The following testcase fails with: sorry, unimplemented: function ‘foo’ can never be copied because it uses variable sized variables When compiled with at least -O1. It works fine with GCC 4.4.3. void __attribute__ ((always_inline)) foo (const unsigned long *addr, unsigned long size) { typedef struct { long x[size]; } addrtype; addrtype *a = (void *) addr; } Unfortunately these patterns are quite common in the Linux kernel - at least for S/390. They always used to compile but mainline currently is not able to build the kernel.
We can't inline it. The sorry() is from #0 sorry ( gmsgid=0x8be6a24 "function %q+F can never be copied because it uses variable sized variables") at /home/richard/src/trunk/gcc/diagnostic.c:639 #1 0x087dde5e in tree_inlinable_function_p (fn=0xb77a6e00) at /home/richard/src/trunk/gcc/tree-inline.c:3041 #2 0x087a2dc6 in compute_inline_parameters (node=0xb773b2e0) at /home/richard/src/trunk/gcc/ipa-inline.c:1865 #3 0x087a2ec0 in compute_inline_parameters_for_current () at /home/richard/src/trunk/gcc/ipa-inline.c:1882 #4 0x0842644f in execute_one_pass (pass=0x8d22d80) at /home/richard/src/trunk/gcc/passes.c:1561 just drop the always_inline attribute.
The question is why we can't inline it, when clearly 4.4 branch can inline it just fine. The 4.4 comment says: /* We cannot inline a function of the form void F (int i) { struct S { int ar[i]; } s; } Attempting to do so produces a catch-22. If walk_tree examines the TYPE_FIELDS chain of RECORD_TYPE/ UNION_TYPE nodes, then it goes into infinite recursion on a structure containing a pointer to its own type. If it doesn't, then the type node for S doesn't get adjusted properly when F is inlined. ??? This is likely no longer true, but it's too late in the 4.0 cycle to try to find out. This should be checked for 4.1. */ As 4.4 walk_tree didn't end up with endless recursion on it, I wonder whether we just can't remove this. Note that inlining functions that return variably modified type might still be problematic, but that's order of magnitude rarer (especially because I think most of GCCs so far ICEd on such code).
(In reply to comment #2) > The question is why we can't inline it, when clearly 4.4 branch can inline it > just fine. Note that comment is http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25566 :). At one point I was going through all the FIXME/??? in gcc and filing bug reports since comments did not get a looking at really once they were written.
Seems the hack not to inline such functions (but until 4.4 always_inline won over it) has been added for PR6994, which has been fixed in a different way anyway. And obviously we are now copying/remapping stuff containing VLAs, e.g. omp-low.c does that. So I'd say we should just nuke that restriction.
Created attachment 19723 [details] gcc45-pr42874.patch I think we should just do this.
Works for me.
Subject: Bug 42874 Author: jakub Date: Wed Jan 27 15:09:23 2010 New Revision: 156287 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=156287 Log: PR middle-end/42874 * tree-inline.c (cannot_copy_type_1): Removed. (copy_forbidden): Don't forbid copying of functions containing records/unions with variable length fields. * gcc.dg/vla-22.c: New test. Added: trunk/gcc/testsuite/gcc.dg/vla-22.c Modified: trunk/gcc/ChangeLog trunk/gcc/testsuite/ChangeLog trunk/gcc/tree-inline.c
Fixed.
