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-rw-r--r--gdb/ChangeLog7
-rw-r--r--gdb/doc/ChangeLog10
-rw-r--r--gdb/doc/gdb.texinfo47
-rw-r--r--gdb/stack.c13
-rw-r--r--gdb/testsuite/ChangeLog14
-rw-r--r--gdb/testsuite/gdb.base/return-nodebug.c49
-rw-r--r--gdb/testsuite/gdb.base/return-nodebug.exp61
7 files changed, 191 insertions, 10 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 71a74ea..e5d892c 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,10 @@
+2009-03-15 Jan Kratochvil <jan.kratochvil@redhat.com>
+
+ * stack.c (return_command <retval_exp>): New variables retval_expr
+ and old_chain. Inline parse_and_eval to initialize retval_expr. Check
+ RETVAL_EXPR for UNOP_CAST and set RETURN_TYPE to the RETURN_VALUE type
+ if RETURN_TYPE is NULL.
+
2009-03-14 Pedro Alves <pedro@codesourcery.com>
* remote.c (PACKET_qAttached): New.
diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index 65aa06b..984011a 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,7 +1,11 @@
+2009-03-15 Jan Kratochvil <jan.kratochvil@redhat.com>
+
+ * gdb.texinfo (Returning): New description for missing debug info.
+
2009-03-14 Pedro Alves <pedro@codesourcery.com>
* gdb.texinfo (Remote Configuration): Document query-attached.
- (General Query Packets): Document qAttached.
+ (General Query Packets): Document qAttached.
2009-03-05 Pedro Alves <pedro@codesourcery.com>
@@ -26,8 +30,8 @@
2009-02-14 Vladimir Prus <vladimir@codesourcery.com>
- * observer.texi: Add parameter 'print_frame' to normal_stop
- observer.
+ * observer.texi: Add parameter 'print_frame' to normal_stop
+ observer.
2009-02-07 Eli Zaretskii <eliz@gnu.org>
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 33bac26..2ec680a 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -12494,6 +12494,53 @@ returned. In contrast, the @code{finish} command (@pxref{Continuing
and Stepping, ,Continuing and Stepping}) resumes execution until the
selected stack frame returns naturally.
+@value{GDBN} needs to know how the @var{expression} argument should be set for
+the inferior. The concrete registers assignment depends on the OS ABI and the
+type being returned by the selected stack frame. For example it is common for
+OS ABI to return floating point values in FPU registers while integer values in
+CPU registers. Still some ABIs return even floating point values in CPU
+registers. Larger integer widths (such as @code{long long int}) also have
+specific placement rules. @value{GDBN} already knows the OS ABI from its
+current target so it needs to find out also the type being returned to make the
+assignment into the right register(s).
+
+Normally, the selected stack frame has debug info. @value{GDBN} will always
+use the debug info instead of the implicit type of @var{expression} when the
+debug info is available. For example, if you type @kbd{return -1}, and the
+function in the current stack frame is declared to return a @code{long long
+int}, @value{GDBN} transparently converts the implicit @code{int} value of -1
+into a @code{long long int}:
+
+@smallexample
+Breakpoint 1, func () at gdb.base/return-nodebug.c:29
+29 return 31;
+(@value{GDBP}) return -1
+Make func return now? (y or n) y
+#0 0x004004f6 in main () at gdb.base/return-nodebug.c:43
+43 printf ("result=%lld\n", func ());
+(@value{GDBP})
+@end smallexample
+
+However, if the selected stack frame does not have a debug info, e.g., if the
+function was compiled without debug info, @value{GDBN} has to find out the type
+to return from user. Specifying a different type by mistake may set the value
+in different inferior registers than the caller code expects. For example,
+typing @kbd{return -1} with its implicit type @code{int} would set only a part
+of a @code{long long int} result for a debug info less function (on 32-bit
+architectures). Therefore the user is required to specify the return type by
+an appropriate cast explicitly:
+
+@smallexample
+Breakpoint 2, 0x0040050b in func ()
+(@value{GDBP}) return -1
+Return value type not available for selected stack frame.
+Please use an explicit cast of the value to return.
+(@value{GDBP}) return (long long int) -1
+Make selected stack frame return now? (y or n) y
+#0 0x00400526 in main ()
+(@value{GDBP})
+@end smallexample
+
@node Calling
@section Calling Program Functions
diff --git a/gdb/stack.c b/gdb/stack.c
index d0c872e..d0ea3bf 100644
--- a/gdb/stack.c
+++ b/gdb/stack.c
@@ -1796,18 +1796,27 @@ return_command (char *retval_exp, int from_tty)
message. */
if (retval_exp)
{
+ struct expression *retval_expr = parse_expression (retval_exp);
+ struct cleanup *old_chain = make_cleanup (xfree, retval_expr);
struct type *return_type = NULL;
/* Compute the return value. Should the computation fail, this
call throws an error. */
- return_value = parse_and_eval (retval_exp);
+ return_value = evaluate_expression (retval_expr);
/* Cast return value to the return type of the function. Should
the cast fail, this call throws an error. */
if (thisfun != NULL)
return_type = TYPE_TARGET_TYPE (SYMBOL_TYPE (thisfun));
if (return_type == NULL)
- return_type = builtin_type (get_frame_arch (thisframe))->builtin_int;
+ {
+ if (retval_expr->elts[0].opcode != UNOP_CAST)
+ error (_("Return value type not available for selected "
+ "stack frame.\n"
+ "Please use an explicit cast of the value to return."));
+ return_type = value_type (return_value);
+ }
+ do_cleanups (old_chain);
CHECK_TYPEDEF (return_type);
return_value = value_cast (return_type, return_value);
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index b047421..e889d34 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2009-03-15 Jan Kratochvil <jan.kratochvil@redhat.com>
+
+ * gdb.base/return-nodebug.exp, gdb.base/return-nodebug.c: New.
