[PATCH] Fix parser to recognize operator?:

[PATCH] Fix parser to recognize operator?:

[Matthias Kretz]

This is a minor bugfix for improved error reporting. Overloading ?: is just as 
disallowed as it is without this change.

2019-10-11  Matthias Kretz  <m.kretz@gsi.de>

	* gcc/cp/parser.c (cp_parser_operator): Parse operator?: as an
	  attempt to overload the conditional operator. Then
	  grok_op_properties can print its useful "ISO C++ prohibits
	  overloading operator ?:" message instead of the cryptic error
	  message about a missing type-specifier before '?' token.

diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 3ee8da7db94..73385cb3dcb 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -15502,6 +15502,15 @@ cp_parser_operator (cp_parser* parser, location_t 
start_loc)
       op = COMPONENT_REF;
       break;
 
+    case CPP_QUERY:
+      op = COND_EXPR;
+      /* Consume the `?'.  */
+      cp_lexer_consume_token (parser->lexer);
+      /* Look for the matching `:'.  */
+      cp_parser_require (parser, CPP_COLON, RT_COLON);
+      consumed = true;
+      break;
+
     case CPP_OPEN_PAREN:
       {
         /* Consume the `('.  */

-- 
──────────────────────────────────────────────────────────────────────────
 Dr. Matthias Kretz                           https://mattkretz.github.io
 GSI Helmholtzzentrum für Schwerionenforschung             https://gsi.de
 SIMD easy and portable                     https://github.com/VcDevel/Vc
──────────────────────────────────────────────────────────────────────────

Re: [PATCH] Fix parser to recognize operator?:

[Marek Polacek]

On Fri, Oct 11, 2019 at 04:06:43PM +0200, Matthias Kretz wrote:
> This is a minor bugfix for improved error reporting. Overloading ?: is just as 
> disallowed as it is without this change.

Thanks.  Can you provide a testcase that shows why this change makes sense?
That testcase then should be part of the patch submission.

> 2019-10-11  Matthias Kretz  <m.kretz@gsi.de>
> 
> 	* gcc/cp/parser.c (cp_parser_operator): Parse operator?: as an
> 	  attempt to overload the conditional operator. Then
> 	  grok_op_properties can print its useful "ISO C++ prohibits
> 	  overloading operator ?:" message instead of the cryptic error
> 	  message about a missing type-specifier before '?' token.
> 
> diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
> index 3ee8da7db94..73385cb3dcb 100644
> --- a/gcc/cp/parser.c
> +++ b/gcc/cp/parser.c
> @@ -15502,6 +15502,15 @@ cp_parser_operator (cp_parser* parser, location_t 
> start_loc)
>        op = COMPONENT_REF;
>        break;
>  
> +    case CPP_QUERY:
> +      op = COND_EXPR;
> +      /* Consume the `?'.  */
> +      cp_lexer_consume_token (parser->lexer);
> +      /* Look for the matching `:'.  */
> +      cp_parser_require (parser, CPP_COLON, RT_COLON);
> +      consumed = true;
> +      break;
> +
>      case CPP_OPEN_PAREN:
>        {
>          /* Consume the `('.  */

--
Marek Polacek • Red Hat, Inc. • 300 A St, Boston, MA

Re: [PATCH] Fix parser to recognize operator?:

[Matthias Kretz]

On Freitag, 11. Oktober 2019 16:17:09 CEST Marek Polacek wrote:
> On Fri, Oct 11, 2019 at 04:06:43PM +0200, Matthias Kretz wrote:
> > This is a minor bugfix for improved error reporting. Overloading ?: is
> > just as disallowed as it is without this change.
> 
> Thanks.  Can you provide a testcase that shows why this change makes sense?
> That testcase then should be part of the patch submission.

I can. Most (all?) testcases reference a PR. Should I open one?

> 
> > 2019-10-11  Matthias Kretz  <m.kretz@gsi.de>
> > 
> > 	* gcc/cp/parser.c (cp_parser_operator): Parse operator?: as an
> > 	
> > 	  attempt to overload the conditional operator. Then
> > 	  grok_op_properties can print its useful "ISO C++ prohibits
> > 	  overloading operator ?:" message instead of the cryptic error
> > 	  message about a missing type-specifier before '?' token.
> > 
> > diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
> > index 3ee8da7db94..73385cb3dcb 100644
> > --- a/gcc/cp/parser.c
> > +++ b/gcc/cp/parser.c
> > @@ -15502,6 +15502,15 @@ cp_parser_operator (cp_parser* parser, location_t
> > start_loc)
> > 
> >        op = COMPONENT_REF;
> >        break;
> > 
> > +    case CPP_QUERY:
> > +      op = COND_EXPR;
> > +      /* Consume the `?'.  */
> > +      cp_lexer_consume_token (parser->lexer);
> > +      /* Look for the matching `:'.  */
> > +      cp_parser_require (parser, CPP_COLON, RT_COLON);
> > +      consumed = true;
> > +      break;
> > +
> > 
> >      case CPP_OPEN_PAREN:
> >        {
> >        
> >          /* Consume the `('.  */
> 
> --
> Marek Polacek • Red Hat, Inc. • 300 A St, Boston, MA


