[10/11] Add global_context parameter to gdb.parse_and_eval

Message ID 20230504-frameless-v1-10-4191201740b0@adacore.com
State New
Headers
Series Fix frame-less expression evaluation in DAP |

Commit Message

Tom Tromey May 4, 2023, 2:21 p.m. UTC
  This adds a 'global_context' parse_and_eval to gdb.parse_and_eval.
This lets users request a parse that is done at "global scope".

I considered letting callers pass in a block instead, with None
meaning "global" -- but then there didn't seem to be a clean way to
express the default for this parameter.
---
 gdb/NEWS                              |  4 ++++
 gdb/doc/python.texi                   |  7 ++++++-
 gdb/python/python.c                   | 28 ++++++++++++++++++++++------
 gdb/testsuite/gdb.python/py-value.c   |  3 +++
 gdb/testsuite/gdb.python/py-value.exp |  5 +++++
 5 files changed, 40 insertions(+), 7 deletions(-)
  

Comments

Eli Zaretskii May 4, 2023, 2:54 p.m. UTC | #1
> Date: Thu, 04 May 2023 08:21:31 -0600
> From: Tom Tromey via Gdb-patches <gdb-patches@sourceware.org>
> 
> This adds a 'global_context' parse_and_eval to gdb.parse_and_eval.
> This lets users request a parse that is done at "global scope".
> 
> I considered letting callers pass in a block instead, with None
> meaning "global" -- but then there didn't seem to be a clean way to
> express the default for this parameter.
> ---
>  gdb/NEWS                              |  4 ++++
>  gdb/doc/python.texi                   |  7 ++++++-
>  gdb/python/python.c                   | 28 ++++++++++++++++++++++------
>  gdb/testsuite/gdb.python/py-value.c   |  3 +++
>  gdb/testsuite/gdb.python/py-value.exp |  5 +++++
>  5 files changed, 40 insertions(+), 7 deletions(-)

Thanks.

> diff --git a/gdb/NEWS b/gdb/NEWS
> index e3c095de09e..4bf5603b550 100644
> --- a/gdb/NEWS
> +++ b/gdb/NEWS
> @@ -162,6 +162,10 @@ info main
>       (program-counter) values, and can be used as the frame-id when
>       calling gdb.PendingFrame.create_unwind_info.
>  
> +  ** gdb.parse_and_eval now has a new "global_context" parameter.
> +     This can be used to request that the parse only examine global
> +     symbols.
> +

This part is OK.

> --- a/gdb/doc/python.texi
> +++ b/gdb/doc/python.texi
> @@ -419,11 +419,16 @@ using the @code{gdb.Value} constructor.
>  @end defun
>  
>  @findex gdb.parse_and_eval
> -@defun gdb.parse_and_eval (expression)
> +@defun gdb.parse_and_eval (expression, @r{[}, global_context@r{]})
                                        ^
That comma is redundant, right?

Reviewed-By: Eli Zaretskii <eliz@gnu.org>
  
Tom Tromey May 23, 2023, 8:17 p.m. UTC | #2
>>>>> "Eli" == Eli Zaretskii via Gdb-patches <gdb-patches@sourceware.org> writes:

>> --- a/gdb/doc/python.texi
>> +++ b/gdb/doc/python.texi
>> @@ -419,11 +419,16 @@ using the @code{gdb.Value} constructor.
>> @end defun
>> 
>> @findex gdb.parse_and_eval
>> -@defun gdb.parse_and_eval (expression)
>> +@defun gdb.parse_and_eval (expression, @r{[}, global_context@r{]})

Eli> That comma is redundant, right?

Yes, I've removed it now.

Tom
  

Patch

diff --git a/gdb/NEWS b/gdb/NEWS
index e3c095de09e..4bf5603b550 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -162,6 +162,10 @@  info main
      (program-counter) values, and can be used as the frame-id when
      calling gdb.PendingFrame.create_unwind_info.
 
+  ** gdb.parse_and_eval now has a new "global_context" parameter.
+     This can be used to request that the parse only examine global
+     symbols.
+
 *** Changes in GDB 13
 
 * MI version 1 is deprecated, and will be removed in GDB 14.
diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi
index 7c3a3ccd379..dca16bb84e0 100644
--- a/gdb/doc/python.texi
+++ b/gdb/doc/python.texi
@@ -419,11 +419,16 @@  using the @code{gdb.Value} constructor.
 @end defun
 
 @findex gdb.parse_and_eval
-@defun gdb.parse_and_eval (expression)
+@defun gdb.parse_and_eval (expression, @r{[}, global_context@r{]})
 Parse @var{expression}, which must be a string, as an expression in
 the current language, evaluate it, and return the result as a
 @code{gdb.Value}.
 
