new file mode 100644
@@ -0,0 +1,183 @@
+# Copyright 1999-2016 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 essential Machine interface (MI) operations
+#
+# Verify that -var-update will provide the correct values for floating
+# and fixed varobjs that represent the pc register.
+#
+
+load_lib mi-support.exp
+set MIFLAGS "-i=mi"
+
+standard_testfile basics.c
+
+if {[gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" \
+ executable {debug}] != "" } then {
+ untested mi-frame-regs.exp
+ return -1
+}
+
+# Return the address of the specified breakpoint.
+
+proc breakpoint_address {bpnum} {
+ global hex
+ global expect_out
+ global mi_gdb_prompt
+
+ send_gdb "info breakpoint $bpnum\n"
+ gdb_expect {
+ -re ".*($hex).*$mi_gdb_prompt$" {
+ return $expect_out(1,string)
+ }
+ -re ".*$mi_gdb_prompt$" {
+ return ""
+ }
+ timeout {
+ return ""
+ }
+ }
+}
+
+# Test that a floating varobj representing $pc will provide the
+# correct value via -var-update as the program stops at
+# breakpoints in different functions.
+
+proc do_floating_varobj_test {} {
+ global srcfile
+ global hex
+ global expect_out
+
+ gdb_exit
+ if {[mi_gdb_start]} then {
+ continue
+ }
+
+ with_test_prefix "floating" {
+ mi_run_to_main
+
+ # Create a floating varobj for $pc.
+ mi_gdb_test "-var-create --thread 1 --frame 0 - @ \$pc" \
+ "\\^done,.*value=\"$hex.*" \
+ "create varobj for pc in frame 0"
+
+ set nframes 4
+ for {set i 1} {$i < $nframes} {incr i} {
+
+ # Run to a breakpoint in each callee function in succession.
+ # Note that we can't use mi_runto because we need the
+ # breakpoint to be persistent, so we can use its address.
+ set bpnum [expr $i + 1]
+ mi_create_breakpoint \
+ "basics.c:callee$i" \
+ "insert breakpoint at basics.c:callee$i" \
+ -number $bpnum -func callee$i -file ".*basics.c"
+
+ mi_execute_to "exec-continue" "breakpoint-hit" \
+ "callee$i" ".*" ".*${srcfile}" ".*" \
+ { "" "disp=\"keep\"" } "breakpoint hit"
+
+ # Get the value of $pc from the floating varobj.
+ mi_gdb_test "-var-update 1 var1" \
+ "\\^done,.*value=\"($hex) .*" \
+ "-var-update for frame $i"
+ set pcval $expect_out(3,string)
+
+ # Get the address of the current breakpoint.
+ set bpaddr [breakpoint_address $bpnum]
+ if {$bpaddr == ""} then {
+ unresolved "get address of breakpoint $bpnum"
+ return
+ }
+
+ # Check that the addresses are the same.
+ if {[expr $bpaddr != $pcval]} then {
+ fail "\$pc does not equal address of breakpoint"
+ } else {
+ pass "\$pc equals address of breakpoint"
+ }
+ }
+ }
+}
+
+# Create a varobj for the pc register in each of the frames other
+# than frame 0.
+
+proc var_create_regs {nframes} {
+ global hex
+
+ for {set i 1} {$i < $nframes} {incr i} {
+ mi_gdb_test "-var-create --thread 1 --frame $i - \* \$pc" \
+ "\\^done,.*value=\"$hex.*" \
+ "create varobj for pc in frame $i"
+ }
+}
+
+# Check that -var-update reports that the value of the pc register
+# for each of the frames 1 and above is reported as unchanged.
+
+proc var_update_regs {nframes} {
+
+ for {set i 1} {$i < $nframes} {incr i} {
+ mi_gdb_test "-var-update 1 var$i" \
+ "\\^done,(changelist=\\\[\\\])" \
+ "pc unchanged in -var-update for frame $i"
+ }
+}
+
+# Test that fixed varobjs representing $pc in different stack frames
+# will provide the correct value via -var-update after the program
+# counter changes (without substantially changing the stack).
+
+proc do_fixed_varobj_test {} {
+ global srcfile
+
+ gdb_exit
+ if {[mi_gdb_start]} then {
+ continue
+ }
+
+ with_test_prefix "fixed" {
+ mi_run_to_main
+
+ # Run to the function 'callee3' so we have several frames.
+ mi_create_breakpoint "basics.c:callee3" \
+ "insert breakpoint at basics.c:callee3" \
+ -number 2 -func callee3 -file ".*basics.c"
+
+ mi_execute_to "exec-continue" "breakpoint-hit" \
+ "callee3" ".*" ".*${srcfile}" ".*" \
+ { "" "disp=\"keep\"" } "breakpoint hit"
+
+ # At the breakpoint in callee3 there are 4 frames. Create a
+ # varobj for the pc in each of frames 1 and above.
+ set nframes 4
+ var_create_regs $nframes
+
+ # Step one instruction to change the program counter.
+ mi_execute_to "exec-next-instruction" "end-stepping-range" \
+ "callee3" ".*" ".*${srcfile}" ".*" "" \
+ "next instruction in callee3"
+
+ # Check that -var-update reports that the values are unchanged.
+ var_update_regs $nframes
+ }
+}
+
+do_fixed_varobj_test
+do_floating_varobj_test
+
+mi_gdb_exit
+return 0
@@ -348,6 +348,14 @@ varobj_create (char *objname,
" as an expression.\n");
return NULL;
}
+ else if (var->root->exp->elts[0].opcode == OP_REGISTER)
+ {
+ /* Force the scope of a register varobj to be the global
+ block. This allows it to be associated with a frame
+ and a thread. */
+ gdb_assert (innermost_block == NULL);
+ innermost_block = block_global_block (block);
+ }
var->format = variable_default_display (var);
var->root->valid_block = innermost_block;