-- 
──────────────────────────────────────────────────────────────────────────
 Dr. Matthias Kretz                           https://mattkretz.github.io
 GSI Helmholtzzentrum für Schwerionenforschung             https://gsi.de
 SIMD easy and portable                     https://github.com/VcDevel/Vc
──────────────────────────────────────────────────────────────────────────

Re: [PATCH] Fix parser to recognize operator?:

[Matthias Kretz]

This time with testcase. Is the subdir for the test ok?

gcc/ChangeLog:

2019-10-11  Matthias Kretz  <m.kretz@gsi.de>

	* gcc/cp/parser.c (cp_parser_operator): Parse operator?: as an
	attempt to overload the conditional operator. Then
	grok_op_properties can print its useful "ISO C++ prohibits
	overloading operator ?:" message instead of the cryptic error
	message about a missing type-specifier before '?' token.

gcc/testsuite/ChangeLog:

2019-10-14  Matthias Kretz  <m.kretz@gsi.de>
	* testsuite/g++.dg/parse/operator9.C: New test verifying the
	correct error message is printed.

diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 3ee8da7db94..73385cb3dcb 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -15502,6 +15502,15 @@ cp_parser_operator (cp_parser* parser, location_t 
start_loc)
       op = COMPONENT_REF;
       break;
 
+    case CPP_QUERY:
+      op = COND_EXPR;
+      /* Consume the `?'.  */
+      cp_lexer_consume_token (parser->lexer);
+      /* Look for the matching `:'.  */
+      cp_parser_require (parser, CPP_COLON, RT_COLON);
+      consumed = true;
+      break;
+
     case CPP_OPEN_PAREN:
       {
         /* Consume the `('.  */
diff --git a/gcc/testsuite/g++.dg/parse/operator9.C b/gcc/testsuite/g++.dg/
parse/operator9.C
new file mode 100644
index 00000000000..d66355afab5
--- /dev/null
+++ b/gcc/testsuite/g++.dg/parse/operator9.C
@@ -0,0 +1,5 @@
+// { dg-do compile }
+
+struct A {};
+struct B {};
+int operator?:(bool, A, B);  // { dg-error "prohibits overloading" }


On Freitag, 11. Oktober 2019 16:17:09 CEST you wrote:
> On Fri, Oct 11, 2019 at 04:06:43PM +0200, Matthias Kretz wrote:
> > This is a minor bugfix for improved error reporting. Overloading ?: is
> > just as disallowed as it is without this change.
> 
> Thanks.  Can you provide a testcase that shows why this change makes sense?
> That testcase then should be part of the patch submission.


-- 
──────────────────────────────────────────────────────────────────────────
 Dr. Matthias Kretz                           https://mattkretz.github.io
 GSI Helmholtzzentrum für Schwerionenforschung             https://gsi.de
 SIMD easy and portable                     https://github.com/VcDevel/Vc
──────────────────────────────────────────────────────────────────────────

Re: [PATCH] Fix parser to recognize operator?:

[Dr. Matthias Kretz]