+
2009-03-14 Jan Kratochvil <jan.kratochvil@redhat.com>
Fix a racy FAIL.
@@ -9,7 +13,7 @@
2009-03-13 Vladimir Prus <vladimir@codesourcery.com>
* gdb.mi/mi-cli.exp: Adjust for output difference in
- sync and async modes.
+ sync and async modes.
2009-03-12 Joel Brobecker <brobecker@adacore.com>
@@ -31,19 +35,19 @@
2009-03-12 Vladimir Prus <vladimir@codesourcery.com>
- * gdb.mi/mi-cli.exp: Remove debug print.
+ * gdb.mi/mi-cli.exp: Remove debug print.
2009-03-12 Vladimir Prus <vladimir@codesourcery.com>
- * gdb.mi/mi-cli.exp: Verify that CLI commands that run inferior
- include the token in ^running and frame info in *stopped.
+ * gdb.mi/mi-cli.exp: Verify that CLI commands that run inferior
+ include the token in ^running and frame info in *stopped.
2009-03-05 Paul Pluzhnikov <ppluzhnikov@google.com>
* solib-display.exp: New file.
* solib-display-main.c: New file.
* solib-display-lib.c: New file.
-
+
2009-03-05 Pedro Alves <pedro@codesourcery.com>
* gdb.arch/i386-permbkpt.S, gdb.arch/i386-permbkpt.exp: New.
diff --git a/gdb/testsuite/gdb.base/return-nodebug.c b/gdb/testsuite/gdb.base/return-nodebug.c
new file mode 100644
index 0000000..e1211b3
--- /dev/null
+++ b/gdb/testsuite/gdb.base/return-nodebug.c
@@ -0,0 +1,49 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2009 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/>. */
+
+#include <stdio.h>
+
+static TYPE
+init (void)
+{
+ return 0;
+}
+
+static TYPE
+func (void)
+{
+ return 31;
+}
+
+static void
+marker (void)
+{
+}
+
+int
+main (void)
+{
+ /* Preinitialize registers to 0 to avoid false PASS by leftover garbage. */
+ init ();
+
+ printf ("result=" FORMAT "\n", CAST func ());
+
+ /* Cannot `next' with no debug info. */
+ marker ();
+
+ return 0;
+}
diff --git a/gdb/testsuite/gdb.base/return-nodebug.exp b/gdb/testsuite/gdb.base/return-nodebug.exp
new file mode 100644
index 0000000..7d43776
--- /dev/null
+++ b/gdb/testsuite/gdb.base/return-nodebug.exp
@@ -0,0 +1,61 @@
+# Copyright (C) 2009 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/>.
+
+proc do_test {type} {
+ set typenospace [string map {{ } -} $type]
+
+ global pf_prefix
+ set old_prefix $pf_prefix
+ lappend pf_prefix "$typenospace:"
+
+ if {[runto "func"]} {
+ # Verify that we do not crash when using "return" from a function with
+ # no debugging info. Such function has no `struct symbol'. It may
+ # still have an associated `struct minimal_symbol'.
+
+ gdb_test "return -1" \
+ "Return value type not available for selected stack frame\\.\r\nPlease use an explicit cast of the value to return\\." \
+ "return from function with no debug info without a cast"
+
+ # Cast of the result to the proper width must be done explicitely.
+ gdb_test "return ($type) -1" "#0 .* main \\(.*" \
+ "return from function with no debug info with a cast" \
+ "Make selected stack frame return now\\? \\(y or n\\) " "y"
+
+ # And if it returned the full width of the result.
+ gdb_test "adv marker" "\r\nresult=-1\r\n.* in marker \\(.*" \
+ "full width of the returned result"
+ }
+
+ set pf_prefix $old_prefix
+}
+
+foreach case {{{signed char} %d (int)} \
+ {{short} %d (int)} \
+ {{int} %d} \
+ {{long} %ld} \
+ {{long long} %lld}} {
+ set type [lindex $case 0]
+ set format [lindex $case 1]
+ set cast [lindex $case 2]
+
+ set typeesc [string map {{ } {\ }} $type]
+ set typenospace [string map {{ } -} $type]
+
+ if {[prepare_for_testing return-nodebug.exp "return-nodebug-$typenospace" "return-nodebug.c" \
+ [list "additional_flags=-DFORMAT=\"$format\" -DTYPE=$typeesc -DCAST=$cast"]] == 0} {
+ do_test $type
+ }
+}
generated by cgit v1.1 at 2024-11-19 08:25:10 +0000