[4/5] Don't memset non-POD types: struct btrace_insn
Commit Message
struct btrace_insn is not a POD [1] so we shouldn't be using memset to
initialize it [2].
Use list-initialization instead, wrapped in a "pt insn to btrace insn"
function, which looks like just begging to be added next to the
existing pt_reclassify_insn/pt_btrace_insn_flags functions.
[1] - because its field "flags" is not POD, because enum_flags has a
non-trivial default ctor.
gdb/ChangeLog:
yyyy-mm-dd Pedro Alves <palves@redhat.com>
* btrace.c (pt_btrace_insn): New function.
(ftrace_add_pt): Remove memset call and use pt_btrace_insn.
---
gdb/btrace.c | 19 ++++++++++++-------
1 file changed, 12 insertions(+), 7 deletions(-)
Comments
> -----Original Message-----
> From: gdb-patches-owner@sourceware.org [mailto:gdb-patches-
> owner@sourceware.org] On Behalf Of Pedro Alves
> Sent: Thursday, April 13, 2017 4:28 AM
> To: gdb-patches@sourceware.org
> Subject: [PATCH 4/5] Don't memset non-POD types: struct btrace_insn
Hello Pedro,
> +/* Return the btrace instruction for INSN. */
> +
> +static btrace_insn
> +pt_btrace_insn (const struct pt_insn &insn)
> +{
> + return {(CORE_ADDR) insn.ip, (gdb_byte) insn.size,
> + pt_reclassify_insn (insn.iclass),
> + pt_btrace_insn_flags (&insn)};
> +}
This is the only user of pt_btrace_insn_flags. If you want, you may
change it to take a const & instead of a const *.
The patch looks good to me.
Regards,
Markus.
Intel Deutschland GmbH
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@@ -1122,6 +1122,17 @@ pt_btrace_insn_flags (const struct pt_insn *insn)
return flags;
}
+/* Return the btrace instruction for INSN. */
+
+static btrace_insn
+pt_btrace_insn (const struct pt_insn &insn)
+{
+ return {(CORE_ADDR) insn.ip, (gdb_byte) insn.size,
+ pt_reclassify_insn (insn.iclass),
+ pt_btrace_insn_flags (&insn)};
+}
+
+
/* Add function branch trace using DECODER. */
static void
@@ -1138,7 +1149,6 @@ ftrace_add_pt (struct pt_insn_decoder *decoder,
end = *pend;
for (;;)
{
- struct btrace_insn btinsn;
struct pt_insn insn;
errcode = pt_insn_sync_forward (decoder);
@@ -1150,7 +1160,6 @@ ftrace_add_pt (struct pt_insn_decoder *decoder,
break;
}
- memset (&btinsn, 0, sizeof (btinsn));
for (;;)
{
errcode = pt_insn_next (decoder, &insn, sizeof(insn));
@@ -1207,11 +1216,7 @@ ftrace_add_pt (struct pt_insn_decoder *decoder,
/* Maintain the function level offset. */
*plevel = std::min (*plevel, end->level);
- btinsn.pc = (CORE_ADDR) insn.ip;
- btinsn.size = (gdb_byte) insn.size;
- btinsn.iclass = pt_reclassify_insn (insn.iclass);
- btinsn.flags = pt_btrace_insn_flags (&insn);
-
+ btrace_insn btinsn = pt_btrace_insn (insn);
ftrace_update_insns (end, &btinsn);
}