gdb/testsuite/gdb.cp/casts.exp

   1 # Copyright 2002-2019 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
  48 gdb_test "break [gdb_get_line_number "casts.exp: 1"]" \
  49     "Breakpoint.*at.* file .*" \
  50     ""
  51
  52 gdb_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.
  64 gdb_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.
  69 gdb_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).
  73 gdb_test "print * (A *) b" ".* = {a = 42}" \
  74     "cast derived class pointer to base class pointer"
  75
  76 # Casting References.
  77 # Check upcasting.
  78 gdb_test "print (A &) br" ".* = .A &.* {a = 42}" \
  79     "cast derived class reference to base class reference"
  80
  81 # Check downcasting.
  82 gdb_test "print (B &) ar" ".* = .B.* {<A> = {a = 42}, b = 1729}" \
  83     "cast base class reference to derived class reference"
  84
  85 # Check compiler casting
  86 gdb_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
  92 gdb_test "print const_cast<const B *> (b)" " = \\(const B \\*\\) $hex" \
  93     "basic test of const_cast"
  94
  95 gdb_test "print const_cast<void *> (0)" " = \\(void \\*\\) 0x0" \
  96     "const_cast of 0"
  97
  98 gdb_test "print static_cast<A *> (b)" " = \\(A \\*\\) $hex" \
  99     "basic test of static_cast"
 100
 101 gdb_test "print static_cast<A &> (*b)" " = \\(A \\&\\) @$hex: {a = 42}" \
 102     "static_cast to reference type"
 103
 104 gdb_test "print reinterpret_cast<A *> (b)" " = \\(A \\*\\) $hex" \
 105     "basic test of reinterpret_cast"
 106
 107 gdb_test "print reinterpret_cast<void> (b)" "Invalid reinterpret_cast" \
 108     "test invalid reinterpret_cast"
 109
 110 gdb_test "print reinterpret_cast<A &> (*b)" " = \\(A \\&\\) @$hex: {a = 42}" \
 111     "reinterpret_cast to reference type"
 112
 113 # Basic tests using typeof.
 114
 115 foreach opname {__typeof__ __typeof __decltype} {
 116     gdb_test "print (${opname}(a)) (b)" " = \\(A \\*\\) $hex" \
 117         "old-style cast using $opname"
 118
 119     gdb_test "print static_cast<${opname}(a)> (b)" " = \\(A \\*\\) $hex" \
 120         "static_cast using $opname"
 121
 122     gdb_test "print reinterpret_cast<${opname}(a)> (b)" " = \\(A \\*\\) $hex" \
 123         "reinterpret_cast using $opname"
 124 }
 125
 126 gdb_test "whatis __decltype(*a)" "type = A \\&"
 127
 128 # Tests of dynamic_cast.
 129
 130 set nonzero_hex "0x\[0-9A-Fa-f\]\[0-9A-Fa-f\]+"
 131
 132 gdb_test "print dynamic_cast<void> (a)" \
 133     ".*must be a pointer or reference type" \
 134     "invalid dynamic_cast"
 135
 136 gdb_test "print dynamic_cast<void *> (0)" \
 137     " = \\(void \\*\\) 0x0" \
 138     "dynamic_cast of 0 to void*"
 139
 140 gdb_test "print dynamic_cast<Alpha *> (&derived)" \
 141     " = \\(Alpha \\*\\) $nonzero_hex" \
 142     "dynamic_cast simple upcast"
 143
 144 gdb_test "print dynamic_cast<Alpha *> (&doublyderived)" \
 145     " = \\(Alpha \\*\\) $nonzero_hex" \
 146     "dynamic_cast upcast to unique base"
 147
 148 gdb_test "print dynamic_cast<Alpha &> (derived)" \
 149     " = \\(Alpha \\&\\) @$nonzero_hex: {.* = ${nonzero_hex}( <vtable for Derived.*>)?}" \
 150     "dynamic_cast simple upcast to reference"
 151
 152 gdb_test "print dynamic_cast<Derived *> (ad)" \
 153     " = \\(Derived \\*\\) ${nonzero_hex}( <vtable for Derived.*>)?" \
 154     "dynamic_cast simple downcast"
 155
 156 gdb_test "print dynamic_cast<VirtuallyDerived *> (add)" \
 157     " = \\(VirtuallyDerived \\*\\) $nonzero_hex" \
 158     "dynamic_cast simple downcast to intermediate class"
 159
 160 gdb_test "print dynamic_cast<VirtuallyDerived *> (ad)" \
 161     " = \\(VirtuallyDerived \\*\\) 0x0" \
 162     "dynamic_cast to non-existing base"
 163
 164 gdb_test "print dynamic_cast<VirtuallyDerived &> (*ad)" \
 165     "dynamic_cast failed" \
 166     "dynamic_cast to reference to non-existing base"
 167
 168 gdb_test "print dynamic_cast<DoublyDerived *> (add)" \
 169     " = \\(DoublyDerived \\*\\) ${nonzero_hex}( <vtable for DoublyDerived.*>)?" \
 170     "dynamic_cast unique downcast"
 171
 172 gdb_test "print dynamic_cast<Gamma *> (add)" \
 173     " = \\(Gamma \\*\\) $nonzero_hex" \
 174     "dynamic_cast to sibling"
 175
 176 if {[prepare_for_testing "failed to prepare" ${testfile}03 $srcfile2 \
 177                          {debug c++ additional_flags=-std=c++03}]} {
 178     return -1
 179 }
 180
 181 if ![runto_main] then {
 182     perror "couldn't run to breakpoint"
 183     continue
 184 }
 185
 186 # Prevent symbol on address 0x0 being printed.
 187 gdb_test_no_output "set print symbol off"
 188
 189 gdb_breakpoint [gdb_get_line_number "casts.exp: 1" $srcfile2]
 190 gdb_continue_to_breakpoint "end of casts03"
 191
 192 # Test that keyword shadowing works.
 193
 194 gdb_test "whatis decltype(5)" " = double"