diff mbox series

[11/13] gdb: remove some uses of alloca from remote.c

Message ID 4818cb026330713c1cbce9ff36a77fa6a3ec3618.1677533215.git.aburgess@redhat.com
State New
Headers
Series Remove a bunch of alloca uses |

Commit Message

Andrew Burgess Feb. 27, 2023, 9:29 p.m. UTC 
  Remove some of the uses of alloca from remote.c and replace them with
either gdb::byte_vector or std::vector<gdb_byte>.

In one case I've used std::vector<gdb_byte> because this handles
automatically zeroing the contents, and this allows me to remove an
associated memset.

There are other uses of alloca in this file (remote.c), but these are
all for types other than gdb_byte so need replacing with something
other than gdb::byte_vector.

There should be no user visible changes after this commit.
---
 gdb/remote.c | 40 ++++++++++++++++++----------------------
 1 file changed, 18 insertions(+), 22 deletions(-)
diff mbox series

Patch

diff --git a/gdb/remote.c b/gdb/remote.c
index ba7a7520cb4..3f0552e7c9e 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -8554,7 +8554,6 @@  remote_target::fetch_register_using_p (struct regcache *regcache,
   struct gdbarch *gdbarch = regcache->arch ();
   struct remote_state *rs = get_remote_state ();
   char *buf, *p;
-  gdb_byte *regp = (gdb_byte *) alloca (register_size (gdbarch, reg->regnum));
   int i;
 
   if (m_features.packet_support (PACKET_p) == PACKET_DISABLE)
@@ -8593,6 +8592,7 @@  remote_target::fetch_register_using_p (struct regcache *regcache,
     }
 
   /* Otherwise, parse and supply the value.  */
+  gdb::byte_vector regp (register_size (gdbarch, reg->regnum));
   p = buf;
   i = 0;
   while (p[0] != 0)
@@ -8603,7 +8603,7 @@  remote_target::fetch_register_using_p (struct regcache *regcache,
       regp[i++] = fromhex (p[0]) * 16 + fromhex (p[1]);
       p += 2;
     }
-  regcache->raw_supply (reg->regnum, regp);
+  regcache->raw_supply (reg->regnum, regp.data ());
   return 1;
 }
 
@@ -8862,7 +8862,7 @@  remote_target::store_register_using_P (const struct regcache *regcache,
   struct remote_state *rs = get_remote_state ();
   /* Try storing a single register.  */
   char *buf = rs->buf.data ();
-  gdb_byte *regp = (gdb_byte *) alloca (register_size (gdbarch, reg->regnum));
+  gdb::byte_vector regp (register_size (gdbarch, reg->regnum));
   char *p;
 
   if (m_features.packet_support (PACKET_P) == PACKET_DISABLE)
@@ -8873,8 +8873,8 @@  remote_target::store_register_using_P (const struct regcache *regcache,
 
   xsnprintf (buf, get_remote_packet_size (), "P%s=", phex_nz (reg->pnum, 0));
   p = buf + strlen (buf);
-  regcache->raw_collect (reg->regnum, regp);
-  bin2hex (regp, p, register_size (gdbarch, reg->regnum));
+  regcache->raw_collect (reg->regnum, regp.data ());
+  bin2hex (regp.data (), p, register_size (gdbarch, reg->regnum));
   putpkt (rs->buf);
   getpkt (&rs->buf, 0);
 
@@ -8900,30 +8900,26 @@  remote_target::store_registers_using_G (const struct regcache *regcache)
 {
   struct remote_state *rs = get_remote_state ();
   remote_arch_state *rsa = rs->get_remote_arch_state (regcache->arch ());
-  gdb_byte *regs;
-  char *p;
 
-  /* Extract all the registers in the regcache copying them into a
-     local buffer.  */
-  {
-    int i;
+  /* Extract all the registers in the REGCACHE copying them into a local
+     buffer REGS.
 
-    regs = (gdb_byte *) alloca (rsa->sizeof_g_packet);
-    memset (regs, 0, rsa->sizeof_g_packet);
-    for (i = 0; i < gdbarch_num_regs (regcache->arch ()); i++)
-      {
-	struct packet_reg *r = &rsa->regs[i];
+     Use std::vector<gdb_byte> here (instead of gdb::byte_vector) because
+     we want the contents to be zero initialized.  */
+  std::vector<gdb_byte> regs (rsa->sizeof_g_packet);
+  for (int i = 0; i < gdbarch_num_regs (regcache->arch ()); i++)
+    {
+      struct packet_reg *r = &rsa->regs[i];
 
-	if (r->in_g_packet)
-	  regcache->raw_collect (r->regnum, regs + r->offset);
-      }
-  }
+      if (r->in_g_packet)
+	regcache->raw_collect (r->regnum, regs.data () + r->offset);
+    }
 
   /* Command describes registers byte by byte,
      each byte encoded as two hex characters.  */
-  p = rs->buf.data ();
+  char *p = rs->buf.data ();
   *p++ = 'G';
-  bin2hex (regs, p, rsa->sizeof_g_packet);
+  bin2hex (regs.data (), p, rsa->sizeof_g_packet);
   putpkt (rs->buf);
   getpkt (&rs->buf, 0);
   if (packet_check_result (rs->buf) == PACKET_ERROR)