ping

On Montag, 14. Oktober 2019 12:27:11 CEST Matthias Kretz wrote:
> This time with testcase. Is the subdir for the test ok?
> 
> gcc/ChangeLog:
> 
> 2019-10-11  Matthias Kretz  <m.kretz@gsi.de>
> 
> 	* gcc/cp/parser.c (cp_parser_operator): Parse operator?: as an
> 	attempt to overload the conditional operator. Then
> 	grok_op_properties can print its useful "ISO C++ prohibits
> 	overloading operator ?:" message instead of the cryptic error
> 	message about a missing type-specifier before '?' token.
> 
> gcc/testsuite/ChangeLog:
> 
> 2019-10-14  Matthias Kretz  <m.kretz@gsi.de>
> 	* testsuite/g++.dg/parse/operator9.C: New test verifying the
> 	correct error message is printed.
> 
> diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
> index 3ee8da7db94..73385cb3dcb 100644
> --- a/gcc/cp/parser.c
> +++ b/gcc/cp/parser.c
> @@ -15502,6 +15502,15 @@ cp_parser_operator (cp_parser* parser, location_t
> start_loc)
>        op = COMPONENT_REF;
>        break;
> 
> +    case CPP_QUERY:
> +      op = COND_EXPR;
> +      /* Consume the `?'.  */
> +      cp_lexer_consume_token (parser->lexer);
> +      /* Look for the matching `:'.  */
> +      cp_parser_require (parser, CPP_COLON, RT_COLON);
> +      consumed = true;
> +      break;
> +
>      case CPP_OPEN_PAREN:
>        {
>          /* Consume the `('.  */
> diff --git a/gcc/testsuite/g++.dg/parse/operator9.C b/gcc/testsuite/g++.dg/
> parse/operator9.C
> new file mode 100644
> index 00000000000..d66355afab5
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/parse/operator9.C
> @@ -0,0 +1,5 @@
> +// { dg-do compile }
> +
> +struct A {};
> +struct B {};
> +int operator?:(bool, A, B);  // { dg-error "prohibits overloading" }
> 
> On Freitag, 11. Oktober 2019 16:17:09 CEST you wrote:
> > On Fri, Oct 11, 2019 at 04:06:43PM +0200, Matthias Kretz wrote:
> > > This is a minor bugfix for improved error reporting. Overloading ?: is
> > > just as disallowed as it is without this change.
> > 
> > Thanks.  Can you provide a testcase that shows why this change makes
> > sense?
> > That testcase then should be part of the patch submission.


-- 
──────────────────────────────────────────────────────────────────────────
 Dr. Matthias Kretz                           https://mattkretz.github.io
 GSI Helmholtzzentrum für Schwerionenforschung             https://gsi.de
 SIMD easy and portable                     https://github.com/VcDevel/Vc
──────────────────────────────────────────────────────────────────────────

Ping2: [PATCH] Fix parser to recognize operator?:

[Matthias Kretz]

ping2

On Montag, 14. Oktober 2019 12:27:11 CET Matthias Kretz wrote:
> This time with testcase. Is the subdir for the test ok?
> 
> gcc/ChangeLog:
> 
> 2019-10-11  Matthias Kretz  <m.kretz@gsi.de>
> 
> 	* gcc/cp/parser.c (cp_parser_operator): Parse operator?: as an
> 	attempt to overload the conditional operator. Then
> 	grok_op_properties can print its useful "ISO C++ prohibits
> 	overloading operator ?:" message instead of the cryptic error
> 	message about a missing type-specifier before '?' token.
> 
> gcc/testsuite/ChangeLog:
> 
> 2019-10-14  Matthias Kretz  <m.kretz@gsi.de>
> 	* testsuite/g++.dg/parse/operator9.C: New test verifying the
> 	correct error message is printed.
> 
> diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
> index 3ee8da7db94..73385cb3dcb 100644
> --- a/gcc/cp/parser.c
> +++ b/gcc/cp/parser.c
> @@ -15502,6 +15502,15 @@ cp_parser_operator (cp_parser* parser, location_t
> start_loc)
>        op = COMPONENT_REF;
>        break;
> 
> +    case CPP_QUERY:
> +      op = COND_EXPR;
> +      /* Consume the `?'.  */
> +      cp_lexer_consume_token (parser->lexer);
> +      /* Look for the matching `:'.  */
> +      cp_parser_require (parser, CPP_COLON, RT_COLON);
> +      consumed = true;
> +      break;
> +
>      case CPP_OPEN_PAREN:
>        {
>          /* Consume the `('.  */
> diff --git a/gcc/testsuite/g++.dg/parse/operator9.C b/gcc/testsuite/g++.dg/
> parse/operator9.C
> new file mode 100644
> index 00000000000..d66355afab5
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/parse/operator9.C
> @@ -0,0 +1,5 @@
> +// { dg-do compile }
> +
> +struct A {};
> +struct B {};
> +int operator?:(bool, A, B);  // { dg-error "prohibits overloading" }
> 
> On Freitag, 11. Oktober 2019 16:17:09 CEST you wrote:
> > On Fri, Oct 11, 2019 at 04:06:43PM +0200, Matthias Kretz wrote:
> > > This is a minor bugfix for improved error reporting. Overloading ?: is
> > > just as disallowed as it is without this change.
> > 
> > Thanks.  Can you provide a testcase that shows why this change makes
> > sense?
> > That testcase then should be part of the patch submission.


-- 
──────────────────────────────────────────────────────────────────────────
 Dr. Matthias Kretz                           https://mattkretz.github.io
 GSI Helmholtzzentrum für Schwerionenforschung             https://gsi.de
 SIMD easy and portable                     https://github.com/VcDevel/Vc
──────────────────────────────────────────────────────────────────────────

Re: [PATCH] Fix parser to recognize operator?:

[Jason Merrill]

[-- Attachment #1: Type: text/plain, Size: 1209 bytes --]

On 10/14/19 11:27 AM, Matthias Kretz wrote:
> This time with testcase. Is the subdir for the test ok?

