diff mbox series

c++: ICE with bogus late return type [PR99803]

Message ID 20210415012136.307994-1-polacek@redhat.com
State New
Headers show
Series c++: ICE with bogus late return type [PR99803] | expand

Commit Message

Marek Polacek April 15, 2021, 1:21 a.m. UTC 
Here we ICE when compiling this code in C++20, because we're trying to
slam a 'typename' after the ->.  The cp_parser_template_id call just
before the spot I'm changing parsed A::template A<int> as a BASELINK
that contains a constructor, but make_typename_type crashes on that.

My fix is the same as c++/88325, add an is_overloaded_fn check.

Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?

gcc/cp/ChangeLog:

	PR c++/99803
	* parser.c (cp_parser_simple_type_specifier): Don't call
	cp_parser_make_typename_type for is_overloaded_fn.

gcc/testsuite/ChangeLog:

	PR c++/99803
	* g++.dg/cpp2a/typename19.C: New test.
---
 gcc/cp/parser.c                         | 2 +-
 gcc/testsuite/g++.dg/cpp2a/typename19.C | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp2a/typename19.C


base-commit: a87d3f964df31d4fbceb822c6d293e85c117d992

Comments

Jason Merrill April 15, 2021, 7:31 p.m. UTC | #1 
On 4/14/21 9:21 PM, Marek Polacek wrote:
> Here we ICE when compiling this code in C++20, because we're trying to
> slam a 'typename' after the ->.  The cp_parser_template_id call just
> before the spot I'm changing parsed A::template A<int> as a BASELINK
> that contains a constructor, but make_typename_type crashes on that.
> 
> My fix is the same as c++/88325, add an is_overloaded_fn check.

Instead of handling this in various callers, maybe make_typename_type 
should handle the error, like it already does for e.g.

   struct A {  template <class T> static T t; };
   A(unsigned) -> A:: template t<int>;

Incidentally, in the testcase for 88325:

> A<T>::A<U> () // { dg-error "partial specialization" }

this error is misleading; this isn't a partial specialization, it's 
redundant template arguments while trying to define the primary 
template.  I wouldn't worry about fixing the compiler now, but let's not 
test for the wrong error.

> Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
> 
> gcc/cp/ChangeLog:
> 
> 	PR c++/99803
> 	* parser.c (cp_parser_simple_type_specifier): Don't call
> 	cp_parser_make_typename_type for is_overloaded_fn.
> 
> gcc/testsuite/ChangeLog:
> 
> 	PR c++/99803
> 	* g++.dg/cpp2a/typename19.C: New test.
> ---
>   gcc/cp/parser.c                         | 2 +-
>   gcc/testsuite/g++.dg/cpp2a/typename19.C | 5 +++++
>   2 files changed, 6 insertions(+), 1 deletion(-)
>   create mode 100644 gcc/testsuite/g++.dg/cpp2a/typename19.C
> 
> diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
> index 3a107206318..3c506d891c9 100644
> --- a/gcc/cp/parser.c
> +++ b/gcc/cp/parser.c
> @@ -18903,7 +18903,7 @@ cp_parser_simple_type_specifier (cp_parser* parser,
>   	  if (TREE_CODE (type) != TYPE_DECL)
>   	    {
>   	      /* ...unless we pretend we have seen 'typename'.  */
> -	      if (typename_p)
> +	      if (typename_p && !is_overloaded_fn (type))
>   		type = cp_parser_make_typename_type (parser, type,
>   						     token->location);
>   	      else
> diff --git a/gcc/testsuite/g++.dg/cpp2a/typename19.C b/gcc/testsuite/g++.dg/cpp2a/typename19.C
> new file mode 100644
> index 00000000000..bd7e5110e00
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/cpp2a/typename19.C
> @@ -0,0 +1,5 @@
> +// PR c++/99803
> +// { dg-do compile { target c++20 } }
> +
> +struct A { template<typename T> A(T); };
> +auto A(unsigned) -> A::template A<int>; // { dg-error "not name a type" }
> 
> base-commit: a87d3f964df31d4fbceb822c6d293e85c117d992
>
Marek Polacek April 16, 2021, 2:02 a.m. UTC | #2 
On Thu, Apr 15, 2021 at 03:31:24PM -0400, Jason Merrill wrote:
> On 4/14/21 9:21 PM, Marek Polacek wrote:
> > Here we ICE when compiling this code in C++20, because we're trying to
> > slam a 'typename' after the ->.  The cp_parser_template_id call just
> > before the spot I'm changing parsed A::template A<int> as a BASELINK
> > that contains a constructor, but make_typename_type crashes on that.
> > 
> > My fix is the same as c++/88325, add an is_overloaded_fn check.
> 
> Instead of handling this in various callers, maybe make_typename_type should
> handle the error, like it already does for e.g.
> 
>   struct A {  template <class T> static T t; };
>   A(unsigned) -> A:: template t<int>;

