[Bug exp/13206] New: support gcc's typeof

[Bug exp/13206] New: support gcc's typeof

[dje at google dot com]

http://sourceware.org/bugzilla/show_bug.cgi?id=13206

             Bug #: 13206
           Summary: support gcc's typeof
           Product: gdb
           Version: HEAD
            Status: NEW
          Severity: enhancement
          Priority: P2
         Component: exp
        AssignedTo: unassigned@sourceware.org
        ReportedBy: dje@google.com
    Classification: Unclassified


IWBN if one could cut-n-paste expressions using typeof and have them Just Work.
Seems like this should be rather easy to implement.

-- 
Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.

[Bug exp/13206] support gcc's typeof

[tromey at redhat dot com]

http://sourceware.org/bugzilla/show_bug.cgi?id=13206

Tom Tromey <tromey at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tromey at redhat dot com

--- Comment #1 from Tom Tromey <tromey at redhat dot com> 2012-02-22 15:36:58 UTC ---
One wrinkle is that there's no way to tell if the source
was compiled with GNU extensions.  So, we can't simply parse
"typeof" as a token.  And, even the heuristic of looking up
a symbol named "typeof" may fail if different source files
were compiled with different options.

__typeof__ seems reasonably easy, though there is the question
of whether we'd want a new OP_TYPEOF.  If not, it simplifies
parsing, but you could have sizeof($x) != sizeof(typeof($x))
if $x changes between parsing and evaluation.

-- 
Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.

[Bug exp/13206] support gcc's typeof

[dje at google dot com]

http://sourceware.org/bugzilla/show_bug.cgi?id=13206

--- Comment #2 from dje at google dot com 2012-02-22 17:07:22 UTC ---
$typeof?

cut-n-paste won't Just Work, but it could Mostly Work.  1/2 :-)

More seriously, a typeof function (of some kind) coud be generally useful.

-- 
Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.

[Bug exp/13206] support gcc's typeof

[tromey at redhat dot com]

http://sourceware.org/bugzilla/show_bug.cgi?id=13206

--- Comment #3 from Tom Tromey <tromey at redhat dot com> 2012-02-22 20:49:53 UTC ---
(In reply to comment #2)
> $typeof?

__typeof__ would work fine for that.

It might be useful in other cases if we could determine whether
or not GNU C was used.  (We currently don't differentiate between
versions of C, either, which would also be useful.)

-- 
Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.

[Bug exp/13206] support gcc's typeof

[tromey at redhat dot com]

http://sourceware.org/bugzilla/show_bug.cgi?id=13206

Tom Tromey <tromey at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at sourceware    |tromey at redhat dot com
                   |dot org                     |

--- Comment #4 from Tom Tromey <tromey at redhat dot com> 2012-06-28 15:39:23 UTC ---
Working on it.

It seems reasonably hard to do in full generality.
E.g., you have to support it in arguments to function types like:

print (void (*) (typeof (x))) &function

I may not do that but I'll at least handle the more obviously
useful cases.

It seems like decltype can use the same code.

-- 
Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.

[Bug exp/13206] support gcc's typeof

[cvs-commit at gcc dot gnu.org]

http://sourceware.org/bugzilla/show_bug.cgi?id=13206

--- Comment #5 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot gnu.org> 2012-07-19 15:38:48 UTC ---
CVSROOT:    /cvs/src
Module name:    src
Changes by:    tromey@sourceware.org    2012-07-19 15:38:18

Modified files:
    gdb            : ChangeLog ax-gdb.c breakpoint.c c-exp.y eval.c 
                     expprint.c parse.c std-operator.def varobj.c 
    gdb/testsuite  : ChangeLog 
    gdb/testsuite/gdb.cp: casts.cc casts.exp 

Log message:
    PR exp/13206:
    * ax-gdb.c (gen_expr) <OP_TYPEOF, OP_DECLTYPE>: New cases.
    * breakpoint.c (watchpoint_exp_is_const) <OP_TYPEOF,
    OP_DECLTYPE>: New cases.
    * c-exp.y (TYPEOF, DECLTYPE): New tokens.
    (type_exp): Add new productions.
    (ident_tokens): Add __typeof__, typeof, __typeof, __decltype,
    and decltype.
    * eval.c (evaluate_subexp_standard) <OP_TYPEOF, OP_DECLTYPE>:
    New case.
    * expprint.c (dump_subexp_body_standard) <OP_TYPEOF,
    OP_DECLTYPE>: New case.
    * parse.c (operator_length_standard) <OP_TYPEOF, OP_DECLTYPE>:
    New case.
    * std-operator.def (OP_TYPEOF, OP_DECLTYPE): New constants.
    * varobj.c (varobj_create): Handle OP_TYPEOF, OP_DECLTYPE.
    gdb/testsuite
    * gdb.cp/casts.exp: Add tests for typeof and decltype.
    * gdb.cp/casts.cc (decltype): New function.
    (main): Use it.

Patches:
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/ChangeLog.diff?cvsroot=src&r1=1.14494&r2=1.14495
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/ax-gdb.c.diff?cvsroot=src&r1=1.104&r2=1.105
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/breakpoint.c.diff?cvsroot=src&r1=1.693&r2=1.694
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/c-exp.y.diff?cvsroot=src&r1=1.99&r2=1.100
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/eval.c.diff?cvsroot=src&r1=1.166&r2=1.167
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/expprint.c.diff?cvsroot=src&r1=1.57&r2=1.58
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/parse.c.diff?cvsroot=src&r1=1.124&r2=1.125
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/std-operator.def.diff?cvsroot=src&r1=1.5&r2=1.6
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/varobj.c.diff?cvsroot=src&r1=1.196&r2=1.197
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/testsuite/ChangeLog.diff?cvsroot=src&r1=1.3297&r2=1.3298
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/testsuite/gdb.cp/casts.cc.diff?cvsroot=src&r1=1.3&r2=1.4
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/testsuite/gdb.cp/casts.exp.diff?cvsroot=src&r1=1.18&r2=1.19

-- 
Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.

[Bug exp/13206] support gcc's typeof

[tromey at redhat dot com]

http://sourceware.org/bugzilla/show_bug.cgi?id=13206

Tom Tromey <tromey at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |7.6

--- Comment #6 from Tom Tromey <tromey at redhat dot com> 2012-07-19 15:41:51 UTC ---
Fix checked in.

-- 
Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.