+@var{global_context}, if provided, is a boolean indicating whether the
+parsing should be done in the global context.  The default is
+@samp{False}, meaning that the current frame or current static context
+should be used.
+
 This function can be useful when implementing a new command
 (@pxref{CLI Commands In Python}, @pxref{GDB/MI Commands In Python}),
 as it provides a way to parse the
diff --git a/gdb/python/python.c b/gdb/python/python.c
index 168a0009f1b..42bb2ed34b1 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -969,19 +969,34 @@  gdbpy_decode_line (PyObject *self, PyObject *args)
 
 /* Parse a string and evaluate it as an expression.  */
 static PyObject *
-gdbpy_parse_and_eval (PyObject *self, PyObject *args)
+gdbpy_parse_and_eval (PyObject *self, PyObject *args, PyObject *kw)
 {
+  static const char *keywords[] = { "expression", "global_context", nullptr };
+
   const char *expr_str;
+  PyObject *global_context_obj = nullptr;
 
-  if (!PyArg_ParseTuple (args, "s", &expr_str))
-    return NULL;
+  if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "s|O!", keywords,
+					&expr_str,
+					&PyBool_Type, &global_context_obj))
+    return nullptr;
+
+  parser_flags flags = 0;
+  if (global_context_obj != NULL)
+    {
+      int cmp = PyObject_IsTrue (global_context_obj);
+      if (cmp < 0)
+	return nullptr;
+      if (cmp)
+	flags |= PARSER_LEAVE_BLOCK_ALONE;
+    }
 
   PyObject *result = nullptr;
   try
     {
       gdbpy_allow_threads allow_threads;
       scoped_value_mark free_values;
-      struct value *val = parse_and_eval (expr_str);
+      struct value *val = parse_and_eval (expr_str, flags);
       result = value_to_value_object (val);
     }
   catch (const gdb_exception &except)
@@ -2591,8 +2606,9 @@  The first element contains any unparsed portion of the String parameter\n\
 (or None if the string was fully parsed).  The second element contains\n\
 a tuple that contains all the locations that match, represented as\n\
 gdb.Symtab_and_line objects (or None)."},
-  { "parse_and_eval", gdbpy_parse_and_eval, METH_VARARGS,
-    "parse_and_eval (String) -> Value.\n\
+  { "parse_and_eval", (PyCFunction) gdbpy_parse_and_eval,
+    METH_VARARGS | METH_KEYWORDS,
+    "parse_and_eval (String, [Boolean]) -> Value.\n\
 Parse String as an expression, evaluate it, and return the result as a Value."
   },
 
diff --git a/gdb/testsuite/gdb.python/py-value.c b/gdb/testsuite/gdb.python/py-value.c
index 5a578de5d50..f0b1f5f160c 100644
--- a/gdb/testsuite/gdb.python/py-value.c
+++ b/gdb/testsuite/gdb.python/py-value.c
@@ -79,6 +79,8 @@  int func2 (int arg1, int arg2)
 
 char **save_argv;
 
+int shadowed = 23;
+
 int
 main (int argc, char *argv[])
 {
@@ -96,6 +98,7 @@  main (int argc, char *argv[])
   int i = 2;
   int *ptr_i = &i;
   struct str *xstr;
+  int shadowed = 97;
 
   /* Prevent gcc from optimizing argv[] out.  */
 
diff --git a/gdb/testsuite/gdb.python/py-value.exp b/gdb/testsuite/gdb.python/py-value.exp
index 898208b90d1..9fc25814721 100644
--- a/gdb/testsuite/gdb.python/py-value.exp
+++ b/gdb/testsuite/gdb.python/py-value.exp
@@ -338,6 +338,11 @@  proc test_value_in_inferior {} {
   gdb_py_test_silent_cmd "python str = '\"str\"'" "set up str variable" 1
   gdb_test "python print (gdb.parse_and_eval (str).string (length = 10))" \
       "gdb.error: Attempt to take address of value not located in memory.\r\nError while executing Python code."
+
+  gdb_test "python print (gdb.parse_and_eval ('shadowed'))" \
+      97 "shadowed local value"
+  gdb_test "python print (gdb.parse_and_eval ('shadowed', global_context=True))" \
+      23 "shadowed global value"
 }
 
 proc test_inferior_function_call {} {