Re: [RFC] Signed/unsigned character arrays are not strings

Jan Kratochvil
2007-01-26T10:37:02Z

[-- Attachment #1: Type: text/plain, Size: 542 bytes --]

Hi Eli,

patch updated - commit approval requested.

Thanks,
Jan

On Fri, 26 Jan 2007 09:54:08 +0100, Eli Zaretskii wrote:
...
> > +@code{-funsigned-char} @value{GCC} options have no effect as @value{GDBN}
>
> Please use @value{NGCC}, not @value{GCC}. The former produces output
> similar to @value{GDBN}, the latter produces a literal lowercase "gcc".
>
> > +* Arrays of specifically SIGNED or UNSIGNED CHARs are now printed as arrays
> > + of numbers.
>
> I think "explicitly SIGNED or UNSIGNED..." is a better wording.
>
> Thanks.

[-- Attachment #2: gdb-cvs-nosign-array3.patch --]
[-- Type: text/plain, Size: 11006 bytes --]

2007-01-26 Jan Kratochvil <jan.kratochvil@redhat.com>

* c-valprint.c (c_val_print): Require strings to be of no-signed CHARs.
* NEWS: Describe CHAR array vs. string identifcation rules.

2007-01-26 Jan Kratochvil <jan.kratochvil@redhat.com>
Eli Zaretskii <eliz@gnu.org>

* gdb.texinfo: Describe CHAR array vs. string identifcation rules.

2007-01-25 Jan Kratochvil <jan.kratochvil@redhat.com>

* gdb.base/charsign.exp, gdb.base/charsign.c: New files.
* gdb.arch/i386-sse.exp: Check $xmm.v16_int8 printing as a number array.
* gdb.base/printcmds.exp: Sign-provided CHARs now became arrays.
* gdb.base/setvar.exp: Likewise.

--- gdb/NEWS 21 Jan 2007 17:48:53 -0000 1.211
+++ gdb/NEWS 26 Jan 2007 10:31:48 -0000
@@ -15,6 +15,9 @@ frequency signals (e.g. SIGALRM) via the
target's overall architecture. GDB can read a description from
a local file or over the remote serial protocol.

+* Arrays of explicitly SIGNED or UNSIGNED CHARs are now printed as arrays
+ of numbers.
+
* New commands

set mem inaccessible-by-default
--- gdb/c-valprint.c 9 Jan 2007 17:58:50 -0000 1.41
+++ gdb/c-valprint.c 26 Jan 2007 10:31:48 -0000
@@ -96,7 +96,7 @@ c_val_print (struct type *type, const gd
}
/* For an array of chars, print with string syntax. */
if (eltlen == 1 &&
- ((TYPE_CODE (elttype) == TYPE_CODE_INT)
+ ((TYPE_CODE (elttype) == TYPE_CODE_INT && TYPE_NOSIGN (elttype))
|| ((current_language->la_language == language_m2)
&& (TYPE_CODE (elttype) == TYPE_CODE_CHAR)))
&& (format == 0 || format == 's'))
--- gdb/doc/gdb.texinfo 26 Jan 2007 08:54:01 -0000 1.380
+++ gdb/doc/gdb.texinfo 26 Jan 2007 10:32:00 -0000
@@ -5632,6 +5632,26 @@ If you ask to print an object whose cont
by the debug information, @value{GDBN} will say @samp{<incomplete
type>}. @xref{Symbols, incomplete type}, for more about this.

+Strings are identified as arrays of @code{char} values without specified
+signedness. Arrays of either @code{signed char} or @code{unsigned char} get
+printed as arrays of 1 byte sized integers. @code{-fsigned-char} or
+@code{-funsigned-char} @value{NGCC} options have no effect as @value{GDBN}
+defines literal string type @code{"char"} as @code{char} without a sign.
+For program code
+
+@smallexample
+char var0[] = "A";
+signed char var1[] = "A";
+@end smallexample
+
+You get during debugging
+@smallexample
+(gdb) print var0
+$1 = "A"
+(gdb) print var1
+$2 = @{65 'A', 0 '\0'@}
+@end smallexample
+
@node Arrays
@section Artificial arrays

