| Message ID | 20131202201045.GI9986@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Mon, 2 Dec 2013, Marek Polacek wrote: > Regtested/botstrapped on x86_64-linux, ok for trunk and 4.8 and > perhaps even 4.7? > > 2013-12-02 Marek Polacek <polacek@redhat.com> > > PR c/59351 > c/ > * c-decl.c (build_compound_literal): Allow compound literals with > empty initial value. > testsuite/ > * gcc.dg/pr59351.c: New test. OK.
On 12/02/13 13:10, Marek Polacek wrote: > We triggered an assert on attached testcase, because when building the > compound literal with empty initial value complete_array_type returns > 3, but we assert it returns 0. It returns 3 only in the pedantic mode, > where empty initializer braces are forbidden. Since we already gave > a warning, I think we could loosen the assert a bit and allow > empty initial values at that point. sizeof on such compound literal > then yields zero, which I think is correct. > The assert exists even in GCC 4.0. > > Regtested/botstrapped on x86_64-linux, ok for trunk and 4.8 and > perhaps even 4.7? > > 2013-12-02 Marek Polacek <polacek@redhat.com> > > PR c/59351 > c/ > * c-decl.c (build_compound_literal): Allow compound literals with > empty initial value. > testsuite/ > * gcc.dg/pr59351.c: New test. I was going to ask for some details about where we detect and warn to review that code as well, but given your test verifies the warning as well, we're good to go. OK for the trunk. Branch maintainers have final say for their branches. Thanks, Jeff
On Tue, Dec 03, 2013 at 01:03:43PM -0700, Jeff Law wrote: > On 12/02/13 13:10, Marek Polacek wrote: > >We triggered an assert on attached testcase, because when building the > >compound literal with empty initial value complete_array_type returns > >3, but we assert it returns 0. It returns 3 only in the pedantic mode, > >where empty initializer braces are forbidden. Since we already gave > >a warning, I think we could loosen the assert a bit and allow > >empty initial values at that point. sizeof on such compound literal > >then yields zero, which I think is correct. > >The assert exists even in GCC 4.0. > > > >Regtested/botstrapped on x86_64-linux, ok for trunk and 4.8 and > >perhaps even 4.7? > > > >2013-12-02 Marek Polacek <polacek@redhat.com> > > > > PR c/59351 > >c/ > > * c-decl.c (build_compound_literal): Allow compound literals with > > empty initial value. > >testsuite/ > > * gcc.dg/pr59351.c: New test. > I was going to ask for some details about where we detect and warn > to review that code as well, but given your test verifies the > warning as well, we're good to go. Yeah, the patch should really only fix the ICE. > OK for the trunk. Branch maintainers have final say for their branches. Note that I already put this into trunk and after ack by Jakub into 4.7/4.8 branches as well. Marek
--- gcc/c/c-decl.c.mp3 2013-12-02 20:23:27.947224366 +0100 +++ gcc/c/c-decl.c 2013-12-02 20:25:56.618779873 +0100 @@ -4693,7 +4693,9 @@ build_compound_literal (location_t loc, { int failure = complete_array_type (&TREE_TYPE (decl), DECL_INITIAL (decl), true); - gcc_assert (!failure); + /* If complete_array_type returns 3, it means that the + initial value of the compound literal is empty. Allow it. */ + gcc_assert (failure == 0 || failure == 3); type = TREE_TYPE (decl); TREE_TYPE (DECL_INITIAL (decl)) = type; --- gcc/testsuite/gcc.dg/pr59351.c.mp3 2013-12-02 20:29:05.612345428 +0100 +++ gcc/testsuite/gcc.dg/pr59351.c 2013-12-02 20:48:47.298751979 +0100 @@ -0,0 +1,8 @@ +/* { dg-do compile } */ +/* { dg-options "-std=c99 -Wpedantic" } */ + +unsigned int +foo (void) +{ + return sizeof ((int[]) {}); /* { dg-warning "ISO C forbids empty initializer braces" } */ +}