This change is relevant only for standard DWARF (as opposed to the GNAT
encodings extensions): at the time of writing it only makes a difference
with GCC patches that are to be integrated: see the patch series
submission at
<https://gcc.gnu.org/ml/gcc-patches/2015-07/msg01353.html>.
Given the following Ada declarations:
subtype Small_Int is Natural range 0 .. 100;
type R_Type (L : Small_Int := 0) is record
S : String (1 .. L);
end record;
type A_Type is array (Natural range <>) of R_Type;
A : A_Type := (1 => (L => 0, S => ""),
2 => (L => 2, S => "ab"));
Before this change, we would get the following GDB session:
(gdb) ptype a
type = array (1 .. 2) of foo.r_type <packed: 838-bit elements>
This is wrong: "a" is not a packed array. This output comes from the
fact that, because R_Type has a dynamic size (with a maximum), the
compiler has to describe in the debugging information the size allocated
for each array element (i.e. the stride, in DWARF parlance: see
DW_AT_byte_stride). Ada type printing currently assumes that arrays
with a stride are packed, hence the above output.
In practice, GNAT never performs bit-packing for arrays that contain
variable-sized elements. Leveraging this fact, this patch enhances type
printing so that ptype does not pretend that arrays are packed when they
have a stride and they contain dynamic elements. After this change, we
get the following expected output:
(gdb) ptype a
type = array (1 .. 2) of foo.r_type
gdb/ChangeLog:
* ada-typeprint.c (print_array_type): Do not describe arrays as
packed when they embed dynamic elements.
gdb/testsuite/ChangeLog:
* gdb.ada/array_of_variable_length.exp: New testcase.
* gdb.ada/array_of_variable_length/foo.adb: New file.
* gdb.ada/array_of_variable_length/pck.adb: New file.
* gdb.ada/array_of_variable_length/pck.ads: New file.
Tested on x86_64-linux, no regression.
+2015-09-15 Pierre-Marie de Rodat <derodat@adacore.com>
+
+ * ada-typeprint.c (print_array_type): Do not describe arrays as
+ packed when they embed dynamic elements.
+
2015-09-15 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* symtab.h (address_class): Document that TLS variables
{
int bitsize;
int n_indices;
+ struct type *elt_type = NULL;
if (ada_is_constrained_packed_array_type (type))
type = ada_coerce_to_simple_array_type (type);
fprintf_filtered (stream, "%s<>", i == i0 ? "" : ", ");
}
+ elt_type = ada_array_element_type (type, n_indices);
fprintf_filtered (stream, ") of ");
wrap_here ("");
- ada_print_type (ada_array_element_type (type, n_indices), "", stream,
- show == 0 ? 0 : show - 1, level + 1, flags);
- if (bitsize > 0)
+ ada_print_type (elt_type, "", stream, show == 0 ? 0 : show - 1, level + 1,
+ flags);
+ /* Arrays with variable-length elements are never bit-packed in practice but
+ compilers have to describe their stride so that we can properly fetch
+ individual elements. Do not say the array is packed in this case. */
+ if (bitsize > 0 && !is_dynamic_type (elt_type))
fprintf_filtered (stream, " <packed: %d-bit elements>", bitsize);
}
+2015-09-15 Pierre-Marie de Rodat <derodat@adacore.com>
+
+ * gdb.ada/array_of_variable_length.exp: New testcase.
+ * gdb.ada/array_of_variable_length/foo.adb: New file.
+ * gdb.ada/array_of_variable_length/pck.adb: New file.
+ * gdb.ada/array_of_variable_length/pck.ads: New file.
+
2015-09-15 Doug Evans <dje@google.com>
* gdb.base/callfuncs.exp (do_function_calls): Handle clang naming
--- /dev/null
+# Copyright 2015 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/>.
+
+load_lib "ada.exp"
+
+standard_ada_testfile foo
+
+if {[gdb_compile_ada "${srcfile}" "${binfile}" executable [list debug]] != "" } {
+ return -1
+}
+
+clean_restart ${testfile}
+
+set bp_location [gdb_get_line_number "BREAK" ${testdir}/foo.adb]
+runto "foo.adb:$bp_location"
+
+# Pck.A is an array that embeds elements with variable size so compilers will
+# emit DWARF attributes such as DW_AT_byte_stride to tell GDB how to fetch
+# individual elements. Array stride is also a way to describe packed arrays:
+# make sure we do not consider Pck.A as a packed array.
+gdb_test "ptype pck.a" "array \\(1 \\.\\. 2\\) of pck\\.r_type"
+
+# Make sure this also works with a type from a fully evaluated value. During
+# evaluation, dynamic types can be "resolved" so GDB internals could "forget"
+# that elements have variable size. Fortunately, type resolution of array
+# elements happens only when processing individual elements (i.e. the resolved
+# array type is still associated to the dynamic element type), so the following
+# is supposed to work.
+gdb_test "print pck.a" \
+ "= \\(\\(l => 0, s => \"\"\\), \\(l => 2, s => \"ab\"\\)\\)"
+gdb_test "ptype $"\
+ "array \\(1 \\.\\. 2\\) of pck\\.r_type"
--- /dev/null
+-- Copyright 2015 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/>.
+
+with Pck; use Pck;
+
+procedure Foo is
+begin
+ Do_Nothing (A); -- BREAK
+end Foo;
--- /dev/null
+-- Copyright 2015 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/>.
+
+package body Pck is
+
+ procedure Do_Nothing (A : A_Type) is
+ begin
+ null;
+ end Do_Nothing;
+
+end Pck;
--- /dev/null
+-- Copyright 2015 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/>.
+
+package Pck is
+
+ subtype Small_Int is Natural range 0 .. 100;
+
+ type R_Type (L : Small_Int := 0) is record
+ S : String (1 .. L);
+ end record;
+
+ type A_Type is array (Natural range <>) of R_Type;
+
+ A : A_Type :=
+ (1 => (L => 0, S => ""),
+ 2 => (L => 2, S => "ab"));
+
+ procedure Do_Nothing (A : A_Type);
+
+end Pck;
projects / binutils-gdb.git / commitdiff