--- gdb/testsuite/gdb.arch/i386-sse.exp 9 Jan 2007 17:59:09 -0000 1.5
+++ gdb/testsuite/gdb.arch/i386-sse.exp 26 Jan 2007 10:32:00 -0000
@@ -83,7 +83,10 @@ gdb_continue_to_breakpoint "continue to
foreach r {0 1 2 3 4 5 6 7} {
gdb_test "print \$xmm$r.v4_float" \
".. = \\{$r, $r.25, $r.5, $r.75\\}.*" \
- "check contents of %xmm$r"
+ "check float contents of %xmm$r"
+ gdb_test "print \$xmm$r.v16_int8" \
+ ".. = \\{(-?\[0-9\]+ '.*', ){15}-?\[0-9\]+ '.*'\\}.*" \
+ "check int8 contents of %xmm$r"
}

foreach r {0 1 2 3 4 5 6 7} {
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ gdb/testsuite/gdb.base/charsign.c 26 Jan 2007 10:32:00 -0000
@@ -0,0 +1,37 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2007 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 2 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, write to the Free Software
+ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+ Please email any bugs, comments, and/or additions to this file to:
+ bug-gdb@prep.ai.mit.edu */
+
+int main()
+{
+ return 0;
+}
+
+char n[]="A";
+signed char s[]="A";
+unsigned char u[]="A";
+
+typedef char char_n;
+typedef signed char char_s;
+typedef unsigned char char_u;
+
+char_n n_typed[]="A";
+char_s s_typed[]="A";
+char_u u_typed[]="A";
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ gdb/testsuite/gdb.base/charsign.exp 26 Jan 2007 10:32:00 -0000
@@ -0,0 +1,70 @@
+# Copyright 2007 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 2 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, write to the Free Software
+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+if $tracelevel then {
+ strace $tracelevel
+}
+
+set prms_id 0
+set bug_id 0
+
+set testfile charsign
+set srcfile ${testfile}.c
+set binfile ${objdir}/${subdir}/${testfile}
+
+proc do_test { cflags } {
+ global srcdir
+ global binfile
+ global subdir
+ global srcfile
+ global gdb_prompt
+
+ if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable [list debug additional_flags=$cflags]] != "" } {
+ untested "Couldn't compile test program"
+ return -1
+ }
+
+ # Get things started.
+
+ gdb_exit
+ gdb_start
+ gdb_reinitialize_dir $srcdir/$subdir
+ gdb_load ${binfile}
+
+ # For C programs, "start" should stop in main().
+
+ gdb_test "p n" \
+ "= \"A\""
+ gdb_test "p s" \
+ "= \\{65 'A', 0 '\\\\0'\\}"
+ gdb_test "p u" \
+ "= \\{65 'A', 0 '\\\\0'\\}"
+ gdb_test "p n_typed" \
+ "= \"A\""
+ gdb_test "p s_typed" \
+ "= \\{65 'A', 0 '\\\\0'\\}"
+ gdb_test "p u_typed" \
+ "= \\{65 'A', 0 '\\\\0'\\}"
+}
+
+# The string identification works despite the compiler flags below due to
+# gdbtypes.c:
+# if (name && strcmp (name, "char") == 0)
+# TYPE_FLAGS (type) |= TYPE_FLAG_NOSIGN;
+
+do_test {}
+do_test {-fsigned-char}
+do_test {-funsigned-char}
--- gdb/testsuite/gdb.base/printcmds.exp 9 Jan 2007 17:59:11 -0000 1.14
+++ gdb/testsuite/gdb.base/printcmds.exp 26 Jan 2007 10:32:01 -0000
@@ -590,18 +590,18 @@ proc test_print_char_arrays {} {
gdb_test "set print address on" ""

gdb_test "p arrays" \
- " = {array1 = \"abc\", array2 = \"d\", array3 = \"e\", array4 = \"fg\", array5 = \"hij\"}"
+ " = \\{array1 = \\{97 'a', 98 'b', 99 'c', 0 '\\\\0'\\}, array2 = \\{100 'd'\\}, array3 = \\{101 'e'\\}, array4 = \\{102 'f', 103 'g'\\}, array5 = \\{104 'h', 105 'i', 106 'j', 0 '\\\\0'\\}\\}"

