[PATCH] gdbserver/s390: Switch on tracepoint support.

["Marcin Kościelnicki" <koriakin@0x04.net>]

Also adds s390 support to gdb.trace testsuite.

gdb/gdbserver/ChangeLog:

	* linux-s390-low.c (s390_supports_tracepoints): New function.
	(struct linux_target_ops): Fill supports_tracepoints hook.

gdb/testsuite/ChangeLog:

	* gdb.trace/mi-trace-frame-collected.exp: Expect 4 registers on s390.
	* gdb.trace/trace-common.h: Add s390 fast tracepoint placeholder.
---
Updated.  This version depends on
https://sourceware.org/ml/gdb-patches/2016-02/msg00627.html .

 gdb/gdbserver/ChangeLog                              |  5 +++++
 gdb/gdbserver/linux-s390-low.c                       | 10 +++++++++-
 gdb/testsuite/ChangeLog                              | 10 +++++-----
 gdb/testsuite/gdb.trace/mi-trace-frame-collected.exp | 16 +++++++++++++---
 gdb/testsuite/gdb.trace/trace-common.h               |  8 ++++++++
 5 files changed, 40 insertions(+), 9 deletions(-)

diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index 326c769..6132bbf 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,5 +1,10 @@
 2016-02-17  Marcin Kościelnicki  <koriakin@0x04.net>
 
+	* linux-s390-low.c (s390_supports_tracepoints): New function.
+	(struct linux_target_ops): Fill supports_tracepoints hook.
+
+2016-02-07  Marcin Kościelnicki  <koriakin@0x04.net>
+
 	* linux-s390-low.c (s390_supports_z_point_type): New function.
 	(struct linux_target_ops): Wire s390_supports_z_point_type in.
 
diff --git a/gdb/gdbserver/linux-s390-low.c b/gdb/gdbserver/linux-s390-low.c
index 533e384..c85c331 100644
--- a/gdb/gdbserver/linux-s390-low.c
+++ b/gdb/gdbserver/linux-s390-low.c
@@ -690,6 +690,14 @@ s390_regs_info (void)
   return &regs_info;
 }
 
+/* The "supports_tracepoints" linux_target_ops method.  */
+
+static int
+s390_supports_tracepoints (void)
+{
+  return 1;
+}
+
 struct linux_target_ops the_low_target = {
   s390_arch_setup,
   s390_regs_info,
@@ -716,7 +724,7 @@ struct linux_target_ops the_low_target = {
   NULL, /* new_fork */
   NULL, /* prepare_to_resume */
   NULL, /* process_qsupported */
-  NULL, /* supports_tracepoints */
+  s390_supports_tracepoints,
   NULL, /* get_thread_area */
   NULL, /* install_fast_tracepoint_jump_pad */
   NULL, /* emit_ops */
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 8d695ec..27b2548 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2016-02-22  Marcin Kościelnicki  <koriakin@0x04.net>
+
+	* gdb.trace/mi-trace-frame-collected.exp: Expect 4 registers on s390.
+	* gdb.trace/trace-common.h: Add s390 fast tracepoint placeholder.
+
 2016-02-19  Marcin Kościelnicki  <koriakin@0x04.net>
 
 	* gdb.trace/ftrace.exp: Remove unnecessary target check.
@@ -312,11 +317,6 @@
 	(foreach_with_prefix): Likewise.
 	* lib/gdb.exp (foreach_with_prefix): New procedure.
 
-2016-01-25  Marcin Kościelnicki  <koriakin@0x04.net>
-
-	* gdb.trace/backtrace.exp: Bump stack collection fudge factor.
-	* gdb.trace/entry-values.exp: Bump stack collection fudge factor.
-
 2016-01-23  Marcin Kościelnicki  <koriakin@0x04.net>
 
 	* gdb.trace/unavailable-dwarf-piece.exp: Fix bitfield handling on big
diff --git a/gdb/testsuite/gdb.trace/mi-trace-frame-collected.exp b/gdb/testsuite/gdb.trace/mi-trace-frame-collected.exp
index 0daaa25..1f0baaa 100644
--- a/gdb/testsuite/gdb.trace/mi-trace-frame-collected.exp
+++ b/gdb/testsuite/gdb.trace/mi-trace-frame-collected.exp
@@ -91,11 +91,21 @@ proc test_trace_frame_collected { data_source } {
 	    ".*\\^done,found=\"1\",tracepoint=\"${decimal}\",traceframe=\"0\",frame=\{.*" \
 	    "-trace-find frame-number 0"
 
+	set reg_pattern "\{number=\"$decimal\",value=\"$hex\"\}"
+
 	# Test MI command '-trace-frame-collected' dumps only
 	# collected registers.
-	mi_gdb_test "-trace-frame-collected" \
-	    "\\^done,explicit-variables=\\\[\{name=\"gdb_char_test\",value=\".*\"\}\\\],computed-expressions=\\\[\\\],registers=\\\[\{number=\"$decimal\",value=\"$hex\"\}\\\],tvars=\\\[\\\],memory=\\\[\{address=\"$hex\",length=\"1\"\}\\\]"\
-	    "-trace-frame-collected (register)"
+	if { [istarget "s390*-*-*"] } {
+	    # Only PC is collected, but on s390 PC is a pseudo-register -
+	    # collecting it also collects the underlying PSWA register.
+	    mi_gdb_test "-trace-frame-collected" \
+		"\\^done,explicit-variables=\\\[\{name=\"gdb_char_test\",value=\".*\"\}\\\],computed-expressions=\\\[\\\],registers=\\\[$reg_pattern,$reg_pattern,$reg_pattern,$reg_pattern\\\],tvars=\\\[\\\],memory=\\\[\{address=\"$hex\",length=\"1\"\}\\\]"\
+		"-trace-frame-collected (register)"
+	} else {
+	    mi_gdb_test "-trace-frame-collected" \
+		"\\^done,explicit-variables=\\\[\{name=\"gdb_char_test\",value=\".*\"\}\\\],computed-expressions=\\\[\\\],registers=\\\[$reg_pattern\\\],tvars=\\\[\\\],memory=\\\[\{address=\"$hex\",length=\"1\"\}\\\]"\
+		"-trace-frame-collected (register)"
+	}
 
 	mi_gdb_test "-trace-find frame-number 1" \
 	    ".*\\^done,found=\"1\",tracepoint=\"${decimal}\",traceframe=\"1\",frame=\{.*" \
diff --git a/gdb/testsuite/gdb.trace/trace-common.h b/gdb/testsuite/gdb.trace/trace-common.h
index eceb182..a330024 100644
--- a/gdb/testsuite/gdb.trace/trace-common.h
+++ b/gdb/testsuite/gdb.trace/trace-common.h
@@ -48,6 +48,14 @@ x86_trace_dummy ()
        "    nop\n" \
        )
 
+#elif (defined __s390__)
+
+#define FAST_TRACEPOINT_LABEL(name) \
+  asm ("    .global " SYMBOL(name) "\n" \
+       SYMBOL(name) ":\n" \
+       "    mvc 0(8, %r15), 0(%r15)\n" \
+       )
+
 #else
 
 #error "unsupported architecture for trace tests"
-- 
2.7.1