Subject: Bug 42874 Author: hjl Date: Sun Feb 7 04:41:22 2010 New Revision: 156562 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=156562 Log: Backport testcases from mainline to 4.4. 2010-02-06 H.J. Lu <hongjiu.lu@intel.com> Backport from mainline: 2010-02-05 Dodji Seketeli <dodji@redhat.com> PR c++/42915 * g++.dg/other/crash-9.C: New test. 2010-02-03 Jason Merrill <jason@redhat.com> PR c++/40138 * g++.dg/ext/builtin11.C: New. 2010-02-03 Richard Guenther <rguenther@suse.de> PR tree-optimization/42944 * gcc.dg/errno-1.c: New testcase. 2010-02-03 Richard Guenther <rguenther@suse.de> PR middle-end/42927 * gcc.c-torture/compile/pr42927.c: New testcase. 2010-01-29 Dodji Seketeli <dodji@redhat.com> PR c++/42758 PR c++/42634 PR c++/42336 PR c++/42797 PR c++/42880 * g++.dg/other/crash-5.C: New test. * g++.dg/other/crash-7.C: New test. * g++.dg/other/crash-8.C: New test. 2010-01-28 Uros Bizjak <ubizjak@gmail.com> PR target/42891 * gcc.target/i386/pr42891.c: New test. 2010-01-28 Richard Guenther <rguenther@suse.de> PR middle-end/42883 * g++.dg/torture/pr42883.C: New testcase. 2010-01-28 Michael Matz <matz@suse.de> * gcc.target/i386/pr42881.c: New test. 2010-01-28 Dodji Seketeli <dodji@redhat.com> PR c++/42713 PR c++/42820 * g++.dg/template/typedef27.C: New test case. * g++.dg/template/typedef28.C: New test case. 2010-01-27 Jakub Jelinek <jakub@redhat.com> PR middle-end/42874 * gcc.dg/vla-22.c: New test. 2010-01-26 Richard Guenther <rguenther@suse.de> PR tree-optimization/42250 * gcc.dg/pr42250.c: New testcase. 2010-01-25 Tobias Burnus <burnus@net-b.de> PR fortran/42858 * gfortran.dg/generic_21.f90: New test. 2010-01-21 Martin Jambor <mjambor@suse.cz> PR tree-optimization/42585 * gcc.dg/tree-ssa/pr42585.c: New test. 2010-01-20 Alexandre Oliva <aoliva@redhat.com> PR debug/42715 * gcc.dg/pr42715.c: New. 2010-01-20 Richard Guenther <rguenther@suse.de> PR tree-optimization/42717 * gcc.c-torture/compile/pr42717.c: New testcase. 2010-01-19 Paul Thomas <pault@gcc.gnu.org> PR fortran/42783 * gfortran.dg/bounds_check_15.f90 : New test. 2010-01-18 Dodji Seketeli <dodji@redhat.com> PR c++/42766 * g++.dg/conversion/op6.C: New test. 2010-01-18 Richard Guenther <rguenther@suse.de> PR tree-optimization/42781 * gfortran.fortran-torture/compile/pr42781.f90: New testcase. 2010-01-17 Richard Guenther <rguenther@suse.de> PR middle-end/42248 * gcc.c-torture/execute/pr42248.c: New testcase. 2010-01-17 Janus Weil <janus@gcc.gnu.org> PR fortran/42677 * gfortran.dg/interface_assignment_5.f90: New test. 2010-01-15 Richard Guenther <rguenther@suse.de> PR middle-end/42739 * g++.dg/torture/pr42739.C: New testcase. 2010-01-14 Jerry DeLisle <jvdelisle@gcc.gnu.org> PR fortran/42684 * gfortran.dg/interface_31.f90: New test. 2010-01-14 Martin Jambor <mjambor@suse.cz> PR tree-optimization/42706 * gcc.dg/ipa/pr42706.c: New testcase. 2010-01-14 Martin Jambor <mjambor@suse.cz> PR tree-optimization/42714 * g++.dg/torture/pr42714.C: New test. 2010-01-14 Alexander Monakov <amonakov@ispras.ru> PR rtl-optimization/42388 * gcc.dg/pr42388.c: New. 2010-01-14 Alexander Monakov <amonakov@ispras.ru> PR rtl-optimization/42294 * gfortran.dg/pr42294.f: New. 2010-01-14 Ira Rosen <irar@il.ibm.com> PR tree-optimization/42709 * gcc.dg/vect/pr42709.c: New test. 2010-01-13 Richard Guenther <rguenther@suse.de> PR tree-optimization/42730 * gcc.c-torture/compile/pr42730.c: New testcase. 