From a56e5dce69bfad45ee6977a916ccea283e087e8b Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Tue, 5 Sep 2023 09:13:14 -0600 Subject: [PATCH] Handle pointers and references correctly in DAP A user pointed out that the current DAP variable code does not let the client deference a pointer. Oops! Fixing this oversight is simple enough -- adding a new no-op pretty-printer for pointers and references is quite simple. However, doing this naive caused a regession in scopes.exp, which expected there to be no children of a 'const char *' variable. This problem was fixed by the preceding patches in the series, which ensure that a C type of this kind is recognized as a string. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30821 --- gdb/python/lib/gdb/printing.py | 16 +++++ gdb/testsuite/gdb.dap/ptrref.cc | 34 ++++++++++ gdb/testsuite/gdb.dap/ptrref.exp | 103 +++++++++++++++++++++++++++++++ 3 files changed, 153 insertions(+) create mode 100644 gdb/testsuite/gdb.dap/ptrref.cc create mode 100644 gdb/testsuite/gdb.dap/ptrref.exp diff --git a/gdb/python/lib/gdb/printing.py b/gdb/python/lib/gdb/printing.py index 1a761a6aa57..223a69929d2 100644 --- a/gdb/python/lib/gdb/printing.py +++ b/gdb/python/lib/gdb/printing.py @@ -280,6 +280,20 @@ class NoOpScalarPrinter: return self.value.format_string(raw=True) +class NoOpPointerReferencePrinter: + """A no-op pretty printer that wraps a pointer or reference.""" + + def __init__(self, value): + self.value = value + self.num_children = 1 + + def to_string(self): + return self.value.format_string(deref_refs=False) + + def children(self): + yield "value", self.value.referenced_value() + + class NoOpArrayPrinter: """A no-op pretty printer that wraps an array value.""" @@ -354,6 +368,8 @@ def make_visualizer(value): result = gdb.printing.NoOpArrayPrinter(ty, value) elif ty.code in (gdb.TYPE_CODE_STRUCT, gdb.TYPE_CODE_UNION): result = gdb.printing.NoOpStructPrinter(ty, value) + elif ty.code in (gdb.TYPE_CODE_PTR, gdb.TYPE_CODE_REF, gdb.TYPE_CODE_RVALUE_REF): + result = NoOpPointerReferencePrinter(value) else: result = gdb.printing.NoOpScalarPrinter(value) return result diff --git a/gdb/testsuite/gdb.dap/ptrref.cc b/gdb/testsuite/gdb.dap/ptrref.cc new file mode 100644 index 00000000000..bfb1afe3d17 --- /dev/null +++ b/gdb/testsuite/gdb.dap/ptrref.cc @@ -0,0 +1,34 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2023 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 . */ + +void +func () +{ + int value = 23; + + int *ptr = &value; + int &ref = value; + + return; /* BREAK */ +} + +int +main (int argc, char *argv[]) +{ + func (); + return 0; +} diff --git a/gdb/testsuite/gdb.dap/ptrref.exp b/gdb/testsuite/gdb.dap/ptrref.exp new file mode 100644 index 00000000000..e0cc74529ab --- /dev/null +++ b/gdb/testsuite/gdb.dap/ptrref.exp @@ -0,0 +1,103 @@ +# Copyright 2023 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 . + +require allow_dap_tests + +load_lib dap-support.exp + +standard_testfile .cc + +if {[build_executable ${testfile}.exp $testfile $srcfile {debug c++}] == -1} { + return +} + +if {[dap_launch $testfile] == ""} { + return +} + +set line [gdb_get_line_number "BREAK"] +set obj [dap_check_request_and_response "set breakpoint by line number" \ + setBreakpoints \ + [format {o source [o path [%s]] breakpoints [a [o line [i %d]]]} \ + [list s $srcfile] $line]] +set line_bpno [dap_get_breakpoint_number $obj] + +dap_check_request_and_response "start inferior" configurationDone +dap_wait_for_event_and_check "inferior started" thread "body reason" started + +dap_wait_for_event_and_check "stopped at line breakpoint" stopped \ + "body reason" breakpoint \ + "body hitBreakpointIds" $line_bpno + +set bt [lindex [dap_check_request_and_response "backtrace" stackTrace \ + {o threadId [i 1]}] \ + 0] +set frame_id [dict get [lindex [dict get $bt body stackFrames] 0] id] + +set scopes [dap_check_request_and_response "get scopes" scopes \ + [format {o frameId [i %d]} $frame_id]] +set scopes [dict get [lindex $scopes 0] body scopes] + +gdb_assert {[llength $scopes] == 2} "two scopes" + +lassign $scopes scope reg_scope +gdb_assert {[dict get $scope name] == "Locals"} "scope is locals" + +gdb_assert {[dict get $scope namedVariables] == 3} "three vars in scope" + +set num [dict get $scope variablesReference] +set refs [lindex [dap_check_request_and_response "fetch variables" \ + "variables" \ + [format {o variablesReference [i %d] count [i 3]} \ + $num]] \ + 0] + +proc fetch_pointer {name var} { + set num [dict get $var variablesReference] + set refs [lindex [dap_check_request_and_response "fetch children of $name" \ + "variables" \ + [format {o variablesReference [i %d] count [i 1]} \ + $num]] \ + 0] + set var [lindex [dict get $refs body variables] 0] + gdb_assert {[dict get $var value] == 23} \ + "value of child of $name" + gdb_assert {[dict get $var variablesReference] == 0} \ + "no children for child of $name" +} + +foreach var [dict get $refs body variables] { + set name [dict get $var name] + + switch $name { + "value" { + gdb_assert {[dict get $var value] == "23"} "check value of value" + gdb_assert {[dict get $var variablesReference] == 0} \ + "$name does not have child" + } + "ptr" - + "ref" { + gdb_assert {[dict get $var variablesReference] != 0} \ + "$name has children" + # The implementation somewhat arbitrarily chooses "named" + # children here. + gdb_assert {[dict get $var namedVariables] == 1} \ + "$name has exactly one child" + fetch_pointer $name $var + } + } +} + +dap_shutdown -- 2.30.2