[PATCH v3] Enable tracing of pseudo-registers on ARM

Antoine Tremblay
2016-02-19T19:29:01Z

In this v3:
* Use gdbarch_remote_register_number to get the remote/tsec register number
Thanks to Pedro for pointing me in the right direction.
-

This patch implements the ax_pseudo_register_push_stack and
ax_pseudo_register_collect gdbarch functions so that a pseudo-register can
be traced.

No regressions, tested on ubuntu 14.04 ARMv7 and x86.
With gdbserver-{native,extended} / { -marm -mthumb }

gdb/ChangeLog:

* arm-tdep.c (arm_pseudo_register_to_register): New function.
(arm_ax_pseudo_register_collect): New function.
(arm_ax_pseudo_register_push_stack): New function.
(arm_gdbarch_init): Set
gdbarch_ax_pseudo_register_{collect,push_stack} functions.

gdb/testsuite/ChangeLog:

* gdb.trace/tfile-avx.c: Move to...
* gdb.trace/tracefile-pseudo-reg.c: Here.
* gdb.trace/tfile-avx.exp: Move to...
* gdb.trace/tracefile-pseudo-reg.exp: Here.
---
gdb/arm-tdep.c | 71 ++++++++++++++++++
gdb/testsuite/gdb.trace/tfile-avx.c | 53 -------------
gdb/testsuite/gdb.trace/tfile-avx.exp | 73 ------------------
gdb/testsuite/gdb.trace/tracefile-pseudo-reg.c | 65 ++++++++++++++++
gdb/testsuite/gdb.trace/tracefile-pseudo-reg.exp | 94 ++++++++++++++++++++++++
5 files changed, 230 insertions(+), 126 deletions(-)
delete mode 100644 gdb/testsuite/gdb.trace/tfile-avx.c
delete mode 100644 gdb/testsuite/gdb.trace/tfile-avx.exp
create mode 100644 gdb/testsuite/gdb.trace/tracefile-pseudo-reg.c
create mode 100644 gdb/testsuite/gdb.trace/tracefile-pseudo-reg.exp

diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c
index ccfefa8..1728de1 100644
--- a/gdb/arm-tdep.c
+++ b/gdb/arm-tdep.c
@@ -8718,6 +8718,73 @@ arm_pseudo_write (struct gdbarch *gdbarch, struct regcache *regcache,
}
}

+/* Map the pseudo register number REG to the proper register number. */
+
+static int
+arm_pseudo_register_to_register (struct gdbarch *gdbarch, int reg)
+{
+ int double_regnum = 0;
+ int num_regs = gdbarch_num_regs (gdbarch);
+ char name_buf[4];
+
+ /* Single precision pseudo registers. s0-s31. */
+ if (reg >= num_regs && reg < num_regs + 32)
+ {
+ xsnprintf (name_buf, sizeof (name_buf), "d%d", (reg - num_regs) / 2);
+ double_regnum = user_reg_map_name_to_regnum (gdbarch, name_buf,
+ strlen (name_buf));
+ }
+ /* Quadruple precision pseudo regisers. q0-q15. */
+ else if (reg >= num_regs + 32 && reg < num_regs + 32 + 16)
+ {
+ xsnprintf (name_buf, sizeof (name_buf), "d%d", (reg - num_regs - 32) * 2);
+ double_regnum = user_reg_map_name_to_regnum (gdbarch, name_buf,
+ strlen (name_buf));
+ }
+ /* Error bad register number. */
+ else
+ return -1;
+
+ /* Get the remote/tdesc register number. */
+ double_regnum = gdbarch_remote_register_number (gdbarch, double_regnum);
+
+ return double_regnum;
+}
+
+/* Implementation of the ax_pseudo_register_collect gdbarch function. */
+
+static int
+arm_ax_pseudo_register_collect (struct gdbarch *gdbarch,
+ struct agent_expr *ax, int reg)
+{
+ int rawnum = arm_pseudo_register_to_register (gdbarch, reg);
+
+ /* Error. */
+ if (rawnum < 0)
+ return 1;
+
+ ax_reg_mask (ax, rawnum);
+
+ return 0;
+}
+
+/* Implementation of the ax_pseudo_register_push_stack gdbarch function. */
+
+static int
+arm_ax_pseudo_register_push_stack (struct gdbarch *gdbarch,
+ struct agent_expr *ax, int reg)
+{
+ int rawnum = arm_pseudo_register_to_register (gdbarch, reg);
+
+ /* Error. */
+ if (rawnum < 0)
+ return 1;
+
+ ax_reg (ax, rawnum);
+
+ return 0;
+}
+
static struct value *
value_of_arm_user_reg (struct frame_info *frame, const void *baton)
{
@@ -9379,6 +9446,10 @@ arm_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
set_gdbarch_num_pseudo_regs (gdbarch, num_pseudos);
set_gdbarch_pseudo_register_read (gdbarch, arm_pseudo_read);
set_gdbarch_pseudo_register_write (gdbarch, arm_pseudo_write);
+ set_gdbarch_ax_pseudo_register_push_stack
+ (gdbarch, arm_ax_pseudo_register_push_stack);
+ set_gdbarch_ax_pseudo_register_collect
+ (gdbarch, arm_ax_pseudo_register_collect);
}