Okay, done.
 
> Incidentally, in the testcase for 88325:
> 
> > A<T>::A<U> () // { dg-error "partial specialization" }
> 
> this error is misleading; this isn't a partial specialization, it's
> redundant template arguments while trying to define the primary template.  I
> wouldn't worry about fixing the compiler now, but let's not test for the
> wrong error.

Makes sense.

Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?

-- >8 --
Here we ICE when compiling this code in C++20, because we're trying to
slam a 'typename' after the ->.  The cp_parser_template_id call just
before the spot I'm changing parsed A::template A<int> as a BASELINK
that contains a constructor, but make_typename_type crashes on that.

This patch makes make_typename_type more robust instead of checking
for is_overloaded_fn prior calling it.

gcc/cp/ChangeLog:

	PR c++/99803
	* decl.c (make_typename_type): Give an error and return when
	name is is_overloaded_fn.
	* parser.c (cp_parser_class_name): Don't check is_overloaded_fn
	before calling make_typename_type.

gcc/testsuite/ChangeLog:

	PR c++/99803
	* g++.dg/cpp2a/typename14.C: Don't expect particular error
	messages.
	* g++.dg/cpp2a/typename19.C: New test.
---
 gcc/cp/decl.c                           | 8 +++++++-
 gcc/cp/parser.c                         | 4 +---
 gcc/testsuite/g++.dg/cpp2a/typename14.C | 4 ++--
 gcc/testsuite/g++.dg/cpp2a/typename19.C | 5 +++++
 4 files changed, 15 insertions(+), 6 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp2a/typename19.C

diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 1cb47313923..6668a65acbf 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -4055,6 +4055,12 @@ make_typename_type (tree context, tree name, enum tag_types tag_type,
 	error ("%qD used without template arguments", name);
       return error_mark_node;
     }
+  else if (is_overloaded_fn (name))
+    {
+      if (complain & tf_error)
+	error ("%qD is a function, not a type", name);
+      return error_mark_node;
+    }
   gcc_assert (identifier_p (name));
   gcc_assert (TYPE_P (context));
 
@@ -4066,7 +4072,7 @@ make_typename_type (tree context, tree name, enum tag_types tag_type,
 	error ("%q#T is not a class", context);
       return error_mark_node;
     }
-  
+
   /* When the CONTEXT is a dependent type,  NAME could refer to a
      dependent base class of CONTEXT.  But look inside it anyway
      if CONTEXT is a currently open scope, in case it refers to a
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 940751b5f05..3640ae51331 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -24730,9 +24730,7 @@ cp_parser_class_name (cp_parser *parser,
   decl = cp_parser_maybe_treat_template_as_class (decl, class_head_p);
 
   /* If this is a typename, create a TYPENAME_TYPE.  */
-  if (typename_p
-      && decl != error_mark_node
-      && !is_overloaded_fn (decl))
+  if (typename_p && decl != error_mark_node)
     {
       decl = make_typename_type (scope, decl, typename_type,
 				 /*complain=*/tf_error);
diff --git a/gcc/testsuite/g++.dg/cpp2a/typename14.C b/gcc/testsuite/g++.dg/cpp2a/typename14.C
index 8d82b6b8d34..ba7dad8245f 100644
--- a/gcc/testsuite/g++.dg/cpp2a/typename14.C
+++ b/gcc/testsuite/g++.dg/cpp2a/typename14.C
@@ -8,7 +8,7 @@ template<typename> struct A
 
 template<typename T>
 template<typename U>
-A<T>::A<U> () // { dg-error "partial specialization" }
+A<T>::A<U> () // { dg-error "" }
 {
 }
 