gdb_test "p parrays" " = \\(struct some_arrays \\*\\) $hex"
- gdb_test "p parrays->array1" " = \"abc\""
+ gdb_test "p parrays->array1" " = \\{97 'a', 98 'b', 99 'c', 0 '\\\\0'\\}"
gdb_test "p &parrays->array1" " = \\(unsigned char \\(\\*\\)\\\[4\\\]\\) $hex"
- gdb_test "p parrays->array2" " = \"d\""
+ gdb_test "p parrays->array2" " = \\{100 'd'\\}"
gdb_test "p &parrays->array2" " = \\(unsigned char \\(\\*\\)\\\[1\\\]\\) $hex"
- gdb_test "p parrays->array3" " = \"e\""
+ gdb_test "p parrays->array3" " = \\{101 'e'\\}"
gdb_test "p &parrays->array3" " = \\(unsigned char \\(\\*\\)\\\[1\\\]\\) $hex"
- gdb_test "p parrays->array4" " = \"fg\""
+ gdb_test "p parrays->array4" " = \\{102 'f', 103 'g'\\}"
gdb_test "p &parrays->array4" " = \\(unsigned char \\(\\*\\)\\\[2\\\]\\) $hex"
- gdb_test "p parrays->array5" " = \"hij\""
+ gdb_test "p parrays->array5" " = \\{104 'h', 105 'i', 106 'j', 0 '\\\\0'\\}"
gdb_test "p &parrays->array5" " = \\(unsigned char \\(\\*\\)\\\[4\\\]\\) $hex"

gdb_test "set print address off" ""
--- gdb/testsuite/gdb.base/setvar.exp 9 Jan 2007 17:59:11 -0000 1.10
+++ gdb/testsuite/gdb.base/setvar.exp 26 Jan 2007 10:32:01 -0000
@@ -233,11 +233,11 @@ test_set "set variable v_char_array\[0\]
#
# test "set variable" for "signed char array[2]"
#
-test_set "set variable v_signed_char_array\[0\]='h'" "set variable v_signed_char_array\[1\]='i'" "print v_signed_char_array" ".*.\[0-9\]* =.*\"hi\"" "set variable signed char array=\"hi\" (string)"
+test_set "set variable v_signed_char_array\[0\]='h'" "set variable v_signed_char_array\[1\]='i'" "print v_signed_char_array" ".*.\[0-9\]* =.*\\{104 'h', 105 'i'\\}" "set variable signed char array=\"hi\" (string)"
#
# test "set variable" for "unsigned char array[2]"
#
-test_set "set variable v_unsigned_char_array\[0\]='h'" "set variable v_unsigned_char_array\[1\]='i'" "print v_unsigned_char_array" ".*.\[0-9\]* =.*\"hi\"" "set variable unsigned char array=\"hi\" (string)"
+test_set "set variable v_unsigned_char_array\[0\]='h'" "set variable v_unsigned_char_array\[1\]='i'" "print v_unsigned_char_array" ".*.\[0-9\]* =.*\\{104 'h', 105 'i'\\}" "set variable unsigned char array=\"hi\" (string)"
#
# test "set variable" for "short array[2]"
#
@@ -289,11 +289,11 @@ test_set "set v_char_pointer=v_char_arra
#
# test "set variable" for type "signed char *"
#
-test_set "set v_signed_char_pointer=v_signed_char_array" "set variable *(v_signed_char_pointer)='h'" "set variable *(v_signed_char_pointer+1)='i'" "print v_signed_char_array" ".*.\[0-9\]* =.*\"hi\"" "print *(v_signed_char_pointer+1)" ".*.\[0-9\]* = 105 \'i\'" "set variable signed char pointer=\"hi\" (string)"
+test_set "set v_signed_char_pointer=v_signed_char_array" "set variable *(v_signed_char_pointer)='h'" "set variable *(v_signed_char_pointer+1)='i'" "print v_signed_char_array" ".*.\[0-9\]* =.*\\{104 'h', 105 'i'\\}" "print *(v_signed_char_pointer+1)" ".*.\[0-9\]* = 105 \'i\'" "set variable signed char pointer=\"hi\" (string)"
#
# test "set variable" for type "unsigned char *"
#
-test_set "set v_unsigned_char_pointer=v_unsigned_char_array" "set variable *(v_unsigned_char_pointer)='h'" "set variable *(v_unsigned_char_pointer+1)='i'" "print v_unsigned_char_array" ".*.\[0-9\]* =.*\"hi\"" "print *(v_unsigned_char_pointer+1)" ".*.\[0-9\]* = 105 \'i\'" "set variable unsigned char pointer=\"hi\" (string)"
+test_set "set v_unsigned_char_pointer=v_unsigned_char_array" "set variable *(v_unsigned_char_pointer)='h'" "set variable *(v_unsigned_char_pointer+1)='i'" "print v_unsigned_char_array" ".*.\[0-9\]* =.*\\{104 'h', 105 'i'\\}" "print *(v_unsigned_char_pointer+1)" ".*.\[0-9\]* = 105 \'i\'" "set variable unsigned char pointer=\"hi\" (string)"
#
# test "set variable" for type "short *"
#