OpenE2K
/
gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

re PR c++/67557 (Calling copy constructor of base class in constructor of derived class produces crashing code) 

PR c++/67557

	* expr.c (store_field): Call store_constructor directly when
	storing a CONSTRUCTOR into a target smaller than its type.
	Guard against unsafe bitwise copy.

From-SVN: r228704
This commit is contained in:
Jason Merrill 2015-10-12 03:58:43 -04:00 committed by Jason Merrill
parent 5330a79d34
commit f5a8677b37
3 changed files with 30 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
gcc/ChangeLog
View File

@ -1,3 +1,10 @@
2015-10-11 Jason Merrill <jason@redhat.com>
PR c++/67557
* expr.c (store_field): Call store_constructor directly when
storing a CONSTRUCTOR into a target smaller than its type.
Guard against unsafe bitwise copy.
2015-10-11 Jan Hubicka <hubicka@ucw.cz>
* cgraphbuild.c (compute_call_stmt_bb_frequency): Use

18
gcc/expr.c
View File

@ -6616,7 +6616,11 @@ store_field (rtx target, HOST_WIDE_INT bitsize, HOST_WIDE_INT bitpos,
operations. */
|| (bitsize >= 0
&& TREE_CODE (TYPE_SIZE (TREE_TYPE (exp))) == INTEGER_CST
&& compare_tree_int (TYPE_SIZE (TREE_TYPE (exp)), bitsize) != 0)
&& compare_tree_int (TYPE_SIZE (TREE_TYPE (exp)), bitsize) != 0
/* Except for initialization of full bytes from a CONSTRUCTOR, which
we will handle specially below. */
&& !(TREE_CODE (exp) == CONSTRUCTOR
&& bitsize % BITS_PER_UNIT == 0))
/* If we are expanding a MEM_REF of a non-BLKmode non-addressable
decl we must use bitfield operations. */
|| (bitsize >= 0
@ -6629,6 +6633,9 @@ store_field (rtx target, HOST_WIDE_INT bitsize, HOST_WIDE_INT bitpos,
rtx temp;
gimple *nop_def;
/* Using bitwise copy is not safe for TREE_ADDRESSABLE types. */
gcc_assert (!TREE_ADDRESSABLE (TREE_TYPE (exp)));
/* If EXP is a NOP_EXPR of precision less than its mode, then that
implies a mask operation. If the precision is the same size as
the field we're storing into, that mask is redundant. This is
@ -6743,6 +6750,15 @@ store_field (rtx target, HOST_WIDE_INT bitsize, HOST_WIDE_INT bitpos,
if (!MEM_KEEP_ALIAS_SET_P (to_rtx) && MEM_ALIAS_SET (to_rtx) != 0)
set_mem_alias_set (to_rtx, alias_set);
/* Above we avoided using bitfield operations for storing a CONSTRUCTOR
into a target smaller than its type; handle that case now. */
if (TREE_CODE (exp) == CONSTRUCTOR && bitsize >= 0)
{
gcc_assert (bitsize % BITS_PER_UNIT == 0);
store_constructor (exp, to_rtx, 0, bitsize/BITS_PER_UNIT);
return to_rtx;
}
return store_expr (exp, to_rtx, 0, nontemporal);
}
}

6
gcc/testsuite/g++.dg/init/vbase1.C
View File

@ -1,4 +1,5 @@
// PR c++/50618
// { dg-options "-fdump-rtl-expand" }
// { dg-do run }
struct Base
@ -37,3 +38,8 @@ int main(int, char**)
Diamond x(2);
x.printText();
}
// Verify that the SubB() mem-initializer is storing 0 directly into
// this->D.whatever rather than into a stack temp that is then copied into the
// base field.
// { dg-final { scan-rtl-dump "set \[^\n\]*\n\[^\n\]*this\[^\n\]*\n\[^\n\]*const_int 0" "expand" } }