| Message ID | 21e018d1-4d2c-5f46-6ec1-1cc54c180e58@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Wed, Oct 26, 2016 at 9:17 PM, Aldy Hernandez <aldyh@redhat.com> wrote: > The following one-liner segfaults on arm-eabi when compiled with > -mfloat-abi=hard -g: > > __simd64_float16_t usingit; > > The problem is that the pretty printer (in simple_type_specificer()) is > dereferencing a NULL result from c_common_type_for_mode: > > int prec = TYPE_PRECISION (t); > if (ALL_FIXED_POINT_MODE_P (TYPE_MODE (t))) > t = c_common_type_for_mode (TYPE_MODE (t), TYPE_SATURATING (t)); > else > t = c_common_type_for_mode (TYPE_MODE (t), TYPE_UNSIGNED (t)); > if (TYPE_NAME (t)) > > The type in question is: > > <real_type 0x7fffefdeb150 HF ...> > > which corresponds to HFmode and which AFAICT, does not have a type by > design. > > I see that other uses of *type_for_node() throughout the compiler check the > result for NULL, so perhaps we should do the same here. > > The attached patch fixes the problem. > > OK for trunk? Your added assert shows another possible issue - can you fix this by assigning the result of c_common_type_for_mode to a new variable, like common_t and use that for the TYPE_NAME (...) case? I think this was what was intended. Richard.
diff --git a/gcc/c-family/c-pretty-print.c b/gcc/c-family/c-pretty-print.c index 90428ca..6bb38a9 100644 --- a/gcc/c-family/c-pretty-print.c +++ b/gcc/c-family/c-pretty-print.c @@ -348,7 +348,7 @@ c_pretty_printer::simple_type_specifier (tree t) t = c_common_type_for_mode (TYPE_MODE (t), TYPE_SATURATING (t)); else t = c_common_type_for_mode (TYPE_MODE (t), TYPE_UNSIGNED (t)); - if (TYPE_NAME (t)) + if (t && TYPE_NAME (t)) { simple_type_specifier (t); if (TYPE_PRECISION (t) != prec) @@ -362,6 +362,7 @@ c_pretty_printer::simple_type_specifier (tree t) switch (code) { case INTEGER_TYPE: + gcc_assert (t != NULL); translate_string (TYPE_UNSIGNED (t) ? "<unnamed-unsigned:" : "<unnamed-signed:");
The following one-liner segfaults on arm-eabi when compiled with -mfloat-abi=hard -g: __simd64_float16_t usingit; The problem is that the pretty printer (in simple_type_specificer()) is dereferencing a NULL result from c_common_type_for_mode: int prec = TYPE_PRECISION (t); if (ALL_FIXED_POINT_MODE_P (TYPE_MODE (t))) t = c_common_type_for_mode (TYPE_MODE (t), TYPE_SATURATING (t)); else t = c_common_type_for_mode (TYPE_MODE (t), TYPE_UNSIGNED (t)); if (TYPE_NAME (t)) The type in question is: <real_type 0x7fffefdeb150 HF ...> which corresponds to HFmode and which AFAICT, does not have a type by design. I see that other uses of *type_for_node() throughout the compiler check the result for NULL, so perhaps we should do the same here. The attached patch fixes the problem. OK for trunk? commit 10c5a54cb1bf4684864b01cb965d83f3fe474797 Author: Aldy Hernandez <aldyh@redhat.com> Date: Wed Oct 26 12:06:09 2016 -0700 PR debug/77773 * c-pretty-print.c (simple_type_specifier): Do not dereference `t' if NULL.