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# Copyright 2002-2020 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/>.
# This file is part of the gdb testsuite
# Test casting, especially between class types or pointer-to-class
# types.
# This file is part of the gdb testsuite
#
# test running programs
#
if { [skip_cplus_tests] } { continue }
standard_testfile .cc casts03.cc
if [get_compiler_info "c++"] {
return -1
}
if {[prepare_for_testing "failed to prepare" $testfile $srcfile {debug c++}]} {
return -1
}
if ![runto_main] then {
perror "couldn't run to breakpoint"
continue
}
# Prevent symbol on address 0x0 being printed.
gdb_test_no_output "set print symbol off"
gdb_test "break [gdb_get_line_number "casts.exp: 1"]" \
"Breakpoint.*at.* file .*" \
""
gdb_test "continue" "Breakpoint .* at .*casts.cc.*" ""
# Casting a pointer to a base class to a pointer to a derived class
# should yield the entire derived class. Until August 2002, GDB got
# the enclosing type on `(B *) a' wrong: while the value's static type
# was `B *', as it should be, the enclosing type (which is supposed to
# be the dynamic type) was `A *'. It's senseless to have a static
# type derived from the dynamic type; it should be the other way
# 'round. Dereferencing this oddly typed pointer yielded a value in
# which only the base class's members were initialized, since GDB uses
# the enclosing type to decide how many bytes to read. Members from
# the derived class were garbage, from GDB's address space.
gdb_test "print * (B *) a" ".* = {<A> = {a = 42}, b = 1729}" \
"cast base class pointer to derived class pointer"
# Check also that we get the same results from letting the compiler do
# the dereference.
gdb_test "print * b" ".* = {<A> = {a = 42}, b = 1729}" \
"let compiler cast base class pointer to derived class pointer"
# Check upcasting (it is trivial but still).
gdb_test "print * (A *) b" ".* = {a = 42}" \
"cast derived class pointer to base class pointer"
# Casting References.
# Check upcasting.
gdb_test "print (A &) br" ".* = .A &.* {a = 42}" \
"cast derived class reference to base class reference"
# Check downcasting.
gdb_test "print (B &) ar" ".* = .B.* {<A> = {a = 42}, b = 1729}" \
"cast base class reference to derived class reference"
# Check compiler casting
gdb_test "print br" ".* = .B.* {<A> = {a = 42}, b = 1729}" \
"let compiler cast base class reference to derived class reference"
# A few basic tests of "new" casts.
gdb_test "print const_cast<const B *> (b)" " = \\(const B \\*\\) $hex" \
"basic test of const_cast"
gdb_test "print const_cast<void *> (0)" " = \\(void \\*\\) 0x0" \
"const_cast of 0"
gdb_test "print static_cast<A *> (b)" " = \\(A \\*\\) $hex" \
"basic test of static_cast"
gdb_test "print static_cast<A &> (*b)" " = \\(A \\&\\) @$hex: {a = 42}" \
"static_cast to reference type"
gdb_test "print reinterpret_cast<A *> (b)" " = \\(A \\*\\) $hex" \
"basic test of reinterpret_cast"
gdb_test "print reinterpret_cast<void> (b)" "Invalid reinterpret_cast" \
"test invalid reinterpret_cast"
gdb_test "print reinterpret_cast<A &> (*b)" " = \\(A \\&\\) @$hex: {a = 42}" \
"reinterpret_cast to reference type"
# Basic tests using typeof.
foreach opname {__typeof__ __typeof __decltype} {
gdb_test "print (${opname}(a)) (b)" " = \\(A \\*\\) $hex" \
"old-style cast using $opname"
gdb_test "print static_cast<${opname}(a)> (b)" " = \\(A \\*\\) $hex" \
"static_cast using $opname"
gdb_test "print reinterpret_cast<${opname}(a)> (b)" " = \\(A \\*\\) $hex" \
"reinterpret_cast using $opname"
}
gdb_test "whatis __decltype(*a)" "type = A \\&"
# Tests of dynamic_cast.
set nonzero_hex "0x\[0-9A-Fa-f\]\[0-9A-Fa-f\]+"
gdb_test "print dynamic_cast<void> (a)" \
".*must be a pointer or reference type" \
"invalid dynamic_cast"
gdb_test "print dynamic_cast<void *> (0)" \
" = \\(void \\*\\) 0x0" \
"dynamic_cast of 0 to void*"
gdb_test "print dynamic_cast<Alpha *> (&derived)" \
" = \\(Alpha \\*\\) $nonzero_hex" \
"dynamic_cast simple upcast"
gdb_test "print dynamic_cast<Alpha *> (&doublyderived)" \
" = \\(Alpha \\*\\) $nonzero_hex" \
"dynamic_cast upcast to unique base"
gdb_test "print dynamic_cast<Alpha &> (derived)" \
" = \\(Alpha \\&\\) @$nonzero_hex: {.* = ${nonzero_hex}( <vtable for Derived.*>)?}" \
"dynamic_cast simple upcast to reference"
gdb_test "print dynamic_cast<Derived *> (ad)" \
" = \\(Derived \\*\\) ${nonzero_hex}( <vtable for Derived.*>)?" \
"dynamic_cast simple downcast"
gdb_test "print dynamic_cast<VirtuallyDerived *> (add)" \
" = \\(VirtuallyDerived \\*\\) $nonzero_hex" \
"dynamic_cast simple downcast to intermediate class"
gdb_test "print dynamic_cast<VirtuallyDerived *> (ad)" \
" = \\(VirtuallyDerived \\*\\) 0x0" \
"dynamic_cast to non-existing base"
gdb_test "print dynamic_cast<VirtuallyDerived &> (*ad)" \
"dynamic_cast failed" \
"dynamic_cast to reference to non-existing base"
gdb_test "print dynamic_cast<DoublyDerived *> (add)" \
" = \\(DoublyDerived \\*\\) ${nonzero_hex}( <vtable for DoublyDerived.*>)?" \
"dynamic_cast unique downcast"
gdb_test "print dynamic_cast<Gamma *> (add)" \
" = \\(Gamma \\*\\) $nonzero_hex" \
"dynamic_cast to sibling"
if {[prepare_for_testing "failed to prepare" ${testfile}03 $srcfile2 \
{debug c++ additional_flags=-std=c++03}]} {
return -1
}
if ![runto_main] then {
perror "couldn't run to breakpoint"
continue
}
# Prevent symbol on address 0x0 being printed.
gdb_test_no_output "set print symbol off"
gdb_breakpoint [gdb_get_line_number "casts.exp: 1" $srcfile2]
gdb_continue_to_breakpoint "end of casts03"
# Test that keyword shadowing works.
gdb_test "whatis decltype(5)" " = double"
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