binutils-gdb/gdb/testsuite/gdb.cp/align.exp

# Copyright 2018-2022 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

# This tests that C++ alignof works in gdb, and that it agrees with
# the compiler.

if {[skip_cplus_tests]} { continue }

# The types we're going to test.

set typelist {
    char {unsigned char}
    short {unsigned short}
    int {unsigned int}
    long {unsigned long}
    {long long} {unsigned long long}
    float
    double {long double}
    empty
    bigenum
    vstruct
    bfstruct
    arrstruct
    derived
    derived2
}

if {[has_int128_cxx]} {
    # Note we don't check "unsigned __int128" yet because at least gcc
    # canonicalizes the name to "__int128 unsigned", and there isn't a
    # c-exp.y production for this.
    # https://sourceware.org/bugzilla/show_bug.cgi?id=20991
    lappend typelist __int128
}

# Create the test file.

set filename [standard_output_file align.cc]
set outfile [open $filename w]

# Prologue.
puts $outfile {
    template<typename T, typename U>
    struct align_pair
    {
	T one;
	U two;
    };

    template<typename T, typename U>
    struct align_union
    {
	T one;
	U two;
    };

    enum bigenum { VALUE = 0xffffffffull };

    struct empty { };

    struct vstruct { virtual ~vstruct() {}  char c; };

    struct bfstruct { unsigned b : 3; };

    struct arrstruct { short fld[7]; };

    unsigned a_int3 = alignof (int[3]);

#if defined __GNUC__ && !defined __clang__
    /* As a GNU C extension, GCC allows void pointer arithmetic, with
       sizeof (void) == 1.
       Another GNU C extension is __alignof__, which can be used to get
       __alignof__ (void), which is also 1.  This is unavailabe on clang.
       GCC used to only warn for alignof (void), but starting with GCC 12.1,
       as well as GCC 11.3, it will generate an error (note that using
       -std=gnu++11 does not prevent the error).
       So we avoid using alignof, and use __alignof__ instead.  */
    unsigned a_void = __alignof__ (void);
#else
    /* No support for __alignof__ (void), hardcode value.  */
    unsigned a_void = 1;
#endif

    struct base { char c; };
    struct derived : public virtual base { int i; };

    struct b2 : public virtual base { char d; };
    struct derived2 : public b2, derived { char e; };
}

# First emit single items.
foreach type $typelist {
    set utype [join [split $type] _]
    puts $outfile "$type item_$utype;"
    puts $outfile "unsigned a_$utype\n  = alignof ($type);"
    puts $outfile "typedef $type t_$utype;"
    puts $outfile "t_$utype item_t_$utype;"
}

# Now emit all pairs.
foreach type $typelist {
    set utype [join [split $type] _]
    foreach inner $typelist {
	set uinner [join [split $inner] _]
	puts $outfile "align_pair<$type, $inner> item_${utype}_x_${uinner};"
	puts $outfile "unsigned a_${utype}_x_${uinner}"
	puts $outfile "  = alignof (align_pair<$type, $inner>);"

	puts $outfile "align_union<$type, $inner> item_${utype}_u_${uinner};"
	puts $outfile "unsigned a_${utype}_u_${uinner}"
	puts $outfile "  = alignof (align_union<$type, $inner>);"
    }
}

# Epilogue.
puts $outfile {
    int main() {
	return 0;
    }
}

close $outfile

standard_testfile $filename

if {[prepare_for_testing "failed to prepare" $testfile $srcfile \
	 {debug nowarnings c++ additional_flags=-std=c++11}]} {
    return -1
}

if {![runto_main]} {
    perror "test suppressed"
    return
}

proc maybe_xfail {type} {
    # See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69560
    # The g++ implementation of alignof is changing to match C11.
    if {[is_x86_like_target]
	&& [test_compiler_info {gcc-[0-8]-*}]
	&& ($type == "double" || $type == "long long"
	    || $type == "unsigned long long")} {
	setup_xfail *-*-*
    }
}

foreach type $typelist {
    set utype [join [split $type] _]
    set expected [get_integer_valueof a_$utype 0]

    maybe_xfail $type
    gdb_test "print alignof($type)" " = $expected"

    maybe_xfail $type
    gdb_test "print alignof(t_$utype)" " = $expected"

    maybe_xfail $type
    gdb_test "print alignof(typeof(item_$utype))" " = $expected"

    foreach inner $typelist {
	set uinner [join [split $inner] _]
	set expected [get_integer_valueof a_${utype}_x_${uinner} 0]
	gdb_test "print alignof(align_pair<${type},${inner}>)" " = $expected"

	set expected [get_integer_valueof a_${utype}_u_${uinner} 0]
	gdb_test "print alignof(align_union<${type},${inner}>)" " = $expected"
    }
}

set expected [get_integer_valueof a_int3 0]
gdb_test "print alignof(int\[3\])" " = $expected"

set expected [get_integer_valueof a_void 0]
gdb_test "print alignof(void)" " = $expected"