Yes.

> gcc/ChangeLog:
> 
> 2019-10-11  Matthias Kretz  <m.kretz@gsi.de>
> 
> 	* gcc/cp/parser.c (cp_parser_operator): Parse operator?: as an
> 	attempt to overload the conditional operator. Then
> 	grok_op_properties can print its useful "ISO C++ prohibits
> 	overloading operator ?:" message instead of the cryptic error
> 	message about a missing type-specifier before '?' token.

The first sentence is enough for a ChangeLog; the second should be an 
explanatory comment above the ChangeLog entries.

Also, this entry belongs in gcc/cp/ChangeLog.

> +++ b/gcc/cp/parser.c
> @@ -15502,6 +15502,15 @@ cp_parser_operator (cp_parser* parser, location_t
> start_loc)

Word wrap broke the patch here.  Feel free to send patches as 
attachments if it's hard to suppress word wrap in your mailer (as it is 
in mine).

I also saw an additional failure in the testsuite:

 > FAIL: g++.old-deja/g++.jason/operator.C  -std=gnu++2a  (test for 
errors, line 8)
 > FAIL: g++.old-deja/g++.jason/operator.C  -std=gnu++2a (test for 
excess errors)

Here's what I'm applying:

Jason

[-- Attachment #2: opcond.diff --]
[-- Type: text/x-patch, Size: 2843 bytes --]

commit c3e97f573b6e29324ef72ded63e0307cec8d2ce2
Author: Jason Merrill <jason@redhat.com>
Date:   Tue Nov 5 17:31:44 2019 +0000

    Fix parser to recognize operator?:
    
    This change lets grok_op_properties print its useful "ISO C++ prohibits
    overloading operator ?:" message instead of the cryptic error message about
    a missing type-specifier before '?' token.
    
    2019-11-06  Matthias Kretz  <m.kretz@gsi.de>
    
            * parser.c (cp_parser_operator): Parse operator?: as an
            attempt to overload the conditional operator.

diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index cbbf946d32c..b17e0336e1c 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -15542,6 +15542,15 @@ cp_parser_operator (cp_parser* parser, location_t start_loc)
       op = COMPONENT_REF;
       break;
 
+    case CPP_QUERY:
+      op = COND_EXPR;
+      /* Consume the `?'.  */
+      cp_lexer_consume_token (parser->lexer);
+      /* Look for the matching `:'.  */
+      cp_parser_require (parser, CPP_COLON, RT_COLON);
+      consumed = true;
+      break;
+
     case CPP_OPEN_PAREN:
       {
         /* Consume the `('.  */
diff --git a/gcc/testsuite/g++.dg/parse/operator9.C b/gcc/testsuite/g++.dg/parse/operator9.C
new file mode 100644
index 00000000000..d66355afab5
--- /dev/null
+++ b/gcc/testsuite/g++.dg/parse/operator9.C
@@ -0,0 +1,5 @@
+// { dg-do compile }
+
+struct A {};
+struct B {};
+int operator?:(bool, A, B);  // { dg-error "prohibits overloading" }
diff --git a/gcc/testsuite/g++.old-deja/g++.jason/operator.C b/gcc/testsuite/g++.old-deja/g++.jason/operator.C
index c2fc212cef0..69a41cf2448 100644
--- a/gcc/testsuite/g++.old-deja/g++.jason/operator.C
+++ b/gcc/testsuite/g++.old-deja/g++.jason/operator.C
@@ -5,7 +5,7 @@
 typedef __SIZE_TYPE__ size_t;
 
 struct A {
-  int operator?:(int a, int b);	   // { dg-error "expected type-specifier" } 
+  int operator?:(int a, int b);	   // { dg-error "prohibits overloading" } 
   static int operator()(int a);	   // { dg-error "14:.static int A::operator\\(\\)\\(int\\). must be a nonstatic member function" }
   static int operator+(A,A);	   // { dg-error "14:.static int A::operator\\+\\(A, A\\). must be either a non-static member function or a non-member function" } 
   int operator+(int a, int b = 1); // { dg-error "7:.int A::operator\\+\\(int, int\\). must have either zero or one argument" }
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index d0b47f7c562..e60a45b869e 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,8 @@
+2019-11-06  Matthias Kretz  <m.kretz@gsi.de>
+
+	* parser.c (cp_parser_operator): Parse operator?: as an
+	attempt to overload the conditional operator.
+
 2019-11-05  Jason Merrill  <jason@redhat.com>
 
 	Implement C++20 operator<=>.