| Message ID | 20181209110506.GV12380@tucnak |
|---|---|
| State | New |
| Headers | show |
| Series | [C++] Fix ICE with offsetof-like initializer (PR c++/88410) | expand |
Hi! On Sun, Dec 09, 2018 at 12:05:06PM +0100, Jakub Jelinek wrote: > The following testcase ICEs starting with my change to move offsetof-like > expression handling from the parsing to cp_fold - if the base expression > is not INTEGER_CST, but a constant VAR_DECL initialized with INTEGER_CST, > then we don't fold it as offsetof-like expression and as we use recursive > cp_fold only on functions, not initializers, we don't fold that VAR_DECL in > there into INTEGER_CST and the middle-end ICEs on it trying to fold it. > > Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for > trunk? > > 2018-12-09 Jakub Jelinek <jakub@redhat.com> > > PR c++/88410 > * cp-gimplify.c (cp_fold) <case ADDR_EXPR>: For offsetof-like folding, > call maybe_constant_value on val to see if it is INTEGER_CST. > > * g++.dg/cpp0x/pr88410.C: New test. I'd like to ping this patch. Thanks. Jakub
On 12/9/18 6:05 AM, Jakub Jelinek wrote: > Hi! > > The following testcase ICEs starting with my change to move offsetof-like > expression handling from the parsing to cp_fold - if the base expression > is not INTEGER_CST, but a constant VAR_DECL initialized with INTEGER_CST, > then we don't fold it as offsetof-like expression and as we use recursive > cp_fold only on functions, not initializers, we don't fold that VAR_DECL in > there into INTEGER_CST and the middle-end ICEs on it trying to fold it. > > Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for > trunk? OK. Jason
--- gcc/cp/cp-gimplify.c.jj 2018-11-23 20:00:26.603273556 +0100 +++ gcc/cp/cp-gimplify.c 2018-12-08 11:39:03.983985326 +0100 @@ -2317,6 +2317,7 @@ cp_fold (tree x) { val = TREE_OPERAND (val, 0); STRIP_NOPS (val); + val = maybe_constant_value (val); if (TREE_CODE (val) == INTEGER_CST) return fold_offsetof (op0, TREE_TYPE (x)); } --- gcc/testsuite/g++.dg/cpp0x/pr88410.C.jj 2018-12-08 11:41:10.946927148 +0100 +++ gcc/testsuite/g++.dg/cpp0x/pr88410.C 2018-12-08 11:40:48.476291414 +0100 @@ -0,0 +1,7 @@ +// PR c++/88410 +// { dg-do compile { target c++11 } } + +typedef __UINTPTR_TYPE__ uintptr_t; +const uintptr_t a = 32; +struct C { int b; int c; }; +uintptr_t d { uintptr_t (&reinterpret_cast<C *>(a)->c) - a };