gdb/testsuite/gdb.cp/casts.exp

   1 # Copyright 2002, 2003, 2004, 2007, 2008, 2009, 2010
   2 # Free Software Foundation, Inc.
   3
   4 # This program is free software; you can redistribute it and/or modify
   5 # it under the terms of the GNU General Public License as published by
   6 # the Free Software Foundation; either version 3 of the License, or
   7 # (at your option) any later version.
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU General Public License
  15 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 # This file is part of the gdb testsuite
  18
  19 # Test casting, especially between class types or pointer-to-class
  20 # types.
  21
  22 # This file is part of the gdb testsuite
  23
  24 if $tracelevel then {
  25         strace $tracelevel
  26         }
  27
  28 #
  29 # test running programs
  30 #
  31
  32
  33 if { [skip_cplus_tests] } { continue }
  34
  35 set testfile "casts"
  36 set srcfile ${testfile}.cc
  37 set binfile ${objdir}/${subdir}/${testfile}
  38
  39 if [get_compiler_info ${binfile} "c++"] {
  40     return -1;
  41 }
  42
  43 if  { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug c++}] != "" } {
  44      untested casts.exp
  45      return -1
  46 }
  47
  48
  49 gdb_exit
  50 gdb_start
  51 gdb_reinitialize_dir $srcdir/$subdir
  52 gdb_load ${binfile}
  53
  54 if ![runto_main] then {
  55     perror "couldn't run to breakpoint"
  56     continue
  57 }
  58
  59 gdb_test "break [gdb_get_line_number "casts.exp: 1"]" \
  60     "Breakpoint.*at.* file .*" \
  61     ""
  62
  63 gdb_test "continue" "Breakpoint .* at .*casts.cc.*" ""
  64
  65 # Casting a pointer to a base class to a pointer to a derived class
  66 # should yield the entire derived class.  Until August 2002, GDB got
  67 # the enclosing type on `(B *) a' wrong: while the value's static type
  68 # was `B *', as it should be, the enclosing type (which is supposed to
  69 # be the dynamic type) was `A *'.  It's senseless to have a static
  70 # type derived from the dynamic type; it should be the other way
  71 # 'round.  Dereferencing this oddly typed pointer yielded a value in
  72 # which only the base class's members were initialized, since GDB uses
  73 # the enclosing type to decide how many bytes to read.  Members from
  74 # the derived class were garbage, from GDB's address space.
  75 gdb_test "print * (B *) a" ".* = {<A> = {a = 42}, b = 1729}" \
  76     "cast base class pointer to derived class pointer"
  77
  78 # Check also that we get the same results from letting the compiler do
  79 # the dereference.
  80 gdb_test "print * b" ".* = {<A> = {a = 42}, b = 1729}" \
  81     "let compiler cast base class pointer to derived class pointer"
  82
  83 # Check upcasting (it is trivial but still).
  84 gdb_test "print * (A *) b" ".* = {a = 42}" \
  85     "cast derived class pointer to base class pointer"
  86
  87 # Casting References.
  88 # Check upcasting.
  89 gdb_test "print (A &) br" ".* = .A &.* {a = 42}" \
  90     "cast derived class reference to base class reference"
  91
  92 # Check downcasting.
  93 gdb_test "print (B &) ar" ".* = .B.* {<A> = {a = 42}, b = 1729}" \
  94     "cast base class reference to derived class reference"
  95
  96 # Check compiler casting
  97 gdb_test "print br" ".* = .B.* {<A> = {a = 42}, b = 1729}" \
  98     "let compiler cast base class reference to derived class reference"
  99
 100
 101 # A few basic tests of "new" casts.
 102
 103 gdb_test "print const_cast<const B *> (b)" " = \\(const B \\*\\) $hex" \
 104     "basic test of const_cast"
 105
 106 gdb_test "print const_cast<void *> (0)" " = \\(void \\*\\) 0x0" \
 107     "const_cast of 0"
 108
 109 gdb_test "print static_cast<A *> (b)" " = \\(A \\*\\) $hex" \
 110     "basic test of static_cast"
 111
 112 gdb_test "print static_cast<A &> (*b)" " = \\(A \\&\\) @$hex: {a = 42}" \
 113     "static_cast to reference type"
 114
 115 gdb_test "print reinterpret_cast<A *> (b)" " = \\(A \\*\\) $hex" \
 116     "basic test of reinterpret_cast"
 117
 118 gdb_test "print reinterpret_cast<void> (b)" "Invalid reinterpret_cast" \
 119     "test invalid reinterpret_cast"
 120
 121 gdb_test "print reinterpret_cast<A &> (*b)" " = \\(A \\&\\) @$hex: {a = 42}" \
 122     "reinterpret_cast to reference type"
 123
 124 # Tests of dynamic_cast.
 125
 126 set nonzero_hex "0x\[0-9A-Fa-f\]\[0-9A-Fa-f\]+"
 127
 128 gdb_test "print dynamic_cast<void> (a)" \
 129     ".*must be a pointer or reference type" \
 130     "invalid dynamic_cast"
 131
 132 gdb_test "print dynamic_cast<void *> (0)" \
 133     " = \\(void \\*\\) 0x0" \
 134     "dynamic_cast of 0 to void*"
 135
 136 gdb_test "print dynamic_cast<Alpha *> (&derived)" \
 137     " = \\(Alpha \\*\\) $nonzero_hex" \
 138     "dynamic_cast simple upcast"
 139
 140 gdb_test "print dynamic_cast<Alpha *> (&doublyderived)" \
 141     " = \\(Alpha \\*\\) $nonzero_hex" \
 142     "dynamic_cast upcast to unique base"
 143
 144 gdb_test "print dynamic_cast<Alpha &> (derived)" \
 145     " = \\(Alpha \\&\\) @$nonzero_hex: {.* = $nonzero_hex}" \
 146     "dynamic_cast simple upcast to reference"
 147
 148 gdb_test "print dynamic_cast<Derived *> (ad)" \
 149     " = \\(Derived \\*\\) $nonzero_hex" \
 150     "dynamic_cast simple downcast"
 151
 152 gdb_test "print dynamic_cast<VirtuallyDerived *> (add)" \
 153     " = \\(VirtuallyDerived \\*\\) $nonzero_hex" \
 154     "dynamic_cast simple downcast to intermediate class"
 155
 156 gdb_test "print dynamic_cast<VirtuallyDerived *> (ad)" \
 157     " = \\(VirtuallyDerived \\*\\) 0x0" \
 158     "dynamic_cast to non-existing base"
 159
 160 gdb_test "print dynamic_cast<VirtuallyDerived &> (*ad)" \
 161     "dynamic_cast failed" \
 162     "dynamic_cast to reference to non-existing base"
 163
 164 gdb_test "print dynamic_cast<DoublyDerived *> (add)" \
 165     " = \\(DoublyDerived \\*\\) $nonzero_hex" \
 166     "dynamic_cast unique downcast"
 167
 168 gdb_test "print dynamic_cast<Gamma *> (add)" \
 169     " = \\(Gamma \\*\\) $nonzero_hex" \
 170     "dynamic_cast to sibling"