Re: c/6024: GCC fails to diagnose mismatch of enum types in prototype/function

Re: c/6024: GCC fails to diagnose mismatch of enum types in prototype/function

[Joseph S. Myers]

The following reply was made to PR c/6024; it has been noted by GNATS.

From: "Joseph S. Myers" <jsm28@cam.ac.uk>
To: <Richard.Earnshaw@arm.com>
Cc: <rearnsha@arm.com>,  <gcc-gnats@gcc.gnu.org>,  <gcc-bugs@gcc.gnu.org>
Subject: Re: c/6024: GCC fails to diagnose mismatch of enum types in 
 prototype/function
Date: Thu, 21 Mar 2002 11:51:07 +0000 (GMT)

 On Thu, 21 Mar 2002, Richard Earnshaw wrote:
 
 > struct s1 {int a, int b};
 > struct s2 {int c, int d};
 
 > s1 and s2 are 'compatible'; but they aren't the same.  Where in the 
 > standard does it say that enum types are 'weak' like this?
 
 s1 and s2 aren't compatible.  Compatibility is defined in 6.2.7#1,
 augmented by 6.7.2.2#4 (which specifies that enumerated types are
 compatible with char or a signed or unsigned integer type) and some other
 clauses.  There are rules about when structure types in different
 translation units are compatible, but nothing that would make s1 and s2
 compatible in any case.  (However, I can't see anything that says that two
 enumerated types compatible with "int" (say) are compatible with each
 other either, so it isn't clear what's intended here.)
 
 -- 
 Joseph S. Myers
 jsm28@cam.ac.uk
 

Re: c/6024: GCC fails to diagnose mismatch of enum types in prototype/function

[bangerth]

Synopsis: GCC fails to diagnose mismatch of enum types in prototype/function

State-Changed-From-To: open->analyzed
State-Changed-By: bangerth
State-Changed-When: Fri Mar  7 02:35:35 2003
State-Changed-Why:
    Still applies, as of today.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=6024

Re: c/6024: GCC fails to diagnose mismatch of enum types in prototype/function

[Richard Earnshaw]

The following reply was made to PR c/6024; it has been noted by GNATS.

From: Richard Earnshaw <rearnsha@arm.com>
To: "Joseph S. Myers" <jsm28@cam.ac.uk>
Cc: rearnsha@arm.com, gcc-gnats@gcc.gnu.org, gcc-bugs@gcc.gnu.org
Subject: Re: c/6024: GCC fails to diagnose mismatch of enum types in 
 prototype/function
Date: Thu, 21 Mar 2002 11:30:58 +0000

 > The types are compatible, which means these declarations are OK.  (Unless
 > you use -fshort-enums, in which case the type in the prototype disagrees
 > with the promoted type from the non-prototype definition.)
 
 
 I *might* accept that argument if -Wall gave a diagnostic message for 
 this.  However, I don't see why this case is any different from
 
 struct s1 {int a, int b};
 struct s2 {int c, int d};
 
 void f(struct s1 *);
 
 void f(x)
   struct s2 *x;
 {
   return;
 }
 
 s1 and s2 are 'compatible'; but they aren't the same.  Where in the 
 standard does it say that enum types are 'weak' like this?
 

Re: c/6024: GCC fails to diagnose mismatch of enum types in prototype/function

[Joseph S. Myers]

The following reply was made to PR c/6024; it has been noted by GNATS.

From: "Joseph S. Myers" <jsm28@cam.ac.uk>
To: <rearnsha@arm.com>
Cc: <gcc-gnats@gcc.gnu.org>,  <gcc-bugs@gcc.gnu.org>
Subject: Re: c/6024: GCC fails to diagnose mismatch of enum types in
 prototype/function
Date: Thu, 21 Mar 2002 11:15:46 +0000 (GMT)

 On 21 Mar 2002 rearnsha@arm.com wrote:
 
 > Gcc fails to diagnose when an enum type in a prototype
 > fails to match the enum type in a function declation.
 > >How-To-Repeat:
 > Compile the following code, GCC compiles it without error: it
 > should generate a diagnostic.
 
 The types are compatible, which means these declarations are OK.  (Unless
 you use -fshort-enums, in which case the type in the prototype disagrees
 with the promoted type from the non-prototype definition.)
 
 -- 
 Joseph S. Myers
 jsm28@cam.ac.uk
 

c/6024: GCC fails to diagnose mismatch of enum types in prototype/function

[rearnsha]

>Number:         6024
>Category:       c
>Synopsis:       GCC fails to diagnose mismatch of enum types in prototype/function
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          accepts-illegal
>Submitter-Id:   net
>Arrival-Date:   Thu Mar 21 03:06:00 PST 2002
>Closed-Date:
>Last-Modified:
>Originator:     Richard Earnshaw
>Release:        unknown-1.0
>Organization:
>Environment:
All gcc targets
>Description:
Gcc fails to diagnose when an enum type in a prototype
fails to match the enum type in a function declation.
>How-To-Repeat:
Compile the following code, GCC compiles it without error: it
should generate a diagnostic.

enum e1 {a, b};
enum e2 {c, d};

void f(enum e1);

void f(x)
  enum e2 x;
{
  return;
}
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: