gdb/testsuite/gdb.cp/casts.exp

   1 # Copyright 2002-2022 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
  28 if { [skip_cplus_tests] } { continue }
  29
  30 standard_testfile .cc casts03.cc
  31
  32 if [get_compiler_info "c++"] {
  33     return -1
  34 }
  35
  36 if {[prepare_for_testing "failed to prepare" $testfile $srcfile {debug c++}]} {
  37     return -1
  38 }
  39
  40 if ![runto_main] then {
  41     perror "couldn't run to breakpoint"
  42     continue
  43 }
  44
  45 # Prevent symbol on address 0x0 being printed.
  46 gdb_test_no_output "set print symbol off"  \
  47     "turn of symbol printing for the first time"
  48
  49 gdb_test "break [gdb_get_line_number "casts.exp: 1"]" \
  50     "Breakpoint.*at.* file .*" \
  51     ""
  52
  53 gdb_test "continue" "Breakpoint .* at .*casts.cc.*" ""
  54
  55 # Casting a pointer to a base class to a pointer to a derived class
  56 # should yield the entire derived class.  Until August 2002, GDB got
  57 # the enclosing type on `(B *) a' wrong: while the value's static type
  58 # was `B *', as it should be, the enclosing type (which is supposed to
  59 # be the dynamic type) was `A *'.  It's senseless to have a static
  60 # type derived from the dynamic type; it should be the other way
  61 # 'round.  Dereferencing this oddly typed pointer yielded a value in
  62 # which only the base class's members were initialized, since GDB uses
  63 # the enclosing type to decide how many bytes to read.  Members from
  64 # the derived class were garbage, from GDB's address space.
  65 gdb_test "print * (B *) a" ".* = {<A> = {a = 42}, b = 1729}" \
  66     "cast base class pointer to derived class pointer"
  67
  68 # Check also that we get the same results from letting the compiler do
  69 # the dereference.
  70 gdb_test "print * b" ".* = {<A> = {a = 42}, b = 1729}" \
  71     "let compiler cast base class pointer to derived class pointer"
  72
  73 # Check upcasting (it is trivial but still).
  74 gdb_test "print * (A *) b" ".* = {a = 42}" \
  75     "cast derived class pointer to base class pointer"
  76
  77 # Casting References.
  78 # Check upcasting.
  79 gdb_test "print (A &) br" ".* = .A &.* {a = 42}" \
  80     "cast derived class reference to base class reference"
  81
  82 # Check downcasting.
  83 gdb_test "print (B &) ar" ".* = .B.* {<A> = {a = 42}, b = 1729}" \
  84     "cast base class reference to derived class reference"
  85
  86 # Check compiler casting
  87 gdb_test "print br" ".* = .B.* {<A> = {a = 42}, b = 1729}" \
  88     "let compiler cast base class reference to derived class reference"
  89
  90
  91 # A few basic tests of "new" casts.
  92
  93 gdb_test "print const_cast<const B *> (b)" " = \\(const B \\*\\) $hex" \
  94     "basic test of const_cast"
  95
  96 gdb_test "print const_cast<void *> (0)" " = \\(void \\*\\) 0x0" \
  97     "const_cast of 0"
  98
  99 gdb_test "print static_cast<A *> (b)" " = \\(A \\*\\) $hex" \
 100     "basic test of static_cast"
 101
 102 gdb_test "print static_cast<A &> (*b)" " = \\(A \\&\\) @$hex: {a = 42}" \
 103     "static_cast to reference type"
 104
 105 gdb_test "print reinterpret_cast<A *> (b)" " = \\(A \\*\\) $hex" \
 106     "basic test of reinterpret_cast"
 107
 108 gdb_test "print reinterpret_cast<void> (b)" "Invalid reinterpret_cast" \
 109     "test invalid reinterpret_cast"
 110
 111 gdb_test "print reinterpret_cast<A &> (*b)" " = \\(A \\&\\) @$hex: {a = 42}" \
 112     "reinterpret_cast to reference type"
 113
 114 # Basic tests using typeof.
 115
 116 foreach opname {__typeof__ __typeof __decltype} {
 117     gdb_test "print (${opname}(a)) (b)" " = \\(A \\*\\) $hex" \
 118         "old-style cast using $opname"
 119
 120     gdb_test "print static_cast<${opname}(a)> (b)" " = \\(A \\*\\) $hex" \
 121         "static_cast using $opname"
 122
 123     gdb_test "print reinterpret_cast<${opname}(a)> (b)" " = \\(A \\*\\) $hex" \
 124         "reinterpret_cast using $opname"
 125 }
 126
 127 gdb_test "whatis __decltype(*a)" "type = A \\&"
 128
 129 # Tests of dynamic_cast.
 130
 131 set nonzero_hex "0x\[0-9A-Fa-f\]\[0-9A-Fa-f\]+"
 132
 133 gdb_test "print dynamic_cast<void> (a)" \
 134     ".*must be a pointer or reference type" \
 135     "invalid dynamic_cast"
 136
 137 gdb_test "print dynamic_cast<void *> (0)" \
 138     " = \\(void \\*\\) 0x0" \
 139     "dynamic_cast of 0 to void*"
 140
 141 gdb_test "print dynamic_cast<Alpha *> (&derived)" \
 142     " = \\(Alpha \\*\\) $nonzero_hex" \
 143     "dynamic_cast simple upcast"
 144
 145 gdb_test "print dynamic_cast<Alpha *> (&doublyderived)" \
 146     " = \\(Alpha \\*\\) $nonzero_hex" \
 147     "dynamic_cast upcast to unique base"
 148
 149 gdb_test "print dynamic_cast<Alpha &> (derived)" \
 150     " = \\(Alpha \\&\\) @$nonzero_hex: {.* = ${nonzero_hex}( <vtable for Derived.*>)?}" \
 151     "dynamic_cast simple upcast to reference"
 152
 153 gdb_test "print dynamic_cast<Derived *> (ad)" \
 154     " = \\(Derived \\*\\) ${nonzero_hex}( <vtable for Derived.*>)?" \
 155     "dynamic_cast simple downcast"
 156
 157 gdb_test "print dynamic_cast<VirtuallyDerived *> (add)" \
 158     " = \\(VirtuallyDerived \\*\\) $nonzero_hex" \
 159     "dynamic_cast simple downcast to intermediate class"
 160
 161 gdb_test "print dynamic_cast<VirtuallyDerived *> (ad)" \
 162     " = \\(VirtuallyDerived \\*\\) 0x0" \
 163     "dynamic_cast to non-existing base"
 164
 165 gdb_test "print dynamic_cast<VirtuallyDerived &> (*ad)" \
 166     "dynamic_cast failed" \
 167     "dynamic_cast to reference to non-existing base"
 168
 169 gdb_test "print dynamic_cast<DoublyDerived *> (add)" \
 170     " = \\(DoublyDerived \\*\\) ${nonzero_hex}( <vtable for DoublyDerived.*>)?" \
 171     "dynamic_cast unique downcast"
 172
 173 gdb_test "print dynamic_cast<Gamma *> (add)" \
 174     " = \\(Gamma \\*\\) $nonzero_hex" \
 175     "dynamic_cast to sibling"
 176
 177 if {[prepare_for_testing "failed to prepare" ${testfile}03 $srcfile2 \
 178                          {debug c++ additional_flags=-std=c++03}]} {
 179     return -1
 180 }
 181
 182 if ![runto_main] then {
 183     perror "couldn't run to breakpoint"
 184     continue
 185 }
 186
 187 # Prevent symbol on address 0x0 being printed.
 188 gdb_test_no_output "set print symbol off" \
 189     "turn of symbol printing for the second time"
 190
 191 gdb_breakpoint [gdb_get_line_number "casts.exp: 1" $srcfile2]
 192 gdb_continue_to_breakpoint "end of casts03"
 193
 194 # Test that keyword shadowing works.
 195
 196 gdb_test "whatis decltype(5)" " = double"