casts.exp revision 1.5
1# Copyright 2002-2015 Free Software Foundation, Inc. 2 3# This program is free software; you can redistribute it and/or modify 4# it under the terms of the GNU General Public License as published by 5# the Free Software Foundation; either version 3 of the License, or 6# (at your option) any later version. 7# 8# This program is distributed in the hope that it will be useful, 9# but WITHOUT ANY WARRANTY; without even the implied warranty of 10# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11# GNU General Public License for more details. 12# 13# You should have received a copy of the GNU General Public License 14# along with this program. If not, see <http://www.gnu.org/licenses/>. 15 16# This file is part of the gdb testsuite 17 18# Test casting, especially between class types or pointer-to-class 19# types. 20 21# This file is part of the gdb testsuite 22 23# 24# test running programs 25# 26 27 28if { [skip_cplus_tests] } { continue } 29 30standard_testfile .cc 31 32if [get_compiler_info "c++"] { 33 return -1 34} 35 36if {[prepare_for_testing $testfile.exp $testfile $srcfile {debug c++}]} { 37 return -1 38} 39 40if ![runto_main] then { 41 perror "couldn't run to breakpoint" 42 continue 43} 44 45# Prevent symbol on address 0x0 being printed. 46gdb_test_no_output "set print symbol off" 47 48gdb_test "break [gdb_get_line_number "casts.exp: 1"]" \ 49 "Breakpoint.*at.* file .*" \ 50 "" 51 52gdb_test "continue" "Breakpoint .* at .*casts.cc.*" "" 53 54# Casting a pointer to a base class to a pointer to a derived class 55# should yield the entire derived class. Until August 2002, GDB got 56# the enclosing type on `(B *) a' wrong: while the value's static type 57# was `B *', as it should be, the enclosing type (which is supposed to 58# be the dynamic type) was `A *'. It's senseless to have a static 59# type derived from the dynamic type; it should be the other way 60# 'round. Dereferencing this oddly typed pointer yielded a value in 61# which only the base class's members were initialized, since GDB uses 62# the enclosing type to decide how many bytes to read. Members from 63# the derived class were garbage, from GDB's address space. 64gdb_test "print * (B *) a" ".* = {<A> = {a = 42}, b = 1729}" \ 65 "cast base class pointer to derived class pointer" 66 67# Check also that we get the same results from letting the compiler do 68# the dereference. 69gdb_test "print * b" ".* = {<A> = {a = 42}, b = 1729}" \ 70 "let compiler cast base class pointer to derived class pointer" 71 72# Check upcasting (it is trivial but still). 73gdb_test "print * (A *) b" ".* = {a = 42}" \ 74 "cast derived class pointer to base class pointer" 75 76# Casting References. 77# Check upcasting. 78gdb_test "print (A &) br" ".* = .A &.* {a = 42}" \ 79 "cast derived class reference to base class reference" 80 81# Check downcasting. 82gdb_test "print (B &) ar" ".* = .B.* {<A> = {a = 42}, b = 1729}" \ 83 "cast base class reference to derived class reference" 84 85# Check compiler casting 86gdb_test "print br" ".* = .B.* {<A> = {a = 42}, b = 1729}" \ 87 "let compiler cast base class reference to derived class reference" 88 89 90# A few basic tests of "new" casts. 91 92gdb_test "print const_cast<const B *> (b)" " = \\(const B \\*\\) $hex" \ 93 "basic test of const_cast" 94 95gdb_test "print const_cast<void *> (0)" " = \\(void \\*\\) 0x0" \ 96 "const_cast of 0" 97 98gdb_test "print static_cast<A *> (b)" " = \\(A \\*\\) $hex" \ 99 "basic test of static_cast" 100 101gdb_test "print static_cast<A &> (*b)" " = \\(A \\&\\) @$hex: {a = 42}" \ 102 "static_cast to reference type" 103 104gdb_test "print reinterpret_cast<A *> (b)" " = \\(A \\*\\) $hex" \ 105 "basic test of reinterpret_cast" 106 107gdb_test "print reinterpret_cast<void> (b)" "Invalid reinterpret_cast" \ 108 "test invalid reinterpret_cast" 109 110gdb_test "print reinterpret_cast<A &> (*b)" " = \\(A \\&\\) @$hex: {a = 42}" \ 111 "reinterpret_cast to reference type" 112 113# Test that keyword shadowing works. 114 115gdb_test "whatis decltype(5)" " = double" 116 117# Basic tests using typeof. 118 119foreach opname {__typeof__ __typeof __decltype} { 120 gdb_test "print (${opname}(a)) (b)" " = \\(A \\*\\) $hex" \ 121 "old-style cast using $opname" 122 123 gdb_test "print static_cast<${opname}(a)> (b)" " = \\(A \\*\\) $hex" \ 124 "static_cast using $opname" 125 126 gdb_test "print reinterpret_cast<${opname}(a)> (b)" " = \\(A \\*\\) $hex" \ 127 "reinterpret_cast using $opname" 128} 129 130gdb_test "whatis __decltype(*a)" "type = A \\&" 131 132# Tests of dynamic_cast. 133 134set nonzero_hex "0x\[0-9A-Fa-f\]\[0-9A-Fa-f\]+" 135 136gdb_test "print dynamic_cast<void> (a)" \ 137 ".*must be a pointer or reference type" \ 138 "invalid dynamic_cast" 139 140gdb_test "print dynamic_cast<void *> (0)" \ 141 " = \\(void \\*\\) 0x0" \ 142 "dynamic_cast of 0 to void*" 143 144gdb_test "print dynamic_cast<Alpha *> (&derived)" \ 145 " = \\(Alpha \\*\\) $nonzero_hex" \ 146 "dynamic_cast simple upcast" 147 148gdb_test "print dynamic_cast<Alpha *> (&doublyderived)" \ 149 " = \\(Alpha \\*\\) $nonzero_hex" \ 150 "dynamic_cast upcast to unique base" 151 152gdb_test "print dynamic_cast<Alpha &> (derived)" \ 153 " = \\(Alpha \\&\\) @$nonzero_hex: {.* = ${nonzero_hex}( <vtable for Derived.*>)?}" \ 154 "dynamic_cast simple upcast to reference" 155 156gdb_test "print dynamic_cast<Derived *> (ad)" \ 157 " = \\(Derived \\*\\) ${nonzero_hex}( <vtable for Derived.*>)?" \ 158 "dynamic_cast simple downcast" 159 160gdb_test "print dynamic_cast<VirtuallyDerived *> (add)" \ 161 " = \\(VirtuallyDerived \\*\\) $nonzero_hex" \ 162 "dynamic_cast simple downcast to intermediate class" 163 164gdb_test "print dynamic_cast<VirtuallyDerived *> (ad)" \ 165 " = \\(VirtuallyDerived \\*\\) 0x0" \ 166 "dynamic_cast to non-existing base" 167 168gdb_test "print dynamic_cast<VirtuallyDerived &> (*ad)" \ 169 "dynamic_cast failed" \ 170 "dynamic_cast to reference to non-existing base" 171 172gdb_test "print dynamic_cast<DoublyDerived *> (add)" \ 173 " = \\(DoublyDerived \\*\\) ${nonzero_hex}( <vtable for DoublyDerived.*>)?" \ 174 "dynamic_cast unique downcast" 175 176gdb_test "print dynamic_cast<Gamma *> (add)" \ 177 " = \\(Gamma \\*\\) $nonzero_hex" \ 178 "dynamic_cast to sibling" 179