[Bug c/772] Statement expressions issues

[Bug c/772] Statement expressions issues

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-03-30 19:56 -------
Subject: Bug 772

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	jsm28@gcc.gnu.org	2005-03-30 19:56:40

Modified files:
	gcc            : ChangeLog c-decl.c c-tree.h c-typeck.c 
	gcc/doc        : extend.texi 
	gcc/objc       : ChangeLog objc-act.c 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/gcc.dg: stmt-expr-label-1.c stmt-expr-label-2.c 
	                      stmt-expr-label-3.c 
Removed files:
	gcc/testsuite/gcc.c-torture/execute: medce-2.c 

Log message:
	PR c/772
	PR c/17913
	* c-tree.h (C_DECL_UNJUMPABLE_STMT_EXPR,
	C_DECL_UNDEFINABLE_STMT_EXPR, struct c_label_list, struct
	c_label_context, label_context_stack): New.
	* c-decl.c (define_label): Check for jumps into statement
	expressions.  Add label to list of defined labels.
	(start_function): Push context on label_context_stack.
	(finish_function): Pop context from label_context_stack.
	* c-typeck.c (label_context_stack): New.
	(c_finish_goto_label): Check for jumps into statement
	expressions.  Add label to list of jumped to labels.
	(struct c_switch): Add blocked_stmt_expr.
	(c_start_case): Initialize it.
	(do_case): Check it.
	(c_finish_case): Verify !blocked_stmt_expr.
	(c_begin_stmt_expr):  Push context on label_context_stack.
	Increment blocked_stmt_expr.  Mark labels jumped to from outside
	as undefinable.
	(c_finish_stmt_expr): December blocked_stmt_expr.  Mark labels
	defined in the statement expression and no longer jumpable to.
	Mark labels jumped to from just outside the statement expression
	as again definable.  Pop context from label_context_stack.
	* doc/extend.texi (Statement Exprs): Update.
	
	objc:
	* objc-act.c (objc_start_function): Push context on
	label_context_stack.
	
	testsuite:
	* gcc.dg/stmt-expr-label-1.c, gcc.dg/stmt-expr-label-2.c,
	gcc.dg/stmt-expr-label-3.c : New tests.
	* gcc.c-torture/execute/medce-2.c: Remove.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.8036&r2=2.8037
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/c-decl.c.diff?cvsroot=gcc&r1=1.642&r2=1.643
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/c-tree.h.diff?cvsroot=gcc&r1=1.198&r2=1.199
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/c-typeck.c.diff?cvsroot=gcc&r1=1.428&r2=1.429
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/doc/extend.texi.diff?cvsroot=gcc&r1=1.246&r2=1.247
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/objc/ChangeLog.diff?cvsroot=gcc&r1=1.31&r2=1.32
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/objc/objc-act.c.diff?cvsroot=gcc&r1=1.267&r2=1.268
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.5237&r2=1.5238
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.c-torture/execute/medce-2.c.diff?cvsroot=gcc&r1=1.1&r2=NONE
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/stmt-expr-label-1.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/stmt-expr-label-2.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/stmt-expr-label-3.c.diff?cvsroot=gcc&r1=NONE&r2=1.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=772

[Bug c/772] Statement expressions issues

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-03-30 19:59 -------
Subject: Bug 772

CVSROOT:	/cvs/gcc
Module name:	gcc
Branch: 	gcc-4_0-branch
Changes by:	jsm28@gcc.gnu.org	2005-03-30 19:59:21

Modified files:
	gcc            : ChangeLog c-decl.c c-tree.h c-typeck.c 
	gcc/doc        : extend.texi 
	gcc/objc       : ChangeLog objc-act.c 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/gcc.dg: stmt-expr-label-1.c stmt-expr-label-2.c 
	                      stmt-expr-label-3.c 
Removed files:
	gcc/testsuite/gcc.c-torture/execute: medce-2.c 

Log message:
	PR c/772
	PR c/17913
	* c-tree.h (C_DECL_UNJUMPABLE_STMT_EXPR,
	C_DECL_UNDEFINABLE_STMT_EXPR, struct c_label_list, struct
	c_label_context, label_context_stack): New.
	* c-decl.c (define_label): Check for jumps into statement
	expressions.  Add label to list of defined labels.
	(start_function): Push context on label_context_stack.
	(finish_function): Pop context from label_context_stack.
	* c-typeck.c (label_context_stack): New.
	(c_finish_goto_label): Check for jumps into statement
	expressions.  Add label to list of jumped to labels.
	(struct c_switch): Add blocked_stmt_expr.
	(c_start_case): Initialize it.
	(do_case): Check it.
	(c_finish_case): Verify !blocked_stmt_expr.
	(c_begin_stmt_expr):  Push context on label_context_stack.
	Increment blocked_stmt_expr.  Mark labels jumped to from outside
	as undefinable.
	(c_finish_stmt_expr): December blocked_stmt_expr.  Mark labels
	defined in the statement expression and no longer jumpable to.
	Mark labels jumped to from just outside the statement expression
	as again definable.  Pop context from label_context_stack.
	* doc/extend.texi (Statement Exprs): Update.
	
