[PATCH] Only print entry values for arguments.

Yao Qi
2013-08-05T00:45:22Z

Hi,
When I think about how to handle entry values in my "skip unavailable"
patch, I played with "set print entry-values" to different values, and
use MI commands '-stack-list-{locals,arguments,variables}' to see the
changes on output. However, I find that "print entry-values" affects
the output of "-stack-list-locals", which is not expected.

-gdb-set print entry-values only
^done
-stack-list-locals --simple-values
^done,locals=[{name="array",type="unsigned char [2]"},{name="i@entry",type="int",value="<optimized out>"}]

-gdb-set print entry-values both
^done
-stack-list-locals --simple-values
^done,locals=[{name="array",type="unsigned char [2]"},{name="i",type="int",value="<unavailable>"},{name="i@entry",type="int",value="<optimized out>"}]

"print entry-values" is the option about printing frame arguments,
which has nothing to do with locals. This patch is to check whether it
is an argument to decide to call read_frame_arg or read_frame_local.
read_frame_local is a new function which is to print local without
considering much on "print entry-values". I have to say that it is
odd to pass "struct frame_arg *" to function read_frame_local, but it
is required by caller and the following calls. Functions
list_args_or_locals and list_arg_or_local process both arguments and
locals by means of "struct frame_arg *", so I have to use "struct
frame_arg *" for function read_frame_local too. Note that "print
entry-values" is for arguments only, but is checked in both
list_args_or_locals and list_arg_or_local. We need some changes here
to apply value of "print entry-values" to arguments only, but it is
not the goal of this patch.

The test case mi-trace-unavailable.exp is updated too, to test the
output of '-stack-list-locals'.

This patch also fixes an internal error I found,

../../../git/gdb/stack.c:223: internal-error: print_frame_arg: Assertion `!arg->val || !arg->error' failed.
A problem internal to GDB has been detected, further debugging may prove unreliable.
Quit this debugging session? "

Patch is tested on x86_64-linux with board file unix.exp and
native-gdbserver.exp.

gdb:

2013-08-05 Yao Qi <yao@codesourcery.com>

* frame.h (read_frame_local): Declare.
* mi/mi-cmd-stack.c (list_args_or_locals): Call
read_frame_local.
* stack.c (read_frame_local): New.

gdb/testsuite:

2013-08-05 Yao Qi <yao@codesourcery.com>

* gdb.trace/mi-trace-unavailable.exp: Don't set
"print entry-values" to "no".
(test_trace_unavailable): Set various values to
"print entry-values" to test the output of
'-stack-list-locals' is not affected.
---
gdb/frame.h | 2 +
gdb/mi/mi-cmd-stack.c | 5 +++-
gdb/stack.c | 27 ++++++++++++++++++++++
gdb/testsuite/gdb.trace/mi-trace-unavailable.exp | 18 ++++++++++++--
4 files changed, 48 insertions(+), 4 deletions(-)

diff --git a/gdb/frame.h b/gdb/frame.h
index 31b9cb7..f02addf 100644
--- a/gdb/frame.h
+++ b/gdb/frame.h
@@ -714,6 +714,8 @@ struct frame_arg
extern void read_frame_arg (struct symbol *sym, struct frame_info *frame,
struct frame_arg *argp,
struct frame_arg *entryargp);
+extern void read_frame_local (struct symbol *sym, struct frame_info *frame,
+ struct frame_arg *argp);

extern void args_info (char *, int);

diff --git a/gdb/mi/mi-cmd-stack.c b/gdb/mi/mi-cmd-stack.c
index 416f0f4..fea7f6f 100644
--- a/gdb/mi/mi-cmd-stack.c
+++ b/gdb/mi/mi-cmd-stack.c
@@ -602,7 +602,10 @@ list_args_or_locals (enum what_to_list what, enum print_values values,
&& TYPE_CODE (type) != TYPE_CODE_UNION)
{
case PRINT_ALL_VALUES:
- read_frame_arg (sym2, fi, &arg, &entryarg);
+ if (SYMBOL_IS_ARGUMENT (sym))
+ read_frame_arg (sym2, fi, &arg, &entryarg);
+ else
+ read_frame_local (sym2, fi, &arg);
}
break;
}
diff --git a/gdb/stack.c b/gdb/stack.c
index 510f20d..9e9ebc1 100644
--- a/gdb/stack.c
+++ b/gdb/stack.c
@@ -301,6 +301,33 @@ print_frame_arg (const struct frame_arg *arg)
annotate_arg_end ();
}

+/* Read in inferior function local SYM at FRAM into ARGP. Caller is
+ responsible for xfree of ARGP->ERROR. This function never throws an
+ exception. */
+
+void
+read_frame_local (struct symbol *sym, struct frame_info *frame,
+ struct frame_arg *argp)
+{
+ volatile struct gdb_exception except;
+ struct value *val = NULL;
+ char *val_error = NULL;
+
+ TRY_CATCH (except, RETURN_MASK_ERROR)
+ {
+ val = read_var_value (sym, frame);
+ }
+ if (val == NULL)
+ {
+ val_error = alloca (strlen (except.message) + 1);
+ strcpy (val_error, except.message);
+ }
+
+ argp->sym = sym;
+ argp->val = val;
+ argp->error = val_error ? xstrdup (val_error) : NULL;
+}
+
/* Read in inferior function parameter SYM at FRAME into ARGP. Caller is
responsible for xfree of ARGP->ERROR. This function never throws an
exception. */
diff --git a/gdb/testsuite/gdb.trace/mi-trace-unavailable.exp b/gdb/testsuite/gdb.trace/mi-trace-unavailable.exp
index 42f6e32..8926a7e 100644
--- a/gdb/testsuite/gdb.trace/mi-trace-unavailable.exp
+++ b/gdb/testsuite/gdb.trace/mi-trace-unavailable.exp
@@ -75,9 +75,6 @@ mi_gdb_test "-trace-save ${tracefile}.tf" ".*\\^done" \
mi_gdb_test "-trace-save -ctf ${tracefile}.ctf" ".*\\^done" \
"save ctf trace file"

-mi_gdb_test "-gdb-set print entry-values no" {\^done} \
- "-gdb-set print entry-values no"
-
proc test_trace_unavailable { data_source } {
global decimal

@@ -89,6 +86,21 @@ proc test_trace_unavailable { data_source } {
".*\\^done,found=\"1\",tracepoint=\"${decimal}\",traceframe=\"0\",frame=\{.*" \
"-trace-find frame-number 0"

+ # Option of print entry-values shouldn't affect the output of
+ # '-stack-list-locals'.
+ foreach entry_values { no only preferred if-needed both compact default } {
+ mi_gdb_test "-gdb-set print entry-values $entry_values" {\^done} ""
+
+ with_test_prefix "$entry_values" {
+ # Test MI command '-stack-list-locals'.
+ mi_gdb_test "-stack-list-locals --simple-values" \
+ ".*\\^done,locals=\\\[\{name=\"array\",type=\"unsigned char \\\[2\\\]\"\},\{name=\"i\",type=\"int\",value=\"<unavailable>\"\}\\\]" \
+ "-stack-list-locals --simple-values"
+ }
+ }
+
+ mi_gdb_test "-gdb-set print entry-values no" {\^done} ""
+
# Test MI command '-stack-list-locals'.
mi_gdb_test "-stack-list-locals --simple-values" \
".*\\^done,locals=\\\[\{name=\"array\",type=\"unsigned char \\\[2\\\]\"\},\{name=\"i\",type=\"int\",value=\"<unavailable>\"\}\\\]" \
--
1.7.7.6