https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91258
Martin Sebor <msebor at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|WAITING |NEW
--- Comment #12 from Martin Sebor <msebor at gcc dot gnu.org> ---
I've reproduced it in a test suite run, but not yet in a debugger. I
instrumented the code to dump LHS, the type of REF in the if block (REFTYPE),
and finally TYPE. Here they are, followed by the warning. TYPE is 1 byte, so
is_char_type (TYPE) returns true.
LHS = <mem_ref 0x3fff84b0d5c0
type <integer_type 0x3fff84970738 int public SI
size <integer_cst 0x3fff84941068 constant 32>
unit-size <integer_cst 0x3fff84941080 constant 4>
align:32 warn_if_not_align:0 symtab:0 alias-set 1 canonical-type
0x3fff8
4970738 precision:32 min <integer_cst 0x3fff84941020 -2147483648> max
<integer_c
st 0x3fff84941038 2147483647>
pointer_to_this <pointer_type 0x3fff84971ae8>>
arg:0 <addr_expr 0x3fff84958560
type <pointer_type 0x3fff84b38dc0 type <array_type 0x3fff84b38d18>
unsigned DI
size <integer_cst 0x3fff84940e28 constant 64>
unit-size <integer_cst 0x3fff84940e40 constant 8>
align:64 warn_if_not_align:0 symtab:0 alias-set -1
structural-equality>
arg:0 <var_decl 0x3fff87002370 D.3146 type <array_type 0x3fff84b38d18>
addressable used ignored SI
/src/gcc/trunk/gcc/testsuite/g++.dg/ubsan/vla-1.C:9:5 size <integer_cst
0x3fff84941068 32> unit-size <integer_cst 0x3fff84941080 4>
align:32 warn_if_not_align:0 context <function_decl 0x3fff84b4f100
main>>>
arg:1 <integer_cst 0x3fff8494b268 type <pointer_type 0x3fff84971ae8>
constant 4>>
REFTYPE = <pointer_type 0x3fff84b38dc0
type <array_type 0x3fff84b38d18
type <integer_type 0x3fff84b38bc8 public unsigned QI
size <integer_cst 0x3fff84940f18 constant 8>
unit-size <integer_cst 0x3fff84940f30 constant 1>
align:8 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type
0x3fff84b38bc8 precision:8 min <integer_cst 0x3fff8494bd90 0> max <integer_cst
0x3fff8494bd48 255>>
SI
size <integer_cst 0x3fff84941068 constant 32>
unit-size <integer_cst 0x3fff84941080 constant 4>
align:8 warn_if_not_align:0 symtab:0 alias-set -1 structural-equality
domain <integer_type 0x3fff84b38c70 type <integer_type 0x3fff84970150
sizetype>
DI
size <integer_cst 0x3fff84940e28 constant 64>
unit-size <integer_cst 0x3fff84940e40 constant 8>
align:64 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type
0x3fff84b38c70 precision:64 min <integer_cst 0x3fff84940e58 0> max <integer_cst
0x3fff8494bdc0 3>>
pointer_to_this <pointer_type 0x3fff84b38dc0>>
unsigned DI size <integer_cst 0x3fff84940e28 64> unit-size <integer_cst
0x3fff84940e40 8>
align:64 warn_if_not_align:0 symtab:0 alias-set -1 structural-equality>
TYPE = <integer_type 0x3fff84b38bc8 public unsigned QI
size <integer_cst 0x3fff84940f18 type <integer_type 0x3fff849701f8
bitsizetype> constant 8>
unit-size <integer_cst 0x3fff84940f30 type <integer_type 0x3fff84970150
sizetype> constant 1>
align:8 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type
0x3fff84b38bc8 precision:8 min <integer_cst 0x3fff8494bd90 0> max <integer_cst
0x3fff8494bd48 255>>
In function 'f',
inlined from 'main' at
/src/gcc/trunk/gcc/testsuite/g++.dg/ubsan/vla-1.C:11:4:
/src/gcc/trunk/gcc/testsuite/g++.dg/ubsan/vla-1.C:6:24: warning: writing 4
bytes into a region of size 0 [-Wstringop-overflow=]
