2/3] C++: provide macro used-before-defined hint (PR c++/72786).
https://gcc.gnu.org/ml/gcc-patches/2017-05/msg00437.html
[PATCH 3/3] C: hints for missing stdlib includes for macros and types
https://gcc.gnu.org/ml/gcc-patches/2017-05/msg00438.html
On Fri, 2017-05-05 at 13:51 -0400, David Malcolm wrote:
> In various places we use lookup_name_fuzzy to provide a hint,
> and can report messages of the form:
> error: unknown foo named 'bar'
> or:
> error: unknown foo named 'bar'; did you mean 'SUGGESTION?
>
> This patch provides a way for lookup_name_fuzzy to provide
> both the suggestion above, and (optionally) additional hints
> that can be printed e.g.
>
> note: did you forget to include ?
>
> This patch provides the mechanism and ports existing users
> of lookup_name_fuzzy to the new return type.
> There are no uses of such hints in this patch, but followup
> patches provide various front-end specific uses of this.
>
> gcc/c-family/ChangeLog:
> * c-common.h (class deferred_diagnostic): New class.
> (class name_hint): New class.
> (lookup_name_fuzzy): Convert return type from const char *
> to name_hint. Add location_t param.
>
> gcc/c/ChangeLog:
> * c-decl.c (implicit_decl_warning): Convert "hint" from
> const char * to name_hint. Pass location to
> lookup_name_fuzzy. Suppress any deferred diagnostic if the
> warning was not printed.
> (undeclared_variable): Likewise for "guessed_id".
> (lookup_name_fuzzy): Convert return type from const char *
> to name_hint. Add location_t param.
> * c-parser.c (c_parser_declaration_or_fndef): Convert "hint"
> from
> const char * to name_hint. Pass location to lookup_name_fuzzy.
> (c_parser_parameter_declaration): Pass location to
> lookup_name_fuzzy.
>
> gcc/cp/ChangeLog:
> * name-lookup.c (suggest_alternatives_for): Convert
> "fuzzy_name" from
> const char * to name_hint, and rename to "hint". Pass location
> to
> lookup_name_fuzzy.
> (lookup_name_fuzzy): Convert return type from const char *
> to name_hint. Add location_t param.
> * parser.c (cp_parser_diagnose_invalid_type_name): Convert
> "suggestion" from const char * to name_hint, and rename to
> "hint".
> Pass location to lookup_name_fuzzy.
> ---
> gcc/c-family/c-common.h | 121
> +++-
> gcc/c/c-decl.c | 35 +++---
> gcc/c/c-parser.c| 16 ---
> gcc/cp/name-lookup.c| 17 +++
> gcc/cp/parser.c | 12 ++---
> 5 files changed, 163 insertions(+), 38 deletions(-)
>
> diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
> index 138a0a6..83c1a68 100644
> --- a/gcc/c-family/c-common.h
> +++ b/gcc/c-family/c-common.h
> @@ -1009,7 +1009,126 @@ enum lookup_name_fuzzy_kind {
>/* Any name. */
>FUZZY_LOOKUP_NAME
> };
> -extern const char *lookup_name_fuzzy (tree, enum
> lookup_name_fuzzy_kind);
> +
> +/* A deferred_diagnostic is a wrapper around optional extra
> diagnostics
> + that we may want to bundle into a name_hint.
> +
> + The emit method is called when no name_hint instances reference
> + the deferred_diagnostic. In the simple case this is when the
> name_hint
> + goes out of scope, but a reference-counting scheme is used to
> allow
> + name_hint instances to be copied. */
> +
> +class deferred_diagnostic
> +{
> + public:
> + virtual ~deferred_diagnostic () {}
> + virtual void emit () = 0;
> +
> + void incref () { m_refcnt++; }
> + void decref ()
> + {
> +if (--m_refcnt == 0)
> + {
> + if (!m_suppress)
> + emit ();
> + delete this;
> + }
> + }
> +
> + location_t get_location () const { return m_loc; }
> +
> + /* Call this if the corresponding warning was not emitted,
> + in which case we should also not emit the deferred_diagnostic.
> */
> + void suppress ()
> + {
> +m_suppress = true;
> + }
> +
> + protected:
> + deferred_diagnostic (location_t loc)
> + : m_refcnt (0), m_loc (loc), m_suppress (false) {}
> +
> + private:
> + int m_refcnt;
> + location_t m_loc;
> + bool m_suppress;
> +};
> +
> +/* A name_hint is an optional string suggestion, along with an
> + optional deferred_diagnostic.
> + For example:
> +
> + error: unknown foo named 'bar'
> +
> + if the SU
[PATCH 1/3] c-family: add name_hint/deferred_diagnostic
In various places we use lookup_name_fuzzy to provide a hint,
and can report messages of the form:
error: unknown foo named 'bar'
or:
error: unknown foo named 'bar'; did you mean 'SUGGESTION?