	objc:
	* objc-act.c (objc_start_function): Push context on
	label_context_stack.
	
	testsuite:
	* gcc.dg/stmt-expr-label-1.c, gcc.dg/stmt-expr-label-2.c,
	gcc.dg/stmt-expr-label-3.c : New tests.
	* gcc.c-torture/execute/medce-2.c: Remove.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=2.7592.2.97&r2=2.7592.2.98
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/c-decl.c.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.630.6.3&r2=1.630.6.4
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/c-tree.h.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.193.4.1&r2=1.193.4.2
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/c-typeck.c.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.419&r2=1.419.2.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/doc/extend.texi.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.240.2.5&r2=1.240.2.6
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/objc/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.29&r2=1.29.8.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/objc/objc-act.c.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.266&r2=1.266.6.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.5084.2.80&r2=1.5084.2.81
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.c-torture/execute/medce-2.c.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.1&r2=NONE
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/stmt-expr-label-1.c.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=NONE&r2=1.1.2.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/stmt-expr-label-2.c.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=NONE&r2=1.1.2.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/stmt-expr-label-3.c.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=NONE&r2=1.1.2.1



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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=772

[Bug c++/772] Statement expressions issues

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-03-31 07:26 -------
Only a C++ front-end problem now.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|c                           |c++


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=772

[Bug c++/772] Statement expressions issues

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-04-03 18:56 -------
*** Bug 20741 has been marked as a duplicate of this bug. ***

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pluto at pld-linux dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=772

[Bug c++/772] Statement expressions issues

[rguenth at gcc dot gnu dot org]

------- Additional Comments From rguenth at gcc dot gnu dot org  2005-09-09 12:38 -------
No testcase?  But I think this is fixed on the mainline and only pending on 4.0.
See PR17913.

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=772

[Bug c++/772] Statement expressions issues

[joseph at codesourcery dot com]

------- Additional Comments From joseph at codesourcery dot com  2005-09-09 15:41 -------
Subject: Re:  Statement expressions issues

On Fri, 9 Sep 2005, rguenth at gcc dot gnu dot org wrote:

> No testcase?  But I think this is fixed on the mainline and only pending on 4.0.
> See PR17913.

The test is gcc.dg/stmt-expr-label-*.c (modulo the exact diagnostic text) 
and I don't think this is fixed for C++ on mainline.  This is separate 
from bug 17913 where there is a case which is valid at compile time and 
invalid at runtime, involving computed gotos: 
gcc.c-torture/compile/pr17913.c, which formerly ICEd with optimization but 
was fixed not to do so (at least for C; appears fixed for C++ as well with 
the mainline/4.0 compilers I have to hand to test but they are rather 
old).  It just happens that almost all cases of bug 17913 were addressed 
for C by fixing bug 772 for C, leaving only the case of computed gotos to 
be fixed separately in 17913 (for C).

The rules for invalidity for jumps into statement expressions are much the 
same as those in C++ for jumps bypassing initializations (imagining that 
each statement expression starts with such an initialization); it might be 
possible to reuse that code to fix this bug for C++.



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=772

[Bug c/772] Statement expressions issues

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-10-27 13:24 -------
Some more discussion here: 
  http://gcc.gnu.org/ml/gcc-patches/2004-10/msg02310.html 

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=772

[Bug c/772] Statement expressions issues

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-10-27 13:21 -------
A similar problem are jumps via 'break'/'continue' out of statement 
expressions. Here's a place where people have really used this: 
  http://gcc.gnu.org/ml/gcc-patches/2003-05/msg00706.html 
(Isn't the ability of people to come up with really bad ideas amazing?) 
 
W. 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=772

[Bug c/772] Statement expressions issues

[neroden at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=772


neroden at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|0000-00-00 00:00:00         |2003-07-14 03:47:16
               date|                            |


------- Additional Comments From neroden at gcc dot gnu dot org  2003-07-14 03:47 -------
Alternate fix: eliminate the statement expression extension.  But you all knew that.