diff mbox

[4/5] Don't memset non-POD types: struct btrace_insn

Message ID 1492050475-9238-5-git-send-email-palves@redhat.com
State New, archived
Headers

Commit Message

Pedro Alves April 13, 2017, 2:27 a.m. UTC 
  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

Metzger, Markus T April 13, 2017, 7:53 a.m. UTC | #1 
> -----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.

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diff mbox

Patch

diff --git a/gdb/btrace.c b/gdb/btrace.c
index 95dc7ab..30359b6 100644
--- a/gdb/btrace.c
+++ b/gdb/btrace.c
@@ -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);
 	}