if (tdesc_data)
diff --git a/gdb/testsuite/gdb.trace/tfile-avx.c b/gdb/testsuite/gdb.trace/tfile-avx.c
deleted file mode 100644
index 3cc3ec0..0000000
--- a/gdb/testsuite/gdb.trace/tfile-avx.c
+++ /dev/null
@@ -1,53 +0,0 @@
-/* This testcase is part of GDB, the GNU debugger.
-
- Copyright 2016 Free Software Foundation, Inc.
-
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 3 of the License, or
- (at your option) any later version.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>. */
-
-/*
- * Test program for reading target description from tfile: collects AVX
- * registers on x86_64.
- */
-
-#include <immintrin.h>
-
-void
-dummy (void)
-{
-}
-
-static void
-end (void)
-{
-}
-
-int
-main (void)
-{
- /* Strictly speaking, it should be ymm15 (xmm15 is 128-bit), but gcc older
- than 4.9 doesn't recognize "ymm15" as a valid register name. */
- register __v8si a asm("xmm15") = {
- 0x12340001,
- 0x12340002,
- 0x12340003,
- 0x12340004,
- 0x12340005,
- 0x12340006,
- 0x12340007,
- 0x12340008,
- };
- asm volatile ("traceme: call dummy" : : "x" (a));
- end ();
- return 0;
-}
diff --git a/gdb/testsuite/gdb.trace/tfile-avx.exp b/gdb/testsuite/gdb.trace/tfile-avx.exp
deleted file mode 100644
index 4c52c64..0000000
--- a/gdb/testsuite/gdb.trace/tfile-avx.exp
+++ /dev/null
@@ -1,73 +0,0 @@
-# Copyright 2016 Free Software Foundation, Inc.
-# This program is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 3 of the License, or
-# (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program. If not, see <http://www.gnu.org/licenses/>.
-
-if { ! [is_amd64_regs_target] } {
- verbose "Skipping tfile AVX test (target is not x86_64)."
- return
-}
-
-load_lib "trace-support.exp"
-
-standard_testfile
-
-if {[prepare_for_testing $testfile.exp $testfile $srcfile \
- [list debug additional_flags=-mavx]]} {
- return -1
-}
-
-if ![runto_main] {
- fail "Can't run to main to check for trace support"
- return -1
-}
-
-if ![gdb_target_supports_trace] {
- unsupported "target does not support trace"
- return -1
-}
-
-gdb_test_multiple "print \$ymm15" "check for AVX support" {
- -re " = void.*$gdb_prompt $" {
- verbose "Skipping tfile AVX test (target doesn't support AVX)."
- return
- }
- -re " = \\{.*}.*$gdb_prompt $" {
- # All is well.
- }
-}
-
-gdb_test "trace traceme" ".*"
-
-gdb_trace_setactions "set actions for tracepoint" "" \
- "collect \$ymm15" "^$"
-
-gdb_breakpoint "end"
-
-gdb_test_no_output "tstart"
-
-gdb_test "continue" ".*Breakpoint $decimal, end .*"
-
-set tracefile [standard_output_file ${testfile}]
-
-# Save trace frames to tfile.
-gdb_test "tsave ${tracefile}.tf" \
- "Trace data saved to file '${tracefile}.tf'.*" \
- "save tfile trace file"
-
-# Change target to tfile.
-gdb_test "target tfile ${tracefile}.tf" "" "change to tfile target" \
- "A program is being debugged already. Kill it. .y or n. $" "y"
-
-gdb_test "tfind 0" "Found trace frame 0, tracepoint .*"
-
-gdb_test "print/x \$ymm15.v8_int32" " = \\{0x12340001, .*, 0x12340008}"
diff --git a/gdb/testsuite/gdb.trace/tracefile-pseudo-reg.c b/gdb/testsuite/gdb.trace/tracefile-pseudo-reg.c
new file mode 100644
index 0000000..473d805
--- /dev/null
+++ b/gdb/testsuite/gdb.trace/tracefile-pseudo-reg.c
@@ -0,0 +1,65 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2016 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+/*
