| Message ID | 20180215000430.GE5867@tucnak |
|---|---|
| State | New |
| Headers | show |
| Series | Fix ICE in maybe_diag_stxncpy_trunc (PR tree-optimization/84383) | expand |
On Thu, 15 Feb 2018, Jakub Jelinek wrote: > Hi! > > The function calls get_addr_base_and_unit_offset on 2 trees, but > that can return NULL if the unit offset is not constant. > The conditional tests just one of them for non-NULL and operand_equal_p > ICEs if one argument is NULL, so depending on the uninitialized poly_int64 > (get_addr_base_and_unit_offset doesn't touch it if it returns NULL), > we either ICE in operand_equal_p or are lucky and dstoff is equal to lhsoff > and just valgrind complains. > > Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for > trunk? Ok. Richard. > 2018-02-15 Jakub Jelinek <jakub@redhat.com> > > PR tree-optimization/84383 > * tree-ssa-strlen.c (maybe_diag_stxncpy_trunc): Don't look at > dstoff nor call operand_equal_p if dstbase is NULL. > > * gcc.c-torture/compile/pr84383.c: New test. > > --- gcc/tree-ssa-strlen.c.jj 2018-02-09 06:44:29.993809176 +0100 > +++ gcc/tree-ssa-strlen.c 2018-02-14 16:38:36.981713666 +0100 > @@ -1878,6 +1878,7 @@ maybe_diag_stxncpy_trunc (gimple_stmt_it > poly_int64 lhsoff; > tree lhsbase = get_addr_base_and_unit_offset (lhs, &lhsoff); > if (lhsbase > + && dstbase > && known_eq (dstoff, lhsoff) > && operand_equal_p (dstbase, lhsbase, 0)) > return false; > --- gcc/testsuite/gcc.c-torture/compile/pr84383.c.jj 2018-02-14 17:33:21.972803287 +0100 > +++ gcc/testsuite/gcc.c-torture/compile/pr84383.c 2018-02-14 17:32:37.639803918 +0100 > @@ -0,0 +1,14 @@ > +/* PR tree-optimization/84383 */ > + > +struct S { char *s; }; > +void bar (struct S *); > + > +void > +foo (int a, char *b) > +{ > + struct S c[4]; > + bar (c); > + __builtin_strncpy (c[a].s, b, 32); > + c[a].s[31] = '\0'; > + bar (c); > +} > > Jakub > >
--- gcc/tree-ssa-strlen.c.jj 2018-02-09 06:44:29.993809176 +0100 +++ gcc/tree-ssa-strlen.c 2018-02-14 16:38:36.981713666 +0100 @@ -1878,6 +1878,7 @@ maybe_diag_stxncpy_trunc (gimple_stmt_it poly_int64 lhsoff; tree lhsbase = get_addr_base_and_unit_offset (lhs, &lhsoff); if (lhsbase + && dstbase && known_eq (dstoff, lhsoff) && operand_equal_p (dstbase, lhsbase, 0)) return false; --- gcc/testsuite/gcc.c-torture/compile/pr84383.c.jj 2018-02-14 17:33:21.972803287 +0100 +++ gcc/testsuite/gcc.c-torture/compile/pr84383.c 2018-02-14 17:32:37.639803918 +0100 @@ -0,0 +1,14 @@ +/* PR tree-optimization/84383 */ + +struct S { char *s; }; +void bar (struct S *); + +void +foo (int a, char *b) +{ + struct S c[4]; + bar (c); + __builtin_strncpy (c[a].s, b, 32); + c[a].s[31] = '\0'; + bar (c); +}