gdb:

	* common/agent.c (struct ipa_sym_addresses) <addr_capability>: New.
	(agent_capability_check, agent_capability_invalidate): New.
	(symbol_list): New array element.
	* common/agent.h (enum agent_capa): New.
	* target.c (target_pre_inferior): Call agent_capability_invalidate.

gdb/gdbserver:
	* tracepoint.c (gdb_agent_capability): New global.
	(in_process_agent_loaded_ust): Renamed to
	`in_process_agent_supports_ust'.
	Update callers.
	(in_process_agent_supports_ust): Call agent_capability_check.
	(clear_installed_tracepoints): Assert that agent supports
	agent.

2 files changed, 57 insertions, 0 deletions

diff --git a/gdb/common/agent.c b/gdb/common/agent.c
index 2bd3206d3e9..f3bdafcfaeb 100644
--- a/gdb/common/agent.c
+++ b/gdb/common/agent.c
@@ -51,6 +51,7 @@ struct ipa_sym_addresses
 {
   CORE_ADDR addr_helper_thread_id;
   CORE_ADDR addr_cmd_buf;
+  CORE_ADDR addr_capability;
 };
 
 /* Cache of the helper thread id.  FIXME: this global should be made
@@ -65,6 +66,7 @@ static struct
 } symbol_list[] = {
   IPA_SYM(helper_thread_id),
   IPA_SYM(cmd_buf),
+  IPA_SYM(capability),
 };
 
 static struct ipa_sym_addresses ipa_sym_addrs;
@@ -303,3 +305,41 @@ agent_run_command (int pid, const char *cmd)
 
   return 0;
 }
+
+/* Each bit of it stands for a capability of agent.  */
+static unsigned int agent_capability = 0;
+
+/* Return true if agent has capability AGENT_CAP, otherwise return false.  */
+
+int
+agent_capability_check (enum agent_capa agent_capa)
+{
+  if (agent_capability == 0)
+    {
+#ifdef GDBSERVER
+      if (read_inferior_memory (ipa_sym_addrs.addr_capability,
+				(unsigned char *) &agent_capability,
+				sizeof agent_capability))
+#else
+      enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);
+      gdb_byte buf[4];
+
+      if (target_read_memory (ipa_sym_addrs.addr_capability,
+			      buf, sizeof buf) == 0)
+	agent_capability = extract_unsigned_integer (buf, sizeof buf,
+						     byte_order);
+      else
+#endif
+	warning ("Error reading capability of agent");
+    }
+  return agent_capability & agent_capa;
+}
+
+/* Invalidate the cache of agent capability, so we'll read it from inferior
+   again.  Call it when launches a new program or reconnect to remote stub.  */
+
+void
+agent_capability_invalidate (void)
+{
+  agent_capability = 0;
+}
diff --git a/gdb/common/agent.h b/gdb/common/agent.h
index 296521579ca..a1ac9b20d23 100644
--- a/gdb/common/agent.h
+++ b/gdb/common/agent.h
@@ -36,3 +36,20 @@ int agent_look_up_symbols (void);
 extern int debug_agent;
 
 extern int use_agent;
+
+/* Capability of agent.  Different agents may have different capabilities,
+   such as installing fast tracepoint or evaluating breakpoint conditions.
+   Capabilities are represented by bit-maps, and each capability occupies one
+   bit.  */
+
+enum agent_capa
+{
+  /* Capability to install fast tracepoint.  */
+  AGENT_CAPA_FAST_TRACE = 0x1,
+  /* Capability to install static tracepoint.  */
+  AGENT_CAPA_STATIC_TRACE = (0x1 << 1),
+};
+
+int agent_capability_check (enum agent_capa);
+
+void agent_capability_invalidate (void);