@@ -19,7 +19,7 @@ template<typename> struct B
 
 template<typename T>
 template<typename U>
-B<T>::foo<int>(int) // { dg-error "partial specialization|declaration" }
+B<T>::foo<int>(int) // { dg-error "" }
 {
   return 1;
 }
diff --git a/gcc/testsuite/g++.dg/cpp2a/typename19.C b/gcc/testsuite/g++.dg/cpp2a/typename19.C
new file mode 100644
index 00000000000..320a14d6a0c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/typename19.C
@@ -0,0 +1,5 @@
+// PR c++/99803
+// { dg-do compile { target c++20 } }
+
+struct A { template<typename T> A(T); };
+auto A(unsigned) -> A::template A<int>; // { dg-error "not a type" }

base-commit: ee351f7fdbd82f8947fe9a0e74cea65d216a8549
Jason Merrill April 16, 2021, 3:29 a.m. UTC | #3 
On 4/15/21 10:02 PM, Marek Polacek wrote:
> On Thu, Apr 15, 2021 at 03:31:24PM -0400, Jason Merrill wrote:
>> On 4/14/21 9:21 PM, Marek Polacek wrote:
>>> Here we ICE when compiling this code in C++20, because we're trying to
>>> slam a 'typename' after the ->.  The cp_parser_template_id call just
>>> before the spot I'm changing parsed A::template A<int> as a BASELINK
>>> that contains a constructor, but make_typename_type crashes on that.
>>>
>>> My fix is the same as c++/88325, add an is_overloaded_fn check.
>>
>> Instead of handling this in various callers, maybe make_typename_type should
>> handle the error, like it already does for e.g.
>>
>>    struct A {  template <class T> static T t; };
>>    A(unsigned) -> A:: template t<int>;
> 
> Okay, done.
>   
>> Incidentally, in the testcase for 88325:
>>
>>> A<T>::A<U> () // { dg-error "partial specialization" }
>>
>> this error is misleading; this isn't a partial specialization, it's
>> redundant template arguments while trying to define the primary template.  I
>> wouldn't worry about fixing the compiler now, but let's not test for the
>> wrong error.
> 
> Makes sense.
> 
> Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?

OK.

