[Bug objc/94637] New: @selector() broken for selectors containing repeated colons

[Bug objc/94637] New: @selector() broken for selectors containing repeated colons

[rfm at gnu dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94637

            Bug ID: 94637
           Summary: @selector() broken for selectors containing repeated
                    colons
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: objc
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rfm at gnu dot org
  Target Milestone: ---

The compiler fails to compile legal Objective-C programs which use the
@selector() syntax to send message to objects, if those messages have multiple
parameters and the method does not describe each one.

eg. when given @selector(styleoffsets::::::) the compiler errors with the
message
 error: expected ‘)’ before ‘::’ token

Within @selector() each colon marks the position at which an argument would be
inserted in a method invocation (when a message is sent to an object).  It is
therefore not legal for the compiler to consider a pair of colons to be a token
in this context.

In the above example, the method declaration looks like this:

- (void) styleoffsets: (float*)l : (float*)r : (float*)t : (float*)b
                     : (unsigned int)style;

While imo it would be better coding style to describe parameters as part of the
method name, it's certainly correct/legal objective-c to have multiple
parameters each preceded only by a colon.

A trivial program to demonstrate the bug would be

#include <stdio.h>
#include <objc/objc.h>

int main()
{
  SEL   s = @selector(example::);
  printf("%s\n", sel_getName(s));
  return 0;
}


This program, if built with the command 'gcc program.m -lobjc' should produce
an a.out which just prints the selector name.

[Bug objc/94637] @selector() broken for selectors containing repeated colons

[rfm at gnu dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94637

--- Comment #1 from rfm at gnu dot org ---
*** Bug 94638 has been marked as a duplicate of this bug. ***

[Bug objc/94637] @selector() broken for selectors containing repeated colons

[egallager at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94637

Eric Gallager <egallager at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |egallager at gcc dot gnu.org,
                   |                            |iains at gcc dot gnu.org,
                   |                            |mikestump at comcast dot net

--- Comment #2 from Eric Gallager <egallager at gcc dot gnu.org> ---
cc-ing Objective C maintainers

[Bug objc/94637] [10 Regression] @selector() broken for selectors containing repeated colons

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94637

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
           Keywords|                            |rejects-valid
   Target Milestone|---                         |10.0
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2020-04-17
            Summary|@selector() broken for      |[10 Regression] @selector()
                   |selectors containing        |broken for selectors
                   |repeated colons             |containing repeated colons

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Most likely caused by g:93313b94fe18f3c3de4f24f5bb3fafb4639f1c7e .

That is CPP_SCOPE should be treated as two CPP_COLON tokens while parsing
@selector like was done for asm parsing.

[Bug objc/94637] [10 Regression] @selector() broken for selectors containing repeated colons

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94637

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
The change needs to happen inside c_parser_objc_selector_arg.

[Bug objc/94637] [10 Regression] @selector() broken for selectors containing repeated colons

[law at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94637

Jeffrey A. Law <law at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |law at redhat dot com
           Priority|P3                          |P4

[Bug objc/94637] [10 Regression] @selector() broken for selectors containing repeated colons

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94637

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
So like:
--- gcc/c/c-parser.c.jj 2020-04-17 16:59:28.727193750 +0200
+++ gcc/c/c-parser.c    2020-04-17 20:00:59.816403446 +0200
@@ -11782,15 +11782,28 @@ c_parser_objc_selector_arg (c_parser *pa
 {
   tree sel = c_parser_objc_selector (parser);
   tree list = NULL_TREE;
-  if (sel && c_parser_next_token_is_not (parser, CPP_COLON))
+  if (sel
+      && c_parser_next_token_is_not (parser, CPP_COLON)
+      && c_parser_next_token_is_not (parser, CPP_SCOPE))
     return sel;
   while (true)
     {
-      if (!c_parser_require (parser, CPP_COLON, "expected %<:%>"))
-       return list;
-      list = chainon (list, build_tree_list (sel, NULL_TREE));
+      if (c_parser_next_token_is (parser, CPP_SCOPE))
+       {
+         c_parser_consume_token (parser);
+         list = chainon (list, build_tree_list (sel, NULL_TREE));
+         list = chainon (list, build_tree_list (NULL_TREE, NULL_TREE);
+       }
+      else
+       {
+         if (!c_parser_require (parser, CPP_COLON, "expected %<:%>"))
+           return list;
+         list = chainon (list, build_tree_list (sel, NULL_TREE));
+       }
       sel = c_parser_objc_selector (parser);
-      if (!sel && c_parser_next_token_is_not (parser, CPP_COLON))
+      if (!sel
+         && c_parser_next_token_is_not (parser, CPP_COLON)
+         && c_parser_next_token_is_not (parser, CPP_SCOPE))
        break;
     }
   return list;
?  Completely untested, will try later.

[Bug objc/94637] [10 Regression] @selector() broken for selectors containing repeated colons

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94637

--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:e1113ffbd619d0568fb3b37e9660d9e0ae7862f5

commit r10-7794-ge1113ffbd619d0568fb3b37e9660d9e0ae7862f5
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Sun Apr 19 12:13:33 2020 +0200

    c, objc: Fix up c_parser_objc_selector_arg after CPP_SCOPE changes
[PR94637]

    Similarly to inline asm, :: (or any other number of consecutive colons) can
    appear in ObjC @selector argument and with the introduction of CPP_SCOPE
    into the C FE, we need to trat CPP_SCOPE as two CPP_COLON tokens.
    The C++ FE does that already that way.

    2020-04-19  Jakub Jelinek  <jakub@redhat.com>

            PR objc/94637
            * c-parser.c (c_parser_objc_selector_arg): Handle CPP_SCOPE like
            two CPP_COLON tokens.

            * objc.dg/pr94637.m: New test.

[Bug objc/94637] [10 Regression] @selector() broken for selectors containing repeated colons

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94637

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |jakub at gcc dot gnu.org
         Resolution|---                         |FIXED
             Status|NEW                         |RESOLVED

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Fixed.