This patch provides a way for lookup_name_fuzzy to provide
both the suggestion above, and (optionally) additional hints
that can be printed e.g.
note: did you forget to include ?
This patch provides the mechanism and ports existing users
of lookup_name_fuzzy to the new return type.
There are no uses of such hints in this patch, but followup
patches provide various front-end specific uses of this.
gcc/c-family/ChangeLog:
* c-common.h (class deferred_diagnostic): New class.
(class name_hint): New class.
(lookup_name_fuzzy): Convert return type from const char *
to name_hint. Add location_t param.
gcc/c/ChangeLog:
* c-decl.c (implicit_decl_warning): Convert "hint" from
const char * to name_hint. Pass location to
lookup_name_fuzzy. Suppress any deferred diagnostic if the
warning was not printed.
(undeclared_variable): Likewise for "guessed_id".
(lookup_name_fuzzy): Convert return type from const char *
to name_hint. Add location_t param.
* c-parser.c (c_parser_declaration_or_fndef): Convert "hint" from
const char * to name_hint. Pass location to lookup_name_fuzzy.
(c_parser_parameter_declaration): Pass location to
lookup_name_fuzzy.
gcc/cp/ChangeLog:
* name-lookup.c (suggest_alternatives_for): Convert "fuzzy_name" from
const char * to name_hint, and rename to "hint". Pass location to
lookup_name_fuzzy.
(lookup_name_fuzzy): Convert return type from const char *
to name_hint. Add location_t param.
* parser.c (cp_parser_diagnose_invalid_type_name): Convert
"suggestion" from const char * to name_hint, and rename to "hint".
Pass location to lookup_name_fuzzy.
---
gcc/c-family/c-common.h | 121 +++-
gcc/c/c-decl.c | 35 +++---
gcc/c/c-parser.c| 16 ---
gcc/cp/name-lookup.c| 17 +++
gcc/cp/parser.c | 12 ++---
5 files changed, 163 insertions(+), 38 deletions(-)
diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index 138a0a6..83c1a68 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -1009,7 +1009,126 @@ enum lookup_name_fuzzy_kind {
/* Any name. */
FUZZY_LOOKUP_NAME
};
-extern const char *lookup_name_fuzzy (tree, enum lookup_name_fuzzy_kind);
+
+/* A deferred_diagnostic is a wrapper around optional extra diagnostics
+ that we may want to bundle into a name_hint.
+
+ The emit method is called when no name_hint instances reference
+ the deferred_diagnostic. In the simple case this is when the name_hint
+ goes out of scope, but a reference-counting scheme is used to allow
+ name_hint instances to be copied. */
+
+class deferred_diagnostic
+{
+ public:
+ virtual ~deferred_diagnostic () {}
+ virtual void emit () = 0;
+
+ void incref () { m_refcnt++; }
+ void decref ()
+ {
+if (--m_refcnt == 0)
+ {
+ if (!m_suppress)
+ emit ();
+ delete this;
+ }
+ }
+
+ location_t get_location () const { return m_loc; }
+
+ /* Call this if the corresponding warning was not emitted,
+ in which case we should also not emit the deferred_diagnostic. */
+ void suppress ()
+ {
+m_suppress = true;
+ }
+
+ protected:
+ deferred_diagnostic (location_t loc)
+ : m_refcnt (0), m_loc (loc), m_suppress (false) {}
+
+ private:
+ int m_refcnt;
+ location_t m_loc;
+ bool m_suppress;
+};
+
+/* A name_hint is an optional string suggestion, along with an
+ optional deferred_diagnostic.
+ For example:
+
+ error: unknown foo named 'bar'
+
+ if the SUGGESTION is "baz", then one might print:
+
+ error: unknown foo named 'bar'; did you mean 'baz'?
+
+ and the deferred_diagnostic allows for additional (optional)
+ diagnostics e.g.:
+
+ note: did you check behind the couch?
+
+ The deferred_diagnostic is emitted when no name_hint instances reference
+ the deferred_diagnostic. In the simple case this is when the name_hint
+ goes out of scope, but a reference-counting scheme is used to allow
+ name_hint instances to be copied. */
+
+class name_hint
+{
+public:
+ name_hint () : m_suggestion (NULL), m_deferred (NULL) {}
+
+ name_hint (const char *suggestion, deferred_diagnostic *deferred)
+ : m_suggestion (suggestion), m_deferred (deferred)
+ {
+if (m_deferred)
+ m_deferred->incref ();
+ }
+
+ name_hint (const name_hint )
+ : m_suggestion (other.m_suggestion), m_deferred (other.m_deferred)
+ {
+if (m_deferred)
+ m_deferred->incref ();
+ }
+
+ name_hint& operator= (const name_hint )
+ {
+m_suggestion = other.m_suggestion;
+if (other.m_deferred)
+ other.m_deferred->incref ();
+if (m_deferred)
+