> -- >8 --
> Here we ICE when compiling this code in C++20, because we're trying to
> slam a 'typename' after the ->.  The cp_parser_template_id call just
> before the spot I'm changing parsed A::template A<int> as a BASELINK
> that contains a constructor, but make_typename_type crashes on that.
> 
> This patch makes make_typename_type more robust instead of checking
> for is_overloaded_fn prior calling it.
> 
> gcc/cp/ChangeLog:
> 
> 	PR c++/99803
> 	* decl.c (make_typename_type): Give an error and return when
> 	name is is_overloaded_fn.
> 	* parser.c (cp_parser_class_name): Don't check is_overloaded_fn
> 	before calling make_typename_type.
> 
> gcc/testsuite/ChangeLog:
> 
> 	PR c++/99803
> 	* g++.dg/cpp2a/typename14.C: Don't expect particular error
> 	messages.
> 	* g++.dg/cpp2a/typename19.C: New test.
> ---
>   gcc/cp/decl.c                           | 8 +++++++-
>   gcc/cp/parser.c                         | 4 +---
>   gcc/testsuite/g++.dg/cpp2a/typename14.C | 4 ++--
>   gcc/testsuite/g++.dg/cpp2a/typename19.C | 5 +++++
>   4 files changed, 15 insertions(+), 6 deletions(-)
>   create mode 100644 gcc/testsuite/g++.dg/cpp2a/typename19.C
> 
> diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
> index 1cb47313923..6668a65acbf 100644
> --- a/gcc/cp/decl.c
> +++ b/gcc/cp/decl.c
> @@ -4055,6 +4055,12 @@ make_typename_type (tree context, tree name, enum tag_types tag_type,
>   	error ("%qD used without template arguments", name);
>         return error_mark_node;
>       }
> +  else if (is_overloaded_fn (name))
> +    {
> +      if (complain & tf_error)
> +	error ("%qD is a function, not a type", name);
> +      return error_mark_node;
> +    }
>     gcc_assert (identifier_p (name));
>     gcc_assert (TYPE_P (context));
>   
> @@ -4066,7 +4072,7 @@ make_typename_type (tree context, tree name, enum tag_types tag_type,
>   	error ("%q#T is not a class", context);
>         return error_mark_node;
>       }
> -
> +
>     /* When the CONTEXT is a dependent type,  NAME could refer to a
>        dependent base class of CONTEXT.  But look inside it anyway
>        if CONTEXT is a currently open scope, in case it refers to a
> diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
> index 940751b5f05..3640ae51331 100644
> --- a/gcc/cp/parser.c
> +++ b/gcc/cp/parser.c
> @@ -24730,9 +24730,7 @@ cp_parser_class_name (cp_parser *parser,
>     decl = cp_parser_maybe_treat_template_as_class (decl, class_head_p);
>   
>     /* If this is a typename, create a TYPENAME_TYPE.  */
> -  if (typename_p
> -      && decl != error_mark_node
> -      && !is_overloaded_fn (decl))
> +  if (typename_p && decl != error_mark_node)
>       {
>         decl = make_typename_type (scope, decl, typename_type,
>   				 /*complain=*/tf_error);
> diff --git a/gcc/testsuite/g++.dg/cpp2a/typename14.C b/gcc/testsuite/g++.dg/cpp2a/typename14.C
> index 8d82b6b8d34..ba7dad8245f 100644
> --- a/gcc/testsuite/g++.dg/cpp2a/typename14.C
> +++ b/gcc/testsuite/g++.dg/cpp2a/typename14.C
> @@ -8,7 +8,7 @@ template<typename> struct A
>   
>   template<typename T>
>   template<typename U>
> -A<T>::A<U> () // { dg-error "partial specialization" }
> +A<T>::A<U> () // { dg-error "" }
>   {
>   }
>   
> @@ -19,7 +19,7 @@ template<typename> struct B
>   
>   template<typename T>
>   template<typename U>
> -B<T>::foo<int>(int) // { dg-error "partial specialization|declaration" }
> +B<T>::foo<int>(int) // { dg-error "" }
>   {
>     return 1;
>   }
> diff --git a/gcc/testsuite/g++.dg/cpp2a/typename19.C b/gcc/testsuite/g++.dg/cpp2a/typename19.C
> new file mode 100644
> index 00000000000..320a14d6a0c
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/cpp2a/typename19.C
> @@ -0,0 +1,5 @@
> +// PR c++/99803
> +// { dg-do compile { target c++20 } }
> +
> +struct A { template<typename T> A(T); };
> +auto A(unsigned) -> A::template A<int>; // { dg-error "not a type" }
> 
> base-commit: ee351f7fdbd82f8947fe9a0e74cea65d216a8549
>
diff mbox series

Patch

diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 3a107206318..3c506d891c9 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -18903,7 +18903,7 @@  cp_parser_simple_type_specifier (cp_parser* parser,
 	  if (TREE_CODE (type) != TYPE_DECL)
 	    {
 	      /* ...unless we pretend we have seen 'typename'.  */
-	      if (typename_p)
+	      if (typename_p && !is_overloaded_fn (type))
 		type = cp_parser_make_typename_type (parser, type,
 						     token->location);
 	      else
diff --git a/gcc/testsuite/g++.dg/cpp2a/typename19.C b/gcc/testsuite/g++.dg/cpp2a/typename19.C
new file mode 100644
index 00000000000..bd7e5110e00
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/typename19.C
@@ -0,0 +1,5 @@ 
+// PR c++/99803
+// { dg-do compile { target c++20 } }
+
+struct A { template<typename T> A(T); };
+auto A(unsigned) -> A::template A<int>; // { dg-error "not name a type" }