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[PATCH] Fix GC PCH bug in dwarf2out.c (PR c++/79821)
- From: Jakub Jelinek <jakub at redhat dot com>
- To: Jason Merrill <jason at redhat dot com>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Mon, 6 Mar 2017 21:56:05 +0100
- Subject: [PATCH] Fix GC PCH bug in dwarf2out.c (PR c++/79821)
- Authentication-results: sourceware.org; auth=none
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
Hi!
gengtype.c considers all GC arrays with char/unsigned char/signed char
element type as strings, for which it computes size e.g. in gt_pch_note_object
using:
if (note_ptr_fn == gt_pch_p_S)
(*slot)->size = strlen ((const char *)obj) + 1;
else
(*slot)->size = ggc_get_size (obj);
That is really undesirable if the array is actually a collection of random
bytes rather than a NUL terminated string - then we can either compute
smaller size if there are zeros in the array, or if unlucky enough and there
are no zero bytes until end of mapped region, segfault.
Fixed by avoiding the gt_pch_*_S handling by using void * pointer instead.
Bootstrapped/regtested on x86_64-linux and i686-linux, and Rainer has kindly
tested it on sparc*-solaris* where it caused bootstrap issues. Ok for
trunk?
2017-03-06 Jakub Jelinek <jakub@redhat.com>
PR c++/79821
* dwarf2out.h (dw_vec_const): Change array type from unsigned char *
to void * for PCH reasons.
* dwarf2out.c (output_loc_operands, output_die): Cast
v.val_vec.array to unsigned char *.
--- gcc/dwarf2out.h.jj 2017-01-01 12:45:37.000000000 +0100
+++ gcc/dwarf2out.h 2017-03-06 12:13:48.809589411 +0100
@@ -163,7 +163,7 @@ enum dw_val_class
/* Describe a floating point constant value, or a vector constant value. */
struct GTY(()) dw_vec_const {
- unsigned char * GTY((atomic)) array;
+ void * GTY((atomic)) array;
unsigned length;
unsigned elt_size;
};
--- gcc/dwarf2out.c.jj 2017-02-25 09:17:44.000000000 +0100
+++ gcc/dwarf2out.c 2017-03-06 12:15:52.668958458 +0100
@@ -2020,7 +2020,7 @@ output_loc_operands (dw_loc_descr_ref lo
elt_size /= 2;
len *= 2;
}
- for (i = 0, p = val2->v.val_vec.array;
+ for (i = 0, p = (unsigned char *) val2->v.val_vec.array;
i < len;
i++, p += elt_size)
dw2_asm_output_data (elt_size, extract_int (p, elt_size),
@@ -2273,7 +2273,7 @@ output_loc_operands (dw_loc_descr_ref lo
elt_size /= 2;
len *= 2;
}
- for (i = 0, p = val2->v.val_vec.array;
+ for (i = 0, p = (unsigned char *) val2->v.val_vec.array;
i < len;
i++, p += elt_size)
dw2_asm_output_data (elt_size, extract_int (p, elt_size),
@@ -10105,7 +10105,7 @@ output_die (dw_die_ref die)
elt_size /= 2;
len *= 2;
}
- for (i = 0, p = a->dw_attr_val.v.val_vec.array;
+ for (i = 0, p = (unsigned char *) a->dw_attr_val.v.val_vec.array;
i < len;
i++, p += elt_size)
dw2_asm_output_data (elt_size, extract_int (p, elt_size),
Jakub