2010-01-13 Martin Jambor <mjambor@suse.cz> PR tree-optimization/42704 * g++.dg/torture/pr42704.C: New test. 2010-01-13 Martin Jambor <mjambor@suse.cz> PR tree-optimization/42703 * gcc.c-torture/compile/pr42703.c: New test. 2010-01-13 Richard Guenther <rguenther@suse.de> PR tree-optimization/42705 * gcc.c-torture/compile/pr42705.c: New testcase. 2010-01-13 Richard Guenther <rguenther@suse.de> PR middle-end/42716 * gcc.c-torture/compile/pr42716.c: New testcase. 2010-01-12 Joseph Myers <joseph@codesourcery.com> PR c/42708 * gcc.c-torture/compile/pr42708-1.c: New test. 2010-01-09 Alexandre Oliva <aoliva@redhat.com> PR middle-end/42363 * gcc.dg/torture/pr42363.c: New. 2010-01-09 Alexandre Oliva <aoliva@redhat.com> PR debug/42604 PR debug/42395 * gcc.dg/vect/pr42604.c: New. * gcc.dg/vect/pr42395.c: New. 2010-01-09 Richard Guenther <rguenther@suse.de> PR middle-end/42512 * gcc.c-torture/execute/pr42512.c: New testcase. Added: branches/gcc-4_4-branch/gcc/testsuite/g++.dg/conversion/op6.C - copied unchanged from r156561, trunk/gcc/testsuite/g++.dg/conversion/op6.C branches/gcc-4_4-branch/gcc/testsuite/g++.dg/ext/builtin11.C - copied unchanged from r156561, trunk/gcc/testsuite/g++.dg/ext/builtin11.C branches/gcc-4_4-branch/gcc/testsuite/g++.dg/other/crash-5.C - copied unchanged from r156561, trunk/gcc/testsuite/g++.dg/other/crash-5.C branches/gcc-4_4-branch/gcc/testsuite/g++.dg/other/crash-7.C - copied unchanged from r156561, trunk/gcc/testsuite/g++.dg/other/crash-7.C branches/gcc-4_4-branch/gcc/testsuite/g++.dg/other/crash-8.C - copied unchanged from r156561, trunk/gcc/testsuite/g++.dg/other/crash-8.C branches/gcc-4_4-branch/gcc/testsuite/g++.dg/other/crash-9.C - copied unchanged from r156561, trunk/gcc/testsuite/g++.dg/other/crash-9.C branches/gcc-4_4-branch/gcc/testsuite/g++.dg/template/typedef27.C - copied unchanged from r156561, trunk/gcc/testsuite/g++.dg/template/typedef27.C branches/gcc-4_4-branch/gcc/testsuite/g++.dg/template/typedef28.C - copied unchanged from r156561, trunk/gcc/testsuite/g++.dg/template/typedef28.C branches/gcc-4_4-branch/gcc/testsuite/g++.dg/torture/pr42704.C - copied unchanged from r156561, trunk/gcc/testsuite/g++.dg/torture/pr42704.C branches/gcc-4_4-branch/gcc/testsuite/g++.dg/torture/pr42714.C - copied unchanged from r156561, trunk/gcc/testsuite/g++.dg/torture/pr42714.C branches/gcc-4_4-branch/gcc/testsuite/g++.dg/torture/pr42739.C - copied unchanged from r156561, trunk/gcc/testsuite/g++.dg/torture/pr42739.C branches/gcc-4_4-branch/gcc/testsuite/g++.dg/torture/pr42883.C - copied unchanged from r156561, trunk/gcc/testsuite/g++.dg/torture/pr42883.C branches/gcc-4_4-branch/gcc/testsuite/gcc.c-torture/compile/pr42703.c - copied unchanged from r156561, trunk/gcc/testsuite/gcc.c-torture/compile/pr42703.c branches/gcc-4_4-branch/gcc/testsuite/gcc.c-torture/compile/pr42705.c - copied unchanged from r156561, trunk/gcc/testsuite/gcc.c-torture/compile/pr42705.c branches/gcc-4_4-branch/gcc/testsuite/gcc.c-torture/compile/pr42708-1.c - copied unchanged from r156561, trunk/gcc/testsuite/gcc.c-torture/compile/pr42708-1.c branches/gcc-4_4-branch/gcc/testsuite/gcc.c-torture/compile/pr42716.c - copied unchanged from r156561, trunk/gcc/testsuite/gcc.c-torture/compile/pr42716.c branches/gcc-4_4-branch/gcc/testsuite/gcc.c-torture/compile/pr42717.c - copied unchanged from