old-cross-binutils/gdb/testsuite/gdb.base/vla-sideeffect.exp
Sanimir Agovic 5ecaaa66e0 vla: evaluate operand of sizeof if its type is a vla
The c99 standard in "6.5.3.4 The sizeof operator" states:

 If the type of the operand is a variable length array type, the operand
 is evaluated;[...]

This patch mirrors the following c99 semantic in gdb:

 1| int vla[n][m];
 2| int i = 1;
 3| sizeof(vla[i++][0]); // No sideffect
 4| assert (i == 1);
 5| sizeof(vla[i++]);    // With sideffect
 6| assert (i == 2);

Note: ptype/whatis still do not allow any sideeffects.

This patch was motivated by:

  https://sourceware.org/ml/gdb-patches/2014-01/msg00732.html

gdb/ChangeLog:

	* eval.c (evaluate_subexp_for_sizeof): Add enum noside argument.
	(evaluate_subexp_standard): Pass noside argument.
	(evaluate_subexp_for_sizeof) <BINOP_SUBSCRIPT>: Handle subscript case
	if noside equals EVAL_NORMAL. If the subscript yields a vla type
	re-evaluate subscript operation with EVAL_NORMAL to enable sideffects.
	* gdbtypes.c (resolve_dynamic_bounds): Mark bound as evaluated.
	* gdbtypes.h (enum range_flags): Add RANGE_EVALUATED case.

testsuite/ChangeLog:

	* gdb.base/vla-sideeffect.c: New file.
	* gdb.base/vla-sideeffect.exp: New file.
2014-04-14 09:21:46 -07:00

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# Copyright 2014 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/>.
# Tests side-effects of sizeof evaluation.
# Based on gcc/testsuite/gcc.dg/vla-4.c; vla-15.c
standard_testfile
if { [prepare_for_testing ${testfile}.exp ${testfile} ${srcfile}] } {
return -1
}
if ![runto_main] {
return -1
}
gdb_breakpoint [gdb_get_line_number "vla-filled"]
gdb_continue_to_breakpoint "vla-filled"
# Check side effects for sizeof argument.
set sizeof_int [get_sizeof "int" 4]
set sizeof_vla [ expr "10" * "$sizeof_int" ]
gdb_test "print sizeof (vla1\[i++\])" " = ${sizeof_int}" \
"print sizeof (vla1\[i++\])"
gdb_test "print i" " = 0" \
"print i - sizeof no side effects"
gdb_test "print sizeof (++vla1\[0\])" " = ${sizeof_int}" \
"print sizeof (++vla1\[0\])"
gdb_test "print vla1\[0\]" " = 10" \
"print vla1\[0\] - sizeof no side effects"
gdb_test "ptype ++vla1\[0\]" "type = int" "ptype ++vla1\[0\]"
gdb_test "print vla1\[0\]" " = 10" \
"print vla1\[0\] - ptype no side effects"
gdb_test "whatis ++vla1\[0\]" "type = int" "whatis ++vla1\[0\]"
gdb_test "print vla1\[0\]" " = 10" \
"print vla1\[0\] - whatis no side effects"
gdb_test "print sizeof (vla2\[i++\])" " = ${sizeof_vla}" \
"print sizeof (vla2\[i++\])"
gdb_test "print i" " = 1" \
"print i - sizeof with side effects (1)"
gdb_test "print sizeof (vla2\[i++ + sizeof(j++)\])" " = ${sizeof_vla}" \
"print sizeof (vla2\[i++ + sizeof(j++)\])"
gdb_test "print i" " = 2" \
"print i - sizeof with side effects (2)"
gdb_test "print j" " = 0" \
"print j - sizeof with no side effects"
gdb_test "ptype vla2\[i++\]" "type = int \\\[10\\\]" \
"ptype vla2\[i++\]"
gdb_test "print i" " = 2" \
"print i - ptype with side effects (1)"
gdb_test "ptype vla2\[i++ + sizeof(j++)\]" "type = int \\\[10\\\]" \
"ptype vla2\[i++ + sizeof(j++)\]"
gdb_test "print i" " = 2" \
"print i - ptype with side effects (2)"
gdb_test "print j" " = 0" \
"print j - ptype with no side effects"
gdb_test "whatis vla2\[i++\]" "type = int \\\[10\\\]" \
"whatis vla2\[i++\]"
gdb_test "print i" " = 2" \
"print i - whatis with side effects (1)"
gdb_test "whatis vla2\[i++ + sizeof(j++)\]" "type = int \\\[10\\\]" \
"whatis vla2\[i++ + sizeof(j++)\]"
gdb_test "print i" " = 2" \
"print i - whatis with side effects (2)"
gdb_test "print j" " = 0" \
"print j - whatis with no side effects"