| Message ID | 20181122200444.GL11625@tucnak |
|---|---|
| State | New |
| Headers | show |
| Series | Avoid duplicate -Warray-bounds warnings (PR tree-optimization/86614) | expand |
On Thu, 22 Nov 2018, Jakub Jelinek wrote: > Hi! > > On the following testcases, we warn twice, once in the FE array bounds > warning code and once later on. > The FE array bounds warning code sets TREE_NO_WARNING on the corresponding > MEM_REF, so it is easy to avoid the duplicate warning later. > > Bootstrapped/regtested on x86_64-linux, ok for trunk? OK. Richard. > 2018-11-22 Jakub Jelinek <jakub@redhat.com> > > PR tree-optimization/86614 > * gimple-ssa-warn-restrict.c (maybe_diag_offset_bounds): Return early > if TREE_NO_WARNING is set on ref.ref. > > * c-c++-common/Warray-bounds-2.c (wrap_strncpy_dstarray_diff_neg, > call_strncpy_dstarray_diff_neg): Don't expect late -Warray-bounds > warnings, just early ones from FE. Remove dg-prune-output. > * c-c++-common/Warray-bounds-6.c: New test. > > --- gcc/gimple-ssa-warn-restrict.c.jj 2018-10-19 10:59:08.279393367 +0200 > +++ gcc/gimple-ssa-warn-restrict.c 2018-11-22 18:13:33.813739648 +0100 > @@ -1582,6 +1582,9 @@ maybe_diag_offset_bounds (location_t loc > if (!warn_array_bounds) > return false; > > + if (ref.ref && TREE_NO_WARNING (ref.ref)) > + return false; > + > offset_int ooboff[] = { ref.offrange[0], ref.offrange[1] }; > tree oobref = ref.offset_out_of_bounds (strict, ooboff); > if (!oobref) > --- gcc/testsuite/c-c++-common/Warray-bounds-2.c.jj 2018-07-23 09:46:57.352997850 +0200 > +++ gcc/testsuite/c-c++-common/Warray-bounds-2.c 2018-11-22 18:29:49.911602501 +0100 > @@ -201,18 +201,16 @@ void call_strncpy_dst_diff_max (const ch > static void > wrap_strncpy_dstarray_diff_neg (char *d, const char *s, ptrdiff_t i, size_t n) > { > - strncpy (d + i, s, n); /* { dg-warning "offset -\[0-9\]+ is out of the bounds \\\[0, 90] of object .ar10. with type .(struct )?Array ?\\\[2]." "strncpy" } */ > -} > + strncpy (d + i, s, n); /* { dg-bogus "offset -\[0-9\]+ is out of the bounds \\\[0, 90] of object .ar10. with type .(struct )?Array ?\\\[2]." "strncpy" } */ > +} /* { dg-warning "array subscript -1 is outside array bounds" "" { target *-*-* } .-1 } */ > > void call_strncpy_dstarray_diff_neg (const char *s, size_t n) > { > - struct Array ar10[2]; /* { dg-message ".ar10. declared here" } */ > - sink (&ar10); > + struct Array ar10[2]; /* { dg-bogus ".ar10. declared here" } */ > + sink (&ar10); /* { dg-message "while referencing" "" { target *-*-* } .-1 } */ > > int off = (char*)ar10[1].a17 - (char*)ar10 + 1; > wrap_strncpy_dstarray_diff_neg (ar10[1].a17, s, -off, n); > > sink (&ar10); > } > - > -/* { dg-prune-output "outside array bounds" } */ > --- gcc/testsuite/c-c++-common/Warray-bounds-6.c.jj 2018-11-22 18:26:00.286397043 +0100 > +++ gcc/testsuite/c-c++-common/Warray-bounds-6.c 2018-11-22 18:31:55.479527492 +0100 > @@ -0,0 +1,18 @@ > +/* PR tree-optimization/86614 */ > +/* { dg-do compile } */ > +/* { dg-options "-O2 -Warray-bounds" } */ > + > +extern char *strncpy (char *, const char *, __SIZE_TYPE__); > + > +void sink (void *); > + > +struct A { char b[17]; } a[2]; > + > +void g (const char *s, unsigned n) > +{ > + int i = (char *)a[1].b - (char *)a + 1; > + char *d = a[1].b; > + /* Ensure the same bug is not diagnosed more than once. */ > + strncpy (d + i, s, n); /* { dg-warning "array subscript \[0-9]+ is outside array bounds of" } */ > + /* { dg-bogus "offset \[0-9]+ is out of the bounds \\\[0, \[0-9]+\\\] of object 'a' with type" "" { target *-*-* } .-1 } */ > +} > > Jakub > >
--- gcc/gimple-ssa-warn-restrict.c.jj 2018-10-19 10:59:08.279393367 +0200 +++ gcc/gimple-ssa-warn-restrict.c 2018-11-22 18:13:33.813739648 +0100 @@ -1582,6 +1582,9 @@ maybe_diag_offset_bounds (location_t loc if (!warn_array_bounds) return false; + if (ref.ref && TREE_NO_WARNING (ref.ref)) + return false; + offset_int ooboff[] = { ref.offrange[0], ref.offrange[1] }; tree oobref = ref.offset_out_of_bounds (strict, ooboff); if (!oobref) --- gcc/testsuite/c-c++-common/Warray-bounds-2.c.jj 2018-07-23 09:46:57.352997850 +0200 +++ gcc/testsuite/c-c++-common/Warray-bounds-2.c 2018-11-22 18:29:49.911602501 +0100 @@ -201,18 +201,16 @@ void call_strncpy_dst_diff_max (const ch static void wrap_strncpy_dstarray_diff_neg (char *d, const char *s, ptrdiff_t i, size_t n) { - strncpy (d + i, s, n); /* { dg-warning "offset -\[0-9\]+ is out of the bounds \\\[0, 90] of object .ar10. with type .(struct )?Array ?\\\[2]." "strncpy" } */ -} + strncpy (d + i, s, n); /* { dg-bogus "offset -\[0-9\]+ is out of the bounds \\\[0, 90] of object .ar10. with type .(struct )?Array ?\\\[2]." "strncpy" } */ +} /* { dg-warning "array subscript -1 is outside array bounds" "" { target *-*-* } .-1 } */ void call_strncpy_dstarray_diff_neg (const char *s, size_t n) { - struct Array ar10[2]; /* { dg-message ".ar10. declared here" } */ - sink (&ar10); + struct Array ar10[2]; /* { dg-bogus ".ar10. declared here" } */ + sink (&ar10); /* { dg-message "while referencing" "" { target *-*-* } .-1 } */ int off = (char*)ar10[1].a17 - (char*)ar10 + 1; wrap_strncpy_dstarray_diff_neg (ar10[1].a17, s, -off, n); sink (&ar10); } - -/* { dg-prune-output "outside array bounds" } */ --- gcc/testsuite/c-c++-common/Warray-bounds-6.c.jj 2018-11-22 18:26:00.286397043 +0100 +++ gcc/testsuite/c-c++-common/Warray-bounds-6.c 2018-11-22 18:31:55.479527492 +0100 @@ -0,0 +1,18 @@ +/* PR tree-optimization/86614 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -Warray-bounds" } */ + +extern char *strncpy (char *, const char *, __SIZE_TYPE__); + +void sink (void *); + +struct A { char b[17]; } a[2]; + +void g (const char *s, unsigned n) +{ + int i = (char *)a[1].b - (char *)a + 1; + char *d = a[1].b; + /* Ensure the same bug is not diagnosed more than once. */ + strncpy (d + i, s, n); /* { dg-warning "array subscript \[0-9]+ is outside array bounds of" } */ + /* { dg-bogus "offset \[0-9]+ is out of the bounds \\\[0, \[0-9]+\\\] of object 'a' with type" "" { target *-*-* } .-1 } */ +}