r156561, trunk/gcc/testsuite/gcc.c-torture/compile/pr42717.c branches/gcc-4_4-branch/gcc/testsuite/gcc.c-torture/compile/pr42730.c - copied unchanged from r156561, trunk/gcc/testsuite/gcc.c-torture/compile/pr42730.c branches/gcc-4_4-branch/gcc/testsuite/gcc.c-torture/compile/pr42927.c - copied unchanged from r156561, trunk/gcc/testsuite/gcc.c-torture/compile/pr42927.c branches/gcc-4_4-branch/gcc/testsuite/gcc.c-torture/execute/pr42248.c - copied unchanged from r156561, trunk/gcc/testsuite/gcc.c-torture/execute/pr42248.c branches/gcc-4_4-branch/gcc/testsuite/gcc.c-torture/execute/pr42512.c - copied unchanged from r156561, trunk/gcc/testsuite/gcc.c-torture/execute/pr42512.c branches/gcc-4_4-branch/gcc/testsuite/gcc.dg/errno-1.c - copied unchanged from r156561, trunk/gcc/testsuite/gcc.dg/errno-1.c branches/gcc-4_4-branch/gcc/testsuite/gcc.dg/ipa/pr42706.c - copied unchanged from r156561, trunk/gcc/testsuite/gcc.dg/ipa/pr42706.c branches/gcc-4_4-branch/gcc/testsuite/gcc.dg/pr42250.c - copied unchanged from r156561, trunk/gcc/testsuite/gcc.dg/pr42250.c branches/gcc-4_4-branch/gcc/testsuite/gcc.dg/pr42388.c - copied unchanged from r156561, trunk/gcc/testsuite/gcc.dg/pr42388.c branches/gcc-4_4-branch/gcc/testsuite/gcc.dg/pr42715.c - copied unchanged from r156561, trunk/gcc/testsuite/gcc.dg/pr42715.c branches/gcc-4_4-branch/gcc/testsuite/gcc.dg/torture/pr42363.c - copied unchanged from r156561, trunk/gcc/testsuite/gcc.dg/torture/pr42363.c branches/gcc-4_4-branch/gcc/testsuite/gcc.dg/tree-ssa/pr42585.c - copied unchanged from r156561, trunk/gcc/testsuite/gcc.dg/tree-ssa/pr42585.c branches/gcc-4_4-branch/gcc/testsuite/gcc.dg/vect/pr42395.c - copied unchanged from r156561, trunk/gcc/testsuite/gcc.dg/vect/pr42395.c branches/gcc-4_4-branch/gcc/testsuite/gcc.dg/vect/pr42604.c - copied unchanged from r156561, trunk/gcc/testsuite/gcc.dg/vect/pr42604.c branches/gcc-4_4-branch/gcc/testsuite/gcc.dg/vect/pr42709.c - copied unchanged from r156561, trunk/gcc/testsuite/gcc.dg/vect/pr42709.c branches/gcc-4_4-branch/gcc/testsuite/gcc.dg/vla-22.c - copied unchanged from r156561, trunk/gcc/testsuite/gcc.dg/vla-22.c branches/gcc-4_4-branch/gcc/testsuite/gcc.target/i386/pr42881.c - copied unchanged from r156561, trunk/gcc/testsuite/gcc.target/i386/pr42881.c branches/gcc-4_4-branch/gcc/testsuite/gcc.target/i386/pr42891.c - copied unchanged from r156561, trunk/gcc/testsuite/gcc.target/i386/pr42891.c branches/gcc-4_4-branch/gcc/testsuite/gfortran.dg/bounds_check_15.f90 - copied unchanged from r156561, trunk/gcc/testsuite/gfortran.dg/bounds_check_15.f90 branches/gcc-4_4-branch/gcc/testsuite/gfortran.dg/generic_21.f90 - copied unchanged from r156561, trunk/gcc/testsuite/gfortran.dg/generic_21.f90 branches/gcc-4_4-branch/gcc/testsuite/gfortran.dg/interface_31.f90 - copied unchanged from r156561, trunk/gcc/testsuite/gfortran.dg/interface_31.f90 branches/gcc-4_4-branch/gcc/testsuite/gfortran.dg/interface_assignment_5.f90 - copied unchanged from r156561, trunk/gcc/testsuite/gfortran.dg/interface_assignment_5.f90 branches/gcc-4_4-branch/gcc/testsuite/gfortran.dg/pr42294.f - copied unchanged from r156561, trunk/gcc/testsuite/gfortran.dg/pr42294.f branches/gcc-4_4-branch/gcc/testsuite/gfortran.fortran-torture/compile/pr42781.f90 - copied unchanged from r156561, trunk/gcc/testsuite/gfortran.fortran-torture/compile/pr42781.f90 Modified: branches/gcc-4_4-branch/gcc/testsuite/ChangeLog