[Bug c/36367] New: warning for questionable compound expression

[Bug c/36367] New: warning for questionable compound expression

[ebotcazou at gcc dot gnu dot org]

This typo in check_for_nested_with_variably_modified was present for 4 years
and hampered the inliner without anyone noticing:

Index: tree-nested.c
===================================================================
--- tree-nested.c       (revision 136121)
+++ tree-nested.c       (working copy)
@@ -693,7 +693,7 @@ check_for_nested_with_variably_modified
   for (cgn = cgn->nested; cgn ; cgn = cgn->next_nested)
     {
       for (arg = DECL_ARGUMENTS (cgn->decl); arg; arg = TREE_CHAIN (arg))
-       if (variably_modified_type_p (TREE_TYPE (arg), 0), orig_fndecl)
+       if (variably_modified_type_p (TREE_TYPE (arg), orig_fndecl))
          return true;


It would be nice for the compiler to warn in this case, i.e. when members of
a compound expression (except for the last) don't have obvious side-effects.


-- 
           Summary: warning for questionable compound expression
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: ebotcazou at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36367

[Bug c/36367] warning for questionable compound expression

[rguenth at gcc dot gnu dot org]

------- Comment #1 from rguenth at gcc dot gnu dot org  2008-05-29 12:00 -------
Confirmed.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
           Keywords|                            |diagnostic
   Last reconfirmed|0000-00-00 00:00:00         |2008-05-29 12:00:46
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36367

[Bug c/36367] warning for questionable compound expression

[pzhao at gcc dot gnu dot org]

------- Comment #2 from pzhao at gcc dot gnu dot org  2010-03-31 09:58 -------
Author: ebotcazou
Date: Thu May 29 11:33:17 2008
New Revision: 136154

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=136154
Log:
        * tree-nested.c (check_for_nested_with_variably_modified): Fix typo.


Added:
    trunk/gcc/testsuite/gcc.dg/nested-func-6.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-nested.c


-- 

pzhao at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36367

[Bug c/36367] warning for questionable compound expression

[ebotcazou at gcc dot gnu dot org]

------- Comment #3 from ebotcazou at gcc dot gnu dot org  2010-03-31 10:08 -------
Not clear what happened but the aforementioned commit is not a fix for this PR.


-- 

ebotcazou at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pzhao at gcc dot gnu dot org
             Status|RESOLVED                    |REOPENED
         Resolution|FIXED                       |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36367

[Bug c/36367] warning for questionable compound expression

[pzhao at gcc dot gnu dot org]

------- Comment #4 from pzhao at gcc dot gnu dot org  2010-04-01 09:19 -------
Sorry! I have misunderstood this issue before.
Is it to ask for warn at the following test case?

=====================
int foo (int a)
{
  return a;
}
int bar (int c)
{
  if (foo (1), c) // Warn foo(1) don't have obvious side-effects here?
    return 1;
  else
    return 0;
}
===================


-- 

pzhao at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2008-05-29 12:00:46         |2010-04-01 09:19:19
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36367

[Bug c/36367] warning for questionable compound expression

[ebotcazou at gcc dot gnu dot org]

------- Comment #5 from ebotcazou at gcc dot gnu dot org  2010-04-01 10:10 -------
> Is it to ask for warn at the following test case?

Yes, it is.  An additional condition could be that the type be non-void.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36367

[Bug c/36367] warning for questionable compound expression

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36367

Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|REOPENED                    |NEW