Re: c/7508: GCC refuses to compile a declartion right after a 'case' in switch

Re: c/7508: GCC refuses to compile a declartion right after a 'case' in switch

[Joseph S. Myers]

The following reply was made to PR c/7508; it has been noted by GNATS.

From: "Joseph S. Myers" <jsm28@cam.ac.uk>
To: <ddcc@email.com>
Cc: <gcc-gnats@gcc.gnu.org>,  <gcc-bugs@gcc.gnu.org>
Subject: Re: c/7508: GCC refuses to compile a declartion right after a 'case'
 in switch
Date: Tue, 6 Aug 2002 19:53:58 +0100 (BST)

 On 6 Aug 2002 ddcc@email.com wrote:
 
 > GCC refuses to compile a declaration that follows immediately after a
 > 'case' in a 'switch', even in C99 mode:
 
 Although C99 allows declarations and statements to be mixed, it does not
 make declarations into statements.  Labels can only be applied to
 statements, not to declarations.  As to allowing this as an extension, see
 the comment in c-parse.in explaining why we don't:
 
    NOTE: we don't allow labels on declarations; this might seem like a
    natural extension, but there would be a conflict between attributes
    on the label and prefix attributes on the declaration.  */
 
 -- 
 Joseph S. Myers
 jsm28@cam.ac.uk
 

Re: c/7508: GCC refuses to compile a declartion right after a 'case' in switch

[jsm28]

Synopsis: GCC refuses to compile a declartion right after a 'case' in switch

State-Changed-From-To: open->closed
State-Changed-By: jsm28
State-Changed-When: Sun Sep 15 13:31:31 2002
State-Changed-Why:
    As explained, we deliberately do not implement this extension.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=7508

c/7508: GCC refuses to compile a declartion right after a 'case' in switch

[ddcc]

>Number:         7508
>Category:       c
>Synopsis:       GCC refuses to compile a declartion right after a 'case' in switch
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          rejects-legal
>Submitter-Id:   net
>Arrival-Date:   Tue Aug 06 09:36:02 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator:     ddcc@email.com
>Release:        GCC 3.1.1
>Organization:
>Environment:
Seen on MinGW, but probably problem on all platforms
>Description:
GCC refuses to compile a declaration that follows immediately after a 'case' in a 'switch', even in C99 mode:

int main()
	{
	int x = 1;
	switch (x) { case 1: int y = 7; }
	return 0;
	}

Says GCC: In function `main': parse error before "int".

However, if I add a dummy statement before the declaration, GCC compiles it fine:

int main()
	{
	int x = 1;
	switch (x) { case 1: 4 + 5; int y = 7; }
	return 0;
	}
>How-To-Repeat:
Compile the first example in the report.
>Fix:

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