+ * Test program for reading target description from tfile: collects AVX
+ * registers on x86_64.
+ */
+
+#if (defined __x86_64__)
+#include <immintrin.h>
+#elif (defined __arm__ || defined __thumb2__ || defined __thumb__)
+#include <arm_neon.h>
+#endif
+
+void
+dummy (void)
+{
+}
+
+static void
+end (void)
+{
+}
+
+int
+main (void)
+{
+ /* Strictly speaking, it should be ymm15 (xmm15 is 128-bit), but gcc older
+ than 4.9 doesn't recognize "ymm15" as a valid register name. */
+#if (defined __x86_64__)
+ register __v8si a asm("xmm15") = {
+ 0x12340001,
+ 0x12340002,
+ 0x12340003,
+ 0x12340004,
+ 0x12340005,
+ 0x12340006,
+ 0x12340007,
+ 0x12340008,
+ };
+ asm volatile ("traceme: call dummy" : : "x" (a));
+#elif (defined __arm__ || defined __thumb2__ || defined __thumb__)
+ register uint32_t a asm("s5") = {
+ 0x2
+ };
+ asm volatile ("traceme: bl dummy" : : "x" (a));
+#endif
+
+ end ();
+ return 0;
+}
diff --git a/gdb/testsuite/gdb.trace/tracefile-pseudo-reg.exp b/gdb/testsuite/gdb.trace/tracefile-pseudo-reg.exp
new file mode 100644
index 0000000..12a2740
--- /dev/null
+++ b/gdb/testsuite/gdb.trace/tracefile-pseudo-reg.exp
@@ -0,0 +1,94 @@
+# Copyright 2016 Free Software Foundation, Inc.
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+if { ! [is_amd64_regs_target] && ! [istarget "arm*-*-*"] } {
+ verbose "Skipping tracefile pseudo register tests, target is not supported."
+ return
+}
+
+load_lib "trace-support.exp"
+
+standard_testfile
+
+if { [is_amd64_regs_target] } {
+ set add_flags "-mavx"
+} elseif { [istarget "arm*-*-*"] } {
+ set add_flags "-mfpu=neon"
+}
+
+if {[prepare_for_testing $testfile.exp $testfile $srcfile \
+ [list debug additional_flags=$add_flags]]} {
+ return -1
+}
+
+if ![runto_main] {
+ fail "Can't run to main to check for trace support"
+ return -1
+}
+
+if ![gdb_target_supports_trace] {
+ unsupported "target does not support trace"
+ return -1
+}
+
+if { [is_amd64_regs_target] } {
+ set reg "\$ymm15"
+ set reg_message "check for AVX support"
+} elseif { [istarget "arm*-*-*"] } {
+ set reg "\$s5"
+ set reg_message "check for Neon support"
+}
+
+gdb_test_multiple "print $reg" $reg_message {
+ -re " = void.*$gdb_prompt $" {
+ verbose "Skipping tracefile pseudo register tests, target is not supported."
+ return
+ }
+ -re " = \\{.*}.*$gdb_prompt $" {
+ # All is well.
+ }
+ -re " = 0.*$gdb_prompt $" {
+ # All is well.
+ }
+}
+
+gdb_test "trace traceme" ".*"
+
+gdb_trace_setactions "set actions for tracepoint" "" \
+ "collect $reg" "^$"
+
+gdb_breakpoint "end"
+
+gdb_test_no_output "tstart"
+
+gdb_test "continue" ".*Breakpoint $decimal, end .*"
+
+set tracefile [standard_output_file ${testfile}]
+
+# Save trace frames to tfile.
+gdb_test "tsave ${tracefile}.tf" \
+ "Trace data saved to file '${tracefile}.tf'.*" \
+ "save tfile trace file"
+
+# Change target to tfile.
+gdb_test "target tfile ${tracefile}.tf" "" "change to tfile target" \
+ "A program is being debugged already. Kill it. .y or n. $" "y"
+
+gdb_test "tfind 0" "Found trace frame 0, tracepoint .*"
+
+if { [is_amd64_regs_target] } {
+ gdb_test "print/x \$ymm15.v8_int32" " = \\{0x12340001, .*, 0x12340008}"
+} elseif { [istarget "arm*-*-*"] } {
+ gdb_test "print \$s5" "2.80259693e-45